LT)

3-

D
CD

D

m
a

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 37ears 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

28589—05 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 lay«r 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

28589—05 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

28589—05 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. el, e2, e3, 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. gl, g2, g3, g4, g5, 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. el, e*, <?, On Spirontocaris suckleyi from Alitak Bay,
Kadiak Island. /, On Spirontocaris herdmani from Queen Char-
lotte Island, off Fort Rupert, Vancouver Island, British Columbia.
g1, g2, g3, g4, g5, 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.

28589—05 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}7s 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

aSar'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 usuall3T 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-dev7eloped 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}res 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}Tes 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. c1, DETAIL OF MANDIBLE, d, ANTERIOR (FIRST) MAXILLA, d1, 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}7es 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.
28589—05 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 M£m. 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.
28589—05 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}Tlus, 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.

aRhoea 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.

uThe 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.

uThe free thoracic segments diminish gradualhr 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.
28589—05 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.

ftSee 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 6b 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 is1 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 distalhT; 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

df. 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)

bf. 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\Tish white, with a light bluish tinge; of female,
yellowish, semipellucid, with scattered brown dots. Length in both
sexes, 4 mm." — G. O. SARS.a

Ohlin6 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

cf. 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
28589—05 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

aSee 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
dact3Tlos 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.
28589—05 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 be37ond 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, V7idensk. 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; Vine3rard
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
28589—05 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 thickhT 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

ax. 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- short not 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._ErRYDicE 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 Wj(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 be37ond 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,
28589—05 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 antenna1
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 antenna1 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 3Tellow, 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)

cf . 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 antenna1. 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.
28589—05 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), V7, 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 nearh7 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 anteriorhT. 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 widel3T 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}7ond 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. E37es 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, wTith 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 angu«tioribus, 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 RUM. (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.
28589—05 - 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.0

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. tridensa 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 antenna1 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.
28589—05 - 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, American Natu-
ralist; XXXIV, 1900, p. 218; Proc. U. S. Nat. Mus., XXIII, 1901, p. 522.

Localities. — Off Fernandina, Florida; off Georgia; off St. Augustine,
Florida; latitude 31° 57' north, longitude 78° 18' 35" west.

Depth,.— 263-tl40 fathoms.

Body oblong-ovate, about two and a half times longer than wide,
7 mm. : 18 mm.

Head about twice as wide as long, rounded anteriorly and produced
in the middle in a small, narrow process, separating the basal articles
of the antenna and meeting the small frontal lamina on the other side.
The eyes are large, oblong, and conspicuous, occupying almost the
entire surface of the head and contiguous in the median line. The
first two articles of the first pair of antennae are small and equal in
length; the third article is long and narrow, nearly three times as long
as the second article. The flagellum is composed of sixteen articles.

«The above description is adapted from the following one of Schioedte and
Meinert' s:

Ovata, supra prseter puncturam ordinariam punctis mlnutis, perraris sparsa.

Frons bisinuata, acumine procumbente dimidiam partem articuli primi anten-
narum primi paris discernente.

Lamina frontalis rhomboidalis, Oculi magni, oblongi, post acuminati, seriebus
ternis ocellorum contigui.

Antennae primi paris angulum posticum annuli primi trunci vix attingentes, scapo
articulum quartum, flagello articulum decimym antennarum secundi paris explentes;
flagellum 7-8 — articulatum, articulo primo perlongo, tenui, articulos tres sequentes
conjunctos longitudine sequante.

Antennae secundi paris dimidiam partem epimeri quinti explentes; flagellum 21 —
articulatum. Segmentum dorsale annuli primi trunci ante late emarginatum; seg-
mentum dorsale annuli septimi maximam partem obtectum.

Epimera latiuscula; anguli postici epimerorum posteriorum acuti, paulum pro-
ducti; epimerum ultimum annulum primum caudalem explens. Pedes prensorii
graciles, subglabri; femora angustiuscula; ungulse primae pusillae, posteriores ali-
quanto majores magisque incurvae.

Pedes gressorii longiusculi, robustiores, parce spinulosi. Annulus primus cau-
dalis maximam partem obtectus. Annulus analis producte lingulatus, supra sub-
aequatus, ad basin obscure bifoveolatus, margine terminali profunde crenulato, medio
in dentes septem exeunte. Pedes anales longiusculi; ramus interior quam exterior
multo longior et duplo latior, post in obliquum late rotundatus; ramus uterque post
in dentes plures obtusiusculos desinens.

Long. 7.5 mm. — SCHICEDTE and MEINERT, Nat. Tidsskr. (3), XII, 1879-80, pp.
372-373.

ISOPODS OF NORTH AMERICA.

181

The first antennas extend to the posterior margin of the first thoracic
segment. The first two articles of the peduncle of the second pair of
antennae are short and about equal in length; the third is a little longer
than the second; the fourth and fifth are subequal and each about
twice as long as the third. The flagellum is composed of fifteen
articles.. The second pair of antennae extend a little beyond the pos-
terior margin of the second thoracic segment. The maxilliped has a
palp of five articles. The frontal lamina is very small, somewhat cone-
shaped, with base small and irregularly rounded and rather convex.

Fourth, fifth, and sixth segments of the thorax longer than the other
four. The epimera of all the segments, from the second to the seventh,

inclusive, are distinctly sep-
a arated from the segments.

The posterior angles of the
last three segments are pro-
duced beyond the posterior
margins of the segments, the
posterior angle being very
acute. In the last three seg-

162. — JEGA

INCISA (AFTER

A R G E R ) .

PIG. 163.— ^EGA INCISA (AFTER SCHI-
(EDTEANDMEINERT). O, FRONTAL LA-
MINA AND BOTH PAIRS OF ANTENNJ5.
j, YOUNG FEMALE. C, LEFT LEG OF
THIRD PAIR. (ENLARGED.)

FlG. 164.— ^EGA INCISA. a, MAXILLIPED.

x 39. b, SECOND LEG. x 11|.

ments a distinct carina extends obliquely from the outer posterior
angle to the middle of the side adjacent to the segment. In the
epimera of the three anterior segments the carina extends obliquely
from the outer post-lateral angle to the inner antero-lateral angle.

All six segments of the abdomen are distinct. The first is parth^
covered by the last thoracic segment. The lateral parts of the seg-
ments are not distinctly separated from the dorsal portion. The sixth
or terminal segment is broadly triangulate, with a small round emar-
gination at the apex. On either side of this emargination the posterior
margin is denticulate and crenulate for a short distance. There are
four spines on either side of the medium notch. The uropoda extend

182

BULLETIN 54. UNITED STATES NATIONAL MUSEUM.

but a short distance beyond the tip of the terminal segment. The
branches are equal in length. The outer branch is narrower than the
inner one, and is pointed at its extremity. The inner branch is
obliquel}T truncate, the inner post-lateral angle being widely rounded,
the outer one being acute. Both are denticulate and furnished with
numerous spines. The basal article of the uropoda extends about half
the length of the terminal segment of the abdomen.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. In the first three pairs the carpus is armed with one spine,
the merus with two.

1EGA ARCTICA Lutken.

jEga Arctica LUTKEN, Vid. Medd. Nat. For., 1859, p. 71, pi. lA, figs. 1-3.—
SCHICEDTE and MEINERT, Naturh. Tidsskrift (3), XII, 1879-80, pp. 374-375.—
HANSEN, Videnskabelige Meddelelser fra den Naturhistoriske Forening i
Kj0benhavn, 1887-88, pp. 183-184. — RICHARDSON, American Naturalist,
XXXIV, 1900, p. 218; Proc. U. S. Nat. Mus., XXIII, 1901, p. 522.

Localities. — Umanekand Hundeoerne near Egedesminde, Greenland;
also Iceland and Finmark.

Found on Somniosus microcephalus.

Body oblong-ovate, nearly two and a half times
* longer than broad, 14 mm. : 34 mm.

Head twice as wide as long, 3 mm.: 6 mm.,
with the anterior margin wjdely rounded and
produced in a small median point between the
basal articles of the first pair of antennae. Eyes
large, oval, composite, occupying almost the
entire surface of the head, and nearly, but not
quite, contiguous in the median line. The first
pair of antennae have the first two articles short
and subequal, neither article being dilated ; the
third article is a little longer than the first two
taken together. The flagellum is composed of
eighteen articles and extends almost to the
middle of the first thoracic segment. The
second pair of antennae have the first three arti-
cles short and subequal; the fourth and fifth are
subequal and each is about twice as long as the
third. The flagellum is composed of twenty-five
articles and extends to the posterior margin of
the second thoracic segment. The maxilliped
has a palp of five articles. The frontal lamina or inter-antenna! plate
is somewhat triangular in shape, the apex pointing downward on the
ventral side, the base meeting the apex of the median point of the
frontal margin.

FlG. 165. — JEGA. A K C T I C A

(AFTER SARS). a, FIRST

AND SECOND ANTENNAE, b,

GENERAL FIGURE, x i.

ISOPODS OF NORTH AMERICA.

183

FIG. 166.— J£GA ARCTICA. a, LEG OF SECOND PAIR, x 27$.
b, MAXILLIPED. x 15}.

The first three segments of the thorax are subequal, each being 3
mm. long. The fourth and seventh are subequal, and each is 3£ mm.
in length. The fifth and sixth are each 4 mm. in length. The epimera
are distinctly separated on all the segments with the exception of the
first. They are broad plates, with the outer post-lateral angles of
the first two and the last two
acute. All are crossed ob-
liquely by an arched carina.

All six segments of the
abdomen are distinct. The
sixth or terminal segment is
rounded posteriorly, with a
small round median notch.
The uropoda do not extend
beyond the extremity of the
terminal abdominal segment.
Both branches are of equal
length. The inner one is a
little wider than the outer branch. The margins are entire and cren-
ulate, and furnished with spines. The outer post-lateral angle of
both branches terminates in two small points.

The first three pairs of legs are prehensile; the last four pairs are
ambulatory. The merus of the first three pairs is armed with one
large and one small spine, the carpus with one large and three small
spines.

JEGA GRACILIPES Hansen.

JEga gradlipes HANSEN, Isopoden, Cumaceen und Stomatopoden der Plankton
Expedition, 1895, pp. 15-16, pi. i, figs. 6-6c. — RICHARDSON, Proc. U. S. Nat.
Mus., XXIII, 1901, p. 523.

Localities. — Gulf of Mexico; North Atlantic, latitude 59° north,
longitude 8.5° west.

Depth. — 730 fathoms; 1,524 meters (Hansen).

Body ovate, about twice as long as wide, 11 mm. : 21 mm.

Head with the anterior margin widely rounded, and produced in a
narrow process, which arches over the antennae, separating the basal
articles, and meets the small frontal lamina on the other side. The
eyes are large, oblong, composite, and occupy almost all of the dorsal
surface of the head, extending from the lateral angles along the ante-
rior margin and almost meeting in the median line. The first two
articles of the first pair of antennae are subequal; the third is nearly
three times as long as the second. The flagellum is composed of
eighteen articles. The first antennae extend a little beyond the pos-
terior margin of the first thoracic segment. The first two articles of
the second antennae are subequal; the third is a little longer than the

184 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

second; the fourth is twice as long as the third; the fifth is a little
shorter than the fourth. The flagellum is composed of eighteen
articles. The second pair of antennae extend to the posterior margin
of the third thoracic segment. The frontal lamina or inter-antennal
plate is about twice as broad as long, transversely placed, has the
base somewhat oval in shape and directed anteriorly. The maxilliped
has a palp of five articles.

The segments of the thorax are of nearly equal length, the first seg-
ment being a little longer and the seventh a little shorter than any of
the others. The epimera are very distinctly separated on all the seg-
ments. They are broad plates, with very acute post-lateral angles,
which in the last three epimera are produced beyond the posterior

margin of the segment. There
a is a carina on all the epimera

which extends from the post-
lateral angle to the middle of

FIG. 167.— ^EGA GRACILIPES (AFTER HANSEN). a,
FRONTAL PAKT OF HEAD FROM UNDERSIDE, b, GEN-
ERAL FIGURE. (ENLARGED.)

FlG. 168. — JEGA. GRACILIPES. O, MAXILLIPED,

x 27j. 6, LEG OF SECOND PAIR, x 9£.

the side adjacent to the segment in the last three and to the inner
antero-lateral angle in the first two; in the third epimera it extends to
a point about halfway between the middle of the side adjacent to the
segment and the inner antero-lateral angle.

All six segments of the abdomen are distinct, the first one being
partly covered 'in the middle of the dorsal surface by the seventh tho-
racic segment. The lateral parts of the segments are not distinct from
the dorsal portion. The sixth or terminal segment is broadly rounded
at the sides with the posterior margin produced in the middle in an
acute point. On either side of the median point the margin is den-
ticulate and furnished with about five spines. The uropoda extend to
the tip of the terminal segment. The branches are equal in length,

ISOPODS OF NORTH AMERICA.

185

and both are pointed at the posterior extremity. The inner branch is
very slightly excavate on the exterior margin about 1 mm. from the
extremity. Both branches are denticulate and furnished with spines.
The first three pairs of legs are prehensile, the last four pairs
ambulatory. All the legs are very slender and free from spines.

JEGA SYMMETRICA Richardson.
JEga symmetrica RICHARDSON, Bull. U. S. Fish Comm., XXIV, 1905, pp. 211-212.

Localities. — Vicinity of Naha Bay, Behm Ganal, southeast Alaska;
Queen Charlotte Sound, off Fort Rupert, Vancouver
Island, British Columbia.

Body ovate, twice as long as broad. Color yellow,
densety covered with light-brown dots, which form
a regular line along the margin of each segment.
Surface smooth. Head with frontal margin pro-
duced in a median point, which arches over the basal
joints of the antennae and meets the frontal lamina
or interantennal plate on the underside. The eyes
are narrow and elongate, composed of numerous
ocelli. They are separated in front by a distance
equal to the length of one eye. The first pair of
antennae extend to the posterior margin of the first
thoracic segment; the joints of the peduncle are not
dilated, although the first two joints are somewhat
wider than the third, nor is there a process at the distal extremity

of the second joint. The first two joints
are of equal length; the third is as long
as the first two together; the flagellum is
composed of eleven joints. The second
pair of antennae reach the middle of the
third thoracic segment; the flagellum is
composed of sixteen joints. The frontal
lamina or interantennal plate is conical,
with the distal end flat, the proximal end
produced to an acute point.

The several segments of the thorax are
about equal in length, the last one being
slightly shorter. The epimera are large,
subquadrate, with the outer distal angle
of the last three produced posteriorly beyond the margin of their
respective segments.

The first three pairs of legs have the propodus beset with three
small spines along the inrter margin; the carpus is short and armed
with one spine; the merus is provided with five spines and the ischium

FIG. 169.— ^EGA SYM-
METRICA. x

FIG. 170. — Y£GA SYMMETRICA. o, MAXIL-
LIPED. x 27J. 6, PALP OF SAME, x 51|.

186 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 171.— ^EGA SYM
METRICA. THIRD
LEG. x Hi.

has one long spine at the outer distal angle. The following four pairs
of legs are long and slender, furnished with hairs at the distal
extremity of the joints and armed with few spines.

The first five segments of the abdomen are short, the first is shortest,
and the fifth the longest in the median dorsal line. The terminal or
sixth segment of the abdomen is linguiform and
rounded posteriorly with serrulated margin.

The uropoda extend a little beyond the posterior
margin of the terminal abdominal segment; the outer
branch is narrow, ovate, and pointed at the distal
extremity; the inner branch is almost twice as wide
as the outer one; both have serrulated margins.

Four specimens come from the U. S. Bureau of
Fisheries steamer Albatross station 4228, vicinity of
Naha Bay, Behm Canal, southeastern Alaska, and one
from Albatross station 4199, Queen Charlotte Sound,
off Fort Rupert, Vancouver Island, British Columbia,
at depths of 41 to 107 fathoms. The type specimen
is in the U. S. National Museum (Cat. No. 29247).
The following note by Mr. Harold Heath accompanies the Fort Rupert
specimen: "Eyes black. Rusty -brown spots on dorsal surface. Ver-
milion-colored ovary (?) shows through translucent cuticle."

Onl3T two other species of ^Ega are known in the Pacific coast fauna
of North America, ^Ega lecontii(D&nsi)a and ^Ega microphthalma Dana.6
The present species differs from ^Ega lecontii, (1) in the greater length
of both pairs of antennae; those of the first pair reach to the posterior
margin of the first thoracic segment, instead of to the end of the peduncle
of the second pair or almost to the posterior margin of the head, and
those of the second pair reach to the middle of the third thoracic seg-
ment instead of almost to the posterior mar-
gin of the first; (2) in having neither the basal
joints of the peduncle of the first pair of an-
tennae greatly dilated nor the second joints
with a process at the apex extending nearly
the length of the third joint; (3) in the much
shorter body, as compared with the width;
(4) in having the terminal segment rounded,
not truncate, at the apex; (5) in the longer
uropoda; (6) in having the median point of
the frontal margin of the head arch over the
basal joints of the antennae to meet the frontal lamina on the ventral
side, and (7) in the different shape of the frontal lamina.

The present species differs from A. microphthalma in the longer
first pair of antennae, which reach the posterior margin of the first

FIG. 172. — J£GA SYMMKTRICA. POS-
TERIOR PART OF ABDOMEN. X 6£.

«Proc. U. S. Nat, Mus., XXI, 1899, pp. 826-827.
&Proc. Acad. Nat. Sci. Phila., VII, 1854, p. 176.

ISOPODS OF NORTH AMERICA. 187

thoracic segment; in Dana's species they are shorter than the basal
part (peduncle) of the external or second pair of antennae; in the larger
eyes, which are narrow and elongate instead of being round and very
small; in the longer uropoda, the branches in A. microphthalma
scarcely surpassing the abdomen; in not having the apex of the inner
branch "faintly arcuate obliquely" and in having all six segments of
the abdomen visible in a dorsal view, only five being apparent in A.
microphthalma.

This species differs from ^Ega longicornis Hansen in the shorter
second antennae, which extend only to the middle of the third thoracic
segment, while in A. longicornis the}^ extend to the middle of the fifth
thoracic segment; in having the first three pairs of legs furnished with
a greater number of spines than in Hansen's species; in having both
branches of the uropoda terminating ki a bifid extremity, while in A.
longicornis the extremities of the uropoda are acute, and in having the
apex of the terminal abdominal segment bifid instead of acutely pointed.

A specimen from off Santa Cruz Island, California, agrees with the
specimens from Alaska, with the exception that the second antennae
have fourteen instead of sixteen articles to the flagellum. They are,
however, just as long, extending to the middle of the third thoracic

segment.

•

JEGA VENTROSA M. Sars.

JEga ventrosa M. SARS, Chr. Vid. Selsk. Forh., 1858-59, pp. 154-156. — SCHICEDTE

and MEINERT, Natur. Tidsskr. (3), XII, 1879-80, pp. 375-377, pi. ix, figs. 7-8.
jEgiochus nordenskidldii BOVALLIUS, Bihang Sv. Vet.-Akad. Handl., X, 1885,

No. 9,, p. 5, pi. i-n.
JEga loveni BOVALLIUS, Bihang Sv. Vet.-Akad. Handl., XI, No. 17, 1886-87, pp.

3-6, pi. i, figs. 1-10.
jEgiochus rentrosus BovALLitfs, Bihang Sv. Vet.-Akad. Handl., XI, No. 17, 1886-

87, pp. 8-9.
JEga nordenskioldii HANSEN, Vidensk. Meddel. Naturh. Foren. i Kj0bh., 1887-88,

pp. 184-187.
JEga ventrosa G. O. SARS, Crust. Norway, II, 1899, p. 64, pi. xxvi, fig. 3. —

RICHARDSON, American Naturalist, XXXIV, 1900, p. 218; Proc. U. S. Nat.

Mus., XXIII, 1901, p. 522.— NORMAN, Ann. Mag. Nat. Hist. (7), XIV, 1904,

p. 432.

Localities. — Greenland; latitude 59° 33' north, longitude 43° 25'
west; also coast of Norway; Finland.

Depth.— 120 fathoms; 203-312 fathoms (Norman). • 4

Body oblong-ovate, about two and one-third times longer than
wide, 13 mm. : 30 mm.

Head twice as wide as long, 3 mm.: 6 mm. In the median line the
front is produced in a process which arches over the antennas, separat-
ing the basal articles, and meets the frontal lamina or interantennal
plate at its upper end. The eyes are large, irregularly oval, com-
posite, situated in the lateral angles of the head and extending along

188 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the anterior margin^ being separated in front by a distance equal to
the length of one eye. The basal article of the peduncle of the first
pair of antennae is larger and a little longer than the second article;
the third article is very slender and about twice as long as the second

article. The flagelluni is composed of about
fourteen articles. The first pair of antenna?
extend a little beyond the end of the pe-
duncle of the second pair, to the end of
the fourth article of the flagellum, or two-
thirds the length of the first thoracic seg-
ment. The first three articles of the pe-
duncle of the second pair of antenna? are
subequal; the fourth article is twice as long
as the second; the fifth is one and a half
times longer than the fourth. The flagel-
lum is composed of twenty-five articles.
The second antennas extend a little beyond
the posterior margin of the third thoracic
segment. The frontal lamina is cone-
shaped, the base of the cone being large
and conspicuous, directed anteriorly and
sightly concave. The frontal process of
the head slightly overlaps the edge of the
base of the cone.

The first, fourth, fifth, and sixth seg-
ments are somewhat longer than any of the
others. The post-lateral angles of the first
segment are very acute. The epimera of
all the segments, from the second to the
seventh, inclusive, are distinctly separated
off from the segments. The}r are broad
plates occupying the entire lateral margins
of the segments. In all, the post-lateral
angles are acute, but especially so in the
epimera of the second, third, and seventh
segments. In all the epimera there is a distinct carina, extending from
the outer post-lateral angle to about the middle of the side adjacent
to the segment in the last four, but to the inner antero-lateral angle
in the first two. The epimeron.of the seventh segment is produced
posteriorly beyond the posterior margin of the segment.

All six segments of the abdomen are distinct, although the first is
partly covered dorsalhT in the middle by the seventh thoracic segment.
The lateral parts of these segments are not separated off from the dorsal
portion, but are completely fused. The terminal segment is broadly
rounded posteriorly with a small point in the middle. The posterior

FlG. 173. — JEGA. VENTROSA (AFTER
SCHICEDTK AND MEINERT). a,
FRONTAL MARGIN WITH BOTH
ANTENNAE AND FRONTAL LAMINA
OF ADULT FEMALE. 6, ADULT FE-
MALE, c, FRONTAL MARGIN WITH

BOTH ANTENNA AND FRONTAL
LAMINA OF YOUNG FEMALE, d,
YOUNG FEMALE. (ALL ENLARGED. )

ISOPODS OF NORTH AMERICA. 189

margin is crenulate. The peduncle of the uropoda has the inner part
produced a little beyond the middle of the sixth segment of the
abdomen. The outer branch is half as wide
as the inner branch; it is pointed at the ex-
tremity. The inner branch has the posterior
extremity obliquely truncate. Both branches
are equal in length and crenulate; they do not
extend be3Tond the tip of the abdomen. The
first three pairs of legs are prehensile; the
,last four pairs ambulatory. In the first three
pairs the propodus is furnished with one spine, FIG< IU.—IEGJL VENTROSA.
the carpus with one, the merus with three. LEG OF SECOND PAIR.

^EGA MICROPHTHALMA Dana.

^Ega microphthalma DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854, p. 176. —
STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, p. 508. — RICHARDSON, Proc. U. S.
Nat. Mus., XXI, 1899, p. 826; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 167;
American Naturalist, XXXIV, 1900, p. 218.

Locality. — Monterey, California.

The eyes are rounded, very small. The body above is bare, smooth.
The second pair of antennae are rather long; the flagellum is composed
of nearly twenty-four articles; the first pair of antennae are shorter
than the peduncle of the second pair. The legs are almost bare, the
anterior ones are short, with the fourth article armed on the inferior
margin with five to six very short, spine-form teeth; the eight poste-
rior ones are short, beset with spines at the apex of the articles. The
abdomen is composed of four segments, the posterior segment being
triangulate, with apex rounded and pubescent, and with the sides
rather straight. The uropoda are armed at the base with a slender
and long spine scarcely shorter than the branches; the branches extend
very little beyond the abdomen, are furnished with short hairs, the
inner branch is wide, with apex obliquely arcuate, the outer branch
half as wide as the inner branch, short and lanceolate. Length 6'"/'

aThe above description is adapted from the following one of Dana's:
Oculi subrotundi, parvuli. Corpus superficie nudum, laeve. Antenna? externse
longiusculse, flagello ferine 24 articulate; internse basi externarum breviores. Pedes
fere nudi; antici breves, articulo 4to, 5-6 den ti bus spiniformibus brevissimus infra
armato; 8 postici breves, apice articulorum spinulosi. Abdomen 4 articulatum, seg-
mento postico triangulate apice rotundato et pubescente, lateribus rectiusculis.
Styli caudales spind tenui et longa ramis parce breviore ad basin armati; rainis abdo-
men vix superantibus, breviter ciliatis, interne lato, apice oblique leviter arcuato,
externo dimidio angustiore, breviter lanceolate. — Long. 6///

The six epimerals either side are large, and, excepting the two anterior, they,
project behind, beyond the segment to which they belong. The eight hinder legs
are naked, excepting the spines at apex and one or two sets of minute spines on the
under side of some of the joints. — DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854,
p. 176.

190 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

31. Genus ROCINELA Leach.

Body depressed. Abdomen not much narrower than thorax. Eyes
present, well developed, and conspicuous.

First two articles of the peduncle of the first pair of antennae not
expanded. Frontal lamina small and narrow.

Mandibles with a linguiform lamella (molar expansion?). Palp of
the maxillipeds composed of two articles.

First three pairs of legs with propodus more or less expanded and
armed with spines; dactylus forming a veiy large, evenly curved hook.
Four posterior pairs with the propodus short.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ROCINELA.

a. Eyes contiguous Rocinela oculata Harger

a' '. Eyes not contiguous.

b. Flagellum of second pair of antennae composed of from fourteen to sixteen

articles,
c. First thoracic segment with antero-lateral angles produced horn-like at sides

of head Rocinela cornuta Richardson

c'. First thoracic segment with antero-lateral angles not produced horn-like at

sides of head.
d. Propodus of prehensile legs armed with from two to four spines.

e. Eyes very close together Rocinela insularis Schioedte and Meinert

e' '. Eyes widely separated.
/. Head bicarinated, the two carinse being separated by a longitudinal

median groove Rocinela dumerilii (Lucas)

/'. Head without carinse.

g. Front of head produced in a widely rounded spatulate process. Two

tubercles on head Rocinela cubensls Richardson

g' '. Front of head not produced in a widely rounded spatulate process.

No tubercles on head.
h. Spots present on both sides of the fourth thoracic segment.

Rocinela maculata Schioedte and Meinert

//. Spots wanting on both sides of the fourth thoracic segment.
i. Spots present on fourth and fifth abdominal segments and base of

terminal segment Rocinela belliceps (Stimpson)

i'. Spots wanting on fourth and fifth abdominal segments and base

of terminal segment. .Rocinela americana Schioedte and Meinert

d'. Propodus of prehensile legs armed with from four to six spines or with as

many teeth.

e. Propodus of prehensile legs armed with a process the edge of which is
furnished with six teeth, meeting squarely and without interval.

llorinela propodiaUs Richardson

tf. Propodus of prehensile legs not armed with denticulate process, but fur-
nished with spines.

/. Abdomen much longer than wide. Outer branch of uropoda one and
a half times wider than inner branch. Propodus of prehensile legs
armed with five or six spines. Abdomen broad when compared with
thorax, last segment widely rounded. Second antennae extend to the
middle of the third thoracic segment Rocinela laticauda Hansen

TSOPODS OF NORTH AMERICA. 191

/'. Abdomen about as wide as long. Outer branch of uropoda twice as
wide as inner branch. Propodus of prehensile legs armed with four
spines. Abdomen narrow when compared with thorax, tapering, last
segment narrowly rounded. Second antennae extend to the middle

of the second thoracic segment Rodnela angustata Richardson

V . Flagellum of second pair of antennae composed of from ten to eleven articles.
c. Small tubercles present on the posterior margins of all the segments of the
thorax. Propodus of prehensile legs armed with three spines.

Rodnela tuberculosa Richardson
c' . No tubercles on body. Propodus of prehensile legs unarmed or armed with

only one spine.

d. Terminal segment of abdomen ornamented with a pair of narrow semilunar
bands, separated by a longitudinal stripe. Propodus of prehensile legs

unarmed Rodnela signata Schicedte and Meinert

d'. Terminal segment of abdomen ornamented with a very wide crescentiform
band from the posterior border of which three large hastiform stripes
project backwards. Propodus of prehensile legs armed with one spine.

Rodnela aries Schicedte and Meinert

ROCINELA OCULATA Harger.

Rodnela oculata HARGER, Bull. Mus. Comp. Zool., Harvard College, XI, No. 4,
1883, pp. 97-99, pi. in, fig. 2-2a; pi. iv, fig. 1. — RICHARDSON, American
Naturalist, XXXIV, 1900, p. 219; Proc. U. S. Nat. Mus., XXIII, 1901, p. 523.

Locality.— Latitude 32° 18' 20" north, longitude 78° 43' west.

Depth.— 252 fathoms.

"Body oval, length a little more than twice the breadth, surface
sparsely punctate.

"Head subreniform, produced in front into a truncated process over
the bases of the antennulse, yoke-shaped behind, the ocular lobes pro-
jecting, upper surface nearly covered with the large eyes in which the
ocelli are large and quincuncially arranged in ten rows along the long
axis of each ejre. Five of these rows meet along the median line.

"The antennula? are slender and scarcely attain the tip of the anten-
nal peduncle; the basal segment is short and concealed from above;
the second is longer than the first; the third is slender, but not as long
as the first two together; flagellum about as long as the peduncle,
slender and composed of five segments, of which the first is much the
longest and the last is the shortest, and does not quite attain the pos-
terior border of the eye when the antennula is reflexed. The antennae
surpass the first thoracic segment; the first two segments are very
short; the flagellum is about twelve-jointed.

"First thoracic segment closely adapted to the head in front; fourth
segment longest in the median line above; sixth short; seventh nearly
concealed and quite small, although bearing a well-developed pair of
legs below.

"The epimera of the second and third segments are oblique, but not
acute nor produced backward in a lateral view; in the four following
segments they are produced and very acute; the seventh epimeron is

192 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

much smaller than the sixth, and, owing to the shortness of the seventh

.segment, ends behind about on a line with it, both epiniera surpassing

the first segment of the pleon.

"Legs of the first pair slender, armed with a long slender dactylus,

much curved near its base; propodus expanded with a large palmar

lobe armed with a marginal row of
eight curved spines; carpus short,
with a single curved palmar spine.
Legs of the second and third pair
much like the first, but with only
six spines on the propodus. Legs
of the fourth and posterior pairs
slender, armed with spines princi-
pally at the distal ends of the
ischium, merus, and carpus.

" First segment of the pleon very
short and nearly concealed by the
thoracic segments, narrower than
the next three segments, which are
about equal, acutely produced at
the sides so as to resemble in shape
the seventh epimeron ; fifth segment
narrower than fourth, but some-
what longer on the median line;
telson semi-oval, regularly rounded
behind and ciliated. Uropods equal-
ing the telson; inner angle of basal
segment produced, about one-third
the length of the inner ramus, which
is Ungulate, rounded behind,
slightly shorter than the outer, and

less than half as broad; outer ramus subovate, spinulose along the

outer border; both ranii ciliated except near the base.
Length, 13.5 mm.; breadth, 6 mm.
A single specimen of this species, the only one as yet known, was

taken at Station 305, latitude 32° 18' 20" north, longitude 73° 43' west,

from a depth of 252 fathoms." — HARGER/'

ROCINELA CORNUTA Richardson.

Rocinela cornuta RICHARDSON*, Proc. Amer. Philos. Soc., XXXVII, 1898, p. 12,
figs. 1-2; Proc. U. S. Nat. Mus., XXI, 1899, p. 827; Ann. Mag. Nat. Hist.
(7), IV, 1899, p. 169; American Naturalist, XXXIV, 1900, p. 219.

Locality. — Off Shumagin Bank, Alaska.
Depth. — 625 fathoms.

FlG. 175.— ROCIXELA OCULATA (AFTER HAR-

GER). a, VENTRAL VIEW, x 4. b, DORSAL
VIEW, x 4. c, LEG OF FIRST PAIR, x 10.

"Bull. Mus. Comp. Zool. Harvard College, XI, No. 4, Pt. 23, 1883, pp. 97-S

ISOPODS OF NORTH AMERICA.

193

FH;. 17fi.— R O C I -
NELA CORNUTA.

HEAD, x 1?.

Length of body two and one-quarter times its greatest breadth.
Outline oval; surface smooth, with scattered points of depression.
Head subtriangular, having a medium excavation. Its frontal margin
is produced forward in a long and broad projection,
widely rounded at its extremity, and curving upward.
Eyes large and situated some distance apart. The
first antenna reaches the anterior margin of the first
thoracic segment; its flagellum is composed of six
articles. The second antenna extends to the posterior
margin of the second thoracic segment; its flagellum is sixteen- jointed.

The thoracic segments are subequal. The
antero-lateral angles of the first segment
are greatly produced and extend forward a
little less than half the length of the head,
including the projection. These antero-
lateral projections of the first segment do
not follow closely the lines of the head, but
rather extend out straight in a direction
which is parallel to that of the frontal pro-
jection of the head. The extremities of
these projections are rounded. The epimera
of all the segments point downward and do
not extend beyond the post-lateral angle of
their respective segments with the excep-
tion of the sixth and seventh

FIG. 177. — a, ROCINELA CORNUTA,

MALE, SLIGHTLY REDUCED. 6,

LEG OF FIRST PAIR, x 4. c, LEG

OF FOURTH PAIR. X 4.

ones.

The first segment of the
abdomen is almost entirely
covered by the seventh tho-
racic segment. The last segment is rounded poste-
riorly and is faintly crenulate. The two branches of
the uropods are similar in shape and size; the inner
branch, being the longer, reaches the extremity of
the abdomen. The uropods as well as the abdominal
segments are furnished with hairs.

The propodus of the prehensile feet is armed with
three spines, and three blunt ones are found on the
merus. The gressorial feet are long and slender
and covered with spines.

Type. — The type specimen was found off Shumagin Bank, Alaska,
Station 3338, 625 fathoms (Cat. No. 20086, U.S.N.M.).

28589—05 13

FIG. 178.— ROCINELA
CORNUTA. MAX-
ILLIPED. X 20|.

194

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ROCINELA INSULARIS Schicedte and Meinert.

Rocinela insularis SCHKEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XII,
1879-80, pp. 390-391, pi. XH, figs. 1-3.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 523.

Localities. — West Indies; between Delta of the Mississippi and Cedar
Keys, Florida; off Fernandina, Florida.
Depth.— 227-273 fathoms.

Body oblong-ovate, about two and a half times longer than wide, 10
mm.: 25 mm.

Head, two and a half times wider than long, 2 mm. : 5 mm. ; tri-
angular in shape, the front produced over
the basal articles of the antennae. Eyes
large, composite, oval, and occupying a large
part of the dorsal surface of the head, being
very close together
in front, but not
contiguous. Basal
article of first an-
tenna small and
almost entirely
concealed by the
front of the head;
second article twice
as long as first;
third article nearly
twice as long as
second. Flagellum
is composed of six
articles. The first pair of antennae extend to the end of the peduncle
of the second antennae, or to the antero-lateral angle of the first tho-
racic segment. The second pair of antennae have the first two articles
short, the first article a little longer than the second; the third is twice
as long as the first; the fourth is but little longer than the third; the
fifth is one and a half times longer than the fourth. The flagellum is
composed of fifteen articles. The second antennae extend to the pos-
terior margin of the second thoracic segment. The frontal lamina is
small and almost inconspicuous. It is rhomboid-shaped at the base
and ventrally placed. The maxilliped has a palp of two articles.

The first three segments of the thorax are subequal; the fourth
is slightly longer than any of the preceding ones; the last three
are the largest. The epimera are distinct from the segments. They
are narrow plates, with the posterior extremities very acute in the
last four. The first two have the posterior extremities rounded.
The epimera of the seventh segment are produced beyond the poste-

FIG. 179.— ROCINELA INSULARIS
(AFTEK SCHICEDTE AND MEIN-
ERT). a, FRONTAL MARGIN

WITH BOTH PAIRS OF ANTENNA:
AND FRONTAL LAMINA, b, ADULT
MALE. (ENLARGED.)

FIG. 180.— ROCINELA INSULARIS.
a, SECOND LEG. x Hi. b, MAX-
ILLIPED. x 20i.

ISOPODS OF NORTH AMERICA.

195

rior margin of the segment. They are all crossed obliquely by faint
carinae.

All six segments of the abdomen are distinct and visible. The first is
almost entirely covered in the middle by the seventh thoracic segment,
but is uncovered at the sides. The sixth or terminal segment is poste-
riorly rounded. The uropoda do not extend beyond the extremity of
the terminal segment. The outer branch is a little shorter and nar-
rower than the inner branch; both are
rounded at the posterior extremity a

and furnished with spines. There
are also a few spines on the posterior
margin of the terminal segment of
the body. The peduncle of the uro-
poda extends about two-thirds the
length of the terminal abdominal
segment.

The first three pairs of legs are
prehensile, the last four pairs ambu-
latory. The first pair of legs have
two spines on the propodus, the sec-
ond and third pairs have three; all
three anterior pairs of legs have
three spines on the raerus. The am-
bulatory legs are beset with spines.

ROCINELA DUMERILII (Lucas).

Acherusia duinertlii LUCAS, Expl. Sc.

Alger., Zool., I, 1849, p. 79, pi. vn,

fig. 3.
Acheruxia complanata GKUBE, Ins. Lussin

Meeresf., 1864, p. 76.
Rocinela dumerilii SCHICEDTE and MEIN-

ERT, Naturhistorisk Tidsskrift (3),

XII, 1879-80, pp. 391-393, pi. xn,

figs. 4-6. — BOVALLIUS, Bihang till k.

Sv. Vet.-akad. Handl., XI, 1886-87,

No. 17, pp. 9-10. — RICHARDSON,

Proc. U. S. Nat. Mus., XXIII, 1901,

p. 524. — NORMAN, Ann. Mag. Nat.

Hist, (7), XIV, 1904, p. 436.

Localities.— Off Habana, Cuba; also Mediterranean Sea; Adriatic
Sea; in the Atlantic Ocean, latitude 36° 47' 7" north, longitude 14°
V 2" west; Vasco de Gama Ft. "S. 75° E., 13i miles" (Stebbing).

Depth. — 230 fathoms. Nature of bottom, fine gray sand.

Body oblong, ovate, twice as long as wide, 15 mm. : 30 mm.

Head not quite twice as wide as long 4 mm. : 7 mm., somewhat tri-
angular in shape, with the front produced over the basal articles of

FIG. 181. — ROCINELA DUMERILII (AFTER
SCHICEDTE AND MEINERT). a, FRONTAL

MARGIN WITH BOTH ANTENNAE AND FRONTAL
LAMINA OF ADULT FEMALE. 6, SAME OF
YOUNG FEMALE. C, ADULT FEMALE. rf,
YOUNG FEMALE. (ENLARGED.)

196 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the antennae The eyes are large, oval, composite, and not contigu-
ous, 4>ut separated in front by two high, conspicuous carinae, each carina
extending along the anterior edge 'of the eye, being somewhat diver-
gent and divided by a median longitudinal depression. The anterior
margin of the head between the eyes is three-lobed, the median lobe
being slightly anterior to the other two. The first pair of antennae have
the basal article short and almost inconspicuous; the second article is
almost twice as long as the first; the third is twice as long as the sec-
ond. The flagellum is composed of seven articles. The first antennae
extend to the middle of the fifth article of the peduncle of the second
pair of antennae. The first two articles of the second pair of antennae
are short, the second one shorter than the first; the third and fourth
are about equal in length and twice as long as the first; the fifth arti-
cle is a little longer than the fourth. The flagellum
is composed of fifteen articles. The second antennae
extend to the middle of the third thoracic segment.
The frontal lamina is small and almost inconspicuous;
it is rhomboid-shaped and ventralty placed. The max-
illiped has a palp of two articles.

The fourth, fifth, and sixth thoracic segments are a
little longer than any of the others. The epimera in
all the segments from the second to the seventh inclu-
sive are distinct and have the posterior extremities
very acute, the angle being sharper in the last four.
In the last three segments the epimeron is produced
FIG. 182.— ROCINELA beyond the posterior margin of the segments. A
carina extends obliquely across all the epimera.

The first segment of the abdomen is almost entirely
covered by the seventh thoracic segment except at the sides. The
lateral parts are not separated from the dorsal portion of the segments.
The sixth or terminal segment is narrowly rounded at the extremity;
its posterior margin is furnished with spines. The uropoda extend to
the tip of the abdomen. The branches are equal in width, but the
inner one is a little longer than the outer one. Both are furnished
with spines. The peduncle extends as far as the extremity of the
outer branch.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. In the three anterior pairs, the propodus is armed with four
spines, the carpus with one, and the merus with three. The ambulatory
legs are furnished with numerous spines.

ISOPODS OF NORTH AMKRfOA.

197

FIG. 183.— Roc i -
NELA CUBENSI8.
HEAD.

ROCINELA CUBENSIS Richardson.

Roanela cubens!* RICIIARDSOX, Proc. Ainer. Philos. Soc., XXXVTI, 1898, pp.
13-14; Proc. I". S. Nat. -Mas., XXIII, 1901, p. 528.

Locality. — Off Habana.
Depth. — 143 fathoms.
Outline of body oval, surface smooth.

Head with rounded lateral margins. Its anterior margin is produced
forward in a large rounded projection, the breadth of
which is equal to its length, and the upper surface deeply
concave with upturned edges. This projection extends
forward for about half its length and then upward, the
change in direction being gradual. Eyes large and
composed of ten rows of ocelli. Two small tubercles
are situated between the eyes, and in the middle of the
head and back of these is an arc-shaped depression. The first antenna
reaches the posterior margin of the head; its flagellum is composed of
six articles. The second antenna extends to the
posterior margin of the third thoracic segment;
its flagellum is composed of fifteen articles.

The thoracic segments are subequal in length.
The epimera are long and narrow, with very acute
posterior angles.

The first segment of the abdomen is almost en-
tirely concealed by the last thoracic
segment. The fifth is likewise
covered at the sides by the fourth
segment. The last abdominal seg-
ment is triangular in shape with a
rounded posterior margin. The
outer branch of the uropods is very
broad and oar-shaped, with a
rounded extremity. The inner
branch is long and slender, of equal
breadth throughout its length and
rounded on its posterior margin.
The inner branch is the longer one.
Both are fringed with hairs.

In the prehensile legs of this spe-
cies the basis presents a row of tubercles on the superior margin.
There are two spines on the propodus. one on the carpus, and two on
the merus. The gressorial legs are but slightly spinulose.

Type. — The tjTpe specimen was found off Habana, latitude 23° 11'
north, longitude 82° 19' 6" west, Station 2341, 143 fa thorns (U.S.N.M.,
Cat. No. 20087).

FIG. 184.— R O C I N E L A

CUBENSIS. a, MALE, x 2J.
6, LEG OF FIRST PAIR.

X 4j. C, LEG OF FOURTH
PAIR. X 4j.

FIG. 185.— ROCI-
NELA CUBENSIS.
MAXILLIPED.
x 39.

198 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ROCINELA MACULATA Schioedte and Meinert.

nuti-nlata SCHKKDTIO mid MKINKKT, Naturhistorisk Tidsskrift (3), XII,
1879-80, p. 393, pi. xn, figs. 10-12.— BOVALLIUS, Bihang till Kgl. Sv. Vet.
Akad. Handling., X, No. 11, 1885, p. 10, pi. n, figs. 18-23.— HANSEX, Vidensk.
Meddel. naturh. Foren. i. Kj0bh., 1887, p. 187. — RICHARDSON, American
Naturalist, XXXIV, 1900, p. 219; Proc. U. S. Nat. Mus., XXIII, 1901, p.
524.

Localities. — West Greenland; Vladivostok; east Asia.
Body short, ovate, punctate on the dorsal surface, with minute scat-
tered dots; the dorsal surface of the fourth thoracic segment is orna-
mented on either side with an obscure suhocellate spot; the last seg-
ment of the abdomen is marked at the
base on either side with an obscure spot.
The front of the head is triangular,
with the apex widely obtuse, smooth
above.

The frontal lamina is minute, narrowly
rhomboidal in shape.

The eyes are minute, pentagonal in
shape, separated by a distance equal to
a third part of the width of the head.
The first pair of antenna? with the four
last articles extend beyond the anterior
angle of the first thoracic segment, reach-
ing with the peduncle as far as a third
part of the fourth article, and with the
flagellum as far as the fifth article of the
second pair of antennae; the flagellum is
composed of six articles, the first article
being a little longer than the second, the
last article being the smallest.

The second pair of antennae extend to
the end of the first epimeron; the flagel-
lum is composed of fifteen articles.

The first segment of the thorax is
slightly bisinuated anteriorly on the dorsal surface.

The epimera are rather large, and rather wide; the posterior angles
of the posterior epimera are very acutely produced; the last epimeron
extends two parts of the length of the second segment of the abdomen.
The prehensile legs are short; the merus is short, and armed with three
or four rather stout, obtuse spines; the propodus is furnished along
the edge with four long, acute spines; the ungulse are rather large,
slender, ornamented with four carinae, somewhat incurved and subequal.
The ambulatory legs are rather long, rather stout, furnished with short
spines. The first segment of the abdomen is almost entirely concealed.

FIG. 186. — ROCINELA MACULATA (AFTER
SCHICEDTE AND MEINERT). a,
FRONTAL MARGIN WITH BOTH ANTEN-
KJE AND FRONTAL LAMINA, ft, RIGHT
LEG OF SECOND PAIR, f, ADULT MALE.
(ENLARGED.)

ISOPODS OF NORTH AMERICA. 199

The last segment of the abdomen is short, Ungulate, smooth above,
and with two depressions at the base.

The uropoda are rather long and large; the inner branch is a little
longer and wider than the outer branch and is posteriorly truncate;
both branches are crenulated on the exterior margin.

Length, 23 mm.«

ROCINELA BELLICEPS (Stimpson).

JEga belllceps STIMPSOX, Proc. Acad. Nat. Sci. Phila., XVI, 1864, p. 155.

/Kga alascensis LOCKINGTON, Proc;. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 46.

Rocinela alascensis RICHARDSON, Proc. Am. Philos. Soc., XXXVII, 1898, p. 11.

Rocinela bdliceps RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 827; Ann.
Mag. Nat. Hist. (7), IV, 1899, p. 169; Amer. Naturalist, XXXIV, 1900, p.
219; Harriman .Alaska Exp. Crust, X, p. 214; Proc. U. S. Nat. Mus.,
XXVII, 1904, p. 214; Bull. U. S. Fish Comm., XXIV, 1905, p. 213.

localities. — Cortes Bank, California to Alaska
and Bering Sea; Yakutat, Alaska; Unalga Pass,
Aleutians.

Parasite of cod and sculpin; from the fish
Ifydrolaqus colliei.

r> ji t ^oo £ Au TD i u u j FIG- 187.— ROCINELA BELLI-

Lfeptfi. — 5-688 fathoms. Kocky beach under CEPS. HEAD AND FIRST
stones; shelly sand, mud, and gravel; in low TWO THORACIC SEGMENTS.

X 2}

water; in brown and green mud, red sand.

Body oblong-ovate, a little more than twice as long as wide, 10 mm. :

22 mm.

« The above description is adapted from the following one of Schicedte and
Meinert's:

Breviter ovata, supra praeter puncturam ordinariam punctis minutis, perraris
sparsa; segmentum dorsale annuliquarti trunci utrinque macula obscura, subocellata
ornatum; annulus analis ad basin utrinque macula obscura notatus.

Frons triangula, apice late obtusa, supra jequata.

Lamina frontalis minuta, anguste rhomboidalis.

Oculi minuti, pentagoni, tertia parte latitudinis capitis distantes. Antenna? primi
paris articulis quaternis ultimis angulum priorem annuli primi trunci superantes,
scapo tertiam partem articuli quarti, flagello articulum quintum antennarum secundi
paris explentes; flagellum 6-articulatum, articulo primo quani secundo paulo longiore,
articulo ultimo minimo.

Antennae secundi paris epimerum primum explentes; flagellum 15-articulatum.
Segmentum dorsale annuli primi trunci ante leviter bisinuatum.

Epimera majuscula, latiuscula; anguli postici epimerorum posteriorum acuti, valde
producti; epimerum ultimum duas partes annuli secundi caudalis explens.

Pedes prensorii breves: femora brevia, aculeis ternis quaternisve crassiusculis,
obtusis armata; tarsi in acie aculeis quaternis longis, acutis instructi; ungulre
majuscula?, gracilis, quadricarinatee, admodum incurvpp, inter se subrequales. Pedes
gressorii longiusculi crassiusculi, breviter spinulosi. Annulus primus caudalis fere
totus obtectus.

Annulus analis breviter lingulatus, supra subsequatus, ad basin bis impressus.

Pedes anales longiusculi, magni; ram us interior quam exterior paulo longior atque
latior, post truncatus; ramus uterque in latere exteriore crenulatus.

Long. 23 mm.— SCHKEDTE AND MEINERT, Nat. Tidsskr. (3), XII, 1879-80, p. 393.

'200

r>4, ITNITKI> STATES NATIONAL MFSKTM.

Head somewhat triangular in shape, one and two-thirds times wider
than long, 3 mm. : 5 mm. Front of head obtusely produced over the
basal articles of the antenna?, partly concealing these articles. The
eyes are large, oval, composite, situated in the post-lateral angles of
the head and extending along the side a little beyond the middle of the
lateral margin. They are separated anteriorly by a distance equal to

FIG. 188.— ROCINELA BELLI-
CEPS. ABDOMEN AND L ST
THORACIC SEGMENT. X 2J.

FIG. 189. — ROCINELA BEL-
LICEPS.

FIG. 190.— ROCINELA
BELLICEPS. MAX-
ILLIPED. X 27J.

one-third the width of the head at the base. The basal article of the first
antennae is almost entirely concealed by the front of the head; the sec-
ond article is short; the third is one and a half times longer than the
second. The flagellum is composed of four articles. The first antenna?

extend almost to the posterior

margin of the head. The second

pair of antenna1 have the first two

articles short, the second one a lit-
tle shorter than the first; the third

and fourth are subequal and each is

about twice as long as the first; the

fifth is about one and a half times

as long as the fourth. The flagel-
lum is composed of fourteen arti

cles. The second antennae extend

to the posterior margin of the

second thoracic segment. Frontal

lamina very small, minute, rhom-
boid-shaped at its base and ventrally placed. The maxilliped has a
palp of two articles.

The first segment of the thorax is a little longer than any of the
others; the second, third, and fourth are subequal; the fifth, sixth,
and seventh are progressive!}7 shorter, the seventh being only half as
long as the sixth. The epimera of all the segments are distinct with
the exception of the first. The posterior extremities of the first three

FIG. 191.— ROCINELA
BELLICEPS. LEG OF
THIRD PAIR. X 7.

FIG. 192.— ROCINELA BEL
LICEPS. UROPOD. x 6i.

ISOPODS OF NORTH AMERICA.

201

are round; those of the last three are acute. A faint carina crosses
the epimera obliquely.

The first segment of the abdomen is entirely concealed by the last
thoracic segment, so that there is no trace of it whatever on the dorsal
side. The lateral parts of the segments are not distinct from the
dorsal portion. The last segment is widely rounded posteriorly with
margin faintly crenulate. The uropoda are alike in shape, being long
and narrow with posterior margins rounded, oar-like; the inner branch
is a little longer than the outer branch and does not extend be}rond
the extremity of the terminal abdominal segment; the branches are
equally wide. The basal segment of the uropoda extends as far as the
end of the outer branch, and nearly to the end of the inner branch.

The first three pairs of legs are prehensile; the last four pairs ambula-
tory. There are three spines on the merus and three on the propodus
of the first three pairs of legs.

The lateral parts of the second, third, fourth, and fifth segments of
the abdomen and the base of the sixth or terminal segment are marked
with black.

ROCINELA AMERICANA Schicedte and Meinert.

Rodnela americana SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XII,
1879-1880, pp. 394-395, pi. xn, figs. 16-18.— HARGER, Bull. Museum Comp.
Zool., Harvard College, XI, 1883, No. 4, pp. 98-99, pi. iv, figs. 3, 3a, 4;
pi. iv, figs. 2-2a. —RICHARDSON, American Naturalist, XXXIV, 1900, p. 219;
Proc. U. S. Nat. Mus., XXIII, 1901, p. 524.

Localities. — Trenton, Maine; latitude 40°
2' 54" north, longitude 70° 23' 40" west; lati-
tude 409 north,
longitude 70° 57'
west; latitude
39° 57' north,
longitude 70° 57'
30" west; lati-
tude 37° 25'
north, longitude
74° 18' west; '
latitude 40° 2'

FIG. 193.— ROCINELA AMERICANA north, longi-

FIG. 194. — ROCINELA AMERICANA, a,
SECOND LEG. x 11J. b, MAXILLIPED.
x 39.

(AFTER SCHICEDTE AND MEIN- frnde 70° 37' 30"
ERT). a, FRONTAL MARGIN WITH

BOTH ANTENNA AND FRONTAL WCSt.

LAMINA, b, YOUNG FEMALE. /-» ^2 Ot

(ENLARGED.) Depth. — 85 -

157 fathoms.

Body ovate, a little more than twice as long as broad, 9 mm. : 20 mm.

Head twice as wide as long, 2 mm. : 4 mm.; triangular in shape,

with the front produced over the basal articles of the antennae Eyes

202

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

large, oval, composite, separated in front by a distance nearly equal
to the width of one eye. Basal article of the first pair of antenna*
short and nearly concealed by the. front of the head; second article
twice as long as the basal article; third article twice as long as the
second one. Flagellum is composed of six articles. The first antennae
extend to the end of the peduncle of the second pair of antenna* or to
the antero-lateral angle of the first thoracic segment. The first two

articles of the second pair of antenna?
are short, the second shorter than the
first; the third is twice as long as the
first; the fourth is equal in length to
the third; the fifth is one and a half
times longer than the fourth. The
flagelluni is composed of fourteen to
fifteen articles. The second antenna?
extend to the posterior margin of the
second thoracic segment. The frontal
lamina is small, almost inconspicuous,
rhomboid-shaped at the base, which is
ventrally placed. The maxilliped has
a palp of two articles.

The first segment of the thorax is a
little longer than the others. The
epimera are distinct from the seg-
ments in all but the first segment;
they are narrow plates with the pos-
terior extremity very acute in the last
four. The epimeron of the seventh
segment is produced beyond the pos-
terior margin of the segment. A
distinct carina obliquely crosses all
the epimera.

The first segment of the abdomen
is almost entirely concealed by the
seventh thoracic segment. The lat-
eral parts of the abdominal segments
are not separated off from the dorsal
portion. The sixth or terminal seg-
ment is rounded posteriorly. The
inner branch of the uropoda is longer than the outer branch and a
little wider. It does not extend beyond the extremit}^ of the terminal
abdominal segment. The peduncle extends as far as the tip of the
outer branch. Both branches are rounded posteriori}7. Uropoda and
terminal abdominal segment furnished with spines along the margins.

FlG. 195.— R.OCINELA AMERICANA (AFTER

HARGER). a, DORSAL VIEW OF FEMALE.
x 2. b, VENTRAL VIEW OF FEMALE, x 2.
c, HEAD AND FIRST THORACIC SEGMENT OF
MALE, x 2. d, LEG OF SIXTH PAIR, x 6|.
e, LEG OF FIRST PAIR, x 6|.

ISOPODS OF NORTH AMERICA.

Leg's of the first three pairs prehensile; those of the last four pairs
ambulatory. There are three spines on the propodus and three on
the nierus of all three anterior pairs.

ROCINELA PROPODIALIS Richardson.

Rocinela propoduilis RICHARDSON, Bull. r. S. Fish Comm., XXIV 1905 pp
214-215.

Locality.— Admiralty Inlet, vicinity of Port Townsend.

Depth. — 15-20 fathoms.

Body nearly twice as long as wide. Color brown, with small black
dots.

Head triangular and produced in front in a broad median process.
Eyes large and separated in front by a distance equal to the length of
one eye. The first pair of antennae extend to the posterior margin of
the head or to the end of the peduncle of the second pair; the flagel-

FIG. 1%.— ROCINELA PRO-
PODIALIS. HEAD WITH
ANTENNAE AND FIRST

TWO THORACIC SEG- FlG. 197. — ROCINELA PROPODIA- FlG. 198. — ROCINELA PROPODIALIS.
MENTS. x 2£. LIS. ABDOMEN, x 2j. THIRD LEG. x 7.

luin has four to six joints. The second pair of antennae reach the
posterior margin of the second thoracic segment; the flagellum has
sixteen joints.

The several segments of the thorax are about equal in length, the
first segment being a little longer and the last a little shorter than the
others. The epimera of all the segments are produced at the outer
posterior angle, becoming more and more pointed in the last four seg-
ments. The epimera of the last segment only project beyond the
posterior margin of the segment.

The first segment of the abdomen is entirely concealed by the last
thoracic segment. The fifth is narrower than the preceding ones,
but longer in the median line. The terminal abdominal segment
is linguiform, rounded posteriorly, with smooth margins furnished
with short hairs. The uropoda do not exceed in length the terminal
abdominal segment. The outer branch is somewhat narrower and
shorter than the inner, and both branches are armed with a few
short spines along the outer margins and with long hairs along the
inner margins.

204

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG

PROPODIALIS
UROPOD. x 6i.

The first three pairs of legs have the propodus armed with a process,
the edge of which is denticulate with six teeth meeting squarely and
without interval, forming an unbroken line; the carpus
is armed with one inconspicuous spine; the merus has
five short blunt spines along the inner margin and the
ischium is furnished with one long spine at the outer
distal angle. The last four pairs of legs are armed with
numerous spines.

Only one specimen, a male and the type (Cat. No.
29248 U.S.N.M.), was taken by the U. S.
Bureau of Fisheries steamer Albatross,
at station 4205, Admiralty Inlet, vicinity
of Port Townsend.

This species differs from R. angustataa
Richardson, which it closely resembles, in the denticu-
late process arming the propodus of the first three pairs
of legs, with six contiguous teeth meeting squarely along
the edge, while in R. angustata the propodus is armed
with four long spines; in having the merus of these
legs armed with five blunt spines instead of four long FIQ 200_
ones; in having the outer branch of the uropoda a little PROPODIALIS. MAX-
•shorter and narrower than the inner branch instead of
almost twice as wide; and in having the frontal process wider and the
distance between the eyes in front greater than in R. angustata.

ROCINELA LATICAUDA Hansen.

Rocinela laiicauda HANSEN, Bull. Mus. Comp. Zool., Harvard College, XXXI,
1897, No. 5, pp. 108-109.— RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899,
p. 828 (part); Ann. Mag. Nat. Hist. (7), IV, 1899, p. 169 (part).

Localities. — Off Acapulco; near Tres Marias Islands; off Mazatlan.

Body oblong-ovate, two and a half times longer than wide, Iti mm. :
40 mm.

Head wider than long, 4 mm. : 7 mm., triangular in shape, with a
median process in front which has a blunt or truncate extremity.
The eyes are large, oval, composite, and situated at the sides of the
head, and separated anteriorly by a distance equal to 2 mm. The first
pair of antennae have the first two articles short and subequal, the first
article being almost entirely concealed dorsally by the frontal process;
the third article is twice as long as the second. The flagellum is com-
posed of six articles. The first antennae extend to the middle of the
fifth article of the peduncle of the second pair of antennae. The sec-
ond pair of antennae have the first two articles short and subequal; the
third and fourth are also subequal and each is about three times as long

«Proc. U. S. Nat. Mus., XXVII, 1904, p. 33.

ISOPODS OF NORTH AMERICA.

205

as the second; the fifth is one and a half times longer than the fourth.
The flagellum is composed of sixteen articles. The second antennae
extend to the middle of the third
thoracic segment. The palp of
the maxillipeds is composed of
two articles.

The segments of the thorax
are subequal in length, each be-
ing 3 mm. long, with the excep-
tion of the first, wrhich is 4 mm.
The epimera are distinctly sepa-
rated on all the segments with
the exception of the first. Those
of the second and third segments
have the posterior extremities
rounded; those of the last four
segments have the posterior ex-
tremities acutely pointed, and
the last three are produced be-
yond the posterior margins of
the .segments.

The first segment of the abdo-
men is entirely concealed by
the seventh thoracic segment.
The remaining five segments
are distinct. The sixth or ter-
minal segment is broader than
long, 14 mm. : 12 mm. It is 14
mm. wide at the base and also
14 mm. wide about the middle
of the segment. The posterior
etremity is widely rounded.
The uropoda extend to the ex-
tremity of the terminal abdom-
inal segment. Both branches
are equal in length and are
rounded posteriorly. The outer
branch is one and a half times
as wide as the inner branch.
The peduncle of the uropoda
has the inner angle produced,

and this process extends a little beyond the middle of the terminal
segment of the abdomen.

The first three pairs of legs are prehensile and have the propodus

FIG. 201. — ROCINELA LATICAUDA (AFTER HANSEN).

a, EPIMEKA OF SMALL FEMALE, x 3. ft, ABDOMEN

WITH UROPODA OF SAME. X 3. C, BOTH PAIRS OF
ANTENNAE OF MALE. X 5. d, FIFTH LEG OF LARGE

FEMALE, x 4. e, SECOND LEG OF SAME, x 4. /,
GENERAL FIGURE, MALE, x 1.

206

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FlG. 202. — ROCINELA LATICAUDA. tt, MAXILLIPED.

x 27j. b, LEG OF SECOND PAIR, x 9j.

dus armed with live spines in the larger specimen, six in the smaller
specimen, the merus with four spines. The four following pairs of

legs are ambulatory and are
thickly beset with spines/'

ROCINELA ANGUSTATA Rich-
ardson.

RocinelalaticaiK/d RICIIAKDSON (not
Hansen), Proc. Am. Philos.
Soc., XXXVII, 1898, pp. 14-
15, figs. 5-6; Proc. U. S. Nat.
Mus., XXI, 1899, p. 828 (part) ;
Proc. U. S. Nat, Mus., XXVII,
1904, p. 33; Bull. T. S. Fish
Comm., XXIV, 1905, p. 214.

Localities. — Oft San Luis Obis-
po Ba}T, California; oft Esteros
Bay, California; Puget Sound,
Washington; Unimak Island, Alaska; Japan; Eastern Passage (vicinity
of Stikine River Delta), southeastern Alaska; vicinity of Yes Bay, Behm
Canal.

Depth.— 67-252 fathoms.

Head, with a median projection, long and broad,
extending slightly downward and having a blunt
extremity. Eyes large, with ten rows of ocelli.
The first antenna, with a flagellum composed of
six articles, reaches the posterior margin of the
head. The second antenna extends to the middle
of the second thoracic segment; its flagellum con-
sists of fifteen articles.

The thoracic segments are equal in length. The first is deeply
bisinuated, its antero-lateral angles extending along the side of the
head to about the middle of the eyes. The epimera of the second,
third, and fourth segments are rounded
posteriorly; those of the remaining seg-
ments have pointed extremities.

The first segment of the abdomen is
almost entirely covered by the last tho
racic segment. The fifth segment, as
well as this one, is narrower than the
intervening segments, and not as broad
as the base of the terminal segment.
The last segment is 9 mm. wide and 7£

mm. long, widely rounded posteriorly, and is fringed with rough hairs,
which almost conceal its crenulated margin; at the base it is impressed

FIG. 203.— ROCINELA AN-
GUSTATA. HEAD, x 2!.

PIG. 204.— ROCINELA ANGUSTATA. HEAD
WITH ANTENN.K AND FIRST TWO SEG-
MENTS OF THOEAX. X 1$. (FROM
JAPAN.)

« The measurements are of the larger specimen,
the smaller specimen.

The drawings arc made from

ISOPODS OF NORTH AMERICA.

207

on either side of a keeled center; the outer branch of the uropods is
almost twice as broad as the inner branch; they are about equal in
length. Both are fringed with hairs and indis-
tinctly erenulate.

The prehensile legs are stout and short. There
are four spines on the propodus and six on the
merus, besides numerous hairs. The gressorial
legs are likewise stout and furnished with spines
and hairs.

The specimen described came from Alaska, off
Unimak Island, station
3225, 85 fathoms (Cat.
No. 20088, U.S.N.M.).
Distribution. — One
specimen was found off
San Luis Obispo Bay,
California, station 3195,
252 fathoms; one off
Esteros Bay, California,
station 3194, 92 fath-
oms, and another at
Puget Sound, Washing-
ton, station 3067, 82
fathoms.

The specimens from the coast of California are smaller in size and of
very much lighter color than the other specimens. They are similar
in other respects.

A specimen from Ja-
pan, one from Esteros
Bay, and one from San
Luis Obispo Bay, Cali-
fornia, have four spines
on the merus of the pre-
hensile legs.

This species differs
from R. modesta Hansen
in the larger eyes, which
are also closer together
than in that species, the differently shaped head and the wider outer
branch of the uropoda.

FIG. 205. — ROCINELA ANGUS-
TATA. UROPOD. x 6i.
(FROM JAPAN.)

FIG. 206.— ROCINELA ANGUS-
TATA, a, MALE, SLIGHTLY

REDUCED. 6, LEG OF FIRST

PAIR, x 4. c, LEG OF

FOURTH PAIR. X 4.

FlG. 207. — ROCINELA ANGUS-
TATA. THIRD LEG. x 7.
(FROM JAPAN.)

FIG. 208.— ROCINELA
TATA. ABDOMEN AND LAST
THORACIC SEGMENT. X 1|.
( FROM JAPAN.)

208 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 209.— Roci-
NELA TUBER-
C U L O S A .

MALE, x 2J.

ROCINELA TUBERCULOSA Richardson.

Kodnda tuberculom RICHARDSON, Proc. Am. Philos. Soc., XXXVII, 1898, p. 16,
fig. 10; Proc. U. S. Nat. Mus., XXI, 1899, p. 828; Ann. Mag. Nat. Hist.
(7), IV, 1899, p. 170.

Locality. — Southern part of Gulf of California.
Depth.— 8-10 fathoms.

Surface of body punctate and marked with small black dots. The
posterior margin of each of the thoracic and abdominal
segments is lined with a row of tiny tubercles, above
which is a row of small black dots.

Head subtriangular, rounded in front. Eyes large
and situated at a distance of one-third of the head apart.
The first antenna, with a flagellum of five articles, reaches
the posterior margin of the head; the second antenna
extends to the posterior margin of the second thoracic
segment; its flagellum is composed of eleven articles.

The posterior margin of all the thoracic segments is
edged with a row of small tubercles. The epimera are
narrow, those of the second, third and fourth segments being rounded
at the tip, while those of the last three segments are more acute.

The first abdominal segment is entirely concealed by the last tho-
racic segment. The second, third, fourth and fifth segments are like-
wise edged with a row of small tubercles.
The last segment is widely rounded.
The outer branch of the uropods is some-
what narrower and shorter than the inner
one and is rounded at its extremity. The
inner one is bluntly rounded. Both are
fringed with hairs, and on their exterior
margins are armed with spines. The
prehensile legs have three long, stout
spines on the merus, one on the carpus,
and three on the propodus. The gresso-
rial legs are covered with spines.

Two individuals of this species were
found in the southern part of the Gulf of California, at station 2824,
eight fathoms, type (Cat. No. 20652, U.S.N.M.), and station 2828, ten
fathoms.

FIG. 210.— ROCINELA TUBERCULOSA. «.
MAXILLIPED. x 27}. b, SECOND LEG.
x 15}.

ISOPODS OF NORTH AMERICA.

209

ROCINELA SIGNATA Schioedte and Meinert.

Rocinela signata SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XII,
1879-80, pp. 399-401, pi. xin, figs. 3-6.— RICHARDSON, Proc. U. S. Nat.
Mus., XXIII, 1901, p. 524.— MOORE, Bull. U. S. Fish Comm., XX, Pt. 2,
1902, p. 171, pi. x, fig. 2.

Localities. — West Indies; shores of Central America; St. Croix
Island; St. Bartholomew Island; Marco and No Name Key, Florida;
between delta of the Mississippi and Cedar Keys, Florida; Key West,
Florida; Anclote section; Gulf of Mexico; Culebra, Porto Rico.

Depth.— 2-26 fathoms.

Found in coarse sand and coral; in rocks. From back of grouper;
off fish Diplectrum formosum; in the gills of Thunnus alatunga; in
gills of a scaroid; on "ffsem-
ulon or Scisena" (Schioedte
and Meinert).

Body oblong-ovate, a little
more than twice as long as
wide, 6 mm. : 13 mm.

Head twice as wide as long,
2 mm.: 4 mm., triangular in
shape and produced in front
over the basal articles of the
antennae. Eyes large, oval,
composite, separated in front
by a distance somewhat

greater than the width of FlG ail.-RodNELA SIGNATA (AFTER SCHKEDTE AND
One eye. The first pair of MEINERT). o, ADULT FEMALE. 6, YOUNG FEMALE, c,

antennae have the basal arti-
cle short, and covered by the
front of the head; second article about twice as long as the first; third
article about one and a half times as long as the second. The flagellum
is composed of four articles. The first pair of antennae extend to the
middle of the fifth article of the peduncle of the second antennas.
The first two articles of the second antennae are short, the second one
being somewhat shorter than the first; the third and fourth are sub-
equal and each is twice as long as the first; the fifth is a little longer
than the fourth. The flagellum is composed of twelve articles. The
second antennae extend almost, but not quite, to the posterior margin
of the second thoracic segment. The frontal lamina is small, almost
inconspicuous, rhomboid-shaped and ventrally placed. The maxilliped
has a palp of two articles.

The first, fourth, fifth, and sixth segments of the thorax are a little
longer than any of the others. The epimera are distinct from the seg-
ments in all but the first. They are narrow plates, with the posterior
28589—05 14

FRONTAL MARGIN WITH BOTH ANTENNAE AND FRONTAL
LAMINA. (ENLARGED.)

210 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

a b

FIG. 212.— ROCINELA SIGXATA. a, M AX-

ILLIPED. x 51|. b, SECOND LEG. x

extremity very acute in the last four. The seventh epimeron is pro-
duced beyond the posterior margin of the segment.

The first segment of the abdomen is almost entirely concealed by the
seventh thoracic segment. The lateral parts of the segments are not

distinct from the dorsal portion. The
sixth or terminal segment is rounded pos-
teriorly and furnished with short spines.
At the base of the terminal segment is a
short median longitudinal black line, with
two much shorter lines, one on either
side, all connected at the base. On either
side of this group of three longitudinal
lines, and connected with the lateral lines,
is a line which runs obliquely for some
distance and then extends in a longitudi-
nal direction for a short distance. The
lines are distinctly marked, but very
narrow.

The uropoda are not longer than the

terminal segment. The outer branch is narrower and shorter than
the inner branch, and is rounded at its posterior end. The inner
branch is obliquely truncate, with rounded post-lateral angles. Both
branches are provided with spines.

The first three pairs of legs are prehensile and with propodus
unarmed; the last four pairs are ambulatory and armed with a few
spines.

ROCINELA ARIES Schicedte and Meinert.

Rocinda aries SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XII,
1879-80, pp. 401-403, pi. xin, figs. 7-8.— RICHARDSON, Proc. U. S. Xat.
Mus., XXI, 1899, p. 828; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 170.

Localities. — Mazatlan; Lower California; Panama Bay; Gulf of
California.

Body ovate; twice as long as wide; 10 mm.: 20 mm.
Head twice as wide as long; 2 mm.: 4 mm.; triangulate, with the
front produced over the basal articles of the antennae. Eyes large,
oval, composite, separated in front by a distance equal to the length
of one eye. Basal article of first antenna short, almost entirely con-
cealed b}T the front; second article about twice as long as the first;
third article one and a half times longer than the second. The flagel-
lum is composed of five articles. The first antenna? extend to the
middle of the fifth article of the peduncle of the second antenna or to
the antero-lateral angle of the first thoracic segment. The first article
of the second antennas is twice as long as the second article, which is
almost inconspicuous; the third article is twice as long as the first;

ISOPOD8 OF NORTH AMERICA.

211

FIG. 213.— ROCIXELA ARIES (AFTER
SCHICEDTE AND MEINERT). «,
FRONTAL MARGIN, ANTENN.K AND
FRONTAL LAMINA. 6, ADULT
FEMALE. (ENLARGED.)

the fourth is a little longer than the third; the fifth is one and a half
times longer than the fourth. The flagellum is composed of twelve
articles. The second antennae extend to the posterior margin of the

second thoracic segment. The frontal
lamina is small and almost inconspicuous,
triangular in shape at the base, which is
ventrall}T placed. The maxilliped has a
palp of two articles.

The first, fourth, fifth, and sixth seg-
ments of the thorax are a little longer
than the others. The epimera are distinct
on all the segments but the first. They
are narrow plates with the posterior an-
gles increasingly acute. The epimera of
the last segment are produced beyond the
posterior margin of the segment.

The first segment of
the abdomen is almost
entirety concealed by
the last thoracic seg-
ment. The lateral
parts are not sepa-
rated from the dorsal portion. The sixth or ter-
minal segment is rounded posteriori. The base

of the terminal seg-
ment is marked with
three longitudinal
black lines, one on
either side of a me-
dian line, and two
oblique lines, one on either side, and all five
connected at the base. The outer branch
of the uropoda is shorter than the inner
branch and half as wide. The inner branch
is obliquely truncate, with rounded an-
gles. The outer branch is posteriorly
rounded. The peduncle of the uropoda is
as long as the outer branch. The margins
of the uropoda and the terminal segment are furnished with spines.

The first three pairs of legs are prehensile, the last four pairs ambu-
latory. The merus of all three anterior legs is furnished with two
spines, the carpus with one spine, and the propodus of the second and
third with one spine. The ambulatory legs are beset with a few spines. a

a For description of the young of the first stage, see Schicedte and Meinert, Nat.
Tidsskr. (3), XII, 1879-80, pp. 402-403.

FIG. 214.— ROCINELA ARIES
(AFTER SCHICEDTE AND
MEINERT). YOUNG. (EN-
LARGED.)

FIG. 215. — ROCINELA ARIES, «, MAX-
ILLIPED. x 3»f . 6, LEG OF SECOND
PAIR, x Hi.

212 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

32. Genus SYSCENUS Harger.

Bod}7 depressed. Abdomen abruptly narrower than thorax.

Eyes wanting.

First two articles of the first pair of antennae not expanded or dilated.

Mandibles without molar expansion. Maxillipeds with the palp
composed of two articles.

First three pairs of legs with the propodus not expanded, cylin-
drical; dactylus abruptly curved in the middle, and terminating in a
very sharp point. Four posterior pairs with the propodal joint elon-
gated.

SYSCENUS INFELIX Harger.

Syscenus infelix HARGER, Report U. S. Commissioner of Fish and Fisheries, Pt.
6, 1880, pp. 387-390; Bull. Mus. Comp. Zool. Harvard College, XI, 1883, No.
4, pp. 100-102, pi. in, figs. 5-5a; pi. iv, figs. 3-3h.

Harponyx « pranzoides SARS, Forhandlungen i Videnskab Selsk. Christiania,
No. 18, 1883 (young).

Rocinela lilljeborgii BOVALLIUS, Bihang. till Vetensk. Akad. Handl., X, No. 10,
1885, pp. 3-10, pis. i-n.

Syscenus lilljeborgii BOVALLIUS, Bihang. till K. Sv. Vet. Akad. Handl., XI, No.
17, 1886-87, pp. 17-18.

Syscenus infelix RICHARDSON, Proc. Amer. Philos. Soc., XXXVII, 1898, p. 8 (foot-
note); American Naturalist, XXXIV, 1900, p. 219; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 524.— NORMAN, Ann. Mag. Nat. Hist. (7), XIV, 1904, p. 437.

Localities.— Latitude 41° 34' 30" north, longitude 65° 54' 30" west;
latitude 40° 11' 40" north, longitude 68° 22' west; Marthas Vineyard;
south of Long Island; off Nantucket Shoals; all along the Atlantic
coast as far south as Delaware Bay; west coast of Norway at Hoitingso
and Bekkervlg (Sars); coast of Bohuslan (Bovallius); British Isles
(Norman).

Dept h.— 80-640 fathoms; 516 fathoms (Norman).

Body elongate, nearly three times as long as broad, 10 mm. : 28 mm.

Head three times as wide as long, 2 mm. : 6 mm. , triangular in shape,
with frontal margin somewhat three-lobed, the median lobe being
anterior to the other two and acutely produced between the basal arti-
cles of the antennas, but not meeting the frontal lamina on the other
side. The eyes are absent. The first pair of antennae have the three
articles of the peduncle of equal length and all conspicuous. The

a In the Proc. U. S. Nat. Mus., XXVII, 1904, pp. 6 and 9, I refer to the genus
Harponyx as a separate genus. Doctor Hansen, in a letter, called my attention to this
error, saying that Sars had suppressed the genus, a fact which I had temporarily
overlooked.

ISOPODS OF NORTH AMERICA.

213

FIG. 216. — SYSCENTTS INFELIX (AFTER HAEGER). a, INFERIOR VIEW OF HEAD, x 8. b, LATERAL VIEW

OF MALE. X lj. C, SECOND PLEOPOD OF MALE. X-4. (I, LEG OF SIXTH PAIR. X 4. g, LEG OF FOURTH
PAIR. X 4. /, LEG Ot FIRST PAIR. X 4. g, TIP OF FIRST MAXILLA. X 75. h, FIRST MAXILLA. X 20.

i, DORSAL VIEW OF MA. E. x H. j, LEFT MAXILLIPED. x 20. k, UROPOD OF MALE, x 4. I, LEFT

MANDIBLE. X 20.

214 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

flagellum is composed of seven articles. The first antennae extend to
the end of the peduncle of the second pair of antennas or to the pos-
terior margin of the head. The second pair of antennae have the tirst
two articles equal in length; the third and fourth are also subequal,
and each is about twice as long as the second; the fifth is one and a
half times longer than the fourth. The flagellum is composed of
twenty-five articles. The second antennae extend to the posterior
margin of the third thoracic segment. The frontal lamina is large,
conspicuous, rhomboid shaped, and ventrally placed. The maxilliped
has a palp of two articles.

The first segment of the thorax is longer than any of the others.
The epimera are distinct from the segments with the exception of the
first. They are broad plates with the posterior extremities very acute.
The post-lateral angles of the first thoracic segment are also acute.
The abdomen is abruptl}" very much narrower than the thorax. All
six segments are distinct. The lateral parts are not
separated oil from the dorsal portion. The terminal
segment is large and triangular in shape, with the pos-
terior extremity acutely produced. The uropoda are
as long as the terminal segment of the abdomen.
The outer branch is wider but shorter than the inner
branch; it is more broadly rounded posteriorly than
the inner branch. The peduncle of the uropoda is not
produced at the inner angle.

The first three pairs of legs are prehensile, the last
INFELIX. MAXIL- four pairs ambulatory. The tirst three pairs are not
furnished with spines. The fifth pair of legs is a little
longer than the fourth pair. The sixth and seventh pairs are equal in
length and extremely long, being very much longer than the fourth
and fifth pairs.

Family IX. CYMOTHOID^.

Antennae strongly reduced and without clear distinction between
peduncle and flagellum. All seven pairs of legs prehensile, terminat-
ing in strong hooked fingers. Pleopods not ciliated. Terminal seg-
ment and uropoda usually not ciliated.

Maxillipeds with palp composed of two articles; terminal article
furnished with hooks.

Mandibles with palps.

First maxillae with masticatory lobe composed of a single tapering
article furnished with four spines at tip.

Second maxillae bilobed at tip and furnished with numerous spines.

Epimera distinct on all the segments with the exception of the first.

Parasitic forms.

ISOPODS OF NORTH AMERICA. 215

. ANALYTICAL KEY TO THE GENERA OF THE FAMILY CYMOTHOIDjE.

a. Head posteriorly produced in three lobes, a larger median lobe and two small
lateral lobes; not at all immersed in first thoracic segment. Anterior margin of
first thoracic segment distinctly trisinuate.
b. Uropoda and terminal segment ciliated. Eyes large, conspicuous.

Genus Jfyathoa Dana

b'. Uropoda and terminal segment not ciliated. Eyes small.
c. Posterior angles of first segment of body prominent or produced, very often
acute; posterior angles of the following segments increasing gradually in
length, the first of these very often scarcely produced, the posterior ones
very often produced, abruptly longer than the first. Epimera of the first
segments extending beyond the posterior angles of the segment; posterior

ones produced, acute Genus Nerocila Leach

c/. Posterior angles of first six segments of body scarcely or not at all promi-
nent, those of seventh segment produced. Epimera of first segments very
often almost reaching, or not reaching by a short distance, the posterior
angle of the segment.

d. Body compact. Head not constricted at the base. Uropoda very often
more or less longer than terminal segment. Legs gradually increasing in

length Genus Anilocra Leach

d'. Body relaxed. Head constricted at the base. Uropoda much shorter than
terminal segment. Legs gradually much longer successively; seventh

pair abruptly very much longer Genus Olencira Leach

a'. Head not produced posteriorly in three lobes; more or less immersed in first

thoracic segment. Anterior margin of first thoracic segment not trisinuate.
b. Antennae very much dilated; those of the first pair contiguous at base.
c. Epimera of the first pair with a carina produced in the form of a spoon in
female. Ungulse very long, unequal in length; those of the third pair
longest, abruptly longer than second pair. Terminal segment trans-
verse Genus Ceratolhoa Dana

c/. Epimera of the first pair not produced in female. Ungulae mostly very short,
very rarely long, equal in length. Terminal segment subtriangular, semi-
circular, often bilobed Genus Meinertia Stebbing

//. Antennae not dilated, but compressed.
c. Antennae of the first pair almost contiguous at base.

d. Body hunched or compressed ; the posterior segments of the body on one

side- flattened, dilated Genus Agarna Schicedte and Meinert

d'. Body evenly convex, not hunched; posterior segments of. the body rather

convex Genus Indusa Schioedte and Meinert

c'. First pair of antennae widely separated at the base.
d. Abdomen manifestly separated from the thorax, abruptly narrower than

thorax Genus Cymothoa Fabricius

d/. Abdomen continuous with thorax, not narrower than thorax.
e. Abdomen very little or scarcely immersed. Segments of thorax either
equal in length or the first segment abruptly longer and the last segment

abruptly shorter than the others Genus Livoneca Leach

ef. Abdomen very deeply and profoundly immersed. First segment of the
thorax manifestly longer than the second; six posterior segments gradu-
ally decreasing a little in length Genus Irona Schioedte

!1 ^o^

? IS

* S> > >

^ *

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.
33. Genus v<EGATHOA« Dana.

s large, oval, composite. Posterior margin of head produced in
three lobes.

Anterior margin of first thoracic segment manifestly trisinuate.
Post-lateral angles of thoracic segments not produced. Epimera dis-
tinct on all the segments of the thorax with the exception of the first;
they extend the full length of the segments and are not acutely pro-
duced posteriorly.

The abdomen is not narrower than the thorax, but continues the
oval outline of the body. The abdominal segments are not shorter
than the last thoracic segments. Pleopods not ciliated. Uropoda arid
terminal segment of abdomen furnished with hairs.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ^EGATHOA.

a. Frontal margin of head produced anteriorly in a median lingulate projection.

jEgalhoa linguifrons Richardson

a' . Frontal margin of head not produced anteriorly in a median lingulate projection.
b. Surface of head smooth, evenly convex. Second pair of antennae composed of
ten articles. First thoracic segment longer than any of the succeeding seg-
ments, which are of equal length Jfyathoa oculala (Say)

V . Surface of head with central portion sharply raised above the lateral portion,
which is deeply excavate just in front of the eyes. Second pair of antennae
composed of eight articles. First three thoracic segments of equal length;
last four subequal and somewhat shorter than first three.

jEgathoa medialis Richardson

jEGATHOA LINGUIFRONS Richardson.

jEgalhoa linguifrons RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 526.
Locality\ — Trinidad.
Body narrow, elongate; abdomen not narrower than thorax.

Head with sides rounded. Frontal margin ab-
ruptly produced anteriorly into a median lingulate
projection, with apex rounded; posterior part of pro-
jection forming a raised surface sharply defined on
anterior part of head, extending back to eyes. Eyes
large, oval, occupying two-thirds the width of head.
First pair of antennse nine-jointed. Second pair
more slender equal in length to first pair and ten-
jointed.

First three thoracic segments long, second one
shortest; last four segments short, of nearly equal
FIG. 2i8.-^GATHoA 1^^ All the abdominal segments distinct; first

' . '

five equal in length, terminal segment rounded at
apex. Uropoda longer than terminal segment. Inner branch obliquely

«This genus, perhaps, represents the young of Livoneca. The figure given by
Schioedte and Meinert of the young female of Livoneca redmanni does not apparently
differ from sEgathoa oculatn (Say). I have not suppressed the genus, however,
because I could not be positive of the identity of these forms.

ISOPODS OF NOETH AMEEICA.

217

truncate at apex and shorter than outer branch, which is obtusely
pointed.

Both branches, as well as the posterior margin of the terminal seg-
ment, are fringed with hairs.

Legs similar in structure, with curved dactyli.

Color, light brown, with scattered black dots.

A single specimen was obtained at Trinidad.

Type.—Qa,t. No. 23903, U.S.N.M.

^GATHOA OCULATA« (Say).

Cymothoa oculata SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 398-399.

JEgathoa loliginea HARGER, Am. Jour. Sci. (3), XV, 1878, p. 376; Proc. U. S.
Nat. Mus., II, 1879, p. 161; Report U. S. Commissioner of Fish and Fish-
eries, Pt. 6, 1880, pp. 393-394, pi. x, fig. 66.— RICHARDSOX, American Natu-
ralist, XXXIV, 1900, p. 220; Proc. U. S. Nat. Mus., XXIII, 1901, pp. 526-
527.

Localities. — Savin Rock, near New Haven, Connecticut; Fort Macon,
North Carolina; St. Johns River, Florida (Say); Crisfield, Maryland;
Cozumel; St. Thomas, West Indies.

Parasite of squid (Loligo pealii); young
mullet.

Say's type of this species, placed in the
Academy of Natural Sciences of Philadel-
phia, is undoubtedly identical with Harger's
^Egathoa loliginea. The earlier name must,
therefore, be accepted for this species.

As the type specimen is dry and not per-
fectly preserved, the following description
is from an alcoholic specimen:

Body elongate, nearly four times longer
than wide, 3 mm. : 11 mm.

Head as wide as long, 2 mm. : 2 mm.
slightly narrower anteriorly than posteri-
orly, with the anterior margin widely
rounded. The posterior margin of the head
is produced in three equal lobes. The eyes
are large, oval, composite, and situated in
the post-lateral angles of the head, but extend along the sides of the
head almost to the antero-lateral angles. The first pair of antennae
are composed of eight articles, and extend to the posterior margin of
the head. The second pair of antennae are composed of nine articles,
and extend to the middle of the first thoracic segment. The basal
articles of the first pair of antennae are not adjacent, but are sep-

FIG. 219. — ^EGATHOA OCULATA
(AFTER HARGEH). a, DORSAL
VIEW, x 4. 6, VENTRAL VIEW.

X4.

° See Harger for more detailed description, Report U. S. Commission of Fish and
Fisheries, Pt. 6, 1880, pp. 393-394.

218 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

arated by a small space. The maxillipeds have a palp composed of
two articles. The palp of the mandibles has three articles.

The first segment of the thorax is the longest, and is 1£ nim. in
length. The second and third segments are each 1 mm. long. The
four following segments are each £ mm. long. The epimera are dis-

FIG. 220. — -EGATHOA OCTTLATA. a, MANDIBLE, x 51}. b, MAXILLIPED. x 51}. c, SECOND MAXILLA.

rf, FIRST MAXILLA, x 51}.

tinctly separated on all the segments with the exception of the first.
They extend the full length of the lateral margins.

The abdomen is as wide as the thorax, and the abdominal segments
are as long as the thoracic segments. The length of the abdomen is
5 mm., or nearly half the entire length of the body. The sixth or
terminal segment is long and rounded posteriorly. The uropoda are
longer than the terminal segment. The outer branch is longer and
narrower than the inner branch and is posteriorly
rounded. The inner branch is broad posteriorly and
is obliquely truncate. The uropoda and the terminal
abdominal segment are fringed with hairs.

All the legs are prehensile and terminate in long,
narrow, curved dactyli. The propodus is furnished
with five spines, the carpus with two in all the
legs.

JEGATHOA MEDIALIS Richardson.

jEgathoamedialis RICHARDSON, American Naturalist, XXXIV,
1900, p. 220; Proc. U. S. Nat. Mus., XXIII, 1901, p. 527.

Locality. — Barren Island, Chesapeake Bay.
Depth. — 3 to 25 fathoms.
Body narrow, elongate; abdomen not narrower than thorax.
Head with anterior margin broadly rounded in front; central por-
tion sharply raised above lateral portion, which is deeply excavate just
in front of eyes. Eyes large, occupying two-thirds the width of the
head. First pair of antennas eight-jointed; second pair more slender,
equal in length, and nine-jointed.

First three segments of thorax subequal, last four subequal and some-

FIG. 221. —

MEDIALIS.

ISOPODS OF NORTH AMERICA. 219

what shorter than first three. First five abdominal segments equal in
length. Terminal segment rounded posteriorly. Uropoda longer
than terminal segment; branches unequal. Outer branch the longer;
inner branch obliquely truncate. Legs similar in structure, with
curved dactyli. Color, light brown, densely covered with black spots.
Single specimen from Barren Island, Chesapeake Bay.

Depth. — 3 to 25 fathoms.

Type.— Cat No. 23904, U.S.N.M.

34. Genus NEROCILA Leach. «

Body relaxed, very often flattened. Head posteriorly produced
in three lobes, not at all immer >ed. First pair of antenme almost con-
tiguous at the base.

First segment of thorax with the anterior margin deeply trisinuate.
Posterior angles of the segments from the second to the last increasing
gradually in length, the first of these often but little produced, the
posterior ones almost always produced and often abruptly longer than
the first ones. The anterior epimera almost always extend to or
beyond the posterior angle of the segment; the posterior epimera are
produced and acute, but do not reach the posterior angle of the segment.

Abdomen free, rarely covered at the base or the sides. Legs rather
long.

ANALYTICAL KEY TO THE SPECIES OF THK GENUS NEROCILA.

a. Terminal abdominal segment quadrate, with post-lateral angles rounded and

posterior margin acuminate and produced in an acute point.

b. Body a little more than one and a half times longer than wide. Head as long
as wide. Post-lateral angles of all the segments of the thorax are produced
backward in long acute processes, increasing in length from the first to the
seventh segment. The epimera of the second segment extend beyond the post-
lateral angles of the segment; those of the third segment extend to the post-
lateral angles of the segment; all the others reach the posterior margins of

the segments Nerocila acuminata Schioedte and Meinert

bf. Body nearly two and a half times longer than wide. Head wider than long.
The post-lateral angles of only the last two segments of the thorax are pro-
duced. The epimera do not extend beyond the posterior margins of the
segments, except in the last segment where they almost reach the extremity

of the post-lateral angles Nerocila calif ornica Schioedte and Meinert

a'. Terminal segment of abdomen not quadrate; posterior margin not acuminate.
6. Last segment of abdomen regularly rounded. Uropoda longer than abdomen.
Eyes black, distinct. Head as wide as long, truncate in front. Terminal
abdominal segment without median longitudinal carina.

Nerocila munda Harger

b'. Last segment of abdomen lanceolate. Uropoda shorter than abdomen. Eyes
entirely wanting. Head wider than long and truncately rounded anteriorly.
Terminal abdominal segment with median longitudinal carina.

Nerocila lanceolata (Say)

«See Schicedte and Meinert for the characters of the genus, Nat. Tidsskr. (3),
XIII, 1881-83, pp. 4-5.

220 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

NEROCILA ACUMINATA Schicedte and Meinert.

Xerocila acuminata SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIII,
1881-1883, pp. 48-50, pi. in, figs. 5-6. — RICHARDSON, American Naturalist,
XXXIV, 1900, p. 220; Proc. U. S. Nat. Mus., XXIII, 1901, p. 527; Trans.
Conn. Acad. Sci., XI, 1902, p. 291.

Localities. — Atlantic Ocean and Gulf of Mexico; St. Anna, Mexico;
Louisiana; Pensacola and St. Marys River, Florida; Fort Macon,
North Carolina; Newpoint, Virginia; Biloxi, Mississippi; Bermudas;
Lake Harley, Florida; south Florida.

Parasites of the saw-fish; Chs&todipterus faher (side of body);
Spheroides maculatus; Alutera schoepfii; Lachnolaimus maximum (on
fin).

Body ovate, a little more than one and a half times longer than
wide, 13 mm. : 21 mm.

Head, somewhat quadrate, as long as wide, 4 mm.: -i mm., with the
anterior margin almost straight, slightly rounded, and the posterior
a margin produced in three lobes, the

middle one being much the larger.
Eyes absent. The first pair of antenna?
are composed of eight articles and ex-
tend to the post-lateral lobe of the head.
The second pair of antennae are com-
posed of nine articles and extend just a
little beyond the first pair of antennas.
The maxillipeds have a palp of two
articles. The palp of the mandibles is
composed of three articles.

The first segment of the thorax is
longer than any of the three following
segments; the fifth, sixth, and seventh
segments are longer than any of the
three preceding segments, but gradu-
ally decrease in length, the fifth being the longest. The body is broad-
est at the fifth and sixth segments. The post-lateral angles of all the
segments are produced backward in long acute processes, increasing in
length from the first to the seventh segment. The epimera are dis-
tinctly separated from the segments, with the exception of the first.
They are long, narrow plates, becoming more acutely pointed at their
posterior extremities from the first to the seventh. The epimera of
the second segment extend beyond the post-lateral angles of the seg-
ment; those of the third segment extend to the post-lateral angles of
the segment; all the others reach the posterior margins of the seg-
ments, but do not extend to the extremity of the post-lateral angles.

Fie. 222. — NEROCILA ACUMINATA (AF-
TER SCHICEDTE AND MEIXEBT). a,
ADULT FEMALE. 6, LATEKAL VIEW.
(ENLARGED.)

ISOPODS OF NORTH AMERICA. 221

The segments of the abdomen are all distinct. The sixth or terminal
segment is a little broader than long, 6 mm. : 5 mm., almost quadrate,
with the post-lateral angles rounded and a small triangular point in
the middle of the posterior margin. The uropoda are longer than the
terminal abdominal segment. Both branches are produced to long,
narrow, acute extremities, the outer branch being slightly narrower at

FIG. 223. — NEROCILA ACUMINATA. a, MAXILLIPED. x 27j. 6, FIRST MAXILLA, x 27|. c, SECOND MAX-
ILLA, x 27J. d, PALP OF MANDIBLE, x 27}. e, SEVENTH LEG. x 9|.

the base and somewhat longer than the inner branch. The inner
branch is 3 mm. long; the outer branch 4 mm. in length.

The legs are all prehensile, slightly increasing in length, with long,
curved dactyli.

There are two longitudinal bands or stripes of a light-brown or j^el-
low color extending the entire length of the body, one on either side
of the median line. The other parts of the body are dark greenish
brown.

NEROCILA CALIFORNICA Schioedte and Meinert.

Nerocila californica SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIII,
1881-83, pp. 72-76, pi. v, figs. 12-13; pi. vi, figs. 1-2.— RICHARDSON, Proc.
U. S. Nat. Mus., XXI, 1899, p. 830; Ann. Mag. Nat. Hist. (7), IV, 1899, p.
172; American Naturalist, XXXIV, 1900, p. 220.

Localities. — San Diego, California; Taboga Island, Panama Bay; off
Point Sur, California; National City, California.

Parasites of Promicrops guttatm; cat-fish on fin; Gyropleurodus
francisci on dorsal fin : on dorsal and caudal fin of Paralabrax clathrata,
Scorpa&na guttata, Triakis semifasciata, Myliobatis sp.

Body oblong-ovate, nearly two and a half times longer than wide,
8 mm. : 19 mm.

Head, wider than long, 2£ mm. : 3£ mm., with the anterior margin
widel}T rounded, the posterior margin produced in three lobes, the
middle one of which is much the larger. The eyes are indistinct and
have almost entirely disappeared. They have degenerated, probably
owing to the parasitic mode of life, and are certainly f unctionless. The
first pair of antennae are composed of eight articles and extend to the
end of the seventh article of the second pair of antennae. The second

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

pair of antennae are composed of ten articles, and extend to the middle
of the first thoracic segment. The maxillipeds have a palp of two
articles. The palp of the mandibles is composed of three articles.

The first segment of the thorax is a little longer than any of the
three following segments; the last three segments are longer than any

FIG. 224. — NEROCILA CALIFORNICA (AFTER SCHICEDTE AND MEINERT). O, LATERAL VIEW. 6, ADULT
FEMALE. C, YOUNG FEMALE, d, LATEBAL VIEW. (ENLARGED.)

of the three preceding segments and are about equal in length to the
first segment. The thorax is broadest at the sixth segment. The post-
lateral angles of only the last two segments are produced, those of the
sixth segment being very little produced, and those of the seventh seg-
ment not much produced. The epimera of all the segments, with the
exception of the first, are distinctly separated from the segments. The

FIG. 225. — NEROCILA CALIFORNICA. a, MAXILLIPED. x 27J. 6, FIRST MAXILLA, x 27J. c, MANDI-
BLE, x 5l|. d, SEVENTH LEG. x 9J.

first three have the posterior extremities rounded; the extremities of
the last three are more acutely pointed. The epimera do not extend
beyond the posterior margins of the segments (and they extend to the
posterior margin) except in the last segment, where they almost reach
the extremity of the post-lateral angles.

ISO PODS OF NOKTH AMERICA.

223

All of the segments of the abdomen are distinct. The sixth or
terminal segment is about as broad as long, 4mm.: 4mm. The seg-
ment is somewhat quadrate, with the post-
lateral angles obtusely rounded, and the pos-
terior margin produced in a small, triangular
median point. The uropoda are longer than
the terminal abdominal segment. The outer
branch is longer than the inner branch, 3
mm.: 4mm. Both branches are produced
to narrow, acute extremities, the outer
branch being also somewhat narrower at the
base than the inner branch.

All the legs are prehensile, gradually
increasing in length, and terminate in long,
curved dactyli.

There are two longitudinal bands or stripes
of a yellow or light-brown color, extending
the entire length of the body, one on either

The other parts of the body are a dark

FIG. 226.— NEROCILA CALIFORNICA
( AFTER SCHKEDTE AND MEINERT).
a, LATERAL VIEW. 6, ADULT FE-
MALE. (ENLARGED.)

side of the median line
greenish brown color.

NEROCILA MUNDA Harger.

Nerodla munda HARGER, with VERRILL, Report U. S. Commissioner of Fiah and
Fisheries, 1873, Pt. 1, p. 571 (277); p. 459 (165), 571.— HARGER, Proc. U. Sv
Nat. Mus., II, 1879, p. 161; Report U. S. Commissioner of Fish and Fish-
eries, 1880, Pt. 6, pp. 392-393, pi. x, fig. 65.— RICHARDSON, American Natu-
ralist, XXXIV, 1900, p. 220; Proc. U. S. Nat. Mus., XXIII, 1901, p. 528.

Locality. — Vineyard Sound, at Woods Hole.

Found on dorsal fin of Alutera schoepfii.

Body oblong-ovate, a little more than twice as long as wide, 6
mm. : 13 mm.

Head large, sub-quadrate, about as wide as long, 2 mm. : 2 mm. , with
the posterior margin tri-lobate, the median lobe being the largest.
The anterior margin is somewhat triangulate, with apex obtusely
rounded. The eyes are small, round, composite, and situated in the
post-lateral angles of the head. The first pair of antennae are com-
posed of eight articles and extend to the middle of the first thoracic
segment. The second pair of antennae are composed of twelve articles
and extend one or two articles beyond the first antennge; the last four
articles are very slender and gradually diminish in size and length.
The maxilliped has a palp of two articles. The palp of the mandibles
is composed of three articles.

The thorax is broadest at the fifth and sixth segments. The first
and fifth segments are longer than any of the others. The post-lateral
angles of the last three segments are acutely produced, and extend

224

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

beyond the epimera. The epimera are distinct on all the segments with
the exception of the first. The first three are small and the first two
have the posterior margins rounded. The last four are acutely pro-
duced, the epimera extending to the
posterior margins of the segments,
but not to the extremity of the post-
lateral angles in the last three seg-
ments.

All the segments of the abdomen
are distinct. The sixth or terminal
segment is rounded posteriorly. The
inner branch of the uropoda is broad
with the extremity obliquely truncate;
it extends a little beyond the tip of
the terminal abdominal segment. The
outer branch is one-fourth longer than
the inner branch, is slightly narrower,
and is produced to a narrow rounded
extremity.
FIG. 227.-NEEOCILA MUNDA (AFTER HAH- ^11 the legs are prehensile, with

GER). X 4. a. LTROPOD. X 6. 1 1 .L T

long, curved dactyli.

There are two light longitudinal stripes or bands extending the
entire length of the body, one on either side of the median line.

!

FIG. 228.— NEROCILA MUNDA. a, MAXILLIPED. x 51f . ft, SECOND MAXILLA, x 51|. c, FIRST MAXILLA.
x 51|. d, PALP OK MANDIBLE, x 51|. e, SEVENTH LEG. 15£.

NEROCILA LANCEOLATA (Say).

Oymothoa lanceolata SAY, Jour. Acad. Nat. Sci. Phila., I., 1818, pp. 397-398. —
RICHARDSON, American Naturalist, XXXIV, 1900, p. 221; Proc. U. S. Nat.
Mus., XXIII, 1901, p. 530.

Locality. — Cumberland Island, Georgia.

Having seen Say's type specimen of Cymothoa lanceolata which is in
the Academy of Natural Sciences of Philadelphia, I find that it should
be referred to the genus Nerocila.

ISOPODS OF NORTH AMERICA.

225

Bod}' oblong-ovate, nearly twice as long as wide, 10 mm. : 19 mm.

Head a little wider than long, 3 mm. :4 mm., with the anterior mar-
gin rounded truncate and the posterior margin produced in three lobes,
the middle lobe being deeper than and about twice as wide as the lateral
lobes. The eyes are entirely absent; no traces of them are to be seen.
The first pair of antennae are composed of eight articles and extend
to the middle of the first thoracic segment; they are separated at the
base by a distance of 1 mm. The second pair of antennae are composed
of nine articles and extend only a little beyond the end of the first pair
of antennae.

The first thoracic segment is 2 mm. long, about twice as long as any
of the three following segments, which are each 1 mm. long in the
middle of the dorsal surface. The fifth segment is 1£ mm. in length.
The sixth segment is as long as the first — about 2
mm. in length. The seventh segment is 1 mm.
long — only half as long as the preceding segment.
The post-lateral angles of the first four segments
are but little produced. The post-lateral angles of
the last two segments are very much produced,
those of the seventh segment being more produced
than those of the preceding segment. The epimera
of the second, third, fourth, and fifth segments
extend to the post-lateral angles of their respective
segments. Those of the second and third segments
are rounded posteriorly. Those of the fourth and
fifth segments are obtusely pointed. The epimera
of the sixth and seventh segments are very acutely
produced and extend to the posterior margins of
their respective segments, but not to the post-
lateral angles. The first five segments of the abdomen are subequal
and all visible in a dorsal view, the first segment not being covered by
the last thoracic segment. The first two have the lateral parts pro-
duced in long acute processes on the underside, these processes not
being visible from a dorsal yiew. The lateral parts of the other seg-
ments are not produced. The sixth or terminal segment is as wide as
long — 5 mm. :5 mm. — and is longer than all the five anterior segments
taken together — 5 mm. : 4 mm. It is triangular in shape, with apex
produced and rounded. The uropoda are shorter than the last abdom-
inal segment, the inner branch being the shorter. a

«The inner branch is probably broken in the specimen, for this branch is described
by Say as triangular, whereas it appears truncate in the specimen.
28589—05 15

FiG.229.— NEROCILA LAN-
CEOLATA. x 3.

226 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The outer branch is a little narrower than the inner branch and
rounded truncate."

35. Genus ANILOCRA Leach.''

Body compact, rather stout. Head posteriorly produced in three
lobes, not at all immersed and not constricted at the base.

Anterior margin of the first thoracic segment more or less distinctly
insinuate. Posterior angles of the first thoracic segment most always
somewhat produced and prominent; those of the second, third, fourth,
fifth, and sixth segments not prominent; those of the seventh segment
prominent and produced. Anterior epimera almost reach or do not
reach by a very short distance the posterior angle of the segment;
the posterior epimera do not reach by a greater or less distance the
posterior angle of the segment.

Abdomen covered at the base. Legs increase gradually in length,
the last pair very often abruptly longer than the others.

ANALYTICAL KEY TO THE SPECIES OF THE GENTS ANILOCRA.

a. Head produced, with sides sinuate and roundly truncate in front. Terminal
abdominal segment varying in width, either equally as long as wide or mani-
festly longer than wide. Uropoda much shorter than caudal segment; inner
branch scarcely much longer and much wider than outer branch.

Anilocra laticauda Milne Edwards

a'. Head rounded as a circle in front. Terminal abdominal segment wider than
long. Uropoda manifestly longer than terminal segment; inner branch much
shorter and scarcely wider than outer branch.

Anilocra plebeia Schioedte and Meinert

«The above description is from a dried specimen, the type, in the collection of the
Philadelphia Academy. Say's description is as follows:

Body oblong-oval; head broader than long; tail dilated, lanceolate, carinate, equal
to the six preceding segments conjunctly.

Inhabits —

Cabinet of the Academy.

Body, the transverse less than half of the longitudinal diameter; segments nar-
rower "before and rounded, acute behind; edge- not thickened; antennae not robust;
abdomen, segments suddenly narrower than the thoracic segments, subequal, the
posterior ones gradually narrower; terminal segment dilated, lanceolate, a transverse
impressed line at base, longitudinally carinated, carina obsolete toward the base,
inner terminal joint of the lateral appendices triangular, outer one linear somewhat
obliquely truncated at tip.

Length, three-fourths of an inch. Found cast on the beach of Cumberland Island,
Georgia.— Say, Journ. Acad. Nat. Sci. Phila., I, 1818, pp. 397-398.

&See Schicedte and Meinert for characters of genus, Nat. Tidsskr. (3), XIII,
1881-83, pp. 100-101.

ISOPODS OF NORTH AMERICA.

227

ANILOCRA LATICAUDA Milne Edwards.

Anilocra latira ut In MII.XK EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 259.

Anilocra mexieana SArssrRE, Rev. Mag. Zool., 1857, p. 505.

Anilocra leachii (KR0YER) SCHICEDTE, Natur. Tidsskrift (3), IV, 1866, p. 205, pi.
xi, figs. 2a-2g.

Anilocra laticauda SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIII,
1881-83, pp. 126-131, pi. ix, figs. 1-3. — RICHARDSON, American Naturalist,
XXXIV, 1900, p. 221; Proc. U. S. Nat. Mus., XXIII, 1901, p. 528.—
MOORE, Report U. S. Commissioner of Fish and Fisheries, XX, Pt. 2, 1902,
p. 172, pi. x, figs. 3-4.

Localities. — From Maryland to the Straits of Magellan; Maryland;
Key West; St. Anna, Mexico; Cozumel, Yucatan; Habana, Cuba; St.
Thomas; St. Croix; St. Bartolomew; Rio de Janeiro, Brazil; Sandy
Point, in Straits of Magellan; Porlamar, Margarita Island, Venezuela;
Arroyo and Vieques, Porto Rico.

Parasite of JIsBm/ul&n plumieri; also of Upeneus martinicus.

FIG. 230. — ANILOCRA LATICAUDA (AFTER SCHICEDTE AND MEINERT). a, YOUNG OF THE SECOND STAGE.
6, ADULT FEMALE, c, YOUNG OF THE FIRST STAGE. (ALL ENLARGED.)

Body oblong-ovate, nearly two and 'a half times longer than wide,
14 rnm. : 34 mm. Bod}^ widest at the fifth thoracic segment.

Head wider at the base than long, 3 mm. : 5 mm. , somewhat triangular
in shape, becoming gradually narrower toward the anterior extrem-
ity, which is produced to a narrow, pointed apex, bending downward
over the antennas, separating the basal articles, and extending on the
ventral side to the mouth parts. From a dorsal view the anterior
margin is 2 mm. wide and is truncate. The eyes are large, oval, twice
as long as wide, composite, and situated in the post-lateral angles of
the head. The head is not at all set in the first thoracic segment.
The first pair of antennae are composed of eight articles, and extend
to the end of the fifth article of the second pair of antennas. The
basal articles are not contiguous, but are separated by a distance of
i mm., the width of the frontal process at this point. The second

228

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

pair of antennae are composed of ten articles and extend beyond the
middle of the first thoracic segment. The maxillipeds have a palp of
two articles. The palp of the mandibles is composed of three articles.
The first and fourth segments of the thorax are subequal and each is
3 mm. in length; the second and third are subequal and each is 2 mm.
long; the fifth and sixth are each 4 mm. in length; the seventh is 2£
mm. long. The epimera are distinctly separated on the 'last six seg-
ments. Those of the second and third segments extend the full length
of the lateral margin; those of the fourth and seventh segments extend

one-half of the lateral
margin; those of the fifth
and sixth extend one-
third of the lateral mar-
gin. The first two are
rounded posteriorly; the
last four have the outer
post-lateral angles
acutely produced.

The first segment of
the abdomen is as wide as
the seventh thoracic seg-
ment. The abdomen is
not set in the thorax and
all the segments are dis-
tinct. The second, third,
fourth, and fifth segments
become gradually some-
what narrower. The
sixth or terminal seg-
ment is not wider at the
base than the fifth seg-
ment; it is widely rounded
posteriorly, and is as long
as wide, 7 mm. :7 mm.
The uropoda are as long as the terminal abdominal segment, are of
equal length and width, and are rounded posteriorly.

All the legs are prehensile with long, narrow, curved dact37li,
those of the second and third pairs being much longer than the others.
The last pair of legs are longer than any of the others. There is a very
low carina on the basis of the last four pairs of legs/*

a See Schioedte and Meinert for complete description of this form, the adult female,
the young of the first stage, and the young of the second stage, Nat. Tidsskr. (3),
XIII, 1881-1883, pp. 126-131.

FIG. 231.— ANILOCRA LATICAUDA. a, MAXILMPED. x 27|. 6,
SEVENTH LEG. x 27|. c, FIRST MAXILLA, x 27y. d, MAN-
DIBLE, x 27|. e, SECOND MAXILLA, x 27|.

ISOPODS OF NOETH AMEEICA. 229

ANILOCRA PLEBIA Schicedte and Meinert.

AnUocra plebia SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIII,
1881-1883, pp. 145-146, pi. x, fig. 3.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 528.

Localities. — Shores of Costa Rica; Central America.

Body elliptical, two or three times longer than wide (9:4). Head
moderately large, subtriangular, one-third as wide as the fourth
thoracic .segment, much wider than long, very slightly immersed, the
front rounded in a circle.

Eyes small, suboval, tumid, separated by a distance of more than
half the width of the head.

The first pair of antennae are straight, rather compressed, and
extend with the two last articles to thie anterior angle of the first
thoracic segment and to the sixth article of the
second pair of antenna; they are composed of eight
articles.

The second pair of antennae are rather com-
pressed, are a little narrower than the first pair
of antennae, and do not reach the posterior angle
of the first thoracic segment; they are composed of
nine articles.

The anterior margin of the first thoracic seg-
ment is manifestly trisinuated, the lateral sinuses
being scarcely deeper than the median sinus.

, • . FIG. 232.— ANILOCRA

Ihe posterior angles of the first six segments of PLEBIA (AFTER SCHI-
the thorax are scarcely or not at all produced, <**"* AND MEINERT).

. ' YOUNG FEMALE. (EN-

bemg rounded or obtuse. Ihe posterior angles of LARGED.)

the seventh segment are a little more produced and

rounded. The angles of the seventh segment do not reach by a small

distance the posterior angle of the first segment of the abdomen.

The epimera are projecting. The first three are rather wide or
rather narrow, decreasing gradually in width, with the posterior mar-
gin widely rounded. The three posterior ones are narrow, subequal
in width, with the posterior margin narrowly rounded. The epimera
of the first and second pairs extend almost to the posterior angle of
the segment; those of the third pair do not reach by a small distance
the posterior angle of the segment; the fourth, fifth, and sixth pairs
of epimera are subequal and do not reach by a large distance the pos-
terior angle of the segment.

The first six pairs of legs gradually increase a little in length; those
of the last parr are manifestly longer and a little more slender than the
others. The ungulse of the first pair are rather long and rather stout;
those of the second, third, fourth, and fifth pairs are long or ver}7 long,
rather stout, subequal in length; those of the sixth pair are long or

230 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

rather long and rather stout; those of the seventh pair are rather short
and slender.

The abdomen is covered at the base, is more than one and a half
times longer than wide (8:5), and is much shorter than the thorax with
the head (i:3). The first five segments gradually increase a little in
length. The sides of the first five segments are a little roundly dilated,
excavate, or emarginate; the first and second segments are obliquely
truncated; the third, fourth, and fifth segments are gradually more
deeply and more angularly emarginate.

The terminal segment of the abdomen is cordate, impressed at the
base, obscurel}7 carinated, much wider than long (6:5), manifestly
longer than the other segments of the abdomen taken together (10:9).
The uropoda are manifestly longer than the terminal abdominal seg-
ment (9:8); the inner branch is very much shorter and scarcely wider
than the exterior branch, becoming narrower back of the middle, sub-
laminar, scarcely surpassing the apex of the last segment; the exterior
branch is narrow, sickle-shaped.

Length 21.5 mm.

Color from graj7 to green, yellow on the terminal abdominal seg-
ment and the uropoda. a

36. Genus OLENCIRA Leach.

Bod}7 relaxed, rather stout, more or less distorted.

Head constricted at the base. First pair of antennae separated at
the base, rather compressed. Second pair of antenna? compressed.
Eyes manifest.

Anterior margin of the first thoracic segment manif estty trisinuated.
The posterior angles of the first six segments of the thorax not pro-

«The above description is adapted from the following one of Schioedte and
Meinert's:

Elliptica, bis vel ter longior quam latior (9:4).

Caput mediocre, subtriangulum, quam annulus quartus trunci ter angustius, multo
latius quam longius, levissime immersum, fronte in orbem rotundata. Oculi parvi,
subovalis, tumidi, plus quam dimidia parte latitudinis capitis distantes. Antennae
primi paris subrectse, compressiusculae; angulum priorem annuli primi trunci articu-
lis binis ultimis superantes, articulum sextum antennarum secundi paris explentes;
8-articulate.

Antennae secundi paris compressiusculae, quam antennae primi paris paulo angus-
tiores, angulum posticuru annuli primi trunci non attingentes; 9-articulatee.

Margo anticus annuli primi trunci manifesto trisinuatus, sinubus lateralibus quam
sinu medio vix profundioribus.

Anguli postici annulorum sex priorum trunci vix vel non prominuli, rotundati vel
obtusi; annuli septimi paulum prominuli, rotundati. Anguli annuli septimi angulum
posticum annuli primi caudalis spatio parvo non attingentes.

Epimera subpendula; terna priora latiuscula vel angustiuscula, per paria sensim
latitudine decrescentia, margine postico late rotundato; terna posteriora angusta,
latitudine subaequalia, margine postico breviter rotundato. Epimera paris primi et
secundi angulum annuli fere explentia; paris tertii angulum annuli spatio parvo non

I80PODS OF NORTH AMERICA. 231

duced; those of the seventh segment produced. The epimera almost
reach the posterior angles of the segments.

Terminal segment of abdomen subtriangular or subcordate. Urop-
oda much shorter than the terminal abdominal segment; inner branch
scarcely shorter than the outer branch. Legs long; the first six pairs
gradually increasing!}" longer; those of the seventh pair abruptly very
much longer than the others. The basis of the four posterior pairs
furnished with a carina. Ungulre long, those of the first pair mani-
festly shorter than the others; those of the seventh pair manifestly
longer than the others.05

OLENCIRA PRiEGUSTATOR (Latrobe).

Oniscus prifgustalor LATROBE, Trans. Amer. Philos. Soc., V, 1802, p. 77, pi. i.
Cymothoa pnvymlator SAY, Jour. Acad. Nat. Sci. Phila. , I, 1818, pp. 395-396.
Olencira lamarkii LEACH, Diet. Sci. Nat., XII, 1818, p. 351. — DESMAREST, Consid.

Gen. Crust, 1825, p. 307.— MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840,

p. 264.
Olencira prtegustator SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIII,

1881-1883, pp. 152-154, pi. x, figs. 6-9. — RICHARDSON, American Naturalist,

XXXIV, 1900, p. 221; Proc. U. S. Nat. Mus., XXIII, 1901, pp. 528-529.

Localities. — Potomac River; York Spit, Virginia; Dividing Cove;
St. George's Island, Maryland; Fort Monroe, Head of Cockrell Creek,
Hampton Creek, Lower Chesapeake Bay; Cape Charles, Virginia; off
Great Wicomico; Pensacola and St. Mary's River, Florida; Mobile,
Alabama; Winyah Bay, South Carolina (mouths of menhaden); Zoo-
logical Park, Washington City (on bug-fish); Crisfield, Maryland;
Florida; Georgetown, District of Columbia.

Parasite of Brevoortia patronus; Brevoortia tyrannm; bug-fish.

attingentia; paris quarti, quinti, sexti angulum annuli spatio. rnagno, subsequali, non
attingentia. Pedes parium sex priorum per paria sensim longitudine paulum cres-
centes; paris ultimi ceteris manifesto longiores et paulo tenuiores. Ungulse paris
primi longiuscula?, crassiusculse; paris secundi, tertii, quarti, quinti longse vel per-
longse, crassiusculre, longitudine subsequales; paris sexti longae vel longiusculse;
crassiuscuhe; paris septimi breviusculee, subtenues.

Cauda ad basin obtecta, longior quam latior plus sesqui (8:5), quam truncus cum
capite multo brevior (4:3). Annuli quinque priores sensim longitudine paulum
crescentes. Latera annulorum quinque priorum paulum rotundate dilatata, excavata,
vix marginata; annuli primi et secundi oblique truncata; annuli tertii, quarti, quinti
per paria sensim profundius atque magis angulate emarginata.

Annulus analis cordatus, ad basin impressus, obscure carinatus, multo latior quam
longior (6:5), ceteris annulis caudalibus conjunctis manifesto longior (10:9). Pedes
anales annulo anali manifesto longiores (9:8); ramus interior quam exterior valde
brevior et vix latior, pone medium angustatus, sublaminatus, apicem annuli vix
superans; ramus exterior angustatus, subfalcatus.

Long. 21, 5 mm.

Color ex griseo olivaceus, annulo anali cum pedibus analibus flavicans. — SCHKEDTE
AND MEINERT, Nat. Tidsskr. (3), XIII, 1881-83, pp. 145-146.

«See Schioedte and Meinert for characters of genus, Nat. Tidsskr. (3), XIII,
1881-83, pp. 150-151.

232 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Body narrow, elongate, gradually increasing in width to the seventh
thoracic segment, 6£ mm. wide, 26 mm. long.

a Head as wide at the base as it is long —

3mm. : 3 mm. — gradually becoming more
and more narrow to the anterior extrem-
ity, which is widely rounded. The ante-
rior extremity is half as wide as the base,
being 1£ mm. in width. The eyes are
large, oblong, twice as long as wide,
composite, and situated in the posterior
half of the head at the post-lateral
angles. The first pair of antennae are
composed of eight articles, and extend to
the seventh article of the second pair of
antennae. The basal articles of the first
antennae are not adjacent, but are sep-
arated by a distance of 1 mm. The sec-
ond pair of antennae are composed of ten
articles and extend to the posterior margin
of the head. The maxillipeds have a palp
of two articles. The palp of the mandi-
bles is composed of three articles.

The first and fourth segments of the
thorax are longest and are subequal,
each being 2£ mm. in length; the second
and third are subequal and each is 2 mm. long; the fifth and sixth are
subequal and each is 1£ mm. long; the a

seventh segment is the shortest and is 1
mm. in length. The epimera are distinct!}7
separated on all the segments, with the ex-
ception of the first; they are narrow, elon-
gate plates, which do not reach the pos-
terior margins of the segments, except
the seventh pair.

The abdomen is abruptly narrower
than the thorax. The first segment is
deeply set in the thorax and is covered
at the sides by the seventh thoracic
segment. The segments increase very
little in width. The sixth or terminal
segment is a little longer than wide,
5 mm.: 6 mm.; it is triangularly pro-
duced to a narrowly rounded apex.

All the legs are prehensile, with long, narrow curved dactyl i. They
increase slightty in length to the seventh pair, which are abruptly very

FIG. 233. — OLENCIKA PR.EGUSTATOR
(AFTER SCHICEDTE AND MEINERT).
a, HEAD OF FEMALE SHOWING AX-

TENNA.E AND MOl'TH PARTS, b, HEAD
OF MALE SHOWIXG SAME. (EN-
LARGED.)

FIG. 234. — OLENCIRA PR.EGUSTATOB
(AFTER SCHICEDTE AND MEIXERT).
a, ADULT FEMALE. 6, LATERAL VIEW.

(EXLARGED.)

ISOPODS OF KOfiTH AMEEICA.

233

much larger and longer than the sixth pair, being extremely long.
The last three pairs have the basis furnished with a low carina.

FIG. 235.— OLENCIRA PK^GUSTATOR. a, MANDIBLE, x 27}. b, MANDIBLE WITHOUT PALP, x 51}.
c, MAXILLIPED. x 27}. d, SECOND MAXILLA, x 27}. e, FIRST MAXILLA, x 27}.

37. Genus CERATOTHOA Dana.«

Body oblong.

Head but little immersed or set in the first thoracic segment. Eyes
small. The first pair of antennae are dilated, contiguous at the base.
The second pair of antennas are compressed.

Anterior margin of the first segment of the thorax rounded. Epim-
era of the first thoracic segment in the female with a carina produced
in the form of a spoon or a tubercle and directed anteriorly. The
anterior epimera do not reach by a great but gradually decreasing
distance the posterior angle of the segment. The posterior epimera
almost reach or extend a little beyond' the posterior angles of the
segments.

The abdomen is deeply immersed or set in the thorax. Terminal
segment transverse. The legs are rather long, with the exception of
the first and second pairs. The ungulse are long and strongly curved,
those of the third pair in the female being the longest of all, and

°See Schicedte and Meinert for characters of genus, Nat. Tidsskr. (3), XIII,
1881-83, pp. 299-300.

234 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

abruptly longer than those of the second pair. There is a high carina
on the basis of the four posterior pairs of legs.
The male is smaller than the female.

CERATOTHOA IMPRESSA (Say).

Cymothoa impressa SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 397.

Ceratolhoa linearis DANA, U. S. Expl. Exp. Crust., XIV, 1853, p. 752, pi. L, fijjp.

la-Id.
Ceratothoa exocasti CUNNINGHAM, Trans. Linn. Soc. London, XXVII, 1869-71, p.

499, pi. LIX, fig. 5.
Glossobius linearis SCHICEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIII,

1881-83, pp. 301-308, pi. xn, figs. 1-2.
Ceratothoa linearis STEBBING, Hist, of Crust., 1893, p. 354. — RICHARDSON, Aim-r-

ican Naturalist, XXXIV, 1900, p. 221; Proc. U. S. Nat. Mus., XXIII, 1901,

p. 529.

Localities.— From latitude 42° to 21° north; latitude 8° to 10° north,
longitude 40° to 50° west; latitude 34° north, longitude 51° west; Rio
a j de Janeiro, Brazil; in the

Gulf Stream everywhere;
Cape May, New Jersey
(Say).

Having had an oppor-
tunity to examine Say's
type specimen of Cymo-
thoa impressa, deposited
in the Philadelphia Acad-
emy of Natural Sciences,
its identity with Cerato-
thoa linearis Dana is
found to be unquestion-
able. The earlier name
will therefore have to be adopted for this specie.-.

Parasite of flying-tish, Exocatua sp. ; e. g., £keoccetu» exiliens, Ex,
lamelliferus, Ex. brachyeephalus (Schioedte and Meinert); on Cory-
phsena sp.

Body elongate, a little more than three times longer than wide, 10
mm. : 33 mm.

Head a little wider than long, 3 mm. :4 mm., not deeply set in the
thorax, with the front excavate on either side of a broad and elongate
median process, 1 mm. in length and 1 mm. in width, the apex of which
is obtusely pointed. The antenna lit in these excavations. The antero-
lateral angles of the head are acutely pointed. The eyes are small,
about twice as wide as long, and somewhat obliquely placed at the
sides of the head, about halfway between the antero-lateral and post-
lateral angles. The first pair of antennae are composed of seven arti-
cles, the basal articles in each antenna being adjacent on the ventral
side. The first antennae extend just below the eyes. The second pair

FIG. 236. — CERATOTHOA IMPRESSA (AFTER SCHICEDTK AXI>
MEINERT). a, ADULT FEMALE. 1>, LATERAL VIEW OF THO-
RAX, c, LATERAL VIEW OF THORAX OF MALE, d, ADVLT

MALE. (ENLARGED.)

ISOPODS OF NORTH AMERICA.

235

of antennae are composed of eleven articles, the last three being very
minute. The articles of both pairs of antennae are greatly dilated and
flattened. The second antennae extend to the posterior margin of the
head. The maxillipeds have a palp of two articles. The palp of the

FIG. 237. — CERATOTHOA IMPRESSA. a, MAXILLIPED OF FEMALE. , x 27s-. 6, SECOND MAXILLA, x 27£.
c, FIRST MAXILLA, x 51|. d, PALP OF MANDIBLE, x 27j.

mandibles is very large and conspicuous and is composed of three
articles. The second or posterior maxillaa are very large and con-
spicuous, are bilobed at the tip, both lobes being furnished with small
hooks.

The first four segments of the thorax are large and about equal in
length; the fifth segment is half as long as any of the four preceding
segments; the sixth and seventh segments are very short in the
median dorsal line and each is about one-half as long as the fifth
segment. The first thoracic segment has the antero-lateral expansion

FIG. 238. — CERATOTHOA IMPRESSA <, AFTER SCHKEDTE AND MEINERT). a, YOUNG OF THE SECOND
STAGE, b, YOUNG OF THE THIRD STAGE, c, YOUNG OF THE FIRST STAGE. (ENLARGED.)

produced in a carinated process, produced outward and forward and
terminating acutety a little anterior to the antero-lateral expansion of
the segment. The epimera are distinctly separated on all the follow-
ing six segments. In the second segment they are directed forward

236 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 239.— CER ATOTHOA
IMPRESSA. SEVENTH

LEG. X 4J.

deeply excavate.

FIG. 240. — CERATOTHOA IM-
PRESSA (AFTER SCHICEDTE
AND MEINERT). a, UNGULA

OF FIRST PAIR OF LEGS OF
YOUNG OF SECOND STAGE, ft,
T'NGULA OF SIXTH PAIR OF
LEGS OF YOUNG OF SECOND
STAGE. (ENLARGED.)

and project in an anteriorly acute process. In the third, fourth, and
fifth segments the epimera are narrow, elongated plates, occupying
the anterior half of the segments. In the last two segments they are
also narrow and elongate, and occupy nearly the entire length of the
segment.

The abdomen is abruptly narrower than the thorax, the first seg-
ment being much narrower and deeply set in the thorax. The four

following segments are as

wide us the seventh thoracic

segment, and gradually in-
crease in width to the sixth

segment, which is very wide.

The terminal segment is nearly

twice as wide as long; it is 10

mm. wide, 4 mm. long in the

median longitudinal line, and

6 mm. long in the lateral por-
tions. The post-lateral angles

of this segment are rounded,

the posterior margin being

The uropoda are as long as the terminal segment,
are equal in width, and are rounded at the extremities. The outer
branch is very slightly shorter than the inner branch.

All the legs are prehensile, with long, narrow curved dactj'li, those
of the fourth pair being the longest. There is a high carina on the
basis of the last four pairs of legs, the height of the carina increasing
from the fourth to the seventh pair, where it is extremely high/'

38. Genus MEINERTIA Stebbing.&

Body oblong.

Head more or less deeply immersed or set in the first thoracic
segment. Eyes distinct. First pair of antennae dilated, contiguous
at the base. Second pair of antennas compressed.

First thoracic segment with the anterior margin widety sinuated or
almost straight. Anterior epimera do not reach by a great but gradu-
ally decreasing distance the posterior angle of the segments. The
posterior epimera almost reach or sometimes extend a little beyond
the posterior angles of the segments.

Terminal segment of abdomen triangular, semicircular, often bilobed.

«For description of the male and the female and the young of the fir^t, second,
and third stages, see Schioedte and Meinert, Nat. Tidsskr. (3), XIII, 1881-83, pp.
301-308.

& See Schioedte and Meinert for characters of genus, Nat. Tidsskr. (3), XIII
1881-83, pp. 322-323.

ISOPODS OF NORTH AMERICA. 237

The first three pairs of legs are more or less manifestly shorter than
the others. Ungulae subequal.

Male is much smaller in size than female.

ANALYTICAL KEY TO THE SPECIES OP THE GENUS MEINERTIA.

a. First pair of antenna? short, extending to the eye or to the posterior margin of the
head. Second pair of antennae short, extending to the posterior margin of the
head, and composed of only eight or nine articles. Head more or less deeply
set in first thoracic segment.

b. High carina present on the basis of the last four pairs of legs. Uropoda extend
beyond the terminal abdominal segment. Eyes small. Last segment of
abdomen about twice as wide as long.

c. Body convex. Terminal abdominal segment trapezoidal and rugose dorsally.

Meinertia gaudichaudii (Milne Edwards)
(/. Body flattened from fourth segment to end of abdomen. Terminal segment

semicircular and smooth dorsally Meinertia deplanata ( Bovallius)

V . No carina developed on the basis of the legs. Uropoda extend only a little
beyond half the length of the abdomen. Eyes large. Last segment of abdo-
men nearly three times as w7ide as long Meinertia gilberti Richardson

a'. First pair of antennae long, extending to the middle of the first thoracic segment.
Second pair of antennae long, extending to the posterior margin of the first
thoracic segment, and composed of fourteen articles. Head but little immersed
in first thoracic segment Meinertia transversa Richardson

MEINERTIA GAUDICHAUDII (Milne Edwards).

Cymothoa gaudichaudii MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 271,

Ceratothoa rapax HELLER, Reise Novara, Crust., 1865, p. 146, fig. 17.

Ceratothoa gaudichaudii SCHIOZDTE and MEINEKT, Naturhistorisk Tidsskrift (3),

XIII, 1881-83, pp. 335-340, pi. xin, figs. 11-15.
Meinertia gaudichaudii STEBBING, Hist, of Crust., 1893, p. 345. — RICHARDSON,

Proc. U. S. Nat. Mus., XXI, 1899, p. 829; Ann. Mag. Nat. Hist. (7), IV,

1899, p. 171; Proc. Wash. Acad. Sci., Ill, 1901, p. 568.— STEBBING, Willey's

Zool. Results, 1902, p. 643.

Localities. — Mazatlan; Pacific Ocean following the shores of Central
America; Coquimbo; shores of Chili; Callao; Peruvian shores; Chin-
chenses Islands; Black Bight, Albemarle Island, Galapagos Islands;
200 miles north of Wenman Island, Galapagos Islands; Panaieti,
Louisiade Archipelago, New Guinea.

Found in the mouth of Thunnus sp.

Body elongate, nearly three times as long as broad; 16 mm. : 45 mm.

Head nearly twice as wide as long (4 mm.: 7 mm.) somewhat tri-
angular in shape, with apex obtuse. The head is deeply set in the
first thoracic segment, the narrow and acute antero-lateral angles of
which extend half the length of the head. Ej^es small, distinct, irreg-
ular in outline, but inclined to be square, and placed at the sides of
the head, a little below the middle.

The first pair of antennas are composed of seven articles, the two
first ones being almost fused; they extend just below the eye. The
second pair of antennae are composed of nine articles and extend to

238

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the posterior margin of the head. The basal articles of the first pair
of antennae are adjacent on the ventral side. The articles of both
pairs of antenme are greatly dilated and flattened. The maxillipeds
have a palp of two articles. The palp of the mandibles is composed

FIG. 241.— MEINERTIA GAUDICHAUDII (AFTER SCHKEDTE AND MEINERT). a, ADULT FEMALE. 6, ADULT
FEMALE, c, LATERAL VIEW OF THORAX. (ENLARGED.)

of three articles, the terminal one being very slender and minute.
The second maxillae terminate in two lobes furnished with small hooks.
The first segment of the thorax is longer than any of the others,
being 6 mm. in length; the second and fifth segments are subequal,
each being 4 mm. long; the third and fourth are each 5 mm. in length;

FIG. 242. — MEINERTIA GAUDICHAUDII. a, MAXILLIPED OF MALE, x 20£. 6, MAXILLIPED OF FEMALE.
x 20£. c, FIRST MAXILLA, x 39.

the sixth segment is 3 mm. long; the seventh is 2 mm. long. The
antero-lateral angles of the first segment are narrow and acute and
are produced forward to about the middle of the head. The epimera
are distinctly separated on all the six following segments. They are
narrow, elongated plates, not extending quite to the posterior margins
of the segments.

I8OPODS OF NORTH AMERICA.

239

The abdomen is deeply set in the thorax. The first segment has
the sides covered by the last thoracic segment. The four following

FIG. 243. — MEINEHTIA GAUDICHAVDII (AFTER SCHICEDTE AND MEINERT). a, YOUNG OF FIRST STAGE.
6, SECOND LEG OF ADULT MALE, c, LATERAL VIEW OF THORAX OF ADULT MALE, d, ADULT MALE.

(ENLARGED.)

segments are as wide as the seventh thoracic segment or wider. The
sixth or terminal segment is trapezoidal, almost twice as wide as

FIG. 244. — MEINERTIA GAUDICHAUDII. a, SECOND MAXILLA.

C, LEG OF SEVENTH PAIR.

b, PALP OF MANDIBLE, x 33.

long, 7 mm : 13 mm. The post-lateral angles are rounded and the
posterior margin straight. The uropoda are a little longer than the
terminal abdominal segment. The inner branch is slightly longer
than the outer branch. Both are
narrow, elongate, and produced
to acute and tapering extremities.
The legs are all prehensile, and
terminate in short, stout dactyli.
There is a high carina on the
basis of the last four pairs of legs,

thp farina inprpjmino- in hpicrht FlG' 245--MEIXERT1A «AUDICHAUDII (AFTER

Teasing 1 teigm SCHKEDTE AND MEINERT). a, SECOND LEG OF

from the fourth to the seventh ADULT FEMALE. 6, SEVENTH LEG OF ADULT FE-

i ... i i • i „ MALE. (ENLARGED.)

pair, where it is extremely high/'

a For description of male, female, and young of the first stage, see Schioedte and
Meinert, Nat. Tidsskr., (3), XIII, 1881-1883, pp. 335-340.

240 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

MEINERTIA DEPLANATA (Bovallius).

Ceratothoa deplanata BOVALLIUS, Bihang till K. Sv. Vet.-Akad. Handl., X, No.
11, 1885, pp. 20-22.

Locality. — Coast of Haiti, West Indies.

"The form of the body is elongate, the anterior and posterior ends
are only a little narrower than the middle, the anterior part is not
very convex; from the fourth segment of the pereion to the end of
the urus the body is quite flattened. The surface is smooth, without
spots.

"The head is broad, triangular, with broadly rounded front, the
sides rounded, not emarginate. The upper side is smooth, convex.
The eyes are mediocre, rhomboidal, surrounded by dark diffuse spots.

FIG. 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 ANTENNA.

(ENLARGED.)

"The first pair of antennae are nearly as long as the second, thick,
not compressed, seven-jointed; they reach quite to the anterior mar-
gin of the first pereional segment. The first joint is the longest; it is
as long as the two following together. The three last ones are small,
tapering.

"The second pair of antennae are but a little more slender than the
first pair, eight- jointed; the first joint the longest; the four last ones
small, tapering; the last very minute.

"The pereion is smooth, the sides feebly rounded. The processes
of the first segment are very broad, short, bent downward; the first
segment is shorter than the fifth, but as long as the second. The sixth

ISOPODS OF NORTH AMERICA. 241

and seventh segments together are shorter than the second segment.
The hinder corners of the two first segments are nearly rectangular;
those of the third and fourth truncated; those of the last three
rounded.

"The epimerals of the second and third segments are broader at the
posterior end, bent downward at the anterior. That of the second
segment occupies the whole side of the segment; those of the third
and fourth segments scarcely more than two-thirds of it; those of the
fifth and sixth segments fully three-fourths of it, and the last one the
T7hole of the segment. The epimerals of the fourth, fifth, and sixth
segments are broader at the anterior margin, narrower behind. The
last one is oblong, with rounded ends.

"The first pair of pereiopoda have the tibia broadly extended, the
dactylus she rt. The two following pairs are subequal, with the femora
much longer than broad. The following four pairs have much broader
femora and strongly developed carinte. In the seventh pair the femur
is as broad as long, the hinder margin is straight.

"The pleon is as broad at the base as long, the first segment longer
than the second, but narrower than half of the fifth (2 : 5). The three
last pleonal segments are broader than the urus (10 : 9) and a little
narrower than the fifth (or fourth) segment of the pereion (10 : 11).
The whole pleon equals the fifth pereional segment in length.

" The urus is broad, nearly semicircular, not quite twice as broad as
long (9:5); the upper side is perfectly plain and smooth.

"The pleon and urus together are about a third of the length of the
pereion with the head (18 : 51).

" The uropoda reach a little beyond the posterior margin of the urus.
The peduncles are long and stout, nearly as long as the inner ramus
(14:17). The inner ramus reaches a little be}Tond the outer. It is
oblong-lanceolate. The exterior one is falciform.

"Color, bright yellow.

"Length, 18 mm." — BOVALLIUS."

MEINERTIA GILBERTI Richardson.
Meinertia gilberti RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 53.

Locality. — Mazatlan.

Parasite of Mugil hospes.

Head set in first segment of thorax, the antero-lateral prolongations
of which extend forward to about the middle of the eye. Shape of the
head some what triangular; posterior margin straight; anterior margin
produced somewhat at the middle, but quite rounded. Eyes very
large, far apart, and situated at the sides of the head. First pair of
antennse consist of seven joints and extend to the middle of the eye;

«Bihang till K. Sv. Vet.-Akad. Handl., X, No. 11, 1885, pp. 21-22.
28589—05 16

242 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 247.— MEINERTIA GILBERTI. a, SECOND MAXILLA.
x 27}. b, FIRST MAXILLA, x 27}. c, MAXILLIPED.
x 15}.

second pair consist of eight joints and reach the posterior margin of
the head.

The first four segments of the thorax are about equal in length, the
second being somewhat shorter. The last three segments decrease

gradually in length. The
epimera are narrow pieces
at the sides of the segments;
in the first five segments
they do not reach the pos-
terior margin of the seg-
ments, although the fifth
pair more nearly reach the
posterior margin than the
others; the epimera of the
last two segments reach
quite to the posterior
margin.

The first segment of the
abdomen is as wide as the last thoracic segment. The others are wrider,
increasing in width gradually to the terminal segment. The last seg-
ment is about three times as broad as long, and quadrangular in shape.
The uropoda are short, reaching only a little beyond half the length
of the abdomen; both branches are alike and of equal
length.

The legs all terminate in long recurved unguli.
There is no high carina developed on the basis of
any of the legs.

Color reddish brown.

Three specimens, two males and one female, were
collected by Prof. C. H. Gilbert at Mazatlan. They
were found in the mouth of Mug! I
hospes.

Type.— Cat. No. 29080,
U.S.N.M.

This species differs chiefly from
M. gaudichaudiH^\\\nQ Edwards)"
from near locality, in the absence
of high carinse, which in M.
gaudichaudii are strongly devel-
oped on the last four pairs of legs; in the much shorter uropoda,
which in M. gaudichaudii extend beyond the terminal segment, both
branches of which are narrowly pointed at their extremities; in the
much larger eyes, and in the smaller size of the species, the adult female
being only half the size of the adult female of M. gaudichaudii.

aNaturhistorisk Tidsskrift, XIV, 1883-84, pp. 335-340, pi. xm, figs. 11-15.

FIG. 248.— MEINERTIA
GILBERTI. LEG OF
SEVENTH PAIR. X 7.

FIG. 249.— MEINERTIA
GILBERTI, X 2|.

ISOPODS OF NOETH AMERICA.

243

FIG. 250.— M EINERTIA

TRANSVERSA. HEAD.

MEINERTIA TRANSVERSA Richardson.

Meinertia transversa RICHARDSON, American Naturalist, XXXIV, 1900, p. 221;
Proc. U. S. Nat. Mus., XXIII, 1901, pp. 529-530.

Locality. — Between the delta of the Mississippi and Cedar Keys,

Florida.

Head very little immersed in first thoracic segment, large, subtrian-

gular, anterior margin pointed with sides slightly sinuate. Eyes

situated at extreme post-lateral margins, almost

obscure. First pair of antennae, with joints

dilated, issuing close together, eight articulate.

Second pair of antennae slender, extending a

little beyond posterior margin of first thoracic

segment; fourteen jointed.
Thoracic segments subequal in length.
Abdomen not at all immersed. All the seg-
ments visible and equal in width and length. Terminal segment sub-
triangular with apex
round, impressed at
the base, equal in
length to the first five
segments taken to-
gether. Uropoda a
little longer than
apex of terminal seg-
ment, branches simi-
lar in shape, oar-like,
and of equal length.
Legs increasing in
length from first to
seventh pair.

FIG. 261. — MEINERTIA TRANSVERSA. a, MAXILLIPED. x 20£. b,
SECOND MAXILLA, x 39. c, FIRST MAXILLA, x 39. d, SEVENTH
LEG. x 11*.

Color yellowish brown.

One specimen from between the delta of the Miss-
issippi and Cedar Keys, Florida, collected by the
U. S. Bureau of Fisheries' steamer Albatross.

Type.— Cut. No. 9728, U.S.N.M.

39. Genus AGARNA Schioedte and Meinert.

Body compressed from side to side and hunched,
very asymmetrical. One side of the posterior seg-
ments of the thorax flattened and dilated.

Head deeply immersed. First pair of antenna separated but little
at the base, almost contiguous, rather compressed.

Anterior margin of the first thoracic segment very deeply sinuated;
antero-lateral angles scarcely produced, rounded. Epimera present

FIG. 252.— MEINERTIA
TRANSVERSA. AB-
DOMEN.

244 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

on all the segments of the thorax with the exception of the first and
the seventh. There are two pairs of epimera on the fourth thoracic
segment and two pairs of legs are attached to this segment. The
seventh segment has no appendages.

Abdomen continuous with thorax, not narrower than thorax; deeply
immersed. Carina on the four posterior pairs of legs moderately
high.

AGARNA CARINATA Schicedte and Meinert.

Agarna carinata, SCHKEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIV,
1883-84, pp. 329-334,- pi. xm, figs. 1-3.— RICHARDSON, Proc. U. S. Nat.
Mus., XXIII, 1901, p. 531.

Localities. — St. Croix Island, West Indies; Key West, Florida.

Found on Teuthis chirurgus.

Body very asymmetrical, with the last four thoracic segments on

one side abruptly ver}^
much wider than the first
three. Body twisted to
one side, which is shorter
than the other side, twice
as long as its width above
the fourth thoracic seg-
ment, 9 mm. : 18 mm.
At the fourth and fifth
thoracic segments it is 11
mm. wide. The body is
also very much hunched,
rising very high, until
at the third and fourth
/ segment it is 7 mm. high.
The head is wider than
long, "2 mm.: 3 mm.,
somewhat rectangular,
with the anterior margin
widely rounded. The

FIG. 253. — AGAENA CARINATA (AFTER SCHICEDTE AND MEIN- eyes are Small 1'OUnd
EKT). a, LATERAL VIEW OF ADULT FEMALE (LEFT SIDE), b,

YOUNG OF THE FIRST STAGE. C, LATERAL VIEW OF ADULT COHlpOSlte and

FEMALE (RIGHT SIDE), d, ADULT MALE, e, ADULT FEMALE. /, in the post-lateral
LATERAL VIEW OF THORAX OF ADULT MALE. (ALL ENLARGED.)

of the head. The first

pair of antennae are composed of seven articles. The basal articles are
almost contiguous. The second pair of antennae are composed of "ten"
articles. The head is deeply set in the first thoracic segment, the
antero-lateral angles of which extend to the anterior margin of the
head. The maxilliped has a palp of two articles. The palp of the
mandibles is composed of three articles.
The first, second, and third thoracic segments are equal in length,

ISOPODS OF NORTH AMERICA.

245

each being 2 mm. long. The fourth and fifth are subequal, each being
1 mm. in length. The sixth and seventh are each only i mm. long.
The epimera are not distinctly separated on the first segment. The
following five segments have distinct epimera. There are none on the
seventh segment, and there are no appendages to this segment. There
are two pairs of legs attached to the fourth segment, two legs on
either side, and two pairs of epimera. The epimera of the second and
third segments are narrow plates, extending the full length of the
lateral margin on the shortened side of the body, the epimera of the
third segment on the longer side not extending quite to the post-lateral
angle. The fourth segment has two pairs of epimera, an anterior and
a posterior pair; the two are equal in size on the short side, the ante-
rior one on the long side of the body being small, the posterior one
being transversely elongated, not laterally placed, but extending along
the posterior margin of the lateral expansion of the segment. The
epimera of the fifth and sixth segments, on the short side of the body,
occupy the post-lateral angles; those of the long side are transversely

FIG. 254.— AGABNA CARINATA. a, MAXILLIPED. x 29. b, SECOND MAXILLA, x 29. c, FIEST MAX-
ILLA, x 29. d, MANDIBLE, x 29. e, PALP OF MANDIBLE, x 29.

elongated, not laterally, but posteriorly placed on the lateral expan-
sions of the segments. There are no epimera on the seventh segment.

The abdomen is deeply set in the thorax, the seventh thoracic seg-
ment covering the lateral parts of the first two or three segments.
The first segment of the abdomen is as wide as the last thoracic seg-
ment; the following segments gradually increase in width, especially
on the shorter side of the body, so that the abdomen here becomes
wider than the thorax. The terminal segment is large, triangular in
shape, with apex rounded; it is 6 mm. long and 8 mm. wide at the
base. The uropoda are very short, extending less than one-third the
length of the abdomen. The outer branch is a little longer and wider
than the inner branch.

The legs are all prehensile, with short, stout, curved dactyli. The
ischium of the last four pairs is flattened and very much longer than
in the first three pairs. There is also a moderately high carina on the
basis of the last four pairs of legs.0

aFor complete description of this form, the male and female and the young of the
first stage, see Schicedte and Meinert, Nat. Tidsskr., (3) XIV, 1883-84, pp. 329-334.

246

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 255.— INDUSA CARINATA.
HEAD AND FIRST THORAC-
IC SEGMENT. X 5.

4O. Genus INDUSA" Schicedte and Meinert.

Body convex, anteriorly narrowed, or compressed from side to side.
Head but little immersed. First pair of antennae almost contiguous
at the base, slender, not dilated.

Anterior margin of the first thoracic segment widely sinuated, the
antero-lateral angles but little produced, rounded.

Abdomen but little immersed.

INDUSA CARINATA'' Richardson.
Indusa carinata RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 52.

Locality. — West coast of Panama.
Parasite of Mugil hospes.

Body very convex, being highly and roundly elevated. Thorax
large, rounded, almost as wide as long, the last two segments rapidly

converging to the narrow

abdomen. Abdomen nearly

three times narrower than

greatest width of thorax,

with all the segments of

equal width.

Head about two and a half

times narrower than first

thoraic segment and four times narrower than
fourth segment; front triangular in shape and pro-
duced into an acute point projecting between the
basal joints of the antennae. £3^68 distinct and
situated at the sides and about the middle of the head. First pair of
antennae, which are almost contiguous, being separated only by the
very acute median point, reach to the eyes; flagellum seven jointed.
Second pair of antennas extend to the posterior margin of the head;
flagellum nine jointed.

First thoracic segment rounded anteriorly and posteriorly, the sides
of the segment surrounding the head, the lateral angles extending to
the e}7es. The first four segments gradually increase in width. The
fourth and fifth are about equally wide. The sixth and seventh
rapidly decrease in width, converging to the narrow abdomen. The
epimera are well developed on all the segments with the exception of
the first; the}T are narrow and elongate, rounded posteriorly and not
reaching the posterior margin of their respective segments.

The abdomen is likewise very convex and is nearly three times
narrower than the thorax at its greatest width. The segments are of

«Schicedte and Meinert, Naturhistorisk Tidsskrift (3), XIV, pp. 334-335.
&This species is included because the fish on which it is parasitic is found on the
coast of Mexico.

FIG. 256. — INDUSA CARIN-
ATA. x 2|.

ISOPODS OF NORTH AMERICA.

247

equal width. The terminal segment is rounded posteriorly or slightly
triangular. The uropoda are very short, less than half the length of
the terminal segment; the branches are equal in length.

FIG. 257. — INDUSA CARINATA. ft, SECOND MAXILLA.
X 39. b, FlKST MAXILLA. X 39. C, MAXILLIPED.

FIG. 258. — INDUSA
•X3ARINATA. LEG
OF SEVENTH PAIR.

X7.

There is a high carina on the four posterior pairs of legs, and a
small one on the three anterior pairs. Color reddish brown.

Two specimens, a male and a female, were collected by Prof. C. H.
Gilbert from the west coast of Panama. They were found in the
mouth of Mugil hospes.

7^.— Cat. No. 28961, U.S.N.M.

41. Genus CYMOTHOA Fabricius.

Body ovate. Head more or less deeply immersed.

First pair of antennte widely separated at the base, rather com-
pressed. First thoracic segment manifestly longer than the second; its
anterior margin more or less sinuated, with the anterior angles short
or produced. Epimera distinct on all the segments with the excep-
tion of the first; those of the first five pairs do not reach by a greater
or less distance the posterior angle of the segment; the posterior ones
reach the posterior angles of the segment or extend beyond by a small
distance.

The abdomen is deeply immersed, manifestly separated from the
thorax, and abruptly narrower than the thorax. The legs are rather
short, those of the first three pairs being a little shorter than the others.
Carina of the four posterior pairs of legs high.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CYMOTHOA.

a. Antero-lateral angles of the first thoracic segment extend half the length of the
head or less. Eyes distinct or only traces of eyes apparent. First segment of
thorax one and a half times longer than second segment. Uropoda short, shorter
than the terminal abdominal segment.

b. Antero-lateral angles of the first thoracic segment narrow,
c. Antero-lateral angles of the first thoracic segment acutely produced and reach-
ing the middle of head Cymothoa excim Perty

248 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

</. Antero-lateral angles of the first thoracic segment obtusely rounded, not reach-
ing the middle of the head ( 'ymothoa exiyua Schi<L>dte and Meinert

V. Antero-lateral angles of the first thoracic segment wide.

Cymothoa caraibica Bovallius

a/. Antero-lateral angles of the first thoracic segment very large and wide, half as
wide as the head, rounded and extending to the anterior margin of the head.
No traces of eyes present. First thoracic segment twice as long as second seg-
ment. Uropoda as long as the terminal abdominal segment. Outer branch
slightly shorter than inner branch Cymothoa oestrum (Linnaeus)

CYMOTHOA EXCISA Perty.

Ctfmothoa excisa PERTY, Del. Amin., 1830-34, p. 211.

Cymothoa parasita SAUSSURE, Revue Mag. Zool. (2), IX, 1857, p. 306; Mem. Soc.

Phys. Geneve, XIV, Pt. 2, 1858, p. 485, pi. v, fig. 44.
Cymothoa excisa SCHKEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIV,

1883-84, pp. 238-244, pi. vi, figs. 11-16. (See Schiccdte and Meinert for

above synonymy.) — RICHARDSON, American Naturalist, XXXIV, 1900, p.

221; Proc. IT* S. Nat. Mus,, XXIII, 1901, p. 530.

Localities. — Massachusetts; Florida Reefs; Charleston Harbor,
South Carolina; Bahamas; Biloxi, Mississippi; Cuba; Maranhao; Rio

FIG. 259. — CYMOTHOA EXCISA (AFTER SCHICEDTE AND MEINERT). a, UNGULA OF THE LEG OF THIRD

PAIR OF YOUNG OF SECOND STAGE (KNGARGED). b, LATERAL VIEW OF THORAX OF ADULT FEMALE

(REDUCED), c, ADULT FEMALE (REDUCED), d, YOUNG OF SECOND STAGE (ENLARGED), e, ADULT

MALE (ENLARGED). /, LATERAL VIEW OF THORAX OF ADULT MALE (ENLARGED).

Janeiro; South Florida; Key West, Florida; Porlaraar, Margarita
Island, Venezuela.

Parasite of chub (from lip); in the gills of a sparid (" Spanis" sp.
Schiosdte and Meinert).

Body oblong-ovate, nearly twice as long as wide, 12 mm. : 23 mm.

Head a little wider than long, 3 mm. :4 mm., and deeply set in the
first thoracic segment, the narrow, acute antero-lateral angles of which
extend half the length of the head. The antero-lateral angles of the
head are rounded and curve slightly upward, the anterior portion of

ISOPODS OF NORTH AMERICA.

249

the head between them and a little anterior to them curving down-
ward, so that in a dorsal view the anterior margin seems slightly
excavate. The eyes are very indistinct, and have almost disappeared;
traces of them are seen on the lateral margins, halfway between the
anterior and the posterior margins. The first pair of antennae are
composed of eight articles and extend almost to the posterior margin
of the head. The basal articles of the first pair of antennae are widely
separated by a distance equal to 2 mm. The second antennae are com-
posed of nine articles, and extend three articles beyond the first pair
of antennae. The maxillipeds have a palp of two articles. The palp
of the mandibles is composed of three articles.

The first segment of the thorax is about one and a half times longer
than any of the three following segments, which are subequal. The
fifth and sixth segments are
each about half as long as
an}- of the three preceding
segments in the median dor-
sal line. The seventh seg-
ment is about half as long
as the sixth. The epimera
are distinctly separated on
all the segments with the
exception of the first; they
are narrow, elongate plates,
which in the second, third,
and fourth segments extend
a little more than two-thirds
the length of the segment,
in the fifth extend almost to
the post-lateral angles of the
segment, and in the last two
extend quite to the extrem-
ity of the post-lateral angles.

The abdomen is deeply set in the thorax, the post-lateral angles of
the seventh thoracic segment reaching to the anterior portion of the
sixth abdominal segment. All the segments of the abdomen are dis-
tinct. The first is abruptly very narrow; the others gradually increase
in width to the last. The terminal segment is twice as wide as long,
4£ mm. : 9 mm. The post-lateral angles are widely rounded and the
posterior margin slightly excavate in the middle. The uropoda are
short, extending a little beyond the median transverse line of the
terminal abdominal segment. The outer branch is a little longer than
the inner branch. Both are similar in shape, and terminate in nar-

d

FIG. 260. — CYMOTHOA EXCISA. a, SECOND MAXILLA, x 39.
b, FIRST MAXILLA, x 39. c, PALP OF MANDIBLE, x 39.
d, MAXILLIPED. x 39. e, MANDIBLE, x 39. /, SEVENTH

LEG. X 7.

row, rounded extremities.

&*£

*,

LIBRARY; so

250 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

All the legs are prehensile, terminating- in long, narrow curved
dactyli. There is a high carina on the exterior margin of the basis
of the last four pairs of legs; the height of the carina increases from
the fourth to the seventh, where it is extremely high."

CYMOTHOA EXIGUA b Schicedte and Meinert.

Cymothoa exigua SCHICEDTE and MEINERT, Naturh. Tidsskrift (3), XIV, 1883-84,
pp. 232-234, pi. vi, figs. 7-8.

Localities. — Panama; also Charles Island, between the Galapagos
Islands.

Found in the mouth of Citharichtkys sordida.

Body ovate, rather compressed, more than twice as long as wide
(9:4).

Head moderately large, subtriangular, widely rounded in front, two
or three times narrower than the fourth thoracic segment (almost 2: 5),
manifestly wider than long (almost 7: 6), a little immersed, frontal mar-
gin incurved, widely rounded.

Eyes distinct, moderately large, subtriangular or subrectangular.
First pair of antennae smooth, rather stout, extending with the last
article to the anterior angle of the first segment of the thorax, or to
the eighth article of the second pair of antenna?; they are composed of
eight articles.

The second pair of antennae are smooth, or rather compressed, much
more slender than the first pair of antennas, and extend with the two
last articles to the anterior angle of the first thoracic segment; they
are composed of nine articles.

The anterior margin of the first thoracic segment is straight, with
the anterior angles short and obtusely rounded; the sides of the
segment are straight.

The posterior angles of the anterior thoracic segments are rounded,
those of the posterior ones truncately rounded.

The epimera are incurved and rather long; those of the first and sec-
ond pairs are rather narrow, posteriorly a little dilated, obliquely and
rounded truncate; those of the third and fourth segments are rather
narrow, posteriorly a little narrower, obliquely and widely rounded;
those of the fifth and sixth pairs are rather wider, posteriorly very
much narrower (but little narrower in the young female), and obliquely
and widely rounded. The epimera of the first, second, and third pairs
do not reach by a great and gradually increasing distance the posterior
angle of the segment; those of the fourth pair do not reach by a small

«For the description of the male, female, and the young of the first and second
stages, see Schioedte and Meinert, Nat. Tidsskr. (3), XIV, 1883-84, pp. 238-244.

& This species is included because the fish on which it is parasitic is found as far
north as the coast of California.

ISOPODS OF NORTH AMERICA. 251

distance the posterior angle of the segment; those of the fifth pair
almost reach the posterior angle of the segment; those of the sixth
pair extend a small distance beyond the posterior angle of the segment.

The legs of the first three pairs are shorter than the others; those of
the last four pairs gradually but slightly increase in length. The
ungulse are long, rather stout, less curved and subequal in length.
The carina of the four posterior pairs is high, gradually and greatly
increasing in height, the exterior angle being rounded, the posterior
margin more or less widely rounded.

The abdomen is deeply immersed (less deeply immersed in the young
female), the inferior angles of the first segment being covered, the
sides of the second, third, fourth, and fifth segments together being a
little sinuated, manifestly divergent; the abdomen is obscurely bisul-
cate, much wider than long (almost 5:4), two or three times shorter
than the thorax with the head (almost 2:5). The first segment is cov-
ered for the greatest part; the second, third, and fourth segments are
subequal in length or gradually increasing a little, manifestly shorter
than the fifth segment. The posterior margin of
the first five segments is widely sinuated, and
produced at the sides in an obtuse lobe. The
superior angles of the second, third, fourth, and
fifth segments are almost vanishing. The inferior
angles of the second, third, and fourth segments
are produced, rather acute, and decrease gradually
in length; those of the fifth segment are pro-
duced and obtusely rounded.

The terminal segment is transverse, with the
sides rounded, the posterior margin widely sin-
uated, depressed at the base in the middle, ANDMEINERT). a, ADULT
obscurely pitted, much wider than the fifth abdom- J^
inal segment, more than twice as wide as long LARGED.)
(7: 3), and a little longer than the other abdominal

segments together. The uropoda are equal in length to the terminal
segment of the abdomen; the inner branch is much shorter and a lit-
tle narrower than the outer branch, becoming a little narrower and
narrowly rounded; the outer branch is sickle shaped and posteriorly
narrowly rounded.

Length of adult female 20 mm.

Length of young female 15.5 mm. Color yellow, sprinkled with
minute obscure spots, the spots on the head confluent in a transverse
row, those of the thorax confluent in a median area, with oblong waxen
spots remaining. a

«The above description is adapted from the following one of Schioedte and Meinert's:

Producte obovata, compressiuscula, plus duplo longior quam latior (9:4). Caput

mediocre, subtrigonum, ante late rotundatum, quam annulus quartus trunci bis vel

252 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

CYMOTHOA CARAIBICA Bovallius.

Cymothoa caraibica BOVALLIUS, Bihang till k. Sv. Vet.-Akad. Handl., X, N.o. 11,
1885, pp. 27-29, pi. v, figs. 58-61.

Locality. — South coast of Ha}Tti, West Indies.

"The head is large and long, only a little shorter than broad, the
front margin forms no border on the under-side, but is only bent

ter angustius (fere 2:5), manifesto latius quam longius (fere 7:6), paulum immersum,
fronte ante incurva, late rotundata.

Oculi manifesti, mediocres, subtrigoni, vel subrectanguli.

Antennae primi paris subteretee, crassiusculse, angulum priorem annuli primi trunci
articulo ultimo superantes, articulum octavum antennarum secundi paris explentes;
8-articulatse.

Antennae secundi paris subteretes vel compressiusculse, quam antennae primi paris
multo tenuiores, angulum priorem annuli primi trunci articulis binis ultimis super-
antes; 9-articulatse.

Margo anticus annuli primi trunci subrectus, angulis prioribus brevibus, rotun-
date obtusis; latera annuli subrecta.

Anguli postici annulorum priorum trunci rotundati, posteriorum rotundate truncati-

Epimera incurva vel subincurva, longiuscula; paris primi et secundi angustius-
cula, post paulum dilatata, in obliquum rotundate truncata; paris tertii et quarti
angustiuscula, post paulum angustata, in obliquum late rotundata; paris quinti et
sexti latiuscula, post valde vel vix (virgini) angustata, in obliquum late rotundata.
Epimera paris primi, secundi, tertii angulum annuli spatio magno, per paria sensim
crescente, non attingentia; paris quarti angulum annuli spatio parvo non attingentia;
paris quinti angulum annuli fere explentia; paris sexti angulum annuli spatio parvo
superantia.

Pedes parium trium priorum ceteris breviores; parium quattuor posteriorum per
paria sensim longitudine vix crescentes. Ungulse longae, crassiusculse, minus curvatse,
longitudine subsequales. Carina pedum parium quattuor posteriorum alta, per paria
sensim valde crescens, angulo exteriore rotundato, margine postico plus vel minus
late rotundato. Cauda profunde vel minus profunde (virgini) immersa, angulis
inferioribus annuli primi obtectis, lateribus annuli secundi, tertii, quarti, quinti, con-
junctim paulum sinuatis, manifesto divergentibus: obscure bisulcata, inulto latior
quam longior (fere 5:4), quam truncus cum capite bis vel ter brevior (fere 2:5).
Annulus primus maximam partem obtectus; annulus secundus, tertius, quartus longi-
tudine subaequales vel sensim paulum crescentes, quam annulus quintus manifesto
breviores.

Margo posticus annulorum quinque priorum late sinuatus, ad latera in lobum
obtusum productus. Anguli superiores annuli secundi, tertii, quarti, quinque fere
evanidi. Anguli inferiores annuli secundi, tertii, quarti producti, acutiusculi, per
paria sensim longitudine decrescentes; annuli quinti prominuli, rotundate obtusi.

Annulus analis transversus, lateribus rotundatis, margine postico late sinuato, ad
basin in medio impressus, obscure foveolatus, quain annulus quintus caudalis multo
latior, plus duplo latior quam longior (7:3), annulis ceteris caudalibus conjunctis
paulo longior. Pedes anales annulum analem longitudine subaequantes; ramus inte-
rior quam exterior multo brevior et paulo angustior, paulum angustatus, breviter
rotundatus; ramus exterior subfalcatus, post breviter rotundatus.

Long, feminse ovigerse 20 mm. Long, virginis 15.5 mm. Color cereus, maculis
minutis, obscuris sparsus, maculis in strigam transversam capitis et in plagam mediam,
maculis oblongis cereis relictis, trunci confluentibus. — Schiredte and Meinert, Nat.
Tidsskr. (3), XIV, 1883-84, pp. 232-233.

ISOPODS OF NORTH AMERICA.

253

downward in the middle; the anterior margin is rounded, the upper
side slightly convex.

"The eyes are of median size, placed a little behind the middle of
the head near the lateral margins.

•'The first pair of antenna? are thick and robust, eight-jointed, with-
out distinction between the peduncle and the flagellum, the last joints
without hairs 01 spines. The second pair of antennae are considera-
bly more slender, a little shorter, eight-jointed. The processes of the
first segment of the pereion are shorter and narrower than in Cymothoa
elegans, rounded at the ends. The anterior margin of the first seg-
ment is slightly emarginate; it
is longer than the fourth seg-
ment (5 :•!), and only a little
narrower than the fifth (5:6).
From the fifth to the seventh,
the segments decrease in length,
but scarcely in breadth. The
seventh segment is longer than
half the sixth. The three first
segments together are as long
as the four last ones together.

"The epimerals of the sec-
ond and third segments are
fixed along the whole length of
the segments, the following
ones only along half or two-
thirds of the length of the cor-
responding segments'; all the
epimerals are equal in length
to their corresponding seg-
ments.

"The first three pairs of pere-
iopoda have long, strong dactyli,
as long as the dadyli of the following pairs. The last four pairs have
strongly developed carinas on the femora. The femur of the seventh
pair is longer than broad (24 : 17).

"The pleon is broad, much broader at the base than long (5: 3).
The first segment is almost totally hidden, the pleon being a little
more immersed than in Cymothoa elegans. The last is broadest and
longest, the three preceding being equal in length. The second pair
of pleopoda carry very long styliform processes.

" The urus is as long as the pleon, and only a little broader than the
last pleonal segment (12:11); it is smooth on its upper side, broadly
rounded at its lateral and hinder margins, exactly twice as broad as

Fio.262.— CYMOTHOA CARAIBICA (AFTER BOVALLIUS).
a, DORSAL VIEW OF MALE, x |. b, SEVENTH LEG OF

RIGHT SIDE. X 12. C, FOURTH LEG OF RIGHT SIDE.

x 12. d, SECOND PLEOPOD. x 12.

254 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

long. The pleon and urus together are equal in length to half of the
pereion without the head.

"The uropoda do not reach to the hinder margin of the urus. The
peduncle is shorter than the inner ramus. The inner ramus is longer
than the outer.

"Color. Yellowish-white, with smaller and larger brown-red spots
on the anterior part of each segment; the posterior part is almost
white.

"Length. The female virgo, 17 mm.

"The males, 12, 15, 16 mm." — BOVALLIUS."

CYMOTHOA OESTRUM (Linnaeus).

Oniscus oestrum LINN.EUS, Syst. Nat., 10th ed., I, 1758, p. 636, No. 2; Fauna sue-
cica., 2d ed., 1761, p. 499, No. 2053; Syst. Nat., 12th ed., I, 1767, Pt. 2, p.
1059, No. 2.

Asellus oestrum OLIVIER, Encycl. Method., IV, 1789, p. 253.

Cymothoa oestrum FABRICIUS, Entom. Syst., II, 1798, p. 505, No. 6. — LEACH, Trans.
Linn. Soc. London, XI, 1815, p. 372; Diet. Sci. Nat., XII, 1818, p. 352.

Cymothoa dufresnei LEACH, Diet. Sci. Nat., XII, 1818, p. 352.

Cymothoa immersa SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 399-400.

Cymothoa oestrum DESMAREST, Consid. Gen. Crust., 1825, p. 309, pi. XLVII, figs.
6-7. — MIERS, Proc. Zool. Soc., 1877, pp. 671-672. — SCHKEDTE and MEINERT,
Naturh. Tidsskr. (3), XIV, 1883-84, pp. 271-279, pi. vm, figs. 5-13.—
RICHARDSON, American Naturalist, XXXIV, 1900, p. 221; Proc. U. S.
Nat. Mus., XXIII, 1901, p. 530.

Localities. — Caribbean Sea and Gulf of Mexico to shores of Virginia;
Swan Island; St. Bartholomew; St. Christopher; Jamaica; Guade-
loupe; St. Georges, Bermudas; St. Anna, Mexico; Key West, Florida;
Curacao, Venezuela; Peru; Barbados (from stomach of a "redfish").

Parasite of Caranx latus, "jackfish" (from branchial cavity); red-
fish (stomach); in the tongue of Scombroid fishes; from the mouth of
Priacanthus arenatus and Trachurops crwnenophthalmus; on Strombus
giganteus.

Body oblong-ovate, twice as long as wide, 15 mm. : 30 mm.

Head, wider than long, 4 mm. : 6 mm., with the antero-lateral angles
rounded and the anterior margin appearing straight from a dorsal
view, but actually being somewhat triangularly produced and bent
downward over the antennae. The head is deeply set in the first tho-
racic segment, the broad and widely rounded antero-lateral angles of
which extend to the anterior margin of the head. The eyes are absent,
and no traces of them are seen. The first pair of antennas are com-
posed of eight articles and extend a iittle beyond the middle of the
head. The second pair of antennae are composed of nine articles and
extend two articles beyond the first pair of antennae. The basal arti-

aBihang till K. Sv. Vet.-Akad. Handl., X, No. 11, 1885, pp. 28-29.

ISOPODS OF NORTH AMERICA.

255

cles of the first pair of antennae are widely separated, being nearly
2 mm. apart. The maxillipeds have a palp of two articles. The palp
of the mandibles is composed of three articles.

The first segment of the thorax is about twice as long as any of the
three following segments, which are subequal. The antero-lateral
expansions of the first segment are half as wide as the head, 3 mm. in
width, and they are widely rounded at the anterior extremity. The
fifth and sixth segments are half as wide in the median longitudinal
line as any of the three preceding segments. The seventh segment is
a little shorter than the sixth. The epimera are distinctly separated

FIG. 263.— CYMOTHOA (ESTRUM (AFTER SCHICEDTE AND MEINERT). a, YOUNG OF THE SECOND STAGE
(ENLARGED), b, YOUNG OF THE FIRST STAGE (ENLARGED). C, LATERAL VIEW OF THORAX OF ADULT
FEMALE (REDUCED), d, ADULT MALE (ENLARGED). «, ADULT FEMALE (REDUCED). /, ADULT FEMALE
(REDUCED).

on all the segments with the exception of the first. They are narrow
plates, extending or nearly extending the full length of the segments.
Those of the second segment are a little broader anteriorly than are
the others.

The abdomen is deeply set in the thorax. All the segments are dis-
tinct, the lateral parts of the first two being covered by the seventh
thoracic segment, so that these segments appear abruptly narrower
than the thorax. The following segments gradually increase in width.
The sixth or terminal segment is twice as broad as long, 6 mm. : 12

256 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

mm. The post-lateral angles are rounded, and the posterior margin
is slightly excavate in the middle. The uropoda are as long as the

terminal abdominal segment.
The outer branch is slightly
shorter than the inner branch.
Both are equal in width,
and narrow, with extremities
rounded.

The legs are all prehensile,
with short, stout, curved dac-
tyli. There is a high carina
on the basis of the last four
pairs, the carina increasing
gradually from the fourth to
the seventh pair, where it is
extremely high."

42. Genus LIVONECA
Leach.

Body suboval, more or less
twisted.

Head most always deeply
immersed. First pair of an-
tennae widety separated at the
base, rather compressed.

Anterior margin of the first
thoracic segment widely sin-

uated in the middle, more or less sinuated or incised at the antero-
lateral angles.

Abdomen very little immersed, continuous with thorax, not nar-
rower than thorax.

FIG. 264. — CYMOTHOA CESTRUM. a, MAXILLIPED.
6, SEVENTH LEG. x 4}. c, FIRST MAXILLA.
d, SECOND MAXILLA, x 15$. e, MANDIBLE.

/, PALP OF MANDIBLE. X 15}.

x 15}.
x 15}.
X 15}.

ANALYTICAL KEY TO THE SPECIES OF THE GENl'S I.IVONECA.

a. Abdomen somewhat immersed in thorax, the sides of the first segment being

almost entirely covered by the seventh thoracic segment.
b. Head quadrate, but little broader at the base than at the anterior end.

Livoneca panamensis Scrmrdte and Meinert

b' '. Head triangular, nearly twice as broad at the base as at the anterior extremity,
c. Head roundly truncate in form. Terminal segment of abdomen nearly twice

as broad as long Livoneca vulgaris Stimpson

cf. Head narrowly rounded in front. Terminal segment of abdomen about as

long as broad Livoneca calif ornica Schioedte and Meinert

a'. Abdomen not immersed in thorax, the sides of the first segment free.

a For complete description of this form, the male and female and the young of
the first and second stages, see Schicedte and Meinert, Nat. Tidsskr. (3), XIV,
1883-84, pp. 271-278

ISOPODS OF NORTH AMERICA.

I. Uropoda much longer than caudal segment; inner branch narrow, obtuse, much
shorter than outer branch. Epimera of last two thoracic segments not longer
than segments Livoneca redmanni Leach

V . Uropoda hardly surpassing the caudal segment; both branches equal in length.
Epimera of last two segments of thorax surpassing the segments.

Livoneca ovalis (Say)

LIVONECA PANAMENSIS Schioedte and Meinert.

Livoneca panamensis SCHIOSDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIV,
1883-84, pp. 349-353, p.'xm, figs. 11-12.— RICHARDSON, Proc. U. S. Nat.
Mus., XXI, 1899, p. 830; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 172.

Localities. — Mazatlan; west shores of Central America; Panama.
Body ovate, less than twice as long as wide, 16

a

mm.: 2< mm.

Head quadrangular, wider than long, 3 mm. : 4
mm., with the anterior margin truncate and about
2 mm. wide. The eyes are small and distinct and
situated at the sides of the head near the posterior
margin. The first pair of antennae are separated
in front by a distance of 1 mm. They are com-
posed of eight articles, and extend to the posterior
margin of the head. The second pair of antennge
are composed of ten articles and extend to the
middle of the first thoracic segment.

The first segment of the thorax has the antero-
lateral angles produced to surround the head,
where they extend to the middle of the lateral mar-
gin. The first segment is 4 mm. in length. The
second and third are subequal and each is 3 mm.
long. The fourth and fifth are subequal and each
is 2£ mm. in length. The sixth is 2 mm. long.
The seventh is li mm. The epimera of all the
segments, with the exception of the first, are dis-
tinctly separated from the segments. The epimera
extend the full length of the lateral margins, with
the exception of those of the fifth and sixth seg-
ments, which do not quite reach the posterior
margins of the segments.

The abdomen is slightly immersed or se.t in the
thorax. The first segment is entirely covered by
the seventh thoracic segment except in the dorsal
portion. All the segments are distinct. The sixth
or terminal segment is large, nearly twice as wide
as long, 6 mm.: 10 mm., and has the posterior margin irregularly
rounded. The uropoda have both branches similar in shape and size
and of equal length. They are long and narrow with posterior
28589—05 17

FIG. 265. — LIVONECA PAN-
AMENSIS (AFTER SCHI-
(EDTE AND MEINEKT).
a, ADULT MALE. 6, LAT-
ERAL VIEW OF THORAX

OF ADULT FEMALE. C,
LATERAL VIEW OF THO-
RAX OF ADULT MALE.

d, ADULT FEMALE. (ALL

ENLARGED.)

258

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

margins rounded and do not extend quite to the extremity of the
terminal abdominal segment.

u x •*

FIG. 266.— i^IVONECA PANAMENSIS. a, MAXILLIPED OF FEMALE. X lit. &, SECOND MAXILLA. X 20i.
C,, FIRST MAXILLA. X 20i- d, SEVENTH LEG. X 7.

The legs are all prehensile. Those of the last four pairs have a
high carina on the basis, the carina increasing gradually in height from
the fourth to the seventh pair.

FIG. 267.— LlVONECA VULGARIS (AFTER SCHICEDTE AND

MEINERT). a, YOUNG OF THE FIRST STAGE. 6, ADULT
MALE, c, LATERAL VIEW OF THORAX OF ADULT FE-
MALE, d, ADULT FEMALE, e, LATERAL VIEW OF THO-
RAX OF ADULT MALE. (ALL ENLARGED.)

LlVONECA VULGARIS
Stimpson.

Livoneca vulgaris STIMPSON,
Bost. Jour. Nat. Hist., VI,
1857, p. 508, pi. xxii, fig.
9. — SCHKEDTE and MEI-
NERT, Naturhistorisk Tids-
skrift (3), XIV, 1883-84,
pp. 344-349, pi. xiv, figs.
1-2. — RICHARDSON, Proc.
U. S. Nat. Mus. , X XI , 1899,
p. 830; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 172.

Anilocra occidentalism RICHARD-
SON, Proc. U. S. Nat. Mus.,
XXI, 1899, pp. 830-831;
Ann. Mag. Nat. Hist. (7),
IV,. 1899, pp. 172-174;'
Amer. Nat., XXXIV,
1900, p. 220.

Livoneca vulgaris RICHARDSON,
American Naturalist,
XXXIV, 1900, p. 221;
Harriman Alaska Expedi-
tion, Crust, X, 1904, p.
214; Proc. U. S. Nat.
Museum, XXVII, 1904,
p. 659.

Localities. — Shores of California, near San Francisco, to Santa
Margarita Island, Lower California; San Francisco Bay.

Parasites of the rock cod; of flounder; from Chinese shrimp nets;
on Ifyjjerprosopon argenteus; in gills of Steindachneria, Ophiodon
elongatus.

«This form is probably the young male of Livoneca vulgaris.

ISOPODS OF NORTH AMERICA.

259

Body ovate, not twice as wide as long, 17 mm. : 28 mm., widest at
the fourth thoracic segment.

The head is triangular, and at the base is wider than long, 3 mm. : 5
mm.; it is partly set in the first thoracic seg-
ment, the antero-lateral angles of which extend
to about the middle of the head. The eyes are
small, oval, composite, situated in the post-
lateral angles of the head, and separated ante-
riorly by a distance nearly equal to the length
of one eye. The posterior margin of the head
is rounded; the anterior margin is widely
rounded. The anterior end is 2 mm. wide.
The first pair of antenna? are composed of eight
articles and extend to the end of the sixth article
of the second pair of antenna?. The basal arti-
cles are not adjacent, being separated by a dis-
tance equal to 1 mm. The second pair of an-
tenna? are composed of ten articles, and extend
to the middle of the first thoracic segment. The maxillipeds have a

FIG. 268.— LIVONECA VUI.GA-
EIS (AFTER STIMPSON).

FIG. 269.— LIVONECA VULGARIS. a, MAXILLIPED OF FEMALE, x 27}. 6, SEVENTH LEG. x 9f. c,
SECOND MAXILLA, x 27£. d, FIRST MAXILLA, x 27J. e, PALP OF MANDIBLE, x 27£.

palp of two articles. The palp of the mandibles is composed of three
articles.

The first and fourth segments of the thorax are the longest, each
being 3 mm. in length. The second and sixth are each 2 mm. long.

260 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The third and fifth are subequal, each being 2£ mm. in length. The
seventh is the shortest, being 1£ mm. long. The epimera are distinctly
separated on the last six segments. They are narrow
plates, extending the full length of the lateral margins
of the segments.

The abdomen is not narrower than the last thoracic
segment. The first segment is covered at the sides
by the seventh thoracic segment. The terminal seg-
ment is nearly twice as wide as long, 5 mm. : 9 mm.
and is widely rounded posteriorly. The uropoda are
as long as the terminal segment. Both branches are
of equal width and length, and are alike in shape, ter-
minating in rounded extremities.

The legs are all prehensile, and are furnished with

FIG. 270. — LIVONECA F. . .

VULGARIS. YOUNG long, narrow dact}rh. I he basis of the last four pairs
MALE- is produced in a not very high carina."

LIVONECA CALIFORNICA Schicedte and Meinert.

Livoneca californica SCHKEDTE and MEINERT, Naturhistorisk Tidsskrift (3), XIV,
1883-84, pp. 372-374, pi. xvi, figs. 1-2.— RICHARDSON, Proc. U. S. Nai. Mus.,
XXI, 1899, p. 829; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 172; Amer. Nat,
XXXIV, 1900, p. 221.

Localities. — Shores of California, near San Francisco; Fort Point,
San Francisco, California; off Point Nuevo, California; San Pedro,
California; South Belmont Oyster Beds, San Francisco Bay, Califor-
nia; Santa Cruz, California.

Parasite of "shiner."

Body oblong-ovate, a little more than twice afs long as wide, 7 mm. :
16 mm., and twisted somewhat to one side, the right side being
shortened.

The head is as wide at the base as it is long, 2 mm. : 2 mm. , and is
somewhat triangular, becoming gradually more narrow to an apex
which is \ mm. wide and narrowly rounded. The eyes are large,
oval, composite, and situated in the post-lateral angles of the head;
they are separated anteriorly by a distance equal to the length of one
eye. The posterior margin of the head is rounded. The first pair of
antennae are composed of eight articles. The basal articles are not
contiguous, but the distance between them is very small, owing to the
narrowness of the anterior part of the head. The second pair of
antennae are composed of eight articles. They extend to the end of
the seventh article of the first pair of antenna? and are very slender
and feeble. The maxillipeds have a palp of two articles. The palp
of the mandibles is composed of three articles.

« For description of this form, the male, female, and the young of the first stage,
see Schioedte and Meinert, Nat. Tidsskr. (3), XIV, 1883-84,. pp. 344-349,

ISOPODS OF NORTH AMERICA.

261

The first segment of the thorax is longest, being 2 mm. in length.
The second and third are subequal, each being 1£ mm. long. The

fourth, fifth, and sixth are subequal,
each being 1 mm. long. The seventh is
shortest, being only i mm. in length.
The head is partly immersed or set in the
first thoracic segment, the antero-lateral
angles of which extend to about the mid-
dle of the head. The epimera are dis-
tinctly separated on the last six segments.
They are narrow plates, which in the SBC-

FIG. 271.— LlVONECA CALIFORNICA
(AFTER SCHICEDTE AND MEINEKT). a,

ADULT FEMALE, b, LATERAL VIEW OF

THORAX. (BOTH ENLARGED.)

ond and third segments do
not quite reach the post-
lateral angles of the seg-
ments. In the last four
the epimera extend the full

length of the lateral margins of the segments.
The abdomen is not narrower than the last
thoracic segment. The first segment is partly
covered at the sides by the seventh thoracic
segment. The terminal segment is rounded
posteriorly ; it is 4 mm. wide and 3£ mm. long.
The uropoda are not longer, but as long as the
terminal abdominal segment. The branches are
equal in length and width, are alike in shape,
terminating in rounded extremities.

All the legs are prehensile, being furnished
with long, narrow, curved dactj'li. There is
no carina on the basis of any of the legs.

bed

FIG. 272.— LlVONECA CALIFORNICA. a, MAXILLIPED. X 33.

6, SECOND MAXILLA, x 33. c, FIRST MAXILLA, x 33. d,

PALP OF MANDIBLE. X 33.

FIG. 273.— LlVONECA CALI-
FORNICA. SEVENTH LEG.
xlli.

LlVONECA REDMANNI Leach.

Livoneca redmanni LEACH, Diet. Sci. Nat., XII, 1818, p. 352.

Livoneca desmarestii LEACH, Diet. Sci. Nat., XII, 1818, p. 352.

Livoneca redmanni DESMAREST, Consid. G£n. Crust., 1825, p. 308.

Livoneca desmarestii DESMAREST, Consid. Gen. Crust., 1825, p. 308.

Livoneca redmanni MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 261.

Livoneca desmarestii MILXE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 261.

Livoneca redmanni MILNE EDWARDS, Cuvier's Regne Anim., pi. LXVI, figs. 4-4a.

Livoneca desmarestii MILNE EDWARDS, Cuvier's Regne Anim., pi. LXVI, figs. 3-3a.

Livoneca redmanni SCHICEDTE and MEINERT, Naturh. Tidsskr. (3), XIV, 1883-84,
pp. 353-358, pi. xiv, figs. 6-12. — RICHARDSON, American Naturalist, XXXIV,
1900, p. 221; Proc. U. S. Nat. Mus., XXIII, 1901, p. 531.

262

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Localities. — Cuba; St. Christopher; Jamaica; Bahia and Rio de
Janeiro, Brazil.

Parasite of kingfish (on gills).

Bod}r ovate, nearly twice as long as wide, 13 mm.: 25 mm.

Head a little wider than long, 3 mm. : 4 mm. ; twice as wide at the
posterior end as at the anterior end, with the posterior margin widely
rounded, the anterior margin somewhat rounded and deflected down-
ward over the antennae. The eyes are indistinct and perhaps func-
tionless; they are situated in the post-lateral lobes of the head. The
first pair of antenna? are composed of eight articles. The basal arti-
cles of each antenna are not adjacent, but are separated by a distance

FIG. 274.— LlVONECA REDMANNI (AFTER SCHICEDTE AND MEINERT). a, ADULT FEMALE. 6, 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, g, THIRD LEG OF SAME. (ALL

ENLARGED. )

of 1 mm. The second antennae are composed of ten articles and
extend almost to the middle of the first thoracic segment. The max-
illipeds have a palp of two articles. The palp of the mandibles is
composed of three articles.

The head is but little immersed or set in the first thoracic segment.
The antero-lateral angles of the first segment extend one-third the
length of the head. The first and fifth segments are a little longer
than any of the others, each being 2£ mm. long. The second, third,
fourth, and sixth segments are subequal, and each is 2 mm. in length.
The seventh segment is shortest, being only 1£ mm. long. The epim-
era are narrow plates, distinctly separated on the last six segments
and extending the full length of the segment.

ISOPODS OF NORTH AMERICA.

263

FIG. 275. — LIVONECA REDMANNIT a, MAXIL-

LIFED OP FEMALE. X 39. 6, SECOND MAXILLA.

x 20|. c, SEVENTH LEG. x 7. d, FIRST MAX-
ILLA, x 39. e, PALP OF MANDIBLE, x 20£.

The abdomen at its base is not abruptly narrower than the thorax.
It tapers to a narrower extremity. The tirst segment is as wide as the
seventh thoracic segment and is
partly covered b}' it. The sixth
or terminal segment* is rounded
posteriorly; it is 6 mm. long and 8
mm. wide at the base. The urop-
oda are much longer than the
terminal abdominal segment and
extend some distance (2 mm.) be-
yond its extremity. The outer
branch is longer and narrower
than the inner branch and has the
posterior extremity rounded. The
inner branch is broad at its pos-
terior end, which is obliquely trun-
cate, with the outer post-lateral
angle produced in a rounded lobe,
the inner angle being obtuse.

The legs are all prehensile,
with long, curved dactyli. The
basis of the last four pairs is produced in a low carina.

LIVONECA OVALIS (Say).

Cymothoa oralis SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 394.

Cymothoa triloba DE KAY, Nat. Hist. New York, Pt. 1, 1843, p. 46, pi. x, fig. 40.

(?) Cymothoa olivacea DE KAY, Nat. Hist. New York, Pt. 1, 1843, p. 47, pi. x, figs.
41-41a.

Livoneca ovalis WHITE, Cat. Crust. Brit. Mus., 1847, p. 109. — HARGER, with VER-
RILL, Eeport U. S. Commissioner of Fish and Fisheries, Pt. 1, 1873, p. 572
(278), pi. vi, fig. 29.— HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 162;
Report U. S. Commissioner of Fish and Fisheries, Pt. 6, 1880, pp. 395-396,
pi. xi, fig. 67.— RICHARDSON, American Naturalist, XXXIV, 1900, p. 222;
Proc. U. S. Nat. Mus., XXIII, 1901, p. 531.

Localities. — New Haven, Connecticut; Thimble Islands; Long Island
Sound; Woods Hole, Massachusetts; Vineyard Sound; New York;
Patapsco River; Bonday's Wharf, Patapsco, Baltimore City, Mary-
land; Charleston, South Carolina; Pensacola, Florida; St. Marys River,
Florida; Mobile, Alabama; Biloxi, Mississippi; Sandy Hook Bay, New
Jersey; Hunger's wharf, Virginia; Chesapeake Bay; South Florida;
Long Island; Great South Bay, Long Island; Tolchester, Maryland.

Parasite of the blue-fish Pomatomus saltatrix (from gills); Lagodon
rhomboides (under gill cover); saw-fish Pristis semisagittatus; scup
Stenotomus chrysops (on gills); Trachurops crumenophtJiahnus (from
gill); trout Cynoscion regalis f (on gills); sun fish (on gills); Micropogon
undulatus.

264

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 276.— LlVONECA

OVALIS. ABDOMEN.

Body ovate, about one and two-thirds times longer than wide, 13
mm. : 21 mm.

Head as wide as long, 3 mm. : 3 mm. . narrower anteriorly than pos-
teriorly with the frontal margin widely rounded. Eyes small, indis-
tinct and situated in the post-lateral angles of the head.
Posterior margin of head rounded. The first pair of
antennae are composed of six to seven articles, and
extend to the antero-lateral angles of the first thoracic
segment, but not to the posterior margin of the head;
they are separated in front by a distance equal to 1
mm. The second pair of antennae are composed of
eight to nine articles and extend to the posterior margin of the head.
The maxillipeds have a palp of two articles.

The first five segments of the thorax are subequal, each being about
2 mm. in length. The sixth and seventh are subequal, each being a

little shorter than any of
the preceding segments,
and each about 1£ mm.
long. The epimera are
distinctly separated on all
the segments with the ex-
ception of the first; they
occupy the entire lateral
margin in the second,
third, fourth, and fifth
segments. In the sixth
and seventh segments the
posterior extremities are
produced beyond the pos-
terior margins of the
segments, a distance of 1
mm. in the seventh seg-
ment.

All six segments of the
abdomen are distinct.
The abdomen is not im-
mersed or set in the tho-
rax, and is not abruptly
narrower than the thorax,
the first segment of the
abdomen being as wide as the seventh thoracic segment. The seg-
ments gradually decrease in width. The sixth or terminal segment is
rounded posteriorly. It is 4$ mm. long and 5 mm. wide at the base.
The uropoda do not reach the extremity of the terminal abdominal

PIG. 277.— LIVONECA OVALIS. a, MAXILLIPED. x 27}. b, MAN-
DIBLE, x 27}. c, SECOND MAXILLA, x 51|. d, FIRST MAX-
ILLA, x 27}. e, SEVENTH LEG.

ISOPODS OF NORTH AMERICA. 2t)5

segment. Both branches are equal in length and similar in shape.
The outer branch is about half as wide as the inner branch. The
branches are of equal width throughout their lengthy the outer branch
is rounded posteriorly; the inner branch is obliquely truncate, with
post-lateral angles rounded.

The legs are all prehensile with long curved dact3rli. There is no
carina on the basis of any of the legs.

The color is brown, with a transverse band of yellow along the pos-
terior margins of all the segments. The epimera are also yellow.

43. Genus IRONA Schioedte and Meinert.«

Body oval. Head deeply immersed.

First pair of antennae widely separated at the base, rather com-
pressed.

The anterior margin of the first thoracic segment widely sinuated,
the ante ro- lateral angles short. First thoracic segment manifestly
longer than the second. Anterior epimera rather long and narrow,
gradually increasing in width; the posterior ones rather short and
rather wide.

Body of female asymmetrical; that of male more symmetrical.

Abdomen continuous with thorax, not narrower than thorax; deeply
immersed. Carina on the four posterior pairs of legs almost absent.

IRONA NANA Schioedte and Meinert.

Irona nana SCHICEDTE and .MEINERT (3), XIV, 1883-84, pp. 390-395, pi. xvu,
figs. 6-11.— RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 531.

Localities. — Caribbean Sea and Atlantic Ocean; St. John; St. Bar-
tholomew; Rio Janeiro; Harrington Sound, Bermudas (collected by
Doctor Linton).

Found parasitic in gills of Hemirhampfais sp. ; on Atherina sp. ; on
Atherina harrinytonensis. Doctor Linton says the attachment is
voluntary, the parasite frequently leaving the host when disturbed.

Body subovate or ovately produced, very much twisted, rather con-
vex, more than one and a half times or twice as long as wide (5 : 3
or 2 : 1).

The head is small, subtriangular or subconical, one-third or one-
fourth as wide as the fourth segment of the thorax (3 : 1 or 4 : 1), much
wider than long (5:4), deeply immersed, with the front bent down-
ward and narrowly rounded. The eyes are large and subpentagonal.

The first pair of antenna? are rather compressed, rather stout, widely
separated, reaching with the fifth article the anterior angle of the first

«See Schkedte and Meinert for characters of genus, Nat. Tidsskr. (3), XIV,
1883-84, pp. 381-383.

266 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

thoracic segment, scarcely as long as the second pair of antenna", they
are composed of eight articles. The second pair of antennre are sub-
filiform, one-half as wide as the first pair of antenna1, almost reaching
with the sixth article the anterior angle of the first thoracic segment;
they are composed of nine articles.

The anterior margin of the first thoracic segment is very widely
sinuated, the angles being produced and narrowly rounded and rather
obtuse; the sides of the segment are not constricted, but are widely
rounded.

The posterior angles of the anterior segments of the thorax are very
widely rounded, those of the posterior segments are subrotund.

The epimera are usually unequally produced; the first three are
rather long, rather narrow, and posteriorly narrowly rounded; the
three posterior ones are rather short or short, rather wide or wide,
gradually increasing in width, posteriorly truncate or truncately
rounded. The three anterior epimera do not reach by a greater or
less distance the posterior angle of the segment, and gradually decrease
in length; the three posterior epimera almost reach the posterior angle
of the segment.

The legs are rather short, gradually increasing in length; the first
three .pairs together are very divergent; the four posterior pairs are
scarcely convergent, incurved on one side. The ungulae are rather
long or long, rather stout or stout, those of the first five pairs gradu-
ally increasing in length and strength; those of the sixth and seventh
pairs are a little shorter and more slender than the preceding ones
and are less curved. The carina of the four posterior pairs of legs is
vanishing.

The abdomen is deeply immersed, the sides of the first three seg-
ments, at least on one side, being covered; the sides of the second,
third, fourth, and fifth segments together are slightly curved, scarcely
converging; the abdomen is rather convex, a little or scarcely wider
than long, less than half as long as the thorax with the head. A large
part or the greater part of the first segment is covered; the second,
third, and fourth segments are subequal in length, almost one and
a half times shorter than the fifth segment. The posterior margin of
the first four segments are very widely sinuated; that of the fifth seg-
ment is straight, obscurely flexuous. The posterior angles of the
second, third, fourth, and fifth segments are produced, entire, and
narrowly rounded.

The terminal segment is narrowly subtriangular, a little narrower
than the fifth segment, almost one and a half times wider than long
(almost 5:7), one and a half times longer than the other segments of
the abdomen together. The uropoda are a little longer than the termi-
nal segment of the abdomen; the inner branch is almost one and a half

IROPODS Ob' NORTH AMERICA.

267

times shorter and a little narrower than the outer branch, and is lami-
nar in shape; the outer branch is sickle-shaped, rather acute, and
lightly flexuous.

FIG. 278.— IRONA NANA (AFTER SCHICEDTE AND MEINEKT). a, ADULT FEMALE, b, YOUNG MALE.
c, YOUNG OF THE SECOND STAGE, d, UNGULA OF THE LEG OF THE THIRD PAIR OF SAME. (ALL

ENLARGED.)

Length, 8-18 mm.

Color yellow, with large or small dark, branching spots, arranged
in transverse series, scattered over the middle of the body; the eyes
are black."

«The above description is adapted from the following one of Schiredte and Meinert's:

Subovata vel producte obovata, valde contorta, convexiuscula, plus sesqui vel
duplo longior quam latior (5 : 3 vel 2:1).

Caput parvum, subtrigonum vel subconicum, quam annulus quartus trunci ter
vel quarter angustius (3:1 vel 4:1), multo latius quam longius (5:4), profunde
immersum, fronte declivi, breviter rotundata. Oculi magni, subpentagoni. Antennae
primi paris compressiusculee, crassiusculee, late distantes, angulum priorem annuli
primi trunci articulo quinto attingentes, antennas secundi paris vix complentes;
8-articulatse.

Antennae secundi paris subfiliformes, quam antennae primi paris duplo tenuiores
angulum priorem annuli primi trunci articulo sexto fere attingentes; 9-articulatse.
Margo anticus annuli primi trunci latissime sinuatus, angulis prominulis, rotundate
angustatis, obtusiusculis; latera annuli non constricta, late rotundata.

Anguli postici annulorum priorum trunci latissime rotundati, posteriorum subro-
tundati.

Epimera in aequum fere porrecta; terna priora longiuscula, angustiuscula, post
breviter rotundata; terna posteriora breviuscula vel brevia, latiuscula vel lata, per
paria sensim latitudine crescentia, post truncata vel rotundate truncata. Epimera
terna priora angulum annuli spatio majore vel minore, per paria sensim longitudine
decrescente, non attingentia; terna posteriora angulum annuli fere explentia. Pedes
breviusculi, per paria sensim longitudine crescentes; parium trium priorum con-
junctim valde divergentes; parium quattuor posteriorum conjunctim vix convergentes,
in latere altero incurvi. Ungulse longiusculse vel longse, crassiusculse vel crassse,

2fi8 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Family X. LIMNORIID^.«

Body oblong, subdepressed, contractile into a ball. Head short
and blunt in front. Both pairs of antennas small, subequal; ftagella
short. Mouth parts normal. Mandibles without molar expansion;
with a small, three-jointed palp. Palp of maxillipeds composed of five
articles. Eyes lateral.

Segments of thorax distinct; first segment longer than second.
Epimera well defined on all the segments of the thorax with the excep-
tion of the first.

Abdomen composed of six distinct segments; terminal segment
large, broad, flattened above.

Legs all ambulatory.

Pleopods uniform in structure, both natatory and branchial; inner
plate of second pair in male with a stylet.

Uropoda small, lateral; outer branch short, unguiform, almost obso-
lete; inner branch linear.

44. Genus LIMNORIA Leach.
Only genus. With characters of family.

pariuin quinque priorum per paria sensim longitudine et robore crescentes, paris
sexti et septimi prsecedentibus paulo breviores atque tenuiores, minus curvatte.
Carina pedum parium quattuor posteriorum evanida.

Cauda profunde immersa, lateribus annulorum triuin priorum, saltern alterius
lateris, obtectis, annul! secundi, tertii, quarti, quinti conjunctim leviter curvatis, vix
convergentibus: convexiuscula, paulo vel vix latior quam longior, quam truncus
cum capite plus duplo brevior. Annulus primus magnam vel maximam partem
obtectus; annulus secundus, tertius, quartus longitudine subjequales, quam annulus
quintus fere sesqui breviores. Margo postieus annulorum quattuor priorum latissime
sinuatus; annuli quinti subrectus, obscure flexuosus. Anguli postici annul! secundi,
tertii, quarti, quinti prominuli, integri, breviter rotundati. Annulus analis breviter
subtriangulus, quam annulus quintus caudalis paulo angustior, sesqui ferme latior
quam longior (fere 5:7), annulis ceteris caudalibus conjunctis sesqui longior. Pedes
anales quam annulus analis paulo longiores; ram us interior quam exterior fere sesqui
brevior et paulo angustior, producte laminatus; ramus exterior subfalcatus, acutius-
culus, leviter flexuosus. Long. 8-18 mm.

Color cereus, maculis majoribus vel minoribus, fuscis, racemosis, in series trans-
versas digestis, in medio corpore sparsus; oculi nigri. — SCHIOSDTE and MKINERT, Nat.
Nat. Tidsskr. (3), XIV, 1883-84, pp. 390-395.

For description of the male and the young of the second stage, see same reference,
pp. 392-395.

« See Sars for characters of family, Crust, of Norway, II, 1899, pp. 74-75.

I8OPODS OF NORTH AMERICA.

269

LIMNORIA LIGNORUM (Rathke).

Ci/mothoa lignorum RATHKE, Skrivt. af Natur. Selsk., V, 1799, p. 101, pi. in,
fig. 14.

Limnoria tenebrans LEACH, Edinb. Encycl., VII, 1813, p. 433 (Am. ed., p. 273);
Trans. Linn. Spc. London, XI, 1815, p. 37; Diet. Sci. Nat, XII, 1818, p.
353. — DESMAREST, Consid. G£n. Crust, 1825, p. 312. — LATREILLE, Regne
Anim., IV, 1829; p. 135.— EDWARDS, Annot. de Lamarck, V, 1838, p. 276;
Hist. Nat. Crust, III, 1840, p. 145.— GOULD, Invert. Mass., 1841, pp. 338,
354. — EDWARDS, Regne Anim. Crust., 1849, p. 197, pi. LXVII, fig. 5.

Limnoria lignorum WHITE, Pop. Hist. Brit. Crust., 1857, p. 227, pi. xii, fig. 5.—
BATE, Report Brit Asso'c., 1861, p. 225.

Limnoria undnata HELLER, Verh. k. k. Zool. Bot, Ges. Wien, XVI, 1866, p. 734.

Limnoria lignorum BATE and WESTWOOD, British Sessile-eyed Crust., II, 1868,
p. 351. — NORMAN, Report British Assoc., 1869, p. 288.

Limnoria tenebrans VERRILL, Proc. Am. Assoc. Adv. Sci., 1874, p. 367.

Limnoria calif ornica HEWSTON, Proc. Cal. Acad. Sci., V, 1874, p. 24 (nomen
nudum ) .

Limnoria lignorum VERRILL, Am. Jour. Sci., VII, 1874, pp. 133-135; Proc. Am.
Assoc., 1874, p. 371. — HARGER with VERRILL, Report U. S. Commissioner of
Fish and Fisheries, Pt. 1, 1873, p. 379 (85), p. 571 (277), pi. vi, fig. 25.—
STEBBING, Trans. Devon. Assoc., 1874, p. 8; Ann. Mag. Nat. Hist. (4), XVII,
1876, p. 79.— HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 161.— SMITH, Proc.
U. S. Nat. Mus., II, 1879, p. 232, fig. 2.— HARGER, Report U. S. Commissioner
of Fish and Fisheries, Pt. 6, 1880, pp. 373-376 (See Harger for synonymy). —
RICHARDSON, Proc. U. S. Nat Mus., XXI, 1899, pp. 821-822; Ann. Mag. Nat.
Hist (7), IV, 1899, pp. 161-162.— SARS, Crust, of Norway, II, 1899, pp. 76-77,
pi. xxxi. — RICHARDSON, American Naturalist, XXXIV, 1900, p. 222; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 532.

Localities. — From Florida to Halifax and Gulf of St. Lawrence;
Pacific Ocean; San Diego, California; also coast of Great Britain;
Kielerbucht, Germany; North Sea; Adriatic
Sea; coast of Norway; Bering Island; Woods
Hole, Massachusetts.

This species is destructive to wood and sub-
merged timber, boring holes which causes its

Body oblong-ovate, twice as long as wide, li
mm. : 3 mm.

Head wider than long, about twice as wide,
with the anterior margin slightly excavate.
Eyes small, distinct, and situated at the sides of
the head. The first pair of antenna have the first
two articles subequal; the third is a little longer
than the second; the fourth or first flagellar arti-
cle is half as long as the third; the fifth or second
flagellar article is minute. The first antennae extend to the end of the
fourth article of the second pair of antenna1. The second pair of
antennae have the first article large; the second is not as long as the
first; the third and fourth are subequal and each is about as long a*s the

FIG. 279.— LIMNORIA LIGNO-
RUM (AFTER HARGER).

270

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 280.— LlMNORIA L I G N O R U M

(AFTER HARGER). a, FIRST AN-
TENNA. x25. 6, SECOND AXTF.XNA.
x 25. c, MAXILLIPED. x 25. <l,
SECOND MAXILLA, x 25. e, FIRST
MAXILLA, x 25. e', DISTAL END OF

FIRST MAXILLA. X 66. /, MANDI-
BLE. X 25.

FIG. 281.— LlMNORIA LIGNOKTM

(AFTER HARGER). o, LAST SEG-
MENT OF ABDOMEN WITH UROPODA.

x 10. b, UROPOD. x 30. c, FIRST

PAIR OF PLEOPODA. X 20. d, SEC-
OND PLEOPOD OF MALE. X 20.

branch reaches the

first; the fifth article is about as long as the fourth. The flagellum is
composed of two or three indistinctly denned articles. The maxilli-

peds have a palp of five articles. The pulp of
^ne man-dibles i* composed of three articles.

The first seg-
ment of the tho-
rax is longer than
any of those fol-
lowing, which are
subequal; it is al-
most twice aslong.
Epimera are dis-
tinctly separated
on all the segments
with the excep-
tion of the first.

The abdomen is composed of six distinct
segments. The first five are short and sub-
equal. The sixth or terminal segment has
the posterior margin widely rounded. The
uropoda are laterally placed. The outer
branch is small and rudimentar}^. The inner
extremity of the abdomen.
All the legs are ambulatory.

Family XI. SPH^ROMID^.

Body short, oval, convex. Head transverse.

First and second pairs of antennae multiarticulate with evident dis-
tinction into peduncle and flagellum. Mandibles with palps. Anterior
segments of abdomen united into a single segment, which, with the
large terminal segment, forms a biarticulate abdomen.

Uropoda lateral, forming, with the terminal abdominal segment, a
caudal fan. Outer branch of uropoda, when present, movable. Inner
branch fixed, immovable.

Epimera united with the thoracic segments.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY SPH^CROMID^.

a. Outer branch of the uropoda entirety wanting Genus Ancinus Milne Edwards

a'. Both branches of the uropoda present.

b. Outer branch of the uropoda small, rudimentary Genus Cassidisca, new genus

b' '. Outer branch of the uropoda not rudimentary.
c. First and second pairs of legs subchelate in male; only first pair subchelate

in female Genus T<'rti<-<-/»< Richardson

cf. Legs all ambulatory.

d. Outer branch of uropoda capable of folding under inner branch; both
branches similar in shape and salient.

ISOPODS OF NOETH AMERICA. 271

e. Terminal segment of abdomen entire.
/. Maxillipeds with second, third, and fourth articles of the palp not

produced into lobes Genus Sphteroma Latreille

/'. Maxillipeds with second, third, and fourth articles of the palp pro-
duced into lobes Genus Exosph;eroma Stebbing

e' '. Terminal segment of abdomen with a median ernargination.
/. Second, third, and fourth articles of palp of maxillipeds produced

into lobes -. Genus Dynamene Leach

/'. Second, third, and fourth articles of palp of maxillipeds not produced

into lobes Genus Paradynamene, new genus

d'. Outer branch of uropoda not capable of folding under inner branch;
branches unlike, only outer one salient Genus C'dicaea Leach

48. Genus ANCINUS Milne Ed-wards.

f

Abdomen composed of two segments, the first segment formed by
the fusion of several segments.

Outer branch of the uropoda entirely wanting.

First and second pairs of legs subchelate; remaining pairs ambula-
tory.

ANCINUS DEPRESSUS (Say).

Nsesa depressa SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 483-484. — RICHARI-
SON, American Naturalist, XXXIV, 1900, p. 224; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 537.

Locality. — Egg Harbor, New Jersey.

Depth. — Found on surface.

"Body broad, depressed, linear; first caudal segment concealed,
second attenuated; anterior feet monodactyle.

"Inhabits Egg Harbor.

"Cabinet of the Academy.

"Body broad, depressed, punctured, sides parallel; segments sub-
equal, anterior ones rather shorter; first segment of the tail not visible,
second equal, as long as the three preceding visible ones, attenuated
to an. obtuse point, which is carinated above and attained by the lateral,
spiniform, acute processes; beneath concave, effuse at tip; eyes appar-
ently lunated, but really rounded', with distant granules, and touching
the anterior segment of the body; hands of the anterior feet dilated,
ovate, thumb as long as the palm, nearly attaining the carpus, tip
closing within a prominent spinose tooth on the base of the palm;
hands of the second pair cylindric, incurved, with a process dentate
at tip and placed at the inner base, armed with an equal incurved
thumb not closing on the hand, obtuse, and furnished with a seta at
tip; remaining feet ciliated.

"Length half an inch, breadth rather more than one-fifth of an inch.

"Found with the preceding species, common." — SAY.*"

oJourn. Acad. Nat. Sci. Phila., 1, 1818, pp. 483^84.

272 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

A single dried specimen of this species, the type, is in the Philadel-
phia Academy of Natural Sciences.

The body is ovate, about twice as wide as long, 6 mm. : 12 mm.
The head is short and wide, being 1 mm.: 4 mm., with lateral mar-
gins and lateral angles rounded. The anterier margin is produced in
a linguiform median process extending forward over the basal articles
of the first antennae.

The segments of the thorax are subequal.

The first segment of the abdomen is almost entirely concealed. The
second or terminal segment is 4 mm. long and 5 mm. wide at the base.
It is triangular in shape, with apex funnel-shaped, the sides being
turned downward and inward. The uropoda are single-branched, and
are in the form of a long, narrow, tapering branch, posteriorly acute,
and extending to the tip of the terminal abdominal segment. This
branch seems fixed to the sides of the abdomen,
and immovable. There is no trace or indication
of an outer branch.

The first pair of antenna? have the first three
peduncular articles dilated, and of nearly equal
length.

As the dried specimen is glued to a piece of
paper, nothing can be ascertained of the structure
FIG. 282.-ANCINUS DE- of the legs.a
PRESSUS. ABDOMEN WITH The specimen was evidently formerly mounted

UROPODA. X 6£. . . , , ,' . . .

on a pin, as there is a hole in the paper and
through the body of the specimen, breaking it at about the middle.

46. Genus CASSIDISCA, new genus.

Body oval, depressed.

Maxillipeds with second, third, and fourth articles of palp not pro-
duced into lobes.

Abdomen composed of two segments, the first segment formed by
the fusion of several segments.

The inner branch of the uropoda is large and well-developed, and is
immovable and firmly fixed to the side of the abdomen. The outer
branch is rudimentary and very short, and not entirely separated from
the inner branch, sometimes being represented by a small incision in
the exterior margin of the inner branch.

Legs all ambulatory.

« This genus is quite similar to Scuteloidea Chilton, but differs, according to Say,
in having the first two pairs of legs subchelate, while in Scuteloidea the legs are all
ambulatory.

ISOPODS OF NOKTH AMERICA.

273

This genus differs from Cassidina® Milne Edwards and Cassldinella
Whitelegge,6in not having the palp of the maxillipeds with the second,
third, and fourth articles produced into lobes.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CASSIDI8CA.

a. Terminal segment of abdomen smooth. Outer branch of uropoda about one-
fourth as long as inner branch. Apex of abdomen truncate.

Cassidisca lunifrom (Richardson)

a'. Terminal segment of abdomen with three low transverse elevations as the base.
Outer branch of uropoda more than one-third bui, not quite one-half as long
as the inner branch. Apex of abdomen triangulate Cassidisca oralis (Say)

CASSIDISCA LUNIFRONS (Richardson).

Cassidina lunifrons RICHARDSON, American Naturalist, XXXIV, 1900, p. 222; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 533.

Locality. — Great Egg Harbor, New Jersey.
Bod}^ oval, surface smooth.

Head broader anteriorly than posteriorly, the antero-lateral angles
being produced in a lateral direction and form-
ing very acute angles. The eyes are situated at
the post-lateral corners of the head. The first
pair of antennae reach two or three joints be}rond
the antero-lateral angle of the head;
flagellum six-jointed. The second
pair almost reach the posterior mar-
gin of the first thoracic segment;
flagellum consists of about eight
joints, the first four being large,
the last four small and setose.

The first thoracic segment is well
fitted to the head, so that the ellip-
tical outline of the body is pre-
served. The segments are sub-
equal, with straight lateral margins. The epimera are not distinct
from the segments.

The first segment of the abdomen is short. The terminal segment
is subtriangular, with apex truncate. The inner branch of the uropoda
is pointed at its extremity, and reaches the tip of the abdomen. The
outer branch is rudimentary, about one-fourth as long as the inner
branch.

«Gerstaecker (Bronn's Klassen und Ordnungen des Thier-Reichs, V, Pt. 2, Pts.
1, 2, 3, 1881, pi. vi, fig. 12a) figures the maxilliped of Cassidina typa Milne Edwards,
and shows the second, third, and fourth articles of the palp produced into lobes.
Specimens of Cassidina emarginata in the collection of the U. S. National Museum
have the maxillipeds with the second, third, and fourth articles of the palp also pro-
duced into lobes.

& Austral. Mus. Mem., IV, 1901, pp. 201-246.
28589—05- 18

FIG. 283. -CASSIDISCA LUNI-
FRONS.

FIG. 284. —CASSI-
DISCA .LUNI-
FRONS. MAXIL-
LIPED. x 77|.

274 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Color, brown.

Specimens were found at Great Egg Harbor, New Jersey, by Dr.
William Stimpson.

Type,— Cat No. 4402, U.S.N.M.

This species is very similar to the following one, and may prove to
be the same. As the type and only specimen of Say's species is in
such a bad state of preservation, I am unwilling as yet to identify this
species with it.

CASSIDISCA OVALIS (Say).

Nsesa ovalis SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 484-485. — RICHARD-
SON, American Naturalist, XXXIV, 1900, p. 224; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 537.

Locality. — South Carolina.
Depth. — Found on surface.

"Body oval, depressed; ultimate segment of the tail obtuse, with
three hardty raised, very obtuse lines at base; lateral appendices
dilated, three caudal segments.

"Inhabits bays and inlets of the United States; common. Cabinet
of the Academy.

" Body perfectly oval, segments subequal, fourth, tifth, and sixth
largest, first segment of the tail equal to the-
preceding one, simple; terminal segment tri-
angular, obtusely rounded at tip, rectilinear
each side, half as long as the body, with three
longitudinal, abbreviated, raised, very obtuse
lines at base, of which the middle one is most
FIG. 285. — CASSIDISCA OVALIS. conspicuous; lateral processes dilated, de-
ABDOMEN- WITH UROPODA. presse(^ rectilinear within and rounded on

the external margin, so as to form with the

terminal segment a perfectly semiorbicular termination of the body,
without interval; head somewhat unequal; e}res conspicuous, hemi-
spherical; antennas equal; labrum triangular, advanced, very conspic-
uous, terminating the head before and forming, with the base of the
superior antennae behind it, a rounded termination without interval,
completing the oval form of the body; feet all armed with bifid nails,
none of which close on the preceding joint.

"Length less than three- twentieths of an inch.

"This little animal is extremely common in sea wrater, usually
creeping on fuci and other marine plants; we found it as far south as
St. Johns River in Florida." SAY."

A dried specimen, mounted on a pin, the type and only specimen of
this species is in the Philadelphia Academy of Natural Sciences. The
specimen was loaned me for examination.

ajourn. Acad. Nat. Sci. Phila., I, 1818, pp. 484-485.

I8OPODS OF NORTH AMERICA. 275

1 have been able to ascertain that the species should be referred to
the genus Cassidisca. The outer branch of the uropoda is more than
one-third as long as the inner branch, and in the dried specimen was
rather difficult to find. By carefully scraping off some of the incrust-
ing substance the form of the uropoda was disclosed.

The body is oval, depressed, about 5 mm., in length.

The seven segments of the thorax are distinct; the first three are
subequal in length; the three following segments are subequal, and
are longer than the three preceding segments; the seventh segment is
a little shorter than the sixth segment.

The first segment of the abdomen is short, about as long or perhaps
a little shorter than the seventh thoracic segment. The terminal seg-
ment is triangular with apex obtusely triangulate. The base of the
segment appears to have a large median longitudinal elevation or boss,
and a smaller one on either side.

The inner branch of the uropoda is as long as the terminal segment;
the inner margin is straight; the outer margin is curved. The outer
branch is a little more than one-third the length of the inner branch,
and is marked off only by a small incision in the exterior margin of the
inner branch. It is separated on the inner margin from the inner
branch only by a depressed line. In a fresh specimen the separation
might be more complete.

Nothing can be ascertained of the antennae.

47. Genus TECTICEPS Richardson.

Body oval and somewhat flattened.

Head subquadrangular, broader anteriorly than posteriorly, with its
anterior and lateral margins produced, concealing the antenna?. The
antennae, which are entirely hidden, extend backward and lie under
the epimeral plates at the sides of the thorax.

The first and second pairs of legs are subchelate in the male; only
the first pair are subchelate in the female; the first pair terminate in
a large oval hand and finger, bearing a small hook; the second pair in
the male terminate in a more irregularly shaped hand. All the other
legs are simple in structure.

The terminal segment of the abdomen is triangular and entire, and
is pointed at the extremity. The uropoda are double branched and
lateral, and resemble closely those of the genus Sphzeroma.

The second, third, and fourth articles of the palp of the maxillipeds
are produced in lobes as in the genus Exosphaeroma.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS TECTICEPS.

a. First pair of antennte, with a flagellum of ten articles, extend to the posterior
angle of the first thoracic segment. Second pair of antennae, with a flagellum of

276

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

twelve articles, extend to the middle of the second thoracic segment. Termi-
nal segment of abdomen acutely pointed. Outer branch of uropoda much
longer than inner branch. Eyes placed on the posterior half of the head.
Sixth and seventh pairs of legs have the propodus and dactylus very much
more elongated than in preceding pairs of legs. . . Tecticeps alascensis Richardson
b. First pair of antennae, with a flagellum of sixteen articles, extend to the posterior
angle of the third thoracic segment. Second pair of antenna, with a flagel-
lum of thirteen articles, extend to the middle of the fourth thoracic segment.
Terminal segment of abdomen posteriorly rounded. Outer branch of uropods
equal in length to inner branch. Eyes placed in the middle transverse line
of the head. Sixth and seventh pairs of legs with propodus and dactylus
only gradually a little longer than those of preceding pairs of legs.

Tecticeps convexus Richardson

TECTICEPS ALASCENSIS Richardson.

Tecticeps alascensis RICHARDSON, Proc. Biol. Soc. Washington, XI, 1897, pp. 181-
183; Proc. U. S. Nat. Mus., XXI, 1899, p. 837; Ann. Mag. Nat. Hist. (7),
IV, 1899, p. 181; American Naturalist, XXXIV, 1900, p. 223.

Localities. — Alaska; Kamchatka; Off Iturup Island, Kurile Islands,
Okhotsk Sea; latitude 60° 16' north, longitude 167° 41' west; Ber-
ing Sea, west of Pribilof Islands (106 fathoms); between Pinnacle
and Ulakhla, Unalaska; Bering Sea, off Nunivak Island.
Depth.— 9-106 fathoms.

Found in fine gray sand, pebbles, gravel, shells, black and red sand,
green mud, and fine dark volcanic sand.

Outline of body oval. Surface quite smooth, but
covered with little points of depression.

Head large; twice as long as any one of the
thoracic segments. The anterior margin is pro-
duced in a way to conceal the antennae, as are also
the ante ro- lateral margins, making the anterior
portion of the head in front of the e}res much
broader than the posterior portion, and forming
very acute antero-lateral angles. This frontal
margin forms a very broad
obtuse angle with its apex in
the median line. On either
side of this apex to the antero-
lateral angle this portion of the head is somewhat
depressed. The antennae are not conspicuous,
lying concealed beneath the frontal margin of
the head. The first pair extend to the posterior
angle of the first thoracic segment; the flagellum consists of ten
articles. The second pair reach the middle of the second segment;
the flagellum is twelve-jointed. The eyes are dorsally situated on the
posterior half of the head.

The thoracic segments are about equal in length. The first one
extends laterally around the posterior portion of the head, forming a

FIG. 286.— TECTICEPS AI.-

ASCENSIS. X 2}.

FIG. 287. — TECTICEPS ALAS-
CENSIS. a, ANTENNA OF
FIRST PAIK. 6, ANTENNA
OF SECOND PAIR. X 5|.

ISOPODS OF NORTH AMERICA.

277

FIG. 288.— TECTICEPS ALASCENSIS. a, MANDIBLE.
b, MANDIBULAK APPENDAGE, x 5J. c, MAX-

ILLJPED. X 20J.

broad plate at the side of the segment. The epimera of all the seg-
ments are about twice as broad as long, with the exception of those of
the fifth segment, which are nearly
square and very conspicuous.

The first segment of the abdomen
has three suture lines, and its pos-
terior margin projects down in two
small triangular processes, on? on
either side, over the terminal seg-
ment. The terminal segment is tri-
angular, and has a very pointed
extremity. The branches of the
uropods differ considerably. The
inner one is broad and tapering,

and does not reach the tip of the abdomen. The outer one is slender
and sharply pointed, and extends be}rond the abdomen.

The first pair of legs are subchelate, as
are also the second pair in the male. In
the first pair the propodus is large and
oval in shape, and bears in the palma a
row of stiff bristles at regular intervals
and pointing obliquely in the same direc-
tion, while a thick row of fine cilia, point-
ing obliquely in the opposite direction,
crosses these almost at right angles. The
dactylus terminates in a single hook, at
the base of which two smaller hooks are
situated. In the legs of the second pair
the propodus is irregular in shape with an
indication of a rudimentary pollex. There
are no hairs or bristles in the palma. The
legs of the third, fourth, and fifth pairs
present nothing unusual in structure, but
resemble the ambulatory legs common to
this family. In the sixth and seventh
pairs the structure is the same as that of
the preceding legs of the third, fourth,
and fifth pairs, but with an increasing
disproportion in the length of the propo-
dus and dactylus. In the seventh pair of
legs these joints, but more especially the
propodus, attain a size most conspicuous
for their length. The propodus becomes
over 3£ times longer than the carpus which immediately precedes it.
Color. — The color varies from dark brown to yellow, more or less

FIG. 289.— TECTICEPS ALASCENSIS. a,
LEG OF FIRST PAIR, x 5|. 6, LAST

TWO JOINTS OF SAME. X lOf . C, LEG
OF SECOND PAIR OF MALE. X 6f . d,

LEG OF THIRD PAIR, x 5}. e, LEG

OF SIXTH PAIR. X 6|. /, LEG OF
SEVENTH PAIR. X 5|.

278 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

dotted with black. In the darker specimens the epimera and the uro-
pods are almost white, with scattered spots of black. Other specimens
are brown with markings of red, and some are bluish-gray in color
tinged with brown or orange.

Type. — The type specimen was found at station 3515, latitude 59° 59'
north, longitude 167° 53' west, at a depth of 13 fathoms. Catalogue
No. 20031, U.S.N.M.

Distribution. — This species extends all along the coast of Alaska,
having been found at the following stations: Station 3272, north of
Amak Island (31 fathoms); station 3297, off Cape Menchikoff (26
fathoms); station 3246, south of Hagemeister Island (17£ fathoms);
station 2841, North Head, Akutan Island (56 fathoms); station 3248,
off Bristol Bay (21 fathoms) ; station 3600, Aleutian Islands, off Unimak
Island (9 fathoms).

TECTICEPS CONVEXUS Richardson.

Tecticeps convexux RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 837-838;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 181-183; American Naturalist,
XXXIV, 1900, p. 223.

Locality. — Monterey Bay, California.

Depth.— 30 feet, sandy bottom.

Body oval, somewhat flattened. Surface smooth; color light yellow
with markings o-f brown.

Head with the anterior margin much broader than the posterior mar-
gin, produced in front but not wholly concealing the basal joints of the
first pair of antennas, and somewhat raised, forming two small convex
elevations. The antero-lateral margin is likewise produced, forming
an acute angular projection, which extends in a lateral direction beyond
the post-lateral margin of the head. The eyes are dorsally situated in
a median transverse line. The first pair of antennae, with a flagellum
of sixteen articles, extend to the posterior angle of the third tho-
racic segment. The second pair of antennas, with a flagellum of thir-
teen articles, extend to the middle of the fourth thoracic segment, and
exceed by one joint the length of the first pair of antennas. Both pairs
of antennas are disposed to lie concealed under the broad epimeral
plates of the thoracic segments.

The thoracic segments are subequal in length. The first segment
has its antero-lateral angles produced around the anterior portion of the
head, forming a broad plate at the .side of the segment. The epimera
are almost twice as broad as long; those of the fifth segment extend
downward, with the anterior margin straight, making the length and
breadth about equal, and forming almost square epimera; in the epim-
era of the sixth and seventh segments the anterior margins are in the
same direction as the posterior margins, which extend downward.

ISOPODS OF NORTH AMERICA.

279

The first segment of the abdomen has three suture lines, and its pos-
terior margin is produced in two small points.
one on each side of the median line, about
equidistant from it and the lateral margin of
the segment. The terminal segment is widely
rounded posteriorly. The inner branch oithe
uropoda is of nearty equal width throughout
its length and is rounded at its extremity; the
outer branch is slender and sharply pointed.
Both branches are of nearly equal length and
neither extends beyond the tip of the abdo-
men.

The first pair of legs have the propodus
dilated and the dactylus reflexible. The pro-
podus is large and oval in shape. In the legs
of the second pair the propodus is irregular in
shape, dilated with reflexible dactylus in the
male, and simple in the female. The legs of the other five pairs are
similar in structure, ambulatory, and show a gradual increase in
length.

FIG. 290. — TECTICEPSCONVEXUS.
a, HEAD, x 5J. 6, ABDOMEN

AND LAST THORACIC SEGMENT.
X 2|.

FIG. 291. — TECTICEPS CONVEXUS. a, MAXILLIPED. x 27j. b, SECOND LEG OF FEMALE, x 27$. e, FIRST
LEG. x 15}. d, MANDIBLE, x 15$. e, SECOND MAXILLA, x 27}. /, FIRST MAXILLA, x 27}.

280 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

A number of individuals were found at Monterey Bay, California,
and sent to the U. S. National Museum by Mr. Heath, who gives the
following note of their habits:

They were taken by the Chinese fishermen from a sandy sea bottom about 30 feet
below the surface (according to the Chinese statement). These are rapid swimmers,
and the moment they are disturbed they roll into a ball and project the exopodite
of. the last free segment. This is undoubtedly for protection. I have not had time
to accurately examine the position nor character of this appendage, but its sharp,
swordlike nature is readily recognized.

Type.— Cat. No. 22572, U.S.N.M.

This species differs from T. alascensis in having longer antenna and
antennulse; in having the terminal segment rounded, which in that
species is very pointed; in having the outer branch of the uropods as
short as the inner, which in that species is much longer; in having only
a gradual increase in the length of the legs, which in that species show
such marked disproportions in the propodus of the sixth and seventh
pairs, and in the position of the eyes, which in this species are situated
in the median transverse line of the head, while in T. alascensis they are
placed in the posterior half of the head.

48. Genus SPH^EROMA Latreille.

Body contractile, able to roll into a complete ball. Abdomen com-
posed of two segments, the first of which is formed by the fusion of
several coalesced segments. The terminal segment is rounded, entire.

The branches of the uropoda are similar, both being salient. The
outer branch of the uropoda is denticulate along the exterior margin;
the inner branch is immovable and fixed to the side of the abdomen;
the outer branch is movable, and capable of folding under the inner
branch.

The second, third, and fourth articles of the palp of the maxillipeds
not produced into lobes, but furnished with exceedingly long hairs.

Legs all ambulatory in structure.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS SPH^ROMA.

a. Abdomen without tubercles Sphseroma quadridentatum Say

a'. Abdomen with tubercles.

b. Tubercles on terminal segment of abdomen arranged in a transverse row of four
on anterior portion. Two tubercles on first abdominal segment, one on either
side of the median line. A transverse row of four tubercles, two on either
side of the median line on the seventh thoracic segment. Posterior extremity
of terminal segment of abdomen without prominent transverse elevation.

Sphseromn destructor Richardson

b'. Tubercles on terminal segment of abdomen arranged in two longitudinal series
of four, a series on eithe.r side of the median line. No tubercles on first seg-
ment of abdomen or on seventh thoracic segment. Posterior extremity of ter-
minal segment of abdomen with prominent transverse elevation.

Sphssroma pentodon Richardson

ISOPODS OF NOBTH AMERICA.

281

FIG. 292.— SPH.EROMA QUADRIDENTATUM
(AFTER HARGER).

SPH^EROMA QUADRIDENTATUM Say.

Sphvroma quadridentatum SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 4CX). —
HARGER, Am. Jour. Sci. (3), V, 1873, p. 314.— HARGER with VERRILL, Eeport
U. S. Commissioner of Fish and Fisheries, 1873, Pt. 1, p. 315 (21); p.
569 (275), pi. v, fig. 21.— HARGER,
Proc. U. S. Nat. Mus., II, 1879, p.
161; Report U. S. Commissioner of
Fish and Fisheries, Pt. 6, 1880, pp.
368-370, pi. ix, fig. 53.— RICHARD-
SON, American Naturalist, XXXIV,
1900, p. 223; Proc. TJ. S. Nat. Mus.,
XXIII. 1901, p, 533.

Localities. — New England; Vine-
yard Sound; Provincetown, Massa-
chusetts; Savin Rock, New Haven;
Cape Charles City, Virginia; St.
Catherine Island, Georgia; Beau-
fort, North Carolina; east Florida;
Key West, Florida; south Florida.
Depth. — Surface to one - half
fathom.

The type locality is St. Catherine Island, Georgia.
Body ovate, nearly twice as long as wide, 5 mm. : 10 mm.

Head twice as wide as long, 1£
mm. : 3 mm. , with a frontal bor-
der arising between the eyes and
produced in a small median point.
The eyes are small, round, com-
posite, and situated in the post-
lateral angles of the head. The
first pair of antennae have the
basal article elongate; the second
article is half as long as the first;
the third is twice as long as the
second. The flagellum is com-
posed of twelve articles. The first
antennae extend to the middle of
the first thoracic segment. The
basal article of the second anten-
nae is inconspicuous; the second
is short; the third is twice as long
as the second; the fourth and fifth

FIG. 293.-spH*ROMA QUADRIDENTATUM. a, MAN- *™ subequal and each is a little
DIBLE. x 41. 6, FRONTAL LAMINA AND CLYPEUS. longer than the third. The fla-

x 23. c, MAXILLIPED. x 41. n • j £ c£±

gellum is composed of fifteen

articles. The second antennae extend to the posterior margin of the
second thoracic segment. The maxilliped has a palp of five articles.

282 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The palp of the mandible is composed of three articles. The. frontal
lamina is large and conspicuous and has the anterior margin broadly
triangulate, the post-lateral angles produced.

The segments of the thorax are about equal in length. The epimera
are not distinct from the segments, but the place of coalescence is
indicated by a light longitudinal area on either side of the segment.
The post-lateral angles of the lateral parts of all the segments is drawn
out into a narrow and somewhat acute process, more pronounced in
the first four segments.

The abdomen is composed of two segments. The first segment has
three suture lines indicating several partly coalesced segments.
The terminal segment is long and widely rounded posteriorly. The
anterior portion is convex. The fixed inner branch of the uropoda
extends a little beyond the extremit}^ of the terminal abdominal seg-
ment and has its margins smooth. The outer movable branch is as
long and wide as the inner branch and has three or four teeth on its
outer margin.

The legs are all ambulatory in character.

SPH..EROMA DESTRUCTOR Richardson.

Sphseroma destructor RICHARDSON, Proc. Biol. Soc. Wash., XI, 1897, pp. 105-107;

American Naturalist, XXXIV, 1900, p. 223; Proc. U. S. Nat. Mus.,

XXIII, 1901, p. 534.
Sphseroma tenebrans STEBBING (part), Spolia Zeylanica, II, Pt. 5, 1904, pp. 16-21.

Locality. — St. Johns River, Palatka, Florida. (Fresh water.)
Bores holes in piers on St. Johns River. Sections of the wood
show that the diameter had been reduced during a period of eight
years from 16 inches to 7i inches. The whole surface of the wood
was bored with holes averaging in size about 5 mm.
in diameter, and in an end section the holes were
arranged in concentric rings between the rings of
annual growth, showing the little animal's preference
for the soft pine. Very strong mandibles projecting
beyond the labrum most conspicuously provide a per-
fect equipment for this destructive work.

Head twice as broad as long, having a small
median projection. Eyes lateral and posteriorly
FIG.294.-SPHJEROMA situated. The first pair of antennae, with a flagellum

DESTRUCTOR. DOR- . , * , , ,

SAL VIEW, x 3. composed of eight articles, reach the posterior margin
of the head; the second pair of antenna extend to
the post-lateral angle of the first thoracic segment; its flagellum is
twelve jointed.

The first and fourth thoracic segments are of equal length and are
one and a half times longer than the other thoracic segments. The

ISOPODS OF NORTH AMERICA.

283

FIG. 295.— SPH«ROMA
DESTRUCTOR. MAN-
DIBULAR APPEND-
AGE. X 10.

epimeral parts are not distinct from the segments, are quite broad, and
terminate lateral^ in acute angles, which point downward. The
seventh thoracic segment bears four tubercles situated in a transverse
line.

The abdomen is composed of two distinct segments, on the first of
which are two tubercles, one on either side of the median line. Suture
lines at the sides of this segment indicate three coa-
lesced segments. The terminal segment is triangu-
larly shaped and rounded posteriorly with an upcurved
margin, which extends all around the terminal half
of the segment. The whole surface of the abdomen
is thickly tuberculated with low but distinct tuber-
cles, each one surmounted with a small tuft of stiff hairs or bristles.
On the anterior part four large tubercles are situated in a transverse
line, the two center ones being somewhat closer to each other than
to the lateral ones. The uropoda extend be-
yond the extremity of the abdomen, the outer
branch being the longer. Both are pointed
and similar in shape. The outer edge of the
exopodite is provided with four teeth, while
that of the endopodite is smooth.

The legs of this species are in three series,
according to structure, the first three pairs
being alike, the fourth and fifth similar, and
the sixth and seventh similar. The legs of the
first series are long and slender (fig. 294 a),
with the second joint or basis nearly cylindrical
in shape. The ischium is nearly as long as the
basis, and this joint, as well as the merus, is
furnished with long straight hairs. The carpus
and propodus are likewise long and slender.
In the first pair the carpus is minute. The
legs of the second series, the fourth and fifth
pairs, are stout and short, being similar in
general form, though differing somewhat in rel-
ative proportions. The basis is about half the
length of the entire leg, while the joints following the ischium are
very short. In the third series the legs are nearly as long as those
of the first series, but differ in size and shape. They are stouter and
not cylindrical.

The whole surface of the body is punctate, and has minute trans-
verse rugae between the points of depression. In color it is a dark
brown, shaded on the edges with a lighter brown.
Type.— Cat No. 19857, U.S.N.M.

FIG. 296.— SPH^ROMA DESTRUC-
TOR, x 10. a, LEG OF SEC-
OND PAIR. 6, LEG OF FOURTH
PAIR. C, LEG OF FIFTH PAIR.
d, LEG OF SIXTH PAIR.

284

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Spence Bate" describes a species of Sphaeroma, Sphseroma vasta-
toi\ which was procured ufrom a piece of wood which had formed
part of a railway bridge over one of the back-
waters of the West Coast of the Indian Penin-
sula." The wood is described as being "honey-
combed with cylindrical holes, in many of which
the animal was rolled up like a ball." Notwith-
standing the close resemblance in habits and
appearance of this species, as described and
figured, to the present one, there are four
points of difference:

I. The number and arrangement of the tubercles
in the two species. — In S. vastator four tubercles
are described on each of the last three segments
of the thorax, and only two are figured on the
anterior portion of the pleon. In the species under discussion, how-

FIG. 297.— SPH^CBOMA DE-
STRUCTOR. ABDOMEN WITH
UROPODA AND LAST SEG-
MENT OF THORAX.

FIG. 298.— SPH^EROMA DESTRUCTOR, a, MAXILLIPED. x 27}. 6, MANDIBLE (PALP OMITTED), x 27}.
c, FIRST MAXILLA, x 27}. d, SECOND MAXILLA, x 27}.

ever, there are four tubercles on the seventh segment of the thorax

« Ann. of Nat. Hist. (3), XVII, p. 28, pi. n, fig. 4.

ISOPODS OF NORTH AMERICA. 285

only, and six on the abdomen, two on the first abdominal segment, and
four on the anterior portion of the terminal segment.

II. The structure of the feet. — In S. vastator the legs of the first
three pairs are not proportionately as long as those of the present
species. The rnerus is differently shaped, not being cylindrical in that
species, and is relatively shorter. Although Spence Bate mentions no
dissimilarity in structure in the legs of the fourth and fifth pairs, still
a difference is shown in the cut in the formation of the merus. With
our species the difference in these two pairs of legs is merely in pro-
portion. There is a greater resemblance in the sixth and seventh
pairs of legs of the two species.

III. The upcurved margin of the posterior half of the terminal seg-
ment of the abdomen.

IV. The presence of numerous tubercles furnished with bristle-like
hairs upon the abdomen.

Neither of these points are mentioned in the description of Sphx-
roma vastator.

In a recent paper, "Gregarious Crustacea from Ceylon," Rev.
T. R. R. Stebbing a places Sphseroma destructor from Florida in the
synonymy of Sphddroma tenebrans Bate from Brazil, and also refers
to that species Sphseroma vastator Spence Bate from Madras, and con-
siders specimens sent him from Ceylon as belonging to that species.

In the above description I have pointed out the differences between
Sphseroma destructor and Sphs&roma vastator. It remains to point
out the differences which exist between Sphderoma destructor and the
specimens which Dr. Stebbing had from Ceylon.

The specimens from Florida have the abdomen " thickly tuberculate
with low but distinct tubercles, each one surmounted with a tuft of
small hairs or bristles." Stebbing says, in reference to this character,
that this feature is not of the highest importance, and in some of his
specimens can not easily be discerned. In the Florida specimens these
tufts are most conspicuous and very apparent in all the specimens.
Stebbing further states that in a dorsal view of Sphseroma destructor
they are not even indicated in the figure. The drawing was merely an
outline drawing, not a finished one, and the statement of the tuber-
culate character of the abdomen was made in the text. The above
illustration (fig. 295) fully shows this point as well as the difference,
in this respect, between the specimens from Florida and those of
Stebbing. Neither in the text nor in the figure is there any indica-
tion of tubercles on the abdomen of Stebbing's specimens.

The specimens from Florida have the inner plate of the first
maxillae tipped with five strong plumose setae and occasionally a sixth
one that is feeble; on the outer plate are eleven spines. Stebbing's

. «Spolia Zeylanica, II, Pt. 5, 1904, pp. 16-21.

286 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

specimens have three strong plumose seta? and one that is feeble on
the inner plate, and nine spines on the outer plate of the tirst maxilhe.

The terminal abdominal segment in Stebbing's specimens has the
sides near the apex incurved. In the Florida specimens the sides are
straight.

The outer branch of the uropoda in S.' destructor has four teeth on
the exterior margin, and a slight indication of a fifth in some speci-
mens. There are never six teeth, and the fifth one is never well
developed and strong as the four, which are constant in size and num-
ber. Stebbing says that this number is also found in the Ceylon
specimens, the precise number being immaterial, but later, in pointing
out the affinity of Sphseroma felix Lanchester, with the species in
question, refers to the outer ramus in Sphseroma felix as having eight
small teeth on the outer margin, this being a character to be consid-
ered in separating the species.

The second, third, and fourth segments of Sphseroma destructor are
each crossed by a transverse ridge. In Stebbing's specimens only the
fourth segment has a transverse ridge.

The apical tooth of the mandibles is sub-bififl in the Florida
specimens.

SPH^ROMA PENTODON Richardson.

Sphseroma pentodon RICHARDSON, Harriman Alaska Exp. Crust., X, pp. 214-215;
Proc. U. S. Nat. Mus., XXVII, 1904, pp. 659-660— HOLMES, Proc. Cal.
Acad. Sciences (3), III, 1904, pp. 323-324, pi. xxxvn, fig. 43.

Localities. — Sausalito, San Francisco Bay, California. Found in
mud flat.

Body elliptical in outine; color dark brown; sur-
face minutely but densely granular.

Head situated transversely, with a prominent
ridge on the anterior margin. Eyes placed post-
laterally, and composed of many ocelli. First pair
of antennae extend to the posterior margin of the
head; flagellum eight-jointed. Second pair of an-
tennae reach the middle of the second thoracic seg-
ment; flagellum composed of fifteen joints.
FIG. 299.— SPH.EROMA Segments of the thorax about equal in length,
upNETDOD°x'27|lAXIL with the exception of the first, which is somewhat
longer than any of those following. The lateral
parts, which are not distinctly separated from the dorsal portion of the
segments, are drawn out in acute processes in the first three segments.
Those of the following segments are more nearly regular in outline.

The abdomen is somewhat broader than the thorax, although this
expansion of the abdomen does not show in a dorsal view. The first

ISOPODS OF NORTH AMEEICA. 287

segment is about equal in length to the last thoracic segment, and is
marked on. either side by two suture lines indicative of coalesced seg-
ments. The terminal segment is entire, and not produced, being
evenly rounded in outline. The anterior portion of the segment is
convex, with a longitudinal series of four small tubercles on either
side of the median line, the two series being close together. The pos-
terior extremity of the segment is marked by a prominent transverse
elevation.

The inner immovable branch of the uropoda is narrow, elongate,
and pointed posteriorly; it extends to the extremit}7 of the abdomen.
The outer mobile branch is provided on the lateral margin with five
strong teeth. Both branches are of equal length.

The first three pairs of legs are slender, and are furnished with long
hairs. The other four pairs are somewhat
stouter.

Ten specimens were collected at Sausa-
lito, California, by Dr. Bitter and party.

This species is perhaps more closely al-
lied to Sphseroma sieboldii Dollfus05 from
Japan than it is to any of the known spe-
cies of the genus from the Pacific coast of
North America. It differs, however, from
that species in having a prominent trans- FIG- SOO.-SPH^ROMA PENTODON.

L , . , . . ,, ABDOMEN, x 8.

verse elevation on the posterior portion 01

the terminal segment, while in S. sieboldii the posterior part of the
segment is distinctly concave; in having five teeth on the lateral mar-
gin of the outer uropod, while in S. sieboldii there are seven; in hav-
ing fifteen joints to the flagellum of the second pair of antennae, while
this organ in S. sieboldii has a flagellum composed of only ten joints;
in having two longitudinal series of four small tubercles, one on either
side of the median line on the terminal abdominal segment, while in
S. sieboldii the granulations on the caudal segment form, in the middle,
two divergent lines; and in having the body covered with minute gran-
ulations, while in S. sieboldii the granulations are strong and more
prominent.

The type is in the Museum of the University of California. The
cotype is in the U. 8. National Museum, Cat. No. 28768.

49. Genus EXOSPH^EROMA Stebbing.

Second, third, and fourth articles of the palp of the uiaxillipeds
produced into lobes.

The outer branch of the uropoda is not denticulate on the exterior
margin.

Characters otherwise as in the genus Sphseroma Latreille.

a Notes from the Levden Museum, XI, 1889, pp. 93, 94, pi. v.

288 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS EXOSPHSEROMA.

a. Body widening gradually from the head backward. Thorax transversely ridged
and provided with three longitudinal rows of small tubercles. Branches of

uropoda very large, expanded Exosphseroma, amplicauda (Stimpson)

a'. Body not increasing in width from the head backward. Surface of thorax

smooth. Branches of uropoda not expanded.
6. Extremity of terminal abdominal segment produced in a rhomboid process.

Exosphseroma rhomburum (Richardson)

b/. Extremity of terminal abdominal segment not produced in a rhomboid process.
c. Surface of abdomen with tubercles.
d. Abdomen posteriorly ending in a triangular apex, on either side of which is

a small tooth.

e. With three tubercles at base of terminal abdominal segment. Outer
branch of uropoda not longer than inner branch and both shorter than
terminal segment of abdomen. Outer branch not acutely produced.

Exosphseroma yucatanum (Richardson)

e! '. With two tubercles at base of terminal abdominal segment. Outer
branch of uropoda extending beyond the inner branch, a distance equal
to half the length of the inner branch. Outer branch very acute at

extremity Exosphseroma faxoni, new species

d/. Abdomen posteriorly rounded. With eight tubercles, six on terminal seg-
ment and two on preceding segment.

Exosphseroma octoncum (Richardson)
c7. Surface of abdomen without tubercles.

d. Outer branch of uropoda smooth on exterior margin.
e. Outer branch of uropoda half as long as inner branch and half as wide.

Exosphseroma Ihermophilum (Richardson)

^. Outer branch of uropoda more than half as long as inner branch.
/. Outer branch four-fifths as long as inner branch and half as wide.

Exosphseroma dugesi (Dollfus)
/'. Outer branch two-thirds as long and as wide as inner branch.

Exosphseroma oregonemis (Dana)
d'. Outer branch of uropoda crenulated on exterior margin.

Exosphseroma crenulatum (Richardson)

EXOSPHSEROMA AMPLICAUDA (Stimpson).

Sphseroma amplicauda STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, p. 510. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 835; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 179; Amer. Naturalist, XXXIV, 1900, p. 222.

Localities. — Tomales Ba}^, California; Kyska Harbor, Alaska; north
coast of Amchitka, Alaska; Monterey Bay, California.

Found in low water on beach.

Body narrower anteriorly than posteriorly, gradually increasing in
width from the head to the abdomen, a little more than one and a
half times longer than broad, 5 mm. : 8 mm.

Head a little more than twice as wide as long, with a frontal border
arising between the eyes, which is produced in a small median point.
The eyes are small, round, composite, and situated in the post-lateral
angles of the head. The first pair of antennae have the basal article
long and equal in length to the third; the second article is half as
long as either of the other two. The flagellum is composed of five

ISOPOD8 OF NORTH AMERICA.

289

articles. The first antennae extend to the posterior margin of the

head. The second antennae have the first two articles very short and

equal in length; the third and fourth are about equal in length and

each is twice as long as the second; the fifth article is one and a half

times longer than the fourth. The flagellum is

composed of nine articles. The second antennae

extend almost to the posterior margin of the first

thoracic segment. The maxilliped has a palp of

five articles. The mandible has a palp of three

articles.

The first segment of the thorax is a little longer
than- any of the others. The lateral parts of all
the segments are bent downward, forming an
angle with the dorsal portion. The epimera are
not distinct from the segments, but are indicated
by a faint line on either side of the segment
a little distance within the place where the
lateral part of the segment forms the angle with the dorsal part.

The abdomen is composed of two segments. The first segment has
three suture lines on either side, indicating three coalesced segments.
The terminal segment is triangular in shape with apex rounded. The
uropoda are very large, both branches extending to the tip of the
abdomen, and being of equal width. The outer movable branch is

FIG. 301. — EXOSPHAiROMA
AMPLICAl'DA (AFTER

STIMPSON). x 8.

FIG. 302.— EXOSPHAIROMA AMPLICAUDA. a, 6, MANDIBLES. X 51|. C, MAXILLIPED. X 51|. (/.FRONTAL

LAMINA AND CLYPEl'S. 51}.

rounded posteriorly. The inner immovable branch has the outer post-
lateral angle rounded, the inner one produced.

The last three segments of the thorax and the first segment of the
abdomen have rudiments of tubercles on their posterior margins.
In the specimens examined there are no tubercles on the anterior seg-
ments, which may be due to size, all the specimens being very small.
There are also four tiny tubercles arranged in two longitudinal series
of two, one on each side of the median line at the base of the terminal
segment. The legs are all ambulatory.
28589—05 19

290

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

EXOSPH/EROMA RHOMBURUM (Richardson).

Sphferoma rhombuntm RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 835-836;
Ann. Mag. Nat. Hist. (7), IV, 1899, p. 179; American Naturalist, XXXIV,
1900, p. 222.

Locality. — Monterey Bay, California.
Surface of body punctate; color, whitish yellow.
Head small. First pair of antennae reach almost to the posterior
margin of the first thoracic segment. Second pair of antenna? extend
quite to the posterior margin of the first thoracic segment. Eyes sit-
uated post-laterally.

Thoracic segments equal in length. Epimera broad and short,
extending downward, forming an angle with the
segments.

First abdominal segment as long as any of the
thoracic segments, crossed by suture lines and
surmounted by two tuber-
cles, close together, one on
either side of the median line.
Terminal segment with its
extremity produced in a
process rhomboid in shape,

FlG. 303.— EXOSPH^ROMA
RHOMBURUM. ABDO"
MEN. X 13J.

FlG. 304.— EXOSPHAIROMA
RHOMBURUM. MAXILLI-
PED. X 51|.

and with sides infolded, forming a kind of fun-
nel-like opening when seen from beneath. At
the base of this segment are two tubercles,
which are continuous with two longitudinal
ridges in the center of the segment. These
ridges unite near the extremity, and continue as
one median ridge. The uropoda are shorter than
the terminal segment; the outer branch is more
lanceolate in shape; both are of equal length.

Two specimens were taken at Monterey Bay, California, by Mr.
Heath.

Type.— Cat. No. 22573, U.S.N.M.

This species is similar to S. ('*.) egregium, Chilton, from Akaroa, but
differs in the presence of two tubercles on the first abdominal segment,
in the presence of two tubercles and two longitudinal ridges uniting
in a single ridge on the terminal segment, and in the equality in length
of the two branches of the uropoda.

ISOPODS OF NORTH AMERICA.

291

EXOSPH/EROMA YUCATANUM (Richardson).

Sphseroma yucalanum RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 534.
Locality. — Cape Catoche, Yucatan.
Depth. — 24 fathoms.

Head transverse; eyes situated at the extreme post-lateral angles.
First pair of antennae short, reaching the posterior
margin of the head; flagellum six -jointed. Second
pair of antennae, with a flagellum composed of ten
joints, extend to the posterior margin of the second
thoracic segment.

First thoracic segment longer than any of the
following segments, its post-lateral angles produced.
The remaining segments of equal length; epimera
produced laterally into acute processes.

First abdominal segment with suture lines. Last segment termi-
nating posteriorly in an obtuse point, on either side of which is a small
tooth. The base of the segment bears three low tubercles, one in the
inediau line and one on either side. The uropoda are short, not reach-

FIG. 305.— EXOSPH.E-
ROMA YUCATANUM.
ABDOMEN.

FIG. 306.— EXOSPH.EKOMA YUCATAM'M. (t, MAXILLIPED. X ~7\. b, FRONTAL LAMINA AND CLYPEUS.

(DIAGRAMMATIC.)

ing the post-lateral teeth. Both branches are equal in length and
width, the outer branch pointed, the inner branch truncate.

Surface of body smooth; color bluish.

One specimen was taken at Cape Catoche, Yucatan.

Type.—C&t. No. 23905, U.S.N.M.

292

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 307. — EXOSPH.EROMA KAXOXI.
XlO.

EXOSPHiEROMA FAXONI, new species.

Body ovate, nearly twice as long as wide, 2£ mm. : 5£ mm.
Head twice as wide as long, 1 mm. : 2 mm. , with the anterior margin
rounded and produced in a small median point. There is a marginal

border extending across the anterior portion
of the head as far as the second article of
the first antenna on either side. Eyes small,
round, composite and situated in the post-
lateral angles of the head. The first pair of
antennae have the first article long and stout',
the second article is half as long as the first;
the third is one and a half times as long as
the second. The flagellum is composed of
twelve articles and extends to the post-
lateral angle of the first thoracic segment.
The second pair of antenna? have the first
article short and almost inconspicuous; the
second article is about twice as long as the
first; the third is about one and a half times
as long as the second; the fourth is one and
a half times as long as the third; the fifth is one and a half times as
long as the fourth. The flagellum is composed of twelve articles and
extends a little be}^ond the flagellum of the first pair of antennae.

The first segment of the thorax is a little longer than any of the
others, which are subequal. The post-lateral angles of the first seg-
ment are produced backward in a long process on either side, extend
ing to the posterior margin of the second thoracic segment and having
the extremities truncate. These processes extend laterally some dis-
tance beyond the lateral margins
of the second segment. The fol-
lowing six segments have the epi-
mera separated by faint lines
from the segments and produced
in acute points directed later-
ally. Those of the fifth seg-
ment extend laterally some dis-
tance beyond those of the other
segments.

The abdomen is composed of
two segments. The first segment
is twice as long as the last thoracic segment and has two small tubercles
on the posterior margin, one on either side of the median line. Lateral
to these the posterior margin is produced backward in a small point on
either side. There are three suture lines on either side of this seg-

FlG. 308. — EXOSPH^EROMA FAXONI. a, MAXILLIPED.

x 51|. 6, FRONTAL LAMINA, x 27J. c, SECOND

MAXILLA. X 51|.

' ISOPODS OF NORTH AMERICA.

293

inent, indicating- partly coalesced segments. The terminal segment
has two tubercles situated on the convex dorsal surface, one on either
side of the median line, about the middle of the segment. This seg-
ment terminates posteriorly in three small teeth, one median and one
lateral to this on either side. The inner fixed branch of the uropoda
does not extend beyond the tip of the terminal abdominal segment.
The outer post-lateral angle is very acute. The outer branch of the
uropoda is very long- and extends beyond the inner branch a distance
equal to half the length of the inner branch. It terminates in a long
acute extremity.

Only one specimen of this species was taken in Florida by Prof.
A. S. Packard.

The type is in the Museum of Comparative Zoology at Harvard
College. Cat. No. 6732, M. C. Z.

This species is named for Prof. W. S. Faxon, who very kindly
assisted me by letting me have for examination the collection in the
Museum of Comparative Zoology at Harvard University.

EXOSPH/EROMA OCTONCUM (Richardson).

Sphieroma octoncum RICHARDSON, Proc. U. S. Nat. Mus.,XXI, 1897, p. 836; Ann.
Mag. Nat. Hist. (7), IV, 1899, p. 180; American Naturalist, XXXIV, 1900,
p. 223.

Locality. — Montere}^ Bay, California.

Body with all the thoracic segments, except the first, marked with
four conspicuous brown spots, two on either side of the median line,
and with two spots on the first abdominal segment, one
on either side of the median line.

Head small. First pair of antennae reach almost to
the posterior margin of the first thoracic segment. Sec-
ond pair extend fully to the posterior margin of the first
segment.

Thoracic segments subequal. Epimera broad and ex-
tending downward, forming an angle with the segments.

First abdominal segment with
two low tubercles close together,
situated one on either side of the
median line; terminal segment
triangular, with apex narrowly
rounded and sides slightly infolded, forming a
small opening when seen from below. Six low
tubercles are situated on this segment, two in
longitudinal series on either side of the median
being a little farther apart than the upper
The uropoda do not reach

&

FIG. 309.— Exos-

PH^EROMA OC-
TONCUM. MAX-
ILLIPED. X51f.

PlG. 310. — EXOSPH^ROMA OC-

TONCUM. ABDOMEN, x 13£.

line — the lower ones

ones — and one on either side of the series.

294

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the extremity of the abdomen by some little distance. The outer
branch is the shorter and is broadty rounded posteriorly. The inner
branch is more pointed at the extremity.

Five individuals of this species were sent by Mr. Heath from Mon-
terey Bay, California.

Type.—C&t. No. 22574, U.S.N.M.

EXOSPH^EROMA THERMOPHILUM (Richardson).

X)>1i:rr<i>n<i tlirrnio/iltiltiiii RICHARDSON, Proc. U. S. Nat. Mns., XX, 1897, pp. 465-
466; Amer. Naturalist, XXXIV, 1900, p. 223.

Locality. — New Mexico, near Socorro, in a warm spring.
Head nearly three times as broad as long, with its anterior margin
widely rounded. Eyes round and post-laterally situated. The first
pair of antenna?, with a flagellum of eight articles,
extend to the middle of the first thoracic seg-
ment. The second pair of antennae reach the pos-
terior margin of the first thoracic segment; the
flagellum consists of eleven articles.

The thoracic segments are all similar with the
exception of the first, which extend.- late rail JT
around the head, almost touching the peduncle
of the first pair of anten-
na? with its anterior angle.
The epimeral parts are
continuous with the seg-
ments, with no indication
of a separation from them.
The abdomen is formed
of two distinct segments,
the first of which is partly
covered by the last thoracic segment, the sec-
ond is subtriangular, rounded posteriori}7.
The internal lamella of the uropods is moder-
ately broad, well rounded, and extends to the
posterior edge of the last abdominal segment,
is half as long and half as broad as the internal one, and is more pointed
at its extremity.

The body is oblong-ovate with almost parallel sides. Its surface
is entirely smooth.

The grayish-brown color of the body is everywhere marked with
small black spots and lines, which run together, forming a broad, black
band in the center of each one of the thoracic segments. All the
exposed edges of the body are tinged with a bright orange.

This species can readily be distinguished from Exosphseroma dugezi,
to which it is closely related, by the absence of hairs on the body,

FIG. 311. — EXOSPH^ROMA
THERMOPHILUM. X 4|.

FlG. 312. — EXOSPH-EROMA THER-

MOPHILVM. MAXILLIPED. x
38 j.

The external lamella

I8OPODS OF NORTH AMERICA.

295

by the relative length of the uropods, the outer branch being only
half as long as the inner one, while in E.i-i>*]>lt;ri'oma dm/esl both
branches are of nearly equal length, and by the difference in color.
Type.— Cat. No. 19609, U.S.N.M.

EXOSPHjEROMA DUGESI (Dollfus).

Rphteroma dugesi DOLLPPS, Bull. Soc. Zool. France, X VIII, 1893, p. 115, figs. 1-2.
Locality. — Mexico (fresh water); Eaux thermales d'Aguas-Calientes,
etat d'Aguas Calientes; Mexico.

FlG. 313. — EXOSPH.EROMA DUO ESI (AFTER DOLLFUS). a, HEAD AND FIRST THORACIC SEGMENT.
6, ABDOMEN AND UROPODA.

Body ovate, twice as long as wide, 6 mm. : 12 mm.
Head twice as wide as long, 2 mm.: 4 mm., with a frontal border
arising between the eyes and produced in a small median point.

FIG. 314. — EXOSPH.EROMA DUGESI. a, MANDIBLE, x 41. 6, FRONTAL LAMINA AND CLYPEPS.

c, MAXILLIPED. x 41.

x 23.

Eyes small, round, composite, and situated in the post-lateral angles
of the head. The basal article of the first pair of antennae is long; the
second is half as long as the first; the third is one and a half times
longer than the second. The flagellum is composed of eight articles.
The first antenna? extend to the middle of the first thoracic segment.

2(.H> BULLETIN f>4, UNITED STATES NATIONAL MUSEUM.

The basal article of the .second antenna1 is very short; the second and
third are longer than the first and subequal; the fourth and fifth are
about equal and each is one and a half times longer than the third. The
flagellum is composed- of twelve articles. The second antennae extend
a little beyond the posterior margin of the first thoracic segment. The
maxilliped has a palp of five articles. The palp of the mandibles is
composed of three articles. The frontal lamina is large and conspicu-
ous, and has the anterior division wide and long, with the post-lateral
or ventral angles drawn out, giving it somewhat of a horse-shoe shape.
The clypeus is transversely oblong, and fits into the concavity of the
posterior part of the frontal lamina; its posterior margin is fringed
with cilia.

The segments of the thorax are equal in length. The epimera are
not distinct from the segments. The lateral margins are nearly
straight.

The abdomen is composed of two segments. The first segment is
about as long as the last thoracic segment and has one suture line on
either side. The terminal segment is triangular, with the apex bluntly
rounded. The inner fixed branch of the uropoda is as long as the ter-
minal segment. The outer moveable branch is about half as wide as
the inner branch, is very pointed at its extremity, and when folded is
not quite as long as the inner branch, being 1 mm. shorter. The
length of the inner branch is 5 mm. ; that of the outer branch is 4 mm.

The legs are all ambulatory.

EXOSPH^ROMA OREGONENSIS (Dana).«

Sphseroma oregonensis DANA, Proc. A cad. Nat. Sci. Phila., VII, 1854-55, p. 177;

U. S. Expl. Exp. Crust., XIV, 1853, p. 778, pi. LII, fig. 4.— STIMPSON, Boat.

Jour. Nat. Hist., VI, 1857, p. 509.

Spltseroma olivacea LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 45.
Sphseroma oregtmenxis RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 836;

Ann. Mag. Nat. Hist., (7), IV, 1899, p. 180; American Naturalist, XXXIV,

1900, p. 223; Harriman Alaska Exp. Crust., X, 1904, p. 214; Proc. U. S. Nat.

Mus., XXVII, 1904, p. 659.

Localities. — Pacific Grove to Alaska; Popof Island (from fresh water),
Yakutat, and Glacier Bay, Alaska; Grenville Channel and Lowe Inlet,
British Columbia; Angel Island, San Francisco Bay, California
(Lockington Coll.); Gulf of Georgia; Alert Bay and Kadiak, Alaska;

ft The following description of Dana's, although concise, gives most of the essen-
tial characters of the species: Corpus Iseve. Segmentum caudale breve, postice latis-
sime rotunatum, supra Iseve. Styli caudales abdomen non superantes, lamella internd
multo longiore quam externa, fere obtusd, externa obtusd. Flagella antennarum 1
marum 2 darurnque 12-14 articulata.

Body smooth. Caudal segment short, very broadly rounded behind, smooth
above. Caudal stylets not reaching beyond line of extremity of abdomen; inner
lamella much the longer, nearly obtuse; outer obtuse. Flagella of antenna of both
pairs twelve to fourteen jointed. Length of body four and a half lines.

ISOPODS OF NORTH AMERICA.

297

near Wrangell, Alaska; Puget Sound; Kyska Harbor, Alaska; Monte-
rey Bay, California; Middleton Island; LInalaska; Sitka, Alaska;
Bering Island; Sanborn Harbor,
Nagai Island; Saginaw Bay,
Alaska: North Grebnitzky.

Found on beach at low tide;
1<)-1'2 fathoms, in gravel, sand,
and stones; rocky beach under
stones; in mud.

Body ovate, twice as long as
wide, 4 mm. : 8 mm.

Head three times as wide as
long, 1 mm.: 3 mm., with the
frontal margin bi-sinuate, or ex-
cavate on either side of a small
median point. Eyes small, round,
composite, and placed in the
post-lateral angles of the head.
The first antennae have the basal
article large; the second article

is half as long as the first; the third is one and a half times longer
than the second. The flagellum is composed of thirteen articles.
The first antenna? extend to the posterior margin of the head. The
second antenna3 have the basal article very short and almost inconspicu-
ous; the second article is about three times as long as the first; the third

FIG. 315. — EXOSPH.EROMA OREGONENSIS (AFTER

DANA), a, SECOND ANTENNA, b, GENERAL FIGURE.
c, ABDOMEN (UNDERSIDE). (ALL ENLARGED.)

FlG. 316. — EXOSPH.EROMA OREGONENSIS. a, MAXILLIPED. X 51|. 6, MANDIBLE, PALP REMOVED.

x 51 f. <*, MANDIBLE WITH PALP, x 61 J. d, FRONTAL LAMINA AND CLYPEUS. x 61|.

is about as long as the second; the fourth is nearly twice as long as the
third; the fifth is as long as the fourth. The flagellum is composed of
thirteen articles. The second antennae extend to the posterior mar-
gin of the second thoracic segment. The maxilliped has a palp of five
articles. Mandibles with a three-jointed palp.

298

BULLETIN 54, UNITED STATES NATIONAL MUSP.'UM.

Color, light brown, with markings of

The tirst segment of the thorax is a little longer than any of those
following. The epimera are not distinct from the segments, but can
be distinguished from the segment by a faint line on either side. They
are laterally produced into a rather acute process on either side.

The abdomen is composed of two segments. The first segment has
three suture lines on either side indicating three partly coalesced seg-
ments. The terminal segment is round posteriorly. The inner immov-
able branch of the uropoda is as long as the terminal segment, and is
narrowly rounded at the extremity. The outer branch is two-thirds
the length of the inner branch and is rounded posteriorly.

The legs are all ambulatory.

EXOSPH^EROMA CRENULATUM Richardson.a

fjphxroma rrenulatum RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp.
292-293, pi. xxxix, fig. 40.

Locality. — Bermudas.
Surface of body smooth,
black.

Head rounded in front with small median point,
on either side of which is a small excavation. Eyes
situated post-laterally.

First pair of antennae with the first joint of the
peduncle long; second joint half as long as first;
third joint equal in length to first; flagellum of five
joints reaches the post-lateral margin of the head.

Second pair of antennae extend to the middle of
the first thoracic segment.

Thoracic segments subequal. Lateral
margins straight. Epimera not dis-
tinctly separated from segments.

First abdominal segment long, a little
longer than any of the thoracic segments, with two suture
lines. Terminal segment very convex, surface smooth,
posterior margin widely rounded. Uropoda not extending
beyond tip of terminal segment. Inner branch somewhat
pointed at its extremity, margin smooth. Outer branch
widely rounded and crenulate on the posterior edge.
Legs similar, all ambulatory, with small curved dactyli.
A number of specimens were collected at the Bermudas
in 1876-77, by Dr. George Brown Goode.
Type in Peabody Museum, Yale University. Cat. No. 3250.

a This species is intermediate between Sphirroma and Exonphseroma, The second,
third, and fourth articles of the palp of the maxillipeds are but little produced.
Stebbing mentions another species, Sphtcroma globicauda Dana, which is also inter-
mediate between Sphiivoiiui. and Exosphseroma, The Fauna and Geography of the
Maldive and Laccadive Archipelagoes, II, Pt. 3, 1905, p. 710.

FIG. 317.— EXOSPH*-
ROMA CRENULATVM.

FIG. 318.— Exo-
SPH.EROMA
CRENULATUM.
MAXILLIPED.

X7T*.

I3OPODS OF NORTH AMERICA. 299

SO. Genus DYNAMENE Leach.

Abdomen composed of two segments, the first of which is formed
by the fusion of several coalesced segments. The terminal segment is
emarginate posteriori}7, without a lobe within the emargination.

The branches of the uropoda are similar, both being salient; the}7
are alike in the two sexes. The inner immovable branch is fixed to
the side of the abdomen. The outer branch is movable and capable
of folding under the inner branch.

The second, third, and fourth articles of the palp of the maxillipeds
are produced into lobes.

Legs all ambulatory.

Sexes alike.

Inasmuch as the male is known in four of the species of this genus
and as the male and female are alike, I am not willing to unite
Cilicsea and Dynamene in a single genus Dynamene, the males of
Cilic&a being unlike the females as is the opinion of Prof. S. *I.
Holmes and Dr. H. F. Moore, the former considering Dynamene
tuberculosa the female of Cilicsea cordata and the latter supposing
Dynamene hei^mudensis to be the female of C'dicsea caudata.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS DYNAMENE.

a. Posterior extremity of terminal segment of abdomen with a heart-shaped opening

immediately above the terminal excavation Dynamene perforata Moore

a'. Posterior extremity of terminal segment of abdomen without heart-shaped open-
ing above the terminal excavation.

6. Surface of abdomen smooth Dynamene glabra Richardson

b'. Surface of abdomen with tubercles or longitudinal ridges,
o. Surface of abdomen with tubercles.
d. Basal part of terminal segment of abdomen with three tubercles.

Dynamene angulata Richardson
d' '. Basal part of terminal segment of abdomen with four small tubercles.

Dynamene moorei, new species
cf. Surface of abdomen with longitudinal ridges.

d. Surface of terminal segment of abdomen with three longitudinal ridges.
Front of head produced in a quadrangular process. First two articles oi
peduncle of the first antenn?e flattened and dilated.

Dynamene dilatata Richardson

d'. Surface of terminal segment oi abdomen with four longitudinal ridges.
Front of head not produced. First two articles of peduncle of second
antennae not flattened and not greatly dilated.

Dynamene benedicti Richardson

DYNAMENE PERFORATA Moore.

Dynamene per jorata MOORE (male) , Bull. U. S. Fish Commission, XX, Pt. 2, 1902,
pp. 173-174, pi. x, figs. 9, 11-19. — RICHARDSON (male), Trans. Conn. A cad.
Sci., XI, 1902, pp. 291-292, pi. xxxix, fig. 39.

Localities. — Culebra, Porto Rico; Bermudas. Found on mangrove
roots.

300

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Head broader than long; eyes situated post-laterally. First pair of
antenna? with the first two peduncular joints large, the second half as
long as the first; the third joint long and slen-
der, twice as long as second joint; flagellum
consists of seven joints. The first two pedun-
cular joints of the second pair of antenna- are
of equal length; the following three are of equal
length and longer than the first two; the fiagel-
lum consists of about seven joints, and extends
to the posterior margin of the third thoracic
segment.

The thoracic segments are of equal length,
with the exception of the first, which is slightly
longer. The seventh segment is produced back-
ward in two rounded lobes, one on either side
of the median line, and close together. '

The first abdominal segment has two suture lines at either side,
indicative of coalesced segments. The terminal segment is very con-

FIG. 319.— DYNAMENE PER-
FORATA. LAST TWO THO-
RACIC SEGMENTS AND AB-
DOMEN.

FIG. 320.— DYNAMENE PERFORATA (AFTER MOORE), a, FIRST ANTENNA. 6, SECOND ANTENNA, c,
MALE, d, TIP OF MAXILLA, e, MANDIBLE. /, MAXILLIPEDS. g, FOURTH LEG. h, FIRST LEG. i,
SEVENTH LEG. j, PART OF TERMINAL SEGMENT OF ABDOMEN WITH UROPOD.

vex at the base, and has four small tubercles, forming a square on the
convexity. Its apex has a heart-shaped opening, formed by the pro-

ISOPODS OF NORTH AMERICA.

301

longation of the lateral margins, which prolongations meet anteriorly
and are divergent posteriorly, so that a triangular excavation is
formed on the posterior end of the segment immediately below the
heart-shaped opening.

The two branches of the uropoda are similar in shape and size.
They are large, very much expanded, rounded posteriorly, with mar-
gins distinctly crenulate or denticulate, and extend some distance
beyond the tip of the terminal abdominal segment.

The color is brown, with markings of black. Surface smooth, with
the exception of the abdomen, which is very granular.

Several specimens differ from the specimen described in not having
the seventh thoracic segment produced in lobes, and are without the
four small tubercles at the base of the terminal segment. Several
differ in having the uropoda not longer than the terminal segment.

Both sexes are known, the male and female being alike in every respect;
in the male the inner branch of the second pleopods carries a stylet.

Cotypes are in the Peabody Museum, Yale University. Cat. No.
3204. '

DYNAMENE GLABRA Richardson.

Dynamene glabra RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 834; Ann.
Mag. Nat. Hist. (7), IV., 1899, p. 178; American Naturalist, XXXIV, 1900,
p. 224.— HOLMES, Proc. Cal. Acad. Sci. (3), III, 1904, No. 11, p. 304.

Localities. — Monterey Bay, California; Mendocino
County, California; San Diego, California.
Body oval; surface smooth.

Head small; e}7es situated post-laterally. First
pair of antennae extend to the eye; first joint oblong;
second joint short, half as long as
first; flagellum consists of six arti-
cles. Second pair of antennae ex-
tend to the posterior margin of the
first thoracic segment; flagellum
consists of about ten articles.

The thoracic segments are subequal; the first is a
little longer than any of the others.

The penultimate abdominal segment consists of
several coalesced segments, as indicated by the suture
lines. The terminal segment is triangular, with a
small median excavation at its extremity. The lower
Part °^ **"s segment is quite flat, the slope being
gradual from the convex upper part or base of the
segment to the extremity. The surface is perfectly
smooth. The inner branch of the uropoda is large
and rounded posteriorly; the outer branch is small, though similar in
shape, and is much shorter than the inner branch.

A number of specimens were collected by Mr. Heath at Monterey
Bay, California, at the surface.

FIG. 321. — DYNAMENE
GLABRA. ABDOMEN
AND LAST TWO THO-
RACIC SEGMENTS.

Xl3}.

FIG. 322.— DYNAMENE
GLABRA. SECOND
PLEOPOD OF MALE.
x 51|.

302

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Type.—C&t. No. 22571, U.S.N.M.

Both sexes of this species are known, the two forms resembling each
other in every respect, with the exception that in the male there is a
stylet on the inner branch of the second pair of pleopods.

Prof. S. J. Holmes writes that the sexes do not show any marked
dimorphism. He also admits the following:" "An examination of
several specimens of the species showed that the males present no
appreciable external differences from the females except that, as a
rule, they are of somewhat larger size."

Specimens of both sexes are in the collection of the U. S. National
Museum. The inner branch of the second pleopod of the male is
figured.

DYNAMENE ANGULATA Richardson.

Dynamene angalata RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 534-535.
Locality. — No Name Key, Florida.
Found among algas at low tide.
Surface of bod}7 smooth; color yellow.

Head large, with small median point on its anterior margin. First
pair of antennae reach the posterior margin of the second thoracic
segment; flagellum composed of nine joints.
Second pair of antennae reach the posterior mar-
gin of the fourth thoracic segment; flagellum
composed of thirteen joints.

The thoracic segments are subequal in length,
the first being a little longer than any of the
others. The epimera are broad and short, with
acute lateral angulations.

The first abdominal segment bears suture lines
indicative of coalesced seg-
ments. There are three small
tubercles in a transverse row,
one median and one on either
side. The terminal segment is subtriangular, with
the extremity produced and deeply excavate, the
excavation being like an inverted V. At the base of
this segment are three large tubercles in a transverse
row, the median one being long and very acute,
the lateral ones rounded. The branches of the
uropoda are similar in shape, the outer one being somewhat longer;
they are obliquely truncated with the outer posterior angles acutely
produced and do not quite reach the tip of the abdomen.

Specimens were found by Mr. Henry Hemphill at No Name Key,
Florida.

Type.— Cut. No. 23906, U.S.N.M.

FIG. 323.— DYNAMENE ANGU-
LATA. MAXILLIPED. x

sat.

FIG. 324. — DYNAMENE
ANGULATA. ABDO-
MEN.

"Proc. Cal. Acad. Nat. Sci. (3), III, No. 11, 1904, p. 304.

ISOPODS OF NORTH AMERICA.

303

FIG. 325.— DYNAMENE
MOOREI (AFTER
MOORE).

DYNAMENE MOOREI, new species.

Dynamene perforata MOORE (female), Bull. U. S. Fish Commission, XX, Pt. 2,
1902, pp. 173-174, pi. x, fig. 10.— RICHARDSON (female), Trans. Conn. Acad.
Sci., XI, 1902, pp. 291-292.

Localities. — Culebra, Porto Rico; Bermudas.
Found on mangrove roots.

This species is what Dr. Moore considered to be the female of
Dynamene perforata. Upon examining the specimens
of Dynamene perforata (females) I found one to be a
male.a

Body oblong-ovate, about twice- as long as wide, 2
.mm.: 4 mm.

Head about twice as wide as long, with the frontal
margin rounded and produced in a small median point.
Eyes large, composite, and situated in the post-lateral
angles of the head. First pair of antennae have the
first and third articles of the peduncle about equal in
length ; the second shorter than either. The flagellum
of eight articles extends to the posterior margin of the first thoracic
segment. The second pair of antennae, with a flagellum of twelve arti-
cles, extends to the posterior margin of the
second thoracic segment.

The first segment of the thorax is about
one and a half times longer than any of the
following segments, which are subequal.
The seventh segment is produced backward
in two small, rather obscure points, close to-
gether, one on either side of the median line.
The abdomen is composed of two segments.
The second or terminal segment bears four
small, rather obscure tubercles on the an-
terior convex portion. This segment is some-
what triangular in shape, with the apex
notched and the sides folded under, forming a
kind of funnel-shaped extremity.
The uropoda are large and broad, similar in shape and size, with the
extremities rounded and the exterior margins crenulate. They extend
but little beyond the extremity of the abdomen.

Both sexes of this species are known, the males and females being
similar.

This species is named for Dr. H. F. Moore.

« Since my manuscript was sent to press, Doctor Hansen has returned specimens
of Dynamene perforata Moore, which he borrowed from the U. S. National Museum.
Two specimens, considered by Dr. H. F. Moore to be the females of that species,
were sent him. I am gratified to find that he has labeled one "immature male,"
and the other "adult male." .

FIG. 326.— DYNAMENE MOOREI.
SECOND PLEOPOD OK MALE.
x 77i.

304

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

DYNAMENE DILATATA Richardson.

Dynamene dilatata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 832-833;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 175-176; American Naturalist,
XXXIV, 1900, p. 223.

Locality. — Monterey Bay, California.

Body oval; surface very granular; color yellow.

Head rugose, with its anterior margin pro-
duced in a quadrangular process, having a small
median projection, sounded antero-lateral
angles and a thickened edge. First pair of an-
tennas extend to the posterior margin of the
head, first two joints flattened and enlarged;
first joint oblong, second joint triangular, and
half as long as preceding joint; third joint
small, as long as second, but half as wide;
flagellum six-jointed. Second pair of antennse
are but little longer than first pair and do not
reach the posterior margin of the first thoracic
segment.

The thoracic segments are of equal length.
The epimera are square or oblong, with straight
lateral margins.

The penultimate abdominal segment is short,
and crossed with suture lines. The terminal
segment is triangular with a small rounded
notch at the apex. There are three longitudinal ridges on the segment,
one in the median line, and one on either side of it. The uropoda are
short, not reaching the extremity of the abdomen, and regular^
rounded.

The legs are slender; the first two pairs are covered with long hairs
and extend in an anterior direction, the other five pairs extend in a
posterior direction.

The type and only specimen was collected by Mr. Heath at Monterey
Bay, California, at the surface. Cat. No. 22568, U.S.N.M.

DYNAMENE BENEDICTI Richardson.

Dynamene benedicti RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 834; Ann.
Mag. Nat. Hist. (7), IV, 1899, p. 177; American Naturalist, XXXIV, 1900,
p. 224.

Locality. — Monterey Bay, California.

Body oblong, oval; surface minutely granular; color dark gray.
Head with small median point. Eyes situated post-laterally. First
pair of antennas extend to the middle of the first thoracic segment;

PIG. 327.— DYNAMENE DILATATA.
a, HEAD AND FIRST THORACIC

x 13i.
10|.

ISOPODS OF NORTH AMERICA.

305

FIG. 329.— DYXAMENE
BENEDICTI. LAST
THORACIC SEGMENT
AND ABDOMEN. X

m. -
This segment is

FIG. 328.— DYXA-
MENE BENB-
DICTI. SECOND
PLEOPOD OP
MALE (INNER

BRANCH). X

51f.

first joint of peduncle longest; second and third joints about equal in
length; flagellum consists of six joints. Second pair of antennae
extend to the posterior margin of the second thoracic
segment; flagellum consists of about eleven joints.
The thoracic segments are of equal length. The
epimera are square with rounded pos-
terior angles.

The penultimate abdominal segment
is crossed by suture lines, indicative
of coalesced segments. The terminal
segment is triangular, terminating pos-
teriorly in two teeth separated by a
narrow, rounded, funnel-shaped sinus,
very convex, and bears two longitudinal ridges on either
side of the median line. The uropoda do not exceed in
length the extremity of the terminal segment. Both
branches are rounded posteriorly and are similar in
shape and size.

The type was collected by Mr. Heath at Monterey Ba}%
California, at the surface. Cat. No. 22570, U.S.N.M.

This species is named for Dr. James E. Benedict,
assistant curator in the Division of Marine Invertebrates. U. S.
National Museum.

Both sexes of this species are known, and are in the collection of
the U. S. National Museum. The male and female are alike in every
respect, with the exception that the inner branch of the pleopoda in
the male is provided with a stylet.

51. Genus PARADYNAMENE, new genus.

Second, third, and fourth articles of the palp of the maxillipeds not
produced into lobes. First article of the peduncle of the first antennas
with a long process at the upper end, which is acutely produced, and
extends to the extremity of the second article.

Characters otherwise as in the genus Dynamene.

Both sexes are known, the male and female being similar, but the
male is larger.

PARADYNAMENE BENJAMENSIS, new species.

Body oblong-ovate, twice as long as wide, 5 mm. : 10 mm.

Head wider than long, 2 mm. :3 mm., with the anterior margin
widely rounded and produced over the basal articles of the antennae,
so as to entirely conceal them. The eyes are small, round, composite,
and situated in the post-lateral angles. The first pair of antennas have
the first or basal article large and elongated, with a long acutely ter-
28589—05 20

306

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

initiating process at the upper end, half the width of the article and
extending to the extremity of the second article; the second article is
half as long as the first article (not including this process); the third
article is half as wide as the second, which is
equal in width to the first, and is about one-half
as long as the second, and hardly to be distin-
guished from the articles of the flagellum. The
flagellum is composed of about ten articles, and
extends to the posterior margin of the first tho-
racic segment. The second pair of antennae have
the first article very short; the second and third
are subequal and each is about twice as long as
the first; the fourth and fifth are subequal and
each is a little longer than the third. The fla-
gellum is composed of fourteen articles and
extends to the posterior margin of the second
thoracic segment.

The first segment of the thorax is about twice

as long as any of the following segments, which are subequal. The
lateral margins of the body are straight. The epimera are separated
on all but the first segment by faint lines.

FIG. 330.— PARA DYNAMENE
BENJAMENSIS. ABDOMEN
AND LAST THORACIC SEG-
MENT OF MALE. X 4.

FIG.-331.—PARADYNAMENE BENJAMENSIS. a, FIRST ANTENNA. X.27}. b, C, MANDIBLES. X27}.

d, FIRST MAXIL.LA. x 27}. e, MAXILLIPED. x 27}.

The abdomen is composed of two segments. The first segment is
two and a half times longer than the last thoracic segment, and has,
three suture lines on either side indicating partly coalesced segments.
It is produced backward in a small point on either side, The second

ISOPODS OF NORTH AMERICA.

307

or terminal segment has the convex anterior portion surmounted with
two very inconspicuously small tubercles, one on either side of the
median line. Its posterior extremit}7 has a deep
rounded excavation, almost quadrangular in shape.
The uropoda are longer than the terminal abdomi-
nal segment. The inner branch has the outer
post-lateral angle produced in an acute point, the
inner angle being rounded. The outer branch is
longer than the inner branch, and terminates in
an acutely pointed extremity.

The male differs from the female in its much
larger size, being 18 mm. long and 7 mm. wide;
in the more granular surface of the abdomen and
its V-shaped rather than rounded excavation, and
in having two depressed lines converging to1 a
point just anterior to the V-shaped excavation,
the apex of the point meeting the apex of the
V-shaped excavation.

-r, £ . j , ,, ,. ., FIG. 332.— PARADYNAMENE

t our females and one male come from the gulf BENJAMENSIS. FEMALE
weed. Collector unknown. (DORSAL VIEW), x 54.

Types in the Museum of Comparative Zoology at Harvard Univer-
sity^ Cat. No. 6733, M.C.Z.

FIG. 333. — PARADYNAMENE BENJAMENSIS. a, FIRST PLEOPOD OF MALE, x 15j. 6, SECOND PLEOPOD

OF MALE, x 15J.

This species is named for Dr. Marcus Benjamin, editor of the Pro-
ceedings of the U. S. National Museum.

82. Genus CILIC^EA Leach.

Last two segments of thorax of equal length.

Abdomen composed of two segments, the first of which is usually
produced (at least in the male) in a long process directed backward.
The last segment of the abdomen has a median posterior emargination,
with or without teeth.

308 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Maxillipeds with the second, third, and fourth articles of the palp
produced into lobes.

Branches of the uropoda unlike in the male, the outer branch being
incapable of folding under the inner branch; only the outer branch
salient.

In the opinion of Dr. H. F. Moore and Prof. S. J. Holmes the
males and females are unlike, the female being similar to the female
of the genus Dynamene.

All the species which I have referred to this genus are without the
long median spine or process of the first abdominal segment charac-
teristic of the type species, C. latreilU Leach. The species of this
genus described by Haswell" and Miers* also have the long spine.
Haswell figures one specimen, which he supposes to be the female of
C. spinulosa or of C. hy strive, which lacks the dorsal spine on the first
abdominal segment, but in which the uropoda are similar to those of
the male.

Miers says that the females of CUicsea latreilU differ from the male
in lacking the spine on the first segment of the abdomen and in hav-
ing the uropoda with the inner branch produced and the outer branch
short, resembling the uropoda of Cyrnodoce.

Milne Edwards0 places Cilicsea caudata (Say) in the section of the
genus Ndesa, corresponding to OUiceea Leach. It may be that a new
genus will be required for these forms which lack the spine on the
first abdominal segment, but until more is known about the sexes I
shall, for the present, not remove them from the genus Cilicaea* where
I originally placed them.

Whitelegge* refers to the genus Cilicae-a several species in which
the male has the first abdominal segment not produced in a long
process.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CILICJEA.

a. Surface of body densely granulated.

b. Terminal sinus of last abdominal segment without tooth on either side of the

lateral angles of the sinus CUicsea linguicauda Richardson

b'. Terminal sinus of last abdominal segment with a tooth on either side of the

lateral angles of the sinus CUicsea granulosa Richardson

of . Surface of body not granulated.

b. Terminal segment of abdomen with three sinuses in a longitudinal series, each
opening into the other, the two upper sinuses being heart-shaped. Outer
branch of uropoda armed with four spines or teeth, and extending but little

beyond the tip of the abdomen CUicsea cordata Richardson

b'. Terminal segment of abdomen with one sinus. Outer branch of the uropoda
unarmed, and extending much beyond the tip of the abdomen.

«Proc. Linn. Soc. New South Wales, VI, 1881, pp. 183-186.
&Zool. Collections of the Alert, 1884, pp. 308-310.
cHist. Nat. Crust, III, 1840, pp. 218-219.
<* Austral. Mus. Mem., IV, 1901, pp. 201-246.

ISOPODS OP NORTH AMERICA. 309

' c. Sinus with teeth.

d. Sinus with four or six teeth.
e. Sinus with six teeth. Medium tubercle at base of terminal segment

double Cilicsra gilliana Richardson

e/ '. Sinus with four teeth. Medium tubercle at base of terminal segment

single Cilicsea caudata (Say)

d'. Sinus with three teeth Cilicsea sculpta (Holmes)

c'. Sinus without teeth Cilicsea carinata Richardson

CILIC^A LINGUICAUDA Richardson.
Cilicsea linguicauda RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 536-537.

Locality. — Cape Catoche, Yucatan.

Depth.— 24-25 fathoms.

Head subtriangular in shape; frontal margin with a small median
point; eyes post-laterally situated. The first pair of antennae reach
the posterior margin of the first thoracic segment; the second pair
touch the fourth segment.

The first segment of the thorax is a little longer than any of the
others, which are similar in size. The epimera are distinct from the
segments, and are produced into acute points, with the
exception of the last, which has the epimera quite rounded.

The abdomen is composed of two segments, the first of
which gives indication of three coalesced segments, and
has a small tooth on each side on its post-lateral margin. FlG 334-_CjLI.
The last segment is swollen anteriorly, and bears three. CJ;A LINGUI-
low tubercles on this portion. The extremity of the ^,^.
abdomen is marked by a sinus, almost complete ly filled
by a single large tooth, which is posteriorly triangular and extends
beyond the lateral teeth formed by the sinus. This central tooth
bears a small, pointed tubercle near its base. The uropoda are slightly
incurved, and are somewhat longer than the abdomen.

The color is a dull yellow.

The lower part of each thoracic segment is densely granulated, as
well as the whole surface of the abdomen. The edges of the segments
and the uropoda are fringed with hairs.

Type.— Cat. No. 23908, U.S.N.M.

CILICSEA GRANULOSA Richardson.

Cilicsea granulosa RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 841; Ann.
Mag. Nat. Hist,, (7), IV, 1899, pp. 186-187.

locality. — Cerros Island, Lower California.

Depth.— -20 fathoms.

Surface of body densely granulated; granules large and close
together.

Head with anterior margin thickened, and produced in a small
median point, on either side of which the margin is lobed. Eyes

310 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

situated post-laterally. First pair of antennae extend to the posterior
margin of the first thoracic segment; first joint of peduncle, oblong;
second joint, short. Second pair of antenme extend to the posterior
margin of the third thoracic segment.

The first thoracic segment is longer than any of the following seg-
ments. The epimera are twice as broad as long.

The first abdominal segment is short and bears indications of three

coalesced segments. There are three
transverse elevations on this segment
which are densely covered with granules.
The terminal segment bears three trans-
verse elevations at the base, the median
one terminating in a spine. On its pos-
terior margin is a quadrangular excava-
tion, with a long median tooth, bearing a
spine at its extremity. At the base of
FIG. 335.-ciLic.EA GRANULOSA. LAST the tooth is a small elevation. On either
THORACIC SEGMENT AND ABDOMEN. s{fe of the terminal excavation, a short

x 8

distance up the lateral margin, is a small

spine. The fixed inner branch of the uropoda is small and short; the
outer branch is long, blunt at the extremity, somewhat incurved, and
reaches, when open, much bej^ond the terminal segment. The margins
of the terminal segment, and the edges of the outer branch of the
uropoda, are pubescent.
The legs are all simple, ambulatory.

One specimen from Cerros Island, Lower California, was collected
by Mr. A. W. Anthon}7 at a depth of 20 fathoms.
"Type.— Cat. No. 22649, U.S.N.M.

CILIC^A CORDATA Richardson.

Cillcfea cordata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 839-840.
Dynamene tuberculosa RICHARDSON, Proc. U. 8. Nat. Mus., XXI, 1899, p. 833.
Cilicsea cordata RICHARDSON, Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 184-185.
Dynamene tuberculosa RICHARDSON, Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 176-

177.

Cilicsea cordata RICHARDSON, American Naturalist, XXXIV, 1900, p. 224.
Dynamene tuberculosa RICHARDSON, Am. Naturalist, XXXIV, 1900, p. 223.
Dynamene cordata HOLMES, Proc. Cal. Acad. Sci. (3), III, 1904, pp. 302-303.

Localities. — Catalina Island, California; Popoff Island; Monterey
Bay, California; Aleutian Islands; Bodega Bay, California; Gualala,
Mendocino County, California. Found in low water; dredged; in
pink coralline at low tide.

Occurs on Haliotis rufescens.

Depth. — 30 to 40 fathoms, in sandy mud.

On the authority of Prof. S. J. Holmes, who has collected specimens
of this species, Dynamene tuberculosa and Cilicsea cordata represent

ISOPODS OF NOKTH AMEEICA,

311

the two sexes of the same species. Similarity of habitat and colora-
tion are the reasons he gives for this conclusion, together with the
fact that all the specimens which he col-
lected of the one were females and of the
other males. An examination of the speci-
mens at my disposition gives the same
results in regard to the sexes. Still I
place Dynamene tuber culosa with much
hesitation un the synonymy of Cilicsea
cordata as representing the female, inas-
much as several males of the genus I)y-
nameneh&ve been found which are in every
respect similar to the females.

Description of mala. — Body attenuated
in front; color a faint yellow, profusely
marked with a delicate pink tint.

Head with the anterior margin thick-
ened, and slightly produced in front.
Prominent median point triangularly
shaped. Frontal margin broadly lobed
on either side of median point. Eye
situated at post-lateral angle of head.
First pair of antennae reach beyond the
posterior margin of head; first joint of
peduncle oblong; second joint very short;
flagellum consists of about nine articles.
The second pair of antenna? extend to the
posterior angle of the third thoracic segment; the iiagellum consists
of about fifteen articles.

The thoracic segments are about equal in length, with the exception
of the first, which is a little longer than any of the
others. The epimera are very broad and drawn out
to an apex, which is rounded. They are scarcely
visible in a dorsal view, as they project downward
laterally, forming an angle with the segments. The
last thoracic segment is furnished with low tubercles
on its posterior margin.

On the first abdominal segment are five double
tubercles. The terminal segment of the body has
three sinuses, one above another, the two upper
openings being heart-shaped. Six teeth are grouped
in series of two each, and are placed in such regu-
larity as to give the appearance of a triple sinus.
At the base of the upper sinus is a large rounded tubercle, peaked at
the top. Three double tubercles are also situated at the base of the
abdomen. The inner branch of the uropoda is fixed and immovable;

FlO. 33G.— ClLIC.EA CORDATA (MALE).

a, HEAD AND FIRST THORACIC SEG-
MENT. &, DORSAL VIEW, x 8.

FIG. 337.— CILIC^A
CORDATA. MAX-
ILLIPED. X 27}.

312

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 338.— ClLIC^EA COR-
DATA. SECOND PLEOPOD
OF MALE. X 15j.

FIG. 339.— ClLIC^A CORDATA

(FEMALE). MAXILLIPED.
X 51|.

it is broad and pointed at its extremity and extends two-thirds the
length of the terminal segment. The outer branch is long and slender,
broad and flattened above, more rounded and
tapering at the extremity, somewhat incurved,
and extends a little beyond the end of the abdo-
men. Its outer edge is cren-
ulate and its under surface
armed with four spines.

The legs are long and
slender, all ambulatoi^, and
with dactylus biunguiculate.
Two specimens were col-
lected at Popoff Island (Aleu-
tian Islands) by Dr. W. H.
Dall at low water.

Type.— Cut. No. 22575, U.S.N.M., Popoff
Island.

Another individual was found at Catalina Island,
California, by Dr. J. G. Cooper. In this specimen the sixth thoracic
segment is also tuberculated. One specimen was
found by Mr. Heath at Monterey Bay on the
pink coralline at low tide, and is shaded with a
delicate pink. In this specimen, on the seventh
thoracic segment and the penultimate abdominal
segment, the tubercles on either side of the median
line of tubercles are single instead of double.

Description of female. — :Bod}^ oblong-ovate;
color, light yellow, almost white; surface of
abdomen tuberculated.

Head large, much broader than long, with a
wide anterior margin, broadly curving on either
side of a small median point. Eyes small, and
situated at the extreme post-lateral angles of the
head. The first pair of antenna?, composed of
eight articles, reach beyond the middle of the
first thoracic segment. The second pair of
antennae, composed of twelve articles, extend to
the posterior angle of the first thoracic segment.
The first segment of the thorax is one and a
half times longer than any of the other segments,
which are about equal in length. The epimera,
which are distinctly marked, and roundly pro-
duced at their posterior angles, are much broader
than long.

abdominal segment is transversely crossed by three

the segment. Three small

FIG. 340.— ClLIC^A CORDATA
(FEMALE). X 8. a, DOR-
SAL VIEW, b, LATERAL
VIEW.

The first
suture lines, indicated at the sides of

ISOPODS OF TSTORTH AMERICA.

813

tubercles are situated in a transverse line on the posterior margin of
this segment. The terminal segment is subtriangular in shape, with
a broad funnel-like excavation at its extremity, formed by the infold-
ing of the lateral edges. The anterior part of the terminal segment
is very convex, upon which elevation are situated three large tuber-
cles in a transverse row, the center one being in the median line. At
the base of the terminal excavation " is also a small tubercle. Both
branch.es of the uropoda are similarly shaped, being of the same width
throughout their entire length, and rounded posteriorly. The outer
branch is somewhat shorter than the inner branch; neither reach the
extremity of the abdomen.

Individuals were found at Gualala, California, on Haliotis rufescens,
by Dr. R. E. C. Stearns; also, one specimen at Catalina Harbor, Cali-
fornia, and one at Popoff Island, Aleutian Islands, at low water, by
Dr. W. H. Dall.

Type.— Cat. No. 22569, U.S.N.M. Popoff Island, Aleutian Islands.

CILICiEA GILLIANA Richardson.

Cilicsca caudata gilliana RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp.
840-841; Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 185-186; American Nat-
uralist, XXXIV, 1900, p. 224.

Localities. — Catalina Island, California; Gualala,
Mendocino County, California.

Depth. — 30-40 fathoms in sandy mud.

Body slightly attenuated in front. Color, light
brown with markings of black.

Head with anterior margin thickened and slightly
produced. Large median point triangularly shaped,
on either side of which the frontal margin of the
head is broadly lobed. Eye situated at the pos-
terior angles of the head. F
pair of antennae reach beyond the
posterior margin of the head;
first joint of peduncle is oblong;
second joint very small; flagellum
consists of eight joints. The second pair of antennae

FIG. 341.— ClLIC^IA GIL-
LIANA. X 8.

are broken in the specimens examined.

The thoracic segments are about equal in length,
with short but very broad epimera, which extend
downward laterally, forming an angle with the
segments. The last segment is ridged with very
low tubercles on its posterior margin.

The first abdominal segment has two suture lines,
indicative of coalesced segments, and bears five
double tubercles. The terminal segment has a large sinus, in which
are situated six sharp teeth. At the base of the sinus is a large

PIG. 342.— CILIC.EA GIL-
LIANA. MAXILLIPED.
x51|.

314

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

tubercle. Three double tubercles are also found at the base of the
terminal segment. The inner branch of the uropoda is affixed to the
sides of the abdomen and extends two-thirds of its length; it is
triangularly pointed at its extremity. The outer branch is long and
slender, almost cylindrical in shape, smooth, somewhat incurved, and
extends much beyond the tip of the terminal segment.

The legs, all ambulatory, are slender with dactylus uniunguiculate.

Specimens were dredged off Catalina Island, California.

Type.—Odt. No. 22576, U.S.N.M.

These specimens differ from Cilicaea caudata (Say), in the presence
of six distinct :,eeth within the sinus of the terminal segment, while in
that species there are but four; in the greater development of the
spine at the base of the sinus, and in the median double tubercle at
the base of the terminal segment.

This species is named in honor of Pr. Theodore Gill, the distin-
guished icthyologist.

CILIC^A CAUDATA (Say).

Nsesa caudata SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 482. — MILNE

EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 219.
Cymodocea caudata IVES, Proc. Acad. Nat. Sci. Phila., 1891, p. 188, pi. vi, figs.

11-14.

Cymodocea bermudensis IVES, Proc. Acad. Nat. Sci. Phila., 1891, p. 194.
Cilicsea caudata RICHARDSON, Proc. U. S. Nat. Mus., XXI, p. 841 (foot-note);
Ann. Mag. Nat. Hist, (7), IV, 1899, p. 186 (foot-note); Proc. U. S. Nat.
Mus., XXIII, 1901, p. 536.

Dynamene bermudensis RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 534;

Trans. Conn. Acad. Sci. XI, 1902, p.
291.

Cilicsea caudata RICHARDSON, Trans. Conn.
Acad. Sci., XI, 1902, p. 291.— MOORE,
Bull. U. S. Commissioner of Fish and
Fisheries, XX, Pt. 2, 1902, p. 172, pi.
x, figs. 5-8.

Localities. — Egg Harbor, New Jer-
sey ; Beaufort, North Carolina; No
Name Ke\^, Florida; between Salt
Pond Key and Stock Island; Key West;
Puntarassa; Sugarloaf Key; northwest

F,G. 343.-ciLic^ CAUDATA (AFTER end St" Martins Reef; Sarasota Bay,
IVES). a, LATERAL VIEW, x 4. 6, DOR- Florida; Cedar Keys, Florida; off Pro-

greso and Cape Catoche, Yucatan;

Bermudas, at Harrington Sound, Castle Harbor, and the Flatts;

Mayaguez, Boqueron Ba}^, Puerto Real, Arroyo, and Fajardo, Porto

Rica; the Bahamas.
Depth. — Found on the surface; also at a depth of 1-12 feet; 25 fms.

Among algae and grass below low tide; from coral reefs.

ISOPODS OF NORTH AMERICA.

315

FIG. 344. — ClLIC.EA CAUDATA
(MALE) (AFTER MOORE).
X 53.

On the authority of Dr. H. F. Moore, who has collected specimens
of this species, Dynamene bermudensis represents the female of Cilicasa
caudata (Say). The two forms are always found associated together.
Only the female of the one is known and the male of the other. I unite
the two with much hesitancy, for, inasmuch as
the males of several species of Dynamene are
known, the male of this form may not be the
one referred to it by Doctor Moore.

Description of male. — Body very slightly in-
creasing in width from the head to the abdomen,
a little more than twice as long as wide from the
anterior margin of the head to the extremity of
the abdomen, 4 mm.: 9 mm. The uropoda ex-
tend 1 mm. beyond the tip of the terminal seg-
ment, making the entire length of the body with
the uropoda 10 mm.

Head three times as wide as long, 1 mm.:
3 mm., with a frontal border arising between
the eyes, and produced in a small median point.

The eyes are small, round, composite, and situated in the post-
lateral angles of the head. The first pair of antennae have the
basal article long and stout; the second is. half as long as the
first and equally wide; the third is one and a half times
as long as the second and about half as wide. The
fiagellum is composed of eight articles. The first an-
tennae extend to the posterior margin of the first tho-
racic segment. The second pair of antennae have the
basal article short; the second is about twice as long as
the first; the third and fourth are about equal in length
and each is a little longer than the second; the fifth is
a little longer than the fourth. The flagellum is com-
posed of fifteen articles. The second antennae extend a
little beyond the posterior margin of the second thoracic
segment. The maxilliped has a palp of five articles.
The palp of the mandibles is composed of three articles.
The frontal lamina is large and conspicuous, the pos-
terior portion forming a thick raised margin in the
shape of an inverted v.

The first segment of the thorax is nearly twice as long as any of
those following. The lateral parts of all the segments are bent down-
ward, forming an angle with the dorsal part of the segment. The
epimera are not distinct • from the segments, but are indicated by a
depression on either side of the segment a little distance within the
place where the lateral part of the segment bends downward. The

FIG. 345.— CIL-
IC.EA CATJDA-
TA. MAXIL-
LIPED. x51f.

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

posterior extremity of the lateral margin or the outer post-lateral
angle is slightly produced.

The abdomen is composed of two segments. The first segment has
two suture lines on either side indicating partly coalesced segments.
Its posterior margin has five low tubercles, two on either side of a

FIG. 346— CILIC.EA CAUDATA (FEMALE) (AFTER IVES). a, DORSAL VIEW.

C, FODRTH LEG OF RIGHT SIDE.

x 4. b, LEFT SIDE, x 4.

median one, and each with a groove in the center from which extends
a long movable spine-like bristle. The terminal segment has the con-
vex anterior half provided with one large median tubercle with a
groove in the center from which extends a bunch of hairs. On either
side of this median tubercle is a row of two large tubercles in longi-
tudinal series, the lower one in each series being
in a transverse line with the median tubercle.
Below this transverse row of three tubercles and
almost hidden by them are three small tubercles
in a transverse row and much closer together than
those directly above them. The posterior half of
the terminal segment is deeply excavate, the post-
lateral angles being very acute. Within the exca-
vation are four acute teeth, two on either side of
the center. The post-lateral angles have a small
rudimentary tooth on the inner side near the
extremity. The fixed immovable branch of the
uropoda extends only half the length of the termi-
nal segment. The outer movable branch is long
and narrow and is curved inward, so that when folded its extremity
meets that of the branch of the opposite side in the median line of the
body. The outer branch is furnished on its exterior margin with
bunches of hairs scattered here and there.

The legs are all ambulatory. On each segment of the thorax there
are seven bunches of a few hairs, forming seven longitudinal series on
the thorax.

FIG. 347.— CILIC.EA CAUDA-
TA (FEMALE) (AFTER

MOORE), x 8.

ISOPODS OF NORTH AMERICA.

317

Description of female. — Body ovate, twice as long as wide, 3 mm.:
G mm.

Head nearly three times as wide as long, 1 mm. :3 mm., with a
frontal border arising between the eyes and produced in a small median
point. Ths eyes are small, round, composite, and situated in the post-
lateral angles of the head. The first pair of antennae have the basal
article long and stout; the second article is less than half as long as
the first and is of equal width; the third is twice as long as the second
and half as wide. The flagellum is composed of ten articles. The
first antennae extend almost to the posterior margin of the first thoracic
segment. The basal article of the second antennae is very short; the
second is twice as long; the third is one and a half times longer than
the second; the fourth is a little longer than the third; the fifth is a
little longer than the fourth. The flagellum is composed of twelve
articles. The second pair of antennae extend to the posterior margin

FIG. 34H. — ClLIC^A CAUDATA (FEMALE), a, MANDIBLE. X 51|. 6, MAXILLIPED. X 6l|. C, FRONTAL

LAMINA AND CLYPEUS. X 51f.

of the second thoracic segment. The maxilliped has a palp of five
articles. The palp of the mandibles is composed of three articles.
The frontal lamina is large and conspicuous and has a V-shaped raised
margin pointing anteriorly.

The first segment of the thorax is twice as long as any of the
others. The epimera are not distinct from the segments, but a
lighter area and a slight depression marks the place of coalescence.
The lateral margins are straight, with the outer post-lateral angle
slightly produced.

The abdomen is composed of two segments. The first segment is
as long as the first thoracic segment, and has three suture lines on
either side, indicating as many coalesced segments. The terminal
segment has the anterior convex portion surmounted with three tuber-
cles in a transverse row, the middle one being in the median longi-
tudinal line. The shape of the segment is somewhat triangular, with
the bluntly rounded apex produced, the sides of the extremity folding
under to form a groove, which is incomplete on the ventral side. The
immovable inner branch of the uropoda extends two-thirds the length

318

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of the terminal segment; it is truncate at the extremity. The mova-
ble outer branch is as wide and as long as the inner branch, and has
the outer posterior angle slightly produced and acute, the inner angle
being rounded.
The legs are all ambulatory.

CILIC-^A SCULPTA (Holmes).

Dynamene sculpta HOLMES, Proc. Cal. Acad. Sciences (3), III, No. 11, 1904,
pp. 300-302, pi. xxxiv, figs. 1-7.

Localities. — San Clemente Island; San Diego, California.
Found in pieces of sponge dredged in shallow water.
"Body increasing slightly in width posteriorly. Head narrowed
and scarcely longer than the first segment of the thorax. Eyes oblong,

FIG. 349. — ClLIC.EA SCULPTA (AFTER HOLMES), d, ABDOMEN OF MALE. 6, ABDOMEN OF FEMALE.

c, HEAD OF MALE (LATERAL VIEW), d, FIRST ANTENNA OF MALE, e, SECOND ANTENNA OF MALE.
/, MAXILLIPED OF MALE, g, LAST THORACIC LEG OF MALE.

situated on prominent, rounded, lateral lobes. Thoracic segments
minutely roughened behind, the lateral angles produced backward
into subacute, triangular processes; first segment longer than the
succeeding ones, the lower side produced forward into a triangular
process extending a little in advance of the eye and backward into a
triangular, acute lobe at the postero-inferior angle; last three seg-
ments with several small setose prominences on the posterior margin.
Abdomen large, with five segments indicated, the anterior segment
marked off by a line extending entirely across the upper surface; the
three following segments are indicated by two pairs of lines which are
visible only at the sides; second segment furnished with three setose
tubercles in a transverse row. Caudal shield large and sculptured,

ISOPODS OF NORTH AMERICA. 319

the anterior portion with three tubercles, the middle one rather blunt
and a little in advance of the others; a pointed tubercle with two lat-
eral ridges in front of the posterior notch; notch deep, with a small
spine at the end, behind which is a pair of larger spines. Inner
branch of the uropods flattened and not nearly reaching the tip of the
caudal shield, the tip subacute; outer branch very long, narrow, and
incurved, extending considerably behind the tip of the caudal shield
and directed obliquely upward. First antennae a little shorter than
the second, the first basal joint enlarged, oblong, and emarginate at
the distal end at the insertion of the small, subquadrate second joint;
flagellum longer than the peduncle and composed of nine to eleven
joints. Second antennae scarcely reaching the middle of the thorax,
the peduncle slender, the last two joints much longer than the pre-
ceding ones; flagellum a little longer than the peduncle, the joints
furnished with short setae. Thoracic legs increasing slightly in length
posteriorly and furnished with short hairs; propodi armed below with
spines; dactyls curved and ending in a spine with a strong spine
behind the tip.

"The females are smaller than the males; the head, antennae, mouth
parts, thoracic legs, and anterior segments are not distinguishable from
those of the male, but the abdomen is markedly different. The caudal
shield is relatively smaller and less sculptured; the notch at the ex-
tremity is simple and shallow; there are three oblong tubercles on the
anterior portion; the three tubercles on the next segment in front are
smaller than in the male. The branches of the uropods are flattened
and of subequal size; neither extends beyond the tip of the caudal
shield."— HOLMES/'

CILIC^EA CARINATA Richardson.

Cilicsea carinata RICHARDSON, American Naturalist, XXXIV, 1900, p. 224; Proc.
U. S. Nat. Mus., XXIII, 1901, pp. 535-536.

Locality. — Coast of Georgia.

Depth. — 440 fathoms.

Head with a median projection on the anterior margin, produced
forward in the form of a large tubercle. Eyes
colorless. First pair of antennae reach the poste-
rior margin of the head; flagellum eight- jointed.
Second pair of antennae reach the posterior margin
of the first thoracic segment.

The segments of the thorax are roughly granu-

. FIG. 360.— CILICSEA CARI-

lated. A transverse median ridge or elevation NATA. HEAD.

appears on each of the segments, giving the dorsum,
from a lateral view, a very rugged appearance. The epimera are
rough and are drawn out laterally in very acute angles.

flProc, Ca.1. Acad. Sciences (3), III, 1904, pp. 300-301.

320

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 351.— ClLIC^A CARINATA
LATERAL VIEW.

FIG. 352. — ClLIC-EA CARINATA.
ABDOMEN.

The abdomen is composed of two segments, the first segment being
formed of several coalesced segments, as indicated by two suture
lines. In the center of this segment are two longitudinal ridges, placed
obliquely, so as almost to meet anteriorly and to spread apart at the

other extremity. This segment projects down

over the last segment at either side. The last

segment has a deep ex-
cavation at its posterior

extremity, around and

above which is a cari-

nated ridge extending

entirely around the

whole of the posterior

half of the segment.

Two small longitudinal

ridges are in the center

of the segment. The inner branch of the uropoda is very short, not
reaching the extremity of the abdomen by some distance; it is quad-
rangular in shape, with sides nearly parallel, and obliquely truncated
at the end. The outer branch of the uropoda is long, curved, and
pointed at the end, resembling a hook somewhat.

The color is a light yellow. In appearance the little isopod is very
rough and rugged looking.

There is but one specimen, which was found off the coast of Georgia.
Depth.— 440 fathoms.
Type.—®**,. No. 23907, U.S.N.M.

Family XII. SEROLID^.

Body strongly depressed.

Both pairs of antennae multiarticulate with well-defined peduncle
and flagellum. Mandible with palp. Maxillipeds with a triarticulate
palp. Head posteriorly fused with first thoracic segment.

Seventh thoracic segment entirely wanting on dorsal side.

Abdomen composed of four segments, three anterior to the large
terminal segment.

Uropoda lateral, with both branches free and subequal. First two
pairs of legs subchelate in male, second pair smaller than first; .only
first pair subchelate in female; last pair of legs smaller than any of
the preceding pairs.

First three pairs of pleopods natatory; fourth and fifth pairs bran-
chial; outer branch of fourth pair forming an operculum.

Marsupium consists of four pairs of plates.

S3. Genus SEROLIS Leach.

With characters of family.
Only genus known.

ISOPODS OF NORTH AMERICA.

321

SEROLIS CARINATA Lockington.

Serolis carinata LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 36. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 842; Ann. Mag. Nat.
Hist, (7), IV, 1899, p. 187; American Naturalist, XXXIV, 1900, p. 224.

FIG. 353.— SEROLIS CARINATA. x

Locality. — San Diego, California.

Body almost round, very much flattened, and nearly as broad as
long, 5 ram : 6 mm.

Head about as wide as long and deeply set in the first thoracic seg-
ment, with which it is fused posteriorly. The eyes are large, oval,

FIG. 354. — SEROLIS CARINATA. a, FIRST LEG. x 27. b, FIRST MAXILLA, x 51|. c, SECOND MAXILLA.
x 51f. d, MAXILLIPED. x 51f. e, MANDIBLE, x 51|.

and composite, and situated in the post-lateral angles of the head.
The anterior margin of the head is bisinuate on either side of a small
median point. The basal article of the first pair of antennae is large
28589—05 21

322 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

and somewhat dilated; the second article is nearly twice as long as the
first, and is also somewhat dilated; the third article is as long as the
second, but more slender; the fourth article is almost as long as the
third. The flagellum is composed of five articles. The first antennae
extend to the posterior margin of the first thoracic segment or to the
end of the peduncle of the second pair of antennae. The basal article
of the second antennae is short and is not visible from a dorsal view;
the second article is about twice as long as the first; the antenme are
geniculate between the second and third articles; the third article is
about as long as the second; the fourth is twice as long as the third;
the fifth is one and a half times longer than the fourth. The flagellum
is composed of seven articles. The second antenna? extend to the
posterior margin of the second thoracic segment. The maxilliped has
a palp of three articles. The palp of the mandibles is composed of
three articles.

The first segment of the thorax is fused with the posterior portion
of the head along the posterior margin. The lateral portions of the
segment are widely expanded and surround the head, the antero-lateral
angles extending to the anterior margin of the head. The five fol-
lowing segments are free, with the lateral parts widely expanded and
subequal. The first segment and the last two (the fifth and sixth) are
very much shorter in the median longitudinal line than the interme-
diate ones. The seventh segment is entirely wanting on the dorsal
side. The epimera are not distinct from the segments, but are per-
fectly coalesced, with no indication of the place of fusion.

The abdomen is composed of four segments, the first three of which
are short and subequal in length. The lateral parts of the first two
are covered by the widely produced lateral parts of the last thoracic
segment. The fourth or terminal segment of the abdomen is large,
somewhat triangular in shape, with apex obtusel}7 rounded. A little
more than one-third the distance from the base to the apex is a sharp
tooth on either side, below which the abdomen becomes more attenu-
ated. The peduncle of the uropoda arises at this point on the ventral
side. The peduncle of the uropoda extends to about the middle of the
lateral margin of the terminal abdominal segment. The branches are
subequal in length and of equal width. They are rounded posteriorly,
somewhat crenulate on the lateral margins, and extend a short distance
beyond the tip of the terminal segment.

The first pair of legs are subchelate, with propodus greatly dilated.
All the other six pairs of legs are ambulatory. In the male the first
two pairs of legs are subchelate, the second pair being smaller than
the first. There are five pairs of pleopoda, one pair for each of the
first three segments; the fourth pair have the outer branch forming
an oper.culum folding over the entire ventral side of the last segment
and attached at the anterior end, being free elsewhere; the fifth pair
are concealed under the operculum.

ISOPODS OF NORTH AMERICA. 323

III. IDOTHEOIDEA or VALVIFERA.

Uropoda lateral, valve-like, ventrally placed, closing over the five
pairs of branchial pleopoda being attached on the outer margins to
the sides of the terminal segment and opening and closing like folding
doors. Legs of the first pair not cheliform.

ANALYTICAL KEY TO THE FAMILIES OF IDOTHEIOIDEA.

a. Body narrow, elongate, somewhat cylindrical, scarcely depressed. Four anterior
pairs of legs unlike the three posterior ones, not ambulatory, nor strictly pre-
hensile, directed forward, slender, ciliated, the first pair very small and closely
applied to the mouth parts; last three pairs stouter and ambulatory with termi-
nal joint bifid Family XIII. ARCTURID.E

a/. Body more or less broad, depressed. Legs usually nearly alike and ambulatory,

but first three pairs sometimes pronouncedly subcheliform in structure

Family XIV. IDOTHEID^E

Family XIII. ARCTURID^.

Body narrow, elongate, somewhat cj^lindrical, scarcely depressed.
First antennae with the flagellum uniarticulate. Second antennae
strongly developed, the peduncle having the last two articles very
much elongated and geniculate at the articulation of the joints; the
flagellum is short. Segments of the abdomen more or less consoli-
dated, the last one being rather large. The four anterior pairs of legs
are unlike the three posterior pairs, are neither ambulatory nor strictly
prehensile, are directed forward, slender, feeble in structure, ciliated
with long delicate hairs, the first pair being very small and applied
to the mouth parts. Last three pairs of legs stouter and ambulatory
with terminal joint bifid.

Mandibles always without palps/'

ANALYTICAL KEY TO THE GENERA OF THE FAMILY ARCTURID^.

a. Fourth segment of thorax greatly longer than any of the others. Marsupium of
female consists of two plates affixed to this segment. .Genus Astacitta Cordiner
a'. Fourth segment of thorax not greatly longer than any of the others. Marsu-
pium of female composed of three pairs of plates.
b. Abdomen composed of three distinct segments, two short ones anterior to the

terminal segment Genus Areturus Latreille

&'. Abdomen composed of two distinct segments, one anterior to the terminal
segment Genus Pleuroprion zur Strassen

54. Genus ASTACILLA Cordiner.

Body slender, cylindrical in form, with the fourth segment of the
thorax very much elongated. Epimera small but distinct on all the
thoracic segments with the exception of the first. Marsupium of
female consists of two plates affixed to this segment. Abdomen com-
posed of only two segments, a single short segment anterior to the
terminal one, which is conically produced.

« See Sars for characters of family, Crust, of Norway, II, 1899, p. 86.

324

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ANALYTICAL KEY TO THE SPECIES OF THE GENTS ASTACILLA.

a. With eyes^ Head excavate in front, without rostriform point. Fourth thoracic
segment subcylindrical. Terminal abdominal segment with a prominent,
subacute tooth on each side above the middle, directed outward and backward;

extremity obtuse Astacilla granulata (G. O. Sars)

a'. Without eyes. Head with a rostriform point in front, between the antennulse.
Fourth thoracic segment wider at the anterior end, and tapering to the poste-
rior end. Terminal abdornofnal segment with a pair of teeth on each side;
extremity acute Astacilla cseca Benedict

ASTACILLA GRANULATA (G. O. Sars).

Leachia granulata G. O. SARS, Arch. Math. Nat., II, 1877, p. 351 (251).

Astacilla americana HARGER, Am. Jour. Sci. (3), XV, 1878, p. 374.

Asiadlla granulata HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 161. — SARS,
Norw. North Atlantic Exp., Crust., 1885, p. 107, pi. ix, figs. 27-35.— HAR-
GER, Report U. S. Commissioner of Fish and Fisheries, Pt. 6, 1880, pp. 364-
367, pis. vm-ix, figs. 48-52. — HANSEN, Videnskabelige Meddelelser fra den
Naturhistoriske Forening i Kj0benhavn, 1887-88, pp. 189-190. — BENEDICT,
Proc. Biol. Soc. Washington, XII, 1898, p. 50. — RICHARDSON, American Nat-
uralist, XXXIV, 1900, p. 230; Proc. U. S. Nat. Mus., XXIII, 1901, p. 550.—
NORMAN, Ann. Mag. Nat. Hist. (7), XIV, 1904, p. 448.

Localities. — Georges Banks; Banquereau; Miquelon Island, south
of Newfoundland; latitude 69° 16' north, longitude 58° 8' west;
latitude 70° north, longitude 58° 38' west; latitude 71° 10' north,
longitude 58° 56' west; latitude 72° 41' north, longitude 59° 50'

west; also between Norway and
Iceland; Grand Banks; latitude
60° 31' north, longitude 9° 18'
west; latitude 60° 21' north, lon-
gitude 5° 41' west.

Depth. — 7-640 fathoms.
Body narrow, elongate, about
six and a half times longer than
wide, 2£ mm. : 16 mm., not in-
cluding the antennae.

The head is as wide as long, 2
mm. : 2 mm., with the anterior
margin deeply excavate. The
FIG. 355.-A8TACILLA GRANULATA (AFTER HARGER). eyes are small, round, composite,

a, FIRST ANTENNA OP MALE. + 4. b, FOURTH an(J situated at the sides of the

THORACIC SEGMENT OF MALE. + 4. C, VENTRAL

SIDE OF ABDOMEN. x 4. head, half way between the ante-

rior and the posterior margins.

The first pair of antennae have the basal article long and somewhat
dilated; the two following articles are short and slender, the two
together being as long as the first article; the fourth or last article is
a little longer than the first. The first antennae extend to the end of
the second article of the peduncle of the second antennae. The basal

ISOPODS OF NORTH AMERICA. 325

article of the second antennae is short, and does not extend beyond the
antero-lateral angles of the head; the second article extends to the
end of the first pair of antennae; the third article is three times as
long as the second article; the fourth is twice as long as the third; the
fifth is a little shorter than the fourth. The flagellum is composed of
three articles. The second antennae are not quite as long as the body,
being 14 mm. in length. The maxilliped has a palp of five articles.
The palp of the mandibles is wanting.

The first segment of the thorax is a little longer than the two fol-
lowing segments, which are subequal. The fourth segment is
extremely long, being 6 mm. long, or 1 mm. longer than all the other
six segments taken together. This segment is broader anteriorly than
the preceding segments; at its posterior extremity it becomes abruptly
narrower. The fifth segment is about one-sixth as long as the fourth
segment; the sixth segment is about equal in length to
the fifth; the seventh is a little shorter than the sixth.
The lateral parts of the first segment are broadly ex-
panded and surround the posterior portion of the head,
the antero-lateral angles extending as far as the eyes.
The epimera are distinctly separated on all the six follow-
ing segments. On the second and third segment they
are small and occupy the whole of the lateral margin.
On the fourth segment they occupy the antero-lateral
angles. In the last three segments they project at the
sides in acutely pointed processes. FIG 356_ASTA

The first two segments of the abdomen are short. The CILLA GRANU-
terminal segment is long and narrow, about one-fifth
the entire length of the body, being 3 mm. long. It is
produced to a narrow, obtuse extremity. Near the base there is a
transverse depression marked at the sides by an acute process or
expansion of the lateral margin.

The first four pairs of legs are slender, directed forward, densely
covered with long hairs on the inferior margins of all the articles.
The first pair are much shorter than the three following pairs, which
are gradually increasingly longer. The last three pairs of legs are
ambulatory and gradually decrease in length.

The whole surface of the body is covered with small granulations.
On the posterior portion of the dorsal surface of the head are two low
tubercles. The three last segments of the thorax have each one low
tubercle in the median longitudinal line. The first two segments of
the abdomen have each two low tubercles, one on either side of the
median longitudinal line. The terminal segment has a double row of
six low tubercles in two longitudinal series, one row on either side of
the median line.

326

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ASTACILLA CJECA Benedict.

Astacilla cseca BENEDICT, Proc. Biol. Soc. Washington^ XII, 1898, p. 51. — RICHARD-
SON, American Naturalist, XXXIV, 1890, p. 230; Proc. U. S. Nat. .Mus.,
XXIII, 1901, p. 550.

Locality.— Latitude 38° 22' north, longitude 70° 17' 30" west (south
of Marthas Vineyard).
Depth.— 1,825" fathoms.

Body narrow, elongate, five times longer than wide, 2 mm. : 9£ mm.
Head wider than long, 1 mm. : 1£ mm., with the anterior margin
deeply excavate between the produced antero-lateral
angles, and a small median point within the excavation.
The lateral margin on either side is produced in two
acute triangular processes, an anterior and a posterior
lobe. The eyes are wanting. There are two tubercles
on the head situated in the median line, one on the
anterior portion and the other on the postcephalic
lobe. The first pair of antennae have the basal article
long and dilated; the second and third articles are sub-
equal in length, slender, and both together about equal
in length to the basal article; the fourth article is one
and a half times longer than the third. The first an-
tenna extend a little beyond the end of the second arti-
cle of the peduncle of the second pair of antennae. The
basal article of the second antennas is short and incon-
spicuous in a dorsal view, being covered by the basal
article of the first antennae; the second article extends
as far as the middle of the fourth article of the first antennae; the third
article is twice as long as the second; the fourth is twice as long as the
third; the fifth is a little shorter than the fourth. The
flagellum is composed of five articles. The second an-
tennae are 6 mm. in length.

The first three segments of the thorax are subequal in
length; the fourth segment is six times longer than the
third, being 3 mm. in* length; the fifth, sixth, and sev-
enth segments decrease gradually in length, the fifth
segment being about 1 mm. long. There is one median
tubercle on each of the thoracic segments; other small
tubercles are situated in a transverse line lateral to the
median tubercle on the first three segments; the fourth
segment is thickly covered with small tubercles over the
whole dorsal surface; the fifth segment has a pair of
tubercles one above the other on either side of the lateral
margin anterior to the epimera; the sixth segment has one tubercle on
either side anterior to the epimera. The epimera of the second, third,
and fourth segments are small; those of the last three segments are
angular and conspicuous. The fourth segment of the thorax is twice

FIG. 357. — ASTACIL-
LA CMCA (AFTER

BENEDICT).

FIG. 358.— ASTA-
CILLA C.ECA.
MAXILLIPED.
X 39.

ISOPODS OF NORTH AMERICA. 327

as wide at its anterior end as it is at its posterior extremity; it
measures 2 mm. in width at the anterior portion and only 1 mm. at the
posterior end.

The abdomen is composed of two segments, the first one of which is
short and narrow. The terminal segment has the lateral margins pro-
duced on either side in two angular processes, one at the base of the
segment and the other a little below the middle. The segment termi-
nates in an acute point. There is also a median tubercle on each one
of the abdominal segments, the tubercle on the terminal segment being
situated at the base of the segment.

The marsupial plates are covered with small tubercles.

S3. Genus ARCTURUS Latreille.

Body slender, somewhat cylindrical in form, with the fourth seg-
ment of the thorax not greatly longer than the others. Epimera small
but distinct on all the thoracic segments with the exception of the
first. Marsupium of female composed of three pairs of plates issuing
from the second, third, and fourth segments. Abdomen composed of
three segments, two segments anterior to the large terminal one.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ARCTURUS.

a. End of terminal segment notched, as seen from above.

b. Body smooth and free from spines Arcturus beringanux Benedict

b' '. Body spiny Arcturus longispinis Benedict

a'. End of terminal abdominal segment without notch.

6. Body without spines or tubercles, perfectly smooth and glabrous.

Arcturus glaber Benedict
I/. Body with spines or tubercles.

c. Terminal segment of abdomen armed with a long median terminal spine, pro-
jecting beyond the end of the segment.

d. Head with two spines. Second joint of second pair of antennae armed with
one spine at upper end. Thorax with few spines. Surface of terminal
abdominal segment smooth.

e. Second joint of peduncle of second pair of antennae without spine at base
on outer margin. First pair of antennae extending one-third the length
of the third joint of second pair of antennae. Dorsal spines wanting on
second abdominal segment. Spines wanting on opercular valves.
Anterior thoracic appendages furnished with a number of spines on

the proximal joints Arcturus purpureus Beddard

ef. Second joint of peduncle of second pair of antennae with spine at base on
outer margin. First pair of antennae extending two-thirds the length
of the third joint of second pair of antennae. Dorsal spines present on
second abdominal segment. Spines present on opercular valves.
Anterior thoracic appendages without spines except on penultimate

joint Arcturus caribbseus Richardson

df. Head with eight spines. Second joint of second pair of antennae armed
with three spines at the upper end. Thorax with many spines. Sur-
face of terminal abdominal segment with three rows of spines on dorsal
surface. Row of spines on each opercular valve.

Arcturus floridanus Richardson

328

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

(J. Terminal segment of abdomen not armed with a long median terminal spine.
</. Four anterior segments of thorax with spines or tubercles. Middle surface
of abdomen with prominent spiny projections. With conical lateral pro-
jections. Epimera pointed Arcturus bajfini ( Sabine)

dr/. Four anterior segments of thorax without spines or tubercles. Middle
surface of abdomen without any indication of prominent spiny projec-
tions. Without conical lateral projections. Epimera less pointed.

Arcturus baffini var. tuberosus Sars

ARCTURUS BERINGANUS Benedict.

Arcturus beringanus BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, pp. 46-
47.— RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 854; Ann. .Mag.
Nat. Hist. (7), IV, 1899, p. 275; American Naturalist, XXXIV, 1900, p. 229.

Localities. — Alaska; Bering Sea.
Depth.— 29-72 fathoms.

Body narrow, elongate, a little more than seven times longer than
wide, 1£ mm. : 11 mm., not including the antennae.

The head is about as wide as long, \\ mm. : li mm. , with the ante-
rior margin deeply excavate. The e}7es are small, round, composite,
and situated at the sides of the head about halfway between the ante-
rior and posterior margins. The first pair of antennae
have the basal article long and somewhat dilated; the
second is longer than the third, and both together are
about equal in length to the first; the fourth is a little
longer than the first. The first antennae extend to the
end of the second article of the peduncle of the second
pair of antenna?. The basal article of the second an-
tennae is short, and extends as far as the antero-lateral
angles of the head, or to the end of the first article of
the first pair of antennae; the second article is longer
and extends to the end of the first pair of antennae;
the third article is twice as long as the second; the
fourth is twice as long as the third; the fifth is a little
shorter than the fourth. The flagellum is composed of
four articles, the last article terminating in a spine.
The second antennae are shorter than the body, being
only T^ mm. in length. The maxilliped has a palp of
five articles. The palp of the mandibles is wanting.
The first three segments of the thorax are subequal; the fourth is
twice as long as any of the preceding segments; the fifth is half as
long as the fourth; the sixth is as long as the fifth; the seventh is a
little shorter than the sixth. The first segment has the lateral parts
somewhat expanded to surround the posterior portion of the head.
The epimera of the second, third, and fourth segments are distinctly
separated from the segments, are small and narrow, not visible from
a dorsal view, and occupy the antero-lateral angles of the segments.
The epimera of the last three segments are also distinctly separated

FIG. 359.— ARCTU-
EUS BERINGANUS
(AFTER BENE-
DICT), x 2i.

I3OPODS OF NOKTH AMEKICA.

329

from the segments, are conspicuous from a dorsal view, and are pro-
duced at the sides in processes which are rather, blunt at their
extremities.

The first two segments of the abdomen are short. The terminal
segment is long and produced to an extremity which has a V-shaped
excavation. The length of the terminal segment is a little less than one-
fourth that of the entire bod}7, being 3 mm. long. Near the base is a
transverse depression marked on either side by a blunt expansion of
the lateral margin, probably indicative of a coalesced segment. The
first four pairs of legs are slender, directed forward, and densely
covered with long, slender hairs on the inferior margins of all the
articles. The first pair of legs is shorter than the three following pairs.
The last three pairs of legs are ambulatory.

ARCTURUS LONGISPINUS Benedict.

Arcturus longispinus BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, pp. 44-
45.— RICHARDSON, Proc. IT. S. Nat. Mus., XXI, 1899, p. 854; Ann. Mag.
Nat. Hist. (7), IV, 1899, p. 275; American
Naturalist, XXXIV, 1900, p. 229.

Locality. — Aleutian Islands.

Depth. — 55 fathoms.

Bodj' narrow, elongate, nearly five times
longer than wide, 7 mm. : 35 mm.

Head wider than long, 7 mm. :4 mm., with
the anterior margin deeply excavate between
the produced antero-lateral angles. The eyes
are small, round, composite, and situated at
the sides of the head halfway between the
antero-lateral angles and the posterior margin.
There are two extremely long spines, 7 mm.
in length, situated about the middle of the
head between the eyes, one on either side of
the median line. The first pair of antennae
have the basal article long and somewhat
dilated, about twice as long as wide; the sec-
ond and third articles are subequal in length,
each being half as wide as the basal article and
much shorter; the fourth article is about one
and a half times longer than the third. The
first antenna extend to the end of the second
article of the peduncle of the second antennae.
The basal article of the second antennas is
short; the second article is 3 mm. long; the third is four times as
long as the second, or 12 mm. long; the fourth is 17 mm. in length;
the fifth is 15 mm. The flagellum is composed of eight articles, the

FIG. 360.— ARCTURUS LONGI-
SPINUS (AFTEK BENEDICT).
xli.

330 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

first being many times longer than the second. The second antennae
are 53 mm. in -length. The palp of the maxillipeds is composed of
five articles.

The first segment of the thorax has two small tubercles or rudiments
of spines, one on either side of the median line. The spines of the
second, third, and fourth segments are 6 mm. in length, placed one on
each side of the median line. The spines of the fifth segment are 2£
mm. long, one on either side of the median line. The spines of the
sixth segment are 2 mm. long, placed one on either side of the median
line. The spines of the seventh segment are 1£ mm. long, situated one
on either side of the median line. Epimera are distinct on all but the
first segment. They increase in size from those of the second to those
of the fifth segment, which are the largest, and then decrease in size;
all have the lateral margins rounded. The epimera of the second,
third, and fourth segments are concealed in a dorsal view by the large
knob-like projections on the lateral margins of the segments.

The abdomen is composed of three segments, the first two of which
are short and are armed each with two spines, one on either side of
the median line, those of the first segment being rudiments as in the
first segment of the thorax, while those of the second segment are 2
mm. long and project backward. The first segment has a triangular
expansion on either side of the lateral margin. The second has none.
The terminal segment has two backward projecting spines situated on
the dorsal surface, one on either side of the median line about the
middle of the segment. This segment is very much compressed
laterally. It terminates in two short points. The lateral margin has
a triangular expansion on either side at the base and a smaller one on
either side just below the middle of the segment.

The first four pairs of legs are directed forward and are strongly
ciliated. The last three pairs are ambulatory.

ARCTURUS GLABER Benedict.

Arcturus glabrus BENEDICT, Proc. Biol. Soc. Wash., XII, 1898, p. 46.

Arcturus glaber RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 855; Ann.

Mag. Nat. Hist. (7), IV, 1899, p. 277; American Naturalist, XXXIV, 1900,

p. 230.

Locality. — Bering Sea.

Depth. — 55 fathoms.

Body narrow, elongate, a little over six times as long as broad, 5 mm. :
31 mm. Head wider than long, 3 mm. : 4 mm. The head measures
4 mm. in length from the antero- lateral angles to the posterior margin.
The front is deeply excavate between the produced lateral angles.
The eyes are small, transversely ovate, composite, and situated at the
sides of the head, halfway between the antero-lateral angles and the

ISOPODS OF NORTH AMERICA.

331

posterior margin. The first pair of antennae have the basal article
large and dilated; the second and third articles are subequal and are
shorter and smaller than the first; the fourth article is twice as long
as either of the two preceding articles. The first antenna extend to
the end of the second article of the peduncle of the second pair of
antennae. The first article of the second antennae
is short, not longer than the basal article of the
first pair of antennae; the second article extends
to the end of the first antennas; the third article
is three and a half times longer than the second;
the fourth is nearly twice as long as the third;
the fifth article is nearly as long as the fourth;
the flagellum is composed of six articles, the
first one of which is about three
times longer than the second or
following articles. The second
antennae are longer than the
body. The palp of the maxilli-
peds is composed of five articles.
The first three segments of
the thorax are subequal, each
being 2 mm. in length. The
fourth segment is twice as long
as either of the three preceding
segments and is 4 mm. in length.
The fifth segment is 2£ mm.
long. The sixth and seventh
segments are each 2 mm. in length. Epimera are not represented on
the first thoracic segment. The epimera of the three following seg-
ments are small and occupy the antero-lateral angles. In the last three
segments the epimera are large and laterally produced.

The first two segments of the abdomen are short and subequal.
The third or terminal segment is long and tapers to a blunt extremity.
The first four pairs of legs extend forward and are strongly ciliated.
The last three pairs are ambulator}^.

ARCTURUS PURPUREUS Beddard.

Arcturus purpureus BEDDARD, Proc. Zool. Soc. London, 1886, p. 109; Report on
the Scientific Results of the Exploring Voyage of H. M. 8. Challenger,
Zool., XVII, 1886, pp. 112-113.— RICHARDSON, Proc. U. S. Nat. Mus., XXIII,
1901, p. 546.

Locality. — Off Sombrero Island.
Depth. — 450 fathoms.

"A single specimen of this species was dredged in the North Atlantic
at station 23 from a depth of 450 fathoms.

FIG. 361. — ARCTURUS GLABER
(AFTER BENEDICT), x !£.

PIG. 362.— ARCTURUS
GLABER. MAXIL-

LIPED. X Hi.

332 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"I have named itpurpureus on account of the purplish color which
appears to characterize the species and is very distinct in the spirit-
preserved specimen.

FIG. 363. — ARCTURUS PURPUREUS (AFTER BEDDARD). a, ONE OF POSTERIOR THORACIC LEGS.
b, LATERAL VIEW, c, ONE OF ANTERIOR THORACIC LEGS.

ISOPODS OF NOKTH AMEKICA.

333

"It is closely allied to Arcturus anna and to Arcturus cornutus,
but differs sufficiently from both to constitute the type of a new
species.

. • FIG. 364. — AKCTUKUS PURPUKEUS (AFTER BEDDARD). DORSAL VIEW.

"The extreme length of the specimen, which is a female, is 18 mm.,
the length of the antennae 31 mm.

334 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

" On the head between the eyes are a pair of long, forwardly curved
spines; the hinder portion of the head is occupied by a rounded median
convexity; at the antero-lateral margin of the head is a very short,
forwardly directed spine, beneath which the margin is excavated by a
semicircular notch.

"Of the first four thoracic segments the fourth is rather the shortest.
Each of the segments bears an outwardly directed spine on each side
of the body, corresponding to the pair on the head and of about equal
length; those on the fourth segment, although broken, appeared to
have been original^ §omewhat shorter; close to the lateral margin of
each segment, near to its junction with the epimeron, is another long
spine projecting outward and over the epimeron. The first segment
differs from the succeeding ones in having no separate epimeron, and
its lateral margin has two spines instead of one, of which the anterior
is the longer; they are both directed forward as well as outward. The
fourth thoracic segment has also a second spine, and its postero-lateral
margin inclined downward and backward as well as outward.

"Of the three posterior thoracic segments the first is the largest, the
two posterior being equal in size; the epimera of all three segments
bears a spine directed outward and at right angles to the longitudinal
axis of the body; that of the first of the three segments is considerably
the longest; this segment bears also a pair of spines upon the tergum
continuous with those on the segments in front, and exactly overlying
that on the epimeron.

"The first three segments of the abdomen are separated by distinct
sutures; the first and the third of the segments have a pair of long
lateral spines; those of the third segment mark the boundary between
it and the caudal shield; the first abdominal segment has a pair of short
ventral spines placed on either side of the median ventral line, and
upon a ridge which forms the posterior margin of the segment; ante-
riorly the segment is bounded by a similar ridge, but without any
distinct spines.

"The caudal shield is oval and convex, with a faintly marked longi-
tudinal carina which terminates in a long spine; the lateral margins of
the caudal shield are flattened and form a ridge like the brim of a hat;
on either side are two long curved spines situated at equidistant inter-
vals, and corresponding in position to the lateral spines on the last
abdominal segment; the lateral ridge does not terminate in a flattened
spine on either side, as in so many other species.

" The appendages in many cases bear long spines like those upon the
body; the antennae, which are very long, have a pair of spines upon
the distal extremity of each of the joints; the anterior thoracic append-
ages are furnished with a number of stout spines upon the proximal

ISOPODS OF NORTH AMERICA.

335

joints; the posterior thoracic appendages are smooth and devoid of
an}- such spines.

"•The uropoda are covered with numerous minute granulations but
bear no spines." — BEDDARD."

ARCTURUS CARIBB^EUS Richardson.
Arcturus caribbseus RICHARDSON, Proa U. S. Nat. Mus., XXIII, 1901, pp. 546-547.

Locality. — Near Aves Island, Caribbean Sea.

Depth.— 683 fathoms.

Head with a deep excavation on the anterior margin, on either side of
which the antero- lateral margins are produced, each bearing a short
spine at the outer angle. Two long
spines are situated on the anterior
portion of the head, between the
eyes. The first pair of antennas, con-
sisting of four joints, reach two-thirds
of the length of the third joint of the
second pair of antennae. The first
joint of the second pair of antennas
is short and unarmed; the second joint
is armed with a small spine at the
base on the outer margin, and a large
spine on the upper lateral margin; the
third joint is about three times as
long as the second joint, and is armed
with two long spines at the upper
end; the fourth joint is about twice
as long as the third joint, and is armed
with a single spine at the upper end;
the fifth joint is somewhat longer
than the fourth and is unarmed; the
flagellum is long and consists of ten
joints.

The first, second, third, and fifth
thoracic segments have each two long
projecting spines, one on either side
of the median dorsal line. The fourth,
sixth, and seventh segments are with-
out these spines. The first segment
has three spines, one large central spine and two small spines on each
antero-lateral margin. All the other thoracic segments have one long
spine on each lateral margin.

"Challenger Report, XVII, 1886, pp. 112-113.

FIG. 366.— ARCTURUS CARIBB.EUS.

336 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first abdominal segment has one lateral spine on each side; the
second segment has two dorsal spines, one on either side of the median
line. The terminal segment has one lateral spine on each side near
the base. It is rounded in outline posteriorly, with two lateral spines
on either side, one a little below the middle and one near the posterior
margin of the segment. There is also a large terminal spine on the
dorsal surface.

The opercular valves are armed each with a single spine about the
center of the valve. The penultimate joint of the second, third, and
fourth anterior pairs of legs is armed with a single spine.

One specimen of this species was taken by the U. S. Bureau of Fish-
eries steamer Albatross near Aves Island, Caribbean Sea.

Type. — Cat. No. 9113, U.S.N.M. This species closely resembles
Arcturus purpureus Beddard, differing from that species in having
two dorsal spines on the second abdominal segment, spines on the
opercular valves and at the base on the outer margin of the second
joint of the peduncle of the second pair of antennae, in wanting spines
on the proximal joints of the anterior thoracic appendages, with the
exception of the penultimate joint, and in the greater lepgth of the
first pair of antennae.

ARCTURUS FLORIDANUS Richardson.

Arcturus floridanus RICHARDSON. American Naturalist, XXX [V, 1900, p. 230;
Proc. U. S. Nat. Mus., XXIII, 1901, pp. 548-549.

Locality. — Fernandina, Florida.

Depth.— -273 fathoms; 270 fathoms.

Head with deep anterior excavation, on each side of which the lateral
margins are produced, bearing each a single spine at the outer angle.
On the anterior portion of the head are two long spines situated
between the eyes. Two long spines are placed on the posterior por-
tion of the head, between the line of the eyes, on either side of which
are two small spines, one near each eye and one on the lateral margin.
The first pair of antennae are short, reaching only half the length of
the third joint of the second pair of antennae. The first joint of the
second pair of antennae is short and unarmed; the second joint has one
short spine at the base and three long ones at the upper end; the third
joint is nearly three times as long as the second joint, and has two long
spines at the upper end; the fourth joint is armed with a single spine;
the fifth joint is unarmed; the flagellum is nine-jointed.

The first thoracic segment has two dorsal spines on the anterior
part, one on either side of the median line, six spines on the posterior
part, three on either side of the median line, and two lateral spines;
the second thoracic segment has three spines on the anterior portion,
one in the median line and one on either side of it, four spines on

ISOPODS OF NORTH AMERICA.

337

the posterior portion, two on either side of the median line, and three
lateral spines; the third thoracic segment has two spines on the
anterior portion, one on either side of the median line, four spines
on the posterior portion, two on either side of the median line, and
four lateral spines; the fourth segment has two spines on the anterior
part, one on either side of the median line, four spines on the poste-
rior part, two on either side of

the median line, and four lateral /

spines; the fifth segment has two
spines widely separated, one on
either side of the median line,
and one lateral spine; the sixth
and seventh segments have six
spines, three on either side of the
median line, and one lateral
spine.

The first two abdominal seg-
ments have each eight small
spines, four on either side of the
median line. The terminal seg-
ment has one median row of
spines and a row on either side
of this and a lateral row. The
median row consists of five small
spines and one large terminal
spine. The dorsal row on either
side of the median row each con-
sists of four spines. The outer
marginal lateral rows each con-
sists of three spines, a pair at
the base, a pair about the middle, and a pair at the extremity. At the
base of the segment is a transverse row of four small spines. The
opercular valves have each a longitudinal row of eight spines.

Both the anterior and the posterior pairs of legs are covered with
spines, the anterior ones more densely.

Two specimens, one imperfect, were obtained by the U. S. Bureau
of Fisheries steamer Albatross at Fernandina, Florida.

Tyj>e.—C8.t. No. 11522, U.S.N.M.

ARCTURUS BAFFINI (Sabine).

Idotea baffini SABINE, Suppl. to App. to Capt. Parry's Voyage, 1824, p. 228, pi. i,

figs. 4-6.

Arcturus tuberculatus LATREILLE in Cuvier, R£gne Animal, 2d ed., IV, 1829, p. 139.
Ardurus baffini WESTWOOD, Trans. Entom. Soc., London, I, 1836, p. 72. — MILNE

EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 123, pi. xxxi, fig. 1.— G. 0. SARS,
28589-4)5 22

FIG. 366.— ARCTCRUS FLORIDANTJS.

338 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Den Norske Nordhavs Expedition, Zool., Crust., I, 1885, p. 97, pi. ix, figs.
1-21. — BEDDARD, Report on the Scientific Results of the Exploring Voyage
of H. M. S. Challenger, Zool., XVII, 1886, pi. xx, fig. 12.— HAXSEX, Vid.
Medd. naturh. Foren. i Kj0bh., 1887-88, pp. 188-189.— AXEL OHLIX, Aka-
demisk Afhandling, XXII, 1895, pp. 15-18.— BENEDICT, Proc. Biol. Soc.
Washington, XII, 1898, p. 43. — RICHARDSON, American Naturalist, XXXIV,
1900, p. 230; Proc. U. S. Nat. Mus., XXIII, 1901, p. 549.— ORTMANN, Proc.
Phila. Acad. Nat. Sci., 1901, pp. 156-157.— NORMAN, Ann. Mag. Nat. Hist.
(7), XIV, 1904, pp. Ill 115.

Localities. — Latitude 65° 35' north, longitude 54° 50' west; latitude
66° 32' north, longitude 55° 34' west; latitude 43° 55' north, longitude
49° 8' west; Granville Bay; Cape Alexander; Elsmere Land and Green-
land; Union Bay, Beechy Island; latitude 67° 59' north, longitude 56°
33' west; latitude 68° 9' north, longitude 56° 32' west; latitude 70° 29'
north, longitude 55° 40' west; latitude 71° 10' north, longitude 58° 56'
west; latitude 78° 24' north, longitude 74° west; Inglefield Gulf; Mur-
chison Sound; Cape Faraday; latitude 60° 21' north, longitude 5C 41'
west; Baffin Bay; near Cape York; Grinnell Land; Franklin Pierce
Bay, or latitude 79° 29' north; Cape Napoleon, or latitude 79° 38' north;
Dobbin Bay, or latitude 79° 40' north; Floeberg Beech, or latitude
82° 27' north; Barden Baj^; Olriks Bay; Robertson Bay; Faroe Chan-
nel; latitude 72° 38' north, longitude 77° 10' west; latitude 72° 8' north,
longitude 74° 20' west.

Depth. — 5-150 fathoms.

Body narrow, elongate, nearly seven times longer than wide, 6 mm. :
40 mm.

Head as wide as long, 5 mm. : 5 mm., with the anterior margin deeply
excavate. The eyes are small, composite, about twice as wide as long,
and situated at the sides of the head, about halfway between the ante-
rior and the posterior margins. There are two large spines on the
posterior half of the head, one on either side of the median line. The
basal article of the first pair of antennae is long and somewhat dilated;
it is as long as the two following articles, which are subequal, taken
together; the fourth article is about one and a half times longer than
the first article. The first pair of antennae extend to the end of the
second article of the peduncle of the second pair of antennas. The sec-
ond pair of antennae have the basal article short and not reaching
be}rond the antero-lateral angles of the head on the dorsal side; the
second article extends to the end of the first pair of antenme; the
third article is about three times as long as the second article; the fourth
is one and a half times longer than the third; the fifth is as long
as the fourth. The flagellum is composed of ten articles, the last
article terminating in a spine. The second antennae are longer than
the body, being 50 mm. in length. The maxillipeds have a palp of
five articles. The palp of the mandibles is absent.

The first three segments of the thorax are equal in length; the fourth
is twice as long as either one of the preceding segments; the fifth is

I8OPODS OF NOETH AMEEICA.

339

also half as long as the fourth; the sixth and seventh are slightly
shorter than the fifth. There are two long spines on each one of the
thoracic segments, one on each side of the median longitudinal
line. The lateral parts of the first segments are broadly expanded and
surround the posterior portion of the head at the sides. The epimera
of the second, third, and fourth segments are small, but distinctly
separated from the segments; they occupy the antero-lateral angles of

FIG. 367.— ARCTURUS BAFFINI (AFTEK G. O. SARS). a, ANTERIOR PART OF BODY, WITH FIRST PAIR OF

ANTENNA AND ORAL APPENDAGES VIEWED FROM BELOW, ft, FIRST ANTENNA. C, BASE OF SECOND
ANTENNA, d, ADULT FEMALE, FROM ABOVE, e, FIRST LEG. /, SECOND LEG. fir, POSTERIOR PART OF
BODY, VIEWED FROM BELOW (ONE OF OPERCULAR VALVES REMOVED), h, TWO SENSORY APPENDICES
OF FIRST ANTENNA, i, LABRUM. j, FLAGELLl'M OF SECOND ANTENNA, k, MANDIBLES. /, ONE OF
ANTERIOR PLEOPOD8. TO, TERMINAL BRANCHES OF OPERCULAR VALVE (INNER SIDE), n, SEVENTH
LEG. O, ONE OF POSTERIOR PLEOPODS. p, FIRST MAXILLA, q, LABIUM. r, SECOND MAXILLA. S, M.A.X-

ILLIPED. t, TERMINAL CLAW OF SEVENTH LEG. u, LATERAL VIEW.

the segments and are not visible in a dorsal view. The epimera of
the last three segments are large and also distinctly separated; they
project at the, sides of the segments, being produced in long, acute
processes, and are conspicuous from a dorsal view.

The first two segments of the abdomen are short, and each is pro-
vided with two dorsal spines, one on either side of the median longi-

340 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

tudinal line. The first segment also has the sides produced in acute
processes, one on either side, not separated from the segment and
simulating the epimera of the last three thoracic seg-
ments. The last or terminal segment is very long,
11 mm., about one-fourth the entire length of the
body. At the base on either side, the lateral margin
is produced in a long, acute process. Halfway be-
tween the base and the apex of the segment, on the
dorsal surface, are two tubercles, one on either side
of the median longitudinal line. The apex of the seg-
ment is acutely pointed.

The first four pairs of legs are slender, directed
forward, and thickly furnished with long slender hairs
FIG. 368.— ARCTUEUS on the inferior margins of all the articles. The ter-
LIPED^'X isfXI minal article is minute; the three preceding articles
are long and slender. The first pair of legs are much
shorter than the three following pairs. The last three pairs of legs
are stout and ambulatory in character. The entire surface of the
body, the antennae, legs, etc., is densely granular.

ARCTURUS BAFFINI var. TUBEROSUS Sars.

Arcturus tuberosus SABS, Archiv Math, og Naturvid., 1877, p. 350.

Arcturus baffini var. fdldeni MIERS, Ann. Mag. Nat. Hist. (4) , XIX, 1877, p. 64,

pi. in, fig. 1.
Arcturus tuberosus SARS, Norwegian North Atlantic Expedition, Crustacea, 1885,

p. 102, pi. ix, fig. 22.
Arcturus feildeni BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, p. 44. —

RICHARDSON, American Naturalist, XXXIV, 1900, p. 230; Proc. U. S. Nat.

Mus., XXIII, 1901, p. 549.

Arcturus baffini ORTMANN, Proc. Acad. Nat. Sci. Phila., 1901, pp. 156-157.
Arcturus baffini var. tuberosus NORMAN, « Ann. Mag. Nat. Hist. (7), XIV, 1904,

p. 445.

Localities. — Camp Clay, Cape Sabine; Davis Straits; off Churchill,
Hudson Bay; Granville Bay; Elsmere Land or Greenland.

Depth. — 20-30 fathoms — clay bottom ; small stones and gravel.

Body narrow, elongate, a little over eight times longer than wide,
4 mm.: 35 mm., not including the antennae.

The head is as wide as long, 4 mm. : 4 mm., with the anterior mar-
gin deeply excavate. The eyes are small, wider than long, composite,
and situated at the sides of the head about halfway between the ante-
rior and the posterior margins. The first pair of antennas have the
basal article long and somewhat dilated; the second and third articles
are subequal, and the two together are equal in length to the basal

« Norman proposes a third variety, A. baffini var. intermedia, in \yhich the tubercles
on the first four segments of the thorax and the elevation on the head are greatly
reduced in size, but on the fifth and succeeding segments they are as well repre-
sented as in the typical form.

ISOPODS OF NORTH AMERICA.

341

article; the fourth article is one and a half times longer than the first
article. The first antenna; extend to the end of the second article of
the peduncle of the second antenna?. The basal
article of the second antennae is short, and, on
the dorsal side, does not extend beyond the
antero-lateral angles of the head; .the second
article extends to the end of the first pair of
antennae; the third article is nearly three times
as long as the second; the fourth and fifth are
subequal, and each is one and a half times
longer than the third. The flagellum is com-
posed of ten articles, the last article termina-
ting in a short spine. The second antennae are
a little longer than the body, being 37 mm. in
length. The maxilliped has a palp of five arti-
cles. The palp of the mandibles is wanting.

The first three segments of the thorax are
subequal; the fourth is twice as long as any of
the preceding ones; the fifth is about half as
long as the fourth; the sixth and seventh are a
little shorter than the fifth. The last three
segments are each furnished with two low
tubercles, one on either side of the median
longitudinal line. The lateral parts of the first
segment are expanded and surround the pos-
terior portion of the head. The epimera on
the second, third, and fourth segments are small, narrow plates, dis-
tinctly separated from the segments and placed on the antero-lateral
angles; they are not visible in a dorsal view. The
epimera of the last three segments are distinctly sep-
arated from the segments and are visible in a dorsal
view; they are large, broad plates with the exterior
angles bluntly rounded.

The first two segments of the abdomen are short,
and each is provided with two low tubercles, one on
either side of the median longitudinal line. The
terminal segment is long, and produced to an ex-
tremity which is somewhat acute. About the middle
of the segment, on the dorsal surface, are two low
longitudinal ridges, one on either side of the median
line. There is also at the base of the segment a
blunt projection, almost inconspicuous, on either
side of the lateral margin.
The first four pairs of legs are slender, directed forward, and
densely covered with long., slender hairs on the inferior margins of all
the articles. The first pair are much shorter than the three following

FIG. 369.— ARCTURTJS BAFFINT
VAE. TUBEROSU& (AFTER
BENEDICT), x 1J.

FIG. 370. — ARCTURUS
BAFFINI VAR. TUBER-
osus. MAXILLIPED.
x 15}.

342 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

pairs. The last article in all four pairs is very minute; the three pre-
ceding articles are long and narrow. The last three pairs of legs are
ambulatory.

Ortmann" says of this form: " Very 3'oung individuals are always
without spines, and thus young individuals always belong to the var.
feildeni (tuberosus), although their mother, to whose antennas they
cling, may be a true baffini. In larger, individuals the spines are
developed in a different degree, and there are all intermediate stages
between the strongly spinous A. haffini and the almost smooth A.
feildeni (tuberosus)"

86. Genus PLEUROPRION zur Strassen. &

Body with the fourth segment of the thorax not greatly longer than
the others. Marsupiuni as in the genus Arcturus. Abdomen com-
posed of only two segments, one segment anterior to the large ter-
minal segment. The head is united a least dorsally with the first
thoracic segment. The epimera are not distinct.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS PLEt'ROPRION.

a. Head with three spines on the anterior part in front of the eyes. Third article of
the peduncle of the second antennae not longer than the second article and
armed with two spines. Four spines present on posterior portion of head.
Two spines present, one on either side of the median line just below the con-
striction in the fourth thoracic segment. Two longitudinal rows of spines, one
on either side of the median line on the terminal abdominal segment. One

spine present on basal joint of legs Pleuroprion murdochi ( Benedict)

a' . Head with a single spine on the anterior part. Third article of peduncle of
second antenme twice as long as the second article and unarmed. Two spines
present on posterior portion of head. Spines absent just below the constric-
tion in the fourth thoracic segment. Longitudinal rows of spines on last
abdominal segment absent. Two spines present on coxal joint of legs.

Pleuroprion intermedium (Richardson)

PLEUROPRION MURDOCHI (Benedict).

Arcturus murdochi BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, pp. 49-50. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 855; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 277; American Naturalist, XXXIV, 1900, p. 230.

Locality. — Point Franklin, Alaska.

Body narrow, elongate, a little more than three times longer than
wide, 3i mm. : 12 mm.

Head wider than long, 1£ mm.: 3 mm., with the front deeply exca-
vate between the lateral angles. The eyes are small, round, composite,
and situated at the sides of the head half way between the antero-lateral
angles and the posterior margin. Just back of the anterior margin of
the head are three spines in a transverse row, one median and one on

« Proc. Acad. Nat. Sciences, Phila., 1901, pp. 156-157.

&Zool. Anzeiger, XXV, 1902, pp. 682-689; XXVI, 1903, p. 31.

ISOPODS OF NORTH AMERICA.

343

FIG. 371. — PLEUROPRION
MURDOCHI (AFTER
BENEDICT), x 8J.

either side of the median spine, all three lying between the eyes. The

median spine is a little anterior to the other two. On the posterior

portion of the head are eight spines in a transverse

row, four on either side of the median line. Four

of these spines lie between the eyes, one behind each

eye, and one lateral to each eye. There is also a

spine on each of the antero-lateral projections.

The lirst pair of antennae have the basal article large

and dilated; the second article is almost as long as

the first, but much more slender; the third is half

as long as the second; the fourth is twice as long as

the third. The first pair of antennae extend to the

end of the second article of the peduncle of the

second pair of antennas. The basal article of the

second antennae is short, and does not extend beyond

the basal article of the first pair of antennae; the

second article is armed with three spines, and ex-
tends to the end of the first pair of antennae; the

third article is one and a half times longer than the

second, and is armed with two spines; the fourth is

two and a half times longer than the third, and is

unarmed; the fifth is twice as long as the third, and

is unarmed. The flagellum is composed of three articles, the first of

which is twice as long as the second; the terminal one is one-third

as long as the second. The maxillipeds have a palp of five articles.
The first segment of the thorax has eight spines
in a transverse row, four on either side of the
median line. The second segment has six spines in
a transverse row, three on either side of the median
line. The third segment has eight spines in a trans-
verse row, four on either side of the median line,
and an additional spine on either side anterior to the
most lateral one. The fourth segment has two
transverse rows of spines, with a constriction
between the two rows. The first row has ten spines
in a transverse series, five on either side of the
median line, with three additional smaller spines,
one anterior and one posterior to the most lateral
spine, and one anterior to the spine next to the
most lateral one; the second row has six spines in a
transverse series, three on either side of the median

line, with an additional smaller spine posterior to and between the

two most lateral spines; there are also two spines anterior to the two

median spines and back of the constriction, one on either side of the

FIG. 372.— PLEUROPRION
MURDOCHI. MAXILLI-
PED. x 27£.

344 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

median line. The fifth segment has eighteen spines, nine on either
side of the median line; they are arranged one on either side of the
median line, two in longitudinal series lateral to these, and two other
longitudinal series of three each, lateral to the others. The sixth seg-
ment has a transverse row of eight spines, four on either side of the
median line, with a smaller spine anterior to each one of the larger
spines with the exception of the two median ones. The seventh s<\o -
ment has eight spines in a transverse row, four on either side of the
median line, with a smaller spine on either side anterior to the most
lateral one.

The abdomen is composed of two segments. The first segment has
two longitudinal rows of three spines in each row, one on either side
of the median line. Lateral to these are two spines on either side in
transverse series. The terminal segment has two longitudinal rows of
four spines in each row, one on either side of the median line; lateral
to each row is another small spine; the lateral margins of the segment
are produced on either side in two downward-projecting spines; it
terminates posteriorly in two long spines, one on either side of the
median line; at the base of the segment, between the longitudinal row
and the first laterally projecting spine is a smaller spine, one on either
side.

The basis of all the legs is furnished with a small spine.

PLEUROPRION INTERMEDIUM (Richardson).

Arcturus intermedius RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 854-
855; Ann. Mag. Nat. Hist., (7), IV, 1899, pp. 275-277; American Naturalist,
XXXIV, 1900, p. 230.

Locality. — Kyska Harbor, Aleutian Islands.

Depth. — 10 fathoms.

Head with a deep excavation on its anterior margin, the antero-
lateral angles being produced in a double process, the inner one
rounded, the outer one acutely pointed. Near the anterior margin in
the median line is one large spine. Just back of the eyes and between
them are two long spines. The lateral margins of the head are pro-
duced in two small angulations with a rounded sinus between, poste-
rior to the double antero-lateral process. On the post-lateral margin
on either side of the head is a small spine.

The first pair of antennae are small and short, not reaching to the
end of the second joint of the second pair of antennw. The first joint
of the second pair of antennae is visible and unarmed; the second joint
is armed with three spines; the third joint is unarmed, and is about
twice as long as the second joint; the fourth and fifth joints are
about equal in length and each is about twice as long as the third;
the flagellum consists of three joints.

The first, second, and third thoracic segments have a transverse
row of six large spines, three on either side of the median longitu-

1SOPODS OF NORTH AMERICA.

345

dinal line, the two center ones being the longest, although all are .very
long. The fourth segment is twice as long as any of the other seg-
ments, and has a transverse constriction on the posterior half of the
segment. On the anterior portion are six spines, three on either side
of the median line, the four outer ones being in a straight line, the
inner two below this line. On the posterior portion are six spines
also, three on either side of the median line. The fifth thoracic seg-
ment has twelve spines, six on either side of the median line. The
sixth segment has ten spines,
five on either side. The sev-
enth and last segment has
eight spines, four on either
side.

The abdomen is composed
of two segments. The first is
short, with twelve spines, six
on either side of the median
line, the four inner ones being
arranged in two longitudinal
series, the two upper ones
being small, the two lower
ones very long. The termi-
nal segment has the upper
surface smooth. This seg-
ment terminates in two long
divergent spines. There is a
single spine on the lateral
margin on either side about
the middle of the segment,
and another near the base of
the segment. The three anterior pairs of legs have each two spines
on the coxal joint and one spine on the basis. The body increases in
width from the first to the fourth segment, and then decreases in width
from the fourth to the terminal segment.

One specimen from Kyska Harbor, Aleutian Islands, 10 fathoms,
collected by Dr. W. H. Dall.

Type.— Cat. No. 22581, U.S.N.M.

This species differs from P. murdochi in the absence of spines on the
third joint of the second pair of antennae; in the greater length of this
joint in relation to the preceding joint; in the greater length of the two
following joints; in the presence of a single spine on the anterior part
of the head, while in P. murdochi there are three, and of two spines on
the posterior part, while in P. murdochi there are four; in the absence
of two small spines just below the constriction in^the fourth segment;
in the absence of the row of spines on the terminal segment of the
body; and in the presence of two spines on the coxal joint and one on

FIG. 373.— PLEUROPRION INTERMEDIUM, x 10.

346 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the basal joint of the legs, while in P. murdochi there is but one spine
on the basal joint.

This species is also distinguished from J\ />//*//•/,/•" in the presence of a
single median spine on the anterior part of the head, while in P. ////.xY/vV
there are two, one on either side of the median line and widely sepa-
rated; in the presence of two spines on the posterior part of the head,
while in P. hystriv there are four; in the absence of the double row of
spines on the terminal segment of the body; and in the absence of the
spine at the articulation of the third joint of the second pair of antennae.

Family XIV. IDOTHEID^E.6

Body more or less broad, depressed. First pair of antennae with
the flagellum uniarticulate. Second pair of antennae with the flagel-
luni uniarticulate or multi-articulate. Mandibles without palps.

Segments of thorax of uniform length and appearance. Epimera
sometimes distinct and sometimes coalesced with the segments.

Abdomen with some or all of the segments fused to form the large
terminal segment.

Legs usually nearly alike and ambulatory, but sometimes the three
anterior pairs are pronouncedly subcheliform in structure.

Incubatory pouch normal.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY IDOTHEID.E.

a. Sides of head emarginate or cleft and laterally produced beyond the eyes, which
are dorsally situated. First three pairs of legs with the sixth article or propodus
dilated and forming, with the reflexible dactylus, a subchelate hand.
b. Palp of maxillipeds composed of five articles. Inner branch of uropoda minute.

Species large Genus Mesidofea, new genus

I/. Palp of maxillipeds composed of three articles. Inner branch of uropoda half

as long as outer branch. Species small Genus Chiridolea Harger

a'. Sides of head in a dorsal view entire and not laterally produced. Eyes lateral.
Legs all nearly alike, with the sixth article or propodus not expanded or but
little expanded; seventh article prehensile.

b. Flagellum of second pair of antenme well developed and multi-articulate.
c. Abdomen (including the terminal segment) consisting of three segments with
lateral sutures of another partly coalesced segment. Epimera of all the
segments, from the second to the seventh, inclusive, well developed and
distinct from the segments.

d. Palp of maxillipeds with four articles Genus IdotJien Fabricius

d' '. Palp of maxillipeds with five articles Genus Pentidotea, new genus

c'. Abdomen consisting of one segment, with lateral sutures of another partly

coalesced segment.

d. Palp of maxillipeds with three articles. All the epimera coalesced and
perfectly united with the segments Genus Synidotea Harger

a Arcturus hystrij- Sars.

&See Sars for characters of family, Crust, of Norway, II, 1899, pp. 78-79.

ISOPODS OF NORTH AMERICA. 347

d/. Palp of maxillipeds with four articles. Epimera of second, third, and
fourth segments coalesced and perfectly •united with the segments; those
of the fifth, sixth, and seventh segments distinct and well developed.

Genus Colidotea Richardson

V. Flagellum of second pair of antennae not multi-articulate,
c. Second pair of antennae shorter than the first pair. Flagellum rudimentary
Epimera of all the segments united with the segments. Abdomen com-
posed of a single segment, with lateral incisions near the base. Maxillipeds

with a palp of three articles Genus Edotea Guerin-Meneville

</. Second pair of antenme much longer than the first pair. Palp of maxillipeds

usually composed of four articles.
d. Abdomen consisting of a single segment. Flagellum of second antennae

consolidated to form a single clavate article.

e. Epimera of all the segments united with the segments except the last
two, which are well developed and distinct. Lateral sutures at base of
abdomen indicate another partly coalesced segment.

Genus Eusymmerus Richardson
ef '. Epimera distinct on all the segments of the thorax, including the first.

No lateral sutures atlbase of abdomen Genus Ericfisonella Benedict

df. Abdomen consisting of more than one segment. Flagellum of second pair
of antennae consolidated to form a single article or composed of only two
or three articles Genus Cleantis Dana

37. Genus MESIDOTEA, new genus. «

Palp of maxillipeds composed of five articles. Sides of head cleft.
Eyes dorsally situated. Second pair of antennae with a multi-articu-
late flagellum. Epimera of all the segments of the thorax, with the
exception of the first, distinctly separated from the segments.

Abdomen composed of four segments, with suture lines at the base
of the fourth or terminal segment indicating another partly coalesced
segment. First three pairs of legs prehensile, with propodus dilated
and dactylus reflexed. Last four pairs of legs ambulatory.

Inner branch of uropoda minute.

Species large.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS MESIDOTEA.

a. Articles of the peduncle of the second antennae not dilated; flagellum composed
of from eight to fourteen articles. Antero-lateral cervical lobes prominent.

Eyes present Mesidotea entomon ( Linnaeus)

a'. Articles of the peduncle of the second antennae greatly dilated; flagellum com-
posed of from seven to eight articles. Antero-lateral cervical lobes not promi-
nent. Eyes absent Mesidotea sabini ( Kr0yer )

« This genus is proposed for the two forms, entomon and sabini, which have been here-
tofore referred to the genus Glyptonotus Eights, and more recently to the genus Chiri-
dotea Harger. The genus Mesidotea differs from the genus Glyptonotus in having the
epimera of all the segments of the thorax, with the exception of the first, distinctly
separated from the dorsal portion of the segments. In Glyptonotus the epimera are
separated on the last three segments only. The new genus differs from both
Chiridotea Harger and Glyptonotus Eights in having the palp of the maxillipeds
composed of five articles instead of three.

348 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

MESIDOTEA'ENTOMON (Linnaeus).«

Oniscus entomon LINNMU-S, Syst. Nat., 12th ed., I, Pt. 2, 1767, p. 1060. — PALLAS,

Spicil. Zool., IX, 1772, p. 64, pi. v, figs. 1-6.
Squilla entomon DE GEEK, Mem. pour servir a 1'Hist. des Insectes, VII, 1778, p.

514, pi. xxxn, figs. 1-10.

Asellua entomon OLIVIER, Encycl. M6th., IV, 1789, p. 253.
(?) Cymothoa entomon FABRICIUS, Ent. Syst., II, 1798, p. 505.
Idotea entomon Bosc, Hist. Nat. des Crust., II, 1802, p. 178. — LATREILLE, Hist.

Nat-. Crust, etlns., VI, 1803-4, p. 361; VII, pi. LVIII, figs. 2-3.— (?) LAMARCK,

Hist, des Anim. sans Vert., 1st ed.,V, 1818, p. 159. — RATHKE, Neuste Schriften

der naturf. Gesellsch. in Danzig, I, 1820, p. 109, pi. iv. — (?) DESMAREST,

Consid. Crust., 1825, p. 289.— KR0YER, Vid. Selsk. Skrift., VII, 1838, p.

323.— MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 128.— KR0YER, Nat.

Tidsskr., II, 1846-49, p. 402.— WHITE, List Cr. Brit. Mus., 1847, p. 93.—

BRANDT, Crust, in Middendorf s Sibirische Reise, II, 1851, p. 145.
(?) Saduria entomon ADAMS in WHITE, Sutherland's Voy. Baffin's Bay, Appendix,

1852, p. 207.

Idotitga longicauda LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 45.
Idotea entomon MEINERT, Nat. Tidsakr. (3), XI, 1877, p. 84. — BRANDT, Comptes

Rendus, 1880, p. 713; Ann. Mag. Nat. Hist., VI, 1880, p. 98.
Glyptonofus entomon MIERS, Trans. Linn. Soc. London, XVI, 1883, pp. 12-13, pi.

i, figs. 1-2. (See Miers for further synonymy.) — RICHARDSON, Proc. U. S.

Nat. Mus., XXI, 1899, p. 843; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 262.

Localities. — Circum polar; west coast of North America to. Pacific
Grove, California; Stockholm's skargard (J. Lindahl); Kielerbucht,
Germany; Nakvak, Labrador; Kara Sea.

Found on beach; 5-8 fathoms in sand and gravel; 15 fathoms.

Body ovate, broad anteriorly, and tapering to a narrow pointed
extremity; about two and a half times longer than broad, 7 mm. : 17
mm. Length of abdomen nearly equal to half the length of entire
body, 8 mm. : 17 mm.

Lateral margins of head cleft, with the two lobes about equal in
size, the anterior one more rounded in outline, the posterior one more
acute; the posterior lobe is not produced at the sides beyond the ante-
rior one. The front of the head is deeply excavate between the antero-
lateral lobes, and there is a small median excavation. The eyes are
distinct, small and round, compound in structure, dorsally placed at
the base of the lateral cleft. The first antennae have the basal article
enlarged, about twice as wide as the second article and very little
longer; the third article is one and a half times longer than the second;
the fourth article is just a little longer than the third. The first antennae
extend to the middle of the fourth article of the peduncle of the second
pair of antenna?. The basal article of the second antennae is almost
inconspicuous; the second, tnird, and fourth articles are all short, about
equal in length, although the second is nearly twice as wide as the two

"The description is from a small specimen. In the adult the flagellum consists of
more joints.

ISOPODS OF NORTH AMERICA.

349

following, being as wide as the basal article; the fifth article is one
and a half times longer than any of the three preceding ones. The

FIG. 374.— MESIDOTEA ENTOMON (AFTER GERST,ECKER). a, DORSAL VIEW, x U. b, MANDIBLE, c,
MANDIBLE, d, VENTRAL VIEW, x H. e, LABIUM. /, MAXILLIPEDS. g, HALF OF TWO THORACIC

SEGMENTS ABOUT THE MIDDLE, WITH ONE LEG. h, ABDOMEN (VENTRAL SIDE). i, CROSS SECTION
OF A THORACIC SEGMENT ABOUT THE MIDDLE, j, SECOND MAXILLA, k, FIRST MAXILLA. I, SEC-
OND ANTENNA. TO, FIRST ANTENNA.

flagellum is composed of five articles, the first one being nearly three
times as long as any of those following. The maxillipeds have a palp
of five articles.

350 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The segments of the thorax arc subequal, the first and the last being
a little shorter than any of the intermediate ones. The epimera are dis-
tinct on all the segments, from the second to the seventh, inclusive,
and occupy the entire lateral margin. Those of the last five segments

are greatly produced pos-
teriorly in extremely long,
acutely pointed processes.

FIG. 375.— MESIDOTEA ENTOMON (AFTER MIERS). a, HEAD FIG. 376.— MESIDOTEA

WITH BOTH ANTENNAE. X J. b, OPERCULAR VALVE (IN- ENTOMON. MAXIL-

NER SIDE). X f. LIPED. X 20J.

increasing in length to the sixth segment; the epimeron of the seventh
segment is only about half as long as that of the sixth.

The first three pairs of legs are subchelate, with propodus dilated,
and dactylus reflexed. The inferior margin of the propodus is armed
with long and short spines. The last four pairs of legs are ambulatory.

The abdomen is composed of five segments, four short ones, followed
by a long terminal segment, parti}7 coalesced with the last short seg-
ment. The sides of the terminal segment converge to a narrow pointed
extremity, with indications of lateral angles about two-thirds the dis-
tance from the base to the extremity of the segment. The opercular
valves are in two parts, a large upper portion and a very small ter-
minal portion. Within the valves on the underside is a small lobe
attached to the terminal division and representing the inner branch of
the modified uropoda.

MESIDOTEA SABINI (Kr^yer.)

Idotea sabini KR0YER, Nat. Tidsskr. (2), II, 1846-49, p. 401. — REINHARDT, Natur.
Bidrag til en Beskrivelse af Gronland, 1857, p. 34. — LUTKEN, List of Crust,
of Greenland in Arctic Manual, 1875, p. 149. — SARS, Arch. f. Math, og
Naturvidensk., II, 1877, p. 350.

Glyptonotus sabini MIERS, Jour. Linn. Soc. London. XVI, 1883, pp. 15-17, pi. i,
figs. 3-5. — HANSEN, Videnskabelige Meddelelser fra den naturhistoriske
Forening i Kj0benhaven, 1887-88, p. 187. — AXEL OHLIN, Akademisk Afhan-
ding, XXII, 1895, pp. 13-14.— RICHARDSON, Proc. U. S. Nat. Mus., XXI,
1899, p. 844; Ann. Mag. Nat, Hist. (7), IV, 1899, p. 263.

Chir Idotea sabini STEERING, Ann. Mag. Nat. Hist. (7), V, 1900, p. 14. — RICHARD-
SOX, American Naturalist, XXXIV, 1900, p. 226; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 538.

ISOPODS OF NORTH AMERICA.

351

FIG. 377.— MESIDOTEA SABINI (AFTER MIERS). a, OPERCULAR
VALVE (INNER SIDE), x }. 6, HEAD WITH BOTH PAIRS OF ANTEN-
NA, x J.

Localities. — Davis Straits; Repulse Bay, North America; Cape
Dudley Digges; Cape Faraday; latitude 73° 43' north, longitude 78°
48' west; latitude 71° 31' north, longitude 49° 12' east; latitude 77°
14' north, longitude 38° 26' east; latitude 71° 57' north, longitude 73°
56' west; latitude 71° 42' north, longitude 73° west; latitude 66° 33'
north, longitude 61° 50' west: Julianehaab and Ivsugigsok, Greenland;
Cape Smyth, Alaska;
Point Barrow, /

Alaska; Ooglaamie.
Alaska; Kara Sea;
circumpolar.

Depth. — Surface to
76 fathoms, in mud
on beach.

Body narrow, elon-
gate, bj,-oad anteri-
orly and tapering
gradually from the

middle of the body to the long, pointed terminal segment. Length
of body almost four times its greatest breadth, 11 mm. : 40 mm.
Length of abdomen almost half the length of entire body, 19 mm. :
40 mm. These measurements are from a small specimen.

Head with the lateral margins cleft, the posterior lobe being much
the larger and produced some little distance beyond the anterior lobe.
Front deeply excavate between the lateral lobes, with a small median
excavation also. Eyes absent. First pair of antenna?
with the basal article large, triangular in shape, the
broad posterior extremity tapering to a narrow apex
at the anterior end; the second article is short, about
half as long as the basal article; the third is twice as
long as the second; the fourth is a little longer than
the third. The first antenna? extend to the third pe-
duncular article of the second pair of antenna?. The
basal article of the second antenna? is short, not reach-
ing beyond the antero-lateral angles; the second article
has the exterior margin produced in a rounded expan-
sion, and is twice as long as the basal article; the third
article is only half as long as the second; the fourth
is a little longer than the third, and has a large, round expanded process
on the inferior margin and a small expansion on the exterior margin;
the fifth article is about twice as long as the third, and is broadly
expanded. The flagellum consists of six articles. The second pair of
antenna? extend to the middle of the first thoracic segment. The
maxilliped has a palp of five articles.

FIG. 378.— MESIDOTEA
SABINI. MAXILLI-
PED. x Hi.

352

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The segments of the thorax are about equal in length. The epimera
of all the segments from the second to the seventh, inclusive, are dis-
tinct and occupy the whole of the lateral margin; they are large plates
which in the last four segments are produced into very long, acutely
pointed extremities.

The first three pairs of legs are subchelate, with propopus expanded
p,nd dactylus reflexed. The last four pairs of legs are ambulatory.
The inferior margin of the propodus in the first three pairs of legs is
armed with numerous long spines alternating with several short ones.

FIG. 379. — MESIDOTKA SABINI (AFTER KKOYEK). SHOWING DETAILED PARTS.

The abdomen is composed of five segments, four short ones followed
by a very long terminal one partly coalesced with the last short seg-
ment. The terminal segment tapers to an extremely long, pointed
extremity. About halfway from the base to the end of this segment
is a slight indication of an angle on either side, possibly rudiments of
lateral angles. The opercular valves are each in two parts, a large
basal part and a short, narrow, pointed terminal part, the exterior
branch; the inner branch is seen on the underside as a small oval lobe
at the base on the exterior side of the other branch.

58. Genus CHIRIDOTEA Harger.

Palp of maxillipeds composed of three articles. Sides of head cleft.
Eyes dorsally situated. Second antennas with a multi-articulate flagel-
lum. Epimera of all the segments of the thorax with the exception
of the first distinctty separated from the segments. Abdomen com-

ISOPODS OF NORTH AMERICA.

353

posed of four segments with lateral sutures at the base of the fourth,
or terminal segment, indicating another partly coalesced segment.
First three pairs of legs prehensile, with propodus dilated and dac-
tylus reflexed. Last four pairs of legs ambulator}^.

Inner branch of uropoda half as long as inner branch.

Species small.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CHIRIDOTEA.

a. First pair of antennae extend beyond the peduncle of the second antennae. Sec-
ond antennae short, extending only to the anterior margin of the first thoracic
segment. Front of head not excavate between the antero-lateral lobes, but

slightly excavate in the middle of the anterior margin Chiridotea cseca (Say)

b. First pair of antennae extend to the middle of the fifth article of the peduncle
of the second antennae. Second antennae long, extending to the posterior
margin of the sixth thoracic segment. Front of head deeply excavate between
the antero-lateral angles Chiridotea tuftsii (Stimpson)

CHIRIDOTEA CJE.CA (Say).

Idotea cseca SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 424. — MILNE EDWARDS,
Hist. Nat. des Crust, III, 1840, p. 131.— GUERIN, Iconog. , Crust. , 1843, p. 35.—
HARGER with VERRILL, Report U. S. Com-
missioner of Fish and Fisheries, Pt. 1,
1873, p. 5(59 (275), pi. v, fig. 22.

Chiridotea aeca HARGER, Am. Jour. Sci., XV,

1878, p. 374; Proc. U. S. Nat. Mus., II,

1879, p. 159; Report U. S. Commissioner
of Fish and 'Fisheries, Pt. 6, 1880, pp.
338-340, pi. iv, figs. 16-19.

Glyptonotus csecus MIERS, Jour. Linn. Soc.
London, XVI, 1883, pp. 17-18.

Chiridotea aeca RICHARD-
SON, American Natu-
ralist, XXXIV, 1900,
p. 226; Proc. U. S.
Nat. Mus., XXIII,
1901, p. 539.

Localities. — Florida;
New Haven, Connecti-
cut; Woods Hole, Massachusetts; Tarpaulin Cove,
Naushon; S. W. end of Campobello, New Brunswick;
Cohasset, Massachusetts; Long Island Sound; Vine-
yard Sound; Nantucket, Provincetown, Nahant, Mas-
sachusetts; Halifax, Nova Scotia; New England coast.
Depth. — Surface; low water; shore; swimming in
fish weir; sand.

Body ovate, broad and short, tapering to a pointed extremity; twice

as long as broad, 4 mm. : 8 mm. Length of abdomen, one-half the

length of entire body, 4 mm. : 8 mm.

28589—05 23

PIG. 380. — CHIKIDOTEA CMCA. (AFTER
HARGER).

FIG. 381. — CHIRIDOTEA
CMCA. MAXILLIPED.
X 51 1.

354 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The lateral margins of the head are cleft, the anterior lobe being
smaller than the posterior, which projects at the sides beyond the
anterior one. The front of the head is not excavate between the
antero-lateral lobes, but on the contrary is expanded beyond them.
There is a pronounced median excavation, in the center of which is a
median point. The eyes are small, round, compound in structure,
dorsally placed at the base of the post-lateral lobe. The first antennas
have the basal article very short and not dilated; second article a little
longer than the first; third and fourth equal in length and each about
twice as long as the first. The first antenna? extend a little beyond
the end of the peduncle of the second antennae. The basal article of
the second antennae is inconspicuous from a dorsal view; the second,
third, and fourth articles are subequal; the fifth is a little longer than
the fourth. The flagellum consists of five articles. When retracted,
the second antennae reach the anterior margin of the first thoracic
segment. The maxillipeds have a palp of three articles.

The segments of the thorax are equal in length. The epimera are
separated dorsally from the first three segments, but are not acutely
produced posteriorly. The epimera of the last four segments are also
distinct, and are produced into acutely pointed processes.

The first three pairs of legs are subchelate, with propodus expanded,
the dactylus short and refiexed. The last four pairs of legs are ambu-
latory. All the legs are thickly beset with spines and hairs along the
free margins.

The abdomen is composed of four segments, three short ones fol-
lowed by a long-pointed terminal one, with lateral sutures of another
partly coalesced segment. The apex of the terminal segment is acute
and its lateral margins near the extremity are denticulate. The sides
of the abdomen taper gradually to about the middle and then converge
more rapidly to the apex, forming slight angles on either side half way
from the base to the apex.

The opercular valves are in two parts, the small terminal part rep-
resenting the outer branch of the uropoda. The inner branch is rep-
resented on the under side attached to the basal portion on the exterior
side.

CHIRIDOTEA TUFTSII (Stimpson).

Idotea tuftsii STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853, p.
39. — HARGER with VERRILL, Report U. S. Commissioner of Fish and Fisher-
ies, Pt. 1, 1873, p. 340 (46); p. 569 (275).— VERRILL, Proc. Amer. Assoc.,
1874, p. 362.

Chiridotea tuftm HARGER, Am. Jour. Sci., XV, 1878, p. 374; Proc. U. S. Nat.
Mus., II, 1879,' p. 159; Report U. S. Commissioner of Fish and Fisheries,
Pt. 6, 1880, pp. 340-341, pis. iv, figs. 20-23.

Glyptonotus tuftm MIERS, Jour. Linn. Soc. London, XVI, 1883, pp. 18-19.

Chiridotea tuft Kit RICHARDSON, American Naturalist, XXXIV, 1900, p. 226; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 539.

ISOPODS OF NORTH AMERICA.

355

FIG. 382. — CHIRIDOTEA TUFTSII
(AFTER HARGEK).

Localities. — Bay of Fundy; Long Island Sound; Massachusetts
Bay; Casco Bay, Maine; Princes Cove, Eastport; Halifax, Nova
Scotia; near Halting Rock, channel outside Bakers Island.
Depth. — Surface to 25 fathoms, in fine sand.
Body ovate, less than twice as long as wide, 3£ mm. : 6 mm.
Head twice as wide as long, 1 mm. : 2 mm. ,
with the front deeply excavate between
the antero-lateral angles, and produced in
a small median point.

The sides of the head, where the lateral
margin is free, are cleft, the posterior lobe
formed by the cleft margin being produced
laterally beyond the anterior lobe. The
posterior portion of the head is deeply set
in the first thoracic segment. The eyes
are small, round, composite, and situated
just within the cleft on the lateral margin.
The first pair of antennas have the basal
article large and somewhat dilated; the
second article is one and a half times longer
than the first; the third is one and a half
times longer than the second; the fourth is as long as the third. The
first antennas extend to the middle of the fifth article of the peduncle
of the second pair of antennas. The second antennas have the basal
article short, and concealed in a dorsal view; the second article is
twice as long as the first; the third is a little shorter than the second;
the fourth is about as long as the second; the fifth
is as long as the third and fourth taken together.
The flagellum is composed of 11 or 12 articles in one
specimen, of 14 in another specimen, and extends
to the posterior margin of the sixth thoracic seg-
ment. The palp of the maxillipeds is composed of
three articles.

The first segment of the thorax has the antero-
lateral parts produced forward to surround the pos-
terior half of the head. The epimera are distinctly
separated in all the segments, with the exception
of the first, and are wide plates, with the outer post-
lateral angles of the last four acutety produced.
The abdomen is composed of four distinct segments, the fourth or
terminal segment being 2£ mm. in length and one-half mm. wide at
the base, and having lateral sutures, indicative of another partly coa-
lesced segment. It is acutely produced at its posterior extremity.

The first three pairs of legs are prehensile, the last four pairs
ambulatory.

FIG. 383. — CHIRIDOTEA
TUFTSII. MAXILLIPED.

356 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

59. Genus IDOTHEA Fabricius 1799.

Flagellum of second antennse multi-articulate. Maxillipeds with a
palp composed of four articles. Epimera of all the segments of the
thorax, with the exception of the first, distinctly separated from the
segments. Abdomen composed of three segments, with a suture line
on either side at the base of the terminal segment, indicating another
partly coalesced segment.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS IDOTHEA.

o. Body slender, linear, filiform.

b. Terminal segment of body truncate at its posterior extremity; post-lateral an-
gles not prominent Idothea gracillima (Dana)

b' '. Terminal segment of body not truncate at its extremity; post-lateral angles

prominent,
c. Post-lateral angles of terminal segment prominent and separated by a notch

from the triangular middle portion.
d. Terminal segment with middle portion obtuse and produced at the apex in

a small point. Lateral angles obtuse Idothea urotoma Stimpson

d' . Terminal segment with middle portion of posterior extremity very acutely

produced. Lateral angles acute Idothea fewkesi, new species

</. Post-lateral angles not separated by a notch from the subtriangular middle
portion, which does not bear a tooth at the middle; the line from the apex

to the lateral angle is straight Idothea rectilinea Lockington

a'. Body oblong-ovate.

b. Terminal segment of body truncate at its extremity Idothea metallica Bosc

V . Terminal segment of body not truncate at its extremity.
c. The epimera of all the segments, from the second to the seventh inclusive,

occupy the entire lateral margins of the segments Idothea battica (Pallas)

</. The epimera of all the segments of the thorax, from the second to the
seventh inclusive, do not occupy the entire lateral margins of the segments.
d. Terminal segment of body with distinct and prominent post-lateral angles.
Basal article of the first pair of antennae very much dilated.

Idothea ochotensis Brandt

d'. Terminal segment of body without distinct post-lateral angles, the sides
of the abdomen tapering to a pointed extremity. Basal article of first
pair of antennae not dilated Idothea phosphorea Harger

IDOTHEA GRACILLIMA (Dana).

Stenosoma gracillimum DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854, p. 175. —
STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, p. 505.

Ido'hea gracillima MIERS, Jour. Linn. Soc. London, XVI, 1883, p. 35. — RICHARD-
SON, Proc. U. S. Nat. Mus., XXI, 1899, p. 844; Ann. Mag. Nat. Hist, (7),
IV, 1899, p. 264; American Naturalist, XXXIV, 1900, p. 226; Harriman
Alaska Expedition, Crust., X, 1904, pp. 216-218; Proc. U. S. Nat. Mus.,
XXVII, 1904, pp. 661-663.

Localities. — California; Bolinas, California.

The description of this species given by Professor Dana is very short
and rather vague. He describes the body as extremely slender and

1SOPODS OF NORTH AMERICA.

357

FIG. 384.— IDOTHEA GRACILLIMA. X 5.

filiform, the thoracic segments subquadrate, head quadrate. He refers
to the linear post-abdomen, which is truncated at the apex, three-
jointed, and marked on either side with a suture. The antennae are
described as being a little shorter than
half the body, with a ten- to twelve-
jointed flagellum.

A species of Idothea was sent to the
U. S. National Museum by Doctor Rit-
ter. The specimens, which are eight in
number, were collected by him at Boli-
nas, California. They are more closely
allied to /. gracillima than to any other
known species of Idotlma from the Pacific
coast of North America. Until evidence
can be given of their distinctness, 1 shall
consider them identical with I. gracil-
lima (Dana).

Body slender, about seven times
longer than wide/' with the sides nearly
parallel. Surface entirely smooth.
Color in alcohol uniformly pinkish. A
note referring to the color of the specimens in life says that they are
green, brown, and striped.

Head quadrate, with rounded antero-lateral margins, and a slight
median excavation in the anterior margin. Eyes situated at the
extreme lateral edge and about the middle of the head; they are small

but distinct. The first pair of
antennae are four-jointed, and ex-
tend a little beyond the extremity
of the second peduncular joint of
the second pair of antennae. The
second pair of antennae are equal
to half the length of the body;
the last two joints of the pedun-
cle are subequal; in the smal lei-
specimens the flagellum is com-
posed of ten joints; in the larger
ones there are eighteen joints.

The first thoracic segment is short in the middle but is produced
antero-late rally on either side; it is not wider than the head. The
second, third, and fourth segments are subequal in length and are
longer than the first segment. The fifth, sixth, and seventh segments
gradually decrease in length. The epimera of all the segments are
extremely narrow; those of the second and third segments extend but
half the length of the segment; those of the fourth and fifth segments

«The female is figured. The body is somewhat broader than in the male.

FIG. 385. — IDOTHEA GRACILLIMA. ABDOMEN, SHOW-
ING VARIATIONS IN FORM.

358 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

extend three-fourths the length of the segment; those of the last two
segments extend the entire length of the segment.

The abdomen consists of three distinct segments, with suture lines
on either side of another partly coalesced segment. The third or
terminal segment has subparallel sides to about the middle, where the
segment gradually becomes narrower to a truncate extremity. On
the posterior margin of the terminal segment is a faint indication of a
double emargination on either side of an obtuse median point.

Legs small and slender and devoid of hairs.

The five small specimens and one large one agree in having the
terminal segment as described above. The two larger specimens
show the double emargination more distinctly, one of the specimens
more so than the other.

Figures showing all three variations are given.

The specimens agree in all other characters.

Dana's specimens were collected by Prof. J. Le Conte on the coast
of California.

IDOTHEA UROTOMA Stimpson.

Idotea urotoma STIMPSON, Proc. Acad. Nat. Sci. Phila., XVI, 1864, p. 155. — MIEKS,
Jour. Linn. Soc. London, XVI, 1883, p. 34. — RICHARDSON, Proc. U. S. Nat.
Mus., XXI, 1899, p. 845; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 264;
American Naturalist, XXXIV, 1900, p. 226.

Locality. — Puget Sound.

Bodj7 linear, elongate, nearly four and a half times longer than broad,

4 mm. : 17£ mm.

Head as wide as first segment of thorax and 2i mm. long. Eyes

small, round, and situated close to the lateral margins. The first pair

of antennae have the basal article large, dilated; the second and third
are small and narrow, subequal; the fourth is
clavate. The first pair of antennae extend to
the end of the second article of the peduncle of
the second pair of antennae. The joints of the
peduncle of the second antennas are short and
thick; the first article is inconspicuous in a
dorsal view; the second and third articles are
subequal; the fourth and fifth are subequal and
each is about one and a half times longer than

PIG. 386.— IDOTHEA UROTOMA. the third article. Flagellum composed of eleven

ABDOMEN, x 6i. A- i

articles.

The first segment of the thorax has the antero-lateral angles pro-
duced to surround the posterior portion of the head, and is shorter
in the middle of the dorsal surface than any of the six following
segments, which are nearly subequal. The epimera of the second,
third, and fourth segments are narrow plates, which in the second and
third segments do not quite reach the middle of the lateral margin,

I80PODS OF NORTH AMERICA.

359

but extend fully to the middle on the fourth segment. The epimera
of the fifth segment do not quite reach the posterior margin, but
extend about three-fourths the length of the segment. The epimera
of the last two segments extend the entire length of the segments.

The abdomen is composed of three segments, two short ones ante-
rior to the terminal segment, which has suture lines on either side indi-
cating another partly coalesced segment. The terminal segment is
quadrangular with sides nearly parallel. The post-lateral angles am
prominent, and are separated by a shallow emargination from the
triangular middle portion, which is somewhat acutely produced in
the middle.

The legs are all similar in structure.

This description is made from specimens sent me by Dr. Walter
Faxon, from the Museum of Comparative Zoology at Harvard Uni-
versity. They were presented by Dr. Alexander Agassiz and are
marked Idothea urotoma Stimpson in Stimpson's handwriting.

IDOTHEA FEWKESI, new species.

Body narrow, elongate, about five and a half times longer than
wide, 71 mm. : 42 mm.

Head one and a half times wider tha"h long, -i mm. : 6 mm. ; with the
anterior margin excavate in the middle between the antero-lateral
angles. The eyes are small, composite, about
twice as wide as long, and situated at the sides
of the head, halfway between the anterior and
posterior margins. The first pair of antennae
have the basal article greatly dilated; the second
and third articles are subequal, and each is
half as wide as the basal article and a little
shorter; the fourth article is clavate, and a
little longer than the third. The first pair of
antennae extend to the end of the second
article of the peduncle of the second pair of
antenna?. The basal article of the second
antennae is short, the second and third articles
are subequal, each being 2 mm. in length;
the fourth and fifth are subequal, each being
4 mm. in length, or twice as long as either
the second or the third article. The fla-
gelkim is composed of sixteen articles and is
10 mm. long. When retracted, the second
antennae extend to the posterior margin of

the fourth thoracic segment. They are about half as long as the
body. The palp of the maxillipeds is composed of four articles.

The first segment of the thorax is a little shorter in the dorsal
median line than any of the others^ being 2£ mm. long. The antero-

FIG. 387. — IDOTHEA FEWKESI.

3(50

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

lateral angles of this segment are produced forward so as to surround
the posterior portion of the head. The following segments are sub-
equal in length, with the exception of the seventh, which is a little
shorter than any of the others. Epimera are distinctly separated on
all the segments with the exception of the first. The epimera of the
second and third segments occupy half the lateral margin of the seg-
ments, being 2 mm. in length. The epimeron of the fourth segment is

2^ mm. in length, the lateral margin
of the segment showing below it being
i£ mm. in length. The epimera of
the fifth and sixth segments occupy
three-fourths of the lateral margin,
being 3 mm. in length, the lateral
margin of the segment below them
being 1 mm. long. The epimeron of
the seventh segment only occupies the
entire lateral margin. The first three
epimera are extremely narrow, being
only i mm. wide. The last three are
1 mm. wide in the region of their
greatest breadth.

The abdomen is composed of three
segments, two short ones and a long
terminal segment, which has a suture line on either side at the base
indicative of another partly coalesced segment. The abdomen is twice
as long as wide, being 14 mm. long and 7 mm. wide at the base, and
is one-third the length of the entire body. The terminal segment has
nearly subparallel sides. Its posterior margin is produced in a median
point, which is strong and acute. The post-lateral angles are rounded.
All the legs are similar in character.

There are two specimens, one imperfect, from Santa Barbara, Cali-
fornia.

This species is named for Dr. J. Walter Fewkes, zoologist and
ethnologist, who collected the specimens.
The type is in the Museum of Comparative Zoology, Cat. No. 6730.

FIG. 388.— IDOTHEA FEWKESI. a, MAXILLI-

PED. x 16}. 6, FIRST ANTENNA, x 15}.

IDOTHEA RECTILINEA Lockington.

36.—

Idotea rectilinea LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p.

MIERS, Jour. Linn. Soc. London, XVI, 1883, p. 34.
Idotea rectilineata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 845; Ann.

Mag. Nat. Hist. (7), IV, 1899, pp. 264-265; American Naturalist, XXXIV,

]900, p. 226.

Localities. — Pacific coast from Humboldt County, California, to
Ensenada, Lower California.

Depth. — 30 to 40 fathoms, in sandy mud.

ISOPODS OF NORTH AMERICA.

361

Body narrow, linear, filiform, about four times longer than wide,
4: mm.: 17 mm.; length of abdomen about one-third that of entire
length of body, 6 mm, : 17 mm.

Head wider than long, with anterior margin slightl}" excavate.
Anterior portion of head but slightly wider than posterior portion.

FlG. 389. — IDOTHEA RECTILINEA.

FIG. 390.— IDOTHEA RECTILINEA. a, MAXILLIPED.
b, FIRST ANTENNA, x 23.

x 23.

E}res very small, transversely ovate, compound in structure, and situ-
ated about the middle of the extreme lateral margin. First pair of
antennae with the basal article enlarged; second and third articles
equal in length, and somewhat shorter than the basal joint; fourth
article clavate and a little longer than either of the two preceding
ones. The first antennae extend to the middle of the third peduncular
article of the second pair of antennae. The basal article
of the second antenna is scarcely visible from a dorsal
view; the second and third articles are of equal length:
the fourth and fifth are subequal and each is about twice
as long as the third. The flagellum is composed of
thirteen long, slender articles. When retracted, the
second antenna? extend to the posterior margin of the
fourth thoracic segment. The maxilliped has a palp of
four articles.

The segments of the thorax are about equal in length,
the first one only being a little shorter than the others.
The first segment is not wider than the head. The epimera of the
second, third, and fourth segments occupy the anterior half of the seg-
ments, and are very narrow; the epimeron of the fifth segment occupies
the anterior two-thirds part of the segment; the epimera of the last
two segments occupy the entire lateral margin.

FIG. 391.— IDOTHEA
RECTILINEA. AB-
DOMEN, x 6i.

362

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The legs are all similar in structure. Along the inferior margin of
the merus, carpus, and propodus are a few hairs.

The first two segments of the abdomen are short, followed by one
long rectilinear segment. The sides of the abdomen are almost parallel,
the posterior end being three-fourths as wide as the anterior end. The
posterior extremity of the terminal segment is produced in a very
obtuse point, which does not extend far beyond the lateral angles.

IDOTHEA METALLICA Bosc.

Idotea metallica Bosc, Hist. Nat. Crust., II, 1802, p. 179, pi. xv, fig. 6. — LATREILLE,

Hist. Nat. Crust, et Insectes, VI, 1803, p. 373.

Idotea peloponesiaca Roux, Crust, de la Mediterranee, 1828, pi. xxx, figs. 10-12.
Idotea atrata COSTA, Fauna del R. Napoli, Crust., 1838, pi. xi, fig. 3.
Idotea rugosa MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 131.
Idotea compada WHITE, List. Crust. Brit. Mus., 1847, p. 95.
Idotea algirica LUCAS, Anim. artic. in Expl. Sci. Algerie, I, Crust., 1849, p. 61,

pi. vi, fig. 2.

Idotea robusta KR^YER, Naturh. Tidsskr. (2) II, 1846-49, p. 108; Voy. en
Scand., Crust., 1849, pi. xxvi, fig. 3. — REINHARDT, Naturhistorisk Bidrag
til en Beskrivelse af Gronland, 1857, p. 35. — STIMPSON, Proc. Acad. Nat. Sci.
Phila., 1863, p. 133.— VERRILL, Am. Jour. Sci., II, 1871, p. 360.— HAROEH
with VERRILL, Report U. S. Commissioner of Fish and Fisheries, Pt. 1, 1873,

p. 439; p. 569, pi. v, fig. 24.— HARGER, Proc.
U. S. Nat. Mus., II, 1879, p. 160; Report
U. S. Commissioner of Fish and Fisheries,
Pt. 6,' 1880, p. 349, pi. vi, figs. 30-32.
Idotea metallica MIERS, Jour. Linn. Soc. Lon-
don, XVI, 1883, pp. 35-38 (see Miers for
synonymy). — HANSEN, Videnskabelige
Meddelelser fra den naturhistoriske Foren-
ing i Kj0benhavn, 1887-88, p. 188. — DOLL-
FUSS, Feuille des jeunes Naturalistes, 1895,
p. 8, fig. 24. — RICHARDSON, American Nat-
uralist, "XXXIV, 1900, p. 226; Proc. U. S.
Nat. Mns., XXIII, 1901, p. 541.— NORMAN,
Ann. Mag. Nat. Hist. (7), XIV, 1904, p.
443.

Localities. — Off Maryland; Chesapeake
Bay; North Carolina; Florida Keys; New-
port, Rhode Island; Long Island; Nan-
FIG. 392,-iDOTHEA METALLICA (AF- tucket; Vineyard Sound; Woods Hole,

Massachusetts; Massachusetts Bay; Georges

Banks; Jeffries Bank; near Isles of Shoals; Halifax, Nova Scotia;
La Have Bank; off No Mans Land; south of Block Island; off Mar-
thas Vineyard; latitude 64° 46' north, longitude 53° 35' west; also,
Mediterranean Sea; southwestern Ireland; between Greenland and
Iceland; between Montevideo and Straits of Magellan; New South

ISOPODS OF NORTH AMERICA.

r

Wales; Borneo; off Cape Negro; Latitude Cove, Patagonia; 40 miles
south of Cape Sable.

Depth. — Surface to 91 fathoms.

From floating fucus.

Body oblong-ovate, about two and one-fourth times as long as wide,
8 mm. :18 mm.

Abdomen a little more than two-fifths the entire length of body,
8 mm. : 18 mm.

Head wider than long, with anterior margin slightly excavate. The
posterior portion is somewhat wider than the anterior portion. Eyes
large and round, compound in structure, and situated at the extreme
lateral margin. First pair of antennae with the basal article not
enlarged, the first and second articles being about equal in length and
width. The third and fourth articles are somewhat longer than either
the first or the second article. The
first antennae extend to the end of the
second article of the peduncle of
the second pair of antennae. The
first article of the second pair of an-
tennae is very short; the second and
third are subequal; the fourth is one
and a half times longer than the third,
and the fifth is twice as long as the
third. The flagellum is composed of

eight articles and reaches when re-
l &

tracted to the anterior margin of the
third thoracic segment. The maxilli-
ped has a palp of four articles.

The segments of the thorax are sub-
equal. The first segment extends a

little beyond the lateral margins of the head on either side. The
lateral portions of this segment and of those following are curved out-
ward and somewhat upward, forming an angle with the portion of the
segment to which it is adjacent. The epimera of all the segments,
from the second to the seventh, inclusive, extend the entire length of
the segment. The epimera are large and very wide, increasing in
width to the seventh, which is wider than long.

The legs are all more or less alike in character. The free margins
of all the joints and the inferior margin of the propodus is furnished
with hairs. The abdomen has two short segments and one long ter-
minal one, with lateral rudiments at its base of another partly coalesced
segment. The terminal segment has the sides converging slightly to
a truncate extremity.

FIG. 393.— IDOTHEA METALLICA. a, MAXILLI-

PED. x 27}. 6, FIRST ANTENNA, x 15}.

A*, eft-

364

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

IDOTHEA BALTICA (Pallas). a

Oniscus balticus PALLAS, Spic. Zool. (9), 1772, pp. 67-68, pi. iv, fig. 6.
Idolea entomon PENNANT, British Zool., IV, 1877, p. 25, pi. xvm, fig. 5.
Stenosoma irrorata SAY, Journ. Acad. Nat. Sci. Phila., I, 1818, p. 423.
Idotea tricuspidata DESMAREST, Diet, des Sci. Nat., XXVIII, 1823, p. 373, pi. XLVI,
fig. 11; Consid. Crust, 1825, p. 289, pi. XLVI, fig. 11.— Roux, Cr. de la Medi-
terrane"e, 1828, pi. xxtx, figs. 11, 12.— GOULD, Rep. Geol. Mass.,2d ed., 1835,
p. 549.— MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 129.
Idotea irrorata MILNE EDWARDS, Hist. Nat. Crust., HI, 1840, p. 132.
Stenosoma irrorata GOULD, Rep. Invert. Massachusetts, 1841, p. 338. — DE KAY,
Zool. New York Fauna, Crust., Pt. 6, 1844, p. 43, pi. x, fig. 42.

Idotea irrorata STIMPSON, Smithsonian Contribu-
tions to Knowledge, VI, 1853, p. 39. — LEIDY,
Journ. Acad. Nat. Sci. Phila., 1855, p. 150.
Idotea tricuspidata SARS, Forh. Vidensk. Selsk.
Christ., 1859, p. 151. — NORMAN, Report British
Assoc., 1868, p. 197. — BATE and WESTWOOD,
British Sessile-eyed Crust., II, 1868, p. 379.
Idotea irrorata HARGER with VERRILL, Report U. S.
Fish Comm., 1873, Pt. 1, p. 569, pi. v, fig. 23;
p. 316. — VERRILL, Am. Journ. Sci. Arts (3),
VII, 1874, pp. 131, 134; Proc. Amer. Assoc.,
1874, pp. 369, 371, 373.— WHITEAVES, Am.
Journ. Sci. Arts (3), VII, 1874, p. 217.
Idotea triaispidata STEERING, Journ. Linn. Sue.

London, Zool., XII, 1874, p. 148.
Idotea irrorata HARGER, Proc. U. S. Nat. Mus., II,
1879, p. 160; Report U. S. Fish Comm., Pt.
6, 1880, p. 343, pi. v, figs. 24-26.
Idolea marina MIERS, Journ. Linn. Soc. London,
Zool., XVI, 1883, pp. 25-31.— RICHARDSON,
Proc. U. S. Nat. Mus., XXIII, 1901, p. 540.
Idotea tricuspidata DOLLFUS, Feuillesdes jeunes Na-
turalistes, 24th year 1893-1895, p. 55.
Idotea baltica SARS, Crust. Norway, II, 1899, pp. 80-81, pi. xxxn. — NORMAN, Ann.

Mag. Nat. Hist. (7), XIV, 1904, pp. 441-442.
Idotea marina PAULMIER, Bull. New York State Museum, 1905, pp. 175-176.

Localities. — Atlantic coast from Nova Scotia and Gulf of St. Law-
rence to North Carolina; Bermudas; Barbados; also Mediterranean,
Black, and Caspian seas; west coast of Europe to Great Britain;
shores of the Netherlands; in German Ocean and Baltic Sea; Bohus-
lan, Sweden (W. Sachs); RunmarO, Stockholms skargard (J. Lindahl);
on Scandinavian and Finland coasts; South America, at Desterro and
Rio Janeiro, Brazil; New Zealand; Red Sea; Java.

Found on surface, on floating seaweed, among algae and eelgrass,
in sand and gravel; from stomach of smelt, Osmerus mordax.

Depth. — Surface to 119 fathoms.

« I have accepted the name adopted by Sars for this form, Oniscus marinus Lin-
naeus being more properly applied to a species belonging to the genus Jsera, as Sars
has suggested. Although Oniscus tridens Scopoli is earlier than Oniscus balticus, it
probably refers to another species of Idothea, as Dollfus has pointed out.

FIG. 3W. — IDOTHEA BALTICA
(AFTER HARGER). x 2.

I8OPODS OF NORTH AMERICA.

365

Body oblong, ovate, almost three times longer than wide, 7 mm. : 20
mm.; length of abdomen a little more than one-third that of entire
body, 8 mm. : 20 mm.

Head wider than long, slightly excavate in front. Eyes large,
round, compound in structure, and situated just anterior to the median
transverse line on the anterior portion of the head, at the extreme
lateral margin. First pair of antennae with the basal article not
expanded, and equal in length to the second article; third and fourth
articles slightly longer than either of the preceding ones. First antennae
extend to the end of the third peduncular article of the second pair of
antennas. The basal article
of the second antenna? is
short; the second and third
articles are about equal in
length; the fourth is very
little longer than the third;
the fifth is about twice as
long as the third. The fla-
gellum consists of fourteen
articles. When retracted,
the second antennae extend
to the middle of the third
thoracic segment. The
maxillipeds have a palp of
four articles.

The segments of the
thorax are about equal in
length, with the exception
of the first, which is some
what shorter than any of
the others. Theepimeraof
all the segments occupy the
entire lateral margins of the segments. They are in the form of large,
broad plates, gradually increasing in width from the first to the sixth.

The legs are more or less alike in structure, and have a few hairs on
the inferior margins.

The abdomen has two short segments followed by a long terminal
one with sutures at the base. The sides of the abdomen converge to a
narrow extremity, the width of which is to the base of the abdomen as
2:5. The posterior margin of the terminal segment is produced in the
middle in an acute point, extending some distance beyond the lateral
angles. Color varies greatly, being sometimes uniformly light or
dark green, or brown and often striped with a median longitudinal
stripe of a light color and a marginal stripe on either side, or with
only marginal stripes. The colors are occasionally arranged in trans-
verse bands or blotches.

FIG. 395. — IDOTHEA BALTICA. a MAXILLIPED. X 41.
b FlEST ANTENNA. X 23.

366

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 3%.— IDOTHEA OCH-

OTENSIS.

as the basal part.

IDOTHEA OCHOTENSIS Brandt.

Idoten ochotensis BRANDT, Middendorff's Sibirische Reise, II, 1851, Crust., p.
145, pi. vi, fig. 33.— MIERS, Jour. Linn. Soc. London, XVI, 1883, p. 32, pi. r,
figs. 8-10. — RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 846; Ann. Mag. Nat. Hist. (7), IV,
1899, p. 265; American Naturalist, XXXIV, 1900, p.
227; Harriman Alaska Expedition, Crust., X, 1904,
p. 219; Proc. U. S. Nat. Mus., XXVII, 1904, p. 663;
Bull. U. S. Fish Comm., 1905, p. 216.

Localities, — Awaatsch Bay, Sea of Ochotsk;
northwest coast of North America to Vancouver
Island; Lands End and Fort Point, California;
Humboldt Ba\r on Popof Island; Karta Bay; Port
Renfrew, British Columbia (J. Lindahl).
From mouth of sculpin; in sand.
Depth. — Surface ; beach ; low water; 7-18 fathoms.
Body oblong-ovate, about three and a half times
longer than wide, 12 mm. : 42 mm. Sides of thorax
nearly parallel; abdomen tapering slightly, the
posterior extremity being about four-fifths as wide
Length of abdomen about two-fifths the entire
length of body, 1(5 mm. :42 mm.

Head a little wider than long, with the anterior margin sinuate. On
either side of a median excavation is another very slight excavation.
The posterior portion of the head is not wider than the anterior por-
tion. The eyes are small, trans-
versely ovate, compound, and situ-
ated on the extreme lateral margin
about the middle of the head. The
first pair of antennae have the basal
article very much dilated; it is
longer and about twice as wide as
any of the following articles. The
first antennae reach almost to the
end of the second article of the pe-
duncle of the second pair of anten-
nae. The basal article of the sec-
ond pair of antennae is almost in-
conspicuous from a dorsal view.
The second and third articles are
about equal in length. The last
two articles are about one and a half times longer than the third article
and are subequal. The flagellum consists of about eleven short articles.
The second antennaa when retracted reach only to the middle of the
third thoracic segment. The maxillipeds have a palp of four articles.
The first segment of the thorax is wider than the head, and produced

FIG. 397.— IDOTHEA OCHOTENSIS. o, MAXII.LI-
PED. x 15J. b, FIRST ANTENNA, x 15J.

ISOPODS OF NORTH AMERICA. 367

anteriorly at the sides to surround the posterior portion of the head.
All the segments are equal in length. The epimeron of the second seg-
ment extends half the length of the lateral margin; it is broader at its
anterior end than at its posterior end. The epimera of the third and
fourth segments occupy the anterior two-thirds of the lateral margin.
The epimeron of the fifth segment extends almost the entire length of
the lateral margin of the segment. The epimera of the sixth and seventh
segments reach the posterior extremity of the lateral margin, and are
broader at the posterior end than at the anterior end. The legs are all
similar. The inferior margin of the merus, carpus, and propodus is
densely furnished with hairs.

The abdomen has two short segments and one long terminal one
with lateral rudiments of another partly coalesced segment. The
terminal segment tapers to about the middle, and from that point to
the post-lateral angles, the sides are nearly parallel. The lateral angles
are rounded. The posterior margin is produced in an obtuse median
process, triangulate in shape, and extending some distance beyond the
lateral angles. The apex of this process is rounded.

IDOTHEA PHOSPHOREA Harger.

Idotea phosphorea HARGER with Verrill, Report U. S. Commissioner of Fish and
Fisheries, Pt. 1, 1873, p. 569 (275); p. 316 (22).— VERRILL, Am. Jour. Sci.,
1874, pp. 43, 45, 131; Proc. Amer. Assoc., 1874,
pp. 362, 367, 369.— WHITEAVES, Am. Jour. Sci.,
VII, 1874, p. 218.— HARGER, Proc. U. S. Nat.
Mus , II, 1879, p. 160; Report U. S. Commis-
sioner of Fish and Fisheries, Pt. 6, 1880, pp. 347-
348, pi. v, figs. 27-29.

Idotea marina var. phosphorea MIERS, Journ. Linn.
Soc. London, Zoology, XVI, 1883, pp. 31-32.

Idotea phosphorea RICHARDSON, American Naturalist,
XXXIV, 1900, p. 227; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 541.— PAULMIER, Bull. New York
State Museum, 1905, pp. 176-177.

Localities. — Coast of New England to Halifax,
Nova Scotia, and the Gulf of St. Lawrence;
Runmaro, Stockholms Skargard (J. Lindahl).

Depth. — Surface to 18 fathoms. Found FIG. sas.— IDOTHEA PHOS-
among seaweed: part of contents of haddock CHOREA (AFTER HAR-

, GER). X 2.

stomach.

Body oblong-ovate, three times longer than broad, 7 mm. : 21 mm.
Length of abdomen a little more than one-third the entire length of
the body, 8 mm. : 21 mm.

Head broader than long, with the anterior margin straight on either
side of a slight median excavation. The eyes are moderately large,
round, compound in structure, and placed just in front of the median
transverse line at the extreme lateral margin. Basal article of first

368

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 399.— IDOTHEA PHOSPHOREA. O, M.VMI.-

LIPED. x 27J. 6, FIRST ANTENNA, x 15J.

pair of antennae not dilated, and but little wider than second article.
First, second, and third articles about equal in length; fourth article a
little longer than any of the others. The first antennas extend to the
end of the third peduncular article of the second pair of antennae. The
basal article of the second antennae is almost inconspicuous; the sec-
ond and third articles are subequal;
the fourth is about one and a half
times longer than the third; the fifth
is a little longer than the fourth.
The flagellum consists of sixteen arti-
cles. When retracted, the second
antennae extend to the posterior mar-
gin of the third thoracic segment.
The maxillipeds have a palp of four
articles.

The segments of the thorax are
subequal, except the first, which is
shorter in the median dorsal line.
The epimera of the second and third
segments occupy the anterior two-
thirds of the lateral margin; the epi-
meron of the fourth segment occupies about four-fifths of the lateral
margin; the epimera of the last three segments occupy the entire
lateral margin and are increasingly broader at the posterior end.

The legs are more or less similar in structure, and are furnished
with hairs along the inferior margin of the merus, carpus and pro-
podus. The first two segments of the abdomen are short, followed
bj- a long terminal one with lateral sutures at the base. The terminal
segment tapers to a pointed extremity, on either side of which is an
indication of a rudimentaiy lateral angle. Color usual ly dark green
or brownish, with transverse patches of yellow.

6O. Genus PENTIDOTEA, new genus.

Flagellum of second antennae multi-articulate. Maxillipeds with a
palp composed of five articles. Epimera of all the segments of the
thorax with the exception of the "first distinctly separated from the
segments. Abdomen composed of three segments, with a suture line
on either side of the terminal segment at the base, indicating another
partly coalesced segment.

There are as yet but four species of this genus, all agreeing in hav-
ing the palp of the maxillipeds composed of five articles.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS PENTIDOTEA.

a. Terminal segment of body with a deep ernargination at its posterior extremity,

the post-lateral angles formed being very acute Pentidotea resecata (Stimpson)

a'. Terminal segment of body not emarginate at its posterior extremity.

ISOPODS OF NORTH AMERICA.

369

b. Terminal segment of body regularly and broadly rounded at its posterior
extremity, with a very small and obtuse median tooth. Epimera of the sec-
ond, third, and fourth segments do not extend quite the entire length of the
segments. Those of the following segments occupy the entire lateral margin.

Pentidotea wosnesenskii (Brandt)

b'. Terminal segment of body with pronounced post-lateral angles, which are
rounded, and with a distinct and acute median tooth at its posterior
extremity.

c. Sides of thorax parallel. Eyes about twice as wide as long. Epimera of all
the segments, from the second to the seventh, inclusive, occupy the entire

lateral margins of the segments Pentidotea. whitei (Stimpson )

(/. Sides of thorax arcuate. Eyes transversely elongated, being five times wider
than long. The first three epimera do not quite reach the post-lateral
angles of the segments Pentidotea stenops ( Benedict)

PENTIDOTEA RESECATA (Stimpson).

Idotea resecata STIMPSON, Bost. Jour. Nat. Hist, VI, 1857, p. 504, pi. xxn, fig. 7;
Proc. Bost. Soc. Nat. Hist., 1859, p. 88. — MIERS, Jour. Linn. Soc. London,
XVI, 1883, p. 45.— RrcHARDsoN, Proc. U. S. Nat. Mus., XXI, 1899, p. 844;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 263-264; American Naturalist,
XXXIV, 1900, p. 226; Harriman Alaska Exp., Crust, X, 1904, p. 216; Proc.
U. S. Nat. Mus., XXVII, 1904, p. 661; Bull. U. S. Fish Comm., 1905, p. 216.

Localities. — Straits Juan de Fuca, opposite Port Townsend, Van-
couver Island; Fort Rupert and Barclay Sound, British Columbia; Gulf
of Georgia, Orcas Island; Ottar Bay, Fender Island; Pacific Grove;
Santa Barbara; San Pedro; Humboldt Bay, and
Monterey Bay, California; Tomales Bay, Cali-
fornia; Kilisut Harbor, Port Townsend; Mawaw-
shone Point, near Port Townsend; Quarantine
Dock, Port Townsend; Karta Bay; Gulf of
Georgia.

Depth. — Surface to 3£ fathoms. Found be-
tween high and low tide lines among rocks, sea-
weed, kelp, eelgrass, etc.

Body narrow, elongate, four and a half times
longer than wide, 8 mm.: 36 mm.; length of
abdomen one-third that of entire body, 12 mm.:
36 mm.

Head but little wider than long, with frontal
margin slightly excavate. Eyes moderately
large, round, compound in structure, and situated

just in front of the median transverse line on the FIG. 400.— PENTIDOTEA RE-
anterior portion of the head, and at the extreme
lateral margin. First pair of antenna? with the
basal articles greatly enlarged. The three following articles are
slender and about equal in length to each other and to the basal
article. The first antenna? extend to the end of the third article of the
peduncle of the second pair of antennae. The basal article of the sec-
ond antenna? is short and almost inconspicuous from a dorsal view; the
28589—05 24

SECATA (AFTER STIMP-
SON). X \\.

370

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 401. — PENTIDOTEA KESECATA. a,
MAXILLIPED. x 15}. 6, FIRST AN-
TENNA, x 15}.

second and third articles are of equal length; the fourth is almost twice
as long as the third; the fifth is slightly shorter than the fourth. The
flagellum consists of twelve articles. The maxilliped has a palp of
five articles.

The first and seventh segments of the thorax are equal in length and
shorter than an}7 of the others. The third and fourth segments are

the longest. The first segment is very
little wider than the head; the antero-
lateral angles are produced to surround
the posterior portion of the head. The
epimera of the second, third, and fourth
segments do not occupy the whole of the
lateral margin of the segment; those of
the second and third segments occupy the
anterior two-thirds, that of the fourth seg-
ment, the anterior three-fourths part; the
epimera of the three following segments
occupy the entire lateral margin. All the
epimera are large and conspicuous from a
dorsal view.

The legs are similar in structure and fur-
nished with hairs on the inferior margin
of the merus, carpus, and propodus. The basis of all the legs is
provided with a carinate process.

The abdomen has two short segments and one long one with lat-
eral sutures at the base. The posterior margin of the terminal seg-
ment is deeply excavate, the lateral angles being acute!}7 produced.
The sides of the abdomen converge slightly from the base to about
the middle of the segment, and then converge again slightly at the
extremity.

PENTIDOTEA WOSNESENSKII (Brandt).

Idotea wosnesewkii BRANDT, Middendorff's Sibirische Reise, II, 1851, Crust.,
p. 146.

Idotea hirtipes DANA, U. S. Expl. Exp., Crust., XIV, 1853, p. 704, pi. XLVI, fig. 6.

Idotea oregonensis DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854, p. 175.

Idotea wosnesenskii STIMPSON, Boat. Jour. Nat. Hist., VI, 1857, p. 504. — SPENCE
BATE, Lord's Naturalist in British Columbia, II, 1866, p. 281.

Idotea media (Dana?) SPENCE BATE, Lord's Naturalist in British Columbia, II,
1866, p. 282.

Idotea wosnesenskii MIERS, Jour. Linn. Soc. London, XVI, 1883, p. 40. — RICHARD-
SON, Proc. U. S. Nat. Mus., XXI, 1899, p. 846; Ann. Mag. Nat. Hist. (7),
IV, 1899, p. 265; American Naturalist, XXXIV, 1900, p. 227; Harriman
Alaska Expedition, Crust, X, 1904, p. 218; Proc. U. S. Nat. Mus., XXVII,
1904, p. 663; Bull. U. S. Commission of Fish and Fisheries, 1905, p. 216.

Localities. — Sea of Ochotsk and Kamchatka Sea; west coast of North
America to Monterey Bay, California; Dutch Harbor on Unalaska
Island; White Water Bay, Alaska; Humboldt Bay on Popolf Island;

ISOPODS OB^ NORTH AMERICA.

371

Yakutat; Glacier Bay; Garforth Island in Muir Inlet and Sitka, Alaska;
Beaver Cove on Vancouver Island; Land's End, California; Gabnola

FIG. 402. — PENTIDOTEA wos-
NESENSKII. MALE.

FIG. 403. — PENDITOTEA WOSNESENS-
KII. FEMALE.

Island; Taylor Bay; Boca de Quadra; Head of Mink Arm; San Fran-
cisco, California; Gulf of Georgia; Farallone Islands, California; Fort
Point, San Francisco, California;
Port Renfrew, British Columbia.
(R. Osburn.)

Depth.— Surface to 9 fathoms.
Found at low tide, on beach, in sand
and rocks; under stones.

Body oblong-ovate, with the sides
of the thorax nearly parallel; length,
three times its greatest breadth, 11
mm.: 32 mm. Length of abdomen
about three-eighths the entire length
of body, 13 mm.: 32 mm. Head
wider than long, with frontal margin
slightly excavate; posterior portion
somewhat wider than anterior por-
tion. Eyes small, compound, transversely ovate, and situated at the
extreme lateral margin, about halfway between the anterior and pos-
terior margins. The first pair of antennae are composed of four
articles; the basal article is about twice as broad as any of those fol-
lowing; the first, second, and third articles are about equal in length;
the fourth is a little longer and clavate in shape. The first antenme
extend a little beyond the middle of the third article of the peduncle
of the second pair of antennas. The second pair of antenna? have

FIG. 404. — PENTIDOTEA
MAXILLIPED. x 15j.
x 15}.

WOS.VESEXSKII. a,

b, FIRST ANTENNA.

372 BULLETIN 5', UNITED STATES NATIONAL MUSEUM.

a peduncle of five articles and a flagellum of sixteen articles. The
basal article is short; the second and third are of equal length, and
longer than the first; the last two are one and a half times longer
than the third, and subequal. The flagellurn consists of sixteen arti-
cles. The raaxillipeds have a palp of five articles.

The thoracic segments are all equal in length. The epimera of the
second, third, and fourth segments do not extend the entire length of
the lateral margins, but occupy more than three-fourths of the margin.
The anterior portion of the segment at the sides is excavate for the
epimeron, and the posterior portion projects laterally as far as the
exterior margin of the epimeron. The epimera of the last three
segments occupy the entire lateral margin, and are increasingly wider
posteriorly. All the epimera are large and conspicuous from a dorsal
view.

The legs are similar in structure, and in the male are thickly fur-
nished with hairs on the free margins of the joints. Those of the
female have the propodus only furnished with thick bristles on the
inferior margin.

The abdomen has two short segments, followed by one large ter-
minal segment, which has lateral rudiments of another partly coalesced
segment. The posterior portion of the segment is regularly and
broadly rounded, with a very small obtuse median point, rounded at
the apex.

The upper division of the opercular valves is crossed obliquely by
a carina formed by the thickened anterior portion.

The following observations and measurements were made by Dr.
James E. Benedict several years ago and intended for publication.
He has given me permission to publish them here.

An examination of numerous lots from California to Alaska appear to show that
the sexual differences are more marked in this than is usual in species of the genus.

Dana's figure is undoubtedly that of a male and agrees well with the specimens in
the collection. The legs of the male are densely covered with hair; their heads are
broad and very prominent. The outline of the thorax is but little arcuate. The
abdomen is broad and but little tapering. The heads of the females are much
smaller in proportion to the size and width of the animal than in the males. The
abdomens are more tapering and the third and fourth segments of the thorax are
wider, giving the animal a suboval outline. The terminal outlines of the abdomens
of both sexes are alike.

In sorting the different lots preserved in alcohol the males can usually be separated
from the females by the color alone, the larger yellow specimens always proving to
be males, while the dark colored ones are usually, though not always, females, and
in this collection commonly with eggs. Some lots contain a large excess of one sex
or the other, while in other lots the sexes are associated in more even numbers. No
females were found with hair on the legs or a well-developed male without it.

Doctor Stimpson says: "An exceedingly common species of a dark-green color
found among seaweeds on rocky or stony shores between high-water and half-tide
marks,"

ISOPOD8 OF NORTH AMERICA. 373

Measurements of a female 25 mm. long.

mm.

Width of head at the outer margin of eyes 4. 5

W iilth of first thoracic segment 6. 5

Width of second thoracic segment 8

Width of third and fourth thoracic segments 9

Width of fifth thoracic segment 8. 5

Width of sixth thoracic segment 8

Width of seventh thoracic segment 7. 5

Length of abdomen 10. 5

Length of antenna with flagellum 9

Measurements of a male 28.5 mm. long.

mm.

Width of head 5.5

Width of first thoracic segment 7. 5

Width of second thoracic segment 8

Width of third, fourth, fifth, and sixth thoracic segments 9

Width of seventh thoracic segment 8. 5

Length of abdomen „ 11

Length of antenna with flagellum 10

Measurements of a male 35 mm. long.

mm.

Width of head 6. 5

Width of first thoracic segment _ 9

Width of second thoracic segment 9. 5

Width of third, fourth, fifth, and sixth thoracic segments 10. 5

Width of seventh thoracic segment 10

Length of abdomen 13

Length of antenna with flagellum 10

PENTIDOTEA WHITEI (Stimpson).

Idotea whitei STIMPSON, Proc. Acad. Nat. Sci. Phila., 1864, p. 155. — MIERS, Jour.
Linn. Soc. London, XVI, 1883, pp. 42-43.— RICHARDSON, Proc. U. S. Nat.
Mus., XXI, 1899, pp. 846-847; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 266;
American Naturalist, XXXIV, 1900, p. 227.

Localities. — Puget Sound; Monterey Bay, California. From Mytilus.

Body narrow, elongate, with sides almost parallel; length equal to
a little over three times its greatest breadth, 11 mm. : 34 mm. Length
of abdomen a little more than one-third that of entire body, 12
mm. : 34 mm.

Head wider than long, with frontal margin very slightly excavate;
posterior portion not wider than anterior portion. Eyes moderately
large, transversely ovate, compound, and placed close to the lateral mar-
gin, about halfway between the anterior and posterior margins. The
first pair of antennas have four articles; the basal article is twice as
broad as any of those following and a little longer; the next two articles

374 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 405. — PENTIDOTEA WHITEI. x

are nearly of equal length; the last one is clavate and somewhat longer
than either of the preceding ones. The first antennae do not extend

beyond the second article of the peduncle
of the second pair of antennae. The sec-
ond pair of antennae have a peduncle com-
posed of five articles and a flagellum of
seventeen articles. The first article of
the peduncle is short, not reaching beyond
the basal article of the first pair of antennae ;
the next two articles are equal in length,
and each is twice as long as the first
article; the last two articles are each
nearly twice as long as the third article.
The maxillipeds have a palp of five
articles.

The segments of the thorax are all of
equal length. The epimera of all the seg-
ments, from the second to the seventh,
inclusive, extend the entire length of the
lateral margin. The epimeron of the sec-
ond segment is somewhat broader anteriorly than posteriorly; the
epimeron of the third segment and that of the fourth also are the same
width throughout their length; those
of the last three segments are increas-
ingly wider posteriorly.

All the legs are similar in structure;
the propodus is furnished with numer-
ous stiff bristles along the proximal
half of the inferior margin.

The abdomen is composed of two
short segments and a long terminal one
having lateral rudiments of another
partially coalesced segment. The ter-
minal segment has the sides somewhat
concave, the post - lateral angles
rounded, and an acute median terminal
point triangularly produced with apex
rounded. The opercular valves are in
two parts each; a long anterior portion, crossed obliquely by a faint
carina, and a short posterior portion.

Only one specimen of this species, a male, was collected at Monterey
Bay by Mr. Harold Heath. It agrees in every detail with Stimpson's
and Mier's descriptions. No figure has ever been given.

FIG. 406.— PENTIDOTEA WHITEI. a, MAXIL-
LIPED. x 15}. b, FIRST ANTENNA, x 15y.

ISOPODS OF NORTH AMERICA.

375

PENTIDOTEA STENOPS (Benedict).

Idotea stenops BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, pp. 54-55. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 846; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 266; American Naturalist, XXXIV, 1900, p. 227;
Harriman Alaska Exp. Crust., X, 1904, p. 219; Proc. U. S. Nat. Mus.,
XXVII, 1904, p. 663.

Locality. — Monterey Bay, California.

Body oblong-ovate, nearly three times as long as wide, 15 mm. : 42 mm.
Head nearly twice as wide as long, 4 mm.: 7 mm. Frontal margin
slightly excavate between the antero- lateral angles. The eyes are
transversely elongated, being' five times as wide as long and are situ-
ated at the sides of the head. The basal article of the first antennae is
greatly dilated; the three following articles are short
and nearly subequal. The first pair of antennas
extend to the end of the second article of the pe-
duncle of the second pair of antennae. The first arti-
cle of the second pair of antennas is short and does
net extend beyond the basal article of the first pair
of antennae; the second and third articles are sub-
equal; the fourth and fifth articles are also subequal
and each is a little longer than either of the two pre-
ceding articles. The fla-
gellum is composed of fif-
teen articles. The second
antennas extend to the
posterior margin of the
second thoracic segment.
The maxillipeds have a palp composed of
five articles.

The first segment of the thorax has the
lateral parts expanded and produced anteri-
orly, surrounding the posterior half of the
head. The second, third, and fourth seg-
ments are subequal and longer than the first,
fifth, and sixth segments, which are subequal.
The seventh segment is a little shorter than
the sixth. The epimera are distinctly separated on all the segments
with the exception of the first. The first three occu-py almost the
entire lateral margin, the epimera being 5 mm. long, and the post-
lateral angle of the segment occupying £ mm. of the lateral margin
below the epimeron. The last three epimera occup}' the whole of the
lateral margin; they are very broad, the last two being broader pos-
teriorly than anteriorly.

The abdomen is composed of three segments — two short ones, fol-
lowed by a long terminal segment which has at its base a suture line
on either side, indicating another partly coalesced segment. The ter-

FIG. 407. — PENTIDOTEA
STENOPS (AFTER
BENEDICT).

FIG. 408. — PENTIDOTEA STENOPS.
a, MAXILLIPED. x Hi. b, FIRST

ANTENNA. X Hi-

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

minal segment is 10 mm. wide at the base. The sides converge from
the base to a point about the middle, where the segment is 8 mm. in
width. From the middle to the extremity the abdomen is of equal
width. The abdomen terminates in an extremity, which is acutely
pointed in the middle of the posterior margin and has the post-lateral
angles pronounced and rounded, but not produced.
All the legs are similar in structure.

61. Genus SYNIDOTEA Harger.

Flagellum of second antenna multi-articulate. Palp of maxillipeds
composed of three articles. Epimera of all the thoracic segments per-
fectly and firmly united with the segments. In the last three segments
there is sometimes a faint depression marking the place of coalescence.
The abdomen is composed of a single segment, with a suture line on
either side at the base indicating another partly coalesced segment.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS SYNIDOTEA.

a. Terminal segment of body emarginate or notched at the extremity.
l>. Two spines or tubercles overhanging the frontal notch.

c. Antero-lateral processes produced horn-like Synidotea ritteri Richardson

</. Antero-lateral processes not produced horn-like.

d. Spines united near the base Synidotea pallida Benedict

d' '. Spines free at base Synidotea erosa Benedict

b' '. No spines or tubercles overhanging the frontal notch,
c. With a low ridge arising between the eyes and interrupted on the median line.

d. Outlines of abdomen subparallel Synidotea nebulosa Benedict

d/. Outlines of abdomen strongly arcuate Synidotea angulata Benedict

c' . Without a ridge between the eyes.
. d. Outline of abdomen subtriangular.

e. Front not excavated Synidotea consolidata ( Stimpson)

ef. Front excavated.

/. Outlines of thorax subparallel Synidotea marmorata (Packard)

/'. Outlines of thorax strongly arcuate Synidotea bicuspida (Owen)

d'. Outlines of abdomen rounded.

e. Length of abdomen equal to width at base Synidotea laticauda Benedict

ef. Length of abdomen equal to one and one-half times the width at base.

Synidotea harfordi Benedict
a'. Abdomen pointed.

b. Undulations of the body not tubercular or spiny.

c. Tubercle in front of the eyes not margined Synidotea nodulosa ( Kr0yer)

cf . Tubercle on the frontal margin and forming a part of it.

Synidotea Isevis Benedict

b'. Undulations of the body tubercular and spiny,
c. Four spines on the front of the head; body spinous.

Synidotea muricata (Harford)
(/. A wedge-shaped tubercle behind the frontal notch; body tubercular.

Synidotea picta Benedict

I80PODS OF NORTH AMERICA.

377

FIG. 409. — a, HEAD OF SYNIDOTEA RITTERI.
6, HEAD OF SYNIDOTEA CONSOLIDATA.

SYNIDOTEA RITTERI Richardson.

Synidotea ritteri RICHARDSON, Harriman Alaska Exp. Crust., X, 1904, pp. 219-
220; Proc. U. S. Nat. Mus., XXVII, 1904, pp. 063-665.

Locality. — Lands End, San Francisco, California.
Body ov7ate in outline* Color yellow, with markings of black;
terminal segment almost entirety black.

Head with prominent rounded antero-lateral angulations, at base of
which, and just above the eyes, is a conspicuous horn-like projection,
hook-shaped, directed upward and
forward, one on either side of the
head. In the median excavation of
the frontal margin on either side of
the median line is a prominent
tubercle. Between the eyes and in
line with them on the posterior por-
tion- of the head are two low tubercles. The eyes are situated at the
extreme lateral margins on the posterior portion of the head, and are
somewhat elevated above the surface; they are black and conspicuous,
and composed of many ocelli. The first pair of antennae consist of
four joints, the last joint clavate and fringed with hairs. The second
pair of antennae have a five-jointed peduncle
and a flagellum composed of eight joints; the
third joint of the peduncle has a prominent
tubercle.

The first four segments of the thorax are
longer than the last three. The lateral parts of
all the segments are widely expanded, with mar-
gins well rounded. The lateral parts are not
separated from the dorsal portion of the seg-
ments, but are firmly anchylosed.

The abdomen consists of one segment, with
suture marks, one on either side, indicative of
another partly coalesced segment; it tapers
gradually to a broadly rounded extremity, which
is slightly excavate in the median line.

The seven pairs of legs are but sparingly fur-
nished with hairs. The upper half of the
opercular valve is black, the lower half yellow.
There are three longitudinal lines of low swellings on the body, one
median, the other two placed one on either side of the median line.

Only one specimen was taken at Lands End, California, by Doctor
Ritter and party.
This species is closely allied to Synidotea consolidates (Stimpson),0

FIG. 410. — SYNIDOTEA RIT-
TEKI. x 10.

«Proc. Cal. Acad. Sci., I, 1856, p. 97; Bost. Jour. Nat. Hist, VI, 1857, p. 503.

378 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

but differs from that species in the shape and greater size of the
tubercles in front of the eyes, the tubercles being hook-shaped and
very prominent in S. ritteri and projecting far in front of the anterior
margin of the head, while in S. consolidata they are small (Stiuipson
speaks of them as being minute), are not hooked, and do not project
any considerable distance in front of the anterior margin of the head;
in the greater size of the two median tubercles on the anterior division
of the head (Stimpson does not mention these tubercles in his descrip-
tion, but in the specimens sent to the U. S. National Museum from
a b Pacific Grove, California, by Mr. J. ().

Snyder, and which Dr. James E. Bene-
dict has identified with S. consolidata
and figured in his paper on the genus
Synidoteaf these tubercles are pres-
ent, but very minute; they do not

FIG. 4ii.-«, ABDOMEN OF svMDOTEA KIT- overhang thefrontal emargination);
TEEI. b, ABDOMEN OF SYNIDOTEA CON- in the shape of the terminal segment

of the body, it being much broader,

and tapering very gradually to a broadly rounded extremity, which
has a slight median notch or excavation in S. ritteri, while in S. con-
solidata the terminal segment of the body is narrower and tapers to an
extremity marked by two pronounced teeth or angulations separated
by a deep median notch.

Specimens of the same size were taken in making the above com-
parisons.

This species is named for Dr. William E. Ritter, of the University
of California, from whom the specimens were received.

SYNIDOTEA PALLIDA Benedict.

Synidotea pallida BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp. 396-397.—
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 848; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 227.

Locality. — Chirikof Island, Alaska.

Depth. — 695 fathoms.

Body narrow, elongate, about two and a half times longer than wide,
5 mm.: 12 mm. Length of abdomen equal to less than half the length
of the entire body, 5 mm. : 12 mm.

Head with the front excavate between the antero-lateral angles. The
sides of the head are produced in a wide border, the exterior margin of
which is straight. There are four tubercles on the anterior portion of
the head, two in the center, one on either side of the median longitu-
dinal line, and two lateral to these, one in front of each eye. The
eyes are round and composite, and placed at the base of the lateral

«Proc. Acad. Nat. Sci. Phila., 1897, p. 393.

ISOPODS OF NORTH AMERICA.

379

expansion, so that they seem more dorsal in position. The first anten-
nae have the basal article not enlarged; the second is about equal in
length to the first; the third and fourth are subequal, and each is about
one and a half times longer than the third. The first pair of antennae
extend to the end of the fourth peduncular article of the second pair

of antennae. The basal article of the
second pair of antennae is almost in-
conspicuous from a dorsal view;
the second article is short; the third,
fourth, and fifth are progressively
longer, each being one and a half
times longer than the preceding arti-
cle. The flagel-
lum consists of ten
articles. When
retracted, the sec-
ond antennae ex-
tend to the poste-
rior margin of the
third thoracic seg-
ment. The maxil-
lipeds have a palp
of three articles.

The first four
segments of the
thorax are longer than the last three. The epimera of all the seg-
ments are firmly united with the segments. Three longitudinal rows
of tubercles, one median and two lateral, extend the entire length
of the thorax. The tubercles in the lateral rows are more pronounced.
In a transverse line the tubercles are arranged three on each seg-
ment.

The abdomen is composed of a single segment with lateral sutures
at the base indicating another partly coalesced segment; it is elongate
with the posterior extremity rounded. There is a very slight indica-
tion of a median excavation at the posterior end.
The legs are more or less similar in structure.

FIG. 412. — SYNIDOTEA PALLIDA (AFTER BENE
DICT). x 2£.

FIG. 413. — SYNIDOTEA
PALLIDA. MAXIL-

LIPED. X 27j.

SYNIDOTEA EROSA Benedict.

Synidotea erosa BENEDICT, Proc. A cad. Nat. Sci. Phila., 1897, pp. 396-397. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 848; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 227.

locality. — Sannakh Island, Alaska.

Depth. — 483 fathoms.

Body oblong-ovate, three times longer than wide, 7 mm. : 21 mm.

380

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

PIG. 414. — SYNIDOTEA
(AFTER BENEDICT).

EROS A
X 2.

Head wider than long, 2£ mm. :5 mm., with the anterior margin
deeply excavate between theantero-lateral angles. The eyes are small,
round, composite, and situated on either side, some distance from the

lateral margin, which is expanded to form
a narrow border. Two prominent tuber-
cles, one on either side of the median line
are placed just behind the anterior margin,
from which position they overhang the
frontal notch. Just in front of each eye is
a low tubercle almost inconspicuous. Be-
tween the eyes, one on either side of the
median line, are two large but low eleva-
tions. Back of these elevations is a low
ridge. The first pair of antennae have the
first two articles short and subequal; the
last two are subequal, and each is one and
a half times longer than either of the two
preceding articles. The first pair of an-
tennae extend to the middle of the fourth
article of the peduncle of the second pair of
antennae. The first two articles of the sec-
ond pair of antennae are short and subequal ; the third and fourth are sub-
equal and each is about twice as long as either of the two preceding
articles; the fifth is one and a half times longer than the fourth. The
flagellum is composed of seventeen articles. The
maxillipeds have a palp of three articles.

The second, third, and fourth segments of the tho-
rax are subequal and are the longest, each being
about £ mm. longer than any of the other segments,
which are nearly subequal, the seventh being a little
shorter than the sixth. The epimera of all the seg-
ments are firmly united with the segments, and there
is no indication of a separation. On each segment
of the thorax, on either side of the median line and
a short distance from the lateral margin, is a low
elevation, which in the first segment at its anterior
portion is produced into two low tubercles.

The abdomen is composed of a single segment, which has a suture
line at its base on either side; it is 7£ mm. long, about one-third the
entire length of the body, and is 5 mm. wide. It tapers to a rounded
extremity, which has a small and shallow median excavation, almost
inconspicuous.

All the legs are similar in structure.

FIG. 415.— SYNIDOTEA
EROSA. MAXILLIPED.
x 15}.

ISOPODS OF NORTH AMERICA.

381

FIG. 416.— SYNIDOTEA NEBULOSA (AFTER
BENEDICT), x 3.

SYNIDOTEA NEBULOSA Benedict.

Synidotea nebulosa BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp. 397-399. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 848; Ann. Mag. Nat. Hist.
(7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 227.

Localities. — Unalaska; Kyska Har-
bor; Semidi Islands; Unimak Island;
Bering Sea; Kamschatka; Constantino
Harbor, Alaska; East of Amak Island,
Alaska.

Depth.— 6 to 32 fathoms.
Body ovate, a little more than twice
as long as wide, 5mm. : 11 mm. Length
of abdomen a little more than one-third
the length of the entire body. 4 mm. : 11
mm. Head, first four segments of
thorax, and abdomen dark in color, the
surface being densely covered with
small black marks. The last three seg-
ments of the thorax are much lighter
in color, being a light brown with only
a few scattered markings of black.

The front of the head is almost
straight, with only a very small median

excavation. The anterior portion of the head is slightly narrower
than the posterior portion. The lateral margins are straight. The
eyes are large and round, composite in structure, and placed about
the middle of the head near the lateral margins. The first pair of
antenna? have the first and second articles about
equal in length, the first article not being dilated; the
third and fourth are subequal and each is about one
and a half times longer than the second. The first
antennae extend to the end of the fourth article of
the peduncle of the second pair of antennae. The
basal article of the second antennae is almost incon-
spicuous from a dorsal view; the second article is
short, not much longer than the first; the third is but
little longer than the second; the fourth and fifth
are subequal and each is twice as long as the third.
The flagellum consists of six articles. When retracted, the second
antennae extend to the posterior margin of the second thoracic seg-
ment. The maxilliped has a palp of three articles.

The first four segments of the thorax are longer than the last three.
All the epimera of all the segments are firmly united with the seg-
ments. The lateral margins of the segments are somewhat rounded.

FIG. 417.— SYNIDOTEA
NEBULOSA. MAXIL-
LIPED. x 27}.

382

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The abdomen is composed of one segment with suture lines at the
base indicating another partly coalesced segment. It is rounded pos-
teriorly with the extremity truncate or slightly emarginate.

The legs are more or less similar in structure.

SYNIDOTEA ANGUL-ATA Benedict.

Synidotea angulata BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp. 395-396.—
RICHARDSON, Proe. U. S. Nat. Mus., XXI, 1899, p. 848; Ann. Mag. Nat. Hist.
(7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 227.

localities. — Off Cape Johnson, Washington; off Destruction Island,
Washington; off Cape Flattery, Washington.

Depth.— 31 to 38 fathoms.
Body narrow, elongate, three times longer
than wide, 4 mm. : 12 mm. Length of abdo-
men one-third the length of the entire body,
4 mm. :12 mm.

Head with a deep excavation between the
antero-lateral angles. Just posterior to the
frontal excavation is a ridge produced into
two low tubercles, one on either side of the
median line. Eyes large and round, com-
posite, and placed about the middle of the
head near the lateral margins. The basal
article of the first antennae is not expanded
and is about as long as the second article;
the third and fourth are subequal and each
is about one and a half times longer than the
second. The first pair of antennae extend a little beyond the end of
the third article of the peduncle of the second pair of antenna?. The
basal article of the second antennae is short and almost inconspicuous
from a dorsal view; the second article is also short;
the third and fourth are about equal in length and
each is twice as long as the second ; the fifth is nearly
twice as long as the preceding article. The flagellum
consists of twelve articles. When retracted the sec-
ond pair of antennae extend to the posterior margin
of the third thoracic segment. The ma-xilliped has a
palp of three articles.

The second, third, and fourth segments of the thorax
are longer than the others. All the epimera of all the
segments are firmly united with the segments. The lat-
eral portions of the first four segments are expanded laterally with mar-
gins angulate. The last three segments have straight lateral margins.
The abdomen is composed of one segment with lateral sutures at the
base, indicating another partly coalesced segment. The posterior por-
tion is rounded, with apex slightly excavate.
The legs are more or less similar in structure.

FIG. 418. — SYNIDOTEA ANGULATA
(AFTER BENEDICT), x 4.

FIG. 419.— SYNIDOTEA
ANGULATA. MAXIL-

LIPED. X 27}.

I8OPODS OF NORTH AMERICA.

383

SYNIDOTEA CONSOLIDATA (Stimpson).

Idotea consolidata STIMPSON, Proc. Cal. Acad. Sci., I, 1856, p. 89; Bost. Jour. Nat.

Hist, VI, 1857, p. 503.

Edotea bicuspida MIERK, Jour. Linn. Soc. London, XVI, 1883, p. 66.
Si/nidotea consolidata BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, p. 393. —

RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 848; Ann. Mag. Nat.

Hist. (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 227.

Locality. — Pacific Grove, California.

Bocty ovate, twice as long as broad, 4 mm. : 8 mm.

Length of abdomen, 3 mm.

Head with a slight median excavation. Posterior

to the median notch are two small tubercles on either

side of the median line. Lateral to these tubercles

and in front of the eyes are two larger tubercles,

one on either side. Between the eyes in a trans-
verse line are two small tubercles, one on either

side of the median line and a little farther apart

than the two anterior tubercles. Posterior to these

two tubercles in the middle of the head is one small

tubercle in the median line close to the posterior

margin. The eyes are large and round, composite

in structure, and placed close to the lateral margins.

The basal article of the first pair of antennae is short

and not dilated; the first, second, and third articles

are about equal in length; the fourth is nearly twice

as long as the third. The first antennae extend to the end of the third

article of the peduncle of the second antennae. The basal article of the
second pair of antennae is almost inconspicuous; the
second is short; the third and fourth are increasingly
longer than the second; the fifth is about one and a
half times longer than the fourth. The flagellum
consists of eight articles. When retracted the second
antennae extend to the middle of the third thoracic
segment.

The second, third, and fourth segments of the thorax
are longer than the others. The epimera of all the
segments are firmly united with the segments. The
lateral portions of the segments are expanded and the
lateral margins rounded in outline. Three longitud-
inal rows of low tubercles extend the entire length

of the thorax, one median row and one on either side of this. On

each segment these tubercles are situated in a transverse row of three.
The abdomen is composed of one segment, with lateral sutures at the

base, indicating another partly coalesced segment. There are two very

FIG. 420.— SYNIDOTEA
CONSOLIDATA (AFTER
BENEDICT), x 6.

FIG. 421.— SYNIDOTEA
CONSOLIDATA. MAX-
ILLIPED. X 39.

384

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

small tubercles in longitudinal series in the median line at the base
of this segment. ' The sides of the abdomen converge gradually to a
narrow extremity, which has a deep median excavation.

SYNIDOTEA MARMORATA (Packard).

Idotea marmorala PACKARD, Mem. Bost. Soc. Nat. Hist., I, 1867, p. 296, pi. vin,

fig. 6.— WHITEAVES, Canad. Nat., 1875, p. 262.

Idotea bicuspida STREETS and KINGSLEY, Bull. Essex Inst., IX, 1877, p. 108.
Synidotea bicuspida HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 160; Report
U. S. Comm. of Fish and Fisheries, Pt. 6, 1880, p. 352.

Edotea bicuspida MIERS, Jour. Linn. Soc.

London, XVI, 1883, p. 66.
tiynidolea marmorata BENEDICT, Proc. Acad.
Nat. Sci. Phila., 1897, p. 392.— RICHARD-
SON, Proc. U. S. Nat. Mus., XXIII, 1901,
p. 542. — ORTMANN, Proc. Acad. Nat. Sci.
Phila., 1901, p. 156.

Localities. — Labrador; Grand Bank;
Battle Harbor, Labrador.
Depth.— 12 to 129 fathoms.
Body ovate, two and three-eighths
times longer than broad, 8 mm. : 19 mm.
Length of abdomen nearly equal to one-
third the entire length of the body,
6 mm. : 19 mm.

Head with a deep median excavation
or notch. On either side of the median
notch the front is produced anteriorly
and has the lateral portion bend down-
ward, forming an angle with the dorsal portion. The eyes are large
and round, composite in structure, and placed about the middle of the
head at the extreme lateral margins. The first pair of
antennas have the basal articles long, not expanded, and
about equal in length to the second article; the third is
a little longer than the second; the fourth is about as
long as the second. The first antennas extend a little
beyond the third article of the peduncle of the second
pair of antennas. The basal article of the second antennae
is short, and almost inconspicuous from a dorsal view;
the second article is also short; the third is twice as long
as the second; the fourth is one and a half times longer
than the third; the fifth is one and a half times longer
than the fourth. The flagellum consists of fourteen
articles. When retracted, the second antennas extend to
the middle of the fourth thoracic segment. The maxilliped has a
palp of three articles.
The four anterior segments of the thorax are longer than the last

FIG. 422.— SYNIDOTEA MARMORATA
(AFTER BENEDICT), x 2£.

FIG. 423.— SYNJ-
DOTKA MAKMO-
RATA. MAXIL-
LIPED. x 201.

ISOPODS OF NORTH AMERICA.

885

three. The epimera of all the segments are consolidated with the
segments. The lateral margins are almost straight and continuous.

The abdomen is composed of one segment, with lateral sutures at the
base, indicating another partly coalesced segment; it tapers to a narrow
extremity, the apex of which is emarginate.

The legs are more or less alike in structure.

SYNIDOTEA BICUSPIDA (Owen).

Idotea bicuspida OWEN, Crustacea of the Blossom, 1839, p. 92, pi. xxvn, fig. 6.
Idotea pulchra LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, p. 44.
Edotea bicuspida MIERS, Jour. Linn. Soc. London, XVI, 1883, p. 66.
Synidotea bicuspida SARS, Crust. Norwegian North Atlantic Exp., 1885, p. 116,

pi. x, figs. 24-26.— BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp.

391-392.— RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 848; Ann.

Mag. Nat. Hist. (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p.

228.

Localities. — West coast of Alaska and Bering Sea; Kara Sea (Han-
sen).

Depth. — 3i to 81 fathoms, in mud, sand, and gravel; from sponges.

Body ovate, about twice as long as wide, 12 mm. : 25 mm. Length of
abdomen equal to one-third the entire length of body, 8 mm.: 24 mm.

Head with front produced on either side
of a median excavation in a wide border,
the lateral portion of which forms an an-
gle with the dorsal portion. Eyes large,
compound, and situated about the middle
of the head at the extreme lateral margin.
The first pair of antennae have the basal
article short and not dilated; the second
and fourth are about equal in length and
not longer than the first article; the third
is a little longer than any of the others.
The first pair of antennae extend to the mid-
dle of the thiri peduncular article of the
second pair of antennae. The basal article
of the second antennae is inconspicuous
from a dorsal view; the second article is
about as long as the first; the third and
fourth are each about twice as long as the second; the fifth is
nearly as long as the third and fourth together. The flagellum con-
sists of fifteen articles. The second antennae extend to the posterior
margin of the third thoracic segment. The maxillipeds have a palp of
three articles.

The segments of the thorax are subequal along the median dorsal
line. The first is perhaps a little shorter. The epimera of all the
segments are coalesced with the segments, with no indication of a
28689—05 25

FIG. 424.— SYNIDOTEA BICUSPIDA
(AFTER BENEDICT), x 2.

386

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

separation on the first four segments. On the last three segments,
however, there is a faint line indicating this. The lateral margins of
the segments are straight.

The segments of the abdomen are all coalesced to form one large
terminal segment. At the base of this segment is a suture line on
either side, indicating another partly coalesced segment. The terminal
segment is triangulate, with apex excavate, forming two blunt teeth
or angles.

The legs are more or less similar in structure.

SYNIDOTEA LATICAUDA Benedict.

Synidotea lat'uxiuda BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp. 393-394. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 849; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 228.

Locality. — San Francisco Bay.

Body oblong-ovate, a little more than two and a half times longer
than wide; 7i mm. : 17£ mm.

Head wider than long; 2£ mm. :4 mm., with the anterior margin
almost straight. Eyes small, round, composite, and situated at the

sides of the head. The first pair of an-
tennae have the first three articles short
and subequal. The fourth article is two
and a half times longer than any of the
preceding ones. The first antennae ex-
tend to the end of the third article of the
peduncle of the second antennae. The
first two articles of the second antennae
are subequal; the third and fourth are
subequal, and each is
about twice as long as the
second; the fifth article is
one and a half times
longer than the fourth.
The flagellum is composed
of seventeen articles.

When retracted the second antennae extend to the pos-
terior margin of the fifth thoracic segment. The
maxillipeds have a palp composed of three articles.

The first, fifth, sixth, and seventh segments of the
thorax are subequal in length. The second, third,
and fourth are subequal and are longer than the others, each
being one-half millimeter longer than either the first, fifth, sixth,
or seventh segments. The epimera of all the segments are perfectly
and firmly coalesced with the segments, with no indication of a sepa-
ration.

FIG. 425.— SYNIDOTEA LATICAUDA
(AFTEB BENEDICT), x 2i.

FIG. 426.— SYNIDO-
TEA LATICAUDA.

MAXILLIPED. x
15*.

ISOPODS OF NORTH AMERICA.

387

The abdomen is composed of a single segment, with a suture line on
either side at the base. The segment becomes somewhat narrower
toward the extremity, which has a broad but shallow excavation or
notch.

The legs are all similar in structure.

SYNIDOTEA HARFORDI Benedict.

Idotea marmorata HARFORD, Proc. Cal. Acad. Sci., VII, 1877, p. 117.

Synidotea harfordi BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, p. 402. — RICH-
ARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 849; Ann. Mag. Nat. Hist.
(7), IV, 1899, p. 269.

Localities. — Magdalena Bay, Lower Cali-
fornia (Benedict); San Diego Bay, Cali-
fornia.

Depth. — 6f fathoms.
Body ovate, two and two-thirds times
longer than wide, 6 mm. : 16 mm. Length
of abdomen 6 mm.

Front of head without any emargination
or median notch, frontal margin straight.
Head slightly narrower at its anterior end
than at its posterior end. Eyes large and
round, composite in structure, and placed
in the middle of the head at the extreme
lateral margins. First pair
of antennae with the basal
article short, not dilated; the
second and third subequal,
and each only a little longer

than the first; the fourth article is twice as long as
the third. The first pair of antennae extend to the end
of the third article of the peduncle of the second pair
of antennae. The basal article of the second antennae
is short; the second article is twice as long as the first;
the third is a little longer than the second; the fourth
is twice as long as the third; the fifth is one and a
half times longer than the fourth. The flagellum con-
sists of thirty -one articles. When retracted the second
antennae extend to the middle of the seventh thoracic segment. The
maxilliped has a palp of three articles.

The first four segments of the thorax are Ipnger than the last three.
All the epimera of all the segments are firmly united with the seg-
ments. The lateral margins of the segments are straight.

The abdomen is composed of only one segment, with lateral sutures
at the base, indicating another partly coalesced segment. The poste-

FIG. 427.— SYNIDOTEA HARFORDI
(AFTER BENEDICT), x 3|.

FIG. 428.— SYNIDO-
TEA HARFORDI.
MAXILLIPED. x
27*.

388 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

rior portion of the abdomen is rounded with a median excavation or
notch at the extremity.
The legs are more or less similar in structure.

SYNIDOTEA NODULOSA (Kr^yer).

Idotea nodulosa KR0YER, Naturhistorisk Tidsskrift (2). II, 1846, p. 100; Voy. en
Scand., Crust., 1849, pi. xxvi, fig. 2. — REINHAKDT, Gronlands Krebsdyr,
1857, p. 34.— LUTKEN, Crust., Greenland, 1875, p. 150.

Synidotea nodulosa HARGER, Am. Jour. Sci. (3), XV, 1878, p. 374; Proc. U. S.
Nat. Mus., II, 1879, p. 160; Report U. S. Commissioner of Fish and Fisher-
ies, 1880, Pt. 6, pp. 351-352; pi. vi, figs. 33-35.— S. I. SMITH, Report of
Progress of the Geological Survey of Canada, 1880, p. 218.

Edotea nodulosa MIERS, Journ. Linn. Soc. London, Zool., XVI, 1883, p. 67. —

HANSEN, Videnskabelige Meddelelser f ra den natur-
historiske Forening i Kj0benhavn, 1887-88, p. 188.
Synidotea nodulosa BENEDICT, Proc. Acad. Nat. Sci.
Phila., 1897, pp. 398-399.— RICHARDSON, American
Naturalist, XXXIV, 1900, p. 228; Proc. U. S. Nat.
Mus., XXIII, 1901, pp. 541-542.— OHLIN, Bihang
till K. Sv. Vet.-Akad. Handl., XXVI, Afd. iv,
1901, No. 12, p. 29.

Localities. — Southern Greenland; Middle
Ground; latitude 66° 46' north, longitude 54° 10'
west; Halifax; Georges Banks; Arctic Seas and
southward on Pacific coast as far as British Co-
lumbia; Jugor Schar (Hansen); Recherche Bay,
between Reindeer Point and Fox Glacier, West
FIG. 429,-SYNiDOTEA NODU- Spitzbergen (Ohlin).
LOSA (AFTER HARGER). Depth.— § to 111 fathoms (Smith). In stones,

sand, and algse.

Ohlina says of the color: "It is a uniform dark olive-green, some-
times on the epimeres with a trace of purplish spots."

Body oblong-ovate, a little over twice as long as wide, 3i mm. : 7£
mm.

Head wider than long, 1£ mm.:2^ mm., with the anterior margin
slightly excavate. The eyes are small, round, composite, and situated
close to the lateral margin. In front of each eye and arising from
the anterior margin is a conspicuous tubercle. In the median line
on the anterior part of the head are two low tubercles in longitudinal
series, the second one being slightly larger than the first. On either
side of this longitudinal row is a small low tubercle. Back of this
arrangement of tubercles are two low elevations, one on either side of
the median line. Posterior to these elevations is a low ridge. The
first pair of antenna? have the first two articles short and subequal; the
third is one and a half times longer than the second; the fourth is

a Bihang till K. Sv. Vet-Akad. Handl., XXVI, Afd. iv, 1901, No. 12, p. 29.

ISOPODS OF NORTH AMERICA.

389

FIG. 430.— SYNI-
DOTEA NODU-
LOSA. MAXIL-

LIPED. X 33.

about twice as long as the second. The first antennae extend to the
end of the fourth article of the peduncle of the second pair of antennae.
The first two articles of the second pair of antennae are short and sub-
equal; the third and fourth are subequal, and each is
about twice as long as either of the two preceding
articles; the fifth is one and a half times longer than
the fourth. The flagellum is composed of six articles.
The second antennae extend to the middle of the second
thoracic segment. The maxillipeds have a palp of three
articles.

The second, third, and fourth segments of the thorax
are subequal and each is a little longer than any of the
others, which are nearly subequal, the seventh being a
little shorter than the sixth. The epirnera of all the seg-
ments are firmly and perfectly united with the segments.
A faint longitudinal depression marks the place of coalescence on the
last three segments. Each segment has on either side a short distance
from the lateral margin a group of five or six low rugosities.

The abdomen is composed of a single segment with a suture line on
either side at the base. It is 2£ mm. wide by 3 mm. in length and
tapers to a pointed extremity.

All the legs are similar in structure.

SYNIDOTEA L^EVIS Benedict.

Synidotea Isevis BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp. 399-400. — RICH-
ARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 849; Ann. Mag. Nat. Hist. (7),

IV, 1899, p. 269; American Naturalist,
XXXIV, 1900, p. 228.

Localities. — Between Bristol Bay and
Pribilof Islands, Alaska; Bering Sea.
Depth.— 29i to 36 fathoms. From
sponges.

Body narrow, elongate,
a little over three times
longer than broad, 4 mm. :
13 mm. Length of abdo-
men equal to a little more
than one-third the length
of entire body, 5 mm.:
13 mm.

Head excavate between
the lateral angles, with
another median excava-
tion or notch. There is a
very low tubercle just below the median notch. The eyes are large,
round, and composite, and situated about the middle of the head at the

FIG.

431.— SYNIDOTEA
BENEDICT).

(AFTER

FIG. 432.— SYNI-
DOTEA L^VIS.
MAXILLIPED.

X27j.

390

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

extreme lateral margin. The first pair of antennas have the basal article
not enlarged; the second article is about equal in length to the first; the
third and fourth are subequal, and each is a little longer than the second.
The first antennae extend to the middle of the third peduncular article of
the second pair of antenme. The basal article of the second antenna?
is scarce^ conspicuous from a dorsal view; the second, third, and
fourth articles are about equal in length; the fifth is one and a half
times longer than the fourth. The flagellum consists of ten articles.
When retracted the second antennae extend to the middle of the third
thoracic segment. The maxillipeds have a palp of three articles.

The first four segments of the thorax are about equal in length, and
each is longer than any of the last three. The epimera are all entirely
coalesced with the segments. The lateral portions of all the segments
are expanded in rounded processes.

The terminal segment of the body or abdomen is acutely pointed at
the extremity. On either side at the base of the segment is a lateral
suture indicative of another partly coalesced segment.

The legs are more or less similar in structure.

SYNIDOTEA MURICATA (Harford).

Idotea muricata HARFORD, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 117.

Synidotea muricata BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, p. 400. — RICH-
ARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 849; Ann. Mag. Nat. Hist. (7),
IV, 1899, p. 269; American Naturalist, XXXIV, 1900, p. 228.

Locality. — Icy Cape, latitude 70U 15'
north, longitude 162° 55' west; latitude
41° 3' north, longitude 154° 15' west.

Depth. — 25 fathoms.

Body ovate, nearly three times longer
than wide, 8 mm. : 22 mm. Length of
abdomen a little more than one-third
the length of the entire body, 8 mm.:
22 mm.

Head with a deep median excavation
or notch. Between the eyes on the
anterior portion of the head is a group
of four small but very pronounced and
clearly defined tubercles, two in longi-
tudinal series and one on either side of
these in transverse line half way be-
tween the other two. In front of the
• eyes and a little lateral to this group
of tubercles are two very large tuber-
cles, one on either side. Just back of the group of four tubercles are
two groups of low tubercles, irregularly arranged in masses, one group
placed on either side of the median line. Posterior to these masses of

FIG. 433.— SYNIDOTEA MURICATA (AFTER
BENEDICT), x 21.

ISOPODS OF NORTH \MERICA. 391

tubercles is a transverse row of three tubercles, the central one being
in the median longitudinal line and larger than either one of the others.
The eyes are large and round, composite in structure, and situated
about the middle of the head, a little distance from the lateral margins.
The basal article of the first pair of antennae is somewhat enlarged and
almost twice as wide as the second article, which it equals in length;
the third and fourth articles are subequal and each is about twice as
long as the second article. The first antennas extend
to the end of the fourth peduncular article of the sec-
ond antennas. The basal article of the second pair of
antennas is inconspicuous from a dorsal view; the sec-
ond, third, and fourth articles are successively a little
longer than the preceding article; the fifth is about
twice as long as the fourth. The flagellum consists of
thirteen articles. When retracted, the second antennas
extend to the posterior margin of the third thoracic
segment. The maxilliped has a palp of three articles.

The four anterior segments of the thorax are longer FIG 434 _SYNIDO_
than the last three. All the epimera are firmly united TEA MURICATA.
with the segments. In the median longitudinal line ^fXILLI'
is a row of large tubercles, one for each segment,
triangular in shape with acutely pointed extremities. On either
side of the median row of tubercles is a group of six or more tuber-
cles, of which the innermost one is larger and more conspicuous than
any of the others in the group, so that a longitudinal series is formed
of these larger tubercles, one on each segment, and placed one row on
either side of the median row of tubercles. The sides of the segments
are expanded with lateral margins rounded.

The abdomen consists of one segment with lateral sutures at the
base indicating another partly coalesced segment. At the base of the
segment in longitudinal series in line with the median row of tuber-
cles on the thorax are two tubercles. There are about six small
tubercles irregularly arranged on either side of the median line on the
anterior portion of the abdomen. The terminal segment of the body
is pointed at the extremity, the posterior half narrowing rapidly to
an acute tip.

The legs are more or less similar in structure.

SYNIDOTEA PlCTA Benedict.

Synldotea picta BENEDICT, Proc. Acad. Nat. Sci. Phila., 1897, pp. 401-402. — RICH-
ARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 849; Ann. Mag. Nat. Hist.
(7), IV, 1899, p. 269; American Naturalist, XXXIV, 1900, p. 228.

Localities. — Alaska and Bering Straits.
Depth. — 5 to 20 fathoms in sand and rocks.

392

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Body ovate, two and two-thirds times longer than broad, 6 mm. :
16 mm. Length of abdomen three-eighths the length of entire body,
6 mm. : 16 mm.

Head with deep median excavation or notch in front. In the median

FIG. 436.— SYNIDOTEA PICTA (AFTER BENEDICT), x 3. a, TYPICAL FORM, b, VARIETY.

line, just below the frontal notch is a large and prominent tubercle,
narrow and elongate. On either side in line with this tubercle is a
small rounded tubercle. These three tubercles are placed in a trans-
verse line between the e37es. A little- in front of these tubercles, and
halfway between the median notch and the lateral
margins are two tubercles, one on either side in front
of the eye. Back of the three tubercles in tran verse
series are two rugosities, one on either side of the
median line, and posterior to these is a low ridge pro-
duced in a median tubercle. The eyes are large and
round, compound in structure, placed about the mid-
dle of the head and a short distance from the lateral
margin. The first antennae have the basal article short
and not expanded; the second and third articles are
about equal in length; the fourth is a little longer than
the third. The first antenna? extend to the end of the
third peduncular article of the second pair of antenna?.
The basal article of the second antenna? is inconspicu-
ous from a dorsal view; the second, third, fourth, and fifth are each
successively a little longer than the preceding article. The flagellum
consists of ten articles. When retracted the second antenna? extend
to the middle of the third thoracic segment. The maxillipeds have
a palp of three articles.

The first four segments of the thorax are longer than the last three.
In all the epimera are firmly united with the segments. Along the

FIG. 436.— SYNIDO-
TEA PICTA. MAX.
ILLIPED. X 27J.

ISOPOD8 OF NORTH AMERICA. 393

median longitudinal line of the thorax is a row of low tubercles, one
for each segment, which increase in size toward the posterior end of
the series. On either side of this median tubercle is a group of low
tubercles on each segment of the thorax, with six or more tubercles in
each group.

The abdomen is composed of a single segment, with lateral sutures
indicative of another coalesced segment. At the base of the segment,
in line with the median row of tubercles on the thorax, are two
tubercles in longitudinal series. On either side of this series are low
rugosities. The abdomen is acutely pointed at the extremity, becom-
ing more rapidly narrow from the middle of the segment.

The legs are more or less similar in structure.

62. Genus COLIDOTEA Richardson.

Flagellum of second pair of antennae multi-articulate. Epimera of
the four anterior thoracic segments coalesced and firmly united with
the segments, there being no indication of a separation. Epimera of
last three segments of thorax distinctly separated from the segments.
Abdomen consisting of a single segment, with a suture line on either
side at the base indicating another partly coalesced segment. Maxilli-
peds with the palp composed of foura articles.

COLIDOTEA ROSTRATA (Benedict).

Idotea rostrata BENEDICT, Proc. Biol. Soc. Washington, XII, 1898, pp. 53-54.

Colidotea rostrata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 849; Ann.
Mag. Nat. Hist. (7), IV, 1899, p. 270; American Nat-
uralist, XXXIV, 1900, p. 228.

Locality. — San Pedro, California.

Body oblong-ovate, about two and a half times
longer than wide, 5 mm. : 12 mm.

Head wider than long, 2i mm. : 3 mm., with the
anterior margin produced in the middle in a shortros-
trum, rounded at the apex. The antero-lateral an-
gles are prominent, rounded, and extend anteriorly
as far as the rostrum. The eyes are small, rounded,
and composite; they are situated at the sides of the FIG. 437.-coLiooTEA
head. The first pair of antennae have the basal arti- KOSTRATA (AFTER

i i i .1 BENEDICT), x.3.

cle somewhat enlarged; the three following articles
are short and nearly subequal, the terminal one being a little longer.
The first pair of antennae extend to the end of the second article of
peduncle of the second pair of antennas. The second antennae have

a In the Proc. U. S. Nat. Mus., XXI, 1899, p. 843 (key) and p. 849, fig. 22, the
maxilliped is described and figured as composed of two articles. The maxilliped
appears two-jointed from the inner side, and the figure and the examination was
made from that side. In reexamining the material for the present paper, the mistake
was noticed and the correction is herein made.

394

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 438.— COLIDOTEA ROSTRATA. a, LEG
OF SECOND PAIR. X 15}. 6, MAXIL-
LIPED. X 27}.

middle of the lateral margin.

the first article almost inconspicuous from a dorsal view; the second

article is large; the third is shorter than the second; the fourth and

fifth are subequal and each is one and a half times longer than the third.

The flagellum is composed of six and seven articles in one specimen;

of four and five in the other. The palp of the maxilliped is composed

of two articles. When retracted the
second antennee extend to the posterior
margin of the second thoracic segment.
The first segment of the thorax has
the antero-lateral angles produced to
surround the posterior half of the head.
The second segment is a little longer
than the first; the third, fourth, and
fifth segments are the longest; the sixth
is about equal in length to the second;
the seventh is as long as the first. There
is no indication of epimera on any of
the first four segments. The epimera
of the fifth segment are narrow, almost
inconspicuous plates, placed about the
The epimera of the sixth and seventh

segments are wide plates occupying the posterior half of the lateral

margin.
The abdomen is composed of a single segment with a suture line on

either side at the base. Its posterior margin is rounded.

All the legs, with the exception of the first pair, have a small rounded

carina on the basis at the proximal extremity. On the four posterior

pairs of legs this carina becomes more triangular in shape.

63. Genus EDOTEA Gue>in-Meneville.

Flagellum of second antennae rudimentary. Maxillipeds have a palp
composed of three articles. Epimera of all the segments of the thorax
firmly and perfectly united with the segments. Abdomen composed
of a single segment, with lateral incisions or suture lines at the base,
indicating another partly coalesced segment. All the legs prehensile.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS EDOTEA.

a. Antero-lateral angles of head produced into horn-like projections. Lateral mar-
gins of thoracic segments produced into horn-like projections. Four tubercles

situated on the dorsal surface of head Edotea acuta Richardson

a' '. Antero-lateral angles of head not produced into horn-like projections but
rounded. Lateral margins of thoracic segments not produced into horn-like
projections. Two tubercles situated on the dorsal surface of head just back
of the anterior margin.

b. Lateral margins of thorax nearly straight. Lateral incisions at base of termi-
nal segment of body slight. Second pair of antennae extend to the middle
of the fourth article of the antennae of the first pair; second article half as

ISOPODS OF NORTH AMERICA.

395

long as first; third twice as long as second ; fourth a little longer than third ;
the fifth is half the length of the fourth. Two longitudinal lateral rows of
low tubercles extend the entire length of the thorax, one row on either

side along the lateral portions of the segments Edotea triloba ( Say )

bf. Lateral margins of thorax rounded. Lateral incisions at base of terminal
segment of body deep. Second pair of antennre do not quite extend to
the end of the third article of the first pair of antennae; first, second, and
third articles subequal; fourth article a little longer than third ; fifth arti-
cle half the length of the fourth. There are no tubercles on the lateral
portions of the segments of the thorax Edotea montosa (Stimpson)

EDOTEA ACUTA Richardson.

Edotea acuta RICHARDSON, American Naturalist, XXXIV, 1900, p. 228; Proc.
U. S. Nat. Mus., XXIII, 1901, pp. 544-546.

Depth. — 105 fathoms.

Head with the antero-lateral angles produced in knob-like projections.
Four tubercles situated on the surface of the head, two on the anterior
part and two on the posterior part. First pair
of antennae twice as long as the lateral projec-
tions. Second pair not reaching beyond the

FIG. 439. — EDOTEA ACUTA.

FIG. 440. — EDOTEA ACUTA. o, MAXILLIPED.
x 51f. 6, SECOND ANTENNA, x 51|. c,

FIRST ANTENNA. X 51|.

lateral projections, and carrying a rudimentary flagellum composed
of one article.

Thoracic segments subequal. Sides of all the segments produced
into knob-like projections.

Terminal abdominal segment with a transverse depression or groove
on either side of which the lateral margin is indented. Apex of seg-
ment produced as in Edotea montosa.

Color white.

Three specimens were found in the stomach of a cod, taken by the
U. S. Bureau of Fisheries steamer Albatross while cruising in the
Atlantic Ocean from Woods Hole, Massachusetts, to Nova Scotia.

Depth.— 105 fathoms.

Type.— QuA,. No. 23909, U.S.N.M.

396

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 441. — EDOTEA TRILOBA (AFTER HAR-

GER). X 10.

EDOTEA TRILOBA (Say).

Idotea trttoba SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p.- 425. — MILNE
EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 134.

Jsera triloba WHITE, List Crust. Brit. Mus., 1847, p. 97.

Epelys trilobus HARGER with VERRILL,
Report U. S. Commissioner of Fish
and Fisheries, 1873, Pt. 1, p. 571
(277), pi. vi, fig. 28; p. 370 (76).—
VERRILL, Am. Jour. Sci., VII, 1874,
p. 135; Proc. Amer. Assoc., 1874,
p. 372.— HARGER, Proc. U. S. Nat.
Mus., II, 1879, p. 160; Report U. S.
Commissioner of Fish and Fisheries,
1880, Pt. 6, pp. 358-359, pi. vn, figs.
42-43.

Edotea triloba MIERS, Jour. Linn. Soc.
London, XVI, 1883, pp. 70-71.—
RICHARDSON, American Naturalist,
XXXIV, 1900, p. 228; Proc. U. S.
Nat. Mus., XXIII, 1901, p. 545.—
PAULMIER, Bull. New York State
Museum, 1905, p. 177.

Localities. — Egg Harbor, New Jer-
sey; eastern shore of Staten Island;
Savin Rock, near New Haven, Con-
necticut; Noank Harbor, Connecticut; Vineyard Sound, Provincetown,
Massachusetts; near Cape Cod; Gloucester; 30 miles northeast of
Portland, Quohog Bay, Casco Bay, Maine.

Depth. — Surface to % fathom, in low, muddy water; in eelgrass.

Body ovate, a little more than twice as long as
wide, 3 mm. : 7 mm. Length of abdomen equal to
3 mm.

Head produced in the middle of the front, with
two consipcuous tubercles, one on either side of the
median line and close together, situated on the
anterior margin. Antero-lateral angles of the head
prominent and produced in rounded lobes, upon
which the eyes are placed. The first pair of antennae
have the first and second articles equal in length; the
third article is twice as long as the second; the fourth
article is about two-thirds the length of the third,
antennae are longer than the second pair, the second antenna? reaching
only to the middle of the fourth article of the first pair of antennae.
The first, second, and third articles are short and subequal; the fourth
is one and a half times longer than the third; the fifth is just a little
longer than the fourth. The flagellum is minute, composed of one
article, which is one-third the length of the fifth article. When
retracted the first antennae extend only to the middle of the lateral

FIG. 442.— EDOTEA TRI-
LOBA. MAXILLIPED.

The first pair of

ISOPODS OF NORTH AMERICA.

397

margin of the first thoracic segment. The maxilliped has a palp of
three articles.

The third and fourth segments of the thorax are longer than any of
the others and are also the widest. The epimera of all the segments
are united with the segments. The lateral portions of the segments
are laterally expanded, the lateral margins being almost straight.
Two longitudinal rows of low tubercles are placed one on either side
along the lateral portions of the segments, each segment having two
tubercles, one on either side.

All the legs are prehensile; the first are much shorter than any of
the others.

The abdomen is composed of one segment with suture lines at the
base indicating another partly coalesced segment as well as slight
incisions in the lateral margins. A large, rounded prominence is situ-
ated in the median line at the base of the abdomen. This prominence
is followed by a depression, so that in a lateral view the abdomen is
seen to be in the form of two elevations with a deep depression sepa-
rating them. The extremity is also separated off from the second
elevation by another depression. The sides of the abdomen converge
rapidly from a point a little below the middle to a narrow and pointed
extremity.

EDOTEA MONTOSA (Stimpson).

Jdotea montosa STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853, p. 40.
Epelys montosus HARGER with VERRILL, Report U. S. Commissioner of Fish and

Fisheries, Pt. 1, 1873, p. 571

(277); p. 370 (76).— VERRILL,

Am. Jour. Sci., VII, 1874, p. 45;

Proc. Amer. Assoc., 1874, p.

367.— SMITH and HARGER, Trans.

Conn. Acad. Sci., Ill, 1874, p.3.—

HARGER, Proc. II. S. Nat. Mus.,

II, 1879, p. 161; Report U. S.

Commissioner of Fish and Fish-
eries, 1880, Pt.6, pp. 359-360, pi.

vni, figs. 44-47.
Edotea montosa MIERS, Jour. Linn.

Soc. London, XVI, 1883, p. 72.—

RICHARDSON, American Natural-
ist, XXXIV, 1900, p. 228; Proc.

U. S. Nat. Mus., XXIII, 1901, p.

545.

Localities. — Block Island Sound ;

Long Island Sound; Vineyard FIG. 443.— EDOTEA MONTOSA (AFTER HARGER).

Sound; Eastport, Maine; Georges

Bank; Stellwagens Bank; Casco Bay; Bay of Fundy; Halifax, Nova

Scotia; Grand Menan.

Depth. — 8 to 25 fathoms, in mud and fine sand.

Body ovate, a little more than twice as long as wide, 4 mm. : 9 mm.

398 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Length of abdomen equal to one-third the length of the entire body,
3 mm.: 9 mm.

Head with the front triangularly produced and with two low tuber-
cles situated on the anterior margin, one on either side of the median
line. Eyes situated on the antero-lateral lobes, which are rounded.
The first pair of antennae have the first and second articles equal in
length; the third is twice as long as the second; the fourth is but lit-
tle longer than half the length of the third. The first pair of antenna?
is longer than the second, the second pair not quite extending to the
end of the third article of the first pair of antennae. The second
antennae have the first, second, and third articles subequal; the fourth
is a little longer than the third; the fifth is one and
a half times as long as the fourth. The flagellum
consists of one article one-half as long as the fourth
peduncular article. When retracted, the first pair of
antennae extend to the middle of the lateral margin
of the first thoracic segment. The maxilliped has a
palp of three articles.

The third and fourth segments of the thorax are
the widest and longest. The epimera are firmly united
FIG. 444.— EDOTEA with the segments in all the segments. There is a
ILLIPEDA x 38i X Alight linear depression on either side of each segment,
probably indicating the place where -the coalescence
has taken place. The lateral margins of all the segments are rounded.
The first pair of legs are much shorter than the other six pairs.
Alls are prehensile.

The abdomen is composed of a single segment. Another coalesced
segment is indicated by lateral incisions at the base of the abdomen,
and a slight depression extending a short distance inward on either
side from these lateral incisions. A depression in the dorsal surface
occurs just a little below the place where the lateral incisions are
situated, thus giving the abdomen the appearance, in a lateral view,
of two elevations separated by a depression. Another depression
near the extremity of the abdomen separates off the small terminal
point from the large median elevation. The sides of the abdomen
converge to a triangulate extremity.

64. Genus EUSYMMERUS Richardson.

Body elliptical. Palp of maxillipeds composed of four articles.
Second pair of antennae with joints of flagellum all consolidated and
forming a single piece. Eyes dorsally situated.

Lateral margins of thoracic segments expanded, edges straight and
full. Epimera of second, third, fourth, and fifth segments coalesced

ISOPODS OF NOKTH AMEKICA.

899

and firmly united with the segments; those of the sixth and seventh
segments distinct and visible.

Abdomen composed of one segment with suture lines indicative of
another partly coalesced segment.

EUSYMMERUS ANTENNATUS Richardson.

Eusymmerus antennatus RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 852-
853; Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 273-274.

Locality. — Abreojos Point, Lower California.

Depth. — 5i fathoms.

Body elliptical, tapering toward the extremity; surface smooth.

Head three times broader than long, with the antero-lateral angles

prominent. Anterior mar-
gin excavate. Lateral mar-
gins expanded. Eyes situ-
ated dorsally on the extreme
lateral margin in the median

FIG. 445.— EUSYMMEKUS ANTENNATUS. X 8.

FIG. 446.— EUSYMMEKUS
ANTENNATUS. MAX-
ILLIPED. X 27J.

transverse line. First pair of antennae composed of four articles, short,
extending only a little beyond the second joint of the second pair of
antennae. Second pair of antennae consist of six articles, and are
geniculate, the last or flagellar joint being somewhat clavate.

Thoracic segments with the lateral margins expanded. Lateral edges
straight, full. Epimera of second, third, fourth, and fifth segments
coalesced and firmly united with the segments; epimera of sixth and
seventh segments distinct and articulating with segments.

Abdomen composed of only one segment with suture lines indicative of
another partly coalesced segment. It is posteriorly rounded, and tapers
from the base to the extremity.

400 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Legs slender, with dactyli bi-unguiculate.

Color of specimen brown. Lateral edges of thoracic segments
colorless.

One specimen from off Abreojos Point, Lower California, station
2835, was collected by the U. S. Bureau of Fisheries steamer Alba-
tross; depth, 5^ fathoms.

Type.— Cat. No. 22580, U.S.N.M.

65. Genus ERICHSONELLA" Benedict.

Flagellum of second antennae consisting of a single clavate article.
The maxillipeds have a palp composed of four articles The epimera
of all the segments of the thorax, including the first, are distinctly
separated from the segments. The abdomen is composed of a single
segment.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ERICHSONELLA.

a. Surface of body smooth throughout. Outline of body regular. First pair of
antennae short. Terminal segment of body shows but slight traces of a lateral

tooth near its base on either side Erichsonella attenuata (Harger)

a'. Surface of body tuberculated. Outline of body serrate. First pair of antennae
long. Terminal segment of body with a prominent lateral tooth near the base
on either side.
b. Large bifid tubercle on center of head. Median longitudinal row of tubercles

on each thoracic segment Erichsonella filiformis ( Say )

b'. Large tridentate spine on center of head. Median longitudinal row of tuber-
cles on each thoracic segment, and a longitudinal row of tubercles on either
side of median row on first four thoracic segments.

Erichsonella floridana Benedict

ERICHSONELLA ATTENUATA (Harger).

Ericlisonia atlenuata HARGER with VERRILL, Report U. S. Commissioner of Fish
and Fisheries, 1873, Pt. 1, p. 570 (276), pi. vi, fig. 27; p. 370(76).— HARGER,
Proc. U. S. Nat. Mus., II, 1879, p. 160; Report U. S. Commissioner of Fish
and Fisheries, 1880, Pt. 6, pp. 356-357, pis. vi, vn, figs. 36-37.

Erichsonella attenuata RICHARDSON, American Naturalist, XXXIV, 1900, p. 228;
Proc. U. S. Nat. Mus., XXIII, 1901, p. 543.

Localities. — Great Egg Harbor, New Jersey; Noank, Connecticut.

Body narrow, elongate, six times longer than wide, 2 mm. : 12 mm.
Head wider than long, 1£ mm. : 2 mm., with the anterior margin
slightly excavate between the antero-lateral angles. Eyes small, com-
posite, and situated at the sides of the head, halfway between the
anterior and posterior margins. There is a prominent elevation sit-
uated on the head between the eyes. The first pair of antennae have
the basal article large and somewhat dilated; the second article is a
little shorter than the first, and about half as wide; the third and fourth
articles are equal in length, and each is one and a half times longer

a Proposed by Dr. James E. Benedict for the preoccupied Erichsonia.

ISOPODS OF NOKTH AMERICA.

401

FIG. 448.— ERICHSONELLA AT-
TENUATA (AFTER HAR-

GER). X 3.

than the second. The first pair of antennae extend to the middle of the
third article of the peduncle of the second pair of antennae. The first
article of the second antennae is short and inconspicuous in a dorsal
view; the second article is long, about three times longer than the first;
the third is about one and a half times longer
than the second; the fourth is about one and a
half times longer than the third; the fifth is a
little shorter than the fourth. The flagellar ar-
ticle is a little longer than the fourth peduncu-
lar article. The second antennae are 7i mm.
long, or longer than half the en-
tire length of the body. The palp
of the maxillipeds is composed of
four articles.

The first segment of the thorax
is a little shorter than any of the
others except the seventh, both of
which are 1 mm. long. The sec-
ond, third, fourth, and fifth seg-
ments are subequal and each is

about H nun. in length. The sixth segment is about li
mm. long. The epimera are distinctly separated on all
the segments, including the first. They are very small,
almost inconspicuous, placed in the first three seg-
ments on the lateral margin anterior to the median trans-
verse line. In the fourth segment they occupy the middle of the lat-
eral margin. In the last four segments they are placed below the
median transverse line. They give the segments a rather angular
appearance.

The abdomen is composed of a single segment. About one-third
the distance from the base to the posterior extremity is a small lateral
process on either side. Below these processes the sides of the abdo-
men are nearty parallel to a point about i mm. from the extremity,
where they converge to a rounded apex.
The legs are all ambulatory with bi-unguiculate dactyli.

ERICHSONELLA FILIFORMIS (Say).

Stenosoma filiformis SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 424. — MILXE
EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 134.

Idotea filiformis WHITE, Hist. Crust. Brit. Museum, 1847, p. 95.

Erichsonia filiformis HARGER with VERRILL, Report U. S. Commissioner of Fish
and Fisheries, 1873, Pt. 1, p. 570 (276); p. 316 (22).— HARGER, Proc. U. S.
Nat. Mus., II, 1879, p. 160; Eeport U. S. Commissioner of Fish and Fisher-
ies, 1880, Pt. 6, pp. 355-356, pi. vn, figs. 38-41.

Erichsonella filiformis RICHARDSON, American Naturalist, XXXIV, 1900, p. 228:

Proc. U. S. Nat. Mus., XXIII, 1901, p. 543.
28589—05 26

FIG. 447.— ERICH-
SONELLA ATTEN-
UATA. MAXIL-

LIPED. X 20J.

402

BULLETIN -54, UNITED STATES NATIONAL MUSEUM.

FIG. 449. — ERICHSONELLA
(AFTER HARGER).

FILIFORMIS
x 5.

Localities. — Great Egg Harbor, New Jersey; Long Island Sound;
Vineyard Sound, Massachusetts; Puntarasa, Florida; Nantucket Sound;
Thimble Islands; Fisher's Island Sound; Noank, Connecticut; the
Bahamas.

Depth. — ±% to IS fathoms, in sand and gravel, algae, etc.; low water.
Body oblong-ovate, nearly three times as long as wide, 3 mm. : 8

mm. Length of abdomen equal to a lit-
tle more than one-third the length of
the entire body, being 3 mm. long.

Head with front deeply excavate be-
tween the antero-lateral angles. Antero-
lateral angles prominentand acute. Eyes
large, round, composite, and situated
about the middle of the head at the ex-
treme lateral margins. On the dorsal
surface of the head', extending from the
anterior to the posterior margins, is a
prominent elevation bearing two tuber-
cles, one on either side of the median
line, which, in a dorsal view, seem to
project forward beyond the frontal
emargination. The first pair of antenna*
have the basal article large and somewhat
dilated; the second and third articles are subequal, and only a little
shorter than the first; the fourth article is a little longer than the third.
The first antenna? extend to the end of the second article of the
second antenna?. The basal article of the second pair of antenna? is
short; the second is long, equal to the third article
in length, and also equal to the first two articles of
the first pair of antennae; the fourth article is nearly
twice as long as the third; the fifth is shorter than
the fourth, being only about one and a half times
longer than the third; the sixth or flagellar article is
about as long as the fourth. When retracted, the
second pair of antenna? extend to the posterior mar-
gin of the fifth thoracic segment. The maxilliped
has a palp of four articles.

The second, third, and fourth segments of the tho-
rax are a little longer than any of the others, which
arc .subequal. In the first two segments the lateral
parts are produced in very acute processes, one
process on either side of each segment. Just anterior to this process
is the epirneron, which is also acutely produced, but lies underneath
the lateral portion of the segment in a lower plane. The epimeron of
the second segment is bilobate, the upper division, in a dorsal view,
concealing the lower lobe, which is also very acute. The lateral parts

FIG. 450. — ERICHSON
ELLA FILIFORMIS
M A X I LLIPED. X 51|.

ISOPODS OF NORTH AMERICA.

403

of the third and fourth segments are produced on each side into two
acute processes — a larger anterior process and a smaller posterior pro-
cess. The epimera of these segments are inconspicuous, as they are
small and acute, and lie just underneath the lateral parts about the
middle of the segment. In the last three segments the anterior part
of the segment is acutely produced, and the acute epimeron occupies
the remainder of the lateral margin, the posterior half of the lateral
part of the segment not being produced. On each of the first four
segments of the thorax is a small tubercle near the posterior margin
in the median line.

The abdomen is composed of one segment only. About one-third
the distance from the base to the extremity, on either side the lateral
margin is produced in an acute angular process. About two-thirds
the distance from the base to the extremity the sides are angulate.
From this point the lateral margins converge rapidly to a triangulate
extremity, posteriorly rounded.

The legs are all more or less alike in structure.

ERICHSONELLA FLORIDANA Benedict^

Erichsonella floridana BENEDICT, in RICHARDSON, Proc. TJ. S. Nat. Mus., XXIII,
1901, p. 543-544.

Locality.. — -Key West, Florida, among algae below low tide.

The body is long and narrow, broadest at the third and fourth seg-
ments. The head is wider than long. A
rectangular projection extends forward in
front of the eyes. The frontal margin be-
tween the projections is arcuate. The eyes
are lateral, slightly projecting. The antennas
are geniculate. The three distal segments
are approximately the same length. The ter-
minal segment or flagellum is hairy.

A large tridentate spine occupies the center
of the head. The main portion of the spine
has a longitudinally compressed apex, the lat-
eral portions arise at a distance from the base
and point divergently forward, falling short
of the elevation of the main portion.

The third and fourth segments of the thorax
are the longest and widest; the posterior seg-
ments are successively shorter. The lateral
margins of the segments are concave, making
the segmental angles acute. The epimera are
exposed in the concave margins. On the posterior margin of each seg-
ment at the median line is a single spine pointing backward. On the

FIG. 451. — ERICHSOXELLA FLORID-
AXA (AFTER BENEDICT).

«The description that follows is from Doctor Benedict's manuscript.

404 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

first four segments there are single lateral spines on the transverse
median line similar in size, shape, and direction to those of the dorsal
line.

The pleon consists of a single elongated segment with subparallel
sides ending in a blunt apex. On each side of the pleon are two widely
separated angular projections.

Type.—(Mt. No. 15786, U.S.N.M.

66. Genus CLEANTIS Dana.«

Flagellum of second antenn* consolidated to form a single article
or formed of only a restricted number of joints. Epimera of all the
segments of the thorax with the exception of the first distinctly sepa-
rated from the segments. Abdomen composed of more than one seg-
ment, distinct and visible in a dorsal view.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS CLEANTIS.

a. Abdomen composed of four distinct segments, three short ones anterior to the

terminal segment.

b. Maxillipeds with a palp composed of five articles. Posterior portion of abdomen
obliquely truncated, the oblique terminus having a raised margin anteriorly.

Cleantis planicauda Benedict

I/. Maxillipeds with a palp composed of four articles. Posterior portion of abdo-
men flat, in a lower plane than the anterior portion and having a median
groove extending forward some distance into the anterior portion.

Cleantis occidentalis Richardson

a'. Abdomen composed of three segments, two short ones anterior to the terminal
segment Cleantis heathii Richardson

CLEANTIS PLANICAUDA Benedict, b

Cleantis planicauda BENEDICT in RICHARDSON, Proc. IT. S. Nat. Mus., XXI, 1899,
p. 851 (footnote); Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 271-273 (foot-
note); American Naturalist, XXXIV7, 1900, p. 229; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 544.— MOORE, Bull. U. S. Commissioner of Fish and Fish-
eries, XX, Pt. 2, 1902, p. 174, pi. xi, figs. 1-6.

localities. — Pensacola, Florida; Arroyo, Porto Rico.
Body linear, densely granulated, five times longer than broad. Feet
folded beneath out of view from above. Body lined longitudinally by

«The type species of the genus, Cleantis linearis Dana, has the abdomen composed
of four distinct segments, three short ones anterior to the terminal segment. Cleantis
planicauda and Cleantis occidentalis agree in this respect with the type. Cleantis
heathii may have to be removed to another genus, but as only a single specimen
exists of this species, I prefer to let it remain, for the present, where it was originally
placed. The maxillipeds have five joints to the palp in C. planicauda and four
articles in C. occidentalis. In order to be consistent, they should also be separated
into different genera, but inasmuch as I have not examined the type species of the
genus it is not possible to tell which one agrees with the type in this respect, or in fact
if either do. Therefore I have decided for the present to keep both species in the
genus as defined by Dana.

6 The description that follows is from Doctor Benedict's manuscript.

ISOPODS OF NORTH AMERICA.

405

six more or less broken black lines. The lines on the sides are more
distinct than those above.

Head subquadrate, partially immersed in the first thoracic segment
and rounded on the posterior margin; sides parallel, anterior margin

FIG. 452.— CLEANTIS PLANICAUDA (AFTER MOORE), a, GENERAL FIGURE, b, FIRST ANTENNA.
c, SECOND ANTENNA, d, FIRST LEG. e, FOURTH LEG. /, SEVENTH LEG.

emarginate; a deep depression or groove runs from the median notch
to the center of the head. The eyes are situated near the antero-lateral
angle; post-occipital lobe distinct; antennae with six seg-
ments; first very short and nearly immobile; second very
short and stout; the third segment is equal in length to the
second, but not so stout; the fourth and fifth are of equal
length and about one-third longer than the second and third
segments. The terminal segment or flagellum is lighter in
color, and is armed with short bristles. The
length of the antennae is equal to the length
of the head and first two thoracic segments.
The antennulae extend to the middle of the
third segment of the antennae. The first seg-
ment is quadrate; the second subquadrate;
the third is pear-shaped; the fourth segment
is very small. Maxillipeds with the palp
composed of five articles.

The segments of the thorax are nearly
equal in length and breadth, the third and
CLEANTIS fourth being but little longer than the others.
PLANI- The epimera of the second, third, and fourth

CATJDA. _ ' _ •• — »•

segments are very small and can not be seen

from above. On the fifth, sixth, and seventh segments the epimera
are large and project well behind the margin of the segment in the
form of an acute angle.

The pleon is composed of four segments; the first three are very
narrow; the terminal segment is elongated with subparallel sides. A

FIG. 454.— CLEANTIS
PLANICAUDA.
MAXILLIPED.

406

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

marked character of the pleon is its obliquely truncated extremity.
The oblique terminus is perfectly flat, with a raised margin.

The feet of this species, as in the typical species described by Dana,
are in two series. The first is composed of the first three pairs of feet,
which are comparatively stout and increase in length to the third
segment. The second series begins on the fourth segment with a
pair of short feet, which fold transversely, the other pairs are suc-
cessively longer and fold backward. The feet of the second series
are much more slender than those of the first. The dactyli of all are
bi-unguiculate. The carpal and propodal joints are spinulose beneath.

The operculum is not traversed by an oblique line. The sides of the
basal segment are subparallel. The terminal segment is about as broad
as long.

Length, 15 mm.; width, 3 mm.

Type.— Cat. No., 22579, U.S.N.M.

CLEANTIS OCCIDENTALIS Richardson, a

Cleantis occidentalis RICHARDSON, Proc. U. S. Nat.
Mus., XXI, 1899, pp. 850-851; Ann. Mag. Nat.
Hist. (7), IV, 1899, pp. 270-272.

Locality. — Magdalena Bay, Lower Cali-
fornia.

Depth. — 12 fathoms.

Body narrow, elongate; surface smooth.

Head of same width as thoracic segments,
and with a small, median anterior depression.
Eyes lateral. First pair of
antennae consisting of four
joints, reach the middle of
the third joint of the second
pair of antennae. Second pair
of antenna consist of six
joints (five seen from a dorsal
view), the last joint being the
flagellum. Maxillipeds with
the palp composed of four
articles.6

The thoracic segments show
a gradual, though marked,
decrease in length, the first
one being the longest and
somewhat excavate on its anterior margin. The epimera of the second,
third, and fourth segments are short and narrow, reaching but half the

« The type of this species unfortunately has been lost.

& The palp of the maxillipeds was heretofore wrongly represented as composed of
only two articles.

PIG. 455.— CLEANTIS OCCIDEN-
TALS, x 10.

FIG. 456. — CLEANTIS
OCCIDENTALIS.
MAXILUPED. x 39.

ISOPODS OF NORTH AMERICA.

407

length of the segments, while those of the last three segments are
broad, with their posterior angles produced beyond the segments.

The abdomen is composed of four segments, three short ones and
the terminal segment, which bears suture lines indicative of another
coalesced segment. The terminal segment is rounded posteriorly.
The anterior three-fourths of the segment is raised considerably above
the posterior fourth, which is flat, and there is a groove in the median
line on the posterior third of the anterior part of the segment.

The legs are similar to those of the tj^pe species of the genus. The
three anterior pairs increase in length, the third pair being the longest,
and all are directed anteriorly. The fourth pair are very short and
fold across the body. The last three pairs increase in length, the
seventh pair being the longest, and all these are directed posteriorly.
The legs are compact and lie folded on the ventral side and can not be
seen from a dorsal view.

There is but one specimen collected by the U. S. Bureau of Fisheries
steamer Albatross in 1888 at Magdalena Bay, Lower California; depth
12 fathoms.

Type.— Cat. No., 22578, U.S.N.M.

CLEANTIS HEATHII Richardson.

Cleantis heathii RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 851-852;
Ann. Mag. Nat. Hist. (7), IV, 1899, p. 272; American Naturalist, XXXIV,
1900, p. 229.

Locality. — Monterey Bay, Lower California.
Body slender, elongate; surface smooth.
Head with lateral margins straight; anterior margin
slightly excavate. Eyes small, lateral. First pair of
antennse consist of four joints and are a little longer
than half the width of the head. The second pair of
antennae are half as long as the body and are composed
of nine joints, the three terminal ones
forming the flagellum, which can not be
distinguished from the peduncle. Palp
of the maxillipeds composed of four
articles.

Thoracic segments subequal, with nar-
row epimera, those of the second, third,
and fourth segments reaching but half
the length of the segments, the last three
epimera extending the entire length of
the lateral margin.

The abdomen is composed of three
segments, with suture lines indicative of
another. The terminal segment is broadly rounded posteriorly, with
small but acute lateral angles. The sides are almost parallel.

The first four pairs of legs are directed anteriorly ; the last th ree pairs

FIG. 457.— CLEANTIS
HEATHII. MAX-
ILLIPED. X 77$.

FIG. 458.— CLEANTIS

HEATHII. X 6f.

408 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

extend in a posterior direction. There is no perceptible inequality in
length. The unguli are bifid.

Two specimens were sent by Mr. Heath from Monterey Bay, Cali-
fornia.

Type.—Ca,t. No. 22577, U.S.N.M.

IV. ASELLOIDEA or ASELLOTA/*

Legs of the first pair not cheliform. Uropoda terminal, biramous.
Pleopoda exclusively branchial, the first pair in the female generally
transformed into a single operculum covering the succeeding pairs..
Epimera very small or obsolete. All the segments of the abdomen
fused together, although occasionally one or two short segments are
partially visible anterior to the terminal segment.

Pleopoda in female reduced in number, only four pairs being present.

ANALYTICAL KEY TO THE FAMILIES OF ASELLOIDEA. *>

a. First pair of pleopoda in the male not coupled with the second pair; the peduncles

short. Second pair small and situated below the first pair. Third pair in both

sexes forming a compound operculum. First pair in female small.

b. Peduncles of first pair of pleopoda in the male free. First pair of pleopoda in

female consist each of a small peduncle and a single branch. Second pair of

pleopoda in male with branches attached at the distal end of the peduncle,

the inner branch not geniculate, the distal joint having an inner cavity; outer

branch nearly as long as inner branch. Fifth pair of pleopoda with both

branches Family XV. ASELLID^E

bf. Peduncles of first pair of pleopoda fused in the male. First pair of pleopoda in
female with branches fused, forming a small operculum. Second pair of pleo-
poda in male with branches attached at the distal end of the inner margin of
the peduncle, the inner branch geniculate, the distal joint without a cavity;
outer branch much shorter than inner branch. Fifth pair of pleopoda each
consisting of only a single branch Family XVI. STENETRIID^;

«See Sars for characters of superfamily, Crust, of Norway, II, 1899, p. 94.

^ Doctor Hansen (Proc. Zool. Soc. London, 1905, II, Pt. 2) divides the Asellota into
but three families — the Asellidse, the Stenetriidte (a new family proposed by him),
and the Parasellidse — which includes all the other Asellota, and represents the fam-
ilies Munnidse, Janiridse, Desmosomidae, and Munnopsidae. His basis of classifica-
tion is on the structure of the pleopoda alone. Although the structure of the
pleopoda in this group forms excellent characters for a basis of classification, other
characters must not be wholly disregarded, nor must all other characters be made
subservient to this character alone. The Munnidfe, Janiridie, and Munnopsidse form
distinct groups which differ in structures quite as essential as those recognized in
other families of the order. The differentiation of the legs of the Munnopsidee into
an anterior and a posterior series, the division of the thorax into an anterior and a
posterior portion, the two being quite dissimilar, are structural differences whicii can
not be ignored. The genus Pseudarachna Sars has the posterior legs distinctly nata-
tory and fringed with plumose cilia, although the joints are not as much dilated as in
the other genera of the family. The Munnidse form also a well differentiated group
well separated from the Janiridse, the characters of which are given in the follow-
ing key.

I80PODS OF NORTH AMERICA. 409

'. First pair of pleopoda in the male coupled with the second pair, the peduncles
being elongate. Second pair in the male large, the peduncles situated outside
of and coupled with the first pair, forming a large operculum. Third pair in
both sexes not forming an operculum. First pair in female large.
b. Last three pairs of legs not natatory. Eyes usually present.
c Three posterior segments of thorax not sharply marked off from the four
anterior ones, and not smaller. Caudal segment large, shieldlike. Eyes,
when present, lateral or subdorsal, not placed on peduncle-like projections
of the head. First pair of antennae issuing close together. Legs subequal

in length Family XVII. JAXIRID.E

cf. Three posterior segments of thorax, as a rule, sharply marked off from four
anterior ones, and much smaller. Caudal segment more or less vaulted
above, subpyriform. Eyes, when present, placed on the tips of lateral
peduncle-like projections of the head. First pair of antennae placed widely
apart. First pair of legs much shorter than others. Succeeding pairs

more or less rapidly increasing in length Family XVIII. MUNNID^:

b'. Last three pairs of legs natatory, with some of joints flattened and ciliated.
First pair of legs shorter than three following pairs. Second, third, and
fourth pairs very elongate. Eyes wanting Family XIX. MUNNOPSID.S

Family XV. ASELLID^E." .

Body depressed.

Lateral parts of head scarcely expanded; front without rostrum.

Segments of thorax with lateral parts lamellarly expanded. Eyes,
when present, small and laterally placed.

Both pairs of antennae with multiarticulate flagella.

Peduncle of second antennae without scale outside of third joint.
First pair of legs subchelif orm ; six following pairs ambulatory;
dactylus usually uni-unguiculate. Four pairs of pleopoda in female.
The first b are very small, not operculif orm ; each consists of a minute
peduncle and a single rounded lamella. The second pair are wanting.
Three succeeding pairs consist each of two lamellae. Outer lamella of
third pair very large and incrusted, and forming with the correspond-
ing lamella of the opposite side a sort of operculum.

Five pairs of pleopoda in male. First pair small with peduncles free,
short, and branches single. Second pair situated below and not coupled
with first pair, with branches attached to the distal margin of the
peduncle; inner branch not geniculate, its distal joint inflated and con-
taining a large cavity at its obtuse end; outer branch nearly as long
as inner one, its distal joint movable. Third pair similar to that of
female. Last two pairs with both branches present.

a See Sars for characters of family, Crust, of Norway, II, 1899, p. 95, and Hansen,
Proc. Zool. Soc. London, 1905, p. 315.

t> Hansen writes that the first pleopoda of the female in this family are attached
far from each other. This is not true of some of the species of Mancasellus, as shown
in the figures to follow. It is also not characteristic of all the species of Asellus
and* of Ctecidotea, for in several species to be mentioned later I have found the
reverse to be true.

41U BULLETIN" 54, UNITED STATES NATIONAL MUSEUM.

The Asellidas are mostly fresh -water forms. All the members of
the genera, Asellus, Mancasellus, and Csecidotea, are found in fresh-
water streams, wells, pools, and lakes.
The species Janirella Bonnier is, however,
marine.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY
ASELLID.E.

a. Mandibles without a palp. Last six pairs of legs
with dactylus bi-unguiculate.

Genus Mancasellus Harger
a'. Mandible with a three-jointed palp.
b. Eyes present. Body oblong, depressed. Head
small, narrower and shorter than first tho-
racic segment. Caudal segment not longer

than broad Genus Asellus Geoff roy

b'. Eyes wan ting. Body elongate, narrow. Head
large, not narrower than first thoracic seg-
ment, and longer. Caudal segment much
longer than broad.

Genus Cseddotea Packard

67. Genus MANCASELLUS Harger.

Eyes present.

Mandibles without a palp. Last six pairs
of legs with dact}Tlus bi-unguiculate. Body
broad, depressed. Terminal segment of
body broad.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS
MANCASELLUS.

a. Lateral margins of head entire.

Mancasellus brachyurus Harger
a' . Lateral margins of head not entire.
b. Uropoda shorter than terminal segment of

body.

c. Uropoda half as long as terminal segment of
body. Propodus of first pair of legs armed
with two triangular processes. Lateral
margins of head with a deep cleft on either side.

Mancasellus macrourus Garman

c' . Uropoda two-thirds as long as terminal segment of body. Propodus of first
pair of legs armed with one triangular process or three acute teeth. Lateral
margins of head with a large rounded sinus on either side.
d. Propodus of first pair of legs armed with one triangular process. Sides of

sinus on lateral margins of head not meeting Mancasellus tenax (Smith )

d'. Propodus of first pair of legs armed with three acute teeth. Sides of sinus on
lateral margins of head sometimes meeting. Mancasellus tenax dilata Harger
. Uropoda as long as terminal segment of body.

c. Propodus of first pair of legs armed with one triangular process. Second pair
of antenme as long as or longer than the body. Inner branch of uropoda
nearly three times as long as outer branch Mancasellus lineatus (Say)

FIG. 459.— MANCASELLUS BRACHYUBUS
(AFTER GARMAN). a, MANDIBLE, b,
OUTLINE OF ONE SIDE OF HEAD, c,

ONE OF SECOND GENITAL PLATES OF

MALE, d, UROPOD. e, HAND.

ISOPODS OF NORTH AMERICA.

411

</. Propodus of first pair of legs armed with two processes, one triangular and the
other truncate. Second pair of antenna? shorter than the body. Inner
branch of uropoda twice as long as outer branch.

Mancasellus danielsi Richardson

MANCASELLUS BRACHYURUS Harger.

Mancasellus brachyurus HARGER, Am. Jour. Sci. and Arts, (3), XI, 1876, pp. 304-
305.— UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 359.— BOVAL-
uus, Bihang till K. svenska Vet.-Akad. Handl., XI, No. 15, 1886, p. 39.—
RICHARDSON, American Naturalist, XXXIV, 1900, p. 296; Proc. U. S. Nat.
Mus., XXIII, 1901, p. 551.

Localities. — McKee's spring, Lexington, Virginia; Gaylord,
Virginia.
Reported injurious to water cress.

FIG. 460.— MANCASELLUS BRACHYURXJS. a, ABDOMEN WITH UROPODA. x 9}. b, SECOND PLEOPOD OF

HALE. X 27}. C, FIRST PLEOPOD OF FEMALE. X 27}. d, THIRD PLEOPOD OF MALE. X 15}. €, UROPOD.

x 27}. /, FIRST LEG. x 27}. g, THIRD PLEOPOD OF FEMALE, x 15}.' h, FIRST PLEOPOD OF MALE.
X27}.

Body. about two and a third times longer than wide, 6 mm. : 14 mm.

Head a little more than twice as wide as long, 1£ mm. : 3£ mm. , with
the anterior margin slightly excavate between the antero-lateral angles.
The sides of the head are entire. The eyes are small, round, com-

412

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

posite, and .situated a short distance from the lateral margins. The
first pair of antenna? have the basal article short and somewhat dilated;
the second article is a little longer than the first and about half as wide;
the third article is shorter than the second; the flagellum is composed
of six articles. The first antennae extend two-thirds the length of the
fifth article of the peduncle of the second antenna. The second pair
of antennae have the first article very short; the second and third are
subequal and each is but little longer than the first; the fourth arti-
cle is twice as long as the third;
the fifth article is one and a half
times longer than the fourth.
The flagellum is composed of
about fifty articles and extends,
when retracted, to the posterior
margin of the fourth thoracic
segment. - The maxilliped has a
palp of five articles. The palp
of the mandibles is wanting.

The segments of the thorax
are subequal, with lateral mar-
gins straight and entire. The
epimera are not separated off
from the segments, but are per-
fectly coalesced.

The abdomen is composed of
a single large segment, rounded
posteriorly, with a small rounded lobe between the uropoda. The
uropoda are very short, being only 1 mm. long, or one-fourth the length
of the abdomen, which is 4 mm. long. The peduncle is about as long
as broad and shorter than the branches. The inner branch is one and a
half times longer than the peduncle; the outer branch is a little shorter
than the inner branch. In the female the first pleopoda are attached
close together, as shown in fig. 460 c.

The first pair of legs are subchelate. The propodus is armed with a
single large spine on the inferior margin. The dactylus is furnished
with a row of small spines along the inferior margin.

FIG. 461. — MANCASELLVS BRACHYURUS. x 4}.

ISOPODS OF NOBTH AMEEICA.

413

MANCASELLUS MACROURUS Garman.

Mancasellus macrourus GARMAX, Bull. Essex Jnstitute, XXII, 1890, pp. 28-30. —
RICHARDSON, American Naturalist,*XXXIV, 1900, p. 297.— HAY, Proc. U. S.
Nat. Mus., XXV, 1903, pp. 423-i24.

Localities. — Kentucky; Tennessee; John Ross spring, at Rossville,
Georgia; outside NickajackCave; "Old Mill" Devils Backbone, Ham-
ilton County, Ohio; Redbank, Hamilton County, Ohio; Batavia Junc-
tion, Ohio; Westwood, Cincinnati, Ohio (J. Lindahl); Echo River,
Mammoth Cave, "Kentucky.

Body oblong-ovate, nearly two and a half times longer than wide,
5 mm. : 12 mm. Sides of body nearly parallel.

Head three times wider
than long, 1 mm. : 8 mm.,
with the anterior part
slightly narrower than the

FIG. 462.— MANCASELLUS MACKOURUS (AFTER GARMAN). a,
OUTLINE OF ONE SIDE OF HEAD. 6, ONE OF SECOND GENITAL
PLATF.S OF MALE. C, MANDIBLE, d, HAND, e, UROPOD.

FIG. 463. — MANCASELLUS MA
CROURUS (AFTER HAY).

posterior part, the anterior margin slightly excavate on either side
of a small median point, and again emarginate on either side of two
small points, each lateral to the median point. The lateral margin is
cleft on either side near the base, just lateral to the eyes, and the pos-
terior part of the lateral margin below the cleft is produced into a
'small lobe on either side. The eyes are small, round, composite, situ-
ated near the lateral margins. The first pair of antennae have the basal
article large and dilated, and it extends to the end of the second article
of the peduncle of the second pair of antennae; the second article is a

414 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

little longer than the first and half as wide; the third is half as long- as
the second. The flagellum is composed of six articles and extends to

the middle of the fifth article of the peduncle
of the second antennae. The basal article of
the second antennse is short; the second article
is about as long as the first; the third is as
long as the second; the fourth is equal to the
first three taken together; the fifth is one and
a half times longer than the fourth. The
flagellum is composed of forty-three articles
and extends to the posterior margin of the
sixth thoracic segment, and is 9 mm. long.
The maxillipeds have a palp of five articles.
The palp of the mandibles is wanting.

The first segment of the thorax is a
little longer than any of the others, being
li mm. long. The others are subequal and
each is 1 mm. in length. The lateral
margins are straight and entire and the
epimera are not separated off from the

FIG. 464.— MANCASELLTJS MACROU- segments.

RUS (AFTER GARMAN). . , .,

The abdomen is composed of one short seg-
ment, visible only in the middle of the dorsal surface and covered at
the sides by the last thoracic segment, and one large terminal segment,

<• d f /

FIG. 465.— MANCASELLUS MACROURUS. a, FIRST LEG. x 15}. 6, MAXILLIPED. x 27}. c, SECOND MAX-
ILLA, x 27}. d, FIRST MAXILLA, x 27}. e, MANDIBLE, x 27}. /, UROPOD. x 15}.

1SOPODS OF NORTH AM.EEICA.

415

which is 4 mm. in length and has the posterior margin widely rounded.
The terminal segment is 5 mm. wide at the base. The uropoda are
half as long as the terminal abdominal segment. The peduncle is 1
mm. long. The outer branch is 1 mm. long. The inner branch is a
very little longer than the outer branch. In the female the first ple-
opoda are attached close together as in the preceding species.

The first pair of legs are strongly prehensile and have the propodus
greatly dilated and the inferior margin armed with two triangular
processes. All the other legs are ambulatory.

MANCASELLUS TENAX (Smith).

Asellus tenax SMITH, Amer. Jour. Science and Arts, (3), II, 1871, pp. 453-454.
Asellopsis tenax HARGER, Amer. Jour. Science and Arts, (3), VII, 1874, p. 601;

HARGER in SMITH, Report U. S. Commissioner of Fish and Fisheries, 1874,

pp. 659-660, pi. i, fig. 3.
MancaseUus tenax HARGER, Amer. Jour. Science and Arts, (3), XI, 1876, p. 304. —

HAY, Arner. Nat., XVI, 1882, p. 242.— UNDERWOOD, Bull. 111. State Lab.

Nat. Hist., II, 1886, p. 359.— RICHARDSON, American Naturalist, XXXIV,

1900, p. 297.

Localities. — Lake Superior; Indiana; Michigan; Lake Huron.

Body oblong-ovate, a little more than two and a half times longer
than wide, 3 mm. : 8 mm.

Head twice as wide as long, 1 mm. : 2 mm., with the anterior mar-
gin excavate on either side of a small median point. Lateral margins
somewhat expanded in an anterior
and a posterior lobe, the posterior
lobe being produced laterally much
beyond the anterior lobe. Between
the anterior and the posterior lobe
the lateral margin is slightly exca-
vate. The eyes are small, round,
composite, and situated opposite
the excavation a short distance
from the lateral margin. The first
pair of antennas have the first arti-
cle large and dilated; the second
article is half as wide as the first
article and twice as long; the third
article is less than half the length
of the second. The fiagellum is
composed of six articles. The first
antenna? extend to the end of the
fourth article of the peduncle of the second pair of antennae. The
second antennae have the first three articles short and subequal; the
fourth is about as long as the first three taken together; the fifth is
about one and a half times longer than the fourth. The flagellum is
composed of thirty articles, and extends to the posterior margin of the

FIG. 466.— MANCASELLUS TENAX (AFTER
HARGER).

416 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

sixth thoracic segment, when retracted. The maxilliped has a palp of

five articles. The palp of the mandibles is wanting.
The segments of the thorax are subequal with lateral margins entire.

The epimera are not separated from the segments, being entirely

coalesced, with no indication of
a separation.

The abdomen consists of two
short segments followed by a
large terminal one, rounded
posteriorly. There is no lobe
on the posterior margin be-
tween the uropoda. The uro-
poda are shorter than the ter-
minal abdominal segment. The
length of the terminal abdomi-
"• nal segment is 3 mm. The

FIG. 467.— MAXCASELLVS TENAX. a, ABDOMEN WITH , , i ,. , i j • ,

VROPODA. X 11*. 6, FIE8T LEG. X 20*. l6n£th °f th6 UTOpoda IS '2 111111.

The peduncle of the uropoda is

1 mm. The inner branch is as long as the peduncle, being 1 mm. long.
The outer branch is half as long as the inner branch.

The first pair of legs are subchelate. The propodus has a single
triangular expansion on the inferior side. There are numerous spines
on the inferior margin of the propodus and dactylus. All the other
pairs of legs are ambulatory with dactyli bi-unguiculate.

MANCASELLUS TENAX DILATA Smith.

Mancasellus tenax dilala SMITH, Report U. S. Commissioner of Fish and Fisheries,
1874, p. 661.

Locality. — Detroit River.

"The flagellum of the antennula? contains one or two more segments
[than in the preceding species]. The lateral portions of the head and
segments of the body, especially in fully adult specimens, are expanded
so that the outline of the animal is a broader oval. The open sinus in
the lateral margin of the head is a narrow incision, rounded at the bot-
tom, but with the sides sometimes meeting. The propodus in the first
pair of legs is nearly as much enlarged in the males as in A. communis,
and is armed on its palmary margin with three acute teeth, of which
the middle one is the largest." — SMITH.

MANCASELLUS LINEATUS (Say).
Asellus lineatus SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 428. — DE KAY, Nat.

Hist. New York, Pt. 6, 1844, p. 50.— UNDERWOOD, Bull. 111. State Lab. Nat.

Hist., II, 1886, p. 359.
Mancasellus lineatus RICHARDSON, American Naturalist, XXXIV, 1900, p. 297;

Proc. U. S. Nat. Mus., XXIII, 1901, p. 551.

Locality. — South Carolina.

"Body oblong; interior antennae much shorter than the peduncle of
the exteriors; caudal appendices, peduncle cylindrical.

ISOPODS OF NORTH AMERICA.

417

"•Inhabits South Carolina.

"Cabinet of the Academy.

"Body oblong, not distinctly attenuated before; segments subequal,
entire; head at base equal to the preceding segment, a sinus each side
in the middle; eyes prominent, black; antennae, exteriors as long as
the body in one sex; in the other, longer, interiors nearly attaining
the tip of the second joint; hands with a prominent angle on the mid-
dle of the inferior edge, thumb closing on and surpassing the angle,
shorter than the hand; nails somewhat bifid at tip; terminal caudal
segment longitudinally subovate, stj^les elongated cylindrical, equal
to the terminal segment of the body, laciniae very unequal, inner one
nearly thrice the length of the outer one, truncate at tip; color, pale
brown with a doable dorsal brown line, united at the tip of the tail, a
brown line or two each side of the tail. Length nearly one-fourth of
an inch.

"This animal is not an uncommon inhabitant of the swamps in the
forests of South Carolina. It might be referred to the genus Janira
of Doctor Leach. '' — SAY."

MANCASELLUS DANIELSI Richardson.

i . -j

Mancasellm danielsi RICHARDSON, Proc. U. S. Nat. Mus., XXV, 1902, pp. 505-507.

Locality. — Lily Lake, La Porte, Indiana.

Body broadly oval, with lateral parts of
segments widely expanded. Head broader
posteriorly than anteriorly, the posterior part
being as wide as the first thoracic segment.
Lateral margins have a deep and wide incision
which separates the narrower anterior lobes
from the widel}T expanded posterior lobes.
The eyes are opposite these incisions. The
frontal margin is produced in a small median
point, on either side of which is a shallow
depression, followed by another point, in turn
succeeded by a slight depression. The anten-
nulae are short, reaching only to the extremity
of the fourth joint of the peduncle of the
antennae; the fiagellum consists of eight joints.
The antennae are very long, extending nearly
the entire length of the body. The mandible
is without a palp.

The thoracic segments are subequal in length,
are widely expanded, with lateral margins entire.

FIG. 468. — MANCASELLUS UANI-

ELSI. X 3|.

The lateral parts
The caudal segment is narrower posteriori}' than anteriorly, with

« Jour. Acad. Nat. Sci. Phila., I, 1818, p. 428.
•27

418 BULLETIN f>4, UNITED STATES NATIONAL MUSEUM.

the end obtusely rounded. Width of segment at base about one and
one-half times its length.

The caudal stylets are long and slender, the length of the stylet
being equal to the length of the caudal segment. The basal joint is
equal to the length of the fifth peduncular joint of the antenna?. The
outer branch is half as long as the inner branch.

The first pair of legs are subchelate. The propodus is broadly
expanded and armed on the inner margin with a large tooth about
halfway between the base and the articulation of the joint with the
dactylus. Between the tooth and the articulation of the dactylus with

the propodus is a proc-
ess having a blunt, trun-
cate extremity. The
dactylus is provided
with two teeth near the
base on the inner mar-
gin. The carpus is small
and triangular in shape.
The merus is produced
at the upper outer angle.

FIG. 469.— MANCASELLUS DANIKLSI.
MANDIBLE.

FIG. 470.— MASCASELH-S
DANIEISI. MAXILLIPED.

(GREATLY EXLARCKIi. i

The remaining six pairs of legs are similar in
structure and ambulatory in character, with bi-
unguiculate dactyli.

Three specimens wrere found at Lily Lake, La-
porte, Indiana, by Mr. Daniels.

Type.— Cut. No. 25693, U.S.N.M.

This species is more closely related to M. tenax
(Smith) than to any other species of the genus.
It differs, however, from M. tenax in the greater
length of the antenna?, which extend nearly the
entire length of the body, while in M. tena<c the}T
are only half the length of the body; in the
greater width of the caudal segment in proportion to its length,
the width being one and one-half times the length, while in J/.
tenax the width and length of this segment are about equal; in the
greater length of the caudal stylets, which are equal to the length of
the caudal segment, while in M. ti'/m.i- they are only a little longer
than half the length of the caudal segment; in the greater length of
the basal segment of the stylet, its length being equal to the length
of the fifth joint of the peduncle of the antenna1, while in M. tena.i- it
is equal to the length of the fourth joint of that organ (the fourth
joint of the peduncle of the antenna1 in both species being shorter than
the fifth joint); in the greater breadth of the entire body in proportion
to its length, M. tenaa- being narrower in width as compared to its
length; and in the difference in the legs of the first pair, the propodus

ISOPODS OF NORTH AMERICA.

FIG. 471.— MANCASELLUS
DANIELSI. LEG OF FIRST

PAIR. X 14|.

iii J/i tenax being armed with one broad low tubercle (in the sub-
species dilata the propodus is armed with three acute teeth), while in
M. danielsi the propodus is armed with one large
tooth and one bluntly ending, truncate process,
the dactylus being provided with two teeth at
the base, the dactylus in M. tenax being armed
with spines on the inner margin, of which the
distal ones are the larger, and at the end with
a large spine.

This species differs from M. lineatm (Say) in
having antennae somewhat shorter, in the fact
that the propodus of the first pair of legs is
provided wit'h a bluntly ending process between
the long tooth, situated about the middle on
the inferior margin, and the articulation of the
dactylus with the propodus, and in the longer
outer branch of the caudal stylets, it being half
as long as the inner branch, while in M. lineatus
it is only one-third the length of the inner one.

Named for Mr. L. E. Daniels, by whom the specimens were col-
lected.

68. Genus ASELLUS Geoffrey.

Mandibles with a palp. Last six pairs of legs with dactylus uni-
unguiculate. Eyes present.

Body broad, depressed. Head small, narrower and shorter than
first thoracic segment.

Terminal segment of body very broad, not longer than broad.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ASELLUS.

a. Propodus of first pair of legs armed with two triangular processes, one or both

processes sometimes replaced by a strong spine.
b. Uropoda almost as long as the terminal segment of the body. Epimera present

on all the segments of the thorax.

c. Head with lateral margins not produced in a lobe on either side. Second
pair of antennae extend to the posterior margin of the fifth thoracic seg-
ment. First pair of antennae extend to the end of the peduncle of the
second antennae; flagellum composed of fourteen articles.

Asellus communis Say

</. Head with lateral margins produced in a lobe on either side. Second pair of
antennae extend to the posterior margin of the seventh thoracic segment.
First pair of antennae extend to the middle of the fifth article of the pedun-
cle of the second pair of antennae; flagellum composed of nine articles.

Asellus intermedim Forbes

//. Uropoda about half as long as the terminal segment of the body. Epimera not
present on all the segments of the thorax. . „

420 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

c. Epiraera present on the first segment of the thorax only. Head with the lat-
eral margins produced in a lobe on either side. First pair of antenna", with
a flagellum of twelve articles, extend to the middle of the fifth article of the
peduncle of the second antennae. Second pair of antennae extend to the
posterior margin of the fifth thoracic segment. Inner branch of the uro-
poda is as long as the peduncle. Uropoda one-fourth of a millimeter longer
than half the length of the terminal segment of body.

Asellus brevicauda Forbes

e7. Epimera not evident on any of the segments of the thorax. Head with the
lateral margins not produced in a lobe on either side. First pair of antenna',
with a flagellum of seven articles, extend almost to the end of the fourth
article of the peduncle of the second antennae. Second pair of antennae
extend to the posterior margin of the seventh thoracic segment. Inner
branch of uropoda is twice as long as peduncle. Uropoda one-third of a
millimeter shorter than half the length of the terminal segment of the

body Asellus hoppinsc Faxon

a'. Propodus of first pair of legs not armed with two triangular processes.
b. Propodus of first pair of legs furnished with few spines.

c. Second pair of antennae as long as the body. Propodus of first pair of legs
elliptical in outline and armed with one long spine. Terminal segment of

body with median lobe small Asellus attenuatus Richardson

</. Second pair of antennae extend to the posterior margin of the fifth thoracic
segment. Propodus of first pair of legs produced in the male on the infe-
rior margin in a roundly triangulate expansion furnished with three long
spines. Terminal segment of body with median lobe large and conspicu-
ous Aselhts aquaticus (Linnaeus)

b'. Propodus of first pair of legs furnished with numerous short spines or stiff
hairs Asellus tomalensis Harford

ASELLUS COMMUNIS Say.

Asellus communis SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 427-428.

Asellus rulgaris GOCLD, Invertebrata of Massachusetts, 1841, p. 337.

Asellus communis DE KAY, Nat. Hist. New7 York, Pt. 6, 1844, p. 49. — SMITH, Report

U. S. Commissioner of Fish and Fisheries, 1874, Pt. 2, p. 657, pi. i, fig. 4.
Asellus militaris HAY, Bull. 111. State Lab. Nat. Hist., No. 2, 1878, p. 90.
Asellus communis HAY, American Naturalist, XVI, 1882, p. 241. — UNDERWOOD,

Bull. 111. State Lab. Nat. Hist., II, 1886, p. 358.— RICHARDSON-, American

Naturalist, XXXIV, 1900, p. 297; Proc. U. S. Nat. Mus., XXIII, 1901, p.

551.— PAULMIER, Bull. New York State Museum, 1905, p. 178.

Localities. — Schuylkill River, Pennsylvania; Connecticut; Massa-
chusetts; New York; Indiana; Illinois; Michigan; Mississippi; San-
dusky, Ohio (E. L. Moseley); Cincinnati, Ohio; Rhode Island; edge
of Potomac River, Virginia side.

Body oblong-ovate, three times longer than wide, 5 mm. : 15 mm.
Sides of body almost parallel.

Head twice as wide as long, 1^ mm. : 3 mm. , with the anterior mar-
gin excavate. The head is narrower anteriorly than posteriorly, being
only 2 mm. wide in front. The eyes are small, round, composite, and
situated at the sides of the head, halfway between the anterior and the
posterior margins. The first pair of antennae have the basal articles

ISOPODS OF NORTH AMERICA.

421

wide but short, and extending to the end of the second article of the
peduncle of the second pair of antenna?; the second article is one and
a half times longer than the first article; the third article is three-
fourths as long as the second. The flagellum is composed of fourteen
articles, and extends to the end of the peduncle of the second pair of
antenna?. The second pair of antenna? have the first three articles
short and subequal; the fourth article is as long as the first three
taken together; the fifth is one and two-thirds times longer than the
fourth. The flagellum is composed of about ninety articles, and
extends to the posterior margin of the fifth thoracic segment, and is
10 mm. long. The maxillipeds have a palp of five articles. The palp

of the mandibles is composed of

three articles.

The first segment of the thorax

is slightly longer than any of the

others, which are subequal, be-

FIG. 472. — ABELLTJS COMMUNIS (AFTER SMITH).

FIG. 473. — ASELLUS COMMUNIS.
O, FIRST LEG OP MALE. X
lli. 6, UROPOD. x Hi.

ing each 1 mm. in length. The first segment is 1^ mm. long. All
the segments, including the first, have small epimera situated at the
antero-lateral angles of the segments.

The abdomen is composed of two short segments, visible only in
the middle of the dorsal surface, and a large terminal segment, 5 mm.
wide and 4$ mm. long, with the post-lateral angles rounded and the
posterior margin produced in a broad triangular process between the
uropoda. The uropoda are about as long as the terminal abdominal
segment, being 4 mm. long. The peduncle is 2 mm. in length and is
1 mm. wide. The inner branch of the uropoda is broad and tapers to
a narrow, acute extremity. The outer branch is half as wide and is
about two-thirds the length of the inner branch; it is also produced
to a narrow and pointed extremity. In the female the first -pleopoda
are attached close together.

The first pair of legs are prehensile and have the propodus greatly
expanded, and the inferior margin produced in one long and one short
triangular process. All the other legs are ambulatory.

422 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ASELLUS INTERMEDIUS Forbes.

Asellus mtermedlns FORBES, Bull. 111. Museum of Nat. Hist., No. 1, 1876, pp.
10-11.— UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 358.—
RICHARDSON, American Naturalist, XXXIV, 1900, p. 297.

Localities. — Found in hill country of southern Illinois, under stones
in small streams.

Body oblong-ovate, about three times as long as wide, 2 mm.: 7 mm.
Head wider than long, 1 mm.: 1£ mm., with the anterior margin
straight. Sides of head entire, with a small
lobe on either side near the base. E3Tes small,
composite, and situated close to the lateral mar-
gins, halfway between the anterior and the
posterior margins. The first pair of antenna?
have the basal article large and somewhat di-
lated; the second article is half as wide as the
first and about as long; the third article is a
little more than half as long as the second. The
flagellum is composed of nine articles and ex-
tends to the middle of the fifth article of the
peduncle of the second pair of antenna?; The
second antenna? have the first three articles
short and about equal in length; the fourth arti-
cle is about as long as the first three taken
together; the fifth is one and a half times longer
than the fourth. The flagellum is composed of
about fifty articles and extends a short distance
be3Tond the posterior margin of the seventh thoracic segment. The
maxilliped has a palp of five articles. The palp of the mandibles is
composed of three articles.

The first segment of the thorax
has the lateral margins entire,
with the anterior angle not devel-
oped and the epimeral lobe large
and conspicuous and placed an-
tero-laterally. The second, third,
and fourth segments have the
lateral margins entire, with the
antero- lateral angles well devel-
oped, and the epimera small and
almost inconspicuous and placed
antero-laterally. The fifth segment has the anterior part of the lat-
eral margin produced iira well-defined lobe, with the epimeron large
and conspicuous and placed about the middle of the lateral margin,

FIG. 474.— ASELLVS INTERME-

Dirs. x 7.

PIG. 475. — ASELLUS INTERMEDIUS. o, FIRST LEG.
x 39. b, ABDOMEN WITH URPODA. x lit.

ISOPODS OF NORTH AMERICA.

423

*! $//'.•
<^\i$£i^"£-f

just below the anterior lobe. The sixth and seventh segments have the
posterior part of the lateral margin excavate, the anterior part pro-
jecting in a large lobe, and the epimera large and conspicuous and pos-
teriorly situated just below the middle of the lateral margin.

The abdomen is composed of two short segments followed by a large
terminal segment, which has a
large rounded median lobe on
the posterior margin between
theuropoda. The uropoda are
as long as the terminal abdom-
inal segment. The outer branch
is as long as the peduncle. The
inner branch is one and one-
third times longer than the outer
branch.

The first pair of legs are sub-
chelate, and have the propodus
armed on the inferior margin
with a triangular process about
the middle, and below this a strong conspicuous spine. The inferior
margin of the dactylus is furnished with a row of numerous short
spines. All the other pairs of legs are ambulatory.

The types of this species from which the above description is made
were sent to me from the Museum of Comparative Zoology of Har-
vard University.

Specimens collected in the Potomac River near Wasnington of the
same or perhaps a closely related species differ onhr in their larger
size, being -i mm. : 11 mm. ; in having three mo re. articles in the flagel-
lum of the first antennae, the flagellum of the second antenna? having
also a larger number of articles, sixty-three altogether, and in having
the uropoda equal to two-thirds the length of the terminal segment.

Fl'i. 476. — ASELLUS INTERMEDIUS (AKTEK FORBES).

n, ONE OF FIRST PAIR OF GENITAL PLATES OF
MALE, x 51. b, ONE OF SECOND PAIR OF GENITAL

PLATES OF MALE. X 51.

ASELLUS BREVICAUDA Forbes.

Asellus br-evicauda FORBES, Bull. 111. Museum Nat. Hist., No. 1, 1876, pp. 8-10. —
I'XDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 359.— RICHARDSON,
American Naturalist, XXXIV, 1900, p. 297.

Localities. — Found in clear, rocky rills in Jackson and Union coun-
ties, in southern Illinois; small creek emptying into Redfoot Lake,
Tennessee.

Body oblong-ovate, three times longer than wide, 4 mm.: 12 mm.

Head more than twice as wide as long, 1 mm. : 2£ mm. , with the
anterior margin excavate and the antero-lateral angles somewhat
truncate. The eyes are small, round, composite, and situated at the

424

BULLETIN T>4, UNITED STATES NATIONAL MUSEUM.

sides of the head, halfway between the anterior and the posterior
margins. The lateral margin of the head near the base is produced in
a small lobe on either side. The first pair of antenna? have the basal

FIG. 477.— ASELLUS BREVICAUIM (AFTER FORBES), a, HAND OK MALE. X 27. b, ONE OF FIRST PAIR
OF GENITAL PLATES OF MALE. X 51. c, ONE OF SECOND PAIR OF GENITAL PLATES OF MALE. X 25.

article short and broad; the second article is a little longer than the
first and more slender; the third article is about half as long as the
second. The flagellutn is composed of twelve articles. The first

antenna? extend to the middle of the fifth
article of the peduncle of the second pair
of antennas. The first three articles of the
second antenna? are short and subequal ; the
fourth article is as long as the first three
together; the fifth is one and a half times
longer than the fourth. The flagellum is
composed of about seventy-five articles and
extends to the posterior margin of the fifth
thoracic segment and is 6 mm. long. The
maxillipeds have a palp of five articles.
The palp of the mandibles is composed of
three articles.

The segments of the thorax are subequal,
each being about 1 mm. in length. The
lateral margins of all the segments are
straight and entire.

Epimera are present on the first segment
only and are placed at the antero-lateral
angles.

The first two segments of the abdomen are short and visible only in
the middle of the dorsal surface, being covered at the sides by the
seventh thoracic segment. The terminal segment is 4 mm. wide and
3£ mm. long. The post-lateral angles are rounded and the posterior
margin produced in a broadly rounded lobe between the uropoda.
The uropoda are 2 mm. long. The peduncle is 1 mm. long and 1

FIG. 478. — ASELLUS BREVIC-AVDA.
xo.

ISOPODS OF NORTH AMERICA.

425

nun. wide. The inner branch i.s 1 nun. long. The outer branch is
narrower and slightly shorter than the inner branch.

FIG. 479.— ASELLVS BREVICAUDA. a, FIRST LEG. X 27}. >>, UROPOD. X 15}. C, PALP OF MANDIBLE.

x 27}. d, MAXILLIPED. x 27}.

The first pair of legs are strongly prehensile, with the propodus
greatly dilated and the inferior margin produced into two spines. All
the other legs are ambulatory.

ASELLUS HOPPING Faxon.

Asellm hoppime FAXON in GARMAN, Bull. Mus. Comp. Zool., XVII, No. 6, 1888-89,
p. 225-239.

FIG. 480.— ASELLUS
HOPPIN.E (AFTER
FAXON), x 4.

FIG. 481. — ASELLUS HOPPING, a, PEDUNCLE OF SECOND
ANTENNA, x 15}. b, ABDOMEN WITH UROPODA. x 9f.
c, FIRST LEG. x 15}.

'Locality. — Day's Cave, Missouri, in mud under stones.
Body oblong-ovate, a little more than twice as long as wide, 4£ mm. :
mm.

426 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Head twice as wide as long, L£ mm. :3 nun., with the untcrior mar-
gin sinuate on either side of a small median point. Eyes dorsally
situated, with the sides of the-head expanded. Lateral margins entire.
The first pair of antennas have the basal article large and expanded;
the second article is as long as the first article and half as wide; the
third is short, about half as long as the second. The flagellum is com-
posed of seven articles, and extends almost to the end of the fourth
article of the peduncle of the second pair of antenna1. The second
antennae have the first two articles short and subequal; the third is a
little shorter than either of the first two; the fourth article is as long
as the first two taken together; the fifth is one and a half times longer
than the fourth. The flagellum is composed of about fort}T-one arti-
cles. The second antenna? are about 9 mm. long and extend to the
posterior margin of the seventh thoracic segment. The maxillipeds
have a palp of five articles. The palp of the mandibles is composed
of three articles.

The segments of the thorax are subequal, with lateral margins
straight and entire. The epimera are not evident and are not sepa-
rated from the segments.

The abdomen is composed of a single segment. It is rounded pos-
teriorly, with a slight indication of a median lobe between the uropoda.
The uropoda are short, being less than half the length of the abdomen.
The length of the abdomen is 3£ mm.; that of the uropoda is 1£ mm.
The basal segment or peduncle of the uropoda is i mm. long. The
inner branch is 1 mm. long. The outer branch is a little shorter than
the inner branch, being about three-fourths its length.

The first pair of legs are subchelate, with the propopus armed with
two triangular processes on the inferior margin. All the other legs
are ambulatory.

ASELLUS ATTENUATUS Richardson.

Asellus attenuatus RICHARDSOX, American Naturalist, XXXIV, 1900, p. 297; Proc.
U. S. Nat. Mus., XXIII, 1901, pp. 552-553.

Locality. — Washington Ditch, Dismal Swamp, Virginia.

Body narrowed anteriorly, gradually increasing in width backward.

Head narrower than the first thoracic segment, rounded at the sides
with margins entire and a small lobe near the base on either side;
front somewhat excavate for the reception of the antennae. Eyes dis-
tinct, lateral. First pair of antennae as long as the peduncle of the
second pair; first joint short and broad; second joint more slender;
third joint not quite as long as second joint; flagellum composed of
thirteen joints. Second pair of antenna? as long as the body; first,
second, and third joints short, about equal in length; fourth and fifth
joints long; flagellum multiarticulate.

ISOPODS OF NORTH AMERICA.

427

Segments of the thorax with the lateral margins of the first segment
slightly emarginate anteriorly, the emargination being tilled by the

FIG. 482. — ASELH'8 ATTENT ATI'S.

Fli,. 4S3.—ASKLLVS
ATTKNUATUS. LEG
OF THE FIRST PAIR
OF FEMALE.

epimeron; second, third, and fourth segments with the margins entire,
the epimera evident at the extreme anterior angles; the fifth segment
with the posterior two-thirds emarginate, the epi-
meron conspicuous in the
emargination ; the sixth and
seventh segments posteri-
orly emarginate, with prom-
inent epimera.

Terminal segment of the
body about as broad as
long, with a small rounded
lobe in the middle of the posterior margin.

AVhat longer than the terminal segment, extremely slender and cylin-
drical in shape, with both branches nearly equal in length, and longer
than the peduncle. The first pleopoda in the female are attached close
together.

FIG. 484.— ASELLUS ATTENUATUS.
a, MAXILLIPED. l>, MANDIBLE.

The uropoda are some-

428

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The legs of the first pair are slender; the dactylus is serrate with
numerous closely set short spines along the inner margin, the pro-
podus is narrow, oval in shape, and armed in the male with one long
spine.

The color is reddish-brown mottled with white. All the free
margins of the body are fringed with hairs. The lateral margins of

the segments and the caudal segment are
armed with spines. The uropoda and the
legs are spinulose.

A large number of specimens were col-
lected by Mr. William Palmer and Dr. Paul
Bartsch at Washington Ditch, Dismal
Swamp, Virginia.

Type.— Cat. No. 23910, U.S.N.M.

ASELLUS AQUATICUS (Linnaeus).

Oniscus aquaticus LINNAEUS, Fauna Suecica, 2d

ed., 1761, p. 500.

Squilla asellus DE GEER, Memoires pour servir
a 1'histoire des Insectes, VII, 1778, p. 496.
Oniscus aquations O. FABRICIUS, Fauna groen-

landica, 1780, p. 251.

Asellus vulgaris LATREILLE, Hist. Nat. Crust, et
des Insectes, VI, 1803, p. 359; VII, pi. LVIII,
fig. 1.
Idotea aquatica LATREILLE, Encycl. Meth., Pt. 24, 1818, p. 6, pi. cccxxvm, figs.

21-22.
Asellus vulgarw DESMAREST, Consid. Generates sur la classe des Crustacea, 1825,

p. 313, pi. XLIX, figs. 1-2.
Asellus gronlandicus ? KR0YER, Kongelige danske videnskabernes Selskabs

naturvidenskabelige og mathematiske Afhandlinger, VII, 1838, p. 318.
Asellus aquaticus GUERIN-MENEVILLE, Iconographie du Regne animal de Cuvier,
pi. LI, fig. 3. — SABS, Histoire naturelle des Crustaces d'eau douce de la
Norvege, 1867, p. 46, pis. vm-x.

Asellus gronlandicus PACKARD, Mem. Bost. Soc. Nat. Hist., I, 1867, p. 296.
Asellus aquaticus BATE and WESTWOOD, Brit, Sessile-eyed Crust., II, 1868, p. 341. —
BOVALLIUS, Bihang till K. Sv. Vet.-Akad., Handl., XI, No. 15, 1886, pp.
7-10. (See Bovallius for full synonymy. )
Asellus gronlandicus f HANSEN, Videnskabelige Meddelelser fra den^naturhistoriske

Forening i Kj0benhavn, 1887-88, p. 190.
Asellus aquaticus G. O. SARS, Crust, of Norway, II, 1899, p. 97.

Localities.— Greenland (Fabricius); Greenland (Kr0yer); Labrador
at Square Island and Hopedale (Packard); ponds and streams all over
Europe.

FIG. 485.— ASELLUS^ ATTENUATUS. a,

LEO OF THE FIRST PAIR. X 39.

b, THIRD PLEOPOD OF FEMALE.
x 20|. e, FIRST PLEOPOD OF FE-
MALE.

ISOPODS OF NORTH AMERICA. 429

This species has three times been recorded from Greenland.
O. Fabricius recorded it as Oniscus ayuaticus. Kr0yer records it as
Asellus gronlandicus f He says of it:rt

This species is without doubt the one mentioned by Fabricius under No. 227, and
which he himself did not see, although it does not appear to be rare. It approaches
so closely our Asellus rulgaris that it is extremely difficult to find sufficient distin-
guishing characters in the two. Nor am I entirely certain that I have found such
distinguishing characters, and therefore hesitatingly give this animal as a distinct
species, although it seems almost incredible to me that the fresh waters of both
Europe and Greenland should be inhabited by the identical species of Asellus.

Hansen b says of Asellus granlandicus that it is probably not different
from Asellus aquations.

Packard records it from Greenland as Asellus gronlandicus.

Specimens collected in Greenland, sent to me from the Museum of
Comparative Zoology at Harvard University and labeled Asellus
gronlandicus^ do not differ in any respect from Asellus aquaticus as
described and figured by G. O. Sars.

Body narrow, elongate, nearly three times as long as wide, 3 mm:
8£ mm., narrower anteriorly and becoming wider posteriori}". 3 mm.
is its greatest breadth.

Head about twice as wide as long, 1 mm: 2 mm., with the anterior
margin slightly excavate. Lateral margins entire, with a small lobe
on either side near the posterior margin. Eyes small, distinct, com-
posed of only three or four ocelli and situated close to the lateral
margin, halfway between the anterior and posterior margins. The
first pair of antennae have the basal article large and dilated ; the second
article is half as wide and but little longer; the third article is two-
thirds the length of the second. The flagellum is composed of eleven
articles and extends to the end of the peduncle of the second pair of
antennas. The second pair of antennas have the first two articles short
and subequal; the third is one and a half times longer than the second;
the fourth article is nearly as long as the first three taken together;
the fifth is one and two-thirds times as long as the fourth. The flagel-
lum is composed of about forty-four articles, and extends to the pos-
terior margin of the fifth thoracic segment. It measures 6 mm. in
length.

The first segment of the thorax has the epimera conspicuous and
situated in the antero-lateral corners. In the second and third seg-
ments they are small and almost inconspicuous lobes situated at the
antero-lateral corners of the segments. In the fourth segment they
are small and inconspicuous and situated just below the antero-lateral

• o Kongelige danske videnskabernes Selskabs naturvidenskabelige og mathematiske
Afhandlinger, VII, 1838, p. 318.

& Videnskabelige Meddelelser fra den naturhistoriske Forening i Kj0benhavn,
1887-88, p. 190.

430 MI'LLETIN 54, FNITKI) STATES NATIONAL Ml'SFFM.

Frc. 486. — AsEi.i.r.s AQUATICUS (AFTER SAKSI. «, DORSAL VIEW OK KEMAI.E. 1>, FIRST AND SECOND

ANTENN.K. 0, UPPER LIP. d, LOWER LIP. e, LEKT MANDIBLE. /, FIRST MAXILLA, g, RIGHT MAN-
DIBLE, h, PALP OF MANDIBLE. I, SECOND MAXILLA, j, LEFT MANDIBLE, k, MAXILLIPED. /, FIRST
PLEOPOD OF FEMALE. TO, FIRST LEG. «, SECOND PLEOPOD OF MALE. O, FIRST PLEOPOI) OF MALE.

p, FOURTH PLEOPOD OF FEMALE, q, UROPOD. r, ABDOMEN OF FEMALE. *, FIRST LEG OF MALE.
( FIFTH PLEOPOD OF FEMALE, u, THIRD PLEOPOD OF FEMALE.

ISOPODS OF NORTH AMERICA. 431

angle of the segment. In the fifth segment they are large and con-
spicuous and situated about the middle of the lateral margin. In the
sixth and seventh segments they are large and conspicuous and sit-
uated in the posterior corners of the segments.

The abdomen is composed of two short segments, followed by the
large terminal segment, which has the posterior margin produced in a
large triangular median lobe between the large post-lateral expansions.
The peduncle of the uropoda is twice as long as wide. The branches
are of equal length and two and a half times longer than the peduncle.

The first pair of legs are subchelate. The propodus in the male has
the inferior margin near the proximal end produced in a rounded
expansion, bearing three long spines. The inferior margin of the
dactvlus is furnished with spines along the entire margin. All the
other legs are ambulatory, with dactylus uni-unguiculate.

ASELLUS TOMALENSIS Harford.

Asellus tomalensis HARFORD. Proc. Cal. Acad. Sci., VII, Pt. 1, 1877, pp. 54-55. —
RICHARDSON, Proc. IT. S. Nat. Mus., XXI, 1899, p. 856; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 322; American Naturalist, XXXIV, 1900, p. 297;
Harriman Alaska Exp., Crust., X, 1904, pp. 224-226; Proc. U. S. Nat.
Mus., XXVII, 1904, pp. 668-669.— HOLMES, Proc. Cal. Acad. Sci. (3), III,
1904, pp. 321-323, pi. xxxvn, figs. 39-42.

Localities.— Tomales Bay, California; Lake Washington, Seattle.
The description of this form is given in the following concise
manner:

Head a little transverse, narrower than the body. Upper antenna not reaching
to the extremity of the peduncle of the lower. Flagellum of lower antennae longer
than its peduncle. Body narrow in front, gradually increasing in width toward the
tail. Peduncle of caudal appendages more than half the length of the terminal fila-
ments. Length ^ inch.

The description is from a single specimen.

Eight specimens of a species of Asellus were collected by the Harri-
man Alaska Expedition at Lake Washington, Seattle. I have referred
them to the above species, being unwilling to describe a new species
of Axellux from a locality so close to that from which A. tomalensis
was found, when so little is known about A. tomalensis. Some of the
specimens were sent to Dr. William PI Ritter for comparison with
the type and only specimen of ^-1. tomalensis in the collection of the
California Academy of Sciences. The result of his comparison is
given in the following quotation from his letter:

About the only difference that I am able to make out is in the fact that the inner
ramus of the sixth pleopods (uropods?) of A. tomalensis is about half as long as the
exdpodite, and that neither is armed with a tuft of hairs at the tip. This is the case
with the one appendage present, but its mate is gone. It is possible that the hair
tuft may have been broken off, but the tips of the rami themselves are perfectly
smooth. They show no evidence of having lost anything. The fact, how'ever, that

432

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the general hairiness of the Academy specimen is about the same as that of your
specimen makes me suspicious that the tuft referred to has been removed. The
antenna* and antennules differ in no essential respect, so far as I can see. The
chelipeds of the type specimen I am, unfortunately, unable to find.

Description. — Body narrow, elongate,
gradually widening somewhat from the
anterior to the posterior extremity.

Head but little narrower than the first
thoracic segment and about twice as wide
as long; frontal margin slightly excavate
and without median process between the
antennae; lateral margins straight, with a
small lobe on either side near the base of
the head. Eyes lateral, situated in the
median transverse line. First pair of an-
tenna? reach the extremity of the peduncle
of the second pair of antennas; flagellum
consists of about ten joints.
Second pair of antenna? are
about two-thirds the length of
the body; the flagellum con-
sists of about 55 joints.

The first segment of the
thorax has the epimeral lobes
distinct and visible from a
dorsal view at the antero-lat-
In the second and third seg-
ments the ephnera are bilobed and occupy the anterior
portion of the lateral margins. In the fourth segment the epimeron
is a small lobe situated at the antero-lateral extremity
of the segment. In the fifth and sixth segments the
epimeron is a small lobe about the middle of the lateral
margin. In the seventh segment it has more of a pos-
terior position on the lateral margin.

The abdomen is broad, with the sides nearly parallel.
Posteriorly it is produced in the center in a large tri-
angularly shaped lobe with rounded apex. The uro-
poda are slender appendages; the peduncle is somewhat
shorter than the branches. The inner branch is about
a fifth longer than the outer branch. The margins of
all the segments, the uropods, and the legs are fringed
with hairs.

The legs of the first pair are subchelif orm ; the pro-
podus is elliptical in outline, with the inferior margin straight. The
other legs are similar and ambulatory in character.

FlG. 487.— ASELLUS TOMALENSIS. X 9.

eral angles of the segment.

FlG.488.— ASEL-
LUS TOMALEN-
S I S. M A N -
DIBLE.

FlG. 489.— A8ELLU8
TOMALENSIS. LEG
OF FIRST PAIR.
X 20i.

ISOPODS OF NORTH AMERICA. 433

The color of the species is a light brown, somewhat mottled.

Prof. S. J. Holmes describes the type specimen" of this species,
which I have not been fortunate enough to obtain for examination.
The description given above is from specimens collected at Lake
Washington, Seattle, and which I still do not think differ from the
type as described by Professor Holmes in any essential characters.
The type specimen is imperfect, one uropod being gone and the other
with the inner branch partly regenerated. The specimens which
Professor Holmes collected at Point Arena have "caudal stylets
shorter than the abdomen," as is also true of my specimens, and
he considers the Point Arena specimens as young specimens of this
species.

A slight difference in the length of the antennae often occurs among
the individuals of a species where the flagellum is multi-articulate.
It may be due to a difference in sex or a difference in age.

The only important difference is in the fact that the three last seg-
ments of the thorax are entire in the type, as described by Professor
Holmes, whereas they are posteriorly notched in the specimens from
Lake Washington. The margins of the segments often appear entire
when the emargination is filled by the epimeron, so that without
having seen the type I would be unwilling to give a new name to the
specimens from Lake Washington, which are otherwise in so close
agreement with Professor Holmes's description.

69. Genus C^ECIDOTEA Packard.

Body narrow, elongate. Eyes wanting. Head large, not narrower
than the first thoracic segment and longer. Terminal segment of body
much longer than broad.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS C^CIDOTEA.

a. Propodus of first pair of legs armed with one or more triangular processes.

b. Propodus of first pair of legs armed with two long triangular processes and three
short ones. Uropoda about as long as the terminal segment of the body; the
inner branch of the uropoda is two-thirds as long as the peduncle; the outer

branch is two-thirds as long as the inner branch dvcidotea stygia Packard

//. Propodus of first pair of legs armed with a triangular process near the distal
end and with a long spine at the proximal extremity. Uropoda shorter than
terminal abdominal segment, about one-half its length; the peduncle is as
long as the inner branch; the outer branch is one- fourth shorter than the inner

branch Cxcidotea nickajackeims Packard

a'. Propodus of first pair of legs not armed with triangular processes, but edged

inside with spines.

'b. First pair of antennae, with flagellum composed of eleven articles, extend one-
third the length of the fifth article of the peduncle of the second antenna-.

"Proc. Cal. Acad. Sci. (3), III, 1904, pp. 321-323.

28589—05 28

434

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Second antennae longer than the body; flagellum composed of about eighty-
six articles < ';r<-i<l»ti'<i rlclmrdsonx Hay

!/. First pair of antennae, with flagellum composed of five articles, extend half the
length of the peduncle of the second antenna'. Second pair of antenna*
"probably as long as body;" fiagellum is composed of "at least forty seg-
ments " deddotea srnitJmi Ulric-h"

C^CIDOTEA STYGIA Packard.

Csecidotea slygia PACKARD, Amer. Naturalist, V, 1871, p. 752, figs. 132-133.
Cseridotea microcephala COPE, Amer. Naturalist, VI, 1872, p. 411, fig. 109; 3d and

4th Report Geol. Indiana, 1872, pp. 163, 174-175. — SMITH, Amer. Naturalist,

VII, 1873, p. 244.
Ciecidotea »tygia PACKARD, 5th Report Peabody Acad. Science, 1873, p. 95. —

SMITH, Report U. S. Commissioner of Fish and Fisheries, 1874, p. 661.
Asellus sti/gius FORBES, Bull. 111. State Lab. Nat. Hist., No. 1, 1876, p. 11.
Gecidotea ntygia HUBBARD, Amer. Entomologist, new series, I, 1880, pp. 36, 71*.

80, fig. 10.

Asellus stygius UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 359.
C&cidotea stygia RICHARDSON, Amer. Naturalist, XXXIV, 1900, p. 297; Proc.

U. S. Nat. Mus., XXIII, 1901, p. 553.

Localities. — Graham's Spring, Lexington, Virginia; also Mammoth
Cave, Kentucky, and wells in Indiana; Illinois
in deep wells; ''Richardson's Spring," Mam-
moth Cave, Kentucky.

Body narrow, elongate, five times longer than
wide, 2 mm.: 10 mm.

Head a little wider than long, 1 mm. : 1£ mm.,
with the anterior margin slightly excavate.
The eyes are absent. The first two articles of
the first pair of antennse are subequal in length,
the second one being more slender than the first;
the third article is about two-thirds the length
of the second. The flagellum is composed of
about twelve articles. The first three articles
of the second antenna? are short and about equal
in length; the fourth is about as long as the
first three together; the fifth is one and a half
times longer than the fourth. The flagellum
is composed of about seventy articles. The
nmxilliped has a palp of five articles. The
palp of the mandibles is composed of three
articles.

The segments of the thorax are loosely articu-
lated. The lateral margins of the segments are not contiguous, but are

FlG. 490. — C^KCIDOTEA STYGIA
(AFTER HAY).

" The first pair of legs in drcidotea smithsi! are not described in detail; they are
simply spoken of as being "subchelate." From the figure, however, they appear
to be armed not with triangular processes, but furnished instead with spines on the
inferior margin of the propodus.

ISOPODS OF NORTH AMERICA.

435

separated by a deep and wide incision between the segments. The
segments are about equal in length. Epimera are present on all
the segments. On the first three they .are small and narrow plates
placed just below the antero- lateral angles. On the fourth segment

they occupy the middle of the
lateral margin. On the last
three segments they are post-
laterally placed.

The first two segments of the
abdomen are short. The third
or terminal segment is narrow,

FIG. 491. — C^ECIDOTEA 8TYGIA. a, TERMINAL SEG-
MENT OF BODY AND UEOPODA. X 20J. 6, MAX-
ILLIPED. X 38 j. C, FIRST LEG. X 20i- (I,

MANDIBLE, x 38f.

elongate, the posterior margin being

almost truncate, the median terminal FIG. 492.— (AFTER HAY.) a, ABDOMEN AND
lobe being broadly rounded and not
prominent, almost vanishing. The
terminal segment is one and a half times
longer than wide, 2 mm. : 3 mm. The
uropoda are about as long as the termi-
nal segment. The peduncle is long and
narrow and is about two-thirds as long
as the terminal segment. The inner
branch of the uropoda is two-thirds as

long as the peduncle. The outer branch is two-thirds as long as the
inner branch. In the female the first pleopoda are attached close
together.

The first pair of legs are prehensile, with propodus greatly dilated
and armed on the inferior margin with two long triangular processes
and three short ones. All the other legs are ambulatory.

UROPODA OF C^OIDOTEA STYGIA (MAM-
MOTH CAVE), b, UROPOD OF C.ECIDOTEA
NICKAJACKENSIS (METCALF, GEORGIA). C,
ABDOMEN AND UROPODA OF C^CIDOTEA
RICHARDSON.*; (NlCKAJACK CAVE). (I,
GNATHOPOD OF C^ECIDOTEA NICKAJACKEN-
SIS (METCALF, GEORGIA), e, FIFTH LEG OF
C^ECIDOTEA NICKAJACKENSIS (METCALF,
GEORGIA). /, FIFTH LEG OF OECIDOTEA

RICHARDSON^. (NlCKAJACK CAVE). g,

FIFTH LEG OF CAICIDOTEA STYGIA (MAM-
MOTH CAVE).

436

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

CyECIDOTEA NICKAJACKENSIS Packard.

nickajackensis PACKARD, Amer. Naturalist, XV, 1881, p. 879. — UNDER-
WOOD, Bull. State Lab. Nat. Hist., II, 1886, p. 359.— RICHARDSON, Amer.
Naturalist, XXXIV, 1900, pp. 297-298.— HAY, Proc. V. S. Nat. Mus., XXV,
1903, pp. 426-429.

Localities. — Tennessee; Metealf, Georgia.

Body narrow, elongate, about seven times
longer than wide, 1 mm. : T mm.

Head wider than long, with the anterior mar-
gin excavate. Sides of head entire. Eyes ab-
sent. First pair of antennae with the first article
about twice as long as broad; second article a
little longer than the first; third article one-
third the length of the second. The flagellum
is composed of nine articles. The second pair
of antenna; have the first two articles short and
about equal in length; the third is about one-
half the length of the second; the fourth is as
long as the first three taken together; the fifth
is one and a half times as long as the fourth. The
flagellum is composed of
fifty-three articles, and is
3£ mm. long. The palp
of the maxilliped is com-
posed of five articles.
The mandible has a palp
of three articles.

The first four segments
of the thorax are about
equal in length. The fifth
is a little shorter. The

sixth and seventh are about one and a half
times longer than the fifth. The first three
segments have the epimera present as a very
small and almost inconspicuous lobe situated on
the anterior part of the lateral margin. The
fourth segment has the epimeron situated about
the middle of the lateral margin. The last
three segments have the epimera posteriorly
situated.

The abdomen is composed of three segments; two short ones, sub-
equal in length, anterior to the long, terminal one. The terminal seg-
ment is about twice as long as wide, 1 mm. : 2 mm. It is subquadrate
in shape, with the post-lateral angles rounded and a very slight indi-
cation of a median lobe. The uropoda are shorter than the terminal

Fl«. 493.— C<ECIDOTEA NICKA-

.IACKEXSIS (AFTER HAY).
METCALK, GEORGIA, SPECI-
MEN.

FIG. 494. — C.SCIDOTEA NICKA-
JACKENSIS (AFTER PACK-
ARD), a, FIRST ANTENNA.
6, UROPODA.

ISOPODS OF NORTH AMERICA..

437

segment, about one-half its length. The peduncle is about as long as
the inner branch. The outer branch is about one-fourth shorter than
the inner branch.

The first pair of legs are subchelate. The propodus is armed on the
inferior margin with a triangular process near the distal end and with
a long spine at the proximal extremity. The dactylus is armed with
numerous spines along the inferior margin. All the other legs are
ambulatory, with dactyli uni-unguiculate.

C^ECIDOTEA RICHARDSON^E Hay.

Ciecidotea richardsanie HAY, Proc. Biol. Soc. Washington, XIV, 1901, pp. 179-180;
Proc. U. S. Nat. Mus., XXV, 1903, pp. 424-428.

Locality. — Nickajack Cave, Tennessee.

Bod}7 narrow, elongate, four and a half times longer than wide, 2
mm. : 9 mm.

Head a little wider than long, with the anterior margin slightly
excavate. Sides of head
entire. Eyes wanting.
The first pair of antennae
have the first article about
twice as long as wide; the
second article is as long as
the first, but half as wide;
the third article is one-
third the length of the sec-
ond; the flagellum is com-
posed of eleven articles
and extends one-third the
length of the fifth article
of the peduncle of the sec-
ond pair of antenna1. The
second pair of antenna?
have the first two articles
equal in length; the third
article is about half the
length of the second; the
fourth is as long as the
first three together; the
fifth is one and a half times
as long as the fourth. The
flagellum is composed of
about eighty-six articles.

body. The maxillipeds have a palp of five articles,
mandibles is composed of three articles.

The first four segments of the thorax are subequal in length. The
fifth is a little shorter. The sixth and seventh are subequal and each

FIG. 495. — C.ECIDOTKA RICHARDSON.E (AFTER HAY), a, DOR-
SAL VIEW, x 6. 6, FIRST ANTENNA, r, SECOND ANTENNA.
d, MANDIBLE, e, FIRST MAXILLA. /, SECOND MAXILLA.
y, MAXILLIPED. h. UPPER LIP. i, LOWER LIP. j, GNATH-
OPOD.

The second antennne are longer than the

The palp of the

438 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

is a little longer than the fifth. The epimera of the tirst three seg-
ments are small and placed antero-laterally. That of the fourth seg-
ment is also small and is placed about the middle of the lateral margin.
Those of the last three segments are small and post-laterally placed.

The abdomen is composed of three segments, two short segments
anterior to the terminal segment. The terminal segment is 2£ mm.
long and 2 mm. wide. Its posterior margin is straight, with the post-
lateral angles rounded. The peduncle or basal article of the uropoda
is 2£ mm. long, or as long as the terminal segment of the abdomen.
The inner branch is 2 mm. long and is twice as long as the outer
branch.

The first pair of legs are subchelate. The propodus is armed on
the inferior margin with about four long spines. The dactylus is
armed with a row of about eleven spines along the inferior margin.
All the other legs are ambulatory, with dactyli uni-unguiculate.

CjECIDOTEA SMITHSII Ulrich.

Csecidotea smithsii ULRICH, Trans. Am. Microscopical Soc., XXIII, 1902, p. 93,
pi. xvi, figs. 10-18.

Locality. — Subterranean stream near San Marcos, Texas; Artesian
well at San Marcos, Texas.

"Body of loosely jointed segments. Head as in C. stygia Packard.

FIG. 4%. — C.HCIDOTEA SMITHSII (AFTER ULRICH). d, BASAL SEGMENT OF UPPER ANTENNA, SHOWING
AUDITORY SPINES. 6, MAXILLA (?) (ACCORDING TO ULRICH). C, UPPER ANTENNA. (/, PORTION OF

BODY, e, FIRST LEG. /, PORTION OF LOWER ANTENNA, g, BASAL PORTION OF SAME. A, LABRUM.
i, SECOND LEG.

No trace of eyes. Inner antennae short, not more than half as long
as basal portion of outer antenna?. Flagellum of inner antennae con-
sists of five segments, the second one-fourth of first, remaining ones

ISOPODS OF NORTH AMERICA. 439

longer. Last segment of fiagellum with a spine more than twice
length of segment, beside which there is an olfactory club two-thirds
as long; another somewhat shorter olfactory club on penultimate
segment. Last segment of the basal portion of the inner antennae
provided with three spines, as in C. stygia. Outer antennae probably
as long as body. Basal portion of five segments, the first three short
and thick, the fourth and fifth much longer and more slender. The
flagellum consists of at least forty segments. Mouth parts essentially
as those of C. stygia. Legs long and slender, first pair subchelate,
remaining ones with a weak claw. Inferior margin of the body seg-
ments beset with short spines. Size, very small, probably not over
3 mm. in length. Color, white.

• '"Habitat. — Subterranean stream near San Marcos, Texas. Collected
by Dr. C. H. Eigenmann, from the U. S. Fish Commission well.

"The above description is from a fragment. The telson and caudal
appendages were gone, also part of the outer antennae. The writer
hopes soon to receive the material which will enable him to fill out the
gaps in the above diagnosis.

"In honor of Dr. H. M. Smith, in charge of scientific inquiry of
the U. S. Fish Commission." — C. J. ULRICH/'

Family XVI. STENETRIID^.6

Eyes present, large, sub-dorsal. Body depressed, elongate.

First pair of antennas with flagellum composed of several articles.
Second pair of antennae with multi-articulate fiagellum.

Mandibles with palp.

Lateral margins of thorax but little produced, not laciniate. First
pair of legs in both sexes subcheliform; following pairs ambulatory,
with dactylus bi-unguiculate.

Scale present outside of third joint of peduncle of second antenna?.

First pair of pleopoda in female with appendages fused to form a
small operculum. Second pair wanting. Third pair with the outer
branches large, and forming, with the corresponding lamella of the
opposite side, a sort of operculum. Fourth pair with two branches.
Fifth pair consisting of a single branch.

First pair of pleopoda in male small, with the peduncles fused;
branches single. Second pair situated below and not coupled with the
first pair; branches attached to the distal part of the inner margin of
the peduncle; inner branch geniculate, with distal joint narrow and
without cavity in its obtuse end; outer branch very short, much
shorter than inner one, and unjointed. Third, fourth, and fifth pairs
similar to those of female.

"Trans. Amer. Microscopical Soc., 24th annual meeting, 1902, p. 93.
6 See Hansen for characters of family, Proc. Zool. Soc. London, 1905, II, Pt. 2,
p. 315.

440 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

7O. Genus STENETRIUM Haswell.

Only genus.

With characters of family.

ANALYTICAL KEY« TO THE SPECIES OF THE GENUS STENETRIUM.

a. Terminal segment of the body armed on each side with five sharp teeth on the
lateral margin. First pair of legs with the upper distal angle of the fifth article

produced in a long process Stenetrium serratum Han sen

a'. Terminal segment of the body with only one tooth at the notch on the lateral
margin on each side. First pair of legs with the upper distal angle of the fifth
article rectangular, without process.

b. In the male the lower margin of the hand has its proximal half concave, and
at the distal end a low broad process, with three or four teeth nearly equal in
size placed in a convex line. In the female the angle between the palmar
and the lower margin of the hand measures about 110°; the hand is a little

more than f as long as deep Stenetrium occidentale Hansen

b'. In the male the lower margin of the hand has its proximal half convex, and
at the distal end two processes separated by a rather deep incision; each
process terminates in two teeth. In the female the angle between the
palmar and the lower margin of the hand measures about 125°; the hand

is twice as long as deep Stenetrium stebbingi Richardson

l/f. In the male the lower margin of the hand has its proximal half convex, and
at the distal end a narrow, moderately long process, with the end bifurcate,
and sometimes besides a feeble tooth on its proximal margin. In the female
the angle between the palmar and the lower margin of the hand measures
less than 100°, and the hand is a little more than f as long as deep.

Stenetrium antillense Hansen

STENETRIUM SERRATUM Hansen.

Stenetrium serratum HANSEN, Proc. Zool. Soc. London, 1905, II, Pt. 2, pp.
323-324, pi. xix, figs. 3a-3d; pi. xx, fig. la.

Locality. — St. Thomas, West Indies.

FIG. 497.— STENETRH'M SERRATVM (AFTER HANSEN). O, HEAD. I), FIRST TWO THORACIC LEGS. C, TER-
MINAL PART OF SECOND LEG. d, TERMINAL PART OF FIRST LEG. €, ABDOMEN. (ALL ENLARGED.)

''Head has its upper surface (the frontal plate excluded) nearly
twice as broad as long; the lateral part is somewhat expanded and

" The key given below is taken from Hansen' s Conspectus, given in Proc. Zool. Soc.
London, 1905, II, Pt. 2, pp. 316-317.

ISOPODS OF NORTH AMERICA. 441

flattened in front, and produced into a moderately large acute process;
the front margin outside the base of each antennula produced into a
rather large process, which is broad at the base, while its distal part is
shaped as a narrow, acute hook, curved somewhat inward. Eyes large,
oblong, very oblique; the outer margin extremely convex, the inner
very concave; their posterior part overlaps the lateral margin of the
head itself.

"Antennulae have the second joint of the peduncle moderately
robust and somewhat shorter than the third; flagellum 9- jointed, as
long as the sum of the two proximal joints of the peduncle.

"Antennae have the basal joint, seen from above, ' distally cut off
transversely, its outer angle acute, but not produced into &ny process.

" First thoracic legs rather short. Third joint distally widened, but
without process; fourth joint with the upper part nearly from the base
strongly expanded, compressed, and distally produced into a process of
moderate length and breadth; fifth joint similarly expanded and dis-
tally produced into a long slender process. Hand a little more than
twice as long as deep; upper margin rather feebly convex, with a few
setse; lower margin straight, only half as long as the upper, with
numerous very long hairs; distal end as long as the lower margin;
palmar edge very oblique, a little sinuate, furnished with six very stiff
setae, proportionate!}" long and increasing in length downward, pecti-
nate along their upper margin, and at the end of the edge a moder-
ately robust very long spine pectinate as the seta?; the angle between
palmar edge and lower margin measures about 130°. Seventh joint
with its claw claw-shaped, reaching a little beyond the lower end of
the palmar edge; the joint is adorned below with serrated spines and
finely curved seta? as in S. mediterranwm, but the spines are less
numerous, only about ten.

"Abdominal shield is somewhat broader than long; each lateral
margin is adorned with five small nearly spiniform processes, increas-
ing in size backward and placed at regular intervals, the last of these
processes being that at the usual notch. Posterior margin is rather
evenly but moderately curved.

" Uropoda wanting.

"Length of the single adult female, 6 mm.v — HANSEN."

STENETRIUM OCCIDENTALE Hansen.

Stenetrium occidentale HANSEN, Proc. Zool. Soc. London, 1905, II, Pt. 2, pp. 324-
325, pi. xx, figs. 2a-2n.

.Locality.— St. Thomas, West Indies.

" Head shaped as in S. antillense; its upper surface (the frontal
plate excluded) is considerably less than twice as broad as long; the
lateral part, seen from above, is feebly expanded and produced into a

«Proc. Zool. Soc. London, 1905, II, Pt. 2, pp. 323-324.

442

BULLETIN

UNITED STATES NATIONAL MUSEUM.

.small acute process; the front margin outside the base of each anten-
nula produced into a broad but rather low process, with the end obtuse.
Eyes of moderate length, oblong, somewhat curved, very oblique, and
considerably removed from the lateral margin of the head.

"Ant.ennula? with the second joint slightly longer than the third.

FIG. 498. — STENETRIUM OCCIDENTALE (AFTER HANSEX). ((.THIRD LEFT PLEOPOD OF FEMALE, x 51.
b, TERMINAL PART OF FIRST LEFT LEG OF ADULT FEMALE, x 97. e, FIRST LEG OF ADULT MALE.
x 39. d, ABDOMEN OF FEMALE, x 28. e, FIRST PLEOPOD OF ADULT MALE, x 51. /, LEFT ANTEX-

XULA OF ADULT MALE. X 39. Q, SECOND LEFT PLEOPOD OF ADULT MALE. X 51. /I, THIRD LEFT
PLEOPOD OF MALE. X 51. i, FIRST LEFT LEG OF IMMATURE MALE. X 39. j, FIRST LEFT LEG OF
ADULT FEMALE. X 39. k, FIRST PAIR OF PLEOPODA OF FEMALE. X 51. I, FOURTH LEFT PLEOPOD

OF MALE, x 51. m, FIFTH LEFT PLEOPOD OF MALE, x 51.

moderately robust; flagellum in the male 9-jointed and as long as the
sum of the two distal joints of peduncle, in the female still shorter,
with four or five joints.

"Antenna; have the basal joint distally cut off transversely, its outer
angle without processes and measuring about 90°.

ISOPODS OF NORTH AMERICA. 443

'' First thoracic legs very different in adult specimens of the two
sexes, but in immature males nearly as in adult females. In the male
they are rather long, robust; third joint is distally much expanded
above and produced into a triangular process directed upward; fourth
joint expands above gradually from the base, forming a broad but
rather low process, a portion of the inner surface of which is furnished
with numerous exceedingly long hairs. Fifth joint has the upper
margin very short, without any process, but it expands below, its
lower margin is several times longer than the upper, and besides it is
produced into a very long oblong-triangular process, the inner side
and both margins of which are closely set with longer very long hairs;
the upper margin of the process is straight nearly to the insertion of
the hand, and the distance from this insertion to the end of the proc-
ess is longer than the distance from the insertion to the base of the
joint. The hand is very large, a little broader near the end than at
the base, two and a half times longer than deep; upper margin strongly
convex, lower margin rather concave from the base to the distal proc-
ess, which occupies the major portion of the short palmar edge; this
process is low, broad, its margin more or less convex and divided into
three or four teeth; the lower major portion of the inner surface of
the hand is closely set with very long hairs. Seventh joint very long,
much curved, especially at some distance from the base, claw-shaped,
with fine, simple hairs spread along both margins and on the inner
side, but without spines; the claw itself is very short. In the female
the legs are much shorter than in the male, robust; process on third
joint proportionately a little longer and broader, that on fourth joint
a little longer than in the male; fifth joint much smaller than in the
male, its lower process small. Hand much smaller than in the male,
subtriangular, a little more than half as long again as deep; upper
margin very convex, two and a half times longer than the lower, which
is straight, with many long hairs; distal end somewhat longer than
the lower margin; palmar edge feebly convex, with an angular notch
at the lower end, so that the usual spine, which is strong and moder-
atel}7 long, is situated a little behind the edge; the edge from the
'claw 'to the notch is occupied by five or six saw-teeth gradually
increasing in size downward, and besides adorned with some stiff setae
pectinate along their upper margin; finally, the angle between lower
margin and palmar edge measures about 110°. Seventh joint with
the claw regularly claw-shaped, when extended reaching slightly
beyond the notch mentioned; the major portion of the lower margin
of the joint is adorned with rather slender spines, serrate along the
lower margin, and some fine hairs.

"Abdominal shield slightly broader than long; lateral margin
unarmed, only with the usual tooth and notch at the end; posterior
margin, reckoned from the notch, is strongly and rather evenly
curved.

444

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"Uropoda considerably more than half as long as the abdominal
shield; exopod slightly longer than the sympod and much shorter
than the endopod.

" Second joint of the endopod of second male pleopoda with the
distal half considerably broader than near the base, the end very
obliquely rounded, the lower surface at the end set with numerous
very short hairs.

'"''Length. — Both sexes similar in this respect, measuring about 3.3
mm. " — HANSEN. a

STENETRIUM STEBBINGI Richardson.

Stenetrium stebbingi RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp.
295-296, pi. xxxix, figs. 46-49.

Localities. — Found at low water in corallines at Bailey Bay, Ber-
mudas, and at Harrington Sound, Bermudas.

Depth.— I to 12 feet.

Body long, narrow, depressed. Color light yellow, with markings
of black.

Head narrowed posteriorly, widening anteriorly; the antero-lateral

b

d

FIG. 499.— STENETRIUM STEBBINGI. a, HEAD AND FIRST THORACIC SEGMENTS, b, FIRST LEG OF MALE.
r, FIRST LEG OF FEMALE, d, TERMINAL SEGMENT OF BODY AND UROPODA.

angles produced into narrow acute processes, curving slightly inward;
the anterior margin is produced in a rostrum,'' which is truncated, on
either side of which is a triangular process. Eyes obliquely situated
on the anterior portion of the head.

The first pair of antennae are placed between the two triangular pro-
cesses and the rostrum; the first peduncular joint is large, broad, the

a Proc. Zool. Soc. London, 1905, II, Pt. 2, pp. 324-325.
& Hansen calls this the frontal plate.

ISOPODS OF NORTH AMERICA.

445

FIG. 500.— STENETRIUM STEBBINOI. a, THIRD PLEOPOD OF MALE, x
41. b, FIRST PLEOPOD OF MALE, x 77£. c, SECOND PLEOPOD OF
MALE, x 77i.

two following joints narrow; the flagellum is composed of nine joints
and reaches a little beyond the middle of the fourth peduncular joint
of the second pair of antenna1.

The second pair of antenna? have the first four joints short, the
third joint being provided with an exopod, the fifth and sixth joints
long and of equal length; the flagellum is multi-articulate.

The first thoracic segment has the lateral margins straight, the ante-
rior angles acutely
produced forward.
The lateral margins
of the second, third,
and fourth segment
are also straight, w ith
the epimera evident
about the middle.

The fifth and sixth
segments have the
posterior half of
the lateral margin
rounded, the epimera
evident below. The
seventh segment has the lateral margin acutely produced posteriorly,
the epimera evident on the posterior margin of the segment within
the processes. The thoracic segments are all widel\T separated from
each other by deep lateral incisions.

The terminal segment of the body has the lateral margin produced
backward in two small spines, between which the posterior margin

is widely rounded. The
uropoda are double
branched, the branches
being nearly equal in
length and about as long
as the basal joint.

The first pair of legs
are subchelate. In the
male the carpus is pos-
tero - distally produced
in a markedly long pro-
cess, which extends half
the length of the propodus, its entire margin being fringed with
long hairs. The propodus is elongate, its lower two-thirds being
fringed with long hairs on the posterior margin, the upper third or
distal margin being provided with three large spines, the inner one
being bifurcate; the dactylus is long and also fringed with hairs upon
its inner margin, and extends half its length beyond the last digital

FIG. 501. — STEXETRIVM STEBBIXGI. u, FOURTH PLEOPOD OF
MALE, x 41. 6, FIFTH PLEOPOD OF MALE, x 41. c. FIRST

PLEOPOD OF FEMALE. X 77£.

446 BULLETIN T>4, UNITED STATES NATIONAL MUSEUM.

spine, almost touching the carpal process. The ischium is antero-
distally produced in a short process.

The other legs are simple, bi-unguiculate.

In the female the carpus of the first pair of legs is not produced in
as long a process as in the male. The propodus is shorter than in the
male, more triangular in shape, denticulate on its distal margin, with
a long, acute, digital spine. The dactylus does not extend beyond the
digital spine. The ischium is antero- distal ly produced in a process
fringed with hairs.

A number of individuals were taken by Prof. A. E. Verrill and part}'
at Bailey Bay, Bermudas, in corallines, at low water, and at Harring-
ton Sound, in 1898. Other specimens were collected at the Bermudas
in 1876-77 by Dr. G. B. Goode.

Type specimens from Harrington Sound in Peabody Museum, Yale
University. Cat. No. 3209.

This species is named for Rev. T. R. R. Stebbing, the English
carcinologist.

STENETRIUM ANTILLENSE Hansen.

Stenetrium antittense HANSEN, Proc. Zool. Soc. London, 1905, II, Ft. 2, pp. 326-327,
pi. xx, figs. 3-3i; pi. xxi, figs, la-le.

Locality. — West Indies. Found on corals in deep water.

"This species is so closely allied to S. occidentals and 8. stebbingi
that it is preferable to point out the differences instead of giving a
complete description.

"The head is shaped as in S. occidentale; the eyes have the same
position .

"Antennula? have second and third joints subequal in length;
flagellum in the male about as long as the sum of the two preceding
joints, with from nine to eleven joints.

"Antenna? have their basal joints as in S. occidentals.

"First thoracic legs show some important differences in their distal
half. In the male the fifth joint is below as much produced as in
S. occidentals, but the process is differently shaped; its proximal half
is expanded above and excavated on the upper half of the outer side
in order to receive the proximal lower part of the hand; the oblong-
triangular, freely protruding part of the process looks therefore much
shorter than in$. occidentals, in which it is regular!}7 oblong-triangular
and quite free to about the articulation of the hand. The hand is
deeper than in S. occidentals and has a different shape; it is slightly
more than twice as long as deep, conspicuous!}- deeper at a shorter
distance from the base than at the distal end; the upper margin is less
convex than in S. occidentals, while the lower margin is considerably
convex in its proximal and concave at its distal half; the distal process
is longer but much narrower than in 8. occidentals, bifurcate at the end

1SOPODS OF NORTH AMERICA.

447

and sometimes with a feeble tooth on its posterior margin; distribu-
tion of hairs as in the species mentioned. The 'claw,"1 formed by the
seventh joint and the claw itself, slightly longer than in S. occidentale
and more hairy at the lower margin. In the young, probably also in
the adult female, the hand differs somewhat in shape from those of

n

FIG. 502. — STENETRIUM ANTILLENSE (AFTER HANSEN). a, ADULT MALE, x 9. b, FIRST LEG OF

ADULT MALE. X 16. C, HEAD OF ADULT MALE. X 24. d, ABDOMEN OF IMMATURE FEMALE. X 36.
P, DISTAL PART OF LEFT MANDIBLE. X 125. /, DISTAL PART OF RIGHT MANDIBLE. X 125. g, DISTAL
PART OF LOBE FROM THIRD JOINT OF LEFT MAXILLULA. X 185. /*, LEFT MANDIBLE OF MALE. X 49.
i, FIRST RIGHT LEG (TERMINAL PART) OF ANOTHER MALE. X 28. j. PARAGNATHA OF MALE. X 49.

k, DISTAL PART OF LEFT LEG OF IMMATURE FEMALE, x 53. I, LEFT MAXILLIPED OF MALE, x 49.
ra, LEFT MAXILLA OF MALE, x 49. n, LEFT MAXILLULA OF MALE, x 49.

the two preceding species: as in £. occidental it is a little more than
half as long again, as broad, but the lower margin is comparatively
longer, measured to the base of the lower sawtooth of the palmar edge

448 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

slightly more than half as long as the upper margin, and the angle
between the lower margin and the palmar edge is less than 100°;
the notch at the distal end of the lower margin is longer than in
S. occidentale.

'"Abdominal shield is slightly longer than broad, otherwise as in
S. occidentale.

" Uropoda seem to be only a little more than half as long as the
abdominal shield; the rami — preserved only in the young female — a
little shorter than in $. occidentale.

"Length of the largest male 4.5 mm." — HANSEN.°

Family XVII. JANIRID^E.*

Lateral parts of head lamellarly expanded. Eyes, when present,
usually subdorsal. First pair of antenna? sometimes well developed
with multi-articulate flagellum, sometimes small with rudimentary
flagellum. Second antennae generally with small scale outside of third
joint of peduncle; peduncle composed of six articles.

First pair of legs sometimes prehensile, sometimes not differing from
the six following pairs, which are ambulatory; dactylus generally bi-
or tri-unguiculate.

First pair of pleopoda in female transformed into a single large oper-
cular plate, undivided; second pair wanting; outer Iamella3 of two
succeeding pairs, third and fourth pleopoda, narrow and confluent with
basal part; both branches well developed; fifth pair with only a single
branch.

First pair of pleopoda in male coupled with the second pair and
forming a sort of compound operculum. The peduncles of the first
pleopoda are fused, are very long, with immovable single branches.
Second pair with the distal joint of the peduncle situated outside of and
coupled with the first pair of pleopods; the branches are attached to
the inner margin of the peduncle; the inner branch is geniculate, two-
jointed, the distal joint containing a cavity and being produced to a
point; the outer branch is very short, two-jointed, and hook-shaped.
The third, fourth, and fifth pairs of pleopoda are similar to those of
female.

ANALYTICAL KEY TO THE GENERA OV THE FAMILY JAXIRID.E.

a. Second pair of antennae long, well developed, with multi-articulate flagellum;
articles of peduncle not dilated. Mandibles with cutting part composed of one
or two serrated teeth.

b. First pair of antennae extremely small, with rudimentary flagellum, composed
of only two articles. Second pair of antenme without a scale attached to the
peduncle. Uropoda extremely small, branches short, nodiform.

Genus Jara Leach

aProc. Zool. Soc. London, 1905, II, Pt. 2, pp. 326-327.

'"'See Sars for characters of family, Crust, of Norway, II, 1899, p. 98, and Hansen,
Proc. Zool. Soc. London, 1905, II, Pt. 2, pp. 308-309, 315-316.

ISOPODS OF NORTH AMERICA. 449

V. First pair of antennae well developed; flagellum multi-articulate. Second pair
of antenna? with scale outside of third article of peduncle. Uropoda largely
developed.

c. Eyes laterally placed. First pair of legs in male nearly twice the length
of the body, enlarged distally, forming a club-like hand armed with trian-
gular processes, to which is articulated a movable finger, the propodus,

armed also with triangular processes Genus Carpias Richardson

(/. Eyes sub-dorsal. First pair of legs in male not twice as long as body; pro-
podus not armed with triangular processes.

d. Maxillipeds with the second and third articles of the palp very much
expanded. Distal extremity of the peduncle and the branch of the first
pleopoda in the male fused and produced and dilated at the tip.

Genus Janiropsis G. O. Sars

d'. Maxillipeds with the second and third articles of the palp not expanded.
Distal extremity of the peduncle and the branch of the first pleopoda in
the male generally not fused nor produced and not dilated at the tip.
e. Terminal segment of body with post-lateral angles produced into a trian-
gular expansion, one on either side. Segments of thorax with lateral

parts produced, laciniate Genus lolella, new name.

e'. Terminal segment of body with post-lateral angles not produced in a tri-
angular expansion, one on either side. Segments of thorax with lateral

parts not produced, not laciniate Genus Janira Leach

of . Second pair of antennae short, with articles of peduncle dilated; flagellum rudi-
mentary. Second antennae equal in length to the width of the head. Cutting
part of mandibles composed of five teeth .Genus Jseropsis Koehler

71. Genus J^ERA Leach. «

Body broad, depressed. Lateral parts of thoracic segments laminarly
expanded.

Head without rostrum. Terminal segment with median emargina-
tion, within which the uropoda are placed. Ej^es dorsal.

First pair of antennae extremely small, with rudimentary flagellum.
Second pair of antennae long and well developed, without a scale
attached to the peduncle of the second antenna?; flagellum multi-articu-
late.

Uropoda extremely small; branches short, nodiform.

Legs of all seven pairs ambulatory in structure; dactylus tri-
unguiculate.

Distal extremity of the peduncle and the branch of the first pleopoda
in the male fused arid dilated at the tip.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS J^ERA.

«. Anterior margin of the head broadly excavated on either side of a median lobe.
Extremity of terminal segment of body notched for the insertion of the uropoda,

the median point being almost imperceptible Jivra marina (Fabricius)

a'. Anterior margin of the head nearly straight. Extremity of terminal segment of
body with a double excavation, the median point not extending beyond the
extremity of the sides Jasra wakishiana Spence Bate

« See Sars for characters of genus, Crust, of Norway, II, 1899, pp. 103-104.
28589—05 39

450 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

MARINA (Fabricius.)

Onfecus marinus FABRICIUS, Faun. Greenland., 1780, p. 252.

Jsera albifrom LEACH, Edinburgh Encyclop., VII, 1813-14, p. 434 (Am. ed., p.
273); Trans. Linn. Soc., XI, 1815, p. 373. — DESMAREST, Diet. Sci. Nat,
XXVIII, 1823, p. 381; Consid. Crust., 1825, p. 316.— LATREILLE, Rc'-gui'
Anini., IV, 1829, p. 141.— EDWARDS, Annot. de Lamarck, V, 1838, p. 267;
Hist. Nat. des Crust., Ill, 1840, p. 150.

Jsera kroyeri ZADDACH, Syn. Crust. Pruss. Prodromus, 1844, p. 11.
Jsera albifrons EDWARDS, Regne Anim., Crust., 1849, p. 204.
Jsera ballica Fr. MULLER, Arch. Naturg., I, 1848, p. 63, pi. iv, fig. 29.
Jsera albifrons LILLJEBORG, Ofvers. vet. Akad. Forh., VIII, 1851, p. 23; IX,

1852, p. 11.
Jfera copiosa STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853, p. 40,

pi. in, fig. 29.

Jsera albifrons M. SARS, Christ. Vid. Selsk. Forh., 1859, p. 153. — BATE, Report
Brit. Assoc., 1860, p. 225, 1861.— G. O. SARS, Nyt. Magazin for Naturvidens-
kaberne, 1866, p. 29.

Jsera nivalis PACKARD, Mem. Bost. Soc. Nat. Hist., I, 1867, p. 296.
Jsera albifrons NORMAN, Report Brit. Assoc., 1866, p. 197, 1867; 1868, p. 288,

1869.— BATE and WESTWOOD, Brit. Sess. Crust., II, 1868, p. 317, fig.
Jsera albifrons SARS, Christ. Vid. Selsk. Forh., 1871, p. 272, 1872.
Jsera copiosa VERRILL, Am. Journ. Sci. (3), VII, 1874, p. 131; Proc. Amer. Assoc.,
1873, p. 369, 1874.— HARGER with VERRILL, Report U. S. Fish Comm., 1873,
Pt. 1, p. 315; p. 571.

Jsera albifrons STEBBING, Journ. Linn. Soc. London, XII, 1874, p. 149; Ann. Mag.

Nat. Hist. (4), XVII, 1876, p.
79, pi. v, figs. 5-6. — MEINERT,
Natur. Tidsskr.(3), XI, 1877, p.
80. — STEBBING, Trans. Devon.
Assoc., 1879, p. 7. — HARGER,
Proc. U. S. Nat. Mus., 1879,
II, p. 158; Report U. S. Fish
Comm., Pt. 6, 1880, pp. 315-318,
pi. i, figs. 4-8 (see Harger for
synonymy). — BOVALLICS, Bih-
ang till K. Sv. Vet. -Akad.
Handl., XI, 1886, No. 15, pp. 42-
44. — HANSEN, Videnskabelige
Meddelelser fra den naturhis-
toriske Forening i Kj0benhavn,
1887-88, pp. 192-193.
Jsera marina SARS, Crust, of Norway,
II, 1899, p. 104.— RICHARDSON,
Proc. U. S. Nat. Mus., XXIII,
1901, p. 554. — PAULMIER, Bull.
New York State Museum x 1905,
pp. 178-179.

FIG. 503.— J -ERA MARINA (AFTER HARGER). X 10.

Localities. — Atlantic coast or

New England; Labrador; Bay of Fundy; also coasts of England, Scot-
land, and Finmark; Fiskenaesset, Godhavn, and Claushavn, Greenland;

1SOPODS OF NORTH AMERICA.

451

Baltic Sea; North Sea; Germany; west coast of Helgoland; Runmaro,
Stockholms skargard (J. Lindahl).

Depth. — Found on surface in tide pools; low water, under stones.

Body oblong-ovate, twice as long as wide, H nun. :3 mm.

Head about twice as wide as long, with the anterior margin produced
in the middle in a large rounded lobe. Lateral margins straight, with
the post-lateral angles round, the antero-
lateral angles not produced. The eyes
are small, oval or round, composite, and
dorsally situated. The first pair of
antennae have the first article large; the
second and third are about equal in
length and a -little shorter than the first.
The nagellum is composed of two articles.
The second pair of antennas have the
first four articles short and subequal;
the fifth article is twice as long as the
fourth; the sixth is one and a half times
longer than the fifth. The flagellum
is composed of about eighteen articles.
The second antennae are short, not reach-
ing beyond the posterior margin of the
fifth thoracic segment. The maxillipeds
have a palp of five articles. The palp
of the mandibles is composed of three
articles.

The lateral margins of the thoracic segments are straight and not
produced into lobes. The epimera are not separated off from the
segments.

The abdomen is composed of a single large segment, rounded pos-
teriorly, with a small median excavation for the reception of the
uropoda. The uropoda are short, not extending beyond the extremity
of the abdomen, and situated within its posterior excavation. The
outer branch is a little smaller and shorter than the inner branch.

All the legs are ambulatory, with tri-unguiculate dactyli.

J^RA WAKISHIANA Spence Bate.

Jsera wakishiana SPEXCE BATE, Lord's Naturalist in British Columbia, II, 1886, p.
282.— C. BOVALLIUS, Bihang till K. Sv. Vet.-Akad. Handl., XI, 1886, No. 15,
p. 49.— RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 857; Ann. Mag.
Nat, Hist. (7), IV, 1899, p. 323; American Naturalist, XXXIV, 1900, p. 298.

Locality. — Esquimault Harbor, British Columbia.

"Posteriorem marginem pleonis habens bis excavatum cuspide inter-
media supra cuspidatos margines non producta; antennae inferiores non
possunt extendere supra quintuin segmentum; pereionis posteriora ple-
opoda non longiora quam posteriori margo latus est.

FIG. 5M.—JJERA. MARINA, a, MAXILLI-
PED. x 77£. b, MANDIBLE, x 77s.
c, ABDOMEN WITH UROPODA. x 41.

452 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"Anterior margin of the cephalon nearly straight; pereion having
the sides subparallel, the greatest width being at the sixth segment;
pleon having a double excavation on the posterior margin, the central
point not extending beyond the extremity of the sides. Superior
antennae reaching to the extremity of the fourth segment of the infe-
rior; inferior antennae nearly two-thirds of the length of the animal.
Posterior pair of pleopoda as long as the posterior margin of the
pleon, terminating in two styliform rami, each of which is tipped with
a few short hairs.

"This species was taken from a sponge dredged in about eight
fathoms of water in Esquimault Harbor.

"The specific name is derived from the circumstance of the animal
having been found on the territory of the tribe of Wakish Indians. "-
SPENCE BATE.**

72. Genus CARPIAS Richardson.

Head without rostrum; frontal margin straight. Both pairs of
antennae multi-articulate; the second pair much longer than the bod}",
and with a scale-like appendage articulated to the peduncle. Uropoda
long, much longer than abdomen.

The first pair of legs in the male are prehensile and remarkably
long, being one and two-thirds times the length of the body; they are
greatly enlarged distally, forming a broad club-like hand armed with
triangular processes, to which is articulated a movable finger, the
propodus, likewise armed with triangular processes.

The ambulatory legs are simple, bi-unguiculate, and are of normal
structure.

CARPIAS BERMUDENSIS Richardson.

Carpias bermudensis RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp.
294-295, pi. XL, fig. 41; pi. xxxix, figs. 42-15.

Locality. — Bermudas.

Surface of body smooth. Color yellow, with arborescent markings
of black.

Head narrower than first thoracic segment, with lateral margins
rounded, entire. Frontal margin straight, antero-lateral angles not
produced, rounded. Eyes large, with many ocelli, and situated on
the lateral margins of the head.

The first pair of antennas have the basal segment of the peduncle
enlarged, the next two segments successively narrower, all about equal
in length; the flagellum is multi-articulate, composed of about four-
teen joints. The second pair of antennae have a scale-like appendage
outside of the third joint; the fifth and sixth joints are long, the sixth

«Lord's Naturalist in British Columbia, II, 1886, p. 282.

ISOPODS OF NORTH AMERICA.

453

a little longer than the fifth; the flagellum is much longer than the
body, and is composed of about one hundred joints.

The first thoracic segment is wider than the head; the lateral mar-
gins are straight, entire. The second and third segments have the
lateral margins excavate, the anterior and posterior angles produced,
with the epimeron situated in the excavation. The fourth segment
has the anterior angle produced, the epimeron being situated in the
excavation of the entire posterior part of the segment. The fifth,
sixth, and seventh segments have the lateral margins entire, the
epimeron showing at the posterior part of the segment.

FIG. 505. — CARPIAS BERMTDENSIS. a, MANDIBLE, x 58. ft, SECOND MAXILLA, x 58. e, FIRST LEG OP
MALE, x 30J. d, DORSAL VIEW OF MALE, x 18g. e, MAXILLIPED. x 58. /, FIRST MAXILLA, x 58.

The terminal segment of the body is about as broad as long, the
entire margin smooth, with a small rounded lobe between the basal
joints of the uropoda.

The uropoda are very long, much longer than the abdominal seg-
ment. The basal joint is about two-thirds the length of the abdominal
segment, and is narrower at the base than at the apex. The two
branches are of nearly equal length, the outer one being slightly
shorter, and they are longer than the basal joint.

The first pair of legs in the male are remarkably long, being one
and two-thirds times the length of the body, and are prehensile. The
basis is as long as the width of the first thoracic segment, and has the

454

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

distal end very much enlarged and inflated. The ischium is not more
than half the length of the basis. The merus is a little longer than
the basis, and is enlarged at its distal end. The carpus is very much
elongated, is longer than the ischium, is greatly enlarged distally, and
has its upper distal margin armed with three large triangularly -shaped
processes. The propodus has the inner surface
armed with two long, sharp, triangular processes,
its distal end being widely expanded and rounded
on the inner surface. The dactylus is bi-ungui-
culate.

The other legs are of normal structure, ambu-
latory in character, and bi-unguiculate. In the
female the first pair of legs are similar in struc-
ture and size to the other legs.

A number of individuals were collected by Dr.
George Brown Goode at the Bermudas.

Type specimens in Peabody Museum, Yale
University. Cat. No. 3203.

73. Genus JANIROPSIS G. O. Sars.«

Head without rostrum.

Lateral parts of thoracic segments but slightly
expanded, not laciniate. E}res well developed.
First pair of antenna? comparative^ small, with
the flagellum composed of only a limited num-
ber of articles. Second pair of antennae of
moderate length; antennal scale very small, but
distinctly defined.

Maxillipeds with the second and third articles
of the palp very much expanded, laminar.
Distal extremity of the peduncle and the
branch of the first pleopoda in the male fused
and produced and dilated at the tip.

Uropoda short, about half as long as abdomen.
Legs bi-unguiculate.

ANALYTICAL KEY TO THE SPECIES OF THE GENTS JANIROPSIS.

a. Head with a prominent rounded median lobe on the anterior margin. Terminal
segment of body narrowly rounded, and with a small median lobe between the
uropoda; no lateral lobes Janiropsis calif ornica Richardson

a/ Frontal margin of head nearly straight, without a median lobe. Terminal seg-
ment of body posteriorly produced in three lobes, a broadly rounded median
lobe and an acute lateral lobe on either side of the median lobe.

Janiropsis kincaidi Richardson

FIG. 506. — CARPIAS BEKMUD-
ENSIS. «, FIRST PLEOPOD
OF MALE, x 58. b, SECOND

PI.EOPOD OF MALE. X 58.

c, FEMALE OPERCULDM.

x 58.

« See Sars for characters of genus, Crust, of Norway, II, 1899, p. 102.

ISO PODS OF NORTH AMERICA.

455

FIG. 507.— JANIROP-
SIS CALIFOKNICA.
ANTERIOR PART
OF BODY, x 27.

JANIROPSIS CALIFORNICA Richardson.

Janiropsis calif ornica RICHARDSON, Harriman Alaska Exp., Crust., X, 1904, pp.
223-224; Proc. U. S. Nat. Mus., XXVII, 1904, pp. 666-667.

Locality. — Sausalito, California.

Body narrow, elongate; surface smooth; color uniform!}' whitish.
Head with a prominent rounded median lobe on the anterior margin;
lateral angulations rounded; lateral margins straight
and converging toward the base. Eyes black, distinct,
but small, and simple in structure. First pair of
antennae are composed of six joints and extend nearly
to the middle of the tifth joint of the peduncle of
the second pair of antenna?. Second pair of antennae
are about equal to one-third the length of the body; the
flagelluni is composed of nineteen or twenty joints.

The first thoracic segment is but little wider than
the head; the margins are entire, lateral lobes rounded.
The second segment has the lateral margin straight,
with the epimeron showing slightly along the edge.
The third and fourth segments have the antero-lateral
lobe rounded, the posterior margin straight, with the
epimeron showing as a rounded lobe. The fifth, sixth,
and seventh segments have rounded lateral margins, with epimera
showing on the posterior part of the segments.

Terminal segment rounded posteriorly with smooth
margins, and a median lobe between the uropoda.

Uropoda very short, about half as long as the ter-*
minal segment. Branches about equal in length and
twice as long as the peduncle.

Legs simple, ambulatory, similar in shape and size,
and bi-unguiculate.

Only two good specimens, both females, were taken at
Sausalito, California, by Doctor Ritter and party. Two
imperfect specimens also are from the same locality.

Until now the only other known species of this genus
was Janiropsis breviremus Sars.a As that author has pointed out, this
genus differs from Janira, to which it is very closely related, in the
much shorter uropoda; in the shorter second pair of antenna?; in the
structure of the first pair of antennae, which have the flagellum com-
posed of only a restricted number of articulations; in the structure of
the first pair of legs in the male, these being " remarkabty developed,
prehensile, much longer than any of the other pairs, with the carpal
joint fusiformly dilated;'1 in the female, however, this pair does not
differ from the other legs, all being ambulatory in character.

FIG. 608.— JANI-
ROPSIS CALIFOR-
NICA. TERMINAL

PART OF BODY.

X 27.

« Crustacea of Norway, II, 1899, p.

456 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 509. — JANIROPSIS KIN-
CAIDI. MAXILLIPED.

X 77.

JANIROPSIS KINCAIDI Richardson.

Janiropsis kincaidi EICHARDSON, Harriman Alaska Exp., Crust., X, 1904, pp.
221-222; Proc. U. S. Nat. Mus., XXVII, 1904, pp. 665-667.

Locality. — Yakutat, Alaska.

Color of body light brown, profusely and densely covered with black
markings.

Head wider than long; frontal margin nearly straight, with lateral
angles rounded. Eyes large,
black, situated some little distance
from the lateral margin. First
pair of antennae 'short; flagellum
consisting of only eight joints in
the female, of ten in the male.
Second pair of antennte lost in all
the specimens. Maxillipeds with
palp consisting of five joints, the
first three of which are very much
dilated.

The first segment of the thorax
has the lateral margins straight;
the epimera are rather bilobed, and occupy most of
the lateral margin of the segment. The second, third,
fourth, and fifth segments have the an tero- lateral an-
gles produced into rounded lobes. The epimera of
the second and third segments are situated about the
middle of the lateral margin; those of the fourth and
fifth segments occupy more of a pos-
terior position on the lateral margin.
The epimera of the last two segments
are situated at the post-lateral angles of the segments.

The abdomen is broad, gradually be-
coming somewhat narrower toward the
posterior extremity. The posterior mar-
gin is produced in three lobes, two lateral
lobes, one on either side of a broadly
rounded median lobe; the two lateral
lobes are acute. The uropoda are short,
not longer than half the length of the
terminal segment of the body; the basal
segment is broad, quadrate in shape, and shorter than
either branch; the inner branch is somewhat longer than
the outer one. The first pleopoda in the male are very
similar to the figure given by Sarsa of the first pleopoda in the type
species of the genus, Janiropsis brevirentus. The distal extremity of
the peduncle and the branch are produced and fused.

Fio.510.— JANIROPSIS

KINCAIDI. X 20}.

FIG. 511. — JANIROP-
SIS KINCAIDI.
LAST THORACIC
SEGMENT, ABDO-
MEN, AND URO-
PODA. X 20£.

Fic.512.— JANIROP-
SIS KINCAIDI.
UROPOD. x 77.

"Crustacea of Norway, II, 1899, p. 102.

ISOPODS OF NORTH AMERICA.

457

Nine specimens were obtained by the Harriman Expedition at
Yakutat, Alaska. They were collected by Mr. T. Kincaid, after whom
the species is named. Five females and four males were collected.
The legs of the first pair in the male are
not greatly longer than the others; they
are longer in the type species of Janiropsis.

The very short superior antennas with

a be

FIG. 513. — JANIROPSIS KINCAIDI. a, FIRST PLEOPOD OF
MALE. 6, SECOND PLEOPOD OP MALE, c, THIRD PLEO-
POD OF MALE. ALL x 41.

FIG. 514. — JANIROPSIS KINCAIDI. a,
LEG OF FIRST PAIR, x 27. b, LEG

OF SECOND PAIR. X 27.

few articulations, the greatly dilated joints of the maxillipeds, the
form and shape of the peduncle of the first pleopoda in the male, which
has the distal extremity fused with the branch and produced and dilated
at the tip, and the shortness of the uropoda, which are only half the
length of the terminal segment of the body, are characters which
undoubtedly place this species with Janropsis Sars.
Type.—Vzi. No. 28,717, U.S.N.M.

74. Genus IOLELLA, new name. «

Head usually with prominent rostral projection.

Lateral parts of head usually produced into very prominent, acute
lappets.

Segments of thorax with the lateral parts laciniate and produced.

Terminal segment of body forming posteriorly on each side a tri-
angular expansion.

Other characters as in Janira.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS IOLELLA.

a. Segments of thorax with spines or tubercles on the dorsal surface.
b. Rostrum as long as head. Flagellum of first pair of anteniue composed of
twelve articles, shorter than the breadth of the head. Flagellum of second
pair of antennpe composed of fifty articles. First thoracic segment shorter
than the second. Second and third segments equal, and longest, much longer
than the seventh. Terminal segment smooth on dorsal side, without spine-
like tubercle. Peduncles of uropoda longer than post-lateral angulations of
terminal segment lolella spinosa ( Harger )

« In a recent letter, Doctor Ortmann informed me that Tole was a typographical
error for lole, and asked me to correct the mistake in this paper. As lole, however,
is preoccupied, having been proposed by Pascoe (Trans. Exit. Soc. London, ne\v
series, IV, 1858, p. 254) for a genus of Coleoptera, I suggest the new name, lolella.
In Marshall and Scudder, instead of I, J has been used for lole, although I is given
in the original reference. (See Sars for characters of genus, Crust, of Norway, II,
1899, pp. 100-101.)

458 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

bf. Rostrum much longer than head. Flagellum of first pair of antenna? composed
of sixty to seventy articles, nearly as long as the breadth of the head. Fla-
gellum of second pair of antenna1 composed of two hundred and eighty articles.
First thoracic segment as long as second. Seventh segment longest. Termi-
nal segment of body, with a single spine-like tubercle on its dorsal side.
Peduncle of uropoda shorter than post-lateral angulations of terminal seg-
ment of body lolella xpeciom (Bovallius )

a'. Segments of thorax smooth on the dorsal surface.
b. Head with prominent rostrum.

c. Lateral margins of head produced into two angulations. Terminal segment
of body with central and post-lateral lobes acute, triangular.

lolella trictngulata (Richardson)
</. Lateral margins of head produced in one angulation. Terminal segment of

body with central and post-lateral lobes rounded.

d. Lateral angulations of head long, about as long as rostrum. Median lobe
of pleon about as wide and long as post-lateral lobes.

lolella libbeyi (Ortmann)

d' '. Lateral angulations of head short, much shorter than rostrum. Median
lobe of pleon much narrower and shorter than post-lateral lobes.

lolella alascensis Benedict, new species

V. Head without rostrum, in place of which is small median point,
c. Antero-lateral angles of head acutely produced. Sides of head not produced.
Epimera of second, third, and fourth segments of thorax consisting each of
a single lobe. Terminal segment of body with post-lateral angles rounded.

lolella erostrata (Richardson)

cf . Antero-lateral angles of head not produced. Sides of head produced. Epi-
mera of second, third, and fourth segments of thorax bifurcate. Terminal
segment of body with post- lateral angles acute.

d. Sides of head produced in a bifurcate process. Terminal segment of body
with one large median lobe between the post-lateral angles.

lolella holmesi (Richardson)

d'. Sides of head produced in an anterior lobe bearing three spines and a small,
inconspicuous lobe armed with three feeble spines. Terminal segment
of body with three small lobes between the post-lateral angles.

lolella sarsi, new species

IOLELLA SPINOSA (Harger).

Janira spinosa HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 158; Report U. S.

Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 323-324.
lanthe spinosa BOVALLIUS, Bihang till Kgl. Sv. Vet. Akad. Handl., XI, 1886,

No. 15, p. 34.
Janira spinosa HANSEN (part), Vid. Medd. naturh. Foren. i Kj0bh., 1887-88,.

p. 191.
lanthe spinosa RICHARDSON, Amer. Naturalist, XXXIV, 1900, p. 299; Proc. U. S.

Nat. Mus., XXIII, 1901, p. 555. '

Localities. — Banquereau; latitude 65° 35' north, longitude 54° 50'
west; latitude 66° 32' north, longitude 55° 34' west; latitude 67° 59'
north, longitude 56° 33' west.

Depth.— 80 to 100 fathoms.

"This species is well marked among our known Isopoda by the
double row of spines along the back and the acute laciniations or
angulations on the lateral margins of the thoracic segments.

ISOPODS OF NORTH AMERICA.

459

"The body is robust, the length but little exceeding twice the
breadth. The head is broad and produced in the median line into a
prominent, acute spine, or rostrum, about as long as the head. The
antero-lateral angles are also produced and very acute, but do not
extend as far as the rostrum. The eyes are rounded, semi-oval, with
the long axes converging toward a point near the base of the rostrum.
The basal segment of the antennulse is less than one-third the length
of the rostrum. The second segment is about as long as the first, but
of only about half its diameter. The flagellum equals, or slightly sur-
passes, the third antennal segment, and consists of about twelve seg-
ments. The scale or spine on the second segment of the antennae is
slender and considerably surpasses the third segment. The external
lamella of the maxillipeds has the
outer angle prominent, though not
acute.

"The thoracic segments are pro-
duced laterally into one or two acute
angulations, giving a sharply ser-
rated or dentated outline to the tho-
racic region. The first segment is
shorter than the second; the sec-
ond, third, and fourth are about
equal in length ; the fifth is about the
length of the first; the sixth and
seventh each a little longer. The
first segment is acutely produced at
the sides, around the sides of the
head, and bears, near the middle
of the anterior margin, two short
spines, situated about half as far
apart as are the eyes, and directed
upward and somewhat forward.
The second segment has both lateral
angles produced into triangular,
acute processes, of which the anterior is more slender than the poste-
rior and directed more strongly forward. The dorsal spines on this
segment are a little farther apart and larger than in the first segment.
In the third segment the lateral angulations are more nearty equal
•than in the second segment and directed less strongty forward. In
the specimen figured the third segment bears, on the left side, a
single broad angulation, apparently representing the posterior, while
the anterior is only indicated by a slight irregularity in the outline.

"Malformations of this kind appear to be common. The dorsal
spines on the third segment are much as in the second. On the fourth
segment the anterior angulation is longer than the posterior, and both
are directed nearly outward. The dorsal spines on the fourth segment

FIG. 515. — lOLELLA SPINOSA (AFTER HAR-
GER). X G.

460 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

are slightly smaller and nearer together than on the third; but, as in
all the preceding segments, they are near the anterior border of the
segment. The last three segments are acutely produced at the sides
into a single angulation, which is directed more and more backward
to the last segment. The dorsal spines on the fifth segment are sit-
uated nearer together than on the anterior segments and rather behind
the middle of the segment. They are also smaller than on the pre-
ceding segments. On the last two segments they are near the poste-
rior border of the segment, and become somewhat smaller and nearer
together on the last segment. The legs are armed with but few and
rather weak spines.

"The pleon is broadest near the base and tapers posteriorly, where
the angles are acutely produced. Between these angles the margin is
rounded and arched over the bases of the uropods, which are about as
long as the pleon and less spiny than in J. alta. The lateral margin
of the pleon is armed with ver}' minute acute spinules, and under a
higher power the margins of the thoracic segments and of the head
are seen to be similarly armed, especially where most exposed.

"Length 8 mm., breadth 3.8 mm.; color in alcohol white." — OSCAR
HARGER.«

IOLELLA SPECIOSA & (Bovallius).

lanthe speciosa BOVALLIUS, Bihang till K. Sv. Vet. Akad. Handl., VI, 1881, No.
4, pp. 5-14, pis. i-ui; XI, No. 15, 1886, p. 35. — RICHARDSON, American Natur-
alist, XXXIV, 1900, p. 299; Proc. U. 8. Nat. Mus., XXIII, 1901, p. 555.

Z,ocality. — Baffin Bay.

"The rostrum is much longer than the head (7:5); the lateral angu-
lations of the head are directed obliquely forward; they are longer
than the head. The eyes are oval. The long diameter of the eyes
equals a sixth of the length of the head. The flagellum of the first
pair of antennae is 60-70 articulated. The first pair of antennae are
nearly as long as the breadth of the head (18: 19). The flagellum of
the second pair of antennas consists of almost 280 articuli. The first
segment of the pereion is as long as the second; the seventh segment
is the longest. All carry each two spine-like tubercles on the dorsal
side. The lateral margins of the first segment carry one angulation
on each side; the second, third, and fourth two, more or less equal;
the fifth, sixth, and seventh, one large and one very minute each. The
pleon carries on its dorsal-side a single spine-like tubercle, and is pro-
duced backward into two flattened, sharp-pointed angulations; between

these the uropoda are attached. The peduncles of the uropoda are

— — . : / 1_

« Report U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 323-324.

6 This species is considered by Hansen and Ortmann to be a synonym of the pre-
ceding species. Since my manuscript went to press, the types of /. spinosa have
been sent from Yale University, and I find it distinct from J. speciosa.

ISOPODS OF NORTH AMERICA.

461

FIG. 516.— lOLELLA SPECIOSA (AFTER BOVALLIUS). O, LABRUM. 6, INNER ANTENNA. X 20. C,

DORSAL VIEW OF ANIMAL, x 4. d, AUDITORY BRISTLE FROM THE THIRD JOINT OF THE PEDUNCLE

OF THE INNER ANTENNA, e, FIRST JOINTS OF THE FLAGELLUM OF THE INNER ANTENNA. X 160.
/, SOME ARTICLES OF THE FLAGELLUM OF THE OUTER ANTENNA. X 60. (/, AN OLFACTORY GLAND OF

SAME, x 260. h, PEDUNCLE OF OUTER ANTENNA, x 15. i, THE LAST JOINTS OF SAME, x 200.
j, HEAD, x 10.

462

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

shorter than the angulations. The outer ramus is almost as long as
the inner (37: 39).

"Color, 3Tellowish white.

"Length, 21.5 mm."— BOVALLIUS. a

IOLELLA TRIANGULATA (Richardson).

lanthe triangulata RICHARDSON, Proc. U.- S. Nat. Mus., XXI, 1899, pp. 857-858;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 323-324; American Naturalist,
XXXIV, 1900, p. 299.

^Locality. — Monterey Bay, California.

Surface of body smooth; color yellow, marked with black dots.

FIG. 517.— lOLELLA TRIANGCLATA. X 13}.

Head with rostrum in front equal to one-half the length of the head.
Anterior margin lobate between the rostrum and the lateral angula-
tions. The side of the head is produced in two angulations, the upper
one extending in an oblique direction and not reaching beyond the
anterior margin of the head. The first pair of antennae are not as long

«Bihang till K. Sv. Vet. Akad. Handl., XI, Xo. 15, 1886, p. 35.

ISOPODS OF NORTH AMERICA.

463

as the width of the head. The second pair of antennae are longer than
the body.

The lateral margins of the first segment are produced on either side
into two angulations; those of the second and third into two, with the
epimera produced into two-lobed angulations; those of the fourth into
two lobes, the small epimeral lobe or angulation between; and those
of the fifth, sixth, and seventh into one large upper lobe and one small
lower lobe.

The terminal segment is produced backward at the sides into two
sharply pointed angulations, with a broad triangulate central lobe
between. The uropoda are longer than the terminal segment, the
outer branch being somewhat shorter than the inner one, and both
fringed with hairs.

The first pair of legs are prehensile; the remaining pairs simple.

Two specimens were collected by Mr. Heath at Monterey Bay,
California.

Type.— Cat. No. 22582, U.S.N.M.

IOLELLA LIBBEYI (Ortmann).

Jolanthe libbeyi ORTMANN, Princeton University Bulletin, XI, No. 3, 1900, pp.

39-40.
Tole libbeyi ORTMANN, Proc. Acad. Nat. Sci. Phila., 1901, p. 157.

Locality. — Cape Alexander, North Greenland.

" Length of body 8 mm. Rostrum about as long as the head, directed
obliquely upward. Head with one lateral angulation, directed for-
ward. Eyes elliptical. Segments of pereion dor-
sally smooth, without any spines or tubercles.
First segment lateral^ with two angulations,
both of them directed obliquely forward. Sec-
ond and third segments with four short angula-
tions, the anterior and posterior subequal, the
third the smallest. Fourth segment with two
angulations, the anterior directed forward, the
posterior smaller and directed a little backward.
Fifth, sixth, and seventh segments with a
large anterior and very small posterior an-
gulation. All the angulations of these seg-
ments are comparatively short. Pleon with two
bluntly triangular angulations on either side
of a bluntly triangular central portion. Uropods
about as long as pleon. styliform, outer
branch a little shorter than inner. Flagellum
of first antenna fifteen articulate; flagellum
of second antenna with more than oue hundred FIG. sis.— IOLELLA

. (AFTER ORTMAXN).

and hity annulations.

"In the wanting tubercles of the dorsal surface and the form of
the lateral angulations this species is related to the two species of the

464 BULLETIN 54, UNITED STATES NATIONAL MCSEUM.

genus known from the North Pacific, and the form of the pleon recalls
that of /. erostrata Richardson (Aleutian Islands). But it differs (1) in
the presence of a long rostrum, (2) in the stronger development of the
lateral angulations of the head, (3) in the slightly different angulations
of the second and third segments of the pereion." — ORTMANN.°

IOLELLA ALASCENSIS Benedict, new species. &

The head is much broader than long; the rostral projection is

nearly" as long as the head itself. The rostrum is broad at the base,
but narrow and tapering throughout the greater part
of its length; the apex is rounded. The sides of the
head are laterally expanded and produced forward
be}-ond the line of the front; the lateral projections
are accentuated b}T a deep concavity occupying the
outer half of the front. The antenna1 are both
broken and lost from the distal end of the third
article of the peduncles.

The first segment of the thorax is strongly pro-
duced at its posterior half; the anterior half is diag-
onal and emarginate. The epimeron is large and pro-
duced and placed at the anterior part of the segment.
The second and third segments are strong^ produced
at both angles with a nearly straight margin between
the projections. The epimera are bifurcate and
placed between the anterior and posterior projections.

The fourth, fifth, sixth, and seventh are produced at the anterior

angles only, the produced portions becoming successively wider. The

epimera are placed at the posterior angles.

The pleon consists of a single segment made up of three longitudinal

lobes; the middle lobe is much narrower and shorter than the outer

ones; all are rounded at the distal extremity.

The anterior feet are as in the genus, but the propodus is wide,

with the basal half of the prehensile edge finely serrate.

From the line of the eyes to the end of the pleon the specimen is

sparsely ornamented with very small rounded black spots.

Described from a single specimen taken by Captain Heal}T, of the

U. S. revenue steamer Corioin, latitude 71.02 north, longitude 157.46

west, in 19 fathoms.

«Proc. Acad. Nat. Sci. Phila., LIII, Pt. 1, 1901, pp. 157-158.

6The following description is from Doctor Benedict's manuscript, which he has
very kindly permitted me to publish at this time.

c Fig. 519 is through the courtesy of Dr. J. E. Benedict.

FIG. 519c.— IOLELLA
ALASCENSIS.

ISOPODS OF NORTH AMERICA.

465

IOLELLA EROSTRATA (Richardson).

lanthe erostrala RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 858-859;
Ann. Mag. Nat. Hist. (7), IV, 1899, p. 325; American Naturalist, XXXIV,
1900, p. 299.

Locality. — Chichagof Harbor, Attu (the Aleutian Islands), Alaska.

Head two and a half times broader than long, with prominent
antero-lateral angulations. Lateral margins pro-
duced, entire. In place of the rostrum, which marks
many of the known species of this genus, there is a
small median point. The eyes are dorsally situated
a short distance from the lateral edges. The first
pair of antennas are short, not equal to the width of
the head. The second pair are broken in the only
specimen.

The first thoracic segment is produced laterally in
two angulations. The second, third, and fourth seg-
ments are each produced in two angulations, with a
small epimeral lobe in between. The fifth, sixth,
and seventh segments have each a large anterior lobe
and a small posterior epimeral lobe.

The terminal segment has two bluntly triangular
angulations, one on either side of a bluntly triangular
central portion. The uropoda are about as long as the
caudal segment, are stj^liform, with branches jiearl\r
equal. The distal extremity of the peduncle and the
branch of the first pleopoda of the male are fused and produced at the
tip, as in Janiropsis Sars. The first pair of legs are prehensile. The
others are simple, bi-unguiculate. One specimen, a male, was collected
at Chichagof Harbor, Attu (Aleutian Islands), by Dr. W. H. Dall.

Type.—C&t. No. 22610, U.S.N.M.

IOLELLA HOLMESI (Richardson).
Tole holmesi RICHARDSON, Bull. U. S. Fish Comm., XXIV, 1905, pp. 216-217.

Localities. — Stephens Passage, southeastern Alaska; vicinity of
Naha Bay, Behm Canal, southeastern Alaska.

Depth. —41 to 188 fathoms.

Body yellow in color, spotted with numerous brown dots.

Head broader than long, with frontal margin almost straight, very
slightly produced in the middle. On either side, a little anterior to the
middle of the lateral margin, is a process terminating in two spines.
The eyes are large, composite, and placed near the lateral margin,
about halfway between the posterior and anterior margins of the
head. The first pair of antennae extend to the end of the fourth joint
of the peduncle of the second pair. The basal joint of the peduncle
28589—05 30

FIG. 520. — I O L E L L A
EROSTRATA. X 13j.

166

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 521. — lOLELLA
HOLMESI. X 7.

is large, dilated; the two following joints are slender; the flagellum

consists of twenty joints. The second pair of antennae are longer

than the body. The first four joints are short, with an articulated

exopod on the third joint; the fifth and sixth joints are very long,
the fifth being slightly longer than the sixth; the
flagellum consists of numerous joints.

The posterior portion of the lateral margin of the
first segment of the thorax is produced on either side
in a triangular process; the epimeron is situated at the
anterior portion of the lateral margin and is produced
in a triangular process about as long as the posterior
one. The anterior as well as the posterior lateral
angles of the second and third segments are each pro-
duced in a long process, with the bifurcate epimeron
situated between. The anterior portion only of the
lateral margin of the fourth segment is produced with
the bifurcate epimeron situated at the posterior portion
of the segment. The fifth, sixth, and seventh segments
have the anterior portion of the lateral margin pro-
duced in a process which extends outward and down-
ward and in the last segment is triangularly produced

at the posterior extremity, the epimeron in each segment occupying

the posterior portion of the segment.

The abdomen is composed of a single segment, the posterior margin of

which has a widely rounded median expansion with an acutely pointed

lateral expansion on either side. The uropoda

are about equal to the abdomen in length; the

outer branch is slightly shorter than the inner

one; the basal joint is equal in length to the

outer branch.

The legs are all furnished with bi-unguiculate

dactyli. The first pair are prehensile, the carpus

being very large and armed with spines along

the inner margin; the propodus is serrulate along

the inner margin at the proximal end.
Two specimens, both females, were taken by

the U. S. Bureau of Fisheries steamer Albatross

at station 4253, Stephens Passage, southeastern

Alaska, and station 4228, vicinity of Naha Bay,

Behm Canal, southeastern Alaska. Depth, 41 to 188 fathoms.

in the U. S. National Museum, Cat. No. 29249.

This species is named for Dr. Samuel J. Holmes, who has done much

work on the Crustacea of the Pacific coast.

FlG. 522.— lOLELLA HOLMESI.
FIRST LEG OF FEMALE. X
20*.

Type

ISOPODS OF NORTH AMERICA.

467

IOLELLA SARSI, new species.

Body twice as wide as long, 5 mm. : 10i mm. ; surface densely cov-
ered with short, stiff hairs.

Head wider than long, 2 mm.: 3 mm. Front without rostrum;
anterior margin nearly straight, with only a small, median obtuse
point. Lateral margins produced in an anterior lobe bearing three
feeble spines and a smaller, almost inconspicuous lobe also armed with
three feeble spines. Antero-lateral angles rounded. Eyes moderately
large, round, composite, situated close to the lateral margins. The
first pair of antennae have the basal article of the peduncle large and
dilated; the second article is half as long and about half as wide; the
third article is a little longer than
the second. The flagellum is com-
posed of numerous short articles.
The second pair of antennae are
broken at the fourth article of the
peduncle, and the distal parts are
lost. There is a distinct scale out-
side the third article. The articles
of the peduncle, as well as the an-
tennal scale, are beset with spines.

The tirst segment of the thorax
has both the anterior and the pos-
terior angles produced in long, nar-
row processes, with the epimeron,
consisting of a single, narrow pro-
cess, situated between the two.
The second and third segments of
the thorax have the anterior and the
posterior margins produced into
long, narrow processes, with the

epimeron, consisting of two long processes, situated between the two.
The fourth segment has the anterior portion only produced in a long,
narrow process, with the epimeron produced in two processes, and
situated in the posterior emargination of the segment. The fifth,
sixth, and seventh segments have the anterior part produced and
gradually increasing in width, with the epimeron situated in the pos-
terior emargination of the segment. The lateral processes of the
segments, as well as the epimera, are beset with spines.

The abdomen consists of a large terminal segment, with two short
segments anterior to it, evident onlv in the middle part, being covered
at the sides by the seventh thoracic segment.

The terminal segment is broader than long, 3 mm.: ^ mm. The

FIG. 523.— IOLELLA SARSI.

468 BULLETIN o4, UNITED STATES NATIONAL MUSEUM.

post-lateral angles are acutely produced but short. Between the post-
lateral angles the posterior margin is trilobate, the median lobe being
the largest, and not longer than the post-lateral angles. The margins
of the segment are beset with spines.

The uropoda are lost in the only specimen.

The distal extremity of the peduncle and the branch of the first
pleopoda of the male are fused and have the tip dilated and pro-
duced as in Janiropxis Sars.

The type, a male, and the only specimen, was collected by Dr. W. H.
Dall at Constantino Bay, Amchitka Islands, Alaska, in 1873. Depth
8 fathoms.

The type is in the U. 8. National Museum, Cat. No. 32076.

This species is very closeh7 related to loletta holmesi (Richardson), but
differs in the shape of the terminal abdominal segment, in having the
anterior angles of the first thoracic segment produced with the epi-
meron situated between the antero- and post-lateral processes, and in
having the lateral margins of the head but little produced and armed
with numerous spines.

This species is named in honor of Prof. G. O. Sars, the distinguished
carcinologist, for whose courteous and generous permission to repro-
duce his plates in this work, I am most grateful.

75. Genus JANIRA Leach. «

Body oblong, depressed. Lateral parts of head not produced or
but slightly produced. Eyes distinct, sub-dorsal. Front of head
obtuse or produced in a comparitively small rostrum.

First pair of antennas well developed, with the flagellum multi-
articulate. Second antennas very much elongated, with scale outside
of third article of peduncle. Maxillipeds with the second and third
articles of the palp not expanded.

Segments of thorax with lateral parts not produced into lappets.

The distal extremity of the peduncle and the branch of the first
pleopoda of the male not dilated at the tip.

Uropoda largely developed.

First pair of legs prehensile in both sexes; dactylus in all the legs
tri-unguiculate.

Terminal segment of the body rounded, not expanded laterally.

ANALYTICAL KEY TO THE SPECIES OP THE GENUS JANIRA.

a. Anterior margin of the head straight.

b. First pair of legs alike in both sexes, with carpus large, subfusiform, and edged
inside with spines. Distal part of lateral margins of terminal segment of body
coarsely serrated. Epimera bilobed Janira maculosa Leach

«See Sars for characters of genus, Crust, of Norway, II, 1899, pp. 98-99.

I8OPODS OF NOKTH AMERICA. 469

l>'. First pair of legs unlike in the two sexes, though prehensile. In male the car-
pus of the first pair of legs is large and produced on the inside at its outer
distal end in a long acute process, between which and the articulation of the
propodus are two long acute processes about half as long as the outer process.
Distal part of lateral margins of terminal segment of body not serrated.

Epimera single lobed Janira minuta Richardson

a'. Anterior margin of the head not straight.
b. Front of head trilobate, the central lobe subacute, rather longer than others,

but not rostrate Janira occidentalis Walker

V . Front of head produced in the middle in a short, sharp rostrum, and the antero-

lateral angles of the head also produced.

c. Antero-lateral angles of head sharp. Lateral margins of first four thoracic
segments obtusely incised, each showing two broad angulations. Uropoda
of female shorter than half the terminal segment; those of male as long as

terminal segment of body Janira tricornis (Kr0yer)

c'. Antero-lateral angles of the head very slightly produced and rounded. Mar-
gins of the first thoracic segment rounded, not emarginate. Uropoda alike
in the two sexes, and longer than the terminal segment of the body.
Abdomen serrate on posterior half of lateral margin . . Janira alta ( Stimpson )

JANIRA MACULOSA Leach.

Janira maculosa LEACH, Edinburgh Encyclop., VII, 1813-14, p. 434.

Oniscoda maculosa LATREILLE, Cuvier's Regne Anirn., 2d ed., IV, 1829, p. 141. —
MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 151.

Henopomus muticus KR0YER, Voy. en Scand., Crust., 1849, pi. xxx, figs, la-n;
Nat. Tidsskr. (2), II, 1846-49, p. 366.— BATE and WESTWOOD, British
Sessile-eyed Crust., II, 1868, pp. 338-340.— HANSEN, Vid. Medd. Naturh.
Foren. i Kj0bh., 1887-88, p. 190.— SABS, Crust. Norway, II, 1899, pp. 99-
100, pi. XL. — RICHARDSON, American Naturalist, XXXIV, 1900, p. 299;
Proc. U. S. Nat. Mus., XXIII, 1901, p. 555.

Localities. — Latitude 66° 32' north, longitude 55° 34' west; lati-
tude 72° 32' north, longitude, 58° 51' west; also, British Isles; Kat-
tegat; Dutch coast; coast of France; coast of Norway.

Depth.— SO to 116 fathoms.

" Body oblong oval in form, about three times as long as it is broad,
and slightly narrowed both in front and behind. Cephalon with the
lateral expansions evenly rounded, frontal edge straight, without a
trace of rostrum. Anterior segments of mesosome with the lateral
parts slightly produced at both corners, but not covering the small
coxal plates, which are bi-lobate. Caudal segment sub-circular, distal
part of lateral edges coarsely serrated. Eyes well developed, rounded
oval, with dark pigment. Superior antennae reaching about to the
end of the penultimate peduncular joint of the inferior ones, flagel-
lum more than twice as long as the peduncle, and composed of about
thirty articulations. Inferior antennae considerably exceeding the
length of the body, the last two peduncular joints rather elongated,
subequal, flagellum about twice the length of the peduncle. Epignath
of the maxillipeds with the outer edge angular in the middle. First
pair of legs with the carpus about the length of the two preceding

470 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

joints combined, and armed inside with 18-20 spines; dactylar claws
in all pairs nearly equal. Middle piece of male operculum not
expanded at the end, which is quadrilobate. Uropoda exceeding in
length the caudal segment, basal part rather elongated, though not

FIG. 524.— JANIKA MACULOSA (AFTER SAKS), a, ANTERIOR LIP. b, DORSAL VIEW OF FEMALE, c,
MAXILLIPED. d, FIRST MAXILLA, e, FIRST ANTENNA. /, SECOND MAXILLA. 0, MANDIBLE. A, MAN-
DIBLE WITH PALP, i, SECOND ANTENNA, j, FIRST LEG. k, POSTERIOR LIP. I, UHOPOD. in, FOURTH

PLEOPOD OF FEMALE. 11, FIFTH LEG. 0, ABDOMEN (INNER SIDE), p, THIRD PLEOPOD OF FEMALE.

q, FIFTH PLEOPOD OF FEMALE, r, FEMALE OPERCULUM. «, FIRST AND SECOND PLEOPODS OF MALE.
t, TERMINAL JOINT OF FIFTH LEG.

quite as long as the inner ramus, outer ramus somewhat smaller than
the inner, both being linear in form. Color, yellowish, densely
mottled with reddish brown specks. Length of adult female, 7 mm.,
of male, 10 mm/'— G. O. SARS.«

« Crust, of Norway, II, 1899, pp. 99-100.

ISOPODS OF NORTH AMERICA.

471

JANIRA MINUTA Richardson.

Janira minuta RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p. 297, pi.
xxxix, figs. 50-52.

Locality. — Castle Harbor, Bermudas, in dead coral.

Surface of body smooth. Color light }-ellow, almost white, spotted
with black.

Head with frontal margin straight ; eyes large, conspicuous, oblong,
and situated at the lateral margin. First pair of antennae with the
three peduncular articles equal in length, the first one, however, being
very much the broadest, the second a little stouter than the third;
flagellum multi-articulate, composed of about ten or eleven articles.
The second pair of antennae have a scale outside the third article of
the peduncle; flagellum multi-articulate, much longer than the body.
Thoracic segments subequal in length. First segment with the lateral

FIG. 526.— JANIKA MINUTA. a, LEG OF FIRST PAIK OF FEMALE, x 58. 6, TERMINAL SEGMENT AND
UROPODA. x 58. c, LEG OF FIRST PAIR OF MALE.' x 58.

margin entire, epirneron not evident from a dorsal view. Second and
third segments with margins entire, straight, epimera evident about
the middle of the segments. Fourth segment with the posterior half
of the lateral margin slightly excavate, the epimeron evident in the
excavation. The last three segments with the lateral margins entire,
the epimera evident as small lobes at the post-lateral angles.

The terminal segment is about as broad as long, rounded posteriorly
with a median lobe between the peduncular joints of the uropoda.
The uropoda extend much beyond the terminal segment, being longer
than that segment. The outer branch is somewhat shorter than the
inner branch; both branches are longer than the peduncle, and are
fringed with long hairs.

In the female the first pair of legs are prehensile; the others are
simple walking legs, with bi-unguiculate dactyli. In the male, how-
ever, the first pair of legs are modified, though prehensile. The

472 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

carpal joint is very much enlarged and is produced on the inside, at
the outer distal end, in a long, acute process, between which and the

articulation of the propodus are two long
acute processes about half as long as the
outer process. The propodus is similar
to that of the female; the dactylus is b.i-
unguiculate.

A number of specimens, both males and
females, were collected by Prof. A. E. Ver-
rill and party in 1898, at Castle Harbor.
Bermudas.

Type specimens in Peabody Museum, Yale
University. Cat. Nos. 3194 and 3261.

JANIRA OCCIDENTALIS Walker.

Janira ocddentalis WALKER, Trans. Liverpool
Biol. Soc., XII, 1898, pp. 280-281, pi. xv, figs.
7-10. — RICHARDSOX, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 859; Ann. Mag. N,at. Hist.
(7), IV, 1899, p. 326; American Naturalist,
XXXIV, 1900, p. 300; Harriman Alaska Exp.,
Crust., X, 1904, p. 224; Proc. U. S. Nat. Mus.,
XXVII, 1904, p. 667.

Locality. — Puget Sound, Washington.
Body oblong-ovate, three times longer
than wide, 2 mm. :6 mm.
Head, about twice as wide as long, with the anterior margin sinuate,
but not produced in a frontal median process. The lateral margins
are straight, with the antero-lateral angles a little produced and
rounded and the post-lateral angles rounded. The eyes are large,

FIG. 526. — JANIKA OCCIDENTALIS
(AFTER WALKER), a, HEAD AND
FIRST THORACIC SEGMENT. b,
ABDOMEN AND PART OF PREVIOUS
SEGMENT OF THORAX.

FIG. 527. — JANIRA OCCIDENTALIS. a, ABDOMEN WITH UROPODA.O 6, MAXILIIPED. x 51| c, MANDI-
BLE, x 61|. d, FIRST LEG. x 27}.

round, composite, and dorsally placed. The first pair of antennae
have the first and third articles about equal in length; the second is

« The outer branch of both uropoda is broken off and lost in the only specimen of
the U. S. National Museum collection.

ISOPODS OF NORTH AMERICA.

478

about one and a half times longer than the third. The flagellum is
composed of eleven articles. The second pair of antennae have the
first four articles short and nearly subequal, the first two being some-
what shorter than the last two. An antennal scale is articulated to the
third article. The fifth and sixth articles are long, the sixth being a
little longer than the fifth. The fifth article is 1 mm. in length; the
sixth is a little more than 1 mm. long. The flagellum is multi-
articulate, and 2 mm. long. The maxillipeds have a palp of five
articles. The palp of the mandibles is composed of three articles.

The first segment of the thorax has the post-lateral lobe large and
produced, the antero-lateral lobe obsolete, with the epimeral lobe at the
antero-lateral angles. The second and
third segments have the antero- and
post-lateral lobes small, but produced
and conspicuous, the lateral margin
between them being straight; the
epimeron is in two lobes, and occu-
pies a position between the antero-
and post-lateral lobes in both seg-
ments. The fourth segment has the
antero- and post-lateral lobes small,
but produced and conspicuous; the
post-lateral lobe is smaller than the
antero-lateral lobe, while in the two
preceding segments the antero-lateral
lobe is the smaller one; the epimeron
of the fourth segment is a single lobe
between the antero- and post-lateral
lobes. In the fifth segment the antero-
lateral lobe is large and produced, the
post-lateral lobe minute, and almost
inconspicuous; the epimeron is a sin-
gle lobe between the two. The sixth
and seventh segments have the antero-lateral lobes large and promi-
nent, the post-lateral lobes obsolete, and the epimeron situated at the
post-lateral angles.

The abdomen is composed of a single large segment, the post-lateral
angles of which are small but very acutely produced. The posterior
margin has a large median rounded lobe. The uropoda are not quite
as long as the abdomen. The peduncle is about one-third the length
of the terminal segment. The inner branch is one and a half times
longer than the peduncle. The outer branch is lost in both uropoda of
the specimen examined.

The first pair of legs are prehensile, but not longer than the others.
The six following pairs are ambulatory, with bi-unguiculate dactyli.

FIG. 528. — JANIRA OCCIDENTALS (AFTER
WALKER), a, FIRST LEG. b, THIRD LEG.

474

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

JANIRA TRICORNIS (Kr0yer).

Henopomus tricornis KR0YER, Voy. en Scand., Crust., 1849, pi. xxx, figs. 2 a-q;

Nat. Tidsskr. (2), II, 1846-19, p. 372-379,

380.

Janira tricornis HAXSEX, Vid. Medd. naturh.
Foren. i Kj0bh., 1887-88, pp. 190-191.—
RICHAKDSOX, Amer. naturalist, XXXIV,

1900, p. 300; Proc. U. S. Nat. Mus., XXIII,

1901, p. 555. — STEBBIXG, Ann. Mag. Nat.
Hist. (7), V, 1900, p. 14.— OHLIX, Bihang
till K. Sv. Vet.-Akad. Handl., XXVI,
Afd. iv, No. 12, 1901, pp. 30-31.

Localities. — Kangerdluarsuk ; Sukker-
toppen; Egedesminde; latitude 65° 11'
north, longitude 53° 33' west.

Depth.— 5 to 50 fathoms; 20 to 80 me-
ters (Ohlin).

Body wide, the width equaling almost
half the length.

Head armed anteriorly with three horns
or spines, placed in a transverse series.

The second pair of antennae are equal
to the length of the bod}^ the second
article of the peduncle is very stout and
armed on the exterior margin with a large spine (scale).

FIG. 529.— JANIRA TRICORNIS (AFTER

KR0YER).

FIG. 530.— JANIRA TRICORNIS (AFTER KROYER). SHOWING DETAILED PARTS.

ISOPODS OF NORTH AMERICA.

475

The abdomen is subelliptical in shape or obsoletely six angulate,
much wider than long.

The median lobe of the covering lamella of the pleopods (the
peduncle of the first pleopoda) in the males is posteriorly entire. a

A fuller description of this species is given in the preceding pages
(372-379) of the work from which the above is quoted.

JANIRA ALTA (Stimpson.)

Asellodes alta STIMPSON, Smithsonian Contributions to Knowledge, VI, 1853, p.
41, pi. in, fig. 30.— VERRILL, Am. Jour. Sci., VI, 1873, p. 439; VII, 1874,
pp. 411-502; Proc. Amer. Assoc., 1874, p. 350.

Janira alta HARGER, Proc. U. S. Nat. Mus., II, 1879, p. 158; Report U. S. Com-
missioner of Fish and Fisheries, 1880, Pt. 6, pp. 321-322, pis. n-iii, figs. 9, 12,
13. — RICHARDSON, American Naturalist, XXXIV, 1900, p. 300; Proc. U. S.
Nat. Mus., XXIII, 1901, p. 556.

Localities. — Long Island; Massachusetts Bay; near Eastport, Maine;
Gulf of Maine; Grand Menan; Bay of Fundy; 120 miles south of
Halifax; Grand Banks; Glarkes Ledge;
30 miles east of Sable Island; off Ghes-
apeake Bay.

Depth.— 35 to 487 fathoms.

Body oblong-ovate, nearly three
times longer than wide, 2£ mm.: 7
mm., not including the uropoda.

Head nearly three times as broad as
long, with the lateral portions expand-
ed and the lateral margins straight.
The front is produced in the middle
in a long narrow process with apex
rounded. The eyes are small, round,
composite, and dorsally placed. The
antero-lateral angles of the head are
very slightly produced and are rounded.
The first pair of antenna? have the
three articles, forming the peduncle,
about equal in length. The flagellum is composed of fourteen articles.
The second pair of antennas have the first four articles short and
subequal; the two following ones are very long, the sixth being longer
than the fifth. The sixth article is 2 mm. in length; the fifth is 1£
mm. long. The flagellum is multiarticulate and is 5 mm. long. The
second antennas are as long as the body. The maxillipeds have a palp

«The above description is adapted from the following one of Kr0yer's:
Latior (latitude dimidiam fere sequans longitudinem ) . Caput antice tribus arma-
tum cornibus vel aculeis, serie positis transversali. Antennae inferiores longitudinem
animalis aequantes, articulo pedunculi secundo crassissimo, aculeo marginis exterioris
maximo. Abdomen subellipticum vel obsolete sexangulatum, multo latius quam
longum. Lobus laminae branchiarum tectorise intermedius apud mares postice
jnteger.— KR0YER, Nat. Tidsskr. (2), II, 1846-49, pp. 372-379, 380.

FIG. 531. — JANIRA ALTA (AFTER HARGER).
x 5.

476

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of five articles. The palp of the mandibles is composed of three

articles.

The first segment of the thorax has the post-lateral lobes large and

prominent; the antero-lateral lobes are obsolete, but small epimeral

lobes, one on either side, are conspicuous at the antero-lateral angles

of the segment. The second,
third, and fourth segments
have each a conspicuous but
small antero-lateral lobe on
either side, produced beyond
the large post-lateral portion
of the segment, and between
the anterior and posterior
lobes is the small but conspic-
uous epimeral lobe. The last
three segments have a large
antero-lateral lobe, with the
post-lateral lobe obsolete, and
the small epimeral lobe situ-
ated at the post-lateral angles.
The abdomen is composed
of a single large segment, the
post-lateral angles of which
are widely rounded, and the
posterior margin has a prom-

FIG. 532.— JANIRA ALTA. a, ABDOMEN WITH UROPODA. inent rounded median lobe.
x 15| . b, MAXILLIPED. x 51|. c, FIRST LEG. x 27|. rpi^ «:^M u i* t ±\ i *

d, MANDIBLE, x 5i|. The posterior half of the lat-

eral margins and the margins

of the post-lateral angles are strongly serrate. The uropoda are about
one and a fourth times longer than the abdomen. The peduncle is as
long as two-thirds the length of the abdomen. The outer branch is as
long as the peduncle. The inner branch is one and a half times the
length of the outer branch.

The first pair of legs are prehensile, but are not longer than the
others. The six following pairs are ambulatory with bi-unguiculate
dactyli.

76. Genus J^EROPSIS Koehler.

Eyes present. Both pairs of antennae extremely small ; flagellum of
first pair obsolete; flagellum of second pair rudimentary. Articles
of peduncle of second antennae dilated. Epignath of maxillipeds nar-
row, produced to a tapering extremity. Apex of mandibles produced
in five teeth.

Segments of thorax separated at the sides, not forming an unbroken
continuous lateral line.

ISOPODS OF NORTH AMERICA.

477

Legs simple, similar in structure; dactylus bi-unguiculate.
Uropoda .short, extremely small.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS J^EROPSIS.

a. Head, second, third, fourth, and seventh thoracic segments and abdomen brown.
First, fifth, and sixth thoracic segments perfectly white and colorless. Median
lobe of terminal segment of body rounded. Frontal process of head as long as

side of head. Eyes moderately large Jaropsis lobata Richardson

a'. Color uniformly white. Median lobe of terminal segment of body acute. Frontal
process of head about half as long as lateral margin of head. Eyes small.

JaeropSM rathbunse Richardson

J^EROPSIS LOBATA Richardson.

Jseropm lobata RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, pp. 859-860;
Ann. Mag. Nat. Hist. (7), IV, 1899, pp. 326-327; American Naturalist
XXXIV, 1900, p. 300.

Locality. — Monterey Bay, California.

Surface of body smooth.

Color very peculiar and striking. The head is brown. The first

thoracic segment is perfectly white, without any markings. The
second, third, and fourth seg-
ments are brown. The fifth and
sixth are white. The seventh
thoracic segment and the caudal
segment are brown. This pe-
culiar marking gives the body a
striped appearance.

Head large; front produced

into two prominent triangular processes, on either
side of a deep median excavation in which is placed a
small lobe; this gives the head the appearance of being
produced in a large rounded median lobe. The antero-
lateral angles of the head are acutely produced on either
side to a distance equal to one-third the length of the
frontal process. The eyes, which are small, are situ-
ated 'on the extreme lateral margins of the head. The
first pair of antennae are extremely small, equal in
length to less than half the width of the head; nagellum
obsolete. The second pair of antennae are also ex-
tremely short, equal in length to the width of the
head, with rudimentar}7 nagellum, composed of about
five joints, and with peduncular joints dilated. Man-
dibles have the cutting part composed of five teeth;

palp, three-jointed.
The thoracic segments are subequal in length, with lateral edges

produced, but not laciniate, and separated from each other by lateral

incisions.

FIG. 533. — JjEROPSIS LOBATA.

HEAD, x 27}.

FIG. 534. — J.EROPSIS
LOBATA. MAXIL-
I.IPED AND MAN-
DIBLE.

478 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Caudal segment regularly rounded, with two small incisions at the
place where the uropoda are attached, between which is a rounded
lobe. Uropoda are extremely small, short, nodiform.
Legs simple, similar in structure, with bi-unguicu-
late dactyli.

Two specimens from Monterey Bay, California,
were sent by Mr. Heath.

Type. —Cat. No. 22583, U.S.N.M.
This species is very close to Jseropxt* krevicomis,
but differs in the following points: The coloring of
the body, which in J. brevicornis is perfectly trans-
— ' — > parent and colorless, with the exception of the head,

} which is marked with a large brown spot, while in

r~r~ \ our species the head is dark, as are

*• ' also the entire second, third, fourth,

and seventh thoracic segments and
the terminal abdominal segment,
the other segments being colorless;
in the shape of the terminal seg-
ment, which is perfectly rounded in
J. hrevicornis and fringed with hairs,
while in our species there are two
posterior incisions for the reception
of the uropoda, and an absence of
hairs; in the larger median lobe on

the anterior margin of the head; in the acuteness of the antero-lateral
angles of the head, which are rounded in J. brevicornis; in the more
angular post-lateral angles of the head, and in the more angular antero-
and post-lateral angles of the thoracic segments. Other differences
are noticed from a comparison of both pairs of antennae.

J^ROPSIS RATHBUN^ Richardson.

Jseropsis rathbunae RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p. 298,
pi. XL, figs. 53-55.

Locality. — Bermudas.

Body elongate, depressed; segments loosely articulated; surface
smooth ; color uniformly light, almost white.

Head with a median excavation, on either side of which the frontal
margin is produced into angulations. On either side of these angula-
tions is another excavation, on the outside of which are lateral angula-
tions. A rounded lobe is placed in the median excavation. The eyes
are small and are situated near the lateral margins about halfway
between the anterior and posterior margins. The first pair of antennae
consist of five joints, the two first joints being large, the three follow-

F I G . 535.— J^KOPSIS
LOB AT A. X20.

FIG. 536.— J,EROPSIS
LOBATA. ANTENNA.

ISOPODS OF NORTH AMERICA.

479

ing ones small, the last fringed with hairs. The second pair of anten-
nae have a rudimentary flagellum, consisting of five or six joints; the
peduncle has the third and fifth joints long and oval in shape, the
fourth joint somewhat triangular.

The thoracic segments are loosely articulated. The lateral mar-
gins are straight, with no indication of
epimera.

The terminal segment of the body is
rounded in outline, the posterior margin
excavated at the insertion of the uropoda,
which do not extend beyond the edge of
the segment, thus preserving the oval
outline. Between the uropoda there is
an acute median projection.

The legs are all simple, with bi-unguic-
ulate dactyli.

One specimen was collected by Prof-.
A. E. Verrill and party at the Bermudas,
and another by Dr. G. B. Goode, from
the same locality.

Type specimens in Peabody Museum,
Yale University. Cat, No. 3251.

Six species of this genus have been
heretofore described: Jseropsis lobata
Koehler, Jseropsis marionis Beddard,
Jseropsis neo-zealandica Chilton, Jseropsis

lobata Richardson, Jseropsis dollfusi Norman, and Jseropsis curmcornis
(Nicolet).a The present species adds another to the above list.

It is named in honor of Miss Mary J. Rathbun.

Family XVIII. MUNNID^E.6

Body ovate, short and stout, with the three posterior segments of
the thorax sharply marked off from the four anterior ones and much
smaller, and gradually becoming narrower. Terminal segment of
body vaulted above, subpyriform.

Eyes, when present, placed on the tips of lateral peduncle-like pro-
jections of the head. First pair of antennae placed widely apart, with
the flagellum multi-articulate. Second pair of antennae without scale.

First pair of legs much shorter than the following pairs and pre-
hensile. Succeeding pairs more or less rapidly increasing in length,
simple, ambulatory. Uropoda small, somewhat separated.

Pleopoda as in the Janiridse.

a Jura curvicornis Nicolet, in Gay's Hist, de Chile, III, 1849, p. 263, Zool. Atlas,
Crust., No. 3, fig. 10. This species should be referred to the genus Jseropsis.
&See Sars for characters of family, Crust, of Norway, II, 1899, p. 105.

FIG. 537. — J.EROPSIS RATHBUN.E. a,
HEAD AND FIRST THORACIC SEGMENT.
6, MAXILLIPED. c, TERMINAL SEG-
MENT AND UROPODA. d, MANDIBLE.

e, MANDIBLE (ANOTHER VIEW).

480 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

77. Genus MUNNA Kr^yer.«

Body sub-pyrif orm, vaulted, with the last three segments of the
thorax very small. Terminal segment of body narrow, sub-pj-riform.

First pair of antennae short. Second antennas very much elongated,
with the last two articles of the peduncle long and slender.

First pair of legs subcheliform, comparatively small in female, but
well developed in male. Last six pairs of legs ambulatory and rapidly
increasing in length. Dactylus bi-unguiculate.
- Uropoda small, simple.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS MUNNA.

a. /Surface of body smooth. Eyes present.

b. Caudal segment with lateral edges evenly convex, ana each armed with a single
slender denticle; apical lamellae distinctly serrated. Eyes large. First pair of
antennae with flagellum composed of four joints, including very small apical
joint. Flagellum of second antennae longer than peduncle. Last pair of
legs scarcely longer than body. Legs slender. Uropoda obliquely truncate

at tip Munna faljricii Kr0yer

b'. Caudal segment with lateral edges rather bulging in front, and each armed with
four strong denticles; without any serrulated lamellae. Eyes small. First pair
of antenme with flagellum composed of three joints, including very small apical
joint. Flagellum of second antennae not attaining length of peduncle. Last
pair of legs scarcely longer than anterior division of body. Legs shorter and
stouter than usual. Uropoda produced at tip into several dentiform projec-
tions, one of which is hook-like Munna kreyeri Goodsir

a' '. Surface of body covered with numerous spines. Eyes absent.

Munna caeca, new species

MUNNA FABRICII KrjzSyer.

Munna fabridi KRISYER, Naturh. Tidsskr.. (2), II, 1846-1849, p. 380; Voy. en
Scand., Crust., 1849, pi. xxxi, figs. la-q. — REINHARDT, Naturhistorisk Bidrag
til en Beskrivelse af Gronland, 1857, p. 35. — M. SARS, Chr. Vid. Selsk. Forh.,
1858, p. 154, 1859. — LUTKEN, Crust. Greenland, 1875, p. 150. — HARGER, Proc.
U. S. Nat. Mus., II, 1879, p. 159; Report U. S. Commissioner of Fish and
Fisheries, 1880, Pt. 6, pp. 325-328, pi. in, fig. 14.— HANSEN, Videnskabelige
Meddelelser fra den naturhistoriske Foreniug i Kj0benhavn, 1887-88, pp.
193-194.— G. O. SARS, Crust. Norway, II, 1899, pp. 108-109, pi. XLV, fig. 2.—
STEBBING, Ann. Mag. Nat. Hist. (7), V, 1900, p. 14. — RICHARDSON, American
Naturalist, XXXIV, 1900, p. 300; Proc. U. S. Nat. Mus., XXIII, 1901, p.
556.

Localities. — South Bay, Eastport; Casco Bay; Western Bank;
Browns Bank; southern Greenland; Godhaven, Egedesminde, Uper-
nivik, latitude 66° 30' north, longitude, 54° 50' west; also coast of
Finmark; coast of Norway.

Depth. — 4 to 200 fathoms. Sars says it occurs, in moderate depths,
among Hydroida.

" Body rather short and compact, with the anterior division rounded

«See Sars for characters of genus, Crust, of Norway, II, 1899, p. 106.

ISOPODS OF NORTH AMERICA.

481

oval in outline. Ocular processes rather thick and less prominent
than in Munna limicola. Caudal segment oblong oval, but slightly
narrowed behind, lateral edges
evenly convex, and each armed
in front with a single slender
denticle; apical lamellae dis-
tinctly serrated. Eyes rather
large, semi-globose. Supe-
rior antenna? scarcely reaching
to the middle of penultimate
peduncular joint of the inferior
ones; flagellum composed of
only four joints, including the
very small apical one. Inferior
antennae rather slender, with
the flagellum longer than the
peduncle. Legs comparatively
slender, though less rapidly in-
creasing in length posteriorly than in the two preceding species ( M. boecM
Kr0yer and M. limicola Sars); first pair, as usual, much the shortest,

FIG. 538. — MtJVNA FABRICII (AFTER HARGER). X 20.

FIG. 539. — MUNNA FABRICII (AFTER SARS). a, FIRST LEG. 6, FIRST ANTENNA, c, DORSAL VIEW. OF
FEMALE. d, SEVENTH LEG. e, -EXTREMITY OF SECOND LEG. /, SECOND LEG. g, ABDOMEN ANP
UROPODA. h, EXTREMITY OF ABDOMEN WITH UROPODA. i, UROPOD.

28589—05 31

482 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

with the carpus somewhat shorter than the propodus, and armed inside
with three spines; last pair scarcely longer than the bod}T, carpal joint
somewhat dilated distally. Uropoda obliquely truncated at the tip,
and setose at each corner. Color dark brown, from numerous pig-
mentary spots forming irregular shadows. Length of adult female
scarcely reaching to 3 mm." — G. O. SARS/*

FlG. 540.— MUNNA KR0YERI (AFTER SAKS), a, DORSAL VIEW OF FEMALE, b, FIRST LEG OF FEMALE.

c, SECOND LEG OF FEMALE, d, FIRST ANTENNA, e, ABDOMEN OF FEMALE WITH UROPODA (DORSAL
VIEW). /.SEVENTH LEG. g, EXTREMITY OF SEVENTH LEG. A, UROPODA. ;', OPERCULUM OF FEMALE.
j, ABDOMEN OF MALE WITH UROPODA (VENTRAL VIEW), k, FIRST LEG OF MALE.

"Crust, of Norway, II, 1899, pp. 108-109.

ISOPODS OF NORTH AMERICA. 483

MUNNA KR0YERI Goodsir.

Munna kr0yeri GOODSIR, Edinburgh New Phil. Jour., XXXIII, 1842, p. 365, pi.

vi, fig. 2. — BATE and WESTWOOD, Brit, sessile-eyed Crust., II, 1868, p. 326.
Munna whiteana BATE and WESTWOOD, Brit, sessile-eyed Crust., II, 1868, p. 329.
Munna kreyerl HANSEN, Vid. Medd. naturh. Foren. i Kj0bh., 1888, pp. 194-195. —

SARS, Crust. Norway, II, 1899, pp. 109-110, pi. XLVI, fig. 1. — EICHARDSON,

American Naturalist, XXXIV, 1900, p. 300; Proc. U. S. Nat. Mus., XXIII,

1901, p. 556.

Localities. — Godhavn and Upernivik, Greenland; also, coast of
Norway.

Depth.— 10 to 60 fathoms.

• "Body of female somewhat robust, with the anterior division oval
in form and the segments very sharply marked off from each other
and clothed laterally with scattered hairs. Body in male, as usual,
much narrower. Ocular processes conically tapered. Caudal seg-
ment comparatively short, scarcely more than half as long as the mes-
osome, and rounded oval in form, lateral edges rather bulging in front,
and each armed with four strong denticles, the posterior pair subdor-
sal, tip bluntly produced, and without any serrated lamellae. Eyes
comparative!}' small, at least in female. Superior antennae very short,
extending not nearly to the middle of the penultimate peduncular
joint of the inferior ones; flagellum composed of only three articula-
tions, including the ver}^ small apical joint. Inferior antennae, as
compared with those in the other known species, of inconsiderable
length, scarcely as long as the body, flagellum not attaining the length
of the peduncle. First pairs of legs in female of the usual structure,
in male considerably stronger, with the carpus considerably expanded
and produced at the end inside to an acute thumb-like projection, the
inner edge of the joint densely setiferous. Ambulator}^ legs in both
sexes shorter and stouter than usual, last pair scarcely exceeding in
length the anterior division of the body. Uropoda produced at the
tip into several dentiform projections, one of which assumes a hook-
like appearance. Color pale yellowish, slightly mottled with light
brown. Length of adult female about 3 mm." — G. O. SARS.°

MUNNA C1ECA, new species.

Body ovate; surface rough and spiny, beset with numerous long
and small spines.

Head produced in front between the basal articles of the antennae
in a rounded process. Eyes absent. Dorsal surface of head beset
with long, narrow spines. About the middle of the head is a long
median spine, with a shorter one on either side. On either side of
the shorter spines is another long spine. Close to the lateral margin
is a long spine. The antero-lateral lobes are produced in bifid spines.

« Crust, of Norway, II, 1899, pp. 109-110.

484

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

On either side of the head the lateral margin is produced in a large
spine. Numerous small spines also beset the dorsal surface of the
head. The first parr of antennte have the first two articles about
equal in length, the second a little more slender than the first; the
third article is twice as long as the second. The flagellum is composed
of twenty -three articles and extends about two-thirds the length of
the fourth article of the peduncle of the second pair of antenna1.
The first three articles of the peduncle of the second pair of antenna?
are short and beset with numerous spines; the fourth article is very

FIG. 541.— MlTNNA CJECA.. X 6.

long; the fifth is equal in length to the fourth. The flagellum is
composed of about twenty-seven articles.

The first four segments of the thorax are the largest. The thorax
is broadest about the third and fourth segments. The following three
segments become gradually much narrower and shorter. The first
segment is beset with numerous long, slender spines. There is a long,
conspicuous spine on either side of the lateral margin of each segment,
and numerous spines, both long and short, with stiff hairs on the dorsal

ISOPODS OF NORTH AMERICA.

485

FIG. 542.— MUNNA CMCA..
FIRST LEG. x 15j.

surface. A long, conspicuous spine projects forward on either side of
the first thoracic segment at the place of union of the lateral part of the
segment with the dorsal portion. The same occurs on the third segment.

The abdomen tapers to a bluntly pointed extrem-
ity. About two-thirds the distance between the base
and the extremity are two strong tubercles, one on
either side of the median line. On either side of
the median line, where there is a comparatively
smooth area, the surface.of the abdomen is covered
with long and short spines. There are also two

long spines on
either side of
the lateral mar-
gin near the
middle of the
segment, and

numerous ones near the base.
The first pair of legs are pre-
hensile. All the others are ambu-
latory, and very much elongated.
The uropoda are small, almost
inconspicuous, single-branched,
and composed of only one tiny
article.

A single specimen of this species was collected by the U. S. Bureau
of Fisheries steamer Albatross at Station 4390, off Santa Catalina
Islands, coast of southern California, latitude 33° 2' 15" north, longi-
tude 120° 42' west. Depth, 2,182 fathoms. The type is in the U. S.
National Museum, Cat. No. 32072.

Family XIX. MUNNOPSID^R.«

Eyes wanting. Two divisions of thorax sharply defined.

First pair of antennae with flagellum well developed. Second pair
of antenna very much elongated.

First pair of legs generally smaller than the others, never subcheli-
form; three following pairs very much elongated and ambulatory in
character; last three pairs of legs natatory in character, with some of
the joints flattened and expanded, and fringed with plumose hairs.

Uropoda small.

Pleopoda as in the Janiridse.

FIG. 543.— MUNNA C.ECA. SECOND LEG.

«See Sars for characters of family, Crust, of Norway, II, 1899, p. 131.

486 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY MUNXOPSID.E.

o. Head of moderate size, deeply emarginate on each side for the insertion of the
antenme, frontal part produced. First four thoracic segments transversely
excavated dorsally. First pair of antennse with flagellum multiarticulate. Nata-
tory legs of the same structure, carpal joint foliaceous.

6. Body with anterior division much broader than posterior; three posterior seg-
ments densely crowded together. Mandibles without any molar expansion;
cutting edge but slightly dentated. First two pairs of legs of same structure,
though somewhat different in size; two succeeding pairs elongated. Dactylus
wanting on natatory legs. Uropoda simple, biarticulate.

Genus Munnopsis M. Sars

V . Body with anterior division less sharply marked off from posterior; three
posterior segments very large and broad. Mandibles with molar expansion ;s
cutting edge divided into strong teeth. First pairs of legs shorter than three
succeeding pairs, which are subequal and very much elongated. Dactylus
distinct on natatory legs. Uropoda biramous, branches single jointed.

Genus JEurycope G. O. Sars

a'. Head very large and broad, transversely truncated in front, lateral parts greatly
expanded. First four thoracic segments slightly excavated transversely.
First pair of antennae with flagellum not much elongated. First two pairs of
natatory legs of similar structure, carpal joint large and expanded, cordiform;
last pair much narrower than two preceding pairs, carpal joint but slightly
expanded. Caudal segment triangular in form... Genus Ilyarathna G. O. Sars

78. Genus MUNNOPSIS M. Sars.«

Anterior division of body broader than posterior division. Head
moderately large, deeply emarginate on either side of a narrow
frontal process. First pair of antennae with a multiarticulate flagel-
lum, longer in male than in female. Second pair of antennae with the
last two articles of the peduncle greatly elongated. Mandibles without
molar expansion; cutting edge but slightly dentated.

First four segments of thorax transversely excavated dorsally ; the
three last segments crowded together and very convex.

Terminal segment of body large, oblong-ovate.

First two pairs of legs of similar structure, but differing in size;
•two following pairs exceedingly long and slender; natatory legs of
similar structure, carpus and propodus expanded, dactylus wanting.
Uropoda simple, biarticulate.

MUNNOPSIS TYPICA M. Sars.

Munnopsis typica M. SARS, Chr. Vid. Selsk. Forh., 1860, p. 84, 1861.— G. 0. SARS,
Chr. Vid. Selsk. Forh., 1863, p. 206, 1864; Nyt. Magazin for Naturvidenska-
berne, 1866, p. 5. — M. SARS, Christ. Fjord Fauna, 1868, p. 70, pis. vi, vn, figs.
101-138; Chr. Vid. Selsk. Forh., 1868, p. 261, 1869.— G. O. SARS, Nyt. Magazin
for Naturvidenskaberne, 1869, p. 44; Chr. Vid. Selsk. Forh., 1872, p. 79,
1873.— BUCHHOLZ, Zweite Deutsche Nordpolfahrt, Crust, 1874, p. 285.—
HKLLER, Denksch. Acad. Wiss. Wien, XXXV, 1878, p. (14) 38.— NORMAN,
Proc. Royal Soc., XXV, 1876, p. 208.— G. O. SARS, Arch. Math. Nat., II,

« See Sars for characters of genus, Crust, of Norway, II, 1899, p. 132.

1SOPODS OF NOKTH AMERICA.

487

1877, p. 353 (253).— MIERS, Ann. Mag. Nat. Hist, (4), XIX, 1877, p. 65.—
HARGER, Proc. U. S. Nat.'Mus., II, 1879, p. 159; Keport U. S. Comm. of
Fish and Fisheries, 1880, Pt. 6, pp. 330-332, pi. n, fig. 11. (See Harger for
synonymy. ) — HANSEN, Videnskabelige Meddelelser fra den natnrhistoriske
Forening i Kj0beuhavn, 1887-88, p. 195. — AXEL OHLIN, Akademisk Afhand-
ing, XXII, 1895, p. 18.— SARS, Crust, of Norway, II, 1899, pp. 133-134, pis.
LVII-LVIII.— STEBBING, Ann. Mag. Nat. Hist. (7), V, 1900, p. 14. — OHLIN,
Bihang till K. Sv. Vet.-Akad. Handl., XXVI, Afd. iv, No. 12, 1901, pp.
31-33.— ORTM ANN, Proc. Phil. Acad. Nat. Sci., 1901, p. 159.— EICHARDSON,
Proc. U. S. Nat. Mus.,. XXIII, 1901, p. 557.

Localities. — Bay of Fundy; Gulf of St. Lawrence; Baffin Bay; Davis
Straits; Murchison Sound; latitude 72° 8' north, longitude 74° 20'

FlG. 544. — MUNNOPSIS TYPICA (AFTER HARGER). a, DORSAL VIEW OF MALE. X 2. 6, MAXILLIPEDS
(TO, BASAL SEGMENT; I, EXTERNAL LAMELLA; 2 AND 3, SECOND AND THIRD SEGMENTS OF PALP). C,

SECOND MAXILLA, d, FIRST MAXILLA, e, SECOND LEG OF MALE. /, ONE OF NATATORY LEGS, g,
OPERCULUM.

west; latitude 71° 57' north, longitude 73° 56' west; latitude 69° 31'
north, longitude 56° 1' west; Umanakfjord; latitude 71° 10' north,
longitude 58° 56' west; Cape Napoleon, Grinnell Land, or latitude
79° 38' north; Cape Frazer, or latitude 79° 447 north; between Nor-
way and Iceland; Christiania fjord; off Storeggen; Loffoden Islands;
coast of Finmark; Spitzbergen; Arctic Ocean; Kara Sea; Foulke
Fjord; Granville Bay; Olriks Bay.

488 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Deptk.—?> to 400 fathoms.

Ohlin says of the color: It is "somewhat light chestnut-brown, the
second pair of antennae and the third and fourth pair of pereiopoda
of the same color, only darker, except a ring on the distal ends of the
fourth and fifth joints of the antenme and of the fourth joint of the
pereiopoda, together with the whole fifth joint and the claw, which
parts are white."0

Body narrow, elongate, the anterior portion, consisting of the head
and the first four thoracic segments considerably wider than the

FIG. 545.— MUNNOPSIS TYPICA (AFTER G.O.SARS). a, UPPER LIP. b, LOWER LIP. c, FIRST ANTENNA.
d, PART OF SECOND ANTENNA, e, END OF MANDIBULAR PALP. /, LEFT MANDIBLE, g, TIP OF LEFT

MANDIBLE. h, FIRST MAXILLA, i, SECOND MAXILLA, j, RIGHT MANDIBLE. k, DORSAL VIEW OF

MALE. I, DORSAL VIEW OF FEMALE, m, LATERAL VIEW OF FEMALE, n, UROPOD. o, FEMALE
OPERCULUM.

posterior portion, consisting of the last three thoracic segments and
the abdomen. Width of anterior portion, 5 mm. Width of posterior
portion, 3 mm. Length of body, 13 mm.

Head with the anterior portion produced in the middle in a wide

aBihang till K. Sv. Vet.-Akad. Handl., XXVI, Afd. iv, 1901, p. 33-34.

ISOPODS OF NORTH AMERICA.

489

rostrum which is truncate in front. On either side of the rostrum
there is an emargination for the reception of the basal articles of the
first pair of antennae. Eyes wanting. Two small spines are situated
on the posterior margin, one on either side of the median line. The
first pair of antennas have the basal articles large and dilated. The
second article is very small. The third article is about half as long as
the second. The flagellura is composed of about twenty-nine articles

FIG. 546. — MUNNOPSIS TYPICA (AFTER G. O. SARS). a, MAXILLIPEDS. 6, HEAD (VENTRAL VIEW).
C, FlI ST LEG OF MALE. (I, SECOND LEG OF MALE. €, VENTRAL VIEW OF MALE. /, FIRST ANTENNA

OF MALE, g, SECOND LEG OF FEMALE, h, EXTREMITY OF THIRD LEG. i, FIRST AND SECOND PLEO-

PODS OF MALE, j, THIRD LEG OF MALE, k, FIFTH LEG OF MALE. I, THIRD PLEOPOD OF FEMALE.

and extends to the middle of the second thoracic segment. The second
pair of antenna? have the first three articles short and about sub-
equal; the fourth article is equal in length to the first three taken
together; the fifth is eight times longer than the fourth article; the
sixth is about as long as the fifth. The flagellum is composed of
numerous articles. The second pair of antennas are many times
longer than the body.

490 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first two segments of the thorax are about equal in length.
The third and fourth are slightly longer. The segments increase a
little in width from the first to the fourth. The last three segments
are abruptly narrower than the first four. The fifth, sixth, and seventh
are equal in length, and the last two bear each two spines near the
anterior margin, one on either side of the median line. The post-
lateral angles of the fifth and sixth segments are produced in a small
small spine on either side.

The abdomen is composed of a single segment, narrow, elongate,
with the sides rounded and the posterior margin triangular between
the small post-lateral angles. At the base of the segment is a small
median spine. The uropoda are simple, single-branched, with each
branch composed of two articles.

The legs are differentiated in two series. The four anterior pairs
are ambulatory; the three posterior pairs natatory. The legs of the
first four pairs are of different lengths. Those of the first pair are
the shortest, the second pair being somewhat more elongated. The
third and fourth pairs are greatly elongated, being many times longer
than the body, the basis, ischium, and merus being short, the carpus
and propodus enormously elongated. The carpus is 13 mm. long.
(In a larger specimen it is 21 mm. long and the propodus 26 mm. long.)
The last three pairs of legs are natatory, with the carpus and propodus
enlarged and fringed with long hairs.

The operculum of the female has a longitudinal median keel or crest.
The fifth segment of the thorax on the ventral side has a conspicuous
median spine. There is a smaller one on the ventral side of the sixth
segment also.

79. Genus EURYCOPE G. O. Sars.«

Body compact, depressed, oval in outline. Anterior division of
thorax less sharply marked off from posterior division.

Head moderately large, deeply emarginate on either side of a
frontal process. First pair of antennae with multi-articulate flagellum.
Second pair of antennae elongated. Mandibles with molar expansion
and cutting edge divided into strong teeth.

Four anterior segments of thorax short, subequal, transversely
excavated dorsally; the three posterior segments very large and
broad, convex.

First pair of legs shorter than three following pairs, which are
subequal and very much elongated; natatory legs of similar structure
with dactylus distinct, and carpus and propodus expanded. Uropoda
small, double-branched, branches uniarticulate.

« See Sars for characters of genus, Crust, of Norway, II, 1899, p. 144.

ISOPODS OF NORTH AMERICA. 491

ANALYTICAL KEY TO THE SPECIES OF THE GENTS EritYCOPK.

n. Front of head produced to an acute rostriform projection. Base of head without
short transverse ridge. First, second, third, and fourth segments smooth, and
produced on each side to acute, anteriorly pointed lappets. Three posterior seg-
ments smooth, with antero-lateral angles acutely produced. Caudal segment
large, semioval in form, edges evenly curved, and perfectly smooth.

Eurycope cornuta G. O. Sars

a'. Front of head has appearance of rostral point caused by frontal margin extending
l>etween antennulae. Base of head with short transverse, tubercular ridge; two
oblong, low tubercles situated behind peduncles of antennulae. First segment of
thorax with transverse groove. Second, third, and fourth segments have deep
transverse depressions, with a sharp spine on anterior portion of each segment,
and a compressed protuberance on the posterior portion. Antero-lateral angles of
each of these segments produced in short, sharp spines. Epimera of first segment
has a single spine, of three following segments two spines each. Three posterior
segments of thorax have each two spines, one on either side of median line. Spine
present at base of abdomen. At extremity of terminal segment is a spine, on
either side of which is a lateral triangular spine Eurycope cariblea Benedict

EURYCOPE CORNUTA G. O. Sars.

Eurycope cornuta G. O. SARS, Chr. Vid. Selsk. Forhandl., 1863, p. 5, 1864.

Eurycope robusta HARGER, Am. Jour. Sci. (3), XV, 1878, p. 375; Proc. U. S.
Nat. Mus., II, 1879, p. 159; Report U. S. Commissioner of Fish and Fisher-
ies, 1880, Pt. 6, pp. 332-334, pi. in, fig. 15.— HANSEN, Videnskabelige Meddel-
elser fra den Naturhistoriske Forening i Kj0benhavn, 1887-88, pp. 195-196.

Eurycope cornuta SARS, Crust. Norway, II, 1899, p. 145, pi. LXIV. — RICHARDSOX,
American Naturalist, XXXIV, 1900, p. 301; Proc. U. S. Nat. Mus., XXIII,
1901, p. 558.

Localities.— Gulf of St. Lawrence; Atlantic coast of North America;
also coast of Norway; Skagerak; Uinanakfjord, Greenland; Kara Sea;
latitude 71° 10' north, longitude 58° 56' west.

Depth.— 50 to 400 fathoms.

"Body oblong oval in outline, being more than twice as long as it is
broad, and with the anterior division not attaining half the length of
the posterior. Cephalon with the lateral corners pointed, front pro-
duced to an acute, rostriform projection, which, however, does not
extend to the end of the basal joint of the superior antenna?. The four
anterior segments of mesosome comparatively short, and produced on
each side to acute, anteriorly pointed lappets. The three posterior
segments of mesosome of nearly equal size, and distinctly defined,
antero-lateral corners acutely produced. Caudal segment very large,
nearly as long as the two preceding segments combined, semi-oval in
form, edges evenly curved and perfectly smooth, antero-lateral corners
projecting. Superior antennae in male fully half the length of the
body, in female somewhat shorter, flagellum very slender and flexible,
being composed of twenty in female, in male of about fifty articulations,
carrying delicate sensory filaments. Inferior antennae more than three

492

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

times as long as the body, penultimate joint of the peduncle clothed
everywhere with adpressed spines, some of which, attached to the
inner edge and tip, are stronger than the others. Epignath of max-
illipeds securiform, outer edge angularly produced. First pair of legs
with the propodus much .shorter than the carpus, both simple, linear,
and clothed with short bristles, dactylus very small; the succeeding
pairs very slender, somewhat exceeding the body in length. Natatory

PIG. 547.— EURYCOPE CORNTTA (AFTER HAEGER). FEMALE. X 6. a, FIRST ANTENNA. X 20. 6,

MAXILLIPED. x 20. e, MANDIBLE, x 20. d, FIRST LEG. x 20. d', PROPODUS AND DACTYLVS OF

SAME. X 38. €, PROPODUS AND DACTYLUS OF SECOND LEG. X 20. /, SIXTH LEG. X 20. <7, UROPOD.
X 20.

legs with the carpal joint cordiform, propodal one of about the same
length, but somewhat narrower, oblong oval, dactylus scarcely exceed-
ing half the length of the former. Female operculum subpentagonal
in form, and distinctly carinated along the middle; male operculum
transformed in the usual manner. Uropoda with the rami subequal in
length, the outer one narrower than the inner. Color of the whole
dorsal face light reddish brown. Length of adult male 4 mm." — G. O.
SAKS."

« Crust, of Norway, II, 1899, p. 145.

I8OPODS OF NORTH AMERICA. 493

EURYCOPE CARIBBEA Benedict.

Eurycope caribbea BENEDICT, in RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901,
pp. 558-560.

Locality. — Windward Islands, West Indies.

Depth.— 687 fathoms.

The head is much wider than long. From the point between the
antennulge a depression curves backward and outward to the post-
lateral margin. On the base of the head is a short, transverse, tuber-
cular ridge. Two oblong, low tubercles are situated closely behind
the peduncles of the antennulae. The sides of the head are swollen.
The peduncles of the antenna? and antennulse occupy a space inclosed
by the front and sides of the head; the margin surrounding these
appendages is strongly raised.

The front of the head running between the antennulse has the
appearance of a rostral point; here the raised margins unite in the
narrowest place and then immediately diverge and extend downward
perpendicularly and around underneath the appendages, where they
meet and lap with the produced and bent antero-lateral projections.
The first joint of the peduncles of the antenna is very stout, with
numerous depressions and prominences; the fourth segment is very
long; the terminal portions are broken in all the specimens. The first
joint of the peduncle of the antennula is excavated on one side to
receive the curvature of the antennal peduncle; the other segments of
the peduncle are very small; the flagellurn is long and slender, with a
great number of articles.

The first segment of the thorax is very narrow; nearly the whole
surface is occupied by a transverse groove; on the median line and
posterior ridge is a prominent granule; the antero-lateral angles of
this segment are rounded. The second, third, and fourth segments
are also short and have deep transverse depressions which are much
narrower than the one in the first segment; on the median line of these
segments the space between the groove or depression and the anterior
margin is occupied by the compressed base of a sharp spine which is
directed forward; between the depression and the posterior margin is
a compressed protuberance; between the protuberances the transverse
groove runs as a narrow cut rounded and enlarged at the bottom.
The antero-lateral angles of the second, third, and fourth segments
are produced forward in short, sharp spines.

The epimera of the four anterior segments have projecting spines;
the first having a single spine, the other three having two spines each.
The three posterior segments of the thorax are very much the same as
in E. fragilis; the spines on either side of the median line decrease in
size successively.

The spine on the base of the abdomen is short; there are two con-

494 BULLETIN 51, UNITED STATES NATIONAL MUSEUM.

spicuous granules nearly in the center and bottom of the two longi-
tudinal depressions. The extremity of the abdomen is formed by a
decurved spine; the upper surface of the spine is concave; on either
side of the base of the terminal spine is a lateral triangular spine;
these lateral spines do not in any measure curve forward, as is the
case with E. frag His.

On the median line of the ventral surface of the thorax there is a
sharp, curved spine on the first segment, prominent longitudinal

FIG. 548.— EURYCOPE CARIBBEA.

ridges on the second, third, and fourth segments, and a spiny tubercle
followed by four longitudinal ridges. The ridges are separated by
transverse grooves on the coalesced fifth, sixth, and seventh segments.
Type.— Cat. No. 23911, U.S.N.M."

"This description ia from Doctor Benedict's manuscript.

I8OPODS OF NORTH AMERICA. 495

SO. Genus ILYARACHNA G. O. Sars.«

Body compact, attenuated behind, with a strongly marked median
constriction.

Head very large and broad, transversely truncated in front, lateral
parts greatly expanded. First pair of antennae with flagellum not
much elongated. Second pair of antennae longer than the body.
Mandibles with molar expansion; cutting edge not divided; palp
feeble.

The first four segments of the thorax crowded together and slightly
excavated transversely; last three segments large and convex, the fifth
segment scarcely narrower than the preceding segments.

Terminal segment of body narrow and triangular.

First pair of legs small, simple; second pair larger; two following
pairs slender and elongated; first two pairs of natatory legs of similar
structure; carpus expanded, cordiform, propodus much narrower,
oblong, dactylus well developed; last pair much narrower with carpus
but slightly expanded, propodus linear, dactylus elongated.

Uropoda small, biarticulate.

ILYARACHNA HIRTICEPS G. O. Sars.

Hyarachna hirticeps SAKS, Forh. Vid. Selsk. i Christiania, 1869, p. 167, 1870. —
HANSEN, Vid. Medd. naturh. Foren. i Kj0bh., 1887-88, p. 195.— SARS, Crust,
of Norway, II, 1899, p. 137, pi. LX. — RICHARDSON, American Naturalist,
XXXIV, 1900, p. 301; Proc. U. S. Nat. Mus., XXIII, 1901, p. 560.— OHLIN,
Bihang till K. Sv. Vet.-Akad. Handl., XXVL Afd. iv, No. 12, 1901, pp.
35-36.

localities. — Latitude 66° 32' north, longitude 55° 34' west; latitude
71° 10' north, longitude 58° 56' west; latitude 72° 41' north, longitude
59° 50' west. (Greenland.)

Depth.— 100-227 fathoms; 20 to 435 meters (Ohlin).

"Body of a similar appearance to that in the type species, but more
than twice as large, and somewhat more robust. Cephalon very broad,
with the dorsal face strongly vaulted, and densely clothed with short,
stout bristles. Anterior edge of the first four segments of mesosome
very distinctly elevated, and minutely crenulated throughout; lateral
parts of first segment imperfectly developed. The three posterior
segments of mesosome combined about the length of the preceding
part of the body; the anterior segment evenly emarginated behind.
Caudal segment of a similar form to that in /. longicornis. Superior
antennae comparatively short, not nearly reaching to the middle of the
penultimate peduncular joint of the inferior ones, basal joint armed
along the inner edge with scattered denticles, flagellum, in female, not
attaining the length of the last two peduncular joints combined.

«See Sars for characters of genus, ("rust, of Norway, II, 1899, pp. 134-135.

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Inferior antennae scarcely twice as long as the body, penultimate joint
of the peduncle armed inside with seven strong spines. Legs, on the
whole, resembling in structure those in the type species, though the
third and fourth pairs are somewhat less elongated, and the natatory

FIG. 549. — ILYARACHNA HIRTICEPS (AFTER SARS) . O, MANDIBLE, b, DORSAL VIEW OF FEMALE. C,

MAXILLIPEDS. d, SECOND ANTENNA, e, FIRST ANTENNA. /, SECOND ANTENNA, g, SECOND LEG. h,
FIRST LEG. i, THIRD PLEOPOD. j, VENTRAL VIEW OF FEMALE, k, FOURTH PLEOPOD. I, ABDOMEN
(VENTRAL VIEW), m, FIFTH PLEOPOD. n, UROPOD. o, FIFTH LEG. p, SEVENTH LEG.

legs more densely fringed with setae. Uropoda with the proximal
joint rather large, and somewhat widening distally, marginal seta?
about 20 in number, distal joint very narrow, linear. Color whitish
grey. Length of adult female 7£ mm." — G. O. SARS/'

« Crust, of Norway, II, 1899, p. 137.

ISOPODS OF NORTH AMERICA. 497

V. BOPYROIDEA OR EPICARIDEA.«

Parasitic forms, ectoparasites, their hosts being other Crustacea.
Sexual dimorphism in all the forms is strongly marked.

Female is often very asymmetrical; segmentation is sometimes
entirely lost.

Head usualty carries two pairs of rudimentary antennas. Mouth
parts are reduced, the mandibles and maxillipeds only being developed.

Rudiments of the second maxillae sometimes present.

Legs, when present, are prehensile.

Pleopods, in adult, all branchial in character.

Uropoda simple, usually very small, and terminal.

Male, when compared with female, is of diminutive size, and dif-
ferent in appearance from female. Development is in the form of a
regressive metamorphosis; there are two and in some forms three
larval stages.

ANALYTICAL KEY TO THE FAMILIES OF BOPYROIDEA.

a. Body of female not a simple sac filled with eggs, and having true limbs and some
or all of the appendages. Male passing beyond the last larval stage of female
into a stage different from it.

b. Body of female distinctly segmented, more or less asymmetrical, twisted either
to right or left. Maxillipeds lamellar, biarticulate, and more frequently exhib-
iting a small terminal joint. Legs in seven pairs, sometimes obsolete on one
side with the exception of the first. Five pairs of incubatory plates present,
more or less arching over the ventral surface of the thorax. Pleopoda
simple, biramous or triramous, all of the same structure, rarely obsolete.
Male with all the segments of the thorax sharply defined. Last larval stage
with the flagelluui of the second antennae composed of four articles; legs of uni-
form structure; u'ropoda with inner branch shorter than outer. Parasitic on

decapodous Crustacea Family XX. BOPYEID^E

b'. Body of female perfectly symmetrical, the segmentation, when present, only
visible in the middle of the dorsal face. Maxillipeds lamellar, without any
terminal joint. Only five pairs of legs present. Incubatory plates compara-
tively small, sometimes greatly reduced in number, and scarcely at all par-
taking in the formation of the marsupium, which constitutes two separate
cavities bounded by the lateral walls of the body. Pleopoda generally rudi-
mentary or wholly absent. Male with head and first segment of thorax
coalesced. Last larval stage with the flagelluui of the second antennae com-
posed of five articles; legs of the first pair shorter and thicker than the
others; uropoda with the branches subequal. Parasitic on Schizopoda.

Family XXI. DAJLD.E

a'. Body of female forming a simple sac, with no true limbs, and all or most of the
appendages lost. Male not different from last larval stage of female, and not
passing beyond this stage Family XXII. CRYPTONISCID.S:

« See G. O. Bars for characters of tribe or superfamily, Crust, of Norway, II, 1899,
pp. 19&-194.

28589—05 32

498 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Family XX. BOPYRID^.«

Body of female distinctly segmented and somewhat asymmetrical*

Both pairs of antenna? rudimentary. Maxillipeds composed of two
articles, and very frequently with a small terminal article, the palp;
two curved lanceolate appendages at the base represent the epignaths.

Coxal plates usually denned.

There are five pairs of incubatory lamellae; the first pair is composed
of two segments.

Abdomen more or less distincthT defined. Pleopoda simple, bira-
mous, or triramous; sometimes obsolete. Uropoda, when present,
simple, lanceolate.

Legs usually in seven pairs, sometimes absent on one side with the
exception of the first; all are similar in structure, short, prehensile.

Male symmetrical. Head rounded in front. All seven segments of
thorax distinct. Segments of abdomen sometimes distinct, sometimes
united. Legs similar in structure, all prehensile.

Parasitic on decapods.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY BOPYRID.E.

a. Body of female with one side greatly swollen and much longer than other side.
Abdomen composed of only five segments. Only first leg present on larger
side; others absent. Coxal plates only visible on shorter side. Marsupial
plates largely developed on longer side of body, and inclosing the entire
incubatory cavity; incubatory lamellae of shorter side small.

Genus Phryxus Rathke
a' '. Body of female with neither side swollen. Abdomen usually composed of six

segments. All the legs of both sides present.

b. Abdomen of female with the lateral parts or pleural lamella? elongated, digitate.

c. All six segments of the abdomen with the pleural parts elongated, digitate.

Male with the lateral parts of the segments of the abdomen or pleural

lamellae elongate Genus lone Latreille

c' '. Only the five anterior segments of the abdomen with the pleural parts
elongated, digitate. Male with the lateral parts of the segments of the
abdomen not elongate.

d. Female without median dorsal tubercles on sixth and seventh segments of
thorax. Exopods present on all seven pairs of legs. Uropoda of male

filiform Genus Leidya Cornalia and Panceri

d' . Female with median dorsal tubercle on sixth and seventh thoracic seg-
ments. Exopods not developed on any of legs. Uropoda of male rep-
resented by two bunches of stiff hairs.

Genus Crapsicepon Giard and Bonnier
b'. Abdomen of female with the lateral parts or pleural lamellae not elongated

or digitate.

c. Lateral parts or pleural lamellae of abdomen of female produced lamellarly.
d. Uropoda in female double-branched. Abdomen in male with segments

fused Genus Munidiou Hansen

d' '. Uropoda in female single-branched. Abdomen in male with segments
distinct.

« See Sars for characters of genus, Crust, of Norway, II, 1899, pp. 195-196.

I80PODS OF NORTH AMERICA. 499

e. Sixth abdominal segment in male with post-lateral angles produced in

long processes Genus Cryplione Hansen

e' '. Sixth abdominal segment in male with post-lateral angles not produced

in long processes Genus Pseudione Kossmann

c' '. Lateral parts or pleural lamellae of abdomen of female rudimentary or absent.
d. Pleopods present in female.
e. Some or all of pleopoda in female tri-ramous.

/. All the pleopoda in female tri-ramous. Sixth segment of thorax greatly
longer than any of others. Uropoda in female oval, with a small

conical process between them Genus Stegophryxus Thompson

/'. First three pairs of pleopods tri-ramous; last two pairs bi-ramous.
Sixth segment of the thorax not greatly longer than any of the
others. Uropoda elongated, with no process between them.

Genus Stegias Richardson
e' '. None of pleopoda tri-ramous in female.
/. Pleopoda bi-ramous in female.
g. Uropoda present in female.

h. Uropoda bi-ramous in female Genus Batkygyge Hansen

h' '. Uropoda simple, single-branched in female.
i. Both branches of pleopoda in adult female similar in size and
shape, narrow, elongated. Male with segments of abdomen
distinct and with a pair of elongated appendages to each of
the first five segments. Uropoda present in male, single-
branched. First abdominal segment in both sexes furnished

with two dorsal papillae Genus Phyllodurus Stimpson

i' '. Branches of pleopoda in adult female unlike; outer branch
narrow, elongated; inner branch oval, small. Male with seg-
ments of abdomen fused and without any appendages to the
abdomen; without uropoda. First abdominal segment in both
sexes not furnished with two dorsal papillae.
j. Posterior lobe of lateral margins of all the segments of the
thorax more or less produced into processes. Abdomen of
male narrow, tapering, not furnished with dorsal tubercle.

Genus Argeia Dana

jf. Posterior lobe of lateral margins of thoracic segments not pro-
duced into processes. Abdomen of male large, rounded,
and furnished with a prominent median dorsal tubercle

near the base Genus Parargeia Hansen

g'. Uropoda wanting in female.

h. Segments of abdomen fused in male. Segments of abdomen dis-
tinct in female Genus Probopyrus Giard and Bonnier

//. First three segments of abdomen distinct in male; last three seg-
ments fused. First four segments of abdomen distinct in female;

last two segments fused Genus Bopyriscus, new genus

/'. Pleopoda simple, single-branched in female.

Genus Bopyrina Kossmann.
d'. Pleopoda wanting in female Genus Bopyroides Stimpson

81. Genus PHRYXUS Rathke.«

Abdominal parasites.

Body of female very asymmetrical, one side being very much larger
than the other.

«See Sars for characters of genus, Crust, of Norway, II, 1899, pp. 214-215.

500 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Segments of thorax distinct on the dorsal surface. Lateral parts of
thoracic segments and epimera defined only on the shorter side.

Abdomen consists of five segments only; the fifth or terminal seg-
ment is small and narrow, bifid at the tip.

Palp of the maxillipeds wanting.

Incubatory plates of the longer side large and well developed and
concealing the entire incubatory pouch; those of the shorter side very
small.

Legs of the larger side of the body all wanting, with the exception
of the first one.

There are four pairs of single-branched pleopoda, the lamella? of the
longer side of the body being larger than those of the opposite side.

Male with all the segments of the thorax distinct; those of the abdo-
men fused, though more or less indicated at the sides, on the lateral
margins. Uropoda wanting. Pleopoda wanting.

PHRYXUS ABDOMINALIS (Kr^yer).

Bopyrus abdominalis KR0YER, Nat. Tidsskr., Ill, 1840-1841, pp. 102-112, 289-299,
pis. i, it ; Kongelige Danske Videnskabenes Selskabs naturvidenskabelige
og mathematiske Afhandlinger, IX, 1842, p. 263.

Phryxas hippolytes RATHKE, Nova Afta Academiae Casariae Leopoldino-Carolinse
Naturae Curiosorum, 1843, p. 40, pi. n, figs. 1-10.

Bopyrus abdominalis KR0YER, Voy. en Scand., Crust., 1849, pi. xxix, fig. 1.

Phryxus abdominalis LILLJEBORG, GEfvers. Kongl. Vet. Akad. Forh., IX, 1852,
p. 11. — STEENSTRUP and LUTKEN, Vidensk. Meddelelser, 1861, p. 275 (9)
1862.— BATE and WESTWOOD, Brit. Sessil-eyed Crust., II, 1868, p, 234.—
NORMAN, Rep. Brit. Assoc., 1869, p. 288; Proc. Royal Soc. Lond., XXV,
1876, p. 209.— MIEBS, Ann. Mag. Nat. Hist. (4), XIX, 1877, p. 65 (15).—
SMITH in HARGER, Proc. U. 8. Nat. Mus., II,' 1879, p. 158. — HARGER, Rep.
U. S. Fish Comm., 1880, Pt. 6, p. 312.— HANSEN, Videnskabelige Med-
delelser fra den naturhistoriske Forening i Kj0benhavn, 1887-88, p. 196. —
AXEL OHLIN, Akademisfc Afhandling, XXII, 1895, pp. 18-19; Bihang till
K. Svenska Vet.-Akad. Handl., XXVI, Afd. iv, No. 12, 1901, pp. 38-39.—
BARS, Crust, of Norway, II, 1899, pp. 215-217. pis. xo, xci. — RICHARDSON,
Proc. U. S. Nat. Mus., XXIII, 1901, p. 577; XXVII, 1904, pp. 58-59; Bull.
U. S. Fish Comm., XXIV, 1905, p. 220.

Localities. — Circumpolar in distribution.

Atlantic coast localities: Massachusetts Bay, on Pandalus borealis,
Spiron.tocaris spinus, S. liljeborgii, and Pandalus montagui; Cashes
Ledge, Gulf of Maine, on Pandalm borealis and S. pusiola; Georges
Bank on Pandalus leptocerus; Halifax, Nova Scotia, on S. pusiola,
S. spinus, and S. liljeborgii; northeastern part of Grand Bank on
S. gaimardii and S. gibba; Cape Cod on P. montagui, P. leptocerus,
S. liljeborgii, /S. pmiola, and S. polar ix; Grinnell Land, Discovery
Bay, Greenland, Cape Dudley Digges on S. phippsii and .V. polaris;
Inglefield Gulf on S. polaris; latitude 73° 48' north, longitude 80° 30'
west, on S. polaris; latitude 64° 56' north, longitude 66° 18' west, on
S. phippsii; off Marthas Vineyard, on Pandalus leptocerus and 8. lilje-

ISOPODS OF NORTfl AMERICA.

501

'borgil; Casco Bay, Maine, on P. borealis; West Greenland; North
Greenland; Baffin Land; East Greenland.

Pacific coast localities: Admiralty Inlet, Puget Sound, Washington,
on Spirontocaris grwnlandica; off North Head, Akutan Island, Alaska,
on S. arcuata; Straits of Fuca, between Washington and Vancouver
Island, on S. townxendi; Admiralty Inlet, Puget Sound, Washington,
on 8. tridens; Washington Sound, Straits of Fuca, Washington, on S.

FIG. 550.— PHRYXUS ABDOMINALIS (AFTER SAKS), a, LEG OP MALE, b, SPECIMEN OF SPIRONTOCARIS

LILLJEBORGII INFESTED WITH PARASITE. C, MALE (DORSAL VIEW), d, DORSAL VIEW OF FEMALE, e,
FIRST LEG OF FEMALE. /, HEAD OF MALE (VENTRAL VIEW), g, FOURTH LEG OF FEMALE, h, VEN-
TRAL VIEW OF FEMALE, i, LAST SEGMENT OF ABDOMEN OF FEMALE, j, RIGHT PART OF BODY OP

FEMALE, k, SAME (VENTRAL SIDE), I, MAXILLIPEDS. m, FIFTH TO SEVENTH RUDIMENTARY LEGS.

tridens; off Queen Charlotte Sound, British Columbia, on S. macroph-
tkalma; off Yahwhit Head, Washington, on S. mawophtfialma; Iliu-
liuk Harbor, Unalaska, on S. suckleyi; Arctic Ocean on S. gaimurdii
$efcA«rt(Bell); Plover Bay, East Siberia, on S. polarix (Sabine); Alaska
on S. polar is (Sabine); off Cape Strogonoff, Alaska, on S. fabricii

502

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

(Kr0yer); off Shumagin Bank, Alaska, on S. biunguis Rathbun; off
Point Arena, California, on S. macrophthalma; Straits of Fuca on
S. townsendi Rathbun; Philippine Islands on Ple-
sionika semilsevis (according to Spence Bate); a Gulf
of Georgia, off Nanaimo, Vancouver Island, British
Columbia, on Spirontocaris kispinosa Holmes; Ad-
miralty Inlet, vicinity of Port Townsend, on Spi-
rontocaris tridens Rathbun; vicinity of Naha Bay,
Behm Canal, southeast Alaska, on Spirontocaris
macropht/ialmall&tbbnn' Uyak Bay, Kadiak Island,
on Spirontocaris suckleyi (Stimpson); latitude 66°
30' north, longitude 54° 50' west, on Paiul<ifnx
montagui Leach; latitude 66° 32' north, longitude
55° 34' west, on Spirontocaris spinus (Sowerby);
latitude 66° 45' north, longitude 59° 30' west, on
Spirontocaris spinus; Ikertokfjord on Spironto-
caris spinus; latitude 66° 56' north, longitude 54°
45' west, on Spirontocaris spinus; latitude 67° 51'
north, longitude 55° 15' west, on Spirontocaris
spinus; latitude 69°54' north, longitude 55° 34'
west, on Spirontocaris spinus; Upernavik on Spi-
rontocaris gaimardii Milne Edwards and Spironto-
caris phippsii Kr0yer; Grinnell Land, Franklin
Pierce Bay, or latitude 79° 29' north; Cape Napo-
leon, or latitude 79° 38' north, on Spirontocaris
polaris (Sabine); Discovery Bay, or latitude 81°
44' north, on Spirontocaris polaris (Sabine); Green-
land on Spirontocaris spinus, Spirontocaris phipp-
sii, and Spirontocaris gaimardii.
Also recorded from the British Isles; Scandinavian coast; Spitz-
bergen; Kara Sea; coast of Norway.

FIG. 551.— PHRYXUS AB-
DOMINALIS. ABDOMEN
OF MALE FROM SPECI-
MENS FOUND ON: a,
PANDALUS LEPTOCERUS
FROM OFF BLOCK IS-
LAND, x 27}. b, PANDA-
LUS LEPTOCERUS FROM
MARTHAS VINEYARD.
x 27}. c, PANDALUS

LEPTOCERUS FROM OFF

BLOCK ISLAND, x 27}.

a bed

FIG. 552.— PHRYXTTS ABDOMINALJS. ABDOMEN OF MALE FROM SPECIMENS FOUND ON: a, SPIRONTOCARIS

GRCENLANDICUS FROM ADMIRALTY INLET, VICINITY OF PORT TOWNSEND. X 27}. 6, PANDALUS LEP-
TOCERUS FROM OFF BLOCK ISLAND, x 27}. r, SPIRONTOCARIS SICA FROM OFF SAN Luis OBISPO BAY,
CALIFORNIA, x 27}. d, SPIRONTOCARIS SICA FROM OFF SAN SIMEON BAY, CALIFORNIA, x 20i.

Depth. — 5 to 351 fathoms.

Body of female very asymmetrical. Length 9 mm. Width 7 mm.

"Challenger Report, 1888: Crustacea Macrura, XXIV, pp. 645-646.

ISOPODS OF NORTH AMERICA. 503

Head as wide as long, 1£ mm. :1| mm., with the anterior margin
straight and produced at the sides in small lateral processes. Poste-
rior margin rounded. Head deeply set in thorax. Eyes absent.

The seven segments of the thorax are well defined on one side and
in the dorsal region. On the opposite side, however, they merge
into and are continuous with the large marsupial pouch which occu-
pies the entire ventral and lateral portion of the individual.

All seven legs are present on the side of the body which has the seg-
ments well defined. On the opposite side, however, only the first leg
is present. Ovarian bosses are present on the first four segments on
the shorter side. Lateral to these are the epimera which occupy the
whole of the lateral margin. Epimera are also present on the last
three segments on the shorter side. Neither ovarian bosses nor epim-
era are present on the longer side of the body.

The abdomen is composed of five segments, all distinct. The fifth
segment is very small and tapers posteriorly to a pointed extremity.

There are no uropoda. There are four pairs of double-branched
pleopoda. The outer branches are large oval, elongated lamella?, leaf-
like in shape and larger on the larger side of the body, where they lie
upon the dorsal surface of the marsupium in its expanded lateral
portion. The inner branches are small. There are five pairs of
incubatory lamella?, of which those of one side are large and greatly
developed, occupying the whole of the lateral and ventral side of the
body and completely inclosing the eggs, while those of the shorter
side of the body are very small and much reduced in size.

The male is narrow, elongate, 3 mm. long and 1 mm. wide. The
head is rounded anteriorly and the eyes are present. The first pair
of antennas consist of three articles. The second pair of antennae are
composed of four or five articles.

The seven segments of the thorax are well defined, and have the
lateral margins straight. All the segments of the abdomen are coal-
esced in a single segment which tapers to a pointed extremity. There
are no uropoda or pleopoda.

The specimen described is found parasitic on Spirontocaris town-
sen di Rathbun.

82. Genus TONE Latreille.

Female with the lateral parts or pleural lamella? of the abdomen
elongated, digitate.

There are usualty five pairs of double-branched pleopoda. The
uropoda consist of two elongate simple curved processes, with mar-
gins smooth, not digitate. Male with the segments of the abdomen
more or less' fused; lateral parts or pleural lamella? in the form of
narrow elongated processes.

Branchial parasites.

504 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS IONE.«

a. Lateral parts or pleural lamellae of the abdominal segments in female twice as
long as the uropoda. Basal article of legs with an elevated eminence the
margin of which is irregular. Abdominal segments in male completely fused.

lone brevicauda Bonnier

a'. Lateral parts or pleural lamellae of the abdominal segments in the female not
longer than the uropoda. Basal article of legs with two elevations or carime
the margins of which are regular. Abdominal segments in male less com-
pletely fused lone thompsoni Richardson

IONE CORNUTA Spence Bate.

lone cornuta SPENCE BATE, Proc. Zool. Soc. London, 1864, p. 668; Lord's Natu-
ralist in British Columbia, II, 1866, p. 282. — BATE and WESTWOOD, British
Sessile-eyed Crustacea, II, 1868, p. 253. — GIARD and BONNIER, Travaux de
1'Institute Zool. de Lille et du Laboratoire Maritime de Wimereux, V, 1887,
p. 77.— RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 869; Ann. Mag.
Nat. Hist. (7), IV, 1899, p. 338; American Naturalist, XXXIV, 1900, p.
308.— BONNIER, Trav. de la Station Zool. de Wimereux, VIII, 1900, pp. 245-
247.— RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 75.

Localities. — Esquimault Harbor, British Columbia, on CaUianassa
longimana; Vancouver Island.

"Mas: pleonem terminatum rotunde.

"The male differs from the description of the European species
chiefly in having the caudal extremity terminating obtusel}r and in
having shorter antennae.

"Fosrn., subequilateralis, lateralia cornua cephalonis habens recur-
vata, pleopoda longa et arborea.

"The female has the antero-lateral horn-like process of the cephalon
curved posteriorly. The pereion is not quite equilate rally developed.
The coxae of the four anterior pairs of the pereiopoda are round,
and all attached to the antero-lateral margin of the segments of the
pereion. The coxae of the three posterior are the larger, and produced
posteriorly to a point. The pleopoda are long and fringed with arbo-
rescent branchiae.

"This is the only species known besides that taken by Colonel
Montagu on the southern coast of England.

"Length, male, i; female f of an inch.

"Taken attached to the branchia of Callianassa longimana."-
SPENCE BATE.*

"This species is much larger than that of the European form and
differs from it chiefly in having the lateral extremities of the somite or
segment which bears the antennae, posteriori}' produced up each side
of the head, after the manner of lateral horns. All the pereiopoda

i lone cornuta Spence Bate is not included in the key because the description of
this form does not give details as to the characters, and because it is very probable
that the form described by Bonnier is identical with lone cornuta.

*> Lord's Naturalist in British Columbia, ll, 1866, p. 282.

ISOPODS OF NORTH AMERICA, 505

are short and powerfully subchelate. The branchial appendages are
arborescent and pendulous; to the inner extremity of which two
appendages are attached, each of which inversely increases as the
other decreases; so that one is largest nearest the pereion of the
animal, while the other is longest nearest the caudal extremity. To
the posterior of these the male animal attaches itself by means of the
seventh pair of pereiopocla." SPENCE BATE."

IONE BREVICAUDA Bonnier.

lone brevicauda BONNIER, Trav. de la Station Zool. de Wimereux, VIII, 1900, pp.
248-250, pi. iv.

Localities. — California, at San Francisco, on Callianassa William
Stimpson; Gulf of Georgia.

The adult female measures 6.7 mm. and differs at first sight from
lone thoracica and lone vicina in the compact form of the body and
the large dimensions of the dorsal surface, which is perfectly symmet-
rical; the pleural lamellae of the first thoracic segments do not present
the differences in dimensions of the other species of the genus; those of
the first two segments are, on the right as on the left, almost equal and
do not extend backward beyond the following segment; those of the
two following segments are smaller, and are inserted in a small and
narrow portion of the pleural margin of the segment, on the anterior
part; finally the pleural lamallae of the last three segments, and
especially those of the sixth and seventh, are not longer than the pro-
longations of the entire lateral margin, the width of which they have,
with, moreover, some small sinuses in their inferior margin.

The first four thoracic segments, moreover, have each a pair of
pleural bosses, regularly rounded and very distinct. The appendages
of the head do not present anything of importance; one can only point
out that the palp of the maxillipeds is exceedingly re.duced and is
merely a small lamella inserted in a notch and terminating in three
little hairs, and also that the inferior lamella of the head is relatively
much larger and that the secondary lamellae are more developed; the
third, the inner lamella, exists also in this American species. The
legs are identical with those of /. thoracica, except perhaps the irreg-
ular elevations (or carime) of the basis are more accentuated. The
oostegites (or incubatory lamellae) are identical with those of the other
species and, as with them, are covered on their external parts with
simple or bifid hairs having rough extremities; the only difference
to be noted is that, in the first oostegite (lamella), the digitatioris of
the inner ridge are much smaller and more numerous and there is also
a difference in the arrangement of the hairs on the inferior margin.

«Brit. Assoc. Adv. Sci., 1863, XXXII, p. 98.

506 BULLETIN 54, UNITED STATED NATIONAL MUSEUM.

The ventral surface of the last segments of the thorax and the first
vsegments of the abdomen has longitudinal keels as is usual.

The abdomen is also very characteristic; the prolongations of the

b c

FIG. 553.— lONE BREVICAUDA (AFTER BONNIER). a, DORSAL VIEW OF ADULT FEMALE. 6, DORSAL
VIEW OF MALE. C, VENTRAL VIEW OF FEMALE, d, FIRST INCUBATORY LAMELLA. €, VENTRAL
VIEW OF HEAD OF FEMALE (RIGHT MAXILLIPED REMOVED). /, BUCCAL ROSTRUM AND ANTENNA 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).

pleural lamellae are here very much more developed than in the Euro-
pean species and they increase in length from the first to the sixth,

I80PODS OF NORTH AMERICA. 507

which is twice as long as the first; they are like long branches which
become narrower toward the distal extremity and they are divided
into distinct articles each one of which gives origin, on its inferior
margin to long ramified digitations, those near the base being espe-
cially long. On the ventral side there are two pairs of bi-ramous pleo-
pods, the branches of which are of equal length, but not of the same
width; the inner branches are certainly much larger, especially on the
first pairs. The uropoda have the usual form of the other species of
the genus, but they are here relatively much shorter and do not reach
even half the length of the pleural prolongation of the sixth segment
of the abdomen.

The male measures 4.5 mm. ; it is relatively large in comparison with
the size of its European congeners and does not present any differences
except in the form of the pleural prolongations of the abdomen; they
are slightly attenuated at their two extremities, especiall}' at the distal
extremity. The first three pairs of legs have the dactylus pointed while
those of the other pairs are blunt, recalling the form of the corre-
sponding organs in the female.0

«The above description is adapted from the following one of Bonnier's:
La femelle adulte (fig. 1 et 2) mesure 6 mm. 7 et differe a premiere vue d'lone
thoracica et d' J. vicina par la forme ramassee du corps et la large dimension de la
surface dorsale, qui est parfaitement symetrique; les lames pleurales des premiers
somites thoraciques ne presentent pas les ihegalites de dimensions des autres especes
du genre; celles des deux premiers sont, a droite comme A, gauche, a peu pres equiva-
lentes et ne depassent pas en arriere le somite suivant; celles des deux segments
suivants sont plus petites, inserees par une partie r^trecie au bord pleural du somite,
sur la partie anterieure; enfin les lames pleurales des trois derniers somites ne sont
plus, surtout celles des sixieme et septieme, que les prolongements de tout le bord
lateral dont elles ont la largeur et avec, en plus, quelques petites sinuosites a leur
bord inferieur. Les quatre premiers somites thoraciques portent en outre chacun
une paire de bosses pleurales regulierement arrondies et tres nette. Les appendices
de la tete n' off rent rien de particulier: on pent seulement noter que la palpe du
maxillipede est excessivement reduit, ce n'est plus qu'une toute petite lamelle decou-
pee dans une echancrure et terminee par trois petits poils (fig. 5), et aussi que la
lame inferieure du cephalon est relativement beaucoup plus large et que les lamelles
secondaires sont plus developp^es; la troisieme, la lamelle interne, existe aussi dans
cette espece americaine. Les p^reiopodes sont identiques a ceux de I. thoracica, sauf
peut-etre que les Eminences irr^gulieres du basipodite sont plus accentu£es (fig. 8).
Les oostegites sont identiques a ceux des autres especes et, comme eux, converts dans
leurs parties externes de poils simples ou bifides a extr^mites squameuses: la seule
difference Ji noter est que, dans le premier oostegite, les digitations de la crete interne
sont beaucoup plus fines et plus nombreuses (fig. 7) et il a aussi une difference dans
Pimplantation des poils du bord inferieur (fig. 6). La surface ventrale des derniers
somites du pereion et des premiers du pleon est pliss£e longitudinalement, comme cela
se presente d' ordinaire.

Le pleon (fig. 9) est aussi tres caracteristique: les prolongements des lames
pleurales sont»ici bien plus developpes que dans les especes d'Europe et ils croissent
de longueur du premier au sixieme qui est deux fois plus long que le premier: ce sont
des sortes de longues tiges qui vont en s'amincissant vers 1'extremite distale et elles
se divisent en de veritables articles distincts dont chacun emet sur son bord inferieur

508 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

IONE THOMPSONI Richardson.-

lone thompsoni RICIIAHDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp. 75-78.

Locality. — North Falmouth, on Callianassa st'unpxon '/.

Body of female longer than broad.

Head deeply set in thorax, its anterior margin produced in a crenu-
lated border. The antero-lateral lobes of the frontal border extend
some distance beyond the sides of the head. The posterior portion of
the head is evenly rounded. The first antennae are three jointed; the
second pair are five jointed.

All the thoracic segments are distinct, with distinct epimera
("lames pleurales" of Giard and Bonnier), in the form of large
rounded lobes, not elongated. In the first two segments these epi-
meral lobes occupy the anterior portions of the lateral parts of the seg-
ments; in the third segment they are placed about the center of the
lateral margin; in the fourth and fifth segments they occupy more of
a posterior position; in the sixth and seventh segments they occupy
the entire lateral margin. Ovarian bosses are present on the first
four segments, along the anterior portion of the segment.

The six segments of the abdomen are distinct, and are produced
laterally, each in a pair of elongated and jointed appendages, furnished
with numerous mammilliform, branching appendages, originating
from the posterior margin and extending downward. Thus there are
six pairs of appendages corresponding to the "lames epimeriennes du
pleon " of Giard and Bonnier.

The pleopoda consist of four pairs of double-branched appendages
and one pair of single-branched appendages. a The inner branches of
the first four pairs fold over the ventral side, meeting in the median
line. These branches are all large and of nearly equal size and thickly

jle longues digitations ramifiees qui le sont d'autant plus qu'elles sont plus pres de
la base. A la face ventrale (fig. 2) on voit deux paires de pl£opodes biram^s, dont
les rames sont de meme longueur, mais non de meme largeur: les endopodites sont
beaucoup plus larges en effet, surtout sur les premieres paires. Les uropodes ont la
forme ordinaire des autres especesdu genre, mais ils sont ici relativement beaucoup
plus courts et n'atteignent meme pas la moitie de la longueur du prolongement
pleural du sixieme somite du pleon.

Le mille (fig. 10) mesure 4 mm. 5; il est grand, relativement a la taille de ses
congeneres d' Europe et il ne presente de differences que dans la forme des prolonge-
menta pleuraux du pleon: ils sont legerement attenues si leurs deux extn'mitc's, sur-
tout a la distale. Les pereiopodes des trois premieres paires ont des dactylopodites
aigus, tandis que ceux des autres paires sont ^mousses et rappellent la forme des
organes correspundants dans lafemelle. — JULES BONNIER, Travaux de la Station zool.
de Wimereux, VIII, 1900, pp. 248-250.

« The young female of lone Ihowpsoni bas the last pair of pleopoda double-branched,
the two branches similar, however. The inner branches of the first four segments
are quite different from those of the outer branches, as is true of the adult female,
and lie folded over the abdomen as in the adult described.

ISOPODS OF NORTH AMERICA.

509

tuberculate, the first two pairs being somewhat larger than the last
two pairs. The outer branches of the first four pairs and the fifth
pair of pleopoda consist of narrow, elongated appendages crenulated
on their outer margins and thickly tuberculate. The appendages of

the sixth abdominal segment, the uropoda, are a pair of simple, cylin-
drical, elongated lobes, recurved at their extremities, and not reach-
ing beyond- the mass of epimeral appendages.

The incubatory pouch is formed of five pairs of lamellae, five issuing
from one side and five from the other. The first pair are much smaller
than the others, and are entirely concealed by the second pair.

The seven pairs of legs are all similar, and terminate in a prehensile

510

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 555.— ION E
THOMPSONI.
MAXILLIPED.

FIG. 556.— lONE THOMPSONI. FIRST
LAMELLA OF MARSUPIUM. X 10.

hand. There are two expansions or carinse on the basis of all the
legs, the anterior one being only half as long as the other.

Male with all the segments of the thorax distinct. Eyes wanting.
Antenna? conspicuous, six jointed. Antennulae, three jointed. The
segments of the abdomen are more or less distinct, all six furnished
each with a pair of elongated leaf -
like tapering appendages.

Two specimens were collected
by Mr. G. M. Gray at North Fal-
mouth, Massachusetts. They
were found on Callianassa stimp-
soni.

The species is named for Dr.
Millett T. Thompson, from whom the speci-
mens were received.

Type.— Cat. No. 29091, U.S.N.M.
This species is apparently very close to 7. cornuta Spence Bate,
from Vancouver Island. It agrees with I. cornuta in the absence of
the elongated epimeral lobes (lames pleurales), in which both species
differ from 7. thoracica (Montagu). lone thompsoni and /. cornuta are
both much larger species than 7. thoracica. In the description of /.
comuta,a the author says that the coxae of the three posterior segments
of the thorax are larger than the four anterior, and are produced
posteriorly to a point. This is
not true of I. thtfnipsoni, in
which the epimera of the three
posterior thoracic segments are
smaller than those of the ante-
rior segments, although they
occupy the entire lateral mar-
gin, and they are rounded pos-
teriorly and not produced to a
point. Spence Bate also speaks, in reference to /.
cornuta, of the antero- lateral "horn-like process of
the cephalon* curving posteriorly." In 7. thomp-
soni, these, lateral processes or lobes extend out
straight at the sides. Bate and Westwood, in describing I. cornuta, state
that the last pair of inner saccular branches of the pleopoda are almost
obsolete. There are but four pairs of inner branches in 7. thompsoni.
The above quoted authors also describe the inner branches of the
pleopoda as gradually diminishing in size to the last pair, whereas
the outer branches gradually increase in size. This is not true of
7. thompsoni.

FIG. 557.— lONE THOMPSONI.
LEG OF SIXTH PAIR OF
ADULT FEMALE. X llj.

FIG. 558. — lONE THOMP-
SONI., MALE. x8.

a Proc. Zool. Soc. London, 1864, p. 668.

& British Sessile-eyed Crustacea, II, 1868, p. 254.

ISOPODS OF NORTH AMERICA.

511

83. Genus LEIDYA Cornalia and Panceri.

Abdomen distinctly segmented. Pleura! lamellae or lateral parts of
the first five segments of the abdomen lanceolate, finely fringed.

Legs of female terminate in a short, blunt claw.

Exopods present and nearly equal on all seven pairs of legs.

The pleopods are "lanceolate and fringed."

Male has the abdomen distinct!}^ segmented. There are five pairs
of simple rudimentary pleopods. Uropoda simple, in the form of two
long appendages attached to the sixth abdominal segment. '

Branchial parasites.

LEIDYA DISTORTA (Leidy).

Cepon distortus LEIDY, Journ. Acad. Nat. Sci. Phila. (2), III, 1855, p. 150, pi. xi,

figs. 26-32.
Leidya dislorta CORNALIA and PANCERI, Mem. R. Acad. Sci., Torino (2), XIX,

1858-1861, p. 114.

Cepon dixtortus HARGER, Rep. U. S. Fish Comm., Pt. 1, 1873, p. 573 (279); Proc.
U.S. Nat. Mus., II, 1879, p. 157; Rep. U. S. Fish Comm., 1879, p. 157;
Pt. 6, 1880, p. 311. — KOSSMANN, Zool. Ergeb. einer Reise in die Kiist. des
Rothen Meeres, III, Malacostraca, 1880, p. 122; Mittheil. aus der Zool.
Station zu Neapel, III, 1881, first half, p. 182.
Phryxus distortus WALZ, Arbeit, aus d. Zoolog. Instit. d. Univers. Wien, IV, 1882,

p. 59.
Leidya distorta GIARD and BONNIER, Trav. du Labor, de Wirnereux, V, 1887, p.

68, fig. 12.

Cepon distortus RICHARDSON, Am. Nat., XXXIV, 1900, p. 309.
Leidya distorta RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 579.
Locality. — Atlantic City,
New Jersey, in the branchial
cavity of Uca pugilator.

u Female: Body com-
pressed and distorted ovoid,
white; abdominal scales com-
pletely concealing the pink-
ish white ova. Head prom-
inent, provided with a pair
of large oval disks situated
posteriorly. Mouth minute,
at the summit of a trilobate
papilla. Antennae very small
and indistinct. Divisions
of the thorax posteriorly
strongly costate. Feet in
seven pairs, curved forward and downward, ending in a short
recurved, abortive booklet. Abdomen deeply segmented. Branchial
appendages lanceolate, fringed.

FIG. 559. — LEIDYA DISTORTA (AFTER LEIDY). a, DOR-
SAL VIEW OF FEMALE. 6, VENTRAL VIEW OF FEMALE.
C, LEG OF FEMALE.

512 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"Male: Body long and slender, divided into fourteen segments.
Head subrotund. Internal antennae short and robust, 3-jointed;

joints spinous. External
antennae long, 7-jointed; the
first two joints spinous, the
others bristled. First joint
of the thorax transversely
oblong, the remainder de-
pressed, pyriform in out-
line. Feet in seven pairs,
the ante-penultimate joint
spinous, the penultimate
joint broad and with the
claw recurved. Abdomi-
nal segments depressed,
pyriform in outline, each
provided with a pair of
peculiar ventral append-
ages, and, except the fifth
one, with a lateral irregu-
lar pigment cell. Caudal
segment round, with a
pair of divergent append-
ages. Length of female
four lines, breadth three
lines; length of male one
and a quarter lines. "-
LEIDT."

FIG. 560.— LEIDYA DISTORTA (AFTER LEIDY). a, DORSAL
VIEW OF MALE, b, ABDOMINAL SEGMENTS OF MALE WITH
PECULIAR APPENDAGES. C, RIGHT LEG OF MALE. d,
HEAD OF MALE WITH ANTENNA. ALL MAGNIFIED.

84. Genus GRAPSICEPON Giard and Bonnier.

Female with two median dorsal tubercles, one on the sixth and the
other on the seventh thoracic segment.

Five anterior segments of abdomen with the lateral parts or pleural
lamellae produced into long, tapering prolongations, which are digi-
tate. Abdomen distinctly segmented. Pleopoda in five pairs, well
developed, double-branched; outer branches similar to the pleural
lamellae of the segments; inner branches in the form of large tubercles.

Uropoda consisting of two elongate lamellae similar to the outer
branches of the pleopoda or the pleural lamellae of the abdominal
segments.

Male with all the segments of the thorax and abdomen distinct.
There are five pairs of rudimentary pleopods. The uropoda are rep-
resented by two bunches of stiff hairs.

Branchial parasites.

«Journ. Acad. Nat. Sci. Phila. (2), III, 1855, p. 150, pi. xi, figs. 26-32,

ISOPODS OF NORTH AMERICA. 513

GRAPSICEPON EDWARDSII Giard and Bonnier.

Grapsicepon edwardsii GIARD and BONNIER, Compt. Rend. Acad. Sciences, CVII,
1888, p. 1. — HANSEN, Ergebn. d. Plankton Exped. der Humboldt Stiftung,
II, 1895, p. 43. — GIARD and BONNIER, Travaux de la Station Zool. de
Wiinereux, VIII, 1900, pp. 263-266, pis. vm, ix.

localities. — Florida stream; also Sargasso Sea.

The adult female has a general globular form, flattened on the
dorsal surface and terminated at its posterior extremit}7 by a group
of slender appendages with digitate edges; it measures 1.9 mm. from
the frontal border to the sixth segment of the abdomen. The head
forms a single and projecting mass, which is surrounded anteriorl}*
and on the sides by a large undulating anterior lamina or border; on
the inner side are found the very small, three-articulate first antennae,
which are situated some distance apart; the last two articles are fur-
nished with several small hairs having a rough surface; the second
pair of antennas are equally short, the first article is large, half con-
solidated with the head, and the other four articles decrease in size to
the last, which is furnished with several hairs; their surface presents
the same appearance as that of the first pair of antennae. The rostrum
is elevated and particularly distinct; from the notched point of the
inferior lip one can see the tip of the mandibles projecting, which is
in the form of the bowl of a spoon with the edge finely denticulate.
The maxilliped possesses an elongated palp terminating in little, short
hairs. The inferior margin of the head is cut up on both sides in a
pair of little lamella? of almost equal size, the cuticle of which is rough
and the extremity blunt.

The first four thoracic segments are large and are in the form of
cushions; on their lateral margins are strong pleural bosses with con-
tours rather indistinct and with a rudimentary pleural lamella; the
three other segments are much narrower, their pleural lamella is
rather distinct, and the dorsal surfaces of the sixth and seventh seg-
ments are elevated in very sharp points in the median line of the body.
The ventral side of the thorax is completely hidden b}^ the incubatory
cavity, which is very regularly developed; the first of the oostegites
(lamellae) has an inner edge with several large digitations, and its pos-
terior part does not present a margin dentated or notched. The legs
are very reduced, which is in correspondence with the almost useless
part which they have to play in the fixation of the parasite, firmly
maintained in place by all the carapace of the host. The fourth of
these appendages is figured; under the rounded lateral margin, the
coxa shows a very solid chitinous armature, intended to move the
oostegite (lamella), which is attached there by the median nerve;
the basis is very large, flattened, and almost square; the ischium is
much narrower; the two following articles are fused and the propodus
28589—05 33

514 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

is not much developed; the dactylus has the form of a little, short
claw, not reaching the end of the palmary margin of the preceding
article.

The abdomen, in the median part, is very short and very slender;
its entire size comes from the extraordinary development of its

FIG. 561. — GRAPSICEPON EDWARDSI (AFTER BONNIER), a, VENTRAL VIEW OF FEMALE. 6, ABDOMEN
OF MALE (VENTRAL VIEW), c, VENTRAL VIEW OF HEAD OF FEMALE (FIRST RIGHT INCUBATORY

LAMELLA REMOVED), d, DORSAL VIEW OF FEMALE, e, HEAD OF MALE (VENTRAL SIDE). /, VEN-
TRAL VIEW OF MALE, g, SEVENTH THORACIC SEGMENT OF MALE (VENTRAL SIDE), h, FIRST LEG
WITH INCUBATORY LAMELLA, i, THE SAME (INNER FACE).

pleural prolongations and of their appendages. The first form long
lamellae which rise parallel toward the anterior part of the body and

ISOPODS OF NORTH AMERICA.

515

the edges of which are formed of a considerable and dense quantity of
long dictations, some of which are subdivided into secondary digita-
tions; these prolongations are especially developed on the first segments
of the abdomen; they decrease in length on the last segments. The

FK;. 562.— GRAPSICEPON EDWARDSI (AFTER "BONNIER), a, VENTRAL VIEW OF ABDOMEN. 6, INFE.

RIOR PART OF HEAD WITH RIGHT MAXILLIPED. C, BOTH ANTENN.fi. d, RIGHT LEG OF FOURTH

PAIR (FEMALE), e, ROSTRUM WITH RIGHT MANDIBLE IN SITU. /, PARASITE IN BRANCHIAL CAVITY
OF HOST, g, LAST THORACIC SEGMENTS (DORSAL VIEW), h, EXTREMITIES OF THE MANDIBLES.

outer branches of the pleopods present exactly the same form as the
pleural parts, but they increase in length in an inverse order, from
the first to the fifth segment, where they are the longest; the inner
branches are reduced to large tubercles with irregular surface, fixed

5K> BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

to the base of the insertion of the pleopods. The last segment of the
abdomen ^ bears only two uropods, of the same conformation as the
pleural lamella? and the outer branches of the pleopoda of the preced-
ing segments, but the}' are of a length exceeding the longest of these
appendages. Turned back and laid on the dorsal surface, they extend
to the middle of the thorax.

The male, unknown in the other species of the genus, recalls a great
deal, in its general form, that of the genus Cancricepon. It measures
in its greatest dimension 0.55 mm. The first antennas are composed
of three articles, the second antennae of five articles, the most of
Avhich are furnished with stiff hairs; there are no maxillipeds. In
the median line of the thorax are spherical tubercles which are also
present in the same place on the first three segments of the abdomen;
their external surface is covered witli little pectinate scales. The legs
are short, robust, and terminate in a pointed claw. The genital open-
ings are visible on both sides of the ventral tubercle of the seventh
thoracic segment, and in a clear area lighter than the rest of the
cuticle. Rudiments of pleopods are seen on the first five segments of
the abdomen, and the uropods are represented on the sixth segment
only by two little bunches of stiff hairs.

In general there is but a single adult male on a female; I ought,
however, to note as rather frequent the presence of several males on
the same female; I have counted just four of them between the pleo-
pods and the pleura, and, a curious thing, all of them having abso-
lutely the same form, they do not have the same size. One of them
was a little more than half the size of the largest, the other two were
of intermediate size. The ventral bosses appeared in the three indi-
viduals of smaller size on the five segments of the abdomen, while in
the largest specimen they actually were present only on the first three.
It is probable that the number of these bosses decrease with age. The
same fact is equally true of Cancricepon eleyans."

«The above description is adapted from the following one of Bonnier's:
La femelle adulte a une forme generale globuleuse, aplatie sur la surface dorsale
et terminee a son extremite posterieure par un bouquet d' append ices ertik's a bords
digites; elle mesure, du bord frontal au sixieme somite du pleon, 1 mm., 9. La tete
forme une masse unique et saillante qui est entouree anterieurement et sur les tutt's
par une large lame ant^rieure flottante; a la face interne se trouvait, a une assez
grande distance, 1'une de 1'autre, les antennules tres petites et tri-articulees; les deux
derniers articles portent quelques petites soies et leur surface est squameuse; les
antennes sont egalernent courtes, le premier article est large, A, moitir soiulr au rt'pha-
lon et les quatre autres articles diminuent d'importance jusqu'au dernier qui portc
quelques soies; leur surface presente le meme aspect que celui de 1'antennule. Le
rostre est preeminent et particulierement net; de la pointe echancree de la levre infe-
rieure on voit sortir 1' extremite des mandibules qui est en forme de cuilleron & bord
finement denticule. Le maxillipede possede un palpe allonge termine par de petites
soies tree courtes. Le bord inferieur du cephalon est decoupe" de part et d'autre par

ISOPODS OF NORTH AMERICA. 517

85. Genus MUNIDION Hansen.

Body of female somewhat asymmetrical.

Ovarian bosses present on all the segments of the thorax; they are
in the form of petiolated processes. Epimera very large, placed on
the lateral margins of all the segments, where they occupy the entire
lateral margin.

Abdomen with the segments distinctly defined; lateral parts of the
first five segments lamellarly expanded in elongated lobes. Sixth or
terminal segment small, not lamellarly expanded, in the form of a
petiolated process.

The pleopoda are five pairs of double-branched well-developed
appendages. The uropoda are a pair of double-branched appendages.

There are five pairs of incubatory lamellae, not quite overlapping in
the median ventral line; the first lamellae have the distal part produced
posteriorly in a small lobe. All seven pairs of legs are present.

The male has all the segments of the thorax distinct. The segments
of the abdomen are fused. Uropoda absent. Pleopoda wanting.
Branchial parasites.

une paire de petites lamelles, si peu pres d'egale importance, a cuticule squameuse et
a extremite mousse.

Les quatre premiers somites thoraciques sont large et en forme de bourrelets; sur
leurs bords lateraux sont de fortes bosses pleurales a contours assez indistincts et a
lame pleurale rudimentaire; les trois autres segments sont beaucoup plus etroits, leur
lame pleurale est assez nette et les surfaces dorsales des sixieme et septieme somites
s'erigent en pointes tres accentuees sur la ligne mediane du corps. La face ventrale
du thorax est completement cachee par la1 cavite incubatrice, qui est tres regulierement
deVeloppee: le premier des oostegites a une crete interne avec quelques larges digita-
tions et sa partie posterieure ne pr^sente pas de bord decoupe ou echancre\ Les
pereiopodes sont tres reduits, ce qui est en rapport avec le rule a peu pres nul qu'ils
ont a jouer dans la fixation du parasite, solidement maintenu en place par toute la
carapace de 1'hote. Le quatrieme de ces appendices est figure pi. ix, fig. 5; sous le
bord lateral arrondi, le coxopodite montre une tres solide armature chitineuse, destinee
a mouvoir 1'oostegite qui s'y rattache par sa nervure mediane; le basipodite est tres
large, aplati et presque carre; 1'ischiopodite est beaucoup plus etroit; les deux
articles suivants sont soudes et le propodite est peu developpe; le dactylopodite a la
forme d'une petite griffe courte, n'atteignant pas le bout du bord palmaire de 1' article
precedent.

Le pl£on, dans sa partie centrale, est tres court et tres mince; toute son importance
vient de 1' extraordinaire developpement de ses prolongements pleuraux et de ses
appendices; les premiers forment de longues lamelles qui remontent parallelement
vers la partie anterieure du corps et dont les bords sont formes d'une quantite con-
siderable et dense de longues digitations dont quelques-unes se divisent elles-memes
en digitations secondaires; ces prolongements sont surtout developpe's sur les premiers
somites du pleon; ils diminuent de longueur sur les derniers somites. Les endopodites
des pleopodes presentent tout a fait la meme forme que les parties pleurales, mais ils
augmentent leur longueur en sens inverse, du premier au cinquieme somite, ou ils
sont le plus long; les endopodites sont reduits a de gros'tubercules a surface irr£-
guliere, fi x£s il la base d' insertion des pleopodes. Le dernier somite du pleon ne porte
que deux uropodes, de la meme conformation que les lames pleurales et les exopodites

518 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

MUNIDION PARVUM Richardson.

Afunidion parva RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp. 81-82.

Locality. — Straits of Fuca, on Munida quadrispina Benedict.

Head large, broader anteriorlj1 than posteriorly, with wide frontal

border. Eyes wanting. Ante-
rior margin nearly straight, pos-
terior margin narrowly rounded.

FIG. 564.— MUNIDION
PARVUM. FIRST LA-
FIG. 563. — MUNIDION PARVUM. a, DORSAL VIEW OF MELLA OF MARSUPIUM.
FEMALE, b, VENTRAL VIEW OF SAME, x 8. x 14J.

The segments of the thorax are distinct, the first two of which are
short in the median dorsal line; the other five segments are about
equal in length. Ovarian bosses present on all the segments, occupy-
ing the posterior portion of the sublateral part of the segment. On

des segments precedents, mais ils sont d'une longueur depassant les plus longs de ces
appendices; retournes et appliques sur la surface dorsale, ils attendraient jusqu'au
milieu du thorax.

Le male, inconnu dans les autres especes du genre, rappelle beaucoup, par sa
forme generate, celui du genre precedent ( Cancricepon) ; il mesure dans sa plus
grande dimension 0 mm. 55. Les antennules sont triarticulees; les antennes comp-
tent cinq articles, dont la plupart sont garnis de poils raides; il n'y a pas de maxil-
lipedes. Sur la ligne mediane du thorax se trouvent des tubercules spheriques que
1'on retrouve egalement, a la meme place, sur les trois premiers somites de 1'abdomen;
leur surface externe est couverte de petites e"cailles pectine"es. Les pereiopodes sont
courts, robustes et termines par une griffe aigue. Les ouvertures genitales sont
visibles de part et d'autre du tubercule ventral du septieme somite thoracique, et au
milieu d'une petite aire plus claire que la reste de la cuticule. Les rudiments des
pleopodes se voient sur les cinq premiers somites du pleon, et les uropodes ne sont
plus represents, sur le sixieme, que par deux petits bouquets de poils raides.

En general le male adulte est unique sur la femelle; je dois pourtant noter, comme
assez frequente, la presence de plusieurs males sur une meme femelle; j'en ai compte
jusque quatre, entre les pleopodes et les pleura et, chose curieuse, tout en ayant
absolument la meme forme, ils n'avaient pas la meme taille; 1'un d'eux etait un peu
plus de la moitie du plus grand et les deux autres etaient de tailles intermediates; les
bosses ventrales se voyaient, dans les trois individus de taille moindre, sur les cinq
somites de pl<§on, tandis que dans le plus grand, ils n'existaient veritablement
que sur les trois premiers, d'ou il resulte probablement que le nombre de ces
bosses dhninue avec Page. Le meme fait se presente egalement chez Cancricep/m
elegans. — JULES BONNIER, Travaux de la Station zoologique de Wimereux, VIII, 1900,
pp. 263-266.

ISOPODS OF NORTH AMERICA.

519

FIG. 565. — MTJNIDION
PARVUM. LEG OF
SIXTH PAIR OF
ADULT FEMALE.

X20i.

all the segments they are in the form of petiolated processes. The
epimera are large plates which occupy the whole of the lateral margin
of the segments. These plates are larger on the posterior segments
than on the anterior ones.

The abdominal segments are all distinct. The first five are pro-
duced laterally in epimeral lobes, elongated and leaf-shaped, decreas-
ing in size gradually from the first to the fifth segments. These lobes
do not cover the dorsal surface of the abdomen, or
obscure the small terminal segment, which is visible
dorsally as a small rounded petiolated process.

The pleopoda are five pairs of double-branched elon-
gated leaf -like appendages; the inner branches are
smaller than the outer. The uropoda consist of a
pair of birainous appendages, each with one large
outer and one small inner branch, similar in shape to
the branches of the pleopoda.

The ventral side of the abdominal segments is keeled on the poste-
rior margin. The pleopoda and abdominal epimera are somewhat
carinated on both surfaces.

The marsupium is bounded by five pairs of incubatory lamellae, the
third pair of which do not overlap in the median ventral line, so that
a small opening is left into the incubatory pouch. The terminal lobe
of the distal segment of the first pair is very small,
but well defined.

The seven pairs of legs are all similar; the basis is
furnished with an extremely high expansion, the an-
terior end of which is twice as high as the other end.
The male has all the segments of the thorax distinct.
The segments of the abdomen are fused into a single
piece. There is no indication of the coalesced seg-
ments on the lateral margins of the abdomen, these
margins being entire. The posterior portion of this
segment is narrower than the anterior portion, its
apex, however, being widely rounded. Its length is
about one and one-half times its greatest breadth.
Eyes are present.

Only one specimen comes from the Straits of Fuca,
taken by the U. S. Bureau of Fisheries steamer Alba-
tross at a depth of 152 fathoms. Parasitic on Munida quadrispina.
Type.—C&t. No. 29095, U.S. KM.

This species is a very much smaller one than the type species of the
genus described by Dr. Hansen," being less than half the size of
Munidion princeps. The present species differs from the type species
in its much smaller size; in the relatively larger and differently shaped

FIG. 566.— MUNIDION
PARVUM. MALE.
X23.

oBull. Mus. Comp. Zool. Harvard College, XXXI, 1897, pp. 115-117.

520 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

head; in the larger thoracic epimera (pleural plates); in the differently
shaped ovarian bosses; in the smaller and differently shaped abdom-
inal epirnera, which do not conceal the abdominal segments dorsally
as in that species; in the differently shaped carina on the basis of all
the legs; in the absence of the sinuous lateral margins of the abdomen
of the male; and in the broader apex and greater length compared
with the width of the abdomen of the male.

86. Genus CRYPTIONE Hansen.

Body of female somewhat asymmetrical.

Ovarian bosses present on the first four thoracic segments. Epimera
well developed and distinct on the first four segments, occupying
the anterior portion of the lateral margin ; those of the last three seg-
ments are not distinct from the segments.

Segments of the abdomen distinct; the lateral parts of the first five
segments are well developed; the sixth or terminal segment is small
and has the lateral parts not developed.

The uropoda are simple, single-branched, and consist of a pair of
elongated lamellae.

The pleopoda consist of five pairs of double-branched lamellae.

There are five pairs of incubatory lamellae which do not completely
inclose the incubatory pouch.

All seven pairs of legs are present.

The male has all seven segments of the thorax distinct.

The segments of the abdomen are also distinct. The sixth or ter-
minal segment has the post-lateral angles produced backward on
either side.

There are five pairs of simple sac-like pleopoda.

Branchial parasites.

CRYPTIONE ELONGATA Hansen.

Cryptione elongata HANSEN, Bull. Mus. Comp. Zool., Harvard College, XXXI,
1897, pp. 112-115, pi. in, figs. 5-5a; pi. iv, figs. 1-lg. — RICHARDSON, Proc.
U. S. Nat. Mus., XXI, 1899, p. 869; Ann. Mag. Nat. Hist. (7), IV, 1899, p.
338.— BONNIER, Trav. de la Station Zool. de Wimereux, VIII, 1900, pp. 285-
287.— RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 87.

Locality. — Near the Galapagos Islands on Nematocardnus agassizii
Faxon, which occurs as far north as Acapulco, Mexico.

Body of female somewhat elongated, asymmetrical. Length 19
mm.: width 11 mm.

Head a little wider than long, 4 mm.: 5£ mm., with the anterior and
posterior margins widely rounded or arcuate, and the lateral margins
produced in a small lobe on either side about the middle. Eyes absent.
The first pair of antennae are composed of three articles, the last of

ISOPODS OF NORTH AMERICA..

521

which is minute. The second pair of antennae are composed of four
articles.

The seven segments of the thorax are distinct. The first four have
well-developed epimera, occupying the anterior half of the lateral
margins, each epimeron being placed lateral to the ovarian bosses and
produced into an anterior and a posterior lobe. The epimera of the last

FIG. 567.— CRYPTIONE ELONGATA (AFTER HANSEN). a, MAXILLIPED OP FEMALE. 6, 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). A, FIRST LEG OF MALE, i, FIFTH LEG OF MALE.

three segments are not distinct from the segments. The anterior por-
tion of the last three segments is produced into a large lobe which occu-
pies the entire lateral margin, the posterior portion of the segment
being small and sublateral, i. e. , it lies on the inner side of the ante-
rior portion. The anterior lobes are larger on one side of the body
than they are on the other side, and they have an additional small,

522 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

rounded process developed at the anterior end. These processes are
almost rudimentary on the other side.

All six segments of the abdomen are distinct. The lateral parts of
the first five segments are well developed. The sixth or terminal seg-
ment is small, and has the lateral parts not developed. The uropoda
are simple, single-branched, and consist of two elongated lamella?.
The pleopoda are five pairs of double- branched
lamellae, which are elongated and tapering, leaf-like
and covered with tubercles. The ventral side of the
first five abdominal segments has the posterior margin
produced into numerous small elongated processes.

There are five pairs of incubator}7 lamella, which
do not completely inclose the marsupial cavity.

The legs are all similar and prehensile, and have
no carinoe on the basis.

The male is 4i mm. long (not including the uropoda)
and H mm. wide. The head is without eyes and has

FIG. 668. — CRYPTIONE ±t f ± t • • j i jj mi />

ELONGATA (AFTER *"& frontal margin widely rounded. The first pair
HANSEN). DORSAL of antennae are composed of three articles. The
second pair of antennae are composed of eight articles,
the last four being minute and rudimentary.

All seven segments of the thorax are distinct. The seven pairs of
legs are prehensile.

All six segments of the abdomen are distinct. The sixth or termi-
nal segment has the post-lateral angles produced in an elongated proc-
ess on either side, which probably represent the uropoda. Between
the uropoda the posterior margin of the terminal segment is triangu-
larly produced. There are five pairs of simple sac-like pleopoda.
87. Genus PSEUDIONE Kossmann.«

Body of female oval, somewhat asymmetrical.

Segments of abdomen distinct. Epimera well defined, not contigu-
ous. Lateral parts of abdominal segments lamellar, more or less
projecting.

Terminal segment of abdomen small, with sides not lamellarly
produced.

Incubatory plates meet in the median ventral line, concealing the
incubatory pouch and the eggs; first pair with the distal segment
usualhr produced in a lobe.

All seven pairs of legs present. Pleopoda well developed, double-
branched. Uropoda simple, consisting of a pair of lanceolate lamellae.

Male with the segments of thorax and abdomen distinct. Pleopoda
present in the form of five pairs of small rudimentary sac-like bodies,
a pair for each of the first five segments. The uropoda are wanting.

Branchial parasites.

«See G. O. Sars for characters ot genus, Crust, of Norway, 11, 1899, pp. 200-201.

ISOPODS OF NORTH AMERICA. 523

ANALYTICAL KEY TO THE SPECIES OF THE GENUS PSEUDIONE.

a. Lateral parts or pleural lamella* of abdomen of female elongated, and covering to

a great extent the pleopods.
b. Distal segment of the first lamella of the inarsupium produced posteriorly in a

lobe.

c. Inner branch of the pleopoda much larger than outer branch, elongate, and
pointed; surface roughened by irregularly transverse rugae. Pleural plates
of the last three segments of the thorax not developed as lamellae. First
incubatory lamellae with the distal segment produced in a lobe which is

small and strongly curved inward Pseudione giardi Caiman

</. Inner branch of the pleopoda a little larger than the outer branch, triangular
or ovate; surface smooth. Pleural plates of the last three segments of
the thorax developed as lamellae. First incubatory lamellae with the distal
segment produced in a lobe which is large and directed straight backward.

Pseudione galacanthx Hansen
It'. Distal part of the first lamella of the marsupium not produced posteriorly in a

lobe Pseudione furcata Richardson

a'. Lateral parts or pleural lamellae of abdomen of female not elongated, but reduced
in size and short, not covering to a great extent the pleopoda.

Pseudione curtata Richardson

PSEUDIONE GIARDI Caiman.

Pseudione giardi CALMAN, Ann. N. Y. Acad. Sci., XI, 1898, pp. 274-281, pi.
xxxiv, fig. 5.— RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 869; Ann.
Mag. Nat. Hist, (7), IV, 1899, p. 337; American Naturalist, XXXIV, 1900,
p. 309. — BONNIER, Trav. de la Station Zool. de Wimereux, VIII, 1900, pp.
299-300.— RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 78.

Locality. — Puget Sound on Pagurus ochotensis (Brandt).

"Description of female. — The single specimen, measuring 12 mm. in
length, was taken from the right branchial cavity of its host (Pagurus
ochotensis (Brandt)), and it is accordingly a dextral individual (Bopyre
droit Giard and Bonnier), though the outline of its body seems at
first sight to indicate a sinistral curvature from the concavity of the
right margin in the region of the posterior thoracic segments. Closer
examination, however, shows that the head and the abdominal region
are turned toward the left and that the pleopods of the right side are
longer than those of the left, as in a normal dextral individual, so that
the peculiar curvature of the body is in all probability merely an acci-
dental variation.

'•'The specimen shows no traces of pigmentation. The dorsal surface
is flat or slightly concave; the ventral is convex, and is covered, except
in the region of the abdomen, by the greatly developed brood-pouch.
The dorsal swelling of the cephalic region which marks the position of
the stomach (cephalogaster) is very slight. An irregularly oval, some-
what convex area, the 'ovarian bosse,' is marked off by a groove on
each side of the first four thoracic segments on the dorsal surface.

"The abdominal segments, six in number, are distinctly separated
from each other. The ventral surface of the abdominal segments and

524 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of the last two or three thoracic segments is roughened by longitu-
dinal rugae, which are most marked on the adjacent margins of the
segments. These rugse are neither so conspicuous nor so regularly
disposed as in the case of the allied Pal&gyge borrei, described by

FIG. 569.— PSEUDIONE GIAKDI (AFTER CALMAN). O, DORSAL VIEW OF FEMALE. 6, EMBRYO. C, VEN-
TRAL VIEW OF MALE. d, MAXILLIPED. 6, ABDOMEN. /, UNDER SURFACE OF HEAD. </, FIRST
INCUBATORY LAMELLA WITH PEREIOPOD. h, SECOND PEREIOPOD. i, MOUTH PARTS.

Giard and Bonnier (Bull. Scient. Fr. et Belg., XIX, 1888, p. 68.)
The anterior margin of the head is bordered by a narrow membranous
expansion (limbe anterieur, G. & B.), which shows a distinct notch and
several fainter undulations on each side of the middle line. No trace

ISOPODS OF NORTH AMERICA. 525

could be discovered on the thoracic segments of the pleural lamellae,
which in Palsegyge are said to be 'rudimentaires et a peine visibles.'

"The antennules (inner antennae) are short, conical, composed of
three joints and bearing a few minute setae at the tip. The antennas
(outer antennae) are composed of five joints, of which the first is indis-
tinctly njarked off from the lower surface of the head; the third is
longer and. much more slender than the second, the fifth is very
minute. The mandibles, which are embraced by the upper and lower
lips to form the characteristic 'beak' of the Epicaridea, are of the
usual shape. The first pair of maxillae appear to be absent. After a
careful examination we have been unable to find any^ distinct rudi-
ments of them, though the triangular areas between the base of the
mandibles and the lower lips on each side bear some resemblance to
the rudiments of these organs in Palsegyge (Giard and Bonnier, in the
work mentioned, pi. v, f. 2). The rudiments of the second maxillae
are to be detected further back on the under surface of the head.
Immediately in front of each a relatively large opening leads into a
capacious tube lined by an imagination of the chitinous cuticle, the
protuberance interpreted as the rudiment of the second maxilla form-
ing the lower or posterior lip of this orifice.

"Unfortunately, these tubes were not discovered till the soft parts
of the head had been removed by caustic potash, so that we are unable
to say anything as to their connections inside the body. This is the
more to be regretted since we know of nothing analagous to these
organs, not only in the Epicarldea but even among the Malacostraca.

"The maxillipeds are similar to those of Palxgyge, but somewhat
narrower. Each consists of a flat, roughly quadrangular plate par-
tially divided into two parts by an oblique line. . The posterior part
has its external angle rounded and pointed as in Pals&gyge borrei,
and the antero-internal angle is produced. The anterior margin of
the maxilliped bears a few setae, and at its inner angle is articulated
the small 'palp,' also setose.

"Posteriorly, the lower surface of the head terminates in a freely
projecting lamina, the ''limbe posterieur^ of Giard and Bonnier. In
the present species this lamina is cut up into a fringe of digitate
processes, commencing on each side a little way from the middle line
and increasing in size outwards. Externally, on each side the lamina
is produced into a long process, narrowing gradually from its base to
a rounded tip, turned inwards and extending beyond the middle line.
In Pald&gyge there are two pairs of shorter processes and no fringe of
minute digitations.

"The thoracic legs are all similar and of the usual structure. The
'adhesive cushions' present on the proximal segments of the first pair
in Palcegyge are here absent. The oostegites or brood lamellae were
unfortunately injured in the single specimen found. The usual five

526 BULLETIN 54, UNITE!) STATES NATIONAL MUSEUM.

pairs are present and are much larger than in r«l;> </!/</<• f><>rrei, all the
pairs except, perhaps, the third and fourth, overlapping across the
median line. The first pair are, as usual, of somewhat complex form.
Roughly quadrilateral in shape, the posterior corner is produced into
a hook-like process directed inward. A little behind the middle of
its length the lamella is crossed by a transverse fold, forming on its
outer or lower surface a deep groove, the anterior margin of which is
produced as an overlapping ridge. On the inner, or, in its natural
position, upper, face of the lamella the fold projects as a strong ridge
which for part of its length is fringed with digitate processes. The
front edge of the second pair of oostegites is received into the groove
on the lower surface of the first pair. The last two pairs are strongly
fringed with setae on the posterior edge.

"Five pairs of biramous pleopods are present, successively dimin-
ishing in size posteriorly, those of the right side being, as already
mentioned, considerably larger than those of the left. In the first
pair the exopodite (lobe 5, according to the nomenclature of Giard and
Bonnier) is roughly quadrilateral in shape and much smaller than the
endopodite (lobe <?), which is long and pointed. In the posterior pairs
the exopodite approaches more-closely in size and shape to the endo-
podite. The last segment of the abdomen is very small, and bears
articulated to its posterior margin a pair of lanceolate lamellae, of
which the right is broader and slightly longer than the left. These
lamellae may possibly represent the sixth pair of pleopods, but a com-
parison with Giard and Bonnier's figure of the corresponding region
in Pals&gyge borrei suggests that we have here to do with the rudi-
mentary pleura! lamellae (lobe a of Giard and Bonnier), which, sepa-
rated by a distinct suture from the fifth and sixth segments in the
last-named species, are here only distinct on the sixth segment. If
this view be adopted the sixth pair of pleopods are entirely absent.0
In all the pleopods the surface of the endopodite is roughened by irreg-
ularly transverse rugae, which are most distinct on the anterior pairs.

"Male. — A male individual about 3 mm. long was found under the
pleopods of the female. The body is symmetrical, lanceolate in out-
line, the fourth thoracic segment being the widest. A pair of eyes
are present near the posterior corners of the head. Both antennules
and antennae are well developed, the former having three, the latter
five segments. As in the female, no distinct rudiments of the first
maxillae could be identified. The second maxillae have the form of
rather large, rounded tubercles. The maxillipeds are present as long,
slender processes, each tipped by a single seta, inserted on each side
close to the base of the lower lip. The seven pairs of thoracic feet
are all similar and of the usual form, with powerful subchelate
terminations.

« These lamellae, attached to the sixth abdominal segment, are the uropoda. — H. R.

ISOPODS OF NORTH AMERICA. 527

"The six abdominal segments are distinct,- regularly diminishing
in size posteriorly, and the first five show rudiments of pleopods in
the form of slight rounded eminences on the ventral surface. In
Palsegyge barrel, Giard and Bonnier describe the male as having rudi-
ments of pleopods on the first three abdominal segments only (p. 70),
but in a later paper the same authors speak of the abdominal segments
of the male in the genus Palsegyge as being all furnished with these
rudiments. (Bull. Sclent., XXII, 1890", p. 373.) The last segment of
the abdomen is very small, cordate in form, being very narrow ante-
riorly, and having its hinder margin notched; its greatest breadth is
about equal to the length." — CALMAN."

A description of the first larval stage of this form follows; as it is
characteristic of this stage in other Epicaridea it is not necessary to
quote the description.

PSEUDIONE GALACANTH/E Hansen.

Pseudione galacanthtc HANSEN, Bull. Mus. Comp. Zool. Harvard College, XXXI,
1897, pp. 118-120, pi. v, tig. 22 L— RICHARDSON, Proc. U. S. Nat. Mus., XXI,
1899, p. 869; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 338.— BONNIER, Trav. de
la Station Zool. de Winiereux, VIII, 1900, pp. 304-306. — RICHARDSON, Proc.
U. S. Nat. Mus., XXVII, 1904, p. 78.

Localities. — Gulf of California, in* the branchial cavity of Galacan-
tha diomedise var. parvispina, Faxon; near Flattery Rocks, Washing-
ton, on Munnida quadrispina- Benedict.

Body of female somewhat asymmetrical. Length 11 mm. Width
8 mm.

Head as wide as long, 3 mm. : 3 mm. , with the anterior margin
straight. The posterior margin is rounded. Eyes absent. The first
pair of antennas are composed of three articles. The second pair are
composed of five articles.

All the seven thoracic; segments are distinct. The lateral parts of
the first four segments are divided into a large anterior lobe and a
small posterior lobe. Ovarian bosses are present on the first four seg-
ments, situated on the anterior portion of the lateral parts of these
segments. The epimera are not distinctly separated on any of the
segments, but occupy the small posterior lobe of the lateral margin of
the first four segments and the entire lateral margin of the last three
segments. All six segments of the abdomen are present. The first
five have the lateral parts well developed and produced in elongated
lamella, which almost entirely conceal the underlying pleopoda. The
sixth or terminal segment is small, and has the lateral parts undevel-
oped. The uropoda are simple, single- branched, elongated lamella?,
attached to the sixth abdominal segment. The pleopoda are five
pairs of double-branched elongated lamella? attached to the first five

«Ann. N. Y. Acad. Sci., XI, 1898, pp. 274-281.

528

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

abdominal segments on the underside. The posterior margins of the
abdominal segments and the anterior as well as the posterior margins
of the last two thoracic segments are, on the ventral side, produced in
small round lamellae or knots. There are five pairs of incubatory
lamellae, the first pair of which have the distal portion produced on the
posterior margin in a small lobe.

All the seven pairs of legs are prehensile, and have a low rounded
carina on the basis.

FIG. 570.— PSEUDIONE GALACANTHwE (AFTER HANSEN). a, FIRST LEG WITH INCUBATORY LAMELLA.
&, SIXTH LEG OF FEMALE. C, HEAD OF SMALLER MALE. d, DORSAL VIEW OF MALE. 6, HEAD OF

FEMALE (VENTRAL VIEW). /, DORSAL VIEW OF FEMALE, g, VENTRAL VIEW OF FEMALE, h, FIRST

LEG OF MALE, i, SEVENTH LEG OF MALE.

The male is narrow, elongate, 4.8 mm. long and about 1.2-1.4 mm.
wide. Eyes small, distinct. Anterior margin of head rounded. The
first pair of antennae are composed of "three" articles. The second
pair of antennae are composed of " five " articles. All seven segments
of the thorax are distinct. The seven pairs of legs are prehensile.
The six segments of the abdomen are distinct. The sixth or terminal
segment is small, with the posterior margin truncate. There are no
uropoda. The pleopoda are five pairs of small, simple, sac-like bodies,
almost rudimentary, a pair attached to each of the first five abdominal
segments.

ISOPOD3 OF NORTH AMERICA.
PSEUDIONE FURCATA Richardson.

529

Pseudione furcata KICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 79.

Locality. — Eastern shore of Virginia.
Body of female longer than broad, more or less ovate.
Head with frontal border; anterior margin nearly straight; posterior
portion narrowly rounded. Head small and deeply immersed in thorax.

FIG. 571. — PSEUDIONE FURCATA. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF SAME, x 4.

Mouth parts and antennae concealed by first lamellaa of marsupium.
The first antennae are composed of three, the second of four joints.

The thorax has all the segments distinct. Ovarian bosses are large
and prominent on the first four segments. The epimera on these seg-
ments are represented by narrow ridges lateral to the ovarian bosses;
those of the three last segments occupy all of the lateral margin.

The segments of the abdomen are all distinct with the epimera pro-
duced in wide plates on either side of the narrow

middle portion of the segment.

The sixth or terminal segment is

without epimera, and terminates

posteriorly in two small, rounded

lobes. The pleopoda are five pairs

of smooth, narrow, elongated,

biramous appendages, all similar

and equal in size, with the excep-
tion of the inner branch of the first

pair, which is exceedingly large
and is inwardly directed, meeting the corresponding branch of the
opposite side in the median ventral line, just below the incubatory
pouch. All the remaining branches are directed post-laterally. The
surfaces of all the lamellae are quite smooth. The uropoda consist of
a single pair of simple appendages, similar in shape and size to the
pleopoda.

The incubatory pouch consists of five pairs of large lamellae, over-
28589—05 34

FIG. 572.— PSEUDIONE
FURCATA. FIRST
LAMELLA OF MAR-
SUPIUM.

FIG. 573.— PSEUDIONE
FURCATA. LEG OF
SIXTH PAIR OF ADULT

FEMALE. X 20£.

530

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

lapping in the median line. The terminal lobe of the first pair of
plates is not defined.

There is a high and widely rounded expansion or carina on the basis
of all the legs.

Male unknown.

Four specimens were collected on the eastern shore of Virginia . by
Prof. H. E. Webster. Host unknown. They were sent from Union
University to the U. S. National Museum.

Type.— Cat. No. 29093, U.S.N.M.

PSEUDIONE CURTATA Richardson.

Pseudione curtata RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp. 80-81.
Locality. — Key West, on Petrolisthes sexspinosus (Gibbes).

FIG. 574.— PSEUDIOXE CURTATA. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF SAME. X 8.

Head very large, with wide anterior margin, almost straight; no
frontal border. Antero-lateral portion produced in a small process
on either side. Posterior por-
tion widely rounded. Eyes
wanting.

The segments of the thorax
are distinct. The epimera are
distinct as narrow pfetes on
the extreme lateral margin of
the anterior portion of the
first four segments. Ovarian
bosses are prominent on the
anterior portion of the first
The epimera occupy almost all of the lateral margin

FIG. 575.— PSEUDIONE CUE-
TATA. FIRST LAMELLA OF
MARSUPIUM. X 14|.

FIG. 576.— PSEUDION E
CURTATA. LEG OF
SIXTH PAIR OF ADULT

FEMALE. X 39.

four segments.

of the three posterior segments.

The abdomen has the six segments distinct. All are produced later-
ally in small rounded epimera with the exception of the last, or termi-
nal segment which is very small and rounded posteriorly.

ISOPODS OF NORTH AMERICA.

531

The pleopoda are five pairs of large, broad, smooth, leaf-like,
double-branched appendages not concealed on the dorsal side by the
small epimeral plates of the abdominal segments,
from which they project in full view. The uropoda
are a pair of single-branched, simple appendages,
similar in shape to the branches of the pleopoda.

The marsupium is formed of five pairs of incuba-
tory lamellas, which overlap- so as to completely
encompass the ventral surface of the body; the first
pair have the terminal lobe of the distal segment
small, but well defined.

There are seven pairs of small legs, all similar in
size and structure; a high triangularly shaped ex-
pansion or carina is present on the basis.

Color uniformly light yellow.

Male, two and one-third times longer than
broad, with all seven segments of the thorax and
all six segments of the abdomen distinct. Eyes
present. Abdomen occupies one-fourth of the
entire length of the body.

Only one specimen was found at Key West by Henry Hemphill.
Parasitic on Petrolisthes sexspinosiis (Gibbes).

Type.— Cat. No. 29094, U.S.N.M.

88. Genus STEGOPHRYXUS Thompson.**

Branchial parasites.

Female with the sixth segment of the thorax greatly longer than any
of the other segments.

Abdomen with all six segments distinct; lateral parts or pleural
lamellae not developed.

There are five pairs of tri-ramous pleopods.

Uropoda consist of a pair of small, rounded, oval bodies, between
which is a small conical process.

Male with all the segments of the thorax distinct.

Abdomen ovoid, without appendages or traces of segmentation.

a See Thompson for characters of genus, Bull. U. S. Fish Comm., XXI, 1902, p. 56.

PlG. 577. — PSEUDIONE

CURTATA. MALE, x
23.

532 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

STEGOPHRYXUS HYPTIUS Thompson.

Stegophry.ms hyptius THOMPSON, Bull. U. S. Fish Comm., XXI, 1902, pp. 53-56,
pis. ix, x.— RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 59.

Localities. — Great Harbor, Woods Hole; Hadley Harbor, Naushon;
Edgartown and Warwick, Rhode Island, on Pagurus longicarpus.

Description of adult female. — " Broad in proportion to length, mar-
supiurn very large; abdomen about half the length of thorax, distinct
from it, six-jointed, with five pairs of triramous pleopoda and a pair of
oval uropoda. Length about 9.1 mm. Color yellowish-white, opaque.
Ovaries^ when full of ripe eggs, orange-yellow.

" Head, from the dorsal side appears as an oblong elevation, ending
anteriorly in a blunt lobe, which represents the median portion of the
much-reduced front. As the lateral portions of the front are almost
wholly obsolete, appearing only as two inconspicuous lobes, the greater
part of the antennules, antennae, and tip of rostrum is visible dorsalty.
The antennules are three-jointed and consist of a large globose basal
joint, surmounted by a small cylindrical second and a minute third
joint; outer joints bristle-tipped. Each antenna arises along the side
of rostrum as a columnar ridge whose distal end is visible dorsally.
From this ridge a four-jointed flagellum arises, its proximal joint
stout, the three distal joints slender; all the joints bristle-tipped.
Ventral surface of head broader than dorsal surface and sharply ele-
vated at posterior border, giving a strong antero-dorsal slope, so that
the erect hypopharynx points almost anteriorly. At sides of poste-
rior border three curved processes arise, and in the midline are two
thin foliaceous plates. Rostrum conical. Mandibles slender, with
expanded tips, the edges of which are incurved so that pressed together
they form a sucking tube. Near the bases of mandibles appear the
oval maxillulae. Hypopharynx erect, highly keeled, and plays no part
in formation of rostrum. Maxillipeds large; each consists of a foli-
aceous anterior and a somewhat thicker posterior blade; during life
these organs keep up a rapid fanning motion. There is no trace of a
palpus.

"The thorax is concealed ventrally by an enormous marsupiurn,
built up of five pairs of thin brood-plates, each strengthened by a
median chitinous rod. The posterior or fifth pair lie externally to the
others and form the major part of marsupium; they are attached
along the border of fifth and sixth thoracic segments. The posterior
angle of each forms a shallow pouch. Nearly concealed by these
plates, and almost closing the marsupium anteriorty, are the third and
fourth pairs of plates, similar to each other in shape and having an
oral ventral and a rounded dorsal portion. This dorsal part conceals
the legs of the parasite. The second pair of plates are oblong and are
hidden under the others. The first pair consists of a rather oval ante-
rior and a triangular posterior blade. The latter is strengthened

ISOPODS OF NORTH AMERICA.

533

along1 its outer (longest) border and across its base by a chitinous rod.
The anterior blades, in company with the dorsal portions of the third
pair of plates, form the funnel-like anterior end of the marsupium.

"The details of the thoracic segments are shown in fig. 578c. The
first five are crowded together, their fleshy lateral portions strongly

Fio. 578. — STEGOPHKYxrs >IYPTIUS (AFTER THOMPSON), a, HERMIT CRAB WITH PARASITE ATTACHED.
x f. 6, ANTERIOR PORTION OF HEAD OF FEMALE (VENTRAL SIDE), c, DORSAL VIEW OF ADULT FEMALE.
x 5£. d, VENTRAL VIEW OF SAME, x 4J. e, LEFT MAXILLIPED OF ADULT FEMALE, x 10. /, HEAD

OF ADULT FEMALE (DORSAL VIEW). X llj. g, HEAD OF ADULT FEMALE (VENTRAL SIDE). A, ABDO-
MEN AND POSTERIOR PART OF THORAX OF ADULT FEMALE (VENTRAL VIEW). X 5}.

bent toward the head. The lateral parts of first four segments end
in a small roughened boss or cushion, on which the roughened third
joint of the pereiopod impinges. This cushion may represent a
modified epimeron. Internally to this cushion is a flat shield-shaped
area which comes in contact with the abdomen of the host. The

534 BULLETIN 54, UNITED 8TATES NATIONAL MUSEUM.

lateral portions of fifth segment end in a sharp crest, and there is no
'shield.' The sixth segment is very long; it narrows posteriorly,
has a fleshy median keel and only slightly developed lateral por-
tions. The seventh segment is short, fleshy, about as wide as sixth

PlG. 579.— STEGOPHRYXfS HYPTIUS (AFTF.R THOMPSON). (I, DoKSAI. VIKW OK AIU'I.T MALE. X 12.

b, VENTRAL SIDE OF HEAD OP SAME, x 22. c, VENTRAL VIEW OF HEAD OF CRYPTONISCID. x 110.
d, CRYPTONISCID FROM YOUNG FEMALE (LATERAL VIEW), x 58. e, PLEOPOD OF THIRD ABDOMINAL

SEGMENT OF CRYPTONISCID. X 70. /, MUSCULATURE OF ONE OF FIRST FOUR PEREIOPODA (ADULT

FEMALE), x 20. g, MUSCULATURE OF ONE OF SIXTH OR SEVENTH PEREIOPODA OF FEMALE, x 20.
h, MUSCULATURE OF PEREIOPOD. x 40. i, DORSAL VIEW OF LARVAL FEMALE, x 12. j, VENTRAL

VIEW OF SAME. X 6}.

and similar to it, except that it is not keeled. Ventral surface of
thoracic segment fleshy, posterior borders of sixth and seventh modi-
fied into complex elevated keels. Pereiopoda of the sixth and seventh
segments are alike and quite simple in construction; those of the other

ISOPODS OF NORTH AMERICA. 535

five segments are modified, the last three joints being twisted to one
side. Extensor muscles enormously developed.

"The abdomen consists of six fleshy segments, five of which bear a
pair of pleopoda. Each pleopod has three oval blades arising from
a short common base. Two of these are subequal and extend in a
lateral direction; the third is smaller and points ventrally. This ven-
tral ramus is broadly expanded in the pleopoda of the first abdominal
segment, especially on the right side. The first segment has ventral
keels similar to those on the las^ thoracic segments. Between the
oval uropoda of the sixth segment is a minute conical prominence."

Description of adult male.— "Three and two-thirds longer than
broad. Abdomen unsegmented, about a third of entire length. Color
dull yellowish. Around ths heart in the abdomen is an orange-colored
area, and a narrow streak of same color runs forward along the mid-
dorsal line. Sometimes splashes of black occur on the sides of the
head and thorax. Length about 3 mm.

"Head oval, elevated in center, the margin entire and not inflexed.
Eyes minute. On the under side is a shallow central depression, in
front of which arise the three-jointed antennula?. From the depres-
sion the eight -jointed antennae and the conical rostrum take their
origin. First joint of antenna? elbowed, the others cylindrical, the
distal ones bristle-tipped. Sixth, seventh, and eighth joints very
small, together scarcely equalling the fifth in length. Rostrum prom-
inent, built up dorsally by the labrum and ventrally by the hypo-
phanrnx. Apex of latter conceals tips of mandibles and median part
of labrum. Mandibles slender, with thick bases and sharp chitinous
tips. I have not found maxillula?. Between the maxilla? and extend-
ing forward from a transverse ridge are the three-jointed maxillipeds.
The thorax consists of seven fleshy segments. It narrows slightly
posteriorly and is moderately convex. Sides subparallel, somewhat
deflexed, epimera not distinct. First segment notched for reception
of head. Seven pairs of pereiopoda, whose structure and muscula-
ture can be understood by reference to the plate. Abdomen ovoid or
sometimes pear-shaped, shows no sign of segmentation, and has no
traces of appendages." — M. T. THOMPSON."

89. Genus STEGIAS Richardson.

Body of female with sixth segment of thorax not greatly longer
than any of the others.

All six segments of abdomen distinct; lateral parts or pleural lamel-
la? not developed. First three pairs of pleopods triramous; last two
pairs biramous. Uropoda consist of a pair of elongated lamella?, with-
out a conical process between the two.

l. U. S. Fish Commission, XXI, 1902, pp. 53-56. Consult this reference also
for description of immature forms.

536 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

STEGIAS CLIBANARII Richardson.
Stegias dibanarii RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp. 59-60.

Locality. — Bermudas, on Clibanarius tricolor.

Head deeply set in thorax, broader posteriorly than anteriorly,
longer than broad, and with straight frontal margin. First pair of
antennae visible on dorsal surface, just anterior to front, as two small
lobes, each antenna terminating in a minute joint. Second pair of
antenna? also visible on dorsal surface, lying on either side of first pair
of antenna?, each antenna terminating in a flagellum composed of
several minute joints.

Thorax divided into seven distinct segments. The first three sur-
round the head, and are closeh7 crowded together. The other four are
very much longer and are of nearly equal length, the fifth being much

b
FIG. 580. — STEGIAS CLIBAKABII. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF FEMALE, x 8.

longer at the sides than the others. The first five segments at the
sides are directed forward, the five pairs of legs all extending in an
anterior direction. A considerable space separates the fifth pair of
legs from the sixth pair. The sixth pair of legs, as well as the seventh
pair, are placed at the posterior extremity of the sixth and seventh
segments, respectively. The epimera of the first four segments are
distinct as narrow ridges on the lateral margins of each segment. The
ovarian bosses are also present on these segments.

The abdomen is composed of six distinct segments, the first three
of which are provided with a pair of triramous pleopods — two dorsal
branches and one ventral branch to each pleopod; the next two seg-
ments, the fourth and fifth, are each provided with a pair of biramous
pleopods, both branches of each pleopod being dorsal, the ventral
branch, corresponding to that of the first three segments, not being
represented; the sixth segment of the abdomen is furnished with a

ISOPODS OF NORTH AMERICA. 537

pair of simple elongated uropoda, equaling in length the dorsal
branches of the pleopoda of the other abdominal segments.

The marsupium is composed of five pairs of lamella?, the lamellae of
the fifth pair being very large, and occupying almost half of the
ventral side of the thorax.

Male unknown.

Only one specimen was collected by Dr. G. Brown Goqde at the
Bermudas in 1876-77. The parasite was found attached to Clibanarius
tricolor.

Type in the Peabody Museum, Yale University.

This genus differs chiefly from Stegophryxus Thompson, to which
it is closely related in having the pleopoda of the fourth and fifth
abdominal segments biramous instead of triramous; in having the
uropoda long and leaf-like, similar in shape and size to the branches
of the pleopoda, while in Stegophryxus hyptius, the type species of
the genus, the uropoda are small, rounded, and knob-like, with a
minute conical prominence between them; and in not having the sixth
thoracic segment great! 3^ longer than the others.

9O. Genus BATHYGYGE Hansen.

Body of female asymmetrical, the abdomen being turned to one
side in a marked degree. Epimeral plates, consisting of large oval
lamella?, anteriorh' very much produced and attached near the inner
posterior margin.

Segments of the abdomen distinct; lateral parts or pleural lamellae
not developed. Abdomen small.

The pleopoda consist of five pairs of double-branched lamella?, the
two branches being unequal in size, and arising from a common
peduncle attached to the lateral margin of the segment.

The uropoda are double-branched.

Male with the abdominal segments fused; abdomen ovate in outline.

Pleopoda and uropoda absent. Segments of thorax distinct.

Branchial parasites.

BATHYGYGE GRANDIS Hansen.

Bathygyge grandis HANSEN, Bull. Mus. Coinp. Zool. Harvard College, XXXI,
1897, pp. 122-124, pi. vi, figs. 2-2e.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 869; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 338.— BONNIER,
Travaux de la Station Zool. de Wimereux, VIII, 1900, pp. 291-292.

Locality. — Off Acapulco, in the branchial cavity of Glyphocrangon
spinulosa Faxon.

"Only a male, and the posterior part of a female have been sent
to me.

"(a) Female. — The rudiment consists of the posterior part of the
thorax, bearing three legs on one and two on the other side, and the
abdomen.

538

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"Thorax: The pleural plates are very large oval lamella1, only con-
nected with the segment by somewhat less than the posterior half of
their interior margin, and this result is due to the fact that they
anteriorly are very much produced, highly overlapping each other,
and posteriorly rather shortly produced. The legs are tolerably
slender; the second joint not expanded; the fifth joint elongate, in
the last pair as long as the hand.

"Abdomen: It is turned to the left in a startling degree and is pro-
portionally small — perhaps very small. The dorsal surface is soft-
skinned, the segments more or less dis
tinctly separated. Pleural plates are not
developed. The pleopods quite soft, of
medium size, decreasing conspicuously
in size from before backward and at-
tached to the lateral margin; each pleo-
pod consists of a short peduncle and
two lamellar oblong rami; the outer
ramus much larger than the inner one.
The uropods biramous; the outer ramus
a little smaller than the outer of the
fifth pleopod, the inner ramus very
short, almost rudimentary. The pleo-
pods are curled to such a degree that it
would have been impossible without
much construction to draw a sketch of
the abdomen.

"(&) Male. — The body is a little more
than three times longer than broad, and
from the fourth thoracic segment it
decreases in breadth towards both ends.
(Fig. 5811.)

' ' Head : The dorsal surface rather con-
vex; the median portion of the anterior
margin almost straight. No eyes. The
frontal border bent slightly downward.
(Fig. 581$. ) The antennulte rather
short, three-jointed; the basal joint tol-
erably thick and partly overlapped by the rostrum; the second joint
slender and rather short; the third very small. The antenme com-
paratively long, seven-jointed; the four proximal joints of about
the same length, but decreasing much in breadth from the rather
thick basal joint to the fourth one; the fifth joint is short and very
slender, the last two joints exceedingly small. The mouth forms a
rostrum, which, when seen from below, is triangular, considerably
depressed, and directed forward, reaching almost to the frontal margin

FIG. 581. — BATHYGYGE GRANDIS (AFTER
HANSEN). a, HEAD OP MALE (YEN
TEAL VIEW). 6, DORSAL VIEW OF MALE.
C, FIRST LEG OF MALE, d, FIFTH LEG OF

MALE.

ISOPODS OF NOETH AMEKICA. 539

of the head. The l^popharynx is very large, and just outside it is
seen the very oblong lateral part of the labrum (d), the median part of
which is concealed by the hypopharynx. At first I believed that
these oblong organs were the mandibles, but a closer examination gave
the result mentioned, while the mandibles, being needles with brown
apex, were discovered within the rostrum. Maxillulse are not
observed; the maxillae (/") are small semicircular lobes lying consid-
erably behind the posterior edge of the labrum. The maxillipeds (y)
are short, extremely slender, almost stj'liform.

"Thorax: The segments are rather convex, the incisions between
them comparatively broad and very deep; the lateral margins are much
curved when seen from the side. The legs increase considerably in
length and very much in thickness from the first (fig. 58lc) to the fifth
pair (tig. 581<^), which is robust, with the hand very large; the two
poterior pairs again decrease somewhat in size. The terminal mar-
gin of the hand is deeply concave, thus differing considerably from
the preceding forms.

"Abdomen: It occupies scarcely one-fourth of the length of the
animal ; it is narrower than the last thoracic segment, shortly ovate in
outline, without the slightest rudiment of segmentation or abdominal
feet; both the ventral and especially the dorsal surface are very
convex.

" Size: Uncommonly large, being 7 mm. long and 2.3 mm. broad. "-

HANSEN.a

91. Genus PHYLLODURUS Stimpson.

"Feminge pedes thoracis sat validi, toti ancorales, unguiculati;
appendicibus branchialibus carentes. Appendices abdominis bran-
chiales; superiores late rales, laminis duabus sequis magnis elongatis;
inferiores papilliformes. Abdominis segmentus primus setis dorsali-
bus unguiculatis instructus." — STIMPSON. b

Abdominal parasites.

Body of female is almost symmetrical.

Ovarian bosses present. Posterior portion of lateral margins of tho-
racic segments not produced. Epimera present on all the segments,
not distinctly separated on the last two; they occupy the anterior part
of the lateral margin on the first four segments; on the fifth segment
they are placed between the anterior and posterior divisions of the seg-
ment; on the last two segments they occupy the posterior portion of
the lateral margin.

The abdomen is distinctly segmented, becoming gradually and rap-
dly narrower from the first to the terminal segment; lateral parts of
segments or pleural lamellae not developed. On the dorsal surface of

« Bull. Mus. Comp. Zool. Harvard College, XXXI, 1897, pp. 122-124.
b Boat. Journ. Nat. Hist., VI, 1857, pp. 511-513.

540 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the first segment of the abdomen close to the anterior margin are two
large papillose processes, one on either side of the median line.

There are five pairs of double-branched pleopoda, the branches in
the adult being similar and subequal, and both branches being in the
form of long, narrow lamella?, issuing from a common peduncle
attached to the lateral margins of the segments and forming a border
surrounding the abdomen.

The uropoda are simple, in the form of two long, narrow, C3'lindrical
lamella? attached to the sixth abdominal segment. All seven pairs of
legs are present.

The abdomen of the male is distinctly segmented. The first abdomi-
nal segment has two large rounded papilla* close to the anterior mar-
gin, one on either side of the median line. The sixth or terminal
segment is posteriorly produced at the apex in a long pointed process.
There are five pairs of single-branched pleopoda, in the form of long,
narrow-sacs, attached one on each side close to the lateral margins of
the segments. The uropoda are a pair of small, simple processes,
attached one on either side of the terminal segment of the abdomen.

All seven segments of the thorax are distinct.

PHYLLODURUS ABDOMINALIS Stimpson.

Phyttodurus abdominalis STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, pp. 511-
513.— LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 57; Ann. Mag.
Nat. Hist. (5), II, 1878, pp. 299-300.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 868; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 337.— BONMKK,
Trav. de la Station Zool. de Wimereux, VIII, 1900, p. 250.— RICHARDSON,
Proc. U. S. Nat. Mus., XXVII, 1904, p. 78.

Localities. — Puget Sound on Upogebiw; Tomales Bay on Upogebia
pugettensis (Lockington) ; San Francisco Bay.

Description of female. — Body ovate, a little longer than wide, about
one and a half times longer than wide, 10 mm. : 14 mm.

Head a little wider than long, 3 mm.: 4^ mm., bilobate, with the
frontal margin produced in a rounded border. Eyes absent. The
first pair of antenna? are small, usualh' inconspicuous from a dorsal
view, composed of three articles, the terminal article being minute,
the first article large and dilated. The second pair of antenna1 are
partly visible from a dorsal view. They are composed of five articles,
the terminal article being minute.

The seven segments of the thorax are distinct. The anterior portion
of the lateral margins of the segments is occupied by the ovarian
bosses. Lateral to the ovarian bosses on the first four segments are
the narrow epimeral plates. The posterior lobe of the lateral margin
is small on the first segment, becoming larger on the three following
segments. On the fifth segment the epimeral plate lies between the
ovarian boss and the posterior lobe, being lateral partly to both. On

ISOPODS OF NORTH AMERICA.

541

FIG. 582. — PHYLLODUBUS ABDOMINALIS.
FEMALE (DORSAL VIEW).

the last two segments the epimera occupy the post-lateral margin and
are not separated from the segment.

The abdomen is composed of six distinct segments. The first seg-
ment is provided on either side near the antero- lateral margin with a
papillose process. This segment is nearly
twice as long as any of the following seg-
ments. The segments of the abdomen
are successively narrower, gradually and
rapidly tapering to the sixth or terminal
segment which is produced posteriorly
in a long, narrow, tapering process.

On either side of the lateral margins of
the first five abdominal segments are at-
tached two long, narrow processes, arising
from a common stem or peduncle. These
are probably the pleopoda, which may be
considered as double-branched. There
are thus ten of these on either side, or
twenty in all — i. e., five pairs of double-
branched pleopoda. On either side of the

sixth or terminal segment the uropoda are attached. They are single-
branched, each consisting of one long, narrow cylindrical process.
The ventral side of the last two thoracic segments is produced on
the posterior margins in keels. The ventral side of the abdominal
segments is slightly keeled.

There are five pairs of incubatory plates. The distal
part of the first lamelhe is posteriorly produced in a
triangularly rounded lobe.

The seven pairs of legs are prehensile in character;
the basis is not produced in a carina.

The young female has one of the branches (the inner
one) of the pleopoda very much shorter than the other
branch. The head is not bilobed, and has the front more
circular in outline. I have examined three adult females,
two young females, and two males. The two young
females had rudiments of the incubatory lamellae, the
plates being larger in one specimen than in the other,
and the inner branch of the pleopoda also larger. One
specimen is a little older than the other.

Most of the specimens were kindly sent to me by Doctor Caiman.
They were sent to him from Columbia University, New York. Another
specimen, a female, was sent to me later by Dr. William E. Ritter, of
the University of California.

Description of male. — Body oblong-ovate, a little more than twice as
long as wide, 2£ mm. : 6 mm.

FIG. 583.— PHYLLO-
DUECS ABDOMI-
NALIS. ONE OF
BIRAMOUS PLE-
OPODS OF ADULT
FEMALE. X 7.

542 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Head about twice as wide as long, with the anterior margin circular
in outline, the posterior margin straight. The eyes are small, dis-
tinct, and situated on the posterior margin, at some distance from the
sides of the head. The first pair of antennae are short and are com-

FIG. 584.— PHYLLODURUS ABDOMINALIS. a, FIRST INCUBATORY LAMELLA, x 27}. b, MAXILLIPED.
x 27i. c, SEVENTH LEG. x 15|.

posed of only three articles. The second pair are composed of five

articles, the terminal article being tipped with hairs.
The seven segments of the thorax are distinct and taper gradually,

becoming successively narrower.
The six abdominal segments are distinct. They taper gradually but

rapidly to the small terminal segment which is posteriorly produced

in a long, narrow process, which is a little longer than the basal

part of the segment. The uro-
poda consist of a small branch on
either side of the sixth or termi-
nal segment and are attached at
the place where the basal part of
the segment gives rise to the long,
narrow terminal process.

There are five pairs of single-
branched pleopoda, a pair for each
of the first five abdominal seg-
ments. They are in the form of
narrow, elongated sacs, rounded
at the extremity, and attached, one

FIG. 585.— PHYLLODURUS ABDOMINALIS. a. MALE. u -j ±1 i ± i

6, YOUNG FEMALE. on each slde> close to the lateral

margin of the segments.

The first abdominal segment bears on the dorsal surface two large
rounded papillae, one on either side, close to the lateral margin.

There are seven pairs of prehensile legs.

Dr. W. T. Caiman says that he thinks it is characteristic for the
males and females to be attached separately to the host. Only in one
case did he find a male attached to the female. The label accompany-
ing one male sent by Doctor Caiman reads: "Found on the second
pleopod of host."

ISOPODS OF NORTH AMERICA. ' 543

The following description of the female is given by Stimpson:

This curious form of parasitic anisopods was found attached to and lying between
the abdominal feet of the common Gebia, adhering by the sharp hook-shaped termi-
nal joints of its feet, and perhaps aided in keeping its position by the sharp dorsal
setse of the abdomen. As might be expected from this external parasitism, the
shape of the body is symmetrical, being never distorted, as is almost always the case
in those forms which live in the usual position — in the confined space under the
thoracic shield of the shrimp or crayfish.

In our species the thorax is somewhat cordate in shape, broadest behind, the
short abdomen being set in the concavity. The thoracic segments are well separated
and provided with distinct tumid epimera; the external envelope is soft, being even
less hard and cru^taceous than in Argeia. The head is somewhat broader than long,
strongly tumid, and in the character of its appendages resembles somewhat that of
lone. The front projects abruptly, forming a horizontal margin to the head, beneath
the anterior part of which the small inner antennae are concealed. The outer
antennae arise laterally, and behind the inner ones, which they much exceed in
length, being as long as half the width of the head. There are no thoracic branchial
appendages. The thoracic feet are similar in character throughout; they gradually
increase in length posteriorly, and are each provided with a small hand, the hooked
finger of which is of moderate length, more than reaching the projecting inferior
angle of the antepenultimate article.

The abdomen is triangular and consists of six deeply separated segments, the
terminal one being very minute. The basal segment is much the largest, and bears
upon its dorsal surface two papillae, one on each side, which are provided with
short, stiff, somewhat hooked setae. The lateral extremities of the abdominal seg-
ments are split by a marginal furrow into superior and inferior rami; the latter
being simply conical with two or three circular wrinkles; and the former (superior)
each surmounted by a cylindrical pedicle which bears two large cultriforni lamella?.
There are thus twelve pairs of these lamellae, which are of large size, and being
crowded, project in different directions, nearly concealing the posterior half of the
animal. Each is about one-fifth as broad as long, compressed on the inner and
thickened along the outer or convex edge. Only females of this species have as yet

been found, The dimensions of one specimen are:

Inch.

Length of body 0. 58

Length of abdomen 12

Length of superior abdominal appendages 24

Breadth of thorax „.. 45

Several examples of this singular crustacean have been found on Gebise from Puget
Sound and Tomales Bay.rt

Lockington says: "The males do not live attached to the Gebia, but
are free to rove." His description of the male is as follows:

Head semi-circular anteriorly, closely united to the succeeding segment. Third
and fourth thoracic segments widest. Body oblong, boat-shaped, tapering slowly
from the fourth to the seventh thoracic segment.

Outer antennae 4-jointed; inner very small, reaching about to the middle of the
second segment of the outer. Eyes too small to be distinguished by a Coddington
lens. First abdominal segment a little narrower than last thoracic, but flat; succeed-
ing segments tapering rapidly to the sixth or telson, which is pointed at the end and
is provided on each side with a small lamella, giving the whole telson somewhat the
appearance of a spearhead.

a Bost. Journ. Nat. Hist., 1857, pp. 511-513.

544 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The lateral laminae of the first five abdominal segments round in sections instead
of segmental as in the female, and considerably longer than the width of the seg-
ments to which they are attached."

92. Genus ARGEIA Dana.

Body of female asymmetrical.

Ovarian bosses present on the first four segments of the thorax.
Epimera present on all the segments; on the first four segments they
are lateral to the ovarian bosses, and are in the form of narrow plates.
The posterior portion of the lateral margins, in all the segments, are
more or less produced, the length of the processes varying in each
individual.

The segments of the abdomen are distinctly defined, and become
gradually but rapidly narrower to the sixth or terminal segment, which
is somewhat bilobed.

The pleopoda are five pairs of double-branched appendages; the
outer branches are in the form of long, narrow lamella? attached close
to the lateral margins of the segments and forming a border surround-
ing the abdomen. The inner branches are in the form of small,
rounded lamellae, decreasing in size from the first to the last.

The uropoda are simple, in the form of two narrow, elongate
lamella? attached to the terminal segment and similar to the outer
branches of the pleopoda.

All seven pairs of legs are present.

The male has all the segments of the abdomen fused. The pleopoda
and uropoda are wanting. All seven segments of the thorax are
distinct.

Branchial parasites.

ANALYTICAL KEY TO THE SPECIES OP THE GENUS ARGEIA.

a. Thoracic processes present on all the segments. Head large. Inner branches of
all the pleopoda present. Incubatory lamellae do not completely cover the

marsupial pouch :. Argeid pugettenis Dana

of . Thoracic processes apparently absent on some of the anterior segments. Head
smaller than in A. pugettensis, and bilobate. Inner branches of the first three
pairs of pleopods present; others wanting Argeia pauperata Stimpson. &

ARGEIA PUGETTENSIS Dana.

Argeia pugettemis DANA, U. S. Expl. Exp., Crust., XIV, 1853, p. 804, pi. LIII,
fig. 7.— STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, p. 511.

Argtia sp.? CALMAN, Ann. N. Y. Acad. Sci., XI, 1898, p. 281.

Argeia pugettensis RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 868; Ann.
Mag. Nat. Hist. (7), IV, 1899, p. 337; American Naturalist, XXXIV, 1900,
p. 308.

«Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 57.

6 The key is made from Stimpson's diagnosis of Argeia pauperata. I have seen no
specimens of his species.

ISOPODS OF NORTH AMERICA.

545

Argeia calmani BONNIER, Travaux de la Station Zool. de Wimereux, VIII, 1900,

p. 329.
Argeia pugettensis BONNIER, Traveux de la Station Zool. de Wimereux, VIII,

1900, pp. 327-328.— RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp.

60-64; Bull. U. S. Fish Comin., XXIV, 1905, p. 220.

localities. — On Crago munita (Dana), at Puget Sound; off Cape
Beale, Vancouver Island. On Crago alascensis (Lockington), off Cape

FIG. 586. — ARGEIA PUGETTENSIS. a, DORSAL VIEW OF ADULT FEMALE. 6, VENTRAL VIEW OF ADULT

FEMALE. X 14£.

Seniavin, Alaska; at Davidson Bank, Alaska; east of Amak Island,
Alaska; off Cape Strogonoff, Alaska; northwest of Unimak Island,
Alaska; Kouloulak Bay, Alaska; off Columbia River, Oregon; Gulf
of Georgia, British Columbia. On Crago dalli (Rathbun), south of
Amak Island, Alaska. On Crago alascensis elongata (Rathbun), off
Columbia River, Oregon. On Nectocrangon ovifer
(Rathbun), off North Head, Akutan Island, Alaska;
west of Pribilof Islands, Alaska. On Crago francis-
corum angustimana (Rathbun), Straits of Fuca; Gulf
of Georgia, British Columbia. On Nectocrangon nigri-
cauda Stimpson, off Port Ano Nuevo, California. On
Nectocrangon crassa Rathbun, off Cape Seniavin, Alaska;
off Cape Newenham, Alaska; north of Bird Island, Shu-
magins, Alaska; Bering Sea, off the Pribilof Islands;
Semidi Islands. On Nectocrangon lar (Owen), off Rako-
vaya Bay; Avatcha Bay; off Cape Strogonoff; off
Kouloulak Bay and off Bristol Bay, Alaska; off Cape FIG. 537.— ARGEIA
Menchikoff, Alaska; off Khoudoubine Islands, Alaska;
off mouth of Yukon River. On Nectocrangon alascensis
Kingsley, southwest of Hagemeister Island, Alaska; south and north-
west of Unimak Island, Alaska; off Moorovskoy^ Bay, Alaska; David-
son Bank, Alaska; off North Head, Akutan Island, Alaska; south
of San Diego Bay, California; off Rootook Island, Alaska; Petro-
paulovski, Kamchatka; off Kouloulak Bay, Alaska; between Bird
and Nagai Islands; Unimak Pass; off Cape Johnson; southwest of San-
nakh Islands, Alaska; off Grays Harbor, Washington; off Destruction
28589—05 35

PUGETTENSIS.

MALE, x 22.

546

BULLETIN f)4, UNITED STATES NATIONAL MUSEUM.

Island; Bering Sea, off Akutan Pass. On Crago nigromaculata
(Lockington), at San Diego Ba}T, California; off Tillainook Rock,
Oregon; Monterey Bay, California; off Cape Johnson. On Crago
communi* (Rathbun), off Grays Harbor, Washington; off Columbia
River, Oregon; Sari Luis Obispo Ba}r, California; Ilhiliuk Harbor,
Unalaska; Straits of Fuca; south of San Diego Ba}T, California;
off Rootook Island, Alaska; off Falmouth Harbor, Shumagins,
Alaska; Bering Sea, off Akutan Island, northwest of Unimak
Island, Alaska; off Point Arena, California; Wash-
ington Sound, Straits of Fuca, Washington. On
Nectocrangon dentata Rathbun, at Kyska Harbor,
Unalaska; Mazan Bay, Atka; Port Etches, Alaska;
Port Levasheff, Unalaska; Ilhiliuk Harbor, Unalaska,
off Round Island, Coal Harbor, Unga Island; off Sit-
kalidak Island, Alaska. On Crago alba (Holmes),
south of San Diego Bay, California; Gulf of Georgia,
off Nanaimo, Vancouver Island, British Columbia;
Kilisut Harbor, near Port Townsend, on Crago <il<tx-
Jcensis (Lockington) ; Admiralty Inlet, vicinity of Port Townsend, on
Crago alascensts (Lockington) and Crago communis (Rathbun); vicinity
of Naha Bay, Behm Canal, southeast Alaska, on Crago communix
(Rathbun) and Nectocrangon dentata (Rathbun).
Depth. - 16 to 89 fathoms.

Immature specimens were found off Seal Islands, Alaska, on Necto-
crangon alascensis; off Rootook Island, Alaska, on Crago communis;
north of Bird Islands, Shumagins, Alaska; Gulf of the Farallones,

FIG. 588.— A KG E i A

PUGETTENSIS.
FIRST LAMELLA
OF MAR8UPIUM.

x 14*.

a I) c d

FIG. 589. — ARGEIA PUGETTENSIS. SIXTH LEG OF SPECIMENS FOUND ON: «, CRAGO NIGRICAUDA FROM
OFF CAPE JOHNSON, WASHINGTON, x 27}. 6. CRAGO COMMUNIS FROM STRAITS OF FUCA. x 27}.
c, NECTOCRANGON CRASSA FROM OFF CAPE NEWENHAM, ALASKA, x 27}. d, NECTOCRANGOX

CRASSA FROM ALASKA. X 27}.

California, on Crago nigromaculata; Coal Harbor, Unga Island, on
Nectocrangon dentata; Captains Harbor, Unalaska, on Nectocrangon
dentata; Sanborn Harbor, Nagai, Shumagins, on Nectocrangon lar;
Mazan Bay, Atka, on Nectocrangon crassa; southwest of Hagemeister
Island, Alaska, on Nectocrangon almcensix; northwest and northeast
of Unimak Island, Alaska, on Nectocrangon alascensis; Bering Sea,
between Pribilof Islands and Cape Newenham, on Nectocrangon lar;
Kouloulak Bay, Alaska, on Nectocrangon lar; between Bristol Bay

ISOPODS OF NORTH AMERICA.

547

and Pribilof Islands, Alaska, on Nectocrangon lar; Arctic Ocean, on
Nectocrangon lar; Popoff Straits, on Nectocrangon crasm; between
Bird and Nagai, Islands, on JVectocrangon alascensis.

List of Crangonidse on which Argeia pugettemix is found parasitic:

Nectocrangon ovifer Rathbun.
Nectocrangon lar (Owen).
Nectocrangon alascensis Kingsley.
Nectocrangon crassa Rathbun.
Nectocrangon dentata Rathbun.
Orago nigromaculata (Lockington).
Orago franciscorum angustimana (Rath-
bun).

Crago dalli (Rathbun).
Orago communis ( Rathbun ) .
Crago propinqua (Stimpson).
Orago nigricauda (Stimpson).
Orago alascensis (Lockington).
Orago alascensis elongata (Rathbun).
Crago alba (Holmes).
Crago munita (Dana).

Immature forms.— A female (probably in the first post-larval stage)
has the thoracic processes well developed, sometimes only on one side.

FIG. 590.— ARGEIA PUGETTENSIS. SIXTH LEG OF SPECIMENS FOUND ON: a, NECTOCRANGON DENTATA
FROM AFOGNAK BAY, AFOGNAK ISLAND, x 39. b, NECTOCRANGON CRASSA FROM CAPE NEWENHAM,
ALASKA, x 20J.

The inner pleopoda of the first pair are usually present; all the outer
pleopoda, the other four inner pleopoda, and the uropoda are not

FIG. 591.— ARGEIA PUGETTENSIS. SEVENTH LEG OF SPECIMENS FOUND ON: a, NECTOCRANGON ALASCEN-
SIS FROM SOUTHWEST OF SANNAKH ISLANDS. ALASKA. X 41. 6, CRAGO NIGROMAC TLATA FROM SAN

DIEGO BAY, CALIFORNIA, x 41. c, CRAGO DALLI FROM SOUTH OF AMAK ISLAND, ALASKA, x 41.
d, CRAGO COMMUNIS PROM AKUTAN ISLAND, BERING STRAIT, x 41.

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

developed at this stage. The marsupial plates are small and just

developing. The male is similar to the male found on adult female.

Immature female of a more advanced stage has the thoracic processes

well developed, although perhaps not quite as long as in the preceding

a be d

FIG. 592. — ARGEIA PUGETTENSIS. FIRST INCUBATORY PLATE FROM SPECIMENS FOUND ON: a, NECTO-

CRANGON CRES8A FROM OFF CAPE NEWENHAM, ALASKA. X 9J. 6, NECTOCRANGON CRASSA FROM

ALASKA, x 9J. c, CRAGO NIGROMACULATA FROM SAN DIEGO BAY, CALIFORNIA, x 9}. d, CRAGO

NIGRICAUDA FROM OFF CAPE JOHNSON. X 9r-

stage. The outer pleopoda and uropoda are small, but all developed.
The first two inner pleopoda are present; the other three may or may
not be present. When present they are usually smaller than the first
two, decreasing in size to the fifth pair, and sometimes difficult to

discern. The marsupial plates are
larger than in the preceding stage,
but not fully developed. The in-
cubatory pouch never carries eggs
in either of these stages. The male
is similar to the male of the adult
female.

Specimens of- both immature
stages were found on the same
species and genera of host as the
adult females.

A male in the cryptoniscan stage
was found on one immature female
(in first post-larval stage).

Thoracic processes of adult fe-
male.— In the adult female the
thoracic processes may be quite re-
duced. In some specimens these
processes are well developed,
though never in all the specimens
examined were they found as long as
in the very young female or as in the

figure given by Dana of the adult female. In other specimens these
processes are very small, and yet in many they were not even present.
Not only is this variation found in specimens taken from different
species and genera of host, but it is also true of those found on the
same species and genus of host. As a result of this observation on a

FIG. 593.— ARGEIA PUGETTENSIS. FIRST INCU-
BATORY LAMELLA FROM SPECIMEN FOUND ON:

a, CRAGO COMMTJNIS FROM STRAITS OF FUCA.
x 14. b, CRAGO COMMUNIS FROM AKUTAN
ISLAND, ALASKA, x 14. c, NECTOCRANGON

ALASCENSIS FROM SOUTHWEST OF SANNAKH

ISLANDS, ALASKA, x 14. d, CRAGO DALLI FROM
SOUTH OF AMAK ISLAND, x 14.

ISOPODS OF NORTH AMERICA.

549

FIG. 594. — ARGEIA PUGETTENSIS. FIRST INCUBA-
TOKY LAMELLA FROM SPECIMENS FOUND ON: «,
NECTOCRANGON DENTATA FROM AFOGNAK BAY,
AFOGNAK ISLAND, x Hi. 6, NECTOCRANGON

CRASSA FROM OFF CAPE NEWENHAM, ALASKA.
X9i.

large number of these forms, the conclusion must be maintained that
these thoracic processes, well developed in the young female, of vary-
ing size and shape and sometimes so reduced as to be practically absent
in the adult female, have no specific value whatever. Giard and Bon-
nier have described their function as organs of fixation, which seems
a reasonable conclusion and one capable of explaining why so much
variation occurs in this respect
with each individual parasite.

Body of adult female some-
what asymmetrical. Length, 14
mm. ; width, 11 mm.

Head wider than long, 2 mm. :
3i mm., somewhat bilobed, with
a narrow frontal border, the an-
terior margin of which is slightly
arched or rounded. The frontal
border projects at the side in a
small angular lobe. Eyes absent.
The first pair of antenna? are composed of two articles — a large basal
article and a small terminal one. The second pair are composed of
four articles. Both are small and not conspicuous on the dorsal side.
All seven segments of the thorax are distinct. Ovarian bosses are
present on the first four segments, where they occupy the sub-lateral
portion of the anterior part of the lateral margin. The epimera are
narrow plates lateral to the ovarian bosses on the anterior part of the

segments. The epimera also
occupy the anterior part of the
lateral margin of the last three
segments, but the ovarian bosses
are not present on these seg-
ments. The posterior lobes on
all the segments are large and
irregular in outline, and more or
less produced in narrow, some-
what elongated processes, these
processes being usually more
developed on one side (the longer
side) than on the other.
All six segments of the abdomen are distinct. The lateral parts
are not developed in any of the segments. The sixth or terminal seg-
ment is small and posteriorly truncate. The uropoda are a pair of
simple, single-branched lamella?, somewhat elongated, with outlines
irregular, and attached to the sixth abdominal segment. There are
five pairs of double-branched pleopoda. The outer branches are elon-

FIG. 595.— ARGEIA PUGETTENSIS. a, DORSAL VIEW

OF IMMATURE FEMALE. 6, VENTRAL VIEW OF
SAME. X 10. (FIRST POST-LARVAL STAGE.)

550 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

gated lamellae, similar in shape to the uropoda, and are placed close to
the lateral margins of the segments on the underside, so that in a dor-

FIG. 596. — ARGEIA PUGETTENSIS. a, DORSAL VIEW OF IMMATURE FEMALE, b, VENTRAL VIEW OF

SAME. X 14^. (SECOND POST-LARVAL STAGE.)

sal view they appear attached to the lateral margins of the segments.
They form a border around the abdomen. The inner branches are
rounded, sac-like bodies, usually decreasing in
size from the first to the last.

There are five pairs of incubatory lamellae
which do not completely inclose the marsupial
pouch. The distal part of the first pair has the
posterior margin not produced in a lobe.

The legs are all prehensile. The basis of all
seven pairs is provided with a high rounded
carina.

The male is narrow, elongate, symmetrical
in outline, 5£ mm. long and 1£ mm. wide.
Eyes are present. The anterior margin of the
head is widely rounded. The first pair of an-
tennae are composed of three articles. The
second pair are composed of four articles. All
the thoracic segments are distinct. The lateral
margins are straight, but not contiguous. All
seven pairs of legs are prehensile. The seg-
ments of the abdomen are coalesced in a single segment, narrower
than the thorax, which tapers to a point. It is 1 mm. wide and 1£
mm. long. There are no uropoda and no pleopoda.

The individual described was found in the branchial cavity of Nec-
tocrangon lar.

FIG. 697. — ARGEIA PUGETTEN-
SIS. (CRYPTONISCAN STAGE.)

ISOPODS OF NORTH AMERICA. 551

ARGEIA PAUPERATA Stimpson.

Argeia pauperata STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, p. 511.

Argeia depauperataa RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 868; Ann.

Mag. Nat. Hist. (7), IV, 1899, p. 337; American Naturalist, XXXIV, 1900,

p. 308.
Argeia pauperata BONNIER, Trav. de la Station Zool. de Wimereux, VIII, 1900,

p. 328.
Argeia depauperata RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 64.

Locality. — San Francisco Bay. on Orago franciscorum.

"This species is somewhat larger than the preceding (Argeia pug et-
tensis Dana); the head is comparative!}- smaller, more tumid, and
bilobate; the egg-pouch covers the eggs more completely; and the
thoracic branchial appendages are apparently absent in some of the
anterior segments. The inner branches of the first three pairs of
abdominal appendages are broader; those of the last three pairs are
wanting. Length, 0.35; breadth, 0.23 inch. This description is taken
from a female. Found in specimens of Orago franciscorum, from
San Francisco Bay." — STIMPSON. *

93. Genus PARARGEIA Hansen.

Branchial parasites.

Female with thoracic processes wanting on all the segments.

Abdomen without pleural lamellae, the lateral parts not developed.

There are five pairs of biramous pleopoda; the outer branches are
elongate and attached close to the lateral margins of the segments; the
inner branches are small, oval.

Uropoda simple, single-branched.

Male with all the segments of the thorax distinct. The segments of
the abdomen are fused in a large rounded, oval, terminal piece, which
has a prominent median dorsal tubercle near the base.

PARARGEIA ORNATA Hansen.

Parargeia ornata HANSEN, Bull. Mus. Comp. Zool. Harvard College, XXXI, 1897,
pp. 120-122, pi. vi, figs. 1-2.— RICHARDSON, Proc. U. S. Nat. Mus., XXI,
1899, p. 869; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 338.— BONNIER, Travaux
de la Station Zool. de Wimereux, VIII, 1900, pp. 329-332.— RICHARDSON,
Proc. U. S. Nat. Mus., XXVII, 1904, p. 64.

Locality. — Off Acapulco, Mexico, on Sclerocrangon procax Faxon.

Body of female somewhat asymmetrical; length 8 mm.; width 7
mm.

Head wider than long, 1£ mm. : 2 mm. Front of head with a marginal
border somewhat upcurved and anteriorly arcuate. Eyes absent. The
first pair of antennae are composed of three articles, the last of which

« By error. &Bost. Jour. Nat. Hist, VI, 1857, p. 511.

BULLETIN 54, UNITED STAGES NATIONAL MUSEUM.

is very minute. The second pair of antennae are composed of four
articles, the last article being also minute.

The first four segments of the thorax have the lateral parts longer
than the middle of the dorsal region. The epimera of the first four
segments are placed on the anterior half of the lateral margin, lateral
to the ovarian bosses; they are distinct and well developed on one side

A_ /

FIG. 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. 6, HEAD
OF FBMALE (VENTRAL VIEW). /, DORSAL VIEW OF MALE, g, HEAD OF MALE (VENTRAL VIEW).

of the body, but small on the opposite side. Ovarian bosses are pres-
ent on all the segments, occupying the anterior half of the lateral mar-
gin, and placed on the inner side of the epimera. Epimera are not
present on the last three segments of the thorax, and the ovarian
bosses occupy the entire upper portion of the lateral margin, being
produced on one side of the body in large rounded lobes. The pos-
terior half of the lateral margin forms a large and conspicuous lobe
or expansion on all the segments.

All six segments of the abdomen are distinct, and they gradually
decrease in size from the first to the last segment, which is rounded
posteriorly. The lateral parts of these segments are not developed.
The uropoda are simple and single-branched, and consist of two elon-
gated lamellae attached to the sixth abdominal segment. There are five
pairs of double-branched pleopoda attached to the first five segments.

1SOPODS OF NORTH AMERICA. 553

The outer branch of each pleopod is elongate and simulates the uro-
poda in appearance. The outer branches are all similar in shape and
of nearly equal size. The inner branches are small, elongated or
rounded, and sac-like. They are not conspicuous in a dorsal view,
whereas the outer lamellae form a conspicuous border around the
abdomen, where they seem to be attached to the lateral margins of
the segments.

There are five pairs of incubatoiy lamellae which entirely inclose
the marsupial cavity, the lamellae overlapping in the medial ventral
line. The basis of all the legs is furnished with a high rounded carina.

The male is 4r£ mm. long and 1£ mm. wide in the region of the
thorax. The abdomen at the base is 2 mm. wide. The anterior mar-
gin of the head is rounded. The eyes are absent. The first pair of
antennae are composed of three articles. The second pair are composed
of five or six articles. All seven segments of the thorax are distinct.
The legs are all prehensile.

The segments of the abdomen are consolidated in a single segment,
which is wider at the base than the segments of the thorax. Its pos-
terior margin is widely rounded. Near the base of the segment is a
single prominent tubercle in the median line. There are no pleopoda
nor uropoda.

94. Genus PROBOPYRUS Giard and Bonnier.

Segments of abdomen in female dorsally defined; lateral parts or
pleural lamellae not developed.

Five pairs of double-branched pleopods are present.

Uropoda wanting.

Segments of abdomen in male fused dorsally, but defined on the
lateral margins. Five pairs of small tuberculiform pleopods present.
Uropoda wanting.

Branchial parasites.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS PROBOPYRUS.

a. Male with the first four segments of the abdomen defined laterally by deep
incisions, the last two fused in a large and broad terminal piece.

Probopyrus pandalicola (Packard)

a' '. Male with all the segments of the abdomen defined laterally by deep incisions.
b. Species large. First incubatory lamella with the distal segment produced poste-
riorly in a lobe at the outer angle.

c. Abdomen of male nearly as long as broad. . .Probopyrus floridensis Richardson
c/. Abdomen of male nearly twice as broad as long.
d. Body of male wide, thick-set; head and thorax two and a half times or less

longer than abdomen Probopyrus bithi/nis Richardson

d'. Body of male narrow; head and thorax three and a half times longer than

abdomen Probopyrus ulphei Richardson

&'. Species small. First incubatory lamella with the distal segment produced
posteriorly at the inner angle Probopyrus latreuticola ( Gissler)

554 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

PROBOPYRUS PANDALICOLA (Packard).

Bopyrus (7) LEIDY, Proc. Acad. Nat. Sci. Phila., 1879, Pt. 2, p. 198.— HAROER,

Report U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, p. 312.
Bopyrus pandalicola PACKARD, Zoology for Students and General Readers, 1879,

pp. 308-309.
Bopyrus palxmoneticola PACKARD, Zoology for High Schools and Colleges, 1881,

p. 289.

Bopyrus manhattensis GISSLER, Scientific American, XLV, Sept. 3, 1881, p. 151.
Bopyrus palxmoneticola GISSLER, American Naturalist, XVI, 1882, pp. 6-12.
Probopyrus palsemoiieticola GIARD and BONNIER, Bull. Scient., XIX, 1888, p. 4. —

STEBBING, Hist. Crust., 1893, p. 416.

Bopyrus pahemoneticola RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 578.
Probopyrus paltemoneticola BONNIER, Travaux de la Station Zool. de Wimereux,

VIII, 1900, pp. 342-343, pi. xxxi.— RICHARDSON, Proc. U. S. Nat, Mus.,

XXVII, 1904, p. 66.— PAULMIER, Bull. New York State Museum, 1905, pp.

185-186.

Localities. — Atlantic City, on Palxmonetes vulgar!* Say; from New
Hampshire to Florida, on P. vulgaris; East Providence, Rhode Island,

b
FIG. 599. — PROBOPYRUS PANDALICOLA. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF SAME, x 4.

on P. vulgaris,' Acushnet River, Massachusetts, on P. vulgaris; Bald-
win Lodge, Mississippi, on Palxmonetes sp.; Latana, Florida, on
Palsemonetes; Brooklyn, New York.

Description. — Color of body white, with patches of black on the
lateral margins of all the thoracic segments on both sides of the body.
Head and abdomen also with a few scattered black markings. Legs
of both sides white; patches of black on the ventral side of the lateral
margins of both sides of the thorax. Incubatory lamellae with patches
of black on all the plates of both sides.

Head deeply set in thorax; anterior margin straight; posterior mar-
gin rounded. Eyes wanting. Ovarian bosses present on the first four
segments of the thorax at the anterior part of the sublateral margin;
epimera evident as narrow plates lateral to the ovarian bosses. The
epimera occupy' the entire lateral margins on the last three segments.
The segments of the abdomen are distinct. The terminal segment is
broad, more or less bilobed. The pleopoda consist of five pairs of

ISOPODS OF NOBTH AMERICA.

555

FIG. 600.— PBOBO-
PYRUS PANDALI-
COLA. LEG OF
SIXTH PAIR OF
ADULT FEMALE.

X 39.

FIG. 601.— PROBOPY-
RUS PANDALICOLA.
MALE, x 41.

double-branched lamellar appendages, closely crowded together on the
ventral side of the abdomen.

The five pairs of incubatory lamellae surround a
large open area normally filled with eggs. The first
pair have the terminal lobe of the distal segment large,
well defined, and incurved.

All the legs have a high quadrangu-
larly shaped expansion or carina on the
basis.

Male with all the segments of the
thorax distinct, and with the lateral
margins contiguous. First four seg-
ments of the abdomen well defined at
the sides, but fused in the middle of the dorsal sur-
face. The last two segments form a single large
piece, the fused terminal segment being indicated only
by a small median point on the posterior margin. The
body is a little more than twice as long as wide. Eyes
are present. The rudimentaiy pleopoda are pairs of
small oval processes, one pair on each abdominal
segment. The abdomen is about one and a half times as broad as
long.

PROBOPYRUS FLORIDENSIS Richardson.

Probopyrus floridensis RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp.
70-71.

Locality. — Satsuma Island, above St. John's River, Florida, on
Pals&monetes exilipes Stimpson.

Body of female light brown, with the head, abdomen, ovarian bosses,
and epimera light yellow, almost white. Markings of black are pres-
ent all over thorax and a few black lines are present on the abdomen.
The incubatory lamellae are almost entirely covered with black mark-
ings, so that the color is uniformly dark. The lateral parts of the
thorax on the ventral side have markings of black, those of one side
being in patches with yellow areas separating them, all the legs of
this side being yellow. The legs of the opposite side are dark.

Head deeply set in thorax, broad anteriorly with frontal margin
nearly straight; posterior margin narrowly rounded; eyes wanting.

The segments of the thorax are distinct. Ovarian bosses are prom-
inent on the anterior portion of the sublateral margin of the first four
segments; the epimera are present as narrow plates lateral to the
ovarian bosses. On the last three segments the epimera occupy the
whole of the lateral margin.

The segments of the abdomen are distinctly separated on the dorsal
side. The lateral margins are narrowly rounded. The terminal seg-
ment of the bod}T is long and narrow, reaching beyond the lateral

556

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

margins of the fifth segment; it is rounded posteriorly, and with or
without a minute excavation.

FIG. 603.— PROBOPYRUS
FI.OKIDEN8IS. FIRST
LAMELLA OF MARSU-

PIUM. X 10.

FIG. 602.— PROBOPYRUS FLORIDENSIS. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF SAME, x 12.

The pleopoda consist of five pairs of double-branched lamellar
appendages.

The incubatory lamellae are large, encircling the incubatory pouch,
leaving only a small opening into the interior. The first pair of plates
have the terminal lobe of the distal segment straight.
All the legs have a well rounded expansion or
carina about the middle of the basis.

Male with all the segments of the thorax well
defined and widely separated at the sides. Body
narrow, elongate, nearly three times as long as wide.

The abdomen has all the segments
well defined at the sides, but fused
in the middle of the dorsal surface.
Length almost equal to the breadth. Terminal seg-
ment well defined, rounded posteriorly, and extending
beyond the lobes of the preceding
segment. The lateral margins of all
the segments are rounded. Pleopoda
are present in the form of pairs of
small rounded processes, a pair on
each segment of the abdomen. Eyes
present.

One specimen was collected by Mr.
W. C. Kendall at Satsuma Island,
above St. Johns River, Florida; parasitic on Palse-
monetes exilipes Stimpson. Two other specimens
were obtained by the U. S. Bureau of Fisheries steamer Albatrosa at
Little River, Miama, Florida; parasitic also on Palsemonetes emlipes
Stimpson.

Type— Cat. No. 29090, U.S.N.M.

FIG. 604.— PROBOPY-
RUS KLORIDENSIS.
LEG OF SIXTH PAIR
OF ADULT FEMALE.
X 39.

FIG. 605.— PROBOPY-
RUS FLORIDENSIS.

MALE, x 41.

ISOPODS OF NORTH AMEEICA.

557

PROBOPYRUS BITHYNIS Richardson.

Proboptjrux bithynis RICHARDSON, Pror. U. S. Nat. Mus., XXVII, 1904, pp. 68-70.

Localities.— Mississippi River near the exposition grounds in New
Orleans, Louisiana, on Bithynis ohionis (Smith); Escondido River,

FIG. 606.— PROBOPYRUS BITHYNIS. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF SAME, x 16

Nicaragua, 50 miles from Bluefields, on Bithynis acanthurus (Wieg-
mann).

Body of female with dorsal surface perfectly white, having only
three small patches of black on one side at the post-lateral parts of the
second, third, and fourth thoracic segments. Ventral side of the body
with the first pair of incubatory lamellse
almost entirely covered with patches of
black, and with all the other lamellae of
one side having patches of black, those
of the other side being without these
patches, with the exception in some speci-
mens of the second lamella. Patches
of black also present on the ventral side
of the lateral margins of the second,
third, and fourth thoracic segments of
one side — the same side on which these
markings occur on the dorsal surface and
to which the incubatory lamellee, likewise marked with patches, are
attached. Legs of both sides white and without any markings.

Head with the antero-lateral corners produced into prominent pro-
cesses; anterior margin between these processes straight; posterior
margin narrowly rounded. Length of head about equal to its breadth.
E}^es wanting.

The thoracic segments are distinctly defined. Ovarian bosses are
present on all the segments, occupying only the anterior portion of
the sublateral margin of the first four segments. The epimera are

FIG. 607. — PROBOPYRUS BITHYNIS.
FIRST LAMELLA OF MARSUPIUM,
RIGHT SIDE. X 10.

558

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 608.— PROBOPY-
RUS BITHYNIS. LEG
OF SIXTH PAIR OF
ADULT FEMALE.

X 39.

evident as narrow pieces lateral to the ovarian bosses on all the
segments.

The segments of the abdomen are distinct on the dorsal side. The
lateral margins of the first five seg-
ments are straight. The sixth or
terminal segment is narrow, elon-
gate, and has a slight emargina-
tion in the middle of the posterior
margin.

The pleopoda are five pairs of
double- branched appendages, the
inner branches of the first pair
being the largest and overlap-
ping in the middle ventral line. The uropoda, are
wanting.

The first pair of incubatory lamellae are large
and extend about half the length of the ventral side
of the thorax. In fact all the lamellae are quite
large, and encompass the marsupium, leaving
only a comparatively small opening into the pouch.

All the legs have an extremely high expansion or carina on the
basis.

The male has the thorax distinctly segmented, the segments not
being widely separated at the sides. Body of male short and thickset,
being only twice as long as wide.

The abdomen is a little more than one and a half times broader than
long. The segments of the abdomen are only indicated at the sides,

FIG. 609. — PROBOPYRCS
BITHYNIS. MALE.
X 41.

FIG. 610. — PROBOPYRUS BITHYNIS. a, DORSAL VIEW OF FEMALE, b, VENTRAL VIEW OF SAME, x 8.

being fused in the middle of the dorsal surface; they gradually de-
crease in size to the sixth or last, which is a narrow piece situated
between the two lobes of the fifth segment and which does not reach

ISOPODS OF NORTH AMERICA.

559

FIG. 611.— PROBOPYRUS BI-
THYNIS. MALE, x 41.

to the extremity of those lobes. Eyes present. Body with markings
of brown.

Six specimens of this species were taken by the U. S. Bureau of
Fisheries steamer Albatross from the Mississippi
River near the Exposition grounds in New
Orleans, Louisiana. Parasitic on Bithynis
ohionis (Smith).

Type.— Cat. No. 29089, U.S.N.M.

About 6 specimens which should probably be
referred to this species were found in Escondido
River, Nicaragua, 50 miles from Bluefields, by
Dr. C. W. Richmond; they are parasitic in the
branchial cavity of Bitkynix acanthurus (Wieg-
mann).

They differ from the type as above described
in having no antero-lateral processes to the
head of the female; in having patches of black
on the lateral margins of all the segments of
the thorax on one side of the body; and in
having sometimes the third and also the
fourth lamellae of the incubatory pouch with patches of black.

In the male the terminal segment has in some specimens a tendency
to be bilobed.

PROBOPYRUS ALPHEI Richardson.

Bopyrus sp.? FRITZ MULLER, Jenaische Zeitschrift, VI, 1871, p. 68.

Bopyrus alphei GIARD and BONNIER, Bull. Scient., XXII, 1890, p. 369 (nomen

nudum).

Bopyrus alphei RICHARDSON, Proc. Wash. Acad. Sci., II, 1900, pp. 158-159.
Gygesp.t H. V. WILSON, American Naturalist, XXXIV, 1900, p. 353.
Bopyrella alphei BONNIER, Trav. de la Station Zool. de Wimereux, VIII, 1900,

p. 352.
Probopyrus alphei RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp. 67-68.

Localities. — Beaufort, North Carolina, on Orangon heterochsdis;
mangroves, Rio Parahyba do Norte, Brazil, on Crangon heterocJisdis;
Desterro, Brazil, on an undetermined species of Crangon (Miiller).

The body of the female is broadly oval, its greatest width being
equal to its length, broadened anteriorly and narrowed posteriorly.
Head widening posteriorly, its antero-lateral angles being produced
into lobes, directed upward. Eyes absent. The thoracic segments
have their lateral margins somewhat elevated and contiguous. The
abdominal segments are not contiguous along the lateral margins, but
are separated by broad lateral incisions.

560

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The incubatory lamelles are very wide apart, SUIT
open space, the marsupium, on the ventral side of

There are five pairs of
double-branched pleopoda,
lamellar in shape and placed
on either side of the median
line. Uropoda absent.
Color, white.
Male, oblong oval. Eyes
wanting. Thoracic s e g -
ments well defined. Ab-
dominal segments imper-
fectly defined, except along
the lateral margins. Color
white.

Type locality. — Mangroves, Rio Parahyba do
Norte, Brazil, in the branchial cavity of Crangon
Cat. No. 23759, U.S.N.M.

ounding a broad
the body.

FIG. 612. — PROBOPYRUS ALPHEI
DORSAL VIEW OF FEMALE.

FIG. 613.— PROBOPYRUS
ALPHEI. MALE.

hetwochxlis Say.

PROBOPYRUS LATREUTICOLA (Gissler).

Bopyroides latreuticola GISSLER, American Naturalist, XVI, 1882, pp. 591^594.
Bopyrus latreutes SPENCE BATE, Challenger Report, XXIV, 1888, p. 584.
' Bopyriha latreuticola BONNIER, Travanx de la Station Zool. de Wimereux, VIII,

1900, pp. 370-373.
Bopyroides latreuticola RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902,

p. 299; Proc. U. S. Nat. Mus., XXVII, 1904, pp. 65-66.

Localities. — Beaufort, North Carolina, on Latreutes ensiferus (Milne
Edwards); latitude 28° 17' 7" north, longitude 66° 17' 37" west; lati-
tude 31° 15' 42" north, longitude 67° 39'
10" west on L. ensiferus; latitude 31° 16'
north, longitude 71° 50' west on L. ensi-
ferus; latitude 27° 38' north, longitude
76° 23' 24" west on Z. ensiferus; Baha-
mas, between Nassau and Andros on L.
ensiferus; off South Carolina, on Z. ensi-
ferus; Bermudas, on Z. ensiferus.

Body of female ovate, asymmetrical,
one and a half times longer than broad,
2 mm.: 3 mm.

Head deeply set in first thoracic segment;
with a frontal border, the anterior margin
of which is widely rounded, and the lateral angles of which project as
triangular lobes at the sides of the head. Eyes distinct and situated
just below the frontal border.

On one side of the body the segments of the thorax have the lateral

a b

FIG. 614. — PROBOPYRUS LATREUTICOLA.
a, MALE, x 51i. b, FEMALE, x 18?.

ISOPODS OF NORTH AMERICA.

561

FIG. 615.— PROBOPYRUS LATREU-
TICOLA. FIRST INCUBATORY
LAMELLA. X 51}.

parts large and expanded. On the shorter side they are less expanded
and upcurvred, showing the legs. Ovarian bosses are not present on
any of the segments. The lateral margins of all the segments of the
expanded side are entire with the exception of the -second, which has
a decided notch separating the anterior two-
thirds from the posterior third. The epimera
seem to be perfectly coalesced in all the seg-
ments with the dorsal part of the segments.
The segments of the abdomen are all fused
in the middle of the dorsal surface. On the
shorter side of the body there is no indication
of the segments, the lateral margin being
straight and continuous. On the opposite
side, however, five distinct segments are
marked off from the terminal lobe by five
deep notches. There are five pairs of double-branched pleopoda in
the form of small, rounded lamellae. No uropoda are developed.
The five pairs of incubatory lamellse do not completely inclose the
marsupial pouch. The plates are small and bound only the lateral
parts of the marsupium. The distal segment of the first pair is pos-
teriorly rounded. There are seven pairs of legs, all equally well

developed and having pre-
hensile hands.

The male is oblong-ovate.
The anterior margin of the
head is widely rounded.
Eyes are distinct. The
seven segments of the
thorax are distinct and
have the lateral margins
rounded. The segments of
the abdomen are fused in
the middle, but are all dis-
tinctly marked at the sides.
Five deep notches separate
the first five segments from
each other and from the
sixth or terminal segment, which has the posterior margin produced
in three small lobes, one median and one on either side, all in a trans-
verse line. There are no uropoda nor pleopoda. The abdomen is not
abruptly narrower than the thorax.

The specimen described is found parasitic on Latreutes tnsiferus
(Milne Edwards).
28589—05 36

FIG. 616. — PROBOPYRUS LATREUTICOLA. a, FIRST PLEOPOD
(SHOWING BOTH BRANCHES), x 54|. ft, SECOND PLEOPOD.
x 103}. c, THIRD PLEOPOD. x 103J. d, FOURTH PLEO-
POD. x 103}.

LIBRA

R V

562

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

95. GENUS BOPYR1SCUS, new genus.

Very close to Probopyrux.

First four segments of abdomen distinct in female; last two seg-
ments fused. Pleopods consist of five pairs of
double-branched lamella. Uropoda absent. Dis-
tal segment of first lamella? of marsupium pro-
duced in a small lobe.

Male with first three segments of abdomen
distinct; last three fused in the terminal piece,
which is trilobate. Uropoda absent.

BOPYRISCUS CALMANI, new species.

Body somewhat asymmetrical, turned more or
less to one side, which is shorter than the other
side; longer than wide, 5 mm.: 3 mm.

Head deeply set in thorax, wider than long,
with the front nearly straight or but slightly
rounded, and the antero-lateral angles acute.
Eyes are present in the
form of black pigment.
The first pair of antennae
are small and are composed
of three articles. The
second pair are also small,
and composed of only a
few articles.

The seven segments of the thorax are distinct,
of the first four are bilobate; the lateral margins of the last three are
straight. Ovarian bosses are faintly indicated on the first four seg-
ments where they occupy the anterior part of the lat-
eral margin. Lateral to them are the narrow epimeral
plates, which are but faintly indicated.

The first four segments of the abdomen are distinct,
being separated by faint lines; the last two segments
are fused, the line separating them being obliterated.

There are no uropoda. The pleopoda consist of five
pairs of double-branched, small rounded lamellae.

There are five pairs of incubatory lamellae that do not
completely inclose the incubatory pouch. The first pair
have the distal segment produced at the extremity in a
small lobe.

The male has the frontal margin of the head rounded.
Eyes distinct, situated near the posterior margin. All seven segments
of the thorax distinct. The first three segments of the abdomen are

FIG. 617.— BOPYRISCUS CAL-
MANI. a, FEMALE, x
llf. 6, FIRST INCUBA-
TORY LAMELLA. X 33.

FIG. 618.— BOPYRISCUS CAL-
MANI. FIRST PLEOPOD.
FEMALE, x 77i.

The lateral margins

FIG. 619. — BOPY-
RISCUS CALMA-
NI. MALE, x
39.

ISOPODS OF NORTH AMERICA. 563

distinct; the last three are fused in the terminal piece, which is tri-
lobate, a lateral lobe on either side and a larger median posterior lobe.

There are no uropoda. This species is named for Dr. W. T. Caiman,
the Scotch naturalist.

Only one specimen was collected by the U. S. Bureau of Fisheries
steamer Albatross at Station 4421, between Santa Barbara and San
Nicolas, California.

The type is in the U. S. Nat. Museum. Cat. No. 320T3.

96. Genus BOPYRINA Kossmann.

Branchial parasites.

Female with segments of abdomen fused in the middle, more or less
defined at the sides; lateral parts or pleural lamellae not developed.

Pleopoda rudimentary; first four pairs single-branched, simple, last
pair wanting. Uropoda wanting.

Male with all the segments of the thorax distinct. Segments of the
abdomen fused in the middle, but more or less defined at the sides.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS BOPYRINA.

a. Segments of the abdomen in female denned only on one side of the body.

Bopyrina abbreviata Richardson
a/. Segments of the abdomen in female distinctly denned on both sides of the

abdomen.
b. First incubatory lamellae with the distal segment produced in a linguiform lobe

at the outer posterior extremity Bopyrina urocaridis Richardson

6'. First incubatory lamelhe with the distal segment roundly produced at the
inner posterior extremity Bopyrina thorii Richardson

BOPYRINA ABBREVIATA Richardson.

Bopyrina abbrenata RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, pp. 71-73.

Locality. — Puntarasa, Florida, on Hippolyte
zostericola (Smith).

Body of adult female very asymmetrical, one
side being veiy much longer than the other.
Color entirely white with a few black dots scat-
tered irregularly over the dorsal surface.

Head large, turned to the shorter side; frontal
border produced in a rounded lobe in the middle.
Antero-lateral angles produced in narrow lobes
or processes. Eyes small, distinct.

The segments of the thorax are distinctly de-
fined. The epimera on the longer side of the body FIG. 620.— BOPYKINA AB-
are distinct on the first three segments, where BREVIATA. DORSALVIEW

, , . . ' , ' - OF FEMALE. X 23.

they occupy the anterior portion of the lateral

margin, but it is impossible to distinguish them on the shorter side.

Ovarian bosses are not present on any of the segments. The epimera

564

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 021. — BOPYRIXA
ABBREVIATA. FIRST
LAMELLA OF MAR-
SUPICM. X 27.

FIG. 622. — BOPYRINA
ABBREVIATA. MAX-
ILLIPED. X 41.

of the last four segments are not separated off from the segments;
they occupy the entire lateral margin.

The abdominal segments are completely fused in the middle of the
abdomen. On the lateral margin of the shorter side of the bod}- there
is no indication whatever of the coalesced segments. The first four
abdominal segments are represented on the longer side of the bod}: by
four rounded lobes. The last two segments are com-
pletehr fused, and are not indicated
on either side.

The pleopoda, as far as could be dis-
cerned, consist of four pairs of single
branched lamellae. Three pairs were
distinctly seen; the last pair are very
indistinct.

The first lamella of the marsupium
on the shorter side extends about one-third the length of the body ; on the
longer side, the first lamella extends to the posterior margin of the
second thoracic segment.

Male with head large, rounded in front. Eyes large, irregularly
shaped. All seven segments of the thorax distinct. Abdomen narrower
than the thorax, and tapering to a narrow extremity. In one specimen all
six segments were more or less defined at the sides; in the other
specimen only the first three. Length of abdomen
about equal to one-third the length of the body.
Color white with markings of black or brown.
Nine specimens were collected by Mr. Henry Hemp-
hill at Puntarasa, Florida, on Hippolyte zostericola
(Smith).

This species differs from Bopyrinavirbii(W&\iz),a
in the much smaller first lamellae in the female, the la-
mella of the shorter side of the marsupium extending
but one-third the length of the body, while in B. virbii
it extends nearly to the abdomen, that of the longer side
reaching only the posterior margin of the second tho-
racic segment, while in B. virbiiit extends to the poste-
rior margin of the fourth segment; in not having any
indicationof segmentation on the shorter side of the ab-
domen, while in B. vvrbii there is some indication, and in having the abdo-
men of the male rounded posteriorly with indications of segmentation at
the sides more or less during its entire length, while in B. virbii the abdo-
men is truncate posteriorly, with only the first two segments indicated.
The specific name refers to the abbreviated first lamella} of the
marsupium.

Type.— Cat. No. 29097, U.S.N.M.

FIG. 623. —BOPYRINA
ABBREVIATA. MALE.
x 77i.

"Kossman, Zeite. f. Wiss. Zool., XXXV, 1881, p. 666-679, pis. xxxiv-xxxv.

ISOPODS OF NORTH AMERICA.

565

BOPYRINA UROCARIDIS Richardson.

Bop-yr'nta urocaridis RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 73.
Localities. — Puntarasa, Florida and west Florida, on Urocaris longi-
caudata Stimpson.

Body of female twice as long as wide.

Head with frontal margin produced in a broadly rounded process.
Eyes present about the middle of the head as small black spots.

FIG. 624. — BOPYRINA UROCARIDIS. a, DORSAL VIEW OF FEMALE. 6, VENTRAL VIEW OF SAME, x 23.

The segments of the thorax are distinct. The epimera are marked
off by faint lines or impressions. The abdomen is composed of six
segments, which are distinct at the sides but fused in the middle.
The posterior margin of the terminal segment
is broad, with a slight median excavation.

The pleopoda consist of four pairs of single-
branched plates or lamellae, each pair directed
toward the median line. There
are no uropoda.

The incubatory pouch is a
large area on the ventral side
of the body, which is not closed
over by the incubatory lamellae.
These lamella consist of five
pairs of plates, the first pair of
which have the second segmentproduced distally in a linguiform process.
Color uniformly light yellow with small black dots on the incubatory
lamellae.

Male unknown.

Four specimens were found — three at Puntarasa, Florida, collected
by Henry Hemphill, and one from west Florida, collected by Mr. J. B.
Henderson and Mr. C. T. Simpson, all parasitic on Urocaris longican-
data Stimpson.

Type.— Cat No. 29088, U.S.N.M.

FIG. 625. — BOPYRINA
UROCARIDIS. . MAX-
ILLIPED. X 39.

FIG. 626. — BOPYRINA UROCA-
RIDIS. FIRST LAMELLA OF
MARSUPIUM, RIGHT SIDE.

X 52.

566

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

BOPYRINA THORII Richardson.
Bopyrina thorii RICHARDSON, Proc. U. S. Nat. Mus., XXVII, 1904, p. 74.

Locality. — Key West, Florida, on Tkor floridanns Kingsley.
Body of adult female asymmetrical, turned very much to one side.
Color yellow, with a few markings of black on one side of the thorax
and in the center of the first three segments of the abdomen.

Head large, with frontal margin produced in a rounded lobe, which
is turned upward in the specimen; the antero-lateral angles are pro-
duced into small processes. The eyes are black and distinct.

The segments of the thorax are all distinctly separated from each
other. The epimera are distinct on the longer side of the body as

long, narrow plates on the anterior
portion of the lateral margin of
the first four segments. Ovarian
bosses are not present on any of the
segments.

The abdomen is composed of six
segments, completely fused in the
middle, but indicated on both lat-
eral margins. The terminal seg-
ment is rounded posteriorly.

There are four pairs of single-
branched pleopoda. The marsu-
pium is a large, open area, nor-
mally tilled with eggs, and inclosed by five pairs of lamella?. The first
lamellae have the distal lobe rounded. The fifth lamellae are narrow,
elongated plates.
Male unknown.

Only one specimen was obtained by the U. S. Bureau of Fisheries
steamer Albatross at Key West, Florida. The species is parasitic on
Thor floridanus Kingsley.

This species differs from the preceding species chiefly in the form
of the distal segment of the first lamellae of the marsupium.
Type.— Cat. No. 29099, U.S.N.M.

97. Genus BOPYROIDES Stimpson.«

Body of female broad, flattened, somewhat asymmetrical.

Abdomen distinctly segmented; lateral parts of segments or pleural
lamellae not developed.

Palp of maxillipeds well defined.

Incubatory plates widely separated, not concealing the entire incu-
batory cavity and not fully covering the eggs; distal segment of first
pair not produced posteriori}7 in a lobe.

«See Sara for characters of genus, Crust, of Norway, II, 1899, p. 198.

FIG. 627.— BOPYRINA THORII. a, DORSAL VIEW or
FEMALE, b, VENTRAL VIEW OF SAME, x 15.

ISOPOD8 OF NORTH AMEKICA.

567

All seven pairs of legs present. Pleopods wanting and replaced by
fleshy ridges. Uropoda wanting. Male with all the segments of the
thorax distinct. Segments of abdomen fused. Pleopoda wanting.
Uropoda absent.

Branchial parasites.

BOPYROIDES HIPPOLYTES (Kr^yer).

Bopyruft hippolytes KR0YER, Kongelige Danske Videnskabenes Selskabs natur-
videnskabelige og mathematiske Afhandlinger, VII, 1838, p. 306, (78), pi.
iv, fig. 22.— EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 283.— KR0YER,
Kongelige Danske Videnskabenes Selskabs naturvidenskabelige og mathe-
matiske Afhandlinger, IX, 1842, p. 262; Voy. en Scand., Crust., 1849, pi.
xxvni, fig. 2.— STIMPSON, Proc. Acad. Nat. Sci., Phila., 1863, p. 140.

FIG. 628. — BOPYROIDES HIPPOLYTES (AFTER SARS). a, FIRST INCUBATORY PLATE. 6, PALP OF MAX-
ILLIPED. c, MAXILLIPED. d, HEAD OF MALE (VENTRAL VIEW), e, ANTERIOR PART OF SPECIMEN OF

SPIRONTOCARIS POLARIS INFESTED WITH THIS PARASITE. /, LEG. g, ANTERIOR PART OF HEAD OF
FEMALE (VENTRAL VIEW), h, DORSAL VIEW OF FEMALE. I, VENTRAL VIEW OF FEMALE, j, DORSAL
VIEW OF MALE.

568

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Bopyroides acutimarginatux STIMPSON, Proc. Acad. Nat. Sci. Phila., 1864, p. 156.

Gyge hippolytes BATE and WESTWOOD, Brit. Sess. Crust., II, 1868, p. 230. — MIERS,
Ann. Mag. Nat. Hist. (4), XIX, 1877, p. 64 (14).— SMITH in HARGER, Proc.
U. S. Nat. Mus., II, 1879, p. 157.— HARGER, Rep. U. S. Fish Comm., 1880,
Pt. 6, p. 311.— HANSEX, Videnskabelige Meddelelser fra den naturhistoriskt-
Forening i Kj0benhavn, 1887-88, p. 197. — AXEL OHLIX, Akademisk Afhand-
ling, XXII, 1895, p. 19.

FIG. 629.— BOPYROIDES HIPPOLYTES. FIRST INCUBATORY LAMELLA OF SPECIMENS FOUND ON: a, SPIR-

ONTOCARIS LAMELLICORNIA FROM PORT TOWN3END BAY, WASHINGTON. X Hi. 5, SPIRONTOCARIS
POLARIS FROM ABERDORE CHANNEL. X 15J. C, SPIRONTOCARIS POLARIS FROM GRAND MENAN, NEW

BRUNSWICK, x 15}. d, SPIRONTOCARISSPINUS FROM OFF NORTH HEAD, AKUTAN PASS, ALASKA, x 77^.

Bopyroides hippolytes G. O. SARS, Crust, of Norway, II, 1899, pp. 199-200, pi.

LXXXIV, fig. 2. — BONNIER, Travaux de la Station Zool. de Wimereux, VIII,

1900, pp. 373-375.

Bopyroides sarsi BONXIER, Travaux de la station Zool. de Wimereux, pp. 376-377.
Bopyroides sp. BONNIER, Travaux de la station Zool. de Wimereux, p. 378.
Bopyroides hippolytes RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 578;

Bull. U. S. Fish Comm., XXIV, 1905, pp. 218-219.

Localities. — Circumpolar in distribution.

Atlantic coast localities: Massachusetts, Bay of Salem, on Spironto-
caris spinus, S. fabricii, and 8. liljeborqii; Casco Bay, on S. polaris

FIG. 630.— BOPYROIDES HIPPOLYTES. FIRST LAMELLA OF MARSUPIUM FROM SPECIMENS FOUND ON: a,
SFIBONTOCARIS SPINUS FROM EASTPORT, MAINE, x 14£. 6, SPIRONTOCARIS SPINUS FROM BAY OF
ISLANDS, ADAKH, ALASKA, x 23. c, SPIRONTOCARIS SECURIFRONS FROM THE HAWAIIAN ISLANDS.
V, SPIRONTOCARIS SPINUS FROM BAY OF ISLANDS, ADAKH, ALASKA, x 23.

and S. pusiola; Bay of Fundy, on S. spinus and S.pusiola; Halifax,
Nova Scotia; Gulf of Maine, on S. liljeborgiisind /S. spinus; Eastport,
Maine, on S. spinus; off Cape Cod, on S. liljeborgii; latitude 73° 48'
north, longitude 80° 30' west, on S. polaris; latitude 72° 33' north,

ISOPODS OF NOKTH AMERICA.

569

longitude 71° 30' west, on S. polar Is; latitude 71° 42' north, longitude
73° west, on S. polaris; latitude 66° 33' north, longitude 61° 50' west,
on S. polaris; latitude 64° 56' north, longitude 66°
18' west, on S. polaris.

Pacific coast localities: Straits of Fuca, between
Washington and Vancouver Island, on Spirontocaris
suckleyi; Heceta Bank, Oregon, on /S. bispinosa; off
North Head, Akutan Island, Alaska, on S. spinus;
Bay of Islands, Adakh, on 8. spinus; Port Etches,
Alaska, on 8. arcuata; west of Amaknak Island,
Unalaska, on 8. arcuata; Bering Sea, north of
Umnak Island, on Pandalus borealis Kr0yer; off
south entrance to Akutan Pass, Alaska, on Pandalus
montagui Leach; between Bird and Nagai islands,
Shumagins, Alaska, on P. montagui; Bering Sea,
south of Pribilof Islands, on P. borealis Kr0yer;
Straits of Fuca, on Pandalopsis dispar Rathbun;
Unalaska, and Lituya Bay, Alaska, on Spirontocaris brevirostris
(Dana); Puget Sound, on /S. brevirostris; Bering Sea, west of Pribilof

PIG. 631. — BOPYKOIDES
HIPPOLYTES. FIRST
INCUBATORY LAMEL-
LA FROM SPECIMEN
FOUND ON SPIRONTO-
CARIS LILLJEBORGII
FROM EASTERN FISH-
ING BANKS (GLOU-
CESTER FISHERMEN).
X 15*.

FlG. 632. — BOPYROIDES HIPPOLYTES. FIRST INCUBATORY LAMELLA FROM SPECIMENS FOUND ON: a, SPI-
KONTOCARIS POLARIS FROM WEST OF PRIBILOF ISLANDS. X 14j. 6, ON SPIRONTOCARIS SUCKLEYI

FROM ADMIRALTY INLET, VICINITY OF PORT TOWNSEND. x 5. c, ON SPIRONTOCARIS SUCKLEYI FROM
AFOGNAK BAY, AFOGNAK ISLAND, x llj. d, ON SPIRONTOCARIS SUCKLEYI FROM ADMIRALTY INLET,
VICINITY OF PORT TOWNSEND. x 11$. c1, e2, c3, ON SPIRONTOCARIS SUCKLEYI FROM ALITAK BAY,
KADIAK ISLAND. /, ON SPIRONTOCARIS HERDMANI FROM -QUEEN CHARLOTTE SOUND, OFF FORT
RUPERT, VANCOUVER ISLAND, BRITISH COLUMBIA, x 31. 01, g-, g\ fir4, y>, ON PANDALUS JORDANI
FROM QUEEN CHARLOTTE SOUND, OFF FORT RUPERT, VANCOUVER ISLAND, BRITISH COLUMBIA.

570

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Islands, on S. polaris (Sabine) ; Straits of Fuca, on S. suckleyi; Lituya
Bay, Alaska, on S. suckleyi; Gulf of Georgia, off Nanaimo, Van-
couver Island, British Columbia; Queen Charlotte Sound, off Fort
Rupert, Vancouver Island, British Columbia, on Spirontocaris herd-

FlG. 633.— BOPYROIDES HIPPOLYTES. SIXTH LEG FROM SPECIMEN'S FOUND ON: a, SPIRONTOCARIS
POLARIS FROM ABERDORE CHANNEL. X 27$. 6, SPIRONTOCARIS SPINUS FROM NORTH HEAD, AKUf AN

ISLAND, ALASKA, x 51}. c, SPIRONTOCARIS SPINCS FROM BAY OF ISLANDS, ADAKH, ALASKA, x 51|.
d. SPIRONTOCARIS SPINUS FROM BAY OF ISLANDS, ADAKH, ALASKA, x 51}.

mani Walker; Queen Charlotte Sound, off Fort Rupert, Vancouver
Island, British Columbia, on Pandalus jordani Rathbun; Admiralty

FIG. 035.— BOPYROIDES HYPPOLYTES. SIXTH

FIG. 634.— BOPYROIDES HIPPOLYTES. SIXTH LEG LEG OF SPECIMENS FOUND ON: a, SPIRONTO-

FROM SPECIMENS FOUND ON: a, SPIRONTOCARIS CARIS POLARIS FROM GRAND MENAN, NEW

SPINUS FROM EASTPORT, MAINE, x 39. b, SPIRON- BRUNSWICK, x 39. b, SPIRONTOCARIS LA-

TOCARISSECURIFRONSFROM BETWEEN HONOLULU MELLICORNIA FROM PORT TOWN8END. X 39.

AND KAUAI ISLAND, HAWAIIAN ISLANDS, x 39.

Inlet, vicinity of Port Townsend,on Spirontocaris suckleyi (Stimpson);

Afognak Bay, Afognak Island, Central Alaska, on Spirontocaris

suckleyi (Stimpson); Alitak Bay, Kadiak Island, Central Alaska, on
Spirontocaris suckleyi (Stimpson); Julienehaab,
on Spirontocaris faJjricii Kr03*er; Sukkertop-
pen on Spirontocaris spinus; latitude 66° 32'
north, longitude 55° 34' west, on Spirontocaris
x I >i n us; Ikertokf jord, on Spirontocaris polaris;
Claushavn, on Spirontocaris polaris; Jakobs-
havn; Upernivik, on Spirontocaris polaris;
Port Foulke or latitude 78° 17' north; Grinnell
Land, Discovery Bay, or latitude 81C 44' north,
on Spirontocaris j>ol</r!x.

Also recorded from Greenland, Barents Sea,

British Isles, coast of Norway; depth, 5 to 116 fathoms.

IB. acutimarginatus Stimpson is undoubtedly identical with B. hip-

polytes (Kr0yer), which is circumpolar in distribution, and infests the

species and genera quoted above common to both coasts of North

America.

FIG. 636. — BOPYROIDES HIPPO-
LYTES. SIXTH LEG FROM
SPECIMEN FOUND ON SPIRON-
TOCAHIS LILLJEBORGII FROM
EASTERN FISHING BANKS
(GLOUCESTER FISHERMEN).

X 15}.

ISOPODS OF NORTH AMERICA.

571

Depth. — 5 to 70 fathoms.

Body of female oval, somewhat asymmetrical. Length, 8 mm.
Width, 7 mm.

FlG. 637.— BOPYROIDES HIPPOLYTES. SIXTH LEG OF SPECIMENS FOUND ON: a, SPIRONTOCARIS POLARIS
FROM WEST OF PRIBILOF ISLAND. X 52. 6, ON SPIRONTOCARIS SUCKLEYI FROM ADMIRALTY INLET,
VICINITY QF PORT TOWNSEND. X 41. C, ON SPIRONTOCARIS SUCKLEYI FROM AFOGNAK BAY, AFOG-

NAK ISLAND, x 52. d, ON SPIRONTOCARIS SUCKLEYI FROM ADMIRALTY INLET, VICINITY OF PORT
TOWNSEND. x 52. e1, e2, e3, ON SPIROXTOCARIS SUCKLEYI FROM ALITAK BAY, KADIAK ISLAND.
/, ON SPIRONTOCARIS HERDMANI FROM QUEEN CHARLOTTE ISLAND, OFF FORT RUPERT, VANCOUVER
ISLAND, BRITISH COLUMBIA, x 77i. gl, g*2, g9, g4, g5, ON PANDALUS JORDANI FROM QUEEN CHAR-
LOTTE ISLAND, OFF FORT RUPERT, VANCOUVER ISLAND, BRITISH COLUMBIA.

Head a little wider than long, 2 mm. : 2£ mm., with the anterior
margin of the frontal border almost straight. The posterior margin
is rounded. The frontal border extends laterally on either side of the

572 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

head in a small lobe. Eyes absent. The first pair of antennas are com-
posed of ''three"' articles. The second pair are composed of "five"
articles. Both pairs are small and inconspicuous in a dorsal view.

The seven segments of the thorax are distinct. Ovarian bosses are
present on the sub-lateral anterior portion of the lateral margins of
the first four segments. The epimera of these segments are very
narrow plates, lateral to the ovarian bosses. On the last three seg-
ments the epimera are narrow plates occupying the anterior portion
of the lateral margin.

All six segments of the abdomen are distinct. The lateral parts of
these segments are not produced. The lateral margins are straight.
The sixth or terminal segment is very small and posteriorly truncate.
There are no uropoda. The pleopoda are represented by fleshy ridges.

There are live pairs of incubatory lamellae. The distal portion of
the first pair has the posterior margin not produced in a lobe.

The seven pairs of legs are small, with prehensile hands and the
basis furnished with a high, more or less rounded, carina.

The male is elongate, 3 mm. long and 1 mm. wide. Head with the
anterior margin rounded. Eyes distinct. The first pair of antennae
are composed of three articles. The second pair are composed of four
articles. All the thoracic segments are distinct, with straight lateral
margins. The legs are prehensile. All the segments of the abdomen
are coalesced in a single segment which tapers posteriorly to a point.
There are no uropoda or pleopoda.

Family XXI. DAJID^.«

Body of female symmetrical. Segmentation, when present, only
visible in the middle of the dorsal surface.

Palp of maxillipeds wanting.

Incubatory plates small, often reduced in number. Incubatory
pouch confined to the lateral parts of the body, one cavity on either
side.

Only four or five pairs of legs present, crowded around the oral area.

Pleopoda usually rudimentary or entirely wanting.

Uropoda developed or absent.

Male with the first thorasic segment coalesced with the head.

Parasitic on Schizopoda.

ANALYTICAL KEY TO THE GENERA OP THE FAMILY DAJID.E.

a. Body of female distinctly segmented in the dorsal region. Uropoda present.

First pair of pleopods well developed; following pairs rudimentary.

Genus Dajus Kr0yer
a'. Body of female without any trace of segmentation. Uropoda absent. Pleopoda

wanting Genus Holophryxus Kichardson

«See G. O. Sara for characters of family, Crust, of Norway, II, 1899, p. 221.

ISOPODS OF NORTH AMERICA. 573

98. Genus DAJUS Kr0yer.«

Female with the head distinct. Middle part of dorsal surface of
thorax distinctly segmented.

Abdomen abruptly narrower than the thorax; all six segments
distinct.

Uropoda present in the form of two simple lamellae, close together.

Five pairs of incubatory plates present.

Five pairs of legs present, short and thick, and of similar structure.

First pair of pleopods well developed, consisting of a pair of simple
large lamellae, placed behind the last pair of incubatory plates; follow-
ing pairs of pleopoda rudimentary.

Male with the segments of the abdomen not distinct. Pleopoda
wanting. Uropoda rudimentary, in the form of two small, almost
inconspicuous lobes.

DAJUS MYSIDIS Krtfyer.

Dajus mysidis KR0YER, Voy. en Scand. Crust., 1849, pi. xxvin, fig. 1.

Bopyrus mysidium PACKARD, Mem. Bost. Soc. Nat. Hist., I, 1867, p. 295, pi. vni,
fig. 3.

Leptophryxus mysidis BUCHHOLZ, Zweite Beutschie Nordpolfahrt, 1874, p. 288, pi.
ii, fig. 2.

Dajus mysidis LUTKEN, Crustacea of Greenland, 1875, p. 150. — G. O. SARS, Arch.
Math. Nat., II, 1877, p. 354 (254).— SMITH in HARGER, Proc. U. S. Nat. Mus.,
II, 1879, p. 158.— HARGER, Report U. S. Comm. of Fish and Fisheries, 1880,
Pt. 6, p. 312. — HAXSEN, Videnskabelige Meddelelser fra den Naturhistoriske
Forening i Kj0benhavn, 1887-88, pp. 197-198. — SARS, Crust, of Norway, II,
1899, pp. 223-224, pis. xcm, xciv.— AXEL OHLIN, Bihang till k. Sv. Vet.-
Akad. Handl., XXVI, Afd. iv, No. 12, 1901, p. 39.— RICHARDSON, Proc.
U. S: Nat. Mus., XXIII, 1901, p. 579.

Localities.— Labrador; Greenland; Kingigtok; Duck Island; Murch-
ison Sound; Claushavn; latitude 73° 48' north, longitude 80° 30'
west; latitude 72° 33' north, longitude 71° 30' west; latitude 71° 57'
north, longitude 73° 56' west; latitude 66° 33' north, longitude 61° 50'
west; latitude 64° 56' north, longitude 66° 18' west; west coast of
Norway; Kara Sea; Sabine Island; Spitzberg; Jan Mayen; Murman
coast.

Depth.— Three to 20 fathoms.

Parasitic on Mysis oculata (O. Fabricius).

" Body of fully grown female oval quadrangular in outline, broadest
in front and slightly narrowed behind. Cephalon imperfectly defined
and curved downward, frontal margin straight. Lateral parts of
mesosome greatly swollen and projecting anteriorly in the form of
bluntly rounded protuberances extending beyond the limits of the
cephalon, median part subdepressed and exhibiting 5 or 6 distinct

«See Sars for characters of genus, Crust, of Norway, II, 1899, p. 222.

574 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

transversal sutures denning the segments. Metasome rather short
and but slightly projecting, being conically tapered; its first segment
much larger than the others. Oral area placed wholly in front, com-
paratively broad, semicircular. Antennulte very short, 3-articulate;
antennae much more slender and extended laterally, being composed
of 8 or 9 articulations successively diminishing in size distally. First

FIG. 638. — DAJUS MYSIDIS (AFTER SARS). a, VENTRAL VIEW OF FEMALE (ADULT). 6, 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. /, UROPODA OF FEMALE, m, YOUNG FEMALE (VENTRAL

VIEW), n, YOUNG FEMALE (DORSAL AND VENTRAL VIEWS), o, YOUNG FEMALE (LATERAL VIEW).

pair of incubatory plates larger than the next succeeding ones and
divided by a transversal fold into two segments; last pair, extending
behind the oral area, rather broadly overlapping each other in the
middle. Body of young female narrower, subclavate, with the nieso-
sonie more distinctly segmented and the metasome more produced;

I8OPODS OF NORTH AMERICA. 575

that of still younger female oblong, attenuated behind, with the
cephalon freely projecting in front, and the coxal plates occupying
the side-edges of the mesosome. Body of immature female, immedi-
ately after the metamorphosis, somewhat resembling the male in shape,
but having only five pairs of legs, and the metasome distinctly seg-
mented. Adult male linear, subcompressed, with the six posterior
segments of mesosome very sharply marked off from each other,
metasome forming a thickish, undivided piece of oval or elliptical
form, earning at the tip two extremely small appendages (rudiments
of uropoda). Color of female along the middle of the dorsal face
reddish brown, lateral parts whitish. Length of fully grown female
4 mm., that of male 1 mm." — G. O. SAKS."

99. Genus HOLOPHRYXUS Richardson.

Body of female without any trace of segmentation.

Abdomen abruptly narrower than thorax, unsegmented, produced
to a tapering extremity. Uropoda absent. Pleopods wanting. Five
pairs of legs present, crowded closely around the oral area.

Five pairs of incubatory lamellae present.

This genus differs from Dajus Kr0yer in the absence of all appendages
to the abdomen of the female and in lacking all trace of segmentation.
It differs from Notophryxm and Aspidophryxm Sars6 in having all five
pairs of incubatory plates, only one pair being present in Sars's genera;
in having no trace of segmentation; in the shape of the oral area and
the position and form of the abdomen, etc. It differs from Iletero-
phryxus Sars'1 in the position of the last pair of legs, which in Hetero-
phryxm are rather anomalous in structure, are placed at the posterior
extremity of the body and are adapted for clasping. It differs from
Branchiophryxus Caullery'' in having five pairs of legs and five pairs
of incubatory plates, while in Branehiophryxus there are but four
pairs of legs and four pairs of incubatory plates. It differs from
Zonophryxus Richardson e in lacking pleopoda, one pair being present
in Zonophryxus; in the form of the abdomen and in the general shape
of the body. It differs from Prodajus Bonnier^ in the form of the
abdomen, which is unsegmented and not bifurcate.

« Crust, of Norway, II, 1899, pp. 223-224.

6 Idem, pp. 225-231; Norwegian North- Atlantic Expedition, Crust., I, 1885, pp.
136-139.

c Challenger Report, XIII, 1885, Pt. 37, Report on the Schizopoda, pp. 220-221, pi.
xxxvin, figs. 8-14.

d Journ. R. Micr. Soc. Lond., 1897, Pt. 3, p. 204; Zool. Anzeiger, XX, 1897, pp.
88-92.

''Bull. U. S. Fish Comm., 1903, pp. 51-52.

/Comptes Rend. Acad. Sci. Paris, CXXXVI, 1903, pp. 102-103.

576 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

HOLOPHRYXUS ALASCENSIS Richardson.

Holophryxus alascensis RICHARDSON, Bull. U. S. Fish Comm., XXIV, 1905, pp.
220-221.

Localities.— Vicinity of Yes Bay, Behm Canal; vicinity of Funter
Bay. Lynn Canal.
Depth.— 147 to 350 fathoms.

Body of female irregular in outline. Color uniformly light yellow.
Head represented by a bilobed prominence anterior to squarish body.

FIG. 639. — HOLOPHRYXUS ALASCENSIS. a, DORSAL VIEW OF FEMALE, x 3}. b, LATERAL VIEW OF

FEMALE. X 3£. C, VENTRAL VIEW OF FEMALE. X 3J.

Eyes wanting. Dorsal surface of thorax with no trace of segmenta-
tion. A few lines only are present, representing creases or folds in
the integument and having no relation to suture lines.

The abdomen projects below the thorax, although there is no dis-
tinct boundary between these two divisions of the body, as a triangular

process without any trace of segmentation and with

no appendages.

Uropoda and pleopoda are entirely wanting.
In a lateral view the first

five segments of the thorax

are represented by the five

coxal plates, which bound

the oral area, and are not

separated by sutures from

the dorsal surface of the

body. On the ventral side

the oral area is bounded
anteriorly by the head and laterally by the two divergent rows of
coxal plates. The antennae and antennulae are quite rudimentary.
The antennae seem to be composed of three joints, the antennulaeof two.
There are five pairs of legs, surrounding the oral area, situated just
within the two rows of coxal plates. From the bases of these legs
five pairs of incubatory plates arise, the last pair overlapping in the
middle ventral line.
No males were found. Three specimens were taken by the U. S.

FIG. 640.— HOLOPHRYXUS
ALASCENSIS. MAXILLI-

PED. X 27}.

FIG. 641.— HOLOPHRYXUS
ALASCENSIS. FIRST IN-
CUBATORY LAMELLA (DIS-
TAL LOBE). X 27}.

ISOPODS OF NORTH AMERICA. 577

Bureau of Fisheries steamer Albatross at Station 4236, vicinity of Yes
Bay, Behm Canal, and Station 4257, vicinity of Funter Bay, Lynn
Canal. Depth, 147 to 350 fathoms.

The host is unknown.

The type of the species is in the U. S. National Museum, Cat. No.
29250.

Another specimen has been collected by the U. S. Bureau of Fish-
eries steamer Albatross from southern California.

Family XXII. CRYPTONISCHXE. «

Body of female forming a sac filled with eggs, with sometimes only
slight traces of segmentation. No true legs present, all or most of the
appendages of the body lost.

Male not different from female larva of the last larval stage and
does not pass beyond this stage. In the last larval stage the first pair
of antennae have two flagella and the basal article is expanded behind,
with the expansion generally pectinate. Epimera usually pectinate.
First two pairs of legs shorter and thicker than others. Both branches
of pleopoda well developed. Outer branch of uropoda generally much
shorter than inner branch.

1OO. Genus CLYPEONISCUS Giard and Bonnier. &

Body of adult female flattened, oval, without any traces of segmenta-
tion. Lateral parts lobular; anterior and posterior extremities incised.
Dorsal surface convex, with an opaque area in front of the middle.
Ventral surface flattened with a longitudinal slit leading to the inner
cavity, and having on either side a number of small valvular lamellae.
At the base of the posterior incision is a small projection. There is
no distinct apparatus for fixing the parasite.

Male short and thick. Basal expansion of the first pair of antennas
broad and pectinate. Epimera distinctly pectinate. Second pair of
antennae short. Uropoda with the outer branch much smaller than
the inner.

First larval stage having a broad operculiform plate covering the
ventral side of the terminal part of the body. Parasitic in the incu-
batory pouch of Isopods of the family Idotheidae.

CLYPEONISCUS MEINERTI Giard and Bonnier.

Clypeoniscus meinerti GIARD and BONNIER, Bull. Scientifique de la France et de la
Belgique (4), XXV, 1893, pp. 421-436, 444.

Localities. — Greenland (Godhavn); Nova Zembla (Jugor Schar)
(Giard and Bonnier).
Depth. — 6 to 10 fathoms.

a For characters of family see Sars, Crust, of Norway, II, 1899, pp. 231-232.
& For characters of genus, see Sars, Crust, of Norway, II, 1899, p. 239.
28589—05 37

578 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

•7-.;. ;••;;-./

FIG. 642.— CLYPEONISCUS MEINEKTI (AFTER GIARD AND BONNIER), o, DORSAL VIEW OF ADULT
FEMALE, x 16. 6, VENTRAL VIEW OF SAME, c, FEMALE AT A STAGE INTERMEDIATE BETWEEN a
AND 6. x 90. d, MODE OF OPENING OF INCUBATORY LAMELLA 3Y MARGINAL FOLDS (ADUJ.T
FEMALE), x W, e, THE $AME SEEN FEOM WJTBIN, x 50,

ISOPODS OF NOKTH AMEEICA. 579

Parasitic in the incubatory pouch of Synidotea nodulosa (Kr03rer).

When the Idotea infested with the parasite is laid on its dorsal side
and presents the ventral side to the observer, one separates the five
pairs of incubatory lamellae and perceives, on a level with the second,
third, and fourth thoracic segments, a body regularly oval, slightly
attenuated at the two extremities of the long axis, and presenting an
appearance very indistinctly segmented; it seems completely tilled
with a compact mass of little grains, yellow in alcohol, which are the
eggs distending the incubatory cavity. Toward the middle of the sur-
face, which is not applied to the ventral part of the host, and a little
toward the base, one notices the mark of a dead white. If one detaches
this oval body and examines the other side, one sees that it is divided
longitudinal!}' by a groove, which extends from one extremity to the
other. On several individuals one finds, generally toward the extrem-
ity the nearest to the head of the host, a very small Isopod, scarcely
visible to the naked eye, measuring 0.85 mm., but presenting all the
typical characters of the group. This last is the male Clypeoniscus,
while the oval mass, filling the incubatory cavity of the host, is the
female, reduced to a simple incubatory sac filled with embryos.

When the female becomes adult it takes the form figured, repre-
senting the dorsal and ventral sides. It is then a globular mass,
which appears divided longitudinally by a groove, scarcely visible on
the dorsal side and interrupted toward the cephalic region by a white
mass, the dorsal organ. This little mass, somewhat thick, the histolog-
ical composition of which we have not determined because of the state
of preservation of the specimen, is all that remains of the visceral part
of the female, the ovary, digestive tube, etc. Outside of this there is
nothing more than the body wall transformed into an incubatory
envelope, preserving nothing to recall the primitive Isopod, neither
segmentation nor appendages. However, if one examines the female
on the ventral side, considering its position in relation to the host, we
see that the dorsal groove continues on this side and assumes an
appearance altogether special. Immersed between the lateral masses
filled with embryos, it is formed by the superposition of a S3rstem of
small lamellae which one can easily enough separate, without tearing,
and which permits of emptying the female completely of eggs; it is
the opening of the incubatory cavity.

We have represented this system of lamellte as we have been able
to expose it under the microscope, after having removed the dorsal
surface of the female. This long opening terminates plainly in two
extremities between the anterior and the posterior bosses of the
animal, and the way in which the lamellae which form it lie over each
other in regular order is rather complicated. Very small at the two
extremities of the opening these lamellae become larger toward the
ventral part; they are ten or eleven pairs in number.

580 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 643.— CYLPEONISCUS MEINERTI (AFTER GIARD AND BONNIER), a, POSTERIOR PART, VIEWED DOR-
SALLY, OF EMBRYO OF FIRST STAGE. X 240. 6, LATERAL VIEW OF EMBRYO. X 240. C, VENTRAL
VIEW OF EMBRYO. X 420. d, SIXTH LEG. X 580. C, POSTERIOR EXTREMITY. X 580. /, FIFTH
LEG. X 580.

ISOPODS OF NORTH AMERICA. 581

The figures represent the anterior extremity of the opening seen
from the exterior and the interior side (the observer being supposed,
in the last case, to be within the incubatory cavity). The first pair of
lamellae is simple, semicircular, and one of them covers the other; but
the second and third become much more complicated; each is formed
of a double fold, presenting in a way two secondary lamella? united
along one of their lateral margins, while the others remain free. They
arrange thus between themselves an opening similar to that formed by
a sheet of paper folded in two. When the lateral margins of the fis-
sure of the opening of the incubatory cavity are brought together,
the inner secondary lamella of the right margin, for example, pene-
trates into the fissure arranged between the inner secondary lamella of
the left side and the outer secondary lamella of the left side, which is
itself covered by the external secondaiy lamella of the right side.

These lamella?, very thin on their free edges, are a little thicker near
their point of attachment and present several little symmetrical swell-
ings. Each pair is separated from the other by an interval which is
apparent only when one stretches the walls of the incubatory cavity.
When the living female rolls up on herself, all the lamella? are covered
over, not only laterally, but also behind and before in such a way as to
close hermetically the cavity where the embryos are inclosed. a

«The above is adapted from the following description of Giard and Bonnier's:

Quand, PIdotee parasitee etendue sur la face dorsale et presentant sa face ven-
trale a 1'observateur, on ecarte les cinq paires de lamelles incubatrices, on apergoit
au niveau des 2e, 3e et 4e segments thoraciques un corps regulierement ovoide, lege-
rement attenue aux deux extremites du grand axe et montrant une apparence tres
vaguement segmentee; il semble rempli exactement d'une masse compacte de petits
grains, jaunatres dans 1'alcohol, qui sont des O3ufs distendant la cavite incubatrice.
Vers le milieu de la surface qui n'est pas appliquee a la partie ventrale de Phote, et
un peu vers le bas, on remarque une tache d'un blanc mat. Si 1'on detache ce corps
ovoide et si 1'on examine 1'autre face, on voit qu'elle est divisee longitudinalement
par un sillon qui s'etend d'une extremite a 1'autre. Sur quelques individus on trouve
generalement, vers 1' extremite la plus rapprochee de la tete de Phote, un tres petit
Isopode, a peine visible a 1'oeil nu, mesurant Omm ,85, mais presentant toutes les
parti cularites typiques du groupe: ce dernier est le male Clypeoniscus, tandis que la
masse ovoide, remplissant la cavite incubatrice de Phote, est la femelle reduite a, un
simple sac incubateur rernpli d'embryons.

Quand la femelle devient adulte, elle prend la forme figuree, representant les faces
dorsale et ventrale. C'est alors une masse globuleuse qui semble divisee longitu-
dinalement par un sillon, peu visible a la face dorsale et interrompu, vers la region
cephalique, par une partie blanchatre que nous appellerons organe dorsal. Cette
petite masse, un peu epaissie, et dont nous n'avons pu determiner la composition his-
tologique, a cause de 1'etat de conservation de Panimal, est tout ce qui reste de la
partie viscerale de la femelle, ovaire, tube digestif, etc. Hors cela, il n'y a plus que
la paroi du corp transformed en enveloppe incubatrice, et ne conservant plus rien
rappelant P Isopode primitif, ni segmentation, ni appendices.

Cependant si on considere la femelle par la face que nous appelons ventrale, vu
sa position par rapport a Phote, nous voyonsque le sillon dorsal se continue sur cette
face et prend un aspect tout a fait special. Enfonce entre les masses laterales, bourrees

582

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

FIG. 644. — OOSACCUS. a, DORSAL SIDE OP FEMALE.
b, VENTRAL SIDE OF SAME.

The young stage of the female and the male of Clypeoniscus lian-
seni is described and figured in the above article. Sars suggests that
perhaps the two species are identical, the occurrence of both forms
on\y has led the authors (Giard and Bonnier) to regard them as dis-
tinct species.

Attached to the ventral side of the abdomen of the Isopod Pancolus

calif 'or 'niensis Richardson was a
parasite which probably belongs
to the family Cryptoniscidse, As,
however, there are no males and
no immature forms to indicate
the relationship of this parasite,
I shall not indicate its systematic
position at present. In case this
should prove to be a new genus
of Cryptoniscidse^ I might sug-
gest the name Oosaccus for its
reception.

Body of female ovate, longer
than broad, 2 mm. : 3 mm. ; perfectly symmetrical, with the anterior
and posterior extremities rounded. There is no trace of segmenta-
tion, and there are no appendages, the body being simply an oval sac.

d'embryona, il est forme par la superposition d'un systeme de petites lamelles qu'on
peut assez facilement separer, sans les dechirer, et qui permettent de vider comple'te-
ment la femelle de ses embryons: c'est 1'ouverture de la cavite incubatrice.

Nous avons represente ce systeme de lamelles tel que nous avons pu Pe"taler sous
le microscope, apres avoir enleve la surface dorsale de la femelle. Cette longue fente
se termine nettement aux deux extrdmites entre les bosses ante>ieures et posterieures
de 1' animal, et la facon dont s'imbriquent les lamelles qui la ferment est assez com-
pliqu^e. Tres petites aux deux extremit£s de la fente, ces lamelles deviennent plus
grandes vers la partie ventrale; elles sont au nombre de dix cu onze paires.

Les figures representent 1'extremit^ anterieure de la fente vue par la partie exte"-
rieure et la partie interieure (1'observateur etant suppose, dans a dernier cas, dans
la cavite incubatrice). La premiere paire de lamelles est simple, semi-circulaire, et
1'une d' elles recouvre Tautre; rnais la deuxieme et la troisieme deviennent bien plus
compliques; chacune d'elles est formee d'un double repli de facon a presenter deux
lamelles secondaires soudees par un de leurs bords lateraux, tandis que les autres
restent libres; elles menagent done entre elles une fente semblable a celle formee par
une feuille de papier pliee en deux. Quand les bords lateraux de la fente d'ouverture
de la cavite incubatrice sont rapproches, la lamelle secondaire interne du bord droit,
par example, penetre dans la fente menagee entre la lamelle secondaire interne du
bord gauche, et la lamelle secondaire externe du meme bord, qui est elle-meme
recouverte par la lamelle secondaire externe du bord droit.

Ces lamelles, tres minces sur leurs bords libres, sont nn peu plus e"paisses vers
leur point d'attache et presentent quelques petits renflements symetriques. Chaque
paire est separee de 1'autre par un intervalle qui n'est sensible que quand on opere
une traction sur les parois de la cavite incubatrice. Quand la femelle vivante se
ramasse sur elle-meme, toutes les lames se recouvrent, non seulement lateralement,
mais aussi d'arriere en avant, de facon tl clore hermetiquement la cavite" ou sont
incubus les embryons. — GIARD and BONNIER, Bull, scient. de la France et de la
Belgique (4), 1893, pp. 422-423, 425-427.

ISOPODS OF NORTH AMERICA. 583

There is no chord of attachment. On the ventral side is a small
rounded opening, where the parasite was attached to the host. There
seems to be an outer wall and an inner wall. The outer wall is prob-
ably attached to the host around the circular opening. The inner wall
is guarded by three or four valves. Through the integument of the
inner wall can be seen the eggs which completely fill the body cavity.
It was found attached to the ventral side of the abdomen of the Isopod
r<incoliL8 californiensis Richardson, belonging to the family Tanaidx.
There are but two specimens, both females, and no males were found.
The types are in the U. S. Nat. Museum, Cat. No. 32111, U.S.N.M.

VI. ONISCOIDEA."

Legs all ambulatory in character. Uropoda terminal, styliform,
composed of a peduncle and two branches, the branches being uniar-
ticulate. Pleopoda fitted for air breathing, the outer opercular plate
of the first two pairs and sometimes of all five pairs containing air
cavities or tracheae. In the male the inner plate of the second pair
and sometimes of the first pair is modified. Abdomen composed of
six well-defined segments.

The first pair of antennae are small, rudimentaiy, and inconspicuous;
they are never composed of more than three articles.

Mandibles strong, without palps. First maxilla? have two mastica-
tory lobes. Second maxillae with, only a very slight indication of a
subdivision into lobes. •

Marsupial pouch in the female composed of four pairs of plates
issuing from the bases of the second, third, fourth, and fifth pairs
of legs.

This superfamily includes all the terrestrial Isopods.

ANALYTICAL KEY TO THE FAMILIES OF ONISCOIDEA.

a. Inner antennae with one to two articles. Pleopoda in four pairs; those of first
segment wanting; those of the second, third, fourth, and fifth segments have
a single branch, all branchial; the branch of the second segment, however, in
the male, is produced on the inside in a long, compressed stylet; uropoda form

an inferior operculum Family XXIII. TYLID.E

a' '. Inner antenna; with three articles. Pleopoda in five pairs, all double branched.

External branch of all five pairs opercular in character. Internal branch

branchial, in the male, however, of the first and second pairs sexual; uropoda

not forming an operculum.

b. First maxillae with inner lobe furnished with from five to fifteen plumose

processes Family XXIV. EI-BELID.K

V . First maxillae with the inner lobe furnished at the tip with only two or three

plumose processes.

c. Buccal mass not very prominent below. First maxillae have two plumose
setae on the inner plate. Mandibles with molar expansion obsolete, with-
out any triturating surface, it being replaced by brushlike recurved setae.

« For characters of family see Budde-Lund, Crustacea Isopoda Terrestria, 1885, and
Sars, Crustacea of Norway, II, 1899, pp. 153-154.

584 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

d. Maxillipeds with terminal joints small and almost rudimentary, hardly

longer than masticatory lobe, which is truncate.

e. External antenna; generally long, close together, with antennal openings
large. Body as a rule scarcely able to be contracted in a ball. Head
less manifestly immersed in first thoracic segment. Lateral parts of the
head separated by a vertical marginal and inframarginal line. Clypeus
arched. Legs generally long. Uropoda produced, reaching beyond
the terminal segment of the abdomen and the preceding segment.
Terminal segment narrower than preceding ones and usually conically

produced at end Family XXV. ONISCIIX*:

ef. External antennae generally short, with antennal openings small. Body
able to be contracted into a ball. Head immersed in first thoracic
segment. Lateral parts of the head undifferentiated. Clypeus perpen-
dicular. Legs generally short. Uropoda short, not reaching beyond
the terminal segment of the abdomen or the preceding segment.
Terminal segment short and broad... Family XXVI. ARMADILLIDID^E
d'. Maxillipeds with terminal joints large, lamellar, much longer than masti-
catory lobe, which is acutely produced Family XXVII. SCYPHACID^E

cf. Buccal mass prominent. First maxillae have three plumose set* on the
inner plate. Mandibles with molar expansion large and broad, exhibiting
a finely fluted triturating surface.

d. Head without any lateral lobes, frontal part rounded. Eyes well developed
or wanting. Inner antennae with last joint very small and without dis-
tinctly developed sensory filaments. Second antennae with flagellum
multiarticulate. Posterior maxillae with two thick, hairy bristles. Max-
illipeds with the terminal part distinctly five-articulate, masticatory lobe
truncate at tip, epignath short. External sexual appendages in male
double. Inner branches of first pair of pleopoda of a similar structure
in both sexes, that of second pair in male terminating in long stylet.

Both branches of uropoda styliform Family XXVIII. LIGYDID.E

d' ' . Head with distinct, though not very large, lateral lobes, front more or less
produced. Eyes small or wanting. Inner antennae with last joint well
developed and tipped with a number of delicate sensory filaments. Sec-
ond antennae with flagellum not more than six jointed. Posterior
maxillae without any bristles. Maxillipeds with the terminal part gen-
erally imperfectly articulated, masticatory lobe terminating in a thin lash,
lepignath narrow, linguiform. Sexual appendage of male simple; inner
branch of both first and second pairs of pleopoda modified. Uropoda
with branches conically tapered Family XXIX. TRICHONISCID.E

Family XXIII. TYLID^.«

Inner lobe of the First maxillse furnished with three subequal
plumose processes. •

First pair of antennas small, composed of one or two articles.
Abdomen composed of six distinct segments.

Four pairs of pleopoda present; the first pair of pleopoda are want-
ing; the pleopoda of the second, third, fourth, and fifth segments have
single branches, all branchial ; the branch of the second segment, how-
ever, in the male is produced on the inside in a long, compressed stylet.

The uropoda form an operculum, with the outer branch very small
and situated at the apex.

«See Budde-Lund for characters of family, Crustacea Isopoda Terrestria, 1885,
p. 272.

ISOFODS OF NORTH AMERICA.

585

1O1. Genus TYLOS Latreille.

With characters of family.
Only genus.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS TYLOS.

a. Terminal abdominal segment triangularly produced, with apex rounded. Ven-
tral plates or inferior processes of the fifth abdominal segment meeting in the

median ventral line. Color white Tylos niveus Budde-Lund

a' . Terminal abdominal segment quadrangular; posterior margin straight, not pro-
duced. Ventral plates of fifth abdominal segment not meeting in the median
ventral line. Color light brown with black spots.

Tylos latreilli Audouin and Savigny

TYLOS NIVEUSt Budde-Lund.

Tylos niveus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 278-279. — RICHARD-
SON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 561; Trans. Conn. Acad. Sci.,
XI, 1902, p. 301.

Localities. — Key West, Florida; Bermudas.

Body oblong-ovate, convex, contractile into a ball, very minutely
and densely punctate, and covered with hairs, especially at the sides.

Eyes small, composite, occupying a
fourth part of the width of the head; about
30 ocelli.

First pair of antennse composed of one
article, immovable.

Second pair lost in the specimen. Front
of head not separated from the epistome;
epistomal shield subtetragonal, becoming
narrow anteriorly, reflexed; clypeus large,
tretragonal, a little impressed transversely.

The first segment of the thorax with the
lateral margin deeply sulcate; epimera of
the two following segments small, rounded,
subtriangular, a little excavate anteriorly.

The fifth segment of the abdomen with
the inferior processes strong, tetragonal, meeting in the middle; the
fourth segment with the processes small, oblong, narrow; the third
segment with the epimera minute; the terminal segment convex,
extending a' little beyond the parallel epimera of the preceding seg-
ment. The uropoda form a rounded operculum, becoming narrower
anteriorly.

Color white.

Length 13 mm. Width 5.5 mm. Height 3 mm.a

«The above description is adapted from the following one of Budde-Lund's:

Oblonge ovalis, convexus, in globum contractilis, minutissime et dense punctatus,
prsesertim ad latera setigerus.

Oculi minores, compositi vel congregati, quartam partem capitis latitudinis possi-
dentes, corneulae vel ocelli circiter 30.

Antennse exteriores .

FIG. 645.— TYLOS NIVEUS (AFTER
DOLLFUS). a, HEAD WITH ANTENNA.
6, LAST TWO SEGMENTS OF ABDOMEN.

(ENLARGED.)

586

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

a

TYLOS LATREILLI Audouin and Savigny.

TijIoK latreilli Aunouix and SAVIGNY, Descript. de 1'Egypte, 1826, pp. 285-287,
pi. xin, fig. 1.

Tylox armadillo LATKEILLE, Cuvier, Regne Animal, 2d ed., IV, 1829, p. 142. —
(TI-ERIN, Iconogr. Crust, 1829-1843, p. 35, pi. xxxvi, fig. 4.

Tylos latreilli MILNE EDWARDS. Hist. Nat. Crust., Ill, 1840, p. 188; Regne anini.,
Crust, 1849, pi. LXX bis., fig. 2.— LUCAS, Expl. d'Alg., I, 1849, p. 73.— HEL-
LER, Verb. Zool.-bot Ver., Wien, XVI, 1866, p. 732.— MIERS, Proc. Zool. Soc.
Lond., 1877, p. 674. — BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 273-
274 (see Budde-Lund for synonymy). — DOLLFUS, Bull. Soc. d'Etudes Scien-
tifiques de Paris, 12th year, 1890, pi. i, fig. 4.

Tylos armadillo DOLLFUS, Mem. Soc. Zool. de France, 1896, p. 550.

Tylos latreilli RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp. 300-301,
pi. XL, fig. 56.

Localities. — Bermudas; Miami, Florida; Long Bird Island, Bermu-
das; also Algeria; Tunisie; Odessa.

Bod>' elliptical in outline, very convex, and able to be contracted
in a ball. Surface smooth or minutely
granular and setigerous. Color }rellow
or light brown, marked
with black spots.

Head with front not
marginate; lateral angu-
lations produced into
lobes, which are trun-
cate. Epistome forming
a triangular shield, ad-
vancing some distance
beyond the surface of
the head. Eyes situated
post - laterally . Second
pair of antennae, with a
five-jointed peduncle and a flagellum consisting of four joints, extend
to the posterior margin of the second thoracic segment.

The seven thoracic segments are subequal. The epimera of the first
segment are represented by a thickening of the lateral edge, which is
incised or cleft posteriorly. The epimera of all the other segments are
dorsally separated by distinct suture lines.

Antennae interiores uniarticulatse, immobiles.

Fronsab epistomate non discreta; epistomatis scutellum subtetragonem, ante angu-
statum, reflexum; clypeus amplus, tetragonus, tranverse paulum impressus.

Trunciannulus primus margine lateral! profundesulcato; epimera annulorum duo-
rum sequentium parva, rotundata, subtriangula, ante paulum excavata.

Caudse annulus quintus processubus inferioribus validis; tetragonis, medio attin-
gentibus; annulus quartus processubus parvis, oblongis, angustis; annulus tertius
epimeris minutis; annulus analis convexus, epimera annuli pneanalis parallela satis
superans. Pedes anales operculum rotundatum, ante angustatum formantes.

Color albidus.

Longitude 13 mm. Latitude 5.5 mm. Altitude 3 mm. — BUDDE-LUND, Crust Isop.
Terrestria, 1885, pp. 278-279.

FIG. 646.— TYLOS LAT-
REILLI. OPERCU-
LUM.

FIG. 647.— TYLOS LATREILLI (AFTER
DOLLFUS). a, HEAD WITH ANTENNA.
6, LAST TWO SEGMENTS OF ABDOMEN.
(ENLARGED.)

ISOPODS OF NORTH AMERICA. 587

The first two abdominal segments have their lateral margins covered
by the seventh thoracic segment. The three following segments com-
plete the elliptical outline of the body, their lateral margins forming a
line curving inward toward the terminal segment. The last abdomi-
nal segment is quadrangular in outline, its post-lateral angles rounded,
and extends a little distance beyond the epimera of the preceding seg-
ment. The uropoda are transformed into opercular valves. At the
posterior end of each large lamellar valve is a small setose joint. The
third, fourth, and fifth abdominal segments have plates on the ventral
side extending from the margin inward in the form of lamellae, those
of the fifth segment being longest and largest, but not meeting in the
median line, being a little distance apart.

The legs are simple, ambulatory.

Three specimens were collected by Mr. J. M. Jones at the Bermudas,
and about twenty more by Prof. A. E. Verrill and part}7 at the same
locality in 1898. Others were collected in 1901 at Long Bird Island,
Bermudas.

Family XXIV. EUBELID^.«

Flagellum of the second antenna? generally more or less obscurely
triarticulate, rarely only biarticulate; peduncle with the first article
very short, the third article always shorter than the second, the fourth
article a little longer than the second, the fifth article always the longest.

Eyes distinct, composed of numerous ocelli.

Head with the epistome forming a continuous frontal marginal line,
often effaced in the middle. The antennal foramina are moderately
large, the antennal tubercles small, often wanting. Clypeus short,
vaulted, lobate at the sides. The pleurae of the head are fused; the
vertical marginal line does not reach the frontal margin; there is no
vertical inframarginal line.

The inner lobe of the first or inner maxillae has numerous plumose
processes (5-15); the outer or second maxillae are wide, obscurely
bifid, the exterior lobe much wider and larger than the inner.

The first segment of the thorax has thick epimera, separated from
the middle of the segment by a sutural furrow, the lateral margin pos-
teriorly cleft, rarely entire. The anterior articulating part of all the
segments (2-7) manifestly separated from the posterior part. The
marsupium is present.

The terminal abdominal segment is triangularly or even quadran-
gularly produced, not extending or extending very little beyond the
epimera of the preceding segment. The outer branch of the first or
generally of all the pleopoda furnished with tracheae. Uropoda short,
not extending or extending very little beyond the terminal segment of
the abdomen. Peduncle large, wide. Outer branch small or minute.

a See Budde-Lund for characters of family, A revision of Crustacea Isopoda Ter-
restria, 1899, Pt. 1, Eubelum, pp. 2-3.

588 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

1O2. Genus ETHELUM Budde-Lund.«

Antennae with the flagellum composed of two articles. Inner lobe
of the first or inner maxillae furnished with four plumose processes.

First segment of the thorax with the epimeron thick, separated
above from the middle of the segment by a longitudinal furrow, lat-
eral margin not excavate, posteriorly cleft. The second segment of
the thorax with the epimera entire.

Outer branches of all the pleopoda furnished with tracheae.

ANALYTICAL, KEY TO THE SPECIES OF THE GENUS ETHELUM.

a. Surface of body smooth, with the side parts of the thoracic segments (two to seven)

and the abdominal segments not bent downward.

b. Prosepistoma plain. Coxopodite of the second segment of the thorax forming a
nearly inconspicuous ridge before the leg. Caudal segment triangular; apex
pointed. Inner branch of the uropoda extends beyond the apex of the caudal

segment Ethelum modestum (Dollfus)

bf. Prosepistoma with a shield-like convexity. Coxopodite of the second segment
of the thorax hardly visible, only a very small dentiform process before the
leg. Caudal segment flat, with rounded apex. Inner branch of the uropoda
reaches two-thirds the length of the caudal segment.

Ethelum americanum (Dollfus)

a'. Surface of body slightly granulated, with the side parts of the thoracic segments
(two to seven) and the abdominal segments bent downward. Caudal segment
with blunt rounded apex. Inner branch of the uropoda reaches two-thirds the
length of the caudal segment Ethelum reflexum ( Dollfus)

ETHELUM MODESTUM (Dollfus).

Mesarmadillo modestus DOLLFUS, Proc. Zool. Soc. London, 1896, p. 397. — RICH-
ARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 573.

Ethelum modestum BUDDE-LUND, A Revision of "Crustacea Isopoda Terrestria,"
1899, p. 25; Ent. Meddel. (2), I, Pt. 2, 1899, p. 91.

Locality. — St. Vincent, West Indies. Dry forest, leeward, under a
log, 800 feet.

"Body rather convex and narrow, smooth. Prosepistoma plain,
continuous with the forehead in the middle, and separated from it on
both sides by a transverse, incomplete, preocular cut. Eyes moderate;
ocelli about 16. Antennae short, flagellum very small, first joint three
times shorter than the second. Pereion: first segment with the antero-
median tubercle hardly perceivable; coxopodites distinct on the entire
length of the edge of the segment, with the hind part diverging and
covered by the posterior angle of the segment. Coxopodite of the
second segment forming a nearly inconspicuous ridge before the leg.
Pleon, telson: pleotelson triangular; sides feebly curved; apex pointed.

« See Budde-Lund for characters of genus, A revision of Crustacea Isopoda Ter-
restria, 1899, Pt. 1, Eubelurn, p. 24.

ISOPODS OF NORTH AMERICA.

589

Uropoda: basis with a large oblong processus; endopodites extending
beyond the apex of the pleotelson; exopodites small, placed at the top

d

FIG. 648.— ETHELTJM MODESTUM (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THORAX
(UPPER SIDE), b, THE SAME (UNDERSIDE), c, FIFTH AND SIXTH SEGMENTS OF ABDOMEN AND URO-
PODA (UPPER SIDE), d, THE SAME (UNDERSIDE).

of the basal processus. Color: gray or reddish, with small light
lineolse on the pereion; uropoda light. Dimensions: 6 by 2£ mm."-

DoLLFUS.a

ETHELUM AMERICANUM (Dollfus).

Mesarmadillo americanus DOLLFUS, Proc. Zool. Soc. London, 1896, pp. 397-398. —
RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 573.

Elhelum americanum BUDDE-LUND, A Revision of ' ' Crustacea Isopoda Terrestria, ' '
1899, p. 24; Ent. Meddel. (2), I, Pt. 2, 1899, p. 90. -

Locality. — St. Vincent, West Indies. Sugar-cane field, under decay-

FIG. 649.— ETHELUM AMERICANUM (AFTER BUDDE-LUND). a, APEX OF INNER LACINIA OF FIRST

RIGHT MAXILLA. X 130. 6, LEFT ANTENNA. X 25. C, FLAGELLUM OF LEFT ANTENNA. X 70.

ing cane-leaves. Leeward, lowland near sea, under stones; under old
boards, 250 feet; under rubbish, shad}7 place.

flProc. Zool. Soc. London, 1896, p. 397,

590 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

"Body convex, rather narrow, smooth. Cephalon: prosepistoma
with a small shield-like convexity; the prosepistoma is continuous with
the forehead in the middle and separated from it on both sides by a trans-
verse, incomplete, preocular cut. Eyes moderate; ocelli about 12.
Antennae short; flagellum small, first joint three times shorter than
the second. Pereion : first segment with the antero-median tubercle
hardly perceivable; coxopodites distinct on the entire length of the
edge of the segment (upper side), forming a thick border, slightly
crossed by the posterior angle of the segment. Coxopodite of the sec-

FIG. 650.— ETHELUM AMERICANTJM (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THO-
RAX (UPPER SIDE). 6, THE SAME (UNDERSIDE), c, FIFTH AND SIXTH SEGMENTS OF ABDOMEN
(UPPER SIDE), d, THE SAME (UNDERSIDE).

ond segment hardly visible as a very small dentiform processus before
the legs. Pleon, telson: pleotelson flat, with curved sides and rounded
apex. Uropoda: basis with a large, oblong processus, extending
between the lateral part of the fifth segment of the pleon and the
pleotelson; endopodite reaching to two-thirds the length of the pleotel-
son; exopodite minute, placed at the top of the basal processus.
Color: brownish, with small light lineolae on the pereion; flagellum
white; uropoda reddish. Dimensions: 6 by 2£ mm." — DOLLFUS."

ETHELUM REFLEXUM (Dollfus).

Mesarmaditto reflexus DOLLFUS, Proc. Zool. Soc. London, 1896, pp. 398-399. —
RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 573.

Ethelum reflexum BUDDE-LUND, A Revision of "Crustacea Isopoda Terrestria,"
1899, pp. 25-26; Ent. Meddel. (2), I, Pt. 2, 1899, pp. 91-92.

Locality. — St. Vincent, West Indies. Open, swampy land, under
rubbish.

a Proc. Zool. Soc. London, 1896, pp. 397-398.

ISOPODS OF NORTH AMERICA.

591

" Body slightly granulated, very convex, and narrowed backward,
the side parts of the pereion (segments 2-7) and of the pleon tending
downward. Cephalon: prosepistoma with a shield-like triangular
convexity; the prosepistoma is continuous with the forehead in the
middle and separated from it on both sides by a transverse, incomplete,
preocular cut. Eyes moderate; ocelli about 12. Antennse short;
flagellum small, first joint four times shorter than the second. Pereion:
first segment with the antero-median tubercle hardly perceivable;
coxopodites distinct on the entire length of the edge of the segment.

FIG. 651.— ETHELUM REFLEXUM (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THORAX
(UPPER SIDE), b, THE SAME (UNDERSIDE), c, FIFTH AND SIXTH SEGMENTS OF ABDOMEN AND URO-

PODA (UPPER SIDE), d, THE SAME (UNDERSIDE).

Coxopodite of the second segment hidden under the bent side part
of the segment. Pleon, telson: the lateral parts being nearly folded
underneath, the hind edge of segments (3-5) seems straight from a
dorsal view. Pleotelson flat, with curved sides and a blunt, rather
rounded apex. Uropoda: basis with a large oblong processus; endo-
podite reaching to two-thirds the length of the pleotelson; exopodite
small, placed at the top of the basal processus. Color: dark brown,
flagellum whitish. Dimensions: 5 by 2 mm. (much decreasing back-
ward."— DOLLFUS."

«Proc. Zool. Soc. London, 1896, pp. 398-399.

592 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Family XXV. ONISCID^E."

Body oval or oblong, rather convex, very little or scarcely contract-
ile, very rarely convex; with difficulty contractile into a ball.

Second pair of antennae generally long, with the flagellum composed
of only a few articles. Antennal foramina large. Pleura! parts of the
head distinctly separated by a vertical marginal line and an infra-
marginal line. Cypeus arched. Eyes generally well developed, com-
pound. Molar expansion of mandibles obsolete, without any triturat-
ing surface, it being replaced by brush-like setae. First maxillae with
the outer lobe tipped with spines, the inner lobe furnished with two
plumose processes. Second maxillae bilobate at the tip. Maxillipeds
with palp composed of three articles and but little longer than masti-
catory lobe; masticatory lobe truncate at tip; epignath large.

There are six thoracic segments in the young before they are
hatched.

The legs are generally long. The uropoda are produced, always
extending beyond the terminal segment and the preceding segment.

First and second pairs of pleopoda modified in the male, the inner
branch of the second pair terminating in a slender stylet.

ANALYTICAL KEY TO THE GENERA OF THE FAMILY ONI8CID.B. &

a. Flagellum of second antennae composed of less than four articles.
b. External opercular ramus of the abdominal appendages containing no special

respiratory organ. Flagellum of external antennae triarticulate.
c. Epimera of thoracic segments large, with all the posterior angles acute.
Abdomen not abruptly narrower than thorax. First two abdominal seg-
ments very short, three following ones large, with large acute epimera.
d. Front of head produced at the middle and at the sides in tubercles; lateral

tubercles horn-like Genus Alloniscus Dana

d'. Front and sides of head not produced in tubercles. With or without lat-
eral lobes.

e. Surface of body smooth Genus Lyprobius Budde-Lund

e'. Surface of body granulated or tuberculate.

/. Terminal segment of body short, widely rounded posteriorly. Basal
article of uropoda broadly expanded inside. Inner branches contig-
uous along their inner lateral margins.. Genus Synuropus Richardson
/'. Terminal segment of body conically produced. Basal joint of uro-
poda oblong Genus Onwcus Linnaeus

</. Epimera of thoracic segments small. Abdomen abruptly narrower than
thorax; first two segments generally equal in length to those following;

epimera very small, but manifest Genus Philosda Latreille

b'. External opercular ramus of the first and second pairs of abdominal append-
ages furnished with tracheae. Flagellum of external antennae biarticulate.
c. Second maxilla not larger than first maxilla, and bilobed at the tip.

« See Budde-Lund for characters of family, Crustacea Isopoda Terrestria, 1885, p.
75, and G. O. Sars, Crustacea of Norway, II, 1899, pp. 169-170.

&The genus Acanthoniscus (White) Kinihan is not included in the key.

ISOPOD8 OF NORTH AMERICA. 593

d. Abdomen not abruptly narrower than thorax. Epimera of abdominal seg-
ments large.

e. Body very convex, capable of being rolled up into a perfect ball. Articles
of nagellum of external antennae subequal. External branchesof the uro-
poda equal in both sexes. External opercular ramus of all the abdomi-
nal appendages furnished with tracheae Genus Cylisticus Schnitzler

ef. Body more or less depressed, scarcely contractile. Articles of nagellum
of external antennae with the first article generally longer than the
second, often subequal, or even a little shorter. External opercular
ramus of the first and second pairs of abdominal appendages fur-
nished with tracheae.

. /. Second antennae long; first article of the flagellum generally longer
than the second. Outer branch of the uropoda flattened, and longer

in male than in female Genus Porcelllo Latreille

/'. Second antennte short; flagellum with first article much shorter than
second. Outer branch of the uropoda conical, and not longer in

male than in female Genus Leptotrichus Budde-Lund

df. Abdomen abruptly narrower than thorax. Epimera of abdominal seg-
ments small.

e. First article of flagellum of external antennae generally longer than second.
Las't abdominal segment reaches sufficiently beyond the epimera of the
preceding segment. External opercular ramus of the first and second
pairs of abdominal appendages, rarely of the third or of all the pairs,

furnished with tracheae ....'.... Genus Metoponorthus Budde-Lund

e' '. Flagellum of external antennae with the first article shorter than the
second. Last abdominal segment reaches much beyond the epimera
of the preceding segment. External opercular ramus of the first and
second pairs of abdominal appendages furnished with tracheae.

Genus Rhyscotus Budde-Lund
c7. Second maxilla more than twice as large as first maxilla and not bilobed

at the tip Genus Hypergnathus, new genus

a' '. Flagellum of second antennae composed of four articles.

Genus Actomiscus Harger

1O3. Genus ALLONISCUS Dana."

Body rather convex, very little or scarcely at all contractile.

Front of head produced in the middle and at the sides into tubercles,
the lateral tubercles being prominent and horn-like. Epistome swollen
within between the antennae, and slightly carinated. Flagellum of
second pair of antennae composed of three articles. Frontal marginal
line wanting, vertical marginal line passing through the pleurae of the
head behind the eyes.

Epimeral parts of the thoracic segments small, not much expanded.

Abdomen not abruptly narrower than the thorax, with the pleural
lamellae of the third, fourth, and fifth segments large.

Legs very spinulose.

a See Budde-Lund for characters of genus, Crust. Isop. Terrestria, 1885, p. 224.
28589—05 38

594 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ALLONISCUS.

a. Surface of body very densely granulated. Epimera with the anterior angles ser-
rate Attoniscus mirabilis (Stuxberg)

a' . Surface of body punctate. Epimera with the anterior angles not serrate.
6. Lateral processes of the head large, prominent.

Attoniscus cornutus Budde-Lund
b'. Lateral processes of the head small, scarcely prominent.

Alloniscus perconvexus Dana

ALLONISCUS MIRABILIS (Stuxberg).

Rhinoryctes mirabilis STUXBERG, Ofvers. Vet. Akad. Forhandl., 1875, No. 2, p. 51.
Attoniscus mirabilis BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 229.
Rhinoryctes mirabilis UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p.

363.
Alloniscus mirabilis RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 864; Ann.

Mag. Nat. Hist. (7), IV, 1899, p. 332; American Naturalist, XXXIV, 1900,

p. 305.

Locality. — California.

Body oval, twice as long as wide, convex, very densely granulated;
epimera serrate on the margins. Second pair of antennae much
shorter than the width of the body (85:100); the fifth article of the
peduncle very long, not very much curved, equal in length to the
three articulate flagellum; the articles of the flagellum equal to each
other in length or the middle one sometimes smallest.

Eyes prominent, subcircular, with numerous ocelli.

The frontal median lobe large, produced, obtuse, extended upward,
equal to a fourth part of the width of the head; lateral lobes pro-
duced, conical, anteriorly rounded, equal to the eyes in length.

All the segments of the thorax with the posterior margin sinuated
in the middle. Epimera moderately large, with the anterior angles
gradually more rounded posteriorly, serrate, the posterior angles
roundly acuminate not very much directed backward.

Abdomen subcircular, a little wider than long, all the segments
equal in length, the epimera of the first and second segments vanishing,
those of the third, fourth, and fifth segments large, directed backward,
rounded on the exterior margin, serrate, almost straight on the inner
margin. The last segment is triangular, twice as wide as long, with
the posterior margins straight, roundly acuminate, rather convex
above and sometimes furnished with a longitudinal furrow not at all
deep. The uropoda have the basal article almost as wide as long,
depressed, with the post-lateral margin very little elevated, circularly
rounded, serrate, the outer branch a little flattened, subconical, with
the exterior margin straight, the inner margin convex, extending not
much beyond the inner branch in length, which extends very little
beyond the last segment of the abdomen.

ISOPODS OF NORTH AMERICA. 595

Color of the dorsal surface reddish or dark gray, the frontal lobes,
especially the middle one, and a longitudinal band on the thorax
darker and covered with veiy numerous paler oblong spots. a

ALLONISCUS CORNUTUS Budde-Lund.

Alloniscus cornutus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 228-229. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 864; Ann. Mag. Nat.
Hist. (7), IV, 1899, p. 332; American Naturalist, XXXIV, 1900, p. 305.

Locality. — California.

„ Body short, oval, subconvex, obscurely but densely roughened and
thickly punctate and setigerous. Second pair of antennae shorter than
half the length of the body (7:17); flagellum shorter than the fifth
article of the peduncle; the second article of the flagellum shortest,
the first equal in length to the third.

Antero-lateral processes large, narrow, prominent, subconical; front
in the middle very much swollen.

The first three segments of the thorax have the posterior nlargin on
both sides slightly sinuated; all the following segments have the poste-
rior margin in the middle rather sinuated posteriorly.

«The above description is adapted from the following one of Stuxberg's:

Rhinoryctes-ovalis, longitudine duplo majore quam latitudine, convexus, densis-
sime granulatus, epimeris margine serratis.

Antennae exteriores corporis latitudine multo breviores ( = 85:100); pedunculi
articulus quintus longissimus, parum curvatus, longitudine flagellum 3 : articulatum
sequans; flagelli articuli inter se eadem longitudine vel medius interdum minimus.

Oculi, ocellis congregatis, prominentes, subcirculares.

Lobus frontalis medius magnus, productus, obtusus, sursum porrectus, quartern
partem latitudinis capitis sequans; lobi laterales producti, conici, antice rotundati,
longitudine oculos sequantes.

Trunci segmenta omnia rnargine postico medio sinuata. Epimera mediocria,
angulis anticis post sensim magis rotundatis, serratis, angulis posticis parum retro-
versis, rotundate-acuminatis.

Cauda subcircularis, latitudine paullo majore quam longitudine, omnium seg-
mentorum longitudine sequali, epimeris segmentorum primi et secundi evanescenti-
bus, tertii, quarti, quinti maximis, retroversis, margine exteriore rotundatis, serratis,
interiore fere rectis. Segmentum ultimum trigonum, duplo latius quam longius,
marginibus posticis rectis, rotundate-acuminatum, supra convexiusculum et inter-
dum fovea longitudinal! haud profunda instructum.

Pedum ultimi paris articulus basalis fere seque latus ac longus, depressus, margine
postico-laterali parum elevato, circulariter rotundato, serrato, appendix exterior
paullum complanata, subconica, margine exteriore recto, interiore convexo, longi-
tudine appendicem interiorem haud multo superans, quee ultimum caudse segmentum
parum excedit.

Color dorsi rufo-vel fusco-griseus, lobis frontal! bus, pnesertim medio, vittaque
trunci longitudinal! nigrioribus, maculis oblongis numerosissimis pallidioribus
inspersis.

Longitudo, 10 mm.; latitude, 4.5-5 mm.; altitudo, 2.3-2.5 mm. — STUXBERG, 0fvers.
Vet. Akad. Forhandl., 1875, No. 2, p. 51.

596

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first two segments of the abdomen scarcely shorter than the
other segments; the epimera of the third, fourth, and fifth segments
strong, subtetragonal.

The terminal abdominal segment is triangular, short, hardly twice
as wide as long, rather convex above.

The basal article of the uropoda is very wide, depressed; the outer
branch is carinated, with the apex rounded; the inner branch is inserted
at the inner angle of the basal article. Color grayish, pale on the
sides. Length, 8.5 mm.; width, 5 mm.; height, 2 mm.a

ALLONISCUS PERCONVEXUS Dana.

Alloniscus perconvexus DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854, p. 176. —
STIMPSON, Boat. Jour. Nat. Hist., VI, 1857, p. 506. — BUDDE-LUND, Crust.
Isop. Terrestria, 1885, p. 225. —UNDERWOOD, Bull. 111. State Lab. Nat. Hist.,
II, 1886, p. 360.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 864; Ann. Mag. Nat. Hist. (7), IV, 1899,
p. 332; American Naturalist, XXXLV, 1900, p. 305.

Localities. — California; Pacific Grove; Santa Bar-
bara; Monterey Bay; Tillamook Head, Oregon.
Dug at mean-tide mark from sandy shore.

Body ovate, very convex, not quite twice as long
as broad, 9 mm. : 16 mm.

Head twice as wide as long, 2 mm.: 4 mm., with
the antero-lateral angles produced on either side into
an acute process, " horn-like," situated just in front
of the eye, and the front produced in the middle in
a large, widely rounded median lobe, extending as
far as the lateral process. The eyes are small,
oblong, composite, and situated in the antero-lateral
angles of the head close to the lateral margins. The
first pair of antennae are rudimentary and inconspicuous. They are
composed of three small articles. The second pair of antennas have

a The above description is adapted from the following one of Budde-Lund' s :

Breviter ovalis, subconvexus, obscure sed dense squamatus et punctis setigeris
crebratus. Antennae exteriores corpore dimidio breviores (7:17); flagellum scapi
articulo quinto brevius; flagelli articnlus secundus brevissimus, primus tertio sequalis.

Processus frontales laterales majores, angustiores, prominentes, subconici; frons
media valde tumosa.

Trunci annuli tres priores jnargine posteriore utrinque leviter sinuato; annuli
sequentes omnes margine posteriore medio post magis sinuato.

Caudse annuli duo priores ceteris annulis vix breviores; epimera annuli 3-4-5
valida, subtetragona. Annulus analis, triangulus, brevis, segre duplo latior qtiam
longior, supra convexiusculus.

Articulus basalis pedum analium perlatus, depressus; extus carinatus, apice rotun-
dato ; ram us interior angulo interior! articuli basalis insertus.

Color griseus, in lateribus dilutior.

Longitude, 8.5 mm.; latitude, 5 mm.; altitude. 2 mm. — BUDDE-LUND, Crust. Isop.
Terrestria, 1885, pp. 228-229.

FIG. 652. — ALLONISCUS
PERCONVEXUS.

ISOPODS OF NORTH AMERICA.

597

the basal article short; the second is about twice as long as the first;
the third and fourth are subequal and each is a little longer than the
second; the fifth is one and a half times as long as the fourth. The
flagellum is composed of three subequal articles. The antennas are
covered with small spines. The maxillipeds have a palp of three arti-
cles. The palp of the mandibles is wanting.

d e f g

FIG. 653.— ALLONISCUS PERCONVEXUS. a, MAXILLIPED. x20£. 6, SECOND ANTENNA. xlH. c, FIRST
MAXILLA (INNER LOBE). x39. d, SECOND MAXILLA. x20J. e, FIRST MAXILLA (-OUTER LOBE).
x2<H. /, MANDIBLE. x20|. g, FIRST ANTENNA. x39.

The first segment of the thorax is 2 mm. in length and is a little longer
than any of the others, which are subequal and each is about li mm.
long. The lateral margins of all the segments are
straight and contiguous. On the first four seg-
ments the epimera are indicated by a distinct lon-
gitudinal suture, which on the first segment is con-
fined to the posterior half of the segment, but in
the three following segments extends the entire
length of the segment. There are no suture lines
on the last three segments.

The abdomen is as wide as the thorax. The
first two segments have the lateral parts covered
by the seventh thoracic segment. The sixth or terminal segment is
triangular in shape and is twice as wide as long, being 3 mm. wide at
the base and 1| mm. long. The uropoda extend 1 mm. beyond the
extremity of the abdomen. The peduncle does not extend beyond the
abdomen. The inner branch extends only to the middle of the outer
branch and is more slender.
All the legs are ambulatory and covered with stiff hairs.

FIG. 654. — ALLONISCUS PER-
CONVEXUS. TERMINAL
SEGMENT OF ABDOMEN

WITH UROPODA. Xlli.

598 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

1O4. Genus LYPROBIUS Budde-Lund.«

Body not convex, scarcely contractile. Head produced into lobes
at the side; front not produced in the middle, marginate. Epimera
of the third, fourth, and fifth segments of the abdomen large.

Peduncle of the uropoda short and wide, with the outer side silicate.

Epimera of the thoracic segments moderately large; those of the
first three segments with the posterior angles roundly obtuse, those
of the fourth segment with the posterior angles straight, and those of
the three posterior segments with the posterior angles acute.

Body setigerous, scarcel}7 granulated.

Flagellum of second antennae composed of three articles.

LYPROBIUS PUSILLUS Budde-Lund.

Lyprobius pusillus BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 230. — RICHARD-
SON, Proc. U. S. Nat. Mus., XXI, 1899, p. 864; Ann. Mag. Nat. Hist. (7),
IV, 1899, p. 333; American Naturalist, XXXIV, 1900, p. 305.

Locality. — California.

Body oval, rather convex, smooth, punctate, very minutely setiger-
ous, especially so posteriorly.

Second pair of antennae a little shorter than half the length of the
body; first article of the flagellum equal in length to the third, almost
half as long as the second.

Antero-lateral lobes small, rounded. Front, with the median mar-
ginal line entire, a little arched and produced.

The terminal segment of the abdomen is triangulate in the middle,
produced, and extends a little beyond the epimera of the fifth abdom-
inal segment; terminal segment a little excavate above.

Color uniformly brown, transparent on the margins, white.

Length 5 mm. Width 2.5 mm. Height 1.2 mm.6

1O5. Genus SYNUROPUS Richardson.

Body oval, not contractile into a ball, with the segments laterally
expanded, as in Oniscm.

Head with lateral and frontal lobes. Second pair of antennae long,
with fiagellum composed of three articles.

o For characters of genus see Budde-Lund, Crust. Isop. Terrestria, 1885, pp. 229-230.

&The above description is adapted from the following one of Budde- Lund's:

Ovalis, convexiusculus, sublaevis, punctatus, minutissime praesertim post setiger.

Antennae exteriores corpore dimidio paulo breviores; flagelli articulus primus
tertio eequalis. secundo fere duplo brevior.

Lobi frontales laterales parvi, rotundati. Frons media linea marginal! integra
paulum curvate producta.

Caudse annulus analis medio triangulo, producto, epimera annuli praeanalis paulum
superante, supra paulum excavatus.

Color uniformis brunneus, in marginibus perlucens, albidus.

Longitudo 5 mm., latitude 2, 5 mm., altitude 1, 2 mm. — BUDDE-LUND, Crust.
Isop. Terrestria, 1885, p. 230.

ISOPODS OF NORTH AMERICA.

599

Abdomen not narrower than thorax; pleural lamellae large.

Terminal segment of body much broader than long, widely rounded
posteriorly, not conically produced as in Oniscus. Basal joint of the
uropoda large, broadly expanded inside, not oblong as in Oniscus;
inner branches close together, their internal lateral margins contigu-
ous. Inner branch inserted but little or scarcely at all in advance of
the outer branch, situated close to the inner post-lateral angle of the
peduncle. Outer branch somewhat longer than inner branch.

SYNUROPUS GRANULATUS Richardson.

Synuropus granulatus RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp.
563-564.

Locality. — El Yunque, Porto Rico, at an altitude of 2,800 feet.
Body oval, not able to be contracted into a ball, with the lateral
parts of the segments expanded.

Entire surface of body covered with small
tubercles.

Head deeply set in the first thoracic segment,
the rounded anterior angulations of which reach
the antero-lateral angles of the head. The an-
terior margin of the head is produced in an ob-
tusely pointed median lobe. The lateral lobes
are very acute. The antennae are geniculate at
the articulation of the fourth and fifth pedun-
cular joints; the flagellum consists of three
joints.

The first thoracic segment is longest; the
others are subequal. The ab-
domen is not narrower than
the thorax. The first two
segments have their lateral
margins concealed. The three
following have their lateral

margins broadly expanded. The terminal segment
is twice as broad as long, with the posterior margin
broadly rounded. The basal joints of the uropoda
are large, being partly covered by the terminal seg-
ment of the body. The outer branch is styliform
and extends its entire length beyond the terminal
abdominal segment. The inner branches are situated close together
in such a way that the inner lateral margins are contiguous through-
out their length. /£&&_
The legs are ambulatory, similar, and subequal.
Color brown, mottled with black.

FIG. 655. — SYNUROPUS GRANU-
LATUS. a, DORSAL VIEW, b,
UROPODA.

FIG. 656.— SYNUROPUS
GRANULATUS. MAX-

ILLIPED.

600 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

One specimen was collected by Dr. L. Stejneger at El Yunque,
Porto Rico, at an altitude of 2,800 feet.
Type.— Cat. No. 23912, U.S.N.M.

1O6. Genus ONISCUS Linnaeus.«

Body broad, depressed, very little or scarcely contractile. Surface
of body granulated or tuberculate. Head with well-defined lateral
lobes; front marginate, not produced in the middle. Abdomen not
abruptly narrower than thorax; third, fourth, and fifth segments with
epimera large, acute, and produced backward. Terminal segment
greatly produced. Eyes large, lateral. Second pair of antennae long;
flagellum composed of three articles.

Opercular plates of the pleopoda without tracheae.

Uropoda produced, with the inner branch inserted far in front of
the outer, near the inner antero-lateral angle of the peduncle.

Lateral parts of the thoracic segments expanded; posterior angles
of all the epimera acute.

ONISCUS ASELLUS Linnaeus.

Oniscus asellus LINNAEUS, Fauna Suecica, 2d ed., 1761, p. 500.

Oniscus murarius CUVIER, Jour. Hist. Nat., II, 1792, p. 23, pi. xxvi, figs. 11-13.

Oniscus affinis SAY, Journ. Acad. Nat. Sci. Phil., I, 1818, pp. 430-431.

Oniscus vicarius STUXBERG, Ofvers. Svenska Vet. Akad., Forh., 1872, Pt. 9, p. 3;
1875, Pt. 2, p. 50.

Oniscus asellus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 202-204.

Oniscus affinis UNDERWOOD, Bull. 111. State Lab. Nat Hist., II, 1886, p. 361.

Oniscus vicarius UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 361.

Oniscus. asellus SARS, Crust. Norway, II, 1899, pp. 171-172. — RICHARDSON, Ameri-
can Naturalist, XXXIV, 1900, p. 305; Proc. U. S. Nat. Mus., XXIII, 1901.
pp. 562-563.

Oniscus affinis RICHARDSON, American Naturalist, XXXIV, 1900, p. 305; Proc.
U. S. Nat. Mus., XXIII, 1901, p. 563.

Oniscus asellus STOLLER, 54th report New York State Museum, 1902, p. 213. —
PAULMIER, Bull. New York State Museum, 1905, pp. 180-181.

Localities. — Greenland; North America, at Woods Hole, Massachu-
setts; Salem, and Beverly, Massachusetts; New York City; Schenec-
tady, New York; Rock Island, Illinois; Providence, Rhode Island;
Syracuse, New York; Freeport, Maine; Pennsylvania; also Sweden;
Denmark; Germany; Newfoundland; Canada, near Niagara; Holland;
Great Britain; France; Spain; Italy; Azores; Iceland; coast of Nor-
way; "Ashensee Tyrol " 950 meters alt. (Dr. Stejneger).

Found under dead logs, dead leaves, and stones; common in hot-
houses.

Specimens identified by Dr. Joseph Leidy as Oniscus affinis Say
and sent to me by Doctor Calvert of the University of Pennsylvania,

«See Budde-Lund for characters of genus, Crustacea Isopoda Terrestria, 1885,
p. 202, and Sars, Crustacea of Norway, II, 1899, pp. 170-171.

ISOPODS OP NORTH AMERICA.

601

do not differ from specimens of Oniscus aselhis in the U. S. National
Museum collection.

Body oblong-ovate, about one and a half times longer than wide, 10
mm. : 16 mm.

Head wider than long, 2 mm. : 3 mm., with the frontal margin
slightly convex and pronounced antero-lateral lobes, narrow and elon-
gated, almost 1 mm. in length and rounded anteriorly. The eyes are

FIG. 657.— ONISCUS ASELLUS (AFTER SARS). a, MANDIBLE, b, POSTERIOR LIP. c, ANTERIOR LIP.
d, 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. TO, 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. M, THIRD PLEOPOD OF FEMALE.

small, composite, and situated at the sides of the head, at the base of
the antero-lateral lobes. The first pair of antennae are small and incon-
spicuous and are composed of two articles. The second antennae have
the basal article short; the second article is twice as long as the first;
the third is equal in length to the second; the fourth is nearly twice as
long as the third; the fifth is one and a half times as long as the fourth.

602 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The flagellum is composed of three articles. When retracted the
second antennas extend to the posterior margin of the third thoracic
segment.

The segments of the thorax are subequal in length. The first seg-
ment has the antero-lateral angles produced to surround the head, and
they extend almost to the extremity of the antero-lateral lobes of the
head. The lateral parts of all the segments are expanded, but there is
no indication of epimera on any of the segments. The lateral margins
are straight.

The segments of the abdomen are all distinct, the first two being
somewhat shorter. The lateral parts of the first two are entirely
concealed by the seventh thoracic segment. The lateral parts of the
third, fourth, and fifth segments are expanded and produced so as to
continue the oval outline of the body; those of the fifth segment
extend posteriorly as far as the extremity of the sixth or terminal
segment. The terminal segment is triangular, with the apex produced
in a long process, 2 mm. in length and pointed posteriorly. The basal
article or peduncle of the uropoda extends to the middle of the pro-
duced portion of the terminal abdominal segment. The inner branch
extends to the extremity of the process of the terminal segment and is
concealed by it except at the lower portion. The outer branch is 2
mm. long and extends the length of 1 mm. beyond the terminal
abdominal segment.

The legs are all ambulatory in character.

In color, the dorsal portion of the body is a dark brown. There is
a longitudinal row of light yellow spots on either side of the thorax,
about the place of union of the epimera with the segments. The
lateral margins of the body are also light j^ellow. The dorsal portion
of the body is slightly granular.

1O7. Genus PHILOSCIA Latreille.«

Body oval, slightly convex, very little or scarcely at all contractile.

Head rounded in front, without lateral lobes. Second pair of
antennae long; flagellum composed of three articles. Frontal mar-
ginal line very often wanting in the middle, bent downward on either
side, surrounding the epistome and extending to the vertical marginal
line back of the eyes.

Abdomen abruptly narrower than thorax; lateral parts of the third,
fourth, and fifth segments very small, appressed; terminal segment not
much produced.

Opercular plates of the pleopoda without trachese. Uropoda with the
inner branch not attached far in front of the outer branch.

Lateral parts of the thorax but slightly expanded.

«For characters of genus see B'f -de-Lund, Crust. Isop. Terrestria, 1885, p. 207,
and Sars, Crust, of Norway, II, 1899, p->. 172-173.

ISOPOBS OF NOKTH AMERICA.

603

ANALYTICAL KEY « TO THE SPECIES OF THE GENUS PHILOSCIA.

a. Surface of body smooth, without spines.
b. Terminal segment of body broadly rounded posteriorly.

Philoscia richmondi Richardson

b/. Terminal segment of body posteriorly triangular, with apex more or less pro-
duced.
c. Second antennae short, shorter than half the length of the body.

d. Front of head indistinctly trilobate Philoscia culebrx Moore

d/. Front of head straight or very slightly arched.

e. Body striped with two broad dorsal bands Philoscia vittata Say

ef. Body violet, covered with white spots, the margins of the segments being

white Philoscia brevicornis Budde-Lund

c/. Second antennae very long, much longer than half the length of the body.

Philoscia bermudensis Dahl
a'. Surface of body covered with numerous spines Philoscia spinosa Say

PHILOSCIA RICHMONDI Richardson.

Philoscia richmondi RICHARDSON, Proc. U. S. Nat. Mue., XXIII, 1901, pp. 564-565.

locality. — El Yunque, Porto Rico, at an altitude of 2,800 feet.
Body oval; surface smooth. Head not set in the first thoracic seg-
ment, evenly rounded, with no lateral or frontal lobes. Eyes large, well
developed, lateral. An-
tennae equal to half the
length of the body; fla-
gellum composed of three
joints.

Segments of thorax
subequal.

Abdomen a b r u b 1 1 y
narrower than thorax,
with the lateral processes
of the segments not pro-
jecting. Terminal seg-
ment equal in length to the preceding segment, much broader than
long, and with the posterior margin broadly rounded. The basal joint
of the uropoda projects beyond the terminal segment of the body.
The inner branch extends to the middle of the outer branch.
Legs gradually increasing in length.
Color, mottled brown and yellow.

A number of specimens were collected by Dr. C. W. Richmond and
Dr. L. Stejneger at El Yunque, Porto Rico, at an altitude of 2,800 feet.
Named for Dr. C. W. Richmond, of the U. S. National Museum.
Type.— Cat. No. 23913, U.S.N.M.

FIG. 658.— PHILOSCIA
RICHMONDI.

FIG. 659.— PHILOSCIA RICHMONDI.
a, MAXILLIPED. b, MANDIBLE.

a The description of Philoscia nigricans Budde-Lund does not give sufficient char-
acters to place it in the key.

604

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

PHILOSCIA CULEBR^E Moore.

PMostia culebne MOORE, Bull. U. S. Fish Commission, XX, Pt. 2, 1902, p. 176,
pi. xi, figs. 13-17.

Locality. — Culebra, Porto Rico, from drift on shore.
"Body elongate-oval, about 2.5 times as long as broad; head about

twice as broad as long, front somewhat
recurved between sides and middle,
producing the appearance of a small
lobe in front of each eye, sides and
posterior margin rounded; first sjeg-
ment of thorax longest, its anterior
and posterior margins strongly curved,
anterior angle rounded and projecting
somewhat beyond sides of head; next
six segments subequal in length, sec-
ond, third, and fourth widest, the last
three successively narrower; posterior
angles of last four segments produced,
successively increasing in length, that
of last reaching almost to posterior
border of third abdominal segment;
abdomen almost as long as last three
segments of thorax, gradually decreas-
ing in width posteriorly; segments sub-
equal in length, the sides of the first
more or less concealed by the lateral
angle of the last thoracic segment;
telson short, hardly longer than other
segments, produced to a blunt point in
median line posteriorly.

"Eyes moderate (for the genus);
first antennae minute, second antennas
when laid against sides of body extend-
ing to about end of second thoracic
segment, spinulose; peduncle, five-
jointed; first joint, short; second and
third, equal; fourth, longer; fifth, long-
est, equal to third and fourth com-
bined; flagellum three- jointed, about
equal to last joint of peduncle. Man-
dible with narrow four or five dentate
tip, at the base of which are two plumulose setse, and lower down a
brush of fine sette; no palp. First maxillae with inner plate furnished
with several small spines; outer plate with many.

FIG. 660.— PHILOSCIA CULEBRA (AFTER
MOORE), a, DORSAL VIEW. 6, SECOND
ANTENNA, o, MANDIBLE, d, FIRST LEG.
e, FOURTH LEG.

ISOPODS OF NORTH AMERICA.

605

"The legs increase slightly in length from before backward and are
furnished with long acute spines. The uropods are broken off.

"From Culebra. Two specimens, under drift on shore, 4.2 by 1.6
mm." — MOORE. a

PHILOSCIA VITTATA Say.

Philoscia vittata SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, p. 429. — DE KAY,
Zool. New York, Crust., 1844, p. 50. — WHITE, List Crust. Brit. Museum,
1847, p. 99. — HARGER with VERRILL, Eeport U. S. Commissioner of Fish and
Fisheries, 1873, Pt. 1, p. 569 (275)f»Proc. U. S. Nat. Mus., II, 1879, p. 157;
Report U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 306-307,
pi. i, fig. 1. — UNDERWOOD, Bull. 111.
State Lab. Nat, Hist., II, 1886, p.
361. — RICHARDSON, American Natu-
ralist, XXXIV, 1900, p. 305; Proc.
TJ. S. Nat. Mus., XXIII, 1901, p.
565. — PAULMIER, Bull. New York
State Museum, 1905, p. 181.

Localities. — Great Egg Harbor,
New Jersey, to Barnstable, Massa-
chusetts; Salem, Massachusetts; Free-
port, Long Island. Found under
stones, wood, etc., in moist places;
under rubbish along the shore; under-
side of boards above high water.

Body oblong-ovate, a little more
than twice as long as wide, 3 mm.:
6i mm.

Head wider than long, 1 mm. : 1£
mm., with the anterior margin
rounded and not produced into a lobe. The antero-lateral angles of
the head are rounded and not produced into lobes. The eyes are small,

FIG. 661.— PHILOSCIA VITTATA (AFTER
HAEGEK). x 6.

FIG. 662. — PHILOSCIA VITTATA. a, MAXILLIPED. b, SECOND MAXILLA, c, FIRST MAXILLA (OUTER
LOBE), d, FIRST MAXILLA (INNER LOBE), e, MANDIBLE. /, TERMINAL SEGMENT OF ABDOMEN,

WITH UROPODA.

round, and composite, and situated in the antero-lateral angles of the
head. The first pair of antennae are small, rudimentary, and incon-

«Bull. U. S. Fish Comrn., XX, Pt. 2, 1902, p. 176.

606

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

spicuous. The first article of the second antenna? is short; the second

and third are subequal and each is more than twice as long as the first;

the fourth is nearly twice as long as either of the two preceding; the
fifth is one and a half times longer than the fourth.
The flagellum is composed of three nearly subequal
articles, the third being a little longer than the second.
The second antennae extend to the posterior margin
of the third thoracic segment. The maxilliped has a
palp of three articles. The palp of the mandibles is
wanting.

The segments of the thorax are subequal, the first
segment being, perhaps, a little longer than any of the
others. There are no epimera separated off on any of
the segments.

The abdomen is abruptly narrower than the thorax.
The first two segments are covered at the sides by the
seventh thoracic segment. The lateral parts of the
segments are not developed. The sixth, or terminal
segment, is triangular in shape, with the apex not
produced but rounded. The peduncle of the uropoda
extends to the extremity of the abdomen. The inner
branch extends half a millimeter beyond the terminal
abdominal segment. The outer branch is not half a
millimeter longer than the inner branch.
All the legs are ambulatory.
Color brown, with lateral margins light and a narrow longitudinal

light area or band in the middle of the dorsal surface, separating the

two wide dark bands.

PHILOSCIA BREVICORNIS Budde-Lund.

Philosda brevicornis BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 218-219. —
RICHARDSON, American Naturalist, XXXIV, 1900, p. 305; Proc. U. S. Nat.
Mus., XXIII, 1901, p. 565.

Locality. — Biloxi, Mississippi.

Body oblong-oval ,*subcon vex, smooth, slightly covered with a few
dots.

Second pair of antennae shorter than half the length of the body;
articles of the flagellum short, subequal.

Frontal margin produced a little in the form of an arch in the mid-
dle, almost entirely inconspicuous; epistome subconvex in the middle.

Abdomen scarcely abruptly narrower than the thorax. The termi-
nal segment short, almost triangular, with sides slightly incurved, and
apex obtusely rounded; sulcate above.

The color varies in the two specimens, being a very light or a very

FIG. 663. — PHILOSCIA
VITTATA. a, SECOND

ANTENNA. X 27}. b,

UROPOD. 51f.

ISOPODS OF NORTH AMERICA.

607

dark violet, covered with white spots, with the margins white. Legs
all yellow, or covered with black dots.

Length 11 mm.; width 5 mm.; height 2.5 mm.a

PHILOSCIA BERMUDENSIS Dahl.

Philoscia bermudensis DAHL, Plankton Expedition, I, 1892, Pt. 1, p. Ill, pi. in,
figs. 2, 4, 5, 7, 8, 10, 13.

Locality. — Bermudas.

This species is not described, but well figured and compared with

a

FIG. 664. — PHILOSCIA BERMUDENSIS (AFTEK DAHL). a, GENERAL FIGURE, x 5. b, SECOND AN-
TENNA, x 16. c, MAXILLIPED. x 40. d, MANDIBLE, x 40. e, FIRST MAXILLA, x 40. /, FIRST
LEG. x 16. <;, UROPOD. x 16.

« The above description is adapted from the following one of Budde-Lund's:

Oblonge ovalis, subconvexa, nitida, tenuiter et sparse punctata.

Antennae exteriores corporis dimidio breviores; flagelli articuli breves, subsequales.

Linea marginalia frontalis medio paulum arcuate producta, fere onmino obliter-
ata; epistoma medio subconvexum.

Cauda trunco vix abrupte angustior. Annulus analis brevis, fere triangulus,
lateribus leviter incurvis, apice rotundato obtuso, supra sulcatus.

Color variat in duobus speciminibus dilutior vel obscurior violaceus, maculis
albidis conspersis, in marginibus late albidus. Pedes toti flavi, vel punctis nigres-
centibus conspersis.

Longitudo, 11 mm.; latitude, 5 mm.; altitude, 2.5 mm. — BUDDE-LUND, Crust.
Isop. Terrestria, 1885, pp. 218-219.

608 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Philoscia couchi Kinahan, from which it is said to differ (1) in having
the second antennae longer and more slender; (2) in having the uro-
poda longer and more slender, and (3) in having for eyes small spots
of pigment with slight rudiments of ocelli, while in P. couchi the eyes
seem to have entirely disappeared. Dahl likewise points out that
these differences also exist between Ligia baudiniana (hirtitarsis) and
Ligia oceanica. He considers that in both cases the Philoscia form
has arisen independently from the Ligia form.

PHILOSCIA SPINOSA Say.

Philoscia spinosa SAY, Jour. Acad. Nat. Sci. Phila., I, 1818, pp. 429-430. —
UNDERWOOD, Bull. 111. State Lab. Nat. Hist, II, 1886, p. 361.— RICHARDSON,
American Naturalist, XXXIV, 1900, p. 305; Proc. U. S. Nat. Mus., XXIII,
1901, p. 565.

Locality.— Savannah, Georgia.

" Brown, oblong-oval, with numerous spines above; feet armed with
short setse beneath.

" Inhabits Georgia.

" Cabinet of the academy.

" Body brown, elongate -oval, armed with numerous spine-like tuber-
cles; sixth and seventh segments produced on each side behind, acute,
the latter attaining the base of the fifth succeeding joint; abdominal
and caudal segments somewhat glabrous, terminal segment surpassing
the first joint of the lateral styles; antenna? rough and subspinose
before, terminal joint glabrous, pale; feet beneath armed with short
distant setae.

"Length nearly one-fifth of an inch.

"Under stones, old wood, etc., in moist situations near Savannah,
Georgia. " — SAY. °

PHILOSCIA NIGRICANS Budde-Lund.

Philoscia nigricans BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 210-211. —
RICHARDSON, American Naturalist, XXXIV, 1900, p. 305; Proc. U. S. Nat.
Mus., .XXIII, 1901, p. 565.

Locality.— Biloxi, Mississippi.

Body oblong-oval, rather convex, smooth, slightly covered with a
few dots.

Second pair of antennas lost in the specimen.

Frontal margin straight; epistome with a median transverse line.

Abdomen abruptly narrower than the thorax; epimera distant. The
last segment of the abdomen short, subtriangular, with the sides
straight or slightly incurved; apex obtuse, sulcate above.

« Jour. Acad. Nat. Sci. Phila., 1. 1818, pp. 429-430.

x ISOPODS OF NORTH AMERICA. 609

Color dark brown, covered with numerous white spots or little
stripes. Legs yellow, with the coxvs spotted with black.
Length, 9 mm.; width, 4 mm.; height, 1.6 mm.a

1O8. Genus CYLISTICUS Schnitzler. &

Body oblong, very convex, contractile into a ball.

Head with lateral lobes distinct; median lobe small; front of head
marginate. Eyes distinct, lateral. Second pair of antennae long; fla-
gellum composed of two subequal articles.

Lateral parts of the thoracic segments large.

Abdomen not abruptly narrower than thorax; lateral parts of third,
fourth, and fifth segments well developed; terminal segment conically
produced.

Opercular plates of all the pleopods furnished with tracheae.

Inner branch of the uropoda inserted far in front of the outer branch,
near the inner antero-lateral angle of the peduncle.

CYLISTICUS CONVEXUS (De Geer).

Oniscus convexus DE GEER, Mem. des Insectes, VII, 1778, p. 553, pi. xxxv, fig. 11.
Porcellio spinifrons BRANDT, Bull, de la Soc. Imp. d. Naturalistes de Moscou, VI,

1833, p. 15.

Porcellio Isevis KOCH, Deutschlands Crustaceen, 1835-1844, p. 6.
Porcellio armadilloides LEREBOI:LLET, M£m. de la Soc. du Museum d'Histoire Nat.

de Strasbourg, IV, 1853, p. 65, pi. i, fig. 18; pi. in, figs. 88-94.
Cylisticus Ixvis SCHNITZLER, De Oniscineis agri Bonnensis, 1853, p. 25.
Porcellio armadilloides KINAHAN, Nat. Hist. Rev., IV, 1857, p. 279.
Porcellio convexus JOHNSON, Academisk Afhandling, Upsala, 1858, p. 32.
Porcellio armadilloides BATE and WESTWOOD, Brit. Sessile-eyed Crust., II, 1868,

p. 485.
Porcellio convexus BUDDE-LUND, Nat. Tidsskr. (3), VII, 1870-71, p. 240. — STUX-

BERG, Ofvers. af Kgl. Vetenskaps Akad. Forh., 1875, p. 60.
Cylisticus convexus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 77-79. (See

Budde-Lund for further synonymy.) — G. O. SARS, Crust, of Norway, II,

1899, p. 186, pis. xi, xii.— RICHARDSON, Amer. Nat., XXXIV, 1900, p. 303;

Proc. U. S. Nat. Mus., XXIII, 1901, pp. 565-566.— STOLLER, 54th Report

New York State Museum, 1902, p. 213.— PAULMIER, Bull. New York State

Museum, 1905, pp. 181-182.

«The above description is adapted from the following one of Budde-Lund's:

Oblonge ovalis, convexiuscula, nitida, tenuiter et sparse punctata.

Antennae exteriores . . .

Linea marginalis frontalis recta; epistoma medio linea transversa.

Cauda trunco abrupte angustior; epimera subdistantia. Annulus analis brevis,
subtriangulus, lateribua subrectis vel leviter incurvis, apice obtuso, supra sulcatus.

Color ex nigro brunneus, maculis vel striolis numerosis albidis conspersus. Pedes
flavi, coxis nigromaculatis.

Longitudo, 9 mm.; latitude, 4 mm.; altitude, 1.6 mm. — BUDDE-LUND, Crust. Isop.
Terrestria, 1885, pp. 210-211.

6 For characters of genus see Budde-Lund, Crust. Isop. Terrestria, 1885, p. 77,
and Sars, Crust, of Norway, II, 1899, p. 185.
28589—05 39

610 BULLETIN f4, UNITED STATES NATIONAL MUSEUM.

Localities. — Westwood, Hamilton County, Ohio; "" Old Mill," Devils
Backbone, Hamilton County, Ohio; Miami Grove, Ohio; Piseco, New
York; Rock Island, Illinois; Spring-field, Ohio; Columbus, Ohio; Clif-
ton, Cincinnati, Ohio; Washington, District of Columbia; New York
City; Norwich, New York; Warwick, Massachusetts; Kelley's Island,
Lake Erie; Syracuse, New York; Las Vegas Hot Springs, New Mexico;

FIG. 665.— CYLISTICUS CONVEXUS (AFTER SARS). a, ANTERIOR LIP. 6, MANDIBLE, c, DORSAL VIEW
OF MALE, d, FIRST ANTENNA, e, SECOND ANTENNA. /, POSTERIOR LIP. g, HEAD (DORSAL VIEW).
h, MANDIBLES, i, LAST TWO SEGMENTS OF ABDOMEN AND TJROPODA. ,;', UROPOD. k, MAXILLIPEDS.
I, LATERAL VIEW OF MALE. »», FIRST MAXILLA, n, SECOND MAXILLA, o, FLAGELLUM OF SECOND

ANTENNA, p, FIRST PLEOPOD OF MALE, q, SEVENTH LEG. T, SECOND PLEOPOD OF MALE. 8, ABDO-
MEN (VENTRAL VIEW), t, FIRST PLEOPOD OF FEMALE. U. FIRST LEG.

Saginaw, Michigan; also Sweden; Denmark; British Isles; German}-;
Bohemia; Holland; Belgium; France; Turkey; and coast of Norway.

Found under bricks and boards; in woods, under logs; along roads,
under stones; in wood sheds.

Body oblong-ovate, contractile into a ball, a little more than twice
as long as wide,

mm.

mm.

Head about twice as wide as long, 1^ mm. : 3 mm., with the anterior

ISOPODS OF NORTH AMERICA. 611

margin produced in three lobes, the median lobe being small and tri-
angular with apex acute, the lateral lobes being large and widely
rounded. The eyes are small and composite and situated at the base
of the antero-lateral lobes. The first pair of antennae are small and
inconspicuous. The second pair have the first article short; the sec-
ond is twice as long as the first; the third is equal in length to the sec-
ond; the fourth is twice as long as the third; the fifth is one and a
half times longer than the fourth. The flagellum is composed of two
subequal articles. The second antennae extend to the posterior margin
of the fourth thoracic segment.

The segments of the thorax are about equal in length. The epimera
are not distinct from the segments. The lateral margins are straight.
The antero-lateral angles of the first segment are produced forward to
surround the head, and they extend to the base of the antero-lateral
lobes of the head; the post-lateral angles of the first segment are pro-
duced backward in acute processes.

All six segments of the abdomen are distinct. The first two have
the lateral parts covered by the seventh thoracic segment. The third,
fourth, and fifth segments have the lateral parts produced to continue
the oval outline of the body. The sixth or terminal segment is tri-
angular with the apex produced in a long acutely terminating process.
This segment is 2 mm. wide at the base and 2 mm. long to the end of
the apical process. The basal article or peduncle of the uropoda
extends just a little beyond the middle of the apical process of the
terminal abdominal segment. The inner branch is 1 mm. long, and
extends to the tip of the terminal abdominal segment. The outer
branch is 1 mm. in length and extends a little more than half its length
beyond the extremity of the abdomen.

All the legs are ambulatory in character.

In color it is a light brown with a longitudinal row of yellow spots
on either side at the place of union of the epimera with the segments.
Between the median line and the longitudinal rows are markings of
yellow wavy lines.

1O9. Genus PORCELLIO Latreille.«

Body oval, more or less depressed, very little contractile. Lateral
parts of the thorax expanded.

Head with the antero-lateral lobes well developed; median frontal
lobe more or less prominent. Front of head marginate. Eyes gen-
erally well developed, dorsally placed. Second pair of antenna long;
flagellum composed of two articles, the first usually longer than the
second, often equally long. or even a little shorter.

« See Budde-Lund for characters of genus, Crust. Isop. Terrestria, 1885, pp. 82-83,
and Sars, Crust, of Norway, II, 1899, p. 176.

612 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Abdomen not abruptly narrower than thorax; lateral parts of third,
fourth, and fifth segments well developed; terminal segment conic-ally
produced.

Opercular plates of the first two pairs of pleopoda and sometimes of
all five pairs furnished with tracheae. Inner branch of the uropoda
inserted far in front of the outer branch near the inner antero-lateral
angle of the peduncle.

ANALYTICAL KEY TO THE SPECIES OF THE GENU8 PORCELLIO.

a. Surface of body smooth or minutely granular.
b. Second pair of antenna? long, equal to half the length of the body. Flagellum

with the first article not shorter than the second.

c. Articles of flagellum subequal. Middle frontal lobe of head rounded; lateral
lobes roundly truncate. Color, dark grayish red with numerous pale, irreg-
ular oblong spots intermixed, arranged in two wide series separated by a

small interval Porcellio formosus Stuxberg.

c'. First article of flagellum of second antenme longer than the second. Middle
frontal lobe of head acutely produced; lateral lobes rounded. Color, dark
gray, with two longitudinal bands of a lighter color in wavy stripes, one on

either side of the median line Porcellio lirvis Latreille.

b'. Second pair of antennae short, equal to one-third the length of the body; flagel-
lum with the first article one-third shorter than the second.

Porcellio panicornis Richardson.
a.'. Surface of body roughly granulate or tuberculate.

b. Inner face of the mandibles with four to five penicils. Body with spots.
c. Third joint of peduncle of second pair of antennae furnished with a small apical
tooth. Frontal lateral lobes of moderate size. Color varying from gray to
black, with three longitudinal lines of white spots. Flagellum with joints

subequal, or first shorter than second Porcellio rathkei Brandt

c'. Second joint of peduncle of second pair of antenna? furnished with a large
apical tooth. Frontal lateral lobes large. Color, yellow; body spotted with
black; spots arranged in longitudinal lines. Flagellum with first joint a

little longer than second joint Porcellio spinicornis Say

b'. Inner face of right mandible with four to five penicils, of left mandible with
seven to eight penicils. Frontal lateral lobes of head large, oblique. Body
without spots Porcellio scaber Latreille

PORCELLIO FORMOSUS Stuxberg.

Porcellio formosus STUXBERG, 0fvers. Vet. Akad. Forh., 1875, No. 2, p. 57. —
BuDDE-LuND, Crust! Isop. Terrestria, 1885, p. 141. — UNDERWOOD, Bull. 111.
State Lab. Nat. Hist., II, 1886, p. 362.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 862; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 329; American
Naturalist, XXXIV, 1900, p. 304.

Localities. — San Francisco and San Pedro, California.

Body ovate, almost half as wide as long, convex, smooth, shining.

Second pair of antennae equal in length to the width of the body;
the first article of the peduncle is half as long as the second, the fourth
has a longitudinal excavation, deep on the outside, light above, the
fifth is the longest, longer than the preceding by a third part, not
much longer than the flagellum, straight, the proximal part incon-

ISOPODS OF NORTH AMERICA. 613

spicuously, the distal part lightly channeled; the articles of the flagel-
luin subequal. Eyes oval, prominent, with numerous ocelli.

The median frontal lobe is a little produced, rounded, the lateral
lobes drawn out, equal in length to the width of the face or to the eyes,
anteriorly roundly truncate, provided behind with a deep semilunar
excavation.

The first three segments of the thorax with the posterior margin
straight, the posterior angles of the epimera straight, the fourth seg-
ment with the posterior angles of the epimera straight, those of the
fifth, sixth, and seventh segments more and more bent backward, but
not very acuminate.

The abdomen is semicircular, about a fifth part wider than long, the
epimera of the third, fourth and fifth segments moderately large, bent
backward, curved on the inner margin, twice as long as wide and a
little acuminate. The last segment is triangular, almost as wide as
long, deeply sinuated on the posterior margins, the apex wide, roundly
acuminate, with a deep and wide longitudinal excavation above. The
basal article of the uropoda seen from below is as wide as long, convex
above; the outer branch is subdepressed, lanceolate, with the inner
margin straight, the outer margin curved, its greatest width equal to
a fourth part of the length; the inner branch is slender and a third part
shorter than the outer branch. The color of the dorsal surface is a dark
grayish red with numerous pale, irregular, oblong spots intermixed
arranged in two wide series separated by a small interval. The abdo-
men is generally of one color, with the last segment bi- or tri-punctate
at the base.

It varies in having a longitudinal band of grayish white and a lateral
series of large spots of the same color.

Length 13 mm., width 6 mm. ; length of the second antenna 6 mm."

«The above description is adapted from the following one of Stuxberg's:

Porcellio ovalis, latitudine dimidiam longitudinem prope assequente (latitud. ad
longitud. =45 : 100). convexus, sublaevis, subnitidus.

Antennae exteriores latitudinern corporis longitudine sequantes; pedunculi articu-
lus primus secundo duplo brevior, quartus extra profundius, supra levius longitudi-
naliter sulcatus, quintus longissimus, prsecedente tertia parte, flagello baud multo
longior, rectus, parte proximali inconspicue, distali levius canaliculata; flagelli
articuli inter se eadem longitudine. Oculi, ocellis congregatis prominentes, ovales.

Lobus frontalis medius paullum productus, rotundatus, laterales evoluti, longi-
tudine altitudine faciei vel oculis sequales, antice truncato-rotundati, pone excava-
tione semilunari profundiore prsediti.

Trunci segmenta tria priora margine postico recto, epimerorum angulis posticis
rectis, quartum subrectis, quintum, sextum, septimum magis magisque retroflexis,
. sed non multum acuminatis.

Cauda subcircularis, latitudine quinta circiter parte majore quam longitudine,
epimeris segmentorum tertii, quarti, quinti mediocribus, retroversis, margine interiore
curvatis, duplo longioribus quam latioribus, paullum acuminatis. Segmentum ulti-
mum trigonum, prope seque longum ao latum, marginibus posticis profunde sinu-
atum, apice lato, rotundate acuminate, supra late et profunde longitudinaliter exca-

614 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

PORCELLIO L^VIS Latreille.

Porcettio Isevis LATREILLE, Hist. Nat. des Crust, et Insectes, VII, 1804, p. 46;

Genera Crustaceorum et Insectorum, I, 1806, p. 71. — LEACH, Edinb. Encycl.,

VII, 1813-14, p. 406; Trans. Linn. Soc. London, XI, 1815, p. 375.
Oniscus Isevis LAMARCK, Hist. Nat. des animaux sans Vertebres, V, 1818, p. 154.
Porcellio degeerli AUDOUIN and SAVKINY, Descript. de 1'Egypte, 1826, p. 289, pi.

xm, fig. 5.
Porcellio eucercus BRANDT, Bull. Soc. Imp. d. Moscou, VI, 1833, p. 177. — MILNE

EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 168.
Porcellio syriacus BRANDT, Bull. Soc. Imp. d. Moscou, VI, 1833, p. 178. — MILNE

EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 170.

Porcellio cinerascens BRANDT, Bull. Soc. Imp. d. Moscou, VI, 1833, p. 178.
Porcellio dubius BRANDT, Bull. Soc. Imp. d. Moscou, VI, 1833, p. 178. — MILNE

EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 170.
Porcellio poeyi GUERIN, Comptes Rendus, 1837, p. 132.
Porcellio Isems MILNE EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 169.
Porcellio urbicus KOCH, Deutsch. Crust., 1835-1844, p. 36.
Porcettio ovatus ZADDACH, Synops. Crust Pruss. prodrornus, 1844, p. 13.
Porcellio degeerii LUCAS, Expl. d'Alg., I, 1849, pp. 69, 139.
Porcellio Isevis LEREBOULLET, M£m. de la Soc. de Strasbourg, IV, 1853, p. 45, pi. i,

fig. 7; pi. in, figs. 55-60.
Porcellio cubensis SAUSSURE, M6m. Soc. phys. Geneve, XIV, 1858, p. 477, pi. v,

fig. 35.
Porcellio sumichrosti SAUSSURE, Me"m. Soc. phys. Geneve, XIV, 1858, p. 478, pi. v,

fig. 36.

Porcellio cotillx SAUSSURE, M<jm. Soc. phys. Geneve, XIV, 1858, p. 478, pi. v, fig. 37.
Porcellio mexicanus SAUSSURE, Me"m. Soc. phys. Geneve, XIV, 1858, p. 479, pi. v,

figs. 39, 40.

Porcellio aztecus SAUSSURE, Mem. Soc. phys. Geneve, XIV, 1858, p. 479, pi. v, fig. 38.
Porcellio Isevis BUDDE-LUND, Nat. Tidsskrift., 3dser., VII, 1870, p. 236.
Porcellio aztecus MIERS, Proc. Zool. Soc. Lond., 1877, p. 669.
Porcellio Isnis BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 138-141 (see Budde-

Lund for further synonymy); Entom. Meddelel., IV, 1893-94, p. 118. — SARS,

Crust, of Norway, II, 1899, pp. 181-182, pi. LXXIX, fig. 2. — RICHARDSON,

Proc. U. S. Nat. Mus., XXI, 1899, pp. 862-863; Amer. Nat., XXXIV, 1900,

p. 304; Proc. U. S. Nat. Mus., XXI, 1901, pp. 566-569.

Localities. — Oakland, California; Cincinnati, Ohio; Raymond, Cal-
ifornia; San Francisco Bay, California; San Antonio, Texas; St.
Marys, Georgia; New Providence, Bahamas; Washington, District of
Columbia; Hamilton,. Bermudas; Coif ax, California; Las Cruces, New
Mexico; Unalaska; Key West, Florida; Monterey Bay, California;

vato. Pedum ultimi paris articulus basalis infra visus eadem latitudine ac longitudine,
supra convexus; appendix exterior subdepressa, lanceolata, margine interiore sub-
recto, exteriore curvato, latitudine maxima quartam longitudinis partem sequante;
appendix interior teres, exteriore tertia parte brevior.

Color dorsi ex rufo fusco-griseus, immixtis maculis pallidioribus oblongis irregu-
laribus numerosis, in duas series latas parvo intervallo distantes digestis. Cauda
plerumque unicolor segmento ultimo ad basin bi- (vel tri-) punctate.

Variat vitta longitudinali albo-grisea serieque macularum majorum ejusdem coloris
lateral!.

Longitudo 13 mm., latitude 6 mm.; longitudo antennarum exteriorum 6 mm. —
STUXBERO, 0fvers. Vet. Akad. Forh., 1875, No. 2, p. 57.

TSOPODS OF NORTH AMERICA.

615

Esenada, Lower California; Mesilla Park, New Mexico; Phoenix,
Arizona; Las Vegas, New Mexico; Cabanas, Cuba; warm spring, a
few miles west of Socorro, New Mexico; Azores; Galapagos Islands;
Alabaster Cave, Eldorado County, California; Alvarez, Mexico, at an
altitude of 8,000 feet; Oahu, Hawaiian Islands; Honolulu, Hawaiian
Islands; Caracas, Venezuela; world- wide in distribution.

This species is said to be injurious to various plants in Fort Worth,
Texas; found at roots of sugar beets; under stones; in cellars. It has
also been found dead near poisoned cotton, showing that it feeds on
the growing cotton plants.

Body oblong-ovate, almost twice as long as wide, 8 mm. : 15 mm.

FIG. 666.— PORCELLIO L.EVIS (AFTER SARS). d, SECOND ANTENNA, b, UROPOD. C, ADULT MALE.

d, LAST TWO SEGMENTS OF ABDOMEN AMD UROPODS. e, SEVENTH LEG. /, FLAGELLUM. g, FIRST

PLEOPODS OF MALE.

Head wider than long, 2 mm. : 3£ mm., with the anterior margin
produced in three lobes, the median lobe being triangulate, the lateral
lobes rounded and larger than the median lobe. The eyes are small,
composite, and situated at the base of the antero-lateral lobes. The
first pair of antennae are small and inconspicuous, and are composed
of two articles. The second pair of antennee have the first article
short; the second article is one and a half times longer than the first;
the third is as long as the second; the fourth is nearly twice as long as
the third; the fifth is one and a half times as long as the fourth. The
flagellum is composed of two articles, the first of which is a little longer

616 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

than the second. The second pair of antennae extend to the middle of
the third thoracic segment.

The segments of the thorax are subequal, the first one having the
autero-lateral angles produced so as to surround the head and extend-
ing as far as the base of the antero-lateral lobes. The epimera are
perfectly united with the segments.

All six segments of the abdomen are distinct, the first two having
the lateral parts concealed by the seventh thoracic segment. The
lateral parts of the third, fourth, and fifth segments are produced to
continue the oval outline of the body. The sixth, or terminal, seg-
ment is 2£ mm. wide at the base, is triangulate, with apex produced
in a long, narrow process. The sixth segment is 2 mm. long from
the base to the extremity. There is a shallow groove extending the
length of the produced apex of the terminal segment. The basal
article or peduncle of the uropoda -extends to the tip of the posterior
angles of the lateral parts of the fifth abdominal segment. The inner
branch is li mm. long, and is partly concealed dorsally by the apical
process of the terminal abdominal segment, but extends half its length
beyond this process. The outer branch is 2£ mm. long, and extends
almost its entire length beyond the extremity of the terminal abdomi-
nal segment.

The legs are all ambulatory in character and spinulose.

In color it is a dark gray, with two longitudinal bands of a lighter
color in wavy stripes, one on either side of the median line.

PORCELLIO PARVICORNIS Richardson.

Porcellio panicornis RICHARDSON, Trans. Conn. Acad. Sciences,
XI, 1902, p. 302, pi. XL, fig. 57.

Locality. — Bermudas.

Body ovate, surface marked with minute granula-
tions. Color yellow, with markings of light brown.

Head with median lobe small, widely rounded.
Lateral lobes small, rounded. Eyes distinct, and situ-
ated on the lateral lobes of the head. Exterior an-
tennae short, about one-third the length of the bodv;

FIG. 667.— PORCEL- . . J '

LIO PABVICOBNIS. flagellum two-jointed, first joint very much shorter
than second joint, about one-third shorter.

Thoracic segments subequal, with the exception of the first, which
is a little longer than any of the others.

First two abdominal segments with lateral parts hidden by the
preceding thoracic segment. Three following segments with lateral
parts expanded, the margins continuing the oval outline of the body.
Terminal segment triangular, with sides somewhat incurved and
rounded at the apex. Basal joint of uropoda reaching a little more
than half the length of the last abdominal segment. Inner branch

ISOPODS OF NORTH AMERICA. 617

extends a short distance beyond the terminal segment of the body;
outer branch extends but very little beyond the inner branch.

One specimen was collected by Prof. A. E. Verrill at the Bermudas
in 1901.

Type specimen in Peabody Museum, Yale University. Cat. No.
3353.

PORCELLIO RATHKEI Brandt.

Porcellio rathkei BRANDT, Bull, de la soc. Imp. d. Naturalistes de Moscou, VI,

1833, p. 15.— MILNE EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 170.
Porcellio ferrugineus BRANDT, Bull, de la soc. Imp. d. Naturalistes de Moscou, VI,

1833, p. 16.— MILNE EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 170.
Porcellio trilineatus KOCH, Deutschl. Crust., 1835-1844, p. 34.
Porcellio trivittatus LEREBOULLET, Me'm. de la Soc. de museum nat. de Strasbourg,

IV, 1853, p. 54, pi. i, figs. 13, 14; pi. HI, figs. 66-70.

Porcellio tetramoerus SCHNITZLER, De Oniscineis agri. Bonnensis, 1853, p. 24.
Porcellio striatus SCHNITZLER, De Oniscineis agri. Bonneneis, 1853, p. 24.
Porcellio trilineatus SILL, Verhandl. u. Mittheilungen des Siebenbiirgischen

Vereins fur Naturwissenschaften zu Hermannstadt, XIII, 1862, p. 26.
Porcellio trivittatus Jonysoy, Academisk Afhandling, TJpsala, 1858, p. 25.
Porcellio trilineatus BUDDE-LUND, Nat. Tidsskr. (3), VII, 1870, p. 239.— STUX-

BERG, Ofvers. af Kgl. Vetenskaps Akad. Forh., 1875, p. 59.
Porcellio rathkei BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 85-87. (See

Budde-Lund for synonymy). — SARS, Crust, of Norway, II, 1899, pp. 180-181,

pi. LXXIX, fig. 1. — RICHARDSON, Amer. Nat., XXXIV, 1900, p. 304; Proc.

U. S. Nat. Mus., XXIII, 1900, p. 567.— PAULMIER, Bull. New York State

Museum, 1905, pp. 182-183.

Localities. — Springfield, Ohio; Lockland, Ohio; Columbus, Ohio;
Clifton, Cincinnati, Ohio; Chaumont, New York; Syracuse, New
York; St. Marys, Georgia; Salem and Beverly, Massachusetts; Lake
Champlain; New York City; Lawrence, Massachusetts; Washington,
District of Columbia; Saginaw, Michigan; Freeport, Maine; Victoria,
Texas; Providence, Rhode Island; also Europe.

Found in woodsheds, greenhouses, on rotten logs, under brick and
boards, under logs, at river bottom.

Body oblong-ovate, a little more than twice as long as wide, 5 mm. :
10i mm.

Head about twice as wide as long, 1 mm. : 2 mm., with the anterior
margin produced in three lobes, the median one being less produced
than the lateral lobes and all having rounded extremities. The eyes
are small, composite, and situated at the base of the antero-lateral
lobes. The first pair of antennae are small and inconspicuous and are
composed of only two articles. The second pair of antennai have the
first article short; the second about one and a half times as long as the
first; the third equal in length to the second; the fourth twice as long
as the third; the fifth one and a half times as long as the fourth. The
flagellum is composed of two subequal articles. The second antennae
extend to the posterior margin of the third thoracic segment.

618

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The segments of the thorax are subequal in length. The first one
has the antero-lateral angles produced to surround the head, and they
extend almost to the base of the antero-lateral angles of the head.
The epimera are perfectly united with the segments. The lateral mar
gins are straight.
a

FIG. 668.— PORCELtlO RATHKEI (AFTER SARS). d, DORSAL VIEW OF MALE. b, DORSAL VIEW OF
FEMALE. C. FIRST ANTENNA. (/, SEVENTH LEG. €, MAXILLIPED. /, LAST SEGMENT OF ABDOMEN
AND UROPODA. g, FIRST PLEOPOD OF MALE, h, FLAGELLCM. i, UROPOD. j, SECOND ANTENNA.

All six segments of the abdomen are distinct, the first two having
the lateral parts covered by the seventh thoracic segment. The third,
fourth, and fifth segments have the lateral parts produced so as to con-
tinue the oval outline of the body. The sixth or terminal segment is
triangular with apex produced in a long, narrow process. The length
of the segment from the base to the extremity of the apex is equal to
its width at the base, 1 mm.: 1 mm. The peduncle or basal article of

I8OPODS OF NORTH AMERICA. 619

the uropoda extends almost to the extremity of the posterior angle of
the lateral part of the fifth abdominal segment, which is a little shorter
than the tip of the apical process of the sixth segment. The inner
branch is 1 mm. long and is partly concealed by the apical process of
the sixth abdominal segment; it extends to the middle of the outer
branch. The outer branch is 1 mm. long, and extends about two-
thirds of its length beyond the apical process of the sixth abdominal
segment.

All the legs are ambulatory in structure.

In color it is a dark brown with three longitudinal lines of light
yellow, one median and one on either side at the place of union of the
epimera with the segments. Between the median line of light yellow
and the lateral lines are wavy lines of light yellow on the brown color,
giving it a broken, mottled effect.

The surface of the body is covered with low granules.

PORCELLIO SPINICORNIS Say.

Porcellio spinicornis SAY, Jour. Ac. Nat. Sci. Phila., I, 1818, pp. 431, 432.
Porcellio pictus BRANDT and RATZEBURG, Med. Zool., II, 1830-1834, p. 78, pi. xn,

figs. 5, 5e, 5f.

Porcellio melanocephalus KOCH, Deutschl. Crust., 1835-1844, p. 28.
(?) Porcellio spinicornis DE KAY, Zool. New York, Pt. 6, 1844, p. 51.
Porcellio mixtus FITCH, Rep. noxious ins., 1856, p. 120.
Porceilio pictus KIN AH AN, Nat. Hist, rev., IV, 1857, p. 278. — BATE and WESTWOOD,

Brit. Sess. Crust., II, 1868, p. 480.— BUDDE-LUND, Nat. Tidsskr. (3), VII,

1870, p. 239; Crust. Isop. Terrestria, 1885, pp. 123-125.— G. O. SARS, Crust.

of Norway, II, 1899, pp. 177, 178, pi. LXXVIII, fig. 1. — STOLLER, 54th Report

New York State Museum, 1902, p. 213.

Localities. — North America, at New York; Niagara; Goshen, Con-
necticut; also Sweden; Denmark; Germany; Britain; France; Hun-
gary; Russia; coast of Norway.

Found in the crevices of rocks and on shady limestone ledges.
(STOLLER.)

Bodj^ nearly twice as long as wide, 7 mm. : 13 mm.

Head twice as wide as long, 1£ mm. :3 mm., with the front pro-
duced in three lobes, the antero-lateral lobes being large and
rounded, the median lobe wide but short and almost truncate on its
anterior margin. The eyes are small, oval, composite, and situated at
the base of the antero-lateral lobes. The first pair of antennas are
rudimentary and inconspicuous. The basal article of the second pair of
antennae is short; the second and third are subequal and each is twice
as long as the first; the fourth is one and a half times as long as the
third; the fifth is one and a half times longer than the fourth. The
flagellum is composed of two articles, the first of which is one and a
half times longer than the second. The second antennae extend to the
posterior margin of the third thoracic segment. The second article

620

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of the second antenna has the inner margin expanded into a spine-
like process, which is very conspicuous. The maxillipeds have a
palp of three articles. The palp of the mandibles is wanting.

FlG. 669.— PORCELLIO 8PINICORNIS (AFTER SARS). a, HEAD. 6, DoBSAL VIEW OF FEMALE. C, SEC-
OND ANTENNA, d, LAST TWO SEGMENTS OF ABDOMEN AND UROPODA. e, FIRST LEG OF FEMALE.
f, LAST SEGMENT OF ABDOMEN. g, FIRST PLEOPOD OF MALE. h, UROPOD. i, FLAGELLVM. j, SEV-
ENTH LEG OF FEMALE, k, SECOND PLEOPOD OF MALE. I, SEVENTH LEG OF MALE.

The first segment of the thorax is 2 mm. in length, a little longer
than any of the others, which are subequal and each is H mm. in
length. The epimera are not separated off from the segments.

ISOPODS OF NORTH AMERICA.

621

The abdomen is as wide as the thorax. The first two segments have
the lateral parts covered by the last thoracic segment. The sixth or
terminal segment is triangular, with apex produced to a long, narrow
process rounded at the extremity. The terminal segment is 2 mm.
wide at the base and 1£ mm. long. The peduncle of the uropoda

FlG. 670. — PORCELLIO SPINICORNIS. a, MAXILLIPED. X 33. 6, SECOND MAXILLA. X 33. C, FIRST MAX-
ILLA (OUTER LOBE), d, MANDIBLE. X 33. €, SECOND ANTENNA.

extends almost to the extremity of the terminal segment of the body.
The inner branch extends a very short distance beyond the terminal
abdominal segment. The outer branch is about twice as long as the
peduncle. The whole surface of the body is closely covered with
small tubercles.

All the legs are ambulatory.

PORCELLIO SCABER Latreille.

Porcellio scaber LATREILLE, Hist. Crust. Ins., VII, 1804, p. 45; Gen. Crust., I,

1806, p. 70.— LEACH, Edinb. EncycL, VII, 1814, p. 406.— Risso, Crust, de

Nice, 1816, p. 155.
Oniscus granulatus LAMARCK, Hist. Nat. des animaux sans vertebres, V, 1818, p.

154.

Porcellio nigra SAY, Journ. Phil. Acad. Nat. Sci., I, 1818, p. 432.
Porcellio granulatus BREBISSON, Mem. Soc. Calv., 1825, p. 261.
Porcellio scaber DESMAREST, Consid. Crust., 1825, p. 321. — BRANDT and RATZE-

BURG, Med. Zool., II, 1830-1834, p. 77, pi. xn, figs. 1-4 and A-B.— BRANDT,

Bull. Soc. Imp. de. Naturalistes de Moscou, VI, 1833, p. 14.
Porcellio brandtii MILNE EDWARDS, Hist. Nat. des. Crust., Ill, 1840, p. 168.
Porcellio granulatus MILNE EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 169, pi.

xxxn, fig. 21.

Porcellio scaber MILNE EDWARDS, Cuvier Rg. An., 1849, pi. LXXI-LXXI bis.
Porcellio nigra GOULD, Rep. Invert. Mass., 1841, p. 337.
Porcellio scaber KOCH, Deutschlands Crust., 1835-1844, p. 34.
Porcellio dubim KOCH, Deutschlands Crust., 1835-1844, p. 34.
Porcellio scaber LEREBOULLET, Mem. Strasb., IV, 1853, p. 34, pi. i, figs. 4, 5; pi.

n, figs. 43-47.
Porcellio gemmulatus DANA, Crust. U. S. Expl. Exp., XIV, 1853, p. 725, pi. XLVII,

fig. 7.— STIMPSON, Bost. Journ. Nat. Hist., VI, 1850-1857, p. 506.
PhUoscia tuberculata STIMPSON, Proc. Cal. Acad. Sci., I, p. 1856, p. 97.

622 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

PorceUio montezumx SAUSSCRE, M6m. Soc. Phys. Hist. Nat. Geneve, XIV, 1858,
Pt. 2, p. 480, pi. v, figs. 41-41 bis.

Porcd-lio scaber BATE and WESTWOOD, Brit. Sess.-eyed, Crust., II, 1868, p. 475.

PorceUio paulense s HELLER, Novara Exp., 1868, p. 136, pi. xn, fig. 5.

PorceUio scaber PLATEAU, Bull. Acad. r. Belgique, 2d ser., XXIX, 1870, No. 2, p.
8.— E. BRANDT, Horse Soc. Ent. Rossi, VIII, 1870, p. 167.— BUDDE-LUND,
Nat. Tidsskrift., 3d ser., VII, 1870, p. 238; Crust. Isop. Terrestria, 1885, pp.
129-131. — SARS, Crustacea of Norway. II, 1899, pp. 176-177, pi. LXXVII. —
RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 863; Amer. Nat., XXXIV,
1900, p. 3Q4; Proc. U. S. Nat. Mus., XXIII, 1901, p. 567.— CHTLTON, Trans.
Linn. Soc. Lond., (2), VIII, 1901, Pt. 4, p. 139.— STOLLER, 54th Report New
York State Museum, 1902, p. 213. — PAULMIER, Bull. New York State Museum,
1905, p. 183.

Localities. — Comax, British Columbia, near Union Wharf, along the
shore; Taylor Bay, Gabriola Island, British Columbia, on the shore;
San Diego. California; Puget Sound; Oakland, California; Norwood,
Ohio; Westwood, Cincinnati, Ohio; Andersons Ferry, Hamilton
County, Ohio; Springfield, Ohio; Bering Island; Woods Hole, Mas-
sachusetts; Colfax, California; Ocean Grove, New Jersey; Westfield,
New York; Magdalen Islands; Victoria, Vancouver Island; Salem,
Massachusetts; Northfield, Cook County, Illinois; Beverly, Massa-
chusetts; Hamilton and Warwick, Massachusetts; Crescent City, Cali-
fornia; Gulf of Georgia; Britainlsland, Nova Scotia; Penikese Island,
Massachusetts; Key West, Florida; San Mateo, California; the Ber-
mudas; New York City; West Haven, Connecticut; Bloomington, Illi-
nois; Lawrence, Massachusetts; Woodside, Maryland; Grand Menan,
New Brunswick; Saginaw, Michigan; Lagonistas Creek, California;
Lake Maxinkuckee, Indiana; Freeport, Maine; Greenland; Newfound-
land; New York; Niagara, New York; San Francisco, California; San
Pedro, California; St. Paul Island; St. Croix; Ascension Island; Kam-
chatka; Iceland; Hawaii; Cape of Good Hope; all Europe; distribu-
tion world-wide.

Found under dead leaves and stumps, under brick and boards; along
the shore; in greenhouses.

Body ovate, not capable of being rolled up into a ball, and less than
twice as long as wide, 6 mm. : 10 mm.

Head twice as wide as long, 2 mm. : 1 mm., with the anterior mar-
gin produced in three lobes, one median and two lateral lobes. The
median lobe is triangular, with apex obtuse; the lateral lobes are
rounded and large and extend as far as the median lobe. The eyes
are small, round, and composite, and are situated at the base of the
antero-lateral expansions. The first pair of antennas are rudimentary
and inconspicuous and are composed of three articles. The second pair
of antennas have the basal article short; the second is about one and a
half times as long as the first; the third is as long as the second; the
fourth is nearly twice as long as the third; the fifth is nearly twice as

I8OPODS OF NORTH AMERICA.

623

long as the fourth. The flagellum is composed of two unequal arti-
cles, the first one being the shorter. The second antennae extend to
the middle of the third thoracic segment. The maxillipeds have a palp
of three articles. The palp of the mandibles is wanting.

The segments of the thorax are subequal. There is no indication
of epimera on any of the segments.

FIG. 671.— PORCELLIO SCABER (AFTER SARS). a, MANDIBLES. 6, 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, MAX-
ILLIPEDS. m, HEAD, n, FIRST PLEO POD OF FEMALE, o, SECOND PLEOPODS OF MALE, p, Var. MAR-

MORATA (DORSAL VIEW OF FEMALE), q, FIRST PLEOPODS OF MALE, r, THIRD PLEOPOD OF MALE.

s, ABDOMEN (VENTRAL VIEW).

The abdomen is as wide as the thorax. The first two segments are
covered at the sides by the lateral parts of the seventh thoracic seg-
ment. The sixth or terminal segment is 1£ mm. wide at the base. It
is triangularly produced to a long, narrow extremity, which is posteri-
orly rounded. The terminal segment is 1 mm. long. The uropoda
are longer than the terminal segment. The outer branch extends £

624 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

mm. beyond the extremity of the abdomen. The inner branch just
reaches the tip of the last segment of the body.

All the legs are ambulatory.

The whole surface of the body is covered with small tubercles.

Color, generally a uniform gray black, sometimes lighter, varie-
gated with irregular dark spots, occasionally black, with the lateral
parts of the segments light yellow, forming a marginal border.

HO. Genus LEPTOTRICHUS Budde-Lund.«

Body rather convex, scarcely contractile, generally setigerous.

Second pair of antennae short, the first four articles of the peduncle
subequal in length; flagellum composed of two articles, of which the
first is much shorter than the second.

Front of head without a margin, produced in the middle with the
epistome bulbous; antero-lateral processes obtuse. Vertical marginal
line posteriorly wanting. Eyes small.

Lateral parts of thoracic segments not expanded.

Terminal segment of abdomen general!}7 triangular; epimera of the
third, fourth, and fifth segments moderately large.

First and second pairs of pleopoda furnished with tracheae.

LEPTOTRICHUS GRANULATUS Richardson.

Leptotrichus granulatus RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p.
303, pi. XL, fig. 58.

Locality. — Found in dead coral at Castle Harbor, Bermudas.

Body roughly and minutely granulated. Color
light reddish or yellowish brown, with markings of
dark brown in patches on each segment, forming
four longitudinal rows, the two median rows not
extending anteriorly beyond the third segment of
the thorax in one specimen, and in the other being
almost obsolete.

The head is produced in front in a prominent
rounded median lobe, and at the sides in large rounded
lateral lobes. The eyes are small, but distinct, and
are placed at the base of the lateral lobes. The ex-
ternal antennae are very short, not reaching the
anterior angle of the first thoracic segment. The
FIG. 672.-LEPTOTRJ- fourth joint of the peduncle is not longer than the
CHUS GRANULATUS. third ; the flagellum is composed of two joints, the
first of which is about half the length of the second.
The thoracic segments are subequal in length, the lateral parts
broadly expanded.

«See Budde-Lund for characters of genus, Crust. Isop. Terrestria, 1885, pp. 192-193.

ISOPODS OF NORTH AMERICA. 625

The first two abdominal segments have the lateral parts undeveloped.
The third, fourth, and fifth segments are broadly expanded laterally,
the outer margins forming a continuous and unbroken line with the
margins of the thoracic segments. The terminal segment of the abdo-
men extends but a distance of half its length beyond the lateral parts
of the preceding segment; its surface is smooth. The basal joint of the
uropoda attains half the length of the terminal segment. The inner
branch reaches the apex of the last segment. The outer branch extends
half its length beyond this.

Two specimens were collected by Prof. A. E. Verrill and party at the
Bermudas in 1898. They were found in dead coral at Castle Harbor.

Type in Peabody Museum, Yale University. Cat. No. 3333.

This species can not be identified with any of the described species
of the genus: L. panzerii (Audouin and Savigny), L, tauricus Budde-
Lund, L. squamatm Budde-Lund, and L.a lentus (Budde-Lund),
although it seems more closely related to the last named than to any
of the former.

111. Genus METOPONORTHUS Budde-Lund.&

Body oblong, depressed, not convex, scarcely contractile.

Head marginate and with lateral lobes very small; frontal lobe want-
ing; vertical marginal line extending to the lateral lobes; second pair
of antennae long; flagellum composed of two articles, the first article
generally longer than the second; abdomen abruptly narrower than
the thorax, with the lateral parts of the third, fourth, and fifth seg-
ments small, appressed; terminal segment short, triangular, extending
moderately beyond the lateral parts of the preceding segment; oper-
cular plates of the first two pairs of pleopods furnished with tracheae,
rarely those of the third or of all the pairs furnished with tracheae.
Inner branch of the uropoda inserted far in front of outer branch,
near the inner antero-lateral angle of the peduncle.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS METOPONORTHUS. c

a. Lateral parts of the third, fourth, and fifth segments of the abdomen well

developed Metoponorthus saussurei Dollfus.

a'. Lateral parts of the third, fourth, and fifth segments of the thorax reduced, small.
b. Epistome furnished with a sinuated transverse line.

o. Second pair of antenme equal to three-fifths the length of the body. First
article of the flagellum much longer than the second. Inner face of right
mandible furnished with four to five penicils, of the left with six penicils.
Terminal segment of abdomen almost flat. Color brown or reddish brown,
often mottled with white spots Metoponorthus pruinosus (Brandt) .

« See Dollfus, Mem. Soc. Zool. de France, 1896, pp. 542-543.

&For characters of genus see Budde-Lund, Crustacea Isopoda Terrestria, 1885, pp.
161-162, and Sars, Crust, of Norway, II, 1899, pp. 183-184.

cThis key has been prepared entirely from the descriptions of the forms, which
give few characters for a synoptical arrangement.
28589—05 40

626

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

'•'. Second pair of antenme a little longer than half the length of the body.
First article of the flagellurn a little longer than the second. Inner face of
the mandibles with three to four penicils. Terminal segment of abdomen
a little excavate above. Color yellow or brown or dark, almost black, with
obscure or yellowish spots arranged in from four to six longitudinal series,
the first two lateral Metoponorthus sexfasciatus ( Koch )

. Epistome smooth Wetoponorthm virgatus Budde-Lund.

METOPONORTHUS SAUSSUREI Dollfus.

Metoponorthita saussurei DOLLFUS, Bull. Soc. Zool. France, XXI, 1896, p. 48.

Locality. — Cordova, Mexico.

Body oval, elongated, feebly and irregularly
granulated; each segment of the abdomen has
a posterior depression and the first segments
are furnished on each side with a little pearl-
like granulation.

Head(?) Thorax: The first segment has the
posterior margin almost straight and not sinu-
ated. Abdomen a little narrower; the lateral
processes of the third to the fifth abdominal
segments are well developed d"nd a little di-
vergent. Terminal segment triangular, with
the sides incurved and obtuse at the apex.
Uropoda with the basal segment reaching
the apex of the terminal abdominal segment;
inner and outer branches very much elon-
gated, the former being linear, the latter lan-
ceolate. Color, browrnish with light wavy
spots; there are three little light spots at the
base of the terminal segment. Dimensions:
Length, 10 mm.(?) Width, 3£ mm.a

«The above description is adapted from the following one by Dollfus:
Corps ovale, allonge, faiblement et irregulierement granule; chaque segment du
pleon pr£sente une depression posterieure et les premiers segments sont munis de
chaque cot£ d'une petite granulation perliforme. Cephalon? Pereion=le premier
segment a le bord posterieur presque droit et non sinueux. Pleon peu retreci; les
processus lateraux des segments 3 a 5 du pleon sont bien developpes et un peu diver-
gents. Pleotelson triangulaire, a cotes incurves et A. sommet obtus. Uropodes a base
atteignant le sommet du pleotelson; endopodites et exopodites tres allonges, les pre-
miers lineaires et les seconds lanceoles. Couleur=brunatre avec des marbrures et
taches claires; trois petites laches claires Jt la base du pleotelson. Dimension=
longueur 10 millimetres? Largeur, 3 millimetres £. — DOLLFUS, Bull. Soc. Zool. France,
XXI, 1896, p. 48.

FIG. 673. — METOPONORTHUS
SAUSSUREI (AFTER DOLL-
FUS). O, FIRST SEGMENT OF

THORAX, b, SEVENTH THO-
RACIC SEGMENT, ABDOMEN,
AND UROPODA.

ISOPODS OF NOETH AMEKICA.

627

METOPONORTHUS PRUINOSUS (Brandt).

Porcellio pruinosus BRANDT, Bull, de la Soc. Imp. d. Naturalistes de Moscou, VI,

1833, p. 19.

Porcellio tnmcatus M. EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 171.
Porcellio maculicornis KOCH, Deutschl. Crust., 1835-44, p. 34.

FIG. 674.— METOPONORTHUS PRUINOSUS (AFTER SARS). a, FIRST MAXILLA. 6, MAXILLIPED. c,
MANDIBLES, d, SECOND ANTENNA, e, ANTERIOR LIP. /, DORSAL VIEW OF MALE, g, FIRST ANTENNA.
h, FLAGELLUM. i, FIRST PLEOPOD OF MALE. .;', 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 PLEOPODS OF FEMALE. S, ABDOMEN WITH UROPODA.

Porcellio frontalis LERKBOULLET, Mem. Soc. Hist. Nat. Strasbourg, 1853, p. 63,

pi. i, fig. 17; pi. in, figs. 81-87.

Porcellio zealandicus WHITE, List Crust. Brit. Mus., 1847, p. 99.
Porcellionides flavo-vittatus MIERS, Proc. Zool. Soc. Lond., 1877, p. 669, pi. LXV'III,

fig. 4.
(?) Porcellio jelskii MIERS, Proc. Zool. Soc. Lond., 1877, p. 668, pi. LXVIII, fig. 3.

628 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Meloponorthw pruinosus BUDOE-LUND, Crust. Isop. Terrestria, 1885, pp. 169-171.
(SeeBudde-Lund for synonymy. ) — DOLLFUS, Bull. Soc. Zool. France, XVIII,
1893, p. 187.— BUDDE-LUND, Entom. Meddelel, IV, 1893-94, p. 118.— SAKS.
Crust. Norway, II, 1899, pp. 184-185, pi. LXXX, fig. 2. — RICHARDS* »x, Amer.
Nat., XXXIV, 1900, p. 303; Proc. U. S. Nat. Mus., XXIII, 1901, p. 569.—
CHILTON, Trans. Linn. Soc. Lond. (2), VIII, 1901, p. 141.— STOLLER, 54th
Report New York State Museum, 1902, p. 213. — PAULMIER, Bull. New York
State Museum, 1905, pp. 183-184.

Localities. — Columbus, Cincinnati, Andersons Ferry, Hamilton
County, Ohio; Marion Center, Kansas; Oakland, California; Spring-
field. Ohio; Washington City; Provo, Utah: Las Vegas, Mesilla Park,
New Mexico; Burlington, Ohio; Smiths Island, Virginia; Woodside,
Maryland; Texas; Miami, Key West, Florida; Beverly and Salem,
Massachusetts; San Antonio, Dallas, Texas; St. Thomas, West Indies;
Hamilton Island, Bermudas; Mangrove Bay, Andros Island, Bahamas;
also Europe; North Africa; Caracas, La Moka, and Merida, Vene-
zuela; Praslin, etc. Found under logs; in greenhouses, dwellings, and
on country roads; along walls and under deca37ing vegetable matter.

Body oblong-ovate, twice as long as wide, 4£ mm. : 9 mm. Abdo-
men abruptly narrower than thorax.

Head twice as wide as long, 1 mm.: 2 mm., with the anterior mar-
gin slightly convex; antero-lateral lobes small. The eyes are small,
composite, and situated at the base of the antero-lateral lobes. The first
pair of antennae are small and inconspicuous. The second pair have
the first article short; the second is twice as long as the first; the third
is equal in length to the second; the fourth is twice as long as the third;
the fifth is one and a half times as long as the fourth. The flagellum
is composed of two articles, the first of which is twice as long as the
second, and both taken together are almost equal in length to the fifth
article of the peduncle. The second antennae extend~to the posterior
margin of the fourth thoracic segment.

The first segment of the thorax is perhaps a little longer than any
of the others, which are subequal. The antero-lateral angles of the
first segment are produced forward to surround the head, and they
extend to the base of the antero-lateral lobes of the head. The epiniera
are not distinctly separated from the segments.

The abdomen is abruptly narrower than the thorax. All six seg-
ments are distinct. The first two have the lateral parts covered by
the seventh thoracic segment. The third, fourth, and fifth segments
have the lateral parts small, not greatly expanded. The sixth or ter-
minal segment is triangular in shape. It is 1 mm. wide at the base and
is hardly more than £ mm. long. The apex is acute, and there is a
slight concavity in its dorsal surface. The basal article or peduncle of
the uropoda is not longer than the apex of the terminal abdominal
segment. The outer branch is 1£ mm. long and extends its entire
length beyond the apex of the terminal abdominal segment. The inner
branch extends about one-third the length of the outer branch.

All the legs are ambulatory in character.

ISOFODS OF NORTH AMERICA. 629

The surface of the body is slightly granulated. In color the pos-
terior and lateral margins are a uniform reddish brown. The other
parts are a lighter color, formed of reddish brown with wavy lines of
a light yellow on either side of the median line.

METOPONORTHUS SEXFASCIATUS (Koch).

fPorcellio sexfasciatus KOCH, System der Myriapoden mit den Verzeichnissen und
Berichtigungen zu Deutschlands Crustaceen, etc., 1847, p. 208, pi. vm, fig. 99.

Metoponorthus sexfaciatus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 167-168. —
DOLLFUS, Bull. Soc. d'Etudes Scientiflques de Paris, 12th year, 1890, p.
4. — RICHARDSON, Trans. Conn. Acad. Sciences, XI, 1902, p. 302.

Localities. — Bermudas (Dollfus); also Mediterranean and Canaries,
Madeira, Azores, Spain, France, and Algeria.

Body oblong or oblong-ovate, slightly convex, finely but manifestly
covered with transverse series of granules. The segments of the
thorax each with a raised transverse line.

Inner face of the mandibles with three or four plumose processes.
The second pair of antennae are a little longer than half the length of
the body; the fourth and fifth articles are sulcate; the first article of the
flagellum is a little longer than the other. The antero-lateral lobes of the
head are bent downward, very small, subrectangular; the median lobe
is wanting, the frontal margin straight in the middle or a little produced;
the transverse line of the epistome is acutely sinuated in the middle,
terminating on both sides far from the frontal margin. The abdomen
is less abruptly narrower than the thorax; the terminal segment is
short, subtriangular, with the sides incurved, the apex acute and a lit-
tle excavate above; the outer branches of the uropoda rather long.

Color yellow or brown, or dark black, covered with obscure or yel-
low spots in from four to six longitudinal series, the first two series
being lateral. The epistome is black. The epimera of the thoracic
segments have a minute shining tubercle. The ventral side and the
legs are yellow; the coxae are spotted with black. Length 10-12 mm.
Width 3, 5 mm. to 4, 5 mm. Height 1, 8 mm. to 2 mm. a

«The above description is adapted from the following one of Budde-Lund's:

Oblongus vel oblonge ovatus, leviter convexus, tenuiter et sparse sed manifesto
transverse subseriatim granulatus. Trunci annuli linea elevata transversa.

Mala interior mandibularum penicillis 3-4.

Antennae exteriores corporig diniidio paulo longiores; articuli 4-5 sulcati; flagelli
articulus prior altero paulo longior.

Lobi frontales laterales deflexi, minimi, subrectanguli; lobus medius nullus,
linea marginalis medio recta vel paulum producta; epistomatis linea transversa
inedio acutius sinuata, utrinque procul a margine frontali desinens. Cauda trunco
minus abrupte angustior; annulus analis brevis, subtriangulus, lateribus incurvis,
apice acuto, supra paulum excavatus; rami exteriores pedum analium sat longi.

Color flavus vel brunneus, vel e nigro fuscus, maculis vel obscuris vel flavescen-
tibus in series longitudinales 4-6, imprimis duas laterales, digestis. Epistoma sub-
nigrum. Epimera trunci annulorum tuberculo perlucente minuto. Venter et pedes
flava; coxae nigromaculatae.

Longitude 10-12 mm., latitude 3, 5-4, 5 mm., altitude 1, 8-2 mm. — BUDDE-
LUND, Crust. Isop. Terrestria, 1885, pp. 167-168.

030 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

METOPONORTHUS VIRGATUS Budde-Lund.

Metoponorthus virgatus BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 182. — RICH-
ARDSON, American Naturalist, XXXIV, 1900, p. 303; Proc. U. S. Nat. Mus.,
XXIII, 1901, p. 569.

Localities. — Florida; Nova Aurelia.

Body oblong oval, convex, smooth or obscurely and finely granu-
lated and tuberculated.

Inner face of the right mandible furnished with four plumose
processes, of the left mandible with five.

Second pair of antennas equal to half the length of the body; the
first article of the flagellum is shorter than the second.

Antero-lateral lobes of the head small, rounded; median lobe very
small, widely rounded; epistome slightly convex, smooth. The termi-
nal abdominal segment is short, triangular, with the sides straight; it
is flat above, scarcely excavated.

Color grayish black; there are white tubercles in the middle of the
thorax and white spots arranged in three longitudinal lines.

The epimera of the thorax are furnished with a shining tubercle dis-
tant from the margin. The legs are spotted with black, thickest on
the coxae.

Length 9-10 mm. Width 4, 5-5 mm. Height 2-2, 2 mm.0

112. Genus RHYSCOTUS Budde-Lund.&

Body rather convex, very little or scarcely at all contractile.

Second pair of antennae long; flagellum composed of two articles,
the first article shorter than the second. Eyes moderately large.
Frontal marginal line bent downward before the eyes on either side,
coming in contact with the vertical marginal line back of the eyes,
passing through the pleurae of the head and surrounding the inconspic-

aThe above description is adapted from the following one of Budde-Lund's:
Oblonge ovalis, convexus, sublaevis vel obscure et tenuiter granulatus et tubercu-
latus.

Mala interior mandibulse dextrse penicillis 4, mandibulse sinistrse 5.

Antennae exteriores corpus dimidium sequantes; flagelli articulus prior altero
brevior.

Lobi fron tales laterales parvi, rotundati; lobus medius minimus, late rotundatus;
epistoma leviter convexum, laeve.

Caudse annulus analis brevis, triangulus, lateribus subrectis, supra planus, vix
excavatus.

Color ex griseo niger; in medio trunco tubercula alba et maculae albidse in lineas
tres longitudinales condensatoe. Trunci epimera tuberculo perlucente a margine
paulum distante munita. Pedes, maxima in coxis, nigromaculati.

Longitude 9-10 mm.; latitude 4, 5-5 mm. Altitude 2-2, 2 mm. — BUDDE-LUND,
Crust. Isop. Terrestria, 1885, p. 182.

6 See Budde-Lund for characters of genus, Crustacea Isopoda Terrestria, 1885, pp.
191-192.

ISOPOD8 OF NORTH AMERICA. 631

nous antero-lateral lobes. Epistome very bulbous, separated from
the front by a transverse groove.

Lateral parts of the thoracic segments small.

Abdomen abruptly narrower than thorax; terminal segment short,
triangular, extending much beyond the epimera of the preceding
segment.

First and second pairs of pleopods furnished with tracheae.

RHYSCOTUS TURGIFRONS (Budde-Lund).

Stmomacrus turgifrom BUDDE-LUND, Prosp. generum specierumque Crust. Isop.
Terrestrium, 1879, p. 5.

Rhijscotus turgifrons BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 192. — RICH-
ARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 569.

Locality. — St. Jean, West Indies.

Body oblong, posteriorly attenuated, rather convex, minutely and
densely punctuate and covered with scattered hairs. The inner face
of the mandibles is furnished with two plumose processes( $).

The second pair of antennae are longer than half the length of the
body; the first article of the flagellum is almost half as long as the
second.

The terminal abdominal segment is short, with the sides slightly
incurved, the apex obtuse; it is sulcate above. The uropoda are
rather long; the basal article is longer than the terminal segment of
the abdomen; the outer branch is conical; the inner branch is slender,
a little curved, with the apex furnished with hairs.

Color brownish black, lighter on the epimera; ventral side a dark
gray; legs dark. Length, 5 mm.; width, 2 mm.; height, 1.3 mm."

113. HYPERGNATHUS, new genus.

Head with antero-lateral lobes obsolete; front not margined but con-
tinuous with epistome. Flagellum of second pair of antennae composed
of two articles, the second one being much longer than the first.
Mandibles without molar expansion; recurved brush-like appendage
wanting. First maxillae with the inner lobe furnished with two plu-
mose processes at the tip; outer lobe furnished with numerous spines

«The above description is adapted from the following one of Budde-Lund's:

Oblongus, post attenuatus, convexiusculus, minute et dense punctatus, sparse
crinitus. Mala interior mandibularum penicillis binis(?).

Antennae exteriores corpore dimidio longiores, flagelli articulus prior altero fere
duplo brevior.

Caudse annulus analis brevis, lateribus leviter incurvis, apice obtuso, supra sul-
catus. Pedes anales longiusculi; articulus basalis annulo anali sublongior; ratnus
exterior terminalis conicus; ramus interior tenuis, paululum curvatus, apice setaceo.

Color e nigro brunneus, in epimeris dilutior; venter e fusco griseus; pedes fusci.

Longitude, 5 mm.; latitude, 2 mm.; altitude, 1.3 mm. — BUDDE-LUND, Crust. Isop.
Terrestria, 1885, p. 192.

632

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

at the tip. Second maxillae more than twice as large as first maxillae,
not bilobed at the tip, the small inner lobe being indicated near the
distal end of the inner margin of the larger outer lobe. Maxillipeds
with palp reduced; masticatory lobe not developed.

Sixth segment of abdomen triangularly produced at the apex; first
and second segments not covered laterall}7 by the last thoracic segment.
Inner branch of the uropoda is inserted at the
inner distal angle of the peduncle.

HYPERGNATHUS TEXENSIS, new species.

Body oblong-ovate, more than twice as long as
wide, 2£ mm. : 6 mm. Surface perfectly smooth.
Head a little wider than long, 1 mm. : H mm.,
with the front not margined, straight, contin-
uous between the eyes with the epistome, which
is strongly arched, and gives the appearance of
a median lobe. There are no lateral lobes. The
lateral angles are rounded. The eyes are small,
round, composite, and situated at the sides of the
head close to the lateral margins. The first pair
of antennae are small and inconspicuous. The
second pair have the first three articles short
and subequal; the fourth is about one and a half
times longer than the third; the fifth is twice as

long as the third. The flagellum is composed of two unequal articles,

the second one being three times as long as the first.
The seven segments of the thorax are about equal in length; the

FIG.

675. — HYPERGNATHUS
TEXENSIS.

FIG. 676. — HYPERGNATHUS TEXENSIS. a, MAXILLIPEDS. x 41. 6, SECOND MAXILLA, x 77J. c, FIRST
MAXILLA, x 77i. d, MANDIBLE, x 77J.

first one has the antero-lateral angles slightly produced forward and
rounded; the last three have the post-lateral angles posteriorly pro-
duced, becoming gradually more acutely produced. The epirnera are
united with the segments.

ISOPODS OF NORTH AMERICA.

FIG. 677. — HYPER-
GNATHUS TEX-
EXSIS. UROPOD.
x51|.

The five anterior segments of the abdomen are subequal in length,
the first two not being covered at the sides by the seventh thoracic
segment. The sixth or terminal segment is posteriorly
produced to a triangular extremity. The uropoda
extend some distance beyond the terminal segment of
the body. The peduncle extends beyond the terminal
abdominal segment. The outer branch is twice as long
as the peduncle. The inner branch is placed at the
inner distal angle of the peduncle and is less than half
the length of the outer branch.

The color is a light yellow, with irregular markings
of brown on the posterior margins of the segments and
on the lateral parts. The head is thickly covered with
brown markings, which on the produced portion are
arranged in definite transverse lines, but on the remain-
ing surface are arranged irregularly around small,
rounded, yellow areas. The abdomen is very closely
covered with the brown as is also the posterior half of the outer uropod.

Types, Cat. No. 32075 U.S.N.M., collected by H. S. Barber in Texas.

114. Genus ACTONISCUS Harger.

Head produced in three lobes, a median lobe and an antero-lateral
lobe on either side. Second pair of antennae with the flagellum com-
posed of four articles. First maxillae with inner lobe furnished at
the tip with two bunches of hairs; outer lobe furnished with numer-
ous spines. Second maxillae small, not larger than first maxillae,
with no indication of lobes at the tip. Masticatory lobe of maxilli-
peds truncate at the tip; palp with joints indistinctly defined.

Abdomen not abruptly narrower than thorax; the first two segments
are covered laterally by the last thoracic segment; lateral parts of the
third, fourth, and fifth segments well developed; terminal segment
with apex not produced.

Basal article of the uropoda large, dilated, and simulating the epim-
era of the fifth abdominal segment; both branches of the uropoda
short, styliform, the outer one inserted about the middle of the inner
margin of the peduncle.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ACTONISCUS.

a. Middle frontal lobe of head acute; antero-lateral lobes rounded. Second and third
articles of flagellum of second antennae equal and longest. Terminal segment
of abdomen broadly rounded. Surface of body smooth. Fifth article of the
peduncle of the second antennae longer than the fourth; terminal article of
flagellum minute. Post-lateral angles of the first thoracic segment not produced.

Actoniscus ellipticus Harger

c\

~

634

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

a'. Middle and antero-lateral lobes of head truncate. Second article of flagellum
of second antenme longest. Terminal segment of abdomen triangulate. Body
covered with low tubercles. Fourth and fifth articles of the peduncle of the
'antenna; subequal; terminal article of flagellum not minute, but as long as pre-
ceding one. Post-lateral angles of the first thoracic segment produced.

Actoniscus lindahli, new species

ACTONISCUS ELLIPTICUS Harger.

Actoniscus ellipticus HARGER, Am. Jour. Sci. (3), XV, 1878, p. 373; Proc. U. S.
Nat. Mus., II, 1879, p. 159; Report U. S. Commissioner of Fish and Fish-
eries, 1880, Pt. 6, pp. 309-310, pi. i, fig. 3.

Armadilloniscus ellipticus BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 239.

Actoniscus ellipticus UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 360.—
RICHARDSON, American Naturalist, XXXIV, 1900, p. 307; Proc. U. S. Nat.
Mus., XXIII, 1901, p. 576; Trans. Conn. Acad. Sci., XI, 1902, p. 305.

Localities. — Savin Rock, near New Haven, Connecticut; Stony
Creek, Long Island Sound; Bermudas; Hungry Bay, Bermudas.

"The body is oval in outline. The
head appears triangular, as seen from
above, and is angularly produced in a
median lobe, but the lateral lobes are also
large and divergent and broadly rounded.
The eyes are small, oval, black, and
prominent. They are situated at the
sides of the median triangular part of
the head, and at the base of the lateral
lobes. The antermulae are minute and
rudimentarj7. The antennae have the
basal segment short; the second enlarged
distally, especially on the inner side; the
third forming an angle with the second
and clavate; the fourth flattened-cylin-
drical, longer than the third; fifth long-
est, slender, bent at base and forming an
angle with the fourth; flagellum shorter
than the last peduncular segment, tipped with setae and composed of
four segments, of which the second and third are equal and longer
than the first, while the last is the shortest and presents indications of
another minute rudimentary terminal segment. The maxillipeds have
the basal segment nearly twice as long as broad; the terminal segment
elongate triangular, ciliated, and somewhat lobed near the tip.

"The first thoracic segment is excavated in front for the head,
admitting it about to the eyes. The next five segments are each a
little longer than the first, but the last thoracic segment is the shortest.
The first segment is dilated at the sides to about twice its length on
the median line. The second and, in an increasing degree, the suc-
ceeding segments are produced backward at the sides. The legs are
rather small and weak and of nearly equal size throughout.

FIG. 678. — ACTONISCUS ELLIPTICUS
(AFTER HARGER). x 10.

ISOPODS OF NORTH AMERICA. 635

'•' The first two segments of the pleon have their lateral processes,
or coxae, obsolete, as usual in the family, but the third, fourth, and
fifth segments are produced laterally into broad plates, which are close
together and at their extremities continue the regular oval outline of
the body with scarcely a perceptible break between the thorax and the
pleon. This outline is further continued by the expanded basal seg-
ment of the uropods, which are even larger than the adjacent coxae of
the fifth segment. At the extremity of the pleon both pairs of rami
are visible, the inner springing from near the base of the basal seg-
ments below, the outer from a notch near the middle of the inner
margin of the basal segment. The rami are tipped with setae, and the
inner just surpass the outer, which in turn surpass the produced por-
tion of the basal segments.

"Length, 4 mm.; breadth, 2 mm. ; color in life, slaty gray."-
OSCAR HARGER."

ACTONISCUS LINDAHLI, new species.

Body oblong-oval, a little more than twice as long as wide, 2 mm. : 4i
mm. Surface of body distinctly covered with low tubercles.

Head with the anterior margin produced in three long lobes, the
median one having the dorsal surface concave and being produced as
far as the lateral lobes. All three lobes have the anterior extremities
truncate. The eyes are small, composite, and placed at the base of
the lateral lobes. The first pair of antennae are small and inconspicu-
ous. The second pair have the first article short; the second is about
twice as long as the first; the third is equal in length to the second;
the fourth and fifth are subequal and each is about one and a half times
longer than the third. The nagellum is composed of four articles, of
which the second is the longest.

The segments of the thorax are subequal. The post-lateral angles
of the first segment are produced backward in acute processes. The
antero-lateral angles of this segment are also somewhat produced to
surround the head. The epimera are not distinctly separated on any
of the segments.

All six segments of the abdomen are distinct. The first two have
the lateral parts covered by the seventh thoracic segment. The lateral
parts of the third, fourth, and fifth segments are expanded so as to
continue the oval outline of the body. The sixth or terminal segment
is triangular in shape, with apex acute. The basal article or peduncle
of the uropoda is large and expanded and simulates the lateral parts
of the fifth abdominal segment. The outer branch is inserted at the
inner margin of the basal article about halfway between the base and
the extremit}7; it does not extend beyond the posterior margin of
the basal article. The inner branch is inserted at the upper inner

"Report U. S. Fish Comm., 1880, Pt. 6, pp. 309-310.

<)3f> BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

angle of the basal article on the underside; it is about twice as long as

the outer branch, but does not extend beyond the extremity of the

outer branch.

The legs are all similar in structure and ambulatory.

In color it is a reddish brown with wavy lines
of a light yellow on either side of the median line.
About ten specimens were collected in Oak-
land, California, by Prof. Josua Lindahl.

This species is very similar to the type and
only described species of the genus, Actoniscus
ellipticus Harger, but differs in having the sur-
face of the body covered with low tubercles;
in having the three lobes of the head anteriorly
truncate, while in A. ellipticus the median one
is acutely pointed, the lateral ones rounded; in
having the fourth and fifth articles of the
peduncle of the antenna? subequal, and the sec-
ond article of the flagellum longest, the-termirial
article not minute, but as long as the preceding

FIG. 679.-ACTONISCUS LIN- Qne. in navjng tne post-lateral single*^ the

first thoracic segment produced in actftK^proc-
esses, and in having the sixth or terminal segment of the abdomen
triangular rather than rounded.

This species is named in honor of Prof. Josua Lindahl, from whom
the specimens were received.

FIG. 680.— ACTONISCUS LINDAHLI. a, MAXILLIPED. X 62. 6, FIRST MAXILLA. X 62. C, SECOND MAX-
ILLA, x 62. d, MANDIBLE, x 62. e, MANDIBLE, x 62.

The types are in the museum of the Cincinnati Society of Natural
History. Cat. No. 16365.

115. Genus ACANTHONISCUS (White) Kinahan.

" Body somewhat globose; head rounded; no true median or lateral
lobes; a pair of small spurious lateral lobes beneath orbits, arising
from production of antennary ring; external antennae (?); internal
antennae three-jointed.

" Cephalothorax : coxae well marked. Abdomen: coxae of first and
second somite obsolete; third to fifth narrow.

ISOPODS OF NORTH AMERICA. 637

"Telson: coxse obsolete; posterior pleopoda (false feet) nearly
uncovered; peduncle (basis) somewhat triangular, broad; accessory
lobe badly marked; accessory appendage inserted nearly on same line
with ischium, flattened, rounded at the extremity; ischium long, sub-
ulate. Species, A. spiniger." — KINAHAN."

ACANTHONISCUS SPINIGER White.

Acanthoniscus spiniger WHITE, List. Crust. Brit. Museum, 1847, p. 99. — GOSSE, A
Naturalist's Sojourn in Jamaica, 1851, p. 65. — KINAHAN, Proc. Dublin Uni-
versity, I, 1859, p. 197, pi. xix, fig. 4. — BUDDE-LUND, Crust. Isop. Terrestria,
1885, pp. 241-242.— RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 569.

Locality. — Jamaica.

"Body covered over with long spines arranged in a double longi-
tudinal row, one spine to each ring. In cephalothorax a second row
of shorter spines (two to each ring) on each side at junction of coxae
and body.

"Head covered with coarse knobs; two minute spines behind; a
raised emarginate ridge marks out front.

"Coxae of first cephalothoracic somite
expanded into a circular lobe; coxae of sec-
ond to sixth somite narrow; seventh some- ,
what quadrilateral.

" Abdominal somites: coxae, first and sec-
ond, obsolete; third, fourth, and fifth, nar-
row, curved, triangular.

' k Telson cordato - pandurif orm : apex FIG- 68i. -ACANTHONISCUS SPINIGEK

, ,11., -A' , ' (AFTER KINAHAN). a, TERMINAL

deeply notched, its extremities triangular, SEGMENT OF ABDOMEN. &.UROPOD.

produced, acuminate; sides of telson deeply

incurved at base and then broadly convex. Posterior pleopods: acces-
sory filament somewhat flattened; rounded at the extremity, about
half length of ischium, and arising from a point distant from apex
about a third of total length of peduncle. Ischium long and subulate.
Peduncle prolonged as a spine external to origin of ischium. Color:
deep chocolate brown black, with lighter patches.

"Locality: Jamaica.

"The specimen in the British Museum, the only one I have seen,
wants the external antenna; but from the fragments of those that
remain, and other characters, an affinity can be traced between this
genus and the Porcellionidae. See Remarks on Deto, infra.

" The form of the telson is unique; the posterior pleopods show an
approximation to Deto; but in the absence of the antennae it is impos-
sible to speak positively." — KINAHAN. a

a Proc. Dublin University, I, 1859, p. 197.

638 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Family XXVI. ARMADILLIDID^.«

Body convex, contractile into a perfect ball.

Pleural parts of the head fused.

Front of head truncate, marginate; an tero- lateral lobes distinct;
median lobe wanting; epistome vertical; clypeus perpendicular.

First pair of antennae small, inconspicuous; flagellum composed of
two or three articles. Second pair of antennae generally short, distant;
antennal foramina small.

Abdomen not abruptly narrower than thorax; terminal segment
short and broad.

Opercular plates of the first two pairs of pleopoda or of all five
pairs provided with tracheae.

Uropoda short, flattened, not extending beyond the extremity of the
terminal abdominal segment or the lateral parts of theprecedingsegment.

The young, when hatched, have all seven segments of the thorax
present.

Mouth parts as in the Oniscidae. Legs comparatively short.

ANALYTICAL KEY TO THE GENERA OF ARMADILLIDID.&.

a. Outer branch of the uropoda very small or minute. Basal joint large.
b. Flagellum of external antennae with two or three joints.
c. Flagellum with two joints.

d. Last abdominal segment subtetragonal, base wider than apex, more or less
contracted in the middle. External branch of the uropoda inserted in the
middle of the internal lateral margin of the basal joint. Coxopodites of
first and usually of the second segments distinct from the segments

(underside) Genus Oubaris Brandt.

d'. Last abdominal segment trapezoidal or subcordiform, narrower at its
truncate apex. External branch of the uropoda inserted in the inner
post-lateral angle of the basal joint. Coxopodites of the first and second

segments distinct (underside) Genus Pseudarmadillo Saussure.

c' . Flagellum with three joints. Coxopodites of the first segment usually distinct
on the underside. Terminal segment of body very short, rounded or pos-
teriorly triangular. External branch of the uropoda inserted in the inner
post-lateral angle of the quadrangular basal joint, and extending down-
ward. Inner branch reaches much beyond the terminal segment of the

body Genus Sphseroniscus Gersteecker.

b'. Flagellum of external antennae with a single joint only. Coxopodite distinct on
the first segment (underside). External branch of the uropoda inserted at

inner post-lateral angle of the basal joint Genus Haplarmadillo Dollfus.

a'. Outer branch of the uropoda large, flattened, lamellar, inserted at the apex of the

basal joint.

b. Terminal abdominal segment triangular in shape. Inner branch of uropoda
conical. All seven pairs of legs present. Seventh thoracic segment with

lateral parts well developed Genus Armadillidium Brandt.

b'. Terminal abdominal segment quadrangular in shape. Inner branch of the
uropoda flattened, rounded. Only six pairs of legs present. Lateral parts of
seventh segment of thorax not developed Genus Uropodias Richardson.

«See Budde-Lund for characters of family, Crust. Isop. Terrestria, 1885, pp. 14-15,
and G. O. Sars, Crust, of Norway, II, 1899, pp. 187-188.

I8OPODS OF NOKTH AMERICA. 639

116. Genus CUBARIS Brandt.

First pair of antennae very small, inconspicuous, composed of three
articles. Second pair of antennae short, generally not longer than
one-third the length of the body; flagellum composed of two articles.

Eyes composite, small or moderately large. Clypeus very short, with
the anterior margin entire, lobate at the sides. Epistome flat, form-
ing a continuously straight frontal marginal line. The vertical mar-
ginal line reaches the frontal line.

First thoracic segment with the epimera posteriorly cleft, often
also the second; rarely entire. Terminal abdominal segment tetrag-
onal, wider at the base than at the apex, more or less contracted in
the middle.

Outer branch of all the pleopoda furnished with trachese. Uropoda
short, not extending beyond the terminal abdominal segment. Basal
article or peduncle large, wide, entire, tetragonal, obliquely produced;
outer branch very small, rather slender, inserted at the middle of the
inner lateral margin of the basal article; inner branch small, rather
slender or rather compressed."

ANALYTICAL KEY & TO THE SPECIES OF THE GENUS CUBARIS.

a. Body tuberculate.

b. Second thoracic segment without a distinct coxopodite.

c. Coxopodite of the first thoracic segment hardly perceptible as a very small
process below the leg. Prosepistoma of head with a shield-like convexity.
Apex of telson half as wide as basis. Endopodite of the uropoda extends

one-half the length of the telson Cubans tenuipunctata (Dollfus)

cf . Coxopodite of the first thoracic segment hardly perceptible, only a feeble
ridge. Prosepistoma of head nearly flat. Apex of telson one-third nar-
rower than basis. Endopodite of the uropoda extends two-thirds the

length of the telson Cubans depressa ( Dollfus)

V . Second thoracic segment with a distinct coxopodite (underside),
c. Coxopodite of the first thoracic segment distant from the edge, crested, and

ended by a tooth-like diverging process Cubans viticola (Dollfus)

</. Coxopodite of the first thoracic segment not distant from the edge and not

crested.
d. Coxopodite of the first thoracic segment distinct along the entire length of

the edge (underside).

e. Coxopodite of the first segment divergent on the half hind part. Cox-
opodite of the second segment forming a tooth-like diverging process.

Cubans silvarum (Dollfus)
e/. Coxopodite of the first segment not divergent. Coxopodite of the second

segment large, square-shaped Cubans perlata (Dollfus)

d'. Coxopodite of the first thoracic segment not distinct along the entire length

of the edge.

e. Coxopodite of the first segment small, dentiform, and very unequally
cleft Cubans murina Brandt

«See Budde-Lund for characters of genus, Crust. Isop. Terrestria, 1885, pp. 15-16.
6 Cubans calif oniica (Stuxberg) is not included in this key, as the description is not
sufficient in detail to obtain characters for synoptics! arrangement.

640

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

e' '. Coxopodite of the first segment not dentiform, subequally cleft.

Oubarix f'nicta (Dollfus)
a'. Body smooth.

b. Upper surface of terminal segment of body with a shallow depression on each

side, and a small median pit near the base Cubaris gigas Miers

b/. Upper surface of terminal segment of body without shallow depression on each

side, or median pit.
c. Inner posterior angle of basal article of uropoda widely excavated.

Cubaris affinis (Dana)
</. Inner posterior angle of basal article of uropoda not excavated.

d. Coxopodite distinct on the entire length of the lateral edge of the first tho-
racic segment ( underside) Cubaris zigzag ( Dollfus)

d' '. Coxopodite not distinct on the entire length of the lateral edge of the first

thoracic segment.
e. Second thoracic segment with a large square coxopodite, distinct on its

total length (underside) Cubaris dumorum (Dollfus)

ef. Second thoracic segment with the coxopodite very small.
/. Coxopodite of second thoracic segment forming a tooth-like process.
g. Inner branch of uropoda about half the length of the terminal abdomi-
nal segment. Terminal abdominal segment with a blunt double

tubercle near the base Cubarw grenadensis ( Budde-Lund)

g' '. Inner branch of uropoda extends about one-third the length of the
terminal abdominal segment. Terminal abdominal segment without

double tubercle near the base Cubaris dugesi (Dollfus)

//. Coxopodite of second thoracic segment not tooth-like.

Cubaris pisum (Budde-Lund)

CUBARIS TENUIPUNCTATA (Dollfus).

Armadillo tenuipunctatus DOLLFUS, Proc. Zool. Soc. London, 1896, p. 389.
Cubaris tenuipunctatus RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 571.

c o

e n

FIG. 682.— CUBARIS TENUIPUXCTATA (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF
THORAX (UPPER SIDE). 6, HEAD AXD FIRST TWO SEGMENTS OF THORAX (UNDERSIDE), c, FIFTH AND

SIXTH SEGMENTS OF ABDOMEN AND UROPODA (UPPER SIDE). (I, THE SAME (UNDERSIDE).

ISOPODS OF NORTH AMEEICA.

641

Locality. — Mustique Island, West Indies. "Beaten from brush."
" Body rather wide, moderately convex, slightly tuberculated on
the pereion. Cephalon: prosepistoma with a shield-like convexity, a
little depressed in the middle. Eyes middling; ocelli about 18.
Antennae short; tirst joint of flagellum twice as short as the second.
Pereion: first segment with two antero-median rounded tubercles;
lateral edges slightly raised; coxopodite hardly perceptible, as a very
small process below the leg. Second segment without a distinct cox-
opodite. Pleon, telson: pleotelson longer than wide, smooth, with a
minute longitudinal wrinkle near the basis; sides feebly curved, the
apex being half as wide as the basis. Uropoda: basis nearty straight;
endopodite extending to half the length of the pleotelson; exopodite
very small, placed near the middle of the internal edge of the basis
(upperside). Color: gray, with irregular light markings; the sides
are light and minutely punctuated with black. Dimensions: 10 by ±%
mm . " — DOLLFUS. a

CUBARIS DEPRESSA (Dollfus).

Armadillo depressus DOLLFUS, Proc. Zool. Soc. London, 1896, p. 390.
Cubaris depresses RICHARDSON, Proc. U. S. Nat. Mus., XXIII. 1901, p. 571.

Localities. — St. Vincent, Chateau belais, West Indies.

FIG. 683. — CUBARIS DEPRESSA (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 (UNDERSIDE).

" Body wide, rather depressed, granulated on cephalon and pereion.
Cephalon: prosepistoma nearly plain, fore edge a little arched in the

«Proc. Zool. Sot:. London, 1896, p. 389.

28589—05

-H

642

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

middle. Eyes middling; ocelli about 16. Antenna?: first joint of
flagellum three times shorter than the second. Pereion: first segment
with a wide, double, antero-median tubercle; lateral edges not raised;
coxopodite hardly perceptible, as a feeble ridge. Second segment
without a distinct coxopodite. Pleon, telson: sides of the pleon
depressed; processus of the fifth segment widening at the apex. Pleo-
telson longer than wide, smooth; sides feebly curved; apex one-third
narrower than the basis. Uropoda nearly straight; endopodite extend-
ing to two-thirds the length of the pleotelson; exopodite very small,
placed near the middle of the internal edge of the basis (upperside).
Color: dark gray, with a narrow light longitudinal line in the middle
of the pereion and light lineolre on both sides. Dimensions: 9 by 4£
mm." — DOLLFI 8.

CUBARIS VITICOLA (Dollfus).

Armadillo citicola DOLLFUS, Proc. Zool. Soc. London, 1896, pp. 396-397.
Cubaris riticola RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 571.

Localities. — Grenada, Balthazar, Chantilly, West Indies. Second-
growth woods, beaten from vines and brush, 250 feet and 400 feet.

"Body very convex in the middle, rather depressed on the sides,
covered with transverse lines of granulations. Cephalon: prosepis-

FIG. 684. — CUBARIS VITICOLA (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THORAX
(UPPER SIDE). 6, THK SAME (UNDERSIDE), c, FIFTH AND SIXTH SEGMENTS OF ABDOMEN WITH
UROPODA (UPPER SIDE), d, THE SAME (UNDERSIDE).

toma plain, fore edge slightly arched in the middle. Eyes moderate;
ocelli 12. Antenna} short; first joint of the flagellum three times
shorter than the second. Pereion: first segment with four large
antero-median granulations; lateral edges hardly raised; coxopodite
distant from the edge, crested and ended by a tooth-like diverging

a Proc. Zool. Soc. London, 1896, p. 390,

ISOPOD8 OF NORTH AMERICA.

643

processus. Second segment with a narrow crested coxopodite. Pleon,
telson: lateral parts of the pleon narrow; pleotelson longer than wide;
sides slightly curved; apex one-half narrower than the basis, with
rounded angles. Uropoda: basis very oblique; endopodite reaching
to one-half the length of the pleotelson; exopodite a little larger than
in the former species (C. perlatux), visible on upper and under sides.
Color: yellowish, veined, and striped with brown. Dimensions: 9 by
± mm." — DoLLFUs.a

CUBARIS SILVARUM (Dollfus).

. I riiiadillo sileamm DOUBTS, Pror. Zool. Soc. London, 1896, pp. 398-394.
Cubaris silvarum RICHARDSON, Proc. U. 8. Nat. Mus., XXIII, 1901, p. 571.

Localities. — St. Vincent, Chateaubelais; Cumberland Valley, West
Indies. Very common under rubbish, forest below 2,000 feet (St.
Vincent). Forest, dry hillside under stones, 1,000 feet (Chateaube-
lais). Damp ground, 1,000 feet (Cumberland Valley).

FIG. 680. — ClTBARIS SILVARUM (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OK THORAX

(UPPER SIDE). 6, THE SAME (UNDERSIDE), c, FIFTH AND SIXTH SEGMENTS OF ABDOMEN AND

UROPODA (UPPER SIDE), rf, THE SAME (UNDERSIDE).

"Body convex, slightty tuberculated on the pereion. Cephalon:
prosepistoma plain. Eyes large; about 20 ocelli. Pereion: first seg-
ment with a blunt, hardly perceptible antero-median tubercle; lateral
edge forming a narrow, raised border; coxopodite distinct on the
entire length of the edge and divergent on the half hind part. Coxo-

«Proc. Zool. Soc. London, 1896, pp. 396-397,

644

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

podite of the second segment forming a tooth-like, divergent processus.
Pleon, telson: pleotelson wider than long, with a small, double, longi-
tudinal ridge near the basis; sides curved near the apex; apex one-
fourth narrower than the basis. Uropoda: endopodite extending to
one-half the length of the pleotelson; exopodite minute, placed near
the middle of the internal edge of the basis. Color: dark gray or
brown, with three longitudiual light lines and a wide spot on the sides
of each segment; antennae and uropoda pale. Dimensions: 16 by 7
mm." — DOLLFUS."

CUBARIS PERLATA (Dollfus).

Armadillo perlatitx DOLLFUS, Proc. Zoo I. Soc. London, 1896, pp. 395-396.
Cubans perlatus RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 571.

Locality. — St. Vincent, West Indies. Dry .forest, leeward, under a
log, 800 feet.

"Body convex, covered with large, pearled granulations. Cepha-
lon : prosepistoma with a shield-like convexity which does not reach
quite to the front edge. Eyes very small; ocelli 3. Antenna* short;

FlO. <W6.— CUBARIS PEKI.ATA (AKTKK Doi.LKUS). <(, HhAD AND FIRSt TWO SEGMENTS (IK TIHiUAX
(UPPER SIDE). t>, THE SAME (UNDERSIDE). C, FIFTH AND SIXTH SEGMENTS OF ABDOMEN (UPPER
SIDE). (I, THE SAME (UNDERSIDE).

first joint of the flagelluni three times as short as the second. Pereion:
first segment with two rounded antero-median granulations; lateral
edges raised; coxopodite distinct on the entire length of the edge, but
not divergent. Second segment with a large and very distinct coxo-
podite. Pleon, telson : pleotelson, nearly as wide as long, with two
large, rounded granulations near the basis; sides curved; apex a little
narrower than the basis. Uropoda: ondopodite reaching to two-

«Proc. Zool. Soc. London, 1896, pp. 393-394.

ISOPODS OF NORTH AMERICA.

645

FIG. 687. — CUBAKIS MURINA. a,

FIRST ANTENNA. X 77|. b, SEC-
OND ANTENNA. X 23.

(See Budde-Lund for syn-

thirds the length of t lie pleotelson; exopodite pnperceivable. Color:
light gray, granulations whitish. Dimensions: 44 by H mm."-
DOLLFIS."

CUBARIS MURINA Brandt.

' 'iilxiri* inurina BRANDT, Bull. Soc. Imp. d. Natural istes de Moscou, VI, 1833, p. 28.
Cnharis brunnea BRANDT, Bull. Soc. Imp. d. Naturalistes de Moscou, VI, 1833, p. 28.
Armadillo murinus MILNE EDWARDS, Hist. Nat. des Crust., Ill, 1840, p. 179.
Armadillo brurmeus MILNE EDWARDS, Hist. Nat.

des Crust,, III, 1840, p. 179.
Armadillo cubemds SArssrRE, Mem. de la Soc.

de Physique et d'Hist. nat de Geneve, XIV,

1858, Pt. 2, p. 65.
Cubans affinis MIERS, Proc. Zool. Soc., London,

1877, p. 666, pi. LXVIII, fig. 4.
Armadillo conglobator BUDDE-LUND, Prosp. gen-

erum specierumque Crust. Isop. Terrestrium,

1879, p. 7.
Armadillo murinus BUDDE-LUND, Prosp. generum

specierumque Crust. Isop. Terrestrium, 1879,

p. 7; Crust. Isop. Terrestria, 1885, pp. 27, 28.

onymy. )
Ci i barist murinus RICHARDSON, Proc. U. S. Nat, Mus., XXIII, 1901, p. 571.

Localities. — Pinar del Rio, Cuba; El
Guama, Cuba; Guanajay, Cuba; Pueblo
Viejo, Porto Rico; St. Thomas; Jamaica;
also, Oahu and Honolulu, Hawaiian Is-
lands; Brazil; Cayenne; Seychelle Islands;
Sumatra.

Found under stones; in damp caves.

Body ovate, very convex, and contrac-
tile into a ball, a little more than twice
as long as wide, 5 mm.: 11 mm.

Head three times as wide as long, 1 mm. :
3 mm., writh the anterior margin straight.
Eyes small, round, composite, and situ-
ated at the sides of the head, halfway be-
tween the anterior and the posterior mar-
gins. The first pair of antenna? are rudi-
mentary and inconspicuous. They are
composed of three articles. The second
pair of antennae have the first two articles
short and subequal; the third article is
about three times as long as the second;
the fourth and fifth are subequal and each
is a little shorter than the third; the sixth article is one and a half times

Fl(i. <>88.— Cl'BARIS MURINA (AFTER

MIERS"). a, HEAD AND FIRST THO-
RACIC SEGMENT. 6, LATEKA I, VIEW OF
BODY, r, ABDOMEN AND UROPODA.

« Proc. Zool. Soc. London, 1896, pp. 395-396.

646

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

longer than the fifth. The nagellum is composed of two articles, the
first of which is about half as long as the second. The second antenna1
extend to the middle of the first thoracic segment. The maxilliped has
a palp of three articles. The palp of the mandibles is wanting.

The first segment of the thorax is about one and a half times longer
than any of the others, which are subequal. The lateral parts of the
first segment are produced backward posteriorly, and anteriorly they

are produced surround-
ing the head and extend-
ing to its anterior mar-
gin. The lateral mar-
gins of the first segments
curve slightly upward.
There are no epimera
separated off on any of
the segments from
above. The epimera of
the first two segments
are distinct on the under-
side. They are very
small. Those of the first
segment do not extend
the entire length of the
segment, but are repre-
sented only at the pos-
terior extremitj^.

The abdomen is not
narrower than the tho-
rax. The lateral parts
of the first two segments
are covered by the
seventh thoracic seg-
ment. The sixth, or ter-
minal, segment is 2 mm.
wide at the base, becom-
ing constricted about the
middle, where it is 1 mm.
wide, and then expanding to a truncate extremity, which is 2 mm. wide.
The length of the terminal segment is H mm. The basal article or
peduncle of the uropoda is narrow and elongate, about twice as wide as
long, and fills the space between the lateral parts of the fifth abdominal
segment and the terminal abdominal segment. The outer branch is
extreme^ small, and is inserted on the inner margin of the peduncle,
about halfway between the anterior and posterior end. The inner

e f fi

Fl&. 689.— CUBARIS MURINA. a, MAXILLIPED. X 51|. b, SEC-
OND MAXILLA. X 51|. C, FIRST MAXILLA (OUTER LOBE). X

51|. d, TERMINAL SEGMENT WITH UROPODA. x 15}. e, MAN-
DIBLE, x 51}. /, FIRST MAXILLA (INNER LOBE), x 51}. r/,
UROPOD. x 27}. (FROM UNDERSIDE.)

isn PODS OF NORTH AMERICA.

Immch is not visible from the dorsal side. Underneath, on the ven-
tral side, it is small and elongated, extending only half the length of
the terminal segment.

CUBARIS CINCTA (Dollfus).

Armadillo cinctus DOLLFHS, Proc. Zool. Soc. London, 1896, p. 392.
Cubans rinctn* RICHARDSON, Proc. II. S. Nat. Mus., XXIII, 1901, p. 572.

Locality. — Near Layon, West Indies. On rotten wood, dry forest.

"Body moderately convex, rather wide, depressed on the fore and
hind parts of the segments, with a transverse range of tubercles on
each segment. Cephalon : prosepistoma nearly plain, fore edge straight.
Eyes middling; ocelli about 16. Antennae: first joint of the flagellum

FIG. 690.— CUBARIS CINCTA (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THORAX
(UPPER SIDE). 6, THE SAME (UNDERSIDE), c, FIFTH AXD SIXTH SEGMENTS OF ABDOMEX AND URO-

PODA (UPPER SIDE). (I, THE SAME (UNDERSIDE).

twice as short as the second. Pereion: first segment with a double
antero- median tubercle; lateral edges raised; coxopodite distinct and
divergent on the third hind part of the edge (underside). Coxopodite
of the second segment forming a narrow, quadrangular processus.
Pleon, telson: pleotelson as long as wide, with a triangular tubercle
near its basis; sides curved; apex one-fourth narrower than the basis.
Uropoda: basis nearly straight; endopodite very small, extending
hardly to one-sixth the length of the pleotelson; exopodite minute,
placed above the middle of the internal edge of the basis (upperside).
Color: dark gray, with small lighter lineolse on both sides of the median
line (pereion) and three light dots on the pleotelson. Dimensions:
Ti by 3imrn." — DOLLFUS."

« Proc. Zool. Soc. lA>nrlon, 1896, p. 392.

(US BULLETIN f>4, UNITED STATES NATIONAL MUSEUM.

CUBARIS GIGAS Miers.

Cubans ffigas MIERS, Proc. Zool. Sor. London, 1877, p. 666, pi. LXVIIT, fi«r. l.
Armadillo </i</ax Brm>K-Lr.\i>, Crust. Isop. Terrestria, 1885, p. 40.
Citbaris yigax RICHARDSON, .Proc. U. S. Nat, Mas., XXIII, 1901, p. 572.

Locality. -Nicaragua, near San Juan.

"Convex oblong-oval, nearly smooth, surface only venr minutely
granulated, and with only very obscure indications of larger tubercles
on each side of the middle line. Head transverse, with the anterior
margin straight, reflexed at a right angle (as seen in a lateral view)
with the upper surface of the head, and (as seen in a dorsal view) also
forming a right angle with the lateral margins; antero-lateral lobes
wanting. First segment of the body very concave on the sides, with

FIG. 691. — CUBARIS GIGAS (AFTER MIERS i. «. ABDOMEN WITH UROPODA' (UPPER SIDE). 1>, HEAD

(UNDERSIDE) SHOWING ANTENN.K. f. LATERAL VIEW. • 1J-. (/. HEAD AND FIRST TTORACIC SE(i-
MENT (UPPER SIDE). '

the lateral margins strongly reflexed; all the segments distinctly flexed
backward on the sides, with the posterior margins angulate-excavate.
Terminal segment of the tail about as broad as long, with the sides
excavated; upper surface flat, with a shallow depression on each side,
and a small median pit near the base. Antennae with the flagellum
much shorter than the last joint of the peduncle, writh the first joint
the shortest. Basal joint of the uropoda (viewed from above) oblong,
terminal (apparent lateral) joint quite minute. Colour light gray.
Length 10i lines." — MIERS/'

CUBARIS AFFINIS (Dana).

Rpherilloaffims'Dwx, Proc. Acad. Nat. Sri. Phila., VII, 1854-55, p. 176.— STIMP-

SON, Bost. Jour. Nat. Hist., VI, 1857, p. 505.

ArmculiUo affinis BuDDE-LrxD, Crust. Isop. Terres-tria, 1885, p. 39.
Oubaris affinis RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 865.

Locality. — California.

Body superficially smooth and uniform; antennae very finely rather
scabrous, the last two articles together (the sixth and seventh) scarcely

«Proc. Zool. Sor. London, 1877, p. 666.

ISOPODft OB' NORTH AMERICA.

649

shorter than the fifth. The last abdominal segment a little transverse,
constricted in the middle. The uropoda wide, not longer than the
width at the base, with the inner posterior angle widely excavated, the
anterior, posterior, and external sides almost straight and rectangular,
the inner anterior angle truncate, the outer anterior angle rounded,
posterior branch minute, scarcely projecting. Length, 4i lines."

CUBARIS ZIGZAG (Dollfus).

Armadillo zif/zny DOLLFITS, Proc. Zool. Soc. London, 1896, pp. 394-395.
Cuba-ris zigzag RICHARDSON-, Proc. U. S. Nat, Mus., XXIII, 1901, p. 572.

Locality. — St. Vincent, West Indies. Forest, damp ground under
rubbish, 1,000 feet.

"Bodjr convex, smooth. Cephalon: prosepistoma plain, fore edge
nearl}' straight. Eyes small; about 12 ocelli. Antennae short; first
joint of the flagellum twice as short as the second. Pereion: first
segment with a slightly perceptible antero-median tubercle; edges
hardly raised; coxopodite distinct on the entire length of the edge

FIG. 692. — CUBARIS ZIGZAG (AFTER DOLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THORAX
(UPPERSIDE). b, HEAD AND FIRST TWO SEGMENTS OF THORAX (UNDERSIDE), c, FIFTH AND SIXTH

SEGMENTS OF ABDOMEN AND UROPODA (UPPERSIDE). '/, THE SAME (UNDERSIDE).

(underside), not divergent. Coxopodite of the second segment nar-
rowly quadrangular. Pleon, telson: pleotelson as wide as long; sides
feebly curved; apex with rounded angles, half as wide as the basis.
Uropoda: basis oblique, endopodite reaching to one-half the length

«The above description is adapted from the following one of Dana's:
Corpus superficie keve et innotatum. Antennae subtilissime scabriculse, articulis
duobus ultimis conjunctis (6 to 7 moque) 5to parce brevioribus. Segmentum abdo-
mini& ultimum paulo transversum, medio constrictum. Styli caudales lati, latitudine
basali non longiores, angulo interno-postiore late excavato, lateribus antico postico
et externo fere rectis et inter sese rectangulatis, angulo interno-anteriore truncato,
externo-anteriore rotundato, raino posteriore minuto, parce exserto. — Long. 4J///. —
DANA, Proc. Acad. Nat. 8ci. Phila., VII, 1854-55, p. 176.

650

HULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of the pleotelson; exopoditc minute, placed near the middle of the
internal edge of the basis (upperside). Color: yellowish, with a
double median and crinkled lateral lines of dark brown; uropoda
pale. Dimensions: 4 by If mm." — DOLLFUS/'

CUBARIS DUMORUM (Dollfus).

Armadillo dumorum DOLLFUS, Proc. Zool. Soc. London, 1896, p. 391.
Culxtrix (himorum RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 572.

Locality. — Mustique Island, West Indies. Found by beating brush.

"Body very convex, nearly smooth. Cephalon: prosepistoma
nearly plain, fore edge straight. Eyes large; about 20 ocelli. Anten-
nae very short; first joint of flagellum twice as short as the second.
Pereion: first segment with a blunt antero-median tubercle; lateral

FIG. 693.— Cl'BARJSVlH'MORUM (AFTER DoLLFUS). a, HEAD AND FIRST TWO SEGMENTS OF THORAX

(UPPER SIDE)., b, THE SAME (UNDERSIDE), c, FIFTH AND SIXTH SEGMENTS OF ABDOMEN WITH

UROPODA (UPPER SIDE). (I, THE SAME (UNDERSIDE).

edges raised on the fore part; coxopodite separated by a cleft extend-
ing to the third hind part of the segment (underside). Second seg-
ment with a square coxopodite, distinct on its total length (underside).
Pleon, telson: pleotelson quite as long as wide; sides curved; apex
one-third narrower than the basis. Uropoda: basis wide, oblique;
endopodite extending to one-third the length of the pleotelson; exop-
odite very small, placed near the middle of the internal edge of the
basis (upperside). Color: dark gray or brown, with light dots and
lineolse on both sides of the median line (pereion). Dimensions: 8 by
3£ mm." — DOLLFUS. b

«Proc. Zool. Soc. London, 1896, pp. 394-395.
«• Idem, p. 391.

1SOPOD3 OF NORTH AMERICA.

651

CUBARIS GRENADENSIS ( Budde-Lund).

Armadillo greinnlt'tiaix I>rm>K-Luxi), Kntoinol. Moddelel., IV, 1893, p. 115. —

DOLLFUS, Proc. Zool. Soc. London, 1896, pp. 392-393.
Cubaris grenadervri.* RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 572.

.— Becquia Island; Grenada; Balthazar, West Indies.
Ravine, damp ground, under rotting- leaves; 250-feet cocoa orchard,
under rotting leaves.

"Body much convex, nearly smooth. Cephalon: prosepistoma
slightly convex, fore edge feebly arched in the middle. Eyes rather
large; ocelli about 16. Antenna' short; first joint of the flagellum

FIG. 694.— CUBARIS GRENADENSIS (AFTER DOLLFUS). a. HEAD AND FIRST TWO SEGMENTS OF THORAX

(UPPER SIDE), b, THE SAME (UNDERSIDE). C, FIFTH AND SIXTH SEGMENTS OF ABDOMEN AND URO-

PODA (UPPER SIDE), d, THE SAME (UNDERSIDE).

three times shorter than the second. Pereion : first segment with a
blunt antero-median tubercle; lateral edges raised; coxopodite distinct
and divergent on the half hind part of the edge (underside). Coxopo-
diteof the second segment forming a toothlikeprocessus. Pleon, telson:
pleotelson as wide as long, with a blunt double tubercle near its basis;
sides curved; apex nearly as wide as the basis; endopodite reaching to
two-thirds the length of the pleotelson; exopodite minute, placed near
the middle of the internal edge of the basis. Color: dark gra}T, with
a light median line and light lineolpe on the sides; antennae whitish.
Dimensions: 1-t by 6 mm." — DOLLFUS/'

«Proc. Zool. Soc. London, 1896, pp. 392-393.

(>52 BTLLETIN 54, UNITED STATES NATIONAL MUSEUM.

CUBARIS DUGESI (Dollfus).
(luges! POLLFPS, Bull. Soc. /<><>!. France, XXI, ISi»l>, p. 47.

. — Corritos and Morelia. Mexico.

Body narrow, convex, smooth, very finely punctate and setaceous.

Head: Prosepistome extending a little beyond the front, especially
on the two sides, surface flat; eyes small, about 14 ocelli; flagel-
luin of the antennae with the first article half as long as the sec-
ond. Thorax: lateral margin of the first segment elevated along its
entire length; antero-median mamelon scarcely visible; coxopodites

FIG. 695. — CUBARIS DUGESI (AFTER DOLLFUS). a, HEAD AND FIRST TWO THORACIC SEGMENTS
(DORSAL VIEW), b, HEAD WITH ANTENNA AND FIRST TWO SEGMENTS OF THORAX WITH COXOPO-
DITES (CO AND Co') (VENTRAL VIEW), f. FIFTH AND SIXTH ABDOMINAL SEGMENTS AND VROPODA
(DORSAL VIEW). (I, SIXTH ABDOMINAL SEGMENT AND UROPODA (VENTRAL VIEW).

distinct only on the posterior third part of the side of the segment,
but reaching to. the extremity of it. .Second segment with the coxopo-
dite very distinct. Pleo , telson: pleotelson as long as wide, with a
little relief, followed by an impression, situated near the base; the
lateral incurvation well indicated; the apex equal to about three-
fourths of the base in size. Uropoda with the basal article a little
oblique; the inner branches very small; the outer branches very small,
situated about two-thirds of the inner side of the base (superior side).
Color uniformly dark gray. Dimensions: Length 8 mm.; width
3i mm.«

«The above description is adapted from the following one of Dollfue's:
Corps etroit, convexe, lisse, tres fineuient ponctue-setace. Cephalon: prosepistome
depassant un pen le front, surtout des deux cotes, face plane; yeux petits, environ
14 ocelles; fouet des antennes a premier article deux fois plus court que le second.
Pereion: bord lateral du premier segment releve sur toute sa longueur; mamelon
antero-median d peine visible; coxopodites distincts settlement sur le tiers posterieur
du ccA)te du segment, mais atteignant a Pextremite de celui-ci. Deuxieme segment a
coxopodite tres distinct. Pleon, telson: pleotelson aussi long que large, avec un petit
relief suivi d'une impression, situe pres de la base; incurvation laterale bien indiquee;
le sommet egal en largeur environ les f de la base. Uropodes a article basilaire pen
oblique; endopodites tfes petits; exopodites minuscules, situes vers les f du cot6
interne de la base (face superieure). Couleur: gris fonce uniforme. Dimensions:
longueur, 8 millimetres; largeur, 3£ millimetres.— DOLLFFS, Bull. Soc. Zool. France.
XXI, 1896, p. 47.

ISOPODS OF NORTH AMERICA. 653

CUBARIS PISUM (Budde-Lund).

Armadillo pisum BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 32.
Cubaris pisum RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 572.

Locality. — Florida.

Body oval, very convex, smooth, shining.

Second pair of antenna a little shorter than half the length of the
bod}', slender; h'rst article of the flagellum one-third as long as the
second. Eyes moderately large, with about fifteen ocelli.

Clypeus with the lobes short and widely rounded; epistome with
the superior margin curved, hardly extending beyoiid the front of the
head; front and top of the head smooth.

The first segment of the thorax with the lateral margin with a high
crest, posteriorly less high and sub-equally cleft, the inner part being
a little smaller; the epimera of the second segment cleft, the inner
part the smallest. The posterior margins of the segments slightly
sinuated on both sides. The terminal segment of the abdomen is a little
wider than long, scarcely compressed in the middle, posteriorly trun-
cate, convex above. The basal article of the uropoda is longer than
wide, for a short time narrower at the apex; outer branch very small,
in the form of a little point, inserted near the apex; inner branch short.

Color, uniformly brown or reddish brown. Length, -i.5 to 5.5 mm.
Width, 2.5 to 3 mm.rt

CUBARIS CALIFORNICA (Budde-Lund).

Ariii<«li//u Kfii'dnxiiK STI-.\BER<J, 0fversigt af Yetensk. Akad. Forhamll., 1875, No.

2, p. 62.
Armadillo calif arnica BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 40.

rrtlifornini RICHARDSON, Pro*.:. U. S. Nat. Mus., XXI, 1«99, p. 865; Ann.

Mag. Nat. Hist. (7), IV, 1899, p. 333; American Naturalist, XXXIV, 1900,

p. 305.

"The above description is adapted from the following one of Budde-Lund's:

Ovalis, valde convexus, la-vis, glaber, subnitidus.

Antenn;i- exteriores dimidio corporis paulo breviores, gracilis; Hagelli articulus
prior altero triplo brevior.

Oculi mediocres; ocelli circiter 15.

Clypeus lobis brevibus, late rotundatis; epistoma margine stiperiore curvato,
frontem vix superante; frons et vertex Itevia.

Trunci annulus primus margine laterali altecincto, post minus profunde et sub-
sequaliter fisso, parte interiore paulo minore; epimera annuli secundi fissa, parte
interiore minima. Margo posterior annulorum leviter utrinque sinuatus.

Caudje annulus analis paulo latior (mam longior, medio vix coarctato, post recte
truncatus, supra convexus. Articulus basalis pedum analium paulo longior quam
latior, ad apicem paulisper angustatus; ramus exterior minutissimus, punctiforrnis,
apici proprius insertus; ramus interior brevis.

Color brunneus vel rufobrunneus, uniformis.

Longitudo 4.5-5.5 mm., latitudo 2.5-3 mm. — BUDDE-LUND, Crust. Isup. Terrestria,
1885, p. 32.

654 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Localities. — California at San Francisco and San Pedro.

Btidde-Lund suggests that this species may be identical with
ajfinix Dana.

Inasmuch as the specific name 8pedo9U8 is applied by Dana to another
species of Ciilxn-!*. Budde-Lund suggests for this form the specific
name California*.

Bod}' ovate, very convex, smooth and shining. Second antenna?
with the second article three times longer than the first, the fifth arti-
cle straight, cylindrical, very long; flagellum with tho articles unequal
in length, the first one one-fourth as long as the second. The first four
segments of the thorax with the posterior margin slightly sinuate on
both sides, the three last segments very slightly sinuate. The epirnera
are moderately large, with the anterior angles obliquely truncate, the
posterior angles of the first segment straight, roundly rectangular,
with the margin sulcate; those of the second, third, fourth, and fifth
segments gradually less widely rounded; those of the sixth and seventh
straight, rounded. The last segment of the abdomen by no means
equal in width to the length. Color of the dorsal surface gray, with
a median line and a lateral series of large light spots on the epimera of
the segments of the body. Head very thickly spotted with light spots.
Abdomen gray, with the third segment bipunctate. Length 5.5 mm.;
width 3 mm.a

117. Genus PSEUDARMADILLO Saussure.

Frontal margin of head produced in three processes, one median
and two lateral. Second pair of antennas with the flagellum composed
of two articles, the first one of which is much shorter than the second.
Coxopodites present on the under side of the first two segments of the
thorax. Terminal segment of the body triangular in shape, with the
apex produced in a truncate process. Basal article of uropoda large,
filling the space between the lateral parts of the fifth abdominal and
the terminal abdominal segments and continuing the oval outline of

"The above description is adapted from the folio-whig one of Stuxberg's:

Armadillo ovalis, valde convexus, leevis, subnitidus.

Antennse exteriores articulo secundo triplo longiore quam primo, qtiinto recto,
cylindrico, longissimo, flagelli articulis insequalibus, interiore quadruplo breviore
quam exteriore.

Trunci segmenta quattuor priora margine postico utrinque leviter, posteriora tria
levissime sinuata. Epimera mediocria, angulis anticis oblique truncatis, angulis
postids primi segment! subreHis, rotundate-rectanguli.s, margine sulcatis, secundi,
tertii, quarti, quinti minus minusque late rotundatis, sexti et septimi subrectis,
rotundatis.

Caudse segmentum ultimum latitudine minima longitudinem assequente.

Color dorsi griseus, linea mediana serieque macularum majorum laterali et epi-
meris segmentorum trunci pallidioribus. Caput creberrime palJide punctulatum.
Cauda grisea, segmento tertio bipunctato. Longitude 5.5 mm., latitude 3 mm. —
STUXBERG, 0fversigt af Vetensk. Akad. Forhandl., 1875, No. 2, p. 62.

I8OPODS OF NORTH AMERICA. 655

the body. The outer branch Is minute and is placed at the inner
posterior angle of the basal article. The inner branch is only visible
from a ventral view, and extends the length of the basal segment on
the under side, being attached to the upper inner angle.

The first two segments of the thorax have the epimera posteriorly
cleft.

ANALYTICAL KEY TO THE SPECIES OP THE GENUS P8EUDARMADILLO.

a. Thorax armed with two longitudinal rows of long spines. Fifth abdominal seg-
ment armed with a long stout spine Pseudarmadillo giUianus Richardson

a' '. Thorax not armed with two longitudinal rows of long stout spines. Fifth abdomi-
nal segment not armed with a long stout spine. •

b. Coxopodites of the first thoracic segment ending in a bifurcate process."* Two
tubercles present in longitudinal series in the median line on the sixth abdomi-
nal segment. Tubercle on the fifth thoracic segment largest.

Pseudarmadillo doll/mi, new species

V. Coxopodites of the first thoracic segment not ending in a bifurcate process.
One tubercle only present in the median line of the sixth abdominal segment.
Tubercle of the sixth abdominal segment largest.

Pseudarmadillo carinulatus Saussure «

PSEUDARMADILLO GILLIANUS Richardson.

Pseudarmadillo giUianus RICHARDSON, Proc. U. S. Nat. Mus., XXV, 1902, pp.
509-511..

Locality. — Isla de Pinos.

Bod}" strongly and thickly tuberculate. The thorax is armed with
two longitudinal rows of long stout spines, each row being halfway
between the median line and the lateral margin. On the seventh
thoracic segment, however, the spines are closer together and are
much longer. A long median spine is present on the fifth abdominal
segment.

The head has the anterior margin produced in three lobes, a median
lobe, which is broad and roundly truncate, and two lateral lobes,
broadly rounded. The posterior portion of the head bears four
prominent tubercles in a transverse series, the two outer ones being
much larger and stouter, with broad bases. The eyes are black and
distinct arid are situated post- laterally. The antennae reach the middle
of the first thoracic segment; the flagellum is two-jointed, the proximal
joint being three or four times shorter than the distal one.

The first thoracic segment is covered with small tubercles, except at
the sides. The posterior portion of the lateral part of the segment is
produced backward a little, the post-lateral anguiation being rounded.

« In redescribing Pseudarmadillo carinulatus Saussure, Budde-Lund says there is a
single median tubercle on the 4-5-6 abdominal segments, all large. He does not
mention the presence of one on the third abdominal segment, although Saussure says
there is one on each segment following the first two. In describing the epimeraiof
the first thoracic segment Budde-Lund does not say that they terminate on each side
in a bifurcate process.

656

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Tin1 lateral border is curved upward, forming a slight concavity. On
either side of the segment halfway between the median line and the
lateral margin, and on the posterior part of the segment, is a long
stout spine, directed backward. The coxopodites are distinct the
entire length of the first segment on the under side and each is in the
form of a ridge, ending in a bifurcate tooth-like process. The second
thoracic segment has the coxopodites of the
under side in the form of tooth-like processes.
The lateral spines of the second, third, fourth,
fifth, and sixth segments form two longitudinal
series, one on either side of the median line,
halfway between that and the lateral margin,
and in line with those of the first segment. The
spines of the seventh thoracic segment are, how-
ever, much closer together and are also much
longer. The seventh segment is produced back-
ward about the center, so that it is longer at
that point than at the sides. The lateral por-
tions of the second, third, fourth, and fifth
segments are drawn out in narrow rounded
processes, slightly curving upward at their
extremities. The sixth and seventh segments
have the lateral portions drawn out in processes
which are somewhat truncate at their extrem-
ities. All these segments are thickly tuberculate
except at the sides and on the anterior portion, where the segment
articulates with the one immediately anterior to it.

The first two segments of the abdomen are concealed by the last
thoracic segment. All the abdominal segments are tuberculate. One
tubercle in the median line of the third segment is somewhat enlarged
and more prominent than the others. One tubercle in the median line
of the fourth segment is slightly more enlarged
than the tubercle of the preceding segment. A
long stout spine directed backward is present on
the fifth abdominal segment in the median line.
At the base of the terminal segment is a large
prominent tubercle, very much larger than those
of the third and fourth abdominal segments.
The terminal segment is triangularly shaped, with the apex produced
in a truncate process. The basal segment of the uropoda, seen from
the dorsal side, is large, wider at the base than at the apex, filling
the space between the lateral process of the fifth abdominal and the
terminal abdominal segments, and continuing the oval outline of the
body. The outer branch is very small and is inserted at the posterior
angle of the basal joint. The basal joint, seen from the under side, la

FIG. 696.— PSETTDARMADILIX

HILUANUS. X 5.

FIG. 697.— PSEUDARMADILLO
GILUANUS. ABDOMEN.

X 5.

ISOPOD8 OF NORTH AMERICA. 657

very large, triangular in shape, the basal joint of either uropod meeting
in the median line at the upper inner angle. From this angle the inner
branches of the uropoda extend in the form of narrow elongate
processes, broader at the apex than at the base and not quite reaching
the posterior extremity of the terminal abdomi-
nal segment.

A single specimen, a female, was collected by
Messrs. Palmer and Riley in Nueva Geroua. Isla
de Pinos, Cuba, July 10, 1900.

Type. — Cat. No. 25694, U.S.N.M. FIG. 698.-psEroARMADiLLo

mi . . !•<!• f 1.1 • f GILLIAN US. LATERAL

This species differs from the type species of VIEW OF ABDOMEN x 5.
the genus, Pxeudarmadillo carinulatus Saussure,"

in the presence of two longitudinal rows of long stout spines on the
thorax, a row on either side of the median line halfway between
that and the lateral margin, while in the description of P. carinulatus

only two tubercles (not spines) are mentioned
as being present on the thorax, the last thoracic
segment alone being armed with two large tri-
angularly shaped (triquetres) tubercles; in the
absence of the longitudinal carina?, mentioned
FIG. 699.— PSEUDARMADILI.O on.- in the description of P. carinidatus as being

™TS™A™™ T9r present °n the iaterai parts °f the th°raci? se£-

ments and the third abdominal segment; in the

presence of a large spine on the fifth abdominal segment in the median
line, which is represented in P. carinulatus by a strong tubercle, and
in the presence of eyes, which are wholly wanting in P. cafnnulatus.b
Named for Dr. Theodore Gill, the eminent naturalist.

PSEUDARMADILLO DOLLFUSI, new species.

Body ovate, about twice as long as wide, 5 mm. : 10 mm.

Head two and a half times wider than long, 1 mm. : 2£ mm., with the
anterior margin produced into three lobes, one median lobe, which is
truncate and broad, and two smaller lateral lobes, which are rounded.
The eyes are small, round, composite, and distinct, and situated close
to the lateral margins. The head is covered with tubercles, of which
there is a prominent line on the posterior margin. The first pair of
antennae are inconspicuous; the second pair have the first article short,
the second twice as long as the first; the third and fourth are subequal
and each is a little shorter than the second; the fifth is nearly twice as
long as the fourth. The flagellum is composed of two articles, the first
of which is one-third as long as the second.

«Mem. de la Soc. de Physique et d'Histoire Naturelle de Geneve, XIV, 1858, p.
483-485, pi. v, fig. 4:1

&Budde-Lund says that PtetldarmadiUo nirhiiilatux lias eyes, and that Saussure was
in error when he described the species as being without eyes.
28589—05 42

658

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The tirst thoracic segment is nearly twice as long as the second, and
is densely and thickly covered with tubercles, except on the lateral
parts, which are produced backward in rounded expansions. The fol-
lowing five segments are subequal and densely covered with tubercles.
The seventh segment is a little longer than any of the preceding five
segments and has two tubercles, a little larger than any of the other
numerous tubercles on its surface, situated on the posterior margin,
one on either side of the median line. The coxopodites are not
evident from above on any of the segments. On the first two they
are present on the under side, being represented in the first seg-
ment by a longitudinal raised carina or ridge extending the full length
of the segment and terminating in a bifurcate process. On the second
segment the coxopodites are also in the form of raised carina? or

ridges extending the length of the segment.
In the second, third, and fourth segments
the lateral margins of the segments are drawn
out in narrow processes terminating laterally
in rounded extremities. The lateral margins
of the last three segments are straight.
There is one tubercle on either side of each
segment on the posterior margin about half-
way between the median line and the lateral
margin, which- is a little larger than any of
the others, those of the sixth segment being
most prominent. A faintly raised line crosses
transversely the lateral parts of all the seg-
ments, with the exception of the first, about
the middle.

The abdomen is composed of six segments,
the first two of which are smooth and short,
and covered laterally by the seventh thoracic
segment. The third, fourth, and fifth segments are subequal and are
covered with tubercles, on each of which is a larger and more con-
spicuous tubercle in the median line, the tubercles in the series increas-
ing in size from the first to the last, and compressed laterally, and in
a lateral view having the upper surface rounded. The terminal seg-
ment is triangular, with the apex produced in a truncate extremity.
There are numerous tubercles on its dorsal surface, one in the median
line being larger than the others; it is as large as the median tubercle
on the fourth segment. Posterior to it are two small tubercles, one
on either side of the median line. The peduncle of the uropoda is in
the form of a large plate, almost rectangular when seen from below, but
from a dorsal view being long and narrow and lying close to the ter-
minal abdominal segment and continuing the oval outline of the body.
It reaches almost to the extremity of the terminal abdominal segment.

FlG. 700. — PSEUDARMADILLO DOLL-

FVSI. X 7.

1SOPODS OF NORTH AMERICA.

659

The outer branch is minute and is placed at the inner post-lateral angle
of the peduncle. The inner branch can only be seen from the under
side, where it is inserted at the upper inner angle of the peduncle, and
extends the length of the peduncle, but does not quite reach the
extremity of the terminal abdominal segment.

Th ree specimens of this species were collected by the Bahama expe-
dition, August 1, 1904, at Mangrove Cay, Andros.

This species differs from /-*. carinulatus Saussure in having the

FIG. 701.— PSEl'DARMADILLO DOLLFUSI. a, SECOND MAXILLA. X 51|. 6, OUTER LAMELLA OF FIRST

MAXILLA, x 51|. c, INNER LAMELLA OF FIRST MAXILLA, x 51|. d, LATERAL VIEW OF ABDOMEN

AND LAST THORACIC SEGMENT. X 9f. 6, MAXILLIPED. X 27J. /, FIRST MAXILLA. 27£. g, MAN-
. DIBLE. X 27J.

epimera of the first thoracic segment ending in a bifurcate process,
in having in the median line on the terminal abdominal segment one
tubercle followed by two in a transverse series instead of one, in hav-
ing the tubercle on the fifth segment of the abdomen largest, and in
not having the tubercles of the seventh thoracic segment ""triquetres."

The types are in the Museum of Comparative Zoology at Harvard
University. Cat. No. 6731.

This species is named in honor of Prof. Adrien Dollfus, who has
done much work on the terrestrial isopods.

660 BULLETIN 54, UNITED STATES NATIONAL MUSEUM,

PSEUDARMADILLO CARINULATUS saussure.

]'x,'iitlariiM(lill<> c'lfiiinlutux S.vrssrHK, Revue et Ma^asin <U- Zoologie (2), IX,

1857, p. 308; Mem. tie la Soc. tie Physique et d'Hist. nut. <le Geneve, XIV,

1858, Pt. 2, ]). 483, pi. v, figs. 43-43a.— BuuuE-LuNi>, Crust. Isop. Terrestria,
1885, pp. 41-42.— RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, p. 572.

Locality. — Mexico or Cuba,

Body rugose, tuberculated; the last segment of the thorax strongly
tuberculated; abdomen ornamented with a median series of tubercles.
Inferior margin of the head forming three rounded lobes, project-
ing in front, the median one of which is the largest and a little more
in advance of the lateral ones, which are obliquely directed. The
uropods are rather deformed. Their second article, seen from below,
presents near the base a kind of transverse ridge; it becomes larger

toward the end and terminates in a large
border, the two extremities of which are
rounded instead of forming angles. The in-
ner margin of this article is thickened, in
such. a way as to offer a small surface some-
what excavated, and separated from the in-
ner surface by a prominent, distorted ridge.
At the base of this surface one sees a little
lamella attached to it, which is probably the
inner branch of the uropoda. Above, the
second article appears in the form of a band,
which is placed along the lateral margin of
the segment; this band is a little distorted
and elevated above, especially at its anterior
extremity, where it is also a little larger;
at its posterior extremity it forms an angle,
which is the inner angle of the margin of
the uropoda, to which is articulated the
third article, which is very small The last abdominal segment is in
the form of a truncated triangle, not extending beyond the extremity
of the uropoda, and which is separated from them a little; its lateral
margins are not straight, but a little sinuated. The body is very
rough, all covered with little tubercles, rugose. The head is bor-
dered anteriorly with a transverse elevation furnished with a line of
tubercles. The first thoracic segment is all covered with rugosities,
except at the sides, which are produced backward in the form of
a large rounded process, the inferior margin of which is elevated
in such a way as to. form a concave surface. The other segments are
entirely rugose, except on the anterior half, which is smooth for articu-
lation; their inferior extremities are produced backward in the form
of narrow processes, a little elevated, less rugose, and carrying above
a projecting longitudinal line, which is still to be seen on the third

PlG. 702. — PSEUDARMADILLO CARIN-
ULATUS (AFTER SAUSSURE). a,
HEAD AND FIRST SEGMENT OF
THORA\. b, ABDOMEN AND URO-
PODA. (ENLARGED.)

ISOPODS OF NORTH AMERICA. 661

abdominal segment. The last thoracic segment is armed above with
two large tubercles "triquetres." directed backward. The abdomen
is rugose and made in the form of a roof; the first two segments are
incompletely visible; the following ones are all armed in the middle
with a strong tubercle, the last of which, placed at the base of the
terminal segment, is the largest. Color, a uniform grayish-brown.
Length, 0.010 m.«

118. Genus SPH^ERONISCUS Gerstsecker.

First pair of antennre very small, inconspicuous, composed of three
articles. Second pair of antennae short; flagellum composed of three
articles.

Eyes .small, composite, composed of about ten ocelli. Clypeus
straight, not lobate. Epistome flat, forming a continuous frontal
marginal line. Vertical marginal line reaching the frontal margin.

First segment of the thorax usually with the epimera posteriorly cleft.

«The above description is adapted from the following one of Saussure's:
Rugosus, tuberculatus; Ihoracii segmentum ultimwn valde bituberculatum; abdomen
serie mediana tuberculorum ornatum.

Bord inferieur de la tete formant trois lobes arrondis, saillants en avant, dont le
median est le plus large et un pen plus avance que les lateraux, lesquels sont diriges
obliquement. Dernieres fausses-pattes abdominales assez difformes. Leurdeuxieme
article vu en dessous, off re, pres de la base, une espece de crete transversale; -il s'elargit
vers le bout et se termine par un large bord dont les deux extremites s'arrondissent
au lieu de former des angles. Le bord interne de cet article est epais, de facon a
offrir une petite face un peu creusee, separee de la face inferieure par une crete
tordue et trancbante. A la base de cette face on voit une petite lame accolee centre
elle, qui est probablement 1'appendice interne des fausses-pattes. En dessus, le
deuxieme article apparait sous la forme d'une bande qui longe le bord lateral du
segment; cette bande est un peu tordue et relevee en bant, .surtout a son extremite
antt'rieure, ou elle est aussi un peu plus large; u son extremite posterieure elle
forme un angle qui est Tangle interne du bord des fausses-pattes, stir lequel est
articule le troisieme article, qui est tres-petit. Dernier segment abdominal en forme
de triangle tronque, ne de passant pas le bout des fausses-pattes lequel s'en ecarte un
peu; ses bords lateraux n'etant pas droits mais un peu sinuc's. Corps tres-raboteux,
tout couvert de petits tubercules rugueux. La tete etant bordee superieurement par
une eminence transversale garnie d'une ligne de tubercules. Premier segment
thoracique tout couvert de rugosites sauf sur les cotes, qui sont prolonges en arriere
en forme de large apophyse arrondie, et dont les bords inferieurs sont releves, de
facon a former une surface concave. Les autres segments, entitlement rugueux,
sauf dans leur moitie anterieure, qui est lisse, pour 1' articulation; leurs extremites
inferieures sont prolongees en arriere en forme d'apophyses etroites, un peu relevees,
moins rugueuses et portant en dessus une ligne saillante longitudinale, qui se voit'
encore sur le troisieme segment abdominal. Dernier anneau thoracique arme en
dessus des deux gros tubercules triquetres, diriges en arriere. Abdomen rugueux,
taille en forme de toit; ses deux premiers segments incompletement visibles; les
suivants tous armes au milieu d'un fort tubercle, dont le dernier, place sur la base
du segment anal, est le plus grand. Couleur d'un gris-brun uniforme. Longueur,
0.010m. — SAUSSI-RE, Mem. de la Soc. de Physique et d'Hist. nat. de Gem-ve, XIV,
1858, Pt. 2, p. 483.

662

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Terminal segment of abdomen very short, usually triangular. Outer
branch of all the pleopoda furnished with trachea1. Uropoda extend-
ing beyond the terminal abdominal segment; the basal article large,
triangular, entire; the outer branch small, rather slender, inserted at the
inner post-lateral angle of the basal article; outer
branch long, rather slender, a little compressed. a

ANALYTICAL KEY TO THE SPECIES OF THE GENfS SPH^RONISCTS.

a. Body smooth. Terminal segment of abdomen broad and
posteriorly rounded, not constricted. First thoracic seg-
ment without distinct coxopodites.

Sphwroimcus portoricensix Richardson

a'. Body covered with little transverse rugse. Terminal seg-
ment of abdomen strongly constricted in the middle
and somewhat enlarged toward the outer border. First
thoracic segment with a tooth-like lobe on the sides
anteriorly (coxopodites?).

Sphieroniscus cacahuamilpensis (Bilimek)

SPH^RONISCUS PORTORICENSIS Richardson.

FIG. 703.— SPH.ERONISCUS

PORTORICENSIS. a, AB-
DOMEN, b. UROPODA

(INSIDE).

Sphxroniscus portoricemis RICHARDSON, Proc. U. S. Nat.
Mus., XXIII, 1901, p. 573.

Locality. — El Yunque, Porto Rico, at an altitude of 2,800 feet.

Body oblong, very convex, con-
tractile into a ball. Surface per-
fectly smooth. Head set in first
thoracic segment; front straight;
epistoma forming a triangular
shield. Eyes very small. An-
tennae with flagellum composed
of three joints.

First thoracic segment twice
as long as head, and longer than
any of the other segments. Cox-
opodites not distinct from seg-
ment.

First two abdominal segments
with the lateral parts concealed,
the three following ones con-
tinuing the outline of the body.
The terminal segment is twice as
broad as long, very short, widely
rounded posteriorly. The basal
joints of the uropoda are large,

FIG. 704.— SPH.ERONISCVS PORTORICENSIS. a, SECOND

MAXILLA. X 51|. 6, MAXILLIPED. X 27J. C,

OUTER LAMELLA OF FIRST MAXILLA, x 51|. (/,
INNER LAMELLA OF SAME.& x iilf. e, MANDIBLE.
x 27J.

« See Budde-Lund for characters of genus, Crustacea Isopoda Terrestria, 1 885, pp.
44-45.

6 This species differs from all the other Armadillidid;e in having the inner lobe of
the first maxilla* armed with three plumose processes instead (if two. I have exam-
ined several specimens and find that they agree in this character.

ISOPODS OF NORTH AMERICA. ()03

square, extending the greater part of their length beyond the terminal
segment. The external branch is inserted at the inner post-lateral
angle of the basal joint and extends downward. The internal branch
extends much beyond the last abdominal segment, is longer than the
basal joint of the uropoda, and reaches the tip of the external branch.

Color reddish-brown with markings of yellow.

Four specimens were taken by Dr. C. W. Richmond at El Yunque,
Porto Rico, at an altitude of 2,800 feet.

Type.— Cat. No. 23914, U.S.N.M.

SPHjERONISCUS CACAHUAMILPENSIS (Bilimek).

Armadillo cacahuamilpemis BILIMEK, Verb, zool.-bot. Ges. Wien, XVII, 1867,
pp. 907-908. — BUDDE-LUND, Crust, Isopoda Terrestria, 1885, p. 40.

Locality. — Cave in Cacahuamilpa, Mexico. Found under stones.

Budde-Lund suggests that this form certainly differs from Oubaris
oecause the flagellum of the second antenna3 is composed of three arti-
cles, according to Bilimek. He suggests that perhaps it is nearer to
PseiidarmadUlo. Inasmuch as the species of PseudarniadUlo recently
described, and which undoubtedly belong to that genus, have but two
articles to the flagellum of the second antenna?, Bilirnek's species must
be referred to the genus Sphs&roniscus^ which is the only genus of
Armadillididse, having the flagellum composed of three joints.

Body grayish brown, slightly rugose transversely, head transversely
dilated, with the anterior margin raised; first thoracic segment very
wide, with a lateral lobe similar to a tooth; last segment of the abdo-
men strongly constricted in the middle; uropoda narrow, twice as long
as wide.

Grayish brown and covered with delicate little transverse ruga?.
Head very broad, three times as broad as it is long, anterior border
turned up broadly, but diminishing in breadth on the sides under the
eyes and especially behind. Antenna 5-jointed, with a 3-jointed flagel-
lum; eyes composed of 14 ocelli. First thoracic segment strongly
arched, broadest in the middle, and edged by a delicate border; a tooth-
like lobe is formed on the sides anteriorly, in front of \vhich there is
found a concave depression; on the back there is a flat transverse depres-
sion. Second segment about one-third narrower; the anterior portion
is depressed transversely by the overly ing anterior segment; the epim-
eron, which becomes narrower on the sides, is rounded and turned
straight downward. Segments 3 to 7 similar, with the exception that the
epimera on the side appears to be more bluntly cut off. First abdominal
segment quite narrow; it does not reach to the outer edge; second-
fourth continue to decrease in breadth and have a horseshoe-shaped
appearance; the fifth is bordered with two lateral lobes and is as long
as it is broad at the base; it is strongly constricted in the middle and
somewhat enlarged toward the outer border. The legs are 5-jointed,

()(>4 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

fourth und tifth joint abundantly covered with spines on the inside.
The uropodti are thin, twice as long as they are broad; color of feet
and antenna1 whitish in the dead animal."

119. Genus HAPLARMADILLO Dollfus.

Eyes monocellated. Flagellum of second antenna* composed of a
single article. Coxopodites distinct on first thoracic segment, Cox-
opodites wanting on second segment of thorax.

Terminal segment of abdomen widely triangular.

Basal article of uropoda square, longer than the terminal segment of
the abdomen; inner branch as long as the basal article; outer branch
minute, inserted at the inner post-lateral angle of the basal article.

«The above description is adapted from the following one of Bilimek's:

Griseo-fuscescens, subtiliter transverse verrucosus; capite trans versim dilatato,
margine anterior! erecto; primo thoracis segmento latissimo, lobo laterali denti
simillimo; abdominis segmento ultimo in medietate valde coarctato; pedibus spuriis
angustis, duplo longioribus. Long. 9 mm. ; lat. 3J mm.

Graubraunlich mit feinen Querwarzchen bedeckt. Kopf in die Breite gezogen,
3 mal so breit als lang, Vorderrand breit aufgeworfen, welcher Rand an den Seiten
unter den Augen und besonders hinten schwiicher wird. Fiihler 5-gliedrig mit 3
gliedriger Geissel; Augen aus 14 Punkten zusammengesetzt. 1. Brustkastenseg-
ment stark gewolbt, in der Mitte am breitesten, mit einer schwachen Randleiste
eingefasst; an den Seiten bildet sich ein zahnartiger Lappen nach vorne zu, vor
welchem ein breiter grubenartiger Eindruck vorhanden ist; am Riicken ein flacher
Quereindruck. 2. Segment um £ sch'miiler; die vordere Hiilfte der Quere nach
eingedriickt von dem darauf sitzenden Vordersegmente; der Lappenfortsatz an den
Seiten schmiiler werdend, abgerundet, gradaus abwiirts gerichtet. 3.-7. Segment
von gleicher Beschaffenheit, nur dass der Lappenfortsatz an der Seite immer stump-
fer abgestutzt erscheint. 1. Hinterleibssegment ganz schmal, erreicht den Aussen-
rand nicht; 2.-4. immer schmiiler werdend in hufeisenformiger Gestalt; das 5. mit 2
Seitenlappen eingesch lessen, so lang wie an der Basis breit, in der Mitte stark
eingeschniirt und nach dem Aussenrande zu etwas erwreitert. Die eigentlichen
Fiisse 5-gliedrig, das 4. und 5. stark mit Stacheln an der Jnnenseite besetzt. Afterfiisse
schmal, 2 mal so lang als breit; Farbe der Fiisse und Fiihler im Tode weisslich.

Aufenthalt in der Hohle Cacahuamilpa in Mexico unter Steinen.

Von Pflanzen fand ich einen einzigen Pilz, der auf einer dunklen Unterlage den
Rand derselben einfasste, weisslich von Farbe 2-3 mm. gross war; er stand an nassen
Stellen auf Kalksinter. — BILIMEK, Verhandl. Zool.-Bot. Vereins in Wien, XVII,
1867, pp. 907-908.

ISOPODS OF NORTH AMERICA.

665

HAPLARMADILLO MONOCELLATUS Dollfus.

Haphrmadttlo nniniM-i'll<ttiis Dou.Krs, Proc. Zool. Soc. London, 189*5, p. 400. —
RICHARDSON, Proc. I". S. Nat. Mus., XXIII, 1901, p. 573.

Locality. — Richmond Valley, St. Vincent, West Indies. Under rot-
ting leaves, l,ioo feet.

" Body convex, smooth, and covered with minute, setose hair.
Cephalon: prosepistoma with a shield-like convexity. Eyes mono-
cellate, hardly perceivable. Antenna? very hairy; flagellum single-

b

FIG. 706.— HAPI.ARMADIJ.I.O MONDCKLLATUS (AFTER DOLLFUS). «, HEAD AND FIRST TWO SEGMENTS
OF THORAX ( rPPKR SIDE). 6, THKSAME ( l-NDK':<! \1Y.\ . f. FIFTH AND SIXTH SEGMENTS OF ABDO-
MF.N M 1'1'F.K SIDE). '/. THE SAME ( I'NDERSIDE ).

jointed, with a long, stitf hair at its distal end. Pereion: tirst segment
with a very blunt antero-median tubercle; hind edge nearly straight;
sides feebly raised forward; coxopodite distinct on the posterior half
of the edge. Second segment with no distinct coxopodite. Pleon.
telson: pleotelson widely triangular, much wider than long. Uropoda
with a square basis, longer than the pleotelson; endopodite as long as
the basis; e*xopodite minute, placed at the internal distal angle of the
basis. Color: dark gray, variegated with lighter lineola? and irregu-
lar stripes. Dimensions: 9 by 4 mm." — DOLLFUS.

12O. Genus ARMADILLIDIUM Brandt."

First pair of antenna? very small, inconspicuous. Body oblong, very
convex, and contractile into a ball.

Front of head marginate, lateral lobes rounded. Epistome vertical,
forming a triangular shield, advancing more or less beyond the frontal

" For characters of genus, see Budde-Lnnd, Crust. Isop. Terrentria, 1885, p. 49, and
T. O. Sars, Crust, of Norway, II, 1899, p. 188.

666 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

edge. Clypeus very short, with the anterior margin slightly sinuated
in the middle, not lobate. Frontal marginal line interrupted in the
middle. Vertical marginal line wanting behind the eyes on both sides.
Eyes small or moderately large, distinct, lateral, composite. Second
pair of antennas scarcely equal to half the length of the bod}'; tiagel-
lum composed of two articles.

First segment of thorax with epimera not cleft posteriori}'.

Terminal segment of abdomen quadrangular or triangular in shape,
not extending beyond the epimera of the preceding segment.

Opercular plates of the first two pairs of pleopoda furnished with
tracheae.

Uropoda short; basal article broad, obliquely quadrate; outer branch
lamellar, flattened; inner branch narrow, cylindrical.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS ARMADILLIDIUM.

«. Head truncate in front, without median emargination, and not surpassed by the
epietome. Outer branch of the uropoda posteriorly truncate.

Armadillidium vulgare (Latreille)

a7. Head with a small median V-shaped' notch in front, and surpassed by the
epistome, which extends some distance in front. Outer branch of the uropoda
posteriorly rounded Armadillidium quadrifrons Stoller

ARMADILLIDIUM VULGARE (Latreille).

Armadillo vulgare LATREILLE, Hist. Crust., VII, 1804, p. 48; Gen. Crust., I, 1806,
p. 71.

Armadillo pilularis SAY, Jour. Ac. Nat. Sci. Phila., I, 1818, pp. 432, 433.

Armadillidinm commutatum BRANDT and RATZEBURCJ, Med. Zool., II, 1830-1834,
p. 81, pi. xin, tigs. 1, 2, 3, A, B.

Armadillo trivialift KOCH, Deutschl. Crust., 1835-1844, p. 28.

Armadillo pilularix GOITLD, Rep. Invert. Mass., 1841, p. 336.— PE KAY, Zool. New
York, 1844, Pt. 6, Crust, p. 52.

Armadillo ater SCHNIT/LER, Pe Oniscineis agri Bonnensis, 1853, p. 26.

Armadillidium ndgare BrnnE-Lrxn, Crust. Isop. Terrestria, 1885, pp. 66-68 (see
Budde-Lund, for synonymy). — SARS, Crust. Norway, II, 1899, pp. 189-190,
pi. LXXXII.— RICHARDSON, Amer. Nat., XXXIV, 1900, p. 305; Proc. U. S.
Nat. Mus., XXIII, 1901, p. 574.— CHILTON, Trans. Linn. Soc. Lond., (2),
VIII, Pt. 4, pp. 142-143.— STOLLER, 54th Report New York State Museum,
1902, p. 210.— PAULMIER, Bull. New York State Museum, 1905, pp. 184-185.

Localities. — Anderson's ferry, Cincinnati, Ohio; Norwood, Ohio;
Clifton, Cincinnati, Ohio; Columbus, Ohio; Coney Island, Ohio; Mount
Auburn, Cincinnati, Ohio; Redbank, Hamilton County, Ohio; Lexing-
ton, Kentucky; Aiken, South Carolina; Harrington Sound, Ber-
mudas; Hamilton, Bermudas; Washington, District of Columbia; Syra-
cuse, New York; Bay Shore, Long Island; Salem, Massachusetts;
Charlestown, South Carolina; Providence, Rhode Island; Canton,
Mississippi; New Orleans, Louisiana; Lexington, Kentucky; Wood-
side, Maryland; Fayal, Azores; Orleans villa, Algeria; world-wide in
distribution.

ISOPODS OF NORTH AMERICA.

667

Found on floating seaweed; in moist meadows; under stones: in
cellars; under hoards in damp soil; in hothouses; under rocks.

In New Orleans, Louisiana, this species is reported to be a menace
to cucumbers and other vegetables grown in hothouses.

It is also said to be injurious to various plants in Fort Worth,

FIG. 706. — ARMADILLIDIVM VULUARE (AFTER SARS). a, HEAD WITH ANTENN.E (VENTRAL VIEW).
/>, DORSAL VIEW OF FEMALE, c, FIRST MAXILLA, d, FIRST ANTENNA, e, ANTERIOR LIP. /, RIGHT
MANDIBLE, g, SECOND MAXILLA, fi, POSTERIOR LIP. i, FIRST LEG. j, LEFT MANDIBLE, k, TIP OF
MAXILLIPED. I, UKOPOD. in, SEVENTH LEG. », LATERAL VIEW OF FEMALE, o, MAXILLIPEDS. p,
FIRST PLEOPOD OF MALE, q, ABDOMEN WITH UROPODA. r, LAST TWO SEGMENTS OF ABDOMEN
WITH VROPODA. s, THIRD PLEOPOD OF MALE, t, SECOND. PLEOPOD OF MALE, u, HEAD WITH

ANTENN.E (DORSAL VIEW). V, ABDOMEN WITH UROPODA (VENTftAL SIDE). W, SECOND ANTENNA.

Texas; found on date palms, imported from Algeria, at the Depart-
ment of Agriculture, Washington, District of Columbia.

Also found injuring young cotton near Dallas, Texas.

At Berkley, Virginia, it is reported to be one of the most destruc-
tive pests with which the mushroom grower has to deal.

Body oblong-ovate, rather convex, and able to be rolled up into a
ball; twice as long as wide; 8 mm.: 16 mm.

668 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Head much wider than long, H mm.: 4 mm., with the front strain-lit.
Kpistome projects hut little beyond the frontal margin The eyes are
small, round, composite, and situated in the antero-lateral angles of
the head. The first pair of antenna* are rudimentary and inconspicu-
ous and are composed of three articles. The second pair of antenna>
have the first article short; the second is about four times as long- as
the first; the third is about half as long as the second; the fourth is
one and a half times longer than the third; the fifth is twice as long
as the fourth. The flagellum is composed of two nearly equal articles.
The second antenna* extend to the posterior margin of the first thoracic
segment. The maxillipeds have a palp of three articles. The palp of
the mandibles is wanting.

The segments of the thorax are subequal, each being 2 mm. in
length. There are no epimera separated off on any of the segments.

The abdomen is as wide as the thorax. The first two segments are
covered at the sides by the seventh thoracic segment. The sixth or
terminal segment is 2 mm. wide at the baseband 1£ mm. long. It
tapers to a truncate extremity, which is 1 mm. wide. The uropoda
are not longer than the terminal segment of the body. The peduncle
is not visible in a dorsal view. The outer branch is broad and fills in
the space between the sixth abdominal segment and the lateral part of
th^ fifth segment; it is truncate at its posterior extremity. The inner
branch is narrow and elongate, but does not ex-
tend beyond the extremity of the abdomen.
All the legs are ambulatory.

ARMADILLIDIUM QUADRIFRONS Stoller.

Armadillidium quadrifrons STOLLER, 54th Report of the
New York State Museum, 1902, pp. 211-212.

Locality. — Schenectady, New York. Found in
greenhouses.

Body ovate, contractile into a ball; nearly twice
as long- as wide, 5 mm. : 9 mm.

Head nearly three times as wide as long, with
a small, median V-shaped notch. The epistome
is triangular in shape; the broad, basal part being
anterior and projecting in front of the head, giv-
FIG. 707.— ARMADILLIDH-M ing the head the appearance of having a broad,

QUADRIFRONS (AFTER j j- i -, rr\\ 11

STOLLER) x 5j quadrate median lobe. The eyes are small, com-

posite, and situated in the antero-lateral angles.

A groove separates the antero-lateral margin of the head from the
antennal lobe, which is large and conspicuous and well rounded. In
this groove the antenna? lie. The first pair of antenna? are small
and inconspicuous. The second pair have the first article short; the
second is twice as long as the first; the third is a little shorter than

I9OPODS OF NORTH AMERICA.

669

the .second; the fourth is equal in length to the second; the fifth is
twice as long as the fourth. The flagelluin is composed of two long,
subequal articles. The second antenna1 extend to the posterior margin
of the first thoracic segment.

The first segment of the thorax is a little longer than any of the
following segments, and has the
antero-lateral angles produced
forward to surround the head,
and the post-lateral angles pro-
duced backward. The epimera
are not distinct in any of the
segments.

The first two segments of the
abdomen have the lateral parts
covered by the seventh thoracic
Hegment. The three following
segments continue the oval out-
line of the body. The sixth or
terminal segment is sub-triangu-
lar. with sides a little concave
and apex rounded. The basal 6

segment Ol' peduncle of the Uro- FIG- ^OX.-ARMADILLIDIUM QUADRIFRONS. a, HEAD.
. ., , . x 14J. b, LAST TWO SEGMENTS OF ABDOMEN WITH

poda is not visible in a dorsal UKOPODA. x m.
view. It is large and somewhat

quadrate. The outer branch occupies all the space between the lateral
part of the fifth abdominal segment and the terminal abdominal seg-
ment. The outer branch is broad posteriorly and well rounded. The
inner branch extends to the extremity of the outer branch and to
the extremity of the abdomen.

All the legs are ambulatory in character.

121. Genus UROPODIAS Richardson.

Head with the front produced in a prominent rounded lobe. Eyes
small, obscure. External antenna1, with a flagelluin of two joints, the
second joint the smaller of the two.

First six thoracic segments with the lateral parts lamellarly expanded.
Seventh segment as long as the six preceding segments, but with the
lateral parts undeveloped, and not wider than the first two abdominal
segments, which likewise have the lateral parts or epimeral plates
undeveloped.

Abdomen not narrower than the thorax, the lateral parts of the
third, fourth, and fifth segments being expanded and continuing
the regular outline of the body. The abdominal segments equal in
length and half as long as the thoracic segments. Terminal segment
quadrangular in shape, the posterior margin produced in a medium

670 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

rounded lobe. The outer branch of the uropoda is large, broad,
flattened, with rounded margins; the inner branch is smaller and
narrower, and rounded posteriorly.

There are only six pairs of legs, the appendages of the last thoracic
segment being wanting.

UROPODIAS BERMUDENSIS Richardson.

Uropodiax bermudensis RICHAKDSON, Trans. Conn. Acad. Sciences, XI, 1902, pp.
304-305, pi. XL, figs. 59-60.

Locality. — Castle Harbor, Bermudas, under stones in dry places.

Body very convex, able to be contracted into a ball. Surface smooth.
Color uniformly light brown.

Head large, produced in front in a prominent rounded projection.
Eyes very small, obscure, and situated about the middle of the lateral

FIG. 709.— UROPODIAS BERMUDENSIS. a, HEAD AND FIRST THORACIC SEGMENT, x 62. 6, ABDOMEN

AND LAST TWO THORACIC SEGMENTS. X 62.

margin. The external antennae, with a flagellum of two joints, extend
to the middle of the first thoracic segment, and are geniculate at the
articulation of the third and fourth joints.

The thoracic segments are subequal in length. The seventh segment
is abruptly narrower than the six preceding segments, and not wider
than the first two abdominal segments. The seventh thoracic and the
first and second abdominal segments have the lateral parts undevel-
oped. The first six thoracic and the third, fourth, and fifth abdominal
segments have the lateral parts lamellarly expanded, so that the regular
outline of the body is preserved, the third abdominal segment not
being narrower than the six thoracic segment, the lateral portions of
which extend down lateral!}7 beyond the seventh thoracic and the first
and second abdominal segments.

The terminal abdominal segment is quadrangular, with the posterior
margin produced in a median rounded lobe. The uropoda extend but
a short distance beyond the lateral parts of the fifth abdominal seg-

ISOPODS OF NORTH AMERICA. 671

merit. The outer branch is broad, flattened, and round; the inner
branch is smaller and narrower, and posteriorly rounded.

There are but six pairs of legs, those of the seventh thoracic seg-
ment being wanting.

A few specimens were collected by Prof. A. E. Verrill and party at the
Bermudas in 1898, and at Castle Island in 19(>1, under stones, in dry
places.

Type in the Peabody Museum, Yale University. Cat. No. 3224.

Family XXV11. SCYPHACID^.

Head without median or antero-lateral lobes. Front not margined,
but continuous with the epistome. Second pair of antennae with flagel-
lum composed of four articles. First maxillae with the inner lobe
furnished with two plumose setae; outer lobe furnished with teeth.
Second maxilla? furnished with hairs. Mandibles without molar
process. Maxilliped with masticatory lobe acutely produced; palp
elongate, much longer than masticatory lobe, with articles large and
not distinctly defined.

Abdomen not abruptly narrower than thorax.

Uropoda extending beyond the tip of the abdomen; inner branch
inserted at the upper inner angle of the basal article.

122. Genus SCYPHACELLA Smith.

i

Outer lobe of first niaxillse furnished along the distal half of the
inner margin with recurved spines.

Inner lobe furnished with two widely separate plumose processes,
one at the tip and the other on the inner margin.

Second maxilla? furnished with hairs at the tip.

Both first and second maxilla? long and slender.

Epignath of maxillipeds long and narrow, acutely produced at the tip.

Eyes large, composed of many ocelli.

Abdomen not narrower than thorax.

Cropoda exposed, both branches styliform.

SCYPHACELLA ARENICOLA Smith.

Scyphacella arenicola SMITH, Report U. S. Commissioner of Fish and Fisheries,
1873, Pt. 1, p. 567 (274).— HARGER with VERRILL, Report U. S. Commis-
sioner of Fish and Fisheries, 1873, Pt. 1, p. 337 (43).— HARGER, Proc. U. S.
Nat. Mus., II, 1879, p. 157; Report U. S. Commissioner of Fish and Fish-
eries, 1880, Pt. 6, pp. 307-308, pi. i, fig. 2.

Trichoniscus arenicola BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 249.

Sci/phacella arenicola UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p.
363.— RICHARDSON, American Naturalist, XXXIV, 1900, p. 307; Proc. U. S.
Nat. Mus., XXIII, 1901, p. 576.

672

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Egg Harbor, New Jersey ; Nobska Beach. Vineyard
Sound; Nantucket Island; Woods Hole, Massachusetts: mouth of
Choptank Kiver. Dorchester County, Maryland. Found in sand,
liodv oblong-ovate, a little more than twice as long as wide, '2 mm.:

4^ mm. ; surface very scaly, thickly covered
with small tubercles, each tipped with a
small spine.

Head wider than long; frontal margin
but little produced; lateral lobes small.
Eyes large, round, composite, and placed
at the sides of the head, close to the lateral

FlG. 710. — SCYPHACEI.I.A ARENICOLA

(AFTER BARKER), x 12.

FlG. 711. — SCYPHACELLA ARENICOLA. HEAD
WITH ANTENNA. K 27.

margin. The epistome is continuous with the front of the head, so
that the head seems to be produced forward in a triangular extremity
which is rounded anteriorly. The tirst pair of antenna? are small,
inconspicuous, the terminal article fringed with hairs at the apex.
The second pair of antennae have the first two articles short, the

abed .1

FlG. 712.— SCYPHACELLA ARENICOLA. fl, UROPOD. X 51|. b, MAXILLIPED. X 51f. . C, FIRST MAXILLA
(OUTER LOBE). X 51|. rf, SECOND MAXILLA. X 51 1. €, MANDIBLE. X 51 f. /, LAST TWO SEGMENTS
OF ABDOMEN. X 27J.

second one a little longer than the tirst; the third and fourth articles
are nearly subequal, and each is a little longer than the second: the
fifth is one and a half times longer than the fourth. The flagellum
is composed of four articles, the tirst article being twice as long as
the second; the articles are with difficulty to be distinguished. The
antenna; are thickly beset with spines.

ISOPODS OF NORTH AMERICA. 673

The segments of the thorax are subequal; the last two have the
post-lateral angles produced backward.

All the segments of the abdomen are distinct. The first two have
the lateral parts covered by the seventh thoracic seg-
ment. The three following segments have the post-
lateral angles produced backward. The terminal
abdominal segment is narrow, produced in the middle
posteriorly in a long, narrow process, broadly rounded
at the apex. The peduncle of the uropoda extends to
the end of the terminal abdominal segment. The
branches are of nearly equal length. FlG- "is.— SCYPHA-

.— , ., , . • • i • CELLA AREXICOLA.

Color of the specimens, for a long time preserved ISXER LOBE Of
in alcohol, dark brown, with the margins of the seg- FIRST MAXILLA.

,, ,. , , ( DIAGRAMMATIC, i

ments or a lighter brown.

Five specimens were collected by Dr. S. D. Judd in the sand on
Ram Island, Woods Hole, Massachusetts, and are in the collection of
the U. S. National Museum.

Family XXVIII. LIGYDID^E."

Body oval. Head without lateral lobes; frontal margin rounded, and
not distinctly defined from the epistome. First pair of antennas with
the terminal joint not furnished with sensoiy hairs. Second pair of
antenna? well developed, with flagellum multi-articulate. Buccal mass
prominent. Mandibles with the molar process large and broad, having
a finely fluted triturating surface. Inner lobe of the first maxilla? fur-
nished at the tip with three plumose processes. Second maxillae also
furnished inside with two similar processes. Maxillipeds with the
palp composed of five articles; masticatory lobe truncate.

Opercular branches of pleppods without trachea?. First two pairs
of pleopods modified in male; inner branch terminating in a long stylet.

ANALYTICAL KEY & TO THE GENERA OF THE FAMILY LIGYDID.E.

«. Uropoda with basal article not produced in a process at the inner distal angle;
branches equal in length. Last segment of abdomen large, with lateral parts

well developed Genus Ligyda Rafinesque

a/. Uropoda with basal article produced in a process at the inner distal angle;
branches unequal in length. Last segment of abdomen small, with lateral parts
obsolete .. Genus Ligidium Brandt

123. Genus LIGYDA" Rafinesque. 1814

Bod}" oval, or oblong oval; abdomen not abruptly narrower than the
thorax. Terminal segment broad, with lateral parts well developed.
First pair of antenna? with the third or terminal joint rudimentary,
nodiform.

«See Sars for characters of family and genus.

&The genus Euphilosda Packard is not included, as it is probably a synonym of

Ligidium.

28589—05 43

674 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

Second pair of antennae strong and elongated; flagellum multi-
articulate.

Palp of maxillipeds with joints rather expanded; epignath rounded.

Uropoda with the basal article not produced inside at the post-lateral
angle; branches subequal. each tipped with a single terminal spine.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS LIGYDA.

a. Uropoda long, equal to two-thirds the length of the body or longer. External
antenna1 long, extending the entire length of the thorax or longer.

b. First pair of legs similar to the others in the male Ligyda olfersii (Brandt)

b'. First pair of legs in the male differing from the others.

c. Propodus of first pair of legs armed with a long narrow process at the distal

end. Peduncle of second antennae extends to posterior margin of the third

thoracic segment. The second antennae extend in the male to the end of

the body or a little beyond. Body loosely articulated . . Ligyda exotica ( Roux )

cf. Propodus of first pair of legs in male unarmed. Merus and carpus in the first

pair of legs in the male furnished with a row of bristles or stiff hairs.

Peduncle of second antennae extends to the posterior margin of the second

thoracic segment. Second antennae extend in the male to the end of the

thorax. Body compact Ligyda baudiniana (Milne Edwards)

of . Uropoda not equal to two-thirds the length of the body.

b. Uropoda equal to half the length of the body. Terminal segment of the body

pointed in the middle Ligyda occidentalis (Dana)

bf. Uropoda not equal to half the length of the body. Terminal segment rounded

in the middle.

c. Branches of the uropoda twice as long as the peduncle. Uropoda equal to one-
eighth the length of the entire body from the tip of the terminal abdominal
segment. Lateral parts of the third, fourth, and fifth segments of the abdo-
men with distinct carinae Ligyda pallasi (Brandt)

c'. Branches of the uropoda four times as long as the peduncle. Uropoda equal to
one-fourth the entire length of the body from the tip of the abdomen.
Lateral parts of the third, fourth, and fifth segments of the abdomen with-
out distinct carinae Ligyda oceanica (Linnaeus)

LIGYDA OLFERSII (Brandt).

Ligia olfersii BRANDT, Bull. Soc. Imp. Naturalistes de Moscou, ^7I, 1833, p. 11. —
BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 268. — RICHARDSON, Proc. U. S.
Nat. Mus., XXIII, 1901, p. 575.

Localities. — Key West and Puntarasa, Florida; St. Thomas; Brazil.

Bodj7 oblong-ovate, a little more than twice as long as wide, 7 mm. :
15 mm. Length of uropoda, from tip of terminal segment, 8 mm.
Entire length of body with uropoda 23 mm.

Head twice as wide as long, 2 mm. : -i mm. Anterior margin widely
rounded. Eyes composite, narrow, oblong, twice as long as wide, sit-
uated on the lateral margins and extending along the anterior margin,
being separated in front by a distance a little less than the length of
one eye. First pair of antennae inconspicuous and rudimentary, com-
posed of two subequal articles and a minute terminal one and extend-
ing only to the end of the first article of the second pair of antennae.

ISOPODS OF NORTH AMERICA.

675

The first and second articles of the second pair of antennae are sub-
equal; the third article is one and a half times longer than the second;
the fourth is twice the length of the third; the fifth is one and a half
times longer than the fourth. The flagellum is composed of twenty-
eight articles. When retracted,
the second pair of antennae extend
to the end of the fifth abdominal
segment. The maxilliped has a
palp of five articles.

The first five segments of the
thorax are about equal in length;
the last two are somewhat shorter.
The posterior angles of the lat-
eral parts of the last three are
produced downward. The lateral
parts of the segments are not sep-
arated oft' from the dorsal portion.

FIG. 714.— LlGYDA OLFERSII. a, MAXILLIPED.

x 20i. b, FIRST LEG OF MALE, x Hi.

FIG. 715.— LlGYDA OLFERSII. X 3.

There is not even any trace, such as a faint line, to mark the place
where coalescence has taken place.

The abdomen is as wide as the thorax, the lateral parts of the
third segment extending as far as those of the seventh thoracic seg-
ment. The lateral parts of the first two segments are not developed.
There is a slight and gradual increase in the length of the segments
from the first to the fifth. The lateral parts of the abdominal seg-
ments are not separated off from the dorsal portion. The middle
portion of the sixth or terminal segment is produced triangularly
in an acute point. The lateral angles are short and acute, and do not
extend to the tip of the median point. Between the lateral parts
and the dorsal portion, there are two angular processes on the poste-
rior margin of the segment, on either side, near the lateral angles,
the process adjacent to the lateral angle being more obtuse than the
other one.

676 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The basal article of the uropoda is 3 mm. in length. The branches
are subequal and are 5 mm. long. The legs are all ambulatory. The
first pair is not furnished with a process at the distal end of the
propodus. The dact37lus is bi-unguiculate.

In the female the second antenna? extend only to the posterior
margin of the seventh thoracic segment.

LIGYDA EXOTICA (Roux).

Ligia exotica Roux, Crust. M£dit., 1828, p. 3, pi. xin, fig. 9.

Ligia grandix PERTY, Delectus animaliura articulatorum, etc., 1830-1834, p. 212,

pi. XL, fig. 13.

Ligia gaudichaudii MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 157.
Ligia (Italica) coriacea KOCH, Deutschlands Crust,, 1835-1844, p. 36.
Ligia gaudichavdii DANA, U. S. Expl. Exp., Crust., XIV, 1853, p. 741, pi. XLIX,

figs. 6 a-h.— NICOLET, in Gay, Hist. Chile, III, 1849, p. 265.
Ligia exotica BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 266-268. — DOLLFUS,

Bull. Soc. Zool. France, XVIII, 1893, p. 189.— RICHARDSON, Proc. U. S. Nat.

Mus., XXI, 1899, p. 866; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 335;

American Naturalist, XXXIV, 1900, p. 306; Proc. If. S. Nat. Mus., XXIII,

1901, p. 575.

Localities. — California; Topolobampo, Mexico; Cedar Keys, Florida;
Lake Harley , Florida; Fort Macon, North Carolina; Mazatlan, Mexico;

Florida Keys; New Providence, Baha-
mas; Beaufort, North Carolina; Key
West, Pine Key, Florida; Port Tampa,
Florida; Panama; Charleston, South
Carolina; Antigua, West Indies; Chusan;
Macao; Bahia, Brazil; Puntarenas; Mad-
ras; Manila; Luzon; Singapore; Mas-
silia; Espiritu-Santo, Balandra Bay, near
Point Diablo; Chili; He Ronde; Mahe;
Tientsin, China; Guadalupe Island; Mi-
saki, Sagaini, Japan; Tokyo, Japan;
Honolulu, Hawaii. Found on piles at
wharf; along the docks. Called "sea
monkeys" in Florida. Very numerous

FIG. 716. — LIGYDA EXOTICA (AFTER •,

ROUX). among rocks.

Body oblong-ovate, a little more than

twice as long as wide, 14 mm. : 30 mm. Length of uropoda from tip
of terminal segment of body equal to 18 mm. Length of body with
uropoda equal to 48 mm. Surface covered with minute granules.

Head twice as wide as long, 3 mm. : 7 mm. Anterior margin regu-
larly rounded. Eyes large, round, composite, and placed at the
extreme lateral margins. The first pair of antenna are inconspicuous
and rudimentary; they are composed of two subequal articles and a
minute terminal one; they extend to the end of the basal article of the

ISOPODS OF NORTH AMERICA.

677

FIG. 717. — LIGYDA EX-
OTICA. MAXILLIPED.
x 15}.

second pair of antennae. The first and second articles of the second
pair of antenna1 are about equal in length; the third article is about
one and a half times longer than the second; the fourth is three times
longer than the third; the fifth is one and a half times longer than
the fourth. The flagellum is composed of fifty -five
articles. When retracted, the second antenna? ex-
tend to the end, or a little beyond the end, of the
peduncle or basal article of the uropoda. The max-
illipeds have a palp of five articles.

The segments of the thorax are subequal. The
epimera are broad plates occupying the entire lat-
eral margins of the segments, but not distinctly
separated off from the dorsal portion of the seg-
ment, only a faint line, almost inconspicuous, indi-
cates the place where the coalescence has taken
place. The lateral parts of the last three segments
extend downward.

The abdomen is not narrower than the thorax,
the third segment being as wide as the seventh thoracic segment. The
lateral parts of the first two segments are not developed. There is a

gradual increase in the length of the seg-
ments from the first to the fifth. The
lateral parts of the third, fourth, and fifth
segments are not distinct from the dorsal
portion of the segment. The sixth or ter-
minal segment has the middle part of the
posterior extremity produced triangularly
in an obtuse point. The post-lateral angles
are very acute and long, extending as far
as the apex of the middle portion. Be-
tween the lateral angles and the middle
portion of the segment, but near the lat-
eral angle, are two small triangular pro-
cesses. The basal article of the uropoda
is 6 mm. in length from the apex of the
terminal abdominal segment. The
branches are of equal Jength and twice
as long as the peduncle, being 12 mm.
The inner branch is furnished with a small
bristle about half a mm. long.
The legs are all ambulatory. In the male the first pair has the pro-
podus furnished near its distal end with a small lateral process. This
process is wanting on the first pair of legs in the female.

FIG. 718. — LIGYDA EXOTICA, a, TER-
MINAL JOINTS OF FIRST LEG. X 11|.

6, FIRST LEG. x llj».

678

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

LIGYDA BAUDINIANA (Milne Edwards).

Ligia baudiniana MILNE EDWARDS, Hist. Nat. Crust, III, 1840, pp. 155-156.
? Ligia baudiana SPENCE BATE, Ann. Mag. Nat. Hist. (4), I, 1868. pp. 443-^46.
? Ligia baudiniana SAUSSURE, M6m. Soc. Physique et d'Hist. Nat. de Geneve,

XIV, 1858, pp. 443-446.
Ligia exotica DOLLFUS, Bull. Soc. d'Etudes Scientifiques de Paris, 12th year, 1890,

p. 7.
Ligia exotica hirtitarsis DOLLFUS, Bull. Soc. d'Etudes Scientifiques de Paris, 12th

year, 1890, p. 7.

Ligia baudiana IVES, Proc. Acad. Nat. Sci. Phila., 1891, pp. 185-186, pi. \i, fig. 2.
Ligia hirtitarsis DAHL, Plankton- Expedition, 1892, pp. 111-112, pi. in.
Ligia baudiniana RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 574-575.
Ligia gracilis MOORE, Report U. S. Commissioner of Fish and Fisheries, XX, Pt. 2,

1902, p. 175, pi. xi, figs. 7-12.
Ligia baudiniana RICHARDSON, Trans. Conn. Acad. Sci., XI, 1902, pp. 306-308,

pi. XL, fig. 61.

Localities. — Hamilton Island, Bermudas; Saint Jean d'Ulloa, Mex-
ico; Yucatan; Rio Janeiro; Cuba; Cayenne; Miami, Florida; Jamaica;

FIG. 719.— LIGYDA BAUDINIANA (AFTER DAHL). a, UROPOD. b, GENERAL FIGURE, c, FIRST LEG OF
MALE, d, MANDIBLE, e, FIRST MAXILLA.

Culebra, Porto Rico; the Bahamas. Found under algae and drift along
shore (Moore).

Body oblong-ovate, nearly two and a half times longer than wide,

I8OPODS OF NORTH AMERICA.

679

10 inin.: 23 mm. Uropoda 10i mm. long, a little less than half the
length of the body. Body, with uropoda, 33£ nun.

The head is twice as wide as long, 2£ mm.: 5 mm., with the anterior

margin widely rounded. The eyes are narrow elongate, about twice

as wide as long, and separated in front by a distance equal to the

length of one e}re, 2 mm. The first pair of antennae are small and

inconspicuous. The second pair have the first

FlG. 720. — LlGYDA BAUDINIANA
(AFTER IVES). X 2|.

PlG. 721. — LlGYDA BAUDINIANA.
FIRST LEG OF MALE. X 11§.

FlG. 722. — LlGYDA BAU-
DINIANA (AFTER
DAHL). MAXILLIPED.
X 24|

two articles short and subequal; the third article is as long as the first
two taken together; the fourth is 3 mm. long, or twice as long as the
third; the fifth is 4i mm. long, or one and a half times longer than the
fourth. The flagellum is composed of thirty-eight articles, and
extends to the posterior margin of the seventh thoracic segment.
The maxilliped has a palp of five articles.

The segments of the thorax are subequal, with lateral margins
straight. The epimera are coalesced with the segments, faint depressed
lines indicating the place of union.

All six segments of the abdomen are distinct; the first two are some-
what shorter than the three following, and have the lateral parts cov-
ered b}7 the seventh thoracic segment. The third, fourth, and fifth
segments gradually increase in length, and have the post-lateral angles
produced backward in long acute processes. The sixth or terminal
segment has the posterior margin triangularly produced in the middle
in a very obtuse point, with two small triangular points just within
the lateral angles, which are short and not much produced.

The peduncle of the uropoda is 4 mm. long, the branches 6i mm.
long, and of equal length.

680

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

The first pair of legs in the male has a fringe or comb of stiff hairs
or bristles along the entire length of the carpus and merus.

FIG. 723.— LlGYDA BACDINIANA (AFTER MOORE). a, SECOND ANTENNA OF FEMALE. 6, FEMALE.

e, FIRST LEG OF FEMALE.

All the legs are ambulatory, with bi-unguiculate dactyli.
The surface of the thorax is covered with small granules.

1SOPODS OF NORTH AMERICA.

681

LIGYDA OCCIDENTALIS (Dana).

Ligiu occidental!* DANA, U. S. Expl. Exp., Crust., XIV, 1853, p. 742, pi. XLIX,
fig. 7; Proc. Acad. Nat. Sci. Phila., VII, 1854-55, p. 176.— STIMPSON, Boat,
Jour. Nat. Hist., VI, 1857, p. 506.— HARPORD, Proc. Cal. Acad. Sci., VII,
1877, p. 116. — BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 264. — UNDER-
WOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 360.— RICHARDSON, Proc.
U. S. Nat. Mus., XXI, 1899, p. 866; Ann. Mag. Nat. Hist. (7), IV, 1899, p.
334; American Naturalist, XXXIV, 1900, p. 306; Harriman Alaska Exp.,
Crust., X, 1904, p. 226; Proc. U. S. Nat. Mus., XXVII, 1904, p. 670.

Localities. — California; San Francisco Bay; San Diego; Santa Cruz
Island, California; Sacra-
mento River; Monterey
Bay ; St. Marguerita Island,
Lower California; Sausa-
lito, California; San Barto-
lome Ba}r, Lower Califor-
nia; Farallones, California
(J. Lindahl); San Jose Is-
land, Gulf of California.

Body oblong-ovate, a lit-
tle more than twice as long
as broad, 12 mm. : 26 mm.
Uropoda 8 mm. long, or less
than one-third the length of
the body. Entire length of
body with uropoda 34 mm.

Head about twice as wide
as long, 2£ mm. : 5£ mm.,
with the anterior margin
widely rounded. Eyes
large, composite, elongate,
and separated in front by a
distance equal to the length
of one eye, 2 mm. First
pair of antennae minute, in-
conspicuous. Second pair
with the first two articles
short and subequal; third
article 1£ mm. long or as
long as the first two articles
together; fourth article 3
mm. long, twice as long as
the third article; fifth arti-
cle 5 mm. in length. The
flagellum is composed of twent\T-nine articles, and extends to the
posterior margin of the sixth thoracic segment. The peduncle

FIG. 724. — LIGYDA OCCIDENTALIS (AFTER DANA), a, PE-
DUNCLE OF SECOND ANTENNA. 6, ABDOMEN AND URO-
PODA. c, JOINTS OF FLAGELLUM. d, TIP OF FLAGELLUM.
e, FIRST LEG OF MALE.

682 - BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

of the second antennae extends to the posterior margin of the second

thoracic segment. The palp of the maxillipeds is composed of five

articles.

The first four segments of the thorax are subequal and each is about

£ mm. longer than any of the last three, which are subequal. The
epimera are perfectly united with the segments, faint
lines of depression marking the place of coalescence.

All six segments of the abdomen are distinct, the first
two being a little shorter than the three following, and
having the lateral parts covered by the seventh thoracic
segment. The third, fourth, and fifth segments gradu-
ally increase in length, and have the post-lateral angles
produced backward in acute processes, which have a
faintly marked carina crossing them obliquely. The

FIG. 725.— LIGYPA terminal segment has the posterior margin triangularly

OCCIDENTALS. , , . . „ , . , ,*'

FIBOT LEG (LAST produced in an obtuse point. Between this and the
TWO JOINTS). > lateral angles, which are acute, are two small points.
The peduncle of the uropoda is 3 mm. long. The
branches are 5 mm. in length and subequal.

The legs are all ambulatory, and have the dactylus bi-unguiculate.
The first pair in the male have the propodus armed at the distal end
on the inner margin with a conspicuous triangular process, similar to
that in L. exotica.
Entire surface of body covered with small granules.

LIGYDA PALLASII (Brandt.)

Ligia pallasii BRANDT, Bull. Soc. Imp£r des Natur. de Moscou, VI, 1833, p. 172.
Ligia dilatata STIMPSON, Bost. Jour. Nat. Hist., VI, 1857, p. 507, pi. xxn, fig. 8.
Ligia septentrionalis LOCKINGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 46.
Ligia slimpsoni MIERS, Proc. Zool. Soc. London, 1877, p. 671 (foot note).
Ligia dilatata SMITH, Report Progress Geol. Survey of Canada, 1880, p. 218.
Ligia pallasii BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 261-262.
Ligia dilatata UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 360.
Ligia pallasii UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 361.—

RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 866; Ann. Mag. Nat

Hist. (7), IV, 1899, p. 334; American Naturalist, XXXIV, 1900, p. 306;

Harriman Alaska Exp., Crust., X, 1904, p. 226; Proc. U. S. Nat. Mus.,

XXVII, 1904, p. 670.

Localities. — Unalaska; Sitka; Wrangel, Alaska; Tanager; Chica
Island, AkutanPass; Lighthouse Rocks, Alaska; Ward Cove, Revilla-
gigedo Island, Alaska; Ky ska Harbor; Aleutian Islands; Nazan Bay,
Atka; Victoria, Vancouver Island; Puget Sound; Port Townsend,
Washington; California; Lowe Inlet, British Columbia; Washington
Territory; Lagonistas Creek, California; Farallones, California; Cape
Mendocino, California. Found on rock beach, under stones.

ISOPODS OF NORTH AMERICA.

683

FIG. 726. — LlGYDA PALLASII (AFTER STJMPSON). X ly.

Body oblong-ovate, nearly twice as long MS broad, 11 nun.: 20 ram.
Length of uropoda from tip of terminal segment of body, 3 mm.
Length of body, including uropoda, 23 mm. Surface covered with
minute granules.

Head more than twice as wide as long, 2 mm. : 5 mm. Anterior mar-
gin widely rounded. Eyes large and round, composite, and situated
close to the lateral margins.
First pair of antennae incon-
spicuous and rudimentary
and composed of two short,
subequal articles and a mi-
nute terminal article. The
first antennae extend only to
the end of the first article of
the peduncle of the second
an te n n 83 . Th e fi rst t wo arti-
cles of the second pair of an-
tennae are equal in length;
the third is nearly twice as
long as the second; the
fourth is 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 twelve articles.
The second pair of antennae extend to the middle of the fourth thoracic
segment when retracted. The maxilliped has a palp of five articles.

The first four segments of the thorax are subequal; the last three
are somewhat shorter in the median dorsal line. The lateral portions

of the last three segments extend
downward. The epirnera of all the
segments are broad plates, occupying
the whole of the lateral margins of
the segments and indicated by dis-
tinct lines.

The abdomen is as wide as the tho-
rax, the lateral parts of the third seg-
ment extending as far as the lateral
parts of the seventh thoracic seg-
ment. The lateral parts of the first
two segments of the abdomen are not
developed; those of the last four segments are well developed and
have the posterior angles produced downward. The lateral parts are
not separated off from the dorsal portion of the segments. On the
lateral parts of the third, fourth, and fifth segments are distinct carinre
extending obliquely from the middle of the segment to the posterior

FlG. 727. — LlGYDA PALLASII. a, MAXILLIPED.
X 20^. b, FIRST LEG OF MALE. X 7J.

684 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

extremity. The terminal segment of the body has the middle portion
of the posterior extremity regularly rounded, the post-lateral angles
not extending quite as far as the middle portion. The basal segment
or peduncle of the uropoda is short, being only 1 mm. in length
from the tip of the middle part of the abdomen. The branches are
equal in length, and are twice as long as the peduncle. The inner
branch is furnished with one short bristle about 1 mm. in length.
The legs are all ambulatory.

LIGYDA OCEANICA (Linnaeus).

Oniscus oceanicus LINNAEUS, Syst. Nat., 12th ed., I, Pt. 2, 1767, p. 1061.
Cymothoa oceanica FABRICIUS, Mantissa Insectorum, I, 1787, p. 242.
Ligia oceanica FABRICIUS, Suppl. Ent. Syst., 1798, p. 301. — BREHISSON, M£m.
Soc. Linn. Calv., 1825, p. 258.

FIG. 728.— LIGYDA OCEANICA (AFTER SARS). a, ANTERIOR LIP. 6, FIRST ANTENNA, c, HEAD

(VENTRAL VIEW), d, TIP OF MANDIBLE, e, SECOND ANTENNA. /, POSTERIOR LIP. Q, MANDIBLE.

h, FIRST MAXILLA, i, DORSAL VIEW OF FEMALE, j, TIP OF MANDIBLE, k, MANDIBLES. I, MAX-
ILLIPED. m, SECOND MAXILLA, n, SEVENTH LEG. o, FIRST LEG. p, SECOND PLEOPOD OF FEMALE.
q, FIRST PEOPOD OF MALE, r, ONE BRANCH OF TJROPODA. s, FIRST PLEOPOD OF FEMALE, t, SEV-
ENTH LEO (TIP), u, UROPOD. v, ABDOMEN (VENTRAL VIEW), w, SECOND PLEOPOD OF MALE.

X, THIKI) 1'I.KOI'OD OF FEMALE.

ISOPODS OF NORTH AMERICA. 685

Ligia onisci'/es BKKHISSOX, Mt'm. Soc. Linn. Calv., 1825, p. 259.

Ligia oceanica BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 259-2H1. — SAKS,
Crust. Norway, II, 1899, pp. 156-157, pi. LXX. — RICHARDSON, American
Naturalist, XXXIV, 1900, p. 306; Proc. IT. S. Nat. Mus., XXIII, 1901, p. 574.

Localities. — Off Newport, Rhode Island; North Sea; Baltic Sea;
Kattegat Sea; Norway; Faroe Islands; coast of Germany; Belgium;
Great Britain; France; Spain; Mediterranean Sea; west shore of
Helgoland.

Body oblong-ovate, a little over twice as long as wide, 8 mm.: IT
mm. Length of uropoda from tip of terminal segment of body equal
to 5 mm. Length of body with uropoda 22-mm. Surface covered
with minute granules.

Head twice as wide as long, 2 mm. : 4 mm. Anterior margin widely
rounded. Eyes large, round, composite, and situated at the extreme
lateral margins. The first pair of antennae are incon-
spicuous and rudimentary; they are each composed of
two articles and a minute terminal one, and reach to
the end of the basal article of the second pair of an-
tennae. The basal article of the second antennae is
veiy short; the second and third are subequal and each
is twice as long as the first; the fourth is twice as long-
as the third; the fifth is one and a half times longer
than the fourth. The flagellum consists of thirteen
articles. When retracted, the second antennas extend
to the posterior margin of the fourth thoracic seg-
ment. The maxilliped has a palp of five articles.

The first six segments of the thorax are subequal; FIG. 729.— LK.JYUA

11 mi 1 1 ' ' • OCEANICA. MAX-

the seventh is a little shorter. The lateral parts of ILLIPED. x 2-{.

the last four segments extend somewhat downward.

The epimera of all the segments are indicated by distinct lines. They

are broad plates and occupy the whole of the lateral margins of the

segments.

The abdomen is not narrower than the thorax, the third segment
being as wide as the last thoracic segment. The lateral parts of the
first two segments are not developed. The lateral parts of the other
segments are not separated off from the dorsal portion. The segments
increase gradually in length from the first to the fifth. The sixth or
terminal segment has the middle part of the posterior extremity regu-
larly rounded. The lateral angles are acute, and do not extend quite
to the tip of the terminal segment. The basal segment or peduncle
of the uropoda is 1 mm. in length from the extremity or tip of the
middle portion of the abdomen. The branches are equal in length,
and are four times as long as the basal segment. The inner branch is
furnished with a short bristle 1 mm. in length.

The legs are all ambulatory.

686 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

124. Genus LIGIDIUM Brandt."

Body oblong; attenuated behind.

First pair of antenna1 projecting in front; terminal joint small, artic-
ulated at one angle of middle joint. Mandibles without ciliated lappet
behind cutting part. Palp of maxillipeds with articles not much
expanded; epignath narrow, linguiform.

Abdomen abruptly narrower than thorax; terminal segment with
the lateral parts not developed.

Uropoda with the peduncle produced at the inner post-lateral angle
in a conical process, to which the inner branch is articulated. Branches
unequal in length; inner branch provided with two long and slender
terminal bristles.6

ANALYTICAL KEY TO THE SPECIES OF THE GENUS LIGIDIUM.

a. Inner branch of the uropoda furnished with two long apical bristles.

b. Inner branch of the uropoda not extending to the tip of the outer branch.

Lit/ldium hypnorum (Cuvier)

I/. Inner branch of the uropoda longer than the outer branch and surpassing it.
c. Inner process of the basal article of the uropoda one-fourth as long as the
outer branch. Inner branch one-sixth part longer than the outer branch;
terminal filaments equal to half the length of the outer branch.

Ligidium tenue Budde-Lund

c'. Inner process of the basal article of the uropoda six or seven times shorter than
the outer branch. Inner branch one-third part longer than the outer
branch. Terminal bristles equal to one-third the outer branch in length.

Ligidium longicaudatum Stoller

of. Inner branch of the uropoda not furnished with apical bristles, but tipped with
setae Ligidium gracilis (Dana)

LIGIDIUM HYPNORUM (Cuvier).

Oniscus hypnorum CUVIER, Jour. d'Hist. Nat., II, 1792, p. 19, pi. xxvi.

Ligidium hypnorum BUDDE-LUND, Naturh. Tidsskrift (3), VII, 1870, p. 225. —
STUXBERG, Ofversigt Vetensk. Akad. Forhandl., 1875, No. 2, p. 48. — BUDDE-
LUND, Crust. Isop. Terrestria, 1885, pp. 254-256. — UNDERWOOD, Bull. 111.
State Lab. Nat. Hist, II, 1886, p. 361.— RICHARDSON, Proc. U. S. Nat. Mus.,
XXI, 1899, p. 867; Ann. Mag. Nat. Hist. (7), IV, 1899, p. 335; American
Naturalist, XXXIV, 1900, p. 306.

Localities. — California; Niagara in Canada; also Sweden, Den-
mark, Germany, France, and the British Isles; Constantinople and
"Chersonese Taurico" (Budde-Lund). Found in moist places. Budde-
Lund thinks that the species found in North America and recorded by
Stuxberg as the above is not likety the same, or rather he doubts that
this species occurs in North America. I have never seen an}* speci-
mens of this species.

«From the description and figures which Prof. S. J. Holmes gives of Styloniscus
gracilw Dana, the species ought to be referred to the genus Ligidium Brandt. The
genus Euphilosciti Packard is probably a synonym of Ligidium.

&See Sars for characters of genus, Crust, of Norway, II, 1899, p. 157, and Budde-
Lund, Crustacea Isopoda Terrestria, 1885.

ISOPODS OF NORTH AMERICA.

687

"Body oblong oval; greatest width not attaining half the length.
Dorsal face rather convex and perfectly smooth and shining. Cepha-
lon of moderate size and evenly rounded in front. Dorsal face trans-
versely grooved behind the eyes. Lateral parts of the three anterior
segments of mesosome but slightly prominent; those of the four pos-
terior segments somewhat larger and terminating behind in obtuse
points. Metasome scarcely exceeding in length one-third of the meso-

FlG. 730.— LlGIDIUM HYPNORUM (AFTER SARS). O, MANDIBLE, b, FIRST ANTENNA. C, ANTERIOR

uv. d, SECOND ANTENNA, e, FIRST ANTENNA. /, FLAGELLUM OP SECOND ANTENNA. </, FIRST MAX-
ILLA, ft, SECOND MAXILLA, i, DORSAL VIEW OF FEMALE. .;', MAXILLIPED. k, MANDIBLES. I, POS-
TERIOR LIP. w, FIRST LEG. M, LATERAL VIEW OF FEMALE, o, SEVENTH LEG, p, UROPOD. q, FIRST

I'LEOPODOF FEMALE. C. LAST SEGMENT OF ABDOMEN AND UROPODA. S, SECOND PLEOPOD OF MALE.

t, EXTREMITY OF OUTER BRANCH OF UROPOD.

some and much narrower, with the epimeral plates small and appressed;
last segment obtusely rounded at the tip, with a slight angle on each
side. Eyes very large, oval, extending down the sides of the cephalon.
Antennulog with the first joint rather thick; second longer, but much
narrower; both armed at the tip inside with three rather long diverg-

688 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

ing spines; last joint very small, narrow cylindric. Antenna- rather
sU-nder, though not nearly attaining half the length of the body.
Flagelluni somewhat shorter than the peduncle, and composed of about
eleven articulations, the last tipped with a dense bunch of delicate hair-
like bristles. Legs armed with scattered slender spines; propodal joint
very narrow and elongated; dactylus simple. Inner plate of first pair
of pleopoda in male slightly produced at the tip and provided with four
apical bristles. Uropoda scarcely exceeding half the length of the
metasome; inner projection of the basal part occupying about half its
length; outer rauius gradually tapering distall3T and carrying on the
tip three short bristles; inner ramus very narrow, linear, not extend-
ing to the tip of the outer; apical bristles nearly as long as the ramus.
Color of dorsal face light fuscous, variegated with irregular dark
patches, which, on each side at the base of the lateral plates of meso-
some, form a nearly continuous longitudinal band. Length of adult
female, 9 mm."— G. O. SARS.«

LIGIDIUM TENUE Budde-Lund.

Ligidium tenue BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 258. — RICHARDSON,
Proc. U. S. Nat. Mus., XXI, 1899, p. 867; Ann. Mag. Nat. I lift. (7), IV,
1899, p. 335; American Naturalist, XXXIV, 1900, p. 306.

Locality. — Sitka Island.

Body elongate, narrow, posteriorly attenuated, somewhat convex,
smooth.

Second pair of antenme lost in the specimen.

Transverse line of the epistome raised, straight, or very slightly
sinuated in the middle.

« Crust, of Norway, II, 1899, p. 158. The description which follows is that of
G. Budde-Lund:

Oblonge ovatum, post attenuatum, leviter convexum, Iseve, nitidum.

Antenna? exteriores graciles, dimidium corpus longitudine requantes; flagellum
10-13 articulatum.

Oculi sat magni.

Caput ante rotundatum, linea frontalis marginalis nulla; epistonia linea trans-
versa elevata, medio acute sinuata; vertex sulco postico supramarginali duobusque
suit-is post oculos arcuatis pra'ditus.

Trunci annul i duo priores margine posteriore curvato, duo sequentes subtraneversi,
tres posteriores post magis medio sinuati. Epimera parva, angulis posticis annulo-
rum duorum priorum rotundate obtusis, annulorum duorum sequentiuin subrectis,
trium posteriorum acutis.

Pedes graciles; unguiculi appendice gemina, flabellata.

Cauda trunco abrupte angustior. Annulus analis late rotundate triangnlns. Pro-
cessus internusarticuli basalis peduin analium ramo terminali exteriore triple brevior.
Ramus terminalis interior gracilis, apicem rami exterioris subattingens, filis duobus
terminalibus tenerrimis, ramum exteriorem longitudine sequantibus.

Color e fusco brunneus, albido vel flavo marmoratus, in lateribns pallidioribus
serie longitudinal! macularum nigrof uscarum ; vivus pruinosus.

Longitude 7-10mm., latitude 3-4 mm. , altitudo, 1.6-1.8 mm. — BUDDE-LCND, Crust.
Isop. Terreatria, 1885, pp. 254-256.

ISOPODS OF NOKTH AMERICA.

689

Inner process of the basal article of the uropoda one-fourth as long
as the outer branch. Inner branch long, extending much beyond the
apex of the outer branch, being a sixth part longer than that branch,
the two terminal filaments short, equal to half the length of the outer
branch.

Color dark, without spots. Length 9 mm. Width 3 mm.a

LIGIDIUM LONGICAUDATUM Stoller.

Ligidium lungicaudatum STOLLER, 54th report New York State Museum, 1902,
pp. 208-211.

Locality. — Schenectady, New York.

Body oblong-ovate, about twice as long as wide, 3 mm.: 6 mm.
Uropoda. 2 mm. Length of body with uropoda, 8 mm. long.

Head twice as wide as long, 1 mm.: 2 mm., with the anterior mar-
gin widely rounded. Eyes round, com-
posite, and situated close to the lateral
margins. The first pair of antennae are
small and almost inconspicuous. They
are composed of three articles — two
subequal ones and a minute terminal
one. They extend to the end of the sec-
ond article of the peduncle of the sec-
ond pair of antenna1. The second pair
of antennae have the first two articles
short and subequal; the third is but
little longer than the second; the fourth
and fifth are equal in length and each is
about twice as- long as the third. The
flagellum is composed of eleven articles,
the terminal article ending in a bunch
of hairs. When retracted, the second
antennae extend to the posterior mar-
gin of the third thoracic segment.

The first four segments of the thorax
are subequal and each is a little longer
than any of the last three, which are sub
equal. The epimera are not distinctly separated on any of the segments.

The first segment of the abdomen has the lateral parts concealed by

«The above description is adapted from the following one of Budde-Lund's:

Elongatum, angustum, post attenuatum, leviter convexum, lyeve, nitidum.

Antenna} exteriores — — .

Epistomatis linea transversa, elevata, subrecta vel medio levissime sinuata.

Processus internus articuli basalis pedum analium ramo terminali exteriore quad-
rnplo brevior. Ramus terminalis interior longus, apicem raini exterioris multum
superani-s illo sexta parte longior, fills dnobus terminalibus brevibus, dimidiam
partetn ranii exterioris ;equantibus.

Color fuscus, immaculatus. Longitude 9 mm., latitudo 8 mm. — BrnDE-Luxn,
Crust. Isop. Terrestria, 1885, p. 258.
28589—05 44

FIG. 731. — LIGIDIUM LONGICAUDATUM
(AFTER STOLLER). x 5^.

690 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

the seventh thoracic segment. The four following segments have the
lateral parts well developed. The sixth or terminal segment is rounded
posteriorly, with a slight emargination on either side of the rounded
median lobe for the reception of the basal articles of the uropoda. The
basal article of the uropoda has the inner distal angle produced so that
the inner side measures one and a half times longer than the outer side.
The inner branch of the uropoda is two and a half times longer than
the peduncle measured from the inner side; it terminates in two long
subequal hairs, which are a little less than one-fourth the length of the
inner branch. The outer branch is shorter than the inner branch, the
inner branch being a little less than one and a half times longer than
the outer branch. The outer branch is also tipped with two short hairs.

All the legs are ambulatory.

In color it is a reddish brown, mottled with yellow, and with two
longitudinal rows of yellow spots, one on either side of the body about
the place where the epimera are united with the segments.

LIGIDIUM GRACILIS (Dana).

Styloniscus gracilis DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854-55, p. 176. —
STIMPSON, Bost, Jour. Nat. Hist, VI, 1857, p. 506.

Alloniscus maculosus HARFORD, Proc. Cal. Acad. Sci., VII, 1877, p. 54.

Styloniscus gracilis BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 271. — UNDER-
WOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 364.— RICHARDSON, Proc.
U. S. Nat. Mus., XXI, 1899, p. 867; Ann. Mag. Nat. Hist. (7), IV, 1899, p.
335; American Naturalist, XXXIV, 1900> p. 306.— HOLMES, Proc. Cal. Acad.
Sci. (3), III, 1904, pp. 318-319.

Locality. — California.

' ' Thoracic segments smooth, glossy, and of subequal length ; postero-
lateral and antero-lateral angles of the first four rounded, the postero-
lateral angles of the last three segments acute and produced backward.

"Abdomen longer than wide, abruptly narrower than the thorax,
the first two segments shorter than the others, the three following
segments with the postero-lateral angles acute and produced backward.
Terminal segment twice as wide as long and very broadly rounded.

"Head transverse, devoid of prominences, front broadly rounded.
Eyes rather large, reaching the lateral margins of the head. Anten-
nules three-jointed, not exceeding the second basal joint of the antennae;
first joint broad, distally widened; second joint subcylindrical, slightly
longer and much narrower than the first; third joint very minute and
joined to one corner of the preceding. Antennae nearly one-half the
length of the body, first joint short, transverse, second and third joints
oblong, cylindrical, subequal, fourth joint as long as the three preced-
ing, fifth joint narrower and slightly longer than the fourth; flagellum
about as long as the two preceding joints and composed of thirteen to
fifteen articulations.

"Mandibles short and ve^ stout, having a large molar tubercle and

ISOPODS OF NORTH AMERICA.

691

a narrow dark colored, dentate cutting edge, but no palp. First max-
illae with the inner plate short and furnished with three short ciliated
setae, the upper one much shorter than the lower two, which are of
subequal length ; outer plate narrow and armed with live curved teeth.
Second maxillae narrow, with two very small ciliated plates on the
inner margin near the rounded tip. Inner plate of the maxillipeds
with several short, densely ciliated processes on the transverse distal
margin and a large ciliated seta on the inner side; palp five-jointed,
the terminal joint minute.

" Legs very spiny below; dactyls short, furnished with several setse
and one or two spines below, near the tip. Uropods slender, fully

FIG. 732. — LlGIDIUM GRACILIS (AFTER HOLMES), a, MAXILLIPED. 6, GENERAL FIGURE. C, FIRST LEG.

one-half the length of the abdomen; peduncle oblong, flattened, the
inner angle strongly produced backward; rami slender, microscop-
ically scabrous but devoid of spines; inner ranius exceeding the outer
in length, but slightly more slender, the tip furnished with setae.

"The body is furnished with scattered fine short hairs, which are
more conspicuous on the posterior margins of the segments.

''Length ?\ inch." — HOLMES. a

«The above description is quoted from Proc. Cal. Acad. Sci., (3), III, 1904, p. 318,
and is made originally from the three type specimens of Allonwcus maculosus Harford,
which Mr. Holmes identifies with Styloniscus gracilis Dana, the description of which
follows:

Corpus gracile. Abdomen paulo oblongum, subovatum, thorace postico subito
paululo angustius, segmentis 3 tio, 4 to, 5 toque lunatis. Styli caudalis basis brevis,
vix duplo longior quam latus, extus ad medium subito angustior. Antennae externse
fere nudae, flagello ferme 14 articulato, nudo, articulos basis duos precedentes longi-
tudine fere aequante. — Long. 5 mm.

As in other species of this genus, the outer antennae have not the double genicu-
lation characterizing the Oniscidae. The surface of the body is smooth; yet there
are a few exceedingly minute hairs, especially along the posterior margin of the seg-
ments of the abdomen. The branches of the caudal stylets in the specimen are
mutilated.— DANA, Proc. Acad. Nat. Sci. Phila., VII, 1854-55, p. 176.

692 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

125. Genus EUPHILOSCIA Packard.

•'The genus Euphiloudd/ differs from Philoscia in the flagellum of
the outer antennae being subdivided into fifteen joints, while it is no
longer than in the latter genus. The second and third joints are rather
short; the inner (and smaller) antennae are very much larger. The
body is longer and slenderer, and the abdomen much longer and
wider in proportion to the rest of the body, being large and rounded,
not mucronate. Uropoda much longer and slenderer than in Philos-
cia, being as long as the basal abdominal segment is wide; thejr are
subequal. Eyes larger than in Philoscia. In the form of the legs
and the setse this genus more closely resembles Philoscia than Phi-
lougria, and is some respects intermediate between the two genera. "-
PACKARD. a

EUPHILOSCIA ELRODII Packard.

Euphilosda elrodii PACKARD, 5th Report Peabody Acad. Sci., 1873, p. 97. — SMITH,
Amer. Jour. Science and Arts (3), IX, 1875, p. 477. — UNDERWOOD, Bull.
111. State Lab. Nat. Hist., II, 1886, p. 361. — RICHARDSON, American Natural-
ist, XXXIV, 1900, p. 306.

Locality. — Indiana.

" Having no other species with which to compare my two specimens
of this species, I can only remark that it is of the usual color of the
species of Philoscia found running about in moss, and the cave specimens
had not been altered by their subterranean life. The eyes are dark as
usual, while the body is mottled with brown and carneous, with no
well-marked dorsal streak." — PACKARD. b

Family XXIX. TRICHONISCID^E/

Body elongated.

Head with distinct lateral lobes; front scarcely marginate, more or
less produced, not separated from the epistome. Eyes composite,
simple or wanting. Inner lobe of the first maxillas furnished with
three plumose processes. Palp of the maxillipeds large, imperfectly
articulated; masticatory lobe terminating in a thin lash, epignath
narrow. Mandibles with the molar expansion well developed. First
pair of antennae very small, inconspicuous; terminal joint furnished
with olfactory hairs. Flagellum of the second pair of antennae com-
posed of a limited number of articles.

Lateral parts of the thoracic segments not much expanded.

Opercular plate of pleopoda not furnished with tracheae.

Uropoda with the basal article expanded inside; branches subequal,
slender, or the outer one stouter, both conically tapered.

"Fifth Report Peabody Academy of Sciences, 1873, pp. 9(5-97.
'' Idem, p. 97.

'" For characters of family see Budde-Lund, Crust. Isopoda Terrestria, 1885, p. 243,
and G. 0. Sars, Crust, of Norway, II, 1899, pp. 159-160.

ISOPOD9 OF NORTH AMERICA. ()93

ANALYTICAL KEY TO THE GENERA OF THE FAMILY TRICHONISCID^E.

a. Eyes present.

ft. Body not sculptured dorsally with longitudinal ribs. Lateral parts of the tho-
racic segments not expanded. Second pair of antenme long. Branches of the
uropoda terminating in a bunch of hairs. Epignath of maxillipeds narrow,
linguiform with a rounded expansion at the base. Abdomen abruptly nar-
rower than thorax Genus Trichoniscus Brandt

b' '. Body sculptured dorsally with longitudinal ribs. Lateral parts of thoracic seg-
ments expanded. Second pair of antenme short. Inner branch of the uropoda
terminating in a slender spine. Epignath of maxillipeds simple, lanceolate.
Abdomen not abruptly narrower than thorax. .Genus Haplophthalmns Schobl
a' '. Eyes absent Genus Brackenridgia Ulrich

126. Genus TRICHONISCUS Brandt."

Body oblong.

Head usuall}' rounded in front, generally with small but distinct
lateral lobes.

Eyes small, distinct, composed of three ocelli. Second pair of anten-
nae generally long.

Palp of maxillipeds with the four joints confluent; masticatory lobe
nearly as large as the palp and terminating in a narrow, ciliated lash;
epignath narrow, linguiform, with a rounded expansion at the base.

Abdomen abruptly narrower than thorax; lateral parts of all the
segments visible, small.

Terminal abdominal segment usually truncate at tip, and slightly
emarginate on each side.

Legs long, slightly increasing in length posteriorly; joints furnished
with spines.

Inner branch of the first pair of pleopods greatly produced and
bi-articulate in the male.

Basal article of uropoda broad and flattened, both branches termi-
nating in a bunch of hairs.

ANALYTICAL KEY TO THE SPECIES OF THE GENUS TRICHONISCUS.

a. Surface of body smooth. Front of head straight with small lateral lobes. Last
three articles of second pair of antenme with the inner margins not beset with
tubercular-like papilla?. Terminal segment of abdomen with apex truncate.

Trichoniscus pusillus Brandt

a' '. Surface of bpdy covered with low tubercles. Front of head triangularly pro-
duced, with apex slightly emarginate; antero-lateral lobes large. Last three
articles of second pair of antenna? with the inner margins beset with tubercular-
like papillae, each surmounted with a tuft of short stiff hairs. Terminal seg-
ment of abdomen with apex rounded Trichoniscus papillicornis Richardson

«See Budde-Lund for characters of genus, Crust. Isop. Terrestria, 1885, p. 243, and
Sars, Crust, of Norway, II, 1899, pp. 160-161.

094 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

TRICHONISCUS PUSILLUS Brandt.

Trii'honisctis pusillw* BRANDT, Bull. Soc. Impor. des Naturalistes de Moscou, VI,
1833, p. 12, pi. iv, fig. 9.

/tea riparia KOCH, Deutschl. Crust., 1835-44, p. 22.

Itea Lrrix ZADDACH, Synops. Crust. Pruss., 1844, p. 16.

Philougria riparia KINAIIAN, Nat. Hist. Rev., IV, 1857, p. 281, pi. xxn, figs. 1-4.

Trichmiscus pusilhts STUXBER<;, Ofversigt-Vetensk-Akad. Forhandl., 1875, -No.
2, p. 49. — BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 244-245.— UNDER-
WOOD, Bull. 111. State l^ab. Nat. Hist., II, 1886, p. 364.— SARS, Crust, Nor-
way, II, 1899, p. 161.— RICHARDSON, American Naturalist, XXXIV, 1900,
p. 307; Proc. U. S. Nat. Mus., XXIII, 1901, p. 575.

c .,...^, ^^^ d

FIG. 733.— TRICHONISCUS PCSILLUS (AFTER SARS). a, ANTERIOR AND POSTERIOR LIPS. 6, FIRST
MAXILLA. <•, DORSAL VIEW OF FEMALE, d, FIRST ANTENNA, e, SECOND ANTENNA. /, TERMINAL

JOINT OF FIRST ANTENNA, g, MANDIBLES, h, MAXILLIPED. i, LAST SEGMENT OF ABDOMEN AND

TTROPODA. j, SECOND MAXILLA, it, 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 PLEOPOD. «, FIFTH PLEOPOD.

ISOPODS OF NORTH AMERICA. <)95

Localities. — North America; also Sweden, Denmark, Germany,
France, Great Britain, Spain, Algeria, and Norway.

Body oblong-ovate, three times as long as wide, 1 mm. : 3 mm.

Head wider than long, with the anterior margin produced in a
widely rounded, obtuse median lobe. There are no antero-lateral
lobes. The eyes are small, round, composite, and situated in the
antero-lateral angles of the head. The first pair of antennae are rudi-
mentary and inconspicuous. The first three articles of the second
antennae are short, the first two being subequal, the third, one and a
half times longer than either of the others; the fourth and fifth are
subequal and each is one and a half times longer than the third. The
flagelluin is composed of four or five ill-defined articles. The maxil-
liped has a palp of two articles. The palp of the mandibles is
wanting.

The segments of the thorax are subequal. The epimera are not
separated oif on any of the segments.

The abdomen is abruptly narrower than the thorax. The first two
segments have the lateral parts covered by the seventh thoracic seg-
ment. The sixth, or terminal, segment is wide posteriorly, with the
post-lateral angles rounded and a slight emargination in the middle of
the posterior margin. The basal article of the uropoda or the peduncle
extends as far as the posterior margin of the terminal segment. The
inner branch is more slender and is a little shorter than the outer
branch. Both branches extend
some distance beyond the abdo-
men. All the legs are ambula-
tory.

TRICHONISCUS PAPILLICOR-
NIS Richardson.

Trichoniscus papillicornis RICHARD-
SON, Harriman Alaska Exp.
Crust., X, pp. 213-230; Proc.
U. S. Nat. Mus., XXVII, 1904,
pp. 670-671.
Locality.— Seldovia, Cook In- FIG- 734.-TBicHoxiscu8 PAFILLICORMS. HEAD AND

FIRST THORACIC SEGMENT. X 41.

let, Alaska.

Body covered with low tubercles. Color light brown.

Head with sides produced at the antero-lateral angles in large lobes;
front triangularly produced with a slight emargination at the apex of
the triangle. E3res situated on the lateral margins at the base of the
antero-lateral lobes; they are small and black and apparently simple
in structure. The peduncle of the antennae consists of five stout joints,
the last three of which have the inner margins beset with numerous
strong tubercular-like papillae, each surmounted with a tuft of short

696

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

stiff hairs or bristles; the fifth joint is also produced at the outer distal
angle in an acute process. The fiagellum is composed of about seven
articles, rather indis-
tinctly defined; the last
article is tipped with
a bunch of hairs. The
buccal mass is very
prominent below.

The segments of the
thorax are about equal
in length. The post-
lateral angles of all
the segments, except
the first, are produced

backward, very slightly in the case of the second,
third, and fourth, but becoming gradually more so,
until the last two segments show this
character very markedly.

The abdomen is narrower than the thorax. All the
segments are visible in entirety, not being covered
laterally bjr the last thoracic segment. The terminal

FIG. 736.— TRICHONISCUS PAPILLICORNIS.
UROPODA AND LAST SEGMENT OF ABDO-
MEN, x 77.

FIG. 735.— TRICHONIS-
CUS PAPILLICORNIS.
x 15.

segment is triangularly produced, with the apex some-
what rounded. The uropoda
are short, styliform; the outer
branch is the stouter, and ex-
tends a little beyond the ex-
tremity of the inner branch.
Both branches are tipped with a
few hairs.

Only a single specimen was

obtained by the Harrirnan Alaska Expedition. It was found on the

beach at Seldovia, Cook Inlet.
The type is in the U.S.N.M., Cat. No. 28772.

127. Genus HAPLOPHTHALMUS Schobl."

Body oblong, somewhat convex, sculptured dorsally with longitudi-
nal ribs.

Head triangularly produced in the middle; lateral lobes large; front
scarcely defined from the epistome. Eyes small, simple/dorsally situ-
ated. Second pair of antennae short, nearly equal to one-third the
length of the body. Palp of maxillipeds obscurely composed of five
articles; epignath simple, lanceolate.

FIG. 737. — TRICHONISCUS PA-
PILLICORNIS. LEG OF FIRST
PAIR, x 15.

FIG. 738.— TKH-HO-
NISCUS PAPn.i.i-
CORNIS. UROPOD
OF LEFT SIDE.
X 77.

«See Sars for characters of genus, Crust, of Norway, II, 1899, pp. 166-167, and
Budde-Lund, Crust. Isop. Terrestria, 1885, p. 249.

ISOPODS OF NORTH AMERICA. 697

Abdomen not abruptly narrower than the thorax; epimera large, dis-
tant; terminal segment truncate.

Lateral parts of the thoracic segments expanded, discontinuous.

Inner branch of the first pair of pleopods in the male, produced,
biarticulate, that of the second pair in the male triarticulate. Inner
branch of the uropoda terminating in a single, slender spine: basal
article broadly expanded inside.

Legs rather short and thick, scarcely increasing in length posteriorly.

HAPLOPHTHALMUS PUTEUS Hay.

Haplophthalmus puteus HAY, Proc. U. S. Nat. Mus., XXI, 1899, pp. 871-872, pi.
LXXXVI, figs. 1-15.

Localities. — Wells in Indiana.

"Male. — Body elliptical, length about three times the breadth, dor-
sal surface strongly convex, covered with longitudinal rows of low
tubercles and scattered seta?. Segments of the person about equal in
length, the posterior pleural angle of all, except the first, more or less
produced backward. Pleura? of third, fourth, and fifth segments of
the pleon thin and directed backward and outward. Terminal seg-
ment of abdomen notched behind and with the postero- lateral margins
concave. Uropods exserted, short, outer ramus longer than inner;
both rami setose. Front margin of head very slightly produced.
Antenna1 longer than the greatest breadth of the body; first and sec-
ond segments of medium length, third short, fourth and fifth long;
flagellum short, pinniform, composed of three very small, closely
articulated segments. Antenna? geniculate between segments four
and five. Antennules minute, composed of three segments entirely
concealed by the front of the head, sensory filaments five. Eyes
small, simple. Upper lip regularly rounded in front and with a
median triangular patch of setae. Mandibles large and powerful,
bearing on the inner surface a broad, ridged molar tubercle; on the
anterior surface, one or two delicate, branched sensory styles. The
cutting portion of the mandibles is different; that on the left consists
of two portions, an outer with four heavy teeth and an inner with
three much smaller teeth: the outer mandible has but one row of
three or four large teeth which, when closed, fit in the space between
the two rows of teeth of the mandible first described. The first max-
illa has both branches erect, the outer bearing five or six acute curved
teeth, the inner three delicate plumose flagelliform processes. The
second maxilla consists of two strap-shaped lamella? closely applied to
one another and bearing seta? at their ends. The maxilliped is a
broad, low, flattened plate, with straight inner and rounded outer
margins, and bearing at the tip two obscurely segmented setose proc-

G98 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

esses. The perseopods are similar in general to one another, differing
only in the arrangement and strength of the spines.

FIG. 739.— HAPLOPHTHALMUS PUTEUS (AFTER HAY), a, DORSAL VIEW OF MALE, b, RIGHT MANDIBLE.

C, TIP OF LEFT MANDIBLE, d, FIRST MAXILLA. C, MAXILLIPED. /, UPPER LIP. g, SECOND ANTENNA.

h, FIRST ANTENNA, i, FIRST LEG. j, FIRST PLEOPOD. fc, SECOND PLEOPOD. I, THIRD PLEOPOD. m,
FOURTH PLEOPOD. n, FIFTH PLEOPOD. o, UROPOD.

ISOPODS OF NORTH AMERICA. 699

"The first and second pairs of pleopoda are two segmented, slender,
and styliform. The second pair appear to be the sexual organs, while
the first are to some degree rudimentary.

" The third pleopod is flattened and somewhat operculiform.

" The fourth and fifth pleopods are broad, flat, thin, and lie flat
upon one another and the last segment of the pleon. They and the
preceding are the branchial appendages of the animal.

"The uropoda have been already described.

"Color white; eyes black; intestine showing through the shell as a
grayish line.

"Female: Similar in general characters to the male, but with the
following differences: Body not more than two and one half times as
long as wide. First and second pleopods absent. Perseopods, with
flattened plates, forming a brood or egg chamber.

"Length, 3 to 4 mm.

"Type.—Ko. 22586, U.S.N.M."— W. P. HAY."

128. Genus BRACKENRIDGIA Ulrich.

Eyes absent.

Median and antero-lateral lobes of head almost obsolete. Flagellum
of second antennae composed of seven articles. Abdomen abruptly
narrower than thorax; sixth or terminal segment posteriorly rounded..
Body without longitudinal ribs.

Right mandible with two appendages back of cutting surface; another
fringed appendage on the hind cutting surface. Left mandible with
two fringed appendages next to cutting surface. Maxilliped with a
palp composed of three articles and with two small projections on the
anterior margin. Outer branch of uropods longer than abdomen,
conical. Inner branch much smaller, spiny.

BRACKENRIDGIA CAVERNARUM Ulrich.

Brackenridgia cavernarum ULRICH, Trans. Amer. Microscopical Soc., XXIII,
1902, pp. 90-93, pi. xvr, figs. 1-9.

Localities. — Ezell's Cave and Beaver Cave, near San Marcos, Texas.

Body oblong-ovate, about three times longer than wide, 1£ mm. : 4£
mm.

Head wider than long, with the frontal margin almost straight, the
median and lateral lobes being almost obsolete. Eyes absent. The
first pair of antennae are rudimentary and inconspicuous. The second
pair have the first and second articles subequal in length; the third
article is a little longer than the second; the fourth is one and a half

« Proc. U. S. Nat. Museum, XXI, 1899, pp. 871-872. Although the types (two or
three fragments) are in the U. S. National Museum, they have been so mutilated,
through dissection, that I have found it more satisfactory to quote the above.

BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

times as long as the third; the fifth is a little longer than the fourth.
The flagellum is composed of seven articles.

The segments of the thorax are subequal in length. The lateral
margins are straight. The epimera arc not distinctly separated from
the segments.

The abdomen is abruptly narrower than the thorax. The first two

FIG. 740.— BRACKENRIDGIA OWERNAKUM (AFTER ULRICH). a, DORSAL VIEW, b, SECOND ANTENNA.

C, LAST ABDOMINAL SEGMENT WITH tJROPODS. d, MAXILLIPED. e, THORACIC LEG. /CLAW. </, ONE

OF UROPODA. h, FIRST MAXILLA, i, MANDIBLES.

segments have the lateral parts covered by the seventh thoracic seg-
ment. The sixth or terminal segment has the posterior margin
rounded. The basal article of the uropoda does not extend beyond
the extremity of the last abdominal segment. The inner branch is
about half as long as the outer branch.

The legs are all ambulatory in character. The seventh pair has the
outer distal extremity of the propodus surmounted with a crest of
hairs.

LIST OF REFERENCES.

ADAMS, ARTHUR, in White, Adam. Sutherland's Voyage Baffin's Bay, II, appendix,

1852, pp. ccvi-ccvii. London, 1852.
AGASSIZ, ALEXANDER. Three cruises of the United States Coast and Geodetic Survey

steamer Blake in the Gulf of Mexico, in the Caribbean Sea, and along the

Atlantic coast of the United States, from 1877-1880. II, Pt. 16. Characteristic

deep-sea types. — Crustacea. Bull. Museum of Comparative Zoology, Harvard

College, XV, 1888, pp. 37-52, figs. 225-259. Cambridge, 1888.
ALCOOK, A., and WOOD-MASON, J. Natural history notes from H. M. Indian marine

survey steamer Investigator, Commander R. F. Hoskyn, R. N., commanding.

No. 21. Note on the results of the last season's deep-sea dredging. Ann. Mag.

Nat. Hist. (6), VII, 1891, pp. 270-271. London.
AUDOUIN, JEAN- VICTOR. Description de 1' Egypte, ou recueil des observations, et des

recherches qui ont ete faites en Egypte pendant 1'expedition de 1'armee fran-

yaise. Explication sommaire des planches de crustaces de 1' Egypte et de la

Syrie. Publiees par J.-C. Savigny. Histoire naturelle, I, Pt. 4, pp. 77-98.

Paris, 1826.
AUDOUIN, JEAN-VICTOR, and EDWARDS, HENRI MILNE. Resume d'eutomologie, ou

d'histoire naturelle des animaux articules, complete par une iconographie de 48

planches. 2 vols. Paris, 1828-29.
Precis d'entomologie ou d'histoire naturelle des animaux articules.

Premiere division. Histoire naturelle des annelides, crustaces, arachnides et

myriapodes, complete par une iconographie. Paris, 1829.
BATE, C. SPENCE. Crustacea in List of the British Marine Invertebrate Fauna, by

Robert McAndrew. Report of the British Association for the Advancement of

Science, 1861, pp. 217-236. London.
Characters of new species of crustaceans discovered by J. K. Lord on the coast

of Vancouver Island. Proc. Zool. Soc. London, 1864, p. 668. London.
Lord's Naturalist in British Columbia, II, 1866. London.

— Carcinological gleanings. No. 3. Ann. Mag. Nat. Hist. (4), I, 1868, pp.

442-446. London.

Report on the Crustacea Macrura collected by H. M. S. Challenger during the

years 1873-1876. Challenger Report, XXIV, 1888, Pt. 52, p. 574; also pp. 645-

646. London.
BATE, C. SPENCE, and WESTWOOD, JOHN O. A History of the British Sessile-eyed

Crustacea, II, 1868. London.
BEDDARD, F. Preliminary notice of the Isopoda collected during the voyage of

H. M. S. Challenger. Proc. Zool. Soc. Lond., 1886, pp. 97-122. London.
Report on the Isopoda. Report of the scientific results of the voyage of

H. M. S. Challenger during the years 1873-1876, XVII, 1886, pp. 1-175, pis.

i-xxv. London, 1886.
BENEDICT, J. E. Preliminary descriptions of a new genus and three new species of

Crustaceans from an artesian well at San Marcos, Texas. Proc. U. S. Nat. Mus.,

XVIII, 1895, pp. 615-617. Washington, 1896.

— A revision of the genus Synidotea. Proc. Acad. Nat. Sci. Phila., 1897, pp.

389-404. Philadelphia.
The Arcturidai in the U. S. National Museum. Proc. Biol. Soc. Washington,

XII, 1898, pp. 41-51. Washington.

701

702 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

BENEDICT, J. E. Two new Isopods of the genus Idotea from the coast of California.
Proc. Biol. Soc. Washington, XII, 1898, pp. 53-55. Washington.

BILIMEK, DOMINIK. Fauna der Grotte Cacahuamilpa in Mexico. Verhandl. zool.-
bot. Gesellsch. Wien, XVII, 1867, pp. 901-908. Vienna.

BONNIER, JULES. Edriophthalmes. (Resultatsscientifiquesdelacampagnedu "Cau-
<lan" dans le golfe de Gascogne.) Ann. Univ. Lyon, XXVI, 1896, pp. 527-689.
Paris.

— Contribution il l'e"tude des Epicarides — les Bopyridae. Travaux de la Station
Zoologique de Wimereux, VIII, 1900, pp. 1-396, pis. I-XLI. Paris.
— and GIARD, ALFRED. Contributions a 1' etude des Bopyriens. Travaux de
1' Institute Zoologique de Lille et du Laboratoire de Zoologie Maritime de Wim-
ereux, V, 1887, pp. 1-252, pis. i-x. Lille.

Sur deux nouveaux genres, Probopyrus et Palsegyge. Bull. Scient. ,

XIX, 1888, pp. 53-77. Paris.

Sur quelques especes nouvelles de ceponiens. Comptes Rendus, CV1I,

1888, pp. 44-47. Paris.

Prodrome d'une monographic des Epicarides du Golfe de Naples.

Bull. Scient., XXII, 1890, pp. 367-391. Paris.

Contributions a 1'etude des Epicarides. Bull. Sci. de la France et de la

Belgique (4), XXV, 1893, pp. 415-493, pis. v-xm. Paris.

Sur deux types nouveaux d'Epicarides parasites d'un Cumace et d'un Schizo-

pode. Comptes Rendus, CXXXVI, 1903, pp. 102-103. Paris.
Bosc, Louis A. G. Histoire Naturelle des Crustaces, II, 1802. Paris.
BOUVIER, E. L. Observations nouvelles sur les Bathynomux, isopodes gigantesques

des grands fonds. Compt. Rend. Acad. Sci., CXXXII, 1901, No. 10, pp. 643-

645. Paris, 1901.

Also in Revue Scientifique (4), XV, No. 12, 1901, p. 376.
La circulation branchiale chez les Bathynomes. [Crust.] Bull. Soc. Entom.

France, 1901, pp. 122-123. Paris.
BOUVIER, E. L., and EDWARDS, A. MILNE. Reports on the results of dredg;ng under

the supervision of Alexander Agassiz in the Gulf of Mexico (1877-1878), in the

Caribbean Sea (1878-1879), and along the Atlantic coast of the United States

(1880), by the U. S. Coast Survey steamer Blake, Lieut. Commander C. D. Sigs-

bee, U. S. Navy, and Commander J. R. Bartlett, U. S. Navy, commanding. XL.

Les Bathynomes. Memoirs, Museum Comparative Zoology at Harvard College,

XXVII, No. 2, 1902, pp. 141-175, pis. i-vin. Cambridge.
BOVALLIUS, CARL. lanthe, a new genus of Isopoda. . Bihang till Kongl. Svenska

Vetenskaps-Akademiens Handlingar, VI, 1881, No. 4, pp. 3-14, pis. i-ni.

Stockholm.

— A new Isopod from the coast of Sweden. Bihang till K. Svenska Vetensk.
Akad. Handlingar, X, No. 10, pp. 3-10, pis. i-ii. Stockholm, 1885.

— New or imperfectly known Isopoda. Pt. I. Bihang till K. Svenska Vet.-
Akad. Handlingar, X, No. 11, pp. 1-32, pis. i-v. Stockholm, 1885.

Notes on the family Asellidae. Bihang till Kongl. Svenska Vet. -Akad.

Handl., XI, No. 15, 1886, pp. 1-52. Stockholm.
New or imperfectly known Isopoda. Pt. II. Bihang till K. Svenska Vet.-

Akad. Handlingar, XI, No. 17, pp. 1-18, 1886, pis. i-n. Stockholm.
BRANDT, ED. Ueber den Albinismus bei den Kellerasseln. Horse Societatis Ento-

mologicse Rossicse, VIII, 1870. St. Petersburg.
BRANDT, F. Middendorff s Reise in den aussersten Norden und Osten Sibiriens, II,

Zool., Pt. I, 1851, pp. 145-147. St. Petersburg.
BRANDT, J. F. Conspectus Monographic Crustaceorum Oniscodorum Latreillii.

Bull. Soc. Imper. des Natur. de Moscou, VI, 1833, pp. 171-193. Moscou.
BRANDT, J. F., and RATZEBURG, J. T. C. Medizinische Zoologie, II, 1830-34. Berlin.

ISO PODS OF NORTH AMERICA. 703

•

BRANDT, M. E. Du systeme nerveux de 1' Idothea entomon (Crustace isopode).

Comptes Kendus, 1880, pp. 713-715. Paris, 1880.
On the nervous system of Idotea entomon. Ann. Mag. Nat. Hi^t, VI, 1880,

pp. 98-99. London.
BREBISSON, M. DE. Catalogue des Crustaces terrestres, fluviatiles et marins, recueillis

dans le Departement du Calvados, lu u la seance du 14 mars 1825. Memoires de

la Societe Linneenne du Calvados, 1825, pp. 225-270. Caen and Paris, 1825.
BUCHHOLZ, REINHOLD. Zweite deutsche Nordpolfahrt "in den Jahren 1869 und

1870, unter Fiihrung des Kapitiin Koldewey." II, Pt. 8, Crustaceen, pp. 262-

399, pis. i-xv, 1874. Leipzig.
BuDDE-LuND, G. Danmarks Isopode Landkrebsdyr. Nat. Tidsskrift. (3), VII,

1870-71, pp. 217-245. Copenhagen.

— Prosp. generum specierumque Crust. Isop. Terrestrium, 1879. Haunise.

— Crustacea Isopoda Terrestria per familias et genera et species descripta. 1885.
Haunia?.

Landisopoder fra Venezuela, indsamlede af Dr. Fr. Meinert. Entomol. Med-

delel., IV, 1893-94, pp. 111-129. Copenhagen.

A revision of "Crustacea Isopoda Terrestria," with additions and illustra-
tions. I. Eubelum, pp. 1-31, pis. i-v. Kj0benhavn, 1899.

A revision of the Crustacea Isopoda Terrestria, with additions and illustra-

tions. Ent. Meddel. (2), I, 1901, pp. 67-97. Copenhagen.
CALMAN, W. T. On a collection of Crustacea from Puget Sound. Ann. N. Y. Acad.

f Sci., XI, 1898, pp. 259-292. New York.
CAULLERY, M. Branchiophryxus nyctiphanse, n. g., sp., Epicaride nouveau de la

famille des Dajida?. Journ. R. Micr. Soc. London, 1897, Pt, 3, p. 204.

Also in Zool. Anzeiger, XX, 1897, pp. 88-92. Leipzig.
CHILTON, CHARLES. The terrestrial Isopoda of New Zealand. Trans. Linn. Soc.

London (2), Zool., VIII, Pt. 4, 1901, pp. 99-152, pis. xi-xvi. London.
GLAUS, C. Ueber Apseudes latreittl Edw. und die Tanaiden. Arbeit, zool. Institut zu

Wien,. V, 1884, Pt, 3, pp. 1-12, pis. i-n. Wien, 1884.

Continued in VII, 1887, Pt. 2, pp. 7-82, pis. i-vn. Wien, 1888.
COPE, E. D. On the Wyandotte Cave and its fauna. American Naturalist, VI, 1872,

p. 411. Salem, Mass.

— Report on the Wyandotte Cave and its fauna. 3d and 4th Annual reports of

the Geological Survey of Indiana. 1872, pp. 157-182. Indianapolis.
CORNALIA, EMILIO, and PANCERI, PAOLO. Osservazioni zoologiche ed anatomiche

sopraun nuovo genere di Isopodo sedentari (Gyge branchialis). Accad. Reale

d. Sci. di Torino (2), XIX, 1858. Turin, 1861.

COSTA, ORONZIO GABRIELE. Fauna del Regno di Napoli, Crostacei. 1838. Napoli.
CUNNINGHAM, ROBERT O. Notes on the Reptiles, Amphibia, Fishes, Mollusca, and

Crustacea obtained during the voyage of H. M. S. Xassau in the year 1866-1869.

Trans. Linn. Soc. London, XXVII, 1869-71, Pt. 4, pp. 498-500. London.
CUVIER, GEORGES. Memoires sur les Cloportes. Choix de Memoires [or Jour. d'Hist.

Nat.], II, 1792, pp. 18-31. Paris.
- Regne animal. 2d ed., IV, 1829. Paris.
DAHL, FR. Die Landfauna von Bermuda. Plankton expedition, 1892, I, Pt. 1, pp.

105-112, pi. in. Kiel und Leipzig, 1892.
DANA, JAMES D. Conspectus Crustaceorum, etc. Am. Journ. Science and Arts

(2), VIII, pp. 424-428. New Haven, 1849.

— Crustacea. U. S. Expl. Exped., XIV, 1853, pp. 696-805, atlas, pis. XLVI-LIII.

Philadelphia.

Catalogue and descriptions of Crustacea collected in California by Dr. John L.

Le Conte. Proc. Acad. Nat, Sci. Phila., VII, 1854-1855, pp. 175-177.
Philadelphia.
DE GEER, C. Meinoires pour servir ii 1'histoire des insectes. VII, 1778. Stockholm.

704 BULLETIN f>4, UNITKD STATES NATIONAL MUSEUM.

•
DELAGE, YVES. Contribution u 1'etude de 1'appareil circulatoire des Crustacea

edriopthalmes marins. Archives de zool. exp. etgen., IX, 1881, pp. 1-172, pis

i-xn. Paris, 1881.
DE KAY, JAMES E. Zoology of New York or the New York Fauna. Pt. 6, 1844.

Albany.
DESMAKEST, A. G. Malacostraces. Dictionnaire des sciences naturelles, XXVIII,

1823, pp. 138-425. Paris, 1823.

— Considerations generates sur la classe des Crustaces. Isopodes, pp. 281-327.
1 aris, 1825.

DOI.I.KI'S, ADRIEN. Isopodes terrestres du Challenger. Bull. Soc. d' Etudes scien-
tiliques de Paris, 12th year, 1890, pp. 63-70. Paris.

— SphrtToma dugesi, nova species. Bull. Soc. zool. France, XVIII, 1893, p.
115, tigs. 1-2. Paris, 1893.

- Voyage de M. Charles Allusiud aux iles Sechelles. Crustacvs isopodes ter-
restres. Bull. Soc. zool. France, XVIII, 1893, pp. 186-190. Paris.

— Lea Idoteidse des cotes de France. Feuille des jeunes Naturalistes, 1893-
1894. 24i6mcannee. Paris, 1893-1895.

On West Indian terrestrial Isopod Crustaceans. Proc. Zool. Soc. London,

1896, pp. 388-400. London.

— Sur les crustaces Isopodes terrestres du Mexique. Bull. Soc. zool. France,
XXI, 1896, pp. 46-49. Paris.

Les Isopodes terrestres du nord de PAfrique, du Cap Blanc si Tripoli. Mem.

Soc. zool. de France, 1896, p. 550. Paris.
Note preliminaire sur les Tanaidse recueillis aux Acores pendant les campagnes

d VHirondelle, 1887-1888. Bull. Soc. zool. de France, XXII, 1897, p. 207.

Paris.
Campagnes de la Melita. Tanaidae recoltes par M. Ed. Chevreux dans

1'Atlantique et dans la Me"diterranee. M6m. Soc. zool. de France, XI, 1898, pp.

35-47. Paris.
Note preliminaire sur les especes du genre Cirolana recueillies pendant les

campagnes de I'Hirondelle et de la Princesse Alice sur la direction de s. a. s. le

prince Albert ler, de Monaco. Bull. Soc. zool. France, XXVIII, 1903, pp. 5-10.

Paris, 1903.
EDWARDS, ALPHONSE MILNE. On a gigantic Isopod from the great depths of the sea.

Ann. Mag. Nat. Hist. (5), III, 1879, pp. 241-243. London.

— Sur un Isopode gigantesque des grandes profondeurs de la mer. Comptes
Rendus, Acad. Sci., LXXXVIII, 1879, pp. 21-23. Paris.

EDWARDS, A. MILNE and BOITVIER, E. L. Reports on the results of dredging under
the supervision of Alexander Agassiz in the Gulf of Mexico (1877-1878), in the
Caribbean Sea (1878-1879), and along the Atlantic coast of the United States
(1880), by the U. S. Coast Survey Steamer Blake, Lieut. Commander C. D. Sigs-
bee, U. S. Navy, and Commander J. R. Bartlett, U. S. Navy, commanding.
XL. Les bathynonies. Mem. Museum Comparative Zoology at Harvard Col-
lege, XXVII, No. 2, 1902, pp. 141-175, pis. I-VIH. Cambridge.

EDWARDS, H. MILNE. Annotations in Histoire naturelle des animaux sans vertebres,
par J. B. P. A. de Lamarck, 2d ed., V, 1838. Paris.

Histoire naturelle des Crustaces, III, 1840, pp. 115-284, pis. \xxi-xxxin.

Paris.

— Le regne animal distribue d'apres son organisation, par Georges Cuvier.
Les crustaces, avec une atlas. [Crochard edition.] 1849. Paris.

EDWARDS, H. MILNE and Arnoi IN, JEAN VICTOR. Precis d'entomologieoud'histoire
naturelle des animaux articuk's. Premiere division. Histoire naturelle des
annelides, crustaces, arachnides et myriapodes, complrt*'- par une ironographie.
Paris, 1829.

ISOPODS OF NOKTH AMERICA. 705

FABRICIUS, J. C. Mantissa insectorum, I. Hafnise, 1787.

Supplementuin entomologue systematic*. Hafnise, 1798.

FABRICIUS, OTHO. Fauna Groenlandica. Copenhagen, 1780.

FAXON, WALTER, in Garman, Samuel. Cave animals from southwestern Missouri.

Bull. Mus. Comp. Zool. Harvard College, XVII, No. 6, 1888-89, pp. 225-239.

Cambridge.

FILHOL, H. La vie au fond des mers. Paris, 1885.
FITCH, ASA. First and second report on the noxious, beneficial, and other insects

of the State of New York, 1856. Albany.
FORBES, S. A. List of Illinois Crustacea. Illinois Museum of Natural History, Bull.

No. 1, 1876, pp. 8-13. Bloomington, Illinois.
GARMAN, H. A new fresh-water Crustacean. Bull. Essex Institute, XXII, 1890,

pp. 28-30. Salem, Massachusetts.
GARMAX, SAMUEL. Cave animals from southwestern Missouri. Bull. Mus. Comp.

Zool., Harvard College, XVII, No. 6, 1888-1889, pp. 225-239. Cambridge. ,
GERSTAECKER, A. Crustacea in Bronn's Klassen und Ordnungen des Thier-Eeichs,

V, Pt. 2, Pis. 1, 2, 3, 1881, pi. vi, fig. 12a.
GIARD, ALFRED, and BONXIER, JULES. Contributions a 1'etude des Bopyriens. Tra-

vaux de 1' Institute zoologique de Lille et du Laboratoire de zoologie maritime

de Wirnereux, V, 1887, pp. 1-252, pis. i-x. Lille.

— Sur deux nouveaux genres, Probopyrus et Palsegyge. Bull. Scient.,

XIX, 1888, pp. 53-77. Paris.

Sur quelques especes nouvelles de C4poniens. Comptes Rendus, CVII,

1888, pp. 44-47. Paris.

Prodrome d'une monographie des Epicarides du golfe de Naples. Bull.

Scient., XXII, 1890, pp. 367-391. Paris.

Contributions a 1'etude des Epicarides. Bull. Sci. de la France et de la

Belgique (4), XXV, 1893, pp. 415-493, pis. v-xni. Paris, 1893.
GISSLER, CARL. The common prawn and its parasite. Scientific American, XLV,

1881, p. 151. New York.

— A singular Parasitic Isopod Crustacean, and some of its developmental stages.
American Naturalist, XVI, 1882, pp. 6-12. Philadelphia.

Bopyroides lalreuticola, a new species of Isopod Crustacean parasitic on a

gulf-weed shrimp. American Naturalist, XVI, 1882, pp. 5.91-594. Philadelphia.
GOODSIR, HENRY D. S. On a new genus, and on six new species of Crustacea, with

observations on the development of the egg and on the metamorphoses of

Caligus, Carcinus, and Pagurus. Edinburgh New Philos. Jour., XXXIII, pp.

174-192, 1842. Edinburgh.

GOSSE, PHILIP H. A naturalist's sojourn in Jamaica. London, 1851.
GOULD, A. A. List of Crustacea in Massachusetts. Report on the geology, miner-
alogy, botany, and zoology of Massachusetts. 2d ed. By Edward Hitchcock.

1835, pp. 548-550. Amherst.

Invertebrata of Massachusetts. 1841, pp. 336-338. Cambridge.

GRUBE, A. E. Die Insel Lussin und ihre Meeresfauna. Breslau, 1864.
GUERIN-MENEVILLE, FELIX EDOUARD. Iconographie du regne animal de Cuvier.

Crustaces. J829-1843. Paris.

- Mag. Zool., 01. VII, 1836, pi. xx. Paris.
Sur une nouvelle espece de Porcellion provenant de File de Cuba. Extrait

d'une lettre. Comptes Rendus de F Academic des Sciences, IV, 1837. Paris.
HANSEX, H. J. Oversigt over de paa Dijmphna-Togtet indsamlede Krebsdyr.

Dijmphna-Togtets zoologisk-botaniske Udbytte, 1886, pp. 185-286, pis. xx-xxiv.

Kj0benhavn, 1887.
Oversigt over det vestlige Gr0nlands Fauna af Malakostrake Havkrebsdyr.

Vidensk. Meddel. fra den Naturh. Foren. i Kj0benh., pp. 177-198, 1887.

Copenhagen. 1888.
28589—05 45

706 BULLETIN f>4, UNITED STATES NATIONAL MUSEUM.

HANSEN, H. J. Cirolanidse et familue nonnulhf propinquse Musei Hauniensis.
Vidensk. Selsk. Skr. (6), V, 1890. Copenhagen.

— Isopoden, Cumaceen und Stomatopoden der Plankton Expedition, 1895, pp.
3-50. Kiel.

- Reports on the dredging operations off the west coast of Central America to
the Galapagos Islands, to the west coast of Mexico, and in the Gulf of Califor-
nia, in charge of Alexander Agassiz, carried on by the U. S. Fish Commission
Steamer Albatross during 1891, Lieut. Commander Z. L. Tanner, U. S. Navy,
commanding. XXII. The Isopoda. Bull. MILS. Comp. Zool., Harvard College,
\ X XI, Xo. 5, 1897, pp. 95-129, pis. i-vi. ' Cambridge.

- The deep-sea Isopod, Anuropm branchiatu* Beddard, and some remarks on

iji'/anteits A. Milne Edwards. Journ. Linn. Soc. London, Zoology,

XXIX, 1903, pp. 12-25, pi. iv. London.

On the morphology and classification of the Asellota group of Crustaceans,
with descriptions of the genus Stenetriurn Haswell and its species. Proc. Zool.
Soc., London, 1904, II, Pt. 2, pp. 302-331, pis. xix-xxi. London, 1905.

Revision of the European Marine Forms of the Cirolanimr, a subfamily of

Crustacea Isopoda. Journ. Linn. Soc. London, 1905, pp. 337-372, pis. xxxm-
xxxv. London.

HARFORD, W. G. W. Description of a new genus and three new species of sessile-eyed
Crustacea. Proc. Cal. Acad. Sci., VII, Pt. 1, 1876, p. 54. San Francisco, 1877.

— Description of three new species of sessile-eyed Crustacea, with remark on
Ligia occidentalis. Proc. Cal. Acad. Sci., VII, Pt. 1, 1876, pp. 116-117. San
Francisco, 1877.

HARGER, OSCAR. The sexes of Sphseroma. Am. Jour. Sci. and Arts (3), V, 1873,
p. 314. New Haven.

— On a new genus of Asellidse. Amer. Jour. Science and Arts (3), VII, pp.
601-602, 1874. New Haven.

— Description of Mancasellus brachyurus, a new fresh-water Isopod. Am. Jour.
Sci. and Arts (3), XI, 1876, pp. 304-305. New Haven.

Descriptions of new genera and species of Isopoda from New England and

adjacent regions. Amer. Jour. Sci. and Arts (3), XV, 1878, pp. 373-379. New
Haven.

— Notes on New England Isopoda. Proc. U. S. Nat. Mus., II, 1879, pp.
157-165. Washington, 1880.

— Report on the Marine Isopoda of New England and adjacent waters. Report
of the U. S. Commissioner of Fish and Fisheries, 1878, Pt. 6, pp. 297-462, pis.
i-xin. Washington, 1880.

— Reports on the results of dredging, under the supervision of Alexander Agas-
siz, on the east coast of the United States during the summer of 1880, by the
U. S. Coast Survey steamer Blake, Commander J. R. Bartlett, U. S. Navy, com-
manding. XXIII. Report on the Isopoda. Bull. Museum Comparative Zool.,
Harvard College, XI, No. 4, 1883, pp. 91-104, pis. i-iv. Cambridge.

with .A. E. VERRILL. Report upon the invertebrate animals of Vineyard

Sound and the adjacent waters, with an account of the physical characters of the
region. Report U. S. Commissioner of Fish and Fisheries, Pt. 1, 1871-72, pp.
295-778 (1-178), pi. i-xxxvm. Washington, 1873.

— and SMITH, S. I. Report on the dredgings in the region of St. George's Banks
in 1872. Trans. Conn. Acad. of Arts and Sciences, III, 1874, pp. 1-57. New
Haven.

- VERRILL, A. E., and SMITH, S. I. Catalogue of the marine invertebrate ani-
mals of the southern coast of New England and adjacent waters. Report U. S.
Commissioner of Fish and Fisheries, Pt. 1, 1871-72, pp. 537-747 (243-453).
Washington, 1873.

ISOPODS OF NORTH AMERICA. 707

HASWELL, WILLIAM A. On some new Australian Marine Isopoda — Part 2. Proc.

Linn. Soc. New South Wales, VI, 1881, pp. 183-186. Sydney.
HAY, O. P. Description of a new species of Asellus. Bull. 111. State Lab. Nat. Hist.,

No. 2, 1878, pp. 90-92. Bloomington, Illinois.
Notes on some fresh-water Crustacea, together with descriptions of two new

species. American Naturalist, XVI, 1882, pp. 241-242. Philadelphia.
HAY, WILLIAM PERRY. Description of a new species of subterranean Isopod. Proc.

U. S. Nat. Mus., XXI, 1899, pp. 871-872. Washington, 1899.
- Two new subterranean Crustaceans from the United States. Proc. Biol. Soc.

Washington, XIV, 1901, pp. 179-180. Washington.

— Observations on the Crustacean fauna of Nickajack Cave, Tennessee, and

vicinity. Proc. U. S. Nat. Mus., XXV, 1903, pp. 417-428. Washington, 1903.
On a small collection of Crustaceans from the Island of Cuba. Proc. U. S.

Nat. Mus., XXVI, 1903, pp. 429-435. Washington, 1903.

HELLER, CAMILL. Reise der osterreichischen Fregatte Novara um die Erde in den
Jahren 1857, 1858, 1859. Zoologischer Theil, II, Crustaceen, pp. 130-148.
Wrien, 1865.

— Carcinologische Beitriige zur Fauna des adriatischen Meeres. Verhandlungen
der k. k. zoologisch-botanischen Gesellschaft in Wien, XVI, 1866, pp. 723-760.
Vienna.

Die Crustaceen, Pycnogonideii, und Tunicaten der k. k. osterr-ungar.

Nordpol-Expedition. Denkschriften der mathematisch-naturwissenschaftlichen

Classe der kaiserlichen Academic der WMssenschaften, XXXV, 1878, pp. 25^16,

pis. i-v. Vienna.
HEWSTON, GEORGE. [Note on Limnoria californica.] Proc. Cal. Acad. Sci., V, 1<S74,

p. 24. San Francisco.
HOLMES, S. J. Remarks on the sexes of Sphferomids, with a description of a new

species of Dynamene. Proc. Cal. Acad. Sciences (3), III, 1904, No. 11, pp.

296-304, pi. xxxiv. San Francisco, 1904.

— On some new or imperfectly known species of West American Crustacea.

Proc. Cal. Acad. Sciences (3), III, 1904, No. 12, pp. 307-324, pis. xxxv-xxxvu.

San Francisco, 1904.
HUBBARD. H. G. Two days collecting in the Mammoth Cave, with contributions to

a study of its fauna. Amer. Entomologist, I, 1880, pp. 34-84. New York.
IVES, J. E. Crustacea from the northern coast of Yucatan, the harbor of Vera Cruz,

the west coast of Florida, and the Bermuda Islands. Proc. Acad. Nat. Sci.

Phila., 1891, pp. 185-189. Philadelphia,
JOHNSON, A. Synoptisk Framstiillning af Sveriges Oniscider. Academisk Afhand-

ling, 1858. Upsala.
KINAHAN, JOHN R. Analysis of certain allied genera of terrestrial Isopoda; with

description of a new genus, and a detailed list of the British species of Ligia,

Philougria, Philoscia, Porcellio, Oniscus, and Armadillidium. Nat. Hist, Review,

IV, 1857, pp. 258-282, pis. xix-xxu. London.
• On the genus Platyarthus (Brandt) ; with notices of allied undescribed genera.

Proc. Dublin University, I, 1859, pp. 188-201. Dublin.
KINGSLEY, JOHN STERLING, and STREETS, THOMAS HALE. An examination of types

of some recently described Crustacea. Bull. Essex Institute, IX, 1877, pp. 103-

108. Salem, 1877.
KOCH, C. L. Deutschlands Crustaceen, Myriapoden und Arachniden, Ein Beitrag

zur deutschen Fauna, VI-X, 1, 2. Regensburg, 1835-44.
System der Myriapoden mit den Verzeichnissen und Berichtigungen zu

Deutschlands Crustaceen, Myriapoden und Arachniden. 1847. Regensburg.
KOSSMANN, R. Zoologische Ergebnisse einer Reise in den Kiistengebiete des Rothen

Meeres, III, Malacostraca, 1880. Leipzig.

708 .BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

KOSSMANN, R. Die Entonisciden: Stadien iiber Bopyriden. III. lone thoracica und

Cepon portuni. Mittheilungen aus der zoologischen Station zu Neapel, III,

1881. Leipzig.
KR0YER, HENRIK. Gronlands Amphipoder. Kongelige Danske Videnskabenes Sels-

kabs, naturvideiiskabelige og mathematiske Afhandlinger, VII, 1838, pp. 229-

326 (1-98), pis. i-iv. Copenhagen.
Bopyrus aldominaltx Kr0yer. Nat. Tidsskr., Ill, 1840-41, pp. 102-112, 289-

299. Copenhagen.
— Nye Arter af Slsegten Tanais. Naturhistorisk Tidsskrift, IV, pp. 167-168, pi.

n. Copenhagen, 1842.

- Karcinologiste Bidrag. Naturh. Tidsskr. (2) II, 1846-49, pp. 1-123, 366-446.

Copenhagen, 1846-1849.
Voyages en Scandinavie, en Laponie, au Spitzberg et aux F4roe. Zoologie,.

Crustacea. (Published under the direction of M. Paul Gaimard.) Atlas, pi.

XXYIII, figs. 1-2; pi. xxix, fig. 1. Paris, 1849.

Monografisk Fremstilling af Slsegten Hippolyte's nordiske Arter. Kongelige

Danske Videnskabenes Selskabs naturvideiiskabelige og mathematiske Afhand-
linger, IX, 1842, pp. 211-360, pis. i-vi. Copenhagen, 1862.

KUHLGATZ, THEODOR. Untersuchungen iiber die Fauna der Schwentinemiindung,
mit besonderer Beriicksichtigung der Copepoden des Planktons. Wissenechaft-
liche Meeresuntersuchungen, herausgegeben von der Kommission zur wissen-
schaftlichen Untersuchung der deutschen Meere in Kiel und der biologischen
Anstalt auf Helgoland, III, 1898, pp. 148-150, pi. in, figs. 4-19. Kiel und
Leipzig, 1898.

LAMARCK, JEAN P. B. A. DE M. DE. Hist. nat. des anim. sans vertebres, 1st ed.,
V, 1818. Paris, 1818.

LATREILLE, P. A. Hist, nat. Crust, et insectes, VI, VII, 1802-1805. Paris.
— Genera Crustaceorum et Insectorum, I, 1806. Parisiis et Argentorati

- Encycl. meth., Pt. 24, 1818, p. 6, pi. cccxxvm, figs. 21-22. Paris.

- In Cuvier's Regne animal, 2d ed., IV, 1829, pp. 129-144. Paris.
LATROBE, BENJAMIN H. A drawing and description of the Clupea tyrannus and

Oniscus prscgustator. Trans. Am. Philos. Soc., V, 1802, pp. 77-81, pi. i. Phila-
delphia.

LEACH, W. E. Crustaceology. Edinburgh Encyclopedia, VII, 1813-14, pp. 221-277;
also appendix, pp. 429-437. Edinburgh.

A tabular view of the external characters of four classes of animals which

Linne arranged under Insecta; with the distribution of the genera composing
three of these classes into orders, etc., and descriptions of several new genera
and species. Trans. Linn. Soc. London, XI, 1815, pp. 306-400. London.
Cymothoadees. Diet, des Sci. Nat., XII, 1818, pp. 338-354. Paris.

LEIDY, JOSEPH. Contributions toward a knowledge of the marine invertebrate fauna

of the coasts of Rhode Island and New Jersey. Journ. Acad. Nat. Sciences,

Phila., 1855, p. 150. Philadelphia.
Notices of some animals on the coast of New Jersey. Proc. Acad. Nat. Sci.

Phila., XXXI, 1879, pp. 198-199. Philadelphia.
LEREBOULLET, A. Memoire sur les Crustacea de la famille des Cloportides qui habi-

tent les environs de Strasbourg. Memoires de la Societ£ d'Histoire naturelle de

Strasbourg, IV, 1853. Strasbourg et Paris.
LILJEBORG, WILHELM. Bidrag till den hognordiska hafsfaunan. Of versigt af Kongl.

Vetenskaps-Akademiens Forhandlingar, VII, 1850, pp. 82-88. Stockholm.

— Norger Crustaceer. Ofversigtaf Kongl. Vetenskaps-Akademiens Forhandlin-
gar, VIII, 1851, pp. 19-25. Stockholm, 1851.

— Hafs-Crustaceer vid Kullaberg. Ofversigt af Kongl. Vetenskaps-Akademiens

Forhandlingar, IX, 1852, pp. 1-13. Stockholm, 1852.

ISOPODS OF NORTH AMERICA. 709

LIL.JEBORG, WILHELM. Bidrag till kannedomen om de inom Sverige och Xorrige
forekommende Crustaceen af Isopodernas underordning och Tanaidernas fainilj.
Upsala Univ. Arsskr., Math, og Naturv., I, 1865, pp. 1-32. Upsala.

LINNJSUS, CARL VON. Systema natura?. 10th ed., I, 1758. Holmue.

Fauna suecica. 2d ed., 1761. Stockholm.

— Systema natura?. 12th ed., I, Pt. 2, 1767. Holmire.

LOCKINGTON, W. N. Remarks on the Crustacea of the Pacific Coast, with descriptions
of some new species. Proc. Cal. Acad. Sci., VII, 1876, Pt. 1, p. 36. San Francisco,
1877.

— Description of Seventeen New Species of Crustacea. Proc. Cal. Acad. Sciences,
VII, 1876, Pt. 1, pp. 44-46. San Francisco, 1877.

— Description of a new genus and species of Decapod Crustacean. Proc. Cal.
Acad. Sci., VII, 1876, p. 57. San Francisco, 1877.

Remarks upon the Thalassinidea and Astacidea of the Pacific Coast of North

America, with description of a new species. Ann. Mag. Nat. Hist. (5), II, 1878,

pp. 299-300. London.
LUCAS, H. Histoire naturelle des animaux articules. Exploration scientifique de

PAlgerie pendant les annees 1840, 1841, 1842. Zool., I, pp. 59-88. Paris, 1849.
LUTKEN, CHRISTIAN FR. Nogle Bemserkninger om de Nordiske jEga-arter samt om

JDga-sla?gtens rette Begrajndsning. Videnskabelige Meddelelser fra den natur-

historiske Forening i Kj0benhavn, pp. 65-78, pi. i A. Copenhagen, 1859.
- Om visse Cymothoagtige Krebsdyrs Ophold i Mundhulen hos forskjellige

Fiske. Videnskabilige Meddelelser fra den naturhistoriske Forening i Kj0ben-

havn, pp. 172-179. Copenhagen, 1859.

til " Nogle Berma?rkninger om de Nordiske ^Ega-arter samt om JEga-

sla'gtens rette Begraendsning " — Om JEga tridens Leach og ^Ega rotundicauda
Lilljeborg-samt om slsegterne Acherusia og ^Egacylla. Videnskabelige Med-
delelser fra den naturhistoriske Forening i Kj0benhavn, 1861, pp. 175-183 (1-9).
Copenhagen, 1861.

The Crustacea of Greenland. Manual of the natural history, geology, and

physics of Greenland and the neighboring regions; prepared for the use of the

Arctic expedition of 1875 by T. Ruppert Jones. London.
LUTKEN, CHRISTIAN FR. and STEENSTRUP, JAPETUS. Mindre Meddelelser fra Kj0ben-

havns Universitets zoologiske Museum. 2. Forelobig. Notits om danske Havs-

Krebsdyr. Videnskabelige Meddelelser fra den Naturhistoriske Forening i

Kj0benhavn, III, 1861, pp. 274-276. Copenhagen, 1862.
MACDONALD, JOHN DENIS. On the external anatomy of Tanais vittatus, occurring

with Limnoria and Chelura terebrans in excavated Pier-wood. Trans. Linn.

Soc. (2), I, (Zoology), pp. 67-71, pi. xv. London.
MARSHALL, WILLIAM. Die Tiefsee und ihr Leben. Leipzig, 1888.
MEINERT, FR. Crustacea Isopoda, Amphipoda et Decapoda Dania? ; Fortegnelse over

Danmarks Isopode, Amphipode og Decapode Krebsdyr. Naturhistorisk Tids-

skrift (3), XI, 1877, pp. 57-248; (3), XII, 1880, pp. 465-472. Copenhagen.
MEINERT, FR. and SCHIOZDTE, J. C. Symbolse ad Monographiam Cymothoarum,
• Crustaceorum Isopodum Familige. Naturhistorisk Tidsskrift, XII, 1879-80, pp.

321-415, pis. vii-xin. Kj0benhavn.

— Symbolse ad Monographiam, Cymothoarum, Crustaceorum Isopodum

Familia?. II. Anilocridte. Naturhistorisk Tidsskrift (3), XIII, 1881-83, pp.

1-167, pis. i-x. Kj0benhavn.

Symbolse ad Monographiam Cymothoarum, Crustaceorum Isopodum

Familia?. III. Saophridae. IV. Cymothoiclse. Trib. I. Ceratothoina?. Natur-
historisk Tidsskrift (3), XIII, 1881-83, pp. 281-3792 pis. xi-xvi. Kj0benhavn.
Symbola? ad Monographiam Cymothoarum, Crustaceorum Isopodum

Familias. IV. Cymothdse. Trib. II. Cymothoinse. Trib. III. Livonecinaj.

710 BULLETIN f>4, UNITED STATES NATIONAL MUSEUM.

Naturhistorisk Tidsmkrift (3), XIV, 1883-84, pp. 221-455, pis. vi-xvin.

Kj0benhavn.
MIEKS, E. J. On a collection of Crustacea, Decapoda and Isopoda, chiefly from

South America, with descriptions of new genera and species. Proc. Zool. So.-.

London, 1877, pp. 653-678. London.
List of the species of Crustacea collected by the Rev. A. E. Eaton at Spitzbergen

in the summer of 1873, with their localities and notes. Ann. Mag. Nat. Hist.

(4), XIX, 1877, pp. 131-140. London.

— Report on the Crustacea collected by the naturalists of the Arctic expedition
in 1875-7(5. Ann. Mag. Xat, Hist. (4), XX, 1877, pp. 63-66. London.

On a small collection of Crustacea made by Edward Whymper, esq., chiefly

in the Xorth Greenland seas; with an appendix on additional species collected
by the late British Arctic expedition. Journ. Linn. Soc. London, Zoology, XV,
1881, pp. 59-73. London, 1881.

— Revision of the Idoteida?, a family of Sessile-eyed Crustacea. Jour. Linn.
Soc. London, XVI, 1883, pp. 1-88, pis. i-in. London. 1883.

Crustacea. Zool. Collections of the Alert, 1884, pp. 308-310. London, 1884.

MONTAGU, GEORGE. Description of several marine animals found on the south coast

of Devonshire. Trans. Linn. Soc. London, VII, 1804, pp. 61-85, pis. vi-vn.

London.
MOORE, H. F. Tanais robmtux, a new species of Anisopoda. Proc. Acad. Xat. Soc.

Phila., 1894, pp. 90-94, pi. v. Philadelphia, 1895.
Report on Porto Rican Isopoda. Bull. U. S. Commissioner of Fish and

Fisheries, 1900, XX, Pt, 2, pp. 161-176, pis. vn-xi. Washington, 1902.
Mri.i.ER, FRIEDRICH. Benierkungen zu Zaddach's Synopseos Crustaceorum Prussi-

coruin prodromus. Archiv fiir Xaturgeschichte, I, 1848, pp. 62-64, pi. iv.

Berlin, 1848.
MfLLER, FRITZ. Bruchstiicke zur Naturgeschichte der Bopyriden. Jen. Zeit-

schrifte Nat., VI, 1871, pp. 51-73, pis. in-iv. Leipzig.
XICOLET. HERCULE, in Gay, Claudio. Historia de Chile, Zool., Ill, 1849, pp.

256^284. Paris.
NORMAX, ALFRED MERLE. Report of the committee appointed for the purpose of

exploring the coasts of the Hebrides by means of the Dredge. Pt. 2. On the

Crustacea, Echinodermata, Polyzoa, Actinozoa and Hydrozoa. Report British

Association for the Advancement of Science, 1866, p. 197. London, 1867.
Preliminary report on the Crustacea, Molluscoida, Echnodermata,and Coelen-

terata, procured by the Shetland dredging committee in 1867. Report British

Association for the Advancement of Science, pp. 437-441. London, 1868.
Last report on dredging among the Shetland Isles, Pt. 2, Crustacea. Report

of the British Association for the Advancement of Science, 1869, pp. 247-336,

344-345. London.
Crustacea, Tunicata, Polyzoa, Echinodermata, Actinozoa, Foraniinifera, Poly-

cistina, and Spongida, in "Preliminary report of the biological results of a

cruise in H. M. S. Valorous to Davis Straits in 1S75." By J. Gwyn Jeffreys.

Proc. Royal Society, XXV, 1876, pp. 202-215. London, 1876.
- British Isopoda Chelifera. Ann. Mag. Nat. Hist. (7), III, 1899, pp. 317-341.

London.
Notes on the Natural History -of East Finmark. Ann. Mag. Nat. Hist. (7),

X, 1902, pp. 478-479. London.
British Isopoda of the families ,E<jid:i, Cirolanidte, Idoteidte, and Arcliir'nln .

Ann. Mag. Nat. Hist. (7), XIV, 1904, pp. 430-450, pis. xii-xm. London.
Revised nomenclature of the species described in Bate and Westwood's

."British Sessile-eyed Crustacea." Ann. Mag. Nat. Hist. (7), XVI, 1905.

London.

ISOPODS OF NORTH AMERICA. 711

NORMAN, ALFRED MERLE. Museum Normanianum, or a Catalogue of the Invert c-
brata of the Arctic and North Atlantic Temperate Ocean and Pakearctic Region,
which are contained in the collection of the Rev. Canon A. M. Norman. III.
Crustacea. Durham, 1905.
— and STEBBIXG, T. R. R. On the Crustacea Isopoda of the /,/<////<-////"/, J'»,-cn-

pine, and Valorous expedition. Trans. Zool. Soc. Lond., XII, 1886, Pt. 4, pp.

77-141, pis. xvi-xxvu. London, 1886.
OHLIX, AXEL. Bidrag till Kannedomen oin Malakostrakfaunan i Baffin Bay och

Smith Sound. Akademisk Af handling, XXII, 1895, pp. 1-70. Lund, 1895.

— Arctic Crustacea collected during the Swedish Arc-tic expeditions 1898 and

1899 under the direction of Prof. A. G. Nathorst. I. Leptostraca, Isopoda,

Cumacea. Bihang. till Kongl. Svenska Vet.-Akad. Handlingar, XXVI, Afd. iv,

No. 12, 1901, pp. 15-40, pis. i-v. Stockholm, 1901.
OLIVIER, M. Histoire naturelle des Insectes. Encycl. method., IV, 1789, pp. 246-

256. Paris.
ORTMAXX, A. E. A new species of .the Isopod genus Bathynomus. Proc. Acad.

Nat. Sci. Phila., 1894, p. 191. Philadelphia, 1895.
- Preliminary report on the Crustacea and Pycnogonida of the Princeton

Arctic expedition, 1899. The Princeton University Bulletin. XI, No. 3, 1900,

pp. 39-iO. Princeton, 1900.

Crustacea and Pycnogonida collected during the Princeton Expedition to

North Greenland. Proc. Acad. Nat, Sci. Phila., 1901, pp. 144-168. Philadelphia.
OWEX, RICHARD. The zoology of Captain Beechey's Voyage to the Pacific Ocean

and Bering's Straits, performed in the H. M. 8. Blossom in the years 1825-1828.

London, 1839.
PACKARD, A. S. View of the recent invertebrate fauna of Labrador. Mem. Bost.

Soc. Nat. Hist., I, 1867, p. 296. Boston.

- The Mammoth Cave and its inhabitants. Amer. Naturalist, V, 1871, pp.
751-752. Salem, Mass.

— On the cave fauna of Indiana. Fifth Report Peabody Academy of Sciences,
1873, pp. 93-97. Salem.

— Zoology for Students and General Readers, 1879, pp. 308-309. ^w York.

- Zoology for High Schools and Colleges, 1881, p. 289. New York.

— A new eyeless Isopod Crustacean from Mexico. Proc. Amer. Assoc., XLIX,
1900, p. 228. Easton, Pennsylvania.

and COPE, E. D. The fauna of Nickajack Cave. Amer. Naturalist, XV,

1881, pp. 879-880. Philadelphia.
PALLAS, PETER SIMON. Spicilegia Zoologica, quibus nova? imprimis et obscurse ani-

malium species iconibus, descript. atque comrnentariis illustrantur. IX, 1772.

Berolini.
PANCERI, EMILIO and CORNALIA, PAOLO. Osservazioni Zoologiche ed anatomiche

sopra un nuovo genere di Isopodo sedentari (Gyge branchialis). Accad. reale

d. sci. di Torino (2), XIX, 1858. Turin, 1861.
PAULMIER, FREDERICK C. Higher Crustacea of New York City. Bull. New York

State Museum, 1905, pp. 169-186. Albany.

PENNANT, THOMAS. British Zoology, IV, 1777, p. 25, pi. xvni. London.
PERTY, M. Delectus animalium articulatorum qufe in itinere per Brazilian! annis

1817-1820 collegerunt J. B. de Spix et C. F. Ph. de Martius. Monachii, 1830-1834.
PLATEAU, F. Crustace's Isopodes terrestres. Bull, de 1' Academic royalede Belgique

(2), XXIX, No. 2, 1870. Brussels.
RAFIXESQUE, C. S. Precis des decouvertes somiologiques. Palerme, 18l4.

— Analyse de la nature, ou tableau de 1'univers et des corps organises. Palerme,

1815.

»~

LIBRARY

712 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

RATHBI-X, MARY J. Fauna of New England. 5. List of the Crustacea. Occasional
Papers of the Bost. Soc. Nat. Hist., VII, 1905, pp. 34-49. Boston.

RATHKE, HEINRICH. Anatomic der Idothea entomon, oder des Schachtwurnies.
Neuste Schriften der Naturf. Gesellsch. in Danzig, I, 1820-1825, pp. 109-136.
Danzig.

Beitriige zur Fauna Nonvegens. Nova Acta Academise Csesarepe Leopoldino-

Carolinse Naturae Curiosorum, XX, pp. 1-264, pis. i-xn. Breslau and Bonn, 1843.

RATHKE, JENS. Jagttagelser henhorende til Indvoldsormenes og Bloddyrenes natiir-
liistorie; med anmiirkningar af O. Fabricius. Skrivter af Naturhistorie-Sel ska-
bet, V, 1799, pp. 61-153, pis. ii-in. Copenhagen.

RATZEBURG, J. T. C. and BRANDT, J. F. Medizinische Zoologie, II, 1830-34. Berlin.

REINHARDT, J. T. Fortegnelse over Grdnlands Krebsdyr, Annelider og Indvold-
sorme. Naturhistorisk Bidrag til en Beskrivelse af Gronland, 1857, pp. 28-49.
Kji>benhavn.

RICHARDSON, HARRIET. Description of a new species of Sphseroma. Proc. Biol. Soc.,
Washington, XI, 1897, pp. 105-107. Washington.

— Description of a new Crustacean of the genus Sphseroma from a warm spring
in New Mexico. Proc. V. S. Nat. Mas., XX, 1897, pp. 465-466. Washington.

Description of a new genus and species of Sphaeromidse from Alaskan waters.

Proc. Biol. Soc. Washington, XI, 1897, pp. 181-183. Washington.
Description of four new species of Rocinela, with a synopsis of the genus.

Proc. Amer. Philos. Soc., XXXVII, 1898, pp. 8-17. ,
Description of a new parasitic Isopod of the genus JEga from the southern

coast of the United States. Proc. Biol. Soc. Washington, XII, 1898, pp. 39-40.

Washington.
Key to the Isopods of the Pacific coast of North America, with descriptions

of twenty-two new species. Proc. U. S. Nat. Mus., XXI, 1899, pp. 815-869.

Washington.

(Reprinted in Ann. Mag. Nat, Hist. (7), IV, pp. 157-187, 260-277, 321-338.

London. )

— Results of the Branner-Agassiz Expedition to Brazil. Pt. 2. The Isopod
Crustacea. Proc. Wash. Acad. Sci., II, 1900, pp. 157-159. Washington.

— Synopses of North-American Invertebrates. VIII. The Isopoda. American

Naturalist, XXXIV, 1900, pp. 207-230, 295-309. Boston.

— Key to the Isopods of the Atlantic coast of North America, with descriptions
of new and little-known species. Proc. U. S. Nat. Mus., XXIII, pp. 493-579.
Washington, 1901.

— Papers from the Hopkins-Stanford Galapagos Expedition, 1898-99. VI. The
Isopods. Proc. Wash. Acad. Sci., Ill, 1901, pp. 565-568. Washington, 1901.

- The marine and terrestrial Isopods of the Bermudas, with descriptions of new
genera and species. Trans. Conn. Acad. Sci., XI, 1902, pp. 277-310, pis. xxxvn-
XL. New Haven.

— A new fresh water Isopod of the genus Mancasellus [danielsi] from Indiana.
Proc. U. S. Nat. Mus., XXV, 1902, pp. 505-507. Washington.

— A new terrestrial Isopod of the genus Pseudarmadillo. Proc. U. S. Nat. Mus.,
XXV, 1902, pp. 509-511. Washington.

Contributions to the natural history of the Isopoda. Proc. U. S. Nat. Mus.,

XXVII, 1904, pp. 1-89. Washington.

— Isopod Crustaceans of the northwest coast of North America. Harriman
Alaska Expedition, Crust., X, 1904, pp. 213-230. New York.

(Reprinted in Proc. U. S. Nat. Mus., XXVII, 1904, pp. 657-671. Washington.)
Isopods of the Alaska Salmon Investigation. Bull. U. S. Bureau of Fisheries,

XXIV, 1904, pp. 209-221. Washington, 1905.

ISOPODS OF NORTH AMERICA. 713

RICHARDSON, HARRIET. Descriptions of a new genus of Isopoda belonging to the
family Tanaidse and of a new species of Tanais, both from Monterey Bay, Cali-
fornia. Proc. U. S. Nat. Mas., XXVIII, 1905, pp. 367-370. Washington.

— Further changes in Crustacean nomenclature. Proc. Biol. Soc. Wash. , X V 1 1 1 ,
1905, pp. 9-10.

Risso, A. Histoire naturelle des crustaces des environs de Nice. 1816. Paris.
Roux, JEAN L. F. P. Crustaces de la Mediterranee et de son littoral. 1828. Paris

and Marseille.
SABINE, EDWARD. Supplement to Appendix to Captain Parry's Voyage. 1824. pp.

219-229, pi. i, figs. 4-6. London.
SARS, G. O. Om en anomal Gruppe af Isopoder. Chr. Vid. Selsk. Forhandl., 1863,

pp. 205-221. Christiania, 1864.
Beretning om en i Sommeren, 1865, foretagen zoologisk Reise ved Kysterne af

Christianias og Christiausands stifter. Nyt Magazin for Naturvidenskaberne.

Christiania, 1866.
Histoire naturelle des Crustaces d'eau douce de Norvege. Chistiania, 1867. '

— Unders0gelser over Christianiafjordens Dybvandsfauna anstillede paa en i
Sommeren 1868 foretagen zoologisk Reise. Nyt Magazin for Naturvidenskaberne.
Christiania, 1869.

— Nye Dybvandscrustaceer fra Lofoten. Chr. Vid. Selsk. Forhdl., 1869, p. 167.
Christiania, 1870.

— Unders0gelser over Hardangerfjordens Fauna. Forhandlinger i Videnskabs-
Selskabet i Christiania, 1871, pp. 246-286. Christiania, 1872.

Bidrag till Kundskaben om Dyrelivet paa vore Havbanken. Vidensk.

Selsk. Forhandl., 1872, pp. 73-119. Christiania, 1873.
Prodromus descriptionis Crustaceorum et Pycnogidarum quse in expeditione

Norvegica anno 1876 observavit G. O. Sars. Arch. Math. Naturv., II, 1877, pp.

237-271 (337-371). Christiania, 1877.

— Revision af Gruppen Isopoda Chelifera. Arch, for Math, og Naturv., 1882,
pp. 1-54. Christiania, 1882.

Oversigt af Norges Crustaceer med fore!0bige Bemserkninger over de nye eller

mindre bekjendte Arter. I. Forhandlinger i Videnskab Selskabet i Christiania,
Nr. 18, pp. 1-124, 1882. Christiania, 1883.

— Crustacea of the Norwegian North Atlantic Expedition, 1876-1878. Chris-
tiania, 1885.

— Report on the Schizopoda. Challenger Report, XIII, 1885, Pt. 37, pp.
220-221. London.

Nye Bidrag til Kundskaben om Middelhavets Invertebratfauna. III. Mid-

delhavets Saxisppoder. Archiv for Mathematik og Naturvidenskab, XI, 1886,
pp. 263-368, pis. i-xv. Christiania, 1886.

Crustacea of Norway. II. Isopoda, 1899. Bergen.

SARS, M. Oversigt over de i den norsk-arctiske Region forekommende Krebsdyr.
Forhandlinger i Vedenskabs-Selskabet i Christiania, 1858, pp. 122-163. Chris-
tiania, 1859.

— Beskrivelse af en ny Slsegt og Art af Isopoder: Munnopsis typica Sars. For-
handlinger i Videnskabs-Selskabet i Christiania, 1860, pp. 84-85. Christiania,
1861.

— Fortsatte Bemserkninger over det dyriske Livs Udbredning i Havets Dybder.
Forhandlinger i Videnskabs-Selskabet i Christiania. 1868, pp. 246-275. Christi-
ania 1869.

- Bidrag till Kundskab om Christiania Fjordens Fauna, Crustacea, 1868.

SACSSCRE, H. DE. Diagnosis de quelques Crustaces nouveaux des Antilles et du
Mexique. Rev. Mag. Zool. (2), IX, 1857, pp. 304-308. Paris.

714 BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

SAUSSURE, H. DE. Memoire sur divers Crustac^s nouveaux du Mexique et des

Antilles. Mem. de la Soc. physique et d'Hist. nat. de Geneve, XIV, 1858,

pp. 60-69. Geneve.
Memoire sur divers Crustacea nouveaux du Mexique et des Antilles. Mem.

Soc. phys., XIV, 1858, pp. 417-490. Geneve.
SAY, THOMAS. An account of the Crustacea of the United States. Jour. Acad. Xat.

Sci. Phila., I, Pt. 2, 1818, pp. 393-401, 423-433. Philadelphia.
S( HKKDTE, J. C. Krebsdyrenes sugemund. Naturhistorisk Tidsskrift (3), IV,

1866, pp. 169-206, pis. x-xi, Kj0benhavn, 1866-67; X, 1875-76, pp. 211-252.
On the structure of the mouth in sucking Crustacea. Pt. 1. Cymothoae. Ann.

Ma«r. Nat. Hist. (4), I, 1868, pp. 1-25, pi. i. London.
On the structure of the mouth in sucking Crustacea. Pt. 1. Cymothore. Ann.

Mag. Xat. Hist. (4), XVIII, 1876, pp. 253-266, 295-305. London.

— and MEIXERT, FR. Symbol* ad Monographiam, Cymothoarum, Crustaceorum

Isopodum Fainiliae. Naturhistorisk Tidsskrift, XII, 1879-80, pp. 321-415, pis.

vii-xui. Kj0benhavn.

Symbolae ad Monographiam Cymothoarum, Crustaceorum Isopodum

Familite. II. Anilocridae. Naturhistorisk Tidsskrift (3), XIII, 1881-83, pp.
1-167, pis. i-x. Kj0benhavn.

Symbols? ad Monographiam Cymothoarum, Crustaceorum Isopodum

Familiae. III. Saophridae. IV. Cymothoidse, Trib. I. Ceratothoinae. Natur-
historisk Tidsskrift (3), XIII, 1881-83, pp. 281-379, pis. xi-xvi. Kj0benhavn.
Symbolae ad Monographiam Cymothoarum, Crustaceorum Isopodum

Familiae. IV. Cymothoidae, Trib. II. Cymothoinae. Trib. III. Livonecinae.

Naturhistorisk Tidsskrift (3), XIV, 1883-84, pp. 221-455, pis. vi-xvin.

Kj0benhavn.
SCHNITZLER, H. J. De Oniscineis agri Bonnensis. Dissertatio zoologica. 1853.

Cononiae.

SCOTT, THOMAS. Notes on some Scottish Marine Isopods. Annals of Scottish Natu-
ral History, 1898, pp. 218-225. Edinburgh, 1898.
SILL, VICTOR. Beitrag zur Kentniss der Crustaceen, Arachniden und Myriapoden

Siebenbiirgens. Verhandlungen u. Mittheilungen des Siebenbiirgischen Ver-

eins fur Naturwissenschaften zu Hermannstadt, XII, 1861; XIII, 1862.

Hermannstadt.
SMITH, S. I. Professor Cope's Cave Crustaceans. Amer. Naturalist, VII, 1873, pp.

244-245. Salem, Massachusetts.

The Crustacea of the Fresh Waters of the United States. Report U. S. Com-
missioner of Fish and Fisheries, 1872-73, Pt. 2, pp. 637-665. Washington,

1874.
The Crustaceans of the Caves of Kentucky and Indiana. American Jour.

Science and Arts (3), IX, 1875, pp. 476-477. New Haven.
Notes on Crustacea collected by Dr. G. M. Dawson at Vancouver and the

Queen Charlotte Islands. Report of Progress of the Geological Survey of

Canada, 1878-1879, p. 218. Montreal, 1880.
— • and VERRILL, A. E. Notice of the Invertebrata dredged in Lake Superior in

1871, by the U. S. Lake Survey, under the direction of Gen. C. B. Comstock.

S. I. Smith, naturalist. Amer. Jour. Sci. and Arts (3), II, 1871, pp. 448-454.

New Haven.

Invertebrata of Southern New England. 478 pages, 38 plates. Wash-

ington, 1874.

— and HARGER, OSCAR. Report on the dredgings in the region of St. Georges
Banks in 1872. Trans. Conn. Acad. Arts and Sciences, III, 1874, pp. 1-57.
New Haven, 1874-78.

ISOPODS OF NORTH AMERICA. 715

SMITH, S. I., VERRILL, A. E., and HARGER, OSCAR. Catalogue of the marine inver-
tebrate animals of the southern coast of New England and adjacent waters.
Report U. S. Commissioner of Fish and Fisheries, Pt. 1, 1871-72, pp. 537-747
(243-453). Washington, 1873.

STEBBIXG, T. R. R. The sessile-eyed Crustacea of Devon. Transactions Devonshire
Association for the Advancement of Science, Literature, and Art. 1874.
Plymouth.

A new Australian Sphseromid, Cyclnra venosa; and notes on Dynamene rubra

and viridis. Journ. Linn. Soc. London, Zoology, XII, 1874, pp. 146-151, pis.
vi-vn. London, 1874.

Description of a new species of sessile-eyed Crustacean, and other notices.

Ann. Mag. Nat. Hist. (4), XVII, 1876, pp. 73-80, pis. iv-v. London.

Sessile-eyed Crustacea of Devonshire. Supplementary list. Trans. ' Devon-
shire Association for the Advancement of Science, Literature, and Art. 1879.
Plymouth.

History of Crustacea. 1893. New York.

- A new West Indian Tanaid. Ann. Mag. Nat. Hist. (6), XVII, 1896, pp.
49-53. London.

On the Isopod Genus Leptochelia. Ann. Mag. Nat. Hist. (6), XVII, 1896,

pp. 156-160. London.

Arctic Crustacea: Bruce Collection. Ann. Mag. Xat. Hist. (7), V, 1900, pp.

1-16. London, 1900.

On seme Crustaceans from the Falkland Islands, collected by Mr. Rupert

Vallentin. Proc. Zool. Soc. London, 1900, pp. 517-568. London, 1900.

— South African Crustacea, Pt. 2, 1902, p. 64. Cape Town.

On Crustacea brought by Doctor Willey from the South seas. Willey's zoo-
logical results based on material from New Britain, New Guinea, Loyalty Islands,
and elsewhere collected during the years 1895, 1896, and 1897, Pts. 1-6, 1902,
pp. 605-690, pis. LXIV-LXXIV. Cambridge, 1902.

— Gregarious Crustacea from Ceylon. Spolia Zeylanica, II, Pt. 5, 1904, pp.
1-28. Ceylon.

Marine Crustaceans. XII. Isopoda, with description of a new genus. The

Fauna and Geography of the Maldive and Laccadive Archipelagoes, II, Pt. 3,
pp. 699-721, pis. XLIX-LIII. Cambridge, 1904.

and NORMAN, A. M. On the Crustacea Isopoda of the Lightning, Porcupine,

and Valorous expedition. Trans. Zool. Soc. Lond., XII, 1886, Pt. 4, pp. 77-141,

pis. xvi-xxvu. London, 1886.
STEENSTRUP, JAPETUS, and LUTKEN, CHRISTIAN, FR. Mindre Meddelelser fra kj0ben-

havns Universitets zoologiske Museum. — 2. Forelobig Notits om danske Hav-

Krebsdys. Videnskabelige Meddelelser fra den Naturhistoriske Forening i

Kj0benhavn, 1861, III, pp. 274-276. Copenhagen, 1862.
STIMPSOX, WILLIAM. Synopsis of the marine invertebrata of Grand Manan, or the

region about the Bay of Fundy, New Brunswick. Smithsonian Contributions to

Knowledge, 1853, VI, pp. 39-44. Washington, 1854.
On some Californian Crustacea. Proc. Cal. Acad. Sci., I, Pt. 2, 1856, pp. 95-

99. San Francisco.

— Descriptions of some new marine invertebrata. Proc. Acad. Xat. Sci. Phila.,
VII, 1856, pp. 385-394. Philadelphia.

The Crustacea and Echinodermata of the Pacific shores of North America.

Boston Jour. Nat. Hist., VI, 1857, pp. 503-513. Boston.

— Notices of new species of Crustacea of western North America; being an
abstract from a paper to be published in the journal of the society. Proc. Bost.
Soc. Nat. Hist, VI, 1859, pp. 88-89. Boston.

— On an oceanic Isopod found near the southeastern shores of Massachusetts.

Proc. Acad. Nat. Sci. Phila., XIV, 1863, pp. 133-134. Philadelphia.

71(> BULLETIN 54, UNITED STATES NATIONAL MUSEUM.

STIMPSON, WILLIAM. Descriptions of new marine invertebrates from Pugets Sound,

collected by naturalists of the Northwest Boundary Commission. Proc. Acad.

Nat. Sci. Phila., XVI, 1864, pp. 155-156. Philadelphia.
STOLLER, JAMES H. Two new land Isopods. 54th report New York State Museum,

1900, pp. 208-213. Albany, 1902.
STREETS, THOMAS HALE, and KINGSLEY, JOHN STERLING. An examination of types

of some recently described Crustacea. Bull. Essex Institute, IX, 1877, pp.

103-108. Salem, 1877.
STCXBERG, ANTON. Om tva nya Oniscider. Ofvers. Svenska Vet. Akad. Forh.,

XXIX, 1872, No. 9, pp. 3-6. Stockholm, 1873.
Om Nord-Amerikas Oniscider. Ofversigt af Svenska Vetensk. Akad. For-

handl., XXXII, 1875, No. 2, pp. 43-64. Stockholm, 1876.
THOMPSON, MILLET T. A new Isopod parasitic on the hermit crab. Bull. U. S. Fish

Comm., XXI, pp. 53-56, pis. ix-x, 1902. Washington, 1902.
ULRICH, CARL JOST. A contribution to the subterranean fauna of Texas. Trans.

Am. Microscopical Spc., XXIII, 1901, pp. 83-100, pis. xiv-xvm. Lincoln,

Nebraska, 1902.
UNDERWOOD, LUCIEN. List of the described species of fresh water Crustacea from

America, north of Mexico. Bull. 111. State Lab. Nat. Hist., II, 1886, pp.

358-364. Champaign, Illinois.
VERRILL, A. E. On the distribution of marine animals on the southern coast of

New England. Am. Jour. Sci. and Arts (3), II, 1871, pp. 357-362. New

Haven.

— Results of recent dredging expeditions on the coast of New England. Ameri-
can Journal of Science and Arts (3), V, 1873, pp. 1-16; VI, 1873, pp. 435-441;

VII, 1874. pp. 38-46, 131-138, 405-414, 498-505, pis. iv-v. New Haven, 1873-74.
Explorations of Casco Bay by the U. S. Fish Commission in 1873. Proceed-
ings American Association for the Advancement of Science, pp. 340-395, pis.

i-vi. Salem, 1874.
Results of the explorations made by the steamer Albatross off the northern

coast of the United States in 1883. Report U. S. Commissioner of Fish and

Fisheries, 1883, pp. 559-560. Washington, 1885.
and SMITH, S. I. Notice of the invertebrata dredged in Lake Superior in 1871,

by the U. S. Lake Survey, under the direction of Gen. C. B. Comstock, S. I.

Smith, naturalist. Amer. Jour. Sci. and Arts (3), II, 1871, pp. 448-454. New

Haven.

Invertebrata of Southern New England; 478 pages, 38 plates. Wash-

ington, 1874.

HARGER, OSCAR, and SMITH, S. I. Catalogue of the marine inverte-

brate animals of the southern coast of New England and adjacent waters.

Report U. S. Commissioner of Fish Fisheries, Pt. 1, 1871-72, pp. 537-747 (243-

453). Washington, 1873.
WALKER, ALFRED O. Crustacea collected by W. A. Herdman in Puget Sound, Pacific

coast of North America. Trans. Liverpool Biol. Soc., XII, 1898, pp. 280-281,

pi. xv, figs. 7-10.
WALZ, RUDOLF. Ueber die Familien der Bopyriden mit besonderer Berucksichti-

gung der Fauna der Adrias. Arbeiten aus d. Zoologischen Institute der Univers.

Wien, IV, 1882. Vienna.
WEBER, FRIDERICO. Nomenclator entomologicus secundum entomologiam systemati-

cam ill. Fabricii adjectis speciebus recens detectis et varietatibtis. Chilonii et

Hamburgi, 1795.
WESTWOOD, JOHN O. Observations on the osculant Crustaceous genus Arcturus of

Latreille; with the description of a British species. Trans. Entom. Soc. Lon-
don, I, 1835, Pt. 2, pp. 69-75, pi. ix. London, 1836.

ISOPODS OF NORTH AMERICA. 717

WESTWOOD, JOHN O., and BATE, SPENCE. A History of the British Sessile-eyed

Crustacea, II, 1868. London.
WHITE, ADAM. List of the Specimens of Crustacea in the Collection of the British

Museum. 1847. London.
A Popular History of British Crustacea, comprising a Familiar Account of

their Classification and Habits. 1857. London.
WHITEAVES, JOSEPH FREDERICK. On recent deep-sea dredging operations in the

Gulf of St. Lawrence. Am. Jour. Sci. and Arts (3), VII, 1874, pp. 210-219.

New Haven.
Notes on a deep-sea dredging expedition round the island of Anticosti, in the

Gulf of St. Lawrence. Canadian Naturalist, 1875 (2), VII, pp. 86-129. Montreal.
WHITELEGGE, Scientific Results of the Trawling Expedition of H. M. C. S. "Thetis"

off the coast of New South Wales in February and March, 1898. Crustacea.

Pt. 2. Isopoda. Austral. Mus. Mem., IV, 1901, pp. 201-246. Sydney, 1901.
WILSON, H. V. Marine biology at Beaufort. American Naturalist, 1900, XXXIV,

p. 353. Boston.
WOOD-MASON J., and ALCOCK, A. Natural history notes from H. M. Indian marine

survey steamer Investigator, Commander R. F. Hoskyn, R. N., commanding.

No. 21. Note on the results of the last season's deep-sea dredging. Ann. Mag.

Nat. Hist. (6), VII, 1891, pp. 270-271. London.
ZADDACH, E. G. Synopseos Crustaceorum Prussicoruni prodromus, 1844, pp. 9-21,

Regiomonti.
ZUR STRASSEN, OTTO. Ueber die Gattung Arcturus und die Arcturiden der Deutschen

Tiefsee-Expedition. Zool. Anzeiger, XXV, 1902, pp. 682-689. Leipzig. '
Zusatz zu meinem Artikel iiber die Arcturiden. Zool. Anzeiger, XXVI, 1903,

p. 31. Leipzig.

INDEX.

Page. Page.

Acanthoniscus 636 Alloniscus maculosus 690, 691

spiniger 637 < mirabilis 594

Acherusia complanata 195 perconvexus 594, 5%

dumerilii 195 Alutera schoepfii 220,223

Actoniscus 593, 633 Anceus americanus 59

ellipticus 633,634 I cristatus 56

lindahli 634,635 * elongatus 58

-Ega 166, 167 hirsutus 57

alascensis 199 j Ancinus 270, 271

antillensis 167, 170 | depressus 271

arctica 167,182 Anilocra 215,226

belliceps 199 , laticauda 226, 227

concharum 95 leachii 227

crenulata 167, 173 mexicana 227

dentata 167,179 j occidental 258

ecarinata 167,171,173 plebia 226,229

emarginata 168 Anonyx 102

entaillee 168 Anthelura ' 63,68

graeilipes 168,183 | abyssorum 68,69

harfordi 109 afflnis 68,70

incisa 167, 180 elongata 69, 71

lecontii 167, 176, 186 Anthura branchiata 72

longicornis .• 187 brunnea 64

loveni 187 carinata 63,64

microphthalma 168,186,187,189 gracilis 63

nordenskioldii 187 polita 64

polita 991 tenuis 67

psora 167,168 Anthuridse 2,54,62,63

symmetrica 168, 185 Anuropus '. . ^ 88, 129

tenuipes 167, 177 Apseudes 37

tridens 172,173 • espinosus 37

ventrosa 168,187 gracilis 37,40

webbii 167, 175 intermedius 46, 47

JEgacylla lecontii 176, 177 propinquus 38, 45, 46

J2gathoa 215,216 triangulatus 38,43

linguif rons 216 Apseudidse 4, 87

loliginea 217 Arcturidae 323

medialis 216,218 i Arcturus 2,323,327

oculata 216, 217 j anna 333

.Egidse 2,55,166 bafflni 328,337,340

-Egiochus nordenskioldii 187 var. feildeni 340

ventrosus 187 intermedia 340

Agarna 215, 243 tuberosus 328, 340

carinata 244 beringanus 327, 328

Alaotanais 35 caribbseus 327, 335

hastiger 35, 36 cornutus 333

serratispinosus 36 feildeni 340

Alcirona 156,157 (tuberosus) 342

hirsute 157, 159 floridanus 327, 336

iusularis 161 glaber 327, 330

krebsii 157 glabrus 330

Alloniscus 592,593,594 hystrix 346

cornutus 594, 595 intermedius 344

719

720

INDEX.

Page.

Arcturus longispinus 329

murdochi 342

purpureus 327, 331, 336

tuberculatus 337

Argeia 499, 543, 544

en 1 1 1 mil i 545

pauperata 544, 551

pugettensis 51-1. ."> i">, :>r>i

Armadillididse 2, 584, 638

Armadillidium 638, 665, 666

commutatum 666

quadrif rons 666, 668

vulgare 666

Armadillo affinis 648

Htor 666

brunneus : 645

cacahuamilpensis 663

californica 653

cinctus §47

conglobator 645

cubensis 645

depressus 641

dugesi 652

dumorum 650

gigas 648

grenadensis 651

murinus 645

perlatus 644

pilularis 666

pisum 653

sil varum 643

speciosus 653

tenuipunctatus 640

tri vialis 666

viticola 642

zigzag 649

Armadilloniscus ellipticus 634

Ascidise callosae 31, 32

Asellidse 408, 409, 410

Asellodes alta 475

Aselloidea 3, 408

Asellopsis tenax 415

Asellota 3, 408

Asellus 409, 410, 419, 431

aquaticus 420, 428, 429

attenuatus 420, 426

brevicauda 420, 423

communis 419, 420

entomon 348

gronlandicus? 428,429

hcppinae 420, 425

intennedius 419, 422

lineatus 416

militaris 420

oestrum 254

Btygius 434

tenax 415

tomalensis 420, 431

vulgaris 420,428

Aspidophryxus 575

Astacilla 323, 324

americana 324

cseca 324, 326

granulata 324

Atherina 265

harringtonensis 265

Page.

Balanus , 8

Bathygyge 499, 537

grandis 537

Bathynomus 82, 130, 133

iloili-rlfini 133

gigan tens 130, 132, 133

Bithynis acanthurus 557,559

ohionis 559

Bopyrella alphei 559

Bopyridse 497, 498

Bopyrina 499, 563

abbreviata 5ti3

lativiitiroln 560

thorii 563,566

urocaridis 5(i3. ">r,:.

virbii :>r,i

Bopyriscus 499, 562

calmani 562

Bopyroidea 3, 497

Bopyroides 499, 566

aeutimarginatus 568, 570

hip]x)lytes 567, 568, 570

latreutieola 560

sarsi 568

Bopyrus (?) 554

u bd< mi inn I is 500

alphei 559

hippoly tes 567

latreutes 560

manhattensis 554

mysidium 573

palsemonetieola 554

pandalicola 554

Brackenridgia 693, 699

cavernarum 699

Branehiophryxus 575

Branchuropus 82, 88, 128

littoral's 88, 128

Brevoortia patronus 231

tyrannus 231

Csecidotea 409, 410, 433

microcephala 434

nickajackensis 433, 436

richardsonse 434, 437

smithsii 434,438

stygia 433,434

Calathura 63, 71, 75. 79

branchiata 71,72

crenulata 71, 74

Callianassa longimana 504

stimpsoni 508, 510

Cancricepon 516, 518

elegans 516,518

Caranx latus 254

Carpias 449, 452

bermudensis 452

Cassidina 273

' emarginata 273

lunifrons 273

typa 273

Cassidinella 273

Cassidisca 270,272,273,275

lunifrons 273

ovalis 273, 274

Cepon distortus 511

Ceratothoa 215,233

INDEX.

721

Page.

Ceratothoa deplanata 240

exocseti 234

gaudichaudii 237

im pressa 234

linearis '£'A

rapax 237

Chsetodipterus fabor 220

Chclifcra 3

Chiridotea 346, 347, 352, 353

caeca 353

snbi ni 350

tuftsii 353,354

Ciliesea 271, 299, 307, 308

carinata 309, 319

caudata 299, 308, 309, 314, 315

gilliana 313

cordata 308, 310, 311

gilliana 309, 313

granulosa 308, 309

hystrix 308

latreilli 308

linguicauda 308, 309

sculpta 309,318

spinulosa 308

Cirolana 82

albida 84, 114

borealis 82, 83, 101, 102, 105, 107

calMornica 109

chiltoni 83, 91

concharum 83,95

cubensis 84,114

gracilis 84,105

harfordi 84,109

impressa 83, 97

japonica '. 85, 86

linguif rons 83, 90

mayana 83, 87

minuta 83,92

neglecta 105, 107

obtruncata 84, 108

parva 84,92,93,94,111

polita 83, 99

sphseromiformis 82, 84

spinipes 101

virginiana 161

Cirolanidse 2, 55, 81

Cirolamides 82, 120

texehsis 120

( 'itharichthys sordida 250

Cleantis 347,404

heathii 404,407

linearis : 404

occidental is 404,406

planicauda 404

Clibanarius tricolor 536, 537

Clypeoniscus 677, 579, 581

hanseni 582

meinerti 577

Colanthura 63, 78

tenuis 79

Colidotea 347, 393

rostrata 393

Colopisthus 82, 133

parvus . 137

Conilera 82,116

concharum 95

28589—05 46

Page.

Conilera cylindracea 116, 120

montagui 116

polita 99

stygia 116, 120

Corallana antillen.sis 148, 151, 152, 153, 154

lissicauda 1 150, 153

oculata 152

quadricornis 144,147

sexticornis 143

subtilis 146

tricornis 139,145,154

occidentalis 141

truncata 145

warmingii 154

Corallanidfe 55, 156

Coryphsena 234

Crago alascensis 545, 546, 547

elongata 545,547

alba 546, 547

communis 546, 547

dalli 545, 547

f ranciscorum 551

aiigustimana 545,547

munita 545, 547

nigricauda 547

nigromaculata 546, 547

propinqua 547

Crangon 559

heterochaelis 559,560

Crossurus vittatus 8

Cruregans 79

Cryptione 499, 520

elongata 520

Cryptocope 4, 16

arctica 16

Cryptoniscidae 497, 577, 582

Cubaris 638, 639, 654, 663

affinis 640, 645, 648, 654

bninnea 645

californica 639, 653, 654

cincta 640, 647

depressa 639,641

dugesi 640,652

dumorura 640, 650

gigas 640,648

grenadensis 640, 651

murina 639, 645

perlatus 639, 643, 644

pisum 640, 653

sil varum : 639, 643

speciosus 654

tenuipunctata 639, 640

vit icola 639, 642

zigzag 640, 649

Cyathura 63

carinata 63, 64

Cylisticus 593, 609

convexus 609

Isevis 609

Cymodoce 308

Cymodocea bermudensis 314

caudata 314

Cymothoa 215, 247

caraibica 248, 252

dufresnei 251

elegans 253

722

INDEX.

Cymothoa entomon 348

excisa 247,248

exigua 248, 250

gaudichaudii 237

immersa 254

impressa 234

lanceolata 224

lignorum 269

oceanica 684

oculata 217

oestrum 248, 254

olivaceu 263

ovalis 263

parasita 248

praegustator 231

•triloba 263

Cymothoidte 2,55,214,215

Cymothoidea 3, 54

Cynoscion regalis ? 263

Dajidse 497,572

Dajus 572,573,575

rnysidis 573

Desmosomidse 408

Deto 637

Diplectrum formosum 209

Dolichochelia forresti 23

Dynamene 271,299,305,308,311,315

angulata 299, 302

benedicti 299, 304

bermudensis 299, 314, 315

dilatata 299, 304

glabra 299,301

moorei 239, 303

perforata 299, 303

sculpta 318

tuberculosa 299,310,311

Edotea 347,394

acuta 394,395

bicuspida 383, 384, 385

montosa 395, 397

nodulosa 388

triloba 395, 396

Epelys montosus 397

trilobus 396

Epicaridea 3,497,525,527

Erichsonella 347,400

attenuata 400

filiformis 400,401

floridana 400,403

Erichsonia attenuata 400

filiformis 401

Ethelum 588

americanum 588, 589

modestum 588

reflexum 588, 590

Eubelidse .*. 583, 587

Euphiloscia 673, 686, 692

elrodii 692

Eurycope 486, 490, 491

caribbea 491,493

cornuta 491

fragilis 494

robusta 491

Eurydice 82,123,129

caudata 123,124

convexa 123, 124

Page.

Eurydiee elegantula 125, 126, 127

grimaldii 125

spinigera 123, 125

Eusymmerus 347, 398

antennatus 399

Exocoetus 234

brachycephalus 234

exiliens -234

lamelliferus 234

Exocorallana 138

antillensis 139, 148, 151, 153

tissicanda 139, 150, 1.VJ. l.V.

mexicana 138, 142

oculata 139,152

quadricornis 138, 144, 147

sexticornis 138, 143

subtilis 139, 146

tricornis 138, 139, 144, 145, 153

truncata 138, 145

warmingii 139,150,154

Exocorallanidse 2, 55, 138

Exosphseroma ' 271, 275, 287, 288, 298

amplicauda 288

crenulatum 288, 298

dugesi 283, 294, 295

faxoni 288,292

octoncum 288,293

oregonensis 288, 2%

rhomburum 288, 290

thermophilum 288,294

yucatanum 288,291

Flabellifera 3,54

Gadus callarias 169

ogac 169

Galacantha diomediie var. parvispina 527

Gebia 643

Glossobius linearis 234

Glyphocrangon spinulosa 537

Glyptonotus 347

csecns 353

entomon 348

sabini 350

tuftsii 354

Gnathia 56

cerina 56, 59

cristata 56

elongata 56, 58

hirsuta 57

Giiathiidse 54, 55

Grapsicepon 498, 512

edwardsii 513

Gyge hippoly tes 568

Gyropleurodus francisci 221

Haemulon 209

plumieri 227

Haliotis rufescens 310, 313

Haplarmadillo 638, 664

monocellatus 665

Haplophthalmus 693, 696

puteus 697

Harponyx pranzoides 212

Hemirhamphus 265

Henopomus muticus 469

^tricornis 474

Heterophryxus 575

Heterotanais 4,21,24

INDEX.

723

Page.

Heterotanais limicola -1

HippoU K- /ostericola 563, 564

Holophryxus 572, 575

alascensis 576

Hydrolagus colliei 199

Hypergnathus 593, 631

texensis 632

Hyperprosopon argenteus '2">*

11 yssiira 79

lanthe spinosa 458

Idotsega longicauda 348

Idothea 346,356,357,579

algirica 362

aquatica 428

atrata 362

baffini 337

baltica • 356,364

bicuspida 384, 385

caeca 353

compacta 362

consolidata 383

entomon 348,364

fewkesi 356, 359

filiformis 401

gracfllima 356, 357

hirtipes 370

irrorata 364

marina 364

var. phosphorea 367

marmorata 384, 387

media 370

metallica 356, 362

montosa 397

muricata 390

nodulosa 388

ochotensis 356, 366

oregonensis 370

peloponesiaca 362

phosphorea 356, 367

pulchra 385

rectilinea 356, 360

rectilineata 360

resecata 369

robusta 362

rostrata 393

rugosa 362

sabini 350

stenops 375

tricuspidata < 364

triloba 396

tuftsii 354

urotoma 356, 358, 359

whitei 373

wosnesenskii 370

Idotheidse 323,346

Idotheoidea 3, 323

Ilyarachna 486, 495

hirticeps 495

longicornis 495

Indusa 215, 246

carinata 246

lole 457

Tolella 449,457

alascensis 458, 464

erostrata 458, 463

holmesi 468,465,468

Page.

lolella libbeyi 458,463

sarsi 458, 467

speciosa 458, 460

spinosa 457, 458

triangulate 458,462

lone 498, 503, 504, 543

brevicaiida 504, 505

cornuta 504, 510

thompsoni 504, 608, 510

thoraeica 505, 510

Irona 215, 265

nana 265

Itea Isevis 694

riparia 694

Jaera 364,448,449

albif rons 450

baltica 450

copiosa 450

curvicornis 479

kr0yeri 450

marina 449, 450

nivalis 450

wakishiana 449, 451

J eeropsis 449, 476, 477, 479

brevicornis 478

curvicornis 479

dollfusi 479

lobata 477,479

marionis 479

neo-zelandica 479

rathbunae 477, 478

Janira 449, 455, 468

alta 469, 475

maculosa 468, 469

minuta 469, 471

occidentals 469, 472

spinosa 458

tricornis 469, 474

Janirella 410

Janiridse 408, 409, 448, 479, 485

Janiropsis 449,454,457,465,468

breviremus 455, 456

califomica 454, 455

kincaidi 454, 456

Jolanthe libbeyi 463

Lachnolaimus maximus 220

Lagodon rhomboides 263

Laminaria 8

Latreutes ensiferus 560, 561

Leachia granulata 324

Leidya 498, 511

distorta 511

Leptochelia 4,22,23,24,25

algicola 26,27,29

cseca 18

dubia 23, 26, 28, 29

edwardsii 27

? fllum 18, 23, 31

forresti 23

incerta 28

limicola 21

minuta 23

rapax 23, 30

savignyi 23, 27, 29

Leptognathia 4, 17, 18

caeca 18

724

INDEX.

Page. Page.

Leptognathia longiremis 18, 19 Meinertia gaudichaudii 237, 242

sarsi.-.t 19 gilberti 23?, 241

Leptophryxus mysidis 573 ! transversa 237, 243

Leptotrichus 593,624 Mesarmadillo americauus 5M)

granulatus 624 modestus 588

lentus 625 reflexus.' 590

panzerii 625 Mesidotea 346, 347

squamatus 625 entomon 347,348

tauricus 625 sabini 347, 350

Ligia 608 Metoponorthus . 593, 625

baudiana 678 pruinosus 625, 627, 628

baudiniana 678 saussurei 625, 626

(hirtitarsis) 608 sexfase'atus 626,629

dilatata 682 virgatus 626,630

exotica 676, 678 Micropogon undulatus 263

hirtitarsis 678 ! Mugil liospes .' 242, 246, 24V

gaudichaudii 676 ! Munidion 498, 517

grandis 676 parvum 518

hirtitursis 678 princeps 519

(Italica) coriacea 676 Munna 480

occidentalis 681 caeca 480, 484

oceanica 608,684,685 fabricii 480

oniscides 685 kr0yeri 480, 483

pallasii 682 whiteana 483

septentrionalis 682 Munnida quadrispina 519, 527

stimpsoni 682 Munnidse 408,409,479

Ligidium 673, 686 Munnopsidse 408, 409, 485, 486

gracilis 686, 690 Munnopsis 4Nj

hypnorum 686 ty pica 486

longicaudatum 686, 689 Myliobatis 221

tenue ' 686,688 Mysis oculata. . 573

Ligyda .1 673,674 Mytilus 373

baudiniana 674, 678 Myxocephalus scorpius 169

exotica 674, 676 Xsesa 308

occidentalis 674, 681 caudata 314

oceanica 674, 6f4 ! depressa 271

olfersii 674 ovalis 274

pallasii 674,682 Nalicora 156,163

Ligydidae 584,673 rapax ; 164

Limnoria 268 Nectocrangon alascensis 545, 546, 547

californica 269 crassa 545, 546, 547

lignorum 269 dentata 54C, 547

tenebrans 269 lar 545,546,547,550

uncinata 269 nigricauda •. 545

Limnoriidse 55, 268 ovifer 545. 547

Livoneca 215,216,256 Neinatocarcinus agassizii 520

californica 256,260 ! Xeotanais 4,32,35

desmarestii 261 i americanus 32

ovalis 257,263 hastigur 32.35

panamensis 256, 257 serratispinosus 35

redmanni 216, 257, 261 Nerocila 215, 219

vulgaris 256,258 acuminata 219,220

Loligopealii 217 califoniica 219,221

Lophohelia 60 lanceolata 219, 224

Lyprobius 592, 598 munda 219

pusillus 598 Notophryxus 575

Malacostraca 525 Olencira 215,230

Mancasellus 409,410 lamarkii 231

brachy urus 410, 411 praegustator 231

danielsi 411,417,419 Oniscidse 2,584,592,638

lineatus 410, 416, 419 Oniscoda maculosa 469

macrourus 410, 413 Oniscoidea 3, 583

tenax '. 410,415,418,419 Oniscus 592,598,599,600

dilata 410,416,419 affinis 600

Meinertia 215,236,237 aquaticus 428,429

deplanata 237,240 asellus 600,601

INDEX.

725

Page.

onisciis lialticus :;iii

convexus 609

cylindraceus 116

entomon 348

granulatiis • -621

hypnorum 686

hi-vis 614

marinus 15u

murarius 600

oceaiiicus 68 t

u'strum 254

prsgustator 231

psora .' 168

tridens 364

vicarius 600

Oosaccus 582

Ophiodon elongatus •_;.>

Osmerus mordax 364

Pagurus longicarpUH 532

ochotensis 523

Puhi-gyge 525, 527

borrei ',24, 525, 52fi, 527

I'lila-inonetes 55 1

exilipes 555, 556

vulguris 55 1

Pancolus 4,5

californiensis 5, 582, 583

I'andalcipsis dispar 569

I'niidalus Ixirealis 500,501, 569

jordani 570

leptocerus 500

montagui 500,502,569

I'aradynamene 271, 305

benjamensis 305

Paralaforax clathrata 221

I'aranthura 63, 75, 79

arctica 72

infundibulato 75,76

norvvegica 72

verrillii 75, 77

Parapseudes 37, 47

goodei 17, I-

latifrons 48

Parargeia 499, 551

ornata 551

Parasellida 408

Paratanais algicola 26

caeca 18

limioola 21

saviifiiyi 26

Pentidotea 346,368

resecata 368. 369

stenops 369, 375

white! 369, 373

• wosnesenskii 369, 370

Petrolisthes sexspinosus 5:51

Philoscia 592, «02, 603, 608, 692

bermudensis 603, 607

bvevicornis 603, 60C

couch! 608

culebrw 603, 604

nigricans 603, 608

richmondi 603

spinosa 603, 608

tuberculata 621

vittata 603,605

Page.

Philougrin .. 692

ripuria 694

Phryxus 498, 499

abdominalis 500

distortus 511

hippolytes 500

Phyllodurus 499, 539

abdomiiiitlis 540

Pinna 8

Plesionika semihfvis 502

Pleuroprion 323, 342

hystrix 346

intermedium 342, 344

murdochi 342,315. :: in

Pomatomus saltutrix 263

Porcellio 593, 611, 612

armadilloides 609

aztecus 614

brandtii 621

cineniscens 014

convexus 609

cotillce 014

cubeusis 614

degeerii 614

dubius 614, 621

eucercus 614

ferrugineus 617

formosus 612

frontalis 027

gcmmulatus 621

granulatus 621

jelskii 627

hevis 609,612,614

maculicornis 627

melanocephalus 619

mexicanas 614

mixtus 619

montezumse 622

nigra 621

ovatus 614

•parvicornis 612, 616

paulenses 622

jiictus t;i9

poey i C14

pruinosus 627

rathkei 612,617

scaber 612, 621, 62.>

sexfasciutus 629

spinicomis 612, 619

spinifrons 609

striatus 617

sumichrasti 614

sy riacus 614

tetramijurus 617

trilineatus 617

t ri vittatus 617

truncatus c,27

urbicus 614

Zealand ions 627

Porcellionides flavo-vittatus 627

Pranizu cerina 59

Priacanthus arenatus 254

Pristis semisagittatus • 263

Probopyrus 499, 553, 562

alphei 553, 559

bithynis 553, 557

720

INDEX.

Page.

Probopyrus floridensis 553,555

latreuticola 553, 560

pahemoneticola 554

pandalicola 553, 554

Prodajus 575

Proraicrops guttatus 221

Pseudarachna 408

Pseudarmadillo 638,654,655,663

carinulatu* 655,657,659,660

dollfusi 655,657

gillianus 655

Pseudione 499, 522, 523

curtuta 523, 530

furcata 523, 529

galaeanthae 523, 527

giardi 523

Pseudotriacis microdon 95

Pterelas webbii 175

Ptilanthura 63, 66

tenuis 66,67

Rhinoryctes mirabilis 594

Rhoea latifrons 48

Rhyscotus 593, 630

turgif rons 631

Rocinela 166, 190

alascensis 199

americana 190, 201

angustata 191, 204, 206

aries 191, 210

belliceps 190, 199

cornuta 190, 192

cubensis 190,197

dumerilii 190, 195

insularis 190, 194

laticauda 190, 204, 206

liljeborgii 212

maculata 190, 198

modesta 207

oculata 190, 191

propodialis 190, 203

signata 191, 209

tuberculosa 191, 20H

(?) Saduria entomon 348

Schizopoda - 497

Sciaena 209

Selerocrangon procax 551

Scorpsena guttata 221

Scuteloidea 272

Scyphacella 671

arenicola 671

Scyphacidse 584, 671

Serolidse 55, 320

Serolis 320

carinata 321

Somniosus microcephalus 169, 173, 182

Spams 248

Sphseroma 271, 275, 280, 287, 298

amplicauda 288

crenulatum 298

destructor 280,282,2*6

dugesi 295

egregium 290

felix 286

globicauda 298

octoncum 293

olivaeea .. 296

Page.

Sphseroma oregonensis 296

pentodon 280, 286

quadridcntatum 280,281

rhomburum 290

sieboldii 287

tenebrans 282

thermophilum 294

vastator 284, 285

yucatanum 291

Sphseromidse 55, 270

Sphseroniscus 638, 661, 662, 663

caciihuamilpensiK 662, 663

portoricensis 662

Spherillo affinis 648

Spheroides maculatus 220

Sphyrapus 37, 50, 51

malleolus 52, 54

tudes 53, 54

Spirontocaris arcuata 569

bispinosa 502, 5C9

biunguis 502

brevirostris 569

fabricii 501, 568, 570

gaimardii 500, 502

belcheri 501

gibba 500

grcenlandica 501

herdmani 570

liljeborgii 500, 568

macrophthalma 501, 502

phippsii 500, 502

polaris 500, 501, 502, 568, 569, 570

pusiola 500, 568

spinus 500,502,568,569,570

suckleyi 501, 502, 569, 570

townsendi 501, 502, 503

tridens 501, 502

Squilla asellus 428

entomon •. 348

Stegias 499, 535

clibanarii 536

Stegophryxus 499,531,537

hyptius 532, 537

Steindachneria 258

Stenetriidse 408, 439

Stenetrium 440

antillense 440,446

occidental 440, 441, 446, 447, 448

serratum 440

stebbingi 440,444,446

Stenomacrus turgifrons 631

Stenosoma filiformis 401

gracillimum 356

irrorata 364

Stenotomus chrysops : 263

Strombus giganteus 254

St y loniscus gracilis 686, 690, 691

Synidotea 2, 346, 376

angulata 376,382

bicuspida 376, 384, 385

consolidata 376, 377, 378, 383

erosa '. 376, 379

harf ordi 376, 387

Isevis 376,389

laticauda 376, 386

marmorata . . . . 376, 384

INDEX.

727

Page.

Synidotea muricata 376, 390

nebulosa 376,381

nodulosa 376, 388, 579

pallida 376,378

picta 376,391

ritteri 376, 377, 378

Synuropus 592, 598

granulatus 599

Sy statins 166, 212

infelix 212

liljeborgii 212

Tanaidse 2,3,4,583

Tanaioidea 3

Tanais 4,7

alascensis 7, 10, 15

cavolinii 7,8

dubius 28

edwardsii 26

filum 26, 31

hirticaudatus 8

islandicus 19

longiremis 19

Icrioatiis 7

nonnani 7, 14

robustus 7, 11

savignyi 26

tomentosus 8

vittatus 8

Tecticeps 270, 275

alascensis 276, 360

convexus 276, 278

Thalassochelys caretta 11

Page.

Thor floridanus 566

Thunnus 1>37

alatunga 209

Tole 457

holmesi 465

libbeyi 463

Trachurops crumenophthalmus 254, 263

Triakis semifasciata 221

Trichoniscidae 584, 692, 693

Trichoniscus 693

arenicola 671

papillicornis 693, 695

pusillus 693, 694

Tridentella 156, 161

virginiana . . 161

Tylidse 583, 584

Tylos 585

armadillo 586

latreilli 585,586

niveus 585

Typhlapseudes 37, 49

nereus 49

Uca pugilator 511

Upeneus martinicus 227

Upogebia pugettensis 540

Upogebise 540

Urocaris longicaudata 565

Uropodias 638, 669

bermudensis 670

Valvifera 3, 323

Zonophryxus 575

o