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SMITHSONIAN INSTITUTION
UNITED STATES NATIONAL MUSEUM

BULLETIN

OF THE

UNITED STATES NATIONAL MUSEUM

No. 54

MONOGRAPH ON THE
ISOPODS OF NORTH AMERICA

BY

HARRIET RICHARDSON

COLLABORATOR, DIVISION OF MARINE INVERTEBRATES

WASHINGTON

GOVERNMENT PRINTING OFFICE

1905

SMITHSONIAN INSTITUTION

UNITED STATES NATIONAL MUSEUM

BULLETIN

OF THE

UNITED STATES NATIONAL MUSEUM

No. 54

1 ''/,

'*$>*

WASHINGTON

GOVERNMENT PRINTING OFFICE

1905

<<VM j

ADVERTISEMENT.

This work (Bulletin No. 54) is one of a series of papers intended to
illustrate the collections belonging to or placed under the charge of
the Smithsonian Institution and deposited in the United States National
Museum.

The publications of the National Museum consist of two series the
Bulletin and the Proceedings.

The Bulletin, publication of which was commenced in 1875, is a
series of elaborate papers issued separately and based for the most
part upon collections in the National Museum. They are monographic
in scope and are devoted principally to the discussion of large zoolog-
ical groups, bibliographies of eminent naturalists, reports of expedi-
tions, etc. The bulletins, issued only as volumes with one exception,
are of octavo size, although a quarto form, known as the Special
Bulletin, has been adopted in a few instances in which a larger page
was deemed indispensable.

The Proceedings (octavo), the first volume of which was issued in
1878, are intended primarily as a medium of publication for newly
acquired facts in biology, anthropology, and geology, descriptions of
new forms of animals and plants, discussions of nomenclature, *etc.
A volume of about 1,000 pages is issued annually for distribution to
libraries, while a limited edition of each paper in the volume is printed
and distributed in pamphlet form in advance.

In addition, there are printed each year in the second volume of the
Smithsonian Report (known as the Report of the U. S. National
Museum), papers, chiefly of an ethnological character, describing col-
lections in the National Museum.

Papers intended for publication by the National Museum are usually
referred to an advisor} 7 committee, composed as follows: Frederick
W. True (chairman), William H. Holmes, George P. Merrill, James
E. Benedict, Otis T. Mason, Leonhard Stejneger, Lester F. Ward,
and Marcus Benjamin (editor).

S. P. LANGLEY,
Secretary of the Smithsonian Institution.

WASHINGTON, U. S. A., December 1, 1905.

in

A MONOGRAPH

ISOPODS OF NORTH AMERICA

BY

HARRIET RICHARDSON

COLLABORATOR, DIVISION OF MARINE INVERTEBRATES

WASHINGTON

GOVERNMENT PRINTING OFFICE

1905

PREFACE.

After several 3 7 ears spent in the preparation of the present mono-
graph, I now offer it to the scientific world, hoping it will meet with
favorable consideration. Most of the work has been done in the
United States National Museum, where an opportunity was afforded
for carrying on the investigation through access to the rich collections
and use of the library. The summer of 19(M was spent at Woods
Hole, Massachusetts, and occupying a table in the Marine Biological
Laboratory through the courtesy of the Carnegie Institution, I con-
tinued the studies which I had already begun in Washington.

It will be noticed that but few changes have been made in the clas-
sification. In a group where there are so many good workers, I have
been glad to follow and adapt to my use what has been already done
so well, and keys and synopses of genera have been freely introduced
with references to those authors from which they have been taken.

Although I am indebted to many friends for their kind assistance,
my obligations to Dr. Theodore Gill are especially great, for it was
at his suggestion that the work was undertaken, and under his judi-
cious guidance and supervision it has grown to its present form.

As is well known the natural habitat of the Isopods is in salt and
fresh water, along the shore or in the interior of the country, usually
in moist situations. They do, however, often occur in places most
remote and unlocked for. Some have been found in warm springs
and in subterranean streams, in caves and grottoes, pumps and wells,
and far from human habitation. The littoral forms are seen around
wharf piles, under rocks and stones, on ledges and cliffs, where the}'
are not easily captured, for they seek refuge, with surprising activity,
among the cracks and crevices.

The curious habitations sought for shelter and protection are the
tubes of worms, the burrows of the crayfish, the nests of mollusks,
and the nests of ants. Some live in siliceous sponges, others in coral-
lines or among ascidians.

The parasitic Isopods attack other Crustacea as well as fishes. The
parasites of fish are found on the skin, fins, gills, and in the mouths of
their hosts, and have even been known to bore holes in the body back
of the fins. One of these, Olencira prseyustator^ attacks the menhaden

VIII PREFACE.

{Brevo&rtia tyrannw), in great numbers. In naming both species, the
host and the parasite, Latrobe aptly and fancifully considered the case
analagous to that of the ancient chief of state (tyrannus] and the taster
(pr&gustator). The parasites of Crustacea infest the shrimps and
crabs or decapodous Crustacea and the schizopods. When the parasite
occupies the branchial cavity of the host, a large protuberance or
swelling is apparent on whichever side the body is infested. The
parasites are sometimes found in the visceral cavity or even in the
incubatory pouch of their hosts.

The destructive habits of some of the marine and fresh-water species
to submerged timber, such as wharfs and bridges, have been hereto-
fore recorded, 8 but not until recently has attention been called to the
fact that even the terrestrial forms ma}* give cause for alarm in the
nature of pests. Several common and well-distributed species have
been found menacing }*oung cotton plants, sugar beets, mushrooms,
and cucumber vines.

The burrowing habits of some Isopods are interesting. Chilton says
of Scyphax ornatus and Actsecia euchroa that they "are found on
sand} 7 beaches, either on the surface or burying themselves a little in
the sand about high water mark or a little lower." Hay, in recently
observing the habits of Scyphacella arenicola. finds that it also burrows
in the sand. The Serolidae, according to Studer, " live by preference
on sandy ground, into which they burrow with their flat bodies up to
the caudal plate."

Whitelegge speaks of the paguroid habits of certain Isopods, which
"live in small univalve shells and in company with young hermit
crabs." Mimicry of external appearance and similarity of habitat is
probably very useful in the struggle for existence.

Many of the species found in North America also occur in other
parts of the world. The terrestrial Isopods have a wide distribution
as well as the parasites of fishes. The Arcturidse form a rather
restricted group. Benedict says of them, in explanation of this fact,
that it is due to structure and habits. "The young are few in a brood
and are cared for by the parent until well able to care for themselves,
clinging to the mother's antennae until ready to undertake a more
independent existence, perhaps on the very object on which the mother
is foraging for herself and brood. With habits of this kind the
chances of a wide distribution for &ny one species must be very much
less than is the case where free-swimming young are produced in
large numbers."

I have not attempted to give here a general account of the mor-
phology, as the reader is supposed to be familiar with the sources

See Charles H. Snow, Marine Wood-Borers, Trans. Amer. Soc. Civil Engineers,
XL, 1898, pp. 196-199, for notes in this connection.

PREFACE. IX

where such an account can be found. In another place a a brief
review of the Isopod structure has already been given.

It has not been considered worth while to encumber the legends with
detailed explanation of many of the figures that have been taken from
other authorities; students, however, who desire to learn the signifi-
cance of the lettering not given in the illustrations, are referred to the
original papers.

As a final suggestion I would like to say that my object in under-
taking this work has been to assist the student in the determination of
the forms by giving figures and descriptions of all the species. It is
to be hoped, in case of omissions or errors, that leniency will be
observed, for the task has not always been eas} v .

HARRIET RICHARDSON.

WASHINGTON CITY, November 1, 1905.

POSTSCRIPT.

Since this monograph has been printed, and within the last few
days, Dr. H. J. Hansen's paper on the Propagation, Structure, and
Classification of the Spheeromidpe has been received. 6 With a large
amount of material, a comparison of types from various museums all
over the world, and a thorough examination of specimens, Doctor Han-
sen has arrived at an excellent classification of this group, which has
heretofore been in an extreme state of confusion and so recognized by
all who have attempted to determine species or to refer them to their
proper genera. In Doctor Hansen's paper new genera have been estab-
lished and some old ones canceled. The changes which particularly
affect the present paper and which I have not been able to make use
of in the text, inasmuch as Doctor Hansen's paper was received too
late, are as follows: The genus Cassidisca, new genus, must be can-
celed as being a sjmonym of Hansen's new genus Cassidinidea; Cili-
csea caudata, C. gilliana, C. sculpta, and C. cordata must be referred to
Hansen's new genus Paracerceis. The following list shows these rela-
tions more exactly : Cassidisca ovalis = Cassidinidea ovalis; Cassidisca
lunifrons = Cassidinidea lunifrons; Cilicsea caudata = Paracerceis can-
data,' Cilicsea gilliana, Paracerceis gilliana; Cilicsea cordata Para-
cerceis cordata; Cilicsea sculpta = Paracerceis sculpta.

While in New Haven last summer 1 examined the second pleopods
of a number of cotypes of Dynamene perforata and found that the
males and females of this species were similar, with the exception that

Contributions to the Natural History of the Isopods, by Harriet Richardson,
Proc. U. S. Nat. Mus. XXVII, 1904, pp. 4-17.

& Quarterly Journal of Microscopical Science, XLIX, Pt. 1. 1905, new ser., pp.
69-135. (October number received here November 11.)

X PREFACE.

the endopod of the second pleopod in the male carried a stylet. The
females had the transverse foramen, which constituted the proximal
part of the abdominal notch, just as did the males. With this modifica-
tion of Hansen's genus Dynamenella, of which he makes Dyminiene
perfomta the type, I can then refer to it the following species: Dyn<i-
inene benedicti, Dynamene glabra, and Dynamen*. moorei. The follow-
ing shows these relations more exactly: Dynamene perforata =Dyna-
iiu ,i,lln j rforata; Dynamene benedicti = Dynamenella benedict! ;
Dynamene glabra = Dynamenella glabraj Dynannn' moorei Dyna-
mendla moorei. Inasmuch as only females are known of Dyimntrn,
angulata and Dynamene dilatata, it can not be stated positively
whether they should be referred to Dynamenella or Paracerceis.
Doctor Hansen says that, judging from the aberrant shape of the
antennulse, D. dilatata must probably be established as the type of a
new genus..

In regard to Cilicsea linguicauda and Cilicasa granulosa, Doctor
Hansen says that the former is probably, the latter perhaps, a specie-
of Cymodoce. Upon an examination of the pleopods subsequent to
the printing of my paper and the publication of Doctor Hansen'- I
find that these two species not only should not be referred to the
genus Cymodoce, but not even to the section Cymodocini or to the
group Spha?rominffi hemi branchiate. Both branches of the fourth
pair of pleopods are similar, fleshy, with transverse folds, without
plumose setse, and the outer branch is not two-jointed. These two
species, therefore, belong to the group Spharominfe eubranchiatae.
In these species the exopod of the third pleopod has an articulation,
and is therefore two-jointed. The character of the abdominal notch
without paired denticles would seem to exclude them from the genus
Paracerceis as restricted by Hansen. The character of the uropods,
which are strongly altered, would exclude them from the genus Cer-
ceis Milne Edwards. They can not be placed with //</*>/ v///V/ Miers,
because they lack the large, mesial process on the sixth thoracic seg-
ment. It will be necessary to establish a new genus for these two
species, for which I propose the name Discerceis, C. granulosa being
the type.

Doctor Hansen does not mention Cilica&a carinata in his discussion
of the species of this family. Upon examination, I find that the
branches of the fourth pleopoda are similar, flesh.} 7 , crossed with trans-
verse folds, the outer branch being unjointed. The outer branch of
the third pleopod is also unjointed. Although the only specimen is a
male, judging from the character of the uropods 'and their similarity
to the males of other genera in this family, there is no stylet attached

PREFACE. XI

to the inner branch of the second pleopod, in this respect being com-
parable to Di/iinim ne (Nsesa) Leach and Ancinella Hansen. I there-
fore make this species the type of a new genus Dynameniscus.

Doctor Hansen says that Sphserama yucatanum has been established
on females or young males of animals belonging to the genus Cymo-
doce. The only specimen is a young female.

Toward the end of his paper Doctor Hansen makes the statement
that the species Tecticeps convexm was established on the female form
of Tectiecpx alascensis, and therefore cancels the first-named species.
As Doctor Hansen had seen only the two sexes of Tecticeps alascensis
and had not seen any specimens of Tecticeps convevus, this error was a
natural one. Inasmuch as both sexes of both species are in the col-
lection of the U. S. National Museum, it would be well to point out
the sexual differences as perhaps I have not done sufficiently hereto-
fore or even in the pages to follow. The females of both Tecticeps
olti.ycensis and Tecticeps convexus differ from the males in having the
second pair of legs ambulatory and similar in structure to those fol-
lowing, while in the males the second pair of legs are subchelate. The
female of Tecticeps alascensis has the exopod of the uropod not longer
than the endopod, and thus differs from the male, which has the exo-
pod longer than the endopod. In the species T. convexus, however,
the exopod of the uropod is equal in length to the endopod in both
sexes. The females of the two species are quite similar, both having
the exopod of the uropod short, but they can easily be distinguished
by the difference in the position of the eyes, the difference in the shape
of the extremity of the terminal abdominal segment, and the difference
in the length of the antennge. Male specimens are compared in the
pages to follow, and the differences given in the key are from a com-
parison of males. It is to be hoped that with these additional notes
no difficulty will be found in distinguishing the two species, and that
the validity of Tecticeps convexus, heretofore established, is correctly
maintained.

H. R.

WASHINGTON CITY, December 1, 1905.

TABLE OF CONTENTS.

Page.

Preface VII

Table of contents XIII

List of illustrations XXV

Order I. Tanaioidea or Chelifera 3

Family I. Tanaidse 4

Genus 1. Pancolus 5

Pancolus californiensis 5

Genus 2. Tanais 7

Tanais loricatus 7

cavolinii = 8

alascensis 10

robustus 11

normani 14

Genus 3. Cryptocope 16

Cryptocope arctica 16

Genus 4. Leptognathia 17

Leptognathia caeca 18

longiremis 19

Genus 5. Heterotanais 21

Heterotanais limicola 21

Genus 6. Leptochelia 22

Leptochelia f orresti 23

savignyi 26

dubia 28

rapax 30

filum 31

Genus 7. Neotanais 32

Neotanais americanus 32

hastiger 35

Family II. Apseudidae. . . 37

Genus 8. Apseudes 37

Apseudes espinosus 38

gracilis 40

triangulatus 43

propinquus 45

Genus 9. Parapseudes 47

Parapseudes goodei 47

Genus 10. Typhlapseudes '. 49

Typhlapseudes nereus 49

Genus 11. Sphyrapus 51

Sphyrapus malleolus 52

XIV CONTENTS.

Page.

Order II. Cymothoidea or Flabellifera 54

Family III. Gnathiid* 55

Genus 12. Gnathia 56

Gnathia cristata 56

elongata 58

cerina 59

Family IV. Anthuridse 62

Genus 13. Cyathura 63

( 'yathura carinata 63

Genus 14. Ptilanthura 66

Ptilanthura tennis 66

Genus 15. Anthelura 68

A nthelura abyssoruni 69

afnni.4 70

Genus 16. Calathura 71

Calathura branchiata 72

crenulata 74

Genus 17. Paranthura 75

Paranthura inf undibulata 76

verrillii 77

Genus 18. Colanthura ! 78

Colanthura tenuis 79

Family V. Cirolanid&e 81

Genus 19. Cirolana 82

Cirolana sphseromiformis 84

niayana 87

linguifrons 90

chiltoni 91

minuta 92

concharum 95

impressa 97

polita 99

borealis 101

gracilis 105

obtrunoata 108

harfordi 109

parva Ill

albida 114

cubensis 114

Genus 20. Conilera 116

Conilera cylindracea 116

st ygia 120

Genus 21. Cirolanides 120

Cirolanides texensis 120

Genus 22. Eurydice 123

Eurydice convexa 124

caudata 124

spinigera 125

Genus 23. Branchuropus . .' 128

Branchuropus littaralis 128

Genus 24. Bathynomus . 130

Bathynomus giganteus 130

Genus25. Colopisthus 133

Colopisthus parvus 137

CONTENTS. XV

Order II. Cymothoidea or Flabellifera Continued. Page.

Family VI. Exocorallanidse 138

Genus 26. Exocorallana 138

Exocorallana tricornis 139

mexicana 142

sexticornis 143

quadricornis 144

truncata 145

subtilis 146

antillensis 148

fissicauda 150

oculata 152

warmingii 154

. Family VII. Corallanidse 156

Genus 27. Alcirona 157

Alcirona krebsii 157

hirsuta 159

Genus 28. Tridentella 161

Tridentella virginiana 161

Genus 29. Nalicora 163

Nalicora rapax 164

Family VIII. ^Egidse 166

Genus aO. ^Ega 167

JSga psora 168

antillensis . N 170

ecarinata 171

crenulata 173

webbii 175

lecontii 176

tenuipes 177

dentata 179

incisa 180

arctica 182

gracilipes 183

symmetrica : 185

ventrosa 187

microphthalma 189

Genus 31. Rocinela 190

Rocinela oculata 191

cornuta 192

insularis 194

dumerilii 195

cubensis 197

maculata 198

belliceps 199

americana 201

propodialis 203

laticauda 204

augustata 206

tuberculosa ; 208

signata 209

aries 210

Genus 32. Syscenus 212

Syseenus infelix 212

2858905 ii

XVI CONTENTS.

Order II. Cymothoidea or Flabellifera Continued. Page.

Family IX. Cymothoidse 214

Genus 33. ^Egathoa 216

yEgathoa linguifrons 216

oculata 217

medialis 218

Genus 34. Nerocila 219

Nerocila acuminata 220

californica 221

munda 223

lanceolata 224

Genus 35. Anilocra 226

Anilocra laticauda 227

plebia 229

Genus 36. Olencira 230

Olencira prsegustator 231

Genus 37. Ceratothoa 233

Ceratothoa impressa 234

Genus38. Meinertia 236

Meinertia gaudichaudii 237

deplanata 240

gilberti 241

transversa , 243

Genus 39. Agarna 243

Agarna carinata 244

Genus 40. Indusa 246

Indusa carinata 246

Genus 41. Cymothoa 247

Cymothoa excisa 248

exigua 250

caraibica 252

oestrum 254

Genus 42. Livoneca 256

Livoneca panamensis 257

vulgaris 258

californica 260

redmanni 261

ovalis 263

Genus 43. Irona 265

Irona nana 265

Family X. Limnoriidse 268

Genus 44. Limnoria 268

Limnoria lignorum 269

Family XI. Sphseromidse 270

Genus 45. Ancinus 271

Ancinus depressus 271

Genus 46. Cassidisca 272

Cassidisca lunifrons 273

ovalis 274

Genus 47. Tecticeps .- 275

Tecticeps alascensis 276

convexus.. 278

CONTENTS. XVII

Order II. Cymothoidea or Flabellifera Continued. Page.
Family XI. Sphaeromidpe Continued.

Genus 48. Sphseroma 280

Sphseroma quadridentatum 281

destructor 282

pentodon 286

Genus 49. Exosphseroma 287

Exosphseroma amplicauda 288

rhomburum 290

yucatanum 291

faxoni 292

octoncum 293

thermophilum 294

dugesi 295

oregonensis 296

crenulatum 298

Genus 50. Dynamene 299

Dynamene perforate, 299

glabra ..< 301

angulata 302

moorei 303

dilatata 304

benedicti 304

Genus 51. Paradynamene 305

Paradynamene benjamensis 305

Genus 52. Cilicsea 307

Cilicaea linguicauda 309

granulosa 309

cordata 310

gilliana # 313

caudata 314

sculpta 318

carinata 319

Family XII. Serolidse 320

Genus 53. Serolis '.. 320

Serolis carinata 321

Order III. Idotheoidea or Valvifera 323

Family XIII. Arcturidse 323

Genus 54. Astacilla 323

Astacilla granulata 324

caeca 326

Genus 55. Arcturus 327

Arcturus beringanus 328

longispinus 329

glaber 330

purpureus 331

caribbseus 335

floridanus . 336

baffini 337

baffini var. tuberosus 340

Genus 56. Pleuroprion 342

Pleuroprion murdochi 342

intermedium.. 344

XVIII CONTENTS.

Order III. Idotheoidea or Valvifera Continued. Page.

Family XIV. Idotheida? 346

Genus 57. Mesidotea 347

Mesidotea entomon 348

sabini 350

Genus58. Chiridotea 352

Chiridotea caeca 353

tuftsii '. 354

Genus 59. Idothea 356

Idothea gracillhna 356

urotoma 358

fewkesi 359

rectilinea ' 360

metallica 362

baltica 364

ochotensis 366

phosphorea 367

Genus 60. Pentidotea 368

Pentidotea resecata 369

wosnesenskii 370

white! 373

stenops 375

Genus 61. Synidotea 376

Synidotea ritteri 377

pallida 378

erosa ., 379

nebulosa 381

angulata '. 382

consolidata 383

marmorata 384

bicuspida 385

laticauda 386

harf ordi 387

nodulosa 388

laevis 389

muricata 390

picta 391

Genus 62. Colidotea 393

Colidotea rostrata 393

Genus 63. Edotea 394

Edotea acuta . 395

triloba 396

montosa 397

Genus 64. Eusymmerus 398

Eusymmerus antennatus 399

Genus 65. Erichsonella 400

Erichsonella attenuata 400

filiformis 401

floridana 403

Genus 66. Cleantis 404

Cleantis planicauda 404

occidentalis 406

heathii .. 407

CONTENTS. XIX

Page.

Order IV. Aselloidea or Asellota 408

Family XV. Asellidse 409

Genus 67. Mancasellus 410

Mancasellus brachyurus 411

macrourus 413

tenax 415

tenax dilata 416

lineatus 416

danielsi 417

Genus 68. Asellus 419

Asellus communis 420

intermedius 422

brevicauda 423

hoppinse 425

attenuatus 426

aquaticus 428

tomalensis 431

Genus 69. Cfecidotea 433

Csecidotea stygia '. 434

nickajackensis 436

richardsonse 437

smithsii - 438

Family XVI. Stenetrjidse. 439

Genus 70. Stenetrium 440

Stenetrium serratum 440

occidentale 441

stebbingi 444

antillense 446

Family XVII. Janiridse 448

Genus 71. Jsera 449

Jsera marina 450

wakishiana 451

Genus 72. Carpias 452

Carpias bermudensis '. 452

Genus 73. Janiropsis 454

Janiropsis californica 455

kincaidi 456

Genus 74. lolella 457

lolella spinosa 458

speciosa 460

triangulata 462

libbeyi 463

alascensis 464

erostrata 465

holmesi 465

sarsi 467

Genus 75. Janira 468

Janira maculosa 469

minuta 471

occidentalis 472

tricornis 474

alta.. 475

XX CONTEKTS.

Order IV. Aselloidea or Asellota Continued. ' Page.
Family XVII. Janiridao Continued.

Genus 76. Jteropsis 47(5

Jseropsis lobata 477

rathbunae 478

Family XVIII. Munnidse 479

Genus 77. Munna 480

Munna fabricii 480

kr0yeri 483

ceeca 484

Family XIX. Munnopsida? -. 485

Genus 78. Munnopsis 486

Munnopsis typica 486

Genus 79. Eurycope : 490

Eurycope cornuta 491

caribbea 493

Genus 80. Ilyarachna 495

Ilyarachna hirticeps 495

Oder V. Bopyroidea or Epicaridea 497

Family XX. Bopyridae 498

Genus 81. Phryxus 499

Phryxus abdominalis 500

Genus 82. lone 503

lone cornuta 504

brevicauda 505

thompsoni .- 508

Genus 83. Leidya 511

Leidya distorta 511

Genus 84. Grapsicepon 512

Grapsicepon edwardsii 513

Genus 85. Munidion 517

Munidion parvum 518

Genus 86. Cryptione 520

Cryptione elongata 520

Genus 87. Pseudione 522

Pseudione giardi 523

galacanthse 527

f urcata 529

curtata 530

Genus 88. Stegophryxus 531

Stegophryxus hyptius 532

Genus 89. Stegias 535

Stegias clibanarii 536

Genus 90. Bathygyge 537

Bathygyge grandis 537

Genus 91. Phyllodurus 539

Phyllodurus abdominalis 540

Genus 92. Argeia 544

Argeia pugettensis 544

pauperata 551

Genus 93. Parargeia 551

Parargeia ornata 551

Genus 94. Probopyrus 553

Probopyrus pandalicola 554

floridensis.. 555

CONTENTS. XXI

Order V. Bopyroidea or Epicaridea Continued. Page.
Family XX. Bopyridse Continued.
Genus 94. Probopyrus Continued.

Probopyrus bithynis 557

alphei 559

latreuticola 560

Genus 95. Bopyriscus 562

Bopyriscus calmani 562

Genus 96. Bopyrina 563

Bopyrina abbreviata 563

urocaridis 565

thorii 566

Genus 97. Bopyroides 566

Bopyroides hippolytes 567

Family XXI. Dajidre 572

Genus 98. Dajus 573

Dajus mysidis 573

Genus 99. Holophryxus 575

Holophryxus alascensis 576

Family XXII. Cryptoniscidse .". 577

Genus 100. Clypeoniscus 577

Clypeoniscus meinerti 577

Order VI. Oniscoidea 583

Family XXIII. Tylidee 584

Genus 101. Tylos 585

Tylos niveus 585

latreilli 586

Family XXIV. Eubelida; 587

Genus 102. Ethelum 588

Ethelum modestum 588 -

americanum 589

reflexum 590

Family XXV. Oniscidse 592

Genus 103. Alloniscus 593

Alloniscus mirabilis : 594

cornutus 595

perconvexus 596

Genus 104. Lyprobius 598

Lyprobius pusillus : 598

Genus 105. Synuropus 598

Synuropus granulatus 599

Genus 106. Oniscus 600

Oniscus asellus 600

Genus 107. Philoscia 602

Philoscia richmondi 603

culebrse 604

vittata 605

brevicornis 606

. berrnudensis 607

spinosa 608

nigricans 608

Genus 108. Cylisticus 609

Cylisticus convexus 609

XXII CONTENTS.

Order VI. Oniscoidea Continued. Page.
Family XXV. OniscidH? Continued.

Genus 109. Porcellio 611

Porcellio formosus 61 2

Isevis 614

parvicornis 616

rathkei 617

spinicornis 619

scaber 621

Genus 110. Leptotrichus 624

Leptotrichus granulatus 624

Genus 111. Metoponorthus 625

Metoponorthus sanssurei 626

pruinosus ". 627

sexfasciatus 629

virgatus 630

Genus 112. Rhyscotus -630

Rhyscotus turgifrons 631

Genus 113. Hypergnathus 631

Hypergnathus texensis 632

( it-mis 114. Actoniscus 633

Actoniscus ellipticus 634

lindahli 635

Genus 115. Acanthoniscus 636

Acanthoniscus spiniger 637

Family XXVI. Armadillidida- 638

Genus 116. Cubaris 639

Cubaris tenuipunctata 640

depressa 641

viticola 642

eil varum 643

perlata 644

murina 645

cincta 647

gigas 648

affinis 648

zigzag 649

dumorum 650

grenadensis 651

dugesi 652

pisum 653

californica 653

Genus 117. Pseudarmadillo 654

Pseudarmadillo gillianus. 655

dollf usi 657

carinulatus 660

Genus 1 18. Sphseroniscus t>61

Sphseroniscus portoricensis 662

cacahuamilpensis 663

Genus 119. Haplarmadillo 664

Haplarmadillo monocellatus 665

Genus 120. Armadillidium 665

Armadillidium vulgare 666

quadrifrons 668

CONTENTS.

XXIII

Order VI. Oniscoidea Continued. Page.
Family XXVI. Armadillididfc Continued.

Genus 121. Uropodias 669

Uropodias bermudensis 670

Family XXVII. Scyphaciidaj 671

Genus 122. Scyphacella 671

Scyphacella arenicola 671

Family XXVIII. Ligydida; 673

Genus 123. Ligyda 673

Ligyda olfersii 674

exotica 676

baudiniana .v 678

occidentals 681

pallasi 682

oceanica 684

Genus 124. Ligidium 686

Ligidium hypnorum 686

tenue 688

longicaudatum 689

gracilis 690

Genus 125. Euphiloscia 692

Euphiloscia elrodii 692

Family XXIX. Trichoniscidte 692

Genus 126. Trichoniscus 693

Trichoniscus pusillus ,. 694

papillicornis 695

Genus 127. Haplophthalmus 696

Haplophthalrnus puteus 697

Genus 128. Brackenridgia 699

Brack enridgia cavernarum 699

List of references 701

Index . . 719

LIST OF ILLUSTRATIONS.

Pa/se.

FIG. 1. Pancolus californiensis 5

2. Pancolus californiensis. First gnathopod 5

3. Pancolus californiensis. a, First antenna, b, Second antenna 5

4. Pancolus californiensis. Mandible 6

5. Pancolus californiensis. Maxilliped 6

6. Pancolus californiensis. Epignath of rnaxilliped '. 6

7. Pancolus californiensis. Posterior lip 6

8. Pancolus californiensis. First maxilla 6

9. Pancolus californiensis. First pieopod 6

10. Pancolus californiensis. Second pieopod 6

11. Tanais cavolinii (After Harger) 9

12. Tanais cavolinii. a, First leg. b, Maxilliped. c, First antenna.

d, Mandible, e, Uropod. /, Second antenna 9

13. Tanais alascensis. a, First antenna, b, Second antenna 10

14. Tanais alascensis. a, Dorsal view, b, Last joints of leg of the first

pair 10

15. Tanais robustus (After Moore), a, General figure, b, Second
antenna, c, Mandible, c', Detail of mandible, d, Anterior (first)
maxilla, d', Tip of first maxilla, e, Maxilliped. /, First gnath-
opod of male, g, First gnathopod of female, h, First pereiopod.

i, Last pereiopod. .;', Pieopod. k, Uropod 13

16. Tanais normani 15

17. Tanais normani. First gnathopod 15

18. Tanais normani. a, First antenna, b, Second antenna 15

19. Cryptocope arctica (After Hansen) 16

20. Cryptocope arctica (After Hansen). a, Antennse of female, b, Uro-
pod of female, c, Uropod of male, d, Anterior part of body of

male 17

21. Leptognathia caeca (After Harger). a, First antenna, b, Leg of

first pair, c, Uropod 18

22. Leptognathia longiremis (After Sars). a, First leg of female, b,
Second antenna of female, c, Lateral view of female, d, Dorsal
view of female, e, First antenna of female. /, Seventh leg of
female, g, Second leg of female, h, Maxillipeds. i, Anterior
(first or inner) maxilla, j, Uropod of female, k, Mandible (right).
I, Left mandible, m, Pieopod of female, n, First leg of male, o,
First antenna of male, p, Dorsal view of male, q, Lateral view
of male, r, Second leg of male, s, Uropod of male, t, Pieopod

of male, u, Second antenna of male, v, Seventh leg of male 20

23. Heterotanais limicola ( After Harger) . Female 22

24. Heterotanais limicola. a, First leg of female, b, First antenna.

c, Second antenna 22

XXVI ILLUSTRATIONS.

Page.

FIG. 25. Leptochelia forresti (After Stebbing). a, Second gnathopod. b,
Front of head with eyes, c, Upper antenna, d, Third leg. e,
Fourth leg. /, Fifth leg. g, Sixth leg. h, Seventh leg. i, Gen-
eral figure, j, Lower antenna, k, First gnathopod of right side.
I, Terminal portion of abdomen with uropoda. MI, Pleopod 24

26. Leptochelia savignyi ( After Harger) . Male 26

27. Leptochelia savignyi ( After Harger) . Female 27

28. Leptochelia savignyi. Female. , First leg. b, First antenna, c,

Second antenna, d, Uropod 27

29. Leptochelia dubia (After Moore), a, General figure, b, First an-
tenna, c, Second antenna, d, Chela, e, Cheliped. /, End of
second leg. g, Uropod 29

30. Leptochelia rapax (After Harger). Male 30

31. Leptochelia rapax. a, First leg of male, b, First leg of female 31

32. Neotanais americanus (After Beddard). a, Second antenna, b,

General figure 34

33. Neotanais hastiger (After Norman and Stebbing). a, Outline of
carapace from above, b, Abdomen, c, Thumb and finger of first
gnathopod. d, Lateral view, e, Second peraeopod. /, Portion of
carapace, seen from the side, g, Last peraeopod (terminal joints). 36

34. A pseud es espinosus (After Moore), a, Uropod. b, First leg. c,

General figure, d, Seventh leg. e, Second leg. /, Chela 39

35. Apseudes gracilis (After Norman and Stebbing). a, Upper antenna.
6, Lateral view, c, Lower antenna, d, Side view of mouth parts
and an abnormally developed first gnathopod. e, Mandible. /,
First gnathopod. g, Anterior part of body, from above. h, Fifth leg.
i, Pleopod. j, Last segment of abdomen, k, Second gnathopod . . 41

36. Apseudes triangulatus. a, Segments of thorax and abdomen. b,
Head, c, Segments of abdomen and part of uropoda. d, First
gnathopod. e, Second gnathopod 43

37. Apseudes propinquus. a, Head. 6, Segments of thorax and abdo-
men, c, Last four segments of body and part of uropoda. d, First
gnathopod 46

38. Parapseudes goodei. a, General figure. 6, Head and first thoracic
segment, c, First gnathopod of male, d, Abdomen with uropods
and last thoracic segment, e, First gnathopod of female 47

39. Typhlapseudes nereus (After Beddard ) 50

40. Sphyrapus malleolus ( After Norman and Stebbing) . a, Second leg or
gnathopod. b, First leg or gnathopod. c, First leg. d, Male, seen
obliquely from above, e, Fourth leg or second perseopod. /, Third
leg or first perseopod. g, Mandible, h, First leg or gnathopod of
female. ?, Antennae, seen from below, j, Terminal segment of
abdomen with pleopod and base of uropods, seen from the side.
k, Seventh leg or fifth perseopod. I, Female, seen from above.
m, Fifth leg or third peraeopod. n, First leg or gnathopod of
female *. 52

41. Gnathia cristata (After Hansen). a, Right mandible (inner side).

b, Male (somewhat mutilated ) 57

42. Gnathia elongata (After Sars). o, First and second antennae, b,
Dorsal view of male, c, Dorsal view of female, d, Second leg.
e, Mandible. /, Pleopod. g, Last segment of abdomen with uro-
poda. h, Maxilliped of male. , Dorsal view of young, j, First
leg of male, k, First leg of female. /, Maxilliped of female 58

43. Gnathia cerina (After Harger). Male 60

ILLUSTRATIONS. XXVII

Page.

FIG. 44. Gnathia cerina. a, Leg of first pair of male. 6, Maxilliped. c, Sec-
ond antenna (male), d, First antenna, e, Mandible. /, First

leg of lam 60

45. Gnathia cerina ( After Harger ) . Female 61

46. Gnathia cerina (After Harger). Larva 62

47. Cyathura carinata (After Harger). a, First antenna, b, Second
antenna, c, First leg. d, Third leg. e, First pleopod. /, Second

pleopod of male, g, Lateral view of abdomen 64

48. Cyathura carinata. a, Mandible, b, Maxilliped. c, First maxilla. 65
49. Cyathura carinata. a, First leg. 6, First antenna, c, Second an-
tenna 65

50. Cyathura carinata (After Norman and Stebbing). a, First gnatho-
pod. b, Lower antenna, c, Maxilliped. d, Labium. e, First
maxilla. /, End of telson. g, Upper antenna, h, Mandible and

palp 66

51. Ptilanthura tenuis (After Harger). a, Head with antennae and first
thoracic segment (ventral side), b, Maxilliped. c, First maxilla.

d, First pleopod. e, Second pleopod of male 67

52. Ptilanthura tenuis. Mandible 67

53. Ptilanthura tenuis. a, First leg. b, First antenna, c, Second
antenna, d, Maxilliped. e, First maxilla. /, Mandible (without

palp ) 68

54. Anthelura abyssoruin (After Norman and Stebbing). a, Lateral
view, b, Head (from above), c, Upper antenna, d, Lower
antenna, e, First gnathopod. /, Second gnathopod. g, Fifth
peraeopod. h, Abdomen (from above), i, Abdomen (from the

side) 69

55. Anthelura affiuis. a, Sixth periopod. b, Second gnathopod.

c, First gnathopod. d, General figure 70

56. Calathura branchiata (After Harger). a, First antenna, b, Second
antenna, c, Right maxilliped. d, First maxilla, d', Distal end
of same, e, First leg. /, First pleopod. g, Second pleopod of

male 72

57. Calathura branchiata. a, First leg. b, Second antenna, c, First

maxilla, d. Maxilliped. e , Mandible. /, First antenna 73

58. Calathura crenulata. Head 74

59. Calathura crenulata 74

60. Calathura crenulata. First gnathopod 75

61. Calathura crenulata. Abdomen 75

62.-~Paranthura infundibulata. a, Last four thoracic segments and abdo-
men. 6, First gnathopod. c, Lateral view of abdomen, d, Man-
dible, e, Antenna of first pair. /, Antenna of second pair.

g, Second gnathopod. h, Maxillipeds 76

63. Paranthura verrillii. a, Antenna of the first pair, b, Antenna of

the second pair, c, Last two thoracic segments and abdomen 78

64. Colanthura tenuis. a, General figure, b, Head and antennae.
c, Leg of first pair, d, Lateral view of uropoda. e, Leg of second

pair. /, Abdomen and last two thoracic segments 80

65. Cirolana sphseromiformis (After Hansen). a, Posterior part of

abdomen, b, Left pleopod of second pair, c, Lateral view of

female, d, Dorsal view of female, e, Leg of second pair. /, Leg

of fifth pair, g, Leg of seventh pair. /(, Anterior part of head. . . 85

66. Cirolana mayana (After Moore), a, General figure, b, Head.

c, First antenna, d, Second antenna 87

XXVIII ILLUSTRATIONS.

\

Page.

FIG. 67. Cirolana mayana (After Ives). a, Fifth leg (right side). b, Dorsal
view of right antenna of second pair, c, Anterior view of same.

d, Last segment of abdomen with uropoda. e, First leg (right
side). /, Fourth leg (right side) 88

68. Cirolana mayana (After Ives). a, Dorsal view, b, Right side, c,

Seventh thoracic segment with male appendage 88

69. Cirolana mayana. a, Mandible, b, c, Abnormal maxilliped. d,

Second maxilla 88

70. Cirolana mayana. Second antenna 89

71. Cirolana linguifrons. a, Head, b, Terminal segment 90

72. Cirolana linguifrons. Maxilliped 90

73. Cirolana chiltoni. a, Head, b, Posterior part of abdomen 91

74. Cirolana minuta ( After Hansen) . a, Posterior part of abdomen, b,
Anterior part of head (from below), c, Left pleopod of second
pair, d, Adult male, e, Lateral view of same. /, Second leg. g,
Fifth leg. h, Seventh leg. i, Maxilliped. j, Mandible, k, First

maxilla. I, Second maxilla 93

75. Cirolana concharum (After Harger) 95

76. Cirolana concharum. a, Maxilliped. b, Mandible, c, First max-
illa, d, Frontal lamina, e, Second maxilla 95

77. Cirolana concharum (After Harger). a, Last segment of abdomen
with uropoda. b, Leg of first pair, c, Leg of fourth pair, d, Leg

of seventh pair 96

78. Cirolana impressa (After Harger). a, Second antenna, b, First
antenna, c, Second pleopod of male, d, Lateral view of female.

e, Leg of first pair. /, Last segment of abdomen with uropoda.

g, Leg of seventh pair, h, Leg of fourth pair 97

79. Cirolana impressa. a, Maxilliped. 6, First maxilla, c, Frontal

lamina, d, Mandible, e, Second maxilla 98

80. Cirolana polita (After Harger). a, Second antenna, b, Lateral view
of female, c, First antenna, d, Last segment .of abdomen with
uropoda. e, Leg of fourth pair. /, Leg of first pair 100

81. Cirolana polita. a, Maxilliped. b, Mandible, c, First maxilla, d,

Second maxilla 100

82. Cirolana borealis (After Harger). a, Last segment of abdomen with

uropoda. b, First leg. c, Fourth leg. d, Seventh leg 101

83. Cirolana borealis (After Harger). a, Lateral view, b, Second antenna.

c, First antenna, d, Pleopod of second pair of male 102

84. Cirolana borealis. a, Maxilliped. 6, Mandible, c, Second maxilla, d,

Frontal lamina , 103

85. Cirolana borealis (After Hansen). a, Leg of fifth pair, b, Left pleo-
pod of second pair of young male, c, Dorsal view of male, d, Leg
of seventh pair, e, Three basal articles of left maxilliped of female.
/, Left pleopod of second pair of adult male, g, Left maxilla of
second pair of male. h. Distal part of molar process of mandible.
i, Mandible (left side), j, Head of male (ventral view). , Man-
dible (right side). I, Middle part of head, right mandible, max-
ilke, and maxillipeds omitted, m, Posterior part of abdomen of
male, n, Left maxilla of first pair, o, Basal part of left maxilliped . 104

86. Cirolana gracilis (After Hansen). a, Left pleopod of second pair.
b, Leg of second pair, c, Leg of seventh pair, d, Leg of fifth
pair, e, Anterior part of head. /, Lateral view of male, g, Dor-
sal view of adult male, h, Posterior part of abdomen 106

ILLUSTRATIONS. XXIX

Page.

Fio. 87. Cirolana obtruncata (After Moore), a, General figure, ft, Abdo-
men (last segment with uropoda). c, Seventh leg. d, First leg.. 108

88. Cirolana obtruncata. Abdomen and last two thoracic segments 108

89. Cirolana obtruncata. a, Mandible, ft, Second maxilla, c, First

maxilla, d, Maxilliped 108

90. Cirolana obtruncata. Frontal lamina, clypeus, and labrum. (Dia-
grammatic) 109

91. Cirolana harfordi. a, Maxilliped. ft, Second maxilla, c, First

maxilla, d, Mandible, e, Frontal lamina 110

92. Cirolana harfordi (After Hansen) . a, Dorsal view of female, ft,
Anterior part of head, c, Fifth leg. d, Seventh leg. e, Lateral
view of female. /, Posterior part of abdomen, g, Second leg 111

93. Cirolana parva (After Hansen). a, Adult male, ft, Lateral view of
same, e, Second leg. d, Anterior part of head (ventral view).
e, Fifth leg. /, Seventh leg. g, Posterior part of abdomen, h,
Left pleopod of eecond pair 112

94. Cirolana parva. a, Maxilliped. ft, Mandible, c, Frontal lamina.

d, First maxilla, e, Second maxilla 112

95. Cirolana parva (After Moore), a, General figure, ft, First antenna.

c, Second antenna 113

96. Cirolana albida. Maxilliped 114

97. Cirolana albida 1 14

98. Cirolana cubensis (After Hay) 115

99. Cirolana cubensis. a, Maxilliped. ft, Mandible, c, Frontal lamina.

d, First maxilla, e, Second maxilla 115

100. Conilera cylindracea (After Hansen). a, Lateral view of female.

ft, Posterior part of abdomen of adult female, c, Anterior part
of head, d, Left pleopod of first pair in adult male, e, Left
pleopod of second pair in adult male 117

101. Conilera cylindracea. a, Maxilliped. 6, Frontal lamina, c, Sec-
ond maxilla, d, Mandible, e, First maxilla 118

102. Conilera cylindracea (After Hansen). a, Adult female. 6, Second

leg. c, Fifth leg. d, Seventh leg 119

103. Cirolanides texensis (After Ulrich). a, Dorsal .view, ft, End of
second antenna, c, First antenna, d, First pleopod. e, First leg.
/, Second. antenna, g, Second leg. h, Third leg. i, Fourth leg.
j, Third pleopod. k, Fifth leg. I, Second pleopod. m, Uropod.
n, Maxilla, o, Mandibles, p, Maxillipeds. q, Ventral side of
head 121

104. Cirolanides texensis 122

105. Cirolanides texensis. a, Maxilliped. ft, First maxilla, c, Second

maxilla, d, Mandible, e, Frontal lamina 122

106. Cirolanides texensis. a, First leg. ft, Second leg. c, Fourth leg.

d, Seventh leg. e, Uropod 123

107. Eurydice convexa. Terminal abdominal segment 124

108. Eurydice caudata. Last two abdominal segments 125

109. Eurydice spinigera (After Hansen). a, Lateral view of adult male.

ft, Anterior part of head (from below), c, Left pleopod of second
pair, d, First antenna, e, Posterior part of abdomen. /, Leg of

fifth pair, g, Leg of seventh pair, h, Leg of second pair 126

110. Branchuropus littoralis (After Moore), a, Front of head from
below, ft, First antenna, c, Second antenna, d, General figure.

e, Mandible. /, Fourth leg. g, Maxilliped. h, First leg. i,
Seventh leg 129

XXX ILLUSTRATIONS.

Page.

FIG. 111. Branchuropus littoralis (After Moore). Uropoda from below 130

112. Bathynomus giganteus (After Ed wards and Agassiz). Dorsal view. 131

113. Bathynomus giganteus ( After Filhol ) . Ventral view 132

114. Bathynomus giganteus (After Edwards and Bouvier). Head with

appendages and first thoracic segment 132

115. Bathynomus giganteus (After Edwards and Bouvier). Lateral

view 133

116. Bathynomus giganteus (After Edwards and Bouvier). a, Corneu-
les in the external layer of the cornea, b, Cutting part of mandi-
ble (inferior external side), c, Corneules in the inner layr of
the cornea. (/, Buccal cavity, e, Inferior side of second antenna.
/, Several articles of the flagellum of the first antenna, g, Several
articles of the flagellum of the second antenna, h, Corneules of
Cirolana elongata. i, First antenna of left side (inferior face), j,
Left mandible, infero-internal face of the anterior part, k, Left

eye 134

117. Bathynomus giganteus (After Ed wards and Bouvier). a, Left man-
dible, b, Cutting part of mandible (dorsal side), c, Left mandi-
ble (dorsal side), d, Left maxilliped (ventral side), e, Second
left maxilla (ventral side). /, Left maxilliped (dorsal side), g,
Second left maxilla (dorsal side), h, First maxilla (dorsal side).
/, The same (ventral side), j, Right second maxilla (ventral
nide). k, Tip of external lacinia of first maxilla. /, Basal part of

first maxilla, m, Tip of maxillary lacinia? of first maxilla 135

118. Bathynomus giganteus (After Edwards and Bouvier). a, Left
anterior pleopod (ventral side), b, Extremity of branchial tuft,
c, Left anterior pleopod (dorsal side), d, Circulation in respira-
tory endopodite. e, Left uropod (inferior side). /, Left pleopod
of third pair with the trunks of the origin of the branchial tufts.
g, Posterior left pleopod (anterior side), h, The same (posterior

side) 136

119. Colopisthus parvus. a, Maxilliped. b, Second maxilla, c, First
maxilla, d, General figure, e, Head and first two thoracic seg-
ments 137

120. Exocorallana tricornis. a, Mandible, b, Maxilliped. c, Firstmax-

illa. d, Frontal lamina 140

121. Exocorallana tricornis (After Hansen). a, Left leg of fifth pair of
male, b, Left leg of second pair of male, c, Left leg of seventh
pair of male, d, Inner parts of mouth from below, e , Inner parts
of mouth (paragnathia omitted). /, First antenna of female, g,
Middle part of left maxilliped of male. //, Basal part of flagellum
of second antenna of male, i, Lateral view of male, j, Left max-
illa of second pair of male, k, Left mandible of male. I, Left
maxilla of first pair, m, Ventral view of head of female, n, Head
of adult male (dorsal view), o, Left maxilliped of female. j>,
Left maxilliped of male, fj, Left pleopod of adult male (second
pair), r, Posterior part of abdomen of adult male. .% Distal part
of left mandible, i, Adult female, tt, Distal part of left mandi-
ble, v, Right mandible 141

122. Exocorallana mexicana. a, Mandible, b, Second pleopod of male. 142

123. Exocorallana mexicana. Male 142

124. Exocorallana sexticornis. a, Maxilliped. l>, Mandible 144

125. Exocorallana sexticornis. Head and first thoracic segment 144

ILLUSTKATIONS. XXXI

Pago.
FK ;. 126. Exocorallana sexticornis. Mandible 144

127. Exocorallana quadricornis (After Hansen). Head 144

128. Exocorallana truncata. <t, Maxilliped. b, Mandible, r, Firxt max-

illa( outer lobe) 145

12it. Exocorallana truncata. a, Head, li, Abdomen and la,t thoracic

segment 14(i

130. Kxocorallana subtilis (After Hansen). a, Posterior part of abdo-
men, b, Head. <>, Young specimen taken in process of ecdysis.
<l, Lateral view of same (right side) 140

131. Exocorallana antillensis (After Hansen). a, Head of adult male
(from above), b, Left maxilliped of same, c, Left mandible,
palp omitted (ventral side), d, Left maxilla (second pair), e,
Left mandible (basal part omitted) (from above). /, Distal part
of left maxilla of second pair (ventral side), g, Distal part of same
(from above), h, Abdomen, i, Head (ventral side), j, Adult
male (lateral view) 148

132. Exocorallana antillensis. a, Maxilliped. b, Mandible, c, Second
maxilla, d, First maxilla (outer and inner lobe), e, Frontal
lamina 149

133. Exocorallana fissicauda (After Hansen). a, Female, b, Lateral
view, c, Leg of seventh pair, d, Apex of fifth article of seventh
leg, bearing setse. e, Posterior part of abdomen with uropoda. . _ 150

134. Exocorallana oculata (After Hansen). n, Head of adult male, b,

Abdomen of adult male, c. Lateral view of adu)t male 1'52

135. Exocorallana warmingii (After Hansen). a, Leg of fifth pair, b,
Leg of seventh pair, c, Leg of second pair, d, Head, e, Dor-
sal view of male. /, Lateral view of male, g, Posterior part of
abdomen 155

136. Exocorallana warmingii. a, Mandible, b, Outer lamella of first

maxilla, c, Maxilliped. d, Tip of mandible 156

137. Alcirona krebsii (After Hansen). a, Dorsal view of male, b,

Lateral view of adult male 158

138. Alcirona krebsii. a, Maxilliped. b, Mandible, c, Frontal lamina. 158

139. Alcirona krebsii ( After Hansen). a, Maxilliped. b, First maxilla. <;
Distal part of mandible, d, Dorsal view of female, e, Left pleopod
of second pair in young male. /, Lateral view of female, g, Leg
of fifth pair, h, Leg of seventh pair, i, Mandible. ,/', Distal part
of mandible, k, Second maxilla. /, Distal part of mandible. /,
Left pleopod of second pair in adult male, n, Leg of second pair,
o, Posterior part of abdomen (adult male), p, Anterior part of
head from below 159

140. Alcirona hirsuta (After Moore. ) c, Right side of terminal abdomi-
nal segment with uropod. b, Seventh leg. c, General figure.
d, First leg. e, Fourth leg 160

141. Tridentella virginiana. Frontal lamina, clypeus, and labrum.

(Diagrammatic) 161

142. Tridentella virginiana. First maxilla 162

143. Tridentella virginiana. Abdomen 162

144. Tridentella virginiana 162

145. Tridentella virginiana. a, Maxilliped. b, Mandible, c, Palp of
mandible, d, Second maxilla, e, First maxilla (outer lobe). /,
Frontal lamina 163

146.- Nalicora rapax. , Second maxilla, b, Outer lobe of first maxilla. 164

2858905 in

XXXII ILLUSTRATIONS.

Page.

FIG. 147. Nalicora rapax (After Moore), a, General figure, b, Second max-
illa, c, Second antenna, d, First maxilla, e, Seventh leg. /,
Mandible. </, Maxilliped. /*, First leg (posterior), i, Fourth
leg. j. First leg (anterior). /.-, First leg (inferior). /, Part of

terminal segment of abdomen with uropoda 165

148. JEga psora (After Harger). a, Ventral view, b, Dorsal view 169

149. .<Ega antillensis (After Schioedte and Meinert). a, Frontal margin

with lx>th an ten me and frontal lamina, b, Young female 170

150. .Ega antillensis. , Maxilliped. b, Leg of second pair 171

151. JEga ecarinata 172

152. yEga ecarinata. Maxilliped 172

153. yEga ecarinata. a, Leg of first pair, b, Leg of third pair, c, Leg

of seventh pair 1 72

154. yEga crenulata (After Schioedte and Meinert). , Young of third

stage, b, Young of second stage 173

155. yEga crenulata. a, Maxilliped. b, Second leg 1 74

156. yEga webbii (After Schioedte and Meinert). a, Frontal margin

with both pairs of antennae and frontal lamina, b, Adult male.. 175

1 17. yEga webbii. a, Maxilliped. b, Leg of the second pair 1 75

158. yEga lecontii 177

159. yEga lecontii. <t, Maxilliped. b, Frontal lamina. (Diagrammatic.)

c, Second leg 177

160. yEga tenuipes (After Schkedte and Meinert). a, Frontal margin
with antenna- and frontal lamina, b, Young female, c, Right

leg of second pair 178

161. yEga dentata (After Schioedte and Meinert). a, Frontal margin

with both pairs of antennae and frontal lamina, b, Young female . . 1 79

162. yEga incisa ( After Harger) 181

163. yEga incisa (After Schioedte and Meinert). a, Frontal lamina and

both pairs of antennae, b, Young female, c, Left leg of third pair. 181

164. yEga incisa. a, Maxilliped. ft, Second leg 181

165. yEga arctica (After Sars). a, First and second antennae, b, Gen-
eral figure 182

166. yEga arctica. a, Leg of second pair, b, Maxilliped 183

167. yEga gracilipes (After Hansen). a, Frontal part of head from

underside, b, General figure 184

168. yEga gracilipes. a, Maxilliped. b, Leg of second pair 184

169. yEga symmetrica 185

170. yEga symmetrica. o, Maxilliped. b, Palp of same 185

171. yEga symmetrica. Third leg 186

172. yEga symmetrica. Posterior part of abdomen 186

173. yEga ventrosa (After Schioedte and Meinert). a, Frontal margin
with both antennae and frontal lamina of adult female, b, Adult
female, c, Frontal margin with both antenna; and frontal lamina

of young female, d, Young female 188

174. yEga ventrosa. Leg of second pair 189

175. Rocinela oculata (After Harger). a, Ventral view, b, Dorsal

view, c, Leg of first pair 192

176. Rocinela cornuta. Head 193

177. a, Rocinela cornuta, male, b, Leg of first pair, c, Leg of fourth pair 193

178. Rocinela cornuta. Maxilliped 193

179. Rocinela insularis ( After Schioedte and Meinert ) . a, Frontal margin

with both pairs of antennae and frontal lamina, b, Adult male. . 194

ILLUSTRATIONS. XXXIII

rage.

FIG. 180. Rocinela insularis. a, Second leg. b, Maxilliped 194

181. Rocinela dumerilii (After Schioedte and Meinert). , Frontal mar-
gin with both antennae and frontal lamina of adult female. ft,

Same of young female, c, Adult female, d, Young female 195

182. Rocinela dumerilii. Leg of second pair 196

183. Rocinela cubensis. Head 197

184. a, Rocinela cubensis, male. ft, Leg of first pair, c, Leg of fourth

pair 197

185. Rocinela cubensis. Maxilliped 197

186. Rocinela maculata (After Schioedte and Meinert). a, Frontal mar-
gin with both antennae and frontal lamina, b, Right leg of second

pair, c, Adult male 198

187. Rocinela belliceps. Head and first two thoracic segments 199

188. Rocinela belliceps. Abdomen and last thoracic segment 200

189. Rocinela belliceps 200

190. Rocinela belliceps. Maxilliped 200

191. Rocinela belliceps. Leg of third pair 200

192. Rocinela belliceps. Uropod 200

193. Rocinela americana (After Schioedte and Meinert). a, Frontal

margin with both antennae and frontal lamina, ft, Young female. 201

194. Rocinela americana. a, Second leg. b, Maxilliped 201

195. Rocinela americana (After Harger). a, Dorsal view of female, ft,
Ventral view of female, c, Head and first thoracic segment of

male, d, Leg of sixth pair, e, Leg of first pair 202

196. Rocinela propodialis. Head with antennae and first two thoracic

segments 203

197. Rocinela propodialis. Abdomen 203

198. Rocinela propodialis. Third leg 203

199. Rocinela propodialis. Uropod 204

200. Rocinela propodialis. Maxilliped ' 204

201. Rocinela laticauda (After Hansen). a, Epimera of small female,
ft, Abdomen with tiropoda of same, c, Both pairs of antennas of
male, d, Fifth leg of large female, e, Second leg of same. ./',

General figure, male ' 205

202. Rocinela laticauda. a, Maxilliped. ft, Leg of second pair 206

203. Rocinela angustata. Head 206

204. Rocinela angustata. Head with antennae and first two segments of

thorax. (From Japan ) 206

205. Rocinela angustata. Uropod. (From Japan ) 207

206. Rocinela angustata. a, Male slightly reduced, ft, Leg of first pair.

c, Leg of fourth pair 207

207. Rocinela angustata. Third leg. ( From Japan ) 207

208. Rocinela angustata. Abdomen and last thoracic segment. (From

Japan) 207

209. Rocinela tuberculosa. Male 208

210. Rocinela tuberculosa. a, Maxilliped. ft, Second leg 208

211. Rocinela signata (After Schioedte and Meinert) . a, Adult female.
ft, Young female, c, Frontal margin with both antennae and

frontal lamina 209

212. Rocinela signata. a, Maxilliped. ft, Second leg 210

213. Rocinela aries (After Schioedte and Meinert). a, Frontal margin,

antennae, and frontal lamina, ft, Adult female 211

214. Rocinela aries (After Schiredte and Meinert). Young 211

XXXIV ILLUSTRATIONS.

Page.

FIG. 215. Rocinela aries. a, Maxilliped. b, Leg of second pair 211

216. Syscenus infelix (After Harger). ti, Inferior view of head. f>, Lat-
eral view of male, c, Second pleopod of male, d, Leg of sixth
pair, e, Leg of fourth pair. /, Leg of first pair. </. Tip >f first
maxilla, /i, First maxilla. !, Dorsal view of male. /, Left max-

illiped. k, Uropod of male. I, Left mandible 213

217. Syscenus infelix. Maxilliped L'14

218. jEgathoa linguifrons 2 Hi

219. vEgathoa oculata (After Harger). a, Dorsal view. t>, Ventral view. L'17
220. yEgathoa oculata. a, Mandible. b, Maxilliped. c, Second maxilla.

d, First maxilla 218

221. jEgathoa medialis 218

222. Nerocila acuminata (After Schioedte and Meinert). a, Adult female.

b, Lateral view 220

223. Nerocila acuminata. a, Maxilliped. 6, First maxilla, c, Second

maxilla, d, Palp of mandible, e, Seventh leg 221

224. Nerocila californica ( After Schioedte and Meinert). a, Lateral view.

b, Adult female, c, Young female, d, Lateral view 222

225. Nerocila californica. a, Maxilliped. b, First maxilla, e, Mandi-
ble, rf, Seventh leg 222

226. Nerocila californica ( After Schuedte and Meinert ) . a, Lateral view.

b, Adult female 223

227. Nerocila munda (After Harger). a, Uropod 224

228. Nerocila munda. a, Maxilliped. b, Second maxilla, c, First max-
illa, d, Palp of mandible, e, Seventh leg .'4

229. Nerocila lanceolata 225

230. Anilocra laticauda (After Schioedte and*Meinert). a, Young of the

second stage, b, Adult female, c, Young of the first stage 227

231. Anilocra laticauda. a, Maxilliped. b, Seventh leg. c, First max-
illa, d, Mandible, e, Second maxilla 228

232. Anilocra plebia ( After Schioedte and Meinert). Young female 229

233. Olencira pnegustator (After Schioedte and Meinert). a, Head of
female showing antennae and mouth parts, b, Head of male
showing same 232

234. Oleucira praegustator (After Sohioedte and Meinert). a, Adult

female, b, Lateral view 232

235. ^Olencira pnegustator. a, Mandible, b, Mandible without palp.

c, Maxilliped. d, Second maxilla, e, First maxilla 233

236. Ceratothoa impressa (After Schioedte and Meinert). a, Adult

female, b, Lateral view of thorax, c, Lateral view of thorax of
male, d, Adult male 234

237. Ceratothoa impressa. a, Maxilliped of female, b, Second maxilla.

c, First maxilla, d, Palp of mandible 235

238. Ceratothoa impressa (After Schioedte and Meinert). a, Young of
the second stage, b, Young of the third stage, c, Young of the
first stage 235

239. Ceratothoa impressa. Seventh leg 236

240. Ceratothoa impressa (After Schioedte and Meinert). a, Ungula of
first pair of legs of young of second stage, b, Ungula of sixth
pair of legs of young of second stage 236

241. Meinertia gaudichaudii (After Schioedte and Meinert). a, Adult

female, b, Adult female, c, Lateral view of thorax 238

242. Meinertia gaudichaudii. a, Maxilliped of male, b, Maxilliped of

female, c, First maxilla 238

ILLUSTRATIONS. XXXV

Page.

FIG. 243. Meinertia gaudichaudii (After Schioedte and Meinert). a, Young
of first stage, b, Second leg of adult male, c, Lateral view of

thorax of adult male, d, Adult male 239

244. Meinertia gaudichaudii. a, Second maxilla. l>, Palp of mandible.

c, Leg of seventh pair 239

245. Meinertia gaudichaudii (After Schioedte and Meinert). a, Second

leg of adult female, b, Seventh leg of adult female 239

246. Meinertia deplanata (After Bovallius). a, First leg. b, Lateral
view of female, c, Uropod. d, Seventh leg. e, Dorsal view of

female. /, Head with both antennae 240

247. Meinertia gilberti. a, Second maxilla, b, First maxilla, c, Max-

illiped 242

248. Meinertia gilberti. Leg of seventh pair 242

249. Meinertia gilberti 242

250. Meinertia trans versa. Head 243

251. Meinertia transversa. ., Maxilliped. b, Second maxilla, c, First

maxilla, d, Seventh leg 243

252. Meinertia transversa. Abdomen 243

253. Agarna carinata (After Schioedte and Meinert). a, Lateral view of
adult female (leftside), b, Young of the first stage, r, Lateral
view of adult female (right side), d, Adult male, e, Adult

female. /, Lateral view of thorax of adult male 244

254. Agarna carinata. a, Maxilliped. b, Second maxilla, o, First

maxilla, d, Mandible, e, Palp of mandible 245

255. Indusa carinata. Head and first thoracic segment 246

256. Indusa carinata 246

257. Indusa carinata. a, Second maxilla, b, First maxilla, c, Maxil-
liped 247

258. Indusa carinata. Leg of seventh pain 247

259. Cymothoa excisa (After Schioedte and Meinert). a, Ungula of the

leg of third pair of young of second stage, b, Lateral view of

thorax of adult female, c, Adult female, d, Young of second

stage, e, Adult male. /, Lateral view of thorax of adult male.. 248

260. Cymothoa excisa. a, Second maxilla, b, First maxilla, c, Palp of

mandible, d, Maxilliped. e, Mandible. /, Seventh leg 249

261. Cymothoa exigua (After Schioedte and Meinert). a, Adult female.

b, Lateral view of thorax 251

262. Cymothoa caraibica (After Bovallius). a, Dorsal view of male, b,

Seventh leg of right side, c, Fourth leg of right side, d, Second
pleopod 253

263. Cymothoa a>strum (After Schioedte and Meinert). a, Young of the
second stage, b, Young of the first stage, c, Lateral view of
thorax of adult female, d, Adult male, e, Adult female. /,
Adult female 255

264. Cymothoa oestrum, a, Maxilliped. b, Seventh leg. c, First max-
illa, d, Second maxilla, e, Mandible. /, Palp of mandible 256

265. Livoneca panamensis (After Schioedte and Meinert). a, Adult
male. 6, Lateral view of thorax of adult female, c, Lateral view
of thorax of adult male. d, Adult female 257

266. Livoneca panamensis. a, Maxilliped of female, b, Second maxilla.

c, First maxilla, d, Seventh leg 258

267. Livoneca vulgaris (After Schioedte and Meinert). a, Young of the

first stage, b, Adult male, c, Lateral view of thorax of adult
female. - d, Adult female, e, Lateral view of thorax of adult male. 258

XXXVI ILLUSTRATIONS.

Page.
FIG. 268. Livoneca vulgaris (After Stimpson ) 259

269. Livoneca vulgaris. a, Maxilliped of female, b, Seventh leg. c, Sec-
ond maxilla, d, First maxilla, e , Palp of mandible 259

270. Livoneca vulgaris. Young male L'tiO

271. Livoneca californica (After Schi<i>dte and Meinert). a, Adult fe-
male, b, Lateral view of thorax 2<>1

272. Livoneca californica. a, Maxilliped. l>. Second maxilla. <; First

maxilla, d, Palp of mandible 261

273. Livoneca californica. Seventh leg 261

274. Livoneca redmanni (After Schioedte and Meinert). a, Adult
female, b, Lateral view of thorax of same. <, Leg of seventh
pair of young female, d, Antenna of second pair of same.
e, Young female. /, Antenna of first pair of same, rj, Third leg
of same 262

275. Livoneca redmanni. , Maxilliped of female, b, Second maxilla.

c, Seventh leg. d, First maxilla, e, Palp of mandible 263

276. Livoneca ovalis. Abdomen 264

277. Livoneca ovalis. a, Maxilliped. b, Mandible, c, Second maxilla.

d, First maxilla, e , Seventh leg 264

278. Irona nana (After Schioedte and Meinert). a, Adult female, b,

Young male, c, Young of the second stage, d, Tngula of the

leg of the third pair of same 267

279. Limnoria lignorum ( After Harger) 269

280. Limnoria lignorum (After Harger). a, First antenna, b, Second
antenna, c, Maxilliped. d, Second maxilla, e, First maxilla.

e, Distal end of first maxilla. /, Mandible 270

281. Limnoria lignorum ( After Harger. ) a, Last segment of abdomen

with uropoda. b, Uropod. c, First pair of pleopoda. d, Second

pleopod of male 270

282. Ancinus depressus. Abdomen with uropoda 272

283. Cassidisca lunifrons 273

284. Cassidisca lunifrons. Maxilliped 273

285. Cassidisca ovalis. Abdomen with uropoda 274

286. Tecticeps alascensis 276

287. Tecticeps alascensis. , Antenna of first pair, b, Antenna of sec-
ond pair 276

288. Tecticeps alascensis. a, Mandible, b, Mandibular appendage.

c, Maxilliped 277

289. Tecticeps alascensis. o, Leg of first pair, b, Last two joints of
same, c, Leg of second pair of male, d, Leg of third pair, e,

Leg of sixth pair. /, Leg of seventh pair 277

290. Tecticeps convexus. a, Head, b, Abdomen and last thoracic seg-
ment 279

291. Tecticeps convexus. a, Maxilliped. b, Second leg of female, c,

First leg. d, Mandible, e, Second maxilla. /, First maxilla. . . 279

292. Spharoma quadridentatum ( After Harger) 281

293. Sphseroma quadridentatum. a, Mandible, b. Frontal lamina and

clypeus. c, Maxilliped 281

294. Sphseroma destructor. Dorsal view 282

295. Spheeroma destructor. Mandibular appendage 283

296. Sphferoma destructor, a, Leg of second pair, b, Leg of fourth

pair, c, Leg of fifth pair. d. Leg of sixth pair 283

297. Sphseroma destructor. Abdomen with uropoda and last segment

of thorax . 284

ILLUSTRATIONS. XXXVlt

Page.
FIG. 298. Sphseroma destructor, a, Maxilliped. b, Mandible (palp omitted) .

c, First maxilla, d, Second maxilla 284

299. Sphseroma pentodon. Maxiliiped 286

300. Sphajroma pentodon. Abdomen 287

301. Exosphaeroma amplicauda ( After Stimpson ) 289

302. Exosphaeroma amplicauda. a, b, Mandibles, c, Maxilliped. d,

Frontal lamina and clypeus 289

303. Exosphaeroma rhomburum. Abdomen 290

304. Exosphaeroma rhomburum. Maxilliped 290

305. Exosphaeroma yucatanum. Abdomen 291

306. Exosphaeroma yucatanum. a, Maxilliped. b, Frontal lamina and

clypeus. (Diagrammatic) 291

307. Exosphaeroma faxoni 292

308. Exosphaeroma faxoni. a, Maxilliped. b, Frontal lamina, c, Sec-
ond maxilla 292

309. Exosphaeroma octoncum. Maxilliped 293

310. Exosphaeroma octoncum. Abdomen 293

311. Exosphaeroma thermophilum 294

312. Exosphaeroma thermophilum. Maxilliped 294

313. Exosphaeroma dugesi (After Dollfus). a, Head and first thoracic

segment, b, Abdomen and uropoda ^ 295

314. Exosphaeroma dugesi. a, Mandible, b, Frontal lamina and cly-
peus. c, Maxilliped 295

315. Exosphaeroma oregonensis (After Dana), a, Second antenna, b,

General figure, c, Abdomen (underside) 297

316. Exosphaeroma oregonensis. a, Maxilliped. b, Mandible, palp
removed, c, Mandible with palp, d, Frontal lamina and cly-
peus 297

317. Exosphaeroma crenulatum 298

318. Exosphaeroma crenulatum. Maxilliped 298

319. Dynamene perforata. Last two thoracic segments and abdomen . . . 300
320. Dynamene perforata (After Moore), a, First antenna, b, Second
antenna, c, Male, d, Tip of maxilla, e, Mandible. /. Maxilli-
peds. g, Fourth leg. h, First leg. i, Seventh leg. j, Part of

terminal segment of abdomen with uropod 300

321. Dynamene glabra. Abdomen and last two thoracic segments 301

322. Dynamene glabra. Second pleopod of male 301

323. Dynamene angulata. Maxilliped 302

324. Dynamene angulata. Abdomen 302

325. Dynamene moorei- (After Mocre) 303

326. Dynamene moorei. Second pleopod of male 303

327. Dynamene dilatata. a, Head and first thoracic segment, b, Dor-
sal view 304

328. Dynamene benedicti. Second pleopod of male (inner branch) 305

329. Dynamene benedicti. Last thoracic segment and abdomen 305

330. Paradynamene benjamensis. Abdomen and last thoracic segment

of male 306

331. Paradynamene benjamensis. a, First antenna. 6, c, Mandibles.

d, First maxilla, e, Maxilliped 306

332. Paradynamene benjamensis. Female (dorsal view ) 307

333. Paradynamene benjauiensis. a, First pleopod of male, b, Second

pleopod of male 307

334. Cilicaea linguicauda. Abdomen 309

335. Cilicaea granulosa. Last thoracic segment and abdomen 310

XXXVIII ILLUSTRATIONS.

Page.
FIG. 336. Cilicsea cordata (male), a, Head and first thoracic segment, b,

Dorsal view 311

337. Cilicaea cordata. Maxilliped 311

338. Cilicsea cordata. Second pleopod of male 312

339. Cilioea cordata (female). Maxilliped 312

340. Cilicsea cordata (female), a, Dorsal view, b, Lateral view 312

341. Cilicsea gilliana 313

342. Cilicaea gilliana. Maxilliped 313

343. Cilicsea caudata (After I ves). a, Lateral view, b, Dorsal view 314

344. Cilicsea caudata (male) ( After Moore) 315

345. Cilicrea caudata. Maxilliped 315

346. Cilicsea caudata (female) (After I ves). , Dorsal view, b, Leftside.

c, Fourth leg of right side 316

347. Cilicsea caudata (female) (After Moore) 316

348. Cilicsea caudata (female), a, Mandible. 6, Maxilliped. r, Frontal

lamina and clypeus 317

349. Cilicsea sculpta (After Hohnes). a, Abdomen of male. f>, Abdomen
of female. <, Head of male (lateral view), d, First antenna of
male, e, Second antenna of male. /, Maxilliped of male, g, Last

thoracic leg of male 318

350. Cilicaea carinata. Head 319

351. Cilicsea carinata. Lateral view 320

352. Cilicsea carinata. Abdomen 320

353. Serolis carinata 321

354. Serolis carinata. , First leg. b, First maxilla, c, Second maxilla.

d, Maxilliped. e, Mandible 321

355. Astacilla granulata (After Harger). a, First antenna of male. l>,

Fourth thoracic segment of male, r, Ventral side of abdomen . . 324

356. Astacilla granulata. Maxilliped 325

357. Astacilla c;eca ( After Benedict) 326

358. Astacilla cseca. Maxilliped 326

359. Arcturus beringanus ( After Benedict) 328

360. Arcturus longispinus ( After Benedict) 329

361. Arcturus glaber (After Benedict) 331

362. Arcturus glaber. Maxilliped 331

363. Arcturus purpureus (After Beddard). o, One of posterior thoracic-
legs, b, Lateral view, r, One of anterior thoracic legs 332

364. Arcturus purpureus ( After Beddard ) . Dorsal view 333

365. Arcturus caribbseus 335

366. Arcturus floridanus 337

367. Arcturus baffini (After G. 0. Sars). o, Anterior part of body with
first pair of antenna and oral appendages viewed from below, b,
First antenna, c, Base of second antenna, rf, Adult female from
above, e, First leg. /, Second leg. g, Posterior part of body,
viewed from below (one of opercular valves removed), h, Two
sensory appendices of first antenna. /, Labrum. j, Flagellum of
second antenna. /;, Mandibles. /, One of anterior pleopods. /,
Terminal branches of opercular valve (inner side). , Seventh
leg. o, One of posterior pleopods. />, First maxilla, q,
Labium. r, Second maxilla. *, Maxilliped. t, Terminal claw

of seventh leg. u, Lateral view 339

368. Arcturus baffini. Maxilliped 340

369. Arcturus baffini var. tuberosus (After Benedict) 341

ILLUSTRATIONS. XXXIX

Page.

PIG. 370. Arcturus baffini var. tuberosus. Maxilliped 341

371. Pleuroprion murdochi ( After Benedict) 343

372. Pleuroprion murdochi. Maxilliped 343

373. Pleuroprion intermedium 345

374. Mesidotea entomon (AfterGerstaecker). a, Dorsal view. ^Mandi-
ble, c, Mandible, d, Ventral view, e, Labium. /, Maxillipeds.
g, Half of two thoracic segments about the middle, with one leg.
h, Abdomen (ventral side). /, Cross section of a thoracic seg-
ment about the middle, j, Second maxilla, k, First maxilla. I,

Second antenna, m, First antenna 349

375. Mesidotea entomon (After Miers). a, Head with both antennae.

b, Opercular valve ( inner side ) 350

376. Mesidotea entomon. Maxilliped 350

377. Mesidotea sabini (After Miers). a, Opercular valve (inner side).

b, Head with both pairs of antennae 351

378. Mesidotea sabini. Maxilliped 351

379. Mesidotea sabini (After Kr0yer). Showing detailed parts 352

380. Chiridotea ca?ca ( After Harger) 353

381 .Chiridotea caeca. Maxilliped .- , 353

382. Chiridotea tuftsii ( After Harger) .' 355

383. Chiridotea tuftsii. Maxilliped 355

384. Idothea gracillima 357

385. Idothea gracillima. Abdomen, showing variations in form 357

386. Idothea urotoma. Abdomen 358

387. Idothea fewkesi 359

388. Idothea fewkesi. a, Maxilliped. b, First antenna 360

389. Idothea rectilinea 361

390. Idothea rectilinea. a, Maxilliped. b, First antenna 361

391. Idothea rectilinea. Abdomen 361

392. Idothea metallica (After Harger) 362

393. Idothea metallica. a, Maxilliped. b, First antenna 363

394. Idothea baltica (After Harger) 364

395. Idothea baltica. a, Maxilliped. b, First antenna 365

396. Idothea ochotensis '. 366

397. Idothea ochotensis. a, Maxilliped. b, First antenna 366

398. Idothea phosphorea (After Harger) 367

399. Idothea phosphorea. a, Maxilliped. b, First antenna. 368

400. Pentidotea resecata (After Stimpson) 369

401. Pentidotea resecata. a, Maxilliped. b, First antenna 370

402. Pentidotea wosnesenskii. Male 371

403. Pentidotea wosnesenskii. Female 371

404. Pentidotea wosnesenskii. o, Maxilliped. b, First antenna 371

405. Pentidotea whitei 374

406. Pentidotea whitei. a, Maxilliped. b, First antenna 374

407. Pentidotea stenops (After Benedict) 375

408. Pentidotea stenops. a, Maxilliped. b, First antenna 375

409. a, Head of Synidotea ritteri. b, Head of Synidotea consolidate . . . 377

410. Synidotea ritteri 377

411. a, Abdomen of Synidotea ritteri. b, Abdomen of Synidotea con-

solidata 378

412. Synidotea pallida (After Benedict) 379

413. Synidotea pallida. Maxilliped 379

414. Synidotea erosa (After Benedict) 380

XL ILLUSTRATIONS.

Page.

FIG. 415. Synidotea erosa. Maxilliped 380

416. Synidotea nebulosa ( After Benedict) 381

417. Synidotea nebulosa. Maxilliped 381

418. Synidotea angulata (After Benedict) 382

419. Synidotea angulata. Maxilliped 382

420. Synidotea consolidata ( After Benedict) 383

421. Synidotea consolidata. Maxilliped 383

422. Synidotea marmorata ( After Benedict) 384

423. Synidotea marmorata. Maxilliped 384

424. Synidotea hicuspida ( After Benedict) 385

425. Synidotea laticauda (After Benedict) 386

426. Synidotea laticauda. Maxilliped 386

427. Synidotea harfordi (After Benedict) 387

428. Synidotea harfordi. Maxilliped 387

429. Synidotea nodulosa ( After Harger ) 388

430. Synidotea nodulosa. Maxilliped 389

431. ^Synidotea Isevis (After Benedict) 389

432. Synidotea Isevis. Maxilliped 389

433. Synidotea muricata ( After Benedict) 390

434. Synidotea muricata. Maxilliped 391

435. Synidotea picta (After Benedict), a, Typical form, b, Variety... 392

436. Synidotea picta. Maxilliped 392

437. Colidotea rostrata (After Benedict) 393

438. Colidotea rostrata. or, Leg of second pair, b, Maxilliped 394

439. Edotea acuta 395

440. Edotea acuta. a, Maxilliped. b, Second antenna, c, First antenna. 395

441. Edotea triloba (After Harger) 396

442. PMotea triloba. Maxilliped 396

443. Edotea montosa (After Harger) 397

444. Edotea montosa. Maxilliped 398

445. Eusymmerus antennatus 399

446. Eusymmerus antennatus. Maxilliped 399

447. Erichsonella attenuata. Maxilliped 401

448. Erichsonella attenuata (After Harger) 401

449. Erichsonella filiformis ( After Harger) "^102

450. Erichsonella filiformis. Maxilliped 402

451. Erichsonella floridana (After Benedict) 403

452. Cleantis planicauda (After Moore), a, General figure, b, First
antenna, c, Second antenna, d, First leg. e, Fourth leg, /,

Seventh leg , 405

453. Cleantis planicauda 405

454. Cleantis planicauda. Maxilliped 405

455. Cleantis occidentalis 406

456. Cleantis occidentalis. Maxilliped 406

457. Cleantis heathii. Maxilliped 407

458. Cleantis heathii 407

459. Mancasellus brachyurus (After Garman). a, Mandible. 6, Out-
line of one side of head, c, One of second genital plates of male.

d, Uropod. e , Hand 410

460. Mancasellus brachyurus. cr, Abdomen with uropoda. &, Second
pleopod of male, c, First pleopod of female, d, Third pleopod
of male, e, Uropod. /, First leg. g, Third pleopod of female.

h, First pleopod of male 411

461. Mancasellus brachyurus 412

ILLUSTEATIONS. XLI

Page,

PIG. 462. Mancasellus macfourus (After Garman). a, Outline of one side of
head. b, One of second genital plates of male, c, Mandible, d,

Hand, e, Uropod 413

463. Mancasellus macrourus (After Hay) 413

464. Mancasellus macrourus (After Garman) 414

465. Mancasellus macrourus. a, First leg. b, Maxilliped. c, Second

maxftla. d, First maxilla, e, Mandible. /, Uropod 414

466. Mancasellus tenax (After Harger) , 415

467. Mancasellus tenax. a, Abdomen with uropoda. b, First leg . .... 416

468. Mancasellus danielsi 417

469. Mancasellus danielsi. Mandible 418

470. Mancasellus danielsi. Maxilliped 418

471. Mancasellus danielsi. Leg of first pair 419

472. Asellus communis (After Smith ) 421

473. Asellus communis. a, First leg of male, b, Uropod 421

474. Asellus intermedius 422

475. Asellus injermedius. a, First leg. 6, Abdomen with uropoda 422

476. Asellus intermedius (After Forbes), a, One of first pair of genital

plates of male, b, One of second pair of genital plates of male. . . 423
477. Asellus brevicauda (After Forbes), a, Hand of male, b, One of
first pair of genital plates of male, c. One of second pair f>i genital

plates of male 424

478. Asellus brevicauda 424

479. Asellus brevicauda. a, First leg. b, Uropod. c, Palp of mandible.

d, Maxilliped 425

480. Asellus hoppinae (After Faxon) 425

481. Asellus hoppinae. a, Peduncle of second antennae, b, Abdomen

with uropoda. c, First leg 425

482. Asellus attenuatus 427

483. Asellus attenuatus. Leg of the first pair of female 427

484. Asellus attenuatus. a, Maxilliped. b, Mandible 427

485. Asellus attenuatus. a, Leg of the first pair, b, Third pleopod of

female, c, First pleopod of female 428

486. Asellus aquaticus (After Sars). a, Dorsal view of female, b, First
and second antennae, c, Upper lip. d, Lower lip. e, Left man-
dible. /, First maxilla, g, Right mandible, h, Palp of mandi-
ble, i, Second maxilla, j, Left mandible, k, Maxilliped.
I, First pleopod of female, m, First leg. n, Second pleopod of
male, o, First pleopod of male, p, Fourth pleopod of female.
q, Uropod. r, Abdomen of female, s, First leg of male, t, Fifth

pleopod of female, u, Third pleopod of female 430

487. Asellus tomalensis 432

488. Asellus tomalensis. Mandible 432

489. Asellus tomalensis. Leg of first pair 432

490. Csecidotea stygia ( After Hay) 434

491. Caecidotea stygia. a, Terminal segment of body and uropoda.

b, Maxilliped. c, First leg. d, Mandible 435

492. (After Hay. ) a, Abdomen and uropoda of Csecidotea stygia (Mam-
moth Cave), b, Uropod of Caecidotea nickajackensis (Metcalf,
Georgia), c, Abdomen' and uropoda of Caecidotea richardsonse
(Nickajack Cave), d, Gnathopod of Caecidotea nickajackensis
(Metcalf, Georgia), e, Fifth leg of Caecidotea nickajackensis
(Metcalf, Georgia). /, Fifth leg of Caecidotea richardsonae (Nick-
ajack Cave), g, Fifth leg of Caecidotea stygia (Mammoth Cave) . . 435

XLII ILLUSTRATIONS.

Page.

FIG. 493. Csecidotea nickajackensis (After Hay). Metcalf, Georgia, specimen. 486
494. Cjecidotea nickajackensis (After Packard), a, First antenna, b,

Uropoda 436

495. Csecidotea richardsome (After Hay), a, Dorsal view, b, First
antenna, c, Second antenna, d, Mandible, e, First maxilla.
/, Second maxilla, g, Maxilliped. h, Upper lip. i, Lower lip.

j, Gnathopod 437

496. Csecidotea smithsii (After Ulrich). a, Basal segment of upper
antenna, showing auditory spines, b, Maxilla (?) (according to
Ulrich). c, Upper antenna, d, Portion of body, e, First leg.
/, Portion of lower antenna, y, Basal portion of same. h, Lab-
rum, i, Second leg 438

497. Stenetrium serratum (After Hansen). a, Head, b, First two
thoracic legs?, c, Terminal part of second leg. d, Terminal part

of iirst leg. e, Abdomen 440

498. Stenetrium occidentale (After Hansen). a, Third left pleopod of
female, b, Terminal part of first leg of adult female, r, First leg
of adult male, d, Abdomen of female, e, First pleopod of adult
male. /, Left antennula of adult male, g, Second left pleopod
of adult male. h, Third left pleopod of male. /, First left leg of
immature male, j, First left leg of adult female, k, First
pair of pleopoda of female. I, Fourth left pleopod of male. ///,

Fifth left pleopod of male 442

499. Stenetrium stebbingi. a, Head and first thoracic segment. 6, First
leg of male, c, First leg of female, d, Terminal segment of body

and uropoda _ 444

500. Stenetrium stebbingi. a, Third pleopod of male, b, First pleopod

of male, c, Second pleopod of male 445

501 . Stenetrium stebbingi. a, Fourth pleopod of male, b, Fifth pleopod

of male, c, First pleopod of female 445

502. Stenetrium antillense (After Hansen). a, Adult male, b, First leg
of adult male, c, Head of adult male, d, Abdomen of immature
female, e, Distal part of left mandible. /, Distal part of right
mandible. </, Distal part of lobe from third joint of left maxil-
lula. h, Left mandible of male, i, First right leg (terminal part)
of another male. ./, Paragnatha of male, k, Distal part of left
leg of immature female. I, Left maxilliped of male, m, Left

maxilla of male, n, Left maxillula of male 447

503. Jrera marina ( After Harger ) 450

504. Jaera marina, a, Maxilliped. b, Mandible, c, Abdomen with

uropoda 451

505. Carpias bermudensis. a, Mandible, b, Second maxilla, c, First
leg of male, d, Dorsal view of male, e, Maxilliped. /, First

maxilla 453

506. Carpias bermudensis. a, First pleopod of male, b, Second pleopod

of male, r, Female operculum 454

507. Janin >psis californica. Anterior part of body 455

508. Janiropsis californica. Terminal part of body 455

509. Janiropsis kincaidi. Maxilliped 456

510. Janiropsis kincaidi 456

511. Janiropsis kincaidi. Last thoracic segment, abdomen, and uropoda. 456

512. Janiropsis kincaidi. Uropod ."*. 456

513. Janiropsis kincaidi. a, First pleopod of male. 6, Second pleopod

of male, c, Third pleopod of male 457

ILLUSTRATIONS. XLIII

FIG. 514. Janiropsis kincaidi. a, Leg of first pair, b, Leg of second pair ___ 457

515. lolella spinosa (After Harger ) ................... : .............. 459

516. lolella speciosa (After Bovallius). o, Labrum. b, Inner antenna.

c, Dorsal view of animal, if, Auditory bristle from the third joint
of the peduncle of the inner antenna, e, First joints of the flagel-
lum of the inner antenna. /, Some articles of the fiagellum of
the outer antenna, g, An olfactory gland of same. /, Peduncle
of outer antenna, i, The last joints of same, j, Head .......... 461

517. lolella triangulata .............................................. 462

518. lolella libbeyi (After Ortmann) ............................ _____ 463

519. lolella alascensis ................. .............................. 464

520. lolella erostrata ......................... ....................... 465

521. lolella holmesi ................................................. 466

522. lolella holmesi. First leg of female ............................. 466

523. lolella sarsi .................................................... 467

524. Janira maculosa (After Sars). a, Anterior lip. b. Dorsal view of

female, c, Maxilliped. d, First maxilla, e, First antenna.
/, Second maxilla, g, Mandible. /(, Mandible with palp, i, Sec-
ond antenna. j, First leg. k, Posterior lip. /, Uropod. m, Fourth
pleopod of female, n, Fifth leg. o, Abdomen (inner side).
p, Third pleopod of female, q, Fifth pleopod of female, r, Female
operculum. s, First and second pleopods of male, t, Terminal
joint of fifth leg .............................................. 470

525. Janira minuta. a, Leg of first pair of female, b, Terminal segment

and uropoda. <; Leg of first pair of male ...................... 471

526. Janira occidentalis ( After Walker), a, Head and first thoracic seg-

ment. b, Abdomen and part of previous segment of thorax ____ 472

527. Janira occidentalis. a, Abdomen with uropoda. 6, Maxilliped.

c, Mandible, d, First leg ............................ . ........ 472

528. Janira occidentalis (After Walker), a, First leg. b, Third leg... 473

529. Janira tricornis (After Kr0yer) ................................. 474

530. Janira tricornis ( After Kr0yer). Showing detailed parts ......... 474

531. Janira alta ( After Harger) ...................................... 475

532. Janira alta. o, Adbomen with uropoda. b, Maxilliped. c, First

leg. d, Mandible ............................................ 476

533. Ja?ropsis lobata. Head ......................................... 477

534. Jseropsis lobata. Maxilliped and mandible ...................... 477

535. Jyeropsis lobata ................................................ 478

536. Jceropsis lobata. Antennse ..................................... 478

537. Jajropsis rathbunte. a, Head and first thoracic segment, b, Max-

illiped. c, Terminal segment and uropoda. d, Mandible, e,
Mandible (another view) ......... ............................

538. Munna fabricii (After Harger) ..................................

539. Munna fabricii (After Sars). a, First leg. b, First antenna, c,

Dorsal view of female, d, Seventh leg. e. Extremity of second
leg. /, Second leg. g, Abdomen and uropoda. h, Extremity, of
abdomen with uropoda. i, Uropod ........................... 481

540. Munna kr0yeri (After Sars). a, Dorsal view of female. 6, First

leg of female, c, Second leg of female, d, First antenna. ^Abdo-
men of female with uropoda (dorsal view). /, Seventh leg.
g, Extremity of seventh leg. A, Uropoda. i, Operculum of
female. ./, Abdomen of male with uropoda (ventral view).
k, First leg of male ........................................... 482

541. Munna caeca . . 484

XLIV ILLUSTRATIONS.

Page.
FIG. 542. Munna ca?ca. First leg 485

543. Munna c?eca. Second leg 485

544. Munnopsis typica (After Harger). a, Dorsal view of male, b, Max-
illipeds (///, Basal segment; 1, external lamella; 2 and 3, second
and third segments of palp) . c, Second maxilla, d, First max-
illa, e, Second leg of male. /, One of natatory legs, g, Oper-
culum 487

545. Munnopsis typica (After G. O. Sars). a, Upper lip. b, Lower lip.
c, First antenna, d, Part of second antenna, e, End of man-
dibular palp. /, Left mandible, g, Tip of left mandible. It, First
maxilla. /, Second maxilla, j, Right mandible, k, Dorsal view
of male. I, Dorsal view of female. /, Lateral view of female.
n, Uropod. o, Female operculum 488

546. Munnopsis typica (After G. O. Sars). a, Maxillipeds. b, Head
(ventral view), c, First leg of male, d, Second leg of male.
e, Ventral view of male. /, First antenna of male, g, Second
leg of female. h, Extremity of third leg. /, First and second
pleopods of male, j, Third leg of male, k, Fifth leg of male.
/, Third pleopod of female 489

547. Eurycope cornuta (After Harger). Female, a, First antenna.

b, Maxilliped. c, Mandible, d, First leg. d', Propodus and
dactylus of same, e, Propodus and dactylus of second leg.

/, Sixth leg. g, Uropod 492

548. Eurycope caribbea 494

549. llyarachna hirticeps (After Sars). a, Mandible, b, Dorsal view
of female, c, Maxillipeds. d, Second antenna, e, First antenna.
/, Second antenna, g, Second leg. h, First leg. /, Third pleo-
pod. j, Ventral view of female, k, Fourth pleopod. I, Abdo-
men (ventral view), m, Fifth pleopod. n, Uropod. o, Fifth leg.

p, Seventh leg 496

550. Phryxus abdominalis (After Sars). a, Leg of male, b, Specimen
of Spirontocaris lilljeborgii infested with parasite, e, Male (dor-
sal view), d, Dorsal view of female, e, First leg of female.
/, Head of male (ventral view), g, Fourth leg of female.
h, Ventral view of female. /, Last segment of abdomen of
female, j, Right part of body of female, k, Same (ventral side).

I, Maxillipeds. t, Fifth to seventh rudimentary legs 501

551. Phryxus abdominalis. Abdomen of male from specimens found
on: o, Pandalus leptocerus from off Block Island, b, Pandalus
leptocerus from Marthas Vineyard, c, Pandalus leptocerus from

off Block Island ". 502

552. Phryxus abdominalis. Abdomen of male from specimens found
on: a, Spirontocaris groenlandicus from Admiralty Inlet, vicinity
of Port Townsend. b, Pandalus leptocerus from off Block Island.

c, Spirontocaris sica from off San Luis Obispo Bay, California.

d, Spirontocaris sica from off San Simeon Bay, California 502

553. lone brevicauda (After Bonnier). , Dorsal view of adult female.

b, Dorsal view of male, c, Ventral view of female, d, First
incubatory lamella, e, Ventral view of head of female (right
maxilliped removed) . /, Buccal rostrum and antennae of female.
g, Abdomen of female (dorsal view) . h, Extremity of maxilliped.
i, Leg of female, j, Longitudinal section of ventral portion of
first incubatory lamella, k, Head of male (ventral side) 506

ILLUSTRATIONS. XLV

Page.
FIG. 554. lone thompsoni. o, Dorsal view of female, ft, Ventral view of

same 509

555. lone thompsoni. Maxilliped 510

556. lone thompsoni. First lamella of marsupium 510

557. lone thompsoni. Leg of sixth pair of adult female 510

558. lone thompsoni. Male 510

559. Leidya distorta (After Leidy). a, Dorsal view of female, b, Ven-
tral view of female, c, Leg of female 51 1

560. Leidya distorta ( After Leidy). a, Dorsal view of male, ft, Abdomi-
nal segments of male with peculiar appendages, c, Right leg of

male, d, Head of male with antenme . t 512

561. Grapsicepon edwardsi (After Bonnier), a, Ventral view of female,
ft, Abdomen of male (ventral view), c, Ventral view of head of
female (first right incubatory lamella removed), d, Dorsal view
of female. <', Head of male (ventral side). /, Ventral view of
male, g, Seventh thoracic segment of male (ventral side).
h, First leg, with incubatory lamella, i, The same (inner face).. 514
562. Grapsicepon edwardsi (After Bonnier). , Ventral view of abdo-
men, ft, Inferior part of head with right maxilliped. c, Both
antenme. d, Right leg of fourth pair (female), e, Rostrum with
right mandible in situ. /, Parasite in branchial cavity of host.
</, Last thoracic segments (dorsal view) . h, Extremities of the

mandibles 515

563. Munidion parvum. a, Dorsal view of female. 6, Ventral view of

same 518

564. Munidion parvum. First lamella of marsupium 518

565. Munidion parvum. Leg of sixth pair of adult female 519

566. Munidion parvum. Male 519

567. Cryptione elongata (After Hansen). a, Maxilliped of female.
ft, Head of male (ventral view), c, First incubatory lamella of
female and first leg. d, Ventral view of male, e, Dorsal view of
female. /, Ventral view of female, g, Head of female with both
maxillipeds omitted (seen from below), h, First leg of male.

i, Fifth leg of male : 521

568. Cryptione elongata (After Hansen). Dorsal view of male 522

569. Pseudione giardi (After Caiman), a, Dorsal view of female, ft,
Embryo, c, Ventral view of male, d, Maxilliped. e , Abdomen.
/, Under surface of head, g, First incubatory lamella with pere-

iopod. h, Second pereiopod. i, Mouth parts 524

570. Pseudione galacanthse (After Hansen). a, First leg with incubatory
lamella, ft, Sixth leg of female, c, Head of smaller male, d,
Dorsal view of male, e, Head of female (ventral view). /, Dor-
sal view of female, g, Ventral view of female, h, First leg of

male, i, Seventh leg of male 528

571. Pseudione furcata. a, Dorsal view of female, ft, Ventral view of

same 529

572. Pseudione furcata. First lamella of marsupium 529

573. Pseudione furcata. Leg of sixth pair of adult female 529

574. Pseudione curtata. , Dorsal view of female, ft, Ventral view of

same 530

575. Pseudione curtata. First lamella of marsupium 530

576. Pseudione curtata. Leg of sixth pair of adult female 530

577. Pseudione curtata. Male 531

XLVI ILLUSTRATIONS.

Page.

FIG. 578. Stegophryxus hyptius (After Thompson), a, Hermit crab with
parasite attached, b, Anterior portion of head of female (ventral
side), c, Dorsal view of adult female, d, Ventral view of same.
f, Left maxilliped of adult female. /, Head of adult female (dor-
sal view), g, Head of adult female (ventral side). /<, Abdomen
and posterior part of thorax of adult female ( ventral view ) 533

579. Stegophryxus hyptius (After Thompson), a, Dorsal view of adult
male, b, Ventral .side of head of same, c, Ventral view of head
of cryptoniscid. d, Cryptoniscid from young female (lateral
view), e, Pleopod of third abdominal segment of cryptoniscid. /,
Musculature of one of first four pereiopoda (adult female), g,
Musculature of one of sixth or seventh pereiopoda of female, h,
Musculature of pereiopod. /, Dorsal view of larval female, j,
Ventral view of same 534

580. Stegias clibanarii. a, Dorsal view of female, b, Ventral view of

female 536

581. Bath ygyge grandis ( After Hansen). a, Head of male (ventral view).

b, Dorsal view of male, c. First leg of male, d, Fifth leg of male. 538

582. Phyllodurus abdominalis. Female (dorsal view) 541

583. Phyllodurus abdominalis. One of biramous pleopods of adult

female 541

584. Phyllodurus abdominalis. a, First incubatory lamella, b, Maxil-
liped. c, Seventh leg .~ 542

585. Phyllodurus abdominalis. a, Male, b, Young female 542

586. Argeia pugettensis. a, Dorsal view of adult female, b, Ventral

view of adult female 545

587. Argeia pugettensis. Male 545

588. Argeia pugettensis. First lamella of inarsupium 546

589. Argeia pugettensis. Sixth leg of specimens found on: a, Crago ni-
gricauda from off Cape Johnson, Washington, b, Crago communis
from Straits of Fuca. c, Nectocrangon crassa from off Cape New-
enham, Alaska. d, Nectocrangon crassa from Alaska 546

590. Argeia pugettensis. Sixth leg of specimens found on: a, Necto-
crangon dentata from Afognak Bay, Afognak Island, b, Nec-
tocrangon crassa from Cape Nevvenham, Alaska 547

591. Argeia pugettensis Seventh leg of specimens found on: a, Necto-
crangon alascensis from southwest of Sannakh islands, Alaska.
6, Crago nigromaculata from San Diego Bay, California, c, Crago
dalli from south of Amak Island, Alaska. (/, Crago communis
from Akutan Island, Bering Strait 547

592. Argeia pugettensis. First incubatory plate from specimens found on:
'/. Nectocrangon crassa from off Cape Newenham, Alaska, b, Nec-
tocrangon crassa from Alaska, c, Crago nigromaculata from San
Diego Bay, California, d, Crago nigricauda from off Cape Johnson 548

593. Argeia pugettensis. First incubatory lamella from specimens found
on: a, Crago communis from Straits of Fuca. b, Crago communis
from Akutan Island, Alaska, c, Nectocrangon alascensis from
southwest of Sannakh Islands, Alaska, d, Crago dalli from south
of Amak Island r 548

594. Argeia pugettensis. First incubatory lamella from specimens found
on: a, Nectocrangon dentata from Afognak Bay, Afognak Island.
b, Nectocrangon crassa from off Cape Newenham, Alaska 549

595. Argeia pugettensis. a, Dorsal view of immature female, b, Ventral

view of same. (First post-larval stage) 549

ILLUSTRATIONS. XLVII

Page.
FIG. 596. Argeia pugettensis. a, Dorsal view of immature.female. b, Ventral

view of same. (Second post-larval stage) 550

597. Argeia pugettensis ( Cryptoniscan stage ) 550

598. Parargeia ornata ( After Hansen ). a, Dorsal view of female, b,

Ventral view of female, c, Leg of seventh pair of female, d,

Leg of seventh pair of male, e, Head of female (ventral view).

/, Dorsal view of male, g, Head of male (ventral view) 552

599. Prohopyrus pandalicola. a, Dorsal view of female, b, Ventral

view of same 554

600. Probopyrus pandalicola. Leg of sixth pair of adult female 555

601. Probopyrus pandalicola. Male 555

602. Probopyrus floridensis. o, Dorsal view of female, b, Ventral

view of same 556

603. Probopyrus floridensis. First lamella of rnarsupium 556

604. Probopyrus floridensis. Leg of sixth pair of adult female 556

605. Probopyrus floridensis. Male 556

606. Probopyrus bithynis. a, Dorsal view of female, b, Ventral view

of same 557

607. Probopyrus bithynis. First lamella of marsupium. Right side . . . 557

608. Probopyrus bithynis. Leg of sixth pair of adult female 558

609. Probopyrus bithynis. Male 558

610. Probopyrus bithynis. o, Dorsal view of female, b, Ventral view

of same 558

611. Probopyrus bithynis. Male 559

612. Probopyrus alphei. Dorsal view of female 560

613. Probopyrus alphei. Male 560

614. Probopyrus latreuticola. a, Male, b, Female 560

615. Probopyrus latreuticola. "First incubatory lamella 561

616. Probopyrus latreuticola. a, First pleopod (showing both branches).

b, Second pleopod. c, Third pleopod. d, Fourth pleopod 561

617. Bopyriscus calmani. a, Female, b, First incubatory lamella 562

618. Bopyriscus calmani. First pleopod. Female 562

619. Bopyriscus calmani. Male 562

620. Bopyrina abbreviata. Dorsal view of female 563

621. Bopyrina abbreviata. First lamella of marsupium 564

622. Bopyrina abbreviata. Maxilliped 564

623. Bopyrina abbreviata. Male 564

624. Bopyrina urocaridis. . Dorsal view of female, b, Ventral view of

same 565

625. Bopyrina urocaridis. Maxilliped 565

626. Bopyrina urocaridis. First lamella of marsupium, right side 565

627. Bopyrina thorii. o, Dorsal view of female, b, Ventral view of

same 566

628. Bopyroides hippolytes (After Sars). a, First incubatory plate, b,
Palp of maxilliped. c, Max lliped. d, Head of male (ventral
view), e, Anterior part of specimen of Spirontocaris polaris in-
fested with this parasite. /, Leg. g, Anterior part of head of
female (ventral view). /;, Dorsal view of female, i, Ventral

view of female, j, Dorsal view of male 567

629. Bopyroides hippolytes. First incubatory lamella of specimens
found on: a, Spirontocaris lainellicornia from Port Townsend Bay,
Washington, b, Spirontocaris polaris from Aberdore Channel.

c, Spirontoearis polaris from Grand Menan, New Brunswick, d,
Spirontocaris spinus from off North Head, Akutan Pass, Alaska . 568

2858905 iv

XLVIII ILLUSTRATIONS,

Page.

FIG. 630. Bopyroides hippolytes. First lamella of marsupium from specimens
found on: a, Spirontocaris spinus from Eastport, Maine, b, Spi-
rontocaris spinus f rom Bay of Islands, Adakh, Alaska, c, Spiron-
tocaris securifrons from the Hawaiian Islands, b', Spirontocaris
spinus from Bay of Islands, Adakh, Alaska 568

631. Bopyroides hippolytes. First incubatory lamella from specimens
found on Spirontocaris lilljeborgii from eastern fishing banks
(Gloucester fishermen) 569

632. Bopyroides hippolytes. First incubatory lamella from specimens
found on: a, Spirontocaris polaris from west of Pribilof Islands.
b, On Spirontocaris suckleyi from Admiralty Inlet, vicinity of
Port Townsend. o, On Spirontocaris suckleyi from Afognak Bay,
Afognak Island, d, On Spirontocaris suckleyi from Admiralty
Inlet, vicinity of Port Townsend. e l , e 2 , e 3 , On Spirontocaris
suckleyi from Alitak Bay. Kadiak Island. /, On Spirontocaris
herd man i from Queen Charlotte Sound, off Fort Rupert, Van-
couver Island, British Columbia. g l , g 2 , g 3 , g 4 , g 5 , On Pandalus
jordani from Queen Charlotte Sound, off Fort Rupert, Vancouver
Island, British Columbia 569

633. Bopyroides hippolytes. Sixth leg from specimens found on: a,
Spirontocaris polaris from Aberdore Channel, b, Spirontocaris
spinus from North Head, Akutan Island, Alaska, o, Spirontocaris
spinus from Bay of Islands, Adakh, Alaska, d, Spirontocaris
spinus from Bay of Islands, Adakh, Alaska 570

634. Bopyroides hippolytes. Sixth leg from specimens found on: a,
Spirontocaris spinus from Eastport, Maine, b, Spirontocaris
securifrons from between Honolulu and Kauai Island, Hawaiian
Islands T . 570

635. Bopyroides hippolytes. Sixth leg of specimens found on : a, Spiron-
tocaris polaris from Grand Menan, New Brunswick, b, Spironto-
caris lamellicornia from Port Townsend 570

636. Bopyroides hippolytes. Sixth leg from specimen found on Spiron-
tocaris lilljeborgii from eastern fishing banks (Gloucester fisher-
men ) 570

637. Bopyroides hippolytes. Sixth leg of specimens found on: a, Spiron-
tocaris polaris from west of Pribilof Island, b, On Spirontocaris
suckleyi from Admiralty Inlet, vicinity of Port Townsend. c, On
Spirontocaris suckleyi from Afognak Bay, Afognak Island, d,
On Spirontocaris suckleyi from Admiralty Inlet, vicinity of Port
Townsend. e l , e*, <?, On Spirontocaris suckleyi from Alitak Bay,
Kadiak Island. /, On Spirontocaris herdmani from Queen Char-
lotte Island, off Fort Rupert, Vancouver Island, British Columbia.
g 1 , g 2 , g 3 , g 4 , g 5 , On Pandalus jordani from Queen Charlotte Island,
off Fort Rupert, Vancouver Island, British Columbia 571

638. Dajus mysidis (After Sars). a, Ventral view of female (adult).
b, Oral area, c, Dorsal view of adult female, d, Right part of
post-oral area with corresponding five legs and incubatory plates.
e, Leg of male. /, Maxilliped. g, Male ( dorsal view ). h, Lateral
view of male, i, Head of male (ventral side), j, Specimen of
Mysis mixta infested with parasite, k, Uropoda of male. Z, Uro-
poda of female. TO, Young female (ventral view), n, Young
female (dorsal and ventral views), o, Young female (lateral
view) 574

ILLUSTRATIONS. XLIX

Page.
FIG. 639. Holophryxus alascensis. a, Dorsal view of female, b, Lateral view

of female, c, Ventral view of female 576

640. Holophryxus alascensis. Maxilliped 576

641. Holophryxus alascensis. First incubatory lamella (distal lobe) ... 576

642. Clypeoniscus meinerti (After Giard and Bonnier), a, Dorsal view

of adult female, b, Ventral view of same, c, Female at a stage

intermediate between a and b. ' d, Mode of opening of incubatory

lamellae by marginal folds (adult female), e, The same seen from

within 1 578

643. Clypepniscus meinerti (After Giard and Bonnier), a, Posterior
part, viewed dorsally, of embryo of first stage, b, Lateral view
of embryo, c, Ventral view of embryo, d, Sixth leg. e, Pos-
terior extremity. /, Fifth leg 580

644. Oosaccus. a, Dorsal side of female, b, Ventral side of same 582

645. Tylos niveus (After Dollfus). a, Head with antenna, b, Last two

segments of abdomen 585

646. Tylos latreilli. Operculum 586

647. Tylos latreilli (After Dollfus). a. Head with antenna, b, Las* two

segments of abdomen 586

648. Ethelum modestum (After Dollfus). a. Head and first two seg-
ments of thorax (upper side), ft, The same (underside), c, Fifth
and sixth segments of abdomen and uropoda ( upper side) . d, The

same (under side) 589

649. Ethelum americanum (After Budde-Lund). a, Apex of inner
lacinia of first right maxilla, b, Left antenna, r, Flagellum of

left antenna 589

650. Ethelum americanum (After Dollfus). a, Head and first two seg-
ments of thorax (upper side), b, The same (underside), r, Fifth
and sixth segments of abdomen (upper side), d, The same (under

side) 590

651. Ethelum reflexum (After Dollfus). a, Head and first two segments
of thorax (upper side), b, The same (under side), c, Fifth and
sixth segments of abdomen and uropoda (upper side), d, The

same (under side) 591

652. Alloniscus perconvexus 596

653. Alloniscus perconvexus. a, Maxilliped. b, Second antenna, c,
First maxilla (inner lobe), d, Second maxilla, e, First maxilla,

. (outer lobe). /, Mandible. </, First antenna 597

654. Alloniscus perconvexus. Terminal segment of abdomen with

uropoda 597

655. Synuropus granulatus. a , Dorsal view. 6, Uropoda 599

656. Synuropus granulatus. Maxilliped 599

657.^-Oniscus asellus (After Sars). a, Mandible, b, Posterior lip. c,
Anterior lip. </, Second antenna, e, First antenna. /, Second
maxilla, g, First maxilla, h, Mandibles, i, Dorsal view of
body, j, Maxillipeds. k, Head (lateral view). I, First pleopods
of male, m, Head (ventral view), n, First pleopods of female.
o, Second pleopod of male, p, Uropod. q, Abdomen (ventral
view), r, Last segment of abdomen, s, Seventh leg. t, First

leg. u, Third pleopod of female 601

658. Philoscia richmondi 603

659. Philoscia richmondi. a, Maxilliped. 6, Mandible 603

ILLUSTRATIONS.

FIG. 660. Philoscia culebne (After Moore), cr, Dorsal view, ft, Second

antenna, c, Mandible, d, First leg. e, Fourth leg .' 604

661. Philoscia vittata (After Harger) 605

662. Philoscia vittata. a, Maxilliped. b, Second maxilla, c, First
maxilla (outer lobe), d, First maxilla (inner lobe), e, Man- '
dible. /, Terminal segment of abdomen, with uropoda 605

663. Philoscia vittata. o, Second antenna, b, Uropod 606

664. Philoscia bermudensis (After Dahl). a, General figure, b, Second
antenna, c, Maxilliped. <i, Mandible, e, First maxilla. /,
First leg. g, Uropod 607

665. Cylisticus convexus (After Sars). a, Anterior lip. ft, Mandible,
c, Dorsal view of male, d, First antenna, e, Second antenna.
/, Posterior lip. g, Head (dorsal view), h, Mandibles. /, Last
two segments of ^abdomen and uropoda. j, Uropod. k, Maxilli-
peds. I, Lateral view of male, in, First maxilla, n, Second
maxilla, o, Flagellum of second antenna, p, First pleopod of
male. q, Seventh leg. r, Second pleopod of male. s. Abdomen
(ventral view), t, First pleopod of female, n, First leg 610

666. Porcellio Irevis (After Sars). a, Second antenna, b, Uropod. c,
Adult male, d, Last two segments of abdomen and uropods. e,
Seventh leg. /, Flagellum. g, First pleopods of male 615

667. Porcellio parvicornis 616

668. Porcellio rathkei (After Sars). a, Dorsal view of male, b, Dorsal
view of female, c, First antenna, d, Seventh leg. e, Maxilliped.
/, Last segment of abdomen and uropoda. </, First pleopod of
male, h, Flagellum. /, Uropod. j, Second antenna 618

669. Porcellio spinicornis (After Sars). a, Head, b, Dorsal view of
female, c, Second antenna, d, Last two segments of abdomen
and uropoda. e, First leg of female. /, Last segment of abdomen.
g, First pleopod of male, h, Uropod. /, Flagellum. /, Seventh
leg of female, k, Second pleopod of male. I, Seventh leg of
male 620

670. Porcellio spinicornis. a, Maxilliped. b, Second maxilla, c, First

maxilla (outer lobe), d, Mandible, e, Second antenna 621

671. Porcellio scaber (After Sars). a, Mandibles, ft, First antenna, c,
Dorsal view of female, d, Second antenna, e, Anterior lip. /,
Second maxilla, g, First maxilla, h, Mandible, i, Posterior lip.
j, Last segment of abdomen and uropoda. k, Uropod. I, Maxil-
lipeds. m, Head, n, First pleopod of female, o, Second pleo-
pods of male, p, Var. marmorata (dorsal view of female), q,
First pleopods of male, r, Third pleopod of male. *, Abdomen
(ventral view ) 623

672. Leptotrichus granulatus 624

673. Metoponorthus saussurei (After Dollfus). a, First segment of tho-
rax, ft, Seventh thoracic segment, abdomen, and uropoda 626

674. Metoponorthus pruinosus (After Sars). o, First maxilla, ft, Max-
illiped. c, Mandibles, d, Second antenna, e, Anterior lip. /,
Dorsal view of male, g, First antenna, h, Flagellum. i, First
pleopod of male, j, Seventh leg. k, Second maxilla. I, First
leg. m, Second pleopod of male, n, Uropod. o, Third pleopod
of female, p, Head, q, Second pleopod of female, r, First pleo-
pods of female, s, Abdomen with uropoda 627

675. Hypergnathus texensis 632

ILLUSTRATIONS. LI

Page.
FIG. 676. Hypergnathus texensis. a, Maxillipeds. b, Second maxilla, c,

First maxilla, d, Mandible 632

677. Hypergnathus texensis. Uropod 633

678. Actoniscus ellipticus (After Harger) 634

679. Actoniscus lindahli 636

680. Actoniscus lindahli. a, Maxilliped. b, First maxilla, c, Second

maxilla, d, Mandible, e, Mandible 636

681. Acanthoniscus spiniger (After Kinahan). a, Terminal segment of

abdomen, b, Uropod 637

682. Cubaris tenuipunctata (After Dollfus). a, Head and first two seg-
ments of thorax (upper side), b, Head and first two segments of
thorax (under side), r, Fifth and sixth segments of abdomen
and uropoda (upper side), d, The same (under side) 640

683. Cubaris depressa (After Dollfus). a, Head and first two segments
of thorax (upper side), b, The same (under side), c, Fifth and
sixth segments of abdomen and uropoda (upper side), d, The
same (under side) 641

684. Cubaris viticola (After Dollfus). a, Head and first two segments
of thorax (upper side), b, The same (under side), c, Fifth and
sixth segments of abdomen with uropoda (upper side), d, The
same (under side) 642

685. Cubaris silvarum (After Dollfus). a, Head and first two segments
of thorax (upper side), b, The same (underside), c, Fifth and
sixth segments of abdomen and uropoda (upper side), d, The
same (under side) 643

686. Cubaris perlata (After Dollfus). a, Head and first two segments of
thorax (upper side), b, The same (underside), c, Fifth and sixth
segments of abdomen (upper side), d, The same (under side). . 644

687. Cubaris inurina. a, First antenna, b, Second antenna 645

688. Cubaris inurina (After Miers). a, Head and first thoracic segment.

b, Lateral view of body, c, Abdomen and uropoda 645

689. Cubaris murina. a, Maxilliped. b, Second maxilla, c, First max-
illa (outer lobe), d, Terminal segment with uropoda. e, Man-
dible. /, First maxilla (inner lobe), g, Uropod (from under
side) 646

690. Cubaris cincta (After Dollfus). a, Head and first two segments of
thorax (upper side), b, The same (under side), c, Fifth and
sixth segments of abdomen and uropoda (upper side), d, The
same (under side) 647

691. Cubaris gigas (After Miers). a, Abdomen with uropoda (upper
side), b, Head (under side) showing antennae, c, Lateral view.
d, Head and first thoracic segment ( upper side ) 648

692. Cubaris zigzag (After Dollfus). a, Head and first two segments of
thorax (upper side), b, Head and first two segments of thorax
(under side), c, Fifth and sixth segments of abdomen and
uropoda (upper side), d, The same (under side) 649

693. Cubaris dumorum (After Dollfus). a, Head and first two seg-
ments of thorax (upper side), b, The same (under side), c,
Fifth and sixth segments of abdomen with uropoda (upper side).
d, The same (under side) 650

694. Cubaris grenadensis (After Dollfus). a, Head and first two seg-
ments of thorax (upper side), b, The same (under side), c,
Fifth and sixth segments of abdomen and uropoda (upper side).
d, The same (under side) 651

LII ILLUSTRATIONS.

Page.

FIG. 695. Cubaris dugeai (After Dollfus). a, Head and first two thoracic seg-
ments (dorsal view), b, Head with antenna and first two seg-
ments of thorax with coxopodites (coand co') (ventral view).

c, Fifth and sixth abdominal segments and uropoda (dorsal view).

d, Sixth abdominal segment and uropoda (ventral view) 652

696. Pseudarmadillo gillianus 656

697. Pseudarmadillo gillianus. Abdomen 656

698. Pseudarmadillo gillianus. Lateral view of abdomen 657

699. Pseudarmadillo gillianus. Abdomen and uropoda (under side).. . 657

700. Pseudarmadillo dollfusi 658

701. Pseudarmadillo dollfusi. a, Second maxilla, b, Outer lamella of

first maxilla, c, Inner lamella of first maxilla, d, Lateral view
of abdomen and last thoracic segment, e, Maxilliped. /, First

maxilla, y, Mandible 659

702. Pseudarmadillo carinulatus (After Saussure). a, Head and first

segment of thorax. 6, Abdomen and uropoda 660

703. Sphaeroniscus portoricensis. a, Abdomen, b, Uropoda (inside) 662

704. Sphaeroniscus portoricensis. a, Second maxilla, b, Maxilliped. c,
Outer lamella of first maxilla, d, Inner lamella of same, e,

Mandible 662

705. Haplarmadillo monocellatns (After Dollfus). a, Head and first two
segments of thorax (upper side), b, The same (under side), c,
Fifth and sixth segments of abdomen (upper side), d, The same

(under side) 665

706. Armadillidium vulgare (After Sars). a, Head with antennae (ven-
tral view) . b, Dorsal view of female, e, First maxilla, d, First
antenna, e, Anterior lip. /, Right mandible, g, Second max-
illa, /i, Posterior lip. i, First leg. j, Left mandible, k, Tip of
maxilliped. I, Uropod. m, Seventh leg. n, Lateral view of
female, o, Maxillipeds. p, First pleopod of male, q, Abdomen
with uropoda. r, Last two segments of abdomen with uropoda.
s, Third pleopod of male, t, Second pleopod of male, u, Head
with antennae (dorsal view), r, Abdomen with uropoda (ven-
tral side), w, Second antenna 667

707. Armadillidium quadrifrons (After Stoller) 668

708. Armadillidium quadrifrons. o, Head, b, Last two segments of

abdomen with uropoda 1 669

709. Uropodias bermudensis. a, Head and first thoracic segment, b,

Abdomen and last two thoracic segments 670

710. Scyphacella arenicola ( After Harger ) 672

711. Scyphacella arenicola. Head with antenna 672

712. Scyphacella arenicola. n, Uropod. b, Maxilliped. o, First maxilla
(outer lobe), d, Second maxilla, e, Mandible. /, Last two seg-
ments of abdomen 672

713. Scyphacella arenicola. Inner lobe of first maxilla. (Diagram-
matic) - 673

714. Ligyda olfersii. a, Maxilliped. b, First leg of male 675

715. Ligyda olfersii 675

716. Ligyda exotica (After Roux) 676

717. Ligyda exotica. Maxilliped 677

718. Ligyda exotica, a, Terminal joints of first leg. b, First leg 677

719. Ligyda baudiniana (After Dahl). a, Uropod. b, General figure.

c, First leg of male, d, Mandible, e, First maxilla 678

720. Ligyda baudiniana (After Ives) 679

ILLUSTRATIONS. LIII

Page.

FIG. 721. Ligyda baudiniana. First leg of male 679

722. Ligyda baudiniana (After Dahl). Maxilliped 679

723. Ligyda baudiniana (After Moore). , Second antenna of female.

b, Female, c, First leg of female 680

724. Ligyda occidentalis (After Dana), a, Peduncle of second antenna.

b, Abdomen and uropoda. c, Joints of flagellum. d, Tip of
flagellum. e, First leg of male. . 681

725. Ligyda occidentalis. First leg ( last two joints ) . , 682

726. Ligyda pallasii (After Stimpson) 683

727. Ligyda pallasii. a, Maxilliped. b, First leg of male 683

728. Ligyda oceanica (After Sars). a, Anterior lip. b, First antenna.

c, Head (ventral view), d, Tip of mandible, e, Second antenna.
/, Posterior lip. g, Mandible, h, First maxilla, i, Dorsal view

of female, j, Tip of mandible, k, Mandibles. /, Maxilliped.
TO, Second maxilla, n, Seventh leg. o, First leg. p, Second
pleopod of female, q, First pleopod of male, r, One branch of
'uropoda. s, First pleopod of female, t, Seventh leg (tip), u,
Uropod. v, Abdomen (ventral view), w, Second pleopod of

male, a;, Third pleopod of female 684

729. Ligyda oceanica. Maxilliped 685

730. Ligidium hypnorum (After Sars). a, Mandible, b, First antenna.
c, Anterior lip. d, Second antenna, e, First antenna. /,
Flagellum of second antenna, g, First maxilla, h, Second
maxilla. /, Dorsal view of female, j, Maxilliped. k, Mandi-
bles. I, Posterior lip. m, First leg. n, Lateral view of" female.
o, Seventh leg. p, Uropod. q, First pleopod of female, r, Last
segment of abdomen and uropoda. s, Second pleopod of male.

t, Extremity of outer branch of uropod 687

731. Ligidium longicaudatum (After Stoller) 689

732. Ligidium gracilis (After Holmes), a, Maxilliped. b, General fig-
ure, c, First leg 691

733. Trichoniscus pusillus (After Sars). a, Anterior and posterior lips.
b, First maxilla, c, Dorsal view of female, d, First antenna.
e, Second antenna. /, Terminal joint of first antenna, g, Man-
dibles. h, Maxilliped. i, Last segment of abdomen and uropoda.
j, Second maxilla, k, Flagellum of second antenna. I, Head
(lateral view), m, First pleopod. n, Outline of terminal segment.
o, Seventh leg. p, Second pleopod. q, First leg. r, Third pleo-
pod. s, Fifthpleopod 694

734. Trichoniscus papillicornis. Head and first thoracic segment 695

735. Trichoniscus papillicornis 696

736. Trichoniscus papillicornis. Uropoda and last segment of abdomen . . 696

737. Trichoniscus papillicornis. Leg of first pair . . . 696

738. Trichoniscus papillicornis. Uropod of left side 696

739. Haplophthalmus puteus (After Hay), a, Dorsal view of male.
b, Right mandible, c, Tip of left mandible, d, First maxilla.
e, Maxilliped. /, Upper lip. g, Second antenna, h, First an-
tenna, i, First leg. j, First pleopod. k, Second pleopod. I,
Third pleopod. m, Fourth pleopod. n, Fifth . pleopod. o,

Uropod 698

740. Brackenridgia cavernarum (After Ulrich). a, Dorsal view, b, Sec-
ond antenna, r, Last abdominal segment with uropods. d, Max-
illiped. e, Thoracic leg. /, Claw, g, One of uropoda. h, First
maxilla, i, Mandibles 700

A MONOGRAPH ON THE ISOPODS OF NORTH AMERICA.

By HAEEIET RICHARDSON,

Collaborator, Division of Marine Invertebrates.

INTRODUCTION.

In the preparation of the present monograph my purpose has been
to give descriptions and figures of all the species of isopodous crus-
tacea, marine, terrestrial, and fresh-water, known to North America,
with synopses, so as to assist the student in the identification of each
species. The descriptions are made as concise and as nearly uniform
as possible. The original descriptions have been prepared primarily
from specimens in the collection of the U. S. National Museum, but
have been supplemented by specimens from other museums. The
collection from the Museum of Comparative Zoology at Harvard Uni-
versity, for the examination of which I am indebted to Prof. Walter
Faxon; the collection in the Peabody Museum of Yale University,
which I obtained through the courtesy of Prof. A. E. Verrill; the col-
lection from the American Museum of Natural History, kindly loaned
me by Prof. W. M. Wheeler; the collection from the University of
Pennsylvania, which I obtained through the kindness of Dr. Philip P.
Calvert and Dr. J. Percy Moore; the collection from the Academy of
Natural Sciences of Philadelphia, including Say's valuable types,
loaned to me by Doctor Pilsbry; the collection from the University of
California, kindty sent by Dr. William E. Ritter, and specimens from
the University of Cincinnati, obtained through the kindness of Prof.
Joshua Lindahl, have been of great assistance in the preparation of
this work. In addition to these valuable sources, specimens have also
been sent me by Dr. Carl Eigenmann, of the University of Indiana, by
the U. S. Bureau of Fisheries, the U. S. Department of Agriculture,
and various others.

A large number of the North American species described are not
represented in the museums of this country. The descriptions of
these forms are quoted from various sources, the original description
being given in some cases in other cases a later description by another
author, where the description seemed better. Where the descriptions
are quoted, 1 have not seen or examined any specimens.

2858905 1 1

2 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Synopses are given for the superfamilies, families, genera, and spe-
cies. In some cases the synopses do not differ from those which I
have previously published for this group. A number of them, how-
ever, have been modified. As stated heretofore in previous papers,
the synopses of other authors have been used partly or entirely when
possible. All the available sources have been investigated and the
work of others introduced with few and only necessary changes,
in order to adapt it to the material at hand. Schioedte and Meinert's
ke} 7 s for the Cymothoidse and the ^Egidse, Hansen's keys for the
Cirolanidee and Exocorallanidse, Budde- Lund's keys for the Oniscidse
and Armadillididee, Stebbing's keys for the Anthuridae and the Tan-
aidas, Benedict's keys for the genus Synidotea and the genus Arcturus
have been adapted or followed to a great extent. New species intro-
duced into the keys have also caused many modifications. The works
of G. O. Bars have been of great service in obtaining definitions of
families and genera for use in the synopses and for diagnoses.

The geographical range included in the present paper is the Atlantic
coast of North America to Panama, including Greenland, the West
Indies, the Bahamas, and the Bermudas; the Pacific coast of North
America to Panama, including Alaska; the fresh-water bodies in North
America, and all the territory north of the Isthmus of Panama.

Most of the illustrations are original, but in many cases the figures
of various authors have been reproduced, and due acknowledgments
have been recorded in the text in every case. I take pleasure, how-
ever, in a collective expression of my thanks and obligations to each
and all of the authors whose valuable monographs and memoirs have
been utilized in this connection.

THE ISOPODA.

The body is dorso-ventrally flattened, and is divided into three parts
a head, a thorax composed of seven segments, and an abdomen of six
segments. One or two of the segments of the thorax may be united
with the head. The head appendages are two pairs of antenna?, a pair
of maxillipeds, two pairs of maxilla?, and a pair of mandibles. The
maxillipeds are often provided with an epignath on the outside. In
the parasitic forms the mouth parts are strongly modified, some of the
parts having entirely disappeared. The eyes which are usually present
are paired, sessile and compound, sometimes contiguous, sometimes
distant. The appendages of the thorax are seven pairs of legs; the
last pair are sometimes wanting. The legs are of uniform structure and
appearance in the terrestrial forms, but in a large number of forms
the first pair, and even the second, third, and fourth pairs differ con-
spicuously in structure, length, and function from the succeeding pairs.
There are six pairs of abdominal appendages, usually five pairs of
pleopods and a pair of .uropods. The pleopoda are in some cases

ISOPODS OF NORTH AMERICA. 3

natatory, but their function is respiratory for the most part. Some
or all of the segments of the abdomen may be united. The telson is
very rarely free.

Marsupial plates are developed in the female, forming an incubatory
pouch.

ANALYTICAL KEY TO THE TRIBES OR SUPERFAMILIES OF NORTH AMERICAN I8OPODA.

a. Legs of first pair cheliform. Uropoda terminal. Pleopoda, when distinctly

developed, exclusively natatory I. TANAIOIDEA or CHELIFERA

a' '. Legs of first pair not cheliform.
b. Uropoda lateral.

c. Uropoda forming together with the terminal segment of the abdomen a
caudal fan. Pleopoda for the most part natatory.

II. CYMOTHOIDEA or FLABELLIFERA
cf . Uropoda valve-like, inflexed, arching over the pleopoda, which to a great

extent are branchial III. IDOTHEOIDEA or VALVIFERA

b'. Uropoda terminal.

c. Pleopoda not fitted for air breathing, exclusively branchial.
d. Pleopoda generally covered by a thin opercular plate (the modified first

pair). Free forms , IV. ASELLOIDEA or ASELLOTA

d' . Pleopoda never cqvered by an opercular plate. Parasitic forms.

V. BOPYROIDEA or EPICARIDEA
c'. Pleopoda fitted for air breathing VI. ONISCOIDE A

I. TANAIOIDEA or CHELIFERA. 6

Head fused with the first and sometimes with the second segment of
the thorax to form a carapace. Branchial cavity on each side of cara-
pace. Following five or six segments of thorax distinctly defined with
epimera small or inconspicuous.

Uropoda terminal, consisting of a short basal segment and one or
two filamentary branches. First pair of legs terminate in a cheliform
hand. Abdomen generally composed of six segments, usually dis-
tinct. First pair of antennae furnished with one or two flagella. First
maxillae have a backward directed palp, situated in the posterior part
of the carapace. Maxillipeds have a four-jointed palp, and a large
backward directed branchial epignath, which passes into the branchial
cavity. Pleopoda, when present, natatory.

ANALYTICAL KEY TO THE FAMILIES OF TANAIOIDEA OR CHELIFERA.

a. Body scarcely attennuated behind. Mandibles without palp. Superior or first
pair of antennae with one flagellum (never two), which is sometimes absent,
usually rudimentary, rarely well developed in female, and multiarticulate in
male. Anterior maxillae with only a single masticatory lobe and a one-jointed
palp; posterior ones quite rudimentary. Second pair of legs ambulatory in
character. Epignath of maxillipeds narrow, falciform Family I. TANAIDJE

a Sar's analytic key has been used with slight modifications. See his An Account
of the Crustacea of Norway, II. Isopoda, 1899, p. 3.

& See Sars' Crust, of Norway, II, 1899, pp. 4, 5, and Norman and Stebbing, Trans.
Zool. Soc. London, XII, 1886, pp. 78-79, for characters of superfamily.

4 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

a' '. Body narrow, produced, depressed. Mandibles with a three-jointed palp.
Superior or first pair of antennae with two multiarticulate flagella. Anterior
maxillae with two masticatory lobes and a two-jointed palp; posterior ones
well developed and setose. Second pair of legs with a large, broad, flat hand.
Epignath of maxillipeds large, laminar, branchial in character.

Family II. APSEUDIDJE

Family I. TANAID^.

Body scarcely attenuated behind. First pair of antennae simple,
without any secondary filament or flagellum. Single flagellum some-
times absent, and generally rudimentary, rarely well developed in
female, and multiarticulate in male. Second antennae without a scale;
flagellum usuall3 T rudimentary, rarely well developed. Mandibles
without palp. Second maxillae represented by minute rudimentary
lobes. Anterior maxillae with only a single masticatory lobe. Epig-
nath of maxillipeds narrow, falciform. Second pair of legs not differ-
ing from the following peraeopods. Gnathopods never furnished with
palps or exopods. Pleopods with branches uniarticulate. Uropoda
simple or furnished with two short filaments.

ANALYTICAL KEY TO THE GENERA OF TANAID.E.

a. Less than five pairs of pleopoda present. Uropoda simple, short, single-branched.

Eyes present.
b. Only two pairs of pleopoda present. Abdomen composed of three segments.

Uropoda composed of only two articles Genus Pancolus Richardson

b'. Only three pairs of pleopoda present. Abdomen composed of five to six seg-
ments. Uropoda composed of three to seven articles.

Genus Tanais Audouin and Edwards
a'. Five pairs of pleopoda present. Uropoda double-branched.

b. Incubatory pouch formed only by two lamellae issuing from bases of fourth pair

of legs Genus Cryptocope Sars

&'. Incubatory pouch normal,
c. Inner branch of uropoda 2-3 jointed. Pleopoda in female very small, or

rudimentary Genus Leptognathia Sars

(/. Inner branch of uropoda more than 2-3 jointed. Pleopoda well developed.
d. Gnathopods in male imperfectly chelate, without any finger, or with finger

very short and immovable ". Genus Heterotanais Sars

d' '. Gnathopods in male with chelae fully developed.

e. Gnathopods in male very much elongated, with carpus attenuated, hand
very large, oblong, fingers elongate and curved ; immovable one strongly
tuberculate within. Thoracic appendages not specialized into an ante-
rior and a posterior series Genus Leplochelia Dana

e / . Gnathopods in male with chelse very stout, the distal section of the
penultimate joint extremely broad, with a toothed margin. Thoracic
appendages specialized into an anterior and a posterior series.

Genus Neotanais Beddard

See Sars' Crust, of Norway, II, 1899, pp. 10, 11, and Norman and Stebbing,
Trans. Zool. Soc. London, 1886, XII, pp. 102-103, for characters given below.

ISOPODS OF NORTH AMERICA. 5

.1. Genus PANCOLUS Richardson.

Eyes present, distinct. First pair of antennae composed of three
articles. Second pair of antennas composed of five articles. First
thoracic segment permanently united with the head to form a cara-
pace. The following six segments are free and distinctly separated.
The abdomen is composed of only three segments, two segments
anterior to the terminal segment. There are but two pairs of well-
developed pleopoda. The uropoda are single branched and consist of
a peduncle and a branch composed of a single article. The first pair
of legs are chelate. All the following six pairs are ambulatory.

PANCOLUS CALIFORNIENSIS Richardson.

Pancolus .californierisis RICHARDSON, Proc. U. S. Nat. Mus., XX VIII, 1905, pp.
367-369.

Locality. Monterey Bay, California.

Body narrow-, elongate, 5 mm. long, and almost H mm. wide.
Head as wide as long, 1 mm. : 1 mm. , with the anterior margin
somewhat triangular between the eyes, which are placed in the

FIG. 1. PANCOLUS

CALIFORNIENSIS.

X9.

FIG. 2. PANCOLUS CALIFORNIENSIS.
FIRST GNATHOPOD. x 20.

FIG. 3. PANCOLUS CALIFORNIENSIS. a,
FIRST ANTENNA, x 44. 6, SECOND AN-
TENNA. X 44.

extreme antero-lateral angles. The head anteriorly is about half as
wide as it is posteriorly. The first pair of antennae have the first
article large and robust, about half as wide as long; the second article
is half as long as the first; the third is a little shorter than the second
and terminates in a bunch of hairs. The second pair of antennae are
shorter than the first, reaching only to the end of the second article of
the first pair of antennae. The first article is longest, being three
times longer than the second; the third is about twice as long as the

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

second; the fourth is more than one and a half times longer than the
second; the fifth is minute and terminates in a bunch of hairs.

The first segment of the thorax is coalesced with the head to form
a carapace. The second or first free segment is a little shorter than
any of those following. The third 'and fourth or second and third
free segments are subequal ; the last three are subequal, and each is a
little longer than either of the two preceding segments.

FIG. 4. PANCOLUS CALI-
FORNIENSIS. MANDIBLE.
x44.

FIG. 5. PANCOLUS CAL-
IFORNIENSIS. MAX-
ILLIPED. X 44.

FIG. 6. PANCO-
LUS CALIFORNI-
ENSIS. EPIG-
NATH OF MAX-
ILLIPED. X 44.

FIG. 7. PANCOLUS CAL-
IFORNIENSIS. POSTE-
RIOR LIP. x 44.

The abdomen is composed of three segments, two short ones followed
by the terminal segment, which is rounded posteriorly. The uropoda
are single branched. The peduncle is short. The branch consists of
a single article, tipped with long hairs. There are but two pairs of
well-dev 7 eloped pleopoda.

FIG. 8. PANCO-
LUS CALIFORNI-

ENSIS. FIRST
MAXILLA. X44.

FIG. 9. PANCOLUS CAL-
IFORNIENSIS. FIRST
PLEOPOD. X 44.

FIG. 10. PANCOLUS CAL-
IFORNIENSIS. SECOND
PLEOPOD. X 44.

The first pair of legs or gnathopods are chelate. The second pair
of legs are long and feeble, and similar to those following, which are
ambulatory, but more robust. The dactyli in the last three pairs are
curved.

Six specimens of this species were collected by Mr. Harold Heath
at Monterey Bay, California.

The types are in the U. S. National Museum. Cat. No. 30614,
U.S.N.M.

ISOPODS OF NORTH AMERICA. 7

2. Genus TANAIS Audouin and Ed-wards.

Eyes present and well developed. Abdomen composed of five or
six segments. Only three pairs of pleopoda present, all fully devel-
oped. Uropoda simple, single-branched. Incubatory pouch formed
of two lamellae issuing from the base of the fifth pair of legs. Man-
dibles strong with the molar expansion well developed.

ANALYTICAL KEY TO THE SPECIES OP THE GENUS TANAIS.

a. Pereiopoda having the first three joints short and broad, affixed to the sides of
the pereion like plates of mail. Inferior antennae scarcely half the length of the

superior antennae Tanais loricatus Spence Bate

a' . Pereiopoda with joints not dilated, slender. First and second antennae of nearly

equal length.

6. Abdomen composed of five segments.

c. Uropoda composed of three articles, a basal article, and a bi-articulate branch.
First and second abdominal segments with transverse setiferous bands.

Tanais cavolinii Milne Edwards

</. Uropoda composed of seven articles, a basal article, and a branch composed
of six articles. First and second segments of abdomen without setiferous

bands Tanais alascensis Richardson

V. Abdomen composed of six segments.

c. Uropoda composed of four articles, the peduncle, and a branch composed of
three articles. Body robust. Last three segments of abdomen not abruptly
narrower than three preceding segments. Posterior end of head about two
and a half times wider than anterior end. First pair of legs with chelae
strong and powerful, the dactylus strongly arched, finger and thumb widely

separated in male Tanais robustus Moore

(/. Uropoda composed of six articles, the peduncle, and a branch composed of
five articles. Body narrow, elongate. Last three segments of abdomen
abruptly narrower than three preceding segments, about half as wide.
Posterior end of head not greatly wider than anterior end. First pair of
legs with finger and thumb not widely separated.

Tanais normani Richardson

TANAIS LORICATUS Spence Bate.

Tanais loricatus SPENCE BATE, Lord's Naturalist in British Columbia, II, 1866,
p. 282. RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 819; Ann. Mag.
Nat. Hist. (7), IV, 1899, p. 159; American Naturalist, XXXIV, 1900, p. 210.

Locality. Esquimault Harbor, British Columbia.

Found in the hollow of a sponge.

"Exemplum imperfectum; inferiores antennas semi-breviores quam
superiores habens; gnathopodum primi paris propoda ovata dactylo
breve et tumido; periopodum primis tribus articulis brevibus et latis
sunt, loricis ad pereionem adherent! bus.

"The only specimen in the collection is imperfect. The first seg-
ment of the pereion appears to be imperfectly fused with the cephalon;
inferior antennse scarcely half the length of the superior. First pair
of gnathopoda having the propodus ovate; dactylos short and tumid,
shorter and less pointed than the digital process of the propodos.

8 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Periopoda having the first three joints short and broad, being affixed
to the side of the pereion like plates of mail (hence the specific name) ;
they terminate in short, pointed dactyli, and have the propodi armed
with two lateral rows of strong, black, pointed teeth.

"This species was taken from the hollow of a sponge dredged in
Esquimault Harbor, at the depth of about ten fathoms." SPENCE
BATE.

TANAIS CAVOLINII 6 Milne Edwards.

Tanais cavolinii MILNE EDWARDS, in Audouin and Milne Edwards Precis d'Ento-
inologie, I, 1829, pi. xxix, fig. 1; Hist. Nat. des Crust, III, 1840, p. 141, pi.
xxxi, fig. 6.

Tanais tomentoms KR0YER, Nat. Tidsskrift, IV, 1842, p. 183.

Crossurus vittatus RATHKE, Nova Acta Academise Csesarese Leopoldino-Carolinse
Natures Curiosorum, XX, 1843, p. 39, pi. i, figs. 1-7.

Tanais tomentoms KR0YER, Nat. Tidsskrift (2), II, 1847, p. 412; Voy. en Scand.,
Crust., 1849, pi. xxvii, figs. 2 a-q. LILLJEBORG, Ofvers. Vet. Akad. Forh.,
irg., VIII, 1851, p. 23.

Tanais hirticaudatus BATE, Rep. Brit. Assoc., 1860, p. 224, 1861.

Tanais vittatus LILLJEBORG, Upsala Univ. Arsskr., Math, og Naturv., I, 1865, pp.
29-30. BATE and WESTWOOD, Brit. Sess. Crust., II, 1866, p. 125. STEBBING,
Trans. Devon. Assoc., 1874, p. 7. MCDONALD, Trans. Linn. Soc. (2), I
(Zoology), p. 67, pi. xv. STEBBING, Ann. Mag. Nat. Hist. (4), XVII, 1876,
p. 78; Trans. Devon. Assoc., 1879, p. 6. HARGER, Proc. U. S. Nat. Mus.,
II, 1879, p. 162; Report U. S. Fish Comm., 1880, Pt. 6, pp. 418-419, pi.
xin, figs. 81-82.

Tanais tomentosus SARS, Archiv. for Math, og Naturvid., 1882, pp. 22-23. SCOTT,
Ann. Scottish Nat. Hist., 1898, pp. 218-219. G. O. SARS, Crust. Norway,

II, 1899, p. 12, pi. v.

Tanais cavolinii DOLLFUS, Bull. Soc. Zool. France, XXII, 1897, p. 207; M6m.
Soc. Zool. France, XI, 1898, p. 35. NORMAN, Ann. Mag. Nat. Hist. (7),

III, 1899, pp. 332-333. (See Norman for synonymy. ) RICHARDSON, Proc.
U. S. Nat. Mus., XXIII, 1901, p. 501; Trans. Conn. Acad. Sciences, XI,
1902, p. 278.

Localiti-es. Noank, Connecticut; Long Island Sound; Greenland;
Castle Harbor, Bermudas, in dead coral; also west coast of Norway;
British Isles; Bay of Fayal; West France; Azores; in the Atlantic at
He Dumet, near Croisac; Gue"tharry; St. Jean de Luz; Hendaye; in
the Mediterranean at Banyuls; Cette; Bandol; Cannes; lie Rousse;
Porto Vecchio; St. Eugene; Lake of Bizerte; Sousse.

Depth. Occurs on piles and among algae and eel-grass (Harger.)
1-6 ft. (Verrill).

Found in sponges, algse; on Pinna; on Balanus; on Laminaria;
on oysters.

Body elongate, four times longer than wide, 1 mm. : 4 mm. Head
about as wide at the base as it is long, 1 mm. : 1 mm., becoming grad-
ually narrower from the base to the anterior end, where it is about

a Lord's Naturalist in British Columbia, II, 1866, p. 282.
&See Harger for more complete description of this form.

ISOPODS OF NORTH AMERICA.

9

one-half mm. wide; the anterior margin is somewhat triangularly

produced, with apex very obtuse. The e} r es are small, composite, and

situated at the antero-lateral angles of the head.

The first pair of antennae have the basal article

very long and about equal to two-thirds the

length of the head; the second article is half as

long as the first; the third is almost as long as

the second; the terminal article is minute. The

first pair of antennas are about 1 mm. in length.

The second antennae have the first article long;

the second article is about half as long as the

first; the third is a little longer than the first;

the fourth is half as long as the third; the fifth

article is minute. The second antennae are

more slender and are shorter than the first pair,

extending only to the end of the second article

of the first pair. The maxillipeds have a palp

of four articles. The palp of the mandibles is

wanting.

The first segment of the thorax is united with the head to form a
carapace. The second and third segments are subequal, and each is a
little shorter than any of the four following, which are about equal in
length.

The abdomen is composed of five segments, four anterior to the
terminal segment. The first two have a transverse row of long plu-
mose hairs fringing the posterior margins. The fourth segment is

FIG. 11. TANAIS CAVOLINII
(AFTER HARGER). x 8.

a b c d e f

FIG. 12. TANAIS CAVOLINII. a, FIRST LEG. b, MAXILLIPED. c, FIRST ANTENNA, d, MANDIBLE.
e, UROPOD. /, SECOND ANTENNA.

very short, not more than half as long as any of the three preceding
segments. The terminal segment has the posterior margin obtusely
pointed. The uropoda are composed of three articles, a basal article
or peduncle and two others, which form a single branch. The second
article of the single ramus is half as long as the first article.

The first pair of legs are chelate; the other six pairs are ambulatory.

There are three pairs of pleopoda.

10

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

TANAIS ALASCENSIS Richardson.

Tanais alascensis RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 819-820;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 159-160; American Naturalist,
XXXIV, 1900, p. 211.

Locality. Kyska Harbor, Alaska.

Depth. 6-12 fathoms, in sand and mud.

Body three and a half times longer than broad.

Head large, narrowed anteriorly. Frontal margin almost straight.

First pair of antenna3 short, stout, consisting of three joints, the first

joint being the longest, and a rudimentary flagellum

of two joints. Second pair of antennas more slender,

a little longer, consisting of five articles, the first

joint being longest, and a rudimentary flagellum of

one joint. Eyes small and pedunculated.

The first segment of the thorax is confluent with

the head. The second, third, fourth, and fifth seg-
ments increase slightly in length; the fifth and sixth

are about equal; the seventh is not quite so long as

the preceding one.
The abdomen is composed of five segments, the

first three of which are subequal; the fourth is short,

about half as long as any of the others and also nar-
rower; the terminal segment is as long as the two

preceding ones together, and is rounded posteri-
orly, with a slight median notch. The segments of

the abdomen decrease in width gradually from the

first to the terminal segment. The terminal filaments
are seven-jointed the pe-
duncle forming the first arti-
c 1 e a n d single-branched,
and are furnished at their ex-
tremities with a few long
hairs. There are three pairs
of pleopoda attached to the
first three segments.

The first pair of legs are stout and chelate;
the propodus is produced into a strong im-
movable finger, irregular in shape, having its
central portion raised and truncate on its
upper surface, which is distinctly serrate. The

dactylus is likewise serrate on its inner surface. The other legs are

slender, with a gradual increase in stoutness.

FIG. 14. TANAIS ALAS-
CENSIS. a, DORSAL
VIEW, x 8. 6, LAST

JOINTS OF LEG OF THE
FIEST PAIR.

FIG. 13. TANAIS ALASCENSIS.

ISOPODS OF NORTH AMERICA. 11

Color brown, marked in some specimens with a darker brown, and
having oval patches of the darker color on the head.

Kyska Harbor, Alaska; Dr. W. H. Dall, collector; depth, 6 to 12
fathoms.

Type. Cat. No. 22563, U.S.N.M.

TANAIS ROBUSTUS Moore.

Tanais robustus MOORE, Proc. Acad. Nat. Sci. Phila., 1894, pp. 90-94, pi. v.
RICHARDSON, American Naturalist, 1900, XXXIV, p. 211; Proc. U. S. Nat.
Mus., 1901, p. 501.

Locality. New Jersey.

Found "inhabiting minute tubes in the crevices between the scales
of the turtle's (Thdlassochelys caretta) carapace. When unmolested
these little crustaceans could be seen crawling carefully about among
their fellow voyagers or lying at the mouths of their domiciles with
only the head and chelae projecting; when disturbed they promptly
retreated out of sight. " MOORE.

"It is quite robust for the family, being less than 3i times as long
as broad. The carapace, which is the broadest portion of the body,
is terminated anteriorly by a minute rostrum, whilst its posterior border
is somewhat concave in the middle line. In front of the origin of the
great gnathopods the lateral outline is strongly concave, but opposite
the bases of these limbs it becomes swollen. When viewed dorsally,
the carapace appears in general figure top-shaped. Two grooves, one
on each side, indicate upon the dorsal surface the inner boundary of
the branchial chamber. Behind the carapace the breadth of the body
becomes gradually less with each successive segment. The fourth free
segment of the peraeon is the longest, slightly exceeding the third,
which is in turn longer than the fifth.

"The pleon is composed of six distinct segments, of which the
fourth and fifth are much shorter than the others and the sixth is
terminated posteriorly by a blunt median projection. The body is
constricted at the joints and. the segmentation is distinctly marked.
The dorsal surface is furnished laterally with a few setae, which on
the first and second segments of the pleon form a short row on each
side, but never form a transverse band crossing the segment.

"The e} T es and eye-lobes are large, the latter being let into deep
recesses in the anterior lateral portion of the carapace.

" The an tennulae consist of three joints, of which the basal one is
somewhat longer than the other two combined. A small knob (rudi-
mentary flagellum) terminates each. In the male the an tennulae usually
about equal in length the carapace with the first free segment, but are
sometimes considerably longer. In the female they are about equal
to the carapace alone.

12 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"The antennae lie close beneath the antennulae, by which they are
slightly exceeded in length in both male and female. They are five^
jointed, the fourth joint being the longest, slightly exceeding the
second; the fifth, third, and first following in the order named, the
last mentioned being very short. Each antenna is terminated by a
densely setiferous rudimentary flagellum. considerably longer than
that of the antennules and sometimes imperfectly articulated.

"The mandibles are of the usual form, curved inward at the tip,
where each bears a pair of horny teeth, shaped like the limbs of the
letter U. Proximad of the middle a stout transverse column passes
mediad bearing at its end an oval plate transversed by a series of par-
allel ridges with deep grooves between. Under a high power each
ridge appears to be broken up by shallow indentations into a series of
rounded teeth.

"The first maxillae consist of a stout forwardly directed column
and a posteriorly directed palpus, bearing at its end a brush of seven
or eight long setae. The anterior ramus is stout and curved toward
the median line, bearing at its tip a group of about eight stout, curved
spines, each with two series of fine, apically directed denticuli. A brush
of stiff setae lies near the base, and laterad of, the spines. A smaller
group of spines lie on one face near the tip; these are not denticulate
and lack the brown color of those in the apical group.

"The maxillipeds are adherent basally by means of short, stout
hooks. The basal joints are prolonged on their anterior or oral
aspects into plate-like processes, which are coupled together in the
median line. Each basal joint bears a flattened palpus, consisting of
four joints, the terminal three being furnished with long setae. The
distal joint is strongly flexed on the penultimate. A somewhat falci-
form branchial epipod is attached to the maxilliped at its base by
means of a slender stalk.

"The first gnathopods are strongly chelate in both sexes, but
especially so in the males. The 'thumb' of the propodite is termi-
nated by a horny tooth, and external to and just within this is a sharp-
edged tubercle; the tooth of the dactylopodite bites between the two.
Fig. 15, f and <?, on page 13, show the gnathopods of male and female
side by side, and give a better idea of their appearance than can be
gained from a description.

"The limbs of the first free segment of the peraeon are long and
slender, their terminal claws being but slightly curved. The two
succeeding pairs are stouter, with the dactylopodite and claw shorter
than in the first pair. The last three pairs are still stouter; the
dactylopodite bears a strongly hooked claw with a comb-like series of
minute, curved teeth on each side, and the distal end of the propodite
bears a row of stout setae. All the limbs except those of the first
free segment have the distal end of the carpopodite crowned with a

ISOPODS OF NORTH AMERICA.

FIG. 15. TANAIS ROBUSTUS (AFTER MOORE), a, GENERAL FIGURE. &, SECOND ANTENNA, c, MAN-
DIBLE. c 1 , DETAIL OF MANDIBLE, d, ANTERIOR (FIRST) MAXILLA, d 1 , TIP OF FIRST MAXILLA.
e, MAXILLIPED. /, FIRST GNATHOPOD OF MALE, g, FIRST GNATHOPOD OF FEMALE, h, FIRST PEREIO-
POP. i, LAST PEREIOPOD. j, PLEOPOD. k, UROPOD.

14 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

few stout spines, some bifid, others serrulate. Only the anterior
three segments of the pleon bear limbs (pleopods). Each of these
consists of a flat basal piece (protopodite), to which are attached two
one- jointed blades, furnished on their outer edges with long pinnate
setae, the exopodite bearing about 35, the endopodite about 15. Both
protopodite and endopodite bear a single stout seta on their inner edge.

"The last segment bears a pair of four-jointed setose limbs (uro-
pods), the segments of which are cylindrical and increase in length
from base to tip. The marsupia of the female are thin-walled pouches
attached to the ventral wall of the sixth thoracic segment (fourth free
segment). They increase in size with the development of the eggs
and in some specimens extend over segments five to seven, to which,
however, they are not attached.

"The largest specimens collected measure from rostrum to tip of
pleon 4.7 mm. and in width 1.4 mm. The ground color in alcoholic
specimens is pale yellow. Upon the carapace this is heavily mottled
with brownish pigment, excepting over about thirty elliptical and
subelliptical areolse symmetrically arranged toward the middle line.
The dorsal surfaces of the chelae are similarly marked. The portion
of the body and the limbs behind the carapace are much paler, being
usually concealed in the tubular dwelling." MOORE.

The type specimens of this species were sent me from the University
of Pennsylvania. As the bottle in which they were placed had been
accidentally broken and the specimens allowed to dry up, they were
not in a condition to redescribe, so 1 have quoted Doctor Moore's
description, which is very full and accurate.

TANAIS NORMANI Richardson.

Tanais normani RICHARDSON, Proc. U. S. Nat. Mus., XXVIII, 1905, pp. 369-370.

Locality. Monterey Bay, California.

Body narrow, elongate, 4 mm. long. : f mm. wide.

Head as wide as long, with the anterior margin triangulate between
the eyes, which are situated at the extreme antero-lateral angles.
The head is half as wide anteriorly as it is posteriorly. The eyes are
small, but distinct. The first pair of antennas are composed of three
articles, and have the first article longest, about two and a half times
as long as wide; the second article is half as long as the first; the third
is a little shorter than the second, and terminates in a bunch of long
hairs. The second pair of antennse are composed of five articles and
have the first article about three times as long as the second; the third
is twice as long as the second; the fourth is one and a half times
longer than the second; the fifth article is minute and terminates in a
bunch of hairs.

Proc. Acad. Nat. Sci. Phila., 1894, pp. 90-94.

ISOPODS OF WORTH AMERICA.

15

The first segment of the thorax is united with the head to form a
carapace. The second or first free segment is the shortest of all; the
third and fourth or second and third free segments are nearly equal in
length, the third being perhaps a little longer; the fifth and sixth or
fourth and fifth free segments are subequal and are the longest; the
sixth or seventh free segment is about equal in length to the third free
segment.

The abdomen is composed of six segments. The first three are sub-
equal in length and carry on the ventral side three pairs of well-
developed pleopoda. The two following segments are subequal, and
each is about one-half as long as any of the three preceding segments
and about one-half as wide, being abruptly narrower. These seg-
ments do not carry pleopoda. There are thus only three pairs of

FIG. 16. TANAIS

NO R M ANI .

x Hi.

FIG. 17. TANAIS NORMANI. FIRST
GNATHOPOD. X 44.

FIG. 18. TANAIS NORMANI. a, FIRST

ANTENNA. X 44. b, SECOND ANTEN-
NA. X 44.

pleopoda. The sixth or terminal segment is as wide as the two pre-
ceding segments and is rounded posteriorly. The uropoda are single
branched; the peduncle is followed by a five-articulate branch.

The first pair of legs or gnathopods are chelate; the following six
pairs of legs are ambulatory.

Only three specimens of this species were collected by Mr. Harold
Heath at Monterey Bay, California.

The types are in the U. S. National Museum. Cat. No. 30615,
U.S.N.M.

This species differs from Tanais alascensis Richardson in having the
abdomen composed of six segments, while in T. alascensis it is com-
posed of five segments; in having the uropoda composed of a peduncle

16 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

and five articles, while in T. alascensis the uropoda are composed of a
peduncle and six articles; and in the smaller size of the specimens.

It is named in honor of Rev. A. M. Norman, the distinguished
carcinologist.

3. Genus CRYPTOCOPE Sars.

E} 7 es wanting. Abdomen composed of six segments. Pleopoda in
female very small and rudimentary; those in the male well developed.
Incubatory pouch formed of two lamella? issuing from the bases of
the fourth pair of legs. Uropoda in female short, biramose, rami
very unequal; those in male much more fully developed. First
gnathopods strong and similar in structure in both sexes. Mandibles
well developed, with the cutting edge coarsely dentated, and having on
the right mandible a rather large secondary lamella; molar expansion
well defined.

CRYPTOCOPE ARCTICA Hansen.

Oryptocope arctica HANSEN, Dijmphna-Togt. zool.-bot. Udb., 1887, p. 209, pi.
xxi, fig. 4; Vidensk. Meddel. Fra. den Naturh. Foren. i Kjobh., 1887-88,
p. 180, pi. vn, fig. 1-lc. STEBBING, Ann. Mag. Nat. Hist. (7), V, 1900,
p. 12. RICHARDSON, American Naturalist, XXXIV, 1900, p. 211; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 502.

Localities. Greenland; Kara Sea; latitude 72 20' north, longitude
59 39' west.

Depth. 100-170 fathoms.

Description of female. The body is subcylindrical, about four and
a half times longer than wide.

The head becomes gradual^ narrower toward the front, with the

anterior margin somewhat pro-
duced, the apex being obtuse.
Eyes absent. The first pair of
antennae are composed of four
tapering articles, and are one-
fourth shorter than the head; the
basal article is two-fifths the

FIG. 19. CRYPTOCOPE ARCTICA (AFTER HANSEN). length of the antenna?, is cvlin-

drical when seen from the side-
seen from above, gradually stouter toward the base; the second article
is more than one-half times longer than the third and somewhat shorter
than the fourth article. Each article is furnished with setae at the
distal end of the external angle. The apex of the fourth article is
furnished with numerous long seta?. The second pair of antenna? are
slender, composed of five articles, and are somewhat shorter than the
antenna? of the first pair.

See Sara for characters of genus,

ISOPODS OF NORTH AMERICA.

17

The first three free segments of the thorax are subequal; taken
together, somewhat shorter than the head and twice as long as the
fourth free segment.

All the segments of the abdomen are pres-
ent and visible. The last segment is taper-
ing, widely rounded, and more than twice
as wide as long.

The first pair of legs are robust; the
chelae are more than half as short as the
head; the fingers are a little shorter than the
hand, the thumb serrate almost to the apex.
The ambulatory legs are all subequal, slen-
der. The pleopoda are very short, and fur-
nished with a few short setae.

The uropoda are very short, double-
branched, both branches being composed of
two articles, the inner branch being twice
as long as the outer branch, and stouter.

The marsupium is composed of two large
lamellae issuing from the base of the fifth
pair of legs. a

FIG. 20. CRYPTOCOPE ARCTIC A
(AFTER HANSEN). a, ANTENNAE

OF FEMALE, b, UKOPOD OF FE-
MALE, c, UROPOD OF MALE, d,
ANTERIOR PART OF BODY OF
MALE. (ENLARGED.)

4. Genus LEPTOGNATHIA Sars.&

Eyes wanting. Pleopods in female small and sometimes wanting;
those in male well developed. Abdomen composed of six segments.
Uropoda usually biramous, sometimes apparently simple, the outer

a The above description is adapted from the following description of Hansen's:
Femina. Corpus subcylindricum, circiter quadruple et dimidio longius quam
latius. Scutum -cephalothoracicum ad f rontem versus sensim angustatum, margine
anteriore aliquantum producto et apice obtuso. Segmenta tria libera anteriora inter
se subaequalia, simul sumpta scuto cephalothoracico aliquanto breviora et segmento
quarto libero duplo longiora. Segmenta caudae omnia manifesta; segmentum ulti-
fnum declive et valde rotundatum, plus duplo latius quam longius. Oculi nulli.
Antennas primi paris quadriarticulatae, anguste conicae; scuto cephalothoracico quarta
parte breviores; articulus basalis duas quintas partes antennae explens, a latere visus
cylindricus, pronus ad basin versus sensim incrassatus; articulus secundus articulo
tertio plus quam dimidio longior et articulo quarto nonnihil brevior; articulus uterque
seta in angulo exteriore apicali instructus; apex articuli quarti setis compluribus
longis ornatus. Antennae secundi paris tenues, quinque-articulatae, antennis primi
paris nonnihil breviores. Pedes primi paris (chelipedes) robusti; chela scuto ceph-
alothoracico plus quam dimidio brevior; digiti manu paulo breviores, pollice prope
apicem serrato. Pedes gressorii omnes inter se subaequales, tenues. Pleopoda bre-
vissima, setis nonnullis brevioribus instructa. Uropoda brevissima, biramea, ramis
ambobus biarticulatis, ramo interno quam externo duplo longiore et crassiore. Mar-
supium e laminis duabus magnis, ad pedes quinti paris affixis, formatum est. Long.
1.67 mm. HANSEN, Dijmphna-Togt. zool.-bot. Udb., 1887, p. 209.
b See Sars for characters of genus.
2858905 2

18 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

branch not being distinctly defined from the peduncle, branches
unequal, inner one larger and biarticulate, outer one composed of one
or two articles. Incubatory pouch normal. Mandibles small and
feeble in structure, cutting part narrow, molar expansion forming a
thin acuminate lappet armed at the tip with a few small denticles.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS LEPTOGNATHIA.

a. In female the inner branch of the uropoda is twice as long as the outer. The
second or first free segment of the thorax is about two-thirds as long as the
third, which in turn is about equal to the fourth and fifth. Sixth and seventh
segments progressively somewhat shorter. Propodus of first pair of legs less
robust than carpus .............................. Leptognathia acca ( Harger )

of. In female the inner branch of the uropoda is more than three times as long as the
outer. The second or first free segment of the thorax is about the same size as
the last one, both being shorter than the others. Propodus of the first pair of
legs scarcely smaller than the carpus ...... Leptognathia longiremis (Lilljeborg)

LEPTOGNATHIA C-ffiCA (Harger).

Paratanais caeca HARGER, Am. Jour. Sci. (3), XV, 1878, p. 378.

Leptochelia caeca HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 164; Report U. S.

Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 427, 428; pi. xm,

fig. 91.
Leptognathia caeca SARS, Archiv for Math, ognaturvid., 1882, p. 45. NORMAN and

STEBBING, Trans. Zool. Soc. Lond., XII, 1886, Pt. 4, p. 110. RICHARDSON,

American Naturalist, XXXIV, 1900, p. 211; Proc. U. S. Nat. Mus., XXIII,

1901, p. 502.

Localities. Massachusetts Bay, off Salem; Provincetown, Massa-
chusetts.

Depth. Surface to 48 fathoms in soft mud.

"This species is at once recognized among
our Tanaids by the absence of eyes. The en-
larged chelate claws joined to the united head and
first thoracic segment, and the six-jointed pleon
serve to distinguish it as belonging to the present
genus.

"Body slender, elongated, and rather loosely
articulated; head narrow in front, not broader
than the bases of the antennulae; eyes wanting;
antennulae distinctly four-jointed in the type speci-

FIG. 21. LEPTOGNATHIA J f

(AFTER HARGER). men, first segment forming less than half the

o, FIRST ANTENNA, x so. length of the organ, second segment longer than

b, LEG OF FIRST PAIR. " .

x so. c, UROPOD. x so. the third, last segment about as long as the sec-
ond, slender, tapering, and tipped with setae; an-
tennae attaining the tip of the third antennular segment. The first
pair of legs are robust, but less so than in the preceding species (Lep-
tochelia filum)', they extend forward in the natural position about to
the tips of the antennae; they have the basal segment subquadrate, the
hand or propodus less robust than the carpus, with a serrated digital
process; dactylus short.

ISOPODS OF NORTH AMERICA. 19

"The second or first free thoracic segment is about two-thirds as
long as the third; this in turn is about equal to the fourth and to the
fifth segments, while the sixth and seventh segments are progressively
somewhat shorter. The second pair of legs are scarcely more slender
than, the following pairs, and the basal segments are not curved around
the base of the first pair.

' ' The uropods are short and biramous ; each ramus two-jointed. The
outer ramus is more slender than the inner, half its length, and bears
a long bristle at the tip.

"Length, 2.5 mm.; color, white." HARGER."

LEPTOGNATHIA LONGIREMIS (Lilljeborg).

Tanais longiremis LILLJEBORG, Upsala Univ. Arsskr., Math, og Naturv., I, 1865,
p. 23-25.

Tanais islandicus G. O. SARS, Archiv for Math, og Naturv., Christiania, II, 1877.
p. 346.

Leplognathia longiremis G. O. SARS, Archiv for Math, og Naturv., 1882, p. 41;
Norwegian North Atlantic Expedition, 1876-1878, Crustacea, I, 1885, pp.
79-82, pi. vii, figs. 17-28; II, 1886, p. 26. HANSEN, Dijmphna-Togtete
zoologisk-botanske Udbytte, 1887, p. 185; Vidensk. Meddel. fra den
Naturh. Foren. i Kj0bh., 1887-88, p. 179, pi. vi, figs. 9-9b. (See Hansen
for synonymy.) SCOTT, Ann. Scottish Nat. Hist., 1898, p. 220. SARS, Crust.
Norway, II, 1899, p. 27, pi. xn. RICHARDSON, American Naturalist,
XXXIV, 1900, p. 211; Proc. U. S. Nat. Mus., XXIII, 1901, p. 502. AXEL
OHLIN,& Bihang till K. Sv. Vet.-Akad. Handl., XXVI, Afd. iv, No. 12, 1901,
pp. 15-16.

Localities. Kekertak, Greenland; Scotland; Norway; Iceland; Den-
mark; latitude 77 9' north, longitude 14 40' east, off Ice Islands;
latitude 74 35' north, longitude 18 23' west, off Little Pendulum
Island.

Depth. 7-200 fathoms; also shallow water.

Found in soft gray clay, in sandy mud and algae.

"Body of female rather slender and elongated, more than seven
times as long as it is broad; cephalosome about the length of the first
two segments of mesosome combined, with the proximal half of uni-
form breadth, the distal one abruptly attenuated; first free segment of
mesosome about same size as the last one, bothjjeing shorter than the
others; metasome well developed, exceeding in length the last two
segments of mesosome combined, terminal segment nearly occupying

Report U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 427-428.

& Hansen in Ohlin (Bihang till K. Sv. Vet.-Akad. Handl., XXVI, Afd. iv, No.
12, 1901, pp. 16-17, footnote) considers Leptognathia longiremis Sare as distinct from
Leptognathia longiremis (Lilljeborg). He proposes to call it Leptognathia sarsi and
considers that it differs in having the last segment of the abdomen armed on each
side with a small denticle, in having the basal part of the uropoda rather short, the
inner branch long, composed of two articles, the other branch short, composed of
two joints, the hand of the chelipeds dentated on the inferior margin.

20

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

one-third of the length of metasome, and armed on each side with a
minute deflexed denticle. Body of male much broader than in female,
being scarcely more than five times as long as it is broad; cephalosome
rather broad in proportion to its length; all free segments both of
mesosome and metasome of about equal length, the terminal one nar-
rowly produced at the tip. Superior antennae in female gradually

FIG. 22. LEPTOGNATHIA LONGIREMIS (AFTER SARS). a, FIRST LEG OF FEMALE, b, SECOND ANTENNA

OF FEMALE. C, LATERAL VIEW OF FEMALE, d, DORSAL VIEW OF FEMALE, e, FIRST ANTENNA OF

FEMALE. /, SEVENTH LEG OF FEMALE, g, SECOND LEG OF FEMALE, h, MAXILLIPEDS. i, ANTERIOR

(FIRST OR INNER) 'MAXILLA, j, UROPOD OF FEMALE, k, MANDIBLE (RIGHT). I, LEFT MANDIBLE.

TO, PLEOPOD OF FEMALE, n, FIRST LEG OF MALE. o, FIRST ANTENNA OF MALE, p, DORSAL VIEW OF
MALE, q, LATERAL VIEW OF MALE, r, SECOND LEG OF MALE, s, UROPOD OF MALE, t, PLEOPOD
OF MALE, u, SECOND ANTENNA OF MALE, v, SEVENTH LEG OF MALE.

tapering distally, basal joint about equaling in length the other three
combined, second joint shorter than the outer two taken together;
those in male attaining in length one-fourth of the body, the first two
joints of the peduncle large and expanded, flagellum about the length
of the peduncle, and having the two outer joints much longer than the

ISOPOD8 OF NORTH AMERICA. 21

other two. Chelipeds in female rather strong, with the hand consid-
erably dilated, oval triangular in form, and scarcely smaller than the
carpus, with a slight dentated crest in front at the insertion of the
dactylus, the latter crested along the middle, thumb distinctly serrated
at the end inside; those in male with the hand much narrower than in
female, and furnished inside with a transverse row of about ten flat-
tened spines increasing in length behind, fingers quite simple, pointed,
the immovable one quite short. Uropoda in female attaining half the
length of the metasome, both rami biarticulate, the inner one more
than three times as long as the outer, and tipped by rather long setae;
inner ramus in male distinctly triarticulate. Length of female 3.75
mm., of male 2.55 mm." G. O. SARS. a

3. Genus HETEROTANAIS Sars.&

Eyes distinct. Abdomen with all six segments well defined. Pleo-
poda normal, all five pairs present. Uropoda biramous, outer branch
small, inner elongate and composed of four to five articles. Incu-
batory pouch normal. First gnathopods in female normal, in male
very different, being imperfectly chelate, thumb very short, or trans-
formed to a posteriorly-pointing lappet.

HETEROTANAIS LIMICOLA (Harger).c

Paratanais limicola HARGER, Am. Jour. Sci., (3) XV, 1878, p. 378.

Leptochelia limicola HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 163; Report
U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, p. 424, pi. xin,
figs. 87-88.

Heterotanais limicola SARS, Archiv for Math, og Naturvid., 1882, p. 31. NORMAN
and STEBBING, Trans. Linn. Soc. London, XII, 1886, Pt. 4, p. 109. HANSEN,
Videnskabelige Meddelelser fra den naturhistorisk Forening in Kj0ben-
havn, 1887-1888, pp. 178-179. RICHARDSON, American Naturalist, XXXIV,
1900, p. 2.12; Proc. U. S. Nat. Mus., XXIII, 1901, p. 503.

Localities. Massachusetts Bay, off Salem; Godthaab, Greenland
(Hansen).

Depth. Forty-eight fathoms in soft mud; 40-60 fathoms.

Body narrow, elongate, 2 mm. long and less than mm. wide.

Head a little longer than wide, gradually becoming narrower from
the base to the anterior end. Eyes "small and inconspicuous." The
first pair of antennas have the first article very long; the second article
is only one-fourth as long as the first; the third is almost twice as
long as the second. The second pair of antennas have the first two
articles short and subequal; the third article is as long as the first two
taken together; the fourth is about half as long as the third. The

Crust, of Norway, II, 1899, p. 27.

6 See Sars for characters of genus, Crust, of Norway, II, 1899.

c See Harger for description of this form.

22

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

second pair of antennas are shorter than the first pair, not extending
much beyond the end of the second article of the first pair.

The first free segment of the thorax is a little shorter than any of
those following. The second and third free segments are subequal,
and each is a little longer than the first segment. The fourth and
fifth free segments are subequal, and each is longer
than either of the two preceding segments. The
last free segment is shorter than either of the two
preceding segments, and is about as long as the
second and third segments.

The abdomen is composed of six segments, five
short, subequal ones anterior to the terminal seg-
ment, which has the posterior margin rounded.

FIG. 23. HETEROTANAIS
LIMICOLA (AFTER
HARGER). FEMALE.
x 20.

FIG. 24. HETEROTANAIS LIMICOLA. a, FIRST LEG OF
FEMALE, x 77. b, FIRST ANTENNA, c, SECOND

ANTENNA. X 77s.

The uropoda are double-branched. The inner branch is composed of.
five articles; the outer branch has two articles.

The first pair of legs or gnathopods" are chelate. All the other six
pairs are ambulatory. The dactylus of the second pair of legs is
longer than the propodus.

There are five pairs of well-developed pleopoda.

I have seen only one rather imperfect specimen.

6. Genus LEPTOCHELIA Dana.

Gnathopods in male with chelae fully developed, very much elon-
gated; fingers elongate and curved, with immovable one strongly
tuberculate within. Marsupium of female composed of eight large
lamellas issuing from the first four free segments. Eyes present.
Five pairs of pleopoda present. Uropoda double-branched; inner
branch multiarticulate; outer branch composed of one or two articles.
Gnathopods in female strong. First pair of antennas in female com-
posed of three articles and a rudimentary flagellum. First antennas
in male much more elongated and with a multiarticulate flagellum.

See Stebbing for characters of genus, Trans. Zool. Soc. London, 1886, XII, p. 108.

IS6PODS OF NORTH AMERICA. 28

ANALYTICAL KEY' TO THE SPECIES OF THE GENUS LEPTOCHELIA.

a. Outer branch of uropoda composed of two articles.. Leptochelia forresti (Stebbing)
a'. Outer branch of uropoda composed of one article.

b. Inner branch of uropoda composed of six articles.. Leptochelia sarignyi (Kr0yer)
b' '. Inner branch of uropoda composed of less than six articles.
c. Inner branch of uropoda composed of five articles.

d. First pair of antennae in male with basal segment about one-third the
length of organ, or about two-thirds as long as the body. Chelipeds in
male with digital process of propodus armed with two teeth. Carpus
extends to the extremity of basal article of first pair of antenna.

Leptochelia dubia (Kr0yer)

d' '. First antennae in male with basal article one-half the length of entire organ.
Chelipeds in male with digital process armed with one low, obtuse tooth
near the base and one more prominent one near the tip. Carpus of
chelipeds more _ than half the length of the body, longer than the
peduncle of the first antennae and about half as long as the body.

Leptochelia rapax Harger
c'. Inner branch of uropoda composed of three or four joints.

Leptochelia? filum (Stimpson)

LEPTOCHELIA FORRESTI (Stebbing).

Dolichochelia forresti STEBBING, Ann. Mag. Nat. Hist. (6), XVII, 1896, pp. 49-56.
Leptochelia minuta STEBBING, Ann. Mag. Nat. Hist. (6), XVII, 1896, pp. 156-160.

RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 503-504.
Leptochelia forresti STEBBING, Willey's Zool. Results, 1902, p. 615.

Locality. West Indies.

Depth. Shallow water.

"The front margin of the head shield projects but slightly, forming
a very obtuse angle, the corners being shallowly excavate for the
ocular lobes. The part of the shield to which the first gnathopods (or
chelipeds) are attached is wider than the front. The pleon at its base
is as wide as the trunk, but narrows distally with a gentle curve; the
sixth segment, which is very little longer than that preceding it, ends
in an obtuse angle similar to that of the frontal margin.

"The eye lobes have a convex outer margin and are not very
sharply pointed in front. The pigment is black in the mounted
specimen.

"First antennae. These are as long as the animal from the front of
the head to the apex of the pleon. The first joint is dilated at the
base, for the rest slender, its length forming two-fifths of the whole
antenna. The second joint is rather less than three-fourths the
length of the first. The third is a fifth of the length of the second,
and so slender as to look like a part of the flagellum, among the eight

The uropoda are described as four to five jointed. If the peduncle is counted as
the first one of these the branch is then three to four jointed. Nothing is known of
the outer branch, but in the table I have placed it with those species in,which the
outer branch is one-jointed, as this is the case with the larger number of species
in this genus.

24

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

joints of which the first is the shortest. The joints carry two or three
setae apiece, giving an appearance very unlike that produced by the
conspicuous sensory filaments in the adult males of Leptochelia and
Heterotanais.

FIG. 25. LEPTOCHELIA FORRESTI (AFTER STEBBING). a, SECOND GNATHOPOD. b, FRONT OF HEAD

WITH EYES. C, UPPER ANTENNA, d, THIRD LEG. 6, FOURTH LEG. /, FIFTH LEG. g, SIXTH LEG.

h, SEVENTH LEG. i, GENERAL FIGURE, j, LOWER ANTENNA, k, FIRST GNATHOPOD OF RIGHT SIDE.
I, TERMINAL PORTION OF ABDOMEN WITH UROPODA. m, PLEOPOD.

"Second antennas. The first three joints are very small, together
not equal to the fourth. The fifth is two-thirds the length of the

ISOPODS OF NOETH AMEEICA. 25

fourth and is distally armed with a seta. The minute tubercle which
represents the flagellum carries two setae. The whole antennae is
shorter than the flagellum in the first pair.

" First gnathopods. These chelipeds are remarkable, both for the
threatening gape of the chela and for their length, which is double
that of the animal's body. The second joint is the stoutest, yet not
much dilated, a little longer than broad. The third joint is short,
almost triangular. The fourth is of great length, narrowest near the
base, and nowhere very wide. The fifth is still longer, with a curva-
ture at its base, adapted for the folding together of these long slender
joints; its narrow immovable digit forms less than half of the total
length of the joint and ends in a sort of pointed claw over which three
setules are distributed, another setule occupying a small prominence
of the inner margin near the base of the claw. The movable finger
is somewhat longer than the immovable one, slender, pointed, curved,
with irregular margins.

" Second gnathopods. As usual in this group, these are gnathopods
only in name, and differ but slightly from the following ambulatory
feet. They are scarcely, if at all, larger than the fifth perseopods,
having the second joint narrower, but the fourth and fifth joints a
little wider than is the case in that pair.

"Perseopods. The general structure is the same in all. The second
joint is the longest, in the last three pairs somewhat dilated. The
third joint is very short, the fifth joint is a little longer than the
fourth, and the sixth considerably longer than the fifth. There are
some spinules about the distal end of the sixth joint. In the first and
second pairs the finger is small, in the other three pairs it is nearly as
long as in the second gnathopod.

"Pleopods. All the five pairs are constructed as in Leptochelia.

" Uropods. The peduncles are a little longer than broad. The
inner branch has six joints, of which the first is the widest, the fourth
the longest. The outer branch has two joints, together not equaling
the length of the first joint of the inner branch. All the joints of the
branches are setiferous.

^''Length. From head to tail the specimen measured less than a
tenth of an inch. From an unmounted specimen with which Mr.
Forrest has favored me since the above description was passed for
press, it appears that the lateral margins of the head anteriorly are
slightty concave; that the first three free segments of the perseon are
very decidedly shorter and a little broader than the following three;
that, viewed dorsally, there is a constriction between the third and
fourth and between the fourth and fifth free segments, and that the first
five segments of the pleon are slightly broader than the immediately
preceding segments of the perseon. In both specimens the mouth
parts appear to be in a very rudimentary condition." STEBBING.

Ann. Mag. Nat. Hist. (6), XVII, 1896, pp. 49-56.

26 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

LEPTOCHELIA SAVIGNYI (Kr0yer).

Tanais savignyi KR0YER, Nat, Tidsskrift, IV, 1842, p. 168, pi. IT, figs. 1-12

(female).
Tanais edwardsii KR0YER, Nat. Tidsskrift, IV, 1842, p. 181, pi. n, figs. 13-19

(male).
Leptochelia edwardsii BATE and WESTWOOD, Brit. Sessile-eyed Crustacea, II, 1866,

p. 134 (male).
Tanais filum HARGER (not Stimpson), Report U. S. Comm. of Fish and Fisheries,

Pt. 1, 1873, p. 573 (male and female).

Paratanais algicola HARGER, Am. Journ. Sci. (3), XV, 1878, p. 377 (both sexes).
Leptochelia algicola HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 162; Report

U. S. Comm. of Fish and Fisheries, Pt. 6, 1880, pp. 421-423 (male and

female).
Paratanais savignyi DELAGE, Arch. zool. expe'rim., 1881, p. 134, pi. xi, figs. 1-8

(female).

Leptochelia savignyi SARS, Archiv. for Math, og Naturvid., 1882, p. 25.
-Leptochelia dubia SARS (not Kr0yer), Archiv. for Math, og Naturvid., 1882, p. 26.
Leptochelia savignyi G. 0. SARS, Archiv. for Math, og Naturvid., Christiania, XI,

1886, p. 326, pi. ix, figs. 4-8 (male and female).
Leptochelia dubia SARS (not Kr0yer) , Archiv. for Math. og. Naturvid., Christiania,

XI, 1886, p. 317, pis. x, xi (male and female).
Leptochelia savignyi DOLLFUS, M6m. de la Soc. zool. de France, XI, 1898, pp.

40-43.
Leptochelia algicola DOLLFUS Mm. de la Soc. zool. de France, XI, 1898, pp.

41-43.

Leptochelia savignii NORMAN, Ann. Mag. Nat. Hist. (7), III, 1899, p. 333.
Leptochelia savignyi RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 503.
Leptochelia dubia RICHARDSON (not Kr0yer), Proc. U. S. Nat. Mus., XXIII,

1901, p. 504.

Localities. Provincetown, Massachusetts; Woods Hole, Massachu-
setts; Vineyard Sound; Noank, Connecticut; Long Island Sound;

Great Egg Harbor, New
Jersey; also England;
Belgrave Bay, Guern-
sey; Sark; Jersey; Na-
ples; Trieste; Spezia;

PIG. 26. LEPTOCHELIA SAVIGNYI (AFTEB HARGER). MALE. Messina* Syracuse' At-
lantic coast from Brit-
tany to Senegal; Birterbuy Bay, Ireland; Falmoutb Harbor; Valentia,
Ireland; France; Azores; Mediterranean; Madeira.

Depth. Found on surface, among eelgrass and algae.

There seems to be no sufficient reason for keeping Z. algicola Har-
ger and Z. savignyi (Kr0y er) distinct. The female of Z. algicola agrees
with Kr0yer's description of Z. savignyi in having the inner branch
of the uropoda six-jointed. The first pair of antennae are usually
composed of three articles, but some specimens from Long Island
Sound in the U. S. National Museum have the last articles of the first
antenna sometimes divided into tw6 articles. The male of Z. algicola

ISOPODS OF KOETH AMEEICA.

27

FIG. 27. LEPTOCHKLIA
SAVIGNYI (AFTER
HARGER) . FEMALE.
x 20.

Harger agrees with the male of L. savignyi described as L. edwardsii
by Kr0yev in having the first pair of antennae composed of eleven
articles. Some of the specimens have the first antenna composed of
only ten articles. Kr0yer describes the uropoda as
having the inner branch seven-jointed, but the speci-
men sent to Professor Harger from Rev. A. M. Nor-
man and labeled Z. edwardsii agreed with the speci-
mens of L. algicola in having the inner branch of
the uropoda six-jointed. Dollf us points out that the
two teeth on the propodus of the chelipeds are nearer
together in the males of L. algicola than in the
males of L. savignyi^ but further states that this
character may be due to a difference in the state of
development, and not be of real specific value.

Description of male. Body narrow, elongated, 2
mm. long, mm. wide.

Head a little longer than wide, with the anterior
portion narrower than the posterior portion. Eyes
large, distinct. First pair of antennae greatly elon-
gated. The basal article is very long and narrow,
and is about equal to the length of the head. The
second article is a little more than one-third as long
as the basal article. The third is one-half as long as the second. The
flagellum is composed of seven or eight articles. The second pair of
antennae are short, and do not reach the extremity of the basal article

of the first pair of antennae.

The first segment of the tho-
rax is coalesced with the head.
The second or first free segment
is the shortest. The third and
fourth or second and third are
subequal and each is a little
longer than the first. The fifth
and sixth or fourth and fifth
free segments are the longest and
are subequal; they are nearly
twice as long as the first seg-
ment. The seventh or sixth
free segment is shorter than
either of the two preceding seg-
ments and about equal in length
to the third free segment.
The abdomen is composed of six segments, five subequal ones ante-
rior to the terminal segment, which posteriorly is triangular, with
apex rounded. There are five pairs of well-developed pleopoda. The

FIG. 28. LEPTOCHELIA SAVIGNYI. FEMALE, a, FIRST

LEG. 6, FIRST ANTENNA. C, SECOND ANTENNA.

d, UEOPOD. x 77J.

28 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

uropoda are double branched, the inner branch being composed of six
articles, the outer one being composed of one short article.

The first pair of legs are greatly elongated and extend some distance
in front of the head. The carpus is long and narrow and extends to
the end of the basal article of the first pair of antennae. The propodus
has the distal extremity produced in a long, narrow, strongly curved
process or thumb, which is armed within on the inner side with two
triangular processes or teeth. The dactylus is also long and narrow,
strongly curved, and furnished with stiff hairs on the inner margin.
All the other legs are ambulatory.

Description of female. Body narrow, elongate, about five times
longer than wide, mm. : 2 mm.

Head longer than wide, becoming gradually narrower from the base
to the anterior end. The anterior margin is very slightty produced in
an obtuse point. The eyes are small, round, composite, and situated
at the antero-lateral angles of the head. The first pair of antennae have
the first article long and robust; the second is less than half as long as
the first; the third is a little longer than the second. This article in
some specimens is subdivided. The second pair of antennae are shorter
than the first pair. The first article is long; the second article is less
than half as long as the first; the third is twice as long as the second;
the fourth is half as long as the third.

The first segment of the thorax is united with the head to form a
carapace. The following six segments are free. The first free seg-
ment or second thoracic segment is a little shorter than the two fol-
lowing, which are subequal. The fourth and fifth free segments or
the fifth and sixth segments are a little longer than either of the two
preceding ones. The last segment is a little shorter than any of the
four preceding segments, but is as long as the first segment.

The abdomen is composed of six segments, five short ones, subequal
in length, anterior to the terminal segment, which has the posterior
margin rounded. The uropoda are composed of a peduncle with two
branches. The inner branch is composed of six articles. The outer
branch has only one article.

There are five pairs of well-developed pleopoda.

The first pair of legs are chelate. The other six pairs are ambula-
tory. The dactylus of the second pair of legs is longer than in those
following, but is not as long as the propodus. a

LEPTOCHELIA DUBIA (Kr^yer).

Tanais dubim KE0YER, Nat. Tidsskrift, IV, 1842, p. 178, pi. n. figs. 20-22.
Leptochelia dubia RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p. 279.
Leptochelia incerta MOORE, Bull. U. S. Comm. of Fish and Fisheries, Pt. 2, XX,
1902, pp. 165-166.

See Harger for full description of this species.

ISOPODS OF NORTH AMEEICA.

29

Localities. Brazil (Kr0yer); Bermudas, at Castle Harbor (Richard-
son); Arroyo and Culebra, Porto Rico (Moore).

Found in dead coral.

This species seems to agree with Leptochelia savignyi (Kr0yer), with
the exception that both males and females have the inner branch of
the uropoda composed of five articles instead of six.

It seems best to keep this species distinct from Leptochelia savignyi,
although they are hardly to be distinguished except for the difference

FIG. 29. LEPTOCHELIA DUBIA (AFTEK MOORE), a, GENERAL FIGURE, x 14. 6, FIRST ANTENNA.
x 77. c, SECOND ANTENNA, x 77. d, CHELA, x 77. e, CHELIPED. x 33. /, END OF SECOND LEG.
X 77. g, UROPOD. x 77. (Female).

in the number of articles to the inner branch of the uropoda. Tlhe
female of L. algicola has been placed in the synonymy of L. diibia by
various authors, notably Sars and Norman, and I have also previously
followed their example. Now, however, I am inclined to think, with
Dollfus, that both the male and female of L. algicola should be placed
in the synonymy of L. savignyi, inasmuch as they both agree in hav-
ing the inner branch of the uropoda six-jointed in both sexes, whereas
L. dubia in both sexes has the inner branch of the uropoda composed
of onlv five articles.

30

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

LEPTOCHELIA RAP AX Harger.a

Leptochelia rapax HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 163; Report
U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 424-426, pi. xni,
figs. 89, 90. SARS, Archiv. for Math, og Naturvid., 1882, p. 28. RICHARD-
SON, American Naturalist, XXXIV, 1900, p. 212; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 503; Trans. Conn. Acad. Sciences, XI, 1902, p. 279.

Localities. Annisquara, Massachusetts; and the Bermudas.
Depth. 3 ft. on muddy bottom; i fathom. Lives in tubes.
Body narrow, elongate, about four times as long as wide, 1 mm. :
4 mm.

Head as wide as long, 1 mm. :1 mm., with the anterior margin
between the eyes triangularly produced. The eyes are small, round,
composite, and situated on the produced antero-
lateral angles of the head. The first pair of antennae
are extremely long in the male; the first article is
li mm. long, or longer than the head; the second
article is one-half as long as the first; the third is
one-half as long as the second. The flagellum is
composed of seven articles. The second pair of
antennae are very short and feeble as compared with
the first antennae, and extend only half the length
of the first article of the second antennae. The
first article of the second antennae is about equal in
length to the second; the third is a little shorter
than the second, and is furnished with hairs at the tip.
The first segment of the thorax is coalesced with
the head. The six following free segments are
about equal in length, with the exception of the
first, which is a little shorter than any of the others.
The abdomen is composed of six segments, sub-
equal in length, the last segment not having the
lateral parts developed as in the five preceding segments. The urop-
oda are double branched. The inner branch is composed of five arti-
cles. The outer branch is composed of only one article. The peduncle
of the uropoda is about as long as wide. There are five pairs of well
developed pleopoda attached to the first five segments of the abdomen.
Between the uropoda and arising from the ventral side is a long narrow
plate, probably attached to the fifth abdominal segment; it terminates
in a rounded extremity.

The first pair of legs in the male are very much elongated and extend
a great distance in front of the head. The carpus is about half the
length of the entire body; the propodus is as long as the carpus, the
digital process being more than half the length of the cai'pus, and
armed on the inner side near the base with a small triangular process

a See Harger for more detailed description of this species.

FIG. 30. LEPTOCHELIA

KAl'A X (AFTER HAK-

GER). MALE, x 12.

ISOPODS OF NORTH AMERICA. 31

and near the distal end with a larger process; the dactylus is more
than half the length of the propodus and is strongly curved. The six
following pairs of legs are small and similar in shape, the dactylus in
the second pair being only about twice as long as in any of the other
five pairs. The dactylus in the last three pairs is more curved than in
the three preceding pairs.

In the female the first pair of antennae are not elongated; the second
and third articles are subequal and each is about half as long as the
first. There is no flagellum. The first pair of legs is not elongated;
the second pair have the dactylus elongated as in the male.

FIG. 31. LEPTOCHELIA RAPAX. a, FIRST LEG OF MALE, x 27|. b, FIRST LEG OF KK-MA J,E. x 27J.
LEPTOCHELIA? FILUM (Stimpson).

Tanais filum STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853,

p. 43. HARGER, Am. Jour. Sci., (3) XV, 1878, p. 378.
Leptochdia filum HARGEH, Proc. U. S. Nat. Mus., II, 1879, p. 164; Report U. S.

Comm. of Fish and Fisheries, 1880, Pt. 6, p. 427. SARS, Archiv for Math.

og Naturvid., 1882, p. 28. RICHARDSON, American Naturalist, XXXIV,

1900, p. 212; Proc. U. S. Nat. Mus., XXIII, 1901, p. 504.

Localities. The Hake Bay, Grand Menan; Gulf of St. Lawrence.

Depth. Eight fathoms, on a sandy bottom; 20 fathoms among
Ascidise callossB. ,

" Very minute, slender, rounded on the back, white, looking very
much like a short piece of thread. Head small, and rather nar-
rowed in front; first thoracic segment of great length; the second
half as long as the third, which is about equal in length with the
fourth, fifth, and sixth; the seventh being a little shorter than the
sixth. The segments of the abdomen are well defined, the first five
equaling each other in length, and the terminal one longer than the
fifth, but narrower, and rounded behind. Antennae short and thick,
without flagella, with blunt tips crowned with few hairs, as are also
their articulations. The inner ones are directed forward, and much
the stoutest, especially toward their bases; while the outer ones are
more slender and curve outward and backward. Firsc pair of legs
exceedingly thickened, with very large ovate hands and strong curved
fingers. They are generally closely applied against the breast. The
remaining thoracic feet are very slender, terminating in sharp, slender
fingers, which in the second pair are very long and nearly straight,

32 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

and in the other pairs short. The legs of the posterior pair are a little
the longest and thickest. The ambulatory feet, in five pairs, are of
great length and resemble those of the Amphipods. The caudal stylets
are in length about four-fifths that of the abdomen, and consist of four
or five articles with few hairs, each article becoming narrower, the last
one with a tuft of few hairs at its extremity. Length, .15 inch;
breadth, .02. Dredged among Ascidise callosse in 20 fathoms in the
Hake Bay." STIMPSON."

7. Genus NEOTANAIS Beddard.&

First pair of antennae (in the male) with a three-jointed peduncle
and a flagellum of four joints. Second pair of antennae with a five-
jointed peduncle and a short four-jointed flagellum. Chelae fully
developed and of normal structure in male. Exopodite of uropoda
two-jointed; endopodite eight-jointed. Thoracic appendages special-
ized into an anterior and posterior series; in the three anterior tho-
racic appendages the distal joint is a simple, elongated, somewhat
curved claw; in the posterior appendages this terminal joint is fur-
nished at its extremity with a circlet of stout spines and a long, mesi-
ally placed, slender hair.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS NEOTANAIS.

a. Rostrum blunt. Ocular lobes minute but separate. .Neotanais americanus Beddard
of. Rostrum sharp. Ocular lobes not distinct.

Neotanais hastiger (Norman and Stebbing)

NEOTANAIS AMERICANUS Beddard.

Neotanais americanus BEDDARD, Proc. Zool. Soc. Lond., 1886, pp. 117-118; Chal-
lenger Report, XVII, 1886, pp. 124-125, pi. xvi, figs. 4-6. RICHARDSON,
American Naturalist, XXXIV, 1900, p. 212; Proc. U. S. Nat. Mus., XXIII,
1901, p. 504.

Localities. Southeast of New York; latitude 38 34' north, longi-
tude, 72 10' west; and latitude 35 39' south, longitude 50 47' west.

Depth. 1,240 fathoms.

"The present species is the only representative of this new genus.
The specific as well as the generic characters depend upon the exam-
ination of two male specimens, each of which measures about 6 mm.
in length.

"The body is depressed and elongated, everywhere of approxi-
mately the same diameter. It is smooth both dorsally and ventrally,
with no hairs or spines.

"The cephalothorax is pear-shaped, narrower anteriorty and wider
posteriorly; it is about as long as the first two segments of the thorax

Smithsonian Contributions to Knowledge, VI, 1853, p. 43.
&See Beddard for characters of genus.

ISOPODS OF NORTH AMERICA. 33

taken together; the anterior margin terminates in the middle line in a
very short, blunt rostrum; on either side of the shallow excavations
which lodge the basal joints of the antennules are the minute but sep-
arate ocular lobes; these are rounded, oval in front, the anterior end
being pointed and prolonged; there is no trace of any ocular structures.
The first free thoracic segment is shorter, rather more than half the
length of the four succeeding segments, which are subequal; the last
thoracic segment is shorter than the foregoing; each of these segments
is rather narrower anteriorly where it articulates with the segment in
front; the general shape of the segment is short, oblong, with rounded
angles; this does not apply to the first-or to the last free segment of
the thorax, which are broader than they are long.

"The five anterior segments of the abdomen are equal in length and
in diameter, only the first one being a trifle longer than the rest.

"The terminal segment of the abdomen is longer and wider than the
rest; it has a pair of lateral projections with which the uropoda articu-
late; posteriorly it is rounded and a minute median triangular process
projects from the extremity; on either side of this the posterior mar-
gin of the abdomen is slightly concave.

"The antennules are considerably stouter than the antennae; the
peduncle has three joints, of which the proximal one is much the long-
est and stoutest; it is furnished with a tuft (three or four) of slender
spines on the outer side, near to its articulation with the second joint;
the second joint is about one-fourth of the length of the first^ and like
it has a tuft of slender spines occupying a similar position to those of
the basal joint, and one slender hair-like spine upon the opposite side;
the third joint of the peduncle is stouter again, with one or two short
slender spines upon the inner as well as the outer margin just before
its articulation with the flagellum; the latter consists of four joints,
of which the first is very much the longest, as well as broader than the
succeeding joints; each of the three distal joints is furnished with a
single olfactory hair.

"The antennas are considerably more slender and shorter than the
antennules; the peduncle consistsof five joints; the basal joint is short
and oval, much stouter than any of the succeeding joints, which are of
equal thickness; the second joint is moderately long, the third stouter,
the fourth and fifth subequal to each other and to the second joint;
the flagellum has four joints which decrease gradually in diameter, the
first being the widest; the first joint of the flagellum is also the long-
est, the two middle ones are shorter and subequal, the fourth shorter
still and provided at its extremity with a tuft of fine hairs.

"As the only specimen was mounted on a slide in Canada balsam it
is impossible to describe in a detailed manner the mouth appendages,
which do not appear, as far as could be seen, to present any marked
differences from those of other species.
2858905 3

34

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

" The chelaB are short and very stout; the second joint is particularly
stout, as compared with the others; the third joint as usual is very small,
a portion of the fourth coming to articulate directly with the second; in
the fifth joint the palm is straight for the first half, the margin being

fringed with fine, closely-set den-
ticles; the distal half is furnished
with blunt tooth-like processes,
and is bent downward at an oblique
angle; it terminates in a short
pointed extremity which is bent
upward; toward the distal extrem-
ity are a few slender hairs scat-
tered here and there; the finger
gradually narrows toward its ter-
mination in a curved pointed ex-
tremity; the inner margin is pro-
vided with a number of low tooth-
like processes, each terminating
in a sharp point which is directed
forward.

"The remaining thoracic limbs
are more or less similar to each
other; there is no difference in
size between the anterior and
posterior series, but a slight differ-
ence in structure; the proximal
joint is very long, the second ex-
tremely short; the third is about
half the length of the proximal
joint, the fourth and fifth are
rather shorter and subequal; the
terminal joint of the limb has the
form of a long slender spine; the
inner margin of the penultimate
joint has a row of stout spines,
of which the distal one or two are
serrate; on the opposite side of the
joint are a number of more slender
hair-like spines; the antipenulti-
mate joint has a similar structure,
but the spines are not so strong;
the distal joints are nearly smooth, having only a very few slender
hairs developed at the point of articulation with the succeeding joints.
The above description applies to the first three pairs of ambulatory
limbs. The fourth, fifth, and sixth pairs of thoracic appendages
differ slightly in their structure from the anterior pairs; this differ-

FIG. 32. NEOTANAIS AMERICANUS (AFTER BED-
DARD). a, SECOND ANTENNA. 6, GENERAL
FIGURE.

ISOPODS OF NOKTH AMERICA. 35

ence mainly concerns the terminal joint of the limb, which is consid-
erably more elongated than in the anterior appendages; it terminates
in a fringe of short spines and mesially in a long slender spine which
is of about half the length of the joint.

"On the abdomen all the appendages are present, but they present
no special features of interest, with the exception of the uropoda,
which have a typical structure.

. "The basal joint of the uropoda is very stout and long, and with it
articulates the minute two- jointed exopodite, as well as the long slender
endopodite, which is made up of eight separate joints, all of which have
tufts of hairs near to their articulation with the succeeding joints.
Both the endopodite and the exopodite end in a tuft of slender hairs;
the length of the uropoda is nearly equal to that of the abdomen.

" Another example of this species was dredged in the North Atlan-
tic from a depth of 1,250 fathoms; it presents certain slight differences
from the above-described species; these differences have reference to
the proportionate length of the thoracic segments. Seeing, however,
that the two specimens come from widely distant localities, it appears
to be unnecessary to found a specific distinction between the two indi-
viduals, at least for the present. The present specimen is stouter and
more robust than the last, but of equal length; the cephalothorax is
nearly as long as the first three segments of the thorax taken together;
the thoracic segments gradually increase in length up to the fourth;
the fifth and sixth segments are subequal and about as long as the
third. " BEDDAKD. a

NEOTANAIS HASTIGER (Norman and Stebbing).&

Alaotanais hastiger NORMAN and STEBBING, Trans. Zool. Soc. Lond., XII, 1886,
Pt. 4, pp. 113, 114, pi. xxin, fig. 2. HANSEN, Videnskabelige Meddel-
elser fra den naturhistoriske Forening i Kj0benhavn, 1887-1888, p. 178.
RICHARDSON, American Naturalist, .XXXIV, 1900, p. 212; Proc. U. S. Nat.
Mus., XXIII, 1901, p. 502.

Locality. Latitude 59 11' north, longitude 50 25' west.

Depth. 1,750 fathoms.

"This species comes very near to the last (N. serratispinosus). It
differs from it in having the eye processes relatively larger, and in the
massiveness of the hand and finger of the first gnathopods; in these
organs all the parts are thickened and straightened without any pro-
portionate increase in length. The effect of this is to make the inner
edge of the thumb and finger overlap when closed all along the line,
except for a small triangular space near the root of the thumb. The
uropods have the inner branch nine, the outer two-jointed.

Challenger Report, XVII, 1886, pp. 124-125.

& Stebbing says that without doubt Alaotanais is a synonym of Neotanais
Crust., 1893, p. 324.

LIBRA R

36

BULLETIN 54, 'UNITED STATES NATIONAL MUSEUM.

"But the characters which at once distinguished this species from
all others known to us are to be found in the microscopic armature of
the limbs. All the peraeopods are everywhere beset with long, very
slender spines, the whole of which, under high powers, are found to be
covered with minute prickles. There are no toothed spines, such as
are found in Alaotanais serratispinv&us, the corresponding limb to
which in A. hastiger hai the finger long, narrow, and curved, and sur-
rounded by a series of long, very slender spines, which all have the
character of being beset irregularly all around with little prickles.

"The hinder peneopods have a finger which, so far as we are aware,
is absolutely unique in structure; the propodus is cleft at the end to
some depth, the cleft portions are rounded at the extremities and cre-

\

FIG. 33. NEOTANAIS HASTIGEE (AFTER NORMAN AND STEBBING). a, OUTLINE OF CARAPACE FROM
ABOVE, b, ABDOMEN, c, THUMB AND FINGER OF FIRST GNATHOPOD. d, LATERAL VIEW, e, SECOND
PEE^OPOD. /, PORTION OF CARAPACE, SEEN FROM THE SIDE, g, LAST PER^OPOD (TERMINAL JOINTS).

nated or serrulated; the finger articulates at the base of the cleft, and
is exactly spear-shaped, with serrated edges. A compaTison of the
fifth perseopod with the figures of the hinder peraeopods of Alaotanais
serratispi'nosus (the fourth peraeopod) will at once give characters suf-
ficient to distinguish these species.

"The carapace, seen from above, is much narrower in front than
behind, and has a short rostrum; the sides are very flexuous, and pre-
sent two constrictions.

"The telson is shield-shaped; the upper corners of the shield (that
is, the sides of the base of the telson) are very protuberant. Length,
5 millimeters." NORMAN and STEBBING. a

"Trans. Zool. Soc., Lond., XII, 1886, Pt. 4, pp. 113-114.

I8OPODS OF NORTH AMERICA. 37

Family II. APSEUDID^E.

Body attenuated behind. First pair of antennae with two unequal
multiarticulate flagella. Second pair of antennae usually furnished with
a scale at the end of the second article of the peduncle. Mandibles with
palp. Anterior maxillae with two masticatoiy lobes. Posterior max-
illje well developed and setose. Epignath of maxillipeds large, lam-
inar, branchial in character. Two anterior pairs of legs, usually
provided at the base with minute, two-jointed exopods (exopodites).
Second pair of legs fossorial in character. Uropoda double-branched;
branches multiarticulate.

ANALYTICAL KEY TO THE GENERA OF APSEUDID^E.

a. Second pair of antennae with a scale articulated to the end of the second article.

Head and first thoracic segment coalesced.
b. Exopods present on both pairs of gnathopods.

c. Five pairs of pleopoda present, with branches uniarticulate. Abdomen com-
posed of six segments Genus Apseudes Leach

c/. Only four pairs of pleopoda present, with one of the branches two-jointed.

Abdomen composed of six segments Genus Parapseudes Sars

b' '. Exopods absent on both pairs of gnathopods. Five pairs of pleopods present,
in which one of the branches is two-jointed. Eyes absent.

Genus Typhlapseudes Beddard

a'. Second pair of antennae without a scale. Head and first two thoracic segments
coalesced. Eyes absent Genus Sphyrapus Norman and Stebbing

8. Genus APSEUDES Leach.

Second antennae with a scale articulated to the end of the second
article. Exopods present on both pairs of gnathopods. Five pairs
of pleopoda present, in which the branches are uniarticulate. First
pair of legs in male larger than in female. First pair of antennae
usually alike in the two sexes.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS APSEUDES.

a. Head with rostrum short, produced to a mere point. Body without spiny arma-
ture. Flagellum of first antenna of same length as secondary filament.

Apseudes espinosus Moore
a'. Head with distinct rostrum. Body with spiny armature. Secondary appendage

of first antenna shorter than flagellum.

b. Basal article of peduncle of first antenna unarmed. Secondary appendage of
first antenna one-fourth as long as flagellum. Long spiny processes on either
side of head, one pair at the place of fusion of the first thoracic segment with
the head, the other pair anterior to these, being the produced outer angles
of the ocular lobes. Last segment of abdomen with posterior margin slightly
emarginate, a small lobe being placed in the center of the emargination.

Apseudes grucilis Norman and Stebbing

See Sars, Crust, of Norway, II, 1899, p. 5, and Norman and Stebbing, Trans.
Zool. Soc., London, XII, 1886, p. 79, for characters given below.

38 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

//. Basal article of peduncle of first antenna armed with numerous spines. Sec-
ondary appendage of first antenna about one-half as long as flagellum. No
spines at side of head at place of fusion of first segment of thorax with the
head. Ocular spines small. Last segment of abdomen with the posterior
margin triangularly produced.

c. Basal article of peduncle of first antenna armed with four spines on the inner
lateral margin. Rostrum in form like a spear point, on either side of which
is a small acute process within the ocular alee. Last thoracic segment
with a ventral spine. Lateral margins of five anterior segments of abdo-
men not produced in acute processes Apseudes triangulatm Richardson

(/. Basal article of peduncle of first antenna armed with three spines on the
inner lateral margin. Rostrum produced in a long, acute deflected process,
on either side of which the lateral margin is expanded and evenly curved.
All six segments of thorax armed with ventral spines. Lateral margins of
five anterior segments of abdomen produced in acute processes.

Apseudes propinquus Richardson

APSEUDES'ESPINOSUS Moore.

Apseudes espinosus MOORE, Bull. U. S. Fish Commission, XX, Pt. 2, 1902, pp.
164-165, pi. vii, figs. 1-6.

Locality. Porto Rico, off St. Thomas.

Depth. 20 fathoms, in coral bottom.

" Cephalothorax short, less than length of first three segments of
thorax, slightly wider than long; rostrum short, produced to a mere
point; eyestalks short, projecting but slightly beyond sides of head.
First three segments of thorax subequal to one another in length
and breadth, approximately equal to head in breadth. Last three seg-
ments narrower; fourth segment longer than segments two and three
combined; fifth free segment about equal to them; sixth segment about
three-fourths as long as fifth. Epimera of first three segments not
evident, none of the segments with lateral spines; epimera of last
three segments small, in dorsal view projecting slightly from beneath
each segment near its articulation with its successor. Abdomen nar-
rower than last segment of thorax, but not abruptly so; the first five
segments equal in length and successively slightly narrower; collec-
tively about as long as sixth thoracic segment; lateral margins rounded,
somewhat produced posteriorly. Telson about as broad as long, slightly
narrower than fifth segment of pleon, bilobate posteriorly.

"Peduncle of antennule as long as head, first joint stout, longer than
other three joints combined, second joint not half as long as first, two
following joints successively shorter; two flagella of equal length, and
longer than peduncle, the outer somewhat shorter, with seventeen
joints, inner flagellum with fifteen joints.

"Antennae about two-thirds as long as antennules; peduncle short,
consisting of five joints, first and second joints stout, second furnished
with a scale beset with long setae, last three joints short. Flagellum
about as long as flagella of antennule, consisting of thirteen setiferous
joints.

1SOPOD8 OF NORTH AMERICA.

' ' Mandibles stout, with a five-dentate cutting edge and a three-jointed
palp. First inaxillsB tipped with a number of brown spines. Maxilli-
peds with a stout four -jointed palp, of which the second joint is very

FIG. 34. APSEUDES ESPINOSUS (AFTER MOORE), a, UROPOD. 6, FIRST LEG. c, GENERAL FIGURE.
d, SEVENTH LEG. e, SECOND LEG. /, CHELA. (ALL ENLARGED.)

large and stout. Details in relation to the oral parts are not known,

as there was but one specimen mounted in balsam and not dissected.

"The chelipeds in the females are long and slender, the fifth joint

being .the longest and the second almost as long, but stouter. The

40 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

third joint is prolonged distalh' into a curved process furnished with
five or six long hairs on the convex margin; the sixth joint, with the
seventh, constituting a slender chela; no molar tubercles; curved mar-
gin of 'thumb' of sixth joint with a row of slender bristles; a row
of blunt spines on cutting edge.

'The second pair of limbs have the joints stout and furnished with
strong spines. The second joint or basis has five or six stout, curved
spines on its outer margin. It is longer than the other joints. The
terminal claw is flanked on each side by a strong spine attached to sixth
joint. There appear to be but five free joints to this and the follow-
ing limbs, but this appearance may be due to defects in the mounting;
following pairs of limbs more slender, the last pair having a second
joint almost as long as all the rest, and with an oblique row of small
spines near distal end of posterior face of sixth joint.

"There are five pairs of pleopods with both branches one-jointed.

"Uropods biramous, the inner ramus with about fifty joints; outer
ramus less than one-half as long, with about twenty-five joints. The
joints of both are of irregular length.

"One specimen, female, from station 6079, 20 fathoms, 6 mm. by
1.4 mm." MOORE/'

APSEUDES GRACILIS Norman and Stebbing.

Apseudes gracilis NORMAN and STEBBING, Trans. Zool. Soc., Lond., XII, 1886, Pt.
4, pp. 95-97, pi. xx. HANSEN, Viden&kabelige Meddelelser fra den natur-
historiske Forening i Kj0benhavn, 1887-1888, p. 178. RICHARDSON, Ameri-
can Naturalist, XXXIV, 1900, p. 212; Proc. U. S. Nat. Mus., XXIII, 1901,
p. 505.

Localities. Davis Strait, latitude 59 10' north, longitude 50 25'
west; also in the North Atlantic.

Depth. 1,750 fathoms.

"The carapace has the frontal margin produced into a long slender
acute rostrum, which is half as long as the basal joint of the upper
antennae, and has a bulbous process on each side at its origin; ocular
processes or alas having their outer sides prolonged into an acute spine-
like termination projecting forward and slightly outward. On each
side of the carapace, at the junction of the first coalesced segment of
the peraeon with the cephalon, there is another pair of spinous proc-
esses closely assimilating in form to those of the alae just described.

"The peneon has the segments remarkably long, more produced
than in any other known species, especially the last four; each segment
bears a pair of lateral acute spinous processes, and in front of these a
pair of small tubercles, while on the ventral surface there is a large
acute curved spine near the hinder margin, and near the front margin
a small tubercle bearing two or three minute cilia. The epistoma is
tumid, arched, carinate, and armed with a small spine near the mouth.

"Bull. U. 8. Fish Commission, XX, Pt. 2, 1902, pp. 164-165.

I8OPODS OF NORTH AMERICA.

41

"The pleon is of great length, the five front segments subequal,
and each as long as the first free segment of the perseon; epimera

6

FIG. 35. APSEUDES GRACILIS (AFTER NORMAN AND STEBBING). o, UPPER ANTENNA. 6, LATERAL
VIEW, e, LOWER ANTENNA, d, SIDE VIEW OF MOUTH PARTS AND AN ABNORMALLY DEVELOPED FIRST

GNATHOPOD. e, MANDIBLE. /, FIRST GNATHOPOD. fir, ANTERIOR PART OF BODY, FROM ABOVE.

h, FIFTH LEG. i, PLEOPOD. j, LAST SEGMENT OF ABDOMEN, k, SECOND GNATHOPOD.

only slightly produced, terminating in small spines, a central ventral
spine on each segment; last segment as long as the preceding three,
having a number of minute tubercles about it; termination slightly

42 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

emarginate, with a small, rounded projection occupying the center
of the emargination.

"Upper antennae with the basal joint moderately stout, a tactile
seta halfway up the outer margin; second and third joints subequal,
their combined length scarcely more than half that of the first joint; fil-
ament consisting of about 17, secondary appendage of 4 articulations.
Lower antennae reaching to the end of the peduncle of the upper; the
scale smaller than usual, only reaching to the middle of the fourth
joint, and bearing only four setae, two on the exterior margin and two
apical, and none on the interior margin.

"The first gnathopods are slender and weak, and without much
character; wrist very long, two and a half times as long as meros,
with many cilia on the front margin; hand with the basal portion
slender, and scarcely wider than the wrist; thumb and finger long,
without any tubercular processes on the inner margin, the distal
portion of that of the thumb bearing a series of microscopic flattened
teeth, arid short, stiff, obtusely ending cilia; finger having about five
short stumpy spine-like teeth just before the unguis commences.

"Second gnathopods strongly built, basos naked; meros having the
front margin ciliate, and bearing a distal spine, upper margin with a
distal bunch of cilia; wrist unusually short, scarcety more than half
the length of meros, above with many cilia and a large distal spine,
below with four cilia and two or three spines; hand widely ovate,
rather longer than the wrist, upper margin with two spines and a few
cilia; palm closely set all round with ten stout spines, but no cilia; all
the spines of the limb are stout, but quite simple in character; finger
strong, with four denticulations on the margin.

"Last peraeopods slender, basos naked, the three succeeding joints
having one or two minute cilia on the front margin, except that the
carpus (which is slightly longer than the meros and hand, which are
subequal to each other) has a long slender distal spine on the front;
hand with a distal spine above and two slender spines on the palm,
and passing obliquely across the last half of the joint, commencing
beyond the middle of the palm and terminating at the upper margin
of the origin of the finger, is a pectinated series of lancet-shaped
spines, of which the margins are apparently simple. Finger of most
unusual length, half as long again as the hand, the unguis especially
being very greatly produced.

"Pleopods greatly developed, the peduncle long.

"Uropods with one branch consisting of about 7, the other of 18,
articulations.

"The foregoing is a description of the females, one of which has
incipient growths of the marsupial sac at the base of the second, third,
fourth, and fifth peraeopods.

ISOPODS OF NORTH AMERICA.

43

"The males, which are known by the cylindro-columnar sexual
organ situated between the last peraeopods, where it takes the place of
the ventral spine of the other sex, differ in having the lateral spines
of the person-segments, and
both epimeral and ventral
spines of the pleon, so much
reduced in size as to become
almost obsolete, while the ven-
tral spines of the earlier seg-
ments of the body are as large
as in the female, and the hand
of the first legs is not more
largely developed than in the
other sex. All these points are
contrary to what is usual, and
not what might have been ex-
pected to characterize the male.
* * * Length half an iuch."-
NORMAN and STEBBING. a

APSEUDES TRIANGULATUS
Richardson.

Apseudes triangulata RICHARDSON,
Trans. Conn. Acad. Sciences,
XI, 1902, pp. 280-281, pi.
xxxvn, figs. }-5.

Locality . Harrington
Sound, Bermudas.

Body narrow, elongated, sur-
face smooth.

Head with frontal margin
produced at the middle in a ros-
trum like a spear point, the
sides of which near the base
are excavated below the lateral
expansion of the rostrum. On
either side of the excavation
thus formed the margin is
acutely produced in a small
anterior process. Lateral to
this process is the ocular proc-
ess, which is produced anteriorly about the same distance.

FIG. 36. APSEUDES TKIANGULATUS. a, SEGMENTS OF

THORAX AND ABDOMEN. 6, HEAD. X 35. C, SEG-
MENTS OF ABDOMEN AND PART OF UROPODA. d,

FIRST GNATHOPOD. e, SECOND GNATHOPOD.

The

eyes are distinct and black and occup} r almost the whole surface of
the ocular lobe.

Trans. Zool. Soc. Lond., XII, 1886, Pt. 4, pp. 95-97

44 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first pair of antenna? have the first joint of the peduncle long,
the inner lateral margin of which is armed with three long spines and
one small one; the outer margin, with one large spine near the apex.
The second joint is one-third the length of the first joint and is
unarmed. The third joint is one-half as long as the second joint.
The flagellum is composed of about fourteen joints; the secondary
appendage of about seven joints. The peduncle of the second pair of
antennae extends to the end of the first joint of the peduncle of the
first pair, and has an exopod developed at the base of the third joint.
The flagellum is composed of about ten joints, and extends about half
the length of the flagellum of the first pair of antennae. There is a
prominent spine on the epistome.

The first free segment of the thorax is shortest, the two following
ones being longer, the next two the longest, and the last but little
longer than the first. The first segment is as wide as the head, the
others decrease in width gradually. The antero-lateral margins of
all the segments except the first are produced into one acute process,
of the fourth and fifth free segments into two acute processes. The
last segment bears a ventral spine.

The abdominal segments gradually decrease in width backward.
The sixth or terminal segment is produced on either side near the base
into two acute processes. Beyond the last process the segment widens
slightly for the attachment of the uropoda, and ends posteriorly in a
triangular process. The uropoda are very long, the inner branch being
half the length of the body, and composed of about twenty-five joints.
The outer branch is composed of seven joints.

First gnathopods with the upper distal margin of the propodus,
finely serrate and armed with a tooth near the articulation of the
dactylus. Second gnathopods have the merus armed with one spine at
the distal extremity on the posteri or margin, and one on the anterior
margin; the carpus armed with two spines on the posterior and one on
the anterior margin at the distal extremity; the margin of the propodus
armed with three spines on the posterior margin, and one large spine
and one small one at the distal extremity on the anterior margin. The
dactylus is serrate on the inner margin. Exopods are present on both
first and second gnathopods. The other legs are beset with spines.

The specimen is a female and has a large marsupium filled with eggs,
extending the length of the first four free segments of the thorax.

Only one individual was collected by Prof. A. E. Verrill and party,
in Harrington Sound, Bermudas.

Type specimen in Peabody Museum, Yale University. Cat. No. 3192.

ISOPODS OF NORTH AMERICA. 45

APSEUDES PROPINQUUS Richardson.

Apseudes propinquus RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp.
281-283, pi. xxxvn, figs. 6-9.

LocaU.tir*. Bailey Bay and Castle Harbor, Bermudas; Gulf of
Mexico.

Found on surface.

Body narrow, elongated, surface smooth.

Head with frontal margin produced in the middle in a long, acute,
deflected process, from base of which on both sides there is an abrupt
lateral expansion, the margin forming an outward curve which
extends to the base of the ocular lobe and then proceeds straight to
the lateral margin of the head. Ocular lobe produced in an acute
process. Eyes large, black, occupying the whole of the ocular lobe.

First pair of antennae with first joint of peduncle long, and armed
on the inner lateral margin with two large spines and one small one
near the base, and on distal end of outer margin with one large spine.
Second joint less than one-third the length of first joint and unarmed.
Third joint one-half as long as second joint. Flagellum composed
of sixteen joints. Secondary appendage composed of eight joints.
Second pair of antennae with an exopod at base of third joint of
peduncle; flagellum composed of ten joints. There is a conspicuous
spine on the epistome.

First two free segments of the thorax about equal in length, the
three following ones longer, increasing in length, the last segment a
little longer than the first two. The antero-lateral margins of all
the segments are acutely produced, those of the fourth and fifth free
segments have two antero-lateral angulations. There is an anteriorly
directed curved spine on the ventral surface of the first free segment.
On the ventral surface of the second segment there is a straight spine
directed posteriorly. The third, fourth, and fifth segments bear each
a ventral curved spine directed anteriorly. The sixth segment has
on the ventral surface a large, stout process.

The lateral margins of all the first five abdominal segments are
drawn out in acute processes.

The terminal segment has two lateral angulations above the attach-
ment of the uropoda. The posterior margin is triangulate. The
inner branch of the uropoda is very long, equal in length to half the
body, and is composed of thirty-four joints. The outer branch con-
sists of eleven joints.

The first gnathopods have a tooth on the distal margin of the pro-
podus near the articulation of the dactylus. There is a conspicuous
spine on the posterior margin of the basis.

The second gnathopods have one spine at the distal end of the merus
on the anterior margin; one spine at the distal end of the carpus on
the anterior margin, and two spines on the posterior margin of the

46

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

same joint; four spines on the posterior margin of the propodus and
two on the anterior margin at the distal extremity; the dactylus is
serrate along the inner margin. Exopods are present on both first
and second gnathopods. The other legs are beset with spines.

A few specimens, both males
b

and females, were collected by
Prof. A. E. Verrill and party
at Bailey Bay and Castle Har-
bor, Bermudas, in 1898.

Type specimen from the
Bermudas is in the Peabody
Museum, Yale University.
Cat. No. 3194.

This species is very closely
related to Apseudes intermedium
Hansen a but differs in the fol-
lowing points:

1. The first joint of the pe-
duncle of the first pair of an-
tennae is armed with three
spines on the inner margin,
and one spine on the outer
margin at the distal end. In
A. intermedius this joint is
unarmed.

2. In the increased number
of joints in the flagella of both
pairs of antennae, there being
sixteen joints in the flagellum
of the first pair of antennas,
eight in the secondary append-
age, and ten in the flagellum
of the second pair of antenna?,
while in Doctor Hansen's
species the flagellum of
the first pair of antennas is
composed of seven joints,
the secondary appendage of
three joints, and the flagellum

of the second pair of antennae of four joints.

3. In the much greater length of the uropoda, the inner branch of
which in A. propinquus is half the length of the body and composed
of thirty-four joints, the outer branch consisting of eleven joints,

Isopoden, Cumaceen, und Stomatopoden der Plankton-Expedition, 1895, p. 49-50,
pi. v. fig. 10-10b; pi. vi, fig. 1.

FIG. 37. APSEUDES PROPINQUUS. a, HEAD. 6, SEG-
MENTS OF THORAX AND ABDOMEN. C, LAST FOUR
SEGMENTS OF BODY AND PART OF UROPODA. d, FIRST
GNATHOPOD.

ISOPODS OF NORTH AMERICA.

47

while in A. intermedium the outer branch has only four joints, and the
inner branch is only twice the length of the terminal abdominal seg-
ment and is composed of only fifteen joints.

9. Genus PARAPSEUDES Sars.

Exopods present on both pairs of gnathopods. Only four pairs of
pleopoda present, with one of the branches two-jointed. Second pair
of antennae with a scale articulated to the end of the second article.

PARAPSEUDES GOODEI Richardson.

Parapseudex goodei RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp.
283-284, pi. xxxvn, figs. 10-14.

Locality. Castle Harbor, Bermudas.^

FIG. 38. PARAPSEUDES GOODEI. a, GENERAL FIGURE. 6, HEAD AND FIRST THORACIC SEGMENT.

C, FIRST GNATHOPOD OF MALE, d, ABDOMEN WITH UROPODS AND LAST THORACIC SEGMENT. , FIRST
GNATHOPOD OF FEMALE

Surface of body smooth; color light yellow.

Head but slightly narrowed anteriorly. Eyes with large, brown
ocelli and placed on ocular processes, articulated to the head.
Frontal margin with a rostrum projecting between the basal joints
of the first pair of antennae. The base of the rostrum is constricted,
the anterior margin broadly rounded.

The first pair of antennas have the peduncle short, the first joint
twice as long as the second; the third half as long as the second; all
three with margins smooth, unarmed, but fringed with long hairs.
The flagellum consists of seven joints; the secondary appendage of
four joints. The second pair of antennae extend only to the end of
the peduncle of the first pair; the flagellum consists of five joints; a
scale is articulated to the peduncle.

48 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first, second, and third free thoracic segments are about equal
in length, the following three being longer than the first three, and
subequal. The first and second segments have a small epirneral lobe
on the antero-lateral margin. The third segment has a small lobe
about the center of the lateral margin. The lobes of the three follow-
ing segments are situated post-laterally.

The abdomen is very short; all the segments together not equaling
in length the last two thoracic segments. The first five segments have
the margins produced at the sides, with deep lateral incisions between
the segments.

The terminal segment is triangulate posteriorly with the apex acute.
The uropoda are quite half the length of the body, the inner branch
consisting of about twenty-five joints, the outer and smaller branch
consisting of six joints. There are but four pairs of pleopoda.

The first pair of legs in the female are much more slender than
those of the male. In the male there is a deep excavation on the dis-
tal margin of the propodus near the articulation of the dactylus, while
in the female this excavation is comparatively small. In the male
there is a spine within this excavation and one on the dactylus, both
situated at the articulation of the dactylus and the propodus. Exopods
are present on both pairs of gnathopods. All the other legs are very
spinulose.

A few specimens (types) were collected by Prof. A. E. Verrill and
party in 1898, at Castle Harbor, Bermudas, and one specimen was
collected by Dr. G. Brown Goode at the Bermudas in 1876-77.

Type in Peabody Museum, Yale University. Cat. No. 3222.

Named in honor of the late Dr. G. Brown Goode.

This species has a close resemblance to Parapseudes latifrons
(Grube), a but differs in the following characters: in P. goodei the first
pair of gnathopods are more robust; the propodus has a deep excava-
tion near the articulation of the dact} T lus, within which is a large spine.
There is also a spine on the dactylus.

The rostrum is constricted at the base in P. goodei, while in P. lati-
frons the line is unbroken from the apex of the rostrum to the lateral
margin of the head.

The secondary appendage of the flagellum of the first antennae is
composed of four joints in P. goodei while in P. latifrons this append-
age is composed of seven joints. The flagellum of the second pair of
antennas consists of five joints in P. qoodei, while in Grube's species it
consists of eight joints.

a Rhoea latifrons Grtibe, Die Insel Lussin tind ihre Meeresfauna, 1864, p. 75.
Parapseudes latifrons G. O. Sars, Archiv for Math, og Naturvidenskab, XI, 1886,
p. 304, pi. vni.

\

ISOPODS OF NORTH AMERICA. 49

1O. Genus TYPHLAPSEUDES Beddard.

Eyes absent. No exopodite present on the first two pairs of thoracic
appendages. All five pairs of pleopoda present. Abdomen composed
of six distinct segments. Antennse with a rudimentary exopodite,
consisting of a single long joint. Pleopoda well developed, the exopo-
dite bi-articulate.

TYPHLAPSEUDES NEREUS Beddard.

Ti/phlapseudes nereus BEDDARD, Proc. Zool. Soc. Lond., 1886, Pt. 1, p. 115;
Report on the Scientific Results of the Expl. Voyage of H. M. S. Challenger,
Zool, XVII, 1886, pp. 112-113. RICHARDSON, Proc. U. S. Nat. Mus., XXIII,
1901, p. 505.

Locality. Off Sombrero Island.

Depth. 450 fathoms.

"This species is represented by a number of individuals dredged in
the North Atlantic from a depth of 450 fathoms. The average length
of the species is about 10 mm. The body is flattened and depressed,
smooth, without any covering of hairs even on the abdomen; it is
wider anteriorly and gradually narrows to the posterior extremity.

u The head and the first segment of the thorax, which are of course
fused together and form a cephalic shield, is flattened in front, but
convex laterally and behind. The frontal margin projects as a short,
sharp rostrum; behind the insertion of the antennary organs is a
triangular ocular lobe pointed in front; it has no trace of any optic
structures; behind this again is another shorter, triangular, pointed
process; more posteriorly the lateral margins of the cephalic shield
are convex outward.

u The free thoracic segments diminish gradualh r in breadth, but
increase in length up to the fifth; the sixth is not .only narrower, but
shorter than the fifth. They are all furnished with very minute epi-
mera, those of the first segment are larger, and project anteriorly in
the form of a short spine. The lateral margins of all but the first
two segments are furnished with a short spine, very broad at its base,
which is situated about halfway between the articulation of the limbs
and the anterior margin of the segment. In the sixth (and last) seg-
ment of the thorax this spine is almost obsolete. In the ventral
surface of the thoracic segments is a median spine.

"In the female the 'first four of the free thoracic segments have
ovigerous lamellae. Of the abdominal segments the first pair are
subequal, but diminish gradually in breadth; they are furnished
with small epimera, terminating in a pointed extremit} 7 and directed
backward.

See Beddard for characters of genus. Challenger Report, XVII, 1886, pp. 111-112.
2858905 i

50

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"The terminal segment of the abdomen equals in length any four
of the anterior abdominal segments; it is cylindrical in form, becoming
gradually wider toward the extremity; it terminates in a truncated
straight posterior margin, and in the middle line in a short oval
prolongation.

"The antennules are stouter, as well as longer, than the antennae;
they are about as long as the cephalothoracic shield and the first seg-
ment of the thorax taken together. The basal joint is long and stout,
the second joint is very much shorter, the third and fourth shorter

still; from the last joint of the
peduncle arise the two flagella,
of which the outer is longer as
well as stouter than the inner;
the outer flagellum is made up
of ten joints, of which the first
is very much the longest; it
diminishes gradually in width
toward the extremity; the inner
flagellum has four or five nar-
row elongated joints.

"The antennae have a five-
jointed peduncle and a flagellum
about as long as the last two
joints. The first joint of the
peduncle is short, the second
long, with a short, cylindrical,
setose exopodite articulated at
its extremity; the third joint
is very short, the fourth and
fifth long and subequal.

" I have not had a sufficient
amount of material at my dis-
posal to give an accurate ac-
count of the mouth appendages.
"The chelae are not remark-
able in any way except for the absence of an exopodite; they appear
to be perfectly similar in both sexes, and agree very closely with those
of the genus Sphyrapus (female), etc. The first joint is very much
stouter than any of the succeeding joints; the second is short and nar-
row and bears a spine on the inner side just before its articulation with
the next joint, which is extremely minute and might easily be over-
looked; it is wedged in between the second and third joints, and is
only apparent on the inner side of the limb. The fourth joint is
longer and stouter and has a number of hairs along the inner margin.
The two fingers cross at their extremity; they are serrate along the
margins which come in contact.

FIG. 39. TYPHLAPSEUDES NEREUS (AFTER BEDDARD).

ISOPODS OF NORTH AMERICA. 51

"The fossorial limbs, which form the second pair, are much longer
and stouter than the succeeding abdominal limbs. The first joint is
long and curved, the second is very minute, the third and fourth are
subequal and rather less than one-half of the length of the basal joint;
the first two joints have no spines, the third has a single strong spine
on the inner margin just before it articulates with the succeeding joint,
and a tuft of hairs on the corresponding opposite side; the fourth
joint has two strong spines on the inner and a single spine on the outer
side, besides hairs and more slender spines; the fifth is shorter than
either of the preceding, its inner margin is fringed with five stout
spines, increasing in length toward the extremity of the joint, and two
strong spines besides more slender ones on the outer side; the terminal
joint of the limb is elongated and claw-like, toothed along the inner
margin. These appendages like the preceding have no exopodite, and
they do not differ in the two sexes to any appreciable extent.

"The succeeding thoracic appendages are similar to each other and
very much more slender than the preceding limbs; the proportionate
length of the joints is, however, the same, the second being, as in the
fossorial limbs, extremely minute. The spines with which the ter-
minal joints of these limbs are ornamented are also more slender than
those of the second pair of thoracic appendages.

"The abdominal appendages, with the exception of the uropoda,
are similar to each other: all the five pairs consist of an elongated
basal joint and of two subequal, rather shorter setose rami; the exopo-
dite is divided by a suture into two joints.

"The uropoda are short and biramose, with an elongated basal joint
and two rami, the outer is the shorter.

"Station 23, off Sombrero Island, March 15, 1873; latitude, 18 24'
north, longitude, 63 28' west; depth, 450 fathoms; Pteropod ooze."-
BEDDARD.

11. Genus SPHYRAPUS Norman and Stebbing.^

First two segments of thorax fused with the head to form a cara-
pace. Eyes absent. Second pair of antennae without scale. Exopods
present on first two pairs of legs. Gnathopods in male with carpus
and merus much more elongated than in female. Second pair of legs
in male of extraordinary length. Pleopoda well developed, with both
branches bi-articulate. Flagellum of first antenna in male with dense
bunches of sensory hairs.

Challenger Report, XVII, 1886, pp. 112-113.

ft See Sars' Crustacea of Norway, II, 1899, pp. 8-9, and Norman and Stebbing,
Trans. Zool. Soc. London, XII, 1886, p. 97, for characters of genus. Sars says that
only the first thoracic segment is fused with the head.

52

BULLETIN 54, UNITED STATES NATIONAL MUSEUM

SPHYRAPUS MALLEOLUS Norman and Stebbing.

Sphyrapm malleolus NOHMAN and STEBBING, Trans. Zool. Soc. London, XI1 ( 1886,
pp. 98-99, pi. xxu, figs. 2-3. BONNIER, Ann. de 1'Univers. de Lyons, XXVI,
1896, p. 665, pi. xxxi, fig. 1. RICHARDSON, American Naturalist, XXXIV,
1900, p. 212; Proc. U. S. Nat. Mus., XXIII, 1901, p. 505.

localities. South of Cape Farewell, Greenland; also latitude 39 39'
north, longitude 9 39' west, off coast of Portugal; latitude 45 57'
north, longitude 6 b 21' west; latitude 44 36' north, longitude 4 25'
west; south of Rockall; Bay of Biscay; Bay of Gascony; latitude 57
11' north, longitude 37 41' west.

FIG. 40. SPHYRAPUS MALLEOLVS (AFTER NORMAN AND STEBBING). a, SECOND LEG OR GNATHOPOD.
b, FIRST LEG OR GNATHOPOD. c, FIRST LEG. d, MALE, SEEN OBLIQUELY FROM ABOVE, e, FOURTH

LEG OB SECOND PERJiOPOD. /, THIRD LEG OR FIRST PER^EOPOD. g, MANDIBLE, h, FIRST LEG OR
GNATHOPOD OF FEMALE. /, AXTF.NN.K. SEEN FROM BELOW, j. TERMINAL SEGMENT OF ABDOMEN
WITH PLEOPOD AND BASE OF UROPODS, SEEN FROM THE SIDE, k, SEVENTH LEG OR FIFTH PER.Ko-

POD. I, FEMALE, SEEN FROM ABOVE, m, FIFTH LEG OR THIRD PER.EOPOD. n, FIRST LEG OR

GNATHOPOD OF FEMALE.

Depth. 1,450 fathoms; 1,410 meters and 650 meters; 740 fathoms.

"Rostrum short and obtusely pointed. Ophthalmic processes
minute, shaped like a baker's cap, and more easily seen from below
than from above. The confluent segments are both wider than the
head, and the second wider than the first: to the rear of these the

ISOPODS OF NORTH AMERICA. 53

animal tapers irregularly, the center person-segment being narrower
than its neighbor, as is also the case in S. titdes, and the pleon tapers
more suddenly than the perseon as far as the base of the sixth seg-
ment, the sides of which diverge to the point of insertion of the
uropods and then suddenly converge to a central and somewhat
upturned, much produced, apical process. Of the perseon- segments
the last two are the shortest. The first five segments of the pleon are
nearly equal in length to one another; only the second has lateral
spine-like processes, but here they are large, produced, and very
conspicuous.

"The upper antennae have the basal joint large, in the male stout,
shorter than the cephalic plate, in the female dilated at the base,
longer than the cephalic plate, in both ciliated on the margins; the
second joint is short, dilated distally; the third is about half the
length and breadth of the second; the flagellum consists of one long,
succeeded by four short, articulations; the secondary appendage is
rudimentary and represented by only one minute articulation. The
lower antennas have the basal joint as broad as it is long, the three
following joints short, the fifth long and slender, carrying on the
outer side two pear-shaped vesicles; the flagellum is three jointed,
the second and third joints furnished with long cilia.

"The first gnathopods have the soldered coxal portion folded beneath;
the basos broad and short, the ischium wanting; the meros narrow at
the base, then dilated, and ending in a point; the carpus in the male is
a little longer than the meros, which it overlaps; it is 1 pointed distally,
its sinuous margins are nearly parallel; upon it the huge hand is set
hammer-wise. In shape the hand is roughly triangular; a line from
the base of the finger to the stout horny thumb may be considered the
base of the triangle; along this (palm) margin is set a row of flat little
teeth, all but one or two of them lying closely side by side; one of the
sides of the triangle runs from the thumb-nail backward, receiving
the wrist in a sinuosity about the middle; the remaining side is formed
by the curved line running from the hinder extremity of the last-
described side to the base of the finger; the finger, which is short and
stumpy, with a nail like the thumb-nail, doubles closely down upon the
palm. In the female the wrist is considerably longer than in the male,
and is of the same breadth at both ends, but has a narrow neck near
its base; the hand in this sex is attached to the wrist by the apex of
the triangle; the thumb is a long process projecting from the base of
the triangle and causing the finger to project in like manner, and the
hand is thus of very different form from that of the male, being ovate;
the inner margins of both thumb and finger are irregular; the thumb
is truncate and has the horny nail set close to the outer margin; the
nail of the finger closes down into the cavity within the thumb-nail
and on the truncated end of the thumb.

54 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"The second gnathopods resemble those of Sphyrapus tudes^ but the
basos is narrower, being only slightly broader than the following
joints; the meros has one distal spine on the front margin, the wrist a
row of five spines, and the hand the same number; the linger is much
curved, slender, and its margin smooth.

"In the first perseopods the wrist is a little dilated, the hand flat,
long, curved, with seven slight spines on the front margin and much
ciliated on both margins.

"The second perseopods are shorter than any except the last; the
third have the hand short, distally dilated, and then surrounded by a
fence of biserrate spines of varying lengths. The fourth and. fifth
pairs are similar in form, but the fifth is smaller than the fourth; the
wrist is longer than the hand, which is small, ciliated, and has two
long spines near the base of the finger.

"The uropods have the peduncle as long as the segment, minus its
produced apex, and a little dilated distalh T ; the inner branch is long,
with about 15 articulations, which vary irregularly in length; the outer
branch is very slight and composed of 3 articulations. Judging from
the spirit-preserved specimens the uropods in this species would seem
to be carried divergently, not following behind parallel to each other.

" Sphyrapus malleolus may at once be distinguished from its allies,
not only by the form of the gnathopods, but by the rudimentary con-
dition of the inner flagellum of the upper antennae, which is reduced
to an unjointed minute tubercle and by the spine-formed wings of the
second segment of the pleon." NORMAN and STEERING. a

II. CYMOTHOIDEA or FLABELLIFERA.

Legs of the first pair not cheliform. Uropoda lateral and forming
with the last segment of the abdomen a caudal fan. Fleopoda for the
most part natatory.

ANALYTICAL KEY TO THE FAMILIES OP THE CYMOTHOIDEA OR FLABELLIFERA.

a. Legs in the adult in six, apparently only in five pairs Family III. GNATHIID^E

a' '. Legs in the adult usually in seven pairs.
b. Uropoda lateral and superior, outer branch arching over base of telson. Body

cylindrical, narrow, elongated Family IV. ANTHURID^E

b'. Uropoda lateral.

c. Abdomen usually composed of six segments.
d. Uropoda with both branches well developed; mostly lamelliform.
e. b Maxillipeds with the palp free, the margins of the last two articles more
or less setose, never furnished with hooks.

Trans. Zool. Soc. Lond., XII, 1886, pp. 98-99.

& Hansen's analytical key as translated by Stebbing has been inserted between
points e and d'. See Hansen, Vidensk. Selsk. Skr., 6th ser., natur. og Math. Afd. V,
1890, p. 317, and Stebbing, Hist, of Crustacea, 1893, pp. 340-341.

I8OPODS OF NORTH AMERICA. 55

/. Mandibles with the distal half stout, very conspicuous, or with only
the anterior margin concealed; from the base toward the middle
directed forward and a little outward.

g. Mandibles with the rather broad, more or less tridentate, cutting
edges meeting squarely behind the large upper lip; the secondary
plate and peculiar equivalent for the molar well developed. First
maxillae having the plate of the first joint armed with three spines,
that of the third with many. Second maxillae of moderate size,
the three free plates very setose. Maxillipeds with the palp rather

broad, very setose Family V. CIROLANID^E

g / . Mandibles with the distal part produced into a long prominent
process, the pair much overlapping; the secondary plate and
molar evanescent. First maxillae having the plate of the first joint
unarmed, of the third carrying one very long spine. Second
maxillae bifid, small and feeble, the free plates almost rudimen-
tary, with few setae. Maxillipeds with the palp narrowed, the

antepenultimate joint elongate Family VI. EXOCOBALLANID^E

/'. Mandibles with the distal half narrow, most or all of it concealed by
the upper and lower lips; from the base toward the apex gradually
directed inward. Mandibles usually without molar process. Apex
of second maxillae simple. Antepenultimate joint of maxillipeds not

elongate'. Family VII. CORALLANID.E

e/. Maxillipeds with the palp embracing the cone formed by the distal parts
of the mouth organs, the inner upper margin and apex never setose,
the apex and sometimes the inner upper margin, at least in the males
and females without eggs, being furnished with outward curved hooks.
/. Antennae of both pairs with well-defined peduncle and flagellum. Man-
dibles with the secondary plate very often visible; palp with no inflated
joint. Maxillipeds with the palp commonly composed of five articles,
sometimes composed of two articles, the last article in the latter case

rather short, obtuse Family VIII. JEGIOJE

f. Antennae much reduced, without clear distinction between peduncle
and flagellum. Mandibles with no secondary plate; palp in adults
with first joint or both first and second joints inflated. Maxillipeds
always with palp composed of two joints, last joint rather long and

narrow, subacute Family IX. CYMOTHOID.E

d f . Uropoda with one of the branches almost obsolete or rudimentary not

lamelliform Family X. LIMNORIID^E

c'. Abdomen composed of less than six segments.
d. Abdomen composed of two segments. Uropoda with one branch fixed,

immovable Family XI. SPH^ROMID*

d'. Abdomen composed of four segments. Uropoda with both branches mov-
able Family XII. SEROLID^:

Family III. GNATHIIDJE."

Thorax with only five pairs of normal walking legs in the adult.
Last pair of legs wanting. First pair of legs modified; in male they
are valve-like, arching over the ventral side of the head; in the female
they are smaller and more distinctly segmented; in the larval form

"See Sars's Crustacea of Norway, II, 1899, p. 50, and Harger, Report U. S. Comm.
of Fish and Fisheries, 1880, Pt. 6, pp. 408-410, for characters given below.

56 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

they terminate in a strong hook. Head of adult male armed with
powerful forward-projecting curved jaws or mandibles. First seg-
ment of thorax is united with the head, but separated by a suture line.
Seventh thoracic segment small, resembling those of abdomen. Abdo-
men abruptly narrower than thorax and composed of six segments.
Mandibles wanting in female. No true incubatory pouch present.
Oral parts in female reduced to maxillipeds only; in male to mandibles
and maxillipeds. Sexes very different in appearance. Body of male
depressed and dilated in front; that of female more or less fusiform.
Larval form also different, but resembling female.

12. Genus GNATHIA Leach.

Head of male large, subquadrangular. Head of female rather
small, subtriangular. Thorax composed of five well -developed seg-
ments, the other two segments being rudimentary, the first being
fused with the head and the seventh placed between the project-
ing lateral parts of the fifth segment. First pair of legs in male
operculiform, composed of two articles; those of female subpediform,
being divided into three or four articles. There are five pairs of
ambulatory legs. Abdomen much narrower than the thorax. Man-
dibles present in male, more or less flattened and projecting anteriorly
beyond the head. Maxillipeds without epignath; palp composed of
four articles.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS GNATHIA.

a. Mandibles in male with the basal part ornamented on the superior margin with
an elevated crest, which is irregularly dentate. Legs furnished with many

spiny processes ' Gnathia criMata ( Hansen)

a' . Mandibles in male without elevated crest on the superior margin. Legs without

spiny processes.

b. Mandibles in male with slight notch outside, inner edge obtusely produced in
the middle, tip acute, slightly incurved. Front of head not produced in the

middle beyond the antero-lateral angles Gnathia elongata (Kr0yer)

b f . Mandibles in male carinate on outer side near the middle, the carina ending in
a tooth-like process, irregularly and bluntly toothed near the base within,
turned upward at apex. Front of head produced in the middle much beyond
the antero-lateral angles Gnathia cerina (Stimpson)

GNATHIA CRISTATA (Hansen).

Anceus cristatus HANSEN, Vidensk. Meddel. Naturh. Foren. i. Kj0bh., 1887-1888,

p. 182, pi. vn, fig. 2-2a.
Gnathia cristata RICHARDSON, American Naturalist, XXXIV, 1900, p. 214;

Proc. U. S. Nat. Mus., XXIII, 1901, p. 506.

Locality. Latitude 72 32' north, longitude 58 51' west.
Depth. 116 fathoms.

See Sars's Crustacea of Norway, II, 1899, p. 50, and Harger, Report U. S. Comm.
of Fish and Fisheries, 1880, Pt. 6, pp. 408-410, for characters given below.

ISOPODS OF NORTH AMERICA.

57

Description of male. This species is closely related to Gnathia
hirsuta (Sars), but differs from all other species of the genus in the
structure of the mandibles.

The body is very short; the thorax is a little narrower than long in
the median line. The fourth free segment of the thorax (fifth seg-
ment) is scarcely longer than the fifth segment. The fifth free seg-
ment (sixth segment) has large lateral areas,
posteriorly very much elongated, with the
posterior angles subrotund.

The abdomen in the specimen is almost
entirely wanting.

The head and the first two free segments
of the body are very rough and ornamented
with acute processes and numerous tuber-
cles; the third free segment (fourth seg-
ment) is ornamented with smaller tubercles
at the anterior portion, but is smooth poste-
riorly; the fourth free segment (fifth seg-
ment) has large swollen lateral areas, orna-
mented with a few tubercles, the median
part being smooth; the fifth free segment
(sixth segment) is smooth. The eyes are
rather large, manifest. The mandibles are
large, ornamented on the basal half of the superior margin with a very
high crest irregularly notched or dentated. The teeth of the crest
have the apex rounded.

The legs are long, rather robust, furnished with many processes, for
the most part, large. The body and the legs are furnished with a few
hairs. Length of the head and thorax together 3.1 mm.

Only a single mutilated specimen/'

The above description is adapted from the following description of Hansen's:
Specimen singulum masculinum sat mutilatujn vidi. Anceo hirsute G. O. Sars
sat affinis, structura mandibularum a speciebus omnibus mihi cognitis diversus.
Corpus brevius; truncus paulo augustior quam in linea media longior. Segmentum
quartum liberum trunci segmento quinto vix longius; segmentum quintum areis
lateralibus magnis, post valde elongatis, angulis posterioribus subrotundatis. (Cauda
in specimine fere tota deest. ) Caput et segmenta duo anteriora libera trunci scabra,
processulis acutis et tuberculis permultis ornata; segmentum tertium liberum ante
tuberculis minoribus instructum, postice glabrum; segmentum quartum area laterali
magna, inflata, tuberculis nonnullis decorata, parte media glabra; segmentum quin-
tum glabrum. Oculi sat magni, dilutiores. Mandibulse rnagnse, parte dimidia basali
marginis superioris crista valde elevata et irregulariter inciso-dentata ornata; dentes
cristee apice rotundato. Pedes longi, sat robusti, processulis multis, ex parte magnis,
muniti. Corpus pedesque setis nonnullis instructa. Long, capitis et trunci juncti 3,
1 mm. HANSEN, Vidensk. Meddel. Naturh. Foren. i Kj0bh., 1887-88, p. 182.

FIG. 41. GNATHIA CKISTATA
(AFTER HANSEN). a, RIGHT MAN-
DIBLE (INNER SIDE), b, MALE

(SOMEWHAT MUTILATED) (EN-
LARGED.)

?

LIBRARY.

58

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

GNATHIA ELONGATA (Krjtfyer).

Anceus elongatus KR0YER, Voy. en Scand., Crust., 1849, pi. xxx, fig. 3a-g; Naturh.

Tidsskr. (2), II, 1846-49, pp. 388-394. HANSEN, Dijmphna-Togtets Zool.-

bot. Udbytte, 1887, p. 205; Vidensk. Meddel. Naturh. Foren. i Kj0bh.,

1887-88, p. 182.
Gnathia elongata G. O. SARS, Crust, of Norway, II, Isopoda, 1899, p. 55, pi. xxm,

fig. 1. RICHARDSON, American Naturalist, XXXIV, 1900, p. 214; Proc. U. S.

Nat. Mus., XXIII, 1901, p. 507. AXEL OHLIN, Bihang till K. Sv. Vet.-Akad.

Handl., XXVI, Afd. iv, "So. 12, 1901, pp. 20-21.

PIG. 42. GNATHIA ELONGATA (AFTER SAKS), a, FIRST AND SECOND ANTENNA, b, DORSAL VIEW OF
MALE, c, DORSAL VIEW OF FEMALE, d, SECOND LEG. e, MANDIBLE. /, PLEOPOD. g, LAST SEG-
MENT OF ABDOMEN WITH UROPODA. h, MAXILLIPED OF MALE, i, DORSAL VIEW OF YOUNG, j, FIRST
LEG OF MALE, k, FIRST LEG OF FEMALE. I, MAXILLIPED OF FEMALE.

Localities. West Greenland; also coast of Finmark; Lofoten Islands;
Kara Sea; King Charles Island; Bremer Sound; latitude 78 50' north,
longitude 29 39' east, King Charles Island (Ohlin).

Depth. 49-55 fathoms (Hansen)- 60-110 m. (Ohlin).

ISOPODS OF NORTH AMERICA. 59

Found in soft clay with great stones; soft, black-grayish clay.

"Male: Body rather elongated, with the mesosome of nearly uni-
form breadth throughout, and the median constriction not very much
pronounced. Cephalosome of moderate size, rounded quadrangular,
with the supraocular processes well denned. Dorsal face of both
cephalosome and mesosome very uneven, with irregular depressions,
and clothed all over with minute spinules and short hairs. Penulti-
mate pedigerqus segment divided dorsally by a narrow longitudinal
groove into two halves. Metasome comparatively narrowband scarcely
longer than the two posterior pedigerous segments combined; epimera
small. Eyes well developed, though not very large. Mandibles com-
paratively small, with only a very slight notch outside; inner edge
obtusely produced in the middle, tip acute, slightly incurved. Perio-
poda with small tubercles inside the outer joints. Terminal segment
of metasome considerably narrowed in its outer part, which is conical
in shape. Uropoda with the rami comparatively narrow. Female:
Body much broader than in male, with the last three pedigerous seg-
ments well-defined, and together forming an oblong oval division
about three times as long as that preceding it. Cephalosome with the
frontal part slightly produced and bidentate at the tip. Pleopoda in
both sexes with the rami quite smooth, forming narrow sac-like plates
not fitted for swimming but apparently respiratory in character.
Color of male gra\ T ish white, with a light bluish tinge; of female,
yellowish, semipellucid, with scattered brown dots. Length in both
sexes, 4 mm." G. O. SARS. a

Ohlin 6 also describes the color of the male as grayish white, that of
the female wax-like yellow, and that of the larvae yellowish-white or
nearly white. The eyes are in all red-brownish.

Sars states that the adult animal is very sluggish in habit, the struc-
ture of the pleopoda showing it to be quite unable to swim. The
larvae, on the other hand, move through the water with great agility,
and most probably at times lead a parasitic life on the skin of various
fishes.

GNATHIA CERINA ( Stimpson ) . e

Praniza cerina STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853,

p. 42, pi. m, fig. 31.
Anceus americanus STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853,

p. 42.
Praniza cerina VERRILL, Am. Jour. Sci. (3), VI, 1873, p. 439; VII, 1874, pp.

38, 41, 411, 502; Proc. Am. Assoc., 1873, pp. 350, 354, 358, 362 (1874).
Gnalhia cerina HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 162; Report U. S.

Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 410-413, pi. xn, figs.

75-79. RICHARDSON, American Naturalist, XXXIV, 1900, p. 214; Proc.

U. S. Nat. Mus., XXIII, 1901, p. 507.

Crust, of Norway, II, 1899, p. 55.

&Bihangtill K. Sv. Vet.-Akad. Handl., XXVI, Afd. iv, No. 12, 1901, pp. 20-21.

c See Harger for excellent description of male, female, and larva.

60

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Localities. Bay of Fundy; Massachusetts Bay; off Salem; Gulf of
Maine; Casco Bay; Gulf of St. Lawrence; Eastport, Maine; off Sable
Island; La Have Bank; South of Martha's Vineyard.

Depth. 10-487 fathoms, in mud, gravel, stones, sand, and rocky
bottom. On sculpin, on cod, and on LopJwlielia (Harger).

Description of male. Body oblong-ovate,
more than twice as long as wide, 1^ mm. :4 mm.
Head large, a little wider than long, 1 mm. :
li mm., with the anterior margin produced in
a prominent rounded median lobe and the antero-
lateral angles acutely produced. The eyes are
small, round, composite, and situated at the
sides of the head at the base of the antero-
lateral lobes. The first pair of antennae have
the first two articles subequal; the third article
is as long as the first two taken together. The
flagellurn is composed of four articles. The
first pair of antenna? extend to the middle of
the fourth article of the second antenna?. The
first two articles of the second pair of antennae
are subequal; the third article is a little longer than the second; the
fourth is nearly twice as long as the third. The flagellum is composed
of seven articles. The mandibles are large and powerful and extend
conspicuously in front of the head. The palp of the maxillipeds is
composed of four articles.

The first segment of the thorax is small and almost inconspicuous,

FIG. 43. GNATHIA CERINA
(AFTEE HARGER). MALE.

a b c d e f

FIG. 44. GNATHIA CERINA. a, LEG OF FIRST PAIR OF MALE, x 61|. 6, MAXILLIPED. x 51|. c, SECOND

ANTENNA (MALE). X 51f. ' d, FIRST ANTENNA. X 51|. 6, MANDIBLE. X 51f. /, FIRST LEG OF
LARVA. X 51|.

rudimentary, and consolidated with the head. The second and third
segments of the thorax are subequal; the fourth segment is a little
longer than either of the two preceding segments; the fifth and sixth
are subequal, and are both longer than the fourth segment; the seventh
segment is abruptly narrower than the sixth segment and is very

I80PODS OF NORTH AMERICA. 61

short, being only as long as the first abdominal segment, and narrower,
about one-third as wide as the sixth thoracic segment; it could easily
be taken for one of the abdominal segments.

The first five segments of the abdomen are short, distinct, and sub-
equal in length; they are but little wider than the seventh thoracic
segment, but abruptly narrower than the sixth thoracic segment.
The sixth or terminal segment is triangular in shape, with apex very
acute. The uropoda extend to the extremity of the abdomen. The
inner branch is a little wider and a very little longer than the outer
branch. Both are narrow, elongate, with extremities obliquely trun-
cate, the post-lateral angles being rounded.

There are apparently only five pairs of thoracic legs. The first
pair are modified and opercular, and are composed of only two arti-
cles. The seventh pair are wanting. The remaining five pairs are
ambulatory.

Description of female. Body ovate, about twice as long as wide,
2 mm. :4 mm. Head smaller than in male, with the front produced in
a lobe which is emarginate in the middle. Eyes
small, round, composite, and situated at the
post-lateral angles of the head. Antennae of
both pairs as in male.

The first segment of the thorax is short and
narrow and almost inconspicuous, appearing as
a small lobe back of the head. The thorax
becomes wider with the second thoracic seg-
ment. The second and third segments are short
and about equal in length. The fourth and
fifth are very long, many times longer than the FlG- 45- ~ GNATHIA

' . (AFTER HARDER). FEMALE.

preceding segments and scarcely to be distin-
guished, being somewhat fused dorsally. They are nearly subequal.
The sixth segment is about half as long as the preceding segment, and
becomes gradually narrower from the anterior to the posterior extrem-
ity. This segment is also somewhat fused dorsally with the preceding
segment. The seventh segment is very short and narrow and not to
be distinguished from the abdominal segments, being of the same length
as the five anterior abdominal segments, but narrower.

The abdomen is similar to that in the male. The five posterior
pairs of walking legs are similar to those in the male. The first pair of
legs are composed of three articles and terminate in a minute rounded
lobe. There is a delicate membraneous plate attached to the base of
the first pair of legs.

The eggs are very clearly seen in the cavity of the thorax, which
they almost completely fill.

Body of female smooth throughout its entire length!

62

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 46. GNATHIA CEEINA
(AFTER HARGEK). LARVA.

Description of larva. Body oblong-ovate, three times as long as
wide, \\ mm. : 4i mm.

Head small, about i mm. long and mm. wide at the base, with the
front produced in a small truncated lobe. The eyes are large, round,

composite, situated at the sides of the head
and occupying almost the whole of the lateral
margin. The first and second antennae are
about as in the male.

The first segment of the thorax is rudimen-
tary and consolidated with the head. The
second and third segments of the thorax are
short and subequal; the fourth and fifth seg-
ments are united into one extremely long
segment, which is also wider than the two
preceding segments. The sixth segment is
short and gradually decreases in width, at its
anterior extremity being almost as wide as
the preceding elongated segment, but at its
posterior extremity being almost as narrow
as the abdomen. The seventh segment is
similar to the abdominal segments.

The abdomen is about \ mm. wide. The first five segments are sub-
equal. The sixth or terminal segment and the uropoda are as in the
male.

There are apparently but five pairs of legs. The first pair of legs
are small and surround the mouth; they are composed of six articles.
The seventh pair is wanting.

The mouth parts project conspicuously in front of the head.

Family IV. ANTHURID^.

Body long and narrow, nearly cylindrical in form. Head compara-
tively small. Segments of thorax well defined and without distinct
epimera. Abdomen comparatively short, with the anterior segments
sometimes completely or partially fused. Mouth parts modified for
suction. First pair of legs larger and stronger than the others and
subchelate; the two following pairs also subchelate, but smaller and
more feeble; the four posterior pairs ambulatory. First pair of pleo-
poda large and expanded, more or less covering the others, especially
in female. Uropoda with the outer or superior branch arching over
the base of the telson.

See Sars, Crust, of Norway, pp. 43-44, and Norman and Stehbing, Trans. Zool.
Soc. Lond., XII, 1886, Pt. 4, pp. 119-120, for characters of family.

ISOPODS OF NORTH AMERICA. 63

ANALYTICAL KEY TO THE GENERA OF THE FAMILY ANTHURID^.

a. Labium terminating in two rounded lobes. Mandibles with cutting edge com-
posed of two or three blunt teeth. First maxillae simple, terminating in con-
spicuous and well-developed teeth. Maxillipeds with palp composed of one to
four articles.

b. First five segments of abdomen coalesced into a single segment in the female.
Maxillipeds with palp composed of two articles. Flagella of both pairs of
antennae rudimentary in both sexes. Flagellum of first pair not greatly devel-
oped in male Genus Cyathura Norman and Stebbing

b'. Segments of abdomen distinct in the female.

c. Maxillipeds with the palp composed of a single article. Flagella of both pairs
of antennae in the female composed of only a few articles. In the male the
first pair has a multi-articulate flagellum. Mandible with a one-jointed

palp Genus Ptilanthura Harger

cf. Maxillipeds with a palp composed of four articles. Flagella of both pairs
of antennae multi-articulate; that of first pair in the male developed into a
remarkable brush-like organ. Mandible with a three-jointed palp.

Genus Anthelura Norman and Stebbing

a'. Labium terminating in two points, acuminate. Mandibles without teeth, ter-
minating in an acutely pointed lancet-like organ. First maxillae simple, spear-
like, terminal part armed with recurved teeth. Maxillipeds with basal part
narrow, oblong; palp composed of three articles. Segments of abdomen dis-
tinct in female.
b. All seven pairs of legs present in adult. Seventh thoracic segment normal,

well developed.
c. Both pairs of antennae in both sexes with multi-articulate flagella.

Genus CaJathura Norman and Stebbing

c f . First pair of antennae in both sexes have the flagellum multi-articulate.
Second pair of antennae in both sexes have a rudimentary flagellum com-
posed of a single article Genus Paranthura Bate and Westwood

b / . Seventh pair of legs absent in adult. Seventh thoracic segment very short,
abruptly narrower than preceding sixth segment and not as wide as the
abdominal segments. First pair of antennae composed of four articles, the
last article being the rudimentary flagellum. Second pair of antennae com-
posed of five articles Genus Colanthura Richardson

13. Genus CYATHURA Norman and Stebbing. &

First five segments of abdomen coalesced into a single segment in
the female. Flagella of both pairs of antennae rudimentary. Maxilli-
peds with a palp composed of two articles. Mouth parts otherwise as
in Ptilanthura and Anthelura.

CYATHURA CARINATA (Krjziyer).c

? Anthura gracilis DE KAY, Zool. New York, Crust, 1844, p. 44, pi. ix, fig. 34.
Anthura carinata KR0YER, Naturh. Tidsskr. (2), II, 1846-49, p. 402; Voy. en
Scand., 1849, pi. xxvii, fig. 3.

"Norman and Stebbing' s key has been used with slight modifications. See Trans.
Zool. Soc. Lond., XII, 1886, Pt. 4, pp. 121-122.

&See Norman and Stebbing, Trans. Zool. Soc., Lond., XII, 1886, Pt. 4, p. 121, for
characters of genus.

c Norman and Stebbing give an excellent description of this form.

64

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Anthura polita STIMPSON, Proc. Acad. Nat. Sci7, Phila., VII, 1856, p. 393.
Anthura carinata SCHICEDTE, Naturh. Tidsskr. (3), X, 1875-76, p. 211, pi. iv,

figs. 1-14.
Anthura brunnea HARGER, with VERRILL, Report U. S. Commissioner of Fish

and Fisheries, Pt. 1, 1873, p. 572 (278); p. 426 (132).
Anthura carinata SCHKEDTE, Ann. Mag. Nat. Hist. (4), XVIII, 1876, p. 253.

MEINERT, Naturh. Tidsskr. (3), XI, 1877, p. 77.
Anthura polita HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 162; Report U. S.

Commissioner of Fish and Fisheries, Pt. 6, 1880, pp. 398-402, pi. xi, figs.

68-69.

Anthura carinata MEINERT, Naturh. Tidsskr. (3), XII, 1880, p. 470.
Cyathura carinata NORMAN and STEBBING, Trans. Zool. Soc. Lond., XII, 1886, Pt.

4, pp. 124-125.
Anthura carinata KUHLGATZ, Wissenchaftliche Meeresuntersuchunger, III, 1898,

pp. 148-149, pi. in, figs. 4-19.
Cyathura carinata RICHARDSON, American Naturalist, XXXIV, 1900, p. 215;

Proc. U. S. Nat. Mus., XXIII, 1901, p. 508.

Localities. Norfolk, Virginia; Great Egg Harbor, New Jersey; Long
Island Sound; Noank Harbor, Connecticut; off Block Island; East

Providence, Rhode Island; Vineyard
Sound; Gloucester, Massachusetts;
Greenland; Denmark; Kielerbucht,
Germany (Karl Moebius).

Depth. Surface to 19 fathoms,
in shells and mud, eel-grass and algae,
sand and stones. (Harger.)

Body very narrow, elongate, a lit-
tle more than seven times longer
than wide, 2 mm. : 15 mm.

Head a little wider than long, 1
mm. : 1| mm., with the anterior mar-
gin excavate on either side of a small
median point. Eyes small, distinct.
The first pair of antennae have the
first two articles about equal in
length; the third article is a little
shorter than the second; the fourth
or flagellar article is about half as
long as the third. The first antennae
extend to the end of the fourth arti-
cle of the second antennae. The
second pair of antennae have the
basal article short; the second article

is about twice as long as the first; the third article is half as long as
the second; the fourth is a little shorter than the third; the fifth is one
and a half times longer than the fourth; the sixth or flagellar article is
very short and is about half as long as the fifth. The second antennae

FIG. 47. CYATHURA CARINATA (AFTER
HARGER). a, FIRST ANTENNA, x 10. 6,
SECOND ANTENNA, x 10. c, FIRST LEG. x
8. d, THIRD LEG. x 8. e, FIRST PLEOPOD.
x 8. /, SECOND PLEOPOD OF MALE, x 8.
g, LATERAL VIEW OF ABDOMEN, x 6.

ISOPODS OF NORTH AMERICA.

65

FIG. 48. CYATHUKA CARINATA. a, MANDIBLE.
x 51|. 6, MAXILLIPED. x 51f. c, FIRST
MAXILLA, x 51|.

are H ram. long. The maxillipeds have a palp of two articles. The
palp of the mandibles is composed of three articles.

The first, fourth, and fifth segments of the thorax are 2 mm. in
length. The second and third segments are H nim. long. The sixth
and seventh segments are each 1
mm. long. The epimera are long
and extremely narrow plates extend-
ing the entire length of the seg-
ments and not separated off by dis-
tinct sutures.

The entire length of the abdomen
is 3-J mm., or a little less than one-
fifth the entire length of the body.
The first six segments are -fused
into a single segment about li mm.
long, which has no trace of suture
lines. The seventh segment or tel-
son is narrow, elongate, and rounded posteriorly. The peduncle of
the uropoda is as long as the superior branch and extends two-thirds
the length of the telson. The inner, lateral branch is placed at the
posterior end of the peduncle and is rounded posteriorly; it extends
the remaining third of the length of the telson and reaches the
extremity of that segment. The dorsal or superior branch does not
arch over the telson, but lies directly upon its dorsal surface; it
extends to the end of the peduncle, is somewhat triangular in shape,

narrow and elongate, with apex acute.
The first three pairs of legs are pre-
hensile. All the others are ambula-
tory in structure. The first pair are
larger and stronger than the two follow-
ing pairs, and there is a tooth on the
inferior margin of the propodus.

Three specimens one from Marco,
Florida, another from Cedar Keys,
Florida, and a third from off South
Carolina differ from the other speci-
mens in the collection, in having the
last article of the first pair of antennae
as long as the third; in having a
rounded prominence instead of a tooth on the propodus of the first
pair of legs; in having the anterior segments of the abdomen quite
apparent at the sides, though fused and not apparent in the middle
of the dorsal surface; in having the peduncle of the uropoda about
half the length of the telson instead of two-thirds its length, the inner
branch being as long as the peduncle; in having the fourth, fifth, and
2858905 5

a be

FIG. 49. CYATHURA CARINATA. a, FIRST
LEG. x Hi. 6, FIRST ANTENNA, x 20i.
c, SECOND ANTENNA, x 20.

06 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

sixth segments of the thorax subequal and each about one-half mm.
longer than any of the other segments, which are about subequal,
and in having the second article of the palp of the maxillipeds quad-
rate and as large as the first article of the palp.

FIG. 50. CYATHURA CARINATA (AFTER NORMAN AND STEBBING). a, FIRST GNATHOPOD. 6, LOWER

ANTENNA. C, MAXILLIPED. d, LABIUM. 6, FIRST MAXILLA. /, END OF TELSON. g, UPPER ANTENNA.

h, MANDIBLE AND PALP.

14. Genus PTILANTHURA Harger.

First live segments of abdomen distinct in the female and in the male.
The flagella of both pairs of antennae in the female are composed of
only a few articles. In the male, the first pair has a multiarticulate
flagellum. The maxillipeds have a palp of one article, which is broad
and flattened and similar to the basal article; epignath small, rounded.
Labium terminating in two broadly rounded lobes. First maxillae ter-
minating in well-developed teeth. Mandibles with a palp composed of
a single article.

PTILANTHURA TENUIS Harger. b

PtUanthura tennis HARGER, Am. Jour. Sci. (3), XV, 1878, p. 377; Proc. U. S.
Nat. Mus., 1879, II, p. 62; Report U. S. Commissioner of Fish and Fisheries,
1880, Pt. 6, pp. 406-408, pis. xi, xn, figs. 71-74.

See Harger, Report IT. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, pp.
405-406, for characters of genus.

6 See Harger for complete description of this species.

ISOPODS OF NORTH AMERICA.

67

Anthura tennis NORMAN and STEBBING, Trans. Linn. Soc. London, XII, 1886,
Pt. 4, p. 124. RICHARDSON, American Naturalist, XXXIV, 1900, p. 215;
Proc. TJ. S. Nat. Mus., XXIII, 1901, p. 508.

Ptilanthura tehuis STEBBING, Willey's Zool. Results, 1902, p. 619.

Localities. Noank Harbor, Connecticut; Long Island Sound; off
Watch Hill, Rhode Island; off Block Island; Waquoit, Vineyard Sound;
Casco Ba} T , Maine; Bay of Fundy;
Grand Menan, New Brunswick.

Depth. Surface to 19 fathoms.
Taken on muddy bottom; in sand,
mud, and stones; at low water, in sand.
Body extremely narrow, elongate,
about eight times longer than wide,
1 mm. : 8| mm. Head about as wide
as long, with the anterior margin tri-
angularly produced in a small median
process. Eyes small, round, distinct,
and situated in theantero-lateral angles
of the head. The second pair of an-
tennae have the basal article short; the
second article is twice as long as the
first; the third and fourth are short and
subequal, both together being as long
as the basal article; the fifth is twice
as long as the fourth; the flagellum is
composed of four articles, the first of
which is about half as long as the last
peduncular article. The second pair

of antennae extend to the end of the fourth article of the peduncle
of the first pair of antennae. The first pair of antennae have the first
article long; the second and third are subequal and
each is a little longer than the first. The first article
of the flagellum is very short, about one-third as
long as the second peduncular article; the second
article of the flagellum is about twice as long as the
first. The flagellum is composed of twenty-one arti-
cles, which are furnished with long hairs. The first
antennae are 2 mm. long. The maxillipeds have
a palp of one article. The palp of the mandibles is
composed of one article.

The first, second, third, and sixth segments of the thorax are sub-
equal, each being 1 mm. in length. The fourth and fifth segments are
a little longer. The seventh segment is half a mm. long.

The first six segments of the abdomen are short, distinct, and sub-
equal, with the exception of the last, which is about half as long as
any of the five preceding ones. The seventh segment or telson is long

FIG. 51. PTILANTHURA TENUIS (AFTER
HARGER). a, HEAD WITH ANTENNAE AND

FIRST THORACIC SEGMENT (VENTRAL

SIDE), x 8. b, MAXILLIPED. x 50. r,

FIRST MAXILLA, d, FIRST PLEOPOD.

x 20. e, SECOND PLEOPOD OF MALE.
x 20.

FIG. 52. PTILANTHURA
TENUIS. MANDIBLE.
X 77.

68 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

and narrow, with the extremity rounded. The peduncle of the uro-
poda is short and extends only half the length of the telson. The
inner lateral branch is placed at the extremity of the peduncle; it does
not quite reach the extremity of the telson, and is posteriorly rounded.

FIG. 63. PTILANTHURA TENUIS. o, FIRST LEG. x 51|. b, FIRST ANTENNA, x 27}. c, SECOND

ANTENNA. X 51|. d, MAXILLIPED. X 51|. , FIRST MAXILLA. X 51|. /, MANDIBLE (WITHOUT

PALP), x 61|.

The outer and superior branch extends to the end of the peduncle and
is somewhat triangular in shape, with apex acute.

The first three pairs of legs are prehensile, the first pair being much
larger and stouter than the two following pairs. All the others are
ambulatory.

IS. Genus ANTHELURA Norman and Stebbing.

Segments of abdomen distinct in female. Flagella of both pairs of
antennas multi-articulate; that of first pair "in the male developed into
a remarkable brush-like organ nearly equal in length to half the animal,
and composed of very numerous, short, broad, and densely ciliated
joints." Maxillipeds with a palp composed of four articles. Mouth
parts otherwise as in Cyathura.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ANTHELURA.

a. Uropoda with the outer and upper plates wide apart dorsally, broadly triangular
or spear-shaped, nearly as long as the inner plate, which is similar in form but
narrower. Telson broadly lanceolate, apex rather acute, about equal in length
to the uropods Anthelura abyssorum Norman and Stebbing

a'. Uropoda with the outer and superior branches meeting dorsally, long, oval in
form. Inner branch with posterior margin widely rounded. Telson narrowly
linguiform, roundly triangular at the apex. Outer and superior branch as long
as telson. Inner branch extending beyond telson. .Anthelura affinis Richardson

a See Norman and Stebbing for characters of genus. Trans. Zool. Soc., Lond.,
XII, 1886, Pt. 4, p. 121.

ISOPODS OF NORTH AMERICA.

69

ANTHELURA ABYSSORUM Norman and Stebbing.

AnLhelura abyssorum NORMAN and STEBBING, Trans. Zool. Soc. Lond., XII, 1886,
Pt. 4, pp. 127-128, pi. xxvn, fig. 2. HANSEN, Videnskabelige Meddelelser
fra den Naturhistoriske Forening i Kj0benhavn, 1887-1888, p. 181. RICH-
ARDSON, American Naturalist, XXXIV, 1900, p. 215; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 508.

Localities. Near entrance of
Davis Straits; latitude 59 10'
north, longitude 50 25' west.

Depth. 1,750 fathoms.

"Head and peraeon of nearly
equal width throughout; second
segment of the latter scarcely
at all constricted behind. The
whole of the segments smooth
above, and devoid of all furrow-
ing and pitting; last segment of
peraeon half as long as the pre-
ceding segments of pleon, very
clearly defined, and (exclusive of
telson) subequal in length to
penultimate segment of peneon.

"The antennae have the joints
of the peduncle in both pairs flat-
tened, the lower pair touching
each other with the compressed
inner margins, and appearing
between the upper pair, as in
Anthelura elongata; flagella of
both pairs many jointed.

"First gnathopods having ba-
sos short and very thick; ischiuni
scarcely longer, and not so broad;
cup of meros well rounded; car-
pus small as usual, bearing five
or six spine-like setae; hand about
twice as long as greatest breadth;
palm concave, bearing about eight
slender spine-like setae.

"Second gnathopods having
basos and ischium more slender
than in first pair; meros of similar form; carpus edged with several
spine-like setaa and one spine; hand elongate-ovate, palm with three
spines and a few setae.

FIG. 54. ANTHELURA ABYSSORUM (AFTER NORMAN
AND STEBBING). a, LATERAL VIEW. 6, HEAD

(FROM ABOVE). C, UPPER ANTENNA, d, LOWER

ANTENNA, e, FIRST GNATHOPOD. f, SECOND

GNATHOPOD. g, FIFTH PERjEOPOD. A, ABDOMEN
(FROM ABOVE). t' v ABDOMEN (FROM THE SIDE).

70

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

" Last peraeopods having the propodus
half as long again as the carpus, and the
dact3 T los subequal to the carpus; carpus
and propodus each furnished with two
forked spines on their anterior margin.

"First pleopods large, covering the
whole of the remaining pleopods, against
which they are closely pressed.

"Uropods with outer and upper plates
wide apart dorsally, broadly triangular or
spear-shaped, longer than wide, and as
long or nearly as long as the inner plate,
which is very similar in form but narrower,
with well-rounded extremities; both are
tipped with a few setae, which are, how-
ever, very easily abraded.

"Telson much depressed, broadly lance-
olate, apex rather acute, about equal in
length to the uropods.

''Length, 9 mm., or about three-six-
teenths of an inch." NORMAN and STEB-

FIG. 55. ANTHELURA AFFINIS. a,
SIXTH PERIOPOD. b, SECOND GNATH-
OPOD. c, FIRST GNATHOPOD. d,
GENERAL FIGURE.

ANTHELURA AFFINIS Richardson.

Anthelura affinis RICHARDSON, Trans. Conn.
Acad. Sciences, XI, 1902, pp. 288-289,
pi. xxxviu, figs. 29-32.

Locality. Bermudas.

Body narrow, elongate. Head with
small median point. Eyes distinct, situ-
ated in antero-lateral angulations.

Antennae of both pairs with flagella con-
sisting of several joints, and fringed with
long hairs at the tip. Maxillipeds con-
sist of five joints.

First three thoracic segments about
equal in length. Three following seg-
ments somewhat longer, and subequal.
Seventh segment fully half the length of
preceding segment.

All the segments of the abdomen dis-
tinctly defined. Terminal segment nar-
rowly linguiform, roundly triangulate at
the apex and with smooth margins.

Outer superior branch of uropoda long,
oval, reaching quite to the extremity of

"Trans. Zool. Soc. Lond.. XII, 1886, Pt. 4, pp. 127-128.

I8OPODS OF NORTH AMERICA. 7l

the terminal abdominal segment, and arching over the telson. Inner
branch with posterior margin widety rounded and extending beyond
telson. Both branches have the margins smooth, entire.

First gnathopods with small hand. Dactylus short. Free inner
margin of propodus furnished with hairs. Second gnathopods and
first periopods similar in shape to, but smaller in size than first pair
of gnathopods. The free inner margin of the propodus is beset with
two spines, the carpus with one spine. The remaining periopods
have a single spine at the distal margin of the propodus and two
spines on the carpus.

One specimen, a female, was collected by Prof. A. E. Verrill at the
Bermudas in 1901.

Type in Peabody Museum of Yale University. Cat. No. 3349.

This species differs from A. elongata Norman, in the shape of the
outer branch of the uropoda; in the length of both branches, as com-
pared with the terminal abdominal segment, and in the fact that the
margins of the outer branch in this species are smooth and not cren-

ulate, as in A. elongata.

16. Genus CALATHURA Norman and Stebbing.

Abdomen short with the segments not very distinctly defined in the
male, but distinct in the female. Both pairs of antennae in both sexes
with multi-articulate flagella. Buccal mass projecting, cone-shaped.
Anterior lip terminating in an obtusely conical point. Posterior lip
slightly bifid at the tip. Anterior maxillae simple, spear-like; termi-
nal part armed with recurved teeth. Maxillipeds with the basal part
narrow, oblong; palp composed of three articles; epignath small,
rounded. Mandibles terminating in an acutely-pointed lancet-like
organ.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CALATHURA.

a. Eyes not conspicuous. First pair of antennae with flagellum twelve jointed, not
longer than the length of the head. Second pair of antennge with the flagellum
twelve jointed. First three segments of thorax bounded laterally by carin.
Terminal segment of body triangular, acute at apex, margin not crenulate.
Superior or outer branch of uropoda oval in form, slightly dentated. Inner
branch acutely triangular Calathura brancldata (Stimpson)

of . Eyes conspicuous. First pair of antenme with flagellum seventeen jointed, more
than twice as long as the length of the head. Second pair of antennae with the
flagellum twenty-three jointed. First three segments of thorax not bounded
laterally by cariiue. Terminal segment of body linguate, rounded posteriorly,
with crenulate margin. Superior or outer branch of the uropoda narrow, elon-
gated, not dentated. Inner branch rounded.

Calathura crenulata Richardson

See Sars, Crust, of Norway, II, 1899, pp. 44-45, and Norman and Stebbing,
Trans. Zool. Soc. Lond., XII, 1886, Ft. 4, p. 122, for characters of genus.

72

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

CALATHURA BRANCHIATA (Stimpson).a

Anthura branchiata STIMPSON, Smithsonian Contributions to knowledge, VI, 1853,

p. 43.

Paranthura norwegica G. O. SARS, Vidensk. Selsk. Forhandl., 1873, p. 88.
Anthura branchiata VERRILL, Am. Jour. Sci. (3), V, 1873, p. 101; VII, 1874,
pp. 42, 411, 502; Proc. Amer. Assoc., 1874, pp. 350, 357. HARGER, with
VERRILL; Report U. S. Commissioner of Fish and Fisheries, Pt. 1, 1873,
pp. 511 (217), 573 (279). SMITH and HARGER, Trans. Conn. Acad. Sci.,
Ill, 1874, p. 16.

Paranthura arctica G. O. SARS, Archiv for Math, og Naturv., 1877, p. 347. HEL-
LER, Denk. Ak. Wien, XXXV, 1878, p. 38-39, pi. iv, figs. 9-12.
Paranthura branchiata HARGER, Report U. S. Commissioner of Fish and Fisheries,

Pt. 6, 1880, pp. 402-405, pi. xi, fig. 70.
Calathura branchiata NORMAN and STEBBING, Trans. Linn. Soc. Lond., XII, 1886,

Pt. 4, pp. 131-133, pi. xxvi, fig. 1.
Paranthura, branchiata HANSEN, Dijmphna Togtets zool.-bot. Udbytte, 1887, pp.

203-204.

Calathura branchiata HANSEN, Vedenskabelige Meddelelser fra den naturhis-

toriske Forening i Kj0benhavn, 1887-
1888, p. 181.

Paranthura branchiata AXEL OHLIN,
Akademisk Afhandling, XXII, 1895,
pp. 12-13.

Calathura branchiata SARS, Crust. Nor-
way, II, 1899, pp. 46-47, pi. xix,
fig. 2. STEBBING, Ann. Mag. Nat.
Hist. (7), V, 1900, p. 13. RICHARD-
SON, American Naturalist, XXXIV,
1900, p. 215; Prcc. U. S. Nat. Mus.,
XXIII, 1901, p. 509. AXEL OHLIN,
Bihangtill K. Sv. Vet.-Akad. Handl.,
XXVI, Afd. iv, No. 12, 1901,
pp. 17-20.

Localities. Bay of Fundy; Vine-
yard Sound; Georges Bank; East-
port, Maine; Gulf of Maine; west of
Jeffreys Ledge; Casco Bay; Nova
Scotia; between Misaine Bank and
Middle Ground; off Head Harbor;
between Middle Ground and Hali-
fax; southeast from Cape Sable;
latitude 70 8' north, longitude 74
20' west; also Franz Josefs Land,
Kara Sea, Greenland, Jan Mayen,

Spitzbergen, off Norway, Scotland, Ireland, and between England and
the Bay of Biscay; latitude 70 north, longitude 58 38' west; Uma-
nak; latitude 71 10' north, longitude 58 56' west; latitude 72 20'
north, longitude 59 39' west (Hansen); latitude 71 35' north, longi-

FIG. 56. CALATHURA BRANCHIATA
(AFTER HARGER). a, FIRST ANTENNA, x
8. 6, SECOND ANTENNA, x 8. c, RIGHT

MAXILLIPED. X 16. d, FIRST MAXILLA.

x 16. d', DISTAL END OF SAME, x 60. e,
FIRST LEG. x 8. /, FIRST PLEOPOD. x 8.
g, SECOND PLEOPOD OF MALE, x 8.

a See Norman and Stebbing for more detailed description.

ISOPODS OF NOKTH AMERICA.

73

tude 22 47' east, between Norway and Beeren Island; latitude 73
27' north, longitude 23 11' east, between Norway and Beeren Island;
latitude 77 25' north, longitude 27 30' east, north of Hope Island;
latitude 76 46' north, longitude 15 22' east, off Horn Sound, West
Spitzbergen; King Charles Island, Bremer Sound; latitude 78 50'
north, longitude 27 39' east, King Charles Island; latitude 78 50'
north, longitude 29 39' east, King Charles Island; latitude 81 14'
north, longitude 22 50' east, northeast of Seven Islands; latitude 79
58' north, longitude 9 30' east; 19'-20' north of Danish Island; lati-
tude 73 3' north, longitude
18 30' east, between Beeren
Island and Norway (Ohlin);
latitude 71 31' north, longi-
tude 49 12' east (Stebbing).

Depth. 10-250 fathoms;
20-460 m., in mud, clay,
gravel, stones, rocks, barna-
cles, sand, and shells.

Body extremely narrow
and elongate, about ten and
a half times longer than
broad, 2 mm. : 26 mm.

Head a little wider than
long, 1 mm.: 2 mm., be-
coming slightly narrower
toward the anterior end,
which is 1 mm. wide, and
has the frontal margin exca-
vate on either side of a small
median point. The eyes are
absent. The first pair of an-
tennae have the three pedun-
cular articles about equal in

length but decreasing in size, the basal one being the largest. The
flagellum is composed of ten articles, and extends to the end of the
peduncle of the second pair of antennae. The second pair of antennas
have the basal article short; the second is nearly twice as long; the
third is half as long as the second; the fourth is twice as long as the
third and about as long as the second, but more slender; the fifth is a
little longer than the fourth, about one and a third times longer. The
flagellum is composed of eleven articles. The second pair of antennae
are about 3 mm. long. The maxillipeds have a palp of three articles.
The palp of the mandibles is composed of three articles.

Basal article of palp not shown in drawing.

FIG. 57. CALATHURA B.RANCHIATA. a, FIRST LES.
x 111. b, SECOND ANTENNA, x 20|. c, FIRST MAX-
ILLA, x 39. d,a MAXILLIPED. x 39. e, MANDIBLE.

X 39. /, FIRST ANTENNA. X 20J.

74

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first segment of the thorax is 2 mm. long; the second and third
are subequal and each is 3 mm. in length; the fourth segment is 4
mm. long; the fifth segment is 3 mm. long; the sixth is 2 mm.; the
seventh is 1 mm. in length. The segments are long and narrow and
have no epimera separated off. The second and third segments have
each at the anterior end two small tubercles, one on either side of the
median line. The fourth, fifth, and sixth segments have each a small
depression at the anterior end in the median line.

The abdomen is short, being only 4 mm. in length, or less than one-
sixth the entire length of the body. The first six segments are indis-
tinctly defined, and are more or less fused in the median dorsal line.
The seventh and last segment or telson is triangular in shape with apex
acute. The peduncle of the uropoda is broad and extends two-thirds
the length of the terminal abdominal segment. The inner lateral
branch is small and placed at the posterior end of the peduncle and
extends the remaining third of the length of the terminal abdominal
segment, reaching the extremity of that segment. The outer or supe-
rior branch is dorsally placed and arches over the telson, meeting the
branch of the opposite side in the median dorsal line; it is about twice
as broad as long and is posteriorly truncate.

The first three pairs of legs are prehensile, the first pair being much
the larger and stouter. The four remaining pairs are ambulatory.

CALATHURA CRENULATA Richardson.

Calathura crenulata RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 509-610.

Localities. Between Nassau and Andros Island, Bahamas; Cape
Catoche, Yucatan.

Depth. 21 fathoms. Found in gulf weed.

Head half as long as first thoracic segment, frontal margin with

small median point
and prominent lat-
eral angles. Eyes
large, distinct, and
very black. First
pair of antennae
more than twice as

long as the length of the head; flagelluni about seven-
teen jointed. Second pair of antennae somewhat longer
than first pair, with joints of flagellum stouter; flagel-
lum about twenty-three jointed.

First six thoracic segments long and narrow; sec-
ond segment narrower posteriorly than anteriorly; FIG. 59. --CALATHURA
last segment very short, one-third shorter than pre- CKENULATA.
ceding segment. Abdomen with all the segments distinct. Terminal

FIG. 58. CALATHURA CRENULATA. HEAD.

ISOPODS OF NOETH AMEEICA.

75

segment long, Ungulate in shape, rounded posteriorly with crenulate
margin. Outer branches of the uropoda arch over telson, but do
not meet in center; narrow, elongated. Inner branches of the uro-
poda extend beyond telson, are rounded posteriorly, and shorter
than peduncular joint; inner margins crenulate. Abdomen about
equal in length to fifth and sixth thoracic segments taken together.

First pair of gnathopods large, sub-
chelate; second pair of gnathopods and
first pair of pereiopods subchelate,
small. Other pereiopods ambulatory,
slender.

One specimen (type) sent by Mr. F.
Stearns to the U. S. National Museum
comes from between Nassau and
Andros Island, Bahamas. Another
specimen was taken by the U. S.
Bureau of Fisheries steamer Albatross off Cape Catoche, Yucatan.
. Cat. No. 23900, U.S.N.M.

FIG. 60.. CALA-
THUKA CRENU-
LATA. FIRST
GNATHOPOD.

FIG. 61. CALATHU-
RA CRENULATA.
ABDOMEN.

17. Genus PARANTHURA Bate and Westwood.

Segments of abdomen distinct in both sexes. First pair of antennae
have the flagellum multiarticulate in both sexes. Second pair of
antennae in both sexes have a rudimentary flagellum consisting of a
single article.

Mouth parts as in Calathura.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS PARANTHURA.

a. Flagellum of first pair of antennae composed of nine articles. First three segments
of thorax of equal length; the three following subequal and each one-third
shorter than either of first tw.o. First five segments of abdomen one-half the
length of seventh thoracic segment. Last abdominal segment funnel-shaped;
posterior margin coarsely denticulate and truncate.

Paranthura infundibulata Richardson

a'. Flagellum of first pair of antennae composed of six to seven articles. First five
segments of thorax of equal length; sixth segment somewhat shorter than any
of preceding segments. First five segments of abdomen as long as seventh
thoracic segment. Last abdominal segment long and narrow, rectangular in
shape, with margins entire Paranthura verrillii Richardson

76 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

PARANTHURA INFUNDIBULATA Richardson.

Paranthura infundibulata RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902,
pp. 284-286, pi. xxxvin, figs. 15-20.

Locality. Bermudas.

Male. Body narrow, elongate; color yellow, with markings of
black.

Head with antero-lateral angles prominent, between which the
frontal margin is excavate for the reception of the antennae, the

fcio. 62. PARANTHURA INFUNDIBULATA. a, LAST FOUR THORACIC SEGMENTS AND ABDOMEN, b, FIRST

QNATHOPOD. C, LATERAL VIEW OF ABDOMEN, d, MANDIBLE. , ANTENNA OK FIRST PAIR. /, ANTENNA
OF SECOND PAIR, g, SECOND GNATHOPOD. A, MAXILLIPEDS.

middle being produced in a conspicuous median point. The eyes are
situated in the antero-lateral prolongations.

The first pair of antennae have the basal joint long, oblong in shape,
the other two joints of the peduncle being short and about equal in
length; the flagellum consists of nine joints.

The second pair of antennas have the second joint of the peduncle
very long, slightly exceeding in length the first and second peduncular

ISOPOD3 OF NORTH AMERICA. 77

joints of the first pair of antennas. The second antennae are geniculate
at the articulation of the second and third joints. The other three
joints following the second are of nearly equal length. The flagellum
consists of a single tapering joint, furnished with hairs.

The first three thoracic segments are about equal in length, elongate,
the first two having their posterior angles rounded. The fourth, fifth,
and sixth segments are equal in length and one-third shorter than the
first three. The seventh segment is about half as long as the preceding
one, and has the posterior angles produced downward.

The segments of the abdomen are distinct and very short, all five
anterior to the terminal segment being no longer than half the length
of the seventh thoracic segment. The terminal segment is long and
narrow, of the same width throughout its length, except at the apex,
where the lateral margins are abruptly drawn out into processes, which
curve upward, giving a funnel-shaped appearance to the posterior end
of the segment, which is very concave. The posterior margin is trun-
cate and coarsely denticulate.

The inner branches of the uropoda do not quite reach the extremity
of the terminal abdominal segment. The basal joint is about half
the length of the terminal abdominal segment. The inner branch is
extremely concave, with its entire margin denticulate, its ventral sur-
face having a longitudinal carina. The outer and superior branch is
long and narrow, quadrangular and somewhat narrowed posteriorly,
and from the middle slightly curving upward, coarsely denticulate on
its inner lateral and posterior margin, the teeth being rather widely
separated. The branches of the uropoda and the terminal abdominal
segment are fringed with hairs.

The first, second, and third pairs of legs are subcheliform. The
second and third pairs have the propodus similar in shape to the first
pair, but more slender, and armed on their posterior margin with
seven or eight large conspicuous spines. The other legs are longer
and more slender, and armed with four spines on the anterior margin
of both the carpus and the propodus.

A number of specimens, all males, were collected by Dr. George
Brown Goode in 1876-77 at the Bermudas.

Type specimens in Peabody Museum, Yale University. Cat. No.
3207.

PARANTHURA VERRILLII Richardson.

Paranthura verrillii RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p. 286,
pi. xxxvm, figs. 21-22.

Locality. Bermudas.

Body narrow, elongate. Color dark brown, with scattered black
dots.

Head with lateral angulations prominent, rounded, between which

78

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the front is excavate on either side of a small median point. Eyes
large, situated in the lateral angulations.

First pair of antennae have the first joint of the peduncle oblong,
the other two shorter and about equal in length, flagellum six to
seven jointed. The second pair of antennae' have a five-jointed
peduncle (the first joint being short and indistinct), of which the
second and fifth joints are longest, the flagellum being consolidated
into a single flattened, tapering joint, furnished with hairs.

The first five thoracic segments are of equal length. The sixth is
somewhat shorter than any of the others, and the seventh is half as
long as the sixth.

The abdominal segments are distinct, the first five taken together

being no longer than the seventh
thoracic segment. The terminal
abdominal segment is long and nar-
row, rectangular in shape, with mar-
gins entire. The basal joint of the
uropoda is half as long as the termi-
nal segment of the abdomen; the
inner branch is rectangular, coarsely
denticulate, and reaches the apex of
the telson. The outer superior
branch is narrow, elongate, rectan-
gular, with margins coarsely denticu-
late, the teeth being close together.
The branches of the uropoda and
the terminal abdominal segment are
fringed with long hairs.

The first three pairs of legs are
subchelate. The second and third
pairs have the posterior margin of the propodus armed with spines,
as in the preceding species. In the four following -pairs of legs the
anterior margin of the propodus is armed with four spines.

A single female was collected by Prof. A. E. Verrill and party in
1898 at the Bermudas. Depth, 1-2 feet.

Type specimen in Peabody Museum, Yale University. Cat. No. 3186.
This species is named in honor of Prof. A. E. Verrill of Yale
University.

18. Genus COLANTHURA Richardson.

Body^ narrow, elongate. First pair of antenna? composed of four
joints, the last joint being the flagellar joint. Second pair of antennas
composed of five joints, the terminal joint fringed with hairs.

The first six segments of the thorax large, the seventh very short,

FIG. 63. PARANTHUKA VERRILLII. a, AN-
TENNA OF THE FIRST PAIR, b, ANTENNA OF
THE SECOND PAIR. C, LAST TWO THORACIC
SEGMENTS AND ABDOMEN.

ISOPODS OF NORTH AMERICA. 79

abrupt!} 7 narrower than the sixth, not as wide as the abdominal seg-
ments and devoid of legs.

The first three pairs of legs are subchelate, the three following
pairs ambulatory.

The abdominal segments are well defined and distinct from one
another. The terminal abdominal segment is rounded, entire. The
inner branch of the uropoda is likewise rounded; the outer and supe-
rior branch arches over the telson.

This genus agrees with both Hyssura Norman and Stebbing and
Cruregans Chilton in the absence of the seventh pair of legs, but dif-
fers from the first named in the structure of the antennae, both pairs
of antennae in Hyssura having multi-articulate flagella; in the structure
of the outer branch of the uropoda, which in Hyssura does not arch
over the telson; and in the structure of the mouth parts. Colanthura
differs from Cruregans in the presence of eyes, which are wanting in
Cruregans^ and in the structure of the outer branch of the uropoda,
the outer branch in Cruregans being very narrow and not arching
over the squamiform telson, while in Colanthura the outer branch is
broad and arches over the rounded terminal segment. The structure
of the mouth parts is the same as found in the genera Paranthura,
Calathura, and Cruregans.

COLANTHURA TENUIS Richardson.

Colanthura tenuis RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp. 287-
288, pi. xxxvm, figs. 23-28.

Locality. Bermudas.

Body narrow, elongate; surface smooth; color light yellow. Head
with a prominent median process extending between the first pair of
antennae. Antero -lateral angles prominent, produced, reaching the
distal end of the first joint of the peduncle of the first pair of antennae.
Eyes large, conspicuous.

First pair of antennae consist of four joints, the terminal or flagel-
lar joint being fringed with long hairs. The second pair of antennae
are composed of five joints, the terminal joint being fringed with
hairs.

The first three thoracic segments are about equal in length. The
fourth and fifth segments are each much longer than any of the three
preceding segments, and are about alike in size. The sixth segment
is short, not quite as long as any one of the first three segments.
The seventh is ver} r short, being one -third the length of the sixth
segment, and in both specimens examined is devoid of legs.

The segments of the abdomen are distinct, the first five together not
being as long as the sixth thoracic segment. The last thoracic seg-

80

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

raent is abruptly narrower than the sixth, and is likewise somewhat
narrower than the abdominal segments.

The terminal segment of the body is linguiform, the posterior mar-
gin evenly rounded and smooth. The inner branch of the uropoda is
likewise rounded posteriorly with a smooth margin. The outer and
superior branch arches over the telson. Both branches, as well as the
terminal abdominal segment, are fringed with hairs.

The first pair of legs are subcheliform, the propodus unarmed. The
second and third pairs are also subcheliform, but smaller, with the pro-
podus armed on the posterior margin with five spines. The three

FIG. 64. COLANTHURA TENTHS, a, GENERAL FIGURE. 6, HEAD AND ANTENNAE. C, LEG OF FIRST

PAIR, rf, LATERAL VIEW OF UROPODA. e, LEG OF SECOND PAIR. /, ABDOMEN AND LAST TWO

THORACIC SEGMENTS.

following pairs of legs are ambulatory in character. The seventh
pair are wanting.

Two specimens were collected by Prof. A. E. Verrill and party at the
Bermudas in 1898. Both specimens are adult females, the marsupium
in one being very large and extending the entire length of the thorax,
from the second segment.

Type specimen in Peabody Museum, Yale University. Cat. No.
3252.

I8OPODS OF NORTH AMERICA. 81

Family V. CIROLANID^.

Body more or less semicylindrical in form. Epimera well defined
on all the segments of the thorax, with the exception of the first.
Abdomen usually composed of six distinct segments. Uropoda lateral,
and forming, with the last segment of the abdomen, a caudal fan.
Eyes usually small, lateral. Antennas usually unequal in length,
multiartlculate, with well-defined peduncle and flagellurn. -First three
pairs of legs usually prehensile; last four pairs ambulatory. Pleopods
well developed and adapted for swimming and breathing. Second
pair of pleopods in the male with a stylet inside the inner plate.
Incubatory pouch composed of five pairs of plates issuing from the
bases of the first five pairs of legs.

Labrum large, two or three times wider than long.

Clypeus large, wide, short, triangular.

Mandibles wide throughout their entire length; the posterior part
seen in position turned a little inward; the distal part directed inward,
wide, but long, and covered for the most part; cutting part long, more
or less trifid, the posterior apex always larger than the other apices; the
movable lacinia is large, furnished with many spines; the molar part
is elongate, triangular, furnished with triangular processes on the
anterior margin.

The first pair of maxillae are robust: the lacinia of the first article
is inflated at the apex and furnished with three plumose processes;
the lacinia of the third article is wide or very wide at the apex and
is furnished with many robust spines.

The second maxillse are well developed; the lacinia of the second
article is wide, free, and short, and furnished with many setae;' the
lacinise of the third and fourth articles are much longer than wide,
with the inner margin furnished with long setse.

The maxillipeds are well developed; the margins of the articles of
the palp are furnished with many setse, but never furnished with hooks.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY CIROLANID.E.

a. All six segments of abdomen distinct, not coalesced.

b. No branchiae developed at base of pleopoda. Eyes, when present, placed on

superior and inferior side of head.

c. Peduncle of the second pair of antennae composed of five articles. Plate of
the second joint of the maxillipeds furnished with hooks. First pair of
antennae with basal article of peduncle not placed at right angles to second
article.

d. First three pairs of legs prehensile. Last four pairs ambulatory. Uropoda
with the inner angle of the peduncle produced.

See Sars, Crust, of Norway, II, 1899, pp. 67-68, for characters of
Hansen, Vidensk. Selsk. Skr. (6), V, 1890, pp. 310-311, 317, 318.
2858905 6

LI B R A R

82 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

e. First and second pair of pleopods similar to each other, the inner branch
being submembranaceous; the peduncle of the second pair of pleopods is

somewhat wider than long Genus Cirolana Leach

ef. First and second pairs of pleopods not similar to each other; first pair of
pleopods with both branches hard, and forming a large operculum.
Second pleopods of the usual structure; the peduncle of the second

pleopods is scarcely wider than long Genus Conilera Leach

d'. Only first pair of legs prehensile. The six following pairs are ambulatory.
Uropoda with the inner angle of the peduncle not produced. Eyes

wanting Genus Cirolanides Benedict

cf . Peduncle of the second pair of antennae composed of four articles. Plate of
the second article of the maxillipeds not furnished with hooks. First pair
of antennae with basal article of peduncle extended straight in front at a
right angle to the remaining part of the antennae.

d. Maxillipeds normal, composed of seven articles. Uropods not attached to
underside of abdomen and not branchial in function.

Genus Eurydice Leach

d'. Maxillipeds composed of two articles. Uropoda attached to the under-
side of abdomen, and branchial in function, being similar to the

pleopods Genus Branchuropus Moore

b' '. Supplementary ramified branchiae developed at the base of the inner branches
of the pleopoda. Eyes placed entirely on inferior side of head.

Genus Bathi/nomus A. Milne Edwards

a' '. Five anterior segments of abdomen fused to form a single segment anterior to
large terminal segment Genus Colopisthus Kichardson

19. Genus CIROLANA Leach.

First pair of antennae with basal article of peduncle not extended
straight in front at right angles to second article. Peduncle of the
second pair of antennae composed of five articles."

The plate of the second article of the maxillipeds furnished with
hooks.

Abdomen with all six segments distinct.

The first and second pairs of pleopods similar to each other, the inner
branch being submembranaceous; the peduncle of the second pair of
pleopods is somewhat wider than long.

The peduncle of the uropoda has the inner angle strongly produced.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CIROLANA.

a. Eyes present.

b. Fifth abdominal segment with lateral angles free, not covered by the fourth
segment.

c. Body short. Sides of head angulated. First pair of antennae short, reaching
only to the posterior margin of the head. Frontal lamina forming a large
rounded projection, extending beyond the apex of the head and separate
from the frontal process. Inner branch of uropoda much longer than outer
branch. Terminal abdominal segment tricarinated.

Cirolana sphseromiformis Hansen

a Hansen recently states that in three species of Cirolana the peduncle of the second
pair of antennae is composed of six articles, C. borealis being one of these.

I8OPODS OF NORTH AMERICA. 83

c'. -Body oblong, ovate. Sides of head rounded. First pair of antennae long,
reaching to or beyond the posterior margin of the first thoracic segment.
Head produced in front in a process continuous with frontal lamina. Inner
branch of uropoda not longer than outer branch. Terminal abdominal
segment not tricarinated.

d. First pair of antennae extend to the posterior margin of the first thoracic
segment. Second pair of antennae extend to the posterior margin of the
third thoracic segment, and are provided with a brush-like structure on
flagellum. Inner branch of uropoda shorter than outer branch. Termi-
nal abdominal segment smooth Cirolana mayana Ives

d' '. First pair of antennae extend to the posterior margin of the third thoracic
segment. Second pair of antennae extend to the posterior margin of the
fifth thoracic segment, and are not provided with brush-like structure on
flagellum. Branches of uropoda of equal length. Terminal abdominal
segment with basal portion raised above posterior portion, with well-
defined edge separating the two parts.

e. First pair of antennae with joints of peduncle subequal. Terminal abdom-
inal segment posteriorly rounded. Basal portion of terminal abdom-
inal segment with median lobe produced in two points, one on either

side of the median line Cirolana linguifrons Richardson

e? . First pair of antennae with first article longer than second, and third
article twice as long as second. Terminal abdominal segment poste-
riorly triangular, with apex acute. Basal portion of terminal abdom-
inal segment with median lobe truncate. . . Cirolana chittoni, new species
b. Fifth abdominal segment with lateral parts covered by the fourth segment.
c. Frontal lamina posteriorly or clypeus anteriorly produced horn-like, espe-
cially so when seen from the side Cirolana minuta Hansen

c'. Frontal lamina and clypeus unarmed, not produced horn-like; anterior mar-
gin of the clypeus manifestly united with the frontal lamina.
d. Frontal lamina narrow, elongate, from four to six times longer than broad.
e. Extremity of exterior margin of inner branch of the uropoda erparginate.
/. Terminal segment of abdomen emarginate at its extremity.

Cirolana concharum (Stimpson)

/'. Terminal segment of abdomen not emarginate at its extremity, pos-
terior margin entire.

g. Second pair of antennae, with flagellum composed of twenty articles,
extend to the posterior margin of the second thoracic segment.
Terminal segment of abdomen furnished with spines. Outer branch
of uropoda extends about six-sevenths of the length of the inner
branch. Inner branch of uropoda, below emargination, is wide,
posteriorly truncate or slightly emarginate. Epimera with im-
pressed lines Cirolana impressa Harger

g / . Second pair of antennae, with flagellum composed of ten articles,
extend to the middle of the first thoracic segment. Terminal
segment of abdomen not furnished with spines. Outer branch of
uropoda extends about three-fourths of the length of the inner
branch. Inner branch of uropoda below emargination is narrow
and posteriorly pointed. Epimera without impressed lines.

Cirolana polita (Stimpson)
e' '. Extremity of exterior margin of the inner branch of the uropoda not

emarginate.

/. Eyes small, black, longer than wide. Branches of uropoda narrow, lan-
ceolate, somewhat elongated; inner branch almost three times longer
than wide. Clypeus even. Terminal segment posteriorly rounded.

Cirolana borealis Lilljeborg

84 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

f. Eyes large, brown, as long an wide. Branches of uropoda short; inner
branch hardly twice as long as wide. Clypeus with margin raised all
around and with a median rib, surrounding two impressed areas.
Terminal segment truncated obliquely with apex acute.

Cirolana gracilis Hansen
df. Frontal lamina broad, short, scarcely twice as long as wide.

e. Terminal segment truncate Cirolana obtnmcata Richardson

e' '. Terminal segment not truncate, rounded.

/. Posterior margin of terminal abdominal segment armed with numerous
(twenty -six) robust spines. Inner branch of uropoda with outer post-
lateral angle rounded Cirolana harfordi ( Lockington )

f '. Posterior margin of terminal abdominal segment armed with a few
(about eight) small spines. Inner branch of uropoda with outer post-
lateral^mgle acute.

g. Body two and two-thirds times longer than wide. Second pair of
antennae extend to posterior margin of the fourth thoracic segment.

Color light brown Cirolana parva Hansen

g'. Body three and two-thirds times longer than wide. Second pair of
antennae extend to the posterior margin of the third thoracic seg-
ment. Color white Cirolana albida Richardson

a'. Eyes wanting Cirolana cubensis Hay

CIROLANA SPH^EROMIFORMIS Hansen.

Cirolana sphseromiformis HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 351-353,
pi. iv, figs. 3-3g. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 512.

Locality. St. Thomas, West Indies.

Body short, subovate, twice as long as wide, rather convex.

Head forming at the sides a prominent angle, produced in front in
a rather- narrow but long frontal process, the margin between the
lateral angle and the base of the frontal process being rather straight,
forming a manifest carina on the surface of the head.

Eyes very small, appearing only on the superior margin of the head
in an angulated process, formed of a few, rather convex ocelli.

The frontal lamina is exceedingly narrow at the basal part, is partly
concealed under the end of the clypeus, becomes exceedingly dilated
toward the apex, which is inflated and widely rounded, and later
somewhat overhangs the frontal process and becomes united with that
process.

The clypeus is very short, produced at the base in a very short, acute
point. The first pair of antenn* are somewhat shorter than the pedun-
cle of the second pair of antennae; the peduncle is twice as long as the
flagellum, and composed of three articles, the basal article being short;
the flagellum is composed of about four articles, with the basal article
elongate, the last three articles being very minute.

The second pair of antennae extend a little beyond the posterior mar-
gin of the second thoracic segment; the peduncle is stout, with the
fourth article much longer than the third article and somewhat shorter
than the fifth article; the flagellum is composed of about twelve articles.

ISOPODS OF NOKTH AMERICA.

85

The mandibles have a wide cutting- edge. The maxillipeds are
almost as in C. japonica.

The segments of the thorax are subequal in length; the first seg-
ment is somewhat shorter than the head and somewhat longer than the
fifth segment; the sixth and seven segments are subequal in length and
ornamented near the anterior margin with a transverse furrow. The
epimera are large, posteriorly produced, and obliquely carinated (the
carina terminating in a fork, very wide particularly in the posterior
epimera, and very deep, forming an excavation), becoming- gradually
wider posteriorly and more produced, the carina becoming higher and
the posterior angle subactite; the epimera of the seventh pair extend
in length as far as the first four segments of .the abdomen.

FIG. 65. ClROLANA SPH^ROMIFORMIS (AFTER HANSEN). O, POSTERIOR PART OF AHDOMEN. ft, LEFT
PLEOPOD OF SECOND PAIR. C, LATERAL VIEW OF FEMALE. (1, DORSAL VIEW OF FEMALE. , LEO OF
SECOND PAIR. /, LEG OF FIFTH PAIR, g, LEG OF SEVENTH PAIR, h, ANTERIOR PART OF HEAD.
(ENLARGED.)

The first three pairs of legs are rather robust, with the second arti-
cle elongate, the fourth article very short with the exterior angle reach-
ing beyond the apex of the fifth article; the legs of the second and
third pairs have the sixth article much wider than in other species,
long,- about twice as long as wide.

The last four pairs of legs are short, rather robust; the sixth and
seventh pairs of legs are subequal in length, the fifth pair of legs being
a little longer.

The first five segments of the abdomen are exposed, are very short
and very convex; the fifth segment has the lateral angles not covered
by the fourth segment.

86 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The anterior pairs of pleopods are furnished with long hairs.

The last segment of the abdomen is somewhat wider than long, sub-
triangular, with apex rather short, truncate, not furnished with spines,
very convex, the dorsal surface being tricarinated and deeply and
equalty excavate between thecarinse; the two lateral carinee are a little
divergent posteriorly, and a little arcuate.

The uropoda are short, wide, and do not extend be3 7 ond the abdomen.
The inner branch is more than twice as long as wide; the exterior
margin is strongly curved, and somewhat angulate a little before the
median line; the distal part is irregularly serrate, not furnished with
spines; the posterior part of the inner margin is also strongly curved,
almost angulate, and furnished with a few very short hairs; the apex
forms a very obtuse angle, and is furnished with a few long hairs.
The outer branch is much shorter than the inner branch, and similar
in form to it. The peduncle has the inner angle not produced, and
not reaching the middle of the inner branch.

The color is a brownish yellow, somewhat grayish."

The above description is adapted from the following description of Hansen's:

Diagn. Corpus breve, duplo longius quam latius. Caput et in lateribus et ante
angulatum. Lamina frontalis ante bullam magnana, apicem capitis paulo superan-
tem, formans. Epimera majora, per paria postice plus producta et altius carinata,
angulo posteriore subacuto. Segmenta 5 anteriora caudje perbrevia. Segmentum
ultimum caudse uropoda vix superans, subtrigonum, apice subtruncato, dorso alte
tricarinato et inter carinas excavato. Uropoda brevia, lata; ramus uterque margine
exteriore valde excurvato ibique fere angulato, parte distali irregulariter inciso-
serrata, margine postero-interiore valde excurvato; ramus interior ramo exteriore
multo longior. Long. 4, 25 mm.

Corpus subovatum, duplo longius quam latius, sat convexum. Caput in lateribus
angulum prominulum formans, ante in processum frontalem angustiorem sat longum
productum, margine inter angulum lateralem et basin processus frontalis subrecto, in
superficie capitis carinam manifestam formante.

Oculi minuti, solum in latere superiore capitis in processu angulato inventi, ex
ocellis paucis, sat convexis formati.

Lamina frontalis parte basali valde angustata, ex parte sub cornu clypei obtecta,
ad apicem versus valde dilatata, alte prominens, parte apicali inflata, ante late
rotundata, ultra processum frontalem nonnihil prominente et cum hoc processu
conjuncta.

Clypeus perbrevis, a basi in cornu brevius, acutum productus.

Antennulae pedunculo antennarum aliquanto breviores; pedunculus flagello duplo
longior, 3-articulatus, articulo basali brevi; flagellum c. 4-articulatum, articulo
basali elongate, articulis 3 ultimis perminutis.

Antennae paulo ultra marginem poster! orem segmenti secundi trunci prominentes;
pedunculus crassior, articulo quarto multo longiore quam artieulo tertio et nonnihil
breviore quam articulo quinto; flagellum c. 12-articulatum. Mandibulse acie latiore.
Maxillipedes fere ut in C. japonica.

Segmenta trunci longitudine minus inrequalia; segmentum primum capite nonni-
hil brevius et segmento quinto nonnihil longius; segmenta sexturn etseptimum long-
itudine subsequalia, stria transversa prope marginem anteriorem ornata. Epimera
majora, postice producta, in obliquum carinata (carina f urea imprimis in epimeris
posterioribus latissima et profundissima, excavationem formante, definita), postice

ISOPODS OF NORTH AMERICA.

87

CIROLANA MAYANA Ives.

Cirolana mayana IVES, Proc. Acad. Nat. Sci. Phil., 1891, pp. 186-187, pi. vi, figs.
3-10. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 512. MOORE,
Bull. U. S. Fish Comm., XX, Pt. 2, 1902, p. 166, pi. vin, figs. 1-5.

Localities. Coast of Yucatan; Santa Marta, United States of Colom-
bia; Boqueron Bay and Culebra, Porto Rico; Brandon's, Barbados
Beach; San Francisco Bay, Lower California.

A large number of dried specimens from San Francisco Bay, Lower

FIG. 66. CIROLANA MAYANA (AFTER MOORE), a, GENERAL FIGURE. 6, HEAD, c, FIRST ANTENNA.

d, SECOND ANTENNA.

California, sent to me by Doctor Hitter, of the University of Cali-
fornia, agree so perfectly with the specimens in the U. S. National
Museum from localities above cited that I have not been able to sepa-
rate them. ,

per paria latiora, plus producta, altius carinata, angulo posteriore subacuto; epimera
septimi paris segmenta quattuor anteriora caudse longitudine explentia.

Pedes trium parium anteriorum sat robusti, artieulo secundo elongate, quarto
brevissimo angulo exteriore ultra apicem articuli quinti prominente; pedes secundi
et tertii parium artieulo sexto multo latiore quam in speciebus ceteris, longo, duplo
longiore quam latiore.

Pedes parium quattuor posteriorum breves, sat robusti; pedes sexti et septimi
parium inter se subseque longi, pedibus quinti paris paulo longiores.

Segmenta quinque anteriora caudse detecta, brevissima, alte convexa; segmentum
quintum angulis lateralibus non a segmento quarto tectis.

Pleopoda parium anteriorum setis longis instructa.

Segmentum ultimum caudrc aliquanto latins quam longius, subtrigonum, apice
brevius, subrecte truncate, non spinoso, alte convexum, dorso alte tricarinato et
inter carinas profunde et aequaliter excavato; carime dure laterales postice paulum
divergentes, paulum arcuatae.

Uropoda brevia, lata, caudam non superantia. Ramus interior plus duplo longior
quam latior; margo exterior valde excurvatus, paulum ante medium subangulatus,
parte distali irregulariter serrata, non spinosa; margo postero-interior interum valde
excurvatus, fere angulatus, setis nonnullis brevissimis instructus; apex angulum
valde obtusum formans, setis nonnullis longioribus instructus. Ramus exterio'r ramo
interiore multo brevior, huic forma similis. Scapus angulo interiore minus producto,
non ad medium ramum interiorem prominente.

Color flavo-brunnescens, nonnihil grisescens. HANSEN, Vidensk. Selsk. Skr., (6),
V, 1890, pp. 351-353.

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

In one specimen examined the maxillipeds consisted each of two
articles. This, of course, was an abnormality, as all the other speci-
mens in the collection had maxillipeds composed of the usual number

FIG. 67. ClROLANA HAYANA (AFTER IVES) . O, FIFTH LEG (RIGHT SIDE). 6, DORSAL VIEW OF RIGHT
ANTENNA OF SECOND PAIR. C, ANTERIOR VIEW OF SAME. (I, LAST SEGMENT OF ABDOMEN WITH URO-
10DA. f, FIRST LEG (RIGHT SIDE). /, FOURTH LEG (RIGHT SIDE).

of articles. The genus Branchuropus Moore is characterized as hav-
ing the maxillipeds two-jointed. Only one specimen of the species,
B. littoral'is, was obtained, and it seems as though there might be

Q

O

FIG. 68. ClROLANA MAYANA (AFTER IVES).

a, DORSAL VIEW, x 4. b, RIGHT SIDE, x 4.
c, SEVENTH THORACIC SEGMENT WITH MALE

APPENDAGE.

FIG. 69. ClROLANA MAYANA. O, MANDIBLE.

x 39. 6, c, ABNORMAL MAXILLIPED. x 39.
d, SECOND MAXILLA, x 39.

some question as to its being normal in this respect. The genus
Anuropw Beddard was also instituted because the type and only speci-
men had, among other characters, the one of having maxillipeds com-
posed of two articles.

ISOPOD8 OF NORTH AMERICA. 89

Body oblong-ovate, two and a half times longer than broad, 4 mm. :
10 mm.

Head two and a half times wider than long, 1 mm. : 2 mm. Front
produced in a long median point which separates the basal articles of
the first pair of antennae and meets and is coalesced with the anterior
end of the frontal lamina, which arches over the second antennae and
forms a dorsal continuation of the median frontal process extending
1 mm. beyond the frontal margin of the head. The eyes are small,
round, composite, and situated in the antero-lateral angles of the
head. The first pair of antennae have the first two articles short and
subequal; the third article is half as long and narrower than either of
the other two. The flagellum is composed of thirteen articles. The
first pair of antennae extend almost to the posterior margin of the first
thoracic segment. The second antennas have the peduncle apparentlv
composed of only four articles; the first article is short and almost
inconspicuous; the second and third articles are subequal; the fourth
and fifth are also subequal and each is a little longer than the third.
The flagellum is composed of twenty-
three articles. The second antenna; ex-
tend to the posterior margin of the third
thoracic segment. The first nine or ten
articles of the flagellum have a tuft of
hairs on the outer margin. The interan-
tennal plate or frontal lamina is wide and
conspicuous and arches over the second
pair of antennae meeting the anterior end *te.m CIBOLAHA HAYAMA. SECOND

, rr.i ANTENNA. X 2<H-

or the frontal process. The clypeus has

the anterior end produced over the posterior end of the frontal lamina
and extends out from it. Maxilliped composed of seven articles.
The mandible has a palp of three articles.

The first, fourth, and fifth segments of the thorax are a little longer
than any of the others. The epimera of all the segments, with the
exception of the first, are distinct. In the second and third segments
they are narrow, increasing in width from those of the fourth to the
seventh segments. The postero-lateral angles of the last three are
acute and produced beyond the posterior margins of the segments.
All the epimera are crossed by an oblique carina.

The first segment of the abdomen is almost entirely covered by the
seventh thoracic segment. The fifth segment is as wide as the fourth,
and is not covered at the sides by the lateral parts of the preceding
segment. The sixth or terminal segment is rounded posteriorly. The
inner branch of the uropoda is as long as the terminal segment of the
body, and is slightly emarginate on its external margin. The outer
branch is longer than the inner branch and is rounded posteriorly.
The peduncle extends as far as the emargination on the exterior
margin of the inner branch. Both branches are beset with spines.

90

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first three pairs of legs are prehensile. The propodus is armed
with four spines, the carpus with three in the first legs, with two in
the second and third pairs; the merus with six spines; and the ischium
with three or four; the outer distal end of the merus is furnished with
one long spine in the first pair of legs. The last four pairs of legs are
also furnished with spines.

CIROLANA LINGUIFRONS Richardson.

823;

Cirolana linguifrons RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 163-164.

Locality. Monterey Bay, California.
Dug at mean tide mark from sandy shore.

Color, yellow, marked with scattered black dots. Body elongate-
ovate, about five times longer than broad, greatly convex.

Head with the frontal margin produced in a long,
straight process, rounded anteriorly and somewhat
dilated. Eyes large, distinct. First
pair of antennae with the articles of
the peduncle large; flagellum of fif-
teen short joints extends to the pos-
terior margin of the third thoracic
segment. Second pair of antennae,
with a flagellum of thirteen long
articles, extend to the posterior mar-
gin of the fifth thoracic segment.

The first three segments of the
thorax are short; the other four seg-
ments are long. The epimera of the
second, third, and fourth segments
ar not produced at the apex; those of the fifth, sixth, and seventh
but slight!}' produced.

All the abdominal segments conspicuous, the first five being of equal
length. The fifth segment is as wide as the fourth, and the lateral
parts are not covered by the post-lateral angles of the preceding seg-
ment. The terminal segment is rounded posterior^, faintly crenulate
and fringed with long hairs. The base of this segment is raised above
the other portion and has a well-defined edge with two points extend-
ing backward, one on either side of the median line. The uropoda
extend beyond the tip of the abdomen; the inner branch is obliquely
truncate; the outer branch is more rounded; both branches are fringed
with long hairs.

The prehensile legs are short; the ambulatory legs are long and
slender. The legs increase gradually in length from the first to the
seventh pair.

FIG. 71. CIROLANA LIN-
GUIFRONS. x I3i. a,
HEAD. 6, TERMINAL

SEGMENT.

FIG. 72. CIRO-
LANA LINGUI-
FRONS. MAX-
ILLIPED. X 51|.

ISOPODS OF NORTH AMERICA.

91

Two specimens, from Monterey Bay, California, collected by Mr.
Heath from sandy shore at mean tide.
7^. Cat. No. 22564, U.S.N.M.

CIROLANA CHILTONI, new species.

Body oblong-ovate, a little more than twice as long as wide, 5 mm. :
11 mm.

Head wider than long, about twice as wide as long, 1 mm. : 3 mm.
with the front produced in a prominent process which widens anteri-
orly beyond the antennae, arches over them and is confluent with the
frontal lamina. The eyes are large, composite, and occupy the antero-
lateral corners of the head. The first pair of antenna? have the first
article large, the second article somewhat shorter, and the third article
about one and a half times longer than the second.
The peduncle extends to the posterior margin of
the head. The flagellum, which is composed of fif-
teen articles, extends to the posterior margin of
the third thoracic segment. The second pair of
antennae have the first two articles extremely short
and about equal in length; the third and fourth
are subequal and each article is about as long as the
first two taken together; the fifth article is twice
as long as either of the two preceding articles.
The peduncle of the second antennae extends to the
middle of the first thoracic segment. The flagel-
lum is composed of thirteen articles and extends a
little beyond the post-lateral angle of the fifth
thoracic segment.

The seven thoracic segments are subequal in
length. Epimera are distinct on the last six seg-
ments. The last three have the post-lateral angles slightly produced
beyond the posterior margins of the segments.

The first segment of the abdomen is short, being partly covered by
the seventh thoracic segment. The second, third, and fourth seg-
ments are equal in length and width. The fifth segment is as wide as
the preceding segment, and the lateral parts are not covered by the
lateral angles of the fourth segment. This segment is a little longer
than any of the three preceding segments in the middle of the dorsal
surface. The sixth or terminal segment is posteriorly triangular, with
apex acute. The inner branch of the uropoda is very broad and
obliquely truncate, the outer and inner posterior angles being acute.
The outer branch is narrow and posteriorly rounded; it extends to
the outer posterior angle of the inner branch. Both branches, as well
as the posterior margin of the terminal segment are fringed with long
hairs. The base of the terminal abdominal segment is raised above

FIG. 73. CIROLANA
CHILTONI. a, HEAD, x
9. b, POSTERIOR PART

OF ABDOMEN. X 9j.

92 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the posterior portion of the segment, and has the posterior edge
sharply defined. This carina is in the form of three lobes, two lateral
lobes and a median lobe, which is truncate.

The first three pairs of legs are short and prehensile; the four fol-
lowing pairs are ambulatory and densely spinulose.

Two specimens, both females, were collected at San Francisco, Cal-
ifornia, by Mr. T. G. Cary, jr. They were found in dead Hippa.
The types are in the Museum of Comparative Zoology, Harvard
University. Cat. No. 1621. M. C. Z.

This species is named for Prof. Charles Chilton, the distinguished
carcinologist.

CIROLANA MINUTA Hansen.

,

drolana minuta HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 347-348, pi. in,
figs. 5-5d; pi. iv, figs. 1-1 f. RICHARDSON, Proc. U. S. Nat. Mus., XXIII,
1901, p. 512. STEBBING, Willey's Zool. Results, 1902, p. 634.

Localities. St. Thomas, West Indies; also Lifu, Loyalty Islands
(Stebbing).

Body oblong-ovate, about two and a third times longer than wide,
somewhat convex.

The head is formed almost as in C. parva.

The eyes are moderately large, larger than in other species, brown-
ish, almost wider than long, the ocelli rather numerous, somewhat
convex.

The frontal lamina is about two and a half times longer than wide,
oblong-pentagonal, or almost hexagonal, with the apex anteriorly
truncate, the basal part furnished with a moderately large acuminate
tubercle. The clypeus is small, much shorter than the labrum.

The first pair of antennae are somewhat elongate, extending some-
what beyond the peduncle of the second pair of antenna; the peduncle
is a little longer than the flagellum, and is composed of two articles;
the flagellum is slender and is composed of seven articles.

The second pair of antenna? do not extend quite to the posterior
margin of the fourth thoracic segment; the peduncle is slender, with
the fourth article almost twice as long as the third article, and a little
shorter than the fifth article; the flagellum is composed of seventeen
or eighteen articles.

The mandibles have the cutting edge partly concealed by the labrum,
seen at first rather narrow.

The maxillipeds are short, with the fifth article largest, wider than
long, somewhat larger than both of the last articles.

The segments of the thorax are almost as in C. parva.

The epimera are moderately large, differing a little in size, and fur-
nished with the two usual fume; the posterior epimera are a little
produced posteriorly, with apex acute.

,

ISOPODS OF NORTH AMERICA.

93

The legs are slender, with the second article somewhat elongate;
the first pair of legs are manifestly stouter than the second pair of
legs; the second and third pairs of legs have the fourth article pro-
duced on the exterior side to the middle of the fifth article; the fifth
and seventh pairs of legs are subequal; the second pair are somewhat
longer and the sixth pair a little shorter.

The anterior segments of the abdomen and the pleopoda are almost
as in C. parva. The last segment of the abdomen is somewhat wider

FIG. 74. ClROLANA MINUTA (AFTER HANSEN). a, POSTERIOR PART OF ABDOMEN. 6, ANTERIOR PART
OF HEAD (FROM BELOW). C, LEFT PLEOPOD OF SECOND PAIR, d, ADULT MALE, e, LATERAL VIEW OF

SAME. /, SECOND LEG. g, FIFTH LEG. h, SEVENTH LEG. i, MAXILLIPED. j, MANDIBLE, k, FIRST
MAXILLA. I, SECOND MAXILLA. (ENLARGED.)

than long, extends a very little beyond the uropoda, is a little linguate
and evenly convex, with the posterior margin widely rounded and
furnished with about eight spines.

The uropoda are short and wide. The inner branch is more than
one-half longer than wide; the posterior part of the inner margin is
strongly curved, and furnished with plumose cilia and a few spines;
the apex forms a right angle, is bifid, and furnished with a few
long simple hairs; the exterior margin is somewhat curved. The

94 BULLETIN 54, UNITED STATES NATIONAL MUSEI M.

outer branch is short, with apex bifid and furnished with long simple
hairs. The peduncle has the inner posterior angle reaching a little
beyond the middle of the inner branch.

The color of the specimens, preserved for a long time in alcohol, is a
pale brown.

The male appendage extends a long distance beyond the inner
branch, is narrow, straight, rather compressed, with apex acuminate."

The above description is adapted from the following one of Hansen's:

Diagn. Corpus oblongo-ovatum. Frons in processum, a fronte visum longiorem,
sat angustum nonnihil circumflexum, cum lamina frontali conjunctum, producta.
Lamina frontalis fere oblongo-hexagona, parte basali cornu instructa. Antennulse
pedunculo antehnarum nonnihil longiores; pedunculus biarticulatus. Antennae cir-
citer medium truncum attingentes. Epimera mediocria, furcis solitis instructa. Pedes
graciliores, simplices. Segmentum ultimum caudte uropoda perpaulum superane,
lingulatum, paulum et sequaliter convexum, margine posteriore late rotundato, spinis
c. 8 ornato. Uropoda brevia, lata; ramus interior ramo exteriore multo longior,
margine postero-interiore valde excurvato, apice bifido angulum subrecto formante.
Long. maris4, 3 mm., long, feminpe 4, 8 mm.

Corpus oblongo-ovatum, circiter duplo et tertia parte longius quam latius, nonnihil
convexum. Frons fere ut in C. parva formata.

Oculi mediocres, majores quam in speciebus ceteris, brunnescentes, fere latiores
quam longiores, ocellis sat numerosis, nonnihil convexis.

Lamina frontalis circiter duplo et dimidio longior quam latior, oblongo-pentagona
vel fere hexagona, apice anteriore truncate, parte basali cornu mediocri, acuminate
instructa. Clypeus parvus, labro multo brevior.

Antennulse nonnihil elongate, pedunculum antennarum nonnihil superantes;
pedunculus flagello paulo longior, biarticulatus; flagellum gracilius; 7-articulatum.

Antennae marginem posteriorem segmenti quarti trunci non attingentes; peduncu-
lus gracilior, articulo quarto fere dtplo longiore quam articulo tertio, paulo breviore
quam articulo quinto; flagellum 17-vel 18-articulatum.

Mandibulse acie ex parte a labro tecta, prino visu sat angusta. Maxillipedes breves,
articulo quinto maximo, latiore quam longiore, aliquanto majore quam articulis
ambobus ultimis.

Segmenta trunci fere ut in C. parva.

Epimera mediocria, magnitudine paulum inter se discrepantia, furcis binis solitis
instructa; epimera posteriora postice paulum producta, apice aciito. Pedes gracili-
ores, articulo secundo nonnihil elongate; pedes priuai paris pedibus secundi paris
manifesto crassiores; pedes secundi et tertii parium articulo quarto in latere exteriore
haud ad medium articulum quintum producto; pedes quinti et septimi parium
sequilongi, pedibus secundi paris nonnihil longiores et pedibue sexti paris paulo
breviores.

Segmenta anteriora caudse et pleopoda fere ut in C. parva. Segmentum ultimum
caudse nonnihil latius quam longius; cetera in diagnosi commemorata.

Uropoda brevia, lata. Remus interior plus quam dimidio longior quam latior;
margo postero-interior valde excurvatus, ciliis mediocribus plumosis et spinis non-
nullis instructus; apex angulum subrectum formans, bifidus, setis nonnullis longis,
simplicibus instructus; margo exterior aliquantum excurvatus. Ramus exterior
brevis, apice bifido, setis longis, simplicibus instructo. Scapus angulo postero-
interiore paulum ultra medium ramum interiorem attingente.

Color in speciminibus diu in spiritu vini asservatis pallide brunnescens.

Appendix masculina ramum interiorem longe superans, recta, angusta, sat com-
pressa, apice acuminato, acuto. HANSEX, V 7 idensk. Selsk. Skr. (6), V, 1890, pp.
347-348.

ISOPODS OF NORTH AMERICA.

95

CIROLANA CONCHARUM (Stimpson).

JEga concharum STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853,

p. 42. LUTKEN, Vidensk. Meddel., 1859, p. 77.
Conilera concharum HARGER in VERRILL, Report U. S.

Commissioner of Fish and Fisheries, 1873, Pt. 1,

p. 572 (278); p. 459 (165).
Cirolana concharum HARGER, Proc. U. S. Nat. Mus.,

II, 1879, p. 161; Report U. S. Commissioner of

Fish and Fisheries, 1880, Pt. 6, pp. 378-381, pis.

ix-x, figs. 58-63; Bull. Mus. Comp. Zool., Har-
vard College, XI, No. 4, 1883, pi. i, fig. 4; pi. n,

figs. 4-4c. RICHARDSON, American Naturalist,

XXXIV, 1900, p. 216; Proc. U. S. Nat. Mus.,

XXIII, 1901, p. 513.

Localities. Currituck, North Carolina;
Charleston, South Carolina; Woods Hole, Mas-
sachusetts; Amagansett, Long Island; Vine3 r ard
Sound; off Fishers Island; off New Shoreham;
Block Island; Long Island .Sound; Halifax, Nova
Scotia.

Depth. Surface to 18 fathoms; muddy and
sandy bottom.

From stomach of skate; under eye of Pseudotriacis microdon.

It feeds on the common blue crab. From a single crab as many as
108 specimens have been taken.

FIG. 75. CIROLANA CONCHA-
RUM (AFTER HARGER).

FIG. 76. CIROLANA CONCHARUM. a, MAXILLIPED. x 15}. b, MANDIBLE, x 15}. c, FIRST MAXILLA.
x 15}. d, FRONTAL LAMINA, x 27}. e, SECOND MAXILLA, x 15}.

Body oblong-ovate, about three times longer than broad; 8 mm.:
23 mm.

Head wider than long, 3 mm.: 4 mm., with the anterior margin
rounded and produced in a small median point. Eyes small, irregular
in outline, composed of numerous ocelli, and situated in the antero-

96

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

lateral angles of the head. The first pair of antennae have the first
two articles short and subequal; the third is as long as the first two
taken together. The flagellum is composed of seventeen articles and
extends to the antero- lateral angles of the first thoracic segment.
The second antennae have the first two articles short and subequal;
the third and fourth are subequal and each is as long as the first and
second together; the fifth is a little longer than the fourth. The
flagellum is composed of sixteen articles and extends to the posterior
margin of the first thoracic segment: The maxillipeds are composed

of seven articles. The
palp of the mandibles
is composed of three
articles.

The first, fourth, fifth,
and sixth segments of
the thorax are subequal
in length, being each 2
mm. long. The second,
third, and seventh are
subequal and each is 1
mm. in length. The
epimera are distinctly
separated from the seg-
ments on all but the first
segment. In the epim-
era of the sixth and sev-
enth segments the outer
post-lateral angle is
acutely produced be-
yond the posterior mar-
gin of the segments.

All six segments of
the abdomen are distinct.

'J'Jjg last Segment IS tH-

. ;

angular, in shape, with
the apex notched. The uropods do not extend beyond the extremity
of the terminal abdominal segment. Both are of equal length, the
outer branch being only one-third as wide as the inner branch. There
is a notch on the exterior margin of the inner branch near its poste-
rior extremity. The inner angle of the peduncle of the uropoda is
produced and extends two-thirds the length of the terminal abdominal
segment.

The first three pairs of legs are prehensile; the last four pairs ambu-
latory.

FIG. 77. CIROLANA CONCHARUM (AFTER HARGER). a, LAST SEG-

MENT OF ABDOMEN WITH uROPODA. x 6. 6, LEG OF FIRST

PAIR. X 8. C, LEG OF FOURTH PAIR. X 8. d, LEG OF SEVENTH
PAIR. X 8.

ISOPODS OF NORTH AMERICA.

CIROLANA IMPRESSA Harger.

Cirolana impressa HARGER, Bull. Mus. Comp. Zool. Harvard College, XI,
1883, No. 4, pp. 93-95, pi. i, figs. 3-3d; pi. n, figs. 3-3c. VERRILL, Report
U. S. Commissioner of Fish and Fisheries, 1885, p. 559, pi. xxxvi, fig. 165.
RICHARDSON, American Naturalist, XXXIV, 1900, p. 216; Proc. U. S. Nat.
Mus., XXIII, 1901, p. 513.

Localities. Latitude 40 2' 24" north, longitude 70 23' 40" west;
latitude 40 3' north, longitude 70 31' west; latitude 39 57' north,

FIG. 78. CIROLANA IMPRESSA (AFTER HARGER). a, SECOND ANTENNA, x 12. b, FIRST ANTENNA.
x 12. c, SECOND PLEOPOD OF MALE, x 8. d, LATERAL VIEW OF FEMALE, x 3. e, LEG OF FIRST

PAIR. X 8". /, LAST SEGMENT OF ABDOMEN WITH UROPODA. X 6. g, LEG OF SEVENTH PAIR. X 8.
h, LEG OF FOURTH PAIR. X 8.

longitude 69 47' west; latitude 39 55' 28" north, longitude 69 47'
west; Chesapeake Bay; off Cape Hatteras.

Depth. 100-321 fathoms.

Body elongate, almost cylindrical, three and a half times longer than
wide, 6 mm.: 21 mm.

Head wider than long, 2 mm.: 3^ mm., with the anterior margin
widely rounded and slightly excavate on either side of a small median
2858905 7

98

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

point. The eyes are small, composite, and situated in the antero-
lateral angles of the head. The first two articles of the first pair of
antennae are short and subequal; the third article is as long as the
first two taken together. The flagellum is composed of twelve short
articles. The first antennae extend to the antero-lateral angles of the
first thoracic segment or to the end of the peduncle of the second pair
of antennas. The first two articles of the second antennae are short;
and subequal; the third and fourth articles are subequal and each is as
long as the first two taken together; the fifth is only a little longer
than the fourth. The flagellum is composed of twenty articles. The
second antennae extend to the posterior margin of the second thoracic
segment. The maxilliped is composed of seven articles. The palp of
the mandibles is composed of three articles. The frontal lamina is
narrow, elongate, and has the anterior margin rounded.

The first segment of the thorax is 2 mm. long, and is longer than
any of the following segments. The second and third are subequal,

FlG. 79. ClKOLANA IMPRESSA. rt, MAXILLIPED. X 15j. 6, FIRST MAXILLA. X 15} C, FRONTAL LAM-
INA, x 27}. d, MANDIBLE, x 15j. e, SECOND MAXILLA, x 15|.

each being 1 mm. long. The fourth, fifth, and sixth are subequal,
being 2 mm. in length, and each a little longer than either the second
or third segments. The seventh segment is li mm. long. The epimera
are distinct, separated on all the segments with the exception of the
first. The first four have the outer post-lateral angles rounded; the
last two have the outer post-lateral angles acutely produced beyond
the posterior margins of the segments. There is a carina on all
the epimera.

The first segment of the abdomen is entirety covered by the seventh
thoracic segment. The sixth or terminal segment is rounded posteri-
orly and has the posterior margin crenu'ate and furnished with spines.
The uropoda are as long as the terminal segment. The inner branch
is a little longer than the outer branch, is emarginate on the exterior
margin near the extremity and has one long spine in the emargination,
and four long ones on the posterior margin; the exterior and posterior
margins are crenulate. Below the emargination the inner branch is

ISOPODS OF NORTH AMERICA. 99

wide and posteriorly truncate or slightly emarginate. The outer
branch is about half as wide as the inner branch', and is furnished with
one long spine at its posterior extremity. The inner angle of the
peduncle extends about two-thirds the length of the terminal segment
of the abdomen.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. The propodus of the first pair is armed with six spines, the
carpus with one, the merus with twelve long ones on the inferior mar-
gin and one at the outer distal angle of the exterior margin. In the
second and third pairs there are five spines on the propodus, four long
ones on the carpus, and nine long ones on the inferior margin of the
merus, with one long spine at the outer distal angle on the exterior
margin.

CIROLANA POLITA (Stimpson).

JEga polita STIMPSON, Smith. Cont. to Knowl., VI, 1853, p. 41. LUTKEN, Vidensk.

Meddel., 1859, p. 77. VERRILL, Am. Jour. Sci. (3), V, 1873, p. 16.
Conilera polita HARGER, in Smith and Harger, Trans. Conn. Acad. Sci., Ill, 1874,

pp. 3, 22. VERRILL, Am. Jour. Sci., VII, 1874, p. 411.
Cirolana polita HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 161; Report U. S.

Commissioner of Fish and Fisheries, Pt. 6, 1880, pp. 381-382. RICHARDSON,

American Naturalist, XXXIV, 1900, p. 217; Proc. U. S. Nat. Mus., XXIII,

1901, p. 514.

Localities. Bay of Fundy; Cape Cod Bay; Salem, Massachusetts;
Georges Bank; east of Banquereau; off Long Beach, Grand Menan,
New Brunswick.

Depth. 1-321 fathoms. Nature of bottom, coarse yellow sand;
soft sandy mud.

Body narrow, elongate, about four times as long as wide, 4 mm. :
16 mm.; very convex, almost cylindrical.

The head is a little wider than long, 2 mm. : 3 mm. ; its anterior
margin is rounded, and produced in a small median point. The eyes
are small, square, and composite, and situated in the antero-lateral
angles of the head. The first pair of antenna? have the first two
articles short and subequal; the third is twice as long as either of the
other two. The flagellum is composed of twelve articles. The first
pair of antennae extend to the end of the peduncle of the second pair
of antennae or to the antero-lateral angles of the first thoracic segment.
The second antennae have the first two articles short and subequal;
the third and fourth are subequal and each is as long as the first two
taken together; the fifth is narrower than the preceding articles, a
little more than half as wide, and is a little longer than the fourth.
The flagellum is composed of ten articles. a The second pair of antennae
extend to the middle of the first thoracic segment. The maxillipeds
are composed of seven articles. The mandibles have a palp of three

a In all the specimens examined.

100

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

articles. The frontal lamina is small, almost inconspicuous. The
terminal lobe of the first article of the maxillae of the first pair is drawn
out into three elongated processes which are fringed with hairs.

FIG. 80. ClROLANA POLITA (AFTER HARGER). O, SECOND ANTENNA. X 12. 6, LATERAL VIEW OF
FEMALE. X 3. C, FIRST ANTENNA. X 12. (I, LAST SEGMENT OF ABDOMEN WITH UROPODA. X 6. ,
LEG OF FOURTH PAIR. X 8. /, LEG OF FIRST PAIR. X 8.

The fourth, fifth, and sixth segments of the thorax are a little longer
than any of the others. The epimera are distinct on all but the first
segment. They are narrow, oblong plates with the posterior angles
of the last two acutely produced some distance beyond the posterior
margin of the segments. All the segments of the abdomen are

FlG. 81. ClROLANA POLITA. a, MAX1LUPED. X 27}. 6, MANDIBLE. X 27}. C, FIRST MAXILLA.

x 27}. d, SECOND MAXILLA, x 27}.

distinct. The sixth or terminal segment is triangular in shape, with
the apex crenulate. The inner branch of the uropoda is as long as
the terminal segment of the body and has a slight emargination on the

ISOPODS OF NORTH AMERICA.

101

exterior margin near the posterior extremity. The exterior margin
of this branch is also crenulate above and below the emargination.
Below the emargination the inner branch is narrow and posteriorly
pointed. The outer branch is half as wide as the inner branch, is
acutely pointed, and terminates in a single long spine. It extends as
far as the emargination in the exterior margin of the inner branch.

FlG. 82. ClEOLANA BOREALIS (AFTER HARGER) d, LAST SEGMENT OF ABDOMEN WITH UROPODA. X 6.

6, FIRST LEG. x 8. c, FOURTH LEG. x 9. d, SEVENTH LEG. x 9.

The peduncle of the uropoda extends two-thirds the length of the last
abdominal segment.

The first three pairs of legs are prehensile. In these legs the pro-
podus is armed with five spines; the carpus with one spine in the first
pair of legs and with three spines in the other two pairs; the rnerus
with ten spines in the last two pairs and with thirteen in the first pair;
at the distal extremity of the merus on the exterior side is a single
long terminal spine. The last four pairs of legs are ambulatory and
are beset with spines.

CIROLANA BOREALIS Lilljeborg.

Cirolana borealis LILLJEBORG, Ofvers. Vet. Akad. Forh., 1851, p. 23.

Cirolana spinipes BATE and WESTWOOD, Brit. Sessile-eyed Crustacea, II, 1868, p.

299. HARGER, Bull. Mus. Comp. Zool., Harvard College, XI, No. 4, 1883,

pp. 91-93, pi. i, figs. 2-2d; pi. n, figs. 1-lc.
Cirolana borealis HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 321-322, pi. i,

figs. 1-1 v. SCOTT, Ann. Scottish Nat. Hist., 1898, p. 222. G. 0. SAKS, Crust.

102

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of Norway, II, 1899, pp. 70-71, pi. xxix. RICHARDSON, American Natural-
ist, XXXIV, 1900, p. 216; Proc. U. S. Nat. Mus., XXIII, 1901, p. 513.
OHLIX, Bihang till K. Svenska Vet.-Akad. Handl., XXVI, Afd. iv, 1901,
No. 12, pp. 23-24. DOLLFCS, Bull. Soc. Zool. France, XXVIII, 1903, pp.
5-6. NORMAN, Ann. Mag. Nat. Hist. (7), XIV, 1904, p. 437. HAXSEX,
Journ. Linn. Soc. London, XXIX, 1905, pp. 342-343.

Localities. Off Cape Florida; Atlantic coast of North America; also
British Isles; Shetland Isles; northern part of the western coast of
France; latitude 61 16' north, longitude 1 18' east; Mediterranean at
Villefranche and Naples; southern and western coast of Norway; Kat-
tegat; latitude 64 48' north, longitude 6 32' east.

Depth. 30-300 fathoms; 140 m. to 1,210 m. (Dollfus); 808 fathoms
(Norman).

Stebbing" says of this form: "It is a good swimmer, tenacious of
life, a savage devourer of fish, and not to be held in the human hand
with impunity."

FIG. 83. ClEOLANA BOREALIS (AFTER HARGSK). O, LATERAL VIEW. X 3. 6, SECOND ANTENNA.

x 10. c, FIRST ANTENNA, x 10. d, PLEOPOD OF SECOND PAIR OF MALE, x 8.

According to Sars, C. borealis is "one of the most effective scaven-
gers of the sea, excelling in this respect even the most voracious species
of Anonyx among the amphipoda." 6

Body oblong-ovate, almost two and a half times longer than broad,
5 mm. :12 mm., very convex.

Head wider than long, 2 mm. :3 mm., with the anterior margin
widely rounded and produced in a small median point. Ej^es small,
round, composite, and placed in {he antero-lateral angles of the head.
The first pair of antennae have the first two articles short, the second

a Hist, of Crustacea, 1893, p. 343. & Crust, of Norway, II, 1899, p. 71.

ISOPODS OF NORTH AMERICA.

103

a little shorter than the first; the third is equal in length to the first two
taken together. The flagellum is composed of twelve articles. The
first antennae extend to the end of the fourth article of the peduncle
of the second antennae. The first two articles of the second pair of
antennas are short; the second is shorter than the first; the third and
fourth articles are about equal in length and each is as long as the first
two taken together; the fifth article is one and a half times longer than
the fourth. The flagellum is composed of twenty-four articles. The
second antennae extend to the posterior margin of the second thoracic
segment. The maxilliped is composed of seven articles. The palp of
the mandible is composed of three articles. The frontal lamina is nar-
row and elongate, with the anterior end rounded and more flattened
than the posterior end, which is attenuated.

The first segment of the thorax is longer than any of those follow-
ing. The seventh segment is shorter than any of the others. The

FIG. 84. ClROLANA BOREALIS. a, MAXILLIPED. X 27. b, MANDIBLE. X 27j. C, SECOND MAXILLA.

x 27. d, FRONTAL LAMINA, x 51f.

epimera are distinct on all the segments with the exception of the first.
They are broad plates, the last four being wider than the first two
and crossed obliquely by a carina. The outer post-lateral angles of
the last three are produced beyond the posterior margin of the seg-
ment and are more acute than in the first three.

The first segment of the abdomen is partly concealed by the last
thoracic segment. The sixth or terminal segment becomes narrower
to a rounded extremity, which is crenulate and furnished with ten
spines. The inner branch of the uropoda is wide and extends some-
what beyond the extremity of the last abdominal segment. Its outer
post-lateral angle is slightly produced. The outer branch is half as
wide as the inner branch, is a little shorter, and is produced to a
pointed extremity. The margins of both branches are crenulate and
armed with spines. The peduncle extends about two-thirds the length
of the terminal abdominal segment.

104

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first three pairs of legs are prehensile and have the propodus
in the first pair armed with five spines, the carpus with one and the
rnerus with eleven long- spines and many short ones on the inferior
margin, and one long one at the outer distal angle, and the ischium
armed with one spine. In the second and third pairs the propodus

FlG. 85. ClROLANA BOREALIS (AFTER HANSEN). a, LEG OF FIFTH PAIR. 6, LEFT PLEOPOD OF SECOND
PAIR OF YOUNG MALE. C, DORSAL VIEW OF MALE, d, LEG OF SEVENTH PAIR. , THREE BASAL ARTI-
CLES OF LEFT MAXILUPED OF FEMALE. /, LEFT PLEOPOD OF SECOND PAIR OF ADULT MALE, g, LEFT
MAXILLA OF SECOND PAIR OF MALE, h, DISTAL PART OF MOLAR PROCESS OF MANDIBLE, i, MANDIBLE

(LEFT SIDE), j, HEAD OF MALE (VENTRAL VIEW), t, MANDIBLE (RIGHT SIDE). JL, MIDDLE PART OF

HEAD, RIGHT MANDIBLE, MAXILLA AND MAXILLIPEDS OMITTED, m, POSTERIOR PART OF ABDOMEN

OF MALE, n, LEFT MAXILLA OF FIRST PAIR, o, BASAL PART OF LEFT MAXILLIPED. (ENLARGED.)

is armed with two spines, the carpus with three long spines and five
short ones, the merus with six long spines and three short ones on the
inner margin and three long ones at the outer distal end, and the
ischium with three spines. The last four pairs of legs are ambulatory
arid furnished with numerous spines.

ISOPODS OF NORTH AMERICA. 105

CIROLANA GRACILIS Hansen.

Cirolana gradlis HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 329-331, pi. n,
figs. 2-2g. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 513.

Locality. St. Thomas, West Indies.

Body more than three times longer than wide, somewhat convex.

Front produced forward in a process a little wider and shorter than
in C. lorealis.

Eyes large, brownish, seen from the side almost as wide as long,
with the superior margin short and straight; the ocelli are few and
large, rather convex on the superior side, somewhat convex on the
inferior side.

The frontal lamina is very narrow, becoming narrower toward the
apex, with the lateral margins disappearing anteriorly but manifest
posteriorly.

The clypeus is scarcely shorter than the labrum with the anterior,
posterior, and lateral margins elevated and with a median rib, enclosing
two impressed, reticulate areas.

The first pair of antennae are a little stouter than in C. borealis, and
extend a little beyond the apex of the fourth article of the penduncle
of the second pair of antennae.

The second pair of antennae reach the posterior margin of the fourth
thoracic segment; the. peduncle has the third article scarcely longer
than the fourth, and a little shorter than the fifth; the flagellum is com-
posed of about twenty-six articles.

The mandibles and the maxillipeds are almost as in C. borealis.

The thoracic segments are subequal in length; the first segment is
scarcely shorter than the head and a little longer than the fifth seg-
ment; the seventh segment is rather long.

The epimera are a little narrower than in C. neglecta, otherwise
formed as in that species with furcae.

The first three pairs of legs are formed almost as in C. fiorealis,
nevertheless they are somewhat more slender and furnished with a few
hairs and a few spines mostly longer.

The last four pairs of legs are more slender than in C. borealis, and
are rather different from them. The fifth pair of legs are elongated,
are somewhat longer than the seventh pair of legs, and a little shorter
than the sixth pair of legs; the second article is formed as in C. borealis
with simple hairs arranged in three series; the other articles are some-
what more slender than in C. borealis and ornamented with hairs and
a few spines; the fourth article is rather dilated; the fifth article is
quite dilated and furnished everywhere on the superior side with a
few spines. The fourth pair of legs are rather short. The seventh
pair of legs are rather different; the second article is flattened and

106

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

very much elongated, about two and a half times longer than wide,
with the exterior margin thickh T furnished with plumose hairs, the
middle margin furnished with a few simple hairs, the interior margin
bare, the apical margin furnished with numerous very long, plumose
hairs; the other articles are simple, scarcely dilated, shorter, and fur-
nished with very few hairs. The sixth pair of legs differ but little
from the fifth pair of legs.

The first five segments of the abdomen and the pleopods have the
usual structure.

The last segment of the abdomen is more than a half wider than
long, having in the middle near the base a transverse depressipn, the

FIG. 86. ClROLA^ CKAC1L1S (AFTER HANSEN). fl, LEFT PLEOPOD OF SECOND PAIR, b, LEG OF
SECOND PAIR. C, LEG OF SEVENTH PAIR, d, LEG OF FIFTH PAIR. , ANTERIOR PART OF HEAD.

/, LATERAL VIEW OF MALE, g, DORSAL VIEW OF ADULT MALE, h, POSTERIOR PART OF ABDOMEN.
(ENLARGED.)

margins posteriorly being obliquely truncate and ornamented with
about eight spines and long hairs, the apex acute.

The uropoda are rather short; the inner branch is scarcely twice as
long as wide, extending somewhat beyond the abdomen, being a little
longer than the exterior branch and much narrower, with the poste-
rior margin much shorter than the anterior margin, the apex scarcely
acute; both branches are furnished with a few small spines and hairs,
mostly long, and longer than in the preceding species ( C. neglectd) ;
the peduncle has the inner angle strongly produced, extending a long
distance beyond the middle of the inner branch.

The color of an old specimen is yellowish brown.

ISOPODS OF NORTH AMEBICA. 107

The male appendage is long, curved almost like a semicircle, extend-
ing beyond the apex of the inner branch, almost of equal width and
thickness throughout, with apex rounded. a

The above description is adapted from the following one of Hansen's:

Diagn. Oculi brunneseentes, a latere visi fere seque lati ac longi, ocellis pauciori-
bus, superioribus sat convexis, inferioribus aliquantnm convexis. Clypeus ad
medium area biimpressa et pulchre sculpta ornatus. Epimera oinnia furca arcuata,
manifesta et furca marginal! ornata. Pedes quinti paris pedibus septimi paris non-
nihil longiores, graciliores, articulo secundo circiter duplo longiore quam latiore.
Pedes septimi paris graciliores, articulo secundo valde elongato et complanato circiter
duplo et dimidio longiore quam latiore. Segmentum ultimum caudte postice mar-
ginibus valde in obliquum truncatis, spinis c. 8 ornatis, apice acuto. Uropoda ramis
valde insequalibus; ramus interior baud duplo longior quam latior, caudam nonnihil
superans, ramo exteriore parvo et angusto multo longior. Long, specini. sing. 8 mm.

Corpus plus triple longius quam latius, aliquantum convexum. Frons prona in
processum, paulo latiorem et breviorem quam in C. boreali, producta.

Oculi majores, brunneseentes, a latere visi fere seque lati ac longi, margine super-
iore breviore, recto; ocelli pauciores et majores, in latere superiore satis convexi, in
latere inferiore aliquantum convexi.

Lamina frontalis angustissima, ad apicem versus angustata, marginibus lateralibus
ante evanidis, postice manifestis.

Clypeus labro vix brevior, margine et ante et in lateribus et postice et costa
media elevatis, areas duas impressas, recticulatas cingentibus.

Antennute paulo crassiores quam in C. boreali, paulum ultra apicem articuli quarti
antennarum pedunculi prominentes.

Antenme marginem posteriorem segmenti quarti trunci attingentes; pedunculus
articulo tertio vix longiore quam quarto et paulo breviore quam quinto; flagellum c.
26 articulatu m .

Mandibulae et maxillipedes fere ut in C. boreali.

Segmenta trunci longitudine minus intequalia; segmentum primum capite vix bre-
vius et segmento quinto paulo longius; segmentum septimum longius.

Epimera paulo angustiora quam in C. neglecta, ceteroquin ut in ilia specie formata
et f urcata.

Pedes parium trium anteriorum fere ut in C. boreali formati, tamen nonnihil gra-
ciliores, setis paucioribus et spinis paucioribus et ex parte longioribus instructi.

Pedes quattuor parium posteriorum graciliores quam in C. boreali et ab eis sat
diversi. Pedes quinti paris elongati, pedibus septimi paris nonnihil longiores et pedi-
bus sexti paris perpaulo breviores; articulus secundus ut in C. boreali formatus, setis
in series tres dispositis simplicibus; articuli ceteri aliquanto graciliores quam in C.
boreali, setis et spinis minus numerosis ornati; articulus quartus sat dilatatus, articu-
lus quintus perpaulum dilatatus, uterque in latere superiore spinis paucis ornatus.
Pedes quarti paris sat breves. Pedes septimi paris sat aberrantes; articulus secun-
dus complanatus et valde elongatus, circiter duplo et dimidio longior quam latior,
margine exteriore setis densis plumosis, margine medio setis paucis simplicibus,
margine interiore nudo, margine apicali setis compluribus perlongis, plumosis
instructo; articuli ceteri simplices, vix dilatati, breviores, setis perpaucis instructi.
Pedes sexti paris a pedibus quinti paris paulum diversi. Segmenta quinque anteriora
caudte et pleopoda structura solita.

Segmentum ultimum caudse plus dimidio latius quam longius, ad medium prope
basin magis in transversum impressum postice marginibus valde in obliquum trun-
catis, spinis c. 8 et ciliis longis ornatis, apice acuto.

Uropoda sat brevia; ramus interior baud duplo longior quam latior, caudam non-
nihil superans, ramo exteriore parvo et angusto multo longior, margine posteriore

108

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

CIROLANA OBTRUNCATA Richardson.

Cirolana obtruncata RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 514.
MOORE, Report U. S. Commissioner of Fish and Fisheries, XX, Pt. 2, 1902,
p. 167, pi. vin, figs. 9-12.

FIG. 87. CIROLANA OBTRUNCATA (AFTER MOORE), a, GENERAL FIGURE. 6, ABDOMEN (LAST SEGMENT
WITH UROPODA). c, SEVENTH LEG. d, FIRST LEG.

Localities. Kingston, Jamaica;
Fajardo, Porto Rico; a third speci-
men is in the collection of the
U. S. National Museum from un-
known locality.

Head transversely oval. Eyes
small, lateral. First pair of an-
tennae short, reaching a little be-
yond the posterior margin of the
head; flagellum, twelve jointed.

FIG. 88. CIROLANA OB-
TRTXCATA. ABDOMEN
AND LAST TWO THORACIC
SEGMENTS.

c a

FIG. 89. CIROLANA OBTRUNCATA. a, MANDIBLE.
6, SECOND MAXILLA, c, FIRST MAXILLA, d, MAX-
ILLIPED. ALL x 51|.

quam margine anteriore multo breviore, apice vix acuto; ramus uterque spinis par-
vis paueioribus et ciliis ex parte longis et longioribus quam in ppeciebus prsecedentibus
instructus; scapus angulo interiore valde producto, longe ultra medium ramum
interiorem prominente.

Color in spechnine vetere flavo-brunnescens.

Appendix masculina longa, fere semicirculariter curvata, ultra apicem rami inte-
rioris prominent, ubique latitudine et crassitudine fere tequali, apice rotundato.
HAXSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 329-331.

ISOPODS OF NOKTH AMERICA. 109

Second pair of antennae reach the middle of the third thoracic seg-
ment; flagellum, twenty -one jointed.

Thoracic segments subequal; first one somewhat longer than others.
Epimera of second, third, and fourth segments posteriorly rounded;
of fifth, sixth, seventh, and eighth segments pointed posteriorly.

First abdominal segment partly covered by last
thoracic segment, following four segments subequal;
terminal segment with its posterior margin truncate
and minutely crenulate.

Uropoda not longer than posterior margin of
terminal segment: inner branch longer and broader
than outer branch, and crenulate. Both branches
rounded posteriorly.

Color, brown.

Type specimen from Kingston, Jamaica; taken from surface.

Type.V&t. No. 23901, U.S.N.M.

CIROLANA HARFORDI (Lockington.)

JEga harfordi LOCKINGTON, P'roc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 46.
Cirolana calif ornica HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 338-339.

CALMAN, Ann. N. Y. Acad. Sci., XI, 1898, p. 274.
Cirolana harfordi RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 822-823;

Ann. Mag. Nat. Hist. (7), IV, 1899, p. 163; American Naturalist, XXXIV,

1900, p. 217. HAKRIMAN Alaska Expedition, Crustacea, X, 1904, p. 213;

Proc. U. S. Nat. Mus., XXVII, 1904, p. 658. HOLMES,, Proc. Cal. Acad. Sci.

(3), III, 1904, pp. 319-321.

Localities. Victoria, British Columbia; California; Santa Rosa
Island; San Diego; Catalina Harbor; Pacific Grove; Monterey Ba}^;
Lower California; Wilson Cove, California; Santa Cruz, California;
Farallones, California; San Pedro, California.

Body oblong-ovate, a little more than twice as long as wide, 3 mm:
8 mm.

Head wider than long, 1 mm.: 2 mm. with the anterior margin
widely rounded. The eyes are small, round, composite, and situated
in the antero-lateral angles of the head. The first pair of antennae
have the first two articles about equal in length; the third is twice as
long as the second. The flagellum is composed of ten articles. The
first antennae extend to the end of the peduncle of the second antennas,
or to the antero-lateral angle of the first thoracic segment. The sec-
ond pair of antennas have the first two articles short, and subequal;
the third is a little longer than the second; the fourth is twice as long
as the third; the fifth is a little longer than the fourth. The liagellum
is composed of thirty-three articles. The second antennae extend to the
posterior margin of the fifth thoracic segment. The maxillipeds are
composed of seven articles. The mandible has a palp of three articles.

110 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The frontal lamina is conspicuous, short and broad, with the anterior
margin somewhat triangulate.

The first segment of the thorax is twice as long as any of the others,
which are subequal. The epimera are distinct on all the segments
with the exception of the first. Those of the last two segments have
the outer post-lateral angle produced beyond the posterior margins of
the segments. A carina crosses all the epimera, being oblique in the
last four and longitudinal in the first two.

The first two segments of the abdomen are entirely concealed by the
seventh thoracic segment. The sixth or terminal segment is attenua-
ted posteriorly , with the apex rounded, and furnished with eighteen
spines placed close together. The inner branch of the uropoda is as

IG. 91. ClROLANA HAEFOBDI. O, MAXILLIPED. X 27}. b, SECOND MAXILLA. X 51f. C, FIRST

MAXILLA, x 51}. d, MANDIBLE, x 27}. e, FROTAL LAMINA, x 51}.

long as the terminal segment of the body. It is broad posteriorly, with
the posterior margin and the distal end of the exterior margin armed
with spines. The outer branch is almost as long as the inner branch,
is narrower and rounded posteriorly, and has its margins armed with
spines. The peduncle of the uropoda has the inner angle produced to
extend two-thirds the length of the last abdominal segment.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. In the first pair-there are three spines on the propodus, one o
the carpus, three small sharp ones on the merus, and six large blunt
ones, one long slender, pointed one, and one large blunt one on the
ischium, with another long stout spine at the outer distal end. On the
second and third pairs there is an additional spine on the propodus,
three spines on the carpus, nine spines on the merus, with a small

ISOPODS OF NORTH AMERICA.

Ill

spine at the outer distal end, two spines on the ischium, with a long
spine at the outer distal extremity.

The specimen described is a very small one. The larger specimens
have a greater number of spines on the terminal abdominal segment.
The number of spines varies from sixteen to twenty-six, twenty to
twenty -two being the average number.

PIG. 92. ClEOLANA HARFORDI (AFTER HANSEN) . a, DORSAL VIEW OF FEMALE. 6, ANTERIOR PART

OF HEAD, c, FIFTH LEG. d, SEVENTH LEG. e, LATERAL VIEW OF FEMALE. /, POSTERIOR PART OF
ABDOMEN, g, SECOND LEG. (ENLARGED.)

CIROLANA PARVA Hansen.

Cirolana parva HAXSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 340-341, pi. n,
figs. 6-6b; pi. in, figs. 1-ld. RICHARDSON, American Naturalist, XXXIV,
1900, p. 217; Proc. U. S. Nat. Mus., XXIII, 1901, p. 514. MOORE, Bull.
U. S. Fish Comm., XX, Pt. 2, 1902, p. 167, pi. vin, figs. 6-8.

Localities. Key West, Florida; Gulf of Mexico; St. Thomas, West
Indies; St. Croix, West Indies; between the delta of the Mississippi
and Cedar Keys, Florida; Andros Island, Bahamas; between Nassau
and Andros, Bahamas; Georgetown, Bahamas.

Depth. 25-27 fathoms.

Among algee, below low tide; banks, low tide.

Body compact, oblong-ovate, nearly three times longer than wide,
3 mm.: 8 mm.

Head wider than long, 1 mm. :2 mm., with the anterior margin
widely rounded and produced in a small median point, which arches
over the antennae to meet the frontal lamina on the other side. The
eyes are small, round, composed of many ocelli, and situated in the

112 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

antero-lateral angles of the head. The first pair of antennae have the
first two articles subequal and difficult to distinguish; the third is
twice as long as the second. The flagelluni is composed of twelve

FIG. 93. ClROLANA PARVA ( AFTER HAN8EN). a, ADULT MALE, ft, LATERAL VIEW OF SAME. C, SECOND

LEG. d, ANTERIOR PART OF HEAD (VENTRAL VIEW), e, FIFTH LEG. /, SEVENTH LEG. g, POSTERIOR

PART OF ABDOMEN, h, LEFT PLEOPOD OF SECOND PAIR. (ENLARGED.)

FIG. 94. ClROLANA PARVA. a, MAXILLIPED. X 51|. b, MANDIBLE. X 51|. C, FRONTAL LAMINA.

x 51 1. d, FIRST MAXILLA, x 51|. e, SECOND MAXILLA, x 51|.

articles. The first antennae extend to the posterior margin of the

head or to the end of the peduncle of the second pair of antennae.

The second antennae have the first two articles short and subequal;

the third is a little longer than the second; the fourth and fifth are

ISOPODS OF NORTH AMEEICA.

113

subequal and each is about twice as long as the third. The flagellum is
composed of thirty-two articles. The second pair of antennse extend
to the fourth thoracic segment. The maxilliped is composed of seven
articles. The palp of the mandibles is composed of three articles.
The frontal lamina is broad and
has the anterior margin trian-
gularly produced, the apex be-
ing rounded and meeting the
anterior portion of the median
point of the front of the head.

The first thoracic segment
is twice as long as any of the
other segments, which are sub-
equal. The epimera are dis-
tinct on all the segments with
the exception of the first. The
last four are crossed by an ob-
lique carina, the first two by a
longitudinal carina. The last
four are also broader than the
first two and have the outer
postlateral angle more acute,
it being produced in the last
two beyond the posterior mar-
gin of the segments.

The first segment of the ab-
domen is entirely concealed
by the seventh thoracic seg-
ment. The sixth or terminal
segment is produced in a
rounded extremity, which is
crenulate and furnished with
eight spines. The inner branch
of the uropoda is wide and is
produced beyond the extremity
of the abdomen; its posterior
end is obliquely truncate, and
crenulate with the outer post-
lateral angle acutely produced

in two prominent teeth; the outer margin is faintly crenulate; both
margins are furnished with spines. The outer branch is half as wide
as the inner branch, is somewhat shorter, and is acutely produced in
two prominent teeth. The peduncle extends to the inner post-lajteral
angle of the inner branch.
2858S

FIG. 95. ClROLANA PAEVA (AFTER MOORE), a, GEN-
ERAL FIGURE, x 53. 6, FIRST ANTENNA, x 33.
c, SECOND ANTENNA, x 33.

^~ <;<?

114 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first three pairs of legs are prehensile. The propodus is armed
with one spine; the merus with five blunt ones. In the second and
third pairs of legs the spines on the merus are sharper, and there is
also a long spine at the outer distal extremity; the ischium is, more-
over, furnished with one spine. In the third pair there is also a spine
on the carpus. The ambulatory legs are beset with spines.

CIROLANA ALBIDA Richardson.
Cirolana albida RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 514-515.

FIG. 96. CIROLANA
ALBIDA. MAXIL-

LIPED. X 39.

Locality. Sugarloaf Ke}^, Florida.

This species is rather doubtful and may have to be suppressed, but
until further evidence is furnished it may be allowed to stand for the
present. It is very close to Cirolana parva.

Body narrow, relaxed, elongate, three and two-thirds
times longer than broad. Head transverse; eyes large,
black. First pair of antennae extend to the end of the
peduncle of the second pair; flagellum nine jointed.
Second pair of antenna extend to the posterior margin
of the third thoracic segment; flagellum twenty-three
jointed.

First thoracic segment but little longer than those
following, which are subequal in length. First ab-
dominal segment entirely covered by
seventh thoracic segment. Terminal
segment triangulate with rounded ex-
tremity, its posterior margin denticu-
late and bearing eight spines, the
spines alternating with the teeth. The uropoda reach
tb.e end of the terminal segment; the inner branch is
obliquely truncate posteriorly, and armed with spines;
the outer branch is shorter and more slender than
the inner branch, is pointed at its extremity, and
armed posteriorly and on its external margin with
spines.

Color white, with scattered black spots.
Several specimens were taken by Mr. E. L. Morris at Sugarloaf Key,
Florida.

Type. Cat. No. 23902, U.S.N.M.

CIROLANA CUBENSIS Hay.
Cirolana cubenm HAY, Proc. U. S. Nat. Mus., XXVI, 1903, pp. 429-435.

Locality. Cuba; in cavern at San Isidro.

Body ovate; a little more than twice as long as wide; 3 mm. : 7 mm.

Head twice as wide as long 1 mm.: 2 mm. with the anterior mar-

gin rounded and produced in a median point. The eyes are absent.

FIG. 97. CIROLANA
ALBIDA.

ISOPODS OF NORTH AMERICA.

115

The first pair of antennae have the peduncle composed of only two
articles, both long and narrow; the second is a little longer than the
first. The flagellum is composed of fourteen articles, and extends to
the posterior margin of the second thoracic segment. The second
pair of antennse have the first three articles short and subequal; the
fourth and fifth articles are subequal in
length, and each is as long as the first three
articles taken together. The flagellum is
composed of thirty articles, and extends to
the middle of the fifth thoracic segment.
The maxillipeds are composed of seven arti-
cles. The palp of the mandibles is com-
posed of three articles. The frontal lamina
is short and broad, with the anterior ex-
tremity rounded.

The second, third, and fourth segments of
the thorax are subequal, and each is about
half as long as the first segment. The fifth,
sixth, and seventh segments are subequal,
and each is a little longer than any of the
three preceding segments. The epimera of all the segments, with
the exception of the first, are distinctly separated from the seg-
ments. The epimera of the last two segments have the outer post-
lateral angle acutely produced. All are crossed by an oblique carina.

FIG.

. ClROLANA CUBENSIS
(AFTER HAY).

FIG. 99. ClROLANA CUBENSIS. a, MAXILLIPED. X 27}. 6, MANDIBLE. X 27}. C, FRONTAL LAMINA.

x 27}. d, FIRST MAXILLA, x 27}. e, SECOND MAXILLA, x 27}.

The first segment of the abdomen is entirely covered by the seventh
thoracic segment, with the exception of the post-lateral angles. The
terminal segment is rounded posteriorly and has the posterior margin
smooth. The uropoda do not extend beyond the extremity of the
abdomen. The inner branch is twice as wide as the outer branch and
is posteriorly pointed. The inner branch is obliquely truncate. The

116 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

margins are smooth and furnished with hairs, as is the terminal abdom-
inal segment. The inner angle of the peduncle of the uropoda is pro-
duced. The first pair of legs are somewhat prehensile. All the others
are ambulatory.

2O. Genus CONILERA Leach.

First pair of antennae with basal article of peduncle not extended
straight m front at right angles to remaining part of antenna. Pedun-
cle of the second pair of antenna? composed of five articles. The plate
of the second article of the maxillipeds is furnished with hooks.

The first pair of pleopods have the peduncle elongated, somewhat
longer than wide, hard, and furnished on the inner side with about nine
hooks; the inner branch is rather elongated, narrow, hard, with the
inner margin straight, thick, almost bare, the outer margin furnished
with moderately long hairs; the outer branch is shorter than the inner
branch, ovate, hard, furnished with a longitudinal furrow, with the pos-
terior margin furnished with moderately long hairs; the pleopods
thus form a large ope rculum, covering the other pleopods. The pedun-
cle of the second pair of pleopods is scarcely wider than long; the
branches are of the usual structure.

The peduncle of the uropoda has the inner posterior angle somewhat
produced.

The six segments of the abdomen are distinct.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CONILERA.

a. Eyes present. First pair of antennae extend to the middle of the fifth article of the
peduncle of the second pair of antennae. The second pair of antennae extend to
the middle of the first thoracic segment. Body four times longer than wide.

Conilera cylindracea ( Montagu )

of. Eyes wanting. First pair of antennae extend to the middle of the first thoracic
segment. The second pair of antennae extend to the middle of the seventh
thoracic segment. Body five times longer than wide Conilera stygia Packard

CONILERA CYLINDRACEA (Montagu).

Oniscus cylindracevs MONTAGU, Trans. Linn. Soc. Lond., VII, 1804, p. 71, pi. vi,

fig. 8.
Conilera montagui LEACH, Diet. Sci. Natur., XII, 1818, p. 348. DESMAREST,

Consid. Crust., 1825, p. 304. MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840,

p. 242.
Conilera c.i/lindracea BATE and WESTWOOD, Brit. Sessile-eyed Crustacea, II, 1868,

p. 304. HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 358-361, pi. iv,

figs. 5-5c; pi. v, figs. 1-ld. RICHARDSON, American Naturalist, XXXIV,

1900, p. 217; Proc. U. S. Nat, Mus., XXIII, 1901, p. 515. NORMAN, Ann.

Mag. Nat. Hist. (7), XIV, 1904, p. 438.

See Hansen for characters of. genus, Vidensk Selsk. Skr. (6), V, 1890, pp. 358.

ISOPODS OF NORTH AMERICA.

117

Localities. Off South Carolina; between the Delta of the Mississippi
and Cedar Keys, Florida; also Gulf of Naples; coast of England;
coast of France.

Depth. lll-lW fathoms.

Off Pilchards.

FlG. 100. CONILERA CYLINDRACEA (AFTER HANSEN). a, LATERAL VIEW OF FEMALE, b, POSTERIOR
PART OF ABDOMEN OF ADULT FEMALE. C, ANTERIOR PART OF HEAD. (1, LEFT PLEOPOD OF FIRST
PAIR IN ADULT MALE. , LEFT PLEOPOD OF SECOND PAIR IN ADULT MALE. (ENLARGED.)

The dog-fish is infested with these parasites, which reduce their
prey to skin and bones. They hunt, according to Dr. F. Day, a in
shoals, driving away the congers and other fish, but are themselves
devoured by the bream.

Proc. Zool. Soc. Lond., 1884, p. 44.

118 ^BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Body narrow, elongate, a little more than four times longer than
broad, 4 mm.: 17 mm., almost cylindrical.

Head wider than long, 2 mm.: 3 mm., with the frontal margin
slightly excavate on either side of a small median point. Eyes small,
round, composite, and situated in the antero-lateral angles of the head.
The first pair of antennae have the basal article short, but somewhat
dilated; the second article is not quite as long as the first; the third is
twice as long as the second. The flagellum is composed of ten articles.
The first antennas extend almost to the middle of the fifth article of
the peduncle of the second antennte. The second pair of antenna? have
the first two articles short, the second a little shorter than the first;
the third article is equal in length to the first two taken together; the
fourth is a little longer than the third; the fifth is a little longer than
the fourth. The flagellum is composed of thirteen articles. The
second antennas extend to the middle of the first thoracic segment.
The maxilliped is composed of seven articles. The mandible has a

FIG. 101. CONILERA CYLINDRACEA. O, MAXILLIPED. X 27}. b, FRONTAL LAMINA. X 51|. C, SECOND

MAXILLA, x 27J. d, MANDIBLE, x 27}. e, FIRST MAXILLA, x 27}.

palp of three articles. The frontal lamina is conspicuous on the ventral
side; the anterior end is rounded; the posterior end is produced in a
narrow process.

The first segment of the thorax is twice as long as the second; the
second and third are equal in length; the fourth, fifth, and sixth seg-
ments are equal and each is one and a half times longer than the third;
the last segment is equal to the third. The epimera are distinct on
all the segments, with the exception of the first. They are narrow,
elongate plates, equal in width, with the posterior angles not produced
beyond the posterior margins of the segments. In the epimera of the
first four segments the posterior extremity is rounded; in the last two
the outer post-lateral angle is not rounded, but' angular. A carina
crosses all the segments obliquely.

The first segment of the abdomen is entirely concealed by the seventh
thoracic segment except at the sides. The terminal segment is trian-
gular, with the apex very acute. The posterior margin at the apex and

ISOPOD3 OF NOBTH AMERICA.

119

on either side of the apex for some distance is denticulate. The inner
branch of the uropoda is a very little longer than the terminal abdomi-
nal segment. It is posteriori}^ very acutely produced with an emar-
gination in the exterior margin near the apex. Both inner and outer
margins are denticulate, the four teeth within the emargination being
very much larger than the others. There is also a large tooth on the
inner margin close to the apex of the branch, giving the extremity a
bidentate appearance. The outer branch is half as wide as the inner
branch, is somewhat shorter, not extending beyond the emargination
in the outer margin of the inner branch, has the extremity acutely
produced and bidentate, and has both margins denticulate. The pedun-

FlG. 102. CONILERA CYLINDBACEA (AFTER HANSEN). a, ADULT FEMALE. 6, SECOND LEG. C, FIFTH

LEG. d, SEVENTH LEG. (ENLARGED.)

cle has the inner angle produced and it extends two-thirds the length
of the terminal abdominal segment.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. In the first three pairs the propodus is armed with three
spines, the carpus with one large spine and one small spine in the first
pair or two smaller ones in the second and third pairs; the merus with
five or six blunt ones on the inner margin and one long one at the
outer distal extremity; the ischium is armed with one spine in the
second and third pairs.

The two specimens from North America in the collection of the
U. S. National Museum are small, measuring 2 mm. : 10^ mm.

The description is from a specimen obtained from the Naples
Zoological Station.

120 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

CONILERA STYGIA Packard.
Conilera stygia PACKARD, Proc. Amer. Assoc. Adv. Sci., XLIX, 1901, p. 228.

Locality. Monterey, Mexico. Found in wells.

"It is totally eyeless, and adds another to the blind fauna of our
caves and wells. Hitherto the genus has been represented by but a
single species, inhabiting the British coast. Compared with Bate and
Westwood's figure of C. cylindracea, the body is longer, the antennae
much longer, reaching to the middle of the first thoracic segment,
those of the second pair nearly to the middle of the seventh thoracic
segment. Only the first three pairs of legs are short, with a very thick
hand; the four hinder pairs of legs are long, slender. The two last
divisions of the pleopoda are unequal, the outer division very narrow,
but a little more than half as long as the broad inner division or endo-
podite. Length of body, 25 mm. ; breadth, 5 mm.

" This form is like most, if not all, other blind or eyeless arthropods
in having a longer body, antennae, and legs in compensation for the
loss of eyes." a PACKARD.

21. Genus CIROLANIDES Benedict.

Eyes absent. First pair of antennae with basal article of peduncle
not extended straight in front at right angles to remaining part of
antenna. Peduncle of the second pair of antennae composed of five
articles.

The plate of the second article of the maxillipeds is furnished with
hooks.

Abdomen has all six segments distinct.

The uropoda have the inner angle of the peduncle not produced.

Only the first pair of legs are prehensile; the following six pairs
are ambulatory.

CIROLANIDES TEXENSIS Benedict.

Cirolanides texensis BENEDICT, Proc. U. S. Nat. Mus., XVIII, 1896, p. 615.
RICHARDSON, American Naturalist, XXXIV, 1900, p. 217. ULRICH, Trans.
Am. Microscopical Soc., XXIII, 1902, pp. 88-90, pi. *v.

Locality. San Marcos, Texas, found in an artesian well.

Body oblong-ovate, about two and a half times longer than wide,
7 mm. : 17 mm.

Head wider than long, 2 mm. :3 mm. Anterior margin widely
rounded. Eyes absent. The first pair of antennae have the basal
article short; the second twice as long as the first; the third one and
a half times longer than the second. The flagellum is composed of
fifteen articles. The first antennae extend to the posterior margin

Proc. Amer. Assoc. Adv. Sci., XLIX, 1901, p. 228.

ISOPODS OP NORTH AMERICA.

121

FIG. 103. ClROLANIDES TEXENSIS (AFTER ULRICH). a, DORSAL VIEW. 6, END OF SECOND ANTENNA,

c, FIRST ANTENNA, d, FIRST PLEOPOD. e, FIRST LEG. /, SECOND ANTENNA. 17, SECOND LSG. h, THIRV>
LEG. i, FOURTH LEG. j, THIRD PLEOPOD. k, FIFTH LEG. I, SECOND PLEOPOD. m, UROPOD. n, MAX-
ILLA, o, MANDIBLES, p, MAXILLIPEDS. q, VENTRAL SIDE OF HEAD.

122 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of the first thoracic segment. The second pair of antennae have the
first two articles short, the second one a little longer than the first;
the third is as long as the first two taken together; the fourth is
nearly one and a half times longer than the third; the fifth is one and

a half times longer than the fourth. The
flagellum is composed of thirty-six articles.
The second antennae extend to the pos-
terior margin of the fifth thoracic seg-
ment. The maxilliped is composed of
seven articles. The mandible has a palp
of three articles. The frontal lamina is
conspicuous on the ventral side, is narrow
and compressed laterally, and elevated; it
is triangular in shape, with the acute apex
of the anterior end extending forward; it
is also about twice as long as broad.

The first, fifth, and sixth segments of
the thorax are longer than any of the
others. The epimera are distinct on all the
segments with the exception of the first.
They are broad, with the post-lateral
angles acutely produced in the last four

beyond the posterior margins of the segments. A carina crosses
obliquely all the epimera.

The segments of the abdomen are all distinct. The sixth or ter-
minal segment is rounded posteriorly. The uropoda are a little longer

FIG. 104.0 ClROLANIDES TEXENSI8.

A

FlQ. 105. ClBOLANIDES TEXENSIS. a, MAXILLIPED. X 27J. 6, FIRST MAXILLA. X 27J. C, SECOND

MAXILLA, x 27J. d, MANDIBLE, x 27i. e, FRONTAL LAMINA, x 61f.

than the terminal abdominal segment. The inner branch is a little
longer than the outer branch and somewhat wider. Both are similar
in shape, bemg wider anteriorly than posteriorly, the narrow extremity
being truncate. The peduncle is as long as the outer branch, a little
more than half the length of the terminal abdominal segment, and is

a Figs. 104 and 106 are by the courtesy of Dr J E. Benedict.

ISOPODS OF NORTH AMERICA.

123

not produced at its inner angle. Both branches are furnished with
spines.

Onty the first pair of legs are prehensile. All the others, from the
second to the seventh inclusive, are ambulatory. The propodus of the
first pair of legs is furnished with three spines; the carpus with one
and the merus with one.

FIG. 106. ClROLANIDES TEXENSIS. a, FlKST LEG. 6, SECOND LEG. C, FOURTH LEG. d, SEVENTH LEG.

e, UHOPOD.
22. Genus EURYDICE Leach.

The peduncle of the second pair of antennae is composed of four
articles.

The first pair of antennae have the basal article of the peduncle
extended straight in front at right angles to remaining part of antenna.

The plate of the second article of the maxillipeds is not furnished
with hooks.

The abdomen has all six segments distinct.

The first and second pairs of pleopods are subequal in structure; the
peduncle is very little or scarcely any wider than long; both branches
are submembranaceous, the posterior margin being furnished with very
long plumose hairs.

The peduncle of the uropoda has the inner posterior angle very little
produced.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS EURYDICE.

a. Terminal abdominal segment rounded posteriorly between the post-lateral tri-
angular teeth. Posterior margin between the lateral teeth denticulate, a spine

alternating with each tooth Eurydice convexa Richardson

a x . Terminal abdominal segment not rounded posteriorly.

b. Terminal abdominal segment truncate between the triangular lateral teeth and
furnished with four long spines on the posterior margin.

Eurydice caudata Richardson

b'. Terminal abdominal segment widely emarginate in the middle between the
truncate post-lateral angles, each angle being furnished with two robust
spines Eurydice spinigera Hansen

124 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

EURYDICE CONVEXA Richardson.

Eurydice convexa RICHARDSON, American Naturalist, XXXIV, 1900, p. 217; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 516.

Locality. Cape San Bias, Florida.

Head transverse; anterior margin rounded. Eyes quadrangular.
First pair of antennae short, reaching the middle of the last peduncular
joint of the second pair of antennas, or the posterior margin of the
head; flagellum four- jointed. Second pair of antenna? long, reaching
the anterior margin of the terminal abdominal segment in the female;
flagellum eighteen-jointed. In the male the second pair of antennae
are equal to the entire length of body, reaching the tip of the terminal
segment.
Thoracic segments subequal in length.

Abdomen in female shprter than thorax and
head together; abdomen in male about equal to
thorax and head.

First five segments equal in length. Terminal
segment rounded posteriorly, with post-lateral
triangular teeth, between which, a space interven-
ing, the posterior margin is denticulate, a spine
FIG. io7. ECKYDICE CON- alternating with each tooth. The uropoda are
VEXA. TERMINAL AB- s h or t no t reaching the extremity of the terminal

DOMINAL SEGMENT. J

segment. Both branches are truncate and crenu-
late on their exterior margins and fringed with long hairs.

Color, light brown, with odd-shaped markings of black.

A number of specimens were taken by the U. S. Bureau of Fisheries
steamer Albatross at Cape San Bias, Florida.

Type. Cat. No. 10049, U.S.N.M.

EURYDICE CAUDATA Richardson.

Eurydice caudata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 824-825;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 164-165. -

Locality. Isthmus Cove, Catalina Island, California.

Body elongate and narrow. In male, abdomen is equal in length to
thorax; in female, it is shorter. Surface of body smooth.

Head widely rounded in front; its anterior margin narrowly thick-
ened. Eyes large and round and situated at a distance of one-third the
width of the head apart. First pair of antenna? extend to the posterior
margin of the head; flagellum consists of five articles, the first of
which is very long and those following quite short. The second pair
of antennae extend as far as the posterior margin of the fourth segment
of the abdomen; the flagellum consists of twenty-five long, slender
joints. In the female, the second pair of antennae are much shorter,
reaching only to the posterior margin of the last thoracic segment;
the flagellum consists of about twenty joints.

1SOPOD8 OF NORTH AMERICA. 125

The thdracic segments are subequal. The epimera are narrow, and
those of the last three or four segments acutely pointed.

All the abdominal segments are visible in a dorsal view. The ter-
minal segment is rounded at the sides and truncate at its extremity,
the lateral angles being produced in a short triangular process, between
which the posterior margin is distinctly denticulate and bears four
spines, which are about twice as long as the lateral teeth. The
uropoda are short, not reaching the extremity of the terminal seg-
ment, are truncate and crenulate on their posterior margins. The
uropoda, as well as the terminal segment, are fringed with short hairs.

The legs are long and slender and armed with many spines.

Color, light brown marked with black spots.

Individuals of this species were collected at Isthmus Cove, Catalina
Island, California, by the U. S. Bureau of Fisheries steamer Albatross.

Type. No. 22565, U.S.N.M.

This species resembles E. grimaldii Dollfus
more closely than any other species of the
genus. It differs in the following characters:

1. The greater number of joints in the flagel-
lum of the first pair of antennae. In our species
there are five joints, while in E. grimaldii the
flagellum is uniarticulate.

2. In the fewer number of joints in the flagel- FlG 108 ._ E r R YDicE CAU-
lum of the second pair of antennae. Inourspecies DATA. LAST TWO AB-
there are only twenty-five, while in E. grimaldii

the flagellum consists of thirty-two articles.

3. In the presence of four spines on the posterior margin of the
terminal segment. In E. grimaldii the posterior margin is denticulate.

EURYDICE SPINIGERA Hansen.

Eurydice spinigera HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 367-369,
pi. v, figs. 4-4c; pi. vi, figs. 1-lc. RICHARDSON, Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 516.

Locality. West Indies. a

This species is similar to E. elegantula. The body is broader than
in the male of E. elegantula and is a little more than three times
longer than wide; the thorax is much wider and not shorter than the
abdomen.

The front of the head is a little emarginate, the median process
being absent. The eyes are as in the male of E. elegantula. The
first pair of antennae are a little stouter than in the female of E.
elegantula; the first article of the peduncle is narrower, manifestly
reaching beyond the second article; the third article is a little wider
than long; the flagellum is furnished with rather numerous, rather

a Hansen, in a paper received since this paper was sent to press, says that this species
was captured in the eastern part of the Atlantic between Denmark and St. Thomas.

126 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

short sensitive hairs, and has the first article two and a half times
longer than the three other articles taken together.

The second pair of antennae extend a little beyond the thorax; the
last article of the peduncle is more than twice as long as the penulti-
mate article; the flagelluin is composed of about twenty to twenty-
four articles, with the exterior articles for the greater part long
and without apical hairs. The clypeus occupies all the area between

the mandibular palps and
is produced in a long
tubercle. The first seg-
ments of the thorax are
ornamented in the mid-
dle transverse line with
short and deep furrows;
the four posterior seg-
ments are ornamented
with long transverse fur-
rows.

All the epimera have
the posterior angle pro-
duced in an acute, coni-
cal process, those of the
sixth segment being the
longest of all, those of
the seventh segment be-
ing the shortest of all.

The first three pairs
of legs are almost as
in E. elegantula, fur-
nished, however, with
more hairs. The last
three pairs of legs are
a very little shorter and

FIG. 109. EURYDICE SPINIGERA (AFTER HANSEN). a, LATERAL W j(Jgi' than itt E fleOCin-
VIEW OF ADULT MALE, b, ANTERIOR PART OF HEAD (FROM BE- *

LOW), c, LEFT PLEOPOD OF SECOND PAIR, d, FIRST ANTENNA, tula} they are, DOWevei',

e, POSTERIOR PART OF ABDOMEN. /, LEG OF FIFTH PAIR. ,LEG furnished with more

OF SEVENTH PAIR, h, LEG OF SECOND PAIR. (ENLARGED.)

hairs. The seventh pair

of legs have the third to the sixth articles furnished on the inferior
side toward the inner margin with many short spines, and are orna-
mented toward the exterior margin with many hairs; the fifth article
is a very little shorter than the sixth, and much longer than the fourth;
the fourth article is a little longer than wide.

The last segment of the abdomen is furnished at the base with a
short and deep median depression and on either side with a deep and
rather large lateral excavation; the median depression is bicarinated
in the bottom; the posterior margin is a little more than a third part

ISOPODS OF NORTH AMEKICA. 127

of the width of the segment, is widely emarginate in the middle, the
angles being obliquely truncate, and armed with two robust spines
(the inner one much longer than the outer one).

The uropoda extend a little beyond the abdomen; they are large,
formed almost as in the male of E. elegantula, with the exterior mar-
gin of the inner branch, however, a little more curved. The color is
brown, covered with scattered black, irregular, and branching spots.

The male appendix does not extend be3 7 ond the inner branch, is
strongly dilated at the apex, the apex being widely rounded and
entire. 68

The above description is adapted from the following one of Hansen's:

Diagn. Corpus paulo plus quam triplo longius quam latius; cauda truncum
longitudine subjrquans. Clypeus areani totam inter palpos mandibularum occupans,
in cornu longum productus. Antennulee articulo primo flagelli circiter duplo et
dimidio longiore quam articulis 3 ceteris cunctis. Antennae articulo ultimo pedun-
culi plus duplo longiore quam articulo penultimo. Epimera ononia angulo posteriore
in processum conicum, acutum producto. Segmentum ultimum caudge margine
posteriore paulum ultra tertiam partem latitudinis segmenti explente, in medio late
ernarginato, angulis in obliquum truncatis, spinis binis (interiore multo longiore
quam exteriore), robustis, affixis ornatis. Uropoda caudarn paulum superantia.
Long, maris adulti 9 mm.

E elegantulie sat similis. Corpus minus angustatum quam in mare E. elegantulse;
truncus sat multo latior et non brevior quam cauda.

Frons ante perpaulum emarginatus, processu medio evanido. Oculi ut in mare
E. elegantulse. Antennulae paulo crassiores quam in femina E. eleganlulx; pedunculus
articulo primo angustiore, ante articulum secundum manifesto prominente, articulo
tertio paulo latiore quam longiore; flagellum setis sensilibus sat numerosis, breviori-
bus instructum.

Antennae truncum paulum superantes; flagellum c. 20-24 articulatum; articulis
exterioribus ex parte majore longis, seta apicali nulla.

Segmenta anteriora trunci stria transversa brevi, media, profunda ornata; seg-
menta 4 posteriora saltern stria transversa longa instructs.

Epimera structura in diagnosi commemorata a speciebus omnibus mihi cognitis
valde di versa; epimera sexti paris processu conico inter omnes longissimo; epimera
septimi paris processu inter omnes brevissimo.

Pedes parium trium anteriorum fere ut in E. elegantula, setis tamen pluribus
instruct!.

Pedes parium trium posteriorem perpaulo breviores et latiores quam in E. elegan-
tula; setis tamen pluribus instructi. Pedes septimi paris articulis tertio-sexto in latere
inferiore ad marginem interiorem versus spinis multis brevioribus instructi, ad margi-
nem exteriorem versus setis multis ornati; articulus quintus perpaulo brevior quam
sextus, multo longior quam quartus; articulus quartus paulo longior quam latior.

Segmentum ultimum caudte ad basin versus impressione media breviore et pro-
funda et utrinque excavatione lateral! profunda et sat magna instructum; impressio
media in fundo bicarinata; reliqua in diagnosi commemorata. Uropoda majora,
fere ut in mare E. elegantulse formata, margine exteriore rami interioris tamen pau-
lum incurvo.

Color brunneus, maculis irregularibus et ramosis nigris minus crebre conspersis.

Appendix masculina ramum interiorem minus superans, ad apicem versus valde
dilatata, apice late rotundato, integro. HANSEN, Vidensk. Selsk. Skr. (6), V, 1890,
pp. 367-369.

128 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

23. Genus BRANCHUROPUS Moore.

Peduncle of second pair of antenna? composed of four articles. First
pair of antenna? with basal article of peduncle extended straight in
front at right angles to remaining part of antenna.

Maxillipeds composed of two articles; basal article long; second
article short, armed with a few hairs.

Uropods attached to underside of abdomen, similar in structure to
the pleopods and probably branchial in function.

Abdomen with all six segments distinct.

BRANCHUROPUS LITTORALIS Moore.

Branchuropus littoralis MOORE, Bull. U. S. Fish Commission, XX, Pt. 2, 1902,
p. 168, pi. vni, figs. 13-21; pi. ix, fig. 1.

Locality. Porto Rico.

"Body moderately convex, about 2.75 times as long as broad; abdo-
men not abruptly narrower than the thorax. Head rounded in front,
about half as wide as greatest width of body about two-thirds as long
as wide.

"Thorax broadest at fifth joint fifth and sixth joints longest; the
rest shorter and subequal. Epimera of all but first joint distinct; sides
of first segment emarginate, the anterior portion being produced some-
what to embrace the eye; epimera of second and third segments not
produced posteriorly; of fourth, fifth, sixth, and seventh produced in
a sharp process terminated by a spine, that of the last extending
beyond the first abdominal segment.

"Abdominal segments all distinct, gradually increasing in length
from first to fifth; first segment somewhat narrower, not produced
posteriorly at sides, exposed throughout its breadth; the other free
segments subequal in breadth, strongly produced posteriorly at sides,
the last two armed at each angle with a stout spine.

"Telson rounded, about five-sixths as long as broad, margin not
armed, abruptty higher in median two-thirds at base, with an ill-
defined, low protuberance or process on each side of middle line.

"Eyes large, black, space between about as great as diameter of
eye. Base of first antennae projecting from beneath overhanging
front; peduncle of three joints, the first and second forming a right
angle, the second and third joints subequal; flagellum four jointed,
the first joint long and tapering, 1.5 times as long as the other three,
second and third joints subequal, last joint short and reaching to
beyond posterior margin of head.

See Moore for characters of genus, Bull. U. S. Fish. Comm., XX, Pt. 2, 1902,
pp. 167-168.

ISOPODS OF NORTH AMERICA.

129

"Second antenna? long and slender, when placed close to sides of
body reaching to about anterior margin of telson; peduncle four
jointed, joints increasing gradually in length and slenderness, second
joint furnished on distal external angle with four or five setae;
flagellum with about eighteen joints, which are longest in its middle.

"Epistome slender, expanded in front and emarginate, reaching to
about the level of frontal margin of head, but not connected with it.

"Mandible with tridentate cutting edge, movable pectinate ap-
pendage and three -jointed palp, in general resembling this organ
in Eurydice.

FIG. 110. BRANCHfRorrs UTTORAUS (AFTER MOORE), o, FRONT OF HEAD FROM BELOW, b, FIRST

ANTENNA. C, SECOND ANTENNA, d, GENERAL FIGURE. , MANDIBLE. /, FOURTH LEG. fif, MAXIL-

LIPED. h, FIRST LEG. (', SEVENTH LEG.

"Maxillipeds two jointed, the basal joint long, somewhat trans-
versely of the head; the second joint short and armed with a few
hairs distalty.

"Thoracic limbs gradually increasing in length posteriorly. First
limb with second joint longest, the third, fourth, and fifth successively
shorter, the sixth joint as long as third, and pectinate by a series of
spines, the last one stoutest, and the seventh not forming with the
sixth a subchelate hand, as in Anuropus.

"The posterior border of the limb is furnished with spines and
setae. Second and third pairs subsimilar with the fifth joint larger.
Fourth to seventh pairs backwardly directed, and becoming success-
ively broader and flatter, resembling the posterior limbs of Eurydice,
2858905 9

130

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the fourth pair with numerous stout spines along its internal edge,
these becoming fewer and weaker on posterior pairs, which are more
abundantly furnished with long slender setae,
the fifth joint of last pair of legs broad and
almost rectangular.

"Abdominal appendages subsimilar, the uro-
pods not projecting beyond the margin of tel-
son, attached to underside, in structure similar
to the pleopods and probably branchial in
function.

"Color gray, with arborescent brown pigmen-
tation becoming more dense posteriorly, on
abdomen collected principally in a median
wedge-shaped mass with the apex on base of
telson, each segment of pleon with two subellip-
tical paler lateral areas, with about twenty-five
to thirty longitudinal lines of pigmentation, the
areas between which are reticulated with brown.
lopus Mandibles, legs, and underside of body more
MTTOKALIS (AFTER or less pigmeiited.

^f "One specimen, from station 6079, 20 fath-

oms, 6 by 2.2 mm." MOORE. a

24. Genus BATHYNOMUS A. Milne Edwards.

Second pair of antennae with a peduncle composed of five articles; 6
rudimentary scale attached to end of peduncle of first antennae.

The plate of the second article of the maxillipeds furnished with
hooks.

Abdomen with all six segments distinct.

Pleopoda with supplementary ramified branchiae developed at the
base of the inner branches.

BATHYNOMUS GIGANTEUS A. Milne Edwards.

Bathi/nomus giganteus A. MILNE EDWARDS, Compt. Rend. Acad. Sci., LXXXV1II,
1879, pp. 21-23; Ann. Mag. Nat. Hist. (5), III, 1879, pp. 241-243. FILHOL,
La vie au fond des Mers, 1885, p. 147. MARSHALL, Die Tiefsee und ihr
Leben, 1888, p. 261, fig. 86. AGASSIZ, Bull. Mus. Comp. Zool., Harvard
College, XV, 1888, p. 49, fig. 252. HANSEN, Vidensk. Selsk. Skr. Math, og
Naturvid., Afd. (6), V, No. 3, 1890, pp. 252, 318, 378. WOOD-MASON and
ALCOCK, Ann. Mag. Nat. Hist. (6), VII, 1891, p. 270. ORTMANN, Proc. Acad.
Nat. Sci. Phila., 1894, p. 191. BOUVIER, Bull. Soc. Entom, France, 1901,
pp. 122-123; Compt. Rend. Acad. Sci., CXXXII, 1901, pp. 643-645. A.
MILNE EDWARDS and BOUVIER, Mem. Mus. Comp. Zool., Harvard College,
XXVII, No. 2, 1902, pp. 141-159, pis. i-vi. HANSEN, Journ. Linn. Soc.
London, Zool., XXIX, 1903, pp. 12-25, pi. iv, figs. 8-9.

oBull. U. S. Fish Comm., XX, Pt. 2, 1902, p. 168.
6 See remarks at end of description.

ISOPODS OF NORTH AMERICA.

131

Localities. West Indies; Gulf of Mexico; Caribbean Sea; Mouth
of Exuma Sound; Bay of Bengal.

Depth. 955 fathoms; 740 fathoms.

Body oblong-ovate, nearly two and a half times longer than wide,
38 mm. : 90 mm.

Head wider than long, 12 mm. : 21 mm., with the anterior margin
produced in a median point which meets the apex of the triangular
frontal lamina. The eyes are
large, composite, and are situ-
ated on the inferior side of the
head. The first pair of antenna 1
have the basal article large,
about as wide as long; the sec-
ond is about as long as the first;
the third is half as long as the
second; there is a small scale
articulated to the end of the
third article of the peduncle;
the flagellum is composed of
forty-six articles and extends
one-fourth the length of the
first thoracic segment. The sec-
ond pair of antennae have the
first article short; the second is
almost at right angles to the first
and is about 2 mm. long; the
third is about as long as the sec-
ond; the fourth is about 3 mm.
in length; the fifth is -t mm. long.
The flagellum is composed of
about sixty-six articles and ex-
tends to the middle of the fourth thoracic segment. The maxillipeds
are composed of seven articles. The frontal lamina is triangular in
shape, with the apex contiguous with the median point of the frontal
margin of the head.

The first segment of the thorax is the longest, being 10 mm. in
length. The second and third are subequal, and each is 6 mm. long.
The fourth and fifth are each 5 mm. in length. The sixth and seventh
are each 4 mm. long. The epimera are distinctly separated on all the
segments with the exception of the first, and are large plates with the
outer post-lateral angle produced in the last four beyond the posterior
margin of the segments.

The six segments of the abdomen are distinct, the first five being
subequal in length. The sixth or terminal segment is wider than

FIG. 112. BATHYNOMl'S GIGANTEITS (AFTER EDWARDS
AND AGASSIZ). DORSAL VIEW.

132

BULLETIN .">4, UNITED STATES NATIONAL MUSEUM.

long, and has the posterior margin widely rounded and armed with
eleven long teeth, live on either side of the median one. This segment
is 27 mm. long. The uropods do not quite reach the extremity of the

terminal abdominal segment.
The inner branch is nearly twice
as wide as the outer branch and
is a little longer. Both are
truncate posteriorly and have
the exterior and posterior mar-
gins armed with numerous
spines. The peduncle of the
uropoda has the inner angle but
little produced. The pleopoda
have ramified branchiae devel-
oped at the base of the inner
branch.

The first three pairs of legs
are prehensile, the last four
pairs ambulatory. They are all
armed with numerous spines.

A larger specimen in the col-
lection of the U. S. National
Museum measures 4: in. : 8 in.
It is from the Gulf of Mexico.
Wood -Mason and Alcock"
describe the living animal as
being a pale lilac color. Bou-

FIG. 113. BATHYNOMVS GIG ANTEUS( AFTER FII.HOIJ.
VENTRAL VIEW.

FIG. 114. BATHYNOMUS GIGANTEUS (AFTER EDWARDS AND BOI-VIER). HEAD WITH APPENDAGES AND

FIRST THORACIC SEGMENT.

vicr says that while the isopods usually have at the most in each
eye thirty to forty ocelli, which measure eight to ten centimeters,
with a diameter of a millimeter, />. </!(/<mf< //* has almost three thou-

Ann. Mag. Nat. Hist. (6), VII, 1891, p. 270.

ISOPODS OF NORTH AMERICA. 133

sand, the .surface of which is almost doubled. This increase in the
measure of the eye is not an effect of the increase in size of the
figure, for B. doderleini. Ortmann has the ocelli almost as large and ;is
numerous as B. giganteus; it is entirely the result of adaptation to
abyssal life. In order to collect in the greatest number the feeble
phosphorent rays which lighten the depth of the seas, the eyes of
Bathynomus are greatly enlarged and resemble the eyes of abyssal
Galatheides (Munida), in which the deficiency of the light at the great
depths has not yet produced blindness.

In the two species of Bathynomus he has been able to prove that
the sympodite of the pleopods has always three articles, that it is
the same for the peduncle of the antennuke, and that a rudiment of an
accessory appendage exists at the apex of this peduncle. The pres-
ence of this accessory appendage is a primitive character which brings

FIG. 115. BATHYNOMUS GIGANTEUS (AFTER EDWARDS AND BOUVIER). LATERAL VIEW.

the Bathynomus* and consequently the Cirolanidae, closer to the group
of Anisopods.

Hansen points out that the peduncle of the second pair of antennse
is really composed of six articles in this form and others, but the first
article is so small it has heretofore been overlooked/' Apparently the
peduncle of the second antenna 1 is composed of five articles.

25. Genus COLOPISTHUS Richardson.

Head transversely elongated. Eyes situated in the middle of the
lateral margins at the extreme edge and elevated knob-like above the
surface.

Both pairs of antennse short; first pair of antennae with basal article
of peduncle not extended straight in front at right angles to remain-
ing part of antenna; second pair reach the posterior margin of the
first thoracic segment.

First five abdominal segments consolidated into one short segment.
Terminal segment strong!} 7 keeled in the median longitudinal line.

"Edwards and Bouvier describe the peduncle as six-jointed, but, according to
Hansen, they were in error in regard to the position of the first joint.

134 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Fia. 116. BATHYNOMCS GIGANTEUS (AFTER EDWARDS AND BOCVIEE). a, CORNEULES IN THE EXTER-
NAL LAYER OF THE CORNEA. 6, CUTTING PART OF MANDIBLE (INFERIOR EXTERNAL SIDE). C, COR-
NEfLES IN THE INNER LAYER OF THE CORNEA, d, Bl'CCAL CAVITY. C, INFERIOR SIDE OF SECOND
ANTENNA. /, SEVERAL ARTICLES OF THE FLAGELLUM OF THE FIRST ANTENNA.- g, SEVERAL ARTICLES
OF THE FLAGELLVM OF THE SECOND ANTENNA. //. CORXEULES OF CIROI.ANA ELONGATA. i, FIRST
ANTENNA OF LEFT SIDE (INFERIOR FACE), j, LEFT MANDIBLE, INFERO-INTERNAL FACE OF THE
ANTERIOR PART. k, LEFT EYE.

ISOPODS OF NORTH AMERICA.

135

FIG. 117. BATHYNOMUS GIGANTEUS (AFTER EDWARDS AND BOUVIER). a, LEFT MANDIBLE. 6,
CUTTING PART OF MANDIBLE (DORSAL SIDE), c, LEFT MANDIBLE (DORSAL SIDE), d, LEFTMAXILLI-

PED (VENTRAL SIDE), e, SECOND LEFT MAXILLA j[VENTRAL SIDE). /, LEFT MAXILLIPED (DORSAL

SIDE), g, SECOND LEFT MAXILLA (DORSAL SIDE), fi, FIRST MAXILLA (DORSAL SIDE), i, THE SAME

(VENTRAL SIDE), j, RIGHT SECOND MAXILLA (VENTRAL SIDE), k, TIP OF EXTERNAL LACINIA OF FIRST

MAXILLA. I, BASAL PART OF FIRST MAXILLA, m, TIP OF MAXILLARY LACINI.K OF FIRST MAXILLA.

136 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 118. BATH YNOMUS GiGAXTErs (AFTER EDWARDS AND BOUVIER). a, LEFT ANTERIOR
(VENTRAL SIDE). 1>, EXTREMITY OF BRANCHIAL TUFT, c, LEFT ANTERIOR PLEOPOD (DORSAL SIDE).
<l, CIRCULATION IN RESPIRATORY ENDOPODITE. e, LEFT UROPOD (INFERIOR SIDE). /, LEFT PLEOPOD

OF THIRD PAIR WITH THE TRUNKS OF THE ORIGIN OF THE BRANCHIAL TUFTS. (/. POSTERIOR LEFT
PLEOPOD (ANTERIOR SIDE), h, THE SAME (POSTEBIOR SIDE).

ISOPODS OF NORTH AMERICA.

137

COLOPISTHUS PARVUS Richardson.

Colopisthus parvus RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp. 289-
290, pi. xxxvin, figs. 33-36.

Localities. Found in low water in the corallines at Bailey Bay, Ber-
mudas, and at Waterloo, Castle Harbor, Ber-
mudas.

Head transversely elliptical, the anterior and
posterior margins rounded. The eyes are
situated in the middle of the lateral margins
at the extreme edge, and are elevated above
the surface of the head like knobs. The head
is concave between the eyes.

The first pair of antennae are short, not
much longer than the width of the head, and
reach the end of the last peduncular joint of
the second pair of antennae. The flagellum is
composed of three articles.

The second pair of antennae are also short,
extending to the posterior margin of the first
thoracic segment; flagellum is composed of
seven articles.

The first thoracic segment is longest. The
others are subequal with well-defined epimera.

The first five a.bdominal segments are all coa-
lesced into one segment. The terminal seg-
ment is triangular and strongly keeled along
the median longitudinal line.

The inner branches of the uropoda extend
beyond the tip of the terminal segment, are
broadly oval and fringed with hairs. The
outer branches are narrowly oval, about half
as wide as the inner branches, and shorter.

Color light 3 T ellow, with numerous black
dots.

About seven specimens were collected by
Prof. A. E. Verrill and party at Bailey Bay,
Bermudas, in 1898. Found at low water in
corallines. Others were collected in 1901 at
Waterloo, on Castle Harbor, Bermudas.

Type specimen from the Bermudas in Peabody Museum, Yale Uni-
versity. Cat. No. 3179.

FIG. 119. COLOPISTHUS PAK-
vus. a, MAXII.LIPED. b, SEC-
OND MAXILLA. C, FlRSTMAX-

ILLA. d, GENERAL FIGURE.
e, HEAD AND FIRST TWO

THORACIC SEGMENTS.

138 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Family VI. EXOCORALLANID^.

Clypeus wide and very short, subtriangular, seen from below con-
cealed by the mandibles. Labrum wide and very short, subhorizontal
or vertical, seen from below very often concealed by the mandibles.
Apical tooth of mandibles of great length; movable lacinia and molar
part wanting.

The first maxilla? are robust; the lacinia of the first article is inflated
at the apex and unarmed; third article very robust, from the middle
to the apex becoming very much narrower and curved somewhat out-
ward, the apex furnished with a single very long and very robust spine
curved somewhat inward. Second maxillae short, narrow, feeble, the
apex with two free almost rudimentary laciniae. Maxillipeds narrow,
free; palp with the antepenultimate article elongated, more than twice
as long as wide.

26. Genus EXOCORALLANA Stebbing.&

ANALYTICAL KEY TO THE SPECIES OF THE GEXUS EXOCORALLANA. c

a. Eyes moderate or large, some distance apart in the middle at the upper end.
b. Left mandible, seen in position, with the apical part profoundly trifid. Clypeus

and labrum very conspicuous.

c. Basal article of the first pair of antennae narrow, without spine. Head of
male ornamented with two or more horn-like tubercles. First segment of
body not ornamented with tubercles.

d. Head of male ornamented with three tubercles, two on the dorsal surface
and one being the produced median point. Thorax not tuberculated.

Exocorcdlana tricornig (Hansen)

d'. Head of male ornamented with two dorsal tubercles. Median point not
produced in tubercles. Thorax tuberculated.

Exocorallana mexicana, new species.

cf. Basal article of the first pair of antennas dilated, ornamented with spine at
inner exposed angle. Head of male ornamented with four horn-like tuber-
cles. First segment of body ornamented with two tubercles.

Exocorallana sexticornis (Richardson)

b' '. Left mandible, seen in position, with the apical part obscurely trifid or forming
a single apex. Labium and clypeus partly or very often entirely covered by
the mandibles.

c. Basal article of the peduncle of the antennulte moderately narrow, seen from
below not prominent above the basal joints of the antennae. Last segment
of the abdomen not ornamented with basal tubercles near the median line.
d. Head of male ornamented with four tubercles.

Exocorallana quadricornis (Hansen)
d'. Head of male not ornamented with tubercles.

Exocorallana truncata ( Richardson )

"See Hansen for characters of family, Vidensk. Selsk. Skr. (6), V, 1890, pp. 311-
313, 317, 376.

& Fauna and Geography of the Maldive and Laccadive Archipelagoes, II, Pt. 3,
1904, p. 704.

<*This key, with the exception of three species which are inserted, is taken entirely
from Hansen, Vidensk. Selsk. Skr., 6th ser., natur. og. math., Afd. V, 1890, pp.
378, 379.

ISO PODS OF NORTH AMERICA.

c' . Basal article of the peduncle of the antennula; very much dilated, seen from
below, so prominent that the basal joints of the antennae are placed in a
transverse cleft moderately deep between the anteunuhe and the mandi-
bles. Last segment of the body ornamented with two large basal tuber-
cles situated near the median line.

d. Fourth and fifth segments of the abdomen a little impressed in the dorsal
median line, not ornamented with carinae or tubercles. Last segment of
the abdomen with two spines at the apex.

Exocorallana subtilis (Hansen)

d'. Fourth and fifth segments of the abdomen with a deep longitudinal exca-
vation in the dorsal median line, ornamented with many carinae and
tubercles. Last segment of the abdomen with four spines at the apex.

Exocorallana antillensis (Hansen)
a. Eyes very large, contiguous in the middle of the head.

. Last segment of the abdomen rather short, widely rounded posteriorly and with
a median excavation deep and moderately wide.

Exocorallana fissicauda (Hansen)
b' '. Last segment of the abdomen rather long, narrowly rounded posteriorly, with

no excavation.

c. Fourth and fifth segments of the abdomen deeply excavate longitudinally in
the dorsal median line and ornamented with carinae. Last segment of the
body with an incision in the middle of the side and ornamented on the
dorsal surface with two densely setose areas and with two large basal tuber-
cles situated near the median line Exocorallana oculata (Hansen)

c f . Fourth and fifth segments of the body very little impressed in the dorsal
median line, ornamented with no carinae. Last segment of the abdomen
entire at the sides, ornamented on the dorsal surface everywhere with very
short hairs remotely scattered Exocorallana u'armingii (Hansen)

EXOCORALLANA TRICORNIS (Hansen).

Corallana tricornis HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 379-381, pi. vi,
figs. 4-4 p; pi. vn, figs. 1-1 d. RICHARDSON, Proceedings U. S. Nat. Mus.,
XXIII, 1901, p. 518. MOORE, Bull. U. S. Fish Comm., XX, Pt. 2, 1902,
p. 169, pi. ix, figs. 2-5.

Localities.- Cape Catoche, Yucatan; between Delta of the Missis-
sippi and Cedar Keys, Florida; St. Thomas, West Indies; Hucares,
Porto Rico; St. Croix, West Indies; Jamaica; Belize, British Honduras;
Realejo, Nicaragua, Central America.

Depth. 24-27 fathoms.

Body narrow, elongate, three times longer than wide, 4 mm. ; 12 mm.

Head wider than long, 1 mm. ; 2 mm. with the antero-lateral mar-
gins rounded and produced in the middle in a prominent triangular
process half a mm. in length, with broad base and apex emarginate or
slightly bifid and directed upward, the whole process forming a right
angle with the dorsal surface of the head. The eyes are large, con-
spicuous, and composite and occupy a large portion of the dorsal sur-
face of the head; they are separated from each other by a median
groove which extends from the base of the frontal process to the
posterior margin of the head. On the posterior portion of the head
are two large, prominent tubercles, one on either side of the median

140 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

groove. The first pair of antenna* have the first two articles almost
confluent and scarcely distinguishable; the lirst is twice as long as the
second; the third is also twice as long as the second. The flagellum is
composed of eleven articles. The first pair of antennae extend almost
to the middle of the last article of the peduncle of the second pair of
antennae. The second pair of antennae have the first two articles short,
the second a little shorter than the first; the third is nearly twice as
long as the second; the fourth and fifth are suhequal and each twice as
long as the third. The flagellum is composed of sixteen articles. The
second antennae extend to the posterior margin of the second thoracic
segment. The maxilliped is composed of seven articles. The palp of
the mandibles is composed of three articles. The frontal lamina is
longer than wide, and has the anterior margin produced in a long,
narrow acute median process.

The first segment of the thorax is slightly longer than any of the
others, and has two small inconspicuous tubercles on the anterior por-

a b c d

FIG. 120. EXOCORALLANA TRICORXIS. a, MANDIBLE. X 61|. 6, MAXILLIPED. X 51|. C, FIRST

MAXILLA, x 51 1. d, FRONTAL LAMINA, x 51|.

tion, one on either side of the median line. The epimera are distinct
on all the segments with the exception of the first. They are all
crossed obliquely by an arched carina. The outer post-lateral angles
of the first two are rounded. In the last four the outer post-lateral
angle is produced beyond the posterior margin of the segments.

All the segments of the abdomen are distinct. The second and third
segments have the posterior margins tuberculate; the fourth segment
has two transverse rows of tubercles; the fifth segment has three
transverse rows of tubercles. In the fourth and fifth segments there
is a narrow median depression, this area having only a single longi-
tudinal row of tubercles right in the median line, two for each of the
segments. The sixth or terminal segment is triangulate in shape
with the apex rounded and furnished with short spines. At the base
is a transverse row of tubercles ' on either side of a shallow median
longitudinal groove or furrow. Below the row of tubercles and on
either side of this median groove the lateral portions of the segment

ISO PODS OF NORTH AMERICA.

141

are somewhat hirsute. A little more than half way between the base
and the apex of the segment the lateral margin is incised on either
side. The inner branch of the uropoda is broad and posteriorly trun-
cate with the lateral angles rounded; it is as long as the terminal
segment of the body. The outer branch is less than half as wide as
the inner branch, is produced to a narrowly rounded extremity, and
is as long as the outer branch. The inner angle of the peduncle
extends a little beyond the lateral incisions of the terminal abdominal
segment.

FlG. 121. EXOCORALLANA TRICORNIS (AFTER HANSEN). a, LEFT LEG OF FIFTH PAIR OF MALE. 6, LEFT
LEG OF SECOND PAIR OF MALE. C, LEFT LEG OF SEVENTH PAIR OF MALE. (I, INNER PARTS OF MOUTH,
FROM BELOW, e, INNER PARTS OF MOUTH (PARAGNATHIA OMITTED). /, FIRST ANTENNA OF FEMALE.

<j, MIDDLE PART OF LEFT MAXILLIPED OF MALE, h, BASAL PART OF FLAGELLUM OF SECOND ANTENNA
OF MALE. /, LATERAL VIEW OF MALE, j, LEFT MAXILLA OF SECOND PAIR OF MALE, k, LEFT MANDIBLE
OF MALE, t, LEFT MAXILLA OF FIRST PAIR, m, VENTRAL VIEW OF HEAD OF FEMALE, n, HEAD OF

ADULT MALE (DORSAL VIEW). O, LEFT MAXILLIPED OF FEMALE, p, LEFT MAXILLIPED OF MALE.

<7, LEFT PLEOPOD OF ADULT MALE (SECOND PAIR) . r, POSTERIOR PART OF ABDOMEN OF ADULT MALE.
S, DISTAL PART OF LEFT MANDIBLE, t, ADULT FEMALE. M, DISTAL PART OF LEFT MANDIBLE. V, RIGHT
MANDIBLE. (ENLARGED.)

The first three pairs of legs are prehensile, the last four pairs
ambulatory.

In the female the tubercles on the head are smaller and less promi-
nent, as well as the median frontal process.

Three specimens, a male and two females are from the Gulf of Cali-
fornia. They differ from the specimens of the East coast only in hav-
ing larger tubercles on the abdominal segments on either side of the
median longitudinal groove. This new subspecies may be known as
tricornis occidental/is.

142

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 122. EXOCORALLANA MKXH ANA. a, MANDIBLE.

x 51|. b, SECOND PLEOPOD OK MALE x 27J.

EXOCORALLANA MEXICANA, new species.

Body ovate, a little more than twice as long as wide, 3 mm., 7 mm.

Head wider than long, about twice as wide as long, 1 mm., 2 mm.,

with the anterior margin widety rounded arid the posterior margin

straight. Eyes large, composed of numerous ocelli, and separated in

front by a distance equal to the
length of one eye. Two small
tubercles are situated about the
middle of the head between the
eyes, one on either side of the
median line. The first pair of
antenna? have the peduncle com-
posed of only two -articles, the
first article being nearly twice
as long as the second. The
flagellum, which is composed
of ten or eleven articles, ex-
tends to the posterior margin
of the head or to the end of the fourth article of the peduncle of the
second pair of antenna 1 . The second pair of antenna? have the first
three articles of the peduncle short, the second one being the shortest;
the fourth and fifth are long and subequal,
each being about as long as the first three
articles taken together. The flagellum is
composed of about twenty-five articles,
and extends to the middle of the fifth tho-
racic segment. The frontal lamina is nar-
row, elongate, and has the anterior end
rounded. The clypeus is short and wide.
The mandible is distinctly tridentate, the
posterior tooth being the most elongate.
The first segment of the thorax is about
one and one-half times longer than any of
the three following segments, which are
subequal. The fifth, sixth, and seventh
segments are subequal and shorter than
the preceding segments, and each is fur-
nished with a double or single transverse
row of small tubercles close to the posterior margin. The anterior
segments are sometimes furnished with a rather indistinct row of tuber-
cles on the posterior margin. The epimera are distinct on all the
segments with the exception of the first; the first two are rounded
posteriorly, the last four have the outer posterior angle gradually more
acutely produced.

FIG. 123. EXOCOKAJ.LA.NA MKXICANA.

MALE, x 6.

ISOPODS OF NOKTH AMERICA. 143

The first segment of the abdomen is entirely covered by the last
thoracic segment, except a small portion in the middle. The four fol-
lowing segments are nearly subequal in length. The first two (the
second and third) have a single transverse row of small tubercles close
to the posterior margin. The fourth segment has a double transverse
row of tubercles, the posterior row of tubercles being larger. The
fifth segment has three transverse rows of tubercles, the middle row
being the largest. The sixth or terminal segment of the abdomen is
triangulate, with apex rounded and furnished with four spines. There
is a lateral incision on either side, a little below the middle transverse
line. At the base of the segment is a transverse row of small tuber-
cles. Below this row are two groups of three tubercles each, a group
on either side of the median line. There are also two small tubercles
on either side of the segment just above the insertion of the uropods.
On the posterior part of the segment is a double longitudinal line of
small tubercles, one row on either side of the median line. Lateral to
these tubercles is a setose area, one on either side. The uropoda are
as long as the terminal segment. The inner branch is twice as wide as
the outer branch and is truncately rounded and furnished with spines
on the posterior margin. The outer branch is obtusely pointed. Both
branches are furnished with hairs, as well as the terminal segment of
the abdomen.

The type, a male, is from the Gulf of Mexico, station 2406, from a
depth of 26 fathoms. Seven other specimens, all males, and thirteen
females, are from between the delta of the Mississippi and Cedar Keys-,
Florida, and from the Gulf of Mexico. The type is in the U. S.
National Museum, Cat. No. 32074.

The females differ from the males only in the shorter second antennae,
which extend only to the posterior margin of the third thoracic
segment.

EXOCORALLANA SEXTICORNIS (Richardson).

Corallana sexlicvrnis RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 518.

Locality. Key West, Florida.

Head in the male ornamented with four spines, forming two trans-
verse series of two spines each, the first two being small, the second two
very large and long, much longer than the first two and situated behind
them. The first antennae have the basal joint large and dilated, with
a spine projecting outward from the inner exposed angle; the flagellum
consists of eight joints. The second antennae with a flagellum of nine-
teen to twenty-one joints reach the posterior margin of the third tho-
racic segment. The head of the male is excavate above and deeply
sunken below the level of the dorsal surface of the body. The head
of the female is unornamented, with only a slight indication of two
small tubercles in the place where the large spines are situated on the

144

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

head of the male. The basal joints of the first antennae of the female
are large and dilated, but without the prominent spine character-
istic of the male.

The first thoracic segment in the male is ornamented
with two small tubercles situated close together on
the anterior portion. These tubercles are wanting
in the female. The posterior segments of the thorax
and the abdominal segments are densely tubercular.

The terminal segment of the
body is pointed posteriorly, and
fringed with hairs. The uropoda
are about as long as the terminal

FIG. 1-24.EXOCOKALI.ANA
8EXTICORNIS. O, MAX-

ILLIPED. x 39. ft, MAN-
DIBLE. X 39.

FIG. 125. EXOCORALLANA
SEXTICORNIS. HEAD AND
FIRST THORACIC SEG-
MENT.

FIG. 126. EXOCORALLANA
SEXTICORNIS. MANDI-
BLE, x 51|.

segment, the outer branch narrow, the inner branch wide; both are
fringed with hairs and armed with a few spines.

One male and a number of females were collected by Henry Hemp-
hill at Key West, Florida.

Type. Cut. No. 13540, U.S.N.M.

EXOCORALLANA QUADRICORNIS (Hansen).

Corallana quadricornis HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, p. 382, pi.
vn, fig. 3. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 518; Trans.
Conn. Acad. Sci., XI, 1902, 290.

Localities. St. Thomas, West Indies; Bermudas, at the Flatts; at
Long Bird Island in the cavities of a massive, black keratose sponge,

living on the grassy sand flats at low tide;
Castle Harbor, in the same sponge.

This species is very similar to E. tricor-
;m-, but differs in the following important
characters: The clypeus, seen from below,
is very narrow and concealed for the mosi
part; the labrum is concealed by the man-
dibles. Half of the distal part of the
mandibles is very prominent and obscurely trifid. The last segment
of the abdomen is a little more impressed at the sides than in E. tricor-
nis. The abdomen is less hairy, the apical part of the last segment
less convex, ornamented, however, with four apical spines.

FIG. 127. EXOCORALLANA QUADRI-
CORNIS (AFTER HANSEN). HEAD.
(ENLARGED.)

ISOPODS OF NORTH AMERICA.

145

The male has the head excavated as in E. tricornis, and ornamented
with two small frontal tubercles rather closer together, and two large
suboccipital tubercles more widely separated. The head of the female
is as in E. tricornis. The flagellum of the second pair of antennae in
the male is composed of sixteen articles; in the female of about twenty
articles. a

EXOCORALLANA TRUNCATA (Richardson).

Corallana truncata RICHARDSON, Proc. U. S. Nat. Mue., XXI, 1899, p. 825; Ann.
Mag. Nat. Hist. (7), IV, 1899, pp. 165-166.

Localities. Catalina Island, California; off Magdalena Bay, Lower
California.

Body elongate, about three and a half times longer than wide; color
yellow.

Head with a small median point. Eyes large, situated but a little
distance apart. First pair of antennae, with a flagellum of about nine
articles, extend to the an-
tero-lateral angle of the
first thoracic segment.
Second pair of antennas
broken in specimen.

First segment of the
thorax is as long as the
head, and about one and
a half times longer than
any of the other seg-
ments. Epimera of the
second and third seg-
ments narrow; those of b c

the remaining segments FlG - 128. EXOCORALLANA TRUNCATA. a, MAXILLIPED. x 27}.

6, MANDIBLE, x 27 J. c, FIRST MAXILLA (OUTER LOBE), x 27|.

very broad.

The first abdominal segment is almost entirely covered by the last
thoracic segment. The second, third, and fourth segments are

The above description is adapted from the following one of Hansen's:

Diagn. Speciei praecedenti (C. tricornis) vakle affinis, characteribus sequentibus
imprimis differt. Clypeus, infra visus, perangustus et ex parte obtectus; labrum a
mandibulis obtectum. Mandibularum pars distalis dimidia sat alte eminens, obscu-
rius trifida. Segmentum ultimum ad latera versus paulo magis impressum quam in
specie preecedente (C. tricornis).

Mas: Caput ut in specie prsecedente excavatum, cornibus duobus frontalibus minor-
ibus, minus distantibus et cornibus duobus majoribus, suboccipitalibus, magis dis-
tantibus ornatum. Long. 6, 3 mm.

Femina: Caput ut in specie prsecedente. Long. 6, 8 mm.

Descr. Haee species Cor. tricorni simillima; charac^eres omnes graviores in diagnosi
commemorati sunt. Pneterea differt cauda minus hirsuta, parte apicali segment!
ultimi minus convexa, spinis tamen 4 apicalibus ornata. (Flagellum antennarum
in mare 16 articulatum, in femina c. 20 articulatum.) HANSKN, Vidensk. Selsk.
Skr. (6), V, 1890, p. 382.
2858905 10

146

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

tuberculated on their posterior margins. The fifth segment is also tuber
culated, the tubercles on either side of the median line of tubercles
being' larger and more conspicuous. At tlie base of the terminal
segment are four tubercles, the two center ones being the largest.
The terminal segment is subtriangular with trun-
cate apex. The posterior margin is armed with
spines. The inner branch of the uropoda is trun-
cate posteriori} 7 and armed with spines; it is
about twice as broad
as the outer branch,
which is lanceolate in
shape.

The type specimen
is from Catalina Is-
land, California; col-
lected by Dr. J. G.

FIG. 129. EXOCORALLANA
TRUNCATA. X 131. ,
HEAD. 6, ABDOMEN AND
LAST THORACIC SEG-
MENT.

Type. Cat. No.

22566, U.S.N.M.

EXOCORALLANA SUBTILIS (Hansen).

Corallana subtilis HANSEN, Vidensk. Selsk.
Skr. (6), V, 1890, pp. 382-383, pi. vn,
figs. 3-3c. RICHARDSON, Proc. U. 6. Nat.
Mus., XXIII, 1901, p. 519.

Locality. St. Thomas, West Indies.

A single young specimen in the process
of ecdysis was taken, and on that account
is rather different from other species in
appearance.

The front of the head is produced in a
rather large triangular process. The
first pair of antennae have the basal ar-
ticle of the peduncle strongly dilated
when seen from above; when seen from
below it projects in such a way that the
basal articles of the second antennae are
placed in a rather deep cleft between the first pair of antenna? and
the mandibles. The first pair of antennae have the second article
of the peduncle slender; the flagellum is composed of about seven
articles. The eyes are slightly granulated.

The frontal lamina is a little longer than wide, somewhat nar-
rower toward the apex, with the apex rounded and superficially
excavated.

FIG. 130. EXOCORALLANA SUBTILIS.
(AFTER HANSEN). a, POSTERIOR PART

OF ABDOMEN. X 16. 6. HEAD. X 19.
C, YOUNG SPECIMEN TAKEN IN PROC-
ESS OF ECDYSIS. x *. d, LATERAL

VIEW OF SAME (RIGHT SIDE).

ISOPODS OF NORTH AMERICA. 147

The clypeus is very narrow, partly concealed; the labrum is con-
cealed.

The last segment of the abdomen is somewhat longer than in E.
quadricornis, being a fourth part wider than long, bare above, and
ornamented on the dorsal surface near the base with two large tuber-
cles, separated a little; the sublateral impressions are deep; the. apex
is furnished with two spines.

The uropoda are wider than in E. quadricornis j the branches are
ornamented with some long hairs and a few spines; the peduncle
has the inner angle short, occupying about a third of the inner
branch.

The color is dark black; the last segment of the abdomen and the
uropoda are brown, ornamented with branching black spots."

Two specimens, both males, from Florida, in the collection of the
U. S. National Museum, I have referred to this species with some
hesitation, as they lack the two large tubercles at the base of the ter-
minal abdominal segment. They agree in other respects with Han-
sen's description of this species, but as Doctor Hansen's only speci-
men was a young specimen, very likely a female and taken in the
process of ecdysis, 1 would hesitate to make a new species until I had
more material.

The above description is adapted from the following description of Hansen's:

Diagn. Feminte Cor. quadricornis subsinrilis, tamen imprimis differt characteribus
sequentibus. Oculi leviter granulati. Antennularum articulus basalis pedunculi
pronus visus valde dilatatus, supinus visus ita prominens, ut articuli basales anten-
narum in riuia sat profunda inter antennulas et mandibulas positi sint. Segmentum
ultimum caudre dorso prope basin nodis duobus magnis, paulum distantibus ornata,
impressionibus sublateralibus profundis, apice spinis 2 instructo. Long. 4, 7 mm.

Descr. Specimen singulum juvenile in mutatione cutis captum et ob earn causam
a speciebus ceteris habitu sat diversum vidi. Characteres prsecipui in diagnosi
exhibit! sunt; pneterea characteres sequentes commemorare possum.

Frons ante in processum trigonum sat magnum producta.

Lamina frontalis paulo longior quam latior, ad apicem versus nonnihil angustata,
apice rotundato, superficie excavate.

Clypeus perangustatus, ex parte detectUs, labrum obtectum. Antennulee articulo
secundo pedunculi gracili, flagello c. 7-articulato.

Segmentum ultimum caudae nonnihil longius quam in speciebus praecedentibus
(C. quadricornis), quarta parte latius quam longius, superne nudum.

Uropoda fere latiora quam in speciebus pra'cedentibus; raini setis nonnihil longi-
oribus et spinis paucioribus ornati; scapus angulo interiore breviore, circiter tertiam
partein rami interioris occupans.

Color fusco-piceus; segmentum ultimum caudee et uropoda brunnea, maculis rainosis
nigris ornata. HANSEN, Vidensk. Selsk. Skr. (6), V 7 , 1890, pp. 3S2-383.

148

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

EXOCORALLANA ANTILLENSIS (Hansen).

Coral lana anlUlt>nxis HANSEX, Vidensk. Selsk. Skr. (6), V, 1890, pp. 383-384, pi.
vn, figs. 4-4i. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 519.

Localities. Key West, Florida; St. Thomas, West Indies.

On reefs, low tide.

Body oblong-ovate, a little more than three times longer than wide,
5 mm.: 16 mm.

Head wider than long, 2 mm.: 4 mm., with the anterior margin
bisinuate on either side of a small median point. The eyes are large

FIG. 131. EXOCORALLAXA ANTILLENSIS (AFTER HANSEN). a, HEAD OF ADULT MALE. X 11 (FROM
ABOVE), ft, LEFT MAXILLIPED OF SAME. X 24. C, LEFT MANDIBLE, PALP OMITTED (VENTRAL SIDE).

x 24. d, LEFT MAXILLA (SECOND PAIR), x 24. e, LEFT MANDIBLE (BASAL PART OMITTED), x 24

(FROM ABOVE). /, DISTAL PART OF LEFT MAXILLA OF SECOND PAIR (VENTRAL SIDE). X 59. g, DISTAL
PART OF SAME (FROM ABOVE), h, ABDOMEN. X 6. i, HEAD (VENTRAL SIDE). X 11. j, ADULT MALE
(LATERAL VIEW). X ^.

and composite, but are not contiguous, being separated by a distance
equal to half the length of one eye. The basal article of the antennae
is very much dilated and very large; the second article is fused with
the first; the third article is small and narrow, half as long as the first
and about one-third as wide. The flagellum is composed of ten arti-
cles. The first antennae extend to the middle of the fifth article of the
peduncle of the second antennae. The second pair of antennae have the
first two articles short and subequal; the third article is equal in length

I8OPODS OF NOKTH AMERICA. 149

to the first two taken together; the fourth and fifth are subequal and
each is nearly twice as long as the third. The flagellum is composed of
thirty-two articles. The second pair of antennae extend to the poste-
rior margin of the third thoracic segment. The maxilliped is com-
posed of seven articles. The palp of the mandibles is composed of
three articles. The frontal lamina is narrow and long, and has the
anterior extremity rounded.

The first segment of the thorax is nearh 7 twice as long as any of
those following. The seventh is a little shorter than the sixth. The
epimera are distinct on all the segments with the exception of the first.
An arched carina crosses all the epimera obliquely. The outer post-
lateral angle of the first two epimera is rounded; that of the last two
acutely produced beyond the posterior margin of the segments.

The first segment of the abdomen is partly concealed by the seventh
thoracic segment. The posterior margin of the second, third, fourth,
and fifth segments is tuberculate. On all of these segments there is a

FIG. 132. EXOCORALLANA ANTILLENSIS. a, MAXILLIPED. X 27}. 6, MANDIBLE. X 27}. C, SECOND
MAXILLA. X 27}. d, FIRST MAXILLA (OUTER AND INNER LOBE). X 27}. f, FRONTAL LAMINA. X 27}.

median depression, in the center of which is a small tubercle, one for
each segment, with the exception of the fifth, which has two tubercles
in longitudinal series. The sixth or terminal segment is triangular
with apex acute and furnished with a few short spines. There is a
median longitudinal depression extending the length of the segment,
on either side of which the dorsal surface is hirsute. At the base of the
segment are two tubercles, one on either side of the median depression.
On either side of these, near the lateral margin and at the base of the
segment, are two other tubercles, the one nearest the lateral margin
being a little anterior to the other. Halfway between the base and
the apex of the segment the lateral margin is cleft on either side.
The inner branch of the uropoda is wide and has the outer post-lateral
angle produced in an acute tooth; the inner posterior margin is crenu-
late and armed with spines. The outer branch is as long as the inner
branch, is half as wide, and is produced in an extremity terminating
in two subequal teeth. The inner angle of the peduncle extends a

150

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

little beyond the incision in the lateral margin of the terminal abdomi-
nal segment.

The first three pairs of legs are prehensile, the last four pairs
ambulatory.

EXOCORALLANA FISSICAUDA (Hansen).

Corallanafisxicauda HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 385-386, pi.
vn, figs. 5-5d. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 519.

Locality. West Indies.

The body is almost three times longer than wide; the thorax is
somewhat longer than the abdomen.

The front of the head has the margin straight, the median process

is bent, having almost disap-
b peared.

The eyes are black, very large,
occupying the entire surface of
the head with the exception of
a small median area at the pos-
terior margin; the ocelli are
very large, semispherical, and
formed as in E. warmingii.

The frontal lamina is almost-
three times longer than wide,
becoming narrower from the
base to the middle, excavated
through the greater part of its
length, with the apical part flat,
and rounded anteriorh T . The
lamina seen from the side is
curved outward and near the
apex curved inward.

The clypeus seen from below
is very manifest for the most
part; the labrum is concealed.

The first pair of antennae ex-
tend to about the apex of the
penultimate article of the peduncle of the second pair of antennae; the
peduncle has the first article somewhat stout, narrow, however, when
seen from above and below; the second article is somewhat shorter
than the first and more slender; the flagellum is somewhat shorter
than the peduncle and is composed of about eight articles.
The second pair of antennae are of the usual structure.
The mandibles are large, robust; the distal part of the left mandi-
ble is very conspicuous, forming a single cone.

FIG. 133. EXOCORALLANA FISSICAUDA (AFTER HAN-
SEN). a, FEMALE, b, LATERAL VIEW. r. LEG OF

SEVENTH PAIR. d, APEX OF FIFTH ARTICLE OF
SEVENTH LEG, BEARING SET^E. , POSTERIOR PART
OF ABDOMEN WITH UROPODA. (ENLARGED.)

ISOPODR OF NORTH AMERICA. 151

The maxillipeds are almost as in E. antillensis.

The segments of the thorax are almost as in E. antillensis; the post-
marginal furrow is well defined only in the seventh segment; in the
fourth, fifth, and sixth segments it is somewhat distinct, formed prin-
cipally of points.

The epimera are almost as in E. antillemis.

The first five segments of the abdomen are a little more smoothly
formed than in E. antillensis.

The last segment of the abdomen is short, about two-fifths wider
than long, posteriorly widel3 T rounded, not furnished with spines, but
furnished with a deep and rather wide median incision, the lateral
margin is entire; the dorsal surface is rather convex, not furnished
with densel} r setose areas, but ornamented with very short, scattered
hairs near the lateral margins, and furnished near the base with a
median excavation which has a carina in a rather short fundus, and
ornamented with acute tubercles rather close together and rather
small, and with lateral tubercles somewhat smaller than in E. antillensis
and not furcate.

The uropoda extend some distance beyond the abdomen and are fur-
nished with hairs as in E. antillensis; the branches are equal in length;
the inner branch is rather wide, with the posterior part of the inner
margin somewhat curved outward, and furnished with a few spines;
the apex is a little produced and acute.

The peduncle has the inner angle extending a little beyond a third
part of the inner branch. The color is brownish yellow. a

The above description is adapted from the following one of Hansen's:

Diagn. Clypeus, supinus visus, ex parte perspicuus, labrum obtectum. Anten-
nularum articulus basalis nonnihil incrassatus, pronus et supinus visus angustus.
Segmenta 5 anteriora caudee fere ut in Cor. nntillensi. Segmentum ultimum caudse
breve, postice late rotundatum et incisura media profunda, sat lata, instructum, mar-
gjne laterali non inciso, dorso ad basin nodis et nodulis ornato, areis spisse setosis
nullis. Uropoda caudam longe superantia, structura fere solita. Long. 11 mm.

Corpus fere triple longius quam latius; truncus cauda aliquanto longior.

Frons margine subrecto, processu medio inflexo, fere evanido.

Oculi nigri, permagni, superficiem totam capitis pneter aream minorem mediam
ad marginem posteriorem occupantes; ocelli permagni, semiglobosi, ut in C. Warm-
ingii formati.

Lamina frontalis fere triple longior quam latior, a basi ad mediam angustata, per
longitudinem majorem excavata, parte apicali subplana, ante rotundata. Lamina a
latere visa excurvata et prope apicem incurva.

Clypeus supinus visus ex parte perspicuus; labrum obtectum.

Antennulse circiter apicem articuli penultimi pedunculi antennarum attingentes;
pedunculus articulo primo nonnihil incrassato, prono et supino viso tamen angusto,
articulo secundo aliquanto breviore quam primo, graciliore; flagellum pedunculo
aliquanto brevior, c. 8-articulatum.

Antenme structura solita. Mandibulae magnae, robustse, pars distalis mandibulae
sinistrae sat alte eminens, ut in speciebus sequentibus conum singulum formans.

Maxillipeds fere ut in C. antillensi.

Segmenta trunci fere ut in C. antillensi; stria postmarginalis solum in segmento

152 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

EXOCORALLANA OCULATA (Hansen).

Corallana oculala HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 386-387, pi.
vii, figs. 6-6b. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 519.

Locality. West Indies.

The body is about three times longer than wide; the last four seg-
ments of the thorax, espe-
cially toward the posterior
margin, and the second to
the fifth segments of the ab-
domen in the male are nearly
bare, in the female they are
rough and furnished with
very short stiff hairs; the
thorax in the male is a little
longer and in the female is
somewhat longer than the
abdomen.

The front of the head is
as in E. fissicauda.

The eyes are almost as in
E. fissicauda, being some-
what larger in the male
and more convex than in
the female; the ocelli are
very large in the male and
very convex, in the female
they are a little less con-

FIG. 134. EXOCORALLANA OCULATA (AFTER HANSEN). VCX.
a, HEAD OF ADULT MALE. 6, ABDOMEN OF ADULT MALE. The frontal lamina is as

c, LATERAL VIEW OF ADULT MALE. (ENLARGED.) -r? /? j

in A Jlss^cauda.

septimo bene definite, in segmentis sexto et quinto et quarto paulum distincta,
imprimis e punctis formata.

Epimera et pedes fere ut in C. antillensi.

Segmenta 5 anteriora caudae paulo levius sculpta quam in C. antillensi.

Segmentum ultimum caudse abbreviatum, circiter f latius quam longius, postice
late rotundatum, non spinosum, ibique incisura profunda etsat lata ornatum, margine
laterali integro; dorsum sat convexum, areis nullis spisse setosis instructum, setis
brevissimis remotius sparsis ad margines laterales versus ornatum, excavatione basali
media in fundo breviore carinata, nodis acutis sat approximatis nonnihil minoribus,
nodis lateralibus aliquanto minoribus quam in specie prsecedente et non furcatis
instructum.

Uropoda caudarn valde superantia, ut in C. antillensi ciliata; rami inter se sequi-
longi; ram us interior sat latus, margine postero-interiore aliquantum excurvato spinis
nonnullis instrticto, apice paulum producto, acuto. Scapus angulo interiore paulum
ultra tertiam partem rami interioris occupans.

Color flavo-brunneus. HANSEN, Vidensk. Selsk. Skr. (6), V, 1890, pp. 385-386.

I8OPOD8 OF NORTH AMERICA. 153

The clypeus is very narrow, very manifest when seen from below;
the labrum is partly concealed by the mandibles.

The first and second pair of antennae are as in E. fissicauda.

The mandibles in the male are more prominent than in the female.

The maxillipeds are furnished below with numerous little knots, for
the most part acute.

The first two or three segments of the thorax have rather distinct
postmarginal furrows; the furrows on the posterior segments in the
male are quite distinct, in the female they are obscured more or less
by hairs.

The epimera and the legs are almost as in E. antillensis.

The five anterior segments of the abdomen are formed almost as in
E. antillensis. The last segment of the abdomen is almost as in E.
antillensis, but differs from that species especially in having the
median excavation at the base shorter, the lateral tubercles rather
narrower, the apex furnished with five spines, and subacute, the
lateral margin not incised in the middle, and the dorsal surface fur-
nished with two thickly setose areas.

The uropoda extend somewhat be} 7 ond the abdomen; the inner
branch extends a little beyond the outer branch, is almost twice as
long as wide, and has the inner posterior margin rather curved, fur-
nished with spines and long hairs, the apex a little produced and acute.
The peduncle has the inner angle somewhat exceeding a third part of
the inner branch.

The color is a brownish yellow. The male appendix is almost as in
E. tricornis. a

The above description is adapted from the following one of Hansen's:

Diagn. Cor. fixsicaudw valde similis, eegmento ultimo caudse fere ut in C. antil-
lensi formato, longiore, apice subacuto, margine lateral! in medio non inciso, dorso
areis duabaa spisse setosis instructo, imprimis ab ea specie diversa. Long, maris
9, 7 mm., long, feminse 11, 5 mm.

Corpus circiter triplo longius quam latius; segmenta 4 posteriora trunci imprimis
ad marginem posteriorem versus et segmenta 2-5 caudse in mare fere nuda, in femina
scabra, setis brevissimis, rigidis instructa; truncus in mare paulo longior et in femina
nonnihil longior quam cauda.

Frons ut in specie prsecedente ( C. fissicauda).

Oculi fere ut in specie prsecedente, in mare nonnihil majores et plus convexi
quam in femina; ocelli permagni in mare valde convexi, in femina paulo minus
convexi.

Lamina frontalis ut in Cor. fissicauda.

Clypeus perangustus, supinus visus perspicuus; labrum ex parte a mandibulis
tectum.

Antennulae et antennae ut in Cor. fissicauda.

Mandibulse in mare plus prominentes quam in femina.

Maxillipedes subtus nodulis compluribus ex parte acutis armati.

Segmenta duo vel tria anteriora trunci stria postmarginali paulum distincta;

154 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

EXOCORALLANA WARMINGII (Hansen).

Corallana mmiiini/li HAXSEX, Yidensk. Selsk. Skr. (6), V, 1890, pp. 387-388,
pi. vn, figs. 7-7f. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 519.

Localities. Off Cape Catoche, Yucatan; latitude 17 47' south, longi-
tude 35 17' west.

Depth. 24 fathoms.

Body oblong-ovate, three times longer than wide, 3 mm. : 9 mm.
Head wider than long, 1 mm.: 2 mm., with the anterior margin widely
rounded. E3 7 es large, composite, contiguous, and occupying the
greater part of the dorsal surface of the head. The first pair of
antennae have the first two articles confluent and scarcely to be dis-
tinguished from each other; they are subequal in length; the third
article is equal to the second in length. The flagellum is composed of
nine articles. The first antennae extend almost to the middle of the
fifth peduncular article of the second antennae. The first two articles
of the second pair of antennae are short, the second one being a little
shorter than the first; the third article is about equal to the first two
taken together; the fourth and fifth are subequal and each is twice as
long as the third. The flagellum is composed of twenty -five articles.
The second antennae extend almost to the posterior margin of the third
thoracic segment. The maxilliped is composed of seven articles. The
mandible has a palp of three articles. The frontal lamina is narrow
and has the anterior margin rounded.

The first segment of the thorax is twice as long as any of the four
following segments; the sixth and seventh segments are shorter than
the fifth, the seventh being very short. The epimera of all the seg-
ments, w T ith the exception of the first, are distinct, the last four being
crossed obliquely by an arched carina. The outer post-lateral angles
of the first two are rounded, those of the last two acutely produced
beyond the posterior margin of the segments.

The first segment of the abdomen is entirely concealed by the last
thoracic segment. The posterior margin of the four following seg-

segmenta posteriora stria in mare bene distincta, in femina a setis plus minusve
abscondita.

Epimera et pedes fere ut in Cor. antillen#i.

Segmenta 5 anteriora fere ut in C. antittensi sculpta.

Segmentum ultimum caudse fere ut in C. anHllenxi, excavatione media basali brevi-
ore, nodis lateralibus magnis angutioribus, apice 5 spinoso imprimis ab ea specie
discrepans.

Uropoda caudam nonnihil superantia; ramus interior ramum exteriorem paulum
superans. fere duplo longior quam latior, margine postero-interiore sat excurvato, sat
spinoso, longe ciliato, apice paulum producto, acuto. Scapus angulo interiore partem
tertiam basalem rami interioris nonnihil superante.

Color flavo-brunnescens. Appendix masculina fere ut in C. tricorni. HANSEN,
Vidensk. Selsk. Skr. (6), V, 1890, pp. 386-387.

ISOPODS OF NORTH AMERICA.

155

ments is slightly tuberculate. The terminal segment is perfectly
smooth on its dorsal surface, is produced to a narrow extremity, which
is rounded, and has the posterior margin crenulate, the crenulations
.it the apex taking the form of five teeth. The inner branch of the

FIG. 135. EXOCORALLANA WARMINGII (AFTER HANSEN). O, LEG OF FIFTH PAIR. 6, LEG OF SEVENTH

PAIR, c, LEG OF SECOND PAIR, d, HEAD, e, DOBSAL VIEW OF MALE. /, LATERAL VIEW OF MALE.
g, POSTERIOR PART OF ABDOMEN. (ENLARGED.)

uropoda is broad, with the inner angle of the posterior end broadly
rounded, the outer angle terminating in an acute tooth; the posterior
and exterior margins are slightly crenulate. The outer branch is nar-
row, less than half the width of the inner branch, is a little shorter

156 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

than the inner branch, and terminates in two acute teeth, the inner
one being the larger and longer one.

The first three pairs of legs are prehensile, the last four pairs
ambulatory.

FlG. 136. EXOCORALLANA WARMINGII. O, MANDIBLF. X 38J. 6, OUTER LAMELLA OF FIRST MAXILLA.

x 38|. c, MAXILLIPED. x 38}. d, TIP OF MANDIBLE, x 38J.

Family VII. CORALLANID^.

Mandibles becoming narrower toward the anterior part and mani-
festly directed inward. Apical part narrow, hidden under the cly-
peus, labrum, and paragnathia. Cutting edge short. Apical tooth of
mandibles not greatly produced. Movable lacinia small or vanishing;
molar part very often vanishing, sometimes well developed. Apex of
second maxillae simple. First maxilla? with the lacinia of the first
article unarmed; the lacinia of the third article becoming more or less
narrower from about the middle to the apex; apex furnished with few
spines. Antepenultimate article of the maxillipeds not longer than
broad. Labrum small, transverse.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY CORALLANID^.

a. First maxillae with the apex of the third article furnished with more than one

spine. Lacinia of first article narrow, elongate, with apex unarmed.
b. First maxillae with the apex of the third article furnished with two spines.
Molar part of mandibles wanting. Second maxillae simple; lacinise not dis-
tinct. Clypeus long and wide, semilunar in shape Genus Alcirona Hansen

b / . First maxillae with the apex of the third article furnished with three spines.
Molar part of mandibles well developed. Second maxillae indistinctly
bilobed. Clypeus short and wide, in the form of an inverted v.

Genus Tridentella, new genus

a'. First maxillae with the apex of the third article furnished with a single, long,
robust, inwardly-curved spine. Lacinia of first article in the form of a quad-
rate curve-faced cap furnished with papillae and covering tip of first article.
Second maxillae four-jointed; first two joints stout; third joint stout and sub-
conical ; terminal joint slender and conical Genus Nalicora Moore

See Hansen for characters of family. Vidensk. Selsk. Skr. (6), V, 1890, pp.
312-313, 317, 390, and Stebbing, Fauna and Geography of the Maldive and Laccadive
Archipelagoes, II, Pt. 3, 1904, p. 703.

ISOPODS OF NORTH AMERICA. 157

27. Genus ALCIRONA Hansen.

Peduncle of the first pair of antennae composed of two articles.

First maxillae with the apex of the third article furnished with two
spines. Second maxillae simple, laciniae not distinct.

Mandibles becoming narrower from the base to the apex; movable
lacinia very small or wanting, molar part absent.

Clypeus very large, long, and very wide, semilunar in shape, with
the post-lateral angle reaching beyond the middle of the mandibles
and almost to the articulation of the mandibular palp.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ALCIRONA.

a. First pair of antennae, with flagellum of seventeen articles, extend to the end of
the fifth article of the peduncle of the second pair of antennae. Second pair of
antennae, with flagellum of thirty-five articles, extend to the posterior margin
of the seventh thoracic segment. The first article of the peduncle of the second
antennae is twice as long as the second; the third is as long as the first; the
fourth is twice as long as the third; the fifth is twice as long as the fourth.
Last three segments of thorax with rows of stiff hairs on the posterior margin,
and all the segments of the abdomen and the uropoda are covered with short
stiff hairs Alcirona krebsii Hansen

a'. First pair of antennae, with flagellum of seven articles, extend to the end of the
fourth article of the peduncle of the second pair of antennae. Second pair of
antennae, with flagellum of seventeen articles, extend to the middle of the
third thoracic segment. The first three articles of the peduncle of the first pair
of antennae are short, the fourth and fifth articles subequal and each about
twice as long as the third article. Last five segments of thorax with rows
of stiff hairs, and all the segments of the abdomen and the uropoda covered
with short stiff hairs Alcirona hirsuta Moore

ALCIRONA KREBSII Hansen.

Alcirona krebsii HANSEX, Vidensk. Selsk. Skr. (6), V, 1890, pp. 391-392, pi. vm,
figs. 1-lq. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 519; Trans.
Conn. Acad. Sci., XI, 1902, p. 290.

localities. Off Cape Catoche, Yucatan; St. Thomas, West Indies;
Castle Harbor, Bermudas, in the cavities of living bathing sponges
and in dead coral. Two specimens were taken from the tins of a Ham-
let Grouper.

Depth. 25-28 fathoms.

Body oblong-ovate, a little more than twice as long as wide, 5 mm.:
11 mm. Head wider than long, 1 mm. : 2 mm. , with the anterior margin
rounded. Eyes small, round, composite, and situated in the antero-
lateral angles of the head. The first pair of antennae have the first
article long; the second is fused with the first; the third is longer than
the first. The flagellum is composed of eighteen articles. The first
antennae extend almost to the end of the fifth article of the peduncle of
the second antennae. The second pair of antennae have the first article

158

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 137. ALCIRONA KREBSII
(AFTER HANSEN). a, DORSAL

VIEW OF HALE. X \ 5 -. 6, LAT-
ERAL VIEW OF ADULT MALE.

xy.

twice as long as the second; the third is as long as the first; the fourth
is twice as long as the third; the fifth is twice as long as the fourth.
The flagellum is composed of thirty-nine articles. The second pair of
antennae extend to the posterior margin of the seventh thoracic seg-
ment; the peduncle extends to the posterior margin of the first thoracic

segment. The maxilliped is composed of
seven articles. The palp of the mandibles
is composed of three articles. The frontal
lamina has the anterior portion broad, the
posterior end attenuated; the anterior mar-
gin is triangulate.

The first segment of the thorax is one and
a half times longer than any of those follow-
ing. The epimera are distinct on all the
segments, with the exception of the first.
The last four are crossed obliquely by an
arched carina; the first two are crossed lon-
gitudinally. The outer post-lateral angles
of the first two epimera are rounded; those
of the last two are acutely produced beyond
the posterior margins of the segments. The last three segments of
the thorax are covered with short stiff hairs.

The first two segments of the abdomen are entirely concealed by
the seventh thoracic segment. The
sixth or terminal segment is trian-
gular in shape, with the apex nar-
rowly rounded and furnished with
six spines. The entire abdomen is
densely covered with short stiff hairs
or bristles. The inner branch of the
uropoda is broad and widely rounded
at the posterior extremity ; it extends
as far as the extremity of the abdo-
men. The outer branch is as long
as the inner branch, is half as wide,
and has the extremity narrow. The
margins of both branches are fur-
nished with spines, and stiff hairs
or bristles densely cover the whole dorsal surface. The inner angle
of the peduncle is produced and extends a little beyond the middle of
the terminal abdominal segment.

The first three pairs of legs are prehensile, the last four pairs
ambulatory.

FIG. 138. ALCIRONA KREBSII. a, MAXILLIPED.
x 51|. 6, MANDIBLE, x 51f. c, FRONTAL
LAMINA, x 51|.

1SOPODS OF NOKTH AMEKICA.

159

ALCIRONA HIRSUTA Moore.

Aldrona hirsuta MOORE, Bull. U. 8. Fish Comm., XX, Pt. 2, 1902, p. 170, pi. ix,
figs. 6-10.

Locality. Off St. Thomas.

Depth. 20-23 fathoms.

Found in coral bottom.

"Front slightly produced and somewhat inflexed between the bases
of the antennules, not joining the epistome; eyes small, lateral, dis-
tance between two or three times their diameter. Body strongly
arched antero- posteriorly. Epistome narrow, pentagonal. First
antennae with two-jointed peduncle reaching to about end of fourth

FIG. 139. ALCIRONA KKEBSII (AFTER HANSEN). a, MAXILLIPED. 6, FIRST MAXILLA, c, DISTAL

PART OF MANDIBLE. (I, DORSAL VIEW OF FEMALE. , LEFT PLEOPOD OF SECOND PAIR IN YOUNG

MALE. /, LATF.RAL VIEW OF FEMALE, g, LEG OF FIFTH PAIR, h, LEG OF SEVENTH PAIR, i, MAN-
DIBLE, j, DISTAL PART OF MANDIBLE, k, SECOND MAXILLA. I, DISTAL PART OF MANDIBLE, in, LEFT

PLEOPOD OF SECOND PAIR IN ADULT MALE. n, LEG OF SECOND PAIR. 0, POSTERIOR PART OF ABDO-
MEN (ADULT MALE), p, ANTERIOR PART OF HEAD FROM BELOW.

joint of antennal peduncle. Flagellum slightly shorter than peduncle,
of seven joints, first joint as long as second and third. Second antennae
reaching to middle of third segment, with five-jointed peduncle; first
three joints short, fourth and fifth joints each about twice as long as
third and subequal, flagellum with seventeen joints. Mandibular palp
rather robust, three-jointed, second joint longest, second and third
joints with setae.

" Maxillipeds with five-jointed rather robust palps.

"First segment of trunk about 1.6 times as long as second, the next
five equal, the seventh a little shorter; third segment with a few setae
on lateral portion of posterior margin; fourth, fifth, sixth, and seventh

160

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

with complete rows becoming successively more dense posteriorly. In
one specimen a very few hairs at side of second segment. First three
pairs of perseopods subsimilar, fourth joint broad and armed with sev-
eral very strong spines, fifth joint very short, almost hidden in the
first leg, somewhat longer in the second and still longer in the third.
Seventh joint pectinate, with four long spines in the first leg, in the
second and third legs these becoming weaker. Claws strong in all.

"Last four legs successively longer and relatively to their length
more slender than the first three pairs, heavily armed with numerous
brown-tipped spines.

FIG. 140. ALCIRONA HIRSUTA (AFTER MOORE), a, RIGHT SIDE OF TERMINAL ABDOMINAL SEGMENT
WITH UROPOD. b, SEVENTH LEG. x 40. c, GENERAL FIGURE, x 8. d, FIRST LEG. x 40. e, FOURTH
LEG. x 40.

"Pleon of five visible segments, dorsally strongly setose, first and
second segments narrow and laterally covered by the seventh thoracic
segment, the first being visible only dorsally; third segment posteri-
orly produced at the sides, covering the lateral portion of the fourth
segment, which is the longest in the median line. This region is so
setose that it is difficult to delimitate the segments.

"Telson triangular, with the tip rounded and armed with six spines,
about two-thirds as long as broad; dorsal surface and posterior mar-
gin with numerous setae. Uropods extending somewhat beyond end
of telson, inner branch the longer, not much longer than broad,
rounded, with about ten marginal spines and numerous seta? about

ISOPODS OF NORTH AMEEICA. 161

half as long as tj>e ramus itself; external ramus narrow, with about
eight spines and numerous setas on the posterior and outer margin.

"This species is close to A. insidaris, from which it differs in its
greater hairiness.

"Two specimens. Station 6079, 20 fathoms, 5 by 2.3 mm."
MOORE/'

28. Genus TRIDENTELLA, new genus.

First pair of antennae with peduncle composed of three articles.

First maxillae with the apex of the third article furnished with three
spines. Second maxillae indistinctly bilobed at the tip.

Mandibles becoming narrower from the base to the apex; movable
lacinia absent; molar part well developed.

Clypeus wide and short, in the form of an inverted v, with the
post-lateral angles produced almost to the articulation of the mandib-
ular palp.

Labrum small.

TRIDENTELLA VIRGINIANA (Richardson).

Cirolana virginiana RICHARDSON, American Naturalist, XXXIV, 1900, p. 216;
Proc. U. S. Nat. Mus., XXIII, 1901, pp. 512-513.

Locality. Chesapeake Bay.

Depth. 81 fathoms.

Body not quite twice as long as broad, oval, thickset. Head trans-
verse, with indications of four small tubercles, two on the anterior
portion, between the eyes, and two on the posterior
portion. Eyes large, lateral. First pair of antennae
long, nearly as long as the second pair, reaching the
posterior margin of the first thoracic segment; flagel-
lum twelve-jointed. Second pair of antennae extend
to the middle of the third thoracic segment; flagellum FlG

eigllteen-jointed. TELLA VIRGINIANA.

First thoracic segment one and a half times longer ctTrera AHD

than any of the other segments. Following segments R UM. (DIAGRAM-

, , ,, MATIC.)

of equal length.

First abdominal segment almost entirely concealed by last thoracic
segment. Four succeeding segments of equal length. Terminal seg-
ment very short and narrow, not longer than the four abdominal
segments taken together, posteriorly rounded and crenulate. Both
branches of the uropoda crenulate. Inner branch broad and equaling
in length the terminal segment. Outer branch narrower and a little
shorter than inner branch.

Abdomen minutely granulose.

Bull. U. S. Fish Comm., XX, Pt. 2, 1902, p. 170.
2858905 - 11

162 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 142. TRIDENTELLA

VIKGINIANA. FlEST
MAXILLA. X 51|.

FIG. 143. TRIDENTELLA VIRGIN-
IANA. ABDOMEN.

Color, light brown.

Two specimens were collected by the U. S. Bureau of Fisheries
steamer Albatross in Chesapeake Bay.
' T >ji>e. Cat. No. 6350, U.S.N.M.

The following description is of two specimens from southern Cali-
fornia which I have not been able to separate from
the species from the Atlantic coast:

Body oblong-ovate, nearly twice as long as wide,
5 mm.: 9 mm.

Head wider than long, H mm.: 2 mm., with the
anterior margin rounded and produced in a small
median point, which
meets the anterior mar-
gin of the frontal lamina.
There is a small tubercle
situated at the base of
the median point. The
eyes are small, round,
composite, and placed at
the post-lateral angles.
There are four tubercles
on the dorsal surface of
the head between the eyes, two close to the anterior margin and the
other two close to the posterior margin, one on either side of the
median line .in each series.

The first pair of antennas have the first two articles short and sub-
equal; the third is about twice as long as
the second. The flagellum is composed
of twelve articles and extends to the pos-
terior margin of the first thoracic seg-
ment. The second pair of antennae have
the first article a little longer than the
second and equal in length to the third;
the fourth is twice as long as the third;
the fifth is a little longer than the fourth.
The flagellum is composed of twenty arti-
cles and extends to the posterior margin
of the third thoracic segment. The maxil-
lipeds are composed of seven articles. The
mandible has a palp of three articles. The
frontal lamina is short and broad.

The first segment of the thorax is twice as long as any of the follow-
ing segments, which are subequal. The epimera are distinctly sepa-
rated on all the segments with the exception of the first. The last

FIG. 144. TRIDENTELLA VIR<; IT-
IAN A. x 6.

ISOPODS OF NOKTH AMEEICA.

163

four have the outer post-lateral angle acutely produced beyond the
posterior margin of the segments.

All six segments of the abdomen are distinct, although the first is
partly covered at the sides
by the last thoracic segment.
The sixth or terminal segment
is wider than long, 3 mm.:
2 mm., and is rounded pos-
teriorly with margins dis-
tinctly crenulate and has a
slight median emargination.
The inner branch of the uro-
poda reaches the extremity of
the terminal segment of the
abdomen. It is broad and
truncate posteriorly, with mar-
'gins distinctly crenulate and
furnished with spines. The
outer branch is shorter than
the inner branch, is narrower
and more pointed at its ex-
tremity. It is also distinctly
crenulate and furnished with
spines.

Two specimens of this spe-
cies were collected by the U. S.

Bureau of Fisheries steamer Albatross at station -1117, S. W. Rock,
Santa Barbara Islands, latitude 8 north, longitude, 6.3' west.

Depth. 29 fathoms.

29. Genus NALICORA Moore. .

"Clypeus small, peduncle of second antennte long; mandible weak,
with bidentate cutting edge and three-jointed palp; first maxillae very
large, robust, and conspicuous in situ, outer joint stout, hooked, and
terminated by a strong, curved spine in the male, continuous in con-
tour with the rest of the part, and with a knob-like process at its base;
inner joint with its tip covered by a quadrate, curve-faced cap covered
with papillae; second maxilla? four- jointed, first two joints stout, short,
third joint stout and subconical, terminal joint slender and conical, with
a tuft of setae near tip; palp of maxillipeds five-jointed, slender. "-
MOORE. a

/ \

FIG. 145. TRIDENTELLA VIRGINIANA. a, MAXILLIPED.
x 5l|. 6, MANDIBLE, x 51|. c, PALP OF MANDIBLE.
x 51|. d, SECOND MAXILLA, e, FIRST MAXILLA
(OUTER LOBE) . x 61|. /, FRONTAL. LAMINA, x 27}.

a Bull. U. S. Fish Commission, XX, Pt. 2, 1902, p. 169.

164 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

NALICORA RAPAX Moore.

Nalicora rapax MOORE, Bull. U. S. Fish Commission, XX, Pt. 2, 1902, pp. 169-170,
pi. ix, figs. 11-22.

Localities. Mayaguez Harbor, Porto Rico; Gulf of Mexico; lati-
tude 29 11' 30" north, longitude 85 29' west; latitude 28 46' north,
longitude 84 49' west; latitude 29 16' 30" north, longitude 85 82'
west; between delta of the Mississippi and Cedar Keys, Florida.
Depth. 25-75 fathoms.

"Body convex, about 2.3 times as long as broad, first thoracic seg-
ment longest, next five about two-thirds as long and subequal, last
shorter; posterior four thoracic segments with a row of setae across
middle and another on posterior margin, hairiness increasing posteri-
orly, occasionally a few setae on second and third. Fifth segment
broadest.

"Pleon and telson about two-fifths as long as rest of body. Pleon

of four visible segments, first short and nar-
rower than second and third and hidden at
side by seventh thoracic; second somewhat
produced at posterior lateral angle; third
segment strongly produced, angle reaching
to beyond base of uropods.

"Epimera of all the thoracic segments
except the first distinct, of second and
third not produced posteriorly, the follow-
ing ones successively more produced, the
last two terminating in strong angles.
LOBE OF FIRST MAXILLA, x 5if. " First antennae about as long as pedun-
cle of second antennae; peduncle of two

equal joints, flagellum slightly longer than peduncle, about eight or
nine jointed; distal ends of segments furnished with a few short hairs;
second antennas reaching to end of second thoracic segment; peduncle
five-jointed, fifth joint longest, slightly exceeding the fourth, which is
as long as first three joints together.

"Mandible weak, with bifid cutting edge and three-jointed palp.
First maxilla large, robust; plate of first joint expanded at distal end
into a somewhat quadrate curved face closely beset with papillae and
looking like a triturating plate; third joint very stout, strongly curved
with a very strong terminal spine continuous in contour with the rest
of the joint; at base of curved portion, on inner side, a stout knob-
like protuberance. The first maxilla is the largest and most conspicu-
ous of the mouth parts, overlapping and hiding the mandible, and in
the male reaching to the base of the antennae. In the female the ter-
minal spine is straighter, not so continuous with the rest of the plate,
and points inward and somewhat backward. Second maxilla four-

ISOPODS OF NORTH AMERICA.

165

jointed; first two joints short and stout; second joint stout, decreasing
distal ly; third joint slender and tapering, set at an angle to second
joint and furnished at its tip with several setie, one of which is usually
longer and stouter than the others. Maxillipeds with rather slender
five-jointed palp, more slender in male, first joint shortest, second
joint longest, two to three times as long as first.

"First pair of thoracic limbs with fifth joint set obliquely to the
plane of the preceding joints, very short, almost hidden on inner or
anterior face, but triangular and appearing to be deeply embedded in

FIG. 147. NALICOBA RAPAX (AFTER MOORE), a, GENERAL FIGURE, b, SECOND MAXILLA, c, SECOND

ANTENNA, d, FIRST MAXILLA. 6, SEVENTH LEG. /MANDIBLE, g, MAXILLIPED. /I, FIRST LEG (POS-
TERIOR), i, FOURTH LEG. j, FIRST LEG (ANTERIOR), k, FIRST LEG (INFERIOR). , PART OF TERMI-
NAL SEGMENT OF ABDOMEN WITH UROPODA.

fourth joint when viewed externally; fourth joint with about four
stout spines on inferior edge, second limb with fifth joint longer and
with slight obliquity; third pair similar but longer. Pairs four to
seven more slender, with numerous spines, the third, fourth, fifth, and
sixth joints subequal.

"Uropods stout, the peduncle prolonged at its inner angle into a
robust process. Inner ramus broad (about 1.5 times as long as broad),
extending beyond end of telson; outer ramus shorter and narrower,
extending barely beyond tip of telson; apex truncate or subbifid.

166 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"Telson triangular, about two-thirds as long as broad, lateral mar-
gins somewhat excavated, apex narrow, rounded.

"Seventeen specimens from stations 6062 and 6063, 25 to 75 fathoms.
Largest 8.5 mm. by 3.8 mm. ; smallest 5.5 mm. by 2.5 mm." MOORE."

Family VIII. MG1DM.

Bod}^ more or less broad, flattened.

Head transverse.

Segments of thorax with epimera distinctly defined on alt the seg-
ments, with the exception of the first.

. Abdomen composed of six well-defined segments, the last segment
ciliated on the posterior margin. Uropoda together with the terminal
abdominal segment forming a caudal fan. Eyes, when present, usually
large. Antennae laterally directed, both pairs furnished with distinct!}'
defined, multi-articulate flagella. Peduncle and flagella well defined.

First three pairs of legs prehensile, last four pairs ambulatory.

Pleopods serving for swimming and for respiration; furnished with
cilia.

First maxillae with only a single slender masticatory lobe, tipped by
short spines.

Second maxillae broader, terminating in two unequal lobes, armed
with recurved teeth.

Last article of palp of maxillipeds armed with strong recurved teeth.

Terminal abdominal segment and uropoda furnished with cilia.

Parasitic forms usually found attached to the skin of fishes.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY JEfilDM.

a. Body compact. First two articles of the peduncle of the first pair of antennae
more or less expanded. . Frontal lamina large. Maxillipeds with the palp com-
posed of five articles. Front of head with median point separating wholly or
partly the first articles of the first pair of antennae. Flagellum of the first anten-
nae composed of numerous articles. Abdomen compact Genus sEga Leach

of. Body depressed. First two articles of the peduncle of the first pair of antennae
not expanded. Frontal lamina small. Maxillipeds with the palp composed of
only two articles. Front of head covering more or less the peduncle of the first
pair of antennae. Flagellum of first antennae composed of four to six articles.
Abdomen relaxed.

b. Eyes present. Three anterior pairs of legs with propodus more or less expanded,
and armed with spines; dactylus forming a very large and evenly curved
hook. Four posterior pairs with the propodus short. Mandibles with the
cutting edge expanded inside in a linguiform lamella. Abdomen not much

narrower than thorax Genus Rocinela Leach

b' '. Eyes wanting. Three anterior pairs of legs with propodus not expanded ; dactylus
abruptly curved in the middle and terminating in a very sharp point. Four
posterior pairs with the propodus elongated. Mandibles without linguiform
lamella. Abdomen abruptly narrower than thorax. .Genus Syscenus Harger

Bull. U. S. Fish Commission, XX, Pt. 2, 1902, pp. 169-170.

ISOPODS OF NORTH AMERICA. 167

SO. Genus ^EGA Leach.

Body rather compact. Abdomen not much narrower than thorax.

Eyes present, usually large, often contiguous.

First two articles of the peduncle of the first pair of antennae more
or less expanded, dilated. Frontal lamina or epistome large.

Mandibles without molar expansion. Palp of maxillipeds composed
of five articles. a

Three anterior pairs of legs with the propodus simple, cylindrical,
not expanded; dactylus abruptly curved in the middle. Four posterior
pairs with the propodus short.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ./EGA.

a. First pair of antenme with the first two articles of the peduncle very much enlarged,

dilated, flattened. The second article is produced at the upper distal angle in a

process which extends half the length of the third article. The third article is

half as wide as the second article, or narrower. Frontal lamina plane or concave.

b. Terminal segment of abdomen pointed posteriorly, triangulate.

c. Eyes distant sEga psora (Linnaeus)

(/. Eyes contiguous JKga antillensis Schioedte and Meinert

b'. Terminal segment of abdomen not pointed posteriorly or triangulate.
c. Terminal segment bisinuate, forming three obtuse teeth on the posterior mar-
gin JEga ecarinata Richardson

c / . Terminal segment of abdomen posteriorly emarginate or truncate.

d. Eyes contiguous ^Ega crenulata Liitken

d' '. Eyes distant.

e. Propodus of second and third pairs of legs furnished at distal end on infe-
rior margin with linguiform process &ga webbii (Guerin)

e' '. Propodus of second and third pairs of legs not furnished at distal end on

inferior margin with linguiform process ^Ega lecontii ( Dana)

a'. Peduncle of the first pair of antennae with the first two articles not enlarged or
dilated, but compressed and rounded. The second article is not produced at
the upper distal angle in a process which extends half the length of the third
article. Third article not narrower than second article. Frontal lamina con-
vex or compressed and elevated.
b. Eyes contiguous.
c. Terminal segment of abdomen whole, entire.

^Ega tenuipes Schioedte and Meinert
c'. Terminal segment of abdomen not whole or entire.
d. Terminal segment of abdomen terminating in seven teeth in the middle.

j-Kga dentala Schiosdte and Meinert
d''. Terminal segment of abdomen with small rounded incision or emargina-

tion at the apex jEga incisa Schioedte and Meinert

b'. Eyes not contiguous,
c. Terminal segment of abdomen with small, round median notch or emargina-

tion JKga arctica Liitken

c'. Terminal segment of abdomen without median notch or emargination.
d. Eyes very large.

In drawing the maxillipeds of the various species it was not always possible to
place the maxilliped in a position to show all five articles of the palp or to represent
the dividing line between the last two articles.

1G8 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

e. All legs free of spines JEga gracilipes Hansen

/''. Legs furnished with spines.
/. Uropoda extend beyond the tip of the abdomen.

JEya symmetrica Richardson
/'. Uropoda,do not extend beyond the tip of the abdomen.

JEga ventrosa M. Sars
d' '. Eyes very small sEga microphthalma Dana

.(EGA PSORA (Linnaeus).

Oniscus psora LINNAEUS, Fauna suecica, 2d ed., 1761, p. 499, No. 2054; Syst. Nat.,
12th ed., I, 1767, p. 1060. O. FABRICIUS, Fauna Groenlandica, 1780, p. 249.

jEga emarginata LEACH, Trans. Linn. Soc. London, XI, 1815, p. 370; Diet. Sci.
Nat,, XII, 1818, p. 349. DESMAREST, Consid. Crust., 1825, p. 305, pi. XLVII,
figs. 4-5.

JEga entaittee LATREILLE, Regne Anim., IV, 1829, p. 134.

JEga emarginata GOULD, Rept. Geol. Mass., 1835, p. 549.

JEga (Oniscus psora) KR0YER, Dansk. Vid. Selsk. Afh., VII, 1838, p. 318.

JEga emarginata MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 240. GOULD,
Invert. Mass., 1841, p. 338. MILNE EDWARDS, Regne Anim. Crust., 1849,
pi. iv, fig. 4; pi. LXVII, fig. 1.

JEga psora LILLJEBORG, Ofvers. Vet.-Acad. Forh., VII, 1850, p. 84; VIII, 1851, p.
24. LiJTKEN.Vidensk. Meddel., 1859, pp. 65, 179; 1861, p. 181 (7). SCHKEDTE,
Ann. Mag. Nat. Hist, (4), 1, 1868, p. 12. BATE and WESTWOOD, British Sessile-
eyed Crustacea, II, 1868, p. 283. M. SARS, Chr. Vid.-Selsk. Forh., 1869,
p. 261. G. O. SARS, Chr. Vid.-Selsk. Forh., 1872, p. 275 (32). VERRILL,
Am. Jour. Sci. (3), V, 1873, p. 16. SMITH and HARGER, Trans. Conn. Acad.
Sci., Ill, 1874, p. 22. LUTKEN, Crustacea of Greenland, 1875, p. 150.
MEINERT, Naturh. Tidsskr. (3), XI, 1877, p. 89. MIERS, Ann. Mag. Nat.
Hist. (4), XIX, 1877, p. 134. HARGER, Proc. U. S. Nat. Mus., II, 1879,
p. 161; Report U. S. Commissioner of Fish and Fisheries, Pt. 6, 1880, pp. 384-
387, pi. x, fig. 64 (see Harger for synomymy). SCHIOSDTE and MEINERT,
Nat. Tidsskr. (3), XII, 1879-80, pp. 357-360, pi. vm, figs. 5-6. MIERS,
Journ. Linn. Soc. London, Zool., XV, 1881, pp. 65-66. HANSEN, Videnska-
belige Meddelelser fra den naturhistoriske Forening i Kjobenhavn, 1887-
1888, p. 183. SARS, Crust, of Norway, II, 1899, p. 59, pi. xxiv. RICHARDSON,
American Naturalist, XXXIV, 1900, p. 218; Proc. U. S. Nat. Mus., XXIII,
1901, p. 521. AXEL OHLIN, Bihang till K. Svenska Vet.-Akad. Handl.,
XXVI, Afd. iv, 1901, pp. 22-23.

Localities. Off Marthas Vineyard; Georges Bank; Browns Bank;
Fishers Island Sound; La Have Bank; Gulf of Maine; Western Bank;
Gloucester; Sable Island Bank; between Peters Bank and Banque-
reau; Nova Scotia; Grand Bank; Newfoundland; Gulf of St. Lawrence;
Nakvak, Labrador; Holstensborg, Nanortalik, Ivigtut, Julianehaab,
Arsukfjord, Godhavn, Egedesminde, Ikerasak, and Umanek, Green-
land; North Greenland in Davis Straits; Hudsons Bay; also Ireland;
British Isles; North Sea; Finmark; Iceland; BjonensBay; Spitzbergen;
in the German Sea; Kattegat; between the delta of the Mississippi and
Cedar Keys, Florida; latitude 43 34' north, longitude 49 west; lati-
tude 43 25' north, longitude 59 50' west; latitude 42 47' north;
longitude 65 30' west.

Depth. 30-640 fathoms.

ISOPODS OF NOETH AMERICA.

169

Parasites of skate, cod, and halibut; on Gadus ogac; on Myxo-
cephalus scorpim; on Somniosus microcephalus; on Gadus callarias.

Body ovate, a little more than one and a half times longer than
broad, 10 mm : 16 mm.

Head two and a half times broader than long, 2 mm : 5 mm. Ante-
rior margin widely rounded, and produced in a small median point,
which does not arch over the antennae to meet the frontal lamina on
the other side. Eyes large, oval, composite, occupying a large part of
the dorsal surface of the head, but not contiguous, although very close
together. The first pair of antennae have the first two articles very
much enlarged; the first article is wider and longer than the second;
the second is produced at the upper distal angle in a process which
extends half the length of the third article; the third article is very
narrow, half as wide as the second article. The flagellum is composed
of fourteen articles. The first antennae extend to the end of the
peduncle of the second pair of an-
tennae. The first three articles of
the second antennae are subequal;
the fourth and fifth are about equal
in length, and each twice as long as
the third. The flagellum is composed
of fifteen articles. The second pair
of antennae extend a little beyond the
posterior margin of the first thoracic
segment. The frontal lamina is large,
with base somewhat quadrate in
shape, with rounded angles, and ven-
trally placed, not directed anteriorly.
The maxilliped has a palp of five
articles.

The first three segments of the thorax are longer than the three
following. The seventh is very short, being only less than half as
wide as the sixth. The epimera of all the segments are distinct with
the exception of the first. They are narrow plates with the posterior
angles produced in the last four, although in the epimeron of the
fourth segment, the posterior angle is rounded. On all the epimera
there is a faint carina extending obliquely across the surface.

All six segments of the abdomen are distinct. The first is com-
pletely covered in the middle by the seventh thoracic segment but is
visible at the sides. The lateral parts of the segments are not sepa-
rated off from the dorsal portion. The sixth or terminal segment is
triangulate, with apex not produced. The branches of the uropoda
do not extend beyond the tip of the terminal abdominal segment. The
basal segment extends two-thirds the length of the sixth abdominal
segment. The branches are about equal in length, the outer one being

FIG. 148. JEGA. 'PSORA (AFTER HARGER). x 3.
o, Ventral view, b, Dorsal view.

170

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

only a very little shorter than the inner one. The exterior margin of
the inner branch has a small notch or excavation about 1 mm. from the
extremity. The inner branch is obliquely truncate at the extremity,
the inner angle being obtusely rounded, the outer one more acute.
The outer branch is rounded posteriorly.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. The second and third pairs have the carpus furnished with
eight spines, the merus with two. The last four pairs of legs are also
furnished with spines.

JEGA. ANTILLENSIS Schicedte and Meinert.

jEga antittensis SCHKEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XII,
1879-80, pp. 361-362, pi. vin, figs. 10-13. RICHARDSON, Proc. U. S. Nat.
Mus., XXIII, 1901, p. 521.

Localities. Cuba, West Indies, off Cozumel; off Habana.
Depth. 163-231 fathoms.

Body oblong-ovate, about three times as long as broad, 12 mm.:
35 mm.

Head a little over three times as wide as long, 2 mm. : 7 mm.

Anterior margin widely rounded with a
a small median process which does not arch"

over the antennae to meet the frontal lam-
ina on the other side. Eyes large, ob-
long, composite, occupying almost the
entire surface of the head and extend-
ing from the lateral angles along the
anterior margin and meeting or con-
tiguous in the median line. The basal
article of the first antennae is about
twice as long as the second; the first
and third are subequal, but the third is
narrower, the first and second being
dilated. The flagellum is composed of
seven articles. The first antennae ex-
tend only to the middle of the fifth
article of the peduncle of the second
antennae and do not reach the ante-
rior margin of the first thoracic segment. The first two articles of
the second pair of antennas are equal in length; the third is about
twice as long as the second; the fourth is one and a half times longer
than the third; the fifth is but little longer than the fourth. The
flagellum is composed of thirteen articles and reaches two-thirds the
length of the first thoracic segment. The maxilliped has a palp of

FIG. 149. ^EGA ANTILLENSIS (AFTER
SCHKEDTE AND MEINERT). a, FRONTAL

MARGIN WITH BOT^I ANTENNJ5 AND
FRONTAL LAMINA. 6, YOUNG FEMALE.
(ENLARGED.)

For description of the young of the third stage, see Schicedte and Meinert, Nat.
Tidsskr. (3), XII, 1879-80, pp. 358-359.

ISOPODS OF NORTH AMERICA.

171

five articles. The frontal lamina has the large round disk of the base
ventrally placed, not anteriorly directed.

The first segment of the thorax is a little longer than any of the
others, and the seventh is shorter. The epimera of all the segments,
from the second to the seventh, inclusive, are distinctly separated from
the segment. They are narrow, with the posterior angle in the last
four acutely produced beyond the posterior margin of the segments.
The first two epimera are rounded posteriorly. A distinct carina
extends obliquely from the posterior angle to the inner antero-lateral
angle in all the epimera.

The six abdominal segments are all distinct. The lateral parts are
not separated off from the dorsal portion. The sixth or terminal seg-
ment is triangularly produced in a long and very acute point, extending
2 mm. beyond the extremity of the
uropoda. The branches of the uro-
poda are equal in length. The inner
branch has a conspicuous notch or
emargination on the exterior margin
about 2 mm. from the posterior ex-
tremity which is acutely produced.
The outer branch is about as wide as
the inner branch, the margins are
entire, and the posterior extremity
rounded. The branches of the uro-
poda are crenulate and furnished with
spines. The basal article or peduncle
extends half the length of the last
segment of the abdomen.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. There are five spines on the merus of the second and third
pairs of legs. The last four pairs of legs are thickly beset with spines.

JEGA ECARINATA Richardson.

-ffiga ecarinata RICHARDSON, Proc. Biol. Soc. Washington, XII, 1898, pp. 39-40;
American Naturalist, XXXIV, 1900, p. 218; Proc. U. S. Nat. Mus., XXIII,
1901, p. 521. MOORE, Bull. U. S. Fish Comm., XX, Pt. 2, 1902, p. 171,
pi. x, fig. 1.

Localities. Off Little Bahama Bank, between delta of the Missis-
sippi and Cedar Keys, Florida; off entrance to San Juan.

Depth. 88-338 fathoms.

Body elongate and narrow. Length more than three times greater
than breadth. Surface punctate. Frontal margin of head bisinu-
ated, the acumen separating the first pair of antennae. Eyes large and
oblong and situated a small distance apart. First pair of antennas

FIG. 150. JEGA ANTILLENSIS. a, MAXILLI-
PED. x 27}. 6, LEG OF SECOND PAIR, x 9|.

172 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

extend almost to the flagellum of the second pair of antennae; the
first two joints of the peduncle very broad; second joint extends ante-
riorly over the third joint, reaching almost to the extremity of that
joint; third joint two-thirds narrower than first and
second; the flagellum is composed of nine articles.
Second pair of antennae extend to the middle of the
first thoracic segment; flagellum is composed of ten
articles.

Epimera of all the thoracic segments narrow, the
first two being rounded, the other four more acute
at their extremities. First two pairs of prehensile
legs rather stout; third pair less so, and the pro-
podus of this pair is furnished with a large cultri-

form process. Five spines
are present on the merus
of all three pairs. Gres-
sorial legs slender and
sparsely spinulose.

All the abdominal seg-
ments are visible in a dor-
sal view. Terminal seg-
ment broad and posteriorly

FIG. 151. JEGA. ECAR-
INATA. X2f.

FIG. 152. MGA
ECARINATA.
MAXILLIPED.
x39.

bisinuated, forming three
teeth with rounded extremi-
ties; its surface is entirely
smooth.

Outer branch of uropods
narrower and somewhat
shorter than the inner branch ;
its extremity is rounded.

Inner branch obliquely truncate and crenulate on
posterior margin. Uropods and terminal abdominal
segment all fringed with a few hairs.

Two individuals of this species were found one
between the delta of the Mississippi and Cedar Keys,
Florida, Station 2403, depth 88 fathoms; the other,
the type (Cat. No. 21001, U.S.N.M.), off Little Ba-
hama Bank, Station 2655, depth 338 fathoms.

This species is closely related to A. tridens a Leach,
but presents many specific differences; in the relative length and
breadth of the body, the length being more than three times greater

For synonymy, see Naturhistorisk Tidsskrift, XII, 1879-80, Schioedte and
Meinert, Symbols ad Monographium Cymothoarum, Crustaceorum Isopodum
Familiae, pp. 340-341.

FIG. 153. JEGA. ECAR-
INATA. X &?. a,
LEG OF FIRST PAIR.
6, LEG OF THIRD

PAIR, c, LEG OF

SEVENTH PAIR.

ISOPODS OF TvTOKTH AMEEICA.

173

than the breadth in A. ecarinata, while in A. tridens Leach the length
is only two and one-half times greater than the breadth; in the number
of joints in the first and second pairs of antennae, ten in the first pair
and nineteen in the second pair being characteristic of A. tridens Leach,
nine in the first and ten in the second pair being true of our species;
in the presence of a cultriform process on the propodus of the third
pair of prehensile legs, which process is entirely wanting in A. tridens
Leach; and in the perfectly smooth surface in the present species of
the terminal segment of the abdomen, which in the other species is
tricarinated.

^EGA CRENULATA Lijtken.

JEga crenulata LUTKEN, Vid. Medd. Naturh. Foren. i Kj0benhavn, 1859, p. 70,
pi. A, figs. 4-5. ScmffiDTE and MEINERT, Naturh. Tidsskrift (3), XII,
1879-80, p. 343, pi. vn, figs. 6-9. MIERS, Journ. Linn. Soc. London, XV,
1881, p. 65. HANSEN, Vid. Medd. Naturh. Foren. i Kj0benhavn, 1887, p.
183. RICHARDSON, American Naturalist, XXXIV, 1900, p. 218; Proc. U. S.
Nat. Mus., XXIII, 1901, p. 521. NORMAN, Ann. Mag. Nat. Hist. (7),
XIV, 1904, p. 434.

Localities. Ritenbenk and Umanek, West Greenland; also Iceland,
Finmark, and coast of Norway; in the German Sea.

Parasite of Greenland shark;
Somniosus microcephahis. a 6

Body oblong -ovate, a little
more than twice as long as
broad, 13 mm. : 28 mm.

Head a little more than twice
as wide as long, 3 mm.: 7 mm.
Anterior margin widely rounded
and produced in a small median
point, which does not arch over
the antennae to meet the frontal
lamina on the other side. Eyes
large, oval, composite, and occu-
pying almost all the dorsal surface of the head, extending from the
lateral angles, along the anterior margin and meeting in the median
line, being contiguous. The first antennae have the two basal articles of
the peduncle very much enlarged; the first article is longer and a little
wider than the second; the second has a process at the anterior angle of
the distal extremity, extending half the length of the third article; the
third article is short and narrow, being one-third as wide as the basal
article. The flagellum is composed of nine articles. The first antennae
extend to the end of the peduncle of the second pair of antennae, but
not quite to the antero-lateral angles of the first thoracic segment.
The first three articles of the second antennae are subequal; the fourth

FIG. 154. ^EGA CRENULATA (AFTER SCHICEDTE AND
MEINERT). o, YOUNG OF THIRD STAGE. 6, YOUNG

OF SECOND STAGE. (BOTH ENLARGED.)

LI B R

174 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

article is about twice as long as the third; the fifth is a little longer than
the fourth. The flagellum is composed of sixteen articles. The second
antennae extend almost to the posterior margin of the first thoracic
segment. The frontal lamina is round in outline at the base, which is

o

ventrally situated, not directed anteriorly. The maxilliped has a palp
of five articles. .

The first, fourth, fifth, and sixth segments of the thorax are longer
than the others. The epimera are distinct on all the segments with
the exception of the first. They are narrow plates with the post-
lateral angles acute. A distinct carina extends obliquely from the

post-lateral angle to the middle of
the side adjacent to the segment in
the last three epimera and to the
inner an tero- lateral angle in the
first three epimera.

All six segments of the abdomen
are distinct. The lateral parts are
not separated from the dorsal por-
tion. The sixth or terminal seg-
ment has the sides converging to an
extremity, which is truncate or but
slightly excavate and about half as
wide as the base, 3 mm.: 7 mm.
The posterior margin is crenulate.
The branches of the uropoda are
about equal in width; the outer one
is rounded posteriorly; the inner
one is obliquely truncate, the inner angle rounded, the outer one being
more acute. The branches of the uropoda are somewhat crenulate
and furnished with spines. The basal article extends two-thirds the
length of the last abdominal segment.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. The propodus of the second and third pairs is furnished with
a linguiform process at the distal end; the carpus has one very small
and inconspicuous spine; the merus also has five small inconspicuous
spines. rt

FIG. 155.

x 27|.

CRENULATA. a, MAXILLIPED.

b, SECOND LEG. x 9|.

o For description of the young of the second and third stages see Sch iced te and
Meinert, Nat. Tidsskr. (3), XII, 1879-80, pp. 344-346.

ISOPODS OF NORTH AMERICA.

175

WEBBII (Guerin).

Pterelas webbii GUERIN, Mag. Zool., Cl. VII, 1836, pi. xx, figs. la-e. MILNE
EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 245.

webbii SCHKEDTE and MEINERT, Naturh. Tidssk. (3), XII, 1879-80, pp.
347-348, pi. x, figs. 1-i.

a webbii HARGER, Bull. Mus. Comp. Zool., Harvard College, 1883, XI, No.
4, p. 95. RICHARDSON, American Naturalist, XXXIV, 1900, p. 218; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 522.

Localities. Off Fernandina, Florida; latitude 31 57' north, longi-
tude 78 18' 35" west (Harger); also Cape of Good Hope; Portugal.
Depth. 333 fathoms.

Body oblong-ovate, twice as long as wide, 8 mm. : 16 mm.
Head twice as wide as long, 2 mm. : 4 mm. Anterior margin widely

FlG. 156. JEGA. WEBBII (AFTER

SCHKEDTE AND MEINERT). a,
FRONTAL MABGIN WITH BOTH
PAIRS OF ANTENNAE AND FRONTAL
LAMINA, ft, ADULT MALE. (EN-
LARGED.)

FIG. 157. ^EGA WEBBII. a, MAXILLIPED. x61f.

ft, LEG OF THE SECOND PAIR. X 15}.

rounded and produced in a small median point, which does not arch
over the antennge to meet the frontal lamina on the other side. Eyes
large, oval, composite, not contiguous, and separated in front by a
distance equal to the width of one eye. The first pair of antennae
have the two basal articles large and dilated, the first one being a little
longer and wider than the second one; the second article has the outer
distal end produced in a process which extends about half the length
of the third article; the third article is about as long and half as wide
as the basal article. The flagellum is composed of eight articles. The
first antennae reach the end of the peduncle of the second antennae, but
do not extend to the posterior margin of the head. The second pair
of antennge have the first three articles about equal in length; the
fourth article is a little more than twice as long as the third; the fifth
is just a little longer than the fourth. The flagellum is composed of

176 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

fifteen articles. The second antenna 1 extend to the posterior margin
of the first thoracic segment. The frontal lamina is large, conspicu-
ous, with the basal part ventrally placed, not anteriorly directed, and
somewhat quadrate in outline, with the anterior margin a little pro-
duced in the middle between the basal articles of the antennas. The
maxilliped has a palp of five articles.

The first, fifth, and sixth segments of the thorax are a little longer
than any of the others. The epimera are distinct from the segments,
are narrow plates, with a distinct carina extending obliquely across
the surface.

All six segments of the abdomen are distinct. The lateral parts are
not separated off from the dorsal portion of the segment. There is a
distinct carina extending from the posterior angle a short distance
across the lateral parts of the first five segments. The sixth or termi-
nal segment is broad, with its posterior extremity truncate, and about
half as wide as the basal part of the segment. The posterior margin
is denticulate. The uropoda are as long as the terminal segment.
The branches are equal in length. The inner one is about one and a
half times wider than the outer one, is posteriorly truncate, while the
outer one is rounded posteriorly; their posterior margins are faintly
crenulate.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. There is a linguiform process at the distal end of the propodus
of the second and third pairs of legs. On the carpus of these legs is
one small blunt spine, on the merus are five small blunt spines, and at
the distal end of the ischium are two small ones.

JEGA LECONTII (Dana).

JEgacylla lecontii DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854, p. 177. STIMPSON,
Bost. Jour. Nat. Hist., VI, 1857, p. 509. RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, pp. 826-827; Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 167-168;
American Naturalist, XXXIV, 1900, p. 218.

Localities. California (Dana); Monterey Bay, California.

Body elongate, oval; surf ace smooth; color yellow, with a few brown
dots; eyes reddish brown.

Head with anterior margin bisinuated, the median point separating
the basal joints of the first pair of antennae and extending one-third the
length of these joints. Eyes large, oval, very close together at upper
inner angle. First pair of antennae with basal joints very large, dilated;
second joint of peduncle dilated, and with a process at the apex extend-
ing nearly the length of the third joint; third joint very narrow, about
one-third the width of two preceding joints; flagellum, composed of
seven joints, extends the length of the peduncle of second pair of
antennae. Second pair of antenna, with a flagellum of twelve joints,
extend almost to the posterior margin of the first thoracic segment.

ISOPODS OF NORTH AMERICA.

177

The last four thoracic; segments are each a little longer than any of
the h'rst three. The epimera are narrow, with rounded post-lateral
angles.

The five abdominal segments are of equal length. The terminal seg-
ment is subtriangular with truncate extremity; its posterior margin is
crenulate and fringed with hairs. The uropoda exceed slightly the
length of the abdomen. The inner branch is about twice as wide as
the 'outer branch; is obliquely truncate, and crenulate. The outer
branch is narrow, rounded posteriorly,
and smooth. Both branches are fringed
with hairs.
The legs are long and slender. Five

spines are present on

the merus of the pre-

hensile legs. The

gressorial legs are but

slightly spinulose.
Two specimens ex-

amined were collected

at Monterey Bay, Cali-

fornia, by Mr. Heath.
The description of

this species of ^Ega by

Dana as ^Egacylla

lecontii was from a
young specimen. The individual sent us is thought to be the adult
form, and differs from Dana's description of the young individual in
the crenulated posterior margin of the terminal segment, in the
truncated inner branch of the uropoda, and in the addition of two
joints to the length of the flagellum of the second pair of antennae.

TENUIPES Schicedte and Meinert.

FIG. 158. JEGA. LECON-
TII. X 2.

FlG. 159. JEGA LECONTII. O, MAXILLI-

PED. x 38j. 6, FRONTAL LAMINA

(DIAGRAMMATIC). C, SECOND LEG.
X ll'i.

JEga tenuipes SCHICEDTE and MEINERT, Naturh. Tidsskrift (3), XII, 1879-80,
p. 371, pi. ix, figs. 4-6. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901,
p. 522.

Locality. Cuba.

Body ovate, surface rather smooth but punctate.

Front of head bisinuate, with the frontal point bent downward and
contiguous with the frontal lamina.

Frontal lamina rhomboid in shape.

Eyes large, oblong, contiguous along the four series of ocelli.

The first pair of antennae reach the posterior angle of the first seg-
ment of the thorax, extending with the peduncle to the fourth article,
with the flagellum to the tenth article of the second pair of antennas.
2858905 - 12

178 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The flagellum is composed of eleven articles, with the fir.st article
slender, equaling in length the following article.

The second pair of antennae extend to the
fourth epiraeron; the flagellum is composed
of twenty-four articles.

The first segment of the thorax is slightty
bisinuate on its dorsal surface. The epimera
are rather narrow; the posterior angles of the
posterior epimera are acutely produced; the
last epimeron extends to the middle of the
first segment of the abdomen.

The prehensile legs are slender, smooth; the
basis is rather narrow; the anterior ungulae are
rather short, somewhat incurved; the poste-
rior ones are somewhat larger.

The ambulatory legs are produced, slender,
and furnished with scattered spines.

The first segment of the abdomen is largely
concealed. The last segment is Ungulate,
posteriorly obscurely crenulate, smooth above.
The uropoda are rather long; the inner branch
is much longer and wider than the outer branch ;
both branches are posteriorly attenuated and
obscurely crenulated.

Length 11.5 mm. a

FIG. 160. ^Eo A TENUIPES ( AF-
TER SCHICE DTE AND MEINERT).
a, FRONTAL MARGIN WITH AN-

TENN.E AND FRONTAL LAMINA.

6, YOUNG FEMALE: c, RIGHT

LEG OF SECOND PAIR. (ALL
ENLARGED.)

The above description is adapted from the following one of Schioedte and
Meinert's:

Producte obovata, supra prseter punctaram ordinariam laeviuscula.

Frons bisinuata, acumine procumbente laminae frontali contiguo.

Lamina frontalis rhomboidalis. Oculi magni, oblongi, seriebus ocel^orum quater-
nis contigui. Antenna? primi paris angulum posticum annuli primi trunci attin-
gentes, scapo articulum quartum, flagello articulum decimutn antennarum secundi
paris explentes; flagellum 11-articulatum, articulo primo tenui, articulum sequentem
longitudine sequante.

Antennae secundi paris epimerum quartum explentes; flagellum 24-articulatum.

Segmentum dorsale annuli primi trunci ante leviter bisinuatum.

Epimera angustiuscula; anguli postici epimerorum posteriorum acuti, product!;
epimerum ultimum dimidiam partem articuli primi caudalis explens.

Pedes prensorii graciles, glabriusculi; femora angustiuscula; ungulse primse brevi-
usculse, admodum incurvse, posteriores aliquanto majores.

Pedes gressorii producti, graciles, parce spinulosi.

Annulus primus caudalis maximam partem detectus.

Annulus analis lingulatus, post obscure crenulatus, supra subaequatus. Pedes
anales longiusculi; ramus interior quam exterior multo longior et latior; ramus
uterque post attenuatus, obscure crenulatus. Long. 11.5 mm. SCHIOEDTE AND
MEINEET, Nat. Tidsskr. (3), XII, 1879-80, p. 371.

I8OPODS OF NORTH AMERICA.

179

1EGA DENTATA Schicedte and Meinert.

JEga dentata SCHICEDTE and MEINERT, Naturh. Tidsskr. (3), XII, 1879-80, pp.
372-373, pi. x, figs. 11-12. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901,
p. 522.

Locality. Cuba.

Body ovate, punctate on the dorsal surface with minute scattered
dots.

Front of head bisinuate, the median point separating and extending
half the length of the first article of the first pair of antenna.

The frontal lamina is rhomboid in shape.

The eyes are large, oblong, posteriorly acuminate, and contiguous
along three series of ocelli.

The first pair of antennae scarcely reach the posterior angle of the
first thoracic segment; with the peduncle
they extend to the fourth article, with the a

flagellum to the tenth article of the second
pair of antennae; the flagellum is composed
of seven to eight articles, the first article
being very long, slender, equaling in
length the three following articles taken
together.

The second pair of antennae extend to
the middle of the fifth epimeron; the fla-
gellum is composed of twenty -one articles.

The first segment of the thorax is widely
emarginate anteriorly on its dorsal sur-
face; a great part of the dorsal surface of
the seventh segment is concealed.

The epimera are rather wide; the pos-
terior angles of the posterior epimera are
somewhat acutely produced; the last
epimeron extends beyond the first segment of the abdomen.

The prehensible legs are slender, smooth; the basis is rather nar-
row; the anterior ungulse are very small, the posterior ones somewhat
larger and more incurved.

The ambulatory legs are rather long, robust, and furnished with
scattered spines.

A large part of the first segment of the abdomen is concealed.

The terminal segment is produced linguiform, smooth above; at the
base are two obscure depressions; the posterior margin is deeply
crenulate, terminating in the middle in seven teeth. The uropoda are
rather long; the inner branch is much longer and twice as wide as

FlG. 161. JEQA. DENTATA (AFTER
SCHKEDTE AND MEINERT). a,
FRONTAL MARGIN WITH BOTH PAIRS
OF ANTENNA AND FRONTAL LAMINA.
b, YOUNG FEMALE. (ENLARGED.)

180 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the outer branch, and posteriorly widel} T and obliquely rounded; both
branches are furnished posteriorly with numerous rather obtuse
teeth.

Length, 7.5 mm. a

JEGA INCISA Schicedte and Meinert.

JEga incisa SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3) , XII, 1879-80,
pp. 373-374, pi. x, figs. 13-15. HARGER, Bull. Mus. Comp. Zool. Harvard
College, XI, 1883, No. 4, p. 96, pi. in, fig. 1. RICHARDSON