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TBRARY

Dix Eee of Crustacea

LIBRARY
Division of Crustacea

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fh THE INTERNATIONAL SCIENTIFIC SERIES

po HISTORY OF

PRUSTACEA

RECENT MALACOSTRACA

BY THE
Rev. THOMAS R. R. STEBBING, NE AG

FORMERLY FELLOW AND TUTOR OF WORCESTER COLLEGE, OXFORD
AUTHOR OF
THE NATURALIST OF CUMBRAE, THE CHALLENGER AMPHIPODA, ETC.

INVERTEBRAT_
\ ZOOLOGY

WITH NUMEROUS ILLUSTRATIONS Prustacea

“4 ae LA,
[Vi pt : 7 :

lig “a a - <
we N,
‘“"——
NEW YORK
DAP PELE LON: AND COMP ANY
1893

Authorized Edition.

PREFACE

—

THE ambition of this volume is that it shall be one to
which beginners in the subject will naturally have re-
course, and one which experienced observers may willingly
keep at hand for refreshment of the memory and ready
‘reference. An attempt has been made in it to bring the
reader face to face with the vastness of the theme, to show
- him how variously it may engage the human mind, and
to give him a groundwork of information as to the objects
to be examined, with a side glance at the literature that
has discussed them.

It is not very generally known that the species of
Crustacea extend to a number of several thousands, and
that some of these species people parts of the ocean in
enormous swarms. Of some of the groups the general
character is familiar to every one, but there are also
groups of which most persons either know nothing or
have not the least idea that they belong to the Crustacea.
The beginner, therefore, will have provinces of a new
world opened to his exploration. There is curiosity to
be gratified. The sporting instinct will discover many
an unexhausted territory. In the manners and customs

vl PREFACE

of the creatures there is much to afford entertainment,
and almost every new observer finds something singular
to relate.

In examining the structure both external and internal,
whether in new species or in those that have been long
established, the acutest powers of observation may be
trained and profitably employed. Moreover, the highest
ingenuity is excited and finds scope in the effort to explain
the meaning of the facts observed. For, judging by dis-
coveries already made, we are warranted in supposing
that, down to the finest hair, every detail of every organism
has its motive and meaning. Nor need man despair of
finding out something for his private and personal benefit
while investigating the physiology of a shrimp.

It is needless to insist that a hundred volumes such as
the present would not suffice to discuss the subject in all
its bearings, since a hundred volumes would be but a
small fraction of what has been already written upon it,
and the incessant stream of publications widens and
deepens as it flows.

By the references made to some of the most recent
and to some of the most important authorities, the student
will be guided in general to adequate lists of literature.
In consulting these bibliographical notices he will be
perhaps as much amazed by the multitude of writers and
writings as at first by the multitude of the genera and
species of the Crustacea themselves. He will be led. to
consider it not unreasonable that the present volume
should have been content to deal with one half of the
entire class, leaving the other half for a future occasion.

PREFACE vil

He will recognise by a perusal of the mere titles of what
has been written, that no manual of this size could cope
with all the branches of the subject, without the certainty
of becoming a dry and repulsive catalogue. Even in what
has been here laboriously put together the gentle reader
is requested to remember that definitions are like the
sermon which the preacher was forced to deliver, but to
which, he reminded his hearers, they were under no sort
of compulsion to listen. A time comes to the student
when he scans every word of a definition with eager
interest, but till then it will do him no harm to pass it
over with cursory eyes and a light heart.

In a volume of the International Series it would have
been inappropriate to devote to the British fauna more
than its proportional space, but I have thought that it
would be neither unfair nor uninteresting to mention at
least the names of all the British species, so far as it has
been possible for me to collect them from and correct
them by the latest and best authorities.

One personal matter remains to be noticed. It was
long the intention of Dr. Henry Woodward, of the British
Museum, to publish in this Series a ‘ History of Recent and
Fossil Crustacea.’ The continual pressure of other engage-
ments has prevented him from accomplishing the con-
genial task. ‘That, nevertheless, the results of his un-
rivalled knowledge of the extinct forms will sooner or
later be gathered into a compendium for general use
should be taken for granted. The other materials which
he had collected for his purposed work, relating principally
to the characters of the living organism, are still in reserve

Vill PREFACE

for the service of a future volume. In the meantime the
production of the present book was entrusted to my hands
at his express desire. A circumstance so honourable to
myself and so well fitted to inspire an initial confidence
in my readers, it would, I think, be false modesty to con-
ceal. My best thanks are due to Dr. Woodward for his
friendly and favourable opinion of my capacity; they will
be best paid if my performance has succeeded in de-

serving it.

THOMAS R. R. STEBBING

TUNBRIDGE WELLS,
February 17, 1892.

CON EEN ES

aos SS
Chapter
I. Classification of Crustacea in outline ‘
II. Where to find specimens. : : .
III. On giants and dwarfs

XV
Beye.

A VIT.
XVIII.

XIX.

XX.

. On the Crustacean segments and fee aon ages
. Crabs; their tribes, legions, and families

. The great eatable crab and its allies

. The land-crabs, and others of the same tribe

. On the ‘sharp-snouted’ crabs, and some of their

manners and customs

. On the tribe called Oxystomata or iciidontiane
. The anomalous crabs
. Hermit-crabs, lobsters, and shrimps; thet lbs:

legions, and families

. Burrowers, and their kindred
. The warty Scyllarus and the spiny labaien or

erawfish

. The Norway lobster, the common ieee sua the

crayfish
Small tribe of the SieAaoides ;
Branchial system, development, and range ae the
Peneidea . : :
A surprising multitude of oe imps a prawns
The Schizopoda; their branching feet; their fami-
lies; their luminosity : ;
The burrowing Squillide, and their ene s pelagic
larvee : . - :
A concise history of the Cumacea . :

x

Chapter

XXI.
XXII.
DEX ETT.
XXIV.
ROY
XXVI.

XXVITI.
XXVIII.

CONTENTS

Tribes and families of the ee the claw-bear-
ing tribe . : : ;

Tsopoda with a caudal fan, a pes ol varied tribe.

The tribe with a valve-bearing tail . -

Tribe of the Asellota; including strange iianes
and anomalous limbs

New tribe of the Phreatoicidea, Bit eos vial
mountain-streams . :

Parasitic Isopods; their asivpralere Tes and trans-
formations .

Woodlice and other Peel Teer

The Amphipoda conspicuous by their absence

Index

TABLES OF CLASSIFICATION

The class Crustacea

The suborder Brachyura : : ° : ;
The suborder Macrura . . . :
Affiliation of the larve of the Siuillidrs A ° -
Distinctive characters of Cumacean families . ° :
The suborder Isopoda . : A ; 5

Synopsis ot the Cymothoid group :
Genealogy of the Epicaridea ; their Girnstacean hosts.
Genealogy of the Entoniscide .

Genera of the Oniscide . ; . °
Genera of the Armadillidide . : :

fist OF thEUSTRATIONS

EGA “E,
To face p. 25.

Lobster devouring a man, and Rhinoceros— Whale devouring
a lobster. Gesner

PEATE, EH.
To face p. 84.

Platyonichus iridescens, Miers. Challenger Brachyura
Gecarcinus lagostoma, Milne-Edwards. Challenger Brachyura
Calappa depressa, Miers. Challenger Brachyura

Cheliped of Calappa depressa - : :
Leucosia australiensis, Miers. Challenger Brachyura -

PLATE III.
To face p. 95:

Kriocheir japonicus, de Haan. With separate figures of the
pleon of male and female, and of the chele of the female
and young male. De Haan

PLATE IV.
To face p. 110.

Platymaia Wyville-Thomsoni, Miers. Challenger Brachyura
Naxia hystrix, Miers. Challenger Brachyura ;
Lambrus intermedius, Miers. Challenger Brachyura
Hippa talpoida, Say. Adult female. S.J. Smith

Second zoea stage of Hippa talpoida. S. I. Smith

Last zoea stage of Hippa talpoida. 8S. I. Smith

Page

110
116
121
150
150
150

Xll LIST OF ILLUSTRATIONS

Page
Catapagurus Sharreri, A. Milne-Edwards, in Epizoanthus :
americanus, Verrill. NS. I. Smith. : Bye 55)
Catapagurus Sharreri removed from the polyp- cole S. I.
Sinith
PLATE TY.

To face p. 187.

Latreillia valida,de Haan. A female specimen, with separate
figure of the head from below, flanked on the left by dorsal
views of the male head and pleon, and on the right by
dorsal views of the female head and pleon. De Haan

PATE 2 L.
To face p. 153.
Lithodes histrix, de Haan. A male specimen, with separate
figures of the right chela and of the pleon, the latter

shown in one view armed with its spines, in the other
denuded of them. De Haan

PLATE VII.
T'o face p. 169.

Birgus latro (Linneus). Desmarest . ’ ° e 156
Tylaspis anomala, Henderson. Challenger Anomura - 166
Pylocheles spinosus, Henderson. Challenger Anomura « £63
Porcellana longicornis (Linneus). Early larval form. Sars 172
Uroptychus insignis, Henderson. Challenger Anomura =. ais

Third maxilliped of Uroptychus insignis
Under surface of Uroptychus insignis, showing the
pleon folded naturally
Uroptychus gracilimanus, Henderson. Challenger Anomura 178
Ptychogaster Milne-Edwardsi, Henderson. Chall. Anomura 178

PLATE VIII.
To face p. 178.

Lithodes maia (Linnzus)
Eupagurus Bernhardus (Linneus)
Porcellana longicornis (Linnzus)
Galathea intermedia, Lilljeborg
Munida rugosa (Fabricius)

End of pleon in the last
larval stage. Sars

LIST OF ILLUSTRATIONS

PLATE IX.
To face p. 186.

Upogebia littoralis (Risso). First post-larval stage. Sars
Palinurus vulgaris, Latreille. Earlhest larval form. Bate
Nephrops norvegicus (Linneus). Second larval stage. Sars
Peteinura gubernata, Sp. Bate. Challenger Macrura
Elaphocaris Dohrni, Sp. Bate. Challenger Macrura

PLATE X.
To face p. 190.

Cheiroplatea cenobita, Sp. Bate. Challenger Macrura
Telson and uropods of Cheiroplatea cenobita
Thaumastocheles zaleucus (v. Willemoes Suhm). Bate
Platybema rugosum, Sp. Bate. Challenger Macrura
Atya sulcatipes, Newport. Bate
First trunk-leg of Atya sulcatipes
Telson and uropods of Atya sulcatipes . : :
Nematocarcinus undulatipes, Sp. Bate. Challenger Macrura

PLATE XI.
To face p. 211.

Stenopus hispidus (Olivier). With separate figures show-
ing the maxille, maxillipeds, first and second pleopods,
and plan of the branchial arrangements and proportions.
Bate

PLATE XII.
To face p. 219.

Hepomadus glacialis, Sp. Bate. Challenger Macrura
Peron from below, showing the thelycum
Epistome, mandible, lower lip, first maxilliped, and
branchial plume in section
2

Xiil

Page
186
198
202
220
221

XIV LIST OF ILLUSTRATIONS

PLATE XIII.
To face p. 272.

Notostomus perlatus, Sp. Bate. Challenger Macrura
Eretmocaris longicaulis, Sp. Bate. Challenger Macrura

Mysis relicta, Lovén. A female specimen in lateral view. Sars
. 5 - Ventral view of the cephalo-thorax
- = 3 Ventral view of telson, with inner
branch of each uropod
te se Pe The eye, and a section of the upper part
of it

Squilla scabricauda, Lamarck. Desmarest
In both the dorsal and ventral view the first raavilie
peds are drawn back behind the large second maxilli-
peds, as otherwise they could not be seen
Squilla empusa, Say. Late larval stage. S. I. Smith

PLATE XIV.
To face p. 338.
Euneognathia gigas (Beddard). Challenger Isopoda. ;
The male, the female, and the first gnathopod of the male
Neasellus kerguelenensis, Beddard. Challenger Isopoda
Ischnosoma spinosum, Beddard. Challenger Isopoda

PLATE XV.
To face p. 352.
Cirolana borealis, Lilljeborg. The adult male. Hansen
Head from below, and mandible
Nerocila Lovéni, Bovallius. Bovallius
Doysal and ventral view .
Ceratothoa auritus (Bovallius). Bovallius ‘
Dorsal and lateral view of female ; dorsal view of male

PLATE XVI.
‘To face p. 389.
Phreatoicus typicus, Chilton. Chilton

Second maxilla, second pleopod, telson, and fanaa of
Phreatoicus typicus
Phreatoicus australis, Chilton. Chilton 3

Page

246
255
272

284

290

308

381
383

342
342
302
302
B54
B04

389

389

LIST OF ILLUSTRATIONS

PLATE XVII.
To face p. 397.

Microniscus calani, Sars. Sars :

. Cyproniscus cypridine (Sars). A female (with a male
in the normal position) affixed to the body of a Cypri-
dina norvegica. The right valve of the host has been
removed. Sars

Adult ovigerous female of as Ge monianas, dekdotad: ia
viewed from above

d. Younger female, not yet ovigerous, in lateral view

e. Male, probably adult, with the anterior extremity carrying

two root-like processes, and embedded in the skin of the
Cypridina
jf. Larva in the last stage of development, seen from above

~ a

is)

PLATE XVIII.
To face p. 414.
Portunion menadis, Giard, on Carcinus menas (Pennant).
Giard and Bonnier : ‘ ‘ :
Portunion Kossmanni, Giard and Bonnier. Giard and
Bonmer : : :
Cancricepon elegans, Ginrd sua eee Lateral view of
female; dorsal view of male and female. Giard and
Bonnier . .
Gigantione Moebu, ae ewe? and vant view of
female. Kossnvann

PLATE XIX.
To face p. 425.

Helleria brevicornis, von Ebner

The head from above, the head and pleon from below ;
the antenna; mandible, lower lip; first maxilla, second
maxilla, maxilliped; first leg; rudimentary first pleopod
with opercular plate of the second, stilet of the second
pleopod, fourth pleopod showing the opercular plate
broadside and edgeways, and the peduncle with the bran-
chial plate; uropod. Von Ebner

XV

Page

397

397

407

408

413

414

xvi LIST OF ILLUSTRATIONS

IELOUSTRATIONS IN THE TEXT

1. ‘The lady in the chair.’ [Herbst] . : ;

2. Ethusa mascarone (Herbst). [Herbst] . ° ;
3. Corystes cassivelaunus (Pennant). [Herbst] . .
4. Gelasimus arcuatus, de Haan. [de Haan|

5. Huenia proteus, de Haan, adult male. [de Haan|

6. Huenia proteus, de Haan, young male. [de Haan]

7. Huenia proteus, de Haan, female. [de Haan]

8. Chorinus aculeatus, Milne-Edwards. [Aurivillius]|

9. Myra fugax (Fabricius). [de Haan]

10.
He
12.
13.
14.
15.
16.
17.

18.

19.

20.

21.
22.

Dorippe japonica, von Siebold. [de Haan|

Ranina scabra (Fabricius). [de Haan]

Zanclifer caribensis (de Freminville). [Henderson]
Lomis dentata (de Haan). [de Haan]

Spiropagurus spiriger (de Haan). [de Haan|

Porcellana longicornis (Linn.), young form. [Stebbing] .
Ibacus incisus (Péron). [Desmarest]

Astacus americanus (Milne-Edwards), tarval form. [S. J.
Smith

Astacus americanus (Milne-Edwards), larval form. [.S. I.
Smith |

Astacus americanus (Milne-Edwards), larval form. [S. J.
Smith |

Sergestes atlanticus, Milne-Edwards. The petasmata
[Spence Bate]

Procletes biangulatus, Spence Bate. [Spence Bate]
Mysis relicta, Lovén. First maxilla. [G. O. Sars]

Page

48

53

73

89
108
108
108
115
128
131
141
144
154
165
172
194

204

204

204

215
254
272

LIST OF ILLUSTRATIONS XVil

Page
23. Mysis relicta, Lovén. Second maxilla. [G.O. Sars] . 272

24. Diastylis stygia, Sars. First maxilliped. [G. 0. Sars] + 297
25. Diastylis Goodsiri (Bell). Second maxilliped. [Hansen] 298
26. Diastylis Goodsiri (Bell). Female. [Hansen] . or B10)
27. Diastylis Goodsiri (Bell). Female. [Hansen] . s. oO
28. Kisothistos vermiformis, Haswell. Male. [Haswell] . 334

29. Hisothistos vermiformis, Haswell. Female. [Haswell]. 334

30. Gnathia asciaferus (Hesse). [Hesse] : 5 - 3838
31. Ceratocephalus Grayanus, Woodward. [Haswell] - 364
32. Kurycope gigantea, Sars. [Hansen| : ; - 385

The names in italics indicate the sources from which the figures
have been copied or adapted. The Brachyura of the Challenger
were described by Mr. HK. J. Miers, the Anomura by Dr. J. R.
Henderson, the Macrura by the late Mr. C. Spence Bate, the
Cumacea by Professor G. O. Sars, the Isopoda by Mr. F. E. Beddard.
The other pictorial authorities are Gesner’s ‘ Historia Animalium,’
Herbst’s ‘ Naturgeschichte der Krabben und Krebse,’ Desmarest’s
‘Considérations générales sur la classe des Crustacés,’ de Haan’s
‘Crustacea’ in von Siebold’s‘ Fauna Japonica,’ and various papers
of modern date by G. O. Sars, S. I. Smith, C. W. S. Aurivillius,
H. J. Hansen, C. Bovallius, C. Chilton, MM. Giard and Bonnier,
R. Kossmann, W. A. Haswell, and Victor von Ebner.

For the text, as distinct from the illustrations, many other
authorities would have to be named, but the text will speak for
itself.

As to the reproduction, on a scale suitable to these pages, of
figures so numerous and so diversified from originals neither equal
in merit nor uniform in style, I am indebted to Mr. James D.
Cooper for the care and skill exhibited in carrying out a task of no
mean difliculty.

~ ELESLORY.

OF

RECENT CRUSTACHA

THE MALACOSTRACA

CHAPTER I

OUTLINE OF CLASSIFICATION

Ir is conceivable that by origin all the animals of the globe
belong to a single family. ‘They now exhibit very great
divergence. Between a star-fish and a crocodile, for ex-
ample, the cousinship is obscure and remote. Yet almost
all species may be included within a few principal clans,
and these are united one to another by a small number of
intermediate forms of life. For the whole series the de-
tails of classification will vary with the increase of know-
ledge. No system has yet been accepted as final. One,
which is sufficiently good for our present purpose, dis-
tributes animals among nine leading divisions. ‘These are
(1) the Protozoa, primitive animals, such as the Foramini-
fera and Infusoria ; (2) the Coelenterata, in which the body-
cavity serves alike for circulation and digestion, a tribe ~~
which includes sponges, corals, and jelly-fish; (5) the
Kchinodermata or prickly-skinned animals, embracing the
sea-lilies, star-fishes, sea-urchins, sea-cucumbers, and a

2 A HISTORY OF RECENT CRUSTACEA

wormlike genus called Balanoglossus ; (4) the Vermes or
Worms; (5) the Arthropoda; (6) the Mollusca, among which
are the well-known oyster, snail, and cuttle-fish ; (7) the
Molluscoidea, containing the mollusc-like lantern-shells,
and the grouped animals of the Polyzoa, in some of which
the so-called ‘ bird’s-head’ organs amuse the observer ;
(8) the Tunicata, the tunic-clad or mantled animals, com-
prising the Ascidians, whether tough-coated or gelatinous,
and the Salpz which roam the sea in alternate genera-
tions solitary or connected in a chain; (9) the Vertebrata,
with the important classes of fish, amphibians, reptiles,
birds, and mammals.

It is with the central group of these nine that we are
here concerned. So far as the name goes the Arthropoda
are animals with jointed limbs. So far as the name goes,
therefore, cats and dogs and vertebrates in general might
belong to this division. But the name was given with
reference not to the vertebrates, but to the vermes, for
originally the worms and arthropods were included in a
division called the Annulosa, animals of which the bodies
contain several annuli, rmgs, metameres, somites, zonites,
arthromeres, or segments, as they are variously called.
These two sections of the Annulosa are now severed, and
are distinguished by the circumstance that the one is, and
the other is not, provided with jointed limbs.

The Arthropoda are defined as animals which have
bodies composed of variously shaped segments; which
have jointed appendages attached to some at least of the
segments; which have (in general) a brain united to a
ventral nerve-cord, or ganglionic chain, and which exhibit
bilateral symmetry.

None of the other divisions will be found to possess all
these characters combined. For example, in the verte-
brata the nerve-cord is dorsal, in the mollusca the body is
unsegmented, in the vermes there are no jointed appen-
dages. Instances, it is true, are to be met with of arthro-
_ pods which do not themselves answer the requirements of
the definition, instances in which the body is unsymme-
trical or unsegmented, and in which there are no articu-

DEFINITION OF THE CLASS : 3

lated limbs. But in all these instances there is a period
of life when the creature possesses, though it subsequently
loses, the characters which determine its place in classifi-
cation.

Under the Arthropoda are included five classes, two of
which are of very prominent importance in the economy
of the world. The five classes are the Crustacea, Pycno-
gonida, Arachnida, Myriapoda, and Insecta. A sixth class,
the Onychophora, is sometimes added for the sake of the
peculiar genus Peripdtus, but for the present it may be as
well to give this the rank of an order among the myria-
pods, a class represented by the familiar but unfavoured
centipede. The Arachnida contain spiders, scorpions,
“mites, as well as some other less commonly known groups.

The Pyenogonida (or Pantopoda), the sea-spiders, at
one time included in the Crustacea and at another time in
the Arachnida, have some remarkable peculiarities, inas-
much as the ovaries of the female are found as a rule not
in the trunk of the body, but in the thighs of the legs, and
when the eggs are laid they are usually carried about not
by the mother but in packets upon the oviferous feet of
the male. |

The Insecta are so strikingly distinguished by the
special number of their legs that this class sometimes
receives the name Hexapoda, the six-footed animals.
Beetles, bees, bugs, flies, fleas, moths, spring-tails, ear-
wigs, grasshoppers, and gnats, in countless profusion people
the globe, sometimes disputing possession with man him-
self or rendering his life a burden, at other times offering
him service direct or indirect of no mean value. It is in
this class, and in this class only, that the present state of
science reckons the number of species not only by scores
of thousands but by hundreds of thousands, and even by
millions. The class which stands nearest to the Insecta
in the multitude of known species is that of the Crus-
tacea, but the interval is so vast that, properly speaking,
the Insecta are in this respect first with no second.

Of the numerous definitions which have been given of
the Crustacea, it will be s ifficient to quote two. According

4, A HISTORY OF RECENT CRUSTACEA

to one of these, they are ‘AquaticArthropoda, which breathe
by means of gills. They have two pairs of antennz,
numerous paired legs on the thorax, and usually also on
the abdomen.’ This is compendious and useful. The
statements clearly exclude all the other classes of the
Arthropoda. They are also widely applicable among crus-
taceans ; yet of these animals there are some which are
not aquatic, some which have no gills, some which have
not two pairs of antennee, and some in which the ‘ paired
legs on the thorax ’ are not numerous.

A different detinition was given by Professor Alphonse
Milne-Edwards in 1860, according to which the class of
Crustacea comprises ‘all the segmented animals with bran-
chial or cutaneous respiration, in which the body is pro-
vided with jointed limbs, whether permanent or transitory.’
The Insecta and Myriapoda breathe by means of the air-
tubes called tracheze; most of the Arachnida by means either
of tracheze or pulmonary sacs known as fan tracheee. From
all these, therefore, the definition separates the Crustacea in
a satisfactory manner, even though some terrestrial Crus-
tacea combine tracheate with branchial respiration. There
are, however, some subordinate members of the Arachnida,
and the whole class Pycnogonida, in which the respiration is
dependent on the surface of the body and not on any special
organs. Asit is only in recent years that the Pycnogonida
have been constituted an independent class, it was no
fault of a definition framed in 1860, that it included them
among the Crustacea, to which they were then supposed to
belong. They are in fact separated by many characters, one
of which is the possession of a proboscis, which is supposed
to have originated in the coalescence of the upper lip and
the mandibles. So far as is known, they are all marine
animals. On the other hand, those Arachnida which have
surface-respiration are apparently all air-breathers. To
meet all existing requirements, then, the definition of the
Crustacea may be framed in the following manner :—

They are Arthropoda without terminal proboscis, with
respiration branchial or cutaneous, the latter only aquatic.

It is not to be expected that any legitimate definition

ORIGIN OF THE NAME 5

of an extensive class will be largely descriptive, because
many features of wide range and great prominence are
likely to be missing in outlying and erratic members of
the group, and these consequently have to be passed over
unnoticed, in favour of less conspicuous, and of alter native,
or even of negative characters.

The name Crustacea is a Latin word of old standing.
Another and probably the original form of it is Crustata.
The animals clothed in a crust, a covering of more or less
flexibility, were distinguished by the ancients from the
Testacea, in which the test, as in the example of an oyster-
shell, is hard and rocky, and like a potsherd more ready to
break than to bend. Dr. Johnson was of opinion that if
the terms of natural knowledge were extracted from Lord
Bacon’s works, few ideas in that branch of learning would
be lost to mankind for want of English words in which
they might be expressed.' Modern science would be much
hampered by such a limitation of its verbal resources.
Johnson’s own dictionary during the last century does not
recognise the substantive, a crustacean. The adjective,
crustaceous, it thus defines: ‘ Shelly, with joints ; not tes-
taceous; not with one continued, uninterrupted shell.
Lobster is crustaceous, oyster testaceous.’ The same dic-
tionary defines and illustrates the word crab as follows:

‘ A crustaceous fish.

‘Those that cast their shell are, the lobster, the crab,
the crawfish, the hodmandod or dodman, and the tortoise.
The old shells are never found, so as it is like they scale
off and crumble away by degrees.—Bacon’s Natural History.

‘The fox catches crab fish with his tail, which Olaus
Magnus saith he himself was an eye-witness of.—Derham.’

Shellfish, crayfish, and crawfish, are expressions still in
use, although the term crab-fish is no longer in fashion.
The uncritical ages had a tendency to regard as fish most
animals which came out of the sea, and a story is told of
a cook who persuaded her Hebrew mistress that a sucking
pig became for all practical purposes a fish by being made

"See A Dictionary of the English Language. Preface. Eighth
Fdition, 1799,

6 A HISTORY OF RECENT CRUSTACEA

to run a few steps into the ocean and out again. With a
similar effort of the scientific imagination, the illustrious
Erasmus Darwin, when a schoolboy, excused himself for
’ eating roast goose during Lent by the scriptural axiom
that ‘all flesh is grass,’ and the goose therefore a species
of vegetable.

So far as the name Crustacea implies a covering of any
considerable toughness, it is little applicable to some of
the parasitic members of the class, but in general much
more confusion than advantage follows from the dis-
placing of long-established names in the effort after
absolute accuracy. If we are never to use the scientific
designation of a group unless it exactly applies to all the
members of it, then what is to be done, one writer
rather maliciously asks, in the case of the species called
Homo sapiens ?

A general though not a complete agreement prevails
in regard to the externa! boundaries of the crustacean class.
The proper mode of subdividing it and the arrangement
of the subdivisions are subjects still open to much dis-
cussion and dispute. Any final decision depends upon
questions of genealogy which have yet to be answered.
In the mean time four sub-classes may be accepted, under
the names Gigantostraca, Malacostraca, Entomostraca, and
Thyrostraca. The Gigantostraca, or giant-shells, are the
oldest in known lineage, and, as the name implies, fore-
most in the average of magnitude. They seem to be
tending to speedy extinction. The Malacostraca include
forms highest in development and of most direct value to
mankind. The Entomostraca probably surpass the rest —
in multitude of individuals, if not also of species, but are
the smallest in average size. The Thyrostraca, commonly
called Cirripedia, though they fall short of the Entomostraca
in numbers, excel them in bulk, and are even more remote
in outward appearance from any general idea of a crusta-
cean, such as the better known malacostracan lobster, or
the crab fish, might suggest.

The Greek word Malacostraca, meaning soft-shelled
animals, is practically equivalent in sense to the Latin

MALACOSTRACA 7

word Crustacea. Like that, it was originally adopted to
distinguish such creatures as crabs and crawfish and
prawns from such others as oysters and clams; not be-
cause of the absolute, but because of the comparative
softness of their shells. Were reasons wanted for dis-
placing the name, they would not be difficult to find.
Many of the Malacostraca have shells harder instead of
softer than those of some Mollusca. In some Malacostraca
the integument has ceased to be of the nature of a shell,
a parasitic habit having cancelled the need for such a
defence. Moreover, the term suggests a false contrast
with the neighbouring sub-class of the Kntomostraca, in
which as a rule the shells or skin-coverings are still softer.
The name Thoracipoda, not open to any of these objec-
‘tions, has been proposed by Dr. Henry Woodward. But
against this it may be urged that, by many students of
the Crustacea, the word thorax is not admitted as a proper
technical term, and among others it is disputed whether
the word, if admitted, should apply to three, to seven, to
eight, or even to nine, of the crustacean segments.
Retaining, therefore, the ancient, familiar, and suffi-
ciently euphonious word Malacostraca, the subdivisions
of this sub-class may next be considered. ‘Two orders
have been formed, named respectively the Podophthalma,
or stalk-eyed, and Edriophthalma, or sessile-eyed, crusta-
ceans. In the former the eyes are mounted upon stalks
or peduncles, which are almost invariably movable ; in the
latter they are in continuity with the general surface of
the head, or, if raised above it, the ocular prominences are
unjointed and immovable. That some species in both
orders are blind, gives a certain vantage-ground for the
disturbers of accepted names to follow their bent. These
may also allege that the terms just explained have not
been at any time in undisputed possession. The Podoph-
thalma have also been called Decapdda, ten-footed, while
the Edriophthalma have been called Tetradecapdda, or
fourteen-footed, Crustacea. The second of these names
has found but little favour, and the first has the dis-
advantage that it would apply to some Crustacea that are

8 A HISTORY OF RECENT CRUSTACEA

not podophthalmous, and does not apply to others that
are. Instead of Podophthalma or Decapéda, Burmeister
proposed Thoracostraca. ‘T'o this, however, the objections
already urged against Thoracipoda will apply, with the
additional one, that the word has a termination which had
been already employed in two, and has since been em-
ployed in the third and fourth of the higher groups.
Some purists correct the word Edriophthalma, in accord-
ance with its derivation, into Hedriophthalma. They may
correct on the printed page, but who can guarantee that
they will have their cherished aspirate pronounced ?

The stalk-eyed Crustacea are portioned out into four
sub-orders: 1. The Brachyara, or short-tails, such as the
edible crab; 2. The Macrara, or long-tails, such as the
common lobster, prawn, and shrimp; 3. The Schizopéda,
or cleft-footed crustaceans, in certain points of structure
so near to the prawns and shrimps that at least one author
of eminence classes them among the Macrira; and 4. The
Stomatopéda, with feet converging about the mouth, crea-
tures abundant in some waters, but rare in those that
wash the shores of Great Britain. A fifth sub-order, the
Anomira, or irregular-tails, has long been accepted, but
modern classification is disposed to distribute its members,
which include the hermit crabs and others of very curious
habits, between the Brachyira and the Macrira, from
which they may be supposed to have respectively diverged,
yet without losing all trace of family connection.

The sessile-eyed Crustacea are at present divided into
three sub-orders, the Cumacea, Isopdda, and Amphipéda.
The Cumacea seem to have entirely escaped the notice of
the ancients, and among the moderns an accurate know-
ledge of their singular structure is not too widely diffused.
One of the genera earliest brought into notice received the
name of Cuma, a wave, and from this was formed the de-
signation Cumacea for the whole sub-order, which is exclu-
sively marine. ‘The Amphipoda, which are common in
fresh as well as in salt water, were so named by the French
naturalist Latreille, as having feet extending in all direc-
tions, their limbs at the same time having much diversity

ENTOMOSTRACA g

of form in correspondence with diversity of function. The
Isopoda, or equal-footed animals, besides being found both
in fresh and salt water, have more decidedly than the
Amphipoda extended their range to the dry land. The
name was invented by Latreille in ignorance of the great
number of species since investigated in which the feet are
strikingly unlike and unequal. Nevertheless the name
may stand, just as a rose remains a rose even when it is
not rose-coloured. To these three sub-orders some authors
are disposed to add a fourth, the Tanaidea, while others,
though agreeing to withdraw these animals from their old
position among the Isopoda, would preter to place them
among the Amphipods. The need for the change in either
direction has not yet been established.

The Entomostraca, by their name, which literally means
testaceous insects, bear witness to an era in classification
when not only they but all other crustaceans were arranged
among the Aptera or insects without wings. As the forms
are multitudinous and very frequently microscopic, and as
moreover crowds of the species have only been made known
within recent years, it is not to be wondered at that the
internal arrangement of this sub-class, like that of the
preceding one, is still open on some points to discussion,
although there is a fair amount of agreement as to the
main lines of division. The method here followed dis-
tinguishes three orders, the Branchiopéda, Ostracéda, and
Copépéda. By Latreille the name Branchiopoda was ap-
plied to the Entomostraca at large. It signifies branchial-
footed, or animals in which the feet are in one way or
another adapted to serve the purpose of respiration. ‘This
order is subdivided into four sub-orders. 1. The Phyllo-
carida, literally leaf-shrimps, derive their name from the
laminar or leaflike expansions with which their legs are
provided. 2. The Phyllopdda, the leaf-footed ones, owe
their name to the same characteristic, although by other
features they are distinguished from the Phyllocarida.
None of the Phyllopods are marine, although a few inhabit
brackish water or strong brine. 3. The Cladocéra, which
are so called from their branched antenne, occur chiefly

10 A HISTORY OF RECENT CRUSTACEA

in fresh water, where they are common, but inconspicuous,
and to the ordinary observer little suggestive of the crus-
tacean type. 4. The Branchitra, represented by the carp-
lice, are so designated from having a branchial tail which
actively assists in the function of respiration.

The Ostracdda, a title which might be interpreted as
the testaceous Crustacea, may be easily mistaken for minute
bivalve mollusca. Like the Branchiopéda they are divided
into four sub-orders, the Podocdpa, Myodocdpa, Cladocopa,
and Platycdpa, in which names words meaning feet, mus-
cles, branch, and broad, are respectively compounded with
the Greek word signifying an oar.

The Copepoda point at once to a connection with the
preceding order, inasmuch as there one of the sub-orders
derived its name from words signifying a foot and an oar,
while the Copepoda are indebted-to the very same compo-
nents, in the inverse order of an oar and a foot. The
actual structure of the animals to some extent justifies
this similarity of names, but in general appearance the
Copepoda, not being shut up in two-valved shells, are
widely different both from the Podocopa and the rest of
the Ostracoda. Three sub-orders are formed: (1) the
Gnathost6ma, having the mouth well provided with jaws;
(2) the Poecilostéma, in which the mouth varies; (3) the
Siphonostéma, having the mouth produced into a siphon
or tube.

The Gigantostraca are as rare as the Entomostraca are
common. ‘They are divided into three orders, the Mero-
stomata, Xiphosiira, and Trilobita. Of these, the first and
third are entirely extinct, so that the knowledge of them
is derived only from fossil remains.

The Merostomata have a name derived from two words,
meaning a thigh and a mouth, this singular combination
alluding to the no less singular fact that in these animals
the mouth is surrounded by a group of limbs which are
not only locomotive and prehensile, but also subservient
to mastication. ‘This peculiarity belongs likewise to the
Xiphosura, or sword-tails, which are named from the long
and sharp piece at the end of the body, their characteristic

THYROSTRACA Ef

tail-spine. Some authorities hold that this order should
be removed from the crustacean class to that of the Arach-
nida. The name of the third order, the Trilobita, refers to
the circumstance that they usually have the body divided
by two longitudinal dorsal grooves into three lobes. They
were extremely abundant in bygone ages, and the natu-
ralists of the Challenger were continually in hopes that
they might obtain a living specimen or two from hitherto
unexplored abysses of ocean. But extinction appears to
have done its work with great thoroughness upon this
order.

The last of the sub-classes consists of the Cirripedia or
curl-footed animals. The alternative name Thyrostraca,
meaning ‘ valve-shells, has the merit of agreeing in ter-
- mination with the names of the other three sub-classes.
But it must be admitted that if it 1s objectionable to call
the whole group cirripedes when some have no cirri, it is
equally inappropriate to call them all ‘ valve-shells’ when
some have no valves. It is a triumph of the present cen-
tury in minute investigation and comparative anatomy,
that has withdrawn the Cirripedes from the zoophytes,
worms, and molluscs, among which, at various times, the
older naturalists placed them, and that has given them
henceforth an undoubted position among the Crustacea.

They may be divided into five orders, or the first two,
the Pedunculata and the Operculata, may be grouped
together as divisions of an order hitherto designated
Thoracica, in which the part called the thorax is provided
with cirri. The Abdominalia have the cirri only on the
so-called abdomen. The Apoda are without cirri, being,
as their name implies, footless. Lastly, the Rhizocephala
are a parasitic set, which send rootlike filaments into the
bodies of their hosts.

we)

12 — A HISTORY OF RECENT CRUSTACEA

CHAPTER II
SPECIMENS

Collecting

To study adequately any branch of natural history, it is
essential to have specimens. Many exemplary forms of
Crustacea are not difficult to obtain. Representatives of
the two highest orders in the group, the crab, the lobster,
the prawn, the shrimp, are exceedingly familiar, as these
creatures lie on the fishmonger’s board, or are brought to
table for food. When the eatable parts have been con-
sumed or otherwise removed, the débris is still of value
for mental nourishment. ‘This refuse may be made to
yield more profit and pleasure than many a costly collec-
tion which can only be viewed intact. By carefully
separating the constituent parts of the head, the trunk,
and the tail, in each of the crustaceans above mentioned,
and comparing them piece by piece, the beginner will be
able to give himself a cheap but invaluable lesson. He
will be surprised at first to detect likenesses in the corre-
sponding parts of animals externally very distinct, and
afterwards he will be surprised at the differences in the
corresponding parts of animals which he has learned to
regard as closely connected. As his range of study widens,
he will find relationships established between forms which,
to any one unacquainted with the intermediate links, must
seem to have absolutely nothing in common. For instance,
while examining the gills of a lobster, he may chance to
observe some small orange-coloured specks, and may
rightly conjecture that these are parasitic animals. But
it is scarcely conceivable that any amount of genius would

BREAKFAST-TABLE ZOOLOGY 13

enable a man to discern, from a comparison of the lobster
alone with its entomostracan parasite, that they are alike
crustaceans, which is, nevertheless, known to be the case.
In a dishful of prawns it may often be noticed that one or
two of the finest have the head swollen on one side, as if
the creature were suffering from a face-ache. There is no
special reason to suppose that the prawn thus affected is
suffering any great inconvenience. Itis merely lending the
shelter of its carapace to a family of isopod crustaceans.
Comfortably ensconced in the bulging cheek-piece will be
found a misshapen animal of no inconsiderable size, in
general laden with innumerable eggs, and accompanied by
a far smaller partner, the father of the brood, symmetrical
in form, and retaining some of the freedom of movement
which belongs to the young when first hatched, but which
the mother has entirely resigned. Thus the zoology of
the breakfast table will supply examples of three very dis-
tinct orders. These examples are none the less curious
because they happen to be common. Any one who is
content to examine them with care will thereby lay a
simple and solid foundation for all subsequent study in
the realm of carcinology.

The novice, however, need not be dependent on the
fishmonger for specimens. In cellars, gardens, hedges
_and ditches, under flat stones, in dry moss, among moist
dead leaves, in the loosened decaying bark of trees, crusta-
ceans are to be met with almost everywhere. These are
the so-called wood-lice, including those known by the
trivial names of Pill-bugs and Slaters, Millepedes, and
Carpenters. One species, small and white and slow in
movement, is frequently to be found in ants’ nests, and
seemingly never elsewhere. All this set of animals,
though air-breathing and living on land and often possess-
ing great agility, belong to the Isopoda in common with
the marine species above mentioned that leads its apathetic
life within the carapace of the prawn.

From almost every little brook and pond in England
the amphipod, Gammarus pulex, and the isopod, Asellus
aquaticus, may be fished without difficulty and without

14, A HISTORY OF RECENT CRUSTACEA

any stint of numbers. Less commonly the innocent well-_

shrimps, which are also amphipod crustaceans, may be
obtained from wells. It may be proper to mention that
the well-shrimp is not poisonous, and that it flourishes in
water which is perfectly wholesome. <A. different view of
its character is probably entertained by many owners of
wells, who are on that account unwilling to mention or
acknowledge its presence. [rom stagnant ponds various
species of Entomostraca may be obtained in vast abund-
ance. Some of the Phyllopoda are found only in brine
pools. The brine shrimp, Artemia, breeds in vast num-
bers in the mud of the great Salt Lake of Utah. In
South America one of the Ostracoda very singularly dwells
on the leaves of a plant. The river crayfish and crusta-
ceans parasitic on freshwater fish are pretty widely dis-
tributed. Highest in known range of all the Crustacea
are the Isopods and Amphipods taken by Mr. Whymper at
a height of 13,300 feet on the Great Andes of the Equator.
In many parts of the world there are land-crabs, but none
of these live in the British Isles. This is referred to as
follows in the ‘ Narrative of the Cruise of the Challenger.’
In describing the visit to Ascension Island in the South
Atlantic Ocean, the writer says :— ;
‘Land-crabs swarm all over this barren and parched

volcanic islet. They go down to the sea in the breeding |

season; they climb up to the top of Green Mountain, and
the larger ones steal the young rabbits from their holes
and devour them. It always seems strange to an English
naturalist to see crabs walking about at their ease high up
in the mountains, although the occurrence is common
enough and not confined to the tropics. In Japan a crab
is to be met with walking about on the mountain high
roads far inland, at a height of several thousand feet, as
much at home there as a beetle or a spider, and crabs of
the same genus (J'helphusa) live inland on the borders of
streams in Greece and Italy.’

France and Germany, as well as England, have reason
to regret that the sunny south should have a monopoly of
these land or river crabs, for they are delicate eating, and,

ide)

#5)

SPECIMENS ON THE SHORE 15

as writers of the sixteenth century inform us, they are
much sought after for the tables of the Pope and cardinals.

From what has been said it will be seen that those who
live inland enjoy no inconsiderable opportunities of ob-
serving crustaceans of various kinds, dead or living. The
common and- uy obra specimens will, as a rule,
not be of fthe-San —e— ifferent parts of the world,
but thi a wean @ to the same or closely allied
genera, 3 d they will in any case afford similar facilities
for study. The traveller would do well to remember that
kinds easy to collect abroad or cheap to buy in foreign
markets will probably be rare in his own country, and
that therefore preserved specimens may be of future value
to himself or acceptable to his friends at home.

Passing, however, from inland resources to those of the
sea coast, the student will find an enormously greater and
an almost bewildering variety of forms to engage his at-
tention. Shore-crabs and hermit-crabs are often obtru-
sively conspicuous, as also are the operculate cirripedes
with their sharp-edged shells coating large surfaces of
rock. When a flat stone is lifted, not unfrequently a
small specimen of the edible crab may be seen nestling in
the mud. If the position is chosen in order to gratify
the sense of smell, one would be inclined to adapt the
words of the poet to the situation, and say that crabs want
but tittle here below, but want that little strong. Cling-
ing to the under surface of a stone, a group of the broad-
clawed Porcelluna, the hairy porcelain crab, will often be
found. ‘They try to look as if they were not there, or they
endeavour to slidder rapidly away. If one is seized by
the claw, it will adhere as tenaciously as it can to the
rock, and sometimes end the unequal contest by relin-
quishing the claw and running off without it. The lobster-
like Galathea, under similar circumstances, is ready either
to fight or run, a very Achilles for courage and speed.
Specimens of the masked crab and of various spider crabs,
and of others not commonly found alive upon the shore, are
often to be met with upon it when an obliging gale of
wind has thrown their carcases landward. The common

16 A HISTORY OF RECENT CRUSTACEA

shrimp will sometimes attract attention by making an.
abrupt spring, after which it sinks softly into the moist
sand, from which its imitative colourmg makes it barely
distinguishable. The stretches of sand on the shore,
which to unobservant or inexperienced eyes might seem
quite barren and deserted, are otten teeming with crusta-
cean life. The upper and driest zone will be riddled with
the burrows of the sand-hopper. Lower down several other
species of amphipods lie at a very small depth beneath the
surface. Little biting carnivorous isopods are there, and
occasionally others that are vegetarians. In some localities
Cumacea can be found, but never very far from the waves,
nor, when they are present, must it be expected that these
animals will make a striking feature in the landscape.
They are remarkably unobtrusive. Where rocks and
rock-pools and various kinds of seaweed abound, and
especially on sheltered coasts, a very large number of
species of amphipods and isopods may be obtained, these
being in most instances distinct from those found in the
sand. Here is to be seen Orchestia, the shore-hopper, a
near ally of the sand-hopper, V'alitrus. Here are two of
the marine species of Gammarus, and examples of their
cousins Melita and Mera, all of which, when on land, slip
or wriggle along on their sides, and have in consequence
been irreverently spoken of as ‘scuds.’ Many other forms,
including some of the Caprellidz or skeleton-shrimps, can
be obtained by examining tufts of the finely branched sea-
weeds. At the lowest ebb of the spring tides, a day or
two after new moon or full moon, species may be obtained
which are rarely or never procurable higher up on the shore.
Several of the isopods, however, may be taken, indepen-
dently of the lowness of the tide, roaming among the
coarser weeds, and mimicking in various ways the colours
around them. ‘The rocks which look least interesting,
having no vegetation except the short black crumbling
foliage of the Lichina pygmcea, supply the curious Cam-
pecopea hirsuta, an isopod easily to be confounded with the
leaves of the tiny plant which shelters it. Found among
cirripedes at low tide, however, it displays much brighter

VARIOUS LODGINGS 17

colouring. Where wooden piles have been driven into the
shore within tide-marks, the part which the water reaches
is almost sure to be very soon attacked and taken posses-
sion of by two or three very distinct crustaceans, the two
constant companions being the strange amphipod Chelura
terebrans, with a name signifying the boring claw-tail, and
a perhaps equally mischievous isopod, known as Limmnoria
lignorum, or the Gribble. With these is frequently asso-
ciated one of the cheliferous isopods, the species Tanais
vittatus in England, and Tanais filwm in America, not con-
cerned, it may be, in making the excavations, but only
using them when made. Some Amphipoda and Isopoda
shelter themselves in sponges and some in the branchial
sacs of Ascidians.

Many free-living Copepoda may be obtained in rock-
pools and by washing seaweeds, others from various Asci-
dians. Those parasitic Copepoda, which are commonly
known as fish-lice, may often be procured by examining
fishes when first brought to shore, and before they have
been prepared for display on the fishmonger’s board. New
species of Crustacea have sometimes been discovered by the
examination of the contents of a fish’s stomach. ‘This
same repository will also occasionally yield good specimens
of already known species.

The Cirripedes are all marine, most of them impatient
even of brackish water, although one species, Baldnus
improvisus, Darwin, will live contentedly for some time in
water that is quite fresh. Several species are obtainable
between tide-marks. Many attach themselves to the sub-
merged sides of ships, and to other floating objects. Some
make their home in sponges, corals, or shells, and in con-
sequence specimens not sought for their own sake are
frequently distributed by the commerce of which their
dwelling-places are the more direct object.

For the Gigantostraca collectors in England must
content themselves either with fossil or with imported
species. In New England, the horseshoe crab, Limulus
polyphemus, may be had at or just below low water.

By availing himself, then, of those Crustacea which

18 A HISTORY OF RECENT CRUSTACEA

live on land or in shallow waters, or on the coast, and of
those specimens which are brought to shore either as or in
connection with articles of food, the student may obtain a
thoroughly representative collection. _Closely as all the
easily accessible localities and resources have been already
searched and examined, even from among them he will
find it still possible to add new species to the long roll of
those hitherto known. In many of the forms that are
common and abundant, and that have long been familiar
to science, he may, by diligent observation, find features
of great interest that have heretofore escaped notice. One
discovery he will almost certainly make, that the objects
of his study do not deserve the epithets of contempt and
disgust so freely lavished upon them by the ignorant. At
every step he will be increasingly charmed by the striking
characters which ditferent species exhibit, by the delicate
grace or the intricate mechanism of the separate parts, and
by the marvellously varied adaptation of the different or-
ganisms to their diverse modes of life.

It is, however, in the waters of the ocean, from the
surface down to the abyssal depths, that the vast majority
of the Crustacea are to be found. Of the lower limits of
the so-called bathymetrical distribution a good general
idea may be formed from the results of the dredging and
trawling carried on by the Challenger, during a voyage
of nearly seventy thousand miles. Of the Brachyura
indeed, only a single specimen of a single species was
taken so low down as 1,875 fathoms. Mr. Miers, who
named it Hthusa (Kthusina) challengeri, says: ‘This is the
greatest depth at which any Brachyurous crustacean was
taken by the expedition, and also, I believe, the greatest
hitherto recorded for any species of crab.’ It was not,
perhaps, to be expected that members of the highest order
in the class would either need or condescend to penetrate
into the very. lowest regions, where hight and heat and
vegetation, not to speak of cheerful society, must at the
best be very scanty and extremely scarce. The very genus
Hthusa, with its sub-genus or neighbouring genus Hthu-
sina, seems to apologise for frequenting levels beneath its

SPECIMENS IN THE DEEP SEA ig

natural rank by including the forms which, as Mr. Miers
observes, ‘ evince the greatest degree of degradation from
the Brachyuran type.’ It approaches in fact the group
which till recently held a distinct position under the name
of the Anomura. Of these Dr. Henderson observes that
they occupy an intermediate position between the Macrura
and the Brachyura, in regard to the limit of depth at
which they are found, the more highly specialised forms
being, like the Brachyura, found in shallow water and at
moderate depths, whereas the more primitive macruran
types extend to the abysses of the ocean. The single and
singular specimen on which the species T'ylaspis anomala,
Henderson (see Plate VII.), was established, ‘came from

the greatest depth at which any anomurous crustacean__~{
was taken by the Challenger, the depth in question being \.~

2,375 fathoms. In the Macruratwo genera, Benthesicymus
and Gennddus, instituted by the late Mr. Spence Bate,

descend to 3,050 fathoms, and have nowhere been found—

dwelling with less than 300 fathoms of water above them.
It is not perhaps surprising that most of the specimens
were brought up ‘in a soft, pulpy, and collapsed condi-
tion,’ for it is calculated that each perpendicular mile,
that is, each 880 fathoms of water, exercises a pressure of
a ton upon each square inch of an animal’s surface. As
long as the fluids within correspond with those outside the
body, there is a state of comfort and efficiency, but when
this equilibrium is suddenly destroyed, uot only a crus-
tacean but any other creature is likely to feel. weak and
discomposed.

Of the Schizopoda Boreomysis obtusata, Sars, was taken
from a depth of 2,740 fathoms. On the other hand the
Stomatopoda are content with far less profound explora-
tions. Mr. W. K. Brooks reports that ‘they are usually
found in very shallow water, and with the exception of the
specimen of Squilla leptosquilla, taken in the trawl by the
Challenger in the Celebes Seas from a depth of 115 fathoms,
and a specimen of Lysiosquilla armata, which Mr.8. I. Smith
found in the stomach of a Lopholatilus from 120 fathoms,
they are all from very moderate depths.’ The Challenger

20 A HISTORY OF RECENT CRUSTACEA

found a cumacean as low down as 2,050 fathoms, but some
years earlier the Swedish Spitzbergen expedition obtained
the appropriately named Diastylis stygia from the still lower
deep of 2,600 fathoms. The Isopoda extend down to 2,740
fathoms, the Amphipoda possibly, but by no means cer-
tainly, to 2,500. Among the Entomostracans, a Phyllo-
carid species came from 2,550 fathoms, Ostracoda from
2,750, the strange copepod, Pontostratidtes abyssicéla,
Brady, from 2,200, and a parasitic copepod, Lernea abys-
sicola, was attached to a deep-sea fish brought by the trawl
from 2,400 fathoms. Lastly, of the Cirripedes the great
Scalpellum regium was dredged from a depth of 2,800
fathoms, the character of these animals giving more cer-
tainty than can be had with free-swimming Crustacea,
that the specimens actually came from the depth assigned.
In the use of trawls and dredges with open mouths, there
is always a chance that specimens may be captured in the
course of lowering or hauling in the instrument, instead of
while it is being dragged along the ocean floor. By this
means the record of the occurrence of specimens at as-
tonishing depths is left open to some question. Yet on
the whole there is fair reason to believe that most of the
principal groups of Crustacea have representatives capable
of supporting existence in regions of dense gloom, with
a temperature icily cold, and under a column of water
from two to three miles in height. Many species, indeed,
of the Crustacea show a preference for a frigid climate,
since where this condition prevails their swarms are far
vaster and their bodies more bulky and solid than in
waters less cold. These Polar forms, therefore, find no
inconvenience, but the reverse, in the unheated tempera-
ture of the great depths, and though probably many of
them could not possibly pass the tropical waters at or near
the surface, far down there is a suitable water-way for
them from one pole of the earth to the other.

It is rather the task of national expeditions than of
any private collector to procure the exceptional forms
which the remotest abysses of the sea have yielded and
may be expected still from time to time to yield. ‘There

METHODS OF CAPTURE 21

are, however, unstinted riches of natural history which
the ordinary student may obtain with comparatively simple
means. By the use of the towing-net from a boat, espe-
cially after sunset in warm and calm weather, numerous
larval forms of Crustacea are to be obtained, as well as
adult forms of various orders. By dredging in a few
fathoms, or even in a few feet, of water, species enough
to occupy weeks and months of study may often readily
be secured. For this work sheltered bays and inlets
are favourable. When the dredge brings up apparently
nothing but rugged pebbles and the worn shells of departed
molluscs, these are not to be despised. Among them may
be found the little crabs of the genus Fbalia, at the first
glance perhaps rejected as if pebbles themselves. Rare
Tanaids may come creeping out of the crevices of an old
oyster shell. When sea-weeds are brought up in the
dredge, they are not to be cast aside after a hasty exami-
nation as unproductive. They should be placed in a
vessel of shallow water, and, though the crafty inhabitants
he close, they will eventually come forth. Sand and
muddy ooze scraped from the bottom requires to be passed
through a sieve or stirred about in a pailful of sea-water.
After the stirring, and before the animals have time to
regain the sand, the water must be poured off through a
muslin bag which will retain the desired specimens. Some
species, besides the edible ones, may be obtained by a sort
of systematic fishing. A dead crab, for instance, let down
in a lobster-pot, will attract one species or another accord-
ing to the locality, the clan trooping to the feast in hun-
dreds and thousands till they have consumed every par:
ticle of the dainty repast. ‘The voracity, indeed, of some
~ among the smaller Crustacea is such, and their numbers in
some places so enormous, that they have been known in a
single night to clear all the flesh off a dead seal. To such
appetites almost any carrion is a sufficiently alluring bait.
There is little need for surprise, under the circumstances,
at the label on certain museum specimens, irtimating that
they were ‘ pulled off the head of a bear let down to the
bottom to be cleaned.’ Some of the Amphipoda attack the

22 A HISTORY OF RECENT CRUSTACEA

head and other parts of the whale while the monster is still
alive. On the other hand, whales and seals, and fishes
large and small, swallow down the Crustacea in a truly
wholesale manner, and so prevent these prodigiously
prolific animals from producing a complete block in the
cooler parts of the ocean. Independently of this interest-
ing exchange of courtesies, which consists in alternately
eating and being eaten, there is another kind of associa-
tion between crustaceans and other animals, known as
commensalism. In this the one creature lives, not at the
expense of the other, but merely in companionship with
it. Thus, on the common starfish there is found a thread-
like minute species of the Caprellide. Though the star-
fish is very frequently to be met with on the shores, its
companion Pariambus typicus (Kréyer)'1is only seen on
dredged specimens, so that apparently this tiny animal
has the sense to disengage itself when its host is being
driven into an unsuitable or dangerous position. Someof _
the Amphipoda Hyperidea are very frequently to be found
upon jelly-fishes. One of the Gammaridea, Iscea Montagui,
Milne-Edwards, appears never to have been found except
upon the Spinous Spider Crab, Maia squinado, for clinging
to which its feet, with their serrate widened extremities,
are peculiarly adapted. A French zoologist, M. Edouard
Chevreux, some five or six years ago, was searching this
interesting crab for its already well-known commensal,
when to his surprise, among the algz and hydrozoa, with
which the carapace is usually decked, he found not only
the species he was in search of, but no less than twenty-
two other species of Amphipoda into the bargain. Maia
sguinado is not found far to the northward. On the other
hand a very distinct crab, but with some external re-
semblance to it, Lithedes mids is not found far to the
southward. Such facts of distribution are often of scien-
tific importance. For instance, with regard to the com-
paratively narrow strip of land which separates North
from South America, the geologist will desire to know how
far the crustacean fauna of the sea on one side of the
1 Formerly Podalirius typicus.

DISTRIBUTION... 23

isthmus corresponds with that on the other. <A close
agreement would dispose him to consider that not so very
long ago, in the large measurements of geological time,
the Atlantic and Pacific may have been connected by a
natural canal. From great divergence, such as is known
to exist in the molluscan fauna, he would infer that the
passage existed, if ever, only at a very remote period. In
the large freshwater lakes of Southern Sweden, it was dis-
covered some thirty years back, that a remarkable marine
fauna existed, and the inference ingeniously drawn from a
review of all the connected facts has been, that these sheets
of water were at one time part of the sea, but have been
cut off from it by the gradual elevation of the land. Upon
this supposition, while the water was gradually losing its
saltness, its marine inhabitants, with equal steps, were
becoming habituated to a freshwater existence. But it
must not be forgotten that the transfer of marine animals to
brackish and fresh waters may take place by various modes
of migration quite independently of geological changes. It
has been noticed as curious, that shells, insects, and plants,
inhabiting fresh water, are of comparatively few species,
but those few very widely distributed. Mr. Belt ingeni-
ously remarks that, in the oscillations of sea and land, the
oceanic and continental domains, though shifting, are con-
tinuous, whereas every freshwater area is liable to be again
and again completely overwhelmed. By this means the
freshwater species of narrow range may be entirely de-
stroyed, and only families of wide distribution will survive.
The application of this theory to the Crustacea is worthy
of study, but the facts which it is designed to explain do
not embrace the whole of the globe. The Isopod Asellus
aquaticus and the Amphipod Gammarus pulew are obvious
instances of freshwater species with an enormous range.
Yet from the fresh waters of the Malay archipelago the
Asellidze and Gammaride are said to be entirely wanting.
On the other hand, Professor Max Weber has recently
observed that, while Europe can show but seven species of
freshwater decapods, the Indian archipelago can boast of
more than eighty.

24 A HISTORY OF RECENT CRUSTACEA

CHAPTER IIL

MAGNITUDE

In zoology, size attracts attention in comparison with
two standards. Man contrasts the bulk of an animal
either with the average in his own order or with that of
the group to which the particular animal belongs. An
elephant is a huge beast, not in competition with a whale,
but with a human being. A hornet less than a man’s
little finger is a monster beside a house-fly or a gnat. As
in all classes the majority of individuals conform pretty
closely to the average magnitude, the mind becomes
trained to regard the exceptional extremes with wonder,
often not unmingled with admiration when the mass is
not smaller but greater than common. Among the Crustacea
there are forms, not indeed surpassing all others in
diminutiveness, but at any rate so exceedingly small that
the sharpest eyes could perhaps never have found out that
they were crustaceans without the aid of the microscope.
Here it is that the philosophical naturalist sometimes finds
chief reason to marvel, in perceiving the whole machinery
of life, enabling active locomotion, nutrition, and repro-
duction, with senses, a power of choice, and the capacity
for feeling pleasure and pain, all packed away as neatly
and conveniently as possible in so extraordinarily small a
casket. For preliminary studies creatures of more con-
siderable compass hold an obvious advantage, and with
most observers it is rather the giants of an order than
the dwarfs that are deemed especially remarkable and
worthy of the notice which they are fitted readily to
engage. Some of the old writers probably understood

a

ASTACT? CXCARINIOT Se HVMER
vocant Germant , ex defcriptione Septentrionalium regionum Olat Ma-
gaiefigies. Ingentem effe [cribit,(inter Orchades F Hebrides in{ulas,)
€5 tam valtduri vt bominemnatantem chelisapprehen[um fuffo-
cet. Sednon proba, quod pedes omnes bifculcos pinxt:
€F5 caudamtabellts tam multis con-
jferuxit, OC. ‘

~

|

3 i
JN EADEM TABVLA AGN

depingit aflacum xu. pedum, qui deuoratur ameonjtromari-
no fimili rhinocerots. .

OLD STORIES a

that their readers would take more interest in a large
crustacean than in a small one. For this reason, no
doubt, Olaus Magnus declares that between the Orkneys
and the Hebrides there lives a kind of lobster so large and
strong that it can catch a swimmer in its claws and
squeeze him to death. His picture, as will be seen, repre-
sents a bearded man as a mere plaything in the lobster’s
arms. ‘The human race is avenged in the companion
picture, where a lobster twelve feet long is itself being
ruthlessly devoured by a ‘rhinoceros whale.’ Though these
myths are many centuries old, they still have an amusing
interest to the Anglo-Saxon from haying been localised in
British waters. It is, however, very extraordinary that
at the beginning of the present century a travelled French
naturalist of eminence should have accepted a statement
- little differing from that of Olaus. LL. A. G. Bose in 1802
published his ‘ Natural History of the Crustacea, contain-
ing a Description of them and their Manners,’ in the In-
troduction to which he says :—

‘Tt is related that on the coasts of the isles of America,
where the crabs are in great profusion, they engage during
the pairing season in desperate conflicts, which often result
in the death of numerous individuals, and always in the
loss of a great many of their limbs. It does not appear
that the Crustacea of Europe have this custom; but their
small numbers, and the perpetual hunting after them, do
not permit so easy an observation of their habits, as in
warm countries, where it is said that they are of a size so
monstrous, that they attack men, and have eaten several,
amongst others the famous sea captain Francis Drake
(Frangois Drack), who, although armed, could not avoid
this fate.’ !

This passage is still retained in the revision of 1830,
edited by the well-informed Desmarest. The story ap-
pears to have been derived from De Paw’s ‘ Recherches
Philosophiques sur les Américains’ (t. i. p. 245), a
work which describes the death of Drake as follows:

1 Histoire Naturelle des Crustacés, contenant leur Description et
leurs Meurs, p. 149.
4

26 A HISTORY OF RECENT CRUSTACEA

‘This navigator having landed on the Isle of Crabs in
America, he was there immediately surrounded by these
animals; although he was armed, although he made a
stout resistance, he had to succumb. ‘These monstrous
crustaceans, the largest known in the world, cut in pieces
with their claws his legs, his arms, and his head, and
gnawed his carcase to the very bones.’! There are some
elements of truth in this blood-curdling story. It is true
that Drake died in the West Indies. It is true that he
landed on Crab Island. It is true that he met with huge
crabs. But he died on board his own ship of a sickness
brought on by disappointment, and his body wrapped in
a leaden shroud was buried in the sea. ‘The Crab Island
on which he once landed was in the Eastern not the
Western Main, nor did he lose his life upon it. The land-
ing was in the course of his successful voyage round the
world, and it was not the crabs that ate Drake, but Drake
and his people that ate the crabs, of which a single one,
they afterwards said, was sufficient to make a meal for four
men. That might well be, if the crabs at all resembled
the giant crab of Australia, Pseudocarcinus gigas (Lamarck),?
in which the carapace is said to be sometimes two feet in
breadth, and in which one of the claws of the front pair
attains a vast bulk. Such crabs as these may be thought
to justify a statement in Linschotten’s ‘ Voyage to Goa,’
according to which, ‘To the South cf Goa, at a place
called St. Peter’s Sand, there are Crabs so great and
numerous, that Men are forced to keep a good Watch to
defend themselves, for if they get one in their Claws it
costs him his life.’

No crustaceans, however, either extinct or extant, can
compete in size and power with those fabled by Olaus
and De Paw. In the far distant Silurian age the fossil
genus Plerygotus among the Merostomata is supposed to
afford the largest specimens of the whole crustacean class.

1 Nouvelle Biographie générale, edited by Hoefer, t.14, p. 737. 1855.

2 An author’s name appended in parentheses by custom signifies
that he is responsible only for the species, and that this no longer
stands in the genus to which he had assigned it.

A WIDE STRETCH 27

The remains make it probable that some of them attained
a length of six feet and a breadth at the widest part of the
body of nearly two feet. The sculpture on the carapace,
like conventional feathers drawn by some old Assyrian
artist, is thought to have led the Scotch quarrymen to
call these giant fossils by the quaint name of Seraphim.'
Great as their size was, their organisation would have
little fitted them to cope with an armed knight. Their
nearest living allies belong to the genus Limulus, in which
the eastern King Crab, Limulus moluccanus, attains a
breadth of a foot by a length of two feet, although, to be
sure, nearly one half of the length consists only of a great
caudal spine. Among the Brachyura, Japan possesses a
species which is certainly from one point of view a rival
-in size to the largest Pterygotus, and may almost seem to
justify the old mythical narratives, for Macrocheira Kdmpfert,
de Haan, as a specimen in the British Museum shows, can
span eight feet, and it is said that sometimes even eleven
feet are within the compass of the outstretched arms ot
the male. But portentous as we must allow these dimen-
sions to be, the animal is after all only a spider crab, with
comparatively weak and spindly legs, and a carapace
which seldom if ever exceeds twelve inches in either
length or breadth.

The fossil Trilobites, which compose the third order of
the Gigantostraca, include indeed many species of incon-
siderable size, but they are also represented by forms such
as Asaphus tyrannus, Murchison, about a foot long, and
others in the genus Parudoxides, measuring twenty-one
inches.

Among the spiny lobsters or crawfish, a New Zealand
species, Palinurus tumidus, has recently been described by
Mr. T. W. Kirk as measuring twenty-four inches from the
tip of the beak to the end of the tail, and as having the
carapace very much swollen, and measuring 214 inches in
circumference. The European Palinurus vulgaris attains a
length of 18 inches, also without including the antennz,

1H. Woodward, Transactions of the Paleontographical Society,
1866, p. 42.

28 A HISTORY OF RECENT CRUSTACEA

which are sometimes considerably longer than the animal’s
body. The common lobster, though less bulky in the
trunk and with more slender antenne, attains an equal —
length, or by inclusion of its long and powerful claws
might claim in this respect far to exceed the weak-limbed
Palinurus. There is an Australian crayfish, Astacopsis
serratus (Shaw), from ten to twenty inches long, and
weighing some pounds, which makes a fine show when
compared with the much more modest dimensions of the
English crayfish. In the same way Leander serratus (Pen-
nant), the common prawn of British markets, is humbled
by contrast with Palemon carcinus, the river prawn of the
West Indies and Guatemala, of Surinam and the Ganges,
with its lobster-like size of twelve inches long. Palemoi
lar, from the Pacific Islands and India, exaggerates one of
the characteristics of the genus to which it belongs, inas-
much as a male specimen five inches in length will have the
second pair of lees nearly eight inches long—much longer,
therefore, than the body which carries them. The Her-
mit Crabs appear to attain their maximum at about eight
inches, a length not inconsiderable, seeing that it has to
be accommodated to the vacant shell of a univalve mollusc.
One, however, of their near kindred, Lithodes camschatica
(Tilesius), has sometimes a span of four feet. This makes
its hermitage not in the shell of a mollusc, but in some
cranny of the rocks. From this fastness it takes vengeance
on the crab-eating octopus, and is itself so firmly lodged
that it cannot easily be dragged out, except in fragments.
Of shrimps, Pasipheea princeps (S. I. Smith), dredged by
the Albatross in 1883, may be accepted as the leader,
seeing that it is not only far larger than any of its own
genus hitherto known, but by its length of more than
eight inches and a half, it exceeds all examples of kindred
geneia.

Among the Schizopoda the more familiar species are
quite the reverse of bulky. A specimen of Gnathophausia
ingens (Dohrn), measuring from the tip of the rostrum to
the extremity of the telson or tail 157 miullimétres, or
G4 inches, is spoken of as possessing ‘a truly gigantic size

A ROYAL GIFT 29

for a Schizopod.’ It is also said that ‘this form ranks,

therefore, as the largest by far of all hitherto known
_ Schizopods,’ although in truth an allied species in the
same genus, Gunathophausia gigas, v. Willemoes Suhm,
obtained by the Challenger from a depth of 2,200
fathoms, measures 142 mm., or 52 inches. Both of these
species, with one or two others in the same genus, such as
Gnathophausia Goliath, A. Milne-Edwards, far surpass
most of those in the sub-order, the length usually ranging
from half an inch to two inches.

Of the Stomatopoda, some are no more than three-
quarters of an inch in length, but of the species Lysio-
squilla maculata (Fabricius), a male specimen, presented
to the naturalists of the Challenger by the King of
_ Amboina, fell short only by three-sixteenths of an inch
of measuring a whole foot.

The Cumacea are a feeble folk. In some species the
slender frame, with trunk and tail and tail appendages all
told, does not exceed, or even equal, a twelfth of an inch.
Only the arctic Diastylis Goodsiri (Bell), occasionally yields
a Goliath of an inch and two-fifths. In the Isopoda there
is a far greater range of size. Within a single genus,
Hurycoipe mutica, Sars, which measures about one milli-
métre and a third, is contrasted with Hurycope gigantéa,
Sars, which reaches 35 millimétres, or about an inch
and a third. Anilocra gigantea (Herklots), measuring
three inches and a third, would seem a veritable monster
in this sub-order, were it not far surpassed by the ex-
tremely exceptional Buthyndmus giganteus of Alphonse
Milne-Edwards, which is nine inches long by four inches
broad.’ This prize was fished up by the United States
Survey steamer Dluke, under the supervision of Alex.
Agassiz, from a depth of 955 fathoms, in the region of the
Gulf Stream, to the north-east of the bank of Yucatan
to the north of the Tortugas. Among the Amphipoda,
none yet discovered reach more than about half the dimen-
sions of this great Isopod. At the other end of the scale

1 Il mesure, en effet, pres de 0™, 23 de long sur 0™ 10 de large.

30 A HISTORY OF RECENT CRUSTACEA

there are Gammarids, Hyperids, and Caprellids, of micro-
scopic proportions, but for colossal species each Amphipod
division must be content to compare its members one with
another, rather than with the outside world. In the
threadlike Caprellidea, some of which might be regarded
as creatures of only one dimension, the Challenger species,
Dodecas elongata, by help of its antennee and hind legs, can
stretch over a space of three inches. In the Hyperidea,
Rhabdoséma armatum'* is not quite so thin, but its length
is greater, since the tip of its rostrum is sometimes nearly
five inches distant from the extremity of its caudal appen-
dages. In the same section the remarkable genus Cystisoma
has species which combine a length of four or five inches
with the respectable breadth and depth of an inch in the
amplest part of the head. The chief boast of the Gam-
maridea is MHurythénes gryllus (Lichtenstein in Mandt). ~
The first specimen observed of this full-bodied animal was
three inches long and two inches and a quarter round the
waist. It was disgorged in the far north by a wounded
arctic petrel. ‘Twenty-seven years later it again attracted
scientific attention, singularly enough the specimen this
time coming from the far south, for it was taken from the
stomach of a fish caught off Cape Horn. Its body was
nine centimétres long and three deep—in other words, more
than three and a half inches in length and more than one
inch in depth. In recent years the apparent anomaly of its
occurrence both in arctic and sub-antarctic waters has been
explained by evidence that it can make itself at home in the
intervening expanse, since in 1885 the American steamer
Albatross captured a specimen over four and a half inches
long, in deep water off the middle Atlantic coast of the
United States. This must be regarded as the bulkiest of
the Amphipoda yet known.

The Entomostracans make their position in the world’s

? It is doubtful whether the change of this name to Xiphocephalus
armatus, as proposed by Dr. Bovallius, can be justified, since the
name Xyphicéphale was only given by Eydouxand Souleyet on Guérin’s
authority in trivial not in scientitic form, an ill-spelt French name for

a genus rather hinted at than established or defined. the name more-
over not being definitely given but only contingently suggested.

A DIMINUTIVE GIANT 31

economy remarkable far more by their incalculable num-
bers than by their individual measurements. In regard
to the Phyllocarida, Dr. Packard remarks that the palao-
zolc Species were gigantic in size, some being about a foot
or more in length, while our recent Nebalia is less than an
inch. ‘The new species, Nebaliopsis typica, Sars, however,
may extend the magnitude of modern examples to an inch
and three-fifths. The Phyllopoda can exhibit Estheria
californica, Packard, in a shell 16 millimétres long, ten
broad, and four thick, and Apus Newberryi, Packard, with
the carapace, the abdomen behind the carapace, and the
slender caudal appendages, each an inch long. But the
amplitude more usual in the sub-class may be estimated
by the respect paid to such a species as Bythotrephes
crassicauda, lalljeborg, 5 mm. long, one of the Cladocera.
This is a colossal species of a fifth of an inch! Among
the Ostracoda, Crossophirus imperator, G. S. Brady, is
one third of an inch long, and with good reason Dr. Brady
cannot restrain his admiration of ‘this noble species, cer-
tainly the largest of the known Cypridinide.’

In the Thyrostraca or Cirripedia a total length of two
or three inches will deserve and earn the lordly epithets
of eximium, regium, and gigas, but the ——— Balanus
psittacus (Molina), which grows rapidly and j is ‘ universally
esteemed as a delicious article of food,’ attains six inches
in length by three and a half in diameter, and a specimen
has been found no less than nine inches in length, though
only two and a half in diameter. Of the pedunculate
species, Lepas anatifera, the common Goose Barnacle, can
grow a stalk more than a foot long. Darwin says: ‘The
largest specimen which I have seen had a capitulum two
inches in length; the longest, including the peduncle, was
sixteen inches.’

o2 A HISTORY OF RECENT CRUSTACEA

CHAPTER IV

ON STRUCTURE

THE body of a crustacean is externally divided into a theo-
retically constant number of segments and paired append-
ages. In the Malacostraca, it generally exhibits a more or
less clear partition into head, trunk, and tail, or, as these
parts are sometimes called, cephalon, thorax, and abdomen.
There is indeed a rather bewildering supply of alternative
names, which it is needless for the moment to discuss.
The objections to the use of the word thorax have been
already mentioned. Throughout the sub-class, however,
the head is found to be united to some portion of the trunk,
and to denote this variable combination the convenient
word cephalo-thoraw is very frequently employed for the
region covered by the carapace. It is a matter of opinion
whether the full number of true segments should be
reckoned as twenty or twenty-one, since that which is
called the telson, and which is regarded by many authors
as the terminal segment, is considered by others not to be
a true twenty-first segment, but a median outgrowth of the
twentieth. Scarcely ever can the whole number be dis-
tinguished in one and the same animal. As the Entomos-
traca always have more or fewer than the theoretical num-
ber, there is some need for the eye of faith to mclude them
in the reckoning. The foundation of the integument
which forms the external skeleton of a crustacean is a
tolerably flexible substance called chitin. This is hardened
and consolidated by being impregnated with calcareous
salts, and the absence of these leaves the skin the requisite
flexibility for acting as a joint between one hardened part

s

2

WHAT IS A HEAD? 30

and another. But the joints themselves are sometimes
consolidated, and then it is said that two or more segments
have coalesced. This is not a merely arbitrary statement, »
for, comparing the Malacostraca one with another, the
conclusion cannot be avoided that a single segment is
limited to a single pair of appendages. Segments which
are not independent in one of the families will be found
well articulated in another, and those which can least
boast of freedom nevertheless frequently point to an origi-
nal independence by some suture or groove, if not by the
actual separateness of the segmental ring in some small
part of its circuit.

No rigid definition is possible of a head. It is bound
to contain the animal’s mouth, and may be expected to
include the brain and organs of the senses of sight and
hearing, smell and taste. In birds and in mammals its
limits are conveniently defined by the neck, but in the
Crustacea there is no such obvious constriction separating
it from the trunk. Consequently its true limits here are
still a subject of dispute, which cannot be settled offhand
by an appeal to the cervical groove, even when that is con-
spicuous. By various authorities the first five, six, or
seven segments have been assigned to the head, and in the
higher crustacea it might not unreasonably be regarded as
comprehending the first nine. This will be understood
from a consideration of the form and functions assumed by
the several appendages, only thos» in front of the mouth-
opening or directly contiguous to it being accepted without
dispute as cephalic, although others in variable number
are concerned in the operation of feeding.

Glancing along the whole line of limbs, as the out-
growths from the segments have some right to be called,
twenty pairs in uumber, we find them successively devoted
to seeing, feeling and otherwise perceiving, feeding and
presumably tasting, grasping and striking, walking and
digging, swimming and leaping. But although the order
in which they act may thus be generally stated, there is
not unfrequently a transfer of function from one part of
the line to another. The feelers may be employed to assist

oA A HISTORY OF RECENT CRUSTACEA

in swimming or climbing or clasping. The mouth-organs
of one’group are the grasping weapons of another. ‘The
walking legs of one set are elsewhere adapted for swim-
ming. ‘There are also other functions conjugal or maternal
in which the swimming legs or the walking legs may take
part, while the breathing apparatus, simple or complicated,
may be connected with the mouth-organs or limbs of the
trunk or both, or else with the swimming organs of the
tail-part, commonly called the pleon. ‘These and other
curious modifications are largely made use of in classifying
the Crustacea, and to understand the unavoidable intrica-
cies of any system of arrangement, the outgrowth of each
segment should be studied, in some form the less abnormal
the better.

1. The first segment is known as the ocular or ophth-
almic. This is clearly articulated in the Squillide, but only
occasionally in other groups, as in the macruran Plesi-
onika uniproducta, Sp. Bate. Its individuality is in no
way indicated in the sessile-eyed Crustacea, in some of
which the eyes pretty well cover the whole dorsal surface
of the head. In the Brachyura and Macrura its original
independence can often be traced, but it is in these chiefly
attested by the pair of movable appendages which it
almost invariably carries. Now, just as it is thought
that all the segments represent a common original type
variously modified, a similar view is applied to all the
appendages that arise from the segments.

The resemblance, in fact, is often very obvious between
the antennze and the swimming feet ; between the laminar
maxillee near the mouth and the opercular and breathing
plates in the tail; between the maxillipeds, which are in-
struments of nutrition, and the ambulatory legs of the
trunk; so that a connection, at first sight very improbable,
is satisfactorily established between them all, when the
comparison has been sufficiently extended. Yet it de-
mands some exercise of faith on the part of a novice to
accept the declaration that this homology holds between
the claw of a lobster and its eye. No two parts of an
animal could well be more unlike in appearance and func-

OPTICAL INSTRUMENTS 35

ticn. It is unusual to think of a creature’s eye as one of
its limbs, for only by a figure of speech do we describe a
person as grasping the whole situation at a glance, Never-
theless, there are very few inclined to dispute that the
eyes of the Podophthalma have really been developed upon
appendages by nature equivalent to the rest of the series.
Any one acquainted only with the extremely short-stalked
eyes of some of the crabs might be excused for thinking
this view extravagant, but its improbability is lessened
when we observe the long-stalked eyes of the Angular
Crab, Gonoplax rhomboides (Linn.), or those of the macruran
Leucifer Reynaud, Milne-Edwards, or those, again, of
Hretmocaris longicaulis (see Plate XIII.), a shrimp in‘which
the eye is projected on a support actually longer than the
animal. Moreover, the ocular appendage, besides being
articulated to the head, is itself composed of two or three
articulations. In the fast-running Ocypide cursor (Linn.),
the peduncle is extended beyond the cornea of the eye,
and terminates like an antenna in a pencil of long hairs.
There is one instance on record in which the eye of a kind
of lobster, Panulirus penicillatus (Olivier), has been observed
to develop a jointed antenna-like lash, while the com-
panion eye remained normal. ‘This evidence is parallel
to that on which a botanist infers that the petals of a
flower are by origin modified leaves when he sees them
occasionally assuming the form of the unmodified leaf.

2. The second segment carries the first pair of an-
tennze, sometimes called the inner or upper, or, without
epithet, the antennules. In the Malacostraca normally
these appendages consist each of a three-jointed peduncle
and two flagella or lashes, composed of many joints or
few, the inner or secondary flagellum being not unfre-
quently absent altogether or rudimentary. In some in-
stances, and in the Amphipoda Caprellidea and in the
Entomostracan Copepoda not as an exception but as the
rule, the first antennze are larger than the second, from
which it results that the diminutive name antennules is
rather convenient than appropriate. The superior size,
however, is no indication of higher rank, but rather the

36 A HISTORY OF RECENT CRUSTACEA |

reverse. These organs are sometimes most dwindled in
families which can claim a decided precedence over others
in which these appendages are well developed. ‘Thus they
are short in the crabs, but long in the lobsters and shrimps,
and short in the normal Isopods, but long or large as a rule
in the Amphipoda, and within the Amphipoda they are
short in the Orchestide, a family that claims superiority
by its tendency to terrestrial habits.

Those who have made themselves acquainted with
Professor Huxley’s volume, ‘The Crayfish, in the Inter-
national Scientific Series, will be aware that in describing
a crustacean appendage he names the first two joints the
protopodite, which bears at its extremity on the inner side
the endopodite, and on the outer side the exopodite. For ©
these terms the shortened forms exopod and endopod will
here be preferred—exopod for exopodite, endopod for
endopodite and protopodite combined—and peduncle will
be used for a variable number of basal joints. In the first
antenne the peduncle consists, as already stated, of three
joints, and by this circumstance the rule which widely
prevails elsewhere that the so-called protopodite ends with
the second joint of an appendage is broken without any
obvious cause. Moreover, that which by its’function and
in general by its superior size appears to be the main
branch is here the outer one, and not as usual the inner.
It is conceivable that the exopod is wanting, that the main
branch or principal flagellum is the true endopod, and that
the secondary flagellum is an independent outgrowth.
For the reasons mentioned, and some others, Dr. J. H. V.
Boas considers that the first antennee are not homologous
with the following limbs, but that both they and the
stalked eyes ought to be regarded as lmb-like sense
organs. ‘That besides being organs of touch, they are
frequently organs of other senses, seems to be beyond
doubt. In the Macrura at large the first joint contains
an auditory apparatus. Sometimes the cavity is provided
with a well-formed otolith or ear-stone. In the lobster
and crayfish, Mr. Spence Bate says, ‘the perforation is
long, narrow, and slit-like, the aperture being scarcely

; AN ACOUSTIC TAIL 3o7

appreciable, and opens into a calcified chamber, more or
less filled with particles of sand, which are voluntarily
placed in position by the animal soon after casting its
exuvium. But while the higher Podophthalma have the
organ of hearing thus placed, there are some—the
Mysidze—which, extraordinary to relate, carry it in the
tail (see Plate XIII.). Insome of the Amphipoda otoliths
have been detected in connection with the brain, notin, but
behind the antenne. In general, the antenne are fur-
nished with delicate plumose hairs, the vibrations of which
assist in the conveyance of sound to the auditory nerves.
Similar hairs in the Mysidze are connected with the caudal
otoliths. The principal flagellum of the upper antennze
is frequently furnished with a number of smooth setz or
filaments, which were at one time described as auditory
‘cilia, though there was nothing to support this guess at
their function, and though the term ciliwm was inappro-
priate to the shape of these rod-like membranous filaments.
It was noticed by various naturalists of eminence that the
setze of this form were much more abundant in the adult
males than in the young males or in the females. Leydig
supposed them to be not auditory but olfactory organs,
and Fritz Miiller independently came to the same conclu-
sion, adducing in support of it their stronger development
in the males, as in other cases male animals are guided by
the scent in pursuit of the females. It can scarcely be
said that their olfactory function is as yet absolutely
proved, but they are evidently not well placed to serve
the sense of taste, and for the senses of sight, hearing,
and touch, there are other organs much better adapted,
so that these glassy filaments, to be sensory organs at all,
are in a manner forced back upon the sense of smell.

The secondary or inner flagellum, according to Dr.
Boas, is wanting in all genuine Nauplii—that is, in the
earliest larval stage of the crustacean. Its after develop-
ment conforms to no known rule, since in some species it
is not found at all, in others it is only rudimentary,
whereas, on the other hand, among the Macrura it is not
- unfrequently much longer than the outer flagellum. Mr.

Ts, A HISTORY OF RECENT CRUSTACEA

Spence Bate suggests that its function may consist in p1oe
tecting and keeping clean the mass of cilia and filaments
attached to the outer branch. In some genera of the
Macrura, for example Paleemon and Alpheus, the principal
flagellum divides at some distance from its base ito two
branches. In the Squillidee, also, there are three flagella.

3. The third segment carries the outer, under, or second
antennz, sometimes called simply the antennze in distinc-
tion from ‘antennules.’ They are rarely absent, as in the
females of some Amphipoda. More often they are strongly
developed, in some instances exceeding in length all the
rest of the animal which carries them, the joints of the
flagellum or lash being then very numerous. In the
Malacostraca the peduncular portion embraces the first
five joints. The exopod, when developed, as it gene-
rally is-in the Macrura, very commonly has the form
of a thin plate known as the antennal scale, in Latin
sguama, while those who love long words are privileged to
call it the scaphocerite. When laterally extended this
broad scale must assist in keeping the animal upright in
the water, a position which would otherwise with difficulty
be maintained by long-bodied forms. In some Crustacea,
the scale, though present, has not a laminar character,
and it is then spoken of as the acicle. ‘The first, or basal
joint of the peduncle, is not unfrequently soldered to the
wall of the head, and very often carries a tubercle in con-
nection with the ‘green gland,’ of which the function is
supposed to be renal, though it has not been with certainty
determined. That this tubercle is of some importance
may be inferred from the fact that im some cases where
the antenna itself is obsolete the tubercle persists.

It is not a little singular that up to thirty years ago
or later, many naturalists of eminence regarded this tuber-
cle as connected with the auditory apparatus, which they
assigned to the base not of the first but of the ‘second
antenne. Milne-Edwards in 1854: refers to the researches
of M. Savart, who had discovered that the stretching of a
fine elastic membrane over an opening was one of the
circumstances best adapted to promote the appreciation of

THE MANDIBLES 39

sound. Just such a membrane Milne-Edwards considers
to exist at the base of the antennz now under discussion,
and in some of the Brachyura he and his colleague Audouin
had investigated an inner apparatus capable of increasing
the tension of the disk at the will of the animal, an
arrangement which he compares with that of the auditory
ossicles and the tympanic membrane of the human ear.
It is only with reluctance that this description of a natural
telephone can be relinquished. In some species, such as
the common rock lobster, Palinurus vulgaris, there is a
stridulating apparatus in the basal joints of the second
antennee, and it is obviously unlikely that a sound-pro-
ducing organ should have been developed in an animal's ear.

A. The fourth or mandibular segment is of great im-
portance, since from this, or from it in conjunction with
the preceding segment, the carapace is developed. Its
appendages also, the mandibles, yield in value to very
few of the other organs. In form they vary extremely,
but are for the most part of powerful structure. Their
edges meet over the mouth-opening between the upper lip
and the lower. The trunk of the mandible is frequently
massive, with a projecting, finely denticulate, grinding
surface called the molar tubercle, and a thick or thin dentate
cutting edge, often having also a variety of spines between
these two processes. It is not seldom surmounted by a
narrow piece, commonly called its palp, which never in
the Malacostraca consists of more than three joints. Very
rarely, and only among the Entomostraca, one of the joints
of the palp has an outgrowth supposed to represent the
exopod. Since theoretically the exopod always arises
from the second joint of an appendage, it is argued that
the trunk of the mandible must represent the first joint.
But to this it may be answered that the exceptional out-
erowth just mentioned is perhaps not an exopod, and that
at any rate in the first antenne there is a similar out-
erowth from the third joint. In Hucheta glacialis, Hansen,
and some other Entomostraca, the mandibular palp divides
into two branches from its second joint. Seeing that the
first joint of a crustacean appendage is very rarely of large

4.0) A HISTORY OF RECENT CRUSTACEA

size, it is a question whether the trunk of the mandible
may not represent a coalescence of the first and second
joints, or even of the first three or four joints. The latter
supposition would explain the circumstance above noticed
that its ‘palp’ or terminal portion in the Malacostraca
never exceeds the number of three joints, though it may
be reduced to two or one, or may vanish altogether (see
Plates XIT., XV., XIX.). On the inner side of the man-
dible there is sometimes, adjoining the cutting edge, a
plate which more or less closely imitates that edge in its
character. It has now been made probable that this
secondary plate is a modification of one of the spines above
noticed, and, as if to show the plasticity of nature, some-
times the series of spines mimic the secondary plate.

The upper and lower lip seem best to be regarded as
modifications of the integument, where it is turned in to
form the alimentary canal, commencing with the cesopha-
gus or gullet.

An American lady, Miss J. M. Arms, however, in her
very clever little work on Crustacea, in Alpheus Hyatt’s
‘Guides for Science-teaching, maintains that the leaves of
the lower lip ‘are independent outgrowths or buds from
the integument, as much as any other pair of appendages;
and the fact that the parts of the segment to which they
must have belonged have disappeared, or cannot be readily
found, is, in her opinion, ‘an argument of doubtful
weight.’

The theory that all the appendages of a crustacean are
either legs or modified legs will strike a casual observer
as rather strained in its application to the mandibles.
That a crab should adapt the basal joints of a pair of
limbs for masticating its food may seem as unlikely and
absurd as that a man should have teeth on his elbows,
and should draw them up in front of his lips for the
purpose of biting and chewing whatever he wished to put
into his mouth. ‘To prevent all cavilling, however, on
this point of the theory, the King Crab, Limulus, is so
obliging as to ignore the ordinary mouth organs, and to
use the bases of its actual walking legs as mandibles.

THE MAXILLARY FAN 41

5. Close up to the lower lip, and as little leg-like a8
any of the appendages, are placed the first maxille. ‘They
are almost always thin and foliaceous, with few joints, and
those few not easy to distinguish. The pattern is ex-
tremely variable. ‘The functions are obscure. There are
sometimes strong fringing spines which may assist in
dividing the food. There are plumose hairs, some of
which may be connected with the sense of taste. The
position of these organs has also suggested that they may
‘be useful in preventing the escape of. food from the
lateral angles of the mouth.’ It is with these that some
authors close the number of true cephalic appendages.
Of those which follow some are frequently, but none with
the same constancy, developed into mouth-organs.

6. The second maxilla, when present, have generally
the same thin flattened character as the first, but their
structure is often more complicated. Among other pecu-
harities they have in some of the higher groups a mem-
branous expansion or large lamina on the outer side,
frequently termed the flabellum or fan, and compared by
Milne-Edwards to a ventilating register (see Plate XI.).
This species of valve is in constant and rapid vibration, in
most cases forcing the water which has aerated the gills to
pass out in front, so that a new supply may be introduced
from behind; but in some crabs (as Dorippe, Ranina, Leu-
cosia) according to de Haan the water is introduced in
front, and passes out behind. Huxley supposes that this
valve may represent the epipod, that is to say, the branch
which is given off by the first joint of an appendage, or
else that it may be a combination of the epipod of the first
joint with the exopod of the second.! Professor Sars re-
gards it as the exopod,? while Dr. Hansen considers that
it springs from the third joint. In those Crustacea which
have the branchiz either not enclosed in a chamber or in
one remote from the head, this part of the maxilla is either
absent or rudimentary (see Plates XVI., XIX.).

1 The Crayfish, p. 170. (The scaphognathite.)
2 The Nornegian North Atlantic Expedition Crustacea, p. 21.

3 Oversigt over de paa Dijmphna-Togtet indsamlede Krebsdyr, p. 193
note, and p. 252.

5

4,2 A HISTORY OF RECENT CRUSTACEA

* 7. The appendages of the seventh segment are dis-
tinguished from the two preceding pairs by the name
maxillipeds, meaning maxillary feet or jaw-feet, because
they often conspicuously combine the function of a mouth-
organ with the general appearance of a crustacean leg.
This is very much the case in the Amphipoda, where they
conclude the series of cephalic appendages, having here
something of the opercular function which they exercise
still more conspicuously in the Isopoda. In the Copepoda,
which-are content with one pair of maxille, there are two
pairs of ‘ foot-jaws,’ in regard to which the singular dis-
covery has been made that they belong to a single segment,
and yet do not violate the rule that a single segment is
limited to a single pair of appendages. By tracing the
process of development Dr. Claus made it clear that they
were in fact the exopods and endopods of a single pair of
limbs, which had separated so as to wear the appearance
of two distinct pairs, which is much as if the radius and
ulna in the human arm were to become independent and
produce a four-handed man.

In the higher Crustacea these appendages, without
being divided, are only the first of a series of three pairs
of maxillipeds. Their forms vary exceedingly in the
different groups. Sometimes the endopod is seven-jointed
like an ordinary limb, at others the terminal part is
reduced to insignificance. Often the epipod and exopod
are important both in size and function.

8. In regard to the eighth segment, a difficulty arises
as to how the appendages should best be designated. In
some groups, such as the Amphipoda and Isopoda, they
belong not only in theory but in fact to the trunk, and
they have in these groups been called gnathopods, a word
which, like maxillipeds, means jaw feet, and which was
chosen to indicate that they grasped the food in a jaw-like
manner. But in the higher Crustacea these appendages
practically belong to the mouth and not to the trunk,
their general appearance and sfunctions allying them
closely to the preceding pair. Under these circumstances
it seems best to call them the second maxillipeds. For,

A CENSUS OF LEG-JOINTS 43

though it has been strongly urged that one and the same
term ought to be applied to homologous parts throughout
the whole crustacean class, either nature has opposed the
rigid application of such a system, or the wit of man has
not yet been able to devise appropriate terms.

It may here be mentioned that the full number of
joints for a malacostracan trunk-leg is seven. With aview
to uniformity of nomenclature, the afflicted naturalist has
for many years had to deal with these seven under the
following names :—Coxa, basis, ischium, merus, carpus,
propodus, dactylus, which respectively signify hip, foot,
socket of thigh joint, thigh joint, wrist, forefoot, and
finger or toe. Originally the names were longer, all being
podites, from coxopodite to dactylopodite, to the use of
which the philosophic French still adhere, though the
time-saving Anglo-Saxon has for the most part rejected
them. Among other difficulties in this terminology under
either form, it has to be remembered that the basis is the
second, not the basal joint of the limb. The more reason-
able plan is now being widely followed of naming these
joints simply according to their numerical order, the coxa
being called the first joint, and the dactylus the seventh.
But the older names have still to be borne in mind by
those who study the older literature. Even the numbers
are attended by a very unfortunate element of confusion.
The late Axel Boeck, when introducing the use of num-
bered joints, was studying the Amphipoda, in which the
first joint of a leg is seldom, if ever, free. Taking into
account, therefore, only the six free joints, he called the
second joint the first, and made the finger the sixth, instead
of seventh. In treating separately of the Amphipoda or
Isopoda, many naturalists have followed Boeck’s usage as
reasonable and convenient. But when other Crustacea are
considered in which an appendage has the first joint or
perhaps all the seven joints free, they must be numbered
from one to seven, and whenever a comparison is needed
between the limbs of thé Kdriophthalma and those in
other groups, two different systems of numbering the
joints cannot fail to be highly embarrassing. It must

44, A HISTORY OF RECENT CRUSTACEA

further be noticed that there are Crustacea in which one
or other of the joints, most often the fifth, is itself multi-
articulate, thus adding to the normal number, which on
the other hand is still more frequently diminished by
coalescence, absorption, or complete failure of develop-
ment, affecting various parts of the limb.

9, The ninth segment carries a very important and,
at the same time, very variable pair of appendages, which,
as the third maxillipeds, have in the higher Crustacea the
same kind of opercular character that has been noticed as
pertaining to the appendages of the seventh segment in
some of the lower groups of the Malacostraca. In his
celebrated and valuable work on the Crustacea of Japan,
de Haan made great use of these third maxillipeds for
classifying the Malacostracan group in respect to families
and genera. The various joints of the endopod by their
shapes, relative size, number, and mode of articulation
one with another, have yielded a multitude of characters.
In the Amphipoda, where the appendages of the ninth
segment are not mouth-organs, but constitute the second
gnathopods, they are commonly the most powerful limbs
of the trunk, being, no doubt in general, the animal’s most
efficient weapons for holding its prey. In the Isopoda, on
the other hand, they are to be called gnathopods only by
courtesy, being in general little distinguishable from the
following pair of limbs.

10, 11, 12, 18, 14. The appendages of the five follow-
ing segments have been and may sometimes conveniently
be called pereeopods, which means walking-feet. Among
the Amphipods and Isopods they are usually adapted for
walking, and in those groups the trunk, to which they are
attached, is often called the perzeon, intended to signify
the ambulatory part. Among the crabs and lobsters, and
various other crustaceans, however, the first of these pairs
is by no means adapted for walking, but ends in large
claws or nippers, on account of which they are known as
the chelipeds, and Mr. J. E. Ives proposes to call the four
following pairs cruripeds, which means leg-feet, while
Dr. A. 8. Packard, unaware of what was intended by

‘?

APPENDAGES OF TRUNK AND TAIL AD5

perzeon, has proposed to substitute for it ‘bzenosome,’ a
word of precisely the same sense. The epithets chelate
and sub-chelate are of constant occurrence in descriptions
of Crustacea. <A limb is chelate when it has joints that
will act together like a pair of tongs. Generally this
character is produced by the hingeing of the seventh joint
a considerable way down on the side of the sixth. When
the seventh joint or finger can be folded back upon the
sixth, although the latter is not produced into any thumb-
like process to oppose it, the limb is then said to be sub-
chelate, the claw being in that case partial, though often
extremely efficient. The possession of chelz is not con-
fined to the first pair of so-called pereeopods, although it is
seldom elsewhere that they attain a monstrous develop-
ment. They may occur on any of the pairs, and on several
in the same animal. In connection both with the maxilli-
peds and the perzopods there are developed in great
variety of form the branchie or gills, also the plates of the
marsupium, wherein, in some groups, the eggs are retained
for a time after their discharge from the ovaries; and
again, in some groups, the exopods are developed as swim-
ming organs. ‘The vulvz, or uterine-openings of the
female, belong to the sternal, that is the ventral, side of
the tweltth segment, while the genital openings of the
male occupy a similar position in the fourteenth segment.
In those Crustacea which have the basal joints of each
pair of legs brought close together, the openings in ques-
tion have been transferred from the wall of the trunk to
the first joint in each of the last pair of legs in the male,
and of the antepenultimate pair in the female.

_» 15, 16,17, 18, 19, 20. The remaining segments belong

to the tail or caudal portion of the animal, which has been

termed the pleon or swimming-part, a convenient and

often a very appropriate name, although on the other
hand there are plenty of crustaceans which do not and
cannot use the pleon to swim with. ‘The first five of these
segments frequently have appendages that are really
natatory and may properly be called pleopods, swimming-
feet. But some or all may be wanting, or rudimentary,

4.6 A HISTORY OF RECENT CRUSTACEA

or devoted to other purposes. They may be partially or
entirely branchial. Among the Stalk-eyed Crustacea they
are often used in the female for retaining the eggs during
an early period of development or hatching. In the
Amphipoda the fourth and fifth pairs are more or less
adapted for springing, and bear the name of uropods, or
tail-feet. This name is also given to the appendages of
the twentieth segment whenever they are present. ‘These
are prominent features in the Cumacea and most other
Kdriophthalma, and in the Macrura they combine with the
telson to form the powerful tail-fan, for which Mr. Spence
Bate has proposed the Greek name rhipidura (see Plate X.).
In the Copepoda there is a ‘ caudal furca,’ homologous with
the caudal rami in the Nebalide, which must be distin-
guished from the terminal uropods of the higher Crustacea,
as ‘being not true limbs, but more properly representing a
bipartite terminal segment.’ !

21. The telson is extremely variable in form and
relative size, and sometimes by coalescence with the pre-
ceding segment shows little trace of independent exist-
ence. ‘The intestinal canal opens on its under side. It
is sometimes deeply cleft, as though the two terga, or
dorsal plates, of a body-ring had come apart. ‘To prove
its claim to be regarded as a segment, the most effective
argument would be to show that it sometimes carries
appendages after the fashion of all the other segments.
Bell, in the ‘ British Stalk-eyed Crustacea,’ says that he
has frequently observed appendages to the telson of the
common prawn, Leander serratus (Pennant), ‘in the form
of extremely minute points attached to the very extremity
of the segment, and moveable.’ Spence Bate says, ‘In
some genera, or even families, the telson is posteriorly
rounded, as in the Astacidz; in others it is anteriorly
hard and calcareous, and posterior ly soft and membranous,
as in the Synaxidea, a circumstance that is suggestive of
a distinct relationship of the two parts, the anterior
which carries the anus belonging to the normal somite,

' Sars. Leport on the Phyllocarida collected by H.M.S. Challenger,
p. 35.

INTERNAL DIFFERENCES 47

wnile the posterior portion represents its appendages.
This idea is still more strongly suggested in the genus
Cheiroplatea, where the separation of the posterior from
the anterior division is clearly defined by a distinct mem-
branous articulation, and the posterior portion is divided
into two lateral lobes..! The older genus Porcellana is
even more to the purpose than Cheiroplatea, and Miss
J. M. Arms, in the Manual before referred to, considers
that it settles the question. Comparing a species of it with
the lobster, ‘This curious little crab, she says, ‘ possesses
a telson with an unmistakable pair of appendages attached
to it, proving that this part is really a ring whose appen-
dages are wanting in the lobster.’ It must, however, be
remarked that neither in the Porcellanide nor in the Gala-
theidz do these apparent appendages of the telson ever
‘become freely articulated with it, and as they are the last
to put in any appearance at all, and then only in a late
stage of the animal’s development, it remains a question
whether they may not be dividing lines of the telson
rather than appendages arising from it.

In the internal organs of crustaceans the differences
are as great as in the external. One writer has even
undertaken to classify the Brachyura according to the
structure of their stomachs. Unless this part of the
organism were tolerably complicated, it will be easily under-
stood that it would not afford sufficient variations for such
a purpose. But though, for establishing a really natural
system, every stage of an animal’s development and all its
parts ought to be studied and taken into account, surely
a systematist ought to aim at founding his classification
as far as possible on the most accessible stages and the
parts most easily observed. At any rate the general
student will have little inclination to arrange his collec-
tion by investigating in the different specimens the walls
of the stomach and the teeth and hairs within it, although
he may occasionally be pleased to observe in that of the
lobster the three horny-looking grinders, the central one

1 Spence Bate. Report on the Macrura collected by H.M.S. Chal-
lenger, p. X\viil.

4A8 - A HISTORY OF RECENT CRUSTACEA

of which has from of old been fancifully called ‘the lady
in the chair.’ The character of all the internal organs of

Fic. 1.—A lobster’s stomach opened to show the teeth, the central one of which has
been supplied with eyes, nose, and mouth, to represent ‘the lady in the
chair. [Herbst]

a crustacean, as exemplified in the crayfish, has been
already discussed in detail by Professor Huxley in a pre-
vious volume of this series. It may here, therefore, suffice
to recall that in a crustacean the heart is ‘dorsal, the nerve~
chain, with the exception of the brain, ventral, and the
alimentary canal central, having in proximity the hepatic
lobes or liver, and the testes and ovaries. Some of the
more or less striking peculiarities which prevail in different
groups in regard to these organs are reserved for mention
as occasion offers in the description of the several sub-
orders and their families.

The following table supplies a synopsis of all the
leading groups of the Crustacea. The literal meaning
of the various names has been explained in the first
chapter :—

A TABULAR VIEW

Class.
CRUSTACEA.

Sub-classes.

Malacostraca. Entomostraca. Gigantostraca.
Thyrostraca (or Cirripedia).

MALACOSTRACA.
Orders,
Podophthalma.” * ~ fdriophthalma,
E Sub-orders. Sub-orders.
Brachyura. Cumacea.
Macrura. Tsopoda.
Schizopoda. Amphipoda.
Stomatopcda.
TEXNTOMOSTRACA.
Orders.
Branchiopoda. Ostracoda. Copepoda.
|
Sub-orders. Sub-orders. Sub-orders.
Phylocarida. Podocopa. Gnathostoma.
Phyllopoda. Myodocopa. Poecilostoma.
Cladocera, Cladocopa. Siphonost ma.
Branchiura. Platycopa.
GIGANTOSTRACA.
Orders.
Merostomata. Xiphosura. Trilobita.

THYROSTRACA (CIRRIPEDIA).

Orders.
Thoracica. - Abdominalia. Apoda. Rhizocephala.
|
Sub-orders.
Pedunculata.

Operculata,

50 A HISTORY OF RECENT CRUSYACEA

CHAPTER V
THE SUB-CLASS MALACOSTRACA

THE head and trunk are together composed of thirteen,
or, 1f an ophthalmic ring be included, of fourteen seg-
ments. ‘The caudal part or pleon is composed of six seg-
ments and a telson. The trunk is clearly distinguished
from the pleon, but some part of it is always more or less
closely united with the head. ‘To every segment normally
belongs a pair of jointed appendages. The eyes are either
pedunculate, and limited to two in number, with rarely a
pair of accessory ocelli, or they are sessile, and then gene-
rally two, but sometimes four, or with the components
variously distributed. There are two pairs of antenne, a
pair of mandibles, and two pairs of maxille. Of the next
eight pairs of appendages, from one to three are maxilli-
peds, organs of the mouth, the remainder, from seven to
five in number, being prehensile or locomotive. All these
are typically seven-jointed. Like the second antenne and
second maxille they may either have or be without an
exopod on the second joint, and they may also have or be
without an epipod on the first. The six pairs of appen-
dages of the pleon, when present, generally have an
exopod. ‘The last pair almost always differs in character
from the rest. The paired appendages of the mouth work
from the sides, the oral aperture itself being fringed by
the labrum or upper lip above, and the bifid labium or
lower lip below. A short cesophagus leads up into the
stomach. ‘The intestinal tube terminates in the under side
of the telson. The heart which is dorsally placed has
lateral openings for the entrance of the blood that has been
oxygenated in the branchize. These slits are in one, two,

SHORT TAILS 5d

or three pairs, only in the Squillide exceeding that num-
ber. The ganglia of the same pair are situated close to
one another, though the commissures may stand a little
apart. By the dorsal and lateral extension backwards
and generally also forwards of one (or two) of the cephalic
segments a shield or carapace is formed covering at least
some part of the trunk and sometimes all of it.

The above characters will suffice for a descriptive defi-
nition of the Malacostraca, but it may be proper to remind
the reader that the segments are sometimes so intimately
coalesced that their separate identity is entirely obscured,
and that moreover almost any pair of the appendages, even
one so seemingly indispensable as the mandibles, may in
certain cases be missing. Absence of eyes is by no means
infrequent, and the telson, though perhaps never properly
speaking absent, is often, by its close union with the pre-
ceding segment, so withdrawn from recognition, that in
practice it is spoken of as absent.

Order 1.—Podophthalma.

In this order there is normally a pair of compound
eyes on movable stalks, the eyes being sometimes absent
but never sessile ; the dorsal shield or carapace extends
back over the ninth segment or further.

Sub-order 1.—Brachyura.

The carapace extends over the whole head and trunk,
with occasional exception of the trunk’s ultimate and pen-
ultimate segments, and is longer than the pleon. In the
carapace are excavated orbits and fossettes, hollows respec-
tively adapted to receive the stalked eyes and the short
first antenne. The third maxillipeds have some of the
joints broad and flat, and they form a more or less com-
plete operculum to the well-defined mouth cavity. The
following pair of appendages are perfectly chelate limbs,
commonly called the chelipeds. The next four pairs are
adapted for walking or swimming, or rarely may have a
prehensile character. In the sternal plastron, or breast-

52 A HISTORY OF RECENT CRUSTACEA

plate, the coalesced ventral plates of the last five seg-
ments of the trunk are distinguishable, and three earlier
segments are obscurely represented. It is never entirely
linear. The vulve of the females are generally placed
upon it, but in some groups are transferred to the basal
joints of the ante-penultimate legs. The pleon is of sub-
ordinate size, usually reflexed against the concavity of the
plastron, in the male generally narrow and pointed, with
only one or two pairs of pleopods, in the female broad,
with four pairs of pleopods. ‘The basal joint of the first ,
antennee contains auditory hairs but no otoliths.

In this definition the Anomura apterura are included.
To the dry bones of definition must be added an even less
appetising explanation of terms in common use for the
description of genera and species. The orbital regions of
the carapace speak for themselves as being those which
contain the eyes. The ‘ front’ lies between them. Behind
it on the under surface are the fossettes of the first an-
tennee, followed in the median line by the epistome, the
buccal or oral frame, and the sternal plastron. The second
antenne are placed outside of and a little behind the first.
The ‘hind margin’ of the carapace separates the trunk
from the pleon, and lies between the first joints of the last
pair of trunk-feet. Between it and the orbits are the
lateral margins, each of which is subdivided into an
antero-lateral and a postero-lateral portion forming, when
not continuous, the epibranchial angle. The dorsal sur-
face of the carapace is marked by several grooves cor-
responding with the insertions of muscles underneath, and
also forming the boundary lines of regions which roughly
coincide with the positions of important internal organs.
Along the centre lie the gastric, cardiac, and intestinal
regions, respectively over the stomach, heart, and intes-
tine. ‘The hepatic regions over the liver flank the gastric
region on either side in front, and behind these lie the two
branchial regions, the ‘cervical groove’ being that which
separates the gastric and hepatic regions from the cardiac
and branchial. On the under side the pterygostomian re-
gions, ‘the wings of the mouth,’ lie between the antero-

MASKS AND FACES ay)

lateral margins of the carapace and the buccal frame.
Milne-Edwards remarks that the grooves are often em-
phasised about the middle of the carapace, so as to pro-
duce the appearance of the capital letter H, the transverse

Fic. 2.—Ethusa mascarone (Herbst). [Herbst]

line being the upper boundary of the cardiac region. In
some cases the grooves are so arranged as to represent
~ very strikingly a human countenance or the caricature of
one, as in the Masked Crab of Great Britain and the grimac-
ing Hthusa mascarone of the Mediterranean, which is here
shown as depicted by Herbst. Such likenesses the old
writers were not at all disinclined to accentuate.

The Brachyura are divided into tribes, in regard to
which, however, there is not at present any absolute agree-
ment among naturalists. We shall here arrange them
under the names Cyclometopa, Catometopa, Oxyrrhyncha,
Oxystomata, Anomala. It is melancholy, but scarcely
avoidable, that an alternative list of names should have to
be mentioned, for these tribes in the same succession may
be called—-Cancroidea, Ocypodiidea, Maioidea, Leucosiidea,
and Anomura apterura. ‘The subjoined table will be use-
ful for reference.

o4 A HISTORY OF RECENT CRUSTACEA

BRACHYURA.
' Tribes. Legions. Families.
Cyclometopa . Cancrinea . Cancride, Trapeziide, Portunide,
Podophthalmidez.

Cyclinea . Cyclide.
Corystinea . Corystide.
Theiphusinea. Thelphuside.
Catometopa . Gecarcinide.
Ocypodidee.
Grapsidee.
Pinnotheridz.
Oxyrrhyncha , Maiinea. . Inachidx, Maiide, Periceride.
Parthenopinea Parthenopidee.
Oxystomata : Calappidee.
Matutide.
Leucosiidee.
Dorippide.
Anomala . - Drominea - Dromidze, Homolidx,
Ranininea . Raninide.

Cx
OU

ROUNDHEADS

CHAPTER VI
TRIBE I.—CYCLOMETOPA

THE name literally means ‘those of a circular forehead.’
In these Crustacea the carapace is often of a breadth
greater than the length, wide and regularly arched in
front, more rarely quadrate or suborbicular, but not
rostrate. The epistome is short, transverse. The first
antennz are in general transversely folded. The third
maxillipeds have the fifth joint articulated at the apex or
the inner front angle of the fourth (except in Pirimela).
There are nine pairs of branchis, with their efferent
channels opening at the sides of the endostome or palate.
The verges of the male are inserted at the bases of the
last legs of the trunk,

Milne-Kdwards states that the different ganglia of the
trunk form a sort of circular ring, of which it is often easy
to distinguish the constituent elements, and that the two
halves of the liver remain distinct without a median lobe.

The tribe has been subdivided into four legions—
Cancrinea, Cyclinea, Corystinea, Thelphusinea, in de-
fining which I shall follow the safe guidance of Mr. E. J.
Miers, as afforded in his report on the eae: ura collected
by the Challenc ger.

Legion 1.—Cancrinea.

The buccal cavity is usually well defined. The flagella
of the second antennz are not greatly elongated. “The
seventh joint in the walking-legs is generally unarmed.
It is either stiliform or in the last pair expanded into an

56 A HISTORY OF RECENT CRUSTACEA

ovate swimming organ. The species are marine or
littoral.

This legion contains four families—Cancride, Trape-
zilide, Portunidee, Podophthalmidee.

Family 1.—Cuncride.

The carapace is commonly transverse and convex, with
the antero-lateral margins arcuate, and armed with several
lobes, teeth, or spines. The ‘front’ is of moderate width,
in general not projecting over the first antennee and the
bases of the second, the latter being seldom excluded from ~
the inner hiatus of the orbits.

In this family are included about half a hundred
genera, some widely and conspicuously distinct, others
separated by fine and almost inappreciable differences.
Thus Mr. Miers observes of Xantho (Leach, 1813), that
‘it 1s connected by almost insensible gradations on the
one hand with Lophoxanthus and Xanthodes, on the other
with Panopeus and Hurypanopeus. Quite recently the
genus Panopeus, H. Milne-Edwards, 1834, has been re-
viewed by James Benedict and Mary Rathbun. They
recognise in it thirty-eight species, and re-include within
its boundaries Hurytium, Stimpson, 1859, and Hurypano-
peus, A. Milne-Edwards, 1880, considering that they have
been separated from the parent genus on grounds in-
sufficient or untenable. It will, however, be quite be-
yond. the range of such a manual as this to enter into
all the minutize of generic distinctions. . Far less can the
characters of innumerable species be discussed. Only the
specially typical or the specially anomalous forms may
court a passing attention. Here and there a comparison, -
a description, a comment, may indicate the variety of
details upon which classification is founded, or may sug-
gest the endless opportunities for the exercise of keen
eyes and acute minds, which the subject provides.

Those whose scientific zeal is limited to the desire of
having the specimens in a cabinet rightly arranged and
ticketed with their proper names are often puzzled and

HOW GENERA ARE GENERATED 57

exasperated to find that there is practically no finality in
these matters. It is important to remember that this cannot
be helped, so long as knowiedge is in the stage of growth,
the stage in which it is most acceptable to the human intel-
lect, by continually holding out the invigorating hope of
new acquisitions. In the progress of science some animal
hitherto unknown or little noticed attracts the attention
of a naturalist. Describing some of its salient features,
he makes it the typical species of a new genus. In course
of time many other animals are found to have characters
almost identical, and they constitute the various species of
the same genus, till the number of them becomes so large
that they are perhaps at first grouped in lettered or num-
bered sections, to which presently names are given as sub-
genera, and these in turn are raised to the rank of genera,
-and sometimes eventually to higher grades in the system.
At each successive improvement there comes a displace-
ment of the old names, and for the accurate designation of
specimens the unskilled are placed at greater and greater
disadvantage. There was a time when all the Crustacea
were included among insects, but to call a lobster an in-
sect would now be regarded as a proof of ludicrous igno-
rance. ‘The existing genus Cancer is an absurd little
remnant of that which was originally established by
Linneeus, and which has been gradually subdivided into
a long array of genera, and families, and legions, and
sub-orders, and orders. Bell, in 1855, in his ‘ British
Stalk-eyed Crustacea,’ says, ‘There is but one species of
this genus, as now restricted, native of the shores of this
country, or indeed of Hurope, all the others being South
American.’ He refers, however, to the species discovered
by Say, which belong to the Kast Coast of North America.

The great eatable crab of our own shores is well known.
Dr. Leach remarks that ‘at low tide they are often found
in holes of rocks, in pairs, male and female, and if the
male be taken away, another will be found in the hole at
the next recess of the tide. By knowing this fact, an
experienced fisherman may twice a day take with little
trouble a vast number of specimens, after having once

6

;

58 A HISTORY OF RECENT CRUSTACEA

discovered their haunts.’ Mr. Couch found that this
referred to the mating time, which occurs just after the
female has cast her coat, her new shell being still soft.
It is easy to understand why the exuviation of the male
takes place at a different period, as otherwise the pair
would be defenceless together. Of this Cancer paqurus,
Linn., small specimens are often sheltered in considerable
numbers in cavities wrought in the vast masses of the
sand-tubes of the marine worm Salellaria alveolata.

Cuncer trroratus, Say, is the commonest species of the
genus in America. It is exceedingly ike the European
species, but smaller, with the chelipeds less bulky, and dis-
tinguished by a strong tooth on the fifth joint. It is said
to be common under the large rocks near low-water mark,
often lying nearly buried in the sand and gravel beneath
them. It is also frequent on sandy shores, and occurs in
the tidal poo!s, where, according to Professor Verrill, ‘ the
comical combats of the males may sometimes be witnessed.’
Miss J. M. Arms founds upon it the following description
of a crab’s method of walking :—

‘The legs of one side are used to push with, and those
of the other to pull with, when the crab is in motion.
Those of the same side do not, however, all move together,
but alternately, so that there is no halting in their gait ;
some of the legs are always in the act of taking new steps,
and by shoving and pulling in unison a continuous motion
is kept up. This crawling by means of jointed appen-
dages can be imitated after having once seen a live crab.
Cross the two wrists side by side, placing the fingers down
on a level table; bind the wrists by an elastic band, hold
them well up from the table, so as to show the fingers.
Then let one set crawl while the other pushes, so as to
keep up a continuous motion sidewise without assistance
from the arms. ‘The terminal sections of the legs show
wear only on the points where these are inserted in the
ground.’

It will subsequently be seen that there are some crabs
which are by no means limited to the slow progression
denoted by the word crawling.

wy

FACT AND FICTION 59

Say established the species Cancer irroratus in 1817,
but in 1859 Stimpson discovered that under one name
Say had combined two species, having been misled into
matching the male of Cancer irroratus with the female ot
Cancer borealis. The differences between the sexes which
often exist in Crustacea have more commonly led naturalists
into the opposite mistake of instituting a separate species
for each sex. Cancer borealis, Stimpson, occurs in the
same localities as Cancer irroratus, only being a heavier
and more massive species it does not equally court shelter
and retirement, but will rest entirely exposed on bare
rocks and ledges, or clinging to weeds amid the onset of
the waves. Yet the strength of its shell does not save it
from the gulls and crows which take advantage of its
venturesome position to carry it off for their own con-
‘sumption.

It is not only the sexes of the adult crustaceans that
often differ considerably in appearance, but in many in-
stances between the egg and maturity there are stages to
be passed through in which the forms of the young are so
startlingly different from those of their parents that they
have been placed in different genera, until the relationship
was eventually proved or made probable. ‘To these lar-
val stages various names have been given, some of them
borrowed from the names of the supposed genera to which
the young animals had been at first assigned.

The Dutch naturalist, Martin Slabber, in 1769, was the
first to publish an account of a crustacean metamorphosis
so striking that, as he says, had he not himself witnessed it,
he should have placed the two forms in different genera.
Yet this singular observation was left barren, until in
1825 Mr. Vaughan Thompson was induced to follow it up,
with results that have since been far-reaching. One very
curious circumstance in this history is that the two forms
which Slabber figures evidently do belong to perfectly dis-
tinct groups, the first or Zoéu form to the Brachyura, and
the second to the Macrura. Bell, in the Introduction to
his ‘ British Stalk-eyed Crustacea,’ reproaches Thompson
tor coming to the conclusion ‘that Slabber lost his Zoéa, in

60 A HISTORY OF RECENT CRUSTACEA

changing the sea-water, and that the new form came from
the added portion.’ The second form has been shown to
correspond very exactly with the larval stage of a prawn,
and from this Bell weakly argues that the observation of
Slabber was correct, although the first form, as Bell had
reason to know, was the larval stage of a crab, and in this
Slabber correctly observed the gradual dwindling of the
horns of the carapace. ‘The minuteness and transparency
of these infants and the readiness with which they perish
will account for the confusion in regard to the principal
change into which he appears undoubtedly to have fallen,
but it is remarkable that such an error should have been
in close agreement with the real facts of the case, that a
discovery apparently so full of interest should have been
neglected for half a century, and that then, when at length
it was placed upon a solid foundation, the facts should
have been hotly and stoutly disputed for a long series of
years. In 1837 Milne-Edwards was still undecided on
many of the details of the question, but as to the state-
ment made by Vaughan Thompson in 1835 that the great
French naturalist had been deputed by the Academy of
Science to investigate the development of the Crustacea,
that he had passed a summer in the Isle of Ré for that
purpose, and had come to the conclusion that the Crustacea
are born in their permanent forms, in all that, Milne-
Edwards retorts, there is not a word of truth. He had
never been in the Isle of Ré, he had never denied that
some Crustacea underwent considerable changes, and he
could only hope that Thompson was more careful in his
observations than in his quotations. Notwithstanding
this sharp denial, Bell in 1853 still sends Milne-Edwards
to the Isle of Ré, and wonders that observations which he
never made should have led him to conclusions which he
did not entertain.

The larval stages of the American Cancer wrroratus
have been studied by Professor 8. I. Smith. As might
have been expected, they agree very nearly with those
of the European Cancer pagurus. In its latest stage
the Zoéa still has a frontal and a dorsal spine that are

WATER-BABIES 61

very conspicuous, but at an earlier period it has much
longer spines on the carapace, and as yet no rudiments
of the legs of the trunk or pleon. After many months
they attain the final Zoéa stage, in which the terminal
segment of the pleon is very broad, and divided nearly
to the base by a broad sinus, formed by long spiniform
diverging processes, at the base of which the sinus is
armed with six to eight spines on each side. Shortly
before the change into the second or Megulopa form, ‘ they
were not quite so active as previously, but still continued
to swim about until they appeared to be seized by violent
convulsions, and after a moment began to wriggle rapidly
out of the old zoéa skin, and at once appeared in the full
megalops form. ‘The new integument seems to stiffen at
once, for in a very few moments after freeing itself from
the old skin the new megalops was swimming about as
actively as the oldest individuals. In this megalops stage
the animal begins to resemble the adult. The five pairs
of cephalothoracic legs are much like those of the adult,
and the mouth-organs have assumed nearly their final
form. The eyes, however, are still enormous in size, the
carapace is elongated and has a slender rostrum and a
long spine projecting from the cardiac region far over the
posterior border, and the abdomen is carried extended,
and is furnished with powerful swimming legs as in the
Macroura.’ Professor Smith observed a few instances of
the change from the megalops or Megalopa stage to the
young crab. ‘The little crab worked himself out of the
megalops skin quite slowly. For a short time after their
appearance the young crabs were soft and inactive, but
the integument very soon stiffened, and in the course of
two or three hours they acquired all the pugnacity of the
adult. They swam about with ease, and were constantly
attacking each other and their companions in the earlier
stages.’

Professor Smith has remarked that in ‘The Crayfish,
fig. 74 represents the Zoéa and Megalopa stages of Carcinus
monas, not, as stated by a misprint, those of Cancer
pagurus.

62 A HISTORY OF RECENT CRUSTACEA

If the tiny young of the Crustacea attack and destroy
one another, it is not for want of innumerable other enemies
fitted to keep their numbers in check. As far as the
timidity of human experience can decide, the Crustacea in
general, though by no means particular as to the food they
consume, invite rapacity by the agreeable quality of the
food they supply. The enormous spines of the very young
and the strong armature of the adults have probably been
called into existence in consequence. Where these are
wanting or inadequate, the life of the species has been
protected by extreme fertility. In Geryon quinquedens,
Smith, for example, it has been computed that one speci-
men was carrying no less than forty-seven thousand eggs,
and there are other species reckoned to be at least twice as
prolific.

To the extensive genus Xantho Bell assigns three
British species, naming them florida, rivulosa, and tuber-
culata. But, Montagu’s floridus having lapsed as a syn-
onym, the first of the three should be named Xantho
incisus, Leach. ‘The second, on Bell’s own showing, ought
to be called Xantho hydrophilus (Herbst), and of this
Couch’s tuberculata is now held to be a variety.

Ozius, Milne-Edwards, 1854, was a genus established
to receive certain species found in the Indian and Austra-
lian waters. The name had been given much earlier by
Dr. Leach, but without published description. It presents
a peculiarity by help of which the large family of the
Cancride is divided into two sections. The space between
the front margin of the buccal frame and the mouth itself
was called by Milne-Edwards the prelabial space. By
English writers it is called the endostome or palate. In
Cancer, Xantho, and many other genera, this endostome is
without distinct longitudinal ridges defining the apertures
of the efferent branchial channels, whereas in Ozius, Pilum-
nus, Hriphia, and others, it has these ridges.

Pseudozius, Dana, 1851, is, as the name implies, a
genus that might be mistaken for Ozius, but the crests of
the endostome do not quite reach the upper margin of the
buccal frame. In 1881 the species Pseudozius Mellissa

MUUH LEARNING 63

from St. Helena was carefully described by Mr. Miers, who
pointed out its resemblance to and differences from Xantho
Bouviert, A. Milne-Edwards, a species from the Cape Verd
Islands. In 1886 Mr. Miers re-described it, and gave a
figure of it in his ‘ Challenger Report,’ but he then placed it
in a new sub-genus Muryozius, entitling it ‘ Pseudozius
bouvieri, var. mellissvi,’ in a hesitating manner identifying
it with the species Xantho Bouviert of A. Milne-Edwards.
In 1888 Professor Th. Barroig, in his catalogue of the
marine Crustacea of the Azores, once more describes this
species, and gives a beautiful figure of it in its natural
colour of bright orange-red, with black tips to the cheli-
peds. He and Mr. Miers are in exact agreement in their
descriptions, as two such excellent naturalists were likely
to be. But Professor Barrois calls the species Ozius
“Hdwardsi, and explains that he had submitted it to the
highly competent judgment of M. Alphonse Milne-Edwards,
who pronounced it to be a new Ozius, of which he had
himself obtained a specimen at the Canaries during the
expedition of the Zulisman. It will be consoling to the
beginner and the amateur, when involved in perplexity
amid species that they cannot name or can only name at
random, to find the past masters of the science thus en-
tangled as it were in their own web. For it must not be
forgotten that Alphonse Milne-Edwards is acknowledged
to be ‘the highest authority on the Brachyura,’! and yet he
leads Barrois to make a new species of that which had
been twice described and twice named by Miers, and which
had probably been already named and described by Pro-
fessor Milne-Edwards himself. The instance is significant
of the stress, to which the highest powers must sometimes
prove unequal, of keeping in mind each individual species
of the vast multitude now known, and each individual
chapter of the vast literature which records them.

Barrois mentions an interesting peculiarity in this ele-
gant crab. The carapace along the antero-lateral margins
is obliquely striated on the under side with fine parallel
grooves, in correspondence with which the fifth joint or

’ Miers, Challenger Report, p. 146.

64: A HISTORY OF RECENT CRUSTACEA

wrist of the chelipeds has a long sharp crest, and the
rapid rubbing of this crest against the strie produces a
shrill sort of stridulating noise such as a grasshopper makes
by drawing the thighs of its hind legs over the salient
nervures of its wing-cases.

Pilumnus, Leach, 1815, is represented in Great Britain
by the single species Pilumnus hirtellus (Linn.), but for
the world at large more than eighty forms have been
described under separate, specific names, and still await
the discriminating criticism of some future monograph.
In this genus, as at present defined, the antero-lateral
margins are normally armed with spines instead of the
usual teeth, and the pleon is seven-jointed in both sexes.
But when the description and figures of Pilumnus wan-
thoides, Krauss, 1843, are examined, they exhibit not
spines but rounded teeth or lobes on the antero-lateral
border, and a five-jointed pleon in the male. Thus there
is prumad facie reason to suppose that this species ought to
be removed to some other genus. Otherwise the boun-
daries of the existing genus must be enlarged, whereas for
convenience they rather require to be narrowed.

Pirimela, Leach, 1815, like Pilumnus, is represented in
Great Britain only by a single species, Pirimela denticulata
(Montagu), which occurs also in the Mediterranean, but,
unlike Pilumnys, it is not represented by any other species
elsewhere. In this genus the pleon of the female is seven-
jointed, but that of the male five-jointed, the three middle
joints being coalesced into a single piece. It differs from
all the rest of the Cyclometopa in the character of the third
maxillipeds, for here the fourth joint receives the articula-
tion of the filth on its inner instead of on its apical
margin.

Family 2.—Trapezude.

‘Carapace depressed and nearly quadrilateral, smooth,
with the postero-lateral angles truncated, the dorsal regions
not defined; the antero-lateral margins are straight, form
aright angle with the front, and are entire or have but one
tooth (the lateral epi-branchial tooth) developed. The

THE COMMON SHORE CRAB 65

front is horizontal, broad, lamellate, and projects over the
antennules and bases of the antennz, which are widely
excluded from the orbits.’

The genera are Trapezia, Latreille, 1825, Tetraha,
Dana, 1851, and Quadrella, Dana, 1851, names indicative
of the prevailing shape. The species in general are small
and confined to the warm seas. According to the Russian
writer, Paulson, 1875, the lower antenne of T'etralia re-
quire that the last clause of the above-quoted definition
should be cancelled.

Family 3.—Portunde.

The carapace is depressed, moderately transverse, and
usually widest at the last antero-lateral marginal spine.
The ‘front’ is horizontal and not spatuliform (see p. 71).

-The orbits and eye-stalks are of moderate length. The
spine or tooth at the outer angle of the orbit does not
project laterally beyond the teeth of the antero-lateral
margin, of which more than one, usually from five to nine,
are developed. The last legs of the trunk are commonly
adapted for swimming, with the seventh joint ovate, flatly
expanded.

The Portunide include about half as many genera as
the Cancride.

Carcinus, Leach, 1815, has the seventh joint of the
fifth legs narrowly lanceolate. The species Carcinus meenas
(Pennant) is the most obtrusive of all the British Brachyura.
Its numbers justify its English designation as the Common
Shore Crab; its extremely vivacious movements and its
reckless audacity when brought to bay justify its scientific
title and the corresponding French name for it of Orabe
enragé. Inthe early part of this century Leach stated that
it was sent to London in immense quantities and eaten by
the poor. Professor Stalio says that at the present day
it is a considerable source of food-supply to the humbler
classes on the shores of the Adriatic, that in the soft state,
just after the shedding of the skin, it is welcome at the
tables of the rich, and that the Istrian fishermen pound it
up and use it as a most attractive bait tothe sardines. On

66 A HISTORY OF RECENT CRUSTACEA

the other hand, complaints are made by English writers of
the mischief which it does to fish already captured, and
Dr. Hoek accuses it of the truly detestable crime of in-
vading the oyster beds, and eating the young oysters while
their shells are still soft and easy to break. In attacking
the adults, it is itself sometimes caught by the snapping
down of the powerfully hinged valves.

The only other species of this genus known is the
American Curcinus granulatus (Say), and even this may
not be really distinct from the Kuropean form.

Portunus, Fabricius, 1798, has the last two joints of
the fifth legs dilated and compressed, and the last joint
ovate. It is by this formation that many of the Portu-
nidg are qualified as swimming crabs. In the Caribbean
Sea, and among the gulf weed in the tropical Atlantic,
Mr. Gosse observed them shooting through the water
almost like a fish, ‘ with the feet on the side that happens
to be the front all tucked close up, and those on the oppo-
site side stretched away behind, so as to hold no water, as
a seaman would say, and thus offer no impediment to the
way. Our British species swim with less facility, and are
often called fiddler crabs, because, as Mr. Gosse explains, ‘the
see-saw motion of the bent and flattened joints of the oar-
feet is so much like that of a fiddler’s elbow.’ The beauti-
ful Velvet Crab, Portunus puber (Linn.), called in the
Channel Islands the Lady Crab, is for ordinary purposes
sufficiently described by Bell in the ‘ British Stalk-eyed
Crustacea,’ together with six other species of the genus
that have been obtained in the waters of Great Britain,
namely depurator (Linn.), corrugatus (Pennant), arcuatus
and pusillus, Leach, holsatus, Fabricius, and its near ally
marmoreus, Leach. To these Canon Norman has added
Portunus tuberculatus, Roux, from the Shetland Isles. He
remarks on the singularity of the circumstance that this
and many other southern forms should be found in the
deep Shetland waters, though they are not known from
localities between those waters and the Mediterranean.

Portumnus, Leach, 1814, both by name and structure,
closely approaches the preceding genus, but it has the

THE AMERICAN LADY-CRAB 67

last joint of the fifth legs lanceolate. The British species
which Bell names Portumnus variegatus, Leach, he ought
in accordance with the rules of priority to have called
Portumnus latipes (Pennant). In distinguishing Por-
tumnus from the closely allied HMatyonichus, Latreille,
1818, Bell or his printer has made a confusing mistake
by attributing to Platyonichus the acutely lanceolate ter-
minal joint in the fifth pair of legs, and the broad oval,
very much rounded joint to Portumnus, instead of putting
the contrast the other way round (see Plate II.). He men-
tions that in Portwmnus, as in many other Portunidee, the
pleon of the male is five-jointed, whereas in Platyonichus
it is seven-jointed. Unfortunately this distinction, which
would have been so convenient, only applies to two out of
the three species which are now allotted to the latter genus,
namely to Platyonichus bipustulatus, Milne-Edwards, and
to Platyonichus wridescens, Miers, a species in which the legs
are said to be beautifully iridescent.

Platyonichus ocellatus was first described in 1799 by
Herbst, who records its habitat in the words, ‘ Das Vater-
land ist Long-EHiland bey Newyorck. Both New
York and the ‘ Lady Crab’ of America have come to be
better known than they were in the time of Herbst.
Verrill and Smith, in their valuable report on the inverte-
brate animals of Vineyard Sound, give a figure of the crab
and many interesting particulars. It is, they say, perfectly
at home among the loose sands at low-water mark, and
also abundant on sandy bottoms off shore. It isa rapid
swimmer, and was not unfrequently taken on the surface
of the sea. ‘When living at low-water mark on the
sand beaches it generally buries itself up to its eyes and
antennee in the sand, watching for prey or on the look-out
for enemies. If disturbed, it quickly glides backward and
downward into the sand, and disappears instantly. ‘This
power of quickly burrowing deeply into the sand it pos-
sesses in common with all the other marine animals of
every class which inhabit the exposed beaches of loose
sand, for upon this habit their very existence depends
during stcrms. By burying themselves sufficiently deep

68 A HISTORY OF RECENT CRUSTACEA

they are beyond the reach of the breakers.’ ‘The lady-
crab is predacious in its habits, feeding upon various
smaller creatures, but like most of the crabs it is also
fond of dead fishes or any other dead animals. In some
localities they are so abundant that a dead fish or shark
will in a short time be completely covered with them, but
if a person should approach they will all suddenly slip off
backwards and quickly disappear in every direction be-
neath the sand ; after a short time, if everything be quiet,
immense numbers of eyes and antennz will be gradually
and cautiously protruded from beneath the sand, and after
their owners have satisfied themselves that all is well, the
army of crabs will soon appear above the sand again, and
continue their operations. ‘The colour of this crab is quite
bright, and does not imitate the sand, probably owing to
its mode of concealment. ‘The ground-colour is white, but
the back is covered with annular spots formed by specks
of red and purple. It is devoured in great numbers by
many of the larger fishes.’

Polybius, Leach, 1820, is closely related to the three
preceding genera, and like the last has the capacity for
swimming highly developed. ‘The single species, Polybius
Henslowni, Leach, is European, and is distinguished by
having much compressed joints not only in the last pair
of legs, but also in the three preceding pairs. It is said
to pursue fishes so active as the mackerel, to fasten upon
them with its sharp pincers, and to hold on tili they
succumb. ‘The fishermen in consequence call it the
nipper crab. Probably it is only fish that are terrified or
hampered by the proximity of the fishing-net that fall vic-
tims to its agility. The Prince of Monaco records that on
one occasion, off the coast of Spain, his bursting trawl-net
brought up from a censiderable depth at a single haul about
five thousand fine specimens, which produced an animated
scene on board his yacht by nimbly fastening with their
cat-like talons on to the bare toes and fingers of the crew.

Scylla, de Haan, 1835, belongs to a group of genera
in which the carapace is very broad, and the antero-lateral
margins are armed with nine er more teeth. Some of the

SCYLLA AND CHARYBDIS 69

species are strikingly handsome, both in shape and colour.
Scylla serrata (Forskal), a widely distributed Indo-Pacific
species, is said by Krauss to be the largest and strongest
of the South African Crustacea. The chelipeds of the
male are much larger and more powerful than those of the
female, and colossal in relation to the carapace. ‘The
damaged limbs and bodies covered with scars, uniformly
exhibited by male specimens, are adduced in support of
the inference that their combats one with another are not
a little intemperate. On the muddy coasts of the Bay of
Natal, Krauss says, this species lives in great deep holes,
and wears the dingy earthy colour of its residence. They
sit at the openings of their holes when the tide is coming
in to snap up the food which it brings them, and to sun
themselves when the tide is going out. At any one’s
“approach they vanish into their holes in a moment, or, if
their escape is cut off, they raise themselves up on their
hind legs, and by clashing together their powerful claws
endeavour to scare away the intruder. By driving a spade
into their slanting tunnels their retreat may be cut off, or
they will clutch at the proffered point of a stick and may
so be drawn out, but the Caffres, who consider them dainty
food, capture them by spear-throwing.

Charybdis, de Haan, 1833, belongs to a group of
genera in which the carapace is said to be only moderately
broad, and the antero-lateral margins have seven teeth or
fewer. However, in Charybdis cruciatus (Herbst), the
carapace is of very considerable breadth. The colouring
of this species is highly remarkable. Herbst in 1796
gives a fine picture and a glowing description of one of
the specimens which he received from the East Indies.
The colours in the plate are vivid, but it cannot be said
that they tally in all respects with the verbal account.
According to the latter, the carapace from the front to
beyond the middle of the field is of blood-red hue upon a
yellowish ground, and marked with the figure of a great
yellowish white cross. Down the sides run broad stripes
of greenish red, shading off into grey. The upper surface
of the chelipeds is marbled with yellow and red, the hands

70 A HISTORY OF RECENT CRUSTACEA

having deep red patches and interlacing lines. The
following pairs of feet are yellowish with faint red lines,
the last pair being marbled with red, its joints very broad,
and the last of them thin and membranous. By some
writers this species is called Goniosoma cruciferum (Fabri-
cius). They would displace de Haan’s Charybdis, not
because of any pre-occupation of that name, which would
have afforded a just reason, but because a different name
Oharybdea had been previously employed, which is no
reason at all for cancelling Charybdis. Again, they would
displace the earliest specific name cruciatus as iImappro-
priate, whereas, they argue, the name cruciferum, given
by Fabricius, is in accordance with the great pale cross
marked upon the carapace. It is true that Herbst pro-
bably tortured the meaning of cruciatus, but it is quite
clear that he intended it to bear the sense of cruciferum,
and even if he had chosen to regard his crab as fixed to
a cross instead of regarding the cross as fixed on the crab,
it would not have justified any tampering with the name
and the rights of priority. It is perhaps this species that
suggested the story found in the old writers that on one
occasion, to calm the sea, Xavier threw a crucifix into it,
and that this was afterwards restored to him by a crab.
Bathynectes, Stimpson, 1871, with a name that means
‘the deep swimmer,’ is closely akin to Charyhdis, but its
antero-lateral margins have only five teeth, the hinder-
most of which is very prominent, being twice as long as
those which precede it. T'hranites velox, of which in
1876 and 1881 Professor Carl Bovallius gave a detailed
description, illustrated by numerous excellent figures, has
since been found to belong to Stimpson’s Bathynectes.
The detailed description is im Swedish, the excellent
figures are in a language which all but the blind can read
with ease. The species has been identified with Stimpson’s
Bathynectes longispina, 1871, but Canon Norman has
recently made it probable that the priority rests with
Portunus superbus, O. G. Costa, and that the name will,
therefore, be Bathynectes superbus, the species having ‘a
range apparently co-extensive with the North Atlantic,

A BATTLEDORE FRONT 71

and belonging to the British fauna as well as the Nearoli-
tan in which it first was named. Another Mediterranean
species, Portunus longipes, Risso, which is also found on
British coasts, and which is figured and described by Bell
in the ‘ British Stalk-eyed Crustacea,’ p. 361, is now called
Bathynectes longipes.

Family 4.—Podophthalmide.

The carapace is widest anteriorly, with the ‘front’
very narrow, spatuliform, and inflexed. The orbits are
extremely large, and the eye-stalks greatly elongated, occu-
pying nearly the whole width of the carapace.

Podophthalmus, Lamarck, 1801, contains but one
recent species, the widely distributed Indo-Pacific Podoph-
thalmus vigil, Fabricius. The long eye-stalks almost
meet at their bases, and consequently the ‘front’ is there
almost linear, but it is prolonged for a short distance below
and transversely dilated, so that, if straightened out, it
might be compared to a battledore, or a broad-bladed
knife, a spatula, whence the expression spatuliform has
been applied to it. The great breadth of the short cara-
pace, the very large denticulate chelipeds, and the unusual
though not unparalleled length of the eye-staiks, make
this a conspicuous and attractive species. According to
Miers (1886) the only other genus that can claim a place
in this family is Huphijlax, Stimpson, 1860, the name of
which, meaning a good watchman, corresponds with the
family character.

Legion 2.—Cyclinea.

The carapace is more or less orbiculate.

Acanthocyclus, Milne-Edwards and Lucas, 1843, has
for its type species Acanthocyclus Gayi, which occurs com-
monly on the shores of Chili and Patagonia, and in the
Straits of Magellan. In this the eye-peduncles are short;
no longitudinal ridges are developed upon the endostome ;
the ‘front’ is rather narrow, with a prominent median
lobe; in the third maxillipeds the third joint is much longer
than the small fourth one; the pleon of the male is narrow

12 A HISTORY OF RECENT CRUSTACEA

and five-jointed. Mr. Miers says, ‘The nearest ally to
Acunthocyclus is, I think, Bellia {Milne-Edwards, 1860},
which resembles Acanthocyclus in the more or less orbicu-
late carapace, in the form of the front, chelipedes, and
ambulatory legs, but is distinguished by the narrower,
more elongated merus | fourth joint] of the exterior maxil
lipedes, by the broader post-abdomen [ pleon | of the male,
and the less distinctly defined buccal cavity.’

The legion Cyclinea, which cannot boast with certainty
of more than a single genus and single species, may
hope to have its ranks filled up in the course of time. At
present it does not make a very good show, even on
paper.

Legion 3.—Corystinea.

The second antennz have elongate flagella. The
third maxillipeds usually do not make a complete closure
of the mouth-cavity and are extended over the anterior
margin of its frame. ‘The sternal plastron is narrow. The
single family Corystidee does not require a separate defini-
tion. It does not appear to contain more than eight genera,
three of which are included in the fauna of Great Britain.
Corystes, Latreille, 1803, has a very distinguishing charac-
ter as compared with the forms previously discussed, in
that the carapace is not transverse, but much longer than
it 18 broad. Corystes cassivelaunus (Pennant) has fre-
quently attracted attention by the amusing resemblance of
the carapace to a human countenance, which Herbst com-
pares to the broad-nosed Kalmuck type. It is in Great

Britain a conveiient species for study, from the number of

dead specimens that are often cast up on sandy shores.
The sexes are easily distinguished. In the male the cheli-
peds are enormously elongated, and the pleon is very
small and has only five joints, although it is quite plain
that the central one of the five is in reality a compound of
three that have coalesced. In the female the pleon, though
small, is broader than in the male, and has the seven joints
distinct ; the openings of the vulvee can without difficulty
be observed on the plastron between the third pair of legs ;

_ ond

ARTISTIC TOUCHES 73

the chelipeds are of no unusual length. The very long
external antenne are a special feature of this crab. When

= Et
5 fh conn \ ey Tp 4
“yes “cama? f

Fic. 3.—Corystes cassivelaunus (Pennant), a female specimen, with the features on the
carapace slightly accentuated. [Herbst.]

the animal is burrowing in the sand according to its wont,
the flagella of these antennze are brought close together,
and the tips alone project from the funnel of the burrow.
They are provided with stiff hairs on the inner margin,
which no doubt assist in maintaining the funnel-opening
of a due width. The joints of the peduncle can be strongly
bent, and by this means, as Mr. Couch observed, the hairy

fringes of the flagella can be made to brush one another
T

74 A HISTORY OF RECENT CRUSTACEA

down and clear away any clinging particles of sand. Mr.
David Robertson had a female of this species alive in his
possession for seven months, and, so far as his observation
went, it would le buried for weeks without seeking to
change, the antennz clasping into each other to form the
tube necessary for its breathing, by giving access to the
water above. Through this tube he was also fortunate
enough to see the ova sent up, and he infers that the
animal at the proper time places them within the influence
of the current which its breathing apparatus must con-
stantly maintain. He notices that the pleon by its small
size 1s less fitted to cover the ova than is generally the
case among the Brachyura, but that this is compensated
and accounted for by the burrowing habit.

In a very young specimen, scarcely three tenths of an
inch long, the ‘front’ quite differs from what is seen in
the adult, being produced into a conspicuous rostrum as in
the genus Galathea, and the telson, instead of being
rounded, is broadly emarginate. As two genera, Nautilo-
corystes and Pseudocorystes, were so named by Milne-
Edwards in 1837, to indicate their great resemblance to
the earlier genus Corystes, it may be interesting to point
out some of the differences by which the three are dis-
tinguished, and which in the early days of classification
would probably have passed unnoticed.

Corystes.—The third maxillipeds have the fourth joint
longer than the third, with the fifth joint inserted
in a deep notch of its inner margin considerably
below the apex. In the fifth pair of legs the
seventh joint is narrow.

Nautilocorystes.—The third maxiliipeds have the fourth
joint a little shorter than the third, with the fifth
joint attached at its apex. In the fifth pair of
legs the seventh joint is widened.

Pseudvocorystes.—The third maxillipeds have the fourth
joint much shorter than the third, small, triangu-
lar, with the fifth joint attached near the apex.
In the fifth pair of legs the seventh joint is
widened.

THE GENDERS OF GENERA 75

The species Pseudocorystes armatus, Milne-Edwards,
was found at Valparaiso, and Milne-Edwards supposes that
it may be the same as the ‘ Grass Crab,’ figured by Browne
in his ‘ History of Jamaica,’ pl. 48, fig. 2.

Atelecyclus, Leach, 1813, is a member of the family in
which the third maxillipeds, contrary to the family custom,
do make a complete closure of the mouth-cavity. The
type species, Atelecyclus septemdentatus (Montagu), was
first observed on the south coast of Devon. Its carapace
is nearly circular. Leach says that to the fishermen it 1s
well known by the name of old man’s face crab. The
antero-lateral margin on each side is furnished with nine
teeth, and probably for this reason Leach thought himself
justified in changing the name to heterddon, in which he
has been followed by Bell. Montagu perhaps did not

‘think that the point at each extremity of the series ought
to be counted in, and at any rate no one can be injured by
the retention of the name which it was his privilege as
the discoverer of the species to choose.

Thia, Leach, 1815, is represented both in the Mediter-
ranean and in British waters, probably by one and the
same species, called Thia polita by Leach in 1815, in allu-
sion to the polished surface of the carapace, but as there is
no substantial reason for thinking it distinct from the
species described and figured by Herbst as Cancer residuus
in 1799, its name ought to be Thia residwus (Herbst),
although some may prefer to call it Thia residua, not re-
flecting that the animals are both male and female, and
ignoring the old rule of Latin grammar that the mascu-
line gender is to be preferred to the feminine. In this
species, which like Corystes is a sand-burrower, the pleon
is very narrow in both sexes, and, though in the male it is
only five-jointed, the transverse grooves of the composite
joint are so strongly marked, that all the seven joints
might at first glance be thought to be distinct, as they are
in the female.

To conclude the discussion of the names used in this
family, it may be mentioned, first, that although de Haan
rightly claims priority for Dicéra which he established

76 A HISTORY OF RECENT CRUSTACEA

in 1833 over Nautilocorystes instituted by Milne-Edwards
in 1837, yet Dicéra must give way, having been already
earlier used in other classes of zoology ; and secondly, that.
Oéidia, de Haan, 1833, a name meaning egg-like, must
likewise be cancelled, having been found to be a synonym
of Gomeza, Gray, 1851, a Corystid genus of the Japanese
fauna.

Legion 4.—Thelphusinea.

The carapace is more or less dilated at tke branchial
regions; the third maxillipeds have the fifth joint articu-
lated at or near the front inner angle of the fourth or at
its apex. The fingers of the walking legs are usually
spinuliferous; the verges of the male pass directly
through the basal joint of the fifth pair.

The species are fluviatile or live in damp forests.

Family Thelphuside.

This being the only family has the characters of the
legion. Yhelphusa, Latreille, 1819, contains numerous
species, of which Mr. Miers observes that ‘ one, the com-
mon Thelphusa fluviatilis, occurs not only on the shores of
the Mediterranean, but also in Asia Minor, Syria, and
Persia; the others are found in all the warmer temperate
and tropical regions of the old world, extending southward
to the Cape of Good Hope, Madagascar, and Australia, but
not to New Zealand ; a species (Thelphusa chilensis) occurs in
Chili” Potamonautes, Macleay, and Geothelphusa, Stimpson,
are so Closely related to Thelphusa that their separation
from it remains a matter of doubtful expedience.

Krauss remarks that the Thelphuside are especially
fond of clear running streams in which they shelter them-
selves under stones and plants. They are easily scared,
and in spite of their monstrous chelipeds their long pe-
reopods carry them off at a great pace. The pearly
Thelphusa (Vhelphusa perlata, Milne-Edwards) has an
earthy greenish colour, which matches its surroundings
in the rivulets, whereas Vhelphusa depressa, a species

RIVER CRABS far

which Krauss found at a waterfall in Natal, is yellowish
and orange-coloured, in accordance with the cushions of
moss among which it has its residence. Thelphusa
dehaaniit, White, occurs in the paddy fields of Japan, and
has been taken at an elevation of 2,500 feet above the sea-
level. It has been already mentioned that the river crab
of Europe is good eating. Muilne-Edwards supposes that
it was to this crustacean that Aristotle referred under the
name Carcinus Heracleoticus.

Paratelphusa, Milne-Edwards, 1855, was at first sup-
posed to be a marine genus, but has since been proved to
be an Indo-Malayan genus of fresh-water crabs, several
species of which have been described by Mr. Wood-Mason.
They differ from the rest of the Thelphusidae in having the
distal end of the fourth joint of the chelipeds armed with
a sharp spine, and are also said to have a greater general
resemblance to some of the Cancride.

Dr. de Man, in his elaborate Report on the Podoph-
thalmous Crustacea of the Mergui Archipelago (‘ Journ.
Linn. Soe.’ 1887, 1888), includes the genus Thelphusa in
the next tribe, and the same arrangement is followed by
Dr. Camil Heller in his ‘ Crustacea of the Novara, 1865,
the Thelphusinea being in fact intermediate in structure
between the Cancridz and the Gecarcinide.

78 A HISTORY OF RECENT CRUSTACEA

CHAPTER VII
TRIBE II1.—CATOMETOPA

Tue ‘front’ is bent downward. The carapace is broad
anteriorly, often subquadrate, sometimes subglobose, trun-
cate or arcuate forwards, but not rostrate. The epistome
is short, often almost linear. The pairs of branchiz are
usually fewer than nine in number; the efferent channels
open at the sides of the endostome. The third maxilli-
peds have the fifth joint articulated at the front outer
angle of the fourth, or less frequently at its apex, or very
rarely at the front inner angle. The male verges are
inserted either in the sternal plastron, or in the basal
joints of the last pair of legs, thence passing through
channels in the sternum beneath the pleon.

The tribe contains four families, the Gecarcinide,
Ocypodidae, Grapside, and Pinnotheridee. The liver is
said by Milne-Edwards to be in general central, extend-
ing little or not at all over the branchial cavities.

Family 1.—Gecareinide.

The carapace is dorsally very convex, especially dilated
over and in front of the branchial regions, with the antero-
lateral margins usually entire and strongly arcuate. ‘The
‘front’ is of moderate width and strongly deflexed. The
orbits and eye-stalks are of moderate size. The third
maxillipeds have the fifth joint articulated at the front
outer or near the front inner angle or at the apex of the
fourth, which sometimes completely conceals it. The
chelipeds in the adult male are powerful, usually unequal.
The seventh joint in the walking legs is nearly always

LAND CRABS 79

granulated and armed with longitudinal rows of spines.
The pleon of the male usually covers the whole space
between the bases of the last pair of walking legs.

These land-crabs are called Towlowroux by the French.
They inhabit the warm territories of both hemispheres.
The third maxillipeds suffice without other details to dis-
criminate the genera.

Uca, Leach, 1817. The third maxillipeds have the
fifth joint attached at the outer angle of the fourth;
the inner edges of the third and fourth joints are
in one line; along their outer edges the exopod is
externally visible, and has a flagellum.

Gecarcinucus, Milne-Edwards, 1842. The third maxilli-
peds have the fifth joint attached to the middle of
the apical margin of the fourth ; the inner edges of
the third and fourth joints are in one line; the
exopod as in Uca.

Cardisbma, Latreille, 1825. The third maxillipeds
have the fifth joint attached at the outer angle of
the fourth ; the inner edges of the third and fourth
joints form a re-entering angle ; the exopod as in
Uca.

Gecarcoidea, Milne-Edwards, 1857. The third maxil-
lipeds have the fifth joint inserted in a deep groove
of the apex of the fourth; the inner edges of the
third and fourth form a re-entering angle; the
exopod is without flagellum and concealed beneath
the third joint.

Gecarcinus, Leach, 1815. The third maxillipeds have
the fifth joint attached on the inner margin of the
fourth and completely concealed by it; the inner
edges of the third and fourth joints form a re-
entering angle; the exopod as in Gecarecoidea.

Hylceocarcinus, Wood-Mason, 1874. The third max-

~ illipeds have the fifth joint attached to the middle
of the apex of the fourth ; the inner edges of the
third and fourth form a re-entering angle; the
exopod as in Gecarcoidea.

80 A HISTORY OF RECENT CRUSTACEA

In the last four genera it will be perceived that the
maxillipeds do not form a complete operculum, but by the
arrangement of the inner edges of their third and fourth
joints they leave a lozenge-shaped space over the mouth-
opening uncovered, while in Uca and Gecarcinucus the
straight inner edges from either side can be brought exactly
together so as to close the cavity completely. Mr. Wood-
Mason points out that the character of the exopod distin-
guishes Gecarcinus, Gecarcoudea (which he calls Pelocar-
cinus), and Hylceocarcinus from the three preceding genera,
and that they are distinguished from one another by a
further character of the maxillipeds, for in- Gecarcinus the
three terminal joints are completely hidden, in Hylcocar-
cinus they are partially visible, and in Gecarcoidea com-
pletely so.

None of the Crustacea have more attracted the atten-
tion and excited the wonder of travellers than some of
those belonging to this group. Like the twin snakes that
came over the sea and deliberately landed at Troy to slay
Laocoon and his two sons, these crabs have, contrary to
nature, forsaken the ample waters of the ocean, scorned _
all the brooks and rivers and lakes, and carried out a
portentous invasion of the dry land. Still they are by no
means indifferent to moisture. The vaulted part of the
carapace over the branchial regions is lined with a very
spongy membrane, and sometimes a fold of the membrane
along the lower edge of the cavity forms a kind of tube in
which water may be held as in a reservoir. But their
form and structure are not so surprising as their manners
and customs. :

Under the heading Cancer ruricola, a species of Gecuwr=
cinus, Herbst brings together many curious particulars,
depending largely upon Patrick Browne’s ‘History of
Jamaica. In the Bahamas, he says, and in tropical
regions these land-crabs are so numerous that when they
creep out of their holes the ground seems to be in motion.
One litile island is so full of them that it has been called
Crab Island. They are just as frequent in certain districts
of Jamaica and in some of the Caribbee islands. The same

REMARKABLE BEHAVIOUR 81

was the case at St. Croix, but since the cutting down of
the forests and destruction of thousands of the crabs, their
number has diminished. They generally take up their
abode on the hills, not less than one mile nor more than
three miles from the coast. It is in the morning and
evening that they are to be found in greatest numbers
under the trees. Go away then without a stick in hand,
and they will approach with uplifted claws as if threatening
an assault. But if they are themselves assailed with a
stick or a switch, they retreat, yet still facing the foe, and
ever and anon clashing their claws together to strike terror
into him. Thus they withdraw to their holes in the rock
or the rotten tree or deep burrows in the ground. They are
capital eating, and are one of the principal food resources of
the natives, who improve the flavour by fattening them up
for three or four days in a potato field. But a warning is
given that they do not always suit the stomach of Kuro-
peans, since they are apt to produce cold hypochondriae
humours, whereby some explain the slow melancholy nature
of the Caribbee islanders. When seized bya leg or a claw
these crabs relinquish it so readily as to produce the im-
pression that their limbs are only stuck on. The lost
appendage would be renewed at the next change of skin,
but it often happens that the sacrifice which has saved the
crab from its human foes exposes it as a defenceless victim
to those of its own race.

The pairing season is said to be in March and April.
In May, the rainy period, they march in great hosts towards
the sea, to bathe and lay their eggs in it. ‘Then all roads
and brooks are filled with them, and it is indeed a very
wonderful instinct, which the Creator has given them, to go
direct to that part of the island where there are stretches of
sand and slopes from which they can most easily arrive at
the sea. Nothing can hinder them from going the straight
road towards the sea, for they go over everything that
comes in their way, be it hedges, houses, churches, hills or
cliffs, straight over everything they go, and rather clamber
up at the peril of their lives, than make a circuit. In the
night, for example, they will creep in at a window, and

82 A HISTORY OF RECENT CRUSTACEA

come on to the beds, causing the unwary occupants no
small alarm by their clatter. If one has the misfortune to
tumble down and damage its limbs, it is immediately
eaten up by the rest. It must be a wonderful sight, to
see them come down the hills. Everywhere they issue
from hollow trees, rotten stems, from under the rocks, and
out of innumerable holes. The fields are so covered with
them, that unless they are chivied away, there is no setting
foot to ground without treading upon them. What with
the infinite variety of their markings, their brilliant
colours, taeir sideways gait, their celerity, I know of
scarcely any sight comparable with this one. Unless the
description of their march has been embellished by the
force of imagination, the journey is conducted with as
much order as if they had a very experienced commander.’
The vanguard, consisting of none but males, starts some
days in advance. Then follows the main army, composed
chiefly of females, their battalions often covering a space
of a mile and a half long by forty or fifty paces broad, and
covering it so closely as almost to hide the ground. Some
days after, the rear-guard, containing both males and
females, closes the vast procession.

Sometimes all the divisions are brought to a halt several
days by the want of rain, a want which makes prolonged
land-travel impossible to a crustacean. But when Herbst
says that these hosts follow the line of the rivers and water-
courses, the statement, though highly probable in itself, is
scarcely consistent with the miraculous bee-line which he
had previously described. If anyone approaches the army
and puts it into alarm, these martial crabs draw back facing
him, with their claws uplifted and open to be constantly
ready for defence. The nip of one of them, it is said, can
tear out a piece of flesh, and the claw, even after it has been
throwr. off by its owner, will continue for a minute to
pinch with incredible force. The noise of their march is
compared to the rattling of the armour of a regiment of
Cuirassiers. Having arrived on the coast, they bathe once
in the sea, and then creep into some shelter to rest. The
females enter the sea a second time and there deposit their

SEASIDE LODGINGS 83

egos. These are cast up by the waves upon the sand, and
in due course out creep the young crabs, which then cling
to the rocks in thousands, but presently quit the water for
any suitable places of protection on land, there acquiring
strength to follow their mothers up the country.

Patrick Browne says: ‘ The eggs are discharged from the
body through two small round holes situated at the sides,
and about the middle of the under shell; these are only
large enough to admit one at a time, and, as they pass, they
are entangled in the branched capillaments, with which the
outer side of the apron is copiously supplied, to which they
stick by means of their proper gluten, until the creatures
reach the surf, where they wash ’em all off, and then they
begin to return back again to the mountains. It is re-
markable that the bag or stomach of this creature changes
its Juices with the state of the body; and, while poor, is
full of a black, bitter, disagreeable fluid, which diminishes
as it fattens, and, at length, acquires a delicate rich
flavour. About the month of July or August the crabs
fatten again, and prepare for mouldering, filling up their
burrow with dry grass, leaves, and abundance of other
materials ; when the proper period comes, each retires to
his hole, shuts up the passage, and remains quite inactive,
until he gets rid of his old shell, and is fully provided with
anew one. How long they continue im this state is un-
certain, but the shell is first observed to burst both at the
back and sides, to give a passage to the body, and it ex-
tracts its limbs from all the other parts gradually after-
ward. At this time the fish is in the richest state, and
covered only by a tender membranous skin variegated with
a multitude of reddish veins, but this hardens gradually
after, and becomes soon a perfect shell like the former ; it
is, however, remarkable that during this change there are
some stony concretions always found in the bag, which
waste and dissolve gradually, as the creature forms and
perfects its new crust. A wonderful mechanism!’ A
footnote remarks that the concretions, which are the well-
known gastroliths or crab’s eyes, ‘are seldom under two or
more than four.’

84, A HISTORY OF RECENT CRUSTACEA

Since it is during this period of ‘ mouldering ’ that the
crabs are fattest and best flavoured, Herbst finds it easy
to suppose that greedy man will not leave them safe in
their repose. On the contrary, he busily digs them out
with a spade. Considering how readily under some cir-
cumstances these crustaceans shed their limbs, it is singu-
lar that in exuviation they are able to cast off their whole
caparison so uninjured and complete that it might be mis-
taken for the livinganimal. Careful inspection is required
to perceive near the insertions of the limbs the ventral slit
through which the animal has made its escape.

It was in a West Indian species of Gecarcinus that
Professor Westwood observed that the young issued from
the egg in a form not materially different from that of
their parents. This experience, combined with Rathke’s
similar observation in regard to the European crayfish,
led him at first to throw doubt upon Vaughan ‘hompson’s
theory of crustacean metamorphoses. But it was soon
brought to light that the examples of the land-crab and
the freshwater crayfish were interesting exceptions to a
still more interesting rule, and there are few who would
now deny that these exceptions are to be explained as
modifications in the life-history of the animals concerned,
acquired late in the course of time to suit the new condi-
tions of existence encountered by creatures emerging from
the sea to a life in fresh water or on dry ground. That no
crustaceans have been able to cut themselves loose from
some dependence upon moisture is not very wonderful,
since in that respect man himself is still an aquatic
animal.

Gecarcinus lagostoma, Milne-Edwards, represented on
Plate II, is a widely distributed species.

Hylcocarcinus Humei, Wood-Mason, occurs in ‘the
dark dense damp forests of the Nicobar Islands.’

Uca una (Linn.), the crab of the mangrove swamps of
Brazil, may be mentioned as a rare instance of one that
has been allowed to possess the names by which it was
figured and described centuries ago. In this genus the
last joints of the walking legs are compressed and un-.

WAZZ
“E

Ses ye
ee a 5
2; Platyonichus a

iridescens

RACERS 85

armed. M. Jobert, in examining the breathing apparatus
of land-crabs, has found that of Uca una to be the most
complete. There is a regular movement of inspiration
and exspiration to keep the air from stagnating in the
breathing chamber, and between the third and fourth and
the fourth and fifth limbs there are small supplemental
inspiratory orifices coated externally with long hairs (see
Sp. Bate, ‘ Brit. Assoc. Report,’ 1880).

Family 2.—Ocypodide.

The carapace is in general moderately convex, cancroid
or trapezoidal, with the antero-lateral margins straight or
arcuate, the branchial regions not greatly dilated. The
‘front’ is of moderate width or very narrow. ‘The orbits
and eye-stalks are of moderate size or greatly developed.
The third maxillipeds have the fifth joint articulated at
the front inner or rarely at the front outer angle. The
chelipeds in the adult males are in general of moderate
size, sometimes slender and elongate. ‘The seventh joint
in the walking legs is stiliform, without strong spines.
The pleon does not always cover the whole width of the
sternum between the last pair of legs.

The species are generally small, littoral, or inhabitants
of shallow water, but are not unknown from considerable
depths. There are nearly forty genera assigned to the
various subdivisions of this family.

Ocypodé, Fabricius, 1798, has the orbits very large
and open, extending all along the anterior margin on either
side of the narrow and deflexed ‘front.’ The eye-stalks
are large, with a short basal joint, the terminal part often
prolonged distally as a spine or tubercle, the large cornee
covering much of the lower surface of this terminal joint.
The chelipeds in the adult male are unequal and well de-
veloped, and usually the palm has a vertical series of short
raised lines or tubercles on the inner surface, which form
a stridulating ridge.

As the name swift-of-foot implies, these Crustacea are
especially noted for their rapidity of movement. They are
just the opposite of some of the strong-armed, thick-

86 A HISTORY OF RECENT CRUSTACEA

shelled, slow-moving Cancride. On wind-swept stretches
of sandy beach, and coloured like the sand, they some-
times seem rather to be borne on the wings of the wind
than to run. Also with their compressed lancet-like
fingers they are extremely dexterous in digging into the
sand. They burrow holes an ell deep, generally perpen-
dicular, and from these they wander far, when the tide is
out, in search of food. Krauss observed in South Africa
the species Ocypode ceratophthalmus (Pallas), and others.
and he says that while they are busy hunting, every now
and then they look carefully round, raising their stalked-
eyes upright, and standing on tiptoe. At the slightest
movement towards them they run with uncommon rapidity
to the nearest hole, or, if the danger is too close, press
themselves flat on the sand, till an attempt is made to
seize them, and then off they dart. In running they carry
their bodies high, doubling and dodging with such speed
and cunning that it is a difficult matter to lay hold of
them. When the tide comes up, they are enclosed in
their flooded burrows, and as soon as the waves retreat,
they are busily employed in clearing them, shovelling out
the wet sand and heaping it at some little distance off.
The American species, Ocypode arenaria (Catesby), 1s de-
scribed by Professor 8. I. Smith as having precisely similar
habits. According to his observation it lives largely upon
the Amphipods of the genus Yalorchestia, known as
‘beach-fleas,’ which inhabit the same localities. ‘It will
lie in wait,’ he says, ‘and suddenly spring upon them, very
much as a cat catches mice. It also feeds upon dead fishes
and other animals that are thrown on the shore by the
waves.’

It is of this species, under the synonym of Ocypoda
rhombea, Fabricius, that Fritz Miiller speaks in his memor-
able work ‘For Darwin.’ ‘In the swift-footed Sand-crabs
(Ocypoda),’ he says, ‘ —which are exclusively land animals,
that can scarcely live in water for a single day, and which
in far less time than that are reduced to a state of com-
plete collapse in which all voluntary movements cease—
there has long been known a peculiar arrangement con-

CROSS-EXAMINING A CRAB 87

nected with the third and fourth pairs of legs, but that
these had anything to do with the branchial cavity was
not suspected. ‘These two pairs are pressed more closely
together than the rest. The opposed surfaces of their
basal joints, that is, the hinder surface in the third, and
the front surface in the fourth pair, are flat and smooth,
and their margins are clos:ly fringed with long, sheeny,
peculiarly formed hairs. Milne-Edwards, who compares
them to articular surfaces, as their appearance warrants,
thinks that they serve to diminish the friction between
the two legs. On this supposition the question arises why
precisely in these crabs and only between these two pairs
of legs such a provision for diminishing friction is neces-
sary, not to mention that it leaves unexplained the singular
hairs, which must augment instead of diminishing friction.
While, then, I was bending to and fro in ever so many
directions the legs of a large Sand-crab, in order to see
in what movements of the animal friction occurred at the
place in question, and whether perhaps these were move-
ments often recurring and of special importance to it, 1
observed, when I had stretched the legs far apart, a round
opening of considerable size between their bases, through
which air could easily be blown into the branchial cavity
or even a slender probe be introduced. The aperture
opens into the branchial cavity behind a conical tubercle,
which stands above the third foot at the place of a bran-
chia which is wanting in Ocypoda. It is laterally bounded
by ridges which rise above the articulation of the legs and
to which the lower edge of the carapace is applied. Also
outwardly it is overarched by these ridges with the ex-
ception of a narrow slit. Over this slit extends the cara-
pace, which just at this point projects farther downwards
than elsewhere, and so a complete tube is formed. While
Grapsus always admits water to its branchize only from in
front, in Ocypoda I saw it also streaming in through the
just described aperture.’

For its details about one particular crustacean such a
passage is interesting, but it is far more important as a
lesson in scientific observation. ‘There are numbers of

8

88 A HISTORY OF RECENT CRUSTACEA

persons who might be familiar with the smooth flat sur-
faces opposed to one another in the legs of a crab, and
who yet would never make the guess that it was an
arrangement to diminish friction. With the guess made
for them by some one else they would be contented for
another lifetime, and so on perhaps with the objection to
the guess that if friction was to be avoided, the legs would
not have been fringed with hairs. Fritz Miiller was well
aware of the old principle that Nature makes nothing in
vain, and was pretty confident to begin with that there
would not at the same point be two arrangements counter-
acting one another, the one increasing and the other
diminishing friction. The smooth surfaces of the limbs
enable them to act as tight-closing lips to the breathing-
aperture which he discovered at their bases. As to the
fringing hairs Fritz Miiller hazards the conjecture that
they may be olfactory. This might seem a very extra-
vagant supposition, that a crab should have the equiva-
lent of a nose attached to its legs, did we not remember
that some crustaceans have organs of hearing in the appen-
dages of the tail. Moreover, Fritz Miiller observed that
in his Ocypode the olfactory filaments in their usual place
on the antennze were much reduced, and that the flagella
of the antenne never make the peculiar beating move-
ments familiar in other crabs, and he argues that in an
air-breathing crab, just as in the air-breathing vertebrates,
the sense of smell might be expected to have its organ at
the entrance of the breathing cavity.

Gelasimus, Latreille, 1818, meaning the laughable crab,
is a genus containing a large number of species that haunt
warm climates. Here, too, the orbits and eye-stalks are
long. The pleon in the male is narrow and distinctly
seven-jointed, and its base does not occupy the whole
width of the sternum between the walking legs. But the
most striking feature is the disproportionate size which in
the male is attained by either the right or the left
cheliped.

According to de Haan his species Gelasimus arcuatus
is called in Japanese Stho maneki, which means ‘ beckon-

THE CALLING CRAB 89

ing for the return of the tide,’ because, when the creature
is left on the dry shore, by the movement of its claws it
seems to be appealing to the waves to come back again.
The specific title of Gelasimus vocans (Linn.), and the trivial

Fig. 4,—Gelasimus arcuatus, de Haan, a male specimen, and pleon of the male detached.
[De Haan.]

name, the calling crab, refer to the like action. Of the
customs of an American species the following account is
given by Professors Verrill and 8. I. Smith :—

‘On sandy beaches near high-water mark, especially
where the sand is rather compact and somewhat sheltered,
one of the “ fiddler-crabs,” Gelasimus pugilator [ Latreille ],

90 A HISTORY OF RECENT CRUSTACEA

is frequently found in great numbers, either running
actively about over the sand, or peering cautiously from
their holes, which are often thickly scattered over con-
siderable areas. These holes are mostly from half an inch
to an inch in diameter, and a foot or more in depth, the
upper part nearly perpendicular, becoming horizontal
below, with a chamber at the end. Mr. Smith, by lying
perfectly still for some time on the sand, succeeded in
witnessing their mode of digging. In doing this they dug up
pellets of moist sand, which they carry under the three
anterior ambulatory legs that are on the rear side, climb-
ing out of their burrows by means of the legs of the side
in front, aided by the posterior leg of the other side.
After arriving at the mouth of their burrows and taking
a cautious survey of the landscape, they run quickly to
the distance often of four or five feet from the burrow
before dropping their load, using the same legs as before
and carrying the dirt in the same manner. They then
take another careful survey of the surroundings, run nimbly
back to the hole, and after again turning their pedunculated
eyes in every direction, suddenly disappear, soon to reappear
with another load. They work in this way both in the
night and in the brightest sunshine, whenever the tide is
out and the weather is suitable. In coming out or going
into their burrows either side may go in advance, but the
male more commonly comes out with the large claw for-
ward. According to Mr. Smith’s observations this species
is a vegetarian, feeding upon the minute algze which grow
upon the moist sand. In feeding, the males use only the
small claw with which they pick up the bits of algee very
daintily ; the females use indifferently either of their small
claws for this purpose. They always swallow more or less
sand with their food. Mr. Smith also saw these crabs
engaged in scraping up the surface of the sand where
covered with their favourite alge, which they formed into
pellets and carried into their holes, in the same way that
they bring sand out, doubtless stowing it until needed for
food, for he often found large quantities stored in the
terminal chamber.’

ARCHITECTURAL EFFORT 9]

An earlier observer, Bose, who studied this same
Species in Carolina, declares that these crabs were to be
seen in thousands and even in millions on the margin of
the sea or of tidal rivers. He remarks that, if a man or
any animal comes among them, they lift up the large claw,
and holding it forward, as if challenging their opponent to
fight, in that attitude they scurry off sideways. They
have, he says, a great number of enemies among the otters,
bears, birds, turtles, alligators, and the like, but they are
so prolific that the devastation made among them by these
foes is imperceptible. He occasionally saw the ‘calling
crabs’ swarming over a carcase on the shore and disputing
with the vultures for strips of the carrion. He was very
anxious to see them make their burrows, but they never
would work in his presence, doubtless not from shyness,

' but from some prudential motive. Gelasimus minaa,

Leconte, the largest of the American ‘ fiddler-crabs,’ lives
in salt marshes or fresh water. Over the mouth of its
burrow Mr. T. M. Prudden ascertained that this crab often
constructs a regular ovenlike arch of mud, and that it sits
in this doorway on the look out for whatever may befall.
Professor Smith kept a large male of this species in a
glass jar containing nothing but a little siliceous sand,
moistened with pure fresh water, for over six months. It was
for ever pacing round the jar and trying to climb out, was
never observed to rest or show fatigue, ‘and after months
of confinement and starvation was just as pugnacious as
ever.

The species Gelasimus arcuatus, de Haan, already
mentioned, was observed by Krauss in South Africa as
occupying muddy ground, and having a bluish-grey colour
suitable to its residence. The appropriateness of the
generic name will be appreciated in the light of his in-
cidental remark that ‘it is truly comical to see these crabs
with uplifted arms in countless numbers scampering over
the dark mud.’

Gonoplax (originally spelt Goneplat and Goneplaz),
Leach, 1814, is a North-Atlantic and European genus,
which till lately contained only one species, Gonoplaa

92 A HISTORY OF RECENT CRUSTACEA

rhomboides (Linn.), called in Bell’s ‘History of the
British Crustacea’ Gonoplax angulata (Fabricius), the
angular crab, the specific name obviously, and the generic
name probably, alluding to the angular character of the
carapace. A second species, closely resembling the first,
and named Gonoplax sinuatifrons, Miers, was obtained by
the Challenger at Amboina. The elongated orbits and
eye-stalks cannot fail to attract attention, and the latter
especially when they are suddenly erected from a position
of rest within the former. The male has the chelipeds of
a remarkable length, and these, at least when in confine-
ment, he is fond of clashing together in a noisy and
perhaps threatening manner. The joints of these limbs
are so proportioned that while they are able to seize food
at a great distance, they can also convey it to the mouth.
The pleon is seven-jointed in both sexes.

Ommatocarcinus, White, 1852, is distinguished from
its near neighbour Gonopluw by a still narrower ‘front,’ a
great development of the antero-lateral spine on each side
of the carapace, and still more elongate eye-stalks, to
which reference is made in the generic name, meaning
‘the crab with the eyes.’ There is but one species, Omma-
tocarcinus Macgillivrayi, White. This is found in Austra-
lian and New Zealand waters.

Macrophthalmus, Latreille, 1829, with a name mean-
ing ‘long-eye,’ surpasses the two preceding genera in the
length of the orbits, and the eye-stalks are exorbitant in
the literal sense in certain species, in which they are pro-
longed laterally beyond the orbit’s outer angle. The
species are numerous, occurring ‘in the littoral or shallow
waters of all parts of the Indo-Pacific region.’ In some of
the species, as also in the genera Helice, de Haan, 1835,
and Metaplaw, Milne-Edwards, 1852, the males have on
the arms of the chelipeds a short horny ridge, which Dr.
de Man calls ‘the musical crest,’ on the supposition that
the crab produces musical sounds by rubbing this crest
against a row of granules below the orbit. Naturally’
this crab-music must only be judged by a crustacean
standard.

THE GRAPSIDZE 93

A certain amount of uniformity, especially as regards
the flatness of the carapace, may be inferred to exist in
this family from the number of genera with names all alike
ending in -plawz, as Acanthoplax, [yoplax, Hemiplax, Camp-
toplax, Bathyplax, with many others.

The genus Gerion, Kroyer, 1837, may claim a passing
notice as one of those instances in which systematic
arrangement finds itself at fault. It is sometimes placed
among the Cyclometopa and sometimes among the Cato-
metopa. Mr. Miers says that it is very nearly allied to
— Pseudorhombila and Pilumnoplax in the latter, and to
Galene in the former group. ‘That, on the theory of the
evolution of different groups from a common stem, such
inosculant forms are almost sure to occur, has long been
recognised. Darwin himself humorously admits that while
as a theorist he delighted in coming across them, as a
naturalist engaged in classification he found them an un-
mitigated nuisance.

Family 3.—Grapside.

The carapace is depressed or moderately convex, more
or less quadrilateral, with the lateral margins straight or
slightly arcuate. The ‘front’ is never very narrow, in
general decidedly broad. ‘The orbits and eye-stalks are
of moderate size. The third maxillipeds have the fifth |
joint articulated at the apex or the front outer angle of
the fourth. The chelipeds in the aduit male are usually
subequal, moderately developed. In the walking legs the
seventh joint is stiliform, compressed, and either smooth
or spiniferous. The pleon at the base usually covers the
whole width of the sternum between the last pair of legs.

The species are almost always littoral or shallow-water
forms, with a rare exception in deep water.

In this family there are about twenty-four genera.

Grapsus, Lamarck, 1801, is a wide-ranging genus
which was brought to the notice of Kuropeans a century
and a half ago in the species Grapsus maculatus (Catesby,

1743 and 1771), to which Bose in 1802 applied the better

94, A HISTORY OF RECENT CRUSTACEA

known name of Grapsus pictus. Professor Th. Barrois, in
his account of the Crustacea of the Azores, speaks of this
and two companion species aS running with astonishing
velocity among the rocks near the sea. The brilliantly
coloured Grapsus, with its limbs of a marvellous red, he
calls a superb species. As it occupies by preference the
sides of the perpendicular cliffs, it is easy to believe the
statement that prodigies of agility and cunning are re-
quired for capturing uninjured specimens. In Charleston
Bay Bosc had a much easier task. There he noticed that
these crabs almost always kept themselves concealed under
stones or pieces of wood, and, as these objects are rare in that
locality, every day on the retreat of the tide he was sure
to find fresh specimens of Grapsus under the hiding-places
from which he had taken other specimens on the previous
day. Darwin, in ‘A Naturalist’s Voyage,’ when speaking
of the nests of the tern at St. Paul’s Rocks in the Atlantic,
says, ‘It was amusing to watch how quickly a large and
active crab (Grapsus), which inhabits the crevices of the
rock, stole the fish from the side of the nest, as soon as we
had disturbed the parent birds. Sir W. Symonds, one of
the few persons who have landed here, informs me that he
saw the crabs dragging even the young birds out of their
nests and devouring them.’ The voracity and audacity,
the cunning and speed and jumping powers of these crabs
of St. Paul’s Rocks are amusingly described in the ‘ Log
Letters of the Challenger,’ by Lord George Campbell, who
however, saw no proof that they ate the young birds.

About a dozen other genera have been formed with
names in which Grapsus is part of the compound, as
Geograpsus, Paragrapsus, Platygrupsus, and the like. Several
of these contain species which were at one time included
in the genus Grapsus, and which are by no means very
remote from it.

The Cancer marmoratus of Fabricius has been trans-
ferred from Grapsus to Pachygrapsus, Randall, by Stimpson,
and to Goniograpsus; Dana, by Miers. It is a European
species, common among chinks of the rocks in the Adriatic.
It prowls about on the shore by night to feed on dead

ON ee Ie - ee a
7 e,

uf il [i

ir japonicus, de Haan.

Erioche

THE GULF-WEED CRAB 95

animals cast up by the waves. It is said to be timid,
running off with great speed if scared, but if stopped it
shows temper and nips hard. It is also very common,
according to Lucas, in Algeria, where it is eaten by the
poor. Fine specimens for a naturalist’s collection are not
easy to catch because of their extreme readiness on the
least alarm to ensconce themselves deep in rifts of the
rock. If in their headlong haste they sometimes slip into
a hole too shallow to contain them entirely, the pursuer
will still be likely only to obtain their cast-off legs, since
they readily relinquish them all rather than be captured.

Nautilograpsus, Milne-Edwards, 1857, like some of the
genera previously described, has third maxillipeds which
do not form a complete operculum. In 1825, in Bowdich’s
‘Excursion to Madeira and Porto Santo,’ Leach gave to
this genus the name Planes, a wanderer, but from want of
a sufficient accompanying description this has been re-
garded as technically only a manuscript name, not entitled
to priority. It may, however, be doubted whether this is
a right decision, since a figure of the type species, Planes
minutus (Linn.), was appended, and there appears to be
but a single species in the genus. ‘The name of wanderer
is very appropriate, since this, the common Gulf-weed
Crab, is said to occur nearly everywhere on floating weed
in the temperate and tropical seas of the globe. If, as is
probable, it was the presence of this little crab on the
Sargassum bacciferum that Columbus adduced as an argu-
ment to prove to his despairing sailors the proximity of
land, it was not quite so much to the point as the sailors
appear to have thought it. Columbus himself had other
and more satisfactory reasons for his own confidence.
Patrick Browne calls it the Turtle-Crab, remarking, ‘I
found this insect on the back of a turtle, near the western
islands.’

Hriocheir, de Haan, 1835, meaning ‘ woolly-hand,’
contains a species, Mriocheir japonicus, of very singular
appearance, the great claws looking as if they were muffled
up in cuffs of long fur. It is represented in the accom-
panying plate, which is reduced from de Haan’s work.

96 A HISTORY OF RECENT CRUSTACEA

The detached figures show the chele of the young male
and the female, and the pleon respectively of male and
female. By the Japanese this species is called the moun-
tain savage or the hairy crab. It occupies brackish
waters, passing from them into fresh-water streams, by
means of which it ascends the mountains, where it is often
observed on dry land.

Varuna, Milne-Edwards, 1830, has the single species
Varuna litterata (Fabricius), common in the Indo-Pacific
region, and attracting attention by the marking on the
carapace to which the specific name refers. The capital
letter H is here considered to be formed with more than
usual distinctness by the longitudinal grooves that sepa-
rate the lateral from the median regions, and the trans-
verse groove which appears to form the upper boundary
of the cardiac region.

Sesarma, Say, 1818, includes a large number of species
found in the shallow waters of all the warm regions of the
globe. In this genus the ‘front’ is broad; the third
maxillipeds, when closed, still leave open a lozenge-shaped
space, and have the large fourth joint traversed by a ridge
from the front inner angle to the outer angle behind ; the
pterygostomian regions have a granular or reticulated sur-
face, which in general is divided into little squares of
extreme regularity.

Reference has been already made to Fritz Miiller’s in-
vestigation of the breathing arrangements in land-crabs.
He was anxious to put the theory of evolution to a test.
The resemblances which prevail among all crabs point, on
that theory, to their derivation from a common ancestral
form, but the differences which prevail in the numerous
genera of land-crabs point to a divergence that must have
begun long before they assumed terrestrial habits. That,
at least, is what Fritz Miiller assumes, and few evolution-
ists will be inclined to deny it. If, then, several different
forms of water-breathers at various times and places have
independently developed into air-breathers, it is unlikely
that the necessary changes will all be of the same pattern.
Jt is so unlikely that, had it proved to be the case, Fritz

DARWIN’S THEORY TESTED 97

Miiller was prepared to regard it as a very damaging blow
to the theory of evolution. The result was just the oppo-
site, as will be seen by a comparison of his observations on
several species and genera. Those on Ocypode have been
already quoted.

In the family Grapsidee he describes, under the name
Aratus Pisoni, the species which Milne-Hdwards calls
Sesarma Pisonii, a sweet little vivacious crab, which climbs
the mangrove-bushes and feeds upon their leaves. Its short
sharp claws are well fitted for climbing, but they prick like
pins when the creature runs over a bare hand. Once,
when he had one of these seated on his hand, Fritz Miiller
noticed that it raised up the hinder part of its carapace,
and that by this means a wide slit was opened upon each side
_ over the last pair of feet, affording a view into the bran-
chial cavity. When studying this phenomenon in another
species, which he took to be a true Grapsus, he observed
that with the formation of the slit behind, the anterior part
of the carapace seems to sink so as partly or entirely to
close the anterior afferent opening. As the lifting of the
carapace never takes place under water, he infers that the
animal opens its branchial cavity in front or behind accord-
ing as it requires to breathe water or air. He had noticed
the elevation of the carapace, also, in species of Sesarma
and Cyclograpsus, which burrow deep in swampy ground,
and often scamper about on the wet mud, or sit watch-
fully before their burrows. But to observe the action in
these is a work of patience, since they can continue to
breathe water long after they have quitted the source of
supply.

That reticulation of the shell between the afferent and
efferent branchial orifices, which has been mentioned in
the character of the genus Sesarma, has a special purpose.
The squared meshes of network are due partly to fine
tuberculation and partly to curious geniculate hairs form-
ing over the surface a sort of fine hair-sieve. When the
water issues from the branchial cavity it spreads through
this network, and can take up fresh oxygen, whereupon
the appendages ot the third maxillipeds, working in the

OG. *, A HISTORY OF RECENT CRUSTACEA

afferent opening on either side, by their powerful move-
ments bring it back to the branchial cavity. ‘The two
ridges on the maxillipeds, which are often densely fringed
with hairs, meet in front and form a triangular break-
water which prevents the streams intended for the bran-
chiee from entering the mouth-opening.

Of the rock-haunting species of the genera Plaqusia,
Latreille, 1806, and Goniopsis, de Haan, 1855, Krauss
speaks with a sort of admiration. ~At low tide they come
bustling out of their crannies in ho-ts. By help of their
soft elastic bodies, and their hmbs cut out for the very
purpose, they clamber over rough blocks and steep sides
of rock, jump from one crag to another, and creep into
the most inaccessible crevices. They are not very swift,
but very canny, so that on their own ground, in spite of
their multitude, it is almost impossible to catch any of
them. In the fear of pursuit they will let themselves drop
several feet from one ledge on to another, or plunge a
fathom down into the sea and paddle off to the nearest
rock. <Acanthdpus clavimanus, de Haan, is a tiny species
nearly allied to Plagusia, but with different habits. It
lurks under stones, and it may seem a light matter to turn
over a stone and catch it, but before the stone is well over
the crab will have whisked to the other side, and when at
length it has been pinned fast, it is no easy task to drag
away its thin body and clinging talon-like claws without
breaking them. The name of this genus having been pre-
occupied, it has been changed by Miers to Letcliphus.

Plagusia contains species that come from the Atlantic
and Pacific, and some of these have been taken in the Medi-
terranean under circumstances worthy of note. In the
winter of 1875 an iron vessel entered the port of Mar-
seilles.. It had come from Pondichéry, by way of the Cape
of Good Hope, having had a long and stormy voyage in
the most rigorous season of the year. To the iron plates
of this ship had become attached a little forest of alge and
barnacles; and living among these were a number of
higher Crustacea of exotic origin. Two of the specimens
were found by Professor Catta to belong to a new species

—

FRIEND OR FOE 99

which in 1876 he named Pachygrapsus advéna; one was a
Nautilograpsus (cr Planes) minutus, a species scarcely ever
found in the Mediterranean ; the remainder belonged to
two species, which M. Catta speaks of as Plagusia squa-
mosa and Plaqusia tomentosa. The latter,a South African
species, should rather, it seems, be designated Plagusia

chabrus (Linn.), and the former Plagusia depressa (Fa-

bricius). It was this last-mentioned one that was the most
numerous, being present in hundreds. As an Atlantic
species, it might not have had far to come. The point
of special interest, however, lies, as Catta explains, in
showing the effects on distribution that may be produced
by unconscious human agency.

Family 4.—Pinnotheride.

The carapace is usually more or less membranaceous,
convex or depressed, with the antero-lateral margins entire
or very slightly dentate. The ‘front,’ orbits, and eye-
stalks are very small. The buccal frame is usually arcuate
anteriorly. ‘The third maxillipeds have the fourth joint
well developed, and usually the third also, the fifth articu-
lated at the apex, or at the front inner angle, or more
rarely the front outer angle, of the fourth. The chelipeds
in the adult male are small or moderately developed. The
walking legs are slender and generally naked, with the
seventh joint stiliform, unarmed. The pleon of the male
in general does not cover the whole width of the sternum
between the last pair of legs.

The crabs of this family are small, and many of them
live in the shells of bivalve molluscs, tests of Echini, tubes
of annelids, and other borrowed habitations. Miers dis-
tributes five-and-twenty genera over four sub-families.

Pinnothéres, Watreille (in Bosc), 1802, was known to
the ancients under the same name, but more commonly
under the name Pinnotéres. It is a great pity that
Latreille did not adopt the latter, which is in all pro-

bability the older form. Small as the difference in sound,

the difference in sense is considerable. Pinnotheres means

100 A HISTORY OF RECENT CRUSTACEA

one that hunts the Pinna, and, in accordance with this
designation of the genus, Oppian tells the story that when
oysters open their valves to take in the mud and water on
which they live, one of these crafty little crabs picks up a
pebble and thrusts it in, so that the oyster is prevented
from closing its shell again, and the crab enters and feeds
upon its nutritious flesh. Gesner in the sixteenth century
expressed his confidence that this was mythical, siace you
never find any bites upon the mussels, pectens, pinnas,
and oysters that are attended by these crabs.

The name Pinnoteres means one that watches or guards
the Pinna, and there can be little doubt that it was the
form used by Aristotle, seeing that he also speaks of it as
Pinnophijlux, a word of precisely the same meaning. Not
only Aristotle, but many succeeding writers of renown, such
as Cicero, Pliny, and seemingly Linnzeus himself, accepted
the opinion that there was a compact between the molluse
and the crustacean for their mutual benefit. Whenever
little fishes swam in between the expanded valves of the
mollusc, it was supposed that its companion gave it a little
friendly nip, upon which the valves snapped together, the
prey was secured, and shared between the confederates.
A similar policy was pursued to exclude the intrusion of a
dangerous foe. The great antiquity of the belief is at-
tested by the fact that the Egyptians in their hieroglyphics
made use of the pinna and crab to symbolise the helpless-
ness of a man without friends. That the behef was un-
tenable was pointed out by many naturalists from Gesner
down to Cuvier, on the ground that molluscs do not feed
on little fishes, and that the residence of the crabs within
the valves was sufficiently explained by the prevailing
sottness of the carapace in this family. This indeed ap-
plies chiefly to the females, and it is the females that
appear to be most frequently found thus domiciled.

It is so much the nature of crustaceans to take refuge
in any sort of cleft or cranny that the first entrance of the
Pinnotheres into any sort of bivalve can be easily under-
stood. When the residence proved to be peculiarly secure,
the shell of the crab wonld by degrees lose a hardness that

.
P.
4

THE OYSTER-CRAB 101

was no longer especially necessary. That the crab may
be at times useful to the. mollusc seems after all not so
very improbable, for at the approach of an enemy so
nervous a creature as a crab would no doubt begin to
scuttle about and in this way communicate its terror to its
more apathetic companion, which would then naturally
close its doors against the danger. Dr. H. Woodward has
recently recorded a remarkable instance of a Pinnotheres
found encysted in a pearl-like formation of the pearl-
oyster, Meleagrina margaritifera.

Pinnotheres veterum, Bosc, and Pinnotheres pisum
(Linn.) are common European and British species. Giard
and Bonnier suppose that under the latter name several
distinct species have been confounded. Its Zoéa, long ago
studied and drawn by Mr. Vaughan Thompson, is a
_singular-looking microscopic object. Among the names
of other species some which indicate the animal’s resi-
dence may be mentioned, as Pinnotheres ascidiicola, Hesse,
from the coast of France, the Japanese Pinnotheres pho-
ladis, de Haan, and Pinnotheres lithodémi, Smith, from the
Pearl Islands and Lower California. A similar indication
is given in the generic name, Holothuriaphilus, Nauck.

In ‘The Civil and Natural History of Jamaica,’ when
speaking of a Pinnotheres, which he calls the Oyster-Crab,
Patrick Browne says: ‘This little species is generally
found with the Mangrove oysters, in their shells, where
they always live in plenty, and spawn at the regular
seasons; and such as eat the oysters, do not think them a
bit the worse for being accompanied with some of these
crabs, which they swallow with the fish. ‘hey are very
small and tender, and nearly of the same length and
breadth, seldom exceeding a quarter of an inch either
way.

Hymenoséma, Desmarest, 1823, was established under
a name invented by Leach, and signifying a membrana-
ceous body. This is a character in which many members
of the family partake. Hymenosoma orbiculare, Latreille
and Desmarest, is a South African species. Halicarcinus,
White, 1846, is closely allied to Hymenosoma, but courts

Hy]

102 A HISTORY OF RECENT CRUSTACEA

attention for the sake of the species Halicarcinus planatus
(Fabricius), which is widely distributed over the Antarctic
or Austral region, being the only Brachyurous Decapod,
it is said, proper to that wide area of distribution. Mr.
Haswell considers that the Hlamene Matheei of Milne-
Edwards is probably the young male of this species, and
that it is quite distinct from the original Hymenosoma
Matheer of Desmarest.

Scopiméera, de Haan, 1853, was established for the
single species, Scopimera globosa, in which the arm of
the chelipeds and the corresponding fourth joint (the so-
called merus) of the hinder legs has the outer margin
cartilaginous instead of crustaceous, with a transparent
membrane in the flat part. This peculiarity explains
de Haan’s choice of a generic name, which means ‘ thighs
with windows in them.’ From the resemblance to the
head of a drum these membranous pieces have been called
‘tympana.’

Dotilia, Stimpson, was substituted for Doto, de Haan,
1833, a pre-occupied name. In this genus Dotilla fenes-
trata, Hilgendorf, from the Hast Coast of Africa, has the
windows or tympana also in the sternum. Dotilla brevi-
tarsis, de Man, is from the Mergui archipelago. Dr. de
Man makes Scopimera a synonym of Dotilla, but, if the
two genera are united, Scoprmera as the older name must
take precedence.

Hexdipus, de Haan, 1835, is entirely devoid of the
last pair of walking legs, so that instead of decapods these
crabs have become octopods, and if the chelipeds are
excluded and only the walking legs counted they may be
regarded as hexapods, or six-legged crabs, and to this
view the name of the genus refers.

Thaumastoplax, Miers, 1381, it is said, ‘1s closely allied
in all its characters and particularly in wanting the fifth
pair of thoracic legs, to the genera Hexapus, de Haan,
and Amorphopus, Bell, but is distinguished from the former
by the much greater development of the second ambula-
tory legs and the structure of the outer [third] maxilli-
pedes, whose merus [fourth] joint is elongated and

TRANSITIONAL FORMS 163

narrowed at its summit, where it is articulated with the
next joint, and from the latter by the well-formed orbits
and the entire absence of rudimentary fifth legs.’ Those
who are always sceptically inquiring for links in the chain
of evolution and for the fine gradations which the trans-
mutation of species postulates, may be invited to observe
in this family the genus Pinniza, White, in which the
fifth legs are often short, the genus Amorphdpus, in which
they are rudimentary, and lastly Thauwmastoplax and Hexa-
pus, from which they have vanished altogether.

Some curious facts relating to the organs of vision
in certain members of this tribe are worthy of mention.
In the family Ocypodide the genus Bathyplax, A. Milne-
Edwards, 1880, contains but a single species. Specimens
taken by the U.S.S. Blake from depths between four and
five hundred fathoms were found to have the eye-stalks
very short, almost immovable, and with the cornez not
developed. Accordingly the species was named typhlus,
‘the blind.’ But specimens taken from smaller depths
by the Challenger agreed with the others in all respects
except just this one, that they possessed small, distinct,
terminal corneze. As these specimens were obviously not
blind, Mr. Miers named them ‘var. oculiferus.’ In regard
to another genus, also but more doubtfully included in
the Ocypodidee, Professor Perrier cites the observation of
A. Milne-Edwards, that in Geryon tridens, Kroyer, a
species which descends to great depths, the eyes are
brilliantly luminous.

104 A HISTORY OF RECENT CRUSTACEA

CHAPTER VIII

TRIBE III.—OXYRRHYNCHA

THE carapace is more or less narrowed anteriorly and
usually rostrate, with the hepatic regions small, the bran-
chial large. ‘I'he epistome is generally large. ‘The buccal
frame is quadrate, with the anterior margin straight.
There are nine pairs of branchiee, with the efferent chan-
nels opening at the sides of the endostome. In this,
as in the two preceding tribes, the afferent channels
open behind the pterygostomian regions, in front of the
base of the chelipeds. ‘The first antennze are longitu- —
dinally folded. The third maxillipeds have the fifth joint
articulated at the apex or at the front inner angle of the
fourth. The verges of the male are exserted through
the bases of the last pair of walking legs.

This tribe of the ‘sharp-snouted’ crabs is divided
into two legions, the Maiinea and Parthenopinea. It has
been observed in many cases that the two halves of the
large liver are not separate, but united by a median lobe.
‘The nervous system is said to attain a higher degree of cen-
tralisation in this group of Crustacea than in any other, the
ganglia of the trunk forming a single solid disk-like mass.

Legion 1.—Maiinea.

The basal joint of the second antennz is well de-
veloped, inserted beneath the eyes, and usually occupies a
great part of the infra-ocular space.

This legion contains three families, the Inachide,
Maiidee, and Periceridz.

Family 1.—Inachide.

The eyes are non-retractile, or retractile against the
sides of the carapace. In general the orbits are not de-

SPIDER-CRABS 105

fined, but there is often a well-developed preeocular and
postocular spine. The basal joint of the second antennz
is generally slender, sometimes moderately enlarged. The
carapace varies in shape, being subtriangular, or trun-
cately triangular or subpyriform, rarely suborbicular.
The rostrum is simple or bifid, sometimes very short.
The chelipeds never have the fingers excavate at the tips.
The walking legs are sometimes very long. In both sexes
the number of distinct segments of the pleon varies from
four to seven.

To this family belong nearly forty genera, three of
which are included in the British fauna.

Macropodia, Leach, 1814, meaning ‘long-foot,’ had
been already called Macropus by Latreille, but that form
of the name was preoccupied. By Lamarck in 1818 it
was named Stenorynchus, ‘narrow-snout, a very appro-
priate name but without any title to supersede the earlier
Macropodia of Leach. Just as the title of the tribe
Oxyrhyncha ought in accordance with its Greek original
to be spelt Oxyrrhyncha, so should Stenorynchus have been
spelt Stenorrhynchus. Part of this correction has been
adopted in the commonly used form Stenorhynchus, and
naturalists have been so much tickled with the pleasing -
sound that, instead of leaving the monopoly of it to the
Crustacea, they have employed it also among beetles,
reptiles, birds, and mammals. The British species Macro-
podia rostratus (Linn.) is described in Bell’s History under
the name Stenorynchus Phalangium (Pennant). The
specific name given by Pennant alludes to the resemblance
which these crabs with long thin legs bear to the Pyeno-
gonids or Sea-spiders, and which has won for them the
designation of spider-crabs. In spite of their long limbs
they are a sluggish and slow-moving race, and in con-
sequence are devoured in great numbers by other inhabi-
tants of the sea. The fact that there are great numbers
of them to be devoured shows that nature has not left
them entirely without means of defence, of which some
account will presently be given. Mucropodia longirostris
(Fabricius), which Bell calls Stenorynchus tenwirostris

106 A HISTORY OF RECENT CRUSTACEA

(Leach), is, like the preceding species, found both in
British and Mediterranean waters, and is distinguished
from the other species partly by the relatively greater
length of the rostrum.

Acheus, Leach, 1815, is so near to Macropodia that ‘it
is in fact only distinguished from it by the absence of
rostral spines; the rostrum in Achceus being composed
merely of two small acute or subacute lobes.’ Of ten
species enumerated by Miers only the type, Acheus Cran-
chu, Leach, belongs to the waters of Europe and Great
Britain.

Indchus, Fabricius, 1798, as at present restricted, con-
tained in 1886 only six species, and these known only
from European seas and the Western North-Atlantic.
Three of these species are found in British waters, namely,
Inachus dorsetlensis (Pennant), Inachus dorynchus, Leach,
and Inachus leptochirus, Leach.

Leptopodia, Leach, 1815, has apparently but one species,
Leptopodia sagittaria (Fabricius), with an extensive range
in the warm waters of the Atlantic and of the West coast
of America. Unlike the three preceding genera this has
the rostrum not bifid, but simple. This beak is very
long and serrate on the edges. The carapace is not
spinous. ‘The chelipeds in the male are rather slender
and very elongate; the walking legs are very slender
and extremely elongated, with the seventh joint stiliform.
Next to this genus Leach placed one which he named
Pactélus, with the species Pactolus Boseu, tounded on a
single female specimen in the British Museum from some
unknown locality. Fabricius, he says, seems to have
described it as the other sex of his Inachus sagittarius.
Pactolus has a body exactly like Leptopodia, but the legs
are of moderate length, and of these the first three pairs
have simple claws, while the last two pairs are didactyle,
that is to say, chelate. In 1793 Fabricius said of his
sagittarius that in one sex the feet were of moderate size
and all chelate, in the other six times as long and simple.
In 1798, without any distinction of. sexes, he states that
eight of the feet are unguiculate and the last four pre-

A DECEPTION DETECTED 107

hensile, thus making six pairs of legs, with a structural
arrangement as regards three of them that would be unique
among the Brachyura. At each date the species is said
to come from the Isle of Guadeloupe. Leach rightly per-
ceived that error and confusion were lurking somewhere,
if it should not rather be said that they are conspicuous
on. the face of the two discordant accounts. Milne-
Edwards in 1837, though with a confession of great un-
certainty, institutes for the single genus Pactolus the tribe of
the Pactoliens, which he places among the Anomura. ~ But
soon after, in 1839, de Haan with great acuteness ob-
served, ‘ Pactolus, Leach, Zoological Miscellanies, vol. 11
tab. 63, seems to me to be made up of the thorax of a
female Leptopodia sagittaria, to which the legs of some
other animal have been united; for the thorax of Pactolus,
just as also the rostrum and abdomen, agrees with the
female Leptopodiu. The unhkeness in colour between the
legs and the thorax in the figure referred to at once
reveals the deception. Never are two alien forms found,
agreeing exactly in the thorax, yet so disagreeing in the
legs.’ The principle here enunciated is worth remembering,
as In some parts of the world there are dealers,who delight
and find profit and have also great skill in fabricating mon-
strosities, sometimes such as have deceived the very elect.
_ Nearly related to Inachus is the gigantic Macrocheira
Kampfert, de Haan, 1839, of which mention has been
earlier made. In Japanese it is called the insular crab.
Huenia is another genus of this family instituted by
de Haan in 1839. The name refers to the acutely trian-
gular form of the carapace, and is derived from the Greek
word wyis, a ploughshare, a derivation which would have
been hard to guess, had not de Haan obligingly mentioned
it himself. At the foot of his plate 25 he names the
figures ‘4. Maya (Huenia) elongata n. 95. id. variet. 6.
Maga (Huenia) heraldica n.’ But the species established
in the text is M-ja (Huenia) proteus. The double generic
name results from the inconvenient practice, still some-
times followed, of splittimg a genus up into sub-genera.
Sub-genera, if they are worth anything, are pretty sure to

108 A HISTORY OF RECENT CRUSTACEA /

Fic. 6.—Huenia proteus, de Haan, young
male,

Fic. 5.—Huenia proteus, de Haan, adult male, with
separate figure of the pleon.

Fic. 7.—Huenia proteus, de Haan, female, with separate figures of the pleon in a sterilised _
and a healthy specimen.

PUZZLES OF PARASITISM 109

be regarded as genera later on, and might therefore just as
well be called so at first. But for his change of the
specific names de Haan had a reasonable though a rather
singular excuse. After his plate had been engraved with
the figures and names of two distinct species, based on
the very great dissimilarity of the carapace in the male
and female specimens at first available, he received a new
series of specimens belonging to each form. These he
found to agree in so many particulars that the protean
form of the carapace no longer sufficed to separate
them specifically, but had to be regarded as depending on
the variations of age or sex. He here also observed that,
as in several other Crustacea, there were what he supposed
to be two forms of the female, the one ovigerous which he
designates as genuine, the other sterile which he speaks
of as spurious. In the present species he says that the
pleon in the genuine females is of five segments, the fourth
thick, very convex, with a longitudinal median impression,
while in the spurious females it has seven segments, is
lamellar and concave, with the fourth, fifth, and sixth
seoments dilated, the seventh narrower and_ truncate.
The mystery of these so-called spurious females has been
recently explained by Professor Giard. In studying the
parasitic Crustacea, as well Isopoda as Rhizocephala, he
was confronted by the statement which Rathke made in
1857, that of the many hundreds of Bopyrus which had
passed through his hands he had never found one in any
but a female Palemon, and also by the statement which
Fraisse made in 1877, that the males of Jnachus, so far as
he had observed, were never attacked by parasites, which
he thought might be the result of the unsuitable shape of
the narrow pleon in that sex.

The parasitic groups will be for after consideration.
but it must here be mentioned that by careful investiga-
tion Professor Giard arrived at the very interesting result
that the specimens of the higher Crustacea infested by the
parasites are as a rule more or less completely sterilised,
and that the secondary sexual characters are considerably
modified, so that the males acquire to some extent the

110 A HISTORY OF RECENT CRUSTACEA

appearance of the females, especially in the widening of
the pleon, which is the first characteristic of sex that would
generally be looked for. It follows, therefore, that amorg
the specimens which in old times have been regarded as
spurious females many spurious males were beyond doubt
included. It is also worth remembering that when the
shape of the pleon leaves the sex of a crab ambiguous, that
may be taken as an indication that some curious species
of parasitic crustacean is likely to be found in some part
of the organism.

A large extension has been given to the family of the
Inachidee by recent voyages of deep-sea exploration, and
in some instances species which, when first discovered
only a few years ago, were naturally supposed to be rare,
have since proved to be cosmopolitan. Thus the little
Lispognithus Thomsoni (Norman), a delicate species with
long slender limbs, taken at a depth of two or three
hundred fathoms in the Faré Channel, and first described
in 1873, has since then been taken at much greater depths
and at places so wide apart as the Straits of Gibraltar, the
neighbourhood of the Cape of Good Hope, and of Sydney
in Australia.

Hrgasticus, A. Milne-Edwards, 1881, has two species
—Ergasticus Clouei, A. Milne-Kdwards, and Hrgastieus
Naresii, Miers. The latter was taken near the Admiralty
Isles in the Pacific, and recalls the name of the honoured
captain of the Challenger; the former was found in the
Mediterranean and the Atlantic, and the name of the
genus founded for it signifies ‘a worker’ in remembrance
of the French ship, the Travaillewr, by which the type-
specimen was dredged. Platymaia Wyville-thomsoni (see
Plate IV.), Cyrtomaia Murrayi, Cyrtomaia Suhmi, Kehi-
noplax Moseleyr, represent new genera and species in this
family instituted by Miers in 1886, in which the specific
names have been chosen expressly to associate some of the
finest of the Brachyura dredged by the Challenger with the
names of its staff of naturalists. Platymaia and Oyrtomaia
are also pointed out as of especial interest from their ‘ being
Malayasian representatives of a section of the sub-family

Pl. iv.

Platymaia Wyville-thomsoni |

Catapagurus
Sharrert

Housed

=

metas \ \
: . Y
Hippa talpoida Ne

H.talpoida
Zoea, 2" stage ‘Ai yy

(vy f
H. talpoida.Zoca,last stage © ae 7
SP ge

———
. a=) 3

intermedius

A MOVING MUSEUM ELT

Inachine, hitherto represented only by types from Eastern
America.’ Among those types the nearest to Platymaia
is supposed to be Huprognatha, Stimpson, 1870. In re-
gard to Huprognatha rastellifera, Professor 8. I. Smith
says: ‘This is apparently by far the most abundant of all
the Brachyura along our whole eastern coast south of
Cape Cod—in the belt from 50 to 200 fathoms depth.
In the U.S. Fish Commission dredgings off Martha’s
Vineyard, many thousands of specimens were often taken
at a single haul of the trawl.’

Family 2.—Maiide.

The eyes are retractile within the orbits, which are
distinctly defined, but often more or less incomplete below
or marked with open fissures in their upper and lower
margins. The basal joint of the second antenne is always
more or less enlarged. The family includes about thirty
genera, three of which are known in British localities.

Maia, Lamarck, 1801, is a genus well known rather to
the south than the north of Great Britain in the species
Maia squinado (Herbst). It is a large, eatable, and, in the
south-west of England, an extremely abundant species.
Its great inflated carapace, covered with prickles and fur,
gives it a ready place in the memory when once it has been
noticed. A pretty little amphipod, called Iscea Montaqua,
Milne-Edwards, with the sixth joint of its legs much
widened, seems to have been specially adapted for ranging
about this hirsute and prickly crab, the only place in which
it is found. The convenience of the residence may be in-
_ ferred from the fact, previously noticed, that from time to
time a score of other species of Amphipoda find it their
interest to occupy the same station. The crab, according
_ to Herbst, is known as Squinado in Provence. In Corn-
wall it is called the Corwich, and Bell was told that in
those parts several dozens could be had for sixpence. But
even this does not give so ample an idea of its abundance
as is conveyed by Olivi in his ‘ Adriatic Zoology’ of a
hundred years ago. Hedeclares that in summer the crabs

112 A HISTORY OF RECENT CRUSTACEA

are dispersed upon the shore, but that in winter the females
collect on the deeper rocky ground in particular spots in a
great crowd, and pile themselves up in such numbers that
they form a sort of mound, which from the depth of eighty
to a hundred feet ascends until the glimmer of it can be
seen at the surface of the water, and that then the Istrian
fishermen go out with two, four, or six boats, surround this
living tower with their nets as easily as possible, and so
make a speedy capture. Professor Stalio, in 1877, en-
dorses this wonderful tale, except that in his account the
boats employed are only two or four, and the instinct which
leads these creatures to cling together and climb up one on
another’s back only produces a great pile of several feet in
height. Yet anything much less than Olivi’s submarine
mountain of crabs would scarcely be visible from the sur-
face at the depths which he mentions.

The Mediterranean possesses another closely allied spe-
cies, Muia verrucosa, Milne-Edwards, smaller in size, and
covered with warts or tubercles, instead of spines or prickles.
This little crab led the way in quite recent years to some
observations that throw a new light upon the mental powers
of the Crustacea.

“A great many of the Oxyrrhyncha have at all periods
excited the surprise of collectors, when dealing for the
first time with living specimens, by their often extreme un-
tidiness. They are overgrown with alge and ever so many
kinds of sedentary animals. ‘They are undoubtedly them-
selves slow-moving creatures, and it was not unnaturally
supposed that these colonies with which they were encum-
bered and disfigured were at once a proof and a result of
their extreme sluggishness. Dr. Graeffe had once occasion
to carry into the aquarium at Trieste a specimen of Maia
verrucosa which had been stripped of most of its vegetable
costume. He happened to place it in the same vessel with
a large mass of the polyp known as Dead Man’s Fingers.
The next day, to his astonishment, he found the whole
back of the Spider-crab covered with pieces which had
evidently been snicked out of the Aleyonium. ‘To make
sure, he kept watch, and at length had the sweet satis-

HOW CRABS PUT THEIR CLOTHES ON 113

faction of seeing how the crab slowly stepped up to the
polyp-mass, and with its claws tweaked off small points of
the branches. At first it let them lie on the floor of the
aquarium, but later on fished one of them up again with
its claw, which it bent over the back of its carapace, and
there among the fur it planted the fragment of the polyp
with the severed surface downwards !

Further experiments showed that not only in the species
of Maia, but also in those of Pisa, Macropodia, Inachus, and
other Oxyrrhyncha, the foreign organisms were fastened to
the crabs’ bodies by the crabs themselves. That the object
was concealment by the wearing of a mask was obvious,
since the costuming was never at random, but always in
strict agreement with the surroundings. Moreover, these
marine zoologists know what sponges and polyps can be
chopped up without causing mortality in the fragments.
The pieces they plant are pieces that will live and thrive,
and, as Dr. Graeffe observes, the keepers of aquaria have
only to consult the crabs to learn what kinds of sea-
animals will bear being thus transplanted piecemeal. For
keeping on their living mask Dr. Graeffe found that the
natural coats of these Crustacea were furnished with hairs
varying in arrangement and shape in the different genera
and species, some of the hairs being fish-hook-shaped,
others clubbed, and others simply tapering, but all more
or less serrate, the simple ones sufficing to detain a coating
of slimy mud, while the others hold captive the —
organisms.

Dr. Graeffe published his observations in 1832, but
already in 1878 Dr. Eisig had reported of a species of
Inachus that he had seen it plucking Hydroids and plant-
ing them on its spines and hairs, and Dr. C. Ph. Sluiter in
1880, when establishing the new species Chorinus alyatec-
tus, described its way of spitting little fragments of algze
on the strongly bent hooklets of its body and legs, to mask
itself from its enemies and its prey. Additional details of
great interest were published in 1889 by the Swedish
naturalist Dr. Carl W. 8. Aurivillius.

Hyas, Leach, 1813, comprises but few species, two of

114 A HISTORY OF RECENT CRUSTACEA

which belong to Great Britain and are also extensively dis-
tributed in the North Atlantic. These are Hyas araneus
(Linn.) and Hyas coarctatus, Leach. In a tiny specimen
of the latter species, taken from off the carapace of the
mother, small spines or tubercles are observable on both
sides of each of the two divisions of the rostrum, on the
outer side of the second antennze, and on the eye-stalks.
These minute characters do not reappear in the adult.
The two species mentioned are very abundant on the coast
of Sweden, and Aurivillius found that they were almost
without exception dressed up either in pieces of different
alge (almost always Floridez) or of shallow-water sponges,
or with Hydroids, tubicolous Annelids, Polyzoa, Cirri-
pedes, or Ascidians simple or compound. His experiments
showed him that, if some of these settled rather by the
crab’s permission than its active interference, yet they had
been originally under its control, while in most cases the
colonists had been actually planted and forced at the will
of the crustacean to occupy their several stations. He
found, just as Mr. David Robertson of Cumbrae had done,
that his specimens of Hyas were capable not only of dress-
ing but of undressing themselves. Of the effectiveness of
their disguises he had often had practical experience, when
upon visiting his aquarinm in the morning he was unable
to find specimens which he had placed there overnight,
and which he at first thought must have escaped. Close
inspection and the help of a magnifying glass, however,
would always show that they were present, but that they
had so decked themselves out with the vegetables and
animals around them as to lose all invidious prominence.
By transplanting into an environment of sponges some
that had clothed themselves in bright-coloured alge, he
ascertained how accurately they knew their business, for
they laboriously picked off the gay colours, and stuck
themselves over with fragments of sponge in their place.
The chelipeds of these crabs are adapted by length and
by the flexibility of the joints to reach to the different parts
of the body which require dressing up. The hooks and
hairs which hold on the tags and patches have been already

A CAREFUL TOILETTE 115

considered. One curious point as to their distribution
may be noticed. When the female is loaded with eggs,
the basal segment or segments of the pleon are forced
upwards so as to need concealment like the carapace.
The result is, in some at least of the Oxyrrhyncha, that
hooks for the attachment of foreign objects occur upon
these segments in the females but not in the males.
While dressing themselves the crabs invariably bring
each portion of their intended coat to their mouths as if

Fie. 8.—Chorinus aculeatus, Milne-Edwards [Aurivillius].

they were going to eat or at least to taste it. Aurivillius
noticed that if a piece did not hold firm where the crab
was seeking to plant it, recourse was had again to the
mouth, and if the piece still proved intractable, it would
be brought to the mouth a third time and then tried on a
fresh spot. The object of this assiduous application to
the mouth is, he thinks, that each piece may be well
licked, a secretion from the mouth organs, especially the
first pair of maxillipeds, bestowing the requisite adhesive
10

116 A HISTORY OF RECENT CRUSTACEA

character. Considering the tolerably ruthless manner in
which the crab gathers the constituents of its costume,
one need not wonder at their needing a little emollient
ointment. Under the circumstances their natural ten-
dency to adhere might otherwise remain for some time
dormant.

Chorinus aculeatus, Milne-Edwards, as depicted on the
preceding page, is suggestive of a wardrobe provided with
a truly enviable number of pegs. In regard to a closely
related species, Chorinus longispina, de Haan remarks that
to the hooked setze of the thorax and legs marine odds and
ends adhere so closely that they can scarcely be removed
without damaging the sete. He is thinking only of man’s
rude handling, for, however remorseless such a crab may
be towards its surroundings, we may feel assured that its
deft fingers will do no violence to the well-appointed furni-
ture of its own carapace.

Pisa, Leach, 1813, is open to the suspicion of being a
synonym of Arctopsis, Lamarck, 1801. ‘There are several
species of this genus in various parts of the world. The
two known in English and Irish waters occur also in the
Mediterranean and have a considerable range north and
south. These are Pisa tetraodon (Pennant) and the species
which Bell calls Pisa Gibbsu, Leach, a name which must
be wrong, whatever other is right. Miers with some hesi-
tation adopts for it the name Pisa (Arctopsis) tribilus
(Linn.).

Naxia, Milne-Edwards, 1834, is narrowly distinguished
from Pisa by the accessory spinules of the two-horned
rostrum. Nawxia hystrivz, Miers (see Plate IV.), was ob-
tained by the Challenger at Amboina.

Inssa, Leach, 1815, is a genus apparently near to Pisa,
but with a rostrum consisting of two truncate laminar
horns side by side, which are somewhat wider at the ex-
tremity than at the base. It was formed for the Mediter-
ranean species Lissa chiragra (Fabricius), which is deep
red in colour, and has the legs so covered with protuber-
ances that its specific name, meaning ‘ gout in the hand,’ is
not Inappropriate, although it so happens that the hands

PROTECTIVE PERIL ip Bg

of the chelipeds are almost the only smooth part about it.
It is said by Stalio to be sensitive to changes of tempera-
ture, and at any increase of cold to crouch closely in the
crevices of the rocks, but as he also says that its habitat
is at a depth of thirty to forty fathoms, it is not easy to
understand how this valetudinarian shrinking has been
ascertained. ‘The crab is only about two inches long, and
according to Herbst is commonly covered with worm-tubes,
corals, algze, and mud, to such an extent that it is scarcely
to be recognised or to be taken for a living creature.
Chionecétes, Kroyer, 1838, is a northern genus, with
a name meaning ‘the snow-dweller,’ founded for the
Greenland species Chionacetes opilio, which, according to
Professor 8. I. Smith, is taken rarely in the deep water
off the New England coast. ‘It is,’ he says, ‘one of the
_ largest arctic crabs, and occasionally attains gigantic pro-
portions.’ In the largest specimen that he examined the
span of the walking-legs was two feet eight inches. The
specimen figured by Kréyer in Gaimard’s voyages was, he
says, even somewhat larger, but though the figure occupies
the whole extent of the folio plate, I do not find that even
with the second pair of legs which are the longest or with
the third pair which are inserted at the broadest part of
the carapace could it span more than twenty-eight inches.
Antihbinia Smithii, M‘Leay, is a South African species
which Krauss observed in its native haunts on the per-
pendicular wave-lashed cliffs of the headland at Natal.
Its legs are powerful and have the terminal joint bent into
a strong hook by which the crab can fasten on to the pores
of the rock. Its body is rounded off and has a very hard
horny shell well adapted to resist the continual beating
upon it of the surf. Among the bright and dark green
alez, and coloured like them, it sits almost completeiy
motionless and lets its food be floated to it by the ever-
moving sea. When Krauss wished to take some speci-
mens away from their dangerous position, they clung so
tight that he had to use considerable force to disengage
them, and was in consequence several times overtaken by
the returning waves before he could effect his purpose. It

118 A HISTORY OF RECENT CRUSTACEA

is pleasant to see how creatures comparatively feeble may
sometimes find security in stations the most unpromising
and the most exposed. ‘The whole tribe of the Oxyrrhyn-
cha are indeed often placed at the head of all the Crustacea
in honour of the ready wit and resource which so many
of them display.

Scyramathia Carpenteri (Norman) 1 is a een crab
first observed on the Porcupine expedition in the Channel
between the Firé and Shetland Isles. It was afterwards
obtained abundantly by the Travailleur from great depths
in the Bay of Biscay, and again the Norwegian North-
Atlantic expedition trawled it from a depth of 220 fathoms
about twenty miles off the west coast of Norway.

According to the description of it by Professor Sars,

‘the whole surface of the body is invested, as it were, with
a dense, felt-like covering, which, on closer inspection, 1S
found to consist of two different. kinds of cutaneous ap-
pendages. Innermost, crowded together, are observed
numerous small tuberculiform excrescences, which, at the
first glance, may be readily taken for granulations on the
skeleton of the skin, but, after a closer examination, are
seen to be of a totally different character, since they have
not only a soft consistence, but admit of being scraped off
with the greatest facility. On treating these protuber-
ances with a solution of potash, they are found to be
true cutaneous vesicles or capsules, that, with a broad
basis, are attached to the skeleton of the skin and sup-
ported in the middle by a slender chitinous-like rod, of
which the point projects more or less distinctly forward
from the top. Between these peculiar cutaneous appen-
dages, and projecting considerably beyond them, are short
and comparatively stiff hairs, somewhat unguiform at the
extremity, and crowded together, in particular on the
anterior part of the dorsal surface of the carapace, which
thus acquires a velvety appearance.’

The rostrum also is highly characteristic. It is divided
from the base into two straight, strongly divergent, branches,
about half as long as the carapace. They are cylindrical
at the base, but taper gradually to a dagger-like point, and

SOME NAMES DISENTANGLED 119

are thickly covered with hair. There is, according to Sars,
a possibility, which, however, 8. I. Smith thinks an impro-
bability, that the species may be the same as one earlier
but all too briefly described by Stimpson, from the coast
of Florida, under the name Scyra umbonatu. The speci-
men taken by the Porcupine was first described as Amathia
Carpenter, but the genus Amathia, Roux, has a pre-occu-
pied name which has in consequence since been changed,
by 8. I. Smith, to Anamathia, and Professor A. Milne-
Edwards discovered that the species Carpenteri could not
be included in that genus. At the same time he noticed
its likeness to Stimpson’s species above mentioned, and
framed for it the new genus Scyramathia. From the fore-
going remarks it will easily be understood what suggested
the composition of this generic name, but it must not be
- forgotten that Seyramathia belongs to the family Maiide,
whereas Anamathia stands in the previously described
Inachidee, and Scyra (though to the exclusion of Stimp-
son’s species umbonata) is a genus belonging to the next
family, the Periceride.

Family 3.—Periceride.

The eyes are retractile within the small circular and
well-defined orbits, which are not incomplete as in the
Maid. The basal joint of the second antenne is well
developed, and constitutes a great part of the inferior wall
of the orbit, the joint being in general much enlarged.

The family contains about twenty genera.

Pericéra, Latreille, 1829, of which the type is Pericera
cornudo (Herbst), 1804, has been despoiled of many of
its species by Miers, who has transferred them to Macro-
celéma, a new genus which he instituted in 1879. Of
the species Macroceloma trispinosa (Latreille) Mr. Ives
says that Yucatan specimens when alive are of a bright
scarlet colour. In the Challenger species, Macroceloma
conciva, Miers, from Bahia and Fernando Noronha, the
body and limbs are covered with a short close pubescence
and with some longer curled hairs. Its colour in spirit is

120 A HISTORY OF RECENT CRUSTACEA

yellowish-brown, but this is little or no guide to what its
colour may have been when living. ‘The specific names in
this genus ought to have either masculine or else neuter
terminations, but many naturalists seem to suppose tbat
any generic name ending in -a is a feminine form, which
is far from being the fact.

In this family the genus Libinia, Leach, 1815, contains
several species, and Mithraw (Leach), Latreille, 1817, a
very large group. Of Labina emarginata, Leach, Miss
Mary Rathbun, in her recent revision of the Periceride,
says that in Long Island Sound occasionally this species by
its numbers ‘so interferes with the steam oyster dredgers
that work is abandoned until the crabs (which are known
to the oystermen as “ spiders”) have passed over,’

Legion 2.—Parthenopinea.

The basal (or true second) joint: of the second antennz
is very small and embedded with the next joint in the
narrow gap between the ‘front’ and the inner orbital
angle, the infraocular space being mainly occupied by the
inferior wall of the orbit.

Lamily 4.—Parthenopide.

The eyes are usually retractile within the small circular
and well-defined orbits; the lower wall of the orbit is con-
tinued to within a very short distance of the ‘front.’ The
second antennz are very slender; the basal joint does not
as in the Periceridee constitute a great part of the inferior
orbital margin, but is very small, seldom reaching the
‘front, and with the next joint occupies the narrow gap
intervening between the ‘ front’ and the inner angle of the
orbit. (In Ceratocarcinus the antennee are completely
excluded from the orbits.)

Some fifteen or twenty genera are reckoned in this
family, of which only one is known in the waters of Great
Britain.

Kurynome, Leach, 1814, has not yet received many

THE GREAT WARTY CRAB 121

additions to the type species Hurynome aspera (Pennant),
for though the names scutellata and boletifera have been
given to forms taken in the Mediterranean, it is probable
that they are not distinct’ from, or at most are only
varieties of, the species found on the British coasts. It 1s,

-as might be guessed from the names, a species rough with

warts or tubercles. The walking-legs are short, but the
chelipeds in the male are elongate, being nearly twice the
length of the body according to Bell, but according to
Leach three times its length. Hurynome tenuicorns,
Malm, from Bohuslin, Guilmarsfjord, 1s there found to-
gether with Hurynome aspera.

Partherépe, Fabricius, 1798, has in its type species,
Parthenope horrida (Linn.), an animal of truly remarkable
appearance. It is recorded from the West and East Indies,

and has been called the great Warty Crab or stigmatised

as the Lazy Crab. Its carapace is pentagonal, broader
than long. While this and the legs are covered with
warts and spines, the pleon is said to be full of pits, almost
as if eaten through. The chelipeds are large and long.
From the picture of it given by Herbst one might suppose
that it was intended to look like a piece of light-red sand-
stone overgrown here and there with green alge.
Lambrus, Leach, 1815, unlike the two preceding genera,
suffers from no paucity of species. So numerous indeed
are they that in 1878 Professor A. Milne-Edwards deemed
it expedient to subdivide Lambrus into ten genera, in-
cluding in the number Solenolambrus, Stimpson, and
Mesorhvea, Stimpson. The species are distributed over all
the warmer seas of the world, and some occur in the Medi-
terranean. Of these Lambrus macrochélos (Herbst), mean-
ing the Lambrus with long chelipeds, justifies its name, but
almost puts its body out of countenance, seeing that the
arms in question are nearly four times as long as either
the length or breadth of the carapace. In Lambrus inter-
medius, Miers (see Plate IV.), from the Corean Seas and
Torres ‘Strait, the disproportion between legs and trunk is
less exaggerated. In the genus at large” it is remarked
that, apart from larval metamorphoses, so many variations

422 A HISTORY OF RECENT CRUSTACEA

of form are undergone during progress to the adult con-
dition, that, without a considerable series of specimens,
young and old of the same species must often almost in-
evitably be considered as distinct.

Heterocrypta, Stimpson, 1871, contains but three
species, and those of small size but singular appearance.
One of these, Heterocrypta Maltzani, Miers, which has been
taken at Goree Island, at the Azores, and off Senegambia,
is also an ornament of the Mediterranean, having been
taken by the T'ravailleur at a depth of about 250 fathoms
off Toulon. The Mediterranean form was at first named
Heterocrypta Marionis, after the distinguished French
zoologist, but it has since been found to be the same
species as Heterocrypta Maltzam.

THE POINT EXPLAINED 125

CHAPTER IX

TRIBE IV.—OXYSTOMATA

THE carapace is convex or depressed, with the antero-
lateral margins arcuate or orbiculate ; or even subglobose ;
or more or less oblong, with subparallel or slightly con-
vergent margins (Dorippide). The epistome is very much
reduced or rudimentary. ‘The buccal frame is more or
less triangular, nearly always produced and narrowed
‘forwards with the margins anteriorly convergent. ‘The
afferent channels to the branchiz open either behind the
pterygostomian regions and in front of the chelipeds, or,
more rarely, at the antero-lateral angles of the palate
(Leucosiide). The efferent channels open at the middle
of the endostome which is produced forwards. There are
six to nine pairs of branchie. The first antenne fold
longitudinally or obliquely. The third maxillipeds have
the fifth joint articulated at the inner or the outer front
angle or at the apex of the fourth, beneath which it is
often concealed. The verges of the male are exserted
either from the surface of the sternal plastron or more
usually from the bases of the fifth pair of legs, which are
elther adapted for walking or for swimming, or are feeble
and raised upon the dorsal surface of the carapace.

It is the narrowing anteriorly of the buccal frame or
‘mouth-cavity ’ that gives the name of ‘sharp-mouths’ to
this tribe, which is divided into four families, the Calap-
pide, Matutida, Leucosiidz, and Dorippidee.

Family 1.—Calappide.

The afferent channels to the branchize open behind
the pterygostomian regions and in front of the chelipeds.

124 A HISTORY OF RECENT CRUSTACEA

The third maxillipeds have the fifth and following joints
not wholly concealed by the fourth joint. The verges of the
male are exserted from the bases of the fifth pair of legs.

There are about ten genera included in this family.

Calappa, Fabricius, 1798, contains some fifteen species,
which are not a little remarkable in appearance. This is
partly due to the form of the carapace, much narrowed in
front where the short-stalked eyes twinkle cunningly, but
widened behind with shield-like expansions over the bases
of the legs. More singular, however, is the development
of the chelipeds, which have.a very flat crested hand of
great size, yet the whole limb withal so arranged that the
pair can be concealed beneath the body to which in that
position they might be said to supply an operculum or in-
complete ventral carapace. Of Calappa granulata (Linn.)
Stalio says that, when it is compelled by fear of some
enemy or by the force of the waves to leave its crevice in
the rock, it draws together its walking-legs under the ex-
panded parts of the carapace, makes its chelipeds meet,
and, being thus reduced to the shape of a ball, launches
itself into the deep. Unfortunately for it, the scouring of
the waves often throws it up on to the shore, where con-
tinuous rolling upon the pebbles puts an end to its exist-
ence. This is a waste of what would otherwise form an
agreeable morsel. It may be eaten with a good conscience,
since it 1s itself very voracious, and when in pursuit of
prey not to be intimidated. Judging from the contents
of the stomachs of various Crustacea, de Haan was able to
decide that Calappa, Matuta, and Dorippe feed on other
Brachyura, Leucosia on species of Palemon, Ranina on
fishes and starfish. Calappa qallus (Herbst) is common to
the Atlantic and the Pacific. ‘The crested claws here carry
to an almost comical extreme the resemblance to the head
of a cock, which they exhibit more or less throughout
this genus. Calappa depressa, Miers (see Plate II.), from
the South Australian coast, is one of the smaller species
and a recent contribution to science.

Paracyclois, Miers, 1886, 1s a genus in which the cheli-
peds and walking-legs agree with those in Calappa and

A QUESTION OF PRIORITY 129

Cryptoséma, and it is considered to connect Cryptosoma,
Brullé, and Platyméra, Milne-Edwards, with Calappa
through such forms .as the above-mentioned Calappa
gallus (Herbst), but Paracyclois is distinguished from the
first two of these genera by the absence of any lateral
spine on the margin of the carapace, and the broader basal
joint of the second antenne, ‘and from Calappa by the
absence of the clypeiform prolongations of the carapace,
which are represented by a slight protuberance of the
postero-lateral margins in Paracyclois, which protuberance
bears several strong spines.’ The type species of this curious
genus, Paracyclois Milne-Hdwardsui, Miers, was dredged
north of the Admiralty Isles from a depth of 150 fathoms.

Cryptosoma cristatum, Brullé, was depicted in Webb
and Berthelot’s ‘ Hist. Nat. des Iles Canaries, and the

genus was instituted at page 16 of that work, for which

Miers gives the dates 1856-1844. Milne-Edwardsin 1837,
while his own pages were passing through the press, refers
to Brullé’s genus and species as about to be published.
In the same year, 1837, de Haan published a new genus
and species, Cycloés granulosa, from Japan. In 1841 he
states that Brullé’s species is clearly the same as this,
and in 1849 he repeats the remark as an example of wide
distribution, the very same crab being found at the
Canaries and in the waters of Japan. But he retains the
name Cycloés, being evidently, and perhaps rightly, under
the impression that it had priority over Cryptosoma.

Orithyia, Fabricius, 1798, is strongly distinguished
from the other genera of this family by the natatorial
character of the last three pairs of legs, which have an
ovate terminal joint, as in the Portunide. The three
preceding pairs of legs have also the terminal joints flat-
tened, and the others more or less compressed, as is usual
in species apt for swimming. There appears to be only
one species, found in the Chinese Sea, and called bima-
culatus by Herbst in 1790, and mammillaris by Fabricius
in 1793. Herbst, whose specific name must prevail, says
that ‘ without dispute this crab is one of the most beautiful
and most rare.’

126 A HISTORY OF RECENT CRUSTACEA

Family 2.—Matutide.

The characters are the same as in the Calappide, ex-
cept that the third maxillipeds have the three terminal
joints concealed beneath the triangular acute fourth joint.

The family contains four genera.

Matata, Fabricius, 1798, is regarded as the genus
among the Brachyura in which the adaptation for swim-
ming attains its highest: development. In the last pair of
legs the oval terminal joint is supplemented by a very
broad expansion of the preceding joint. Moreover, the
other three pairs of legs are natatorial, having broad flat-
tened joints, in particular the pair next the chelipeds evi-
dently forming paddles of great) power. Nevertheless,
none of these limbs are fringed with hairs, the ordinary
armature of swimming legs. The sufficient reason as-
signed for this is that the crab’s safety often depends upon
the extraordinary rapidity with which it can bury itself
in the wet sand. Its flattened joints have sharp points
and edges, with the digging powers of which any fringe
of fur would seriously interfere. As it is, they can slip
themselves under the sand in a moment, and before the
troubled water has cleared over their departing footsteps
the traces of them are smoothed and lost. Yet sometimes,
it is said, their movements may be perceived under the feet
of a person walking along the shore. Among the Japanese
specimens of Matuta victor, Fabricius, de Haan observed
some of what he calls ‘spurious’females, but he mentions
no peculiarities in them except their smaller size. If
Paulson’s identification be right, the name of this species
should become Matuta lunaris (Forskal.)

Alepitus, Latreille, 1806, has, according to de Haan,
the third joint much shorter than the fourth in the third
maxillipeds, whereas in Matuta those two joints are equal
in length. Hepatus princeps (Herbst) appears to be the
proper name of the type species, which occurs both in the
Kast and West Indies. This genus, and with it Osachila,

BEAUTIFUL COLOURING fa

Stimpson, and Acteeomorpha, Miers, are distinguished from
Matuta by having the terminal joints of the legs adapted,
not for swimming, but for walking. Osachila and Actewo-
morpha are, according to the author of tLe latter genus,
perhaps identical.

Family 3.—Leucosude.

The afferent channels to the branchiz open at the
antero-lateral angles of the endostome and not behind the
pterygostomian regions. The third maxillipeds have the
three terminal joints wholly concealed by the triangular
fourth joint. The verges of the male are exserted from
the sternal plastron.

In this family twenty-nine genera are accepted by
Miers in 1886. One of them is included in the fauna of
Great Britain.

Leucosia, Fabricius, 1798, contains numerous species,
which occur in the littoral and shallow waters of the Indo-
Pacific region. They are often remarkable for the beauty
of their colouring, testimony to which is borne in the
names of the species, Leucosia splendida, Haswell, and
Leucosia pulcherrima, Miers. ‘They have the frontal re-
gion of the carapace narrowed and produced anteriorly,
and in front of and above the bases of the chelipeds there
is a pit defined by a series of granules. This, which is
continued as a shallow excavation beneath the postero-
lateral margins of the carapace, has received the name of
the thoracic sinus. ‘The walking-legs are small, succes-
sively shorter from the front to the rear. The pleon of
the male in some species has all the segments united ex-
cept the first and last, in others the third coalesced with
the fourth, and the fifth with the sixth. A figure of
Leucosia australiensis, Miers, is given on Plate II. The
type species, scabriuscula, Fabricius, has been transferred
to the next genus.

Philijra, Leach, 1817, is a genus nearly allied to Leu-
cosia, with a similar range, and also containing several
species. But, among other distinctions, the ‘front’ is

128 A HISTORY OF RECENT CRUSTACEA

broader and not at all prominent, and there is no ‘ thora-
cic sinus.’ Philyra piswm, de Haan, is said to be infested,

Fie. 9.— Myra fugax (Fabricius) [de Haan].

like Leander squilla and Leander serratus, by a Bopyrus, .«
making the sides of the crab bulbous. De Haan remarks
that he never saw the Bopyrus in true females, and that
in males they occupy the right side, in spurious females

SOMETHING ABOUT SUB-GENERA 129

the left side, of the crab. The parasite referred to would
no doubt now stand under some other generic name.

Myra, Leach, 1817, is another genus of common occur-
rence throughout the Indo-Pacific region, of which the
species Myra fugax (Fabricius) has been frequently re-
named. It is remarkable for the great length which the
slender chelipeds sometimes attain, and which have caused
the Japanese to call it the long-handed crab.

Hbalia, Leach, 1817, has an extremely extended range,
and includes numerous species, among which several occur
in Kuropean seas, and four of them in the waters of Great
Britain. These four are Hbalia tuberosa (Pennant), Hhalia
tumefacta (Moutagu), Kbalia Cranchir, Leach, and Kbalia
nux, Norman. It is curious that Bell, in his ‘ History of
British Stalk-eyed Crustacea,’ should have thought it right
_ to follow Leach in calling the first two of these respectively
Lbalia Pennantii and Hbalia Bryeriz, while he relegated
the earlier names to the synonymy. ‘The resemblance
which these little creatures, with their legs all tucked up,
assume to a rugged little fragment of stone has been
already mentioned. Comparing Ebalia with a genus
Phlywia instituted by Bell in 1855, Mr. Miers says :—‘ The
genera Hbalia and Phlyaia are now connected by so many
intermediate species, that not one of the distinctive cha-
racters mentioned by Bell can be regarded as constant.
I propose, therefore, to unite these genera, but to separate
the species under two primary sections or sub-genera (for
which the names Hbalia and Phlyxia may conveniently be
retained) as follows :-—

‘I. Front slightly concave or truncated, not quadri-
dentated (Hbalia).’ This is followed by a list of twenty-
SIX species.

‘II. Front with four distinct (usually tuberculiform)
lobes or teeth, including the tooth at the interior angle of
the orbit (Phi yaa). This is followed by a list of seven
Species, in regard to which it is pointed out that all are
restricted to Australia. ‘The convenience of having a
generic name to indicate so small a mark of separation
may well be questioned, but the inconvenience of the sub-

130 A HISTORY OF RECENT CRUSTACEA

generic name scarcely admits of question, especially when
it leads to the possibility of a creature being called

‘ Kbalia (Phlyxia) undecimspinosa (Kinahan), var. orbi-
cularis, a name which is even then incomplete without
the addition of the names (Haswell) Miers, to show that
Mr. Miers has made Haswell’s Phlyzxia orlicularis a variety
of Kinakan’s Hbalia undecimspinosu.

Iva, Leach, 1815, has perhaps, according to Mr. Miers,
only one species, though five have been named. This one
is the Iva cylindrus (Fabricius), called Iva canaliculata by
Leach. It is widely distributed in the Indo-Pacific region,
and has a very remarkably shaped carapace, transversely
rhomboidal or somewhat elliptical, and prolonged at either
side into a cylindrical lobe, which is often as long as the
width of the main portion of the carapace.

Oreophorus, Riippell, 1830, ‘the hill-bearer,’ and
Spelceophorus, A. Milne-Edwards, 1866, ‘ the cave-bearer,’
have names referring to the prominences and depressions
im the carapace.

Fumily 4,—Dorippide.

The afferent channels to the branchize open behind the
pterygostomian regions, and in front of the chelipeds.
The three terminal joints of the third maxillipeds are not
concealed by the fourth joint. The last pair or last two
pairs of legs are short and feeble, and raised on the dorsal
surface of the carapace. The verges of the male are ex-
serted from the sternal plastron.

The family includes eight or nine genera, the position
of Cyclodorippe, A. Milne-Edwards, being rather doubtful,
since in it there are no afferent openings to the branchiz
in front of the chelipeds.

Dorippe, Fabricius, 1798, has a wide range, and in-
cludes several species. One of them, Dorippe facchino
(Herbst), is found both in the Mediterranean and at Hong
Kong. The first two pairs of walking-legs are long, and
enable the creature to run fast. The two following pairs
are very slender and short. To account for their dorsal
position various reasons have been suggested. Herbst ~

LOOKING LIKE A BUFFOON 131

says that the crab can run either way up. Another view is
that these hind legs lift foreign objects on to the carapace, \

pecimen, with separate figures, showing the chelipeds of the

male from the inner and outer sides, the left cheliped being the stouter [de Haan].

Fic. 10.—Dorippe japonica, von Siebold, a female s

and a third that they help to repel animals that might
otherwise tread on the crab’s back. The specific name
which Herbst gave it means a knave, and is its trivial name

11

132 A HISTORY OF RECENT CRUSTACEA

among the Italians, in,evident allusion to the resemblance
it bears to a comic mask. Similarly, Dorippe dorsipes
(Linn.) is not inappropriately named by the Japanese ‘ the
demon-faced crab.’ Dorippe japonica, von Siebold, repre-
sented on the preceding page, is closely allied to Herbst’s
Dorippe facchino.

Ethisa, Roux, 1828, unlike Dorippe, which usually
has the carapace broader than long, in general has the
carapace much longer than broad. Miers notices that
the species of this genus are the forms which evince
the greatest degree of degradation from the Brachyuran
type. In other words, they make the nearest approach
to the next tribe, which in Mr. Miers’ work is not in-
cluded among the Brachyura. Hthusa mascarone, Roux, is
a Mediterranean species. Ithusina, 8. I. Smith, 1884, is
closely allied to Hthusa, but distinguished by the form of
the first antennae, the basal joints of which are very large
and swollen, occupying the whole width of the ‘ front,’ and
crowding back the eyes and second antennee into an almost
transverse position. The type species, Hihusina abyssicéla,
Smith, was dredged off the East Coast of the United States
at a depth of about 1,500 fathoms, the members of this
genus and Hthusa being those which descend to greater
depths in the ccean than any of the Brachyura which we
have been hitherto discussing. ‘The species Ethusa granu-
luta, Norman, has been transferred to a separate genus,
Cymonomus, by Professor A. Milne-Edwards.

Cymopolia, Roux, 1828, has for its type species, Cymo-
polia Caronii, Roux, from the Mediterranean, but it includes
twelve species in all, of which eight have been recently in-
stituted by Professor A. Milne-Edwards from dredgings in
the Gulf of Mexico and Straits of Florida. De Haan con-
sidered that it ought to stand among the Maiacea, but his
opinion has not been followed.

CASHIERING THE ANOMURA i3a

CHAPTER X

TRIBE V.—ANOMALA

THe sternal plastron or breastplate is wide. The
branchiz lie obliquely, and may attain the number of
fourteen pairs. ‘The vulva open not on the breastplate,
but in the bases of the third pair of legs.

This tribe of Anomalous Brachyura has long been con-

-sidered a division of a separate sub-order called the

Anomura, meaning Stalk-eyed Crustaceans ‘with un-
symmetrical tails.’ To this division the name Apterira
was given, to distinguish it from another division called
Pterygira. The first name signifies those that have
unwinged tails, the second those that have winged
tails. The wings referred to are formed by the ap-
pendages of the sixth segment of the pleon, which in

the Pterygura are expanded on either side of the telson,

but which in the Apterura are not developed. By the
transfer of the latter division to the Brachyura its old
name becomes unsuitable, since all of that sub-order are
apterurous. It contains two legions, the Drominea and
Ranininea.

Legion 1.—Drominea.

The carapace is subglobose or subquadrate, the
‘front’ narrow. ‘The third maxillipeds have the third
and fourth joints subquadrangular. he lateral apode-
mata! of the trunk are united in a common centre, form-
ing a sternal canal. The last pair, and often the last two

1 The apodemata or apodemes are processes formed by an infolding
of the cuticle and extending inwards to give surfaces of attachment for
the muscles and to assist in protecting the internal organs.

134 A HISTORY OF RECENT CRUSTACEA

pairs of legs, are subdorsal in position and of small size.
he pleon folds under the trunk. In the female it has
five pairs of appendages, of which the first is rudimentary.

This legion is divided into two families, the Dromide
and Homolidee, the characters of which are here accepted
as laid down in Professor J. R. Henderson’s Report on
the Anomura of the Challenger.

Family 1.—Dromide.

The carapace is subglobular, rarely flattened. The
eyes are retractile into well-defined orbits. The first an-
tennee fold in special fossettes. The fifth and usually also
the fourth pair of legs are short, subdorsal in position,
and in general prehensile. The vasa deferentia of the
male pass through the bases of the fifth pair of legs and
form tubular prolongations.

The family contains some ten genera, one of which is
British.

The species, Dr. Henderson says, inhabit shallow
water and moderate depths. The majority protect the
body by an ascidian, a sponge, or by one of the shells of
a bivalve mollusc. Milne-Edwards says that of the four-
teen pairs of branchie! the last two spring from the last
two segments of the trunk, which in the Brachyura in
general never carry any. He regards two little lateral
pieces intercalated between the sixth and seventh seg-
ments of the pleon in Dromia as rudiments of the appen-
dages of the sixth segment, but that may be regarded
rather as a pious opinion than an established fact.

Dromia, Fabricius, 1798, almost monopolised the
family until it was subdivided by Stimpson into six
genera in 1858, this subdivision being grounded chiefly
on the disposition of the sternal sulci in the female.* In

1 Branchiz are called pleurobranchie when attached to the pleura
or sides of the segment, podobranchiz when attached to the first joint
of the limb, arthrobranchiz when they spring from the interarticular
membrane between the segment and the limb.

2 For the structure of these sulci and the correspondence of the ap-

pendages on the pleon of the male, see the account in de Haan, Fauna
Japonica, Crustacea, p. 10d,

A MISNOMER AND A MISAPPREHENSION 135

Dromia, as restricted by Stimpson, these sulci are ‘not
approximated, only produced as far as the segment which
bears the second pair of legs.’ The carapace in this genus
is subglobose and usually hairy. Fabricius, in describing
Dromia Rumphi as the type species from the East Indies,
says that it hides in the sand holding the valve of a shell
over its body with its hind feet, and so lies in wait for
little fishes. It was called Cancer dormia by Linnzeus,
perhaps in allusion to the widely prevailing idea that it
is poisonous and narcotic. Herbst, for this reason, im-
proved the Linnzan name into Cancer dormitator, meaning
the crab that sends you to sleep, for he rejected a previous
improvement of the name into dromia, on the ground that
to call it the running crab was to name it quite in contra-
diction to its habits. In spite of, or in ignorance of, this
- criticism, Fabricius converted the specific name dromia
into the name of the genus, which holds its ground not-
withstanding the inappropriateness to a creature of espe-
cially sluggish habits.

Dromia vulgaris, Milne-Edwards, is sometimes taken
in English waters. It is very common in the Adriatic,
and according to Stalio the ancients were quite mistaken
in attributing to it a poisonous character. Herbst seems
to have thought the Dromia Rumphi ‘by the hand of
nature marked, quoted and signed, to do a deed of shame,’
for, after describing its rough, brown, furry coat, its short,
thick legs, and the last pair armed with sharp-pointed
claw like a scorpion’s tail, he adds that ‘ everything con-
tributes to give this crab a repulsive and horrible appear-
ance, perhaps to scare men from eating it, since it is very
poisonous. He subsequently noticed that when stripped
of its fur it lost its grimness of aspect.

The habit of concealment that runs through this
family is referred to in several of the generic names, as in
Cryptodromia, Stimpson,.1858, the concealed Dromia, in
Hypoconcha, Guérin Méneville, 1854, the crab under a
shell, in Conchecétes, Stimpson, 1858, the shell-dweller.
Among the Crustacea collected a few years back by
Surgeon-Major Archer on the sand and mud banks north

136 A HISTORY OF RECENT CRUSTACEA

of Singapore, there were, he says, ‘two species with curved
hooks on their hindmost claws, by means of which they
hold on to a mangroyve-leaf or a dead valve of a shell which
conceals the animal from view; these leaves and dead
valves may be seen apparently walking along on the shore.’
The species in question are supposed by Mr. A. O. Walker,
in his account of the collection, to be Dorippe sima, Milne-
Edwards, Dorippe astuta, Fabricius, and Conchcecetes conchi-
jera (Haswell). Bell says of numerous young specimens
of Dromia vulgaris, which he had received from Sicily,
that every one had the carapace entirely covered with a
sponge, which concealed the two hinder pairs of legs, and
rendered them immovable. In Cryptodromia lateralis
(Gray), a species which ranges from Australia and New
Zealand to the coasts of Japan, the animal is said to have
almost invariably a sponge fixed on the carapace, covering
it completely. Hypoconcha sabulosa (Herbst), besides
protecting itself with the shell of a Lamellibranch mollusc,
perhaps wears an inner vest of sand, for the museum speci-
men which Herbst examined was, he says, more like a
lump of sand than a crab, and the carapace he found
was extremely thin, delicate, and almost membranaceous.
In this genus the sternal sulci of the female are widely
separate, ‘each terminating in a tubercle opposite the
basal joint of the second ambulatory leg. The terminal
joints of the last two pairs of legs are described as Y-
shaped, but it must be remembered that the two arms of
the Y are by no means equal.

Petaloméra pulchra, Miers, a Melanesian species of
very small size, may be noticed as one member of this
family which has obtained the epithet of beautiful,
although in general figure it is not so very remote from
the Dromia of which Herbst speaks so disrespectfully.

Dynomene, Latreille, 1825, is distinguished from the
rest of the family by having only the fifth pair of legs sub-
dorsal in position.

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APPEARANCES DECEPTIVE 137

Family 2.—Homolide.

The carapace is quadrangular or subtriangular. The
eye-stalks are usually slender and very long, the orbits
very incomplete. The first antennee are not retractile into
special fossettes. The last pair of legs are small, pre-
hensile, subdorsal in position.

The family may include five genera. The species ex-
tend to moderate depths.

Dieranodromia, A. Milne-Edwards, 1880, is what is
called an inosculant genus. By the character of the last
two pairs of legs it should belong to the Dromide, but the
defective orbits and the want of fossettes for the first
- antennee place it among the Homolide.

Homéla, Leach, 1815, has the carapace quadrilateral,
of greater length than breadth. The eye-stalks have a
long slender basal part and a shorter dilated corneal por-
tion. The chelipeds are of moderate size, the three follow-
ing pairs of limbs are long and flattened, while the last
pair are short and subchelate. Homola barbata (Herbst)
and Homola Cuvieri, Risso, occur in the Mediterranean
and Atlantic. Homola orientalis, Henderson, is a Pacific
species.

Latreillia, Roux, 1828, has a triangular carapace. The
eye-stalks are very long and slender, cylindrical, turned
forwards, and divergent. The legs are slender and cylin-
drical, the three middle pairs being very long. The four
species belonging to this genus are apportioned two to
Japan, one to Australia, and one, Latreillia elegans, Roux,
to the Mediterranean and Atlantic. The figures in Plate V.
represent the Japanese Latreillia valida of de Haan, from
whose work they are copied on a reduced scale. At the
first glance any one would be tempted to place the genus
among the spider-crabs in the tribe Oxyrrhyncha, but
de Haan showed the impropriety ofthis. ‘The same struc-
ture, he says, ‘which prevails in Dromia and Homola is
found in the species of Latreillia. They agree in the organs

138 A HISTORY OF RECENT CRUSTACEA

of feeding, motion, and generation, and in the fabric of the
trunk within. The vulve are not in the trunk, but in the
bases of the third pair of legs. The sternum is deeply ex-
cised between the last pair of legs; the turkish saddle!
and median apodeme are wanting; the transverse septum
of the apodemes forms in the middle a central yoke and
central canal. Jurther, they show a peculiar affinity to
Homola by the eye-stalks, which are very long, thin,
apically inflated, as good as free,” by the first antennee not
retractile into fossettes, by the first and third maxillipeds,
which so agree in the two genera that they can scarcely
be distinguished. With the Maiacea, therefore, Latreilliu
cannot be confounded, although the form of the trunk is
triangular, the legs are very slender, the epistome is qua-
drate, and of the branchie there are ten pairs, of which
three are connected with the maxillipeds, two with the
chelipeds, and three with the following legs, but the last
united with the penultimate legs.’

Latreillopsis, Henderson, 1888, with a type species,
Latreillopsis bispinosa, from the Philippine Islands, ‘ occu-
pies an intermediate position between the genera Homola
and Latreillia. From Homola it is distinguished by the
arrangement of the rostrum and supraorbital spines, the
greater length of the ocular peduncles, and more especially
by the elongated cylindrical legs. In Latreillia, on the
other hand, the frontal region is narrow and produced so
as to give the carapace a triangular outline, the supra-
orbital spines are more strongly developed, and the eye-
stalks and legs are of greater length.’ It may perhaps be
regarded as something more than a mere coincidence that
this link between Homola and Latreillia was obtained by
the Challenger in one of the two localities in which the
same vessel took specimens of those two genera.

Homologénus, A. Milne-Edwards, 1888, bears a name
altered from the pre-occupied Homolopsis, 1880. It differs

1 The expression ‘posterior turkish saddle,’ is applied by Milne-
Edwards to the small arch formed by the sternal apodemes which
spring from the hind margin of the last segment of the trunk.

2 The Latin is totis quantis liberis.

THE RANININEA 139

from Homola in having a more ovoid carapace, a more de-
veloped rostrum, feebler legs, and especially in the form
of the eyes which are very small and not narrowed at the
base.

Here also should perhaps be placed some Australian
species of the genus Paratymolus, Miers, 1879, in which
the carapace is deflexed in front, flat behind, with the
sides nearly straight, the ‘front’ being prominent and
narrow. For a new family Paratymolide Mr. Haswell ©
gives the characters, ‘carapace in general form similar to
the Maioidea. External maxillipedes partly over the epi-
stome. He thinks that it would perhaps be better placed
among the Corystoidea. Mr. Miers, however, does not
agree with this view, but thinks that it ought to stand
near the Dromide. It is an argument the more for in-

cluding the present tribe in the Brachyura, that two

experts should be unable to agree whether a genus belongs
to it or another tribe which is brachyuran beyond question.

Legion 2.—Ranininea.

The carapace is ovate-oblong, with the regions not
defined, and the ‘front’ of varying width. The orbits
are well marked. ‘The first antenne are without special
fossettes, and are placed to some extent behind the second
pair. The third maxillipeds are moderately elongate.
The sternal plastron or breastplate is wide anteriorly.
The walking-legs have the terminal joint broad and com-
pressed ; the last pair of legs are small and subdorsal in
position. ‘The vasa deferentia of the male are protruded.
The pleon is short, partially extended, not folded under
the trunk, with four pairs of appendages in the female.

Dr. Henderson includes the epithet ‘smooth’ in the
description of the carapace, but this is obviously unsuited
to Ranina scabra.

Dr. Boas has ingeniously suggested that the position
of the vulvz in the bases of the legs instead of in the
sternal plastron has been brought about by the extreme
narrowing of the plastron, and this may well have been

140 A HISTORY OF RECENT CRUSTACEA

so, though such a species as Petalomera pulchra in the pre-
ceding legion does not seem to suit the theory. One may,
however, suppose that in some instances a re-widening of
the plastron may have been developed without any re-
arrangement as to the position of the vulvee.

This legion contains the single family Raninide, for
which, therefore, no separate character is needed. It
includes some nine genera, limited to the warm seas, and
inhabiting chiefly the tropics, with a range of depth
apparently not exceeding 300 fathoms.

Ranina scabra (Fabricius), originally called Cancer
raninus, Linn., and afterwards Ranina serrata, Lamarck,
and Feaiind dentate, Latreille, from Amboina andl the Sand-
wich Islands, was known to fame long before a separate
genus was established for it. The carapace has been com-
pared to an inverted triangle. It is very broad anteriorly, but
the sides slope very gradually to the rounded hinder margin.
The eye-stalks are three-jointed, strongly geniculate, and
have a very deep orbit. The pterygostomian regions of the
carapace unite with the sternal plastron so as completely
to separate the third maxillipeds from the chelipeds. The
plastron itself is anteriorly almost trefoil-shaped, but to
the rear becomes linear. The branchie, Milne-Edwards
says, are arranged as in the Brachyura, but in the confor-
mation of the respiratory cavity there is a peculiarity of
which he knew no other example. As in the Leucosiide,
the carapace is joined to the sternum and the cavity of the
sides, without leaving above the base of the feet or maxil-
lipeds any space for the entrance of the water necessary
for breathing, but the afferent channel instead of being
pierced beside the efferent channel, on the sides of the
mouth, is situated behind and has a special opening below
the base of the pleon. This view, however, is criticised by
de Haan in a passage that is not free from perplexity.
‘In Portunus and Grapsus, he says, ‘the water is brought
to the branchize by a double path and removed by a double
path ; it reaches the branchial cavity by the mouth and
the apertures near the base of the chelipeds; but it passes
out both by the space between the inferior lateral margin

A DISCUSSION ON BREATHING 141

of the trunk and the epimera and by two ducts under the
insertion of the pleon. In Hthusa the case is the same.

Fie. 11 —Ranina scabra (Fabricius), a male specimen, with separate figure of the pleon
[de Haan].

In Calappa and Matuta the hinder ducts are not below but
close to the pleon over the first joints of the fifth pair of

142 A HISTORY OF RECENT CRUSTACEA

legs. In Dorippe, Leucosia, and Ranina, the lower border
of the trunk closely coheres with the epimera (compare
Milne-Edwards, vol. 2, p. 193). In the first the anterior
apertures, in which the first joints of the third maxillipeds
work, are remote from the base of the chelipeds; but in
the following they are altogether wanting; so that these
have only one path on each side by which the water reaches
the branchiz, aud one by which it is withdrawn. The
hinder ducts in fanina are broader than in other families
and amplified by lateral apophyses, but otherwise in Portu-
nus and Grapsus they are in the same place.. The water
appears to enter the branchial cavity by the anterior aper-
tures, and to issue by the hinder ones, and not to have a
diverse or in Ranina and Leucosia a contrary motion
(compare Milne-Edwards, vol. 1, p. 88, vol. 2, p. 194).
In the anterior part there is a force, namely the movement
of the maxillipeds, by which the water is brought in ; that
being expelled behind, follows the movements of the body ;
the apertures beside the base of the chelipeds and the
branchial appendages of the maxillipeds are ciliated on
the margin, and by these cilia alien bodies are kept away
from the branchiz, when water is brought to them from
in front, whereas [they would be] of no use but a hindrance
to breathing, were the water brought from behind.’

Fritz Miiller refers to the statement made by Milne-
Edwards about the breathing arrangements of Ranina, but
does not mention de Haan’s contrary opinion. Fritz Muller
himself unfortunately had not had an opportunity of per-
sonally investigating the question Judging from Milne-
Edwards’ figure of Ranina dentata, it would appear to
have an arrangement of the pterygostomian regions not
unlike that already described in the genus Sesarma, by
which the crab when on dry land is enabled for a long
time to go on breathing the same small stock of sea-water.
Such an arrangement would undoubtedly be convement
for the Ranina, if the story be true that it has a decided
propensity for climbing on to the roofs of houses. Milne-
Edwards attributes this story to Rumphius, but nothing
of the kind appears to be included in that author’s account

DOG-CRAB AND FROG-CRAB 143

of his Cancer raniformis, though in the next preceding
description he tells of a swift-running ‘ dog-crab,’ Cancer
caninus, which is said to burrow under houses and enter
them. When the limbs of Ranina are drawn together it is
said to look not unlike a frog, a resemblance to which the
generic name points, as well as the trivial name of frog-
crab, and the specific name raniformis given it by
Rumphius.

Raninoides, Milne-Edwards, 1837, is nearly allied to
Ranina, but has the last pair of legs very short and thread-
like instead of equal in size and similar in shape to the
preceding flattened pair. In Raninoides personatus, Hen-
derson, the pterygostomian areas are described as being
strongly granulated as well as slightly pubescent, and the
same is said of the type species of a new genus, Notopoides
latus, Henderson, 1888. In the female of this species
there is an ovoid median opening in the sternum, between
the third and fourth pairs of legs. Raninoides personatus
has a similar opening but of very small size. The function
of these apertures does not appear to have been ex-
plained.

Notépus, de Haan, 1841, includes several species, in
which the last pair of legs are of moderate size, not fili-
form. As the name of the genus implies, their position
is dorsal, and this, though a character common to the
family, is again emphasised in the specific name of Notopus
dorsipes (Fabricius). Of a crustacean allied to this,
Darwin, in his ‘ Naturalist’s Voyage,’ gives the following
account :—‘ During our different passages,’ he says, ‘ south
of the Plata, I often towed astern a net made of bunting,
and thus caught many curious animals. Of Crustacea
there were many strange and undescribed genera. One,
which in some respects is allied to the Notopods (or those
crabs which have their posterior legs placed almost on
their backs, for the purpose of adhering to the under side
of rocks), is very remarkable from the structure of its
hind pair of legs. ‘The penultimate joint, instead of ter-
minating in a simple claw, ends in three bristle-like
appendages of dissimilar lengths—the longer equalling

144 A HISTORY OF RECENT CRUSTACEA

that of the entire leg. These claws are very thin, and are
serrated with the finest teeth, directed backwards: their
curved extremities are flattened, and on this part five most
minute cups are placed which seem to act in the same
manner as the suckers on the arms of the cuttle-fish. As
the animal lives in the open sea, and probably wants a
place of rest, I suppose this beautiful and most anomalous
structure 1s adapted to take hold of floating marine
animals.’

Tyreidus, de Haan, 1841, has the eye-stalks short and
the orbits are ill-defined, which is contrary to the family
character. The genus was originally instituted for Lyrei-
dus tridentatus, the lyre-shaped crab of Japan. That
species has been traced southwards to Australia; another
species, Lyreidus Bairdi, 8S. I. Smith, has been found off
the east coast of the United States.

Zanclifer, Henderson, 1888, has the eyes rudimentary,
with cornez of small size though
pigmented, on short peduncles,
in ill-defined orbits. The first
antenne are small, completely
concealed by the massive pedun-
cles of the second pair, which meet
together in the middle line. The
name means sickle-bearing, in
allusion to the uncinate character
of the terminal joint in the walk-
ing-legs. There is at present only
one species, Zanclifer caribencis
(de Freminville), and of this only

| two specimens are known. One

te eenicis (Henderson). Of these, ‘the figure of whichts
here reproduced, was obtained. by

the Challenger off the coast of Brazil, the other was taken
more than forty years earlier by M. de Freminville in the
Caribbean Sea. The French captain described it under
the name of Hryon caribensis, thus referring it to a fossil
genus with which it has nothing to do, and making im-
portant mistakes in the descriptioa which were pointed

A RARE SPECIES 145

out by Milne-Edwards a few years afterwards. Dr. Hen-
derson was only able to identify the Challenger specimen
with de Freminville’s by help of a pencil-drawing pointed
out to him by Professor Alphonse Milne-Edwards in the
library of the Natural History Museum at Paris. The
elder Milne-Edwards, though assigning the species to the
vicinity of the Raninidee, did not alter the generic name.
Judging by the rudimentary nature of the eyes and the
structure of the limbs, Dr. Henderson conjectures that
this crustacean may be fossorial in habit. If it be so, the
rarity of its capture would be the less to be wondered at.

To one of the genera of this family may probably be
assigned the West-Indian crab, which for some inscru-
table reason has been called the Mamma Shrimp. It is
figured and described by Patrick Browne in his ‘ History
of Jamaica.’ Herbst (Bd. I., p. 196), in 1790, supposed
it to be a near relation of Corystes cassivelaunus, but this
notion is based only on a very slight superficial resem-
blance between the two species.

Since Iyreidus and Zanclifer agree in having the
orbits ill-defined, the statement that in this legion ‘the
orbits are well marked’ is too absolute. In the defini-
tions of natural history, where living things are con-
cerned, almost every assertion sooner or later requires to

be qualified by the adverb ‘ usually.’

146 A HISTORY OF RECENT CRUSTACEA

CHAPTER XI

SUB-ORDER II.—MACRURA

THE carapace in general is shorter than the pleon and has
the ‘front’ produced into a more or less decided rostrum.
The stalked eyes are not enclosed in orbits, but usually
rest in a hollow on the upper surface of the basal joint of
the first antennz. Both pairs of antennz- are generally
elongate, the first not planted in fossettes, the second
usually carrying a scale or acicle attached to the second
joint. The third maxillipeds are elongated and pediform.
The five pairs of pereeopods or limbs of the trunk vary
greatly, as any of them may be chelate and any of them
simple. ‘The sternal plastron or breastplate is linear in
general. The vulvee of the female open in the basal joints
of the third pair of legs, and the vasa deferentia of the
male pass through those of the fifth pair. ‘The pleon is
seldom completely reflexed against the breastplate. Of
the six pairs of pleopods the first varies from the succeed-
ing, and all may be absent; but except in the Lithodide
that belonging to the sixth segment is always present,
this pair with the telson forming the Rhipidura or tail-fan.
Otoliths of some kind are very commonly present in the
basal joint of the first antenne.

In the above definition the Pterygurous division of
Milne-Edwards’ Anomura is included. After explaining
the grounds upon which Milne-Edwards had introduced
his tripartite arrangement, de Haan makes the following
comment upon it:—‘The division of the Decapoda into
Brachyura and Macroura is for various reasons to be pre-

REVIVAL OF AN EARLIER VIEW 14,7

ferred. The Anomoura are not distinguished from the
Brachyura and Macroura by any common character ; from
the former they differ by the disposition of the vulvz,
from the latter by not having a fan-shaped termination to
the pleon. But all the organs vary extremely in the
Anomoura, and no bond of connexion between the Apte-
rura and Pterygura is found either in the shape of the
antennee, mouth, maxillipeds, trunk, plastron, branchiz,
or in that of the pleon. The Anomoura contain forms
which differ more from one another, than the Brachyura —
do from the Macroura. By the Anomoura the closest re-
lationships are torn asunder, as the Dromiacea from the
Maiacea, the Raninoidea from the Leucosiz, the Porcel-
lanidea from the Galatheze, the Megalopidea from the
Astacoidea.’ : |

This criticism, published in 1841, appears now to be
winning deserved acceptance. The recent researches of
M. F. Mocquard into the armature of the stomach also
show the Anomura to be an artificial division. With the
transfer of the Pterygura to the Macruran sub-order, in
which all the families are pterygurous, the name becomes
inappropriate and may give place to the older name
Anomala, used by Latreille, though in a narrower applica-
tion. Any slight inconvenience that may result from the
similarity of name between the Brachyura anomala and
Macrura anomala will be compensated by the reminder
thus supplied that these two tribes correspond with the
collective Anomura of Milne-Edwards.

The Macrura contain the following tribes :—Anomala,
Thalassinidea, Scyllaridea, Astacidea, Stenopidea, Penzi-
dea, Caridea, among which will be found along with others
those popularly well known as Hermit Crabs, Lobsters,
Crayfishes, Prawns, and Shrimps.

The following Table shows the subdivision of the tribes
into legions and families :—

148 A HISTORY OF RECENT

Tribes.

Anomala .

Thalassinidea

Scyllaridea

Astacidea .

Stenopidea

Pensidea .

Caridea .

M ACRURA
Legions.
Hlippinea . .
Lithodinea 3
Pagurinea . .
Poreellaninea

Galatheinea :

{Crangoninea .

Polycarpinea

Monocarpinea

Haplopodinca .

CRUSTACEA

° Hippide.

Families.

Albuneide. Y
Lithodide.

Paguride.

| Coenobitidee.

foe

Parapaguridee.
Porcellanide.
Galatheide.

Callianassidee.
Axiide.
Thaumastochelidee.
Scylaridee.
Palinuride.

(/Eryontide.
Nephropside.
Potamobiidie.
Parastacide.
Stenopide.

s Penzide.

( Sergestidee.
Crangonide.

( Nikidee.
Alpheide.

‘ (Bees

Pandalide.

Thalassocaridse
Atyidee.
Pontoniidee.
Caricyphide.
Acanthephyride.
Paleemonide.
Nematocarcinide. .
Tropiocaridz. (?)
Stylodactylidee.
Pasipheeidee.
Oodeopide.

Hectarthropida,

MACRURA ANOMALA 149

TRIBE I.—ANOMALA.

The pterygostomian regions are free from the epistome
and marked off from the back by a suture or continuous
furrow. ‘The fifth pair of legs are generally weak, not fit
either for walking, swimming, or grasping food and prey.

The tribe embraces five legions, Hippinea, Lithodinea,
Pagurinea, Porcellaninea, Galatheinea.

Legion 1.—Hippinea.

The carapace is ovate or subquadrate, comparatively
smooth, the regions ill defined, the ‘ front’ broad. The
corneze of the eyes are small. The first antennz are in
general strongly developed, with one flagellum elongate,
the other of moderate size or absent. The second antennee
have usually a short flagellum and a massive peduncle of
four or five joints, with or without a movable acicle on
the second. The third maxillipeds are moderately broad,
sub-operculiform. The walking-legs have a flattened
terminal joint. ‘The fifth pair are slender and filiform and
folded under the preceding pair. The sterna of the trunk
are linear. The pleon is partially extended, with the tel-
son large, longer than broad, and the preceding segment
carrying a pair of biramous lamellar appendages, not so
arranged as to form a rhipidura. The males have no
appendages to the pleon but those of the penultimate
segment. |

The members of this legion inhabit the shallow waters
of tropical and subtropical seas. They are divided between
the two families of the Hippide and Albuneide.

Family 1.—Hippide.

The third maxillipeds are sub-operculiform, with a brcad
fourth joint; the exopod is wanting. The first pair of legs
are sub-cylindrical and not chelate. The telson is elongate,
lanceolate.

This family includes three genera.

Hippa, Fabricius, 1793, has been much restricted since
it was first instituted. It is now especially distinguished

150 A HISTORY OF RECENT CRUSTACEA

from its companions by the large and long flagellum of
the second antennee. LHippa emeritus (Linn.) is regarded
by Mr. J. E. Ives as a very variable species widely distri-
buted on the east and west coasts of North and South
America. Itis used, he says, by the fishermen for bait,
and large numbers are dug from the sand. It is not un-
likely, as suggested by Milne-Edwards, that Hippa tal-
poida, Say, the ‘ mole-like’’ Hippa, is the same species. It
was upon this that Professor 8. I. Smith made his obser-
vations at the United States’ Biological Station at Wood’s
Hole, Massachusetts, in the summer of 1875. He was
there able to obtain a nearly complete series of the post-
embryonal stages, and has since elaborately described the
second, third, and last zoéa forms, and the succeeding me-
galopa condition. Some of his figures are reproduced on
Plate [V. He observed that the adults preferred a very
narrow zone of the shore, at or very near low-water mark,
where they lived gregariously, burrowing in the loose and
changing sands.

‘The smooth, oval form of the animal, he says, ‘ with
the peculiar structure of the short and stout second, third,
and fourth pairs of thoracic legs, enables them to burrow
with far greater rapidity than any other crustacean I have
observed. Like many other sand-dwelling crustaceans,
they burrow only backwards; and the wedge-shaped pos-
terior extremity of the animal, formed by the abrupt bend
in the abdomen, adapts them admirably for movement in
this direction. When thrown upon the wet beach, they
push themselves backward with the burrowing thoracic
legs, and by digging with the appendages of the sixth
segment of the abdomen slightly into the surface, direct
the posterior extremity of the body downward into the
sand.’

The second antennz are generally held between the
second and third maxillipeds, with the peduncles crossed
in front, and the flagella curved down and entirely round
the mouth so that the setee with which they are densely
armed all project inward. Their function is not un-
reasonably supposed to be that of removing objectionable

WEAK JAWS 151

particles from the other appendages within their reach.
For this brushing service they must be well adapted,
since in ordinary adult specimens there are from a hun-
dred to a hundred and fifty joints in the flagellum, and
from eight to twelve setz to each joint. Most of these
setze are only slightly bent, but armed on the outside of
the curve with a great number of variously shaped teeth.
On either side of each bundle, however, there is a very
long seta, convolutely curved inward at the extremity, and
along nearly its whole length densely furnished with long,
slender, secondary setze, arranged in a double series on the
inner side of the curve. Already in the megalopa stage,
Professor Smith found that the mandibles had become thin
and foliaceous and completely consolidated with the walls
of the oral opening. ‘This extremely unusual condition of
_ those organs persists in the adult, and seems to have per-
plexed the few naturalists who have earlier examined them.

It must be a subject of surprise that a crustacean of such
a family as this should be able to dispense with the biting
power usually so strongly developed in the mandibles. But
we are told that in all specimens examined the alimentary
canal was filled with fine sand, and as the material from
‘the stomach showed under the microscope a small quantity
of vegetable matter, the inference is not improbable that,

much after the fashion of the earthworm, the creature ob-
tains nutriment from the sand which it passes through its
body. Milne-Edwards was evidently under the impression
that the true second segment of the pleon in this genus
was its first segment, but Professor Smith has shown very
clearly that the first pleon-segment is in the adult coalesced
with the trunk, a thing very unusual but none the less in
this case quite to be depended on.

Remipes, Latreille, 1806, has the peduncle of the
second antenne large, but the flagellum quite small. The
first segment of the pleon is free, the telson lanceolate, of
great length. As in Hippa, the female carries appendages
on the second, third, fourth, and sixth segments of the pleon.
The founder of the genus and several writers since have
supposed the first pleon-segment to be the last segment of

452 A HISTORY OF RECENT CRUSTACEA

the trunk, a mistake which Professor Smith has now cor-
rected. Lemipes testudinarius, Latreille, has been recorded
by this and various other names from many parts of the
Indo-Pacific region. Its true name would seem to be
Remipes adactylus (Fabricius). Remipes scutellatus (Fabri-
clus) is found in the Atlantic.

Mastigochirus, Miers, 1877, meaning ‘ with a whip-like
hand,’ was previously called Mastigdpus by Stimpson in
1858, but the name being pre-occupied had to be changed.
Its chief distinction from Remipes rests on the form of the
long and slender first pair of legs, which have the terminal
joint subdivided. The type specimen of Mastigochirus
qguadrilobatus, Miers, came from the Philippine Islands.
A comparison of this with others subsequently obtained by
the Alert in the Prince of Wales’ Channel showed Mr.
Miers that ‘the number of joints in the terminal flagelli-
form portion of the anterior limbs (which are imperfectly
seen on account of the hairs with which they are thickly
clothed) was understated in the original description ; in-
stead of being ten or twelve, they are usually twice as
pumerous.’

Lamily 2. —Albunciden.

The third maxillipeds are subpediform, with the fourth
joint not greatly dilated; there is a small exopod. The
first pair of legs are flattened and chelate. The telson is
ovoid.

Albunea, Fabricius, 1798, has for its type species the
little Albunea symnista (Linn.), from eastern waters. The
carapace is strongly grooved behind for the reception of
the small first segment of the pleon. In Milne-Edwards’
‘ Histoire Naturelle des Crustacés,’ vol. 2, p. 202, the dis-
tinguishing characters of Remipes and Albunea are trans-
posed, but the error is subsequently corrected.

Legion 2.—Lithodinea.

The carapace is broadly ovate, uneven, with the regions
well defined and a prominent rostrum. ‘The first antenne
have cylindrical peduncles of moderate size and short

aad ‘UeeH Op *Xld}Sly Sapoyy!T

by

GLOBE-TROTIERS 15a

flagella. The second antennez have an acicle on the second
joint. The third maxillipeds are subpediform, with the
third and fourth joints elongate. The first legs of the
trunk are chelipeds; the three following pairs are well de-
veloped, more or less cylindrical, and the last pair are
slender, chelate, folded in the branchial chambers. The
sternal plastron is wide. The pleon is bent under the
trunk, having the first segment small and dorsally fused
with the second; it has appendages only in the female,
these being a rudimentary pair on the first segment, and,
as a rule, a single one-branched appendage on the left
side of each of the four following segments.

The single family Lithodidee has the characters of the
legion. The members of it are found in the cold and tem-
perate shallow waters of both hemispheres, but deep-sea
dredgings, especially those of the Talisman, have shown
that at great depths, even below a thousand fathoms,
species occur in the tropics. Thus, it has been pointed
out, the Arctic and Antarctic zones are connected by a
submarine tunnel of cold water. The genera are not very
numerous. One is found in the waters of Great Britain.

Inthodes, Latreille, 1806, is now represented by several
fine species from distant parts of the world. Lithodes
maia (Linn.) has long been known. It is the devil-crab
of the Norwegian fishermen, according to Herbst. Bell
calls it the Northern Stone Crab, and is surprised that
what he calls its slight resemblance to Maia squinado
should have caused it to be at times confused with that
species. The superficial resemblance, however, is not in-
considerable, when the dorsal view alone is regarded.
The ventral view permits of no confusion or mistake, for
in Inthodes the pleon has in the third, fourth, and fifth
segments paired calcified plates, the median portion being
membranous with scattered calcareous particles. In the
female the plates are greatly developed on the left side to
the disparagement of those on the right, producing a want
of symmetry akin to that which is found in the Paguride.
The rostrum in Lithodes is spinulose, like almost all the
other external parts of the animal. Lithodes histriz, de

154 A HISTORY OF RECENT CRUSTACEA

Haan, portrayed in the adjoining Plate, is called by the
Japanese Aka-oni-gani, which according to de Haan means
the red crab of the devil. ILnthodes Agassiz, Smith, has
been taken in the Atlantic from depths of a thousand and
twelve hundred and fifty fathoms. Lithodes Murrayi, Hen-
derson, was obtained in the Southern Ocean from three
hundred and ten fathoms depth.

Oryptolithédes, Brandt, 1849, with its species Crypto-
lithodes typicus, Brandt, from California, is especially dis-
tinguished by the great development of the carapace,
which completely hides the legs, antennze, and pleon, and
these when viewed from below appear to be placed in the
bottom of a cup-like cavity. According to Stimpson, this
development of the carapace is unequalled in any even of
the higher decapods, not excepting Cryptopodia and ithra,
and this is the only instance in which the carapace con-
ceals all the feet.

Kchidnocérus, White, 1848, contains one or two mas-
sive species from the West Coast of America, the carapace
in Echidnocerus setimanus (Gibbons) sometimes measuring
ten inches in length and as many in width, and by a
weight of over seven pounds exceeding that of the cara-
pace even of the giant Macrocheira of Japan.

Lomis, Milne-Edwards, 18357, has a very
small rostrum, consisting of a single tooth.
The little Lomis dentata is described by
de Haan from Japan. Its carapace about
half an inch in diameter forms a strong con-
trast to the preceding species.

Fic. 13.—Lomis den- Paralomis, Stimpson, 1858, has a ros-

‘aa (de Haan]. tram which is usually trispinose, and in this
genus the third, fourth, and fifth segments of the pleon in
the female have the lateral plates subequal, and the median
portion occupied by a series of large calcareous plates
instead of particles.

Hapalogaster, Brandt, 1851, has the appendages of the
second pleon-segment in the female biramous instead of
one-branched as in the other Lithodide. Its second
antenne are much longer than the carapace, as in Porcel-

<>

a

)

RANGE OF THE HERMIT-CRABS 155

lana. The pleon is soft as in a hermit-crab, but. re-
flexed. —

That the fifth pair of legs in the crustaceans of this
family should be folded in the branchial chambers must
seem a very strange arrangement, unless consideration is
directed to the advantage which may thus be attained in
keeping the branchiz clear from parasites.

Legion 2.—Pagurinea.

The carapace is elongate, becoming weak or membra-
naceous behind the cervical groove, which divides the
gastric and hepatic regions from the cardiac and branchial.
The second antennz have an acicle. The third maxill-
peds are subpediform, with the third and fourth joints
elongate. The chelipeds and two following pairs of legs

~ are well developed, the last two pairs are small, one or

both being usually chelate. The sternal plastron is linear.
The pleon is spirally twisted or extended; the tergal ele-
ments are as a rule rudimentary. There is generally a
single biramous appendage to the second, third, fourth,
and fifth segments of the pleon on the left side, the first
three of these being well-developed and ovigerous in the
female. The sixth segment in both sexes has a pair of
appendages.

Common as the Hermit-Crabs are between tide-marks,
they are also found in depths of over two thousand fathoms.
The legion contains three families, the Cenobitide, Pagu-
ride, and Parapaguride. The first two of these families
are phyllobranchiate, that is, have the branchial plumes
formed by a series of foliaceous plates, whereas the third
family is trichobranchiate, having the branchial plumes
made up of long cylindrical filaments.

Family 1.—Cenobitide.

The first antenne have a very elongate peduncle, its
first joint deflexed and as long as or longer than the eye-
stalks, the second and third joints narrow and cylindrical ;
one of the flagella enlarged: In the second antenne the

156" A HISTORY OF RECENT CRUSTACEA

peduncle is compressed, the terminal joint long. The
branchial plumes are laminar.

The species are partially terrestrial. The family in-
cludes two well-known genera.

Birgus, Leach, 1815, is a genus of eminent distinction.
The broadly ovate carapace covers large branchial cham-
bers, of which, however, the fourteen pairs of small
branchize only occupy a small fraction, but on the other
hand, in evident adaptation to an aerial life, the lining
membrane of the chambers is covered with vascular pul-
monary outgrowths. The pleon is not twisted. It is very
broad. Dorsally its first segment is represented by a
corneous band, as the four following are by four corneo-
calcareous overlapping plates, flanked by small corneous
pieces which seem to represent the side-plates. The
second, third, and fourth segments have a large biramous
appendage on the left side, but only in the female. All
the underside of the pleon is membranous, until a quadri-
lateral plate is reached which represents the sixth segment
and which gives attachment to a rudimentary appendage
on each side and to the terminally rounded telson.

The account given by Darwin of that which is probably
the type and perhaps the only species of this genus is too
interesting to be omitted. When treating of the Coral
Islands of the Pacific, he says:—‘I have before alluded to
a crab which lives on the cocoa-nuts: it is very common
on all parts of the dry land, and grows to a monstrous
size ; it 1s closely allied or identical with the Birgos latro.
The front pair of legs terminate in very strong and heavy
pincers, and the last pair are fitted with others weaker
and much narrower. It would at first be thought quite
impossible for a crab to open a strong cocoa-nut covered
-with the husk; but Mr. Liesk assures me that he has re-
peatedly seen this effected. The crab begins by tearing
the husk, fibre by fibre, and always from that end under
which the three eye-holes are situated; when this is com-
pleted, the crab commences hammering with its heavy
claws on one of the eye-holes till an opening is made.
Then turning round its body, by the aid of its posterior

THE COCOANUT-CRAB 157

and narrow pair of pincers, it extracts the white albumin-
ous substance. I think this is as curious a case of instinct
as ever I heard of, and likewise of adaptation in structure
between two objects apparently so remote from each other
in the scheme of nature, as a crab and a cocoa-nut tree.
The Birgos is diurnal in its habits; but every night it is
‘said to pay a visit to the sea, no doubt for the purpose of
moistening its branchiz. The young are likewise hatched,
and live for some time, on the coast. ‘These crabs inhabit
deep burrows, which they hollow out beneath the roots of
trees ; and where they accumulate surprising quantities of
the picked fibres of the cocoa-nut husk, on which they
rest as on a bed. The Malays sometimes take advantage
of this, and collect the fibrous mass to use as junk. ‘These
crabs are very good to eat ; moreover, under the tail of the
larger ones there is a great mass of fat, which, when
melted, sometimes yields as much as a quart bottle full of
limpid oil. It has been stated by some authors that the
Birgos crawls up the cocoa-nut trees for the purpose of
stealing the nuts: I very much doubt the possibility of
this; but with the Pandanus! the task would be very much
easier. I was told that on these islands the Birgos lives
only on the nuts which have fallen to the ground. Captain _
Moresby informs me that this crab inhabits the Chagos
and Seychelle groups, but not the neighbouring Maldiva
archipelago. It formerly abounded at Mauritius, but only
a few small ones are now found there. In the Pacific, this
species, or one with closely allied habits, is said? to inhabit
a single coral island, north of the Society group. To show
the wonderful strength of the front pair of pincers, I may
mention, that Captain Moresby confined one in a strong
tin-box, which had held biscuits, the lid being secured
with wire ; but the crab turned down the edges and escaped.
In turning down the edges, it actually punched many
small holes quite through the tin!’

Mr. Boddam-Whetham, in his ‘ Pearls of the Pacific’
(1876), declares that the crab first ascends the tree to push

1 See Proceedings of Zoological Society, 1832, p. 17.
2 Tyerman and Bennett, Voyage, §c., vol. ii. p. 33.

158 A HISTORY OF RECENT CRUSTACEA

down a nut, descends to strip it of its husk, and then ‘re-
ascends the tree, if the situation is favourable, and holding
the nut by a bit of the fibre, which it leaves on for the
purpose, it lets it fall upon a rock, or stone, and thus
breaks it.’ I could wish that he had spoken of having
seen this wonderful manoeuvring with his own eyes. Dr.
T. H. Streets declares that ‘the wonderful stories about
these crabs climbing the trees after cocoa-nuts are purely
fictitious.’

Rumphius is the original authority for the statement
that these crustaceans in their night ramblings ascend the
cocoa-nut palms and appropriate the nuts. It is to their
love of that food that they owe the title of the robber-crab.
It is said that they can be lured out of their holes by pre-
senting to them a cocoa-nut attached to the end of a stick.
Rumphius says that this crab in the language of Amboina
is named Catattut and Atattut, but that it is familiarly
called by his own countrymen ‘ Don Diego in ’t volle har-
nasch,’ its Latin name being Cancer crumenatus, of which
the Belgic equivalent is Beurs-Krabbe. This title of purse-
crab alludes to the packet of fat under the tail, which is
accounted a delicious marrow-like morsel by those who
like it. The oil from it is, or once was, regarded as a
panacea for sprains and centusions. Herbst declares that
the claws of the Birgus are so strong that they easily crack
a cocoa-nut which a human being could not break open
with a stone. He says, moreover, that if they have once
seized hold of an object, it is easier to break the claws than
to make them let go. Yet what cannot be done by force
may be achieved by cunning, for if, he says, you just tickle
the creature under the tail, it becomes so irritated that it
gives itself a nip on the tail, and dies by its own claw!
Herbst wrongly figures the fourth pair of legs as simple,
whereas they are, in fact, chelate. The naturalists of the
Challenger were informed by an intelligent native at Sam-
boangan that the female crab carries about large masses of |
the eggs with it in the month of May, and retains them so
attached until the young are developed just like the parent.
At Samboangan it is called ‘Tatos, and appreciated as

THE PAGURID® 159

a delicacy. The naturalists visited Santa Cruz-Major in
search of it for the curious reason that there are no pigs in
that island, ‘ Wild pigs,’ they say, ‘destroy not only these
crabs, but: -dig up Sore cokes (Ocypoda) and Land Crabs
from their holes. € near Trincomali, the wild
swine come down every elite the beach to dig up crabs,
and large tracts of sandy beach are ploughed up by them
in the search.’

Cenobita, Latreille, 1826, while agreeing with the pre-
ceding genus in the character of the antenna, approaches
the next family in the formation of the pleon. This is
soft and membranous and twisted on itself; the dorsal
plates are narrow, with appendages to the segments as in
Birgus, but those of the sixth segment are well developed
and unsymmetrical, the appendage on the left being the
larger. The species protect themselves in a variety of
shells, and are widely distributed over the Indo-Pacific
region, Cenobite rugosa, Milne-Edwards, being within
- those limits almost ubiquitous.

Pumily 2.—Paguride.

The first antennze have a peduncle of moderate size,
the first joint short and stout, the second and third slender
and cylindrical; both the flagella are small. In the second
antenne the peduncle is sub-cylindrical. The branchial
plumes are laminar. The species are marine. The genera
in Dr. Henderson’s reckoning are nineteen, two or three
of which are included in the British Fauna. In fourteen
of the genera the pleon is spirally twisted or bent abruptly,
soft and membranous, with imperfect segmentation, while
in the remaining five it is not spirally twisted, and it
has distinct movable segments which are. usually cal-
cified.

Pagtrus, Fabricius, 1798, originally included the whole
family of crustaceans that walk about with borrowed shells,
though beginning with the above-described latro, which
has no such domicile. It is now greatly restricted, and it
may be useful to point out some of the char acters by

13

160 A HISTORY OF RECENT CRUSTACEA

which this genus and some of its immediate neighbours
are distinguished from one another.

Pagirus (in restricted sense). The ‘front’ without
distinct rostral projection. Hye-stalks stout, with basal
scales usually wide apart. Acicle of second antennz short
and robust, the flagellum long and naked. The third
maxillipeds approximate at the base. The left cheliped
usually the larger. ‘The fourth pair of legs chelate.

Hupagirus, Brandt, 1851. The ‘front’ with a dis-
tinct rostral projection. Hye-stalks stout, with basal
scales wide apart. Acicle of second antennz long and
slender, the flagellum long and naked. The third maxil-
lipeds distant at the base. ‘The right cheliped usually the
larger. The fourth pair of legs subchelate.

Olibanarius, Dana, 1852. The ‘front’ with a distinct
rostral projection. The eye-stalks usually slender, with
the basal scales close together. Acicle of second antennze
short, the flagellum naked. The chelipeds subequal and
similar. The fourth pair of legs chelate.

Aniculus, Dana, 1852, and Calcinus, Dana, 1852, agree
with Clibanarius as above defined, except that Aniculus
has the fourth pair of legs subchelate, and Calcinus has
the chelipeds very unequal.

Diogénes, Dana, 1852. There is a movable rostriform
process between the eye-stalks, distinct from the rostrum.
The acicle of the second antennee has a broad base; the
flagellum is ciliated. The left cheliped is the larger. The
fourth pair of legs chelate.

When characters are set out in this way, it would
seem that there should be little difficulty in determining
to what genus a species belongs, but nature does not
always lend itself very obligingly to the necessities of
classification. Thus, in regard to Pagurus similimdinus,
Henderson, its author is obliged to say: ‘The chelipedes
are of equal size, and in every respect similar to one
another, belonging essentially to the form which is charac-
teristic of the genus Clibanarius,’ and presently afterwards,
under the species Clibanarius strigimanus (White), Dr.
Henderson observes: ‘As in the case of Pagurus simile

SPECIES RE-ASSORTED 161

mdnus, this species shares the characters of Pagurus
and Clibanarius, though its affinities are more with the
latter genus ; the chelipedes are subequal, a distinct ros-
tral projection is present, and the ocular peduncles are
tolerably long and slender; at the same time the ophthal-
mic scales are arranged as in Pagurus.’ He adds that
‘the special features of Clibanarius strigimanus are the
curious striated (stridulating ?) areas on the inner surface
of the hand of each chelipede, and the narrow and acute
terminal portions of the ophthalmic scales.’

In Bell’s ‘ History of British Stalk-eyed Crustacea,’
ten species are named and described as belonging to the
genus Pagurus, but the majority of them are now differ-
ently classified. Thus Pagurus Bernhardus (Linn.) and
Pagurus ulidianus, Thompson, both become Fupagurus
- Bernhardus (Linn.) ; Pagurus Prideaux (needlessly altered
to Prideauxir), Leach, and Pagurus cuanensis, Thompson,
are likewise transferred to Hupagqurus, though retaining
their original specific names; Pagurus Thompsoni, Bell, is
a synonym of Hupugurus pubescens (Kroyer), Pagurus For-
best, Bell, a synonym of Hupagurus sculptimanus (Lucas),!
and a British species not mentioned by Bell, Pagurus
tricarinatus, Norman, is now identified with Hupagurus
excavatus (Herbst). Payurus Hyndmanni, Thompson, Pa-
gurus levis, Thompson, and another British species not
mentioned by Bell, Pagurus ferrugineus, Norman, are now
transferred to the genus Anapagurus, the last-mentioned
being a synonym of Anapagurus chiroacanthus (Lilljeborg).
All the nine species are at a glance distinguished from
Pagurus by having the right cheliped larger than the left.
In Bell’s two remaining species the left cheliped is the
larger. Of these Pagurus Dilwynii, Sp. Bate, is a synonym
of Diogenes varians, Costa, thus leaving to the original
genus no British species except Pagurus fasciatus, Bell, a
species which may be the same as Pagurus striatus, La-
treille, and which, at any rate as far as Bell was con-
cerned, was not described from nature at all, but from a

1 G. O. Sars refers the Pagurus Forbesii, Bell, to the genus Spiro-
pagurus.

162 A HISTORY OF RECENT CRUSTACEA

coloured drawing supplied him by a friend! Natural his-
tory would probably soon be enlivened by many miraculous
illustrations if it became lawful to construct a fauna upon
the sketches of friends, however trustworthy. It may here be
noticed that one of the most attractive figures in Herbst’s
work is that of his Cancer megistos, afterwards called
Pagurus megistus, but of this Milne-Edwards observes that
it appears to be an imaginary species, the bulk of which
belongs to a Pagurus, while the fan-tail termination has
been taken from some lobster-like animal. Many of the
Pagurids are very beautifully coloured, but they are deci-
dedly weak about the tail. Just as the quarrymen in old
days used to make Ammonites ‘perfect’ by carving the
front of the shell into a serpent’s head, so no doubt some
HKastern artist made the really handsome Pagurus into a
perfect specimen by giving it what he thought a satisfactory
tail, regardless of the fact that such an ornament would
have made life impossible to the creature itself. He had
not before his eyes the fear of J. C. Fabricius, who winds
up his acknowledgments to his predecessors by the awe-
inspiring denunciation, ‘damnandz vero memorie John
Hill et Louis Renard, qui insecta ficta proposuere.’

In regard to Pagurus striatus, Latreille, or, as it ought
perhaps rather to be called, Pagurus arrosor (Herbst), the
facts of distribution are noteworthy, since the specimens
taken in the Mediterranean, among the Philippine Islands,
and at Japan, show no points of distinction. When
Kupagurus excavatus was dredged among the Shetland
Isles, Canon Norman, though not then knowing it by its
right name, shrewdly suspected that it would prove to be
a deep-water Mediterranean form, and as Portunus tuber-
eulatus, Roux, and the echinoderm Spatangus meridionalis,
Risso, had been dredged in the same locality, he takes
occasion to remark that ‘all deep-water dredging seems
to establish this fact more clearly, that deep-water species
have a much more extended geographical range than
shallow-water and littoral forms. These Mediterranean
species must have made their way northwards in the abyss
of the sea round the western coast of Ireland, in which

HERMITS ON THE WAR-PATH 163

locality they will doubtless at some future day be found’
Pagurus granulatus, Olivier, one of the largest Pagurids,
being seven inches and a half in length, has a range from
the West Indies to the Cape.

The names Hermit-crab and Soldier-crab, as applied
to the Pagurids, are of ancient date, the ensconced crus-
tacean being supposed to resemble a hermit in his cell or a
warrior in his castle. It is a disputed point whether the
Pagurids kill and eat the molluscs before taking possession
of their shells. Some writers, as Bell, are persuaded that
they do. Others, as Stalio, deny this, maintaining that they
are always, as without dispute they are often, conteut with
dead shells. A hermit has from time to time to change its
abode to suit its own increase in size, and it is said that when
on search for new lodgings, if it meets one of its own kind
occupying a desirable shell, it will engage in combat, and
if possible take the coveted fortress for itself. As the occu-
-pant of the envied shell is likely by the nature of the case
to be equal in size to its antagonist, and has besides the
point of vantage which its occupancy gives, the attack
can seldom be successful, and it must be a lucky chance
that has enabled any one to witness such a conflict, at
least under natural conditions. In their account of the
invertebrate animals of Vineyard Sound and the adjacent
waters, Verrill and Smith say :—‘ Active and interesting
little “‘ Hermit-crabs,” Hupagurus longicarpus [Say], are
generally abundant in the pools near low-water, and con-
cealed in wet places beneath rocks. In the pools they
may be seen actively running about, carrying upon their
backs the dead shell of some small gastropod, most com-
monly Anachis avara or Ilyanassa obsoleta, though all the
small spiral shells are used in this way. They are very
pugnacious and nearly always ready for a fight when two
happen to meet, but they are also great cowards, and very
likely each, after the first onset, will instantly retreat into
his shell, closing the aperture closely with the large claws.
They use their long slender antennz very efficiently as
organs of feeling, and show great wariness in all their
actions.’ The natural pugnacity and greediness of these

164 A HISTORY OF RECENT CRUSTACEA

creatures may be restrained under the influence of the
tender passion, for at the Hamburg Aquarium the late Mr.
W. A. Lloyd observed the male Hupagurus Bernhardus,
in the spring of the year, ‘take hold of the shell in which a
female was contained, and carry her about for weeks
together, grasping the thin edges of the shell, and when
the female was fed, the male did not take away the food as
he would if a male one fed in his vicinity.’ Aristotle
supposed that the Pagurids were generated out of earth and
mud, and Gesner argues from this that he can never have
taken a gravid female out of her shell, or he would have
been disabused of his opinion by seeing the bunches of
egos on the appendages of the pleon. Stalio says that the
mother takes care to discharge the young ones in some
place where they will have a good chance of finding shells
appropriate to their size. According to Mr. Spence Bate
it is not necessary for the mother to leave her shell in
order to release the young, for when they issue from the
ego they are ejected by the current of water that passes
outward during the process of respiration. He reports
that he had himself seen them thus ejected through the
branchial passage under the wing of the carapace. The
same writer quotes an interesting experience on the part
of Mr. Gurney, who found in a capsule of Buccinum eges a
little whelk-shell, not larger than No. 5 shot, occupied by
a young Hermit-crab about an eighth of an inch long, and
in another capsule a second Hermit-crab of similar size,
but not ensconced in a shell. Hence it appears that the
instinct of seeking an extraneous covering is developed at
a very early age. In the earliest stages of life the Pagurids
are symmetrical and therefore unsuited to the occupation
of a spiral shell. It may not be possible absolutely to
prove that in their later phases they have gradually
acquired the formation that suits them to so peculiar a
lodging, but it may at least be said that no other explana-
tion looks equally probable.

The genus Anapagurus has been already referred to as
containing some British species. This genus and two others
form a group by themselves, distinguished from Hupaqurus

A JAPANESE HERMIT 165

and its immediate neighbours by the possession of a con-
Spicuous appendage in the male at the fifth pair of legs,
and distinguished from one another by the shape and

Fic. 14.—Spiropagurus spiriger (de Haan), with separate figure of the fifth pair of feet
carrying the spiral appendage.

position of that appendage. They are alike in having the
fourth pair of legs subchelate.

Spiropagurus, Stimpson, 1858. The fifth leg of the
male on the left side has at the base a more or less spirally
twisted appendage (the protruded vas deferens).

Catapagurus, A. Milne-Edwards, 1880. The fifth leg
of the male on the right side has at the base an appendage
curved in one plane round the right side of the pleon.

Anapagurus, Henderson, 1886. ‘The fifth leg of the
male on the left side has at the base an appendage which
is short and curved, instead of long and coiled.

That the distinguishing feature of Spiropagurus did not
escape the notice of de Haan is clear from the description,
the figures, and the specific name of his Pagurus spiriger.
This, which is the type species of Spiropagurus, is now
found to be widely distributed in Eastern waters.

166 A HISTORY OF RECENT CRUSTACEA

The genus Ostracondtus, A. Milne-Edwards, 1880, and
Tylaspis, Henderson, 1885, require notice, because, unlike
all other Paguride, they have the hinder part of the
carapace broad and firm, a character to which their names
‘shelly-back ’ and ‘ callous shield’ make reference, whilst
they also have the pleon poorly developed. The species
Tylaspis anomala, Henderson (see Plate VII.), was dredged
ny the Challenger in the mid-South Pacific, from a depth
of 2,575 fathoms, the greatest depth, as already mentioned,
at which any of ‘the Anomala were found. This strange-
looking animal has the pleon not spirally twisted, and the
appendages of its sixth segment are almost symmetrical.
It is inferred therefore that it occupies some other dwell-
ing-place than a Gastropod shell. ‘This species has.in the
male a pair of genital appendages on each of the first two
segments of the pleon, agreeing in that particular with
Paguristes, Dana, 1852, and Sympagurus, 8. I. Smith, 1883.
The last-named genus, though belonging to the phyllo-
branchiate Pagurids, nevertheless shows a slight tendency
in the formation of the branchiz to agree with the next

family.

Laumily 3.—Parapaguride.

The definition is the same as that of the Paguridee, ex-
cept that the branchial plumes are filamentous.

The species are marine and confined to deep water.
There are six genera. Dr. Henderson says :—‘ In all, the
gills are modified trichobranchie, each consisting of a cen-
tral stem which gives rise to two collateral rows of rounded
filaments, gradually decreasing in size towards the apex,
whereas in the Paguride the stem gives rise to two rows
of flattened leaflets.’

Parapaqurus, S. I. Smith, 1879, is typical of the ad-
vances made in recent years in submarine science, since a
genus So lately known now includes six species, together
covering in their range the whole breadth of ocean between
40° north latitude and 45° south. The genus agrees with
Hupagurus in having the third maxillipeds widely separated

A MUTUAL BENEFIT SOCIETY 167

at the bases, the chelipeds very unequal, and the eleven
pairs of branchie distributed in couples to the third max-
illipeds and three following appendages, while the fourth
pair of legs have the three remaining pairs of branchie.
But it differs from Hupagurus as well in the structure ot
the branchiz as in having well-developed pairs of male
appendages on the first and second segments of the pleon.
The type species, Parapagurus pilosimdnus, Smith, has a
great range in depth, since American dredging expeditions
have taken it at thirty or forty stations in the Atlantic
between deeps of 250 to 2,221 fathoms. Low down in the
ocean a species may be prolific, for at 319 fathoms nearly
four hundred specimens were taken at once.

Notice has often been taken of the curious habit which
Eupaqurus Prideaux has of associating itself with the sea-
. anemone, Adamsia palliata. Surmises are sometimes made
as to the advantages which the companions may hope to
obtain from the alliance. 'heanemone may obviously obtain
a greatly increased range for supplies of food, by the
superior locomotive powers of the hermit, and though the
weight of both anemone and shell may seem an unneces-
sary encumbrance to the crustacean, that objection is
gradually diminished by the circumstance that the anemone
in course of time almost entirely absorbs the shell. On
the other hand the presence of the anemone may be a very
valuable protection to the hermit, since numerous fishes
are in the habit of swallowing these recluses, shell and all,
merely spitting out the shell after they have digested its
inmate. But it is most probable that to many fishes an
Adamsia palliata would be by no means an agreeable
morsel, even when flavoured with crab-sauce. It is also
not unlikely that the anemone may contribute to the com-
missariat by throwing out its darts as some swift gliding
shrimp passes by, and thus reducing it to a condition in
which it can be captured by the pagurid. This alliance,
however, which is so familiar, is very far from being the
only one in this legion of the Crustacea. Rather it may be
regarded as a well-known example of a very prevalent
habit. Thus upon shells containing Hupagurus pubescens

168° A HISTORY OF RECENT CRUSTACEA

the Epizoanthus americanus fixes itself. First a single
polyp finds lodgment, and as its basal membrane spreads
over the shell, buds arise from it forming fresh polyps, and
gradually this same membrane absorbs the shell though
retaining its spiral shape. In this absorption there is a
great advantage to the hermit, because as it grows its in-
crease of bulk still finds room in the yielding polyp-mass,
without any necessity arising for a change of domicile. In
the case of Catupagurus Sharreri, A. Milne-Edwards (see
Plate IV.), there is sometimes a triple alliance, for over a
colony of Epizoanthus americanus there settles itself the
single polyp Adamsia sociabilis. The numerous specimens
of Parapagurus pilosimanus that were taken in depths
reaching to six or seven hundred fathoms were found only
in colonies of Hpizoanthus paguriphilus, but those that were
taken at much greater depths ‘ were either in a very different
species of Hpizoanthus, in naked gastropod shells, or in an
actinian closely resembling, if not identical with, Urticina
consors, Verrill.” Dr. Carl Aurivillius has recently pub-
lished very interesting observations on the ‘Symbiosis’ or
living together of Hydroids, Sponges, and Pagurids. Hy-
dractinia echinata is frequently found coating the outside
and inside of various shells that are occupied by Hermit-
crabs. The mode of growth is such that the hydroid not
only repairs in effect the damaged mouth of a shell, but
also frequently extends its boundaries. This is especially
the case in districts where shells are few, and where the
growing Pagurid might be put to much inconvenience to
find a larger lodging. By the extension of the hydroid
colony, which sometimes gives a quite monstrous appear-
ance to the shell, the hermit is saved the trouble of making
any change of abode. The hydroids are saved from the
danger and damage they would be exposed to from the
rolling about of an empty shell. On the inside of it they
do not develop any of the nutritive polyps which might
incommode the hermit and also suffer injury from its
movements, but they line the interior with a network, to
the satisfactory smoothness of which the hermit itself con-
tributes. It might be supposed that this was effected by

wal Vinee

te seed

a

a

Pl. vit.

T h S Porcellana
pate) iene longicornis,
insignis uae

U.insiqnis U .insiqnis

om Maxulliped Folded leon

Uroptychus gracilimanus

—si-

DUBIOUS DOMICILES 169

the friction of its body, but Aurivillius shows that there
is a secretion from glands in the sides of the carapace
adapted for the purpose, and that the joints in the fourth
and fifth pairs of legs of Hupaqurus are nicely arranged to
assist in distributing the secretion.

Paguropsis, Henderson, 1888, is regarded as holding a
unique position among Hermit-crabs, inasmuch as the last
two pairs of legs of the trunk are subdorsally placed, and
the unpaired appendages of the pleon are on the right side
instead of the left. Dr. Henderson observes that ‘ among
the Pagurids generally, the soft abdomen, as a result of
its being thrust into a Gastropod shell, the spiral of which
is normally right-handed, has assumed a similar curve, and
the original right side thus closely applied to the columella
loses its appendages.’ The two specimens taken at a depth
_ of about a hundred fathoms off Tables Island, were free, but
the character of the pleon makes it probable that it was
protected in some way. ‘The position of the appendages
on the right side might be explained as adapted to some
species of Gastropod with a left-handed spiral, but the fact
that the pleon is simply bent on itself points to some other
kind of dwelling.

Pylochéles, A. Milne-Edwards, 1880, has the carapace
completely calcified, the chelipeds equal, the pleon sym-
metrical and well developed with broad semi-calcareous
terga and paired appendages of one kind or another on the
first six segments, those of the sixth segment forming with
the telson a powerful swimming fin. This remarkable
genus is said to form a connecting link between the Pagu-
ride and Thalassinide. The type species, Pylocheles
Agassizii, A. Milne-Edwards, was dredged by the Flake
from a depth of 200 fathoms off Barbados, and found in
the hollow of a piece of sandstone, the mouth of which was
closed by its claws, as the mouth ofa shell is by those of
of an ordinary hermit. Pylocheles spinosus, Henderson,
which is depicted on Plate VII., is Australian. Nothing
is known about its mode of lodging itself. For this genus
Mr. Spence Bate in 1888 established the family Pyloche-
lidee, which he placed between the Galatheidze and Thalas-

170 A HISTORY OF RECENT CRUSTACEA

sinide. In the family he only places, besides Pylocheles,
Pomatochéles, Miers, 1879, and a new genus Cheiroplatéa,
and, as he states that it imcludes all those paguriform
Anomura that are trichobranchiate, he was evidently un-
aware that the family Parapaguridz had been already
established by Smith for this very purpose. His Cheiro-
platea cenobita (see Plate X.) from the Pacific is no doubt a
remarkable animal, having among other singular charac-
ters a chelate extremity to the third maxillipeds. The
single specimen is a female with very large but not very
numerous ova. Mr. Bate compares it with Glaucothoé,
Milne-Edwards, which Miers and Bate agree in regarding
as only an adolescent form. Considering Cheiroplatea in
its adult condition as representing a link between Cenolita
and the trichobranchiate Macrura, Mr. Bate remarks that
‘it has an appearance strongly suggestive of its being allied
to a Pagurus that had failed to obtain a molluscous shell
for itself, and had consequently retained some of the ma-
crurous characters of its youthful condition.’ Both Pylo-
cheles and Cheiroplatea recall the earliest post-larval forms
observed in the Paguridee. .

Legion 4.—Porcellaninea.

The carapace is well developed, broadly ovate, smooth,
with the regions faintly defined. The eye-stalks are short
and stout, the eyes always pigmented and partially con-
cealed in orbits. The first antennze are concealed. Inthe
second antenne the peduncle is directed backwards, its
second and third segments are coalesced, the flagellum is
long and slender. ‘The third maxillipeds have the third
joint broad, the fourth provided with a prominent internal
lobe. The chelipeds are broad and often flattened, the first
three pairs of walking-legs well developed, the last pair
slender and inflexed. The pleon is symmetrical, bent under
the trunk, having on the sixth segment a pair of lamellar
appendages which with the telson form a swimming fan ;
also in the male it has a pair of genital appendages on the
second segment, and in the female a pair of uniramous

THE PORCELAIN CRABS PEt

appendages to the fourth, to the fifth, and sometimes to the
- third segment.

Notwithstanding the brachyuran characteristics this
legion is found to be in close affinity with the next, the
Galatheinea. Here it is supposed that the pleon has
become reduced in size and has lost its importance as an
organ of locomotion, owing to the special habits which
the animals have adopted. They are found under stones
between tide-marks and in shallow water among stones,
sponges, and corals. One species has been taken at a
depth of 390 fathoms. There is but one family.

Family Porcellanide.

The characters of the single family are those of
the legion. Eleven genera are assigned to it, most of
which were instituted by Stimpson in 1858, and some on
very slender distinctions. Ouly one belongs to British
waters.

Porcellana, Lamarck, 1801, has the ‘front’ dentate,
the first joint of the second antennee much produced, fully
reaching the margin of the carapace. ‘The chelipeds
have a projecting lobe near the base of the inner margin
of the fifth joint, the terminal joint often contorted. The
walking-legs have the terminal joint short and robust,
ending in a single claw. ‘To this genus belong the only
British species of the family, Porcellana platychéles (Pen-
nant) and Porcellana longicornis (Linn.), both of which
are common under stones, along which they slidder with
some rapidity. They will sometimes flatten themselves
against the upturned stone, remaining quiet and evidently
trying to look as if they were not there. Quite after the
fashion of their kindred, the Galatheidze, they will lift up
their claws to resist attack, but their flattened habit of
body makes this posture of defence in their case ridicu-
lously ineffective. If one of the threatening claws be
seized, they pretty readily relinquish it and skurry away.
To understand the likeness between these crustaceans and
the Galatheide it is necessary to flatten out the pleon of

172 A HISTORY OF RECENT CRUSTACEA

the Porcellana and so institute a comparison. The zoea of —
Porcellana longicornis (see Plate VII.) has not unfrequently
been studied, and the reality of its connection with the adult

Fic. 15,—Porcellana longicornis (Linn.), an early post-larval form [Stebbing].

form need not be doubted, but the extraordinary difference
between the one and the other can scarcely fail to surprise
any one who for the first time compares them. It is
strange that the smooth circular carapace of the grown-up
Porcellana should result from a larval form in which the

TROPHIES FROM EGYPT 173

dorsal shield has two long horns behind and one of porten-
tous length in front. Even after the general appearance
of the adult has been assumed, the young crustacean
shows several interesting differences from its elders. The
accompanying figure of a little one, an eighth of an inch
long, taken off the back of its mother, exhibits a carapace
with numerous little spines not found in the parent, and
the telson simply ovate, instead of being subdivided by
sutures into seven portions. Porcellana Robertsoni, Hen-
derson, is remarkable as having been taken not in shallow
water, but at a depth of 390 fathoms in the West Indies.
Dr. de Man states that ‘the genus Porcellana is represented
in the Bay of Bengal by no fewer than fifteen species.’
Several of them, however, as he explains, belong to the
other genera of this family, which Dr. de Man retains as
- subgenera.

Petrolisthes, Stimpson, 1858, has the ‘ front’ undulated,
the first joint of the second antennz remarkably short,
not reaching the margin of the carapace, the fifth joint of
the chelipeds often dentate on the inner margin, and the
walking-legs as in Porcellana. Among the Crustacea
collected on Napoleon’s celebrated Egyptian expedition, a
species, beautifully and elaborately figured by Savigny, was
named Porcellana Bosc by Audouin, to whom the French
Government entrusted the task of describing the species in
Savigny’s splendid work, in consequence of the latter
author’s long-continued illness. ‘This species was trans-
ferred by Stimpson to his genus Petrolisthes, and it well
exhibits the unusual prominence which in this family is
often assumed by the third maxillipeds, projecting as if
they were a powerful pair of feathered antennee. The name
of the genus meaning ‘ rock-slider’ points to one of the
characteristic habits of the family.

Porcellanella (White), Stimpson, 1858, differs from
_Porcellana chiefly in having the last joint in the walking-
legs not simple but multiunguiculate. Between these two,
and agreeing with Porcellanelia and Polydnyx, Stimpson,
in the multiunguiculate joint, the Russian writer Czerni-
avsky has insinuated his genus Porcellanides, 1884, in his

14

174 A HISTORY OF RECENT CRUSTACEA

work on the Decapod Crustacea of the Black Sea. The
book, which is more in Latin than in Russian, contains a
wealth of bibliographical information.

Legion 5.—Galatheinea.

The carapace is elongate, the regions well defined and
usually rugose, with a prominent and acute rostrum. ‘The
eyes are placed in very incomplete orbits, the eye-stalks
short and stout. The first antennz are exposed. The
peduncle of the second antenne is directed forward and
generally has the second and third joints coalesced; the
flagellum is long and slender. The third maxillipeds are
subpediform, with the third and fourth joints narrow and
often spinous within. The chelipeds and walking-legs are
often elongate and slender ; the last pair of legs are feeble
and inflexed. The sterna of the trunk are broad. The
pleon is broad and well developed, simply bent, or folded
on itself, never adpressed to the trunk. In the female the
second to the fifth segments have each a pair of simple and
slender ovigerous appendages, those of the second and
fourth sometimes rudimentary. In the male the pair of
accessory genital appendages of the first segment are well
developed, rudimentary, or absent; those on the second
segment are well developed; the short, usually flattened
pair of appendages on each of the next three segments,
are well developed or rudimentary. In one genus the male
is destitute of appendages on the first five segments. In
both sexes the appendages of the sixth segment and the
telson form a swimming fan that is usually powerful. The
number of branchiz, so far as is known, is generally four-
teen pairs in this and the preceding legion. There is only
one family.

The proximity which is now accorded to the three
legions, the Pagurinea, Porcellaninea, and Galatheinea, in
spite of external unlikeness, is confirmed, as M. Jules
Bonnier observes, in a very interesting indirect manner by
the circumstance that Bopyrids of the same genus Pleuro-
crypta occur in all three.

A WELL-CONSTRUCTED KEY 175

Family Galatheide.

The characters are those of the legion. About ten
genera are included, two of which—Galathea and Munida—
belong to the British Fauna, and, according to Dr. Hender-
son, have many species inhabiting shallow water. With
the exception of one doubtful genus, the remainder are as
yet known only from deep water, and it must be said that
according to Dr. Henderson’s own report, only a few out
of the species of Munida come from small depths, some
going down to more than 2,000 fathoms, and the majority
being taken most abundantly at depths varying from 100
to 300 fathoms.

Galathéa, Fabricius, 1793, has the carapace usually
- free from spines, except on the anterior gastric area, but
furnished with furry transverse strie. The rostrum is
flattened, rather broad, generally having teeth on the
margins. The seyments of the pleon are unarmed. There
are numerous species occurring at very varied depths.
They swim backwards with activity, and Mr. Couch states
that it is very remarkable to witness the accuracy with which
they will dart backward for several feet into a hole very
little larger than themselves, an acrobatic performance
which he had often seen carried out, and always with pre-
cision. There are five British species, all of which occur
also on the coasts of France, where they have been studiea
and described very carefully by M. Jules Bonnier. He
supplies a very useful key to discriminate them, depending
partly on the shape of the third maxillipeds, and partly on
the presence or absence of an epipod in the limbs of the
trunk. The epipod, it will be remembered, is the branch
which issues from the basal joint of an appendage. In
Galathea squamifera, Leach, Galathea neva, Embleton, and
Galathea dispersa, Spence Bate, there are epipods to the
chelipeds and the two following pairs of limbs ; in Galathea
intermedia, Lilljeborg, there are epipods to the chelipeds,
but not to the following pairs of limbs; in Galathea stri-
gosa, Fabricius, there are no epipods to any of the three

176 A HISTORY OF RECENT CRUSTACEA

pairs. The third maxillipeds in squamifera have the third
joint shorter than the fourth, in neva equal to it, in dis-
persa longer than it. By this simple combination all the
five species are neatly distinguished. The sexes of Gala-
thea often show a considerable difference in the chelipeds,
those of the male being the longer. In Galathea squami-
fera, the two last joints of the chelipeds in the female
touch all along the inner margins of the chelee, whereas in
the male they stand apart, and have a peculiar curvature,
meeting only at the apices. This is so pronounced a
feature that it misled Spence Bate into establishing a
separate species, which he called digiti-distans, meaning
‘with the fingers wide apart.’ Galathea magnifica, Has-
well, an Australian species, only half an inch long, ap-
pears to make up for diminutive size by its striking
appearance. The description of it says, ‘Colour bright
red, with a brilliant purple stripe down the centre of the
carapace ; legs ornamented with transverse bands of
darker red and purple; fingers dark reddish brown, yellow
at the tips.’

Munida, Leach, 1820, nearly resembles Galathea, but
is distinguished by having a slender stiliform rostrum, and
the supraorbital spine on each side of its base not small
but well developed. Moreover, in general, the carapace
has a spinulose surface, and its cardiac region distinct,
and the pleon has one or more segments with a series of
spinules on the anterior dorsal margin. The chelipeds
and walking-legs are elongate and slender. The type
species Munida rugosa (Fabricius, 1775) is distributed over
all the seas of Europe. The very long chelipeds make it
conspicuous. The third maxillipeds have the third joint
longer than the fourth. The chelipeds and ambulatory
legs are without epipods. It is not to be met with in
shallow waters. Bell, on insufficient grounds, altered the
name to Munida Rondeletii. Though the old naturalist
Rondelet well deserved honour, this was not the right
way to pay it. It may be noticed, however, that G, O.
Sars, writing in 1889, speaks of Munida Rondeletiw, Bell,
and Munida ruyosa (Fabricius) as two distinct though

THE OBJECT OF LARGE OVA 177

clesely allied species. In 1882 he had explained that
Bell’s Munida Rondeletii was distinguished from the other
species by its very small eyes, not furnished with a circlet
of hairs, and by the complete want of the two dorsal
spines on the third pleon-segment. But Bell gives an-
other specific character, ‘ second and third segments of the
abdomen, the former with six, the latter with four small
spines on the anterior margin ; the other segments with-
out spines.’ In two specimens from the Clyde, both having
circlets of hairs to the eyes, the pleon has on successive
segments, in one case, six, four, and two spines, but in the
other six and four and none.

Grimothea, Leach, 1820, established to receive the
Galathea gregaria of Fabricius, is still in an uncertain
position, it being supposed by some that the species is a
young form of Munida subrugosa, Dana.

Munidopsis, Whiteaves, 1874, has eyes devoid of pig-
ment, and the stalkof the eye frequently prolonged beyond
the cornea in the form of a spine or spines. ‘l'he species
are found in depths varying from 100 to more than 2,000
fathoms. ‘It is probable, Dr. Henderson remarks, ‘ that
the loss of sight is compensated by a greater development
of the tactile sense, and in some species this is evidenced
by the great length of the antennal flagella, which in all
probability enable the animal to grope its way about on
the bottom. The eggs are few and large, as is often
the case with the ova of deep-water species, which are
supposed to find their advantage in passing through
several of their metamorphoses within the egg, so that
the young one is hatched in a form nearly like that of the
parent.

EKumunida, 8. 1. Smith, 1883, occupies an exceptional
position, for the peduncle of the second antenne has five
distinct joints, the third maxillipeds are without the usual
two pairs of rudimentary arthrobranchiz, and the pleon
of the male is without appendages on the first five seg-
ments. The type species, Humunida picta, Smith, was
taken in the North Atlantic.

Uroptychus, Henderson, 1888, is the equivalent of

178 A HISTORY OF RECENT CRUSTACEA

Diptijchus, A. Milne-Edwards, 1880, the name Diptychus
being pre-occupied. Of the species Uroptychus insignis,
Henderson, and Uroptychus gracilimanus, Henderson, figures
are given on Plate VII. In this genus the second antennz
have on the second (the first free) joint of the peduncle an
acicle, thus differing from all the rest of the family, except
Eumunida, in which one is also present, though of very
small size. Dr. Henderson says :—‘ In those species which
I have examined, the fifth arthrobranchia, counting from
before backwards, is not of larger size than the others,
whereas in most of the Galathodea it is distinctly en-
larged.’ According to M. Jnles Bonnier, in the species
Groptychus rubrovittatus (A. Milne-Edwards) there are no
arthrobranchiz, their places being taken by a correspond-
ing number of pleuro-branchize—that is, by branchiz in-
serted on the pleura or sides of the segments, instead of
being placed on the articulating membranes that unite the
appendages tothe segments. In this genus, and in Ptycho-
gaster, A. Milne-Edwards, 1880, and in Humunida, there
is a comparative weakness of the swimming-fan, which
probably for that reason is twice folded on itself. The
members of these genera being sometimes found in the
branches of Gorgonie, it is conjectured that they lead a
sedentary life, that the swimming-fan is in consequence
losing its importance, and an advance is thus being
made towards the brachyuran type. Ptychogaster Mulne-
Edwardsi, Henderson (see Plate VII.), from Patagonia, has
the pleon, except the telson and uropods, covered with
rows of short stout spines.

The larval development in species of the genera
Tithodes, Eupagurus, Anapagurus, Munidopsis, Galathea,
Munida, and Porcellana, has been carefully studied by
G. O. Sars, and his results confirm from this point of view
the close union of the legions to which these genera re-
spectively belong, as well as the propriety of including
the whole group among the Macrura. From Sars’ work
on this subject have beea borrowed the figures grouped
together on Plate VIII., representing the end of the pleon
in the last larval stage respectively of Lithodes maia

End of Pleon in the last larval stage

a. Lithodes maia (Linn.). b. Eupagurus Bernhardus (Linn.). c. Porcellana
longicornis (Linn.). d. Galathea intermedia, Lilljeborg
e. Munida tugosa (Fabricius)

PERILS OF BABY-FARMING 179

~

(Linn.), Eupagurus Bernhardus (Linn.), Porcellana longi-
cornis (Linn.), Galathea intermedia, Lilljeborg, and Munida
rugosa (Fabricius).

It will be remembered that the larval forms of Crus-
tacea often show not the smallest resemblance to the
adults, and also that it is extremely difficult to breed in
confinement those which pass through many transforma-
tions from the egg to the perfect condition. In this in-
terval at every moult, the shedding of the skin is attended
with danger. The movement, the saltness, the temperature,
of the water in which they are kept should correspond with
the conditions they would have experienced in their proper
marine home. When all this has been suitably cared for,
the supply of appropriate food must be considered, and this
will probably not be the same for all the stages. When
several specimens occupy a common nursery the more ad-
vanced are very apt to destroy the less forward, and the
creatures being as a rule very small there are risks of
confusions, the larve of distinct species being perhaps
mistaken for the stages of one and the same species. In
calm weather, and, at least, in the latitude of Great
Britain, especially, though not exclusively, after dark in the
months of August and September, it is easy in many parts
of the sea by means of a surface-net to obtain an abundance
of larval forms, but there is a great difficulty in determining
the species and genera to which they severally belong.
Being minded to connect together the several stages of a
erustacean’s life with some approach to certainty, Professor
Sars made a practice of carefully drawing and dissecting
the forms he met with, and then by comparison of a long
series he was able in numerous instances to assign them in
proper sequence to species of which the adults were already
known. Considering the vast numbers of the Crustacea,
it is evident that there is valuable work to be done on these
lines, enough to occupy a crowd of zoologists for many
years to come, and the plan is available for many who have
no access to the constantly improving resources of the
modern scientific aquarium or marine biological station.

189 A HISTORY OF RECENT CRUSTACEA

CHAPTER XII

TRIBE II.——THALASSINIDEA

THE carapace is short and compressed, with litile or no
rostrum. The last segment of the trunk is articulated
with the preceding. The eye-stalks are small. Both pairs
of antennz have long peduncles. Of the trunk-legs the
first pair are perfectly or imperfectly chelate, the last pair
are short, more or less abnormal, directed backwards.
The pleon has the segments not overlapping, with the
side-plates feebly developed and having their hinder angles
generally rounded. The pleopods are long, biramous,
variable ; the swimming fan is strong. The branchiz vary
in number and form.

In this tribe are included four families, the Thalassi-
nidee, Callianassidee, Axiidee, and Thaumastochelide. The
division of the Macrura adopted by the late Mr. Spence
Bate, into Trichobranchiata, in which the branchial plumes
are made up of long cylindrical filaments, Phyllobranchiata,
in which the plumes are formed by a series of foliaceous
plates, and Dendrobranchiata, in which the branches of
the various plumes divide and subdivide in an arborescent
manner, does not seem practically very convenient. It
has been already seen that two families so intimately
allied as the Paguride and Parapaguridz would have to
be placed, the former in the Phyllobranchiate, the latter
in the Trichobranchiate, division. But also in the present
tribe Spence Bate himself points out a weakness in the
arrangement, for of the genus Callianassa he says :—‘ The
structure of the branchiz of Cullianussa is so intermediate
in character that it may be claimed by anatomists as be-

EYE-LASHES AND EAR-SLITS 181

longing to either the Phyllobranchiata or to the Tricho-
branchiata, as the plumes consist of two rows of long
slender filaments so closely impacted together that they
are flattened into plates, and elsewhere he remarks that
‘in some genera, as in T'halassina, the branchiz are both
foliaceous and filamentous.’

Family 1.—Thalassinide.

The carapace is dorsally flattened, with rostrum. The
eyes are small, the eye-stalks cylindrical. The first pair of
antennee have the flagella long; the second have no scale
on the second joint. The first pair of trunk-limbs are un-
equal, imperfectly chelate, the last joint or finger being
longer than the thumb; the four following pairs are
simple, with the terminal joint long. In the pleon the
uropods, that is, the appendages of the sixth segment, are
slender and acute, the outer branch not transversely
sutured ; the telson is also without suture, obtusely pointed.
The branchize are complex.

The family includes but one genus.

Thalassina, Latreille, 1806, has the characters of Ee
family. It contains but few species, perhaps only the type
Thalassina anomalus (Herbst, vol. 3, part 4, p. 45, 1804),
which Latreille in 1806 called Thalassina scorpionoides.
This is widely distributed in the Pacific. A specimen nine
inches long was procured by the Challenger at Kandavu, one
of the Fiji Islands. Some points of Mr. Spence Bate’s
minute description will teach the student what to look for
in various other species of the Macrura. For the small
sub-conical eyes imperfect orbits are formed by help of the
rostrum and depressions in the upper surface of the first
antenne. Projecting forwards from the rostrum and
upper part of the orbit and backwards from the antennz
are numerous hairs which form for the eyes a protecting
fringe, which is in Greek the blephdris in English the
eye-lashes. The basal joint of the first antennz has a
long triangular slit, the opening of the ear, which is thus
described :—‘ The auditory apparatus consists of a large

182 A IIISTORY OF RECENT CRUSTACES&

calcareo-membranous chamber, attached to the upper wall
of the antenne. Around the orifice that opens into it,
within the chamber, there is a curved row of closely
planted delicately ciliated hairs, each of which is attached
to the base by a flexible membranous articulation, from
which it proceeds flattened and tolerably broad for more
than half its length, when it narrows rapidly and becomes
ciliated, the cilia being short and fine; the hairs extend
nearly if not quite across the auditory chamber, the floor
of which is covered with small points, while the cavity
contains much angular calcareous sand. This I found
mostly gathered into a compact mass, but most probably
when the animal was in a living condition it was not so,
being then kept in a state of motion by the aid of the long
slender ciliated hairs that have just been described.’ In
discussing the peculiar combination of slender filaments
and flattened plates in the branchiz of this crustacean,
Mr. Spence Bate observes :—‘ In a respiratory chamber,
such as in the genus now before us, the water flows in by
the posterior extremity, for which purpose the carapace
van be raised or depressed at will within certain limits;
and as we may assume that in a large chamber such as
the present, the water flows along the lower margin, pass-
ing out at the anterior end only, it is probable that the
largest amount of current will correspond with that por-
tion of the chamber where the trichobranchiate filaments
are best developed and most abundant, whereas the phyl-
lobranchial plates are present in the centre and deeper
recesses of the chamber, where the circulation will be
more quiescent, and the power of oxygenation less effi-
cient. As there is reason to suppose that the animal may
inhabit hollow passages in the mud, where the circulation
of water through the branchial chamber would not be very
vigorous, and least so in the part most distant from the
direct current, Mr. Spence Bate infers that in the central
portion of the chamber the branchize have been developed
into thin foliaceous plates of considerable dimensions, so
that through the tenuity of their structure the blood may
be brought over a large surface into contact with the
aerating medium within the chambers.

MONTAGU’S CALLIANASSA 183

Family 2.— Callianassidee.

The carapace is laterally compressed, with rostrum
minute or absent. The eyes and antenne are as in the
preceding family. The first pair of trunk-limbs are un-
equal, perfectly or imperfectly chelate, the third and fourth
pairs simple, the others variable. The uropods and telson
are usually broad, without sutures. The branchiz are
filamentous, with the filaments sometimes compressed.

_Six or seven genera are assigned to this family, of
which two are British.

Callianassa, Leach, 1814, was instituted to receive a
species which Colonel Montagu described in 1805 (and
‘published in 1808) under the name Cancer Astacus sub-
terraneus. He found it at the depth of nearly two feet
beneath the surface, while digging into a sandbank in the
estuary of Kingsbridge or Salcombe in South Devon.
Though it was by no means plentiful, he ascertained that
the larger arm was not constant to one side, and that the
extreme disproportion sometimes exhibited by it was not
invariable. The crustaceous covering of the body he
describes as ‘very thin and not far remote from mem-
branaceous.’ The exceedingly narrow attachment between
the first four joints of the larger cheliped and the follow-
ing three which form its monstrous termination give to
this species a very peculiar appearance. The second pair
of feet are minutely chelate. The second pair of pleopods
are slender and filamentous, while the following three pairs
are broad and foliaceous. A. Milne- Edwards in 1870 dis-
tinguishes seventeen recent species. Czerniavsky in 1884
points ont that the Mediterranean Callianassa laticauda,
Otto, should be added to the list.

Callianassa Stimpson, Smith, is a species found on
the east coast of the United States. This and other deep-
burrowing crustaceans are more often obtained from the
stomachs of fishes than by intentional methods of capture.

Cherémus, Spence Bate, 1888, was instituted chiefly

184 A HISTORY OF RECENT CRUSTACEA

on account of the contradictions in different writers in
regard to the third maxillipeds of Callianassa, some call-
ing them pediform, others operculiform. In Cheramus
they are distinguished as pediform, but it seems rash to
establish a new genus on the very character which some
authors ascribe to the old one, especially as Callianassa is
not unrepresented in England, France, and the Mediterra-
nean, and specimens might have been examined to clear
up the disputed point. In the British Museum Leavh’s
type- -specimens of Callianassa subterranea, from Kings-
bridge in South Devon (Salcombe at the mouth of the
Kingsbridge estuary being probably intended), have third
maxillipeds that might well be described as pediform.
But other specimens at the same museum, which have
been labelled as belonging to the same species, were
shown me by Mr. Pocock, and in these, which came from
Jersey, the third and fourth joints of the maxillipeds in
question are greatly expanded, quite deserving the name
operculiform. But these specimens also have a more
quadrate telson than those from Devonshire, and are
doubtless quite distinct. Since, however, in the type of
Callianassa the maxillipeds are pediform, the chief reason
for the institution of Cheramus is cut away. Its name
signifies ‘a gap, but it has not succeeded in filling one.

Callianidea, Milne-Edwards, 1837, closely resembles
Callianassa, but with some differences in the branchial
arrangements, and, besides having the second pleopods
like the following three pairs, in all these pleopods ‘ the
margins, instead of being fringed with small hairs or cilia,
have these modified into soft and flexible articulated mem-
branous filaments.’ Milne-Edwards supposed that these
were true branchial appendages, and that a link was thus
established between this family and the Squillide in the
sub-order Stomatopoda. With his own genus he coupled
Guérin’s sea. But Mr. Spence Bate regards it as pro-
bable that Guérin’s genus was founded on a damaged
specimen of Callianidea, and with some reason thinks that
the fringed pleopods of that genus cannot be regarded as
branchial for purposes of classification.

UPOGEBIA BROUGHT TO LIGHT 185

Upogebia, Leach, 1814, was founded to receive another
Species discovered by the industrious Montagu, and de-
scribed by him in 1805 (1805) as Cancer Astacus stellatus.
The colour, he says, is ‘yellowish-white, covered with
minute stellated orange spots, as it appears under a lens,
which give a predominance to the last.’ In this genus
the first pair of legs are subequal and subchelate, the
other pairs being simple; the second pair of pleopods is
like the three following pairs, with the margins strongly
ciliated ; the components of the swimming fan are broad-
ended. It seems to have escaped the notice of writers sub-
sequent to Leach that the earliest name of this genus was
Upogelna, which must therefore be retained in preference
to Leach’s own alteration of it into Gebia, or Risso’s Gebios.
Bell refers to the ‘ Edin. Encycl., xi. p. 400, as an authority
for Gebia stellata, printing xi. by mistake for vil., and
probably guessing at Gebia by mistake for the actual
Upogebia. :

The type species was taken along with the type of
Callianassa. On the nearly allied American species de-
scribed by Say, Verrill and Smith make the following
observations :—‘ The Gebia affinis is a crustacean somewhat
resembling a young lobster three or four inches in length.
It lives on muddy shores and digs deep burrows near low-
water mark, in the tenacious mud or clay, especially where
there are decaying sea-weeds buried beneath the surface.
The burrows are roundish, half an inch to an inch in
diameter, very smooth within, and go down obliquely for
the distance of one or two feet, and then run off laterally
or downward, in almost every direction, to the depth of
two or three feet, and are usually quite crooked and wind-
ing. We have found them most abundant on the shore of
Great Ege Harbour, New Jersey, near Beesley’s Point,
but they also occur at New Haven and Wood’s Hole, &c.
‘This species is’ quite active; it swims rapidly and jumps
back energetically. It is eagerly devoured by such fishes
as are able to capture it. When living the colors are
quite elegant. Along the back there is a broad band of
mottled, reddish brown, which is contracted on the next to

186 A HISTORY OF RECENT CRUSTACEA

the last seoment; each side of this band the mottlings are
fewer, and the surface somewhat hairy. The last segment
and the appendages of the preceding one are thickly
specked with reddish brown; their edges are fringed with
grey hairs.’ Leach’s statement that Upogebia stellata
makes winding horizontal passages in the mud, ‘ often of.
a hundred feet or more in length, appears still to await
confirmation.

A second British species was named Gebia deltdura by
Leach, on the ground that the interior lamella of the tail-
fan is ‘truncate and formed like the Greek Delta.’ No
doubt he was alluding to the inner branch of the uropods.
This is an obscure feature on which to base the specific
name, and Bell has been not unnaturally misled into sup-
posing that Leach was referring to the telson, which, how-
ever, is not at all deltoid in form, and which Leach himself
expressly describes as ‘quadrate’ and ‘nearly quadrate.’
According to Leach ‘ this species lives with G. stellata,’ and
Bell suggests that it is probably identical with it. The
Mediterranean ‘ Gebios littoralis, Risso, is a nearly allied
species, which ranges to the coast of Norway, and may
therefore be expected to occur in intermediate waters. The
name Gebia no doubt signifies ‘life in the ground,’ and
Upogebia ‘ subterranean life, in allusion to the burrowing
habits which make specimens of the genus rare. The young
ones, however, may be taken pretty plentifully at the sur-
face, and Sars has in consequence been able to describe the
first larval stage or Zoea-form, the second or transition
from Zoea to Mysis stage, the third or Mysis-form, the last
larval stage, and the first post-larval stage of adolescence
(see Plate IX.) From these descriptions it will be seen, he
observes, that Gelia in some respects is very distinct from
Nephrops and Calocdris, two of the genuine Macrura which
he had previously been examining, as well as from all the
Carides, while in several points of development it ap-
proaches the Anomura. In the Carides as in Calocaris the
rule appears to be that the first larval stage or Zoea form
is characterised by the presence of three pairs of well-
developed swimming appendages, representing the exopods

GY mM SANNN

Upogebia littoralis

Palinurus vulgaris.
Larva, [% stage.

Peteinura ee ee
gubernata ve Nephrops

norvegicus
Larva, 2™ stage

15

LARVAL LINKS 187

on the three pairs of maxillipeds, while the endopod of the
last pair of maxillipeds is fully developed, distinctly articu-
lated and setiferous. On the other hand in Gebia, or, to
give it its right name, in Upogebia, as in the Brachyura and
Anomura, this last pair of maxillipeds is entirely unde-
veloped in the first larval stage, the exopod or swimming
branch being developed later on, but the endopod remaining
undeveloped during the whole larval life. But again from
both Brachyura and Anomura the larva of Upogebia is
distinguished, because, just as in the Carides, a real Mysis-
stage 1s passed through, in which not merely the three
pairs of maxillipeds, but also the first three pairs of trunk-
limbs are furnished with swimming-branches. As to the
intimate structure of the maxillipeds and mouth-organs
generally, Sars remarks that the larva of Upogebia shows
~ avery striking likeness to the larve of certain Anomura,
for example, Galathea.

The Jaxea nocturna, Nardo, 1847, which Heller in
1856 called Calliaxis adriatica, may belong to this family,
but the rostrum is well marked.

Aaiide.

Family 3.

The carapace is produced to a horizontally flattened
point or rostrum. ‘The first pair of trunk-legs are chelate
and subequal; the second pair are small, chelate, equal ;
the last three pairs are simple. ‘The first segment of the
pleon is very short. The outer branch of the uropods is
not longer than the inner. The branchiz are filamentous,
cylindrical, and compressed. The family contains three
genera, one of them British.

Agius, Leach, 1815, has for type species Awius stiryn-
chus, Leach, first found at Sidmouth. Norman says that
this species has ‘ the telson quadrangular, the hands smooth,
the fingers channelled, the particular articulation of cepha-
lothorax and abdomen described by Mr. Couch, and the
transverso-lateral tufts of hair on the abdominal segments.’
He supposes that Leach and Bell, in attributing an
elongate-triangular form to the telson, were misled by

188 A HISTORY OF RECENT CRUSTACEA

the appearance of a dried specimen. Spence Bate declares
that ‘ Avius has been taken only on the southern coast of
England,’ but Bell and Marion have reported it from the
Mediterranean and Milne-Edwards from the coasts of
France. The name of the species may be guessed to
signify ‘with a stiff rostrum.’ The same feature belongs
to a second species, Awius glyptocérus, von Martens, found
in Australian waters. ‘The second antenne in this genus
have a movable spine or scale representing the exopod on
the second joint.

Paraxius, Spence Bate, 1888, was founded for a species
taken off Celebes Island, in which the second antennz
have no ‘ scaphocerite, that is, no scale, spine, or other
representative of the exopod on the second joint, and no
‘ stylocerite.’

Eiconaxius, Spence Bate, 1888, has three species, all
taken from depths of some hundreds of fathoms in the
Pacific. Here the second antenne have ‘the peduncle
furnished with a scaphocerite and stylocerite.’ ‘This
genus,’ the author says, ‘ differs from Parawius in having
both scaphocerite and stylocerite, which are absent in that
genus; this character also separates it from Agius, which
has a small scaphocerite only. The stylocerite, which is
present in this genus, is wanting in Awius, as it is in all
the Macrura, except Hiconaxius and Cheiroplatea. Its
presence is a feature most prevalent in the Anomurous
Crustacea.’ In the description of the type species, Hiconaxius
ucutifrons, Spence Bate says of the second pair of antenna,
‘its third joint is externally produced to a long sharp
tooth or stylocerite.’ Yet in his glossary ‘stylocerite’ is
defined as ‘style or large spine on outer margin of the
first joint of the first pair of antennz,’ and in the Intro-
duction to his Report on the Challenger Macrura, he
attributes a stylocerite to the first antennze in species of
Peneus, &c., but states that it does not exist in the
Trichobranchiata. Under all the circumstances it seems
as if it would be just as well to call a spine a spine instead
of a stylocerite. The single specimen of Hiconaxius parvus,
half an inch long, taken from a depth of 520 fathoms, had

A STRANGE CLAW 189

seven ego's, which, as so commonly in deep-water species,
were extremely large. From one of these Mr. Spence
Bate extracted a young animal, and this proved to be not
unlike the young of the lobster at the same stage, but,
more advanced, thus so far confirming the view that the
great size of the deep-water ova is in relation to the
more than usual advancement of the embryo before it is
hatched. ‘

PFumily 4.—Thaumastochelide.

The carapace is produced to a flattened point or ros-
trum. The first pair of antennz have on each peduncle
two long subequal flagella; the second have a scale or
exopod. The first pair of trunk-limbs are chelate, un-
equal, somewhat unsymmetrical; the small second pair
are chelate, subequal, symmetrical; the outer branch of
the uropods is larger than the inner. ‘The branchiz are
filamentous, cylindrical.

To this family Spence Bate assigns “only two genera,
one of which is British.

Thaumastochéles, WWood-Mason, 1874, is appropriately
named ‘the creature of wonderful claws.’ The type spe-
cies, Thaumastocheles zaleucus (von Willemoes Suhm) (see
Plate X.), was taken by the Challenger from a depth of 450
fathoms in the West Indies, along with a great number of
other curious marine animals frequenting the globigerina
ooze in that locality. It is blind, and not only without eyes
but without eye-stalks, unless perchance the latter are re-
presented by a pair of tubercles projecting from the ‘front.’
The ‘ front’ is sub-membranous and translucent, and Spence
Bate supposes that the optic nerve may terminate so
closely behind it as to receive impressions of light. But
though there are no eye-stalks, there are excavations
in the anterior margin of the carapace corresponding to
orbits, and also depressions in the first pair of antennz
such as eye-stalks often rest in. The inference then is
clear that eye-stalks once existent have been lost, and this
probably from their being detrimental instead of useful to
a burrowing creature. The burrowing character is in-

190 A HISTORY OF RECENT CRUSTACEA

ferred from the general agreement of the species with
others that are known to be fossorial. This agreement is
exhibited more especially in the tail-fan, but other features
favour the notion of such a habit. The flagella of the first
antenne, fringed with long fine hairs, may assist in keeping
open abreathing hole. The anterior outlet of the branchial
chamber is protected against intrusive particles by a joint
of the first maxillipeds so disposed as to serve for an
operculum. Of the very unequal first legs the limb on
the right side has the thumb and finger monstrously
developed into a pair of combs carrying about sixty
unequal teeth apiece, and, as Spence Bate observes, ‘it
appears probable that when partially closed it bas the
power of raking the neighbourhood to a considerable
distance, and so entrapping small animals and other
material from which the blind creature has the power of
selecting its food. As this extremely elongate hand
could not convey the food to the mouth, the short second
and third pairs of legs are also conveniently chelate. The
fifth pair are the same, at least in the female, but in
these the minute chela buried in a thick brush of fur
probably has some function other than that of assisting its
mistress to feed.

Calocaris Bell, 1853, has but a single species, Calocaris
Macandree, Bell, found in the waters of Ireland, Scotland,
and Norway. It is still comparatively rare, as might be
expected of an animal which burrows at depths of 80 and
150 fathoms. Its habits would seem to be tolerably
sluggish, since specimens are sometimes overgrown with
a small zoophyte, the polyzoon T'riticella flava, Dalyell,
which can scarcely serve any purpose of concealment. The
eyes are present but have lost their pigment, so that vision
is probably dim. The first pair of legs are unequal, but
not strikingly so. These and the next pair are chelate,
while the remaining three pairs are simple. Spence Bate
makes it a character of the family that tbe tail-fan has the
outer plates much larger than the inner, but, though this
is true of Thawmastocheles, it scarcely applies to Calocaris.

, Pl._x:

C.cenobita Sed D\
Telson and Uropods Gath y

4

4
bem
% Platybema |
2 rugosum |

Nematocarcinus
undulatipes
ae }

= SS =e

A.sulcatipes. 1°’ Leg =
1g. Mg : fA. sulcatipes

P/Q yao Telson and Uropods

A NEW TRIBAL NAME 191

CHAPTER XIII

TRIBE III.—SCYLLARIDEA

Tue first antenne carry two flagella; the second have no
scale. The trunk-legs are six-jointed through coalescence.
The first pair are not much larger than the second, and
simple or scarcely subchelate; the three following pairs
are simple, and the fifth pair is simple in the male, more
or less minutely chelate in the female. The branchize are
wel] developed ; epipodal plates on the first joint in the
first four pairs of trunk-legs have podobranchiz attached
to them as distinct plumes. All these same limbs have
arthrobranchiz, and the last four segments of the trunk
have pleurobranchiz. The first segment of the pleon is
without appendages.

In this tribe Spence Bate says that the ova are very
small, and that the young are hatched in a Phyllosoma-
form. With the Astacidea and Stenopidea it forms
what he calls the normal group of the Trichobranchiate
Macrura. It contains two families, the Scyllaride and
Palinuride, and the tribal name given it by Spence Bate
was Synaxidea (see p. 46), derived from a new genus
Synaxes, which he considered to combine some of the
features of both families. As Synavzes is itself a synonym,
it was not possible to retain the tribal name derived from
it, while Heller’s term loricata adopted by Paulson, Boas,
and others, is not in conformity with the names of the
neighbouring tribes.

Family 1.—Scyllaride.

“The carapace is depressed, with orbits for the eyes
excavated in the dorsal surface. The second antenne are

192 A HISTORY OF RECENT CRUSTACEA

short, squamiform. The mandibles have a one-jointed
‘palp. The trunk-legs are simple, except the fifth pair
in the female, which are minutely chelate.

To this family there are assigned six or seven genera,
one of which is occasionally met with in the waters of
Great Britain. In this and other families in which the
fifth pair of legs are chelate in the females only, they are
supposed to be so constructed to assist in rupturing the
ovisac, and liberating the embryo from the ovum. Bell
explains the unusual structure of the second antenne by
suggesting that they have been developed into bread flat
organs of natation, and probably also constitute a pair
of shovels for the purpose of burrowing.

Scyllarus, Fabricius, 1793, has been much subdivided
since its first institution. As re-defined by Dana, it has
the rostrum very salient, the sides of the carapace not
incised, the second antennz almost contiguous, the exopod
of the third maxillipeds ending in a lash; the pairs of
branchize twenty-one.

In various writers the expression will be found in such
definitions as the above, that the palp of the third maxil-
lipeds is or is not furnished with a flagellum. Now Pro-
fessor Huxley in ‘The Crayfish’ says that, in the terms
usually applied to the maxillipeds by writers on descriptive
zoology, ‘the exopodite is the palp, and the metamor-
phosed podobranchia, the real nature of which is not
recognised, is termed the flagellum.’ It must therefore
be borne in mind that the flagellum mentioned by Huxley
as an equivalent to the podobranchia or epipod on the first
joint is quite distinct from the flagellum of the exopod,
the term being used in the latter instance merely to signify
a whip-like termination, a many-jointed, more or less flexi-
ble lash.

Scyllarus latus (Rondelet), Latreille, is found in the
Mediterranean and Atlantic. It is said sometimes to
attain a length of a foot anda half, and to be delicious
food, superior to the lobster itself. Patrick Browne in his
‘History of Jamaica,’ calls it ‘The Mother Lobster,’ and
Petiver designates it, ‘the great broad warty crab.’ In

THE MOTHER LOBSTER 193

Savigny’s fine folio plate its characteristics are beautifully
delineated. The enormously broad ultimate and antepen-
ultimate joints of the second antennz will astonish and
perplex any one who for the first time becomes acquainted
with a crustacean of this family. In the present species
the quadrangular rostrum, the little eyes very wide apart,
and implanted at a little distance from the sharp anterior
angles of the great oblong tuberculate carapace, the com-
parative smallness of the legs entirely unchelate, and the
breadth of the tail-fan, are characters which will attract
and deserve attention.

Thenus, Leach, 1819, has still only the type species,
Thenus orientalis (Fabricius), in which the carapace is
broader than long, with a bilobed rostrum, and the eyes
placed on visible stalks at its anterior angles. There are
_twenty-one pairs of branchiee.

Ibaicus, Leach, 1815, has the carapace much broader
than long, deeply incised on the sides, with a bilobed
rostrum, and the small eyes planted far from the front
angles; the broad second antennz not very remote on
their inner margins, the pairs of branchiz twenty-one or
twenty-two. Species of this remarkable genus are dis-
tributed all over the Eastern seas, but Ibacus verdi, from
St. Vincent, Cape Verde Islands, and also from Sambo-
angan in the Philippines, is said to afford the only speci-
mens of the genus taken elsewhere than along the Pacific
coasts of Asia and the Australasian Islands. ‘ Hence,
Spence Bate who instituted the species observes, ‘the
similarity that it bears to Lbaccus incisus (Péron) is the
more remarkable, and, judging hy the several figures
and descriptions published, the differences are slight,
except in the character and number of the dentations that
arm the margins of the carapace and antenne.’ He also
calls attention to the thinning out of the sharp lateral
margins to an extent equalling that of some of the
Brachyura. Moreover, while the cervical groove, often so
conspicuous in the Macrura, is here wanting, the lateral
notches are greatly deepened, and widely separate the
suborbital and hepatic regions from the branchial. As in

194 A HISTORY OF RECENT CRUSTACEA

others of this family, the basal joint of the second antenne
is not free, but closely fused with the ventral portion of

Ha
AIH

Sl?

Fic. 16.—Jbacus incisus (Peron) [Desmarest].

the head. Spence Bate enumerates twenty-two pairs of
branchiz in this species. Why he cnanges Jbacus into
Ibaccus he has not bequeathed us any explanation.

Pseudibacus Veranyi, Guérin, may receive a passing
mention, as a Mediterranean species.

Arctus, Dana, 1852, has the rostrum very short and
truncate, the second antenne remote from one another,
the exopod of the third maxillipeds without a lash, and the
pairs of branchiz nineteen in number.

In the definition of this genus Dana is practically fol-
lowing de Haan in stating that the palp of the third
maxillipeds is without a flagellum. Mr. Spence Bate
translates this into his own terminology, and speaks of the
genus ‘ having no ecphysis attached to the second pair of
gnathopoda,’ which would mean that there was no exopod
to the third maxillipeds at all. But that is not the case.

THE CRAWFISH 195

The exopod, or ‘ecphysis,’ or ‘palp,’ is present, but as
de Haan’s figure shows, and as his statement declares, the
lash-lke termination is absent.

It rather looks as if Dana had stolen the type species
of Scyllarus, on which to found his new genus. At any
rate he changed Scyllarus arctus into Arctus ursus, both in
the generic and specific name making allusion to a bear,
not because of any resemblance in shape between Bruin
and this crustacean, but evidently because of the thick and
short pilose substance which protects the tuberculate sur-
face of the latter, and which is said to give it in its perfect
condition a smooth velvety appearance, lke the shining
coat of the bear.

Arctus ursus occasionally makes its appearance in Eng-
lish waters. It is recorded from many parts of the Medi-
_terranean, and also from Australia and Japan. There are
several other species of the genus. ‘They do not seem to
attain any remarkable size.

Family 2.—Palhinuride.

The carapace is longitudinally subcylindrical, with
orbits for the eyes partially excavated. ‘The second an-
tenn are subcylindrical, with a long rigid multiarticulate
flagellum.

Spence Bate assigns to this family five genera, one of
which is found in British waters.

Paliniirus, Fabricius, 1797, is restricted by Spence Bate
to those species which have asmall central rostriform tooth
or tubercle that overhangs but does not cover or enclose
the ocular segment, which have short flagella to the first
antenne, and in which the segment that carries those
antenne is anteriorly produced and laterally compressed in
front. Such species appear to be confined to the northern
hemisphere. The type, Palinurus vulgaris, Latreille, of
which the true specific name is involved in some perplexi‘y,
is found in many parts of Hurope, including the shores of
Great Britain. Bell considers that it is without doubt the
Curabos of Aristotle. It.is a very handsome species, some-

196 A HISTORY OF RECENT CRUSTACEA

times attaining a length of eighteen inches, and is valued
for food, though it has a less delicate flavour than the lob-
ster. Though its front legs make a very feeble show in
comparison with the powerful chele of the lobster, when
the mandibles are compared the advantage is greatly in
favour of the Palinurus, or Crawfish as it is often called.
Spence Bate has pointed out that in this genus and its
immediate kindred there are button-shaped tubercles on
either side of the trunk, which fit into cavities on the under
surface of the carapace, and have a very great power of re-
tention, this buttoning of the carapace being probably an
important protection to the branchiz that are placed
beneath it. Its long stiff antenne are said frequently to
prevent it from entering the pots set for catching crabs
and lobsters, and thus, while disappointing it in its search
for food, indirectly help to save its life. As in Palinurus
the ear-stones are introduced, and yet the animal has no
claws with which to pick up grains of sand and place them
in the auditory cavity at the base of the first antenna, it
might well be wondered how the otoliths reach their de-
stination; but Hensen explains that the crustacean has
only to burrow with its head in the sand, and the required
particles will easily find their way into the ear-chamber.

| Pulinosytus |, Spence Bate, 1888, has the rostrum an-
teriorly produced so as to reach beyond the ocular segment,
and by its connection with the segment belonging to the
second antenne forms a channel for the protection of the
ocular segment. The first antennz have two short
flagella, and their segment is not produced beyond the
extremity of the rostrum. This genus belongs at present
only to the southern hemisphere. A specimen of Palinosytus
Lalandw (Lamarck), ten inches long, was taken by the
Challenger near Tristan daCunha. Also a small specimen,
about an inch long, was taken near the Cape of Good Hope,
and this in all but sexual character already appeared to
have the perfect adult form. Palinosytus Htigelu (Heller)
is the common Crawfish of Sydney, in Australia, and if, as
Haswell supposes, it be the same as the New Zealand
Palinurus tumidus, Kirk, it must be credited with attaining

a a _

ADAM WHITE 197

the great size of two feet in length, with a carapace more
than twenty-one inches in circumference. Already in 1883,
Mr. T. Jefirey Parker, F.R.S., had proposed a new sub-
genus Jasus for those species of Palinurus which have the
rostral character assigned to Palinosytus and which have
no stridulating organ. He therefore claims that the name
Jasus should supersede Palinosytus.

Tinuparis, White, 1847, has the rostrum dilated, bi-
partite, with the processes flat, and the anterior margin
spinulose. To this genus belongs Linuparis trigdnus (de
Haan).

Panulirus, White, 1847, contains the numerous Eastern
and one or two Western species, in which there is no central
rostriform tooth, which have the ocular segment exposed
and membranous, the flagella of the first antennze long and
slender, and their segment produced considerably in ad-
vance of the frontal margin, that being generally armed
with strong teeth. Panulirus penicillatus (Olivier) has
already been mentioned as having exhibited the singular
monstrosity of an eye-stalk developing a flagellum or lash-
like termination. In this species Spence Bate enumerates
twenty-six pairs of branchie, this number including six
pairs of ‘mastigobranchie, which are in fact epipods,
whether accompanied or not by podobranchiz, which also
arise from the first jomt. With the help of Mr. R. I.
Pocock, I have come to the conclusion that Linuparis and
Panulirus were not named as generally supposed by Dr. J. E.
Gray, but by Mr. Adam White, in 1847, the characters of
the new genera being left to be inferred from those of the
known species which were transferred to them, a slovenly
method of definition which is much to be deprecated.

Palinurellus, von Martens, 1878, is distinguished from
Palinurus, by the feeble antenne, the nearly smooth cara-
pace, and its rostriform front covering the base of the
antennee and eye-stalks.. The type Palinurellus gundlacha
is from Cuba. The genus Synawes, which Spence Bate
established in 1881, and retained in 18858, is described as
having the rostrum produced beyond the segment of the
first antenne and united with that of the second antennz

198 A HISTORY OF RECENT CRUSTACEA

so as to make a perfect orbit and to cover the ocular seg-
ment. Itis said to have the antenne of Pulinurus, the
trunk-limbs like those of Scyllarus, the carapace like that
of Astacus, and the pleopods like those of Scyllarus, so as to
form a truly inosculant genus. The type species is Synames
hybridica, Spence Bate, from the West Indies. Spence
Bate himself observes that ‘ Palinurellus, von Martens, ac-
cording to that author differs from Synaxes in having the
posterior pair of pereiopoda chelate in the female,’ but does
not explain how that can be any distinction, if, in Synazes,
‘the pereiopoda are like those of Scyllarus,’ as he declares
them to be, for in Scyllarus also the last pair are chelate
in the female. The student must be prepared sometimes
to find it as difficult to reconcile authors with themselves
as with one another. Under the circumstances one may
accept the decision of Dr. Boas, quoted with evident ap-
proval by von Martens, in 1882, that Synaxes is a synonym
of Palinurellus.

The strange form known as Phyllosoma was at one time
regarded as belonging to a distinct genus, but is now
known to be larval, by such marks as the median eye, and
the rudimentary character or unjointed condition of the
various parts. A considerable number of specimens of
Phyllosoma were obtained by the Challenger, of sizes
varying from the seventeenth of an inch up to an inch and
two-fifths, the latter being larger than some specimens of
Palinurus that have attained the permanent form. In a
general way the Phyllosoma forms may .be assigned to
ditferent stages in the development of the Scyllaride and
Palinuride, bat to assign the successive stages to par-
ticular species does not seem always possible at present, and
in especial there appears to be an awkward gap between
the most advanced Phyllosoma and the earliest post-larval
form. No such perplexity, however, affects the first
larval form, or brephalos, when actually extracted from
the ovum. A specimen of this kind is shown on Plate IX.,
in Spence Bate’s figure of a juvenile Palinurus vulgaris.

are Se

AS

A FOSSIL’S KITH AND KIN 19

CHAPTER XIV
TRIBE IV.—ASTACIDEA

THE first antenne carry two multiarticulate flagella; the
second are furnished with a scale. The trunk-legs have
seven distinct joints. The first three pairs of trunk-legs,
and sometimes the other two pairs also, are chelate. The

- first pair are the largest. The branchiz are well developed.

The first segment of the pleon has appendages, except in
the Parastacidee.

In this tribe the young are said to be hatched in the
Megalopa form. It contains four families—the Eryontide,
Nephropsidee, Potamobiidee, and Parastacidee.

Family 1.—LHryontide.

The carapace is dorsally depressed, with little or no
rostrum. ‘lhe eyes are wanting or abnormal. The second
antennee have a long multiarticulate flagellum. The third
maxillipeds are pediform. The pleopods, exce;.t the first
pair, have a process attached to the inner branch (the
stylamblys of Spence Bate’s terminology). The uropods
have no transverse suture. ‘The telson is tapering.

To this family are assigned seven genera, but one of
these, Lryon, Desmarest, 1820, which gives its name to
the family, i is a fossil genus from the Lias of England and
the lithographic limestone of Bavaria. It is only in re-
cent years that the depths of the ocean have yielded forms
which appear to be properly classified in close proximity
to the ancient fossil species.

Polychéles, Heller, 1863, has the avterior angles of the

16

200 A HISTORY OF RECENT CRUSTACEA

carapace projecting ; the eye-stalks obscure, ‘immovably
Jodged in an orbit excavated in the dorso-frontal margin
of the carapace, more or less covered by the antero-lateral
margin of the carapace ;’ the second antenne terminating
in a long and slender flagellum; the first four pairs of
trunk-legs chelate ; the fifth pair simple in the male, some-
times chelate in the female ; the pleon not longer than the
carapace. ‘lhe type-species, Polycheles typhlops, Heller, was
first taken in the Mediterranean. Since then various species
have been recorded from both the Atlantic and the Pacific,
and from depths varying from 220 to 1,070 fathoms. Since
in the female all the legs are usually chelate, the generic
hame, meaning ‘ with many chelee,’ is not inappropriate.

Pentachéles, Spence Bate, 1878, meaning ‘the creature
with five chelee,’ seems to differ from Polycheles only in the
particular alluded to in the generic name, the male in this
instance, as well as the female, having the fifth pair of legs
chelate. The genus has a wide range in both the great
oceans, and the species descend to great depths.

Spence Bate observes that Pentacheles euthrix (v. Wil-
lemoes Suhm) has a close general resemblance to his own
Polycheles baccata.

Stereomastis, Spence Bate, 1888, is said to differ in
nothing externally from Pentacheles, but to be established
‘to receive those species in which the mastigobranchial
lush does not exist.’ It was probably foreseen that some
apology would be expected for such a definition, and the
remark is accordingly appended, that ‘ difference of in-
ternal structure as a specific character is of more value
than any exteraal distinction, which, though more con-
venient for classification, is of little importance if it does
not represent structural variation.’ Yet the example of
the present genus gives but feeble support to this senten-
tious aphorism, especially as in the two preceding genera
the mastigobranchial lashes are for the most part of great
tenuity, and in Stereomastis Suhmi, Spence Bate, the third
maxillipeds have ‘a rudimentary mastigobranchial plate,’
though the trunk-limbs are without any. The meaning
of the generic name would naturally imply the presence

WHERE THE FOOD THERE THE FEEDERS 201

of a solid lash, but it is explained to mean ‘ the absence of
a lash.’

Willemoesia, Grote, 1873, was at first named Deodamia
by Dr. v. Willemoes Suhm, but that name was pre-
occupied. Here the eye-stalks are rudimentary, not lodged
in a notch in the dorsal surface of the carapace, but in the
frontal space. ‘The first antennz have the first joint pro-
duced to a scale-like process, which is forced up into a
crest-like ridge; the two flagella are very unequal. The
trunk-limbs are all chelate in both sexes. The telson
tapers to a joint. The type species, Willemoesia lepto-
dactyla (v. Willemoes Suhm), occurs in the Mediterranean,
Atlantic, and Pacific between the depths of 1,300 and
2,225 fathoms. This and the species of the kindred genera
are almost always taken on an oceanic floor of globigerina
- ooze, and Mr. Spence Bate infers from this that the cha-
-racter of the food may have been one of the most perma-
nent influences in their geographical distribution. The
remark is capable of a very extended application.

Family 2.—Nephropside.

The carapace is sub-cylindrical, with a pronounced
rostrum. The second antennz have a long multiarticulate
flagellum. The segments of the pleon are dorsally imbri-
cated. ‘The outer branch of the uropods has a transverse
suture. The ‘mastigobranchiz’ or epipodal plates are
large, havinga well-developed podobranchial plume attached

to all the trunk-legs except the last pair.

Six genera are assigned to this family. Spence Bate |
calls it the Homaride, from Homarus, the name which «
Milne-Edwards gave to the genus containing the common
lobster, but since that genus was already named Astacus
by Leach, Homarus must be discarded as a synonym.
Since a freshwater genus in a different family has been
misnamed Astacus, by which the application of Astacidz
as a family name has been confused, it seems better to
give a new family name to the lobsters, and for this pur-
pose Nephropside readily suggests itself.

202 A HISTORY OF RECENT CRUSTACEA

Nephrops, Leach, 1819, has the eyes wider than their
foot-stalks and reniform or kidney-shaped in accordance
with the meaning of the generic name. ‘The scale of the
second antenne is large, reaching the end of the peduncle.
The first pair of trunk-legs are long, slender, and pris-
matic in shape, not very unequal. The type-species,
Nephrops norwegicus (Linn.), is distributed generally
through the seas of Europe, belonging not only to Nor-
way, but also to Great Britain and the Mediterranean. It
is a beautiful species both in form and colourmg. Accord-
ing to Spence Bate, the branchial arrangement is identical
with that of the common lobster, but Huxley draws a
slight distinction, saying that ‘the branchial plume of the
podobranchiee of the second maxillipeds is small or absent,
so that the total number of functional branchiee is reduced
to nineteen on each side’ in Nephrops, as compared with
twenty in the lobster.

Sars has figured and described the ‘second larval stage’
(see Plate IX.),! the ‘last larval stage,’ and the ‘ first post-
larval stage’ of this species. The larval pleon is highly
remarkable, not so much on account of the great dorsal
spines that arise from the fourth, fifth, and sixth segments,
as of the telson, which spreads itself out imto two ciliated
and spinulose spine-like branches, which together make its
arch equal in breadth to the length of the animal.

A second species, Nephrops Thomsoni, Spence Bate,
has been taken between Australia and New Zealand, and
in the Phihppines.

Eunephrops, 8. I. Smith, 1885, 1s very near to
Nephrops, except that, ike the American lobster, it has a
well-developed podobranchia to the second maxillipeds,
and the scale of the second antenne is very small. The
type species, Hunephrops Bairdii, was taken in the
Caribbean Sea.

Astdeus, Leach, 1814, has the eyes not wider than the
foot-stalks and subglobose. The scale of the second an
tennee is spine-like, not reaching the end of the peduncle.

1 The form norvegicus, accidentally used on the Plate, is not the
original spelling, but a later refinement.

FROM ARISTOTLE UNTO THIS DAY 203

The first pair of trunk-legs are large, robust, markedly un-
equal. The type-species is Astacus gammédrus (Linn.), which
Milne-Edwards and Bell speak of as Homarus vulqaris.
Occasionally this is corrected by authors into Homarus
gammarus. Spence Bate admits that Leach has un-
doubted priority, but regrets that to acknowledge his
claim would only have the result of creating great con-
fusion, which Leach himself would have deprecated, and
that it would introduce terms not likely to be generally
accepted. The sentimental consideration that Dr. Leach
would deprecate a particular result may be dismissed,
since in natural history the author of a name once pub-
lished has no more control over it than any other person.
In the due recognition of priority there is probably a
better chance than any other principle affords of eventually
clearing away confusion. No doubt, to our eyes, the age
of Leach, as far as Crustacea are condemned, seems a kind
of primitive antiquity, but in the perspective of another
century or two the writers of to-day will seem to stand
close by his side or very little in front, and if our nomen-
clature is carried out without principle, we must expect to
be treated like the pre-Linnzean zoologists, and have our
nomenclature put altogether out of court. It may be
mentioned that Adam White, a considerable authority in
his time, uses the name Astacus gammarus for the lobster,
in his ‘Popular History of British Crustacea,’ published
in 1857, thus showing that he was not to be daunted or
led astray by the authority either of Milne-Edwards or of
Bell. Leach remarks that ‘ Aristotle has very distinctly
described this species under the name actaxos.’ He is
referring no doubt to the very interesting but rather per-
plexing second chapter of the fourth book of Aristotle’s
‘ History of Animals.’

Astacus americanus (Milne-Edwards) closely resembles
the European species, but has two spines on the under
surface of the rostrum, which are wanting in its congener.
It is, like the other, a ‘large and extremely prolific species,
much sought after for food. It is reckoned that a million
a year are consumed in Boston alone. Professor S. I.

204 A HISTORY OF RECENT CRUSTACEA

Smith has studied its development, and carefully. described
the embryo as it appears some time before hatching, also
the first, second, and third larval stages, and the first post-
larval stage. In this genus it appears that the Zoea stage

{\,\), BY
oy \ Ni)

Fia.18.— AstacusAmericanus (Milne-Edwards),
wen] | early larval form, lateral view [S. 1. Smith].

Fic. 17.—Astacus Americanus (Milne-
Edwards), early laival form, dorsal
view [S. I. Smith].

is omitted, as far as the free existence of the animal is con-
cerned, and that the young one is hatched in the Mysis

——SS =

MIN OSS

SA

Fic. 19.—Astacus Americanus (Milne-Edwards), third stage [S. I. Smith].

form. Professor Smith did not accurately ascertain the
age of the youngest larve he described, but supposed them
to be at most a few days old and not to have moulted more

LARVAL LOBSTERS 205

than once. In this stage they are free-swimming Schizo-
pods about a third of an inch long, without appendages to
the pleon, but with six pairs of pediform appendages under
the carapace, each with an exopod developed into a power-
ful swimming organ. ‘The eyes are bright blue; the
anterior portion and the lower margin of the carapace and
the bases of the legs are speckled with orange; the lower
margin, the whole of the penultimate, and the basal por-
tion of the ultimate segment of the abdomen [pleon], are
brilliant reddish orange.’ In the second stage appendages
to the pleon have appeared on the segments from the
second to the fifth, these same segments carrying dorsal
spines as in the preceding and following stages, but with
successive reductions in their size. In the third stage the
appendages of the sixth segment of the pleon are well
developed, although quite different from those in the adult.
Considering that the Norway Lobster and the Common
Lobster when adult are so nearly allied that they might
almost be included in a single genus, the difference be-
tween the larval forms of the two is at first sight rather
startling, but when more narrowly examined it will be
seen that the structure in both is essentially the same,
only that the telson of the larval Nephrops has been trans-
versely outdrawn to a portentous extent. The larval
Porcellana has been already mentioned as developing a
monstrous spine in the longitudinal direction ; the larvee
of the Cirripede, Lepas fascicularis, bristle with spines,
and it is likely that many of the infant Crustacea may
find in these processes an efficient protection to their
minute and delicate frames against foes not much bigger
than themselves. That they have such enemies it is easy
to guess, and Professor Smith says of his young lobsters
of the first stage, ‘They appeared, while thus in confine-
ment, to feed principally upon very minute animals of
different kinds, but were several times seen to devour
small zoéee, and occasionally when much crowded, so that
some of them became exhausted, they fed upon each other,
the stronger ones eating the weaker.’ We cannot afford
to find fault with their juvenile morals, since similar prac-

206 A HISTORY OF RECENT CRUSTACEA

tices have been followed, in some stages of society, by
human beings themselves.

Phobérus, A. Milne-Edwards, 1881, has the eyes close
together, small, and implanted on short rudimentary eye-
stalks. The scale of the second antennz is large. The
first pair of trunk-legs are long, slender, and cylindrical ;
the second and third more slender and not quite so long;
the fifth slightly subchelate. In Phoberus tenwimdnus,
Spence Bate, from New Guinea, the entire surface of the
animal is spinous.

Nephropsis, Wood-Mason, 1873, has the eye-stalks
small, the second antenne without a scale, the first pair of
trunk-legs large, the second slender, the third slender and
with the chele minute, the last two pairs slender and
simple. All the recorded specimens have been taken at
creat depths, from two or three: hundred down to eight
hundred fathoms. The type-species, Nephropsis Stewarti,
Wood-Mason, from the Andamans, was supposed to be
blind, but, according to Spence Bate, ‘it appears both
from Wood-Mason’s own figures and from an examination”
of the Challenger specimens, that this genus cannot be
described as being without organs of vision.’ Nephropsis
atlantica, Norman, from the Fiiré Channel, has small and
immature eyes.

Eutrichochéles, WWood-Mason, 1876, was instituted to
receive the Cancer modestus of Herbst from India, which,
according to Wood-Mason, is ‘especially interesting as
being the nearest known blood-relation of the remarkable
blind crayfish,’ Nephropsis Stewurtt.

Family 3.—Potamobude.

The carapace is sub-cylindrical, with a pronounced
rostrum. ‘The fourth and fifth pairs of trunk-legs are not
chelate. The outer branch of the uropods has a transverse
suture. The first maxillipeds have an epipod devoid of
branchial filaments; the second maxillipeds and the first
three pairs of trunk-legs have the podobranchiz always
provided with a plaited lamina. None of the branchial fila-

CRAYFISHES 207

ments and attendant sete terminate in hooks. The first
segment of the pleon has appendages in the male and
usually also in the female, those of the four following
seoments being relatively small; in the male those of the
first segment are stiliform, and those of the second segment
are always peculiarly modified. The telson is frequently
divided by a transverse incomplete hinge.

To this family three genera are assigned, which belong
to the fresh waters of the northern hemisphere only.

Potamobia, Leach, 1819, meaning ‘the creature that
lives in a river,’ is the genus that has so commonly of late
years been called Astacus. The name is often also quite
needlessly altered into Potamobius, and that by writers who
use the name Gebia unchanged, properly ignoring Risso’s
pseudo-correction of it into Gebios. In Potamobia the last
_ segment of the trunk carries a pleurobranchia and the two

or the three preceding segments have rudiments of the

pleurobranchiz. According to Mr. Walter Faxon, whose
authority on this subject is not likely to be disputed, the
English species should be called pallipes (Lereboullet),
the Potamohia torrentium (Schrank), and the Potamobia
fluviatilis (Auctorum) being distinct. It will be remem-
bered that it was on this genus that the celebrated Ré-
aumur conducted his investigations into what was at the
time something of a mystery, namely the exuviation or
shedding of the coat of the crustacean. Here too Rathke
found materials for studying the development of the em-
bryo, unfortunately for the commencement of such a study
lighting upon an exceptional group, in which the young
enters into liberty in a form not very remote from that of
its parents.

Cambdérus, Erichson, 1846, has the pleurobranchiee
entirely suppressed, so far as is known, and the podo-
branchia of the fourth pair of trunk-legs has no lamina.
The third pair of trunk-legs, and sometimes also the second
or the fourth pair, have in the male the third joint provided
with a conical, recurved, hook-like process, and in the
female the hinder edge of the penultimate sternum of the
trunk is elevated into a transverse prominence, on the

208 A HISTORY OF RECENT CRUSTACEA

posterior face of which there is a pit or depression, an
arrangement designated by Dr. Hagen as the annulus
ventralis. Mr. Faxon enumerates no less than fifty-five
species, twenty-one of them being described by him as new
in 1884. Cambarus Diogenes, Girard, which is widely
distributed in the United States, constructs curious
‘chimneys’ at the mouth of its burrows, and Cambarus
dubius, Faxon, it is said, ‘makes mud chimneys like C.
Diogenes, which it seems to represent in the meuntain
regions, U. Diogenes belonging to the low lands. Cam-
barus argillicéla, Faxon, is closely related to the two pre-
ceding species. ‘The types of it were dug out of burrows
in solid blue clay in, Detroit, Michigan. ‘The burrows
were three to five feet deep. At the bottom of each
burrow was a pocket in a layer of loose gravel and clay,
holding water. Just above the water-line an enlargement
in the burrow formed a shelf on which the animal rested.’
It is a pleasing picture of retirement, safety, and comfort,
if one can accommodate one’s mind to the feelings and re-
quirements of a crayfish. Cambarus pellucidus (Tellkampf)
is the blind species of Mammoth Cave, Kentucky, in which
it is noticed as a singular circumstance that Cambarus
Barton (Fabricius) occurs with well-developed eyes.
Cambaroides, Faxon, 1884, is only introduced by its
author as a sub-genus of Potamobia, but it may as well
follow its destiny at once and become a genus. Huxley in
‘The Crayfish’ mentions Astucus dauwricus, Pallas, and
Astacus Schrenkii, Kessler, as restricted to the basin of the
Amur, which sheds its water into the Pacific over against
Japan. He points out that the branchial system of the
Amurland Astaci is apparently the same as that of the rest
of the genus, but that the second and third trunk-legs in
the male have a hook-like process on the third joint, and
that the females have the transverse prominence already
noticed in Cambarus. It is on this combination of charac-
ters from Cambarus and Potamobia that Faxon has founded
his Cambaroides, to include the two species just mentioned
and the Astacus japonicus of de Haan. In this species he
suspects the existence of two forms of the male, a pecu-

THE GLOBE PARTITIONED BY CRAYFISHES 209

liarity that has long been known in the genus Cambarus.
It was at one time supposed that one of the forms, not
much differentiated from the female, might be sterile, and
that the more highly developed and specialised form was
the fertile male. But Mr. Faxon, having kept some |
specimens of the latter form under observation, found that
after pairing at the next exuviation they assumed the less
differentiated form, and his inference has been generally
accepted that the two forms alternate in the same individual
during a certain part of its hfe. As it is not probable
that the Potamobidze have a monopoly of this curious
changefulness, the chance of its occurrence is one more
pitfall to be guarded against in the institution of new
species.

Family 4.—Parastacide.

These agree very closely with the preceding family
except in regard to the branchiz, appendages of the pleon,
and the telson. Here the first maxillipeds have the
epipod almost always provided with a certain number of
well-developed branchial filaments; the podobranchie of the
following appendages are devoid of more than a rudiment
of a lamina, while some of their filaments and attendant
setze terminate in hooks. The first segment of the pleon
has no appendages in either sex, and the appendages of
the four following segments are large. The telson is
never divided by a transverse hinge.

To this family there are allotted six genera, all be-
longing to the Southern hemisphere, and living, like those
of the preceding family, only in fresh or brackish waters.
The facts of distribution in regard to the two families are
remarkable. Several species of Potamobia are found in
rivers of Europe and Asia, and five species of that genus
exist in rivers of North America, west of the Rocky
Mountains, whereas fifty-two species of Cambarus inhabit
the rivers and lakes of North America east of that range.
Of the Parastacide, Astacoides, Guérin, 1859, with its
solitary species madagascariensis, is found only in Mada-
gascar; Parastacus, Huxley, 1878, was established for

210 A HISTORY OF RECENT CRUSTACEA

species that belong to Southern Brazil; Paranephrops,
White, 1831, is found only in New Zealand and (possibly)
Fiji, while even within the limits of New Zealand its two
species, planifrons and zealandicus, are found by Mr. Chilton
to have distinct and separate ranges; Astacopsis, Huxley,
1878, and Hngeus, Erichson, 1846, belong to Australia
and ‘Tasmania, while Chceraps, Erichson, 1846, belongs to
Australia alone. Cheraps was instituted only as a sub-
genus by Erichson, and by Mr. Haswell it is united with
Astacopsis. Spence Bate, in remarking upon the peculi-
arities of distribution here set forth, speaks of ‘ the several
genera being adapted each to its own locality, no two
genera being known to exist in one habitat,’ but to support
this statement he assigns Astacopsis to Austraha, Hngceus
to l'asmania, and Cheraps to Van Diemen’s Land, intend-
ing perhaps a just reproach to those who altered the name
of Van Diemen’s Land into Tasmania. In fact the small
burrowing Hngeus may be peculiar to that island, and,
if not, it 1s separated by rather subtle distinctions from
Astacopsis, so that the three genera in question form a very
united group, and it is singular that, while they agree
together in their branchial arrangement, they differ in that
respect from all the other genera in the two families under
discussion. ‘The unnamed ‘ Australian Crayfish’ of Huxley,
which sometimes reaches a length of twenty inches, is pro-
nounced by Mr. Haswell to be Astacopsis serratus (Shaw).
In Paranephrops zealandicus, Mr. Wood-Mason has ob-
served that the young are specially fitted for attachment
under the pleon of the mother. The specimens examined
were under a third of an inch in length. The two hind-
most pairs of legs have the sixth joint ‘provided at its
extremity with a strongly hooked, exceedingly acute,
movable claw, and on the lower edge at the end with six
or seven sharp spines, against which the claw folds, and
thus forms a very efficient prehensile arrangement.’

Pl. 3

if Second Pleopod |

/

aT

ia

Path

| First Maxilia
TN \ aN

Second First Second
Mazilla Maxilluped Maxulliped

| Ces

_Stenopus hispidus (Olivier)

A SMALL TRIBE 211

CHAPTER XV

TRIBE V.——STENOPIDEA

THE carapace is produced to a laterally compressed ros-
trum. The first antenne have two flagella, the second
have a scale. The mandibles have a three-jointed palp.
The exopod of the third maxi!lipeds is small, slender, and
almost rudimentary. The first three pairs of trunk-legs
are chelate, the third pair being the longest and largest.
The branchie are filamentous ; only the second maxillipeds
have a podobranchial plume ; the hindmost pleurobranchial
plume is the largest. The first pair of pleopods is one-
branched and foliaceous ; the uropods and telson have no
transverse suture.

Family Stenopide.

This being the only family has the characters of the
tribe. It contains two genera long included among the
Penzid, with which they agree in having the third pair
of trunk-legs larger than the two preceding pairs, but sepa-
rated from that group by the structure of the branchie.
Of the third genus now transferred to this family, the
branchize have not been described.

Stendpus, Latreille (in Desmarest), 1825, has a long,
flat, obtusely pointed scale on the second antenne, the
third trunk-legs long and slender, the fourth and fifth pairs
with the antepenultimate joint subdivided, the telson taper-
ing. The genus ranges from the eastern to the western

hemisphere and from the Arctic regions to the tropics.
_ Stenopus hispidus (Olivier) is recorded from the Pacific,
from Bermudas, and perhaps from Greenland. Spence
Bate’s figures of this species are reproduced on a re-

212 A HISTORY OF RECENT CRUSTACEA

duced scale in the adjoining Plate. Stenopus spinosus,
Risso, is from the Mediterranean.

Spongicila, de Haan, 1849, has but one species, Spongi-
cola venusta, with an extensive range in the Pacific. The
scale on the second antennz is broad, not ending in a
point, and fringed with long plumose hairs. The third
pair of trunk-legs have the hand large and thick and ihe
preceding joint short. In the two following pairs the
antepenultimate joint is not subdivided, and the terminal
joint is tridentate. The telson is ovate. The species is
said to live in the beautiful Huplectella and other similar
sponges

Aphireus, Paulson, 1875, has the third trunk-legs
long and slender; the fourth and fifth pairs with ante-
penultimate joint undivided and finger unidentate. The
telson is acute. he third maxillipeds resemble antenne,
each of the two slender terminal joints being subdivided
into four jointlets. The type species is Aphareus inermus
from the Red Sea.

BRANCHING BRANCHI& - 213

CHAPTER XVI
TRIBE VI.—PENAIDEA

THE branchial structure typically consists of a series of
plumes, that are attached by, or very near, their basal
extremity to the animal, and from a long central stalk
send off on each side a single row of branches that divide
and subdivide in a variety of ways according to the genus
-or even the species. The appendages of the trunk are
supplied with nerves from separate ganglionic centres,
except the last pair, which is supplied not from its own
segment but the preceding. ‘The third pair of trunk-legs
are chelate, the two following pairs never are. The ex-
truded ova do not appear to be definitely attached to the
appendages of the mother prior to hatching as in most
other Macrura. ‘The first larval form is supposed to be a
Nauplius.

This tribe corresponds with what Spence Bate calls
the Dendrobranchiata normalia, in allusion to the rami-
fied, or tree-like structure of the branchie. He allots to
it two families, the Penzeidee and Sergestidee.

Family 1.—Peneide.

The carapace at the sides is deeply produced and
carried further back than in the median dorsal line; its
rostrum is laterally compressed, this part at least being
carinated. Of the segments of the pleon the first three
are usually not longitudinally carinate, but the three that
follow are almost always much so. ‘The sides of the first _
are produced so as to overlap the hind lateral margin of
the carapace and the front lateral margin of the second

Ay

214 A HISTORY OF RECENT CRUSTACEA

segment of the pleon. The telson is generally dorsally
flattened or grooved. ‘The eye-stalks are usually two-
jointed. The first antenne have two multiarticulate
flagella, and the first joint of the peduncle flattened to
receive the eye-stalk and laterally strengthened on the
outer side by a spine-like process, on the inner by an un-
jointed appendage often fringed with hairs. The second
antenne have a broad, thin, foliaceous scale. and a long
~ flagellum. The mandibular ‘ palp’ is never more than two-
jointed. The third maxillipeds are long and pediform.
Both the second and third maxillipeds and the three or
four following pairs of appendages carry ‘ mastigobranchise ’
or epipodal plates. The first three pairs of trunk-legs are
chelate and similar, the second longer than the first, and
the third than the second. ‘The trunk-legs with occasional
exception of the third pair have the antepenultimate
joint unusually long in relation to the penultimate (in
this respect agreeing with the Stenopidea and Nemato-
Curcinus).

This family includes nearly a score of genera, only one
of which frequents the shores of Great Britain. In his
very detailed discussion of the family Mr. Spence Bate
says that in the Penzide the anterior three segments of
the pleon ‘ are never carinated, but those that are posterior
to them are always extremely so. Yet he subsequently
mentions that Penceus velutinus, Dana, has the ‘ pleon cari-
nated from the second somite to the posterior extremity
of the sixth,’ and he gives a similar account of three of his
own species, besides mentioning two others in which the
carina begins on the third segment. On the other hand
in the description of Penceus gracihs, Dana, he says nothing
of any carina on the pleon, but states that all the six seg-
ments are dorsally smooth. Similar remarks will apply
to other genera. In Sicyonia, for example, he describes
species which have the carina of the pleon extending from
the first to the sixth segment, and in Gennadas species
that have no carina on any segment of the pleon except
the sixth.

Peneus, Fabricius, 1798, has a dorsally serrate rostrum,

APPENDAGES OF THE PENAIDEA 200

two- or three-jointed eye-stalks, flagella of the first
antennz not longer than the carapace, a two-jointed man-
dibular ‘palp,’ the third maxillipeds long and pediform,
the first three pairs of trunk-legs carrying exopods, the
fourth and fifth pairs
not longer than the
preceding, the pleo-
pods with two foliace-
ous branches in every
pair except the first,
which in the male has
a large membranous
appendage attached to
the base. This ap-
pendage, called by
-Spence Bate the pe-
tasma or curtain, is
rudimentary in the
female. In this genus
there are no _ podo-
branchiz. ‘The first
species assigned to it
by Fabricius was the
large Penceus monidon,
which occurs in the FiG. 20.—Sergestes Atlanticus (Milne-Edwards), first
n eighbourh ood of C ey- tian ee ae fap Bete petasmata united in
lon, Western Australia,

and the Philippines, and is perhaps identical with the
Japanese Penceus semisulcatus of de Haan. Penceus cara-
mote (Risso) is found in the Mediterranean and Atlantic,
and is sometimes taken in English waters.

Penceus canaliculatus, Olivier, appears to extend with
little variation from Japan to Australia, and to differ only
in small particulars from Penceus caramote. Thus, it has
nine teeth instead of twelve on the dorsal crest, straight
instead of wavy ridges on either side of the carina of the
carapace, the spine on the outer margin of the first joint
of the first antenna not nearly instead of quite reaching
the extremity of the eye, no tooth on the second joint of

>

216 A HISTORY OF RECENT CRUSTACEA

the third trunk-legs ; and the two teeth on each side of the
telson in caramote are wanting in canaliculatus.

Penceeus esculentus, Haswell, is said to be the common
edible prawn of Sydney, Newcastle, and other places in
Australia, and but few must be required to make a dish,
if they often reach, as they do sometimes, the length of
nine inches. It is perhaps not distinct from the type
species of Fabricius.

~ In Penceus and some at least of the other genera in the
family, there is on the ventral surface of the trunk a struc-
ture peculiar to the females, to which Spence Bate has given
the name of Thélyjcum (see Plate XII.), ‘which,’ he says,
‘so far as I am aware, has never been previously figured or
described by any naturalist.’ Yet he presently after refers
to one description of it by de Haan, and might have men-.
tioned that it is described by that author in no less than
four species. Of the female of Pencus canaliculatus, de
Haan says that ‘the sternum is channelled between the
three anterior legs, between the fourth having a narrow
rounded horny Jobe, and between the fifth a broader
membranacecus orbiculate lobe, which in advance of the
middle is cleft and embraces the median spine.’ Referring
to the same species and sex, Spence Bate says :—‘ On the
ventral surface in both our specimens, between the poste-
rior pair of pereiopoda, is a large thelycum, consisting of a
dichotomous, calcareous capsule, which extends forwards
as far as the base of the antepenultimate pair of pereiopoda,
whence project two large, leaf-like, membranous appen-
dages (Plate XXXII. fig. 49). They appear to be con-
nected with the internal organs by means of foramina in
the floor of the capsule, and have no connection with the
filth pair of pereiopoda.’ Paulson also, in 1875, figures and
describes these appendages in various species of Penceus.
The organ appears to vary considerably in different species,
but the question is complicated by the probability that it
may undergo important changes of form at different stages
of the animal's existence. Spence Bate’s figures and de-
scriptions will no doubt lead the way to the clearing up of
this question.

QUESTIONS OF DEVELOPMENT ZUG

Another intricate matter is the development of Pencus.
Fritz Miiller in 1864 believed himself to have discovered
the earliest stage. Of the brood of some prawns belong-
ing to Peneus or some immediately kindred genus, he
says, ‘they quit the egg with unsegmented oval body, an
unpaired frontal eye, and three pairs of swimming-feet, of
which the first are simple, the other two two-branched,
belonging, therefore, to the larval form so frequent among
the lower Crustacea, to which O. F. Miiller gave the name
of Nauplius. No indication of a carapace, of the paired
eyes, of mouth-organs near the mouth which is over-arched
by a helmet-shaped hood!’ Between this and the adult
there are various Zoea and Mysis or Schizopod stages, not
to mention the Protozoea of Claus interposed between the
egg and the Nauplius form. Spence Bate alludes to the
claim made by Professor Brooks in 1882 that, having
captured and kept in confinement a specimen, he had
witnessed every moult between the youngest Protozoea
and the young Peneus, but against this is set the comment
of Mr. Walter Faxon in 1883 that Professor Brooks’
‘youngest Protozoea is an older stage than the youngest
stage secured by Fritz Miiller, to which he adds that ‘no
observer has rediscovered Miiller’s Nauaplius.’ Hence
Spence Bate himself says that ‘two links of importance
are yet wanting: the one is that which connects the
earliest Protozoea form with Fritz Miiller’s Nauplius, and
the other that which connects the Nauplius with Peneus ;
either of these being demonstrated will prove the con-
nection, and establish the splendid hypothesis of Fritz
Miiller.’

Solenocéra, Lucas, 1850, with its Mediterranean species
Solenocera Philippi, Lucas, is by Victor Carus made a
synonym of Peneus siphonocéras, Philippi, but it differs
from Penceus in having the flagella of the first antennee
longer than the carapace, and should therefore be called
Solenocera siphonoceras (Philippi), the earlier name Penceus
membranaceus, Milne-Hdwards, having been already used
by Risso for a different species. The fiagella in question
are rather remarkable, since the primary is very slender,

218 A HISTORY OF RECENT CRUSTACEA

whereas the secondary is dilated and longitudinally hollowed
so that its companion can be sheltered within it when not
in use, but at other times the two pairs of flagella together
form the efferent branchial tube, which is continued back-
wards by the peduncles of the first and the scales of the
second :antennee, these making a broad channel between
the bases of the peduncles of the second antenne, where
it is closed in below by the mandibular ‘ palp,’ and diverges
on each side of the upper lip into the passages from the
branchial chambers. The generic and specific names alike
signify ‘a creature with channel- or pipe-forming antenne.’

Pleoticus, Spence Bate, 1888, also has the flagella of
the first antennze longer than the carapace, but without
the grooved arrangement. Its second antennz claim
notice as having the flagellum ‘three times the length of
the animal, or more.’

Sicyonia, Milne-Edwards, 1830, has its species, two of
which occur in the Mediterranean, distinguished for the
rigidity of the imtegument. The flagella of the first
antennee are very short; there are no exopods to the
trunk-legs as there are in Penceus, and the pleopods are
all single-branched. From Penceus it differs in the struc-
ture and arrangement of the branchiz, though agreeing
with it apparently in the absence of podobranchiz. In
defining the genus Spence Bate says that the second
maxillipeds carry ‘a mastigobranchial plate without a.
podobranchia,’ ‘ one arthrobranchial and one pleurobran-
chial plume.’ On the next page, after giving a scheme of
the branchie of Sicyonia which includes six pleurobranchize
and no podobranchie, he states that it differs from Penceus
‘in the absence of any traces of pleurobranchiz, in the
reduction of the arthrobranchial plumes, and in the pre-
sence of one podobranchial plume attached to the first
pair of gnathopoda’ [7.e. second maxillipeds]. Presently
after, in the description of Sicyonia carinata (Olivier), he
says of these same second maxillipeds that the first joint
‘carries a long and slender mastigobranchia shaped like
that in Penceus, and, as in that genus, there is no bran-
chial plume attached to it... Thus there both is and is not

Pereon,
showing the_..

~ 5
Thelycum a

Lower Lip |
Branchial Plume, in Section fipiataam

Hepomadus glacialis, Sp. Bate

THOUSANDS OF FATHOMS 219

2 podobranchia to the second maxillipeds, and there are
no traces of pleurobranchiz although pleurobranchiz are
developed on six pairs of appendages. ‘These are riddles
which those who have specimens to compare with the de-
scriptions may be able to solve.

Aristeus, Duvernoy, 1841, is distinguished from Penceus
chiefly by the circumstance that on the second and third
maxillipeds and the first three trunk-legs it has the podo-
branchize which the other is without. Avristews antennatus
(Risso) occurs in the Mediterranean and Atlantic, and is
described as having a smooth pleon. .

Hepémidus, Spence Bate, 1881, is distinguished from
Aristeus by a hepatic tooth on the shoulder of the carapace.
Hepomadus glacialis, of which Spence Bate’s figures are
given in the adjoining Plate on a reduced scale, was taken
- near Yokohama at the frigid depth of 1,875 fathoms.

Several new genera from Atlantic exploring expedi-
tions have been described in recent years by Professor S. I.
Smith, as Hymenopenceus, 1882, meaning the membrana-
ceous Penzeus, Amalopenceus, 1882, which, at least in the
type species Amalopencus elegans, has only the sixth seg-
ment of the pleon carinate. Some of the lately described
genera have names alluding to the great depths from which
they were obtained : Benthesicymus, Spence Bate, 1881,
Benthecétes, S. 1. Smith, 1884, Benthonectes, S. I. Smith,
1885, all meaning those that dwell or swim in the abysses
of the billowy ocean. enthesicymus has a submembran-
ous integument, exopods to the limbs as in Penceus, podo-
branchiz as in Aristeus, and the last two pairs of trunk-
leas longer than the preceding pairs. One of the species,
Benthesicymus pleocanthus, Spence Bate, was trawled from
a depth of 3,050 fathoms in the North Pacific, while other
specimens were taken twenty degrees further south in the
smaller depths of 450 and 1,050 fathoms. Benthonectes is
specially characterised by the multiarticulate flagelliform
dactyli, that is the subdivided terminal joints, of the last
two pairs of trunk-legs. Xiphopeneus, 8. 1. Smith, 1885,
and Benthacetes have a corresponding peculiarity in the
propodi or sixth joint of the same limbs. In some of the

220 A HISTORY OF RECENT CRUSTACEA

species of the deep-sea genera, such as Benthesicymus and
Gennadas, Spence Bate, the eye-stalk sends out a promi-
nently pointed tubercle, with a small circular lens at its
extremity, served by a distinct branch of the optic nerve,
this single lens being very translucent and without trace
of pigment. Gennadas received its name, meaning ‘of a
noble race,’ because it ‘approximates nearer than any
other to the little crustacean named Penceus (Kolqa) spe-
ciosus in Salter and Woodward's map of fossil Crustacea.’

Peteinira, Spence Bate, 1888, meaning ‘ flying-tail,’ is
established for a single species Peteinura gubernata (see
Plate 1X.), founded on a single specimen an inch long, taken
at the surface of the Atlantic at night time. There can
be no doubt that the supposition is justified that the
specimen is an immature form. There is a very long
slender rostrum such as is common in larval forms, but
the strangest peculiarity is at the other extremity of the
animal. The sixth segment of the pleon, which is about
as long as the four preceding segments together, carries a
pair of uropods of which the inner branch is small and
rudimentary, whereas the outer is nearly as large as the
rest of the animal, a truly prodigious rudder! If ever
the tail could wag the deg, one might expect a parallei
to that phenomenon in this instance.

Cerataspis, Gray, 1828, of which Cryptopus, Latreille,
1829, is a synonym, has been lately shown to have ‘ almost
all the characters of the typical Peneeidee.’ Gray referred
his Cerataspis monstrosus to the ‘Fam. Nebaliadee (Les
Schizopodes Latr.), but Giard and Bonnier say, ‘the
antennules, the anteune are absolutely those of the
Penzeide ; the second maxilla possesses the four charac-
teristic plates ; the endopod of the first maxilliped is five-
jointed, the second maxilliped is geniculate, the third is
transformed into a locomotive appendage; the thoracic
legs are provided with long swimming branches (exopods) ;
the first three pairs end in chele ; the last two are simple,
&c.’ Referring also to P. J. van Beneden’s discovery of
the nauplian embryo, they remark that ‘ among the Schizo-
pods the nauplian embryo has only as yet been observed

LONG NAMES FOR SHORT LARVZE 294

in the Huphausie, while on the contrary it is very frequent
among the Peneide.’

Family 2.—Sergestide.

The branchial system is impoverished or lost, the
epipodal plates and podobranchial plumes, when present,
being restricted to rudimentary structures on the second
maxillipeds. The first pair of trunk-legs, and some-
times the second, are simple, the chele of the third are
minute, the fourth and fifth pairs are feeble, rudimentary,
or absent.

The genera assigned to the family are Sergestes, Milne-
Edwards, 1830 ; Acetes, Milne-Edwards, 1830 ; Petalidium,
Sp. Bate, 1881; Sciacaris, Sp. Bate, 1881; and Lucrfer,
Vaughan Thompson, 1829, a pre-occupied name altered
to Leucifer by Milne-Edwards in 1837. <A very few re-
marks must suffice on the discrimination of these genera.
In Sergestes the last two pairs of trunk-legs are rudi-
mentary, in Acetes the last but one is reduced and the last
is wanting, in Leucifer both pairs are absent. In Sergestes
the arthrobranchiz are wanting, in Petalidiwm they are
found on the second and third maxillipeds and the first
three pairs of trunk-legs. In Sergestes, Professor Smith
remarks, the branchiz are compound phyllobranchiz,
while those of Peneews in the preceding family are com-
pound trichobranchie.

The larval forms of Sergestes have been partitioned into
genera and species. ‘The youngest form known is desig-
nated Hlaphocaris by Dohrn (see Plate IX.); another, and
presumably later form, is called Platysdcus by Bate ; this is
followed by Acanthoséma, Claus, and that by Mastigépus
of the same author. The species known as adults are
very numerous, of very various sizes, from many differing
localities, Sergestes atlanticus, Milne-Edwards, being found
both 1m the Mediterranean and in the Atlantic from
Greenland to the tropics. The account of the genus occu-
pies eighty-eight quarto pages and seventeen plates of
Spence Bate’s ‘ Report on the Challenger Macrura.’ It

222 A HISTORY OF RECENT CRUSTACEA

was the subject of a monograph by Kréyer in 1856, and
the interest of the subject seems still very far from being
exhausted.

Sciacaris, ‘ the shadow shrimp,’ is interesting as having
a telson which ends in ‘two lateral uniarticulate appen-
dages, but it is doubtfully founded on three specimens
from the Pacific, none of which is adult, and none of which
exceeds by more than a hair’s breadth a sixth of an inch
in length.

Acetes indicus was described by Milne-Edwards in
1830, the type-specimens having been taken at the mouth
of the Ganges. According to Spence Bate, these are the
only specimens known, so that some one must be respon-
sible for a wrong date when he says that with them in the
Paris Museum ‘ was a note stating that they were taken
in 1852 from a large fish “21 feet in length and 25
broad” (Dicerobates eroogoodoo); its stomach was filled
with myriads of these little crustaceans, which were
carried away in bucketfuls by the fishermen, and thou-
sands were left scattered about the shore. As the
crustacean is only an inch long, the above-mentioned fish,
otherwise known as the Ox-ray, or Sea-devil, which may
attain the weight of a ton, and has a mouth large enough
to swallow a man, would no doubt find room for a shoal of
these little shrimps. The Ox-ray occurs in the Mediter-
ranean, and might well be the ‘great fish’ referred to in
the book of Jonah.

Leucifer is without branchie ; it has the two anterior
pairs of trunk-legs without chele, and the chelee of the
third pair imperfect; the ova are carried beneath the
trunk, but apparently without any special means of attach-
ment. The genus is widely distributed over the tropical and
sub-tropical waters of the Atlantic and Pacific, but is sup-
posed to be limited to the two long known species,
Leucifer typus (Vaughan Thompson) and Leucifer Rey-
naudit, Milne-Edwards. It has been made the subject
of an elaborate study by Professor Brooks. Atter the
Nauplius and Zoea stages, the young appear to go through
transformations corresponding with those of Sergestes.

A PROBLEM IN CLASSIFICATION Des

The ingenious comparison instituted by Darwin between
the Macruran Leucifer and the Cirripede Lepas is well
known, and, as the illustrative figures have often been
reproduced, the long neck, the projecting eyes, and feeble
limbs of Leucifer are comparatively familiar. The petasma,
or curtain, at the first pleopods of the male, is in this
genus a very conspicuous object.

Schizopoda.

Spence Bate regards the Schizopods as an aberrant
group of his Macrura dendrobranchiata, and urges that,
‘with the exception of the variable condition of the pereio-
poda, the several genera do not possess a single character
that is not held in common with some genus of the
Macrura. Without any wish to pronounce upon the
_validity of the arguments and facts which he adduces in
support of his view, I must here simply follow the dictates
of convenience, and leave the Schizopoda to be treated
later on as a separate sub-order.

—Q9A A HISTORY OF RECENT CRUSTACEA

CHAPTER XVII
TRIBE VII.—CARIDEA

THE respiratory system is phyllobranchiate, that is, the
series of branchial plumes are ‘developed in the form of
broad foliaceous plates of extreme tenuity, attached to a
central stalk.’ The first two pairs of trunk-legs are fre-
quently but not invariably, and the last three pairs are
never, chelate. The ova when extruded are carried at-
tached to the pleopods of the female.

This tribe contains four legions, the Crangoninea,
Polycarpinea, Monocarpinea, and Haplopodinea. It cor-
responds with the group of normal phyllobranchiate
Macrura of Spence Bate, to which he assigns four tribes
of the same extent as the four legions just named.

Something like the Grecian bend, at one time fashion-
able in feminine gait and costume, is often conspicuous in
the species of this tribe. To this may be attributed the
title eukyphota, meaning the well-beut animals, applied
by Dr. Boas to a group in which he includes the genera
Paleemon, Palemonetes, Pontonia, Hippolyte, Pandalus,
Alpheus, Caridina, Crangon, Pasiphcea, all of them members
of the present tribe.

Legion 1.—Crangoninea.

The first pair of trunk-legs is subchelate, the second
feeble or imperfect, with the fifth joint not subdivided.

Family—Crangonide.

This being the only family might be content with the
characters of the legion, but others are added for conveni-
ence of comparison with those in families of the next

THE EATABLE SHRIMP 225

legion. The hind margin of the carapace is overlapped at
the sides by the first segment of the pleon ; in the rear the
pleon is laterally compressed. The eye-stalks are short
and one-jointed. The first antenne have two flagella, the
second have a large scale, and all the joints of the pedun-
cle free. ‘The mandibles are without a cutting edge, and
have no ‘ palp.’ The second maxillipeds end in a rudi-
mentary sixth joint, and the third pair have neither the
sixth nor the seventh joint. The second and third pairs
of trunk-legs are slender, the others robust. ‘The pleo-
pods are two-branched, the swimming-fan well developed.

This family at present contains some eight or nine
genera, in most of which the second pair of trunk-legs are
more or less chelate, but in Salinea, Owen, 1835, they are
simple, and in Paracrangon, Dana, 1852, this pair of legs
is completely obsolete.

Crangon, Fabricius, 1798, the parent genus, has the
carapace and minute rostrum dorsally flattened. The type
species, Orangon vulgaris (Linn.), is abundant on the sandy
shores of Great Britain. So also in the Mediterranean
and on the shores of Europe at large, in the seas of Japan,
on the East and West Coasts of North America, in short
over all the northern hemisphere this species seems to
make itself at home wherever there is a plentiful supply of
fine sand. Apparently in the zoological ideas of many
persons it is not only the typical shrimp, the shrimp par
eacellence, but the only shrimp. At least the information
that there is more than one species of shrimp, in fact that
there are several or indeed a rather large number of species,
often excites surprise not always wholly unmingled with
scepticism. Familiar also as the eatable shrimp is to
every one, vague notions sometimes prevail as to its ana-
tomical structure. A very intelligent student, on being
told that the eyes were stalked, candidly confessed to
having always thought that this appearance was due to
their having been forced out of the head by boiling. The
colour of the species is said to vary much with the ground
it inhabits, but specimens that live in shallow waters are
of a speckled grey which harmonises wel! with the wet

226 A HISTORY OF RECENT CRUSTACEA

sand, in which they may often be observed to bury them-
selves with great facility after making an abrupt leap to
escape the hand stretched out to capture them. ‘They
need, it is said, all their powers of concealment, being
eagerly hunted and captured by nearly all the larger fishes
which frequent the same waters, and, according to Verrill
and Smith, on the American coast this species constitutes
the principal food of the weak-fish, king-fish, white perch,
blue-fish, flounders, striped bass, and others. It may be
readily surmised that many of the flat-fishes, lying as they
do on the floor of the sea, must have a great advantage in -
the sport of shrimping. A second species, Crangon All-
manni, Kinahan, found in Great Britain and Norway, is
distinguishable by the two parallel keels of the sixth seg-
ment of the pleon, the groove between the two keels being
an easily discerned feature. This is found in deep water.
Kinahan in 1864 instituted for ita new genus Steiracran-
gon, Which may be allowed to lapse. It is not mentioned in
‘Bell’s History of the British Stalk-eyed Crustacea,’ not
being known when that was published. Bell there records
six species of Crangon, but, except in the case of Crangon
vulgaris, the names he gives them are not universally
accepted. For Crangon fasciatus, the name Lgeon fasciatus,
Risso, is sometimes preferred, Bell’s own species Crangon
sculptus being transferred to the same genus, because the
carapace in these species is not dorsally depressed.
Crangon spinosus, Leach, 1815, according to Sars, pro-
perly belongs to the genus Pontophilus, Leach, 1817, of
which it is the type. Crangon trispinosus (Hailstone) and
Crangon bispinosus (Westwood) have been assigned (but
the first with very doubtful correctness) to Cheraphilus,
Kinahan, 1864, in which, as in Pontophilus, the second
trunk-legs are much shorter than the third, instead of
being equal to them im length as in Crangon. Crangon
bispinosus is now identified with Orangon nanus of Kroyer,
and may therefore be called Cheraphilus nanus. Never-
theless all the seven species above menticned are by some |
writers still retained in the genus Crangon, together with
two others also found in British as well as Norwegian

a

A NATURAL PUZZLE pia

waters, the Cheraphilus echinulentus of Michael Sars,
aud Cheraphilus neglectus, G. O. Sars. The last-named
author, however, has quite recently been able to make
a very unexpected contribution to the settlement of the
question, for, in examining the development of different
members of the family, he has found that the various
genera and species are often more strongly distinguished
in the larval forms than in the adults, so that the
hesitation felt about separating, for example, the species
Crangon vulgaris and Crangon Allmanni, or the genera
Sheraphilus and Pontophilus, can no longer reasonably be
persisted in. Cheraphilus, 11 may be mentioned, agrees
with Crangon in having five pairs of branchie attached
respectively to the five pairs of trunk-legs, but Pontophilus,
while agreeing with Cheruphilus in the shortness of the

_ second legs, differs both from it and Crangon in having six

pairs of well-developed branchiz, besides a rudimentary
pair on the second maxillipeds. Since the species Hgeon
fasciatus, Risso, has been provided by nature with a re-
markable brown band across the fourth segment of the
pleon and similar colouring on the tail-fan, as if to sepa-
rate it unmistakably from ail other species, and to enable
the collector to identify it without further trouble, it may
be well to notice that Cheraphilus neglectus also has a deep
brown band across the fourth segment of the pleon and a
narrower one across the tail-fan, so that after all the col-
lector has need to be cautious.

The arctic Sabinea septemcarinata (Sabine) agrees with
Pontophilus in the branchial formula. In describing it in
1821 Sabine calls attention to the fact that the second legs
are ‘unarmed,’ that is, simple or not chelate, and, while
recognising that this is an ‘essential point’ of distinction
from the known species of Crangon and Pontophilus, he
enters one of the common but always useless protests
against the multiplication of genera. If he spoke thus in
1821, what would he have thought in 1891? Kroyer,
who redescribed the species in 1842, after stating that 16
is very abundant at Spitzbergen, adds that he had found
the stomach of the seal Phocw burbata quite filled with 16.

18

i)

28 A HISTORY OF RECENT CRUSTACEA

It has been ascertained by Sars that a curious form which
Kréyer described under the name of Myto Gaimardii is
one of the larval stages of this seven-keeled Sabinea. In
1842 Kroyer also instituted the new genus Argis, to re-
ceive the Arctic Crangon lar, described by Owen in the
‘Zoology of Captain Beechey’s Voyage.’ Some years later
Brandt established for the same species the genus Necty-
crangon, meaning ‘the swimming shrimp,’ in allusion to
the swimming properties of the very dilated fourth and
fifth pairs of legs. But, however appropriate, the name
must yield priority to Argis.

Sclerocrangon, Sars, 1882, has a hard and thickly in-
crusted integument, a rostrum expanded below into a
hatchet shape, a very short finger to the second legs, and
the pleopods with the inner branch much shorter than the
outer. This genus has been established to receive the
Cancer Boreas, described in 1774 by the arctic voyager,
J. C. Phipps, afterwards Lord Mulgrave. To the same
genus is referred another Arctic species, the Crangon sale-
brosus of Owen, and with less certainty the Mediterranean
Crangon cataphractus, Olivi.

Pontecaris, Spence Bate, 1888, with two species from
the south of New Guinea, has a multicarinate carapace,
short chelate second legs, and a branchial formula nearly
the same as that of Pontophilus.

Rthynchocinétes, Milne-Edwards, 1837, derives its name
from the circumstance that the very large lamellate ros-
trum is articulated with the carapace. The species Rhyn-
chocinetes typus, Milne-Edwards, is found on the coasts of
New Zealand, Australia, and Chili.

Legion 2.—Polycarpinea,

The name signifies literally ‘many-wristed,’ and the
distinguishing character of the legion is that in the
slender second pair of trunk-legs the carpus, wrist, or fifth
joint is multiarticulate, that is, subdivided into a greater
or Jess number of minor joints. It includes four families,

Nikidze, Alpheidee, Hippolytide, and Pandalida.

wd
° ait
LS a
ro
\e

FROM CORNWALL TO AMBOINA 229

Lamily 1.—Nikide.

The rostrum is horizontal with the dorsal surface of
the carapace; the mandibles are without a cutting edge,
and are without ‘palp ;’ the first pair of trunk-legs are
simple or chelate, and stronger than the second, but not
so long ; the second are minutely chelate.

To this family Spence Bate apparently refers three
genera distinguished as follows :—

Nika, Risso, 1816, with one of the trunk-legs of the
first pair chelate, and the other simple.

Glyphocrangon, A. Milne-Edwards, 1881, with both of
the trunk-legs of the first pair simple.

Lysmata, Risso, 1826, with both of the trunk-legs of
the first pair chelate.

There are various other marks of distinction, such as

the flagella of the first antenne, of which in Nika one is
long, the other short, while both are short in Glyphocran-
gon, and both long in Lysmata, this latter genus carry-
ing also a third lash which is short. In Nika, the second
pair of trunk-legs are, like the first, not strictly a pair,
since they differ greatly in length. Nika ediilis, Risso, is
found in British waters. On the shores of the Mediter-
ratiean it is used for food, as the specific name implies,
and the same is said of Lysmata seticaudata, Risso, a coral-
red species, longitudinally striped with whitish lines. Bell
describes a second British species of Nika, as Nika Couchii,
in which the telson is not channelled, and Spence Bate
speaks vaguely of a British specimen of his Nika processa
taken by the Challenger at Amboina, but apparently with-
out any intention of separating the British specimens from
Nika edulis, and in his edition of Couch’s ‘Cornish Crus-
tacea, he expressly says that Nika Couchit of Bell is
nothing more than a variety of N. edulis. Of Glypho-
crangon many species have been described from north and
south and east and west, some of the forms descending to
great depths; but Spence Bate, who names no less than
six of the species, says that ‘tbe various forms of this
genus can scarcely be considered as being more than

2:30 A HISTORY OF RECENT CRUSTACEA

varieties of one great type.” In Gliyphocraungon aculeatus,
A. Milne- Edwards, the carapace is ornamented with eight
carine, but in Glyphocrangon granulosus, Spence Bate,
there are five on each side of the median hie, besides a
small central one on the rostrum. The telson in this
genus is described as a long bayonet-shaped organ, which
the animal during life has the power of locking in a fixed
position, so as to render it a very powerful weapon of
offence, and of again unlocking at its own will. When
fixed for striking it is supported in position by having a
strong cusp or tubercle on its dorsal surface brought into

contact with a curved process of the preceding segment.
Gyphocrangon rimapes, Spence Bate, was trawled in the
South Atlantic from a depth of 1,715 fathoms, and it is
noted as an instructive coincidence that m Willemoesia
leptodactyla, obtained in the same haul, the organs of
vision are reduced to a rudimentary condition, while in
Glyphocrangon they are unusually large.

Nikoides, Paulson, 1875, is distinguished from Nika by
having an exopod on the first pair of feet, and by subdi-
vision of the fourth joint as well as of the fifth im the
second pair. The type Nikoides Dance is from the Red Sea.

Family 2.-—Alpheide.

The rostrum is minute or of moderate size; the eye-
stalks are short, and more or less covered by the projection
of the frontal margin of the carapace ; the mandibles have
a cutting edge distinct from the molar process, and a one-
or two-jointed ‘palp;’ the first pair of trunk-legs are

robustly chelate, sometimes unsymmetrical, the second pair

are long and slender, minutely chelate.

Spence Bate makes a two-jointed mandibular ‘ palp ’
a character of the family, but in describing his own genus
Paralpheus, he says that it is uniarticulate, and in Alpheus,
Fabricius, ‘ three-jointed, the Jatter being probably a slip
of the pen for two-jointed. Ten or more genera have
been assigned to the family, two of which occur on the
coasts of Great Britain.

Alpheus, Fabricins, 1778, has a short pomted rostrum,

MIMICKING A STAR-FISH 231

the eye-stalks covered by the translucent anterior region
of the carapace. The inner flagellum of the first antennz
bas a tendency to bifurcate. The second antennz have a
long flagellum and a strong scale with a subapical tooth.
The mandibular ‘palp’ is short and two-jointed. The
third maxillipeds are five-jointed. Spence Bate says that
the second also are five-jointed. In de Haan’s figure they
are six-jointed. In Spence Bate’s own figure they are ob-
scurely, in Savigny’s figure they are clearly, seven-jointed.
The trunk-legs of the first pair are unequal and unsymme-
trical, the hand or sixth joint on the right side being gene-
rally longer than that on the left, and more or less abnormal
in form, especially in the male. The outer branch of the
uropods has a transverse suture. The telson is broad and
terminally rounded. The genus has a vast range between,
the north and south temperate zones, but seemingly con-
fined to moderate depths. ‘A specimen of Alpheus minus
has been recorded from an inland fresh-water pond in
south-west Colorado.’ Spence Bate enumerates seventy
species ; but with a warning that many of them are sepa-
rated by trifling distinctions, and are probably at most
not more than varieties. Referring to de Haan’s account
of Alpheus avarus, Fabricius, he says that it appears to
have no strongly marked feature separating it from Al-
pheus Edwardsw (Audouin). Mr. KE. J. Miers in his
account of the latter species identifies with it not only
de Haan’s Alpheus avarus, but some fourteen other names.
On the other hand he considers that the avarus of Fa-
bricius is distinct from that of de Haan. Alpheus comatu-
larum, Haswell, is an eastern species said to be invariably
found clinging to the arms of a Comatulid star-fish, to
which its variously distributed stripes and markings of
purple and white and light and dark brown give it a
general resemblance that is presumably protective.
Alpheus ruber, Milne-Edwards, is occasionally taken
on the English coast as well as in the Mediterranean.
Alpheus meqachéles, Hailstone, is identified by Canon Nor-
man with the Alpheus affinis, Guise, from the Channel
Islands, which is described as of a ‘deep scarlet colour,

2on A HISTORY OF RECENT CRUSTACEA

except on the chele, which are mottled with yellow.’
Krauss at Natal found Alpheus Edwardsii in monstrous
numbers in the mud of the bay, in which, he says, they
dig deep perpendicular holes. When the tide is out they
sit at the mouths of their burrows, but at any one’s ap-
proach, rapidly ensconce themselves, making as they do
so a snapping noise. How the sound was produced Krauss
was unable with all his pains to discover.

Athinas, Leach, 1814, differs in several respects from
the character of the family as given by Spence Bate in his
report on the Challenger Macrura, since the rostrum is
well developed instead of being reduced to a minimum,
the eye-stalks are only partially instead of entirely covered
by the carapace, and the first pair of trunk-legs, though
unequal in size, are not unsymmetrical in shape. The
first antennz have three flagella, the second a long ovate
scale with distal tooth.

Athanas nitescens, Leach, is British, and is found also
in the Mediterranean. Spence Bate describes a new species
Athanas veloculus, from the Cape Verde Islands.

Parathanas, Spence Bate, 1888, is said to be closely
allied to Athanas, but to have on the first antenne only
two flagella, one of which is very short. The type species is
Parathanas decorticus, but to this is added Parathanas im-
maturus n, sp., founded on a specimen scarcely a fifth of
an inch in length, from which ‘ unfortunately all the pereio-
poda are broken off short.’ It is spoken of as ‘a damaged
specimen of what appears to be another species,’ and the
admissions are made that ‘ there is little to determine the
true character of the specimen,’ and that ‘the only dis-
tinguishable difference is that the rostrum is longer in
proportion to the animal.’ Since comparative measure-
ments in immature animals have no specific value, one is
tempted to transfer the ungallant observation about ‘ most
women’ to Purathanas immaturus, and say that ‘some
species have no character at all.’

Betweus, Dana, 1852, has no rostrum, and the ‘hands’ -
of the first legs more or less inverted, so that the finger or
seventh joint is on the outer instead of the inner side. In

THE HIPPOLYTIDZE 239

other respects it agrees with Alpheus, and the motive of its
name seems to be that as Beta stands close to Alpha in the
Greek alphabet, Betceus may be understood to stand close
to Alpheus in generic character. Betceus malleodigitus,
Spence Bate, from Fiji, has the finger of the first legs
shaped like a mallet, in that respect resembling Alpheus
malleator, Dana, and Alpheus obesimanus, Dana. Betous
microstylus, Spence Bate, is distinguished with some doubt
from Betwus equimdanus, Dana.

Family 3.—Hippolytide.

The rostrum is of important size; the eyes are not
covered by the carapace ; the mandibles may havea cutting
edge and ‘ palp, or be without one or both. ‘The first
pair of trunk-legs have moderate-sized chele; the second
_ pair are also chelate, with the wrist or fifth joint sometimes
much and sometimes little subdivided.

A dozen or more genera are included in this family.
It is impossible here to do more than give an indication of
the complexity to which Spence Bate has afforded a clue
so far as his own views of the family are involved, but
there is little agreement as yet as to the precise classifica-
tion of some of the genera concerned.

The Challenger collection gave Spence Bate occasion
to deal with nine genera, seven of which were named or
established by himself. With these may be arranged
Caridion, a name substituted by Goés in 1863 for the pre-
occupied Doryphorus of Norman, and two genera that
were instituted in 1869 by G. O. Sars, although in neither
of them is the rostrum quite up to the importance de-
manded by the character of the family. It must suffice
here to refer only to the mandibles and the second pair of
trnnk-legs, using the word ‘wrist,’ for brevity’s sake,
instead of saying in full the fifth joint of the second pair
of trunk-legs.

Platybéma, Spence —— 1888. Mandibles without

cutting edge or ‘ palp. Wrist two-jointed.

Caridion, Goés, 1863. Mandible with cutting edge

and three-jointed ‘ palp.’ Wrist two-jointed.

234 A HISTORY OF RECENT CRUSTACEA

Latreutes, a 1860. Mandibles without cutting
edge or ‘palp.’ Wrist three-jointed.

Hippolijte, Leach, 1813. Mandible with cutting edge,
without “palp.’ Wrist three-jointed.

Cryptochéles, Sars, 1869. Mandible with cutting edge,
without ‘ palp.’ Wrist seven-jointed.

Bythocaris, Sars, 1869. Mandible with cutting edge,
without ‘ palp.’ Wrist nine-jointed.

Spirontocadris, Spence Bate, 1888. Mandible with
rudimentary cutting edge, and ‘palp.’ Wrist
seven-jointed.

Nauticdris, Spence Bate, 1888. Mandible without
cutting edge, with three-jointed ‘ palp.’? Wrist
seven-jointed.

[ Hetairus], Spence Bate, 1888. Mandible with cutting
edge and two-jointed ‘ palp.’ Wrist seven-jointed.

Merhippolijte, Spence Bate, 1888. Mandible with
cutting edge and three-jointed ‘palp.’ Wrist
many-jointed.

Chorismus, Spence Bate, 1888. Mandible with rudi-
mentary cutting edge and three-jointed ‘ palp.’
Wrist many-jointed.

Amphiplectus, Spence Bate, 1888. Mandible with
cutting edge and two-jointed ‘palp.’ Wrist
many-jointed.

Of these genera the first is not new but newly named,
having been originally called Cyclorhynchus by de Haan,
and then Rhynchocyclus by Stimpson, in allusion to the
laterally compressed, deep, and terminally orbiculate
rostrum. Unfortunately both names were preoccupied.
The new name literally means a broad platform, but was
evidently given under the impression that, as m Enelish |
the word rostrum may stand either for a beak or a plat-
form, so the Greek word for a platform might equally well
stand for a beak, which is not exactly the case. The dis-
tinctions between this genus and Latreutes reach almost a
vanishing point, when it is observed that both Stimpson
and de Haan give to the type species Platyhema planirostris

LIKE A CHAMELEON prs 9

a three-jointed wrist, not a two-jointed one as in Platybema
rugosus, Spence Bate. The last-named author appears
only to have read de Haan’s generic and’ not his specific
description. One mark of distinction alone appears to
stand, namely, that the second maxillipeds of Platybemu
are six-jointed, and those of Latreutes seven-jointed.

Caridion contains the British species Caridion Gordom
(Spence Bate).

Hetairus must, I think, become a synonym of Spiron-
tocaris. In his synopsis (‘ Challenger Macrura,’ p. 577)
Bate says that Hetairus has no cutting edge to the man-
dibles, which is contrary to the fact and to his own state-
ments on pp. 610 and 612. He says that its third
maxillipeds differ from those of Hippolyte and Spironto-
caris in having noexopod. Yet in Hippolyte Gaimardi,
-Milne-Edwards, which he makes the type-species of
Hetairus, they undoubtedly have an exopod. Further he
says that the first and second maxille of that species are
‘unlike those of Spirontocaris. This is clearly a slip of
the pen. Yet it is a pity that reference should be made
to a figure which is not given to illustrate an unlikeness,
which does not exist.

Hippolyte is a genus that has been involved in much
confusion, and that has been made the recipient of many
species. Bell, in 1853, was content to assign to it six
British species, but Adam White, in 1857, augménts the
number to twelve. Some of these have since been trans-
ferred to the genus Virbius, Stimpson, 1860, but not
correctly, for Spence Bate points out that Hippolyte varians,
Leach, is the type-species of Hippolyte, and, as Stimpson
has placed it in his genus, it shows that Virbius is a
synonym of Hippolyte. The species is very common in
tidal pools, and sometimes it has the red hue of the sea-
weed among which it is found, and at other times it is dark
green or light green, but the name is appropriate to the
fact not that the colour is different in different speci-
mens, but that it varies in the same specimens, so that
an animal which is red at one time will be green at
another ; or may possibly go through the whole series of

236 A HISTORY OF RECENT CRUSTACEA

hues which Professor Kinahan mentions when he says,
‘the specimens vary remarkably and beautifully in colour ;
pink, red, salmon, emerald-green, cobalt-blue, gray, choco-
late-brown, opal white, are among the prevailing tints ;
the ova of a chocolate-brown.’ Hippolyte viridis (Otto) is
another species common to Great Britain and the Medi-
terranean, of which two species mentioned by Adam White,
namely Hippolyte Mitchel, Thompson, and Huippolyte
Whitei, Thompson, are merely synonyms, while in the
opinion of Czerniavsky, at least in 1869, viridis itself is a
synonym of Hippolyte Prideauxiana, Leach, which is found
on the coast of Devon. A third British species is Hippolyte
fascigera, Gosse, which has the ‘body studded with de-
ciduous tufts of plumes, and a fourth is the slender Mysis-
like Hippolyte producta, Norman, 1861.

Having restored Hippolyte to the place occupied by
Virbius, Spence Bate established the genus Spirontocdris
to receive those species which could in consequence no
longer stand under Hippolyte. Of this new genus he makes
Hippolyfe spinus (Sowerby) the type as Spirontocaris spinus,
and considers Hippolyte securifrons, Norman, a synonym of
it. The species extends its range from the north of Great
Britain to Iceland and Greenland. -A Norwegian species
was briefly described in 1861 as ITippolyte Liljeborgi, by
Danielssen, who says: ‘The rostrum is very prominent, _
laterally compressed, and ending in a strongly upward
bent spine; the upper margin furnished with ten nearly
equally large, strong spines ; yet the two first are a little
smaller ; the innermost margin is strongly convex and in
front furnished with three spines.’ As this is acknow-
ledged to be identical with Norman’s securifrons, it will, if
Spence Bate be right, become an additional synonym of
Spirontocaris spinus. To the same genus must apparently
be referred two other British species, that which Bell calls
Hippolyte Cranchir, Leach, and one named Hippolyte pusiola
by Kroyer. . Bell’s species pandaliformis has been identi-
fied with the earlier Hippolyte Gaimardi, Milne-Edwards,
above mentioned; J. Sp. Schneider records its occurrence
in quite incredible numbers among algzat small depths

THE PANDALID® 237

in the arctic fiords of Norway. Lastly, Bell’s Hippolyte
Thompsoni belongs to a different family, having been
identified with Rathke’s Pandalus brevirostris.

Nauticaris, Merhippolyte, and Amphiplectus, are said by
Spence Bate to differ from most of the other genera in the
family by having a series of arthrobranchiz which are
elsewhere wanting, Chorismus, however, having a single
pair.

Oryptocheles pygmeea, Sars, is only half an inch long,
and owes its specific name to its small size, but the generic
name, meaning ‘with concealed chele,’ refers to the un-
usual circumstance that in the first trunk-legs the chele
are so small as to escape notice altogether without close
inspection. This little species, found between 120 and
300 fathoms off the coast of Norway, brings forth its
young in a condition to require no special metamorphosis.

Bythocaris resembles Cryptocheles in hatching the
young with their full number of appendages, and in in-
habiting very considerable depths. To this genus are now
referred Hippolyte Payeri, Heller, and Hippolyte Panschii,
Buchholz, besides the type species Bythocaris simplici-
rostris, Sars, Bythocaris nana, S. I. Smith, and a new one
obtained by the Norwegian North Atlantic Expedition
from 1,110 fathoms between Jan Mayen and Finmarken.
All the species are northern or distinctively arctic, and
the last, Bythocaris leucdpis, Sars, is large and beautiful,
being nearly four inches long, and in colour a magnificent
rosy red,

Family 4.—Pandalide.

The rostrum is long and slender, more or less abund-
antly armed with teeth or spines. The eyes are well
developed. The mandibles have a two- or three-jointed
palp. The first pair of trunk-legs are not chelate, the
second pair are chelate. The pleopods are biramous, the
tail-fan is well developed and strong.

In this family Spence Bate discriminates seven genera.
In two of these, Chlorotécus, A. Milne-Edwards, 1882, and
Dorodétes, Spence Bate, 1888, he states that the second

238 A HISTORY OF RECENT CRUSTACEA

pair of trunk-legs are uniform in length, while in the
other five genera they are unequal. Chlorotocus, however,
has the wrist of these legs two-jointed, while in Dorodotes
it is six-jointed. The ‘palp’ of the mandibles is two-
jointed in Chlorotocus, undescribed in Dorodotes, three-
jointed in the other five genera.

Pandélus, Leach, 1814, has the ‘anterior portion of
the carapace carinated and produced to a long rostrum
that is armed on the dorsal or upper surface with movable
spines, intermingled with hairs, and on the lower surface.
with fixed and rigid teeth.’ Also, the first pair of antennze
are not longer than the carapace, and the spine on the
outer margin of their basal joint is obtusely pointed. Two
British species belong to this genus, Pundalus Montagu,
. Leach, which has priority over the more generally used
name, annulicornis, Leach, and Pandalus brevirostris,
Rathke. ‘There are numerous other species in various
parts of the world, among which Pandalus narwal, Milne-
Edwards, in the Mediterranean, exceeds a length of five
inches. Pandalus Montagu, though its usual length is
given by Bell as from two to two and a half inches, is said
by S. L. Smith to attain a length between four and five
inches off the coast of the United States.

Pandalopsis, A. Milne-Edwards, 1888, is most ob-
viously distinguished from Pundalus by having the flagella
of the first antenne much longer than the carapace. ‘The
other genera are distinguished by some minute and curious
characters, for while the frontal crest and rostrum of
Pandalus are armed on the upper surface with movable
spines only, in Nothocdris, Spence Bate, 1888, the dorsal
crest has several spines that articulate in sockets, and
several teeth that are fixed and rigid, but in Plesionika,
Spence Bate, 1888, and Heterocarpus, A. Milne-Edwards,
1881, there are teeth only, and no movable spines. In
Plesionika, as also in Nothocaris, the spine on the outer
margin of the basal joint of the first antenne is large and
pointed, but in Heterocarpus it is said by Spence Bate to
be rudimentary ; yet he identifies with the type species,
Hleterocarjpus ensifer, A. Milne-Edwards, the Heterocarpus

AN UNDIVIDED WRIST 239

curinatus of 8. I. Smith, who says that the basal joint of

the first antenne is ‘furnished externally with a large

lamellar process terminating anteriorly in an acute angle

in front of the eye,’ a description ill-suited to the epithet
rudimentary.

Legion 3.—Monocarpinea.

The wrist, or fifth joint of the second pair of trunk-legs,
is not subdivided, and generally the chelz of this pair are
larger than those of the first.

Spence Bate arranges in this group eleven families—
the Thalassocaride, Atyidee, Pontoniide, Caricyphide,
Acanthephyridz, Paleemonidz, Nematocarcinide, Tropio-
caridee, Stylodactylide, Pasipheide, Oodeopide, among
which the first differs from all the rest by having the first
pair of trunk-legs simple, and the last differs from all the
rest by having the second pair simple. The Tropiocaride
do not seem to deserve a separate existence, without
further consideration.

Family 1.—Thalassocaride.

The first trunk-legs are simple, the second chelate.
Three genera are assigned to the family, one of them,
Diaphorépus, Spence Bate, 1888, founded on what ‘is
evidently the immature condition of some undetermined
form.’

Thalassocaéris, Stimpson, 1860, takes the - place of
Regulus, Dana, 1852, the latter name being pre-occupied.
The species as yet known belong to the Pacific, and are
regarded as a link connecting the Pandalide with the
Palzemonidee.

Family 2.—Atyide.

The carapace is dorsally smooth, with flattened ros-
trum ; the scale of the second antenne short. The man-
dibles have a molar process and cutting edge, but no ‘ palp.’
The third maxillipeds are f»ur-jointed and pediform. The
first and second trunk-legs are chelate, with spoon-shaped
fingers. The telson is flattened, truncate.

240 A HISTORY OF RECENT CRUSTACEA

There appear to be only two or three genera belonging
to this family, and those confined to fresh water.

Atya, Leach, 1817, was called Atys in 1815, but the
name was pre-occupied. It has in the first two pairs of
trunk-legs the chele fringed with long hairs; the third
pair are large and long, the fourth and fifth robust, shorter
than the third. The genus Atyoida, Randall, 1839, is by
Spence Bate considered a synonym of Wie. and he also
seems to contemplate the possibility that species of Caridinu,
Milne-Edwards, 1857, may prove to be young stages of Atya.
The latter genus includes several species, distributed in
the islands of the Pacificand Atlantic, in New Zealand, and
Mexico. Atya sulcatipes, Newport (see Plate X.), is found
in the Cape Verde Islands, and is perhaps only a variety
of the older Atya scabra, Leach, while Atya serrata, Spence
Bate, also from the Cape Verde Islands, is said to exhibit
only slight and unimportant differences from Atya bisulcata
(Randall), which is found in the Sandwich Islands. The
structure of the first two pairs of trunk-legs in this genus
is nota little remarkable. The first joint has a tuft of
long hairs set on a tubercle, and has a rudiment of an
epipodal plate fringed with hairs; the third and fourth
joints have hairy fringes; the tifth joint or wrist is short
and crescent-shaped ; “but the chief pecuharity is in the
arrangement of the sixth and seventh joints, which together
have something of the form of a horseshoe magnet, the hand
being articulated near its centre with the lower angle of the
wrist, and both hand and finger have their flattened ends
furnished with long finely ciliated hairs. ‘ When the hand
is opened,’ according to Fritz Miiller, ‘the hairs upon the
margin of the fingers spread like a fan, gather and retain
fine mud ; when the hand is closed these hairs close round
the mud and compress it into a pellet which is passed into
the mouth, and so the animal lives on the small organiz
substances that exist in the mud, which it collects with
great rapidity.’ According to Mr. Spence Bate himself,
‘these animals, of which the male is smaller than the
female, as is frequently the case when they are not pro-
vided with offensive weapons, are only known to inhabit

THE PONTONIID 241

fresh water, and, singular to relate, although they are in-
habitants of distant localities, several of which are oceanic
islands, yet all the species bear so close an affinity of form
that it is difficult to deterarine one from the other by any
permanent character. To explain this distribution, it is
suggested that ova may be carried in mud on the feet of
wading birds, and by this means species transferred from
one locality to another even over great distances. The in-
genious theory, already referred to, by which Mr. Thomas
Belt accounts in general for the wide distribution of fresh-
water species, does not seem applicable to those occupying
oceanic islands. Genera related to Atya are Atyephyra,
Brito Capello, 1867, for a Portuguese species, Paratya,
Miers, 1882, conditionally proposed for the Japanese
Hphyra? compressa of de Haan, Troglocdris, Dormitzer,
18538, which inhabits caves in Carinthia, and Fvatya, S. I.
Smith, 1872, which belongs to Central America.

Family 3—Pontoniide.

The mandibles have a molar process and cutting edge
but no ‘palp.’ The first pair of trunk-legs are subequal,
slender, and chelate, the second unequal, one of the pair
very large in the male.

Two genera are assigned to the family, both of which
occur in the Mediterranean.

Pontonia, Latreille (1818), 1829, has the dorsal surface
flattened, and the rostrum dorsal y flat. There is no
ocellus on the hind margin of the eye. The first antennee
have one of the two flagella bifid at the extremity, the
second have a short but strong scale. The fully developed
branchiz are only four or five pairs. It is not correct to
say that ‘ the telson carries no spine on the dorsal surface.’
Several species certainly have them. In Australian speci-
mens received from Mr. F. H. Haynes there are two pairs.
The apical margin of the telson in the Australian species
is fringed with six spines. The type species, Pontonia
custos (Forskal), takes up its atode between the valves of
a Pinna, and is supposed to be referred to by Aristotle
when he says that a little shrimp (caridion) may take the

242 A HISTORY OF RECENT CRUSTACEA

place of the little crab (carcinion) in companionship with
the Pinna. In Australian and other Eastern waters, Pon-
tonia meleagrine (Peters) occupies the shell of the pearl
oyster, Meleagrina margaritifera, and probably also that of
Tridacna squamosa. Professor 'Th. Barrois found the male
and female of Pontonia custos constantly together in large
specimens of Pinna rudis at the Azores.

Typton, Costa, 1844, though much like Pontonza in
many points, has the dorsal surface arched and the rostrum
laterally compressed, an ocellus on the hind margin of the
eye, both flagella of the first antennz undivided, the scale
of the second rudimentary, and six or seven pairs of
branchie. Typton spongicdla, Costa, is, as 1ts name im-
plies, a lodger in sponges; it Is a British as well as a
Mediterranean species.

Family 4.—Caricyphide.

The rostrum is slender and sharp-pointed. ‘The first
antenne have two short flagella, the second a long and
narrow scale. ‘The first two pairs of trunk-legs are chelate,
subequal. Frequently the third segment of the pleon is
dorsally elevated and compressed. The telson is long and
slender. Here are placed three genera—Caricyphus, ‘the
bowed shrimp ;’ Rhomaleocdaris, ‘ the robust shrimp ;’ Anébo-
caris, ‘the immature shrimp,’ all instituted by Spence Bate
in 1888, and all from immature specimens, the largest of
which was three-fifths of an inch in length. The seven
species included in these three genera are all from Hastern
and Southern waters. Though they will interest the
specialist concerned with development, they seem but ill-
suited to constitute a separate family.

Family 5.—Acanthephyride.

The animal is laterally compressed and dorsally cari-
nate. The first antennae have two long flagella; the
second a sharp and rigid scale. ‘The mandibles have molar
tubercle, cutting edge, and ‘ palp.’ The first two pairs of
trunk-legs are slender, subequal. The telson is long,

FINE COLOURING 243

narrow, and tapering to a truncate point. To this family
belong apparently half a score of genera, almost all of
which have been established within recent years. For the
name of the family 8. I. Smith’s Miersiide has priority,
but on the other hand the subfamily name Acanthephyri-
nee is older than Miersiide, and moreover the species of
Miersia which led to the use of the name Miersiidee were
subsequently transferred to the genus Acanthephyra, so
that Acanthephyridee would seem to be legitimate.
Acanthephyra, A. Milne-Edwards, 1881, is now repre-
sented by numerous species, practically from all parts of
the world, except the Arctic regions, in the South reach-
ing as far as Kerguelen Island. The species have been
taken from great depths, seeming to descend even to
nearly 3,000 fathoms. In the Albatross dredgings the
species Acanthephyra Agassiz, S. I. Smith, which Spence
Bate identifies with <Acanthephyra purpurea, A. Milne-
Kdwards, was taken at forty-five stations ranging in depth
from 105 to 2,949 fathoms, and since then a specimen has
been taken alive in a dip-net, actually at the surface.
From a deep haul off the Azores, at 1,675 fathoms, the
Challenger obtained an example of which it is said, ‘ The
specimen is beautifully preserved both in form and colour,
the latter bemg of a rich crimson-lake, which suffuses
every part of the animal. The hairs which fringe the legs
are long, delicate, and generally planted perpendicularly
to the surface.’ The suggestion is made that this species
is probably a free swimmer, able to range without incon-
venience from one depth to another. In Acanthephyra
microphthalma, 8. I. Smith, the smallness of the eyes is
considered to indicate that it is a truly abyssal species, in
accord with the depths of a little more and a little less
than 2,600 fathoms from which the specimens were ob-
tained. There is always the chance that dredges and
trawls with open mouths may catch a variety of animals
while going down or coming up and not on the deep floor
of the ocean, but the vast number of species which have
only become known since deep-sea dredging commenced,
makes it sufficiently clear that the general abode of the
£9

2A4, A HISTORY OF RECENT CRUSTACEA

majority of them is very far down in the waters, as other-
wise they might just as well have been discovered earlier.
Acanthephyra sica, Spence Bate, is as remarkable as any
of the species for its range, the specimens taken by the
Challenger coming from depths that varied between half a
mile and over three miles, and from places so distant as
New Zealand and Japan, Bermudas and the Falkland
Islands. Acanthephyra pellucida, A. Milne-Edwards, is of
a beautiful rose-colour in daylight and abundantly lumi-
nous in the dark.

Ephyrina, 8. I. Smith, 1885, is distinguished from
Acanthephyra by the unusual dilatation of the third and
fourth joints of the last trunk-legs. The type Hphyrinw
Benedicti, Smith, was taken by the Albatross. -

Oplophirus, Milne-Edwards, 1837, if the want of an
aspirate be forgiven, is well named ‘the bearer of heavy
arms. Especially this applies to the long and strong
scale on the second antenne, which tapers to a sharp
point, and is described as capable of being rigidly locked
in position and unfixed at will. It is judged that this
weapon must be capable of inflicting a deep wound, which
the serrate outer margin of the scale would render all the
more dangerous. Spence Bate argues that the animal’s
power of progression must be great, for ‘the teeth upon
the dorsal surface of the pleon can be tightly compressed
against the body; the appendages not utilised are capable
of being drawn close to the animal, and its narrow form
and polished sides seem fitted to enable it to shoot through
the water. With the rostrum and outstretched antennal
scales it would, he thinks, be capable of a formidable
attack on animals larger than itself, nor, when at rest,
with these same weapons extended forwards and outwards
could it be easily approached, especially as the dorsal
spines on the pleon would then be in a posture of defence
in the rear, and on the flanks its strong integument sup-
ports and is defended by spines on the carapace and first
pleon-segment. In the account of Oplophorus typus,
Milne-Edwards, Spence Bate says :—‘ The most remarkable
feature of the carapace is a lateral process on the posterior

CRUSTACEANS THAT ARE NOT CRUSTACEOUS 245

margin that projects and les beneath a corresponding
process of the anterior margin of the first somite of the
pleon, and bolts down the carapace so securely that it is
difficult to elevate it.’ Some of the other genera show a
falling off from this vigorous character, for Bentheocdris
exuens, Spence Bate, from 2,357 fathoms in the South
Pacific, ‘resembles many of the deep-sea forms in being
soft and membranous,’ and both Hymenodora, Sars, 1876,
and Meningodora, 8. I. Smith, 1882, alike signify ‘a mem-
branous skin, the latter having for its type Meningodora
mollis from the Atlantic, and the former having been
instituted to receive Pasiphaé glacialis, Buchholz.

In describing Hymenodora, Sars observes :---‘ With the
genus Pasiphaé its chief agreement consists simply in the
two foremost pairs of feet being furnished with chele, and
in all of the pairs having a natatory branch (exopodite) ;
but this branch is far more powerfully developed than in
the former genus, where it has merely the appearance of a
rudimentary appendix. Moreover, the two foremost pairs
of legs are considerably smaller, whereas the three suc-
ceeding pairs, which in Pusiphaé are small and feeble,
exhibit a powerful development. [rom the genus Pasi-
phaé it also differs by reason of its comparatively more
thickset, almost rounded form of body, the unusually thin,
membranaceous integuments, the rudimentary character
of the eyes, the very different structure of the oral parts,
and the peculiar form of the caudal appendages.’ He
looks upon it as ‘marking in some respects a kind of
transition to the Schizopod type, an admission which
Spence Bate would appear to have overlooked, since he
does not refer to it in support of his own view that the
Schizopoda should be included among the Macrura.

Spence Bate makes Meningodora a synonym of Hymeno-
dora, to which he adds several species, placing it, together
with Notostémus, A. Milne-Edwards, 1881, and his own
new genus, Z’ropiocdris, 1888, in a separate family Tropio-
caridz. But as he says that T’ropiocaris in many of its parts
approximates so nearly to Acunthephyra and Notostomus
that it can only be considered as a separate genus for the

246 ' A HISTORY OF RECENT CRUSTACEA

convenience of classification, it seems hardly worth while
for the present to separate the Tropiocaride from the
Acanthephyridee. Notostomus and Gonatondtus, two genera
established by A. Milne-Edwards in 1881, from the West
Indies, are both said to be near Oplophorus, and both to
have exopodal appendages to the feet. Notostomus perlatus,
Spence Bate (see Plate XIII.), is from the Philippines.

Family 6.—Palemonde.

The carapace is dorsally rounded and laterally com-
pressed, the rostrum long, laterally compressed, and gene-
rally armed with teeth. The eyes are well developed and
pyriform. The first antennze have the basal joint dorsally
hollowed, with a strong spine on the outer side, and
frequently one of the flagella branched; the second pair
have a long and narrow foliaceous scale, its rigid outer
margin ending in a small tooth. The mandibles have
molar tubercle and cutting edge, and either have or have
not a‘ palp. The third maxillipeds are pediform.

The family includes about half a dozen genera, two of
which are found in British waters.

Palemon, Fabricius, 1798, has been subdivided since
its institution, and Stimpson in 1860 rightly recognised
that Pulemon carcinus, the first in the list of species
assigned to the genus by Fabricius, should be the type.
Hence the genus Bithynis of Philippi, to which this and
other fresh water species have been referred, is a mere
synonym of Palemon. ‘The marine species, which have
been commonly retained under the name Palcemon are
referred by Stimpson to Desmarest’s genus Leander with a
fresh definition.

Spence Bate gives a synopsis of the genera into which
the original Palemon of Fabricius has been divided, which,
with the necessary modifications, may be thus set out :—

Paleemon, Fabricius, 1798, has one tooth on the frontal

margin of the carapace, and a second on the
hepatic region nearly in the same horizontal line;
the second trunk-legs with the wrist long.

Leander, Desmarest, 1849, has the frontal margin of

MONSTER PRAWNS 24,7

the carapace armed with two antennal teeth, one
above the other; the second trunk-legs with the
wrist long.

Palemonella, Dana, 1852, has one tooth on the frontal
margin, and a second on the hepatic region nearly
in the same horizontal line ; the second trunk-legs
with the wrist not long.

Drachycarpus, Spence Bate, 1888, has one tooth on the
frontal margin, and a second on the hepatic re-
gion, below the horizontal line ; the second trunk-
legs with the wrist short.

Paleemon carcinus is found in American rivers ; Paleemon
lar, the second in the list of Fabricius, in the East Indies.
Palemon jamaicensis has been obtained by Mr. Osbert
Salvin from Lake Amatitlan, ‘where it reaches a large
size and forms an important article of commerce in the
market at Guatemala.’ Of Palemon heterochirus, Wieg-
mann, Stimpson remarks that ‘this is another of the
large freshwater shrimps of Mexico. They frequently
attain a length of two feet, including that of the chelopoda,
which are at least as long as the body.’ Other species
range over the isles of the Pacific and Australia. In this
genus the most striking feature is the elongation of the
second legs in the male, which not infrequently even
exceed the total length of the animal’s body; a specimen
of Paleemon lar may measure about five inches from the
front margin of the carapace tothe tip of the telson, and
carry limbs eight inches long.

Palemonella, Dana, has the rostrum slender instead of
deep as in the other three genera, and the ‘ palp’ of the
mandible perhaps only two-jointed instead of three-jointed.
Dana’s two species tenuipes and orientalis are both from
Kastern waters.

To Leander must be transferred the three species which
Bell calls Palemon serratus (Pennant), Paleemon squilla
(Linn.), and Paleemon Leachii, Bell, the last of these be-
coming Leander Fabricia (Rathke). Norman now considers
that his Palemon minans from Guernsey, may be merely
an abnormal specimen of Leander squilla. Puleemon varians,

248 A HISTORY OF RECENT CRUSTACEA

Leach, was at one time called Anchistia migratoria by
Heller. But it differs from Dana’s Anchistia by having
three flagella instead of only two on the first antenna, and
by having the two spines of the carapace one above in-
stead of one behind the other. Heller therefore instituted
for it in 1869 the new genus Palemonetes, which agrees
with Anchistia but differs from Palemon in having no
‘palp’ tothe mandibles. The development and larval me-
tamorphoses of Palcemonetes varians have formed the sub-
ject of important studies by Dr. Boas, Mr. W. Faxon, and
Dr. Paul Mayer. Its distribution has been summed up by
Professor Th. Barrois. The same genus includes also the
American fresh-water species, Palemonetes exilipes, Stimp-
son, and Palemonetes vulgaris (Say), which appears like
varians to be almost equally at home in salt water and
fresh. It affords an abundant supply of food to many of
the fishes on the east coast of the United States, and is in
turn itself supported with equal liberality by other animals.

Messrs. Verrill and Smith, after speaking of its inhabiting
the brackish pools and ditches, even where the water is
but little salt, remark that it ‘also occurs in immense
numbers on the muddy bottoms and among the eel-grass of
the estuaries. In the pools there are also 1 myriads of small
Entomostraca of many kinds, upon which the prawn and
other species feed,while the Entomostraca find an abundance
of ciliated Infusoria and other microscopic animals for
food.’ In regerd to Palemonetes varians an observation,
perhaps generally applicable, was made by Hensen and
confirmed by P. Mayer, that specimens in confinement will
speedily shed their skins if well fed. The same authors
showed also by very conclusive experiments that the
animals after exuviation introduce fresh otoliths into the
ear-cavity of the first antenne. Dr. Mayer supplied
crystallised silver, and had the satisfaction of seeing a
bright scale of this metal in one ear of his young Pale-
monetes. Hensen points out that the introduction of
otoliths must as a rule take place while the softness of the
new skin permits the narrow opening into the ear-chamber
to be stretched to the utmost limit.

SPINDLE-LEGS 249

The species Dennisia sagittifera, Norman, 1861, from
Guernsey, has since been identified with the Mediterranean
Anchistia scripta (Risso). The earlier specific name is
referred to letter-like markings on the underside of the
female, the later one to a beautiful arrow-like mark on the
back, Norman describing the pleon as ‘very pale lilac,
elegantly painted on the third segment with a chevron of
a bright lilac.’

Family 7.—Nematocarcinide.

The animal is smooth and slender. The first antennze
have two long slender flagella, the second a long narrow
scale and a long slender flagellum. The mandibles have a
molar tubercle, cutting edge, and ‘palp. The trunk-legs
have the fifth joint much longer than the sixth; the first
_two pairs are small and slender. ‘The telson is slender and
tapering.

Spence Bate places two genera in this family.

Nemutocarcinus, A. Milne-Edwards, 1881, meaning the
‘threadlike crustacean, has a two-jomted mandibular
‘palp,’ a spoon-shaped terminal joint to the third maxilli-
peds, the second trunk-legs much longer than the first,
and the three following pairs extremely long. The first
antenn are frequently three or four times the length of
the animal. In the trunk-legs the articulation between
the third and fourth joints is ‘of peculiar and unique
character, and seems probably adapted for the great
muscular strain consequent upon the length of the joints.’
The extremity of the third lies longitudinally under the
fourth, so that these joints overlap and support each other.
In the male the last three segments of the trunk have each
ventrally a pair of flat anteriorly projecting plates or
processes, only the middle pair being present in the female.
The range of depth of the species, which are now numerous,
seems to be from two or three hundred down to about two
thousand fathoms, and the distribution extends over the
Pacific and Atlantic, and to the Mediterranean. Nemato-
carcinus ensifer, S. 1. Smith, was originally made the type
of a new genus Humiersia, which was afterwards recog-

250 A HISTORY OF RECENT CRUSTACEA

nised as a synonym of Nematocurcinus. To this genus
Spence Bate adds fourteen species from the Challenger
collection. His Nematocarcinus lanceopes is from the
Antarctic Sea. The delicacy of the framework in this
genus sometimes makes fulness of description out of the
question, as in the case of Nematocarcinus altus, Spence
Bate, taken from 2,150 fathoms depth, south of the Philip-
pines. ‘Only one specimen of this species was procured,
from which all the appendages are wanting, and the
rostrum is broken near the apex.’ Nematocarcinus undu-
latipes, Spence Bate, shown on Plate X., appears to be the
commonest species.

Stochasmus, Spence Bate, 1888, means ‘a conjecture,’
the name alluding to the inconvenient circumstance that
‘unfortunately only one very imperfect specimen was ob-
tained ; all the pereiopoda are gone, and its relation to
Nematocarcinus can therefore only be conjectured.’ It
differs from that genus in having a ‘ dactylos’ or seventh
joint attached to the extremity of the third maxillipeds ;
in other respects it is in close agreement with it. It is
said to differ from Nematocarcinus cursor, A. Mailne-
Edwards, only in the number and character of the spines
on the rostrum.

Family 8.—Stylodactylidee.

The second maxillipeds have a two-branched termina-
tion, and the first two pairs of trunk-legs have the arms
of the chela, the so-called thumb and finger, long, slender,
and feeble. There is but one genus in the family.

Stylodactylus, Milne-Edwards, 1883. ‘he name evi-
dently alludes to the very peculiar stiliform fingers in the
chelipeds, and the spelling follows the old-standing confu-
sion between the Greek word crdXos, a pillar, and the
quite distinct Latin word stilus, a pointed instrument.
The genus occurs both in the Pacific and the Atlantic.
The rostrum is a very long and conspicuous feature, in
Stylodactylus serratus, A. Milne-Edwards, having forty
spines on the upper and twenty on the lower margin, and
being just upon an inch long in a specimen of which the
entire length was two inches and three-fifths.

A DESCRIPTION BY SAVIGNY 251

Family 9.—Pasipheide.

The rostrum is small or obsolete, the mandibular ‘ palp’

two- or one-jointed or wanting. The trunk-legs carry
exopods. The third, fourth, and fifth pairs are inferior
in size to the two pairs of chelipeds, the fourth being
generally smallest of all.

Three genera are included in this family by Spence
Bate, and a fourth has been established by S. I. Smith.
One of these four is represented in British waters.

Pasipheea, Savigny, 1816, was established in a rather
casual manner in the footnotes to Savigny’s celebrated
‘Mémoires sur les animaux sans vertébres,’ to receive the
Mediterranean species, Alpheus sivado, Risso, which also
occurs in tolerably deep water off the coasts of England,
Ireland, and Scotland. Bell says that Savigny gave no
description of the genus, but he does in fact refer to the
peculiarity that the appendages of the trunk exhibit exo-
pods, as in species of Squilla and Mysis. Moreover, when
insisting on the pediform character sometimes shown by
the maxillipeds, he subjoims a note that ‘the Alpheus
Sivado of M. Risso has really twelve thoracic feet em-
ployed in locomotion.’ Lastly,in a note to the description
of the maxillipeds of an Amphipod, he observes that ‘in
Alpheus Sivado, the second joints of the two front cheli-
peds are united into the form of a lip, a peculiarity all the
more remarkable for its occurring in only one of the sexes.’
Subsequent writers do not appear to have repeated or ex-
plained this last observation. The figures of this species
in Risso, in Bell, and in the completed edition of Leach’s
‘ Malacostraca’ (1875), are misleading as to the real
shape of the animal, which is strongly bent at the middle.
The mouth organs examined in a British specimen differ
considerably from those depicted by de Haan for this
species, hut approach very closely those figured by Spence
Bate for his Pasipheea cristata from the Fiji Islands. In
this genus the mandibular palp is wanting. The second
maxillipeds are quite devoid of exopod, which Spence Bate
notes as very unusual in the Macrura. Kroyer’s Pasiphea

Zon A HISTORY OF RECENT CRUSTACEA

tarda has the apex of the telson cleft instead of truncate.
Pasiphea princeps (S. I. Smith), 1884, obtained from a
depth of 1,542 fathoms in the North Atlantic, is much
larger than the type-species, since it attains a length of
between eight and nine inches. ' The apex of the telson is
cleft.

Leptochéla, Stiinpson, 1860, is distinguished by having
a short one-jointed mandibular ‘palp,' and the second
maxillipeds not pediform as in Pasiphcea, but with the last
joint armed with long spines or hairs. The species are
not large, Leptochela robusta, Stimpson, being only an inch
long, and his Leptochela gracilis and Spence Bate’s Lepto-
chela serratorbita being still smaller.

Parapasiphaé, 8. 1. Smith, 1884, has a very small and
slender mandibular ‘ palp,’ composed of two nearly equal
joints. In Orphania tenuimdna, Spence Bate, these organs
were not examined, the specimen on which the genus and
species were founded being ‘ unique and not very perfect.’

Lamily 10.—Oodeopide.

The carapace is short, produced to a long horizontal
rostrum. ‘he eye-stalks are short, the eyes large. The
mandibles are without ‘ palp ;’ the third maxillipeds long,
slender, and pediform. ‘The first pair of trunk-legs are
chelate or subchelate and larger than the second, which
are simple.

This family was formed for a single genus, but may
perhaps receive a second.

Oodedpus, Spence Bate, 1888, starts with seven species,
but as they are all founded on immature animals, their
actual characters remain vague, and with them those of
the genus and family. The generic character makes the
‘first pair of pereiopoda large and chelate,’ but a following
observation states that the most advanced specimen in the
collection ‘shows a tendency to develop the first pair of
pereiopoda into a chela in the adult stage. All the other
specimens exhibit them in the simple form,’ which Spence
Bate no doubt rightly takes te be a still more immature

AN ODD NAME 258

condition. The genus is compared with Rachitia spinalis,
Dana, a young animal taken in the Atlantic, which, how-
ever. differs ‘in having the rostrum short, in the first pair
of antennz having only a single flagellum, and in the
form of the telson.’ The name Oodeopus perhaps alludes
to the circumstance that in some of the specimens the feet
were beginning to swell or bud out, but for swollen feet
the Greeks had already provided the name Gdipus, and
Dana had already used this name for another genus of
prawns, and other naturalists had used it for other pur-
poses before Dana. The alternative derivation of Oodeopus,
as meaning ‘ with feet on the ground, seems to make the
name entirely pointless.

Autonomeea, Risso, 1816, may here be mentioned as a
genus of which the position is obscure. It is described as
having the first pair of trunk-legs chelate, the second
simple. Risso distinguishes it from Alpheus and Nika.
Milne-Edwards places it next to Pontonia, Victor Carus
puts it between Anchistia and Pandalus. The type species
was named Autonomea Oliviit by Risso, but as he makes
Cancer glaber, Olivi, a synonym, it is hard to see why it
should not be called Autonomea glaber. Jonathan Couch
in his Cornish Fauna is quoted by Adam White and
Spence Bate as saying of it: ‘This species has been
hitherto unknown as British, but I have examined several
specimens taken from the stomachs of fishes, from the
depth of fifteen or twenty fathoms. Some of these were
of larger size than described from the Mediterranean ;
one, not the largest, measuring three inches from snout to
tail, with antennz of the length of five inches.’

Legion 4.—Haplopodinea.

| All the trunk-legs are similar in structure to each
other, simple, six-jointed, with the fifth joint not sub-
divided, and all but the last pair carry exopods.

254 A HISTORY OF RECENT CRUSTACEA

Family Hectarthropide.

As this is the only family, its characters are those of
the legion. The four genera assigned to it were instituted
at the same time as the family and legion.

Proclétes, Spence Bate, 1888, meaning ‘ Challenger,’
is represented only by two specimens, the one here de-

FiG. 21.—Procletes biangulatus, Sp. Bate [Chall. Rep.].

picted, which is just two-thirds of an inch long, and which
is described as Procletes bianqulatus, the other Procletes El-
iott, which has a smoother carapace, a shorter flagellum,
and a longer telson, being described, it seems, only from a
drawing, not from the original specimen taken by the late
Sir Walter Ellot, years ago, off the coast of Coromandel.
Icotépus and Hecturthropus proclaim their adhesion to
the family by the meanings of the names, the former
signifying ‘with similar feet,’ the latter ‘with six-jointed
feet. The fourth genus which Spence Bate establishes in
this family, Hretmocdris, ‘the oar-shrimp,’ in allusion to
the provision of exopods or swimming-branches, 13 pre-
sumably founded on immature specimens, since it is ob-
served that ‘the first three pairs of appendages in this
genus, the eyes and two pairs of antenne, are attached to
a portion of the cephalon projected in front of the carapace,
which still retains the embryonic ocellus.’ The animals
have a very striking appearance from the unusual and

A TRIBUTE TO SPENCE BATE oe

surprising length of the eye-stalks. This reaches its
maximum in Hretmocaris longicaulis (see Plate XIII.), so
far as comparative measurements are concerned. ‘The
specimen, it is true, is less than a quarter of an inch long,
if the eyes are not counted in, but the length is doubled
if they are, for these stalked eyes are more than a quarter
of an inch long, a proportion between the organ of vision
and the rest of the body which probably no other animal
in the world can boast of.

In quitting at this point the assistance of Mr. Spence
Bate’s ‘ Report on the Challenger Macrura,’ it is right to pay
a tribute to the vast labour which that work must have
involved, and to the great ability shown in it although
amidst many inaccuracies and much want of method.
Unfortunately the nomenclature which Mr. Spence Bate
_adopted makes it sometimes more difficult to read his
descriptions than those written in a foreign tongue. He
formed the grand conception of giving one invariable
name to each part of a crustacean, as it might appear
under every possible modification, throughout the whole
class. For the comparative anatomist no scheme could be
more valuable, but for the students of different orders
there is always the chance that such an arrangement
will be irritating and repellent. The name that may
commend itself as obvious and natural in one group
becomes wholly inappropriate in another. Supreme skill
might override many difficulties by inventing terms of
great simplicity, not inappropriate to any group by being
especially appropriate to none. But simplicity seems to
have been the very last thing considered in Spence Bate’s
terminology, and though such words as phymacerite,
psalist6ma, and stylamblys, may help to curtail the length
of descriptions, they are only too likely also to curtail the
number of those that read them.

956 A HISTORY OF RECENT CRUSTACEA

CHAPTER XVIII
SUB-ORDER III.—SCHIZOPODA

Tur mandibles have generally an elongate ‘palp.’ The
second and third maxillipeds are similar in general struc-
ture and function to the series of trunk-legs, the whole
seven pairs of appendages, and in general the first maxilli-
peds also, being provided with well-developed exopods or
swimming-branches. There are no chelipeds. The ova
are carried by the female beneath the trunk, either with
or without the protection of marsupial plates, and gene-
rally one or two of the larval stages are passed through
before the hatching of the young animal. The males are
generally distinguished by a special appendage on the first
antennee and by larger pleopods.

The name Schizopoda, ‘ cleft-footed,’ refers to the
double character borne by so many of the appendages, in
which the main stem or endopod is more or less ambulatory
and the exopod is adapted for swimming. The affinity
which the Schizopoda show to some of the Macrura, such as
the Pasipheeidee, and the definite opinion of Mr. Spence
Bate that they ought to be included as an aberrant group
among the Macrura dendrobranchiata, have been already
noticed. Whether they should stand just inside or just
outside the sub-order of the Macrura, is a nice point of
classification for the learned to decide.

Four families are at present included in the Schizopoda,
the Lophogastride, HEucopiide, Huphauside, and My-
side. But on the one hand a suggestion has been made
that two forms hitherto assigned to the Mysidae may re-
quire the institution of a separate family, and on the other
hand Mr. G. M. Thomson, the well-known naturalist of

Wee? ©

SCHIZOPODS, VOCALLY SKIZOPODS 257

Dunedin, New Zealand, has informed me by letter that
among specimens which he collected in Tasmania during
January, 1892, ‘one is especially interesting, a freshwater
Schizopod from the very summit of Mount Wellington,
that is, from a height of 4,000 feet, and that this crus-
tacean is quite unique, and will require a new family all
to itself.’ Writing again, he tells me that the animal has
no carapace, but is divided like an amphipod, so that he
has named the genus Anaspis, which means ‘ without a
shield.’ From the available informatior, therefore, it is not
difficult to predict that the number of Schizopod families
will in the near future be augmented from four to six.

Family 1.—Lophogastride.

The carapace is rather large, more or less calcareous,
loosely covering more or less of the trunk, the segments
of which are well defined dorsally. The first maxillipeds
are robust, with exopod imperfectly developed or wanting,
the epipod very large and projecting within the branchial
cavity. The second maxillipeds have the terminal joint
obtuse. The six following pairs of appendages are uniform
and ambulatory, with well-marked finger. The branchiz
are arthrobranchiz, very complex, arborescent, consisting
of three or four principal branches, the innermost largest
and freely projecting beneath the trunk, and of others
covered by the carapace; the hindmost pair are rudi-
mentary or wanting. ‘The marsupium or maternal pouch
consists of seven pairs of plates. The pleopods are well
developed in both sexes, uniform, natatory. The develop-
ment is without any free metamorphosis.

G. O. Sars, from whose exceedingly valuable report on
the Challenger Schizopods this definition is adapted, allots
four genera to this family.

Lophogaster, Michael Sars, 1856, still possesses but a
single species, Lophogauster typicus, M. Sars, which at
present is only known from the North Atlantic and the
South Atlantic, without having been discovered in inter-
mediate positions. It is recorded by Canon Norman from
the Shetiand Isles. Its sculptured carapace has a short

258 A HISTORY OF RECENT CRUSTACEA

and broad tridentate frontal plate, and leaves the last
segment of the trunk dorsally uncovered. The scale of
the second antenne is broad and heart-shaped with a
fringed inner margin. The elongate telson terminates in
some strong spines and a little serrate plate.

Ceratolépis, G. O. Sars, 1883, has also only one species,
Ceratolepis hamata, which much resembles the preceding,
but its hard and large carapace leaves no segment of the
trunk uncovered. The scale of the second antennz is
narrow and flexuous, forming a sort of hook on either
margin, with no fringe of hairs, and the telson 1s not
truncate at the apex but cleft into two diverging lappets,
‘somewhat resembling the tail of a swallow.’ The single
specimen was scarcely half an inch long, and hence the
smallest of the known Lophogastridee, and, though its
organisation seems to mark it out as a deep-sea form
like the rest of the family, it was in fact taken at the
surface of the Pacific.

Gnathophausia, v. Willemoes Suhm, 1879, has a
parchment-like integument, the carapace in front drawn
out into a long spear-shaped and denticulate rostrum, and
behind in general into a backward pointing spine. ‘The
greater part of the carapace, as in the genus Nebalia,
would appear to form, so to speak, merely a loose mantle
arching the back and sides of the trunk, and within which
the body is freely movable.’ This part is surmounted by
two longitudinal keels on each side. On the upper side
of the eye-stalk there is always a small prominence called
the ocular papilla. Of the first antennz the outer
flagellum is very long and so compressed as to be almost
ribbon-shaped. The scale of the second antenne 1s
variable. The first maxillee have on the outer side of the
basal part a two-jointed ‘palp,’ which, contrary to what
is the case in the other Podophthalma, is bent directly
backwards. Though looking like an epipod, this appears
to be part of the endopod. . Both joints are armed with
setee or bristles, those on the second joint elongate, the
apparatus being no doubt destined to sweep the branchial
cavity, as is the ease with the similar formation in the

LUMINOUS ORGANS 259

Cumacea and some of the Isopoda. The second maxillee
exhibit exteriorly at the base a very conspicuous mam-
milliform prominence, which Sars supposes to be a
phosphorescent organ. Dr. v. Willemoes Suhm considered
it an accessory eye, and hence gave the genus a name
meaning ‘light in the jaw, which is equally appropriate
to the new explanation of this curious prominence. The
lamellar exopods of these maxillz fit pretty closely into
the lateral emargination of the carapace at each side of
the buccal area, ‘ forming, as it were, a kind of piston, by
the oscillatory movements of which the postero-anterior
current of water produced beneath the free portion of the
carapace may be regulated.’ The first maxillipeds have
the basal part much widened, the indistinctly separated
second joint in some species carrying a rudimentary
-exopod, but not in others; the basal joint has an epipod,
a freely movable membranous plate, projecting within the
branchial cavity. This, ‘as in Lophogaster, is of very
considerable size, almost equalling in length the whole
maxilliped, and exhibits a narrow lanceolate form, the
apex being somewhat recurved. Its function, too, is more
properly to produce, by its rhythmical movements to and
fro, the current of water flowing beneath the free portion of
the carapace, and bathing the gill-branches attached out-
side the bases of the legs.’ The seven following pairs of
appendages have the fifth joint elongate, the exopod de-
veloped into a powerful swimming branch, of which the
base is muscular and the terminal part multiarticulate and
setiferous. The complex branchie are strongly developed
at the bases of all the pairs, except the last, on which
they are small and rudimentary. The pleopods in both
sexes are developed in the same manner as powerful
swimming organs. The sixth segment of the pleon has a
transverse suture, as in Lophogaster. The telson is large,
channelled along the middle, and after tapering to the
apex there ends in an almost semilunar projection. Of
this strange genus nine species are now known, ranging
in depth from 255 to 2,200 fathoms, and over almost all
the ocean. ‘The first species described was called Lopho-
20

260 A HISTORY OF RECENT CRUSTACEA

gaster ingens by Dr. Dohrn in 1870. This is the largest
species, the specimens measuring rather more than six
inches, while those of Gnathophausia gigas, v. Willemoes
Suhm, measure rather less than six inches. Vivid red
and magnificent carmine appear to be the prevalent
colouring in the genus. It is probable that the two
species mentioned, together with two others, calcarata,
Sars, and gracilis, vy. Willemoes Suhm, will be eventually
retained in this genus to the exclusion of the other
species, which are destitute of the rudimentary exopod on
the first maxillipeds.

Chalaraspis alata 1s accepted by Sars from the drawings
and manuscript notes of v. Willemoes Suhm, but there
was no specimen in the Challenger collection by which to
control these records.

Family 2.—Eucopiide.

The carapace is very large, membranous, with the
lateral margins produced over the base of the pleon. ‘The
segments of the trunk are all well defined. The first
maxillipeds are nearly as in the Lophogastride ; the three
following pairs of appendages are inclined towards the
parts of the mouth, and have a rather short and powerful
structure, while the next three pairs are exceedingly long
and slender, with nearly straight acute fingers, the remain-
ing pair being shorter and iess slender, not at all prehen-
sile. The branchiz, marsupium, and pleopods are nearly
as in the Lophogastridz. The development is unknown.

The family contains but one genus.

Eucopia, Dana, 1852, has but a single species, Hucopia
australis, Dana. This has no rostrum ; the eyes are small,
the scale of the second antennz large, the mandibular
‘palp’ very slender, the first maxillze with no reflexed ap-
pendage, the second with a very large strongly fringed
exopod. ‘The first maxillipeds have a rather small exopod,
but the epipod ‘enormously developed, lanceolate in form,
and of a very soft and almost spongy structure.’ The three
pairs of legs preceding the last, remarkably long and

THE EUPHAUSIID/ 261

slender as they are, would not seem, it is said, ‘to be
specially adapted for the usual ambulatory motion, but are
more likely used for the purpose of seizing hold of any
delicate submarine objects, as Hydroids or Crinoids, fixed
at the sea bottom.’ In preserved specimens these limbs
are geniculate between the third and fourth joints. Their
fingers, though nearly straight, bend back against the
spines of the preceding joints, and may thus be very
efficiently prehensile. Dana’s specimen was obtained
from the stomach of a penguin in the Antarctic ocean, a
habitat which gave little reason to suspect the actual dis-
tribution of the species. According to the Challenger re-
searches it ranges from Japan to the Southern Ocean
and from the Southern Ocean to Nova Scotia, preferring
depths between 1,000 and 2,000 fathoms, though descend-
ing lower and mounting higher. It is presumed that the
Specimen snapped up by the penguin must have made an
excursion to near the surface.

Family 3.—Euphausiide.

The carapace is rather small, not calcareous, firmly
connected with the trunk dorsally, only the last segment
being completely defined above. The first maxillipeds are
pediform, elongate, with well-developed natatory exopod,
the epipod rudimentary or wanting. The seven following
pairs of appendages are generally uniform in structure, not
effectively ambulatory, geniculate and densely setose, with-
out any distinct finger, the hinder pairs more or less im-
perfectly developed. The branchize are podobranchia,
wholly uncovered, digitiform-arborescent, the hinder pairs
rather complex, sending off a branch beneath the trunk.
The egg-pouch, when present, is under the hinder part of the
trunk, single or double, not formed by marsupial plates.
The pleopods are strongly developed in both sexes, natatory,
with a secondary lobe on the inner branch; the first two
pairs are sexually modified in the male. The telson is very
slender, tapering to an acute point, and carrying two large
spiniform slightly divergent appendages, affixed at some

262 A HISTORY OF RECENT CRUSTACEA

distance from the apex, but generally reaching much
beyond it. Luminous globules are generally present on
various parts of the animal. The heart is furnished with
six pairs of lateral slits or venous openings. The develop-
ment is complex, the larva after hatching passing through
the Nauplhius- and Zoéa-stages.

Hight genera are included in this family, three of which
are represented in the British Fauna.

Huphausia, Dana, 1852, which means ‘a bright light,’
was so called in reference to the luminous character which
all the species of this genus share with most others in the
same family. This genus is distinguished from the rest
by haying the last two pairs of legs quite rudimentary,
although the branchiee are well developed. By the nume-
-rous species it is almost universally distributed. It is
pelagic in habit, that is to say, its members occupy the
surface of the ocean when it suitsthem. They may or may
not descend to great depths, but often, and especially at
night time, they are to be found in great profusion at the
surface. MHuphausia pellucida, Dana, a colourless species,
was met with ‘in almost every tract of the ocean traversed
‘by the Challenger, and has also been taken in the Medi-
terranean and off the coast of Norway. Huphausia superba,
Dana, from the Antarctic Sea, has its whole body, except
the legs and branchia, tinged with a brilliant red. ‘The
luminous globules in these animals were at one time sup-
posed to be accessory eyes, but Sars regards them as con-
stituting ‘a very complicated and peculiarly developed
luminous or phosphorescent apparatus.’ They are ‘ very
conspicuous in the living animal by reason of their beauti-
ful red pigment and glistening lustre.’ The pigment coats
only the hinder half of the globule, which is filled up with
cellular matter enclosing a bunch of iridescent fibres, while
the front hemisphere is quite pellucid and contains a highly
refractive lenticular corpuscle. This last is supposed to
act ‘as a condenser, producing a bright flash of light, the
direction of which admits of being changed at the will of
the animal, by simply rolling the organ by means of its
muscular apparatus.’

HERRING FOOD 263

[ Boreophausia],G. O. Sars, 1883, has the basal joint of
the first antenne without an apical leaflet. It was esta-
blished to receive two northern species, which had been
successively placed in the genera Thysanopoda and EHu-
phausia, and which are now Boreophausia inermis (Kroyer)
and Boresphausia Iaschii (Michael Sars). Both are found
in Scottish waters, and since Norman identifies Boreophau-
sia Raschit with Rhoda Jardineana, G. Sim, 1872, it seems
that the generic name ought to be Rhoda.

Thysanopoda, Milne-Edwards, 1830, has only the last
pair of legs rudimentary, and even these have a well-
developed exopod; the last pair but one are like those
that precede them. All the true branchiz are provided
with an anteriorly bent branch. ‘The type species is
Thysanopoda tricuspida, Milne-Edwards. The British
species Uhysanopoda Couchii, Bell, and various others have
been transferred to different genera.

Nyctiphdnes, G. O. Sars, 1883, which means ‘ one that
shines by night,’ like Thysanopoda, has only the last pair
of legs rudimentary, but the preceding pair are a little
imperfect, being devoid of the three terminal joints. In
both pairs the exopod is developed in the male, but want-
ing in the female. The basal joint of the first antenne
carries a peculiar reflexed leaflet at the apex. Nyctiphanes
norvegica (Michael Sars) is reported from the Firth of
Clyde as abundant and fine everywhere in-deep water, on
a muddy bottom, as far up as Loch Goil. Young speci-
mens are said to be not uncommon at the surface in the
Firth of Forth, especially in winter and spring. In certain
districts it forms an important part of the food of the
herrings. A specimen has been taken alive on the shore at
low water in North Devon. Nyetiphanes Couchii (Bell) is
distinguished from the preceding species by having no
lateral spines on the carapace and by having a spine over
the base of the telson. It is recorded from Cornwall and
Banff. Very like it is Nyctiphanes australis, Sars, which
appears to be restricted to the Australian seas. In de-
scribing this species Sars says that two of the female
specimens were ovigerous, a condition seldom met with

264 A HISTORY OF RECENT CRUSTACEA

among preserved specimens of Euphausiidee. The two coni-
cal ovisacs, placed side by side between the last two pairs
of appendages of the trunk, ‘do not consist of incubatory
lamellze, as in other Schizopoda, but merely of an exceed-
ingly thin membrane, derived, it would seem, from some
glutmous fluid issuing along with the ova and coagulated
by the action of the sea-water as a delicate envelope sur-
rounding aud keeping the ova together during the em-
bryonal development.’ The curious fact is noticed that of
the northern species the specimen of Nyctiphanes Couchit
figured by Bell in his ‘ History of British Crustacea’ is the
only ovigerous one that has as yet been recorded.

Bentheuphausia, Sars, 1885, has all the legs distinctly
developed, and though the last pair are rather short, they
have both branches of a structure similar to that of the
preceding pairs. The single species, DBentheuphausia
aumblyops, Sars, has small and imperfectly developed eyes.
The three specimens on which it was founded were taken
from depths between 1,000 and 1,800 fathoms, and appear
to be devoid of the luminous globules found in so many
other members of this family.

Thysanoessa, Brandt, 1851, has the last pair of legs quite
rudimentary, and the preceding pair exceedingly small,
devoid of the three terminal joints. On the other hand,
the second maxillipeds are very elongate, much longer
than the following legs. They have the last two joints
armed with spiniform bristles on both margins. The
eyes in this genus are of a somewhat irregular form, with
the cornea divided, as it were, into two compartments by
a transverse constriction. The type species, Tysanvessa
longipes, Brandt, from the Siberian Sea, is identified by
Norman with the earlier Thysanopoda neglecta, Kroyer.
Sars has added a southern species, Thysunoessa macrura ;
a wide-ranging species, Thysunoessa gregaria, which is found
in the Mediterranean ; and two from the coast of Norway,
which he has named borealis and tenera. Dr. H. J. Hansen,
however, having examined Kréyer’s specimens in the Co-
penhagen Museum, has come to the conclusion that
Thysanoessa borealis, Sars, should be called Thysanoessa

m ae

SEVEN STAGES OF LARVAL LIFE 265

neglecta (Kroyer), and. that Yhysanoessa tenera, Sars,
should be named Thysanoessa longicaudata (Kroyer).
The latter species was supposed by Sars to belong to his
genus boreophausia, on the faith apparently of Kréyer’s
figures drawn from a defective specimen. Both neglecta
and longicaudata are known from British localities.

Nematoscélis, Sars, 1883, agrees in many respects with
Thysanoessa, but has the second maxillipeds, or first legs,
as Sars calls them, far more remarkably elongated and
almost filiform. In the type species, Nematoscelis megalops,
Sars, they are described as having little or no armature,
except a bunch of peculiar spiniform sete at the apex.
But Norman points out that in British specimens the
fourth joint has several hooked spines, which look as if
they might hold the sixth joint when bent back upon the
fourth. Should this form hereafter prove distinct, he pro-
poses for it the name borealis already published, but with-
out description, in 1872. The genus is distinguished by the
enormous development ofthe eyes, ‘ of larger size, perhaps,
than in any other known form of Podophthalmia, the re-
mark applying to the actual eyes, and not to the stalks
which are quite short.

Stylochewron, Sars, 1883, has the third maxillipeds, or
second iegs, greatly produced, the two terminal joints
being armed with spiniform bristles and spines, and the
two forming together a kind of grasping organ. The last
pair of legs are quite rudimentary, and the two preceding
pairs are incomplete. In this genus the mandibles have
no ‘palp, the first maxille no exopod, and the first
maxillipeds no epipod. ‘The ovisac is single. One of the
species, Stylocheiron longicorne, Sars, has been taken both
in the Mediterranean and south of the Cape of Good
Hope. Chun notes that in his mastigophdrum the lumi-
nous organs are bright red.

_Messrs. G. Brook and W. KE. Hoyle follow up the
labours of Claus, Metschnikoff, and Sars, by tracing the
Euphausid larva through seven stages—(1) the Nauplius,
with body oval, unsegmented, median unpaired eye, first
antenne (long) simple, second antennz (long) and man-

266 A HISTORY OF RECENT CRUSTACEA

dibles (short), both the latter being biramous and natatory 3
(2) a second Nauplius stage, in which maxille and maxilli-
peds appear as bud-like rudiments; (3) Metanauplius, with
the carapace commencing, and the mandibular legs lost;
(4) Calyptopis, with body divided into two regions, and
much other development, but eyes not mobile, and no trace
of legs or pleopods ; (5) an unnamed intermediate stage,
in which the eyes become stalked and mobile; (6) Furcilia,
with the compound eyes more fully developed, and the
anterior legs and pleopods taking form; (7) Cyrtopia,
in which the flagellum of the first antennz becomes
elongate and distinctly articulate, so that these appen-
dages cease to serve the purposes of locomotion. ‘In
their metamorphosis,’ the authors say, ‘the Huphau-
slide stand almost alone, and none of the later larval
stages are identical with the Zoea and other larvee of Deca-
pods. They commence their larval life in the Nauplius con-
dition, a type of larva frequent in other groups, particularly
among the Copepods, Cirripedes, some Decapods, and vari-
ous parasitic forms. The larval function of the antennze is
retained until the commencement of the Cyrtopia stage,
a feature which is not usual among the Crustacea. The
Calyptopis stage, in which the compound eyes, while
undergoing development, are covered by an anterior ex-
pansion of the carapace, is a remarkable one, which, so far
as we know, is only met with in one other group, an
aberrant section of the Decapcds, including Lucifer, &c.,
where this condition obtains in the Protozoea stage.’ The
names of the so-called Calyptopis, Furcilia, and Cyrtopia
stages have been adopted from three supposed genera,
established by Dana, who assigned the first two to the
Mysidee, and the third to the Euphausiide, all of them, in
fact, representing stages in the development of the latter
family.

Fumily 4.—Myside.
The carapace is generally rather small, loosely covering

the trunk behind, of which the segments are distinctly
defined, though narrow and crowded dorsally. The first

ee

THE MYSIDZ 267

maxillipeds have usually a natatory exopod, and an epipod
projecting within the branchial cavity. The second pair are
modified to serve the mouth. The remaining appendages
of the trunk are uniform, rather feeble, the terminal part
generally subdivided into short setiferous articulations,
the finger being small or wanting. ‘There are no true
branchiz. The marsupium is composed of seven or more
often of only two or three pairs of plates. The pleo-
pods in the female are as a rule quite rudimentary, in the
male either natatory or modified for sexual purposes. The
inner branch of the uropods usually contains an audi-
tory apparatus. The development is without any free
metamorphosis.

The eighteen genera included in this family by Sars
in 1885 are Mysis, Latreille, 1803, Svriella, Dana, 1850,

-Promysis, Dana, 1850, Anchidilus, Kroyer, 1861, Hetero-

mysis, S. I. Smith, 1874, Petalophthalmus, v. Willemoes
Suhm, 1879, and the following twelve all instituted by
Sars himself, Amblyopsis, Boreomysis, Erythrops, Hemimysis,
Leptomysis, Mysideis, Mysidopsis, Parerythrops, Psewdomma,
under the common date of 1869, Mysidella, 1872, Macropsis,
1876, and Huchetoméra, in 1883. The list (no doubt acci-
dentally) omits a nineteenth genus, Pseudomysis, Sars, 1880,
and a twentieth, Gastrosaccus, Norman, 1869, from which
yet another has been severed in Haplostylus, Kossmann,
1880. From Siriella Claus has separated Pseudosiriella, in
1884. From Mysideis Norman in 1892 distinguishes Stilo-
mysis, and in the same year recognises Macromysis, White,
1847, Neomysis, Czerniavsky, 1882, and a new genus
Schistomysis, as distinct from Mysis. Thus with Arctomy-
sis, Hansen, 1887, added since Sars drew up his list, and
with Arachnomysis, Chun, the number of genera, if all are
accepted, amounts to twenty-eight. But further, Nor-
man has called my attention to Czerniavsky’s Monographia
Mysidarum, 1882-3, in which several new but not always
well-founded genera appear. One of these preoccupies the
name Arctomysis, so that Hansen’s genus must be re-named.
Macromysis also must yield to the rather queer but much
earlier generic name Praunus, Leach, 1818, of which the

268 A IlIISTORY OF RECENT CRUSTACEA

unabashed author himself remarks that ‘this genus was

instituted by Mr. Leach, who has derived the name from

the English word prawn. He assigned to it the species
exuosus, Miiller, and integer, Leach.

Petalophthalmus was so called from having the eyes
leaf-like. They are described in the single species, Petal-
ophthalmus armiger, as ‘quite rudimentary, without any
trace either of pigment or visual elements, constituting
merely two thin and pellucid lamellee, of an oblong form,
and mounted on very short and narrow pedicles.’ ‘The
species was obtained in the tropical Atlantic from a depth
of 2,500 fathoms. ‘The telson is not incised at the apex.
The male is distinguished by the astonishing and perhaps
unique development of the mandibular * palp,’ and by the
lamellar prolongation of the fourth joint in the first and
second mavxillipeds, the first pair being, contrary to the
custom in this family, devoid of exopod and epipod. A
female with seven pairs of marsupial plates has been, per-
haps incorrectly, assigned to this species.

For the preoccupied Arclomysis, Hansen, I propose the
name Hansenomysis. It has a short carapace, the mandi-
bles with prominent cutting edge, long molar tubercle,
and very large ‘palp, the first maxillipeds without
exopod, and with none of the joints expanded, but with an
epipod, the second maxillipeds with a small ovigerous plate
at the base, and the short fourth joint expanded into a
large plate. ‘The three following pairs of appendages are -
very slender, with a short hairy terminal joint, and there
is a very long, sharp, bare nail on the next three pairs.
Hansen considers that his Hansenomysis Fyllcee and the
male of v. Willemoes Suhm’s Petulophthalmus armiger
might form a separate family inthe Schizopoda. ‘The sup-
posed female of the latter species he regards as belonging
to Boreomysis scyphops and not to Petalophthalmus.

Boreomysis, of which the type species is Boreomysis
arctica (Kroyer), taken off the coasts of Greenland and
Norway, includes among others Boreonvysis scyphops, Sars,
which is far from being only a boreal Mysis. It was in
fact first met with by the Challenger at great depths in the

CURIOUS EYES 269

Southern Ocean, in 1,950 fathoms, at latitude 53° 55’ south,
but afterwards it was taken at a depth of 1,110 fathoms,
north-west of Finmark, by the Norwegian North Atlantic
Expedition. This is one of the instances in which a species
has only been found far to the north and far to the south,
yet it seems hasty to infer that such species will not in
time be discovered in many intermediate localities. Boreo-
mysis scyphops is gigantic for a Mysidan, attaining a length
of more than three inches. Jn this genus there are seven
pairs of marsupial plates, which are attached to the second
maxillipeds and the following limbs. Apparently all the
rest of the Mysidze are content with a much smaller num-
ber of incubatory lamelle. Boreomysis is without the
abnormal characters of the male found in Petalophthalmus,
and it has the telson apically incised.

Amblyopsis was altered into Amblyops by Sars in 1872.
The name has reference to the character of the eyes, which
are ‘imperfectly developed, transformed into two immobile
plates, extending horizontally in front of the carapace and
contiguous in the middle.’ There are only two species,
the Norwegian Amblyopsis abbreviata, and from the
Southern Ocean Amblyopsis crozetii. In this genus the
legs are tolerably strong, having the sixth joint subdivided
into three articulations, and the terminal joint unguiform ;
the telson is not incised at the apex.

Pseudomma has the ‘eyes quite rudimentary, forming
merely broad petaloid expansions of the ocular seoment,
partly connate in the middle, and not exhibiting the slightest
trace of pigment or visual elements.’ Here the legs are
exceedingly slender, the sixth joint subdivided as in the
preceding genus, but the terminal joint obtuse, not ungui-
form. The telson is not incised. Three northern and two
southern species have been described, Pseudomma trunca-
tum, 8. I. Smith, being arctic, and Pseudomma Sarsit, v.
Willemoes Suhm, antarctic.

Mysis, as understood prior to the recent restriction of
the genus, has the sixth joint of the trunk-legs subdivided,
and the fourth pair of pleopods in the male developed into
long backward-directed stilets, the third pair being also

270 A HISTORY OF RECENT CRUSTACEA ©

generally unlike those in the other sex, but the three re-
maining pairs: usually simple and rudimentary like the
pleopods of the female. The telson is either incised or whole
at the apex. The very numerous species may be distin-
guished by the general shape, by the structure of the scale
of the second antennz and its size in relation to the
peduncle of the first antennze, by the number of articulations
in the subdivided joint of the trunk-legs, by the shape of
the telson and its length in relation to the uropods, and by
the structure of the fourth pleopods in the male.

Several of the species occur in British waters, but only
two of them are definitely described in Bell’s ‘ History of
the British Stalk-eyed Crustacea,’ namely Mysis flexuosus
(Miiller), under the name of Mysis chameleon, J. Vaughan
Thompson, which has the telson incised, and Mysis vulgaris,
Vaughan Thompson, which has the apex of the telson un-
divided, and which may be the same as the Praunus i-
teger of Leach, from Loch Ranza. Mysis neglecta, Sars,
has been taken by Norman at the Channel Islands, and is
reported by Dr. Henderson from the Clyde. Meinert
does not feel sure that it is distinct from Mysis flexuosus,
he having often met with individuals which seemed to
be links between the two. Norman groups them both
with Mysis inermis, Rathke, a species found in Shetland,
observing that all three are distinguished by an antennal
scale which is long, lanceolate, subparallel-sided, and having
the apex scarcely produced beyond the unciliated external
margin, but that in flecuosus the scale is seven or eight
times as long as broad, in neglecta about five times, in
inermis about four times. Mysis spiritus, Norman, has
the eyes on long stalks, the spines on the inner branch
of the uropods closely crowded, the fourth pleopods in the
male ‘ with the first three joints subequal in length, and
the last joint subequal to the fourth. On the other
hand, Mysis ornata, Sars, has the eyes short, the spines on
the inner branch of the uropods not crowded, the fourth
pleopods in the male, with ‘the outer branch very like
that of M. spiritus, but the third joint is much longer than
either of the two first, which are subequal; fifth joint not

NORMAN ON THE GENUS MYSIS 271

more than half the length of the fourth. Mysis Helleri,
Sars, a Mediterranean species also found at the Channel
Islands and on the coast of Devon, is very like in general
character to Mysis spiritus, from which, Norman observes,
it may be at once distinguished by the very short and
nodulously swollen first articulation of the subdivided sixth
joint in the trunk-legs. ysis Lamornee, Couch, has the
telson deeply but narrowly cleft. Mysis arenosa, Sars, is
a small species in which the pleon is shorter than usual,
the eyes are short, the fourth pleopods of the male do not
reach the apex of the telson, the incision in the telson is
about one-fourth of its length. This species, first described
from the Mediterranean, has since been found in South
Devon and in Scotland. Thus nine species of the genus
have been assigned to the British Fauna. In the ‘ Annals

~ and Magazine of Natural History’ for September, 1892,

Canon Norman has distributed these species among four
genera, in which the distinctions depend chiefly upon the
remarkable and varied modifications of the pleopods in the
male sex, and upon the form of the antennal scale. Under
this arrangement the species flewuosus, neglecta, and inermis,
are referred to Macromysis ; spiritus, ornata (including Ker-
vuler), arenosa, Helleri, and Parkeri, to Schistomysis ; and
vulgaris to Neomysis. Mysis Lamorne is transferred to
Hemimysis. As already observed, for Macromysis must be
substituted the older name Praunus. The species Parkeri,
Norman, 1892, from South Devon, is a new one. It is
very near to Schistomysis spiritus, from which it may be
distinguished by the more twisted and bent inner uropod,
armed with about fifteen spines on the inner. margin,
increasing in size from the base of the appendage. In
Schistomysis the antennal scale is sub-rhomboidal, with
the apex greatly produced beyond the spine of the unviliated
external margin ; in Neomysis this scale is ciliated on both
margins, and runs out to a spine-like apex. The species
Themisto longispinosa, Goodsir, and Themisto brevispinosa,
Goodsir, from the Firth of Forth, are evidently male forms
of the genus Mysis, but their specific identity has not been
determined. ‘The generic name Themisto is preoccupied.

272 A HISTORY OF RECENT CRUSTACEA

The Greenland species, Mysis oculatus (O. Fabricius), is
of special interest on account of the variety relicta, Lovén,
found in great hordes in several of the large freshwater
lakes of northern Europe, descended, it is supposed, from
ancestors which occupied those regions when the waters
were still salt and in connection with the open sea. In
Mysis relicta the antennal scale is elongate, ciliated all

Fic. 22.—Mysis relicta, Loven,
the tirst maxilla [Sars].

Fig. 23.—Mysis relicta, Loven, the second maxilla.

round. Norman has obtained it from Lough Neagh in
Ireland, and by this discovery provides the genus Mysis
with at least one representative in the British fauna, after
despoiling it of all the rest. Sars, in his ‘ Histoire des
Crustacés d’eau douce de Norvége,’ has given a most
elaborate description of this species, illustrated by highly
finished and most instructive plates, and more recently it
has been studied by Hansen with his accustomed acute-
ness. ‘The accompanying figures in the text are copied
from Sars. Others from the same author are given in
Plate XIII. on a reduced scale.

Macropsis, ‘the long-eyed, is the only other genus
agreeing with Mysis in the characters of the pleopods of
the male, and it is distinguished from Mysis both by the
extremely elongate eyes and by the structure of the first
antennx, which, in addition to the two flagella and the
setose appendage usual in the males of this family, have
the apex of the peduncle armed with yet a fourth process,

Pl. xiii.

= fr
agtyn
AND
ey

Notostomus
perlatus

a
:
4
;
J

;
j

ee

Eretmocaris
longicaulis

‘

aS:
) [}
mx

Sqguilla.
scabricauda.
= Dorsal view

M.relicta
Telsan

.relictas

|

\S.scabricauda ps

A\ Ventral view

we
ayy
2

M.relicta
Section of Eye

An

“FOO

a ee ke

Z | TRUMPET-SHAPED EYES 273
r

thin, narrowly conical, ending in a single long seta. This
process is not met with in any other genus. The telson
is not incised at the apex. There is only a single species
known, Macropsis Slabberi (van Beneden), first described
by Slabber, asa shrimp with trumpet-like eyes. It belongs
to British and most other Huropean coasts. Slabber was
not. a little struck by its organisation, and van Bene-
den improves the occasion by observing that in a steam-
engine on a railway we admire the marvel of human in-
dustry that has contrived its complicated parts, but that,
if such a locomotive were comprised in a grain of sand, if
we could see several of its kind deploying with precision
in a drop of water, we ought to be far more excited to
astonishment and admiration.

Heteromysis, of which the type is the American, British,

and Norwegian species, Heteromysis formosa, S. I. Smith,

is distinguished from almost all other Mysidez by having
the pleopods rudimentary in the male as well as the female,
and also by having the third maxillipeds much stronger
than the rest of the legs and ending in a sort of subchelate
finger, which induced Sars to call the genus Chiromysis,
‘the Mysis with a hand,’ before he knew that it had been
otherwise named by Professor Smith. The telson is in-
cised.

Mysidella is said to stand nearer to Heteromysis than
to any other genus, but with the first instead of the
third maxillipeds strongly built and peculiar. It has the
body short and stout, the scale of the second antennz
small, obtusely lanceolate, and fringed with hairs on both
margins. ‘The upper lip is obtuse in front, and deeply
incised behind ; the mandibles have a large cutting plate
which is quite simple, without any teeth. The legs are
small and weak, the genital appendages of the male being
very elongate. The pleopods in the male have the same
rudimentary structure as in the femile. The telson is

- short, not deeply incised, and finely aculeate on the hinder

portion of each lateral margin. It includes the two Nor-
wegian species, typica and typhlops, of Sars.
Mysidopsis has the scale of the second antenne fringed
21

274 A HISTORY OF RECENT CRUST.CEA

with hairs on both edges. The molar tubercle, which in
Mysis is large, has here become obsolete. The pleopods in
the male are all natatory. The telson is truncate except in
one species. The type species, Mysidopsis didelphys (Nor-

man), is British, as are also Mysidopsis gibbosa, Sars, and —

Mysidopsis angusta, Sars. All three are also Norwegian,
and the last is unique in having no spines or teeth or setz
within the cleft of the telson. Mysidopsis hibernica, Nor-
man, 1892, has only been taken at Valentia in Ireland.

Mysideis insignis, Sars, agrees with the preceding genus
in having the pleopods of the male natatory, but differs in
the mouth-organs, and in the very short incision of the
telson it has two long plumoss sete.

Leptomysis agrees with the two preceding genera as to
the male pleopods, but agrees nearly with Mysis in the
mouth-organs ; the scale of the second antenne is divided
into two distinct segments, which are setose on both mar-
gins. ‘The telson is tongue-shaped, with numerous spines
about the apex, which is not incised. Two of the species,
Leptomysis lingvura, Sars, and Leptumysis gracilis, Sars, are
British. Norman supposes Cynthia Flemingii, Goodsir, to
be a synonym of the former.

Hemimysis abyssicola, Sars, is not far remote from Afysis,
but among other differences has the fifth pleopods in the
male well developed as swimming-organs. As a deep-
water form itis distinct from most of the species of Mysis,
which are littoral or sublittoral as a rule.

Stilomysis grandis (Goés), formerly included in Mysideis,
has the first, second, and fifth pleopods in the male similar
to those of the female, but the third and fourth pairs with a
stiliform outer branch.

Pseudomysis abysst, Sars, has the eyes quite rudimen-
tary, without either pigment or visual elements. The scale
of the second antennez is fringed with sete on both mar-
gins. ‘The mouth-organs are like those of Mysideis. The
legs are rather feeble, the sixth joint being much sub-
divided, and the exopods unusually long. The auditory
apparatus in the inner branch of the uropods is rudimen-
tary. The telson is exceedingly short, lamelliform, and

4

EYES OF A RUBY RED 249

aimost quadrate, deeply incised. This, the single repre-
sentative of the genus, was obtained from depths beyond
eleven and twelve hundred fathoms in the Northern Ocean.

Anchialus typicus, Kroyer, belongs to a genus in which
the scale of the second antennz is remarkably small, the
pleopods in the male well developed, but partly obsolete in
the female. The telson is large and incised at the apex.
The female has on the first segment of the pleon smail
horizontally projecting side-plates. Of the small but ro-
bust and very broad species Anchialus agilis, Sars, a speci-
men is recorded from Plymouth. <Anchialus pusillus, Sars,
from the Pacific, was at first assigned to Dana's genus
Promysis. ‘The specimens described have greatly developed
marsupial pouches, from which it is inferred that they were
full-grown, and yet in length they barely attain one-eighth
of an inch, about as small a size as an adult shrimp could
well be expected to content itself with.

Erythrops, ‘the red-eyed, was a name given by Sars in
1869 to part of the genus Nematipus, a preoccupied name
which he had used in 1863. As the earlier name implies,
the legs are very slender, nearly filiform. They terminate
in a well-formed nail. The telson is very short, scarcely
longer than broad, apically broadly truncate. Of the three
species here mentioned, all are British. Hrythrops serratus,
Sars, is distinguished by Norman ‘from all other British
Mysidea by the serrations of the outer margin of the an-
tennal scale.’ He says that ‘the very large reniform eyes
are of a lovely and brilliant ruby red.’ Lrythrops erythro-
phthalmus (Goés) refers to this colouring of the eyes both in
the specific and generic names. Sars changed the name of
Goés’ species, which had been originally assigned to Mysis,
into Nematopus Goési1, on the very ground that the red-
ness of the eyes was common to all the species of the new
genus, but the earlier name should be retained notwith-
standing. Hrythrops pygmeus, Sars, has been identified by
Sars with his own earlier Nematopus elegans, so that the
name must be Hrythrops elegans. Parerythrops obesus, Sars,
was at first doubtfully included in the genus Nematopus,
with the other more slender species.

276 A HISTORY OF RECENT CRUSTACEA

Euchetomiéra, with two species typica and tenuis from
the Pacific, agrees with Hrythrops in the form of the very
short, lamellar, unincised telson. ‘The scale of the second
antenne is smooth on the outer margin. The legs are
very slender. Some of the joints of the legs, the pleopods
in both sexes, and the uropods, are fringed with long sete,
from which circumstance it may be supposed that the
generic name is derived, meaning ‘ with the parts beauti-
fully hairy.’ Professor Chun comments on the astonishing
length of the upper antennee in the type species, which
he regards as a transitional form between Mysis and his
own Arachnomysis Leuckartw.

Siriella, Dana, was originally named Cynthia, by
Vaughan Thompson, but the name was preoccupied, and
Dana’s Siriella takes precedence of White’s Cynthilia. The
genus is characterised chiefly by the structure of the legs,
‘which are more decidedly unguiculate than in any other
known genus of Mysidans, and have the sixth joint entire
or subdivided into two articulations only ; also by the pleo-
pods of the male, which are natatory, and have the ‘ basal
lobe of inner branch usually transformed into two gill-like,
more or less spirally twisted stems.’ ‘The outer branch of
the uropods is broader than the inner, and has an imperfect
articulation at the apex. ‘The telson is elongate, densely
spinose at the edges, with the apex not incised. The
species are numerous, and many of them are met with at
the surface of the sea, far from the coast. ‘The British
species, as far as at present known, are: 1. Siriella nurve-
gica, Sars, in which the third joint of the first antennee has
three setze on the inner margin, and between the spines
at the angles of the telson three spinules, of which the
central is the largest. 2. Siriella Claus, Sars, of which
Norman gives the distinguishing characters as ‘the single
seta on inner margin of last joint of peduncle of antennules,
the slender legs and claws, and three equal-sized spinules
between the ultimate spines of the telson.’ 38. Siriella
jaltensis, Ozerniavsky, identified by Norman with the later
Siriella crassipes, Sars, in which the form is somewhat
more robust and the legs much stronger than in the

Bee

SIRIELLA AND GASTROSACCUS 277

preceding species, while the telson terminates ‘in a
small spinule flanked on each side by the usual sete, and a
more minute spinule between the ultimate pair of spines.’
4, Siriella Brooki, Norman, which seems to be intermediate
between Siriella Clausii and Siriellu jaltensis, having the
single antennular seta of the former, and the apex of the
telson armed as in the latter, the legs also being of inter-
mediate thickness. 5. Siriella armata (Milne-Edwards),
which is distinguished by an elongate rostrum reaching
the end of the second joint of the first antenne, and by the
telson ‘terminating usually in four equal-sized spinules
and two sete between the ultimate spines.’ In Norman’s
opinion both Mysis Griffithsie, Bell, and Mysis productus
(Gosse) may be synonyms either of this or of the next
species. Pseudosiriella, Claus, was instituted to receive the

_ species Mysis frontalis, Milne-Edwards, which Sars had

previously transferred to Siriella. It has a well-developed
rostrum like Siriella armata, but the appendages, to which
a branchial function has been attributed, on the pleopods
of the male, are here simple instead of being coiled. Ac-
cording to Canon Norman, Pseudosiriella frontalis belongs
to the British as well as the Mediterranean Fauna.

Gastrosaccus, Norman, is distinguished by the laterally
compressed carapace, and in the female by the great de-
velopment of the side-plates of the first pleon-segment
which appear to assist the marsupium in the retention of
the eggs. The marsupial plates are two pairs, the first
pair being very small and sending a strap-shaped setiferous
process into the cavity of the pouch. The first pleopods in
the female are very large, the rest very small. All the
pleopods of the male are biramous and at least in part
natatory. The telson is apically incised. Gastrosuccus
sinctus (van Beneden) is found in the Mediterranean, on
the Belgian and French coasts, and at Jersey. Gastrosaccus
spinifer (Goés) is found both in the Baltic and on the coasts
of Great Britain, and is distinguished from the preceding
species by the dentately fringed hind margin of the carapace
and by a well-developed dorsal spine on the fifth pleon-
segment.

278 A HISTORY OF RECENT CRUSTACEA

Haplostylus, Kossmann, was established to receive the
Mediterranean species, Gastrosaccus Normant, Sars, which
is also found off the coast of Ireland, and a Red Sea species,
Hapltostylus erythreus, Kossmann, the generic distinction
consisting in the absence of the forward directed lobes on
the concave hinder rim of the carapace, which are found in
the species of Gastrosaccus above mentioned, and also in
the reduction to a rudiment of the inner natatory branch
of the third pleopods of the male.

It will be seen from the foregoing notes that fifteen
genera of this family are represented in the Fauna of Great
Britain, and it is quite possible, and even probable, that
extended research may show that others of the genera
and species occur round the very varied coasts of the
British Isles, which in their southern parts, especially if
the Channel Islands are included, are in rather marked
contrast to the region of the Orkneys and the Shetland
Isles, among which Norwegian and Arctic forms may
readily present themselves. It will be understood that,
although an endeavour has been made to mention all the
valid, or at least all the commonly accepted, genera of the
Schizopoda, there are very numerous species belonging to
those genera of which it has been impossible to take
notice.

DR. BOAS ON THE SQUILLIDA 279

CHAPTER XIX
SUB-ORDER IV.—STOMATOPODA

THE carapace is feebly developed, leaving uncovered at
least the last three segments of the trunk; the pleon is
powerful, and, like the carapace, usually depressed, not
laterally compressed. ‘The eyes are stalked. The second
antennze have a scale. The mandibles have a small or
‘rudimentary ‘palp.’ The three pairs of maxillipeds and
the two following pairs of appendages are variously modified
as six-jointed prehensile limbs, with epipods, but without
exopods ; the second maxillipeds being predominant in
size and importance. The three following pairs of legs are
feebly developed, with exopods, but without epipods. The
first five pairs of pleopods generally carry eacha pair of large
ramified branchiz arising from the outer branch. There
is a special apparatus on the inner branch of the first
pleopods in the male. The caudal fan is powerful. The
heart is elongate, with several pairs of lateral venous fis-
sures. The ovaries and testes lie chiefly in the pleon, and
have their two halves united by a median piece. There are
no spermatophores. The spermatozoa are simple, rounded
cells. The young are hatched not: as Nauplii, but in a more
advanced stage. The carapace of the young is largely
expanded.

The above definition is chiefly taken from that given
by Dr. J. E. V. Boas for the ‘Order Squillacea,’ in his
highly esteemed ‘ Studies on the Relationships of the Mala-
costraca.’ It is in this sub-order that the typical number
of “twenty-one segments has been distinguished in a
single animal. Usually the first antenne have three flagella,
one of the two principal ones sending off a branch from

280 A HISTORY OF RECENT CRUSTACEA

near its base. The ocular and antennal segments are
more or less movable. and not covered by the carapace.
The two pairs of maxille are rather simply constructed.
The first of the two series of legs are closely applied to the
mouth, and from this circumstance the sub-order has re-
ceived its appellation of ‘ mouth-footed.’ According to Pro-
fessor W. K. Brooks, in his Report on the Challenger Stoma-
topoda, there are about sixty species known of adults, and
an equal or greater number of larvee, from the tropical,
sub-tropical, and temperate waters of the Atlantic, Pacific,
and Indian Oceans. Some of the species range over the
whole of this area, while others are known from only
a single restricted locality, almost a fourth of the species
having been described from single specimens. They are
usually found in very shallow water, only one or two
species being reported from depths like a hundred and
twenty fathoms. ‘The wide distribution of many of the
species is undoubtedly due to the great: length of their larval
life, during which they swim at the surface, and are swept
to great distances by the oceanic currents.’ On the other
hand, the adults are extremely active in their movements
and retiring in their habits, most of them being burrowing
animals, from which it results that they may long remain
undiscovered even in localities where they are abundant.
Some, lke Sguilla empusa, which hunt far from their
burrows, are often caught in nets and trawls, but ‘ others,
such as Lysiosquilla excavatrix, are the Myrmeleons of the
ocean, lying in wait for their prey, covered with sand, with
only the tips of their eyes exposed, at the mouths of their

very deep burrows, to the bottoms of which they dart at the
‘least alarm.’ At a station where they were extremely
numerous, Professor Brooks could scarcely capture one, till
he devised the insidious plan of holding bait in one hand
and a trowel in the other at the mouth of the burrow, and
even so with his best speed the trowel often cut in two the
retreating quarry,

CHARACTERISTIC SPINES . 28]

Family Squillide.

As this is now the only family, it has the characters of
the sub-order. The family Erichthidee, which was formerly
its companion, has been shown to consist entirely of larval
forms. Inthe Squillidee Brooks accepts ‘ seven'genera, Pro-
tosquilla, Gonodactylus, Pseudosquilla, Coronida, Lysiosquilla
Gncluding Coronis), and Squilla Gncluding Chloridella).’
As only six genera are named, it is doubtful whether seven
is a misprint, or intended tacitly to include Leptosquilla,
Miers, which had been previously spoken of as very shghtly
known. Professor Brooks lays great stress on the marginal
spines of the telson, of which there are usually six, arranged
in three pairs. These he designates as the primary mar-
ginal spines, and distinguishes the two nearest the middle
' line as fhe re ee the two nearest the anterior edve,
which are usually the farthest from the middle line, as the
laterals, and the one between the lateral and the submedian
on each side as the intermediate. ‘ Between these six
primary marginal spines there are others which are equally
large and prominent in the young larve, but minute or
absent in the adults;’ these he calls the secondary mar-
ginal spines. ‘The characters of the great second maxilli-
peds, spoken of as the raptorial claws, and the connection
of the sixth segment of the pleon with the telson, are also
of great importance in distinguishing the genera. Another
structure, which ‘ often presents characteristics of specific
value, and differs conspicuously in the different genera,’ is
that found upon the inner branch of the first pleopods in
the male, ‘a complicated grasping organ which probably
serves for seizing the female, like the grasping forceps of
many of the lower Crustacea and some few of the Mala-
costraca.’

Squilla, Fabricius, 1793, agrees with all the other
genera, except Protosguilla (and perhaps Coronidw), in
having the sixth pleon-segment separated from the telson
by a movable joint. The terminal joint of the second
maxillipeds is without a basal enlargement, but with a
series of spines, usually not more than six in number, on

282 A HISTORY OF RECENT CRUSTACEA

its inner edge. The pleon is depressed and wide; the inner
spine of the ventral prolongation from the peduncle of the
uropod is longer than the outer; the telson is usually
longer than wide, and it has more than four secondary
spines between the intermediate and submedian marginals.

There are numerous species in this genus. Squilla
mantis received the name which it still bears from the
French naturalist Rondelet in the sixteenth century. That
author warns his readers that they will not find any
account of this species in the older writers, such as Aristotle
and Pliny, Athenzeus and Oppian. He chose the specific
name because of the likeness which this long-armed marine
animal shows to the Mantis insect, and he explains that
the Mantis or ‘soothsayer,’ also known in the south of
France as the Preguediou or praying insect, derived the
latter name from its emaciated devotee-like figure, and the
former from the childish superstition thatif asked the road
to Rome or to St. James of Compostella, it would indicate
it by holding out one or other of its arms. He takes the
opportunity of observing that his contemporary Bellon has
given a very bad drawing of this species, leaving out much
that should have been put in, and putting in much that
ought to have been left out. Yet Rondelet himself appears
to bestow upon the pleon several more segments than it is
by nature endowed with. ‘This species is occasionally
found in British waters, but is much more common in the
Mediterranean, where it is used as an article of food. It
attains a length of seven inches. The membranaceous
carapace has a longitudinal central ridge, and on either
side there are strong grooves. It narrows forwards, and
in a specimen six and a half inches long, the carapace, in-
cluding the rostrum or movable frontal plate, is about an
inch and three quarters long. ‘The eyes have a peculiar
hammer-like appearance, being very wide on narrow stalks.
The second maxillipeds have the terminal joint armed with
in al] six long teeth which can close against pits in the
margin of the strong preceding joint. This joint itself has
a minutely denticulated border alongside of the pits, and
also three movable spines near its base. The outer margin

ww

a TO BE HANDLED WITH CARE 283

may be clasped back into a deep groove in the outer mar-
gin of the joint next but one preceding it. The three
following pairs of limbs are very much smaller, the ter-
minal joint finger-like and clasping against the much
dilated preceding joint. The next three pairs of legs are
slender and four-jointed, with a slender exopod on the
second joint. The very large pleon has the centre of the
back smooth, but four carinz on each side, which com-
mence indeed on the last three segments of the trunk, but
are not continued on to the telson. This latter has a power-
ful central carina ending in a tooth a little before the apex
is reached. Between the strong submedian spines there
are eight minute dentic'es, and between each submedian
and its corresponding intermediate there are nine denticles.
Another Mediterranean species, also occasionally found on
-the English coast, Squilla Desmarestii, Risso, is distin-
guished by having only five teeth on the claws, and fewer
longitudinal keels on the first five sezments of the pleon.
In the United States Squilla empisa, Say, is often thrown
on the beaches by the waves, and it probably burrows near
low-water mark or not far out beyond it. Large speci-
mens, Professor Smith says, ‘are eight or ten inches long
and about two broad.’ After describing the second maxilli-
peds as much in accordance with those of Squilla mantis,
he remarks :—‘ By means of this singular organ they can
hold their prey securely, and can give a severe wound to
the human hand, if handled incautiously. It also uses the
stout caudal appendages, which are armed with spines, very
effectively. ‘The body is usually pale green or yellowish
green, each segment bordered posteriorly with darker green
and edged with bright yellow; the tail is tinged with rose
and mottled with yellow and blackish; the outer caudal
lamellz: have the base and spines white, the last joint yel-
low, margined with black ; the inner ones are black, pale at
base ; the eyes are bright emerald-green ; the inner antennz
are dark, with a yellow band at the base of each joint ; and
the flagellum is annulated with black and white.’ Squilla
armata, Milne-Kdwards, is another species very little re-
mote from Squilla mantis, but among other differences the

284 A HISTORY OF RECENT CRUSTACEA

claws have seven teeth. This species, originally described
from Chili, has been found also in New Zealand, a locality
to which Squitla nepa, Latreille, has likewise been assigned,
but of its occurrence there Mr. Charles Chilton thinks there
is much doubt. The genus Chlorida, Eydoux and Souleyet,
184], had a preoccupied name, which was changed into
Chloridella by Miers in 1880, but Professor Brooks thinks
it unnecessary to separate it from Squilla.

Squilla scabricauda, Lamarck, is from. the Antilles.
Desmarest’s figures of it (see Plate XIII.) are designed to
show the series of limbs as distinctly as possible, the small
first maxillipeds being pulled back behind the large second
par, which would otherwise obscure them. The species
should probably be referred to Lysiosquilla, the genus next
mentioned.

Lysiosquilla, Latreille, 1825, has the terminal joint of
the second maxilipeds not enlarged at the base, and armed
with more than six spines. The pleon is depressed, loosely
articulated, and wide. The outer spine of the ventral
prolongation from the peduncle of the uropod is usually
longer than the inner. Between the submedian and inter-
mediate marginal spines of the telson there are no more
than four secondary spines, and there is often only one
spine. The species Coronis scolopendra, Latreille, has been
incorporated in this genus, the generic name Coronis,
though earlier, having been preoccupied. Lysivsquilla
maculata (Fabricius) has nine spines on the claw of the
adult male, and seven or eight on that of the female, those
of the female moreover tending to weaker development,
although, it is said, such ‘ secondary structural differences
between the sexes are extremely rare among the Stoma-
topoda.’ Lysivsquilla spinosa (Wood Mason) is found at
various parts of New Zealand, and is there the only species
of the genus, according to Mr. Chilton, who has recently
re-described it, with special reference to the apparatus on
the first pleopods of the male. Lysiosquilla excavatria,
Brooks, has on its claw fourteen or fifteen short curved
pointed teeth, besides the long terminal one. The whole
dorsal surface, rostrum and telson included, is smooth and

<li

PROFESSOR BROOKS ON BURROWING 285

highly polished, and without carinee or spines. The
female is much larger than the male, of an opaque olive
brown, almost black colour, while the male is of a trans-
parent grey. Professor Brooks gives an interesting ac-
count of its habits :—

‘It is found in the sand of the ocean beach just below
low-tide mark, where it is exposed to the full force of the
ocean swell, and it inhabits a very deep cylindrical burrow
which is nearly vertical and goes down for several feet.
While watching for its prey the animal stations itself at
the mouth of the burrow, which is arched over with sand,
so that only the tips of the eyes are exposed. The food
consists of small Crustacea, fishes, and other small animals,
and when one approaches within reach the Coronis [ Lysio-
squilla] darts out of the burrow, knocking away the loose

‘sand, and seizing it in its raptorial claw it darts backwards

with it and retreats to the bottom of the burrow. When
hungry it often captures prey at a distance of six or eight
inches, but, as a rule, it waits until it is near enough to
be caught without leaving the opening. The food which
is captured is usually stored away at the bottom of the
burrow, and the animal returns to the mouth and resumes
its watch. In excavating its burrow the animal begins
by stretching its body out on the sand, which is then
swept away from under it by the action of the abdominal
appendages, until all of the body except the eyes and
telson are buried. It then forces its head into the loose
sand which has been stirred up by the action of the
abdominal appendages, and dragging its body down it
quickly becomes buried vertically, head downwards, and it
continues to burrow until it reaches the hard undisturbed
sand, when it bends upon itself, and passing the head up
on the ventral side of the swimmerets it reverses its posi-
tion and works upwards to the surface, hardening and
compressing the sand by the pressure of the dorsal surface.
After the upper end of the burrow is thus rendered firm
and circular, it again doubles upon itself, and going to
the bottom gathers an armful of sand, which is clasped
against the ventral surface of the body between the large

286 A HISTORY OF RECENT CRUSTACEA

second maxillipeds, where it is held in place by the flat
oval chele: which are tightly clasped over it. At the
opening it stretches out as far as it can reach without
leaving the burrow, and dropping the armful of sand it
smoothes it down until it is level with the surrounding
surface. This process is then repeated until the burrow
reaches a great depth, for I have dug for three or four feet
without reaching the end, and all the specimens which I
kept in confinement burrowed to the bottom of the
aquarium. When the burrow is finished the animal
spends most of its time near the top, and as the semi-

circular exopodites of the abdominal appendages complete —

the outline formed by the convex dorsal surface, 1t com-
pletely fills the circular tube, into which the constantly
vibrating scoop-like abdominal appendages carry a con-
tinuous current of water, which escapes through the loose
sand.’

Pseudosquilla, Dana, 1852, has a name originally coined
but not published by Guérin. .

In this genus the terminal joint of the second maxil-
lipeds is without basal enlargement and with few marginal
spines or none; the pleon is smooth, convex, and narrow ;
the terminal joint of the first pleopods of the male im-
perfectly divided by a marginal notch into an inner and
outer lobe; the telson has the submedian spines long and
tipped with movable spinules, and usually it has a single
secondary spinule, but sometimes two, three, or four such
spinules between the submedians and intermediates.
Pseudosquilla ciliata, Miers, a species found alike at Hono-
lulu and in the West Indies, is of a bright cherry red
colour.

Gonodactylus, Latreille, 1825, has the terminal joint of
the second maxillipeds enlarged at the base, and without
marginal spines; the pleon narrow, convex, thick; the
primary marginal spines of the telson very large, with one
or two secondary spines between the submedians and
intermediates.

Gonodactylus faleatus (Forsk&l), according to Koss-
mann, must supersede the better known name Gonodac-

NAMES GIVEN WITH A PURPOSE 287

tylus chiragra (Fabricius). The species appears to have
a vast range, and its colour is said to be exceedingly
variable.

Coronida, Brooks, 1886, has the carapace flat and
nearly rectangular. ‘The rostrum ends in a small median
spine; the scale of the second antennez is very small; the
terminal joint of the second maxillipeds is dilated at the
base, and armed with spines on the inner margin. The
pleon is depressed; its hind segments and the telson
are thickly set with small spines. The uropods are very
small. The name of the genus is compounded from the
names of the rejected genera Coronis and Chlorida (or
Chloridella), to indicate Professor Brooks’s view that like
them it contains somewhat primitive species. These are
Coronida Brady: (A. Milne-Edwards) and Coronida trachi-

‘rus (Miers), both of which were originally assigned to

Gonodactylus. The professor seems inclined to suspect
that the sixth pleon-segment may prove to be fused with
the telson, but the type-specimens of Miers’s species in the
British Museum show that at least in Coronida trachurus
the telson is quite distinct from the preceding segment
and freely movable upon it.

Protosquilla, Brooks, 1886, has the rostrum furnished
with long acute median and anterolateral spines; the eyes
and the scale of the second antennz small; the terminal
joint of the second maxillipeds dilated at the base, with-
out marginal spines; the pleon convex, its sixth segment
more or less completely fused with the telson ; the uropods
small. Professor Brooks considers the name of this genus
‘the more appropriate inasmuch as all the other Stomato-
poda present evidences of divergent descent from a
common stem form, which, like the living representatives
of the genus Protosyuilla, was characterised by the small
size of its eyes, antennary scales, and uropods.’ Seven
species are included in the genus, among which Proto-
squilla elongata, Brooks, with a carinate and bilobed but
otherwise simply constructed telson, presents a rather
striking contrast to Protosquilla Guerinit (White), in
which the dorsal surface of the telson carries twenty-two

288 A HISTORY OF RECENT CRUSTACEA

long spines symmetrically arranged, while the preceding
segment, which in the other species has some rather
inconspicuous carine, here has about fifty-six long cylin-
drical spines, ‘each of which ends in a blunt rounded tip
with a perforation from which a soft tubular fleshy process
protrudes.’ :

Leptosquilla, Miers, 1880, is defined as having the
‘ophthalmic segment greatly elongated; rostrum not
reaching beyond half the length of this segment,’ and to
it is assigned the single species Leptosquilla Schmeltzuw
(A. Milne-Edwards), from the Samoa Islands.

For a history of the development of the Stomatopoda
the foundation was laid by Dr. Claus in 1871. Many
additions have been made and much precision given to
the knowledge of this subject by the researches of Pro-
fessor Brooks. ‘The transparent pelagic larve are fre-
quently captured, and in consequence of their glass-like
clearness the individual organisms can be easily studied,
but there are special difficulties connected with tracing
the series of changes which they pass through between
the egg and the adult condition. Unlike most Malaco-
straca, the Squillide do not carry their eggs about with
them, but deposit them in their deep burrows, there to be
aerated by the currents of water which the pleopods of the
parent maintain. Hence the hatching of eggs in an
aquarium has not yet been brought about. The older
larvee are hardy, but seldom found near the shore. The
younger larvee can be found near the shore, bat seldom
moult in confinement. ‘The life-history has, therefore, to
be traced by a comparison of numerous forms collected
from the open sea, and here there is a twofold risk, of
uniting the larvae of quite distinct animals as stages in
the life-history of a single species, and of disuniting the
larval stages of a single species as though they belonged
to distinct species or even distinct genera. In this laby-
rinth the explorer has to be guided in part by general
resemblances, but more especially by comparative measure-
ments. Professor Brooks, having obtained a number of
specitnens which by general resemblance seemed to make

heh gk
see ae ae

SCIENCE IS MEASUREMENT 289

a good series, proceeded to tabulate the measurements in
millimetres. He was disappointed, however, not to find
any such conformity to a general law as he had expected.
It then occurred to him that in the larva change of form
and increase of size are going on together, and that one
organ might be diminishing relatively to another organ
while it was increasing relatively to itself in a former
stage. He therefore reduced his measurements to a
common standard, expressing them in thousandth parts of
the total length of the larva at each stage, and this usually
enabled him to decide whether a given larva did or did
not belong to a particular series. Apart from this, in one
instance which he mentions his comparative measurements
obtained a triumph parzllel in its way to that of Kepler
when he found that the positions of the planets conformed
to a numerical law. Having a series of larve apparently
of the so-called Coronis (Hrichthus) minutus, of which the
youngest measured 4°16 millimetres, the second 5:29 mm.,
the third 6°49 mm., and the fourth 10:21 mm., he observed
that if 4°16 is multiplied by five-fourths, and the result
by five-fourths, and so on, the resulting series of numbers
is

(1) 4:16, (2) 5-20, (3) 6:50, (4) 8-13, (5) 10-16,

which corresponds as exactly as need be with the series of
larvee, allowing for the absence of the fourth stage. It is
highly improbable that larvae bearing a general resem-
blance to one another would have this curious numerical
relationship unless they also had a very near relationship
by blood likewise. Professor Brooks considers that ‘the
free prolonged larval life has brought about modifications
which have no reference to the life of the adult, so that
the larvee differ among themselves more than the adults
do.’ By reason of their small size and great transparency
some of these larval forms are very suitable and interest-
ing objects for the microscope.

The following list will show the names attached to
the young forms of the different genera :—

22

290 - A HISTORY OF RECENT CRUSTACEA

Alima is the larva of . . . Squilla.
Alimerichthus . Squilla (Chloridella group).
Lysioerichthus (short-spined) Lysiosquilla.
Lysioerichthus (long-spined). Lysiosquilla

(Coronis group).
Erichthalima . . . . ~ Coronida:
Pseuderichthus . . . . . Pseudosquilla.
Gonerichthus . . . . . Gonoductylus.
An unknown form. . . . Protosquilla.

In support of this affiliation Brooks says, ‘ Faxon has
reared a Squilla empusa from an Alima larva. The Chal-
lenger collections show that the larva of Lysiosquilla macu-
lata is one of the short-spined Lysioerichthi; I have reared
Lysiosquilla (Coronis) excavatrix, one of the more primitive
Lysiosquille, from a long-spined Lysicerichthus. Claus has
figured a series which shows beyond question that at least
one species of Pseuderichthus becomes a Pseudosquilla, and
the Challenger collections furnish equally good proof that
the Chiragra group of Gonodactyli come from Gonerichthus
larvee, and I therefore believe that we may very safely
assume that all the Lvysioerichthus larvee are young Lysio-
squille, all the Alima larve young Squwille, Alimerichthus
one of the lower Squillae or Chloridelle, all the Gonerichtht
young Gonodactyli, Erichthalima very probably a young
Coronida, and ail the Pseuderichthi very probably young
Pseudosquillee.’

TIE SESSILE-EYED CRUSTACEANS — 291

CHAPTER XX

ORDER Il.—EDRIOPHTHALMA

In this order there is generally a pair of compound eyes,
which are sessile ; they may be prominent, but are never
movably stalked ; they may be absent, or placed so closely
together as to form apparently, but not really, a single
eye. On the other hand, the visual elements may be
variously distributed, so as to form compound eyes from
one to four in number, or simple eyes that are not limited
to four. The last seven segments of the trunk are gene-
rally not, and the last four are never, included in the cara-
pace.

Three sub-orders are comprised in this order—the
Cumacea, Isopoda, and Amphipoda.

Sub-order 1.—Cumacea.

As with the Squillidz, so with the Cumacea, nothing
is to be found about them in the writers of antiquity, but
about the latter sub-order even the sixteenth century
knew no more than its predecessors. Not a single species
was recorded before the year 1779, and for sixty years
after that date science contented itself with half a dozen
species, some of which were so obscurely or imperfectly
described that they are still doubtful. Since 1841, by
the exertions of a few naturalists, chiefly Scandinavian
and Anglo-Saxon, the characters of the group have been
investigated with great thoroughness. The distribution
extends to all oceans, and from tide-marks down to very
ereat depths. By rapidly repeated discoveries the known
forms have now become numerous, and are classified in

292 A HISTORY OF RECENT CRUSTACEA

eight families, together containing twenty-five or twenty-
six well-defined genera, and about a hundred and eighteen
satisfactorily determined species. In certain localities the
extreme abundance of some of these supplies a welcome
food to shoals of herring. In size and number of indivi-
duals the Arctic species appear to excel all others. .It is
probable that many forms still remain to be discovered,
since up to 1876 a single species obscurely described from
the Black Sea was the sole representative of the sub-order
in the’area of the Mediterranean, where in the winter of
1876 Professor Sars found no less than twenty-three
species, of which fourteen were new to science. Before
1859 none were known from the waters of the Clyde, and
in these Mr. David Robertson, of Cumbrae, has since
found fifteen species.

Among the curiosities of scientific literature are the
disputes which have occurred actually within the last fifty
years, as to whether the Cumacea did or did not possess
organs of vision, and as to whether they were or were not
merely larval forms. The well-known and diligent ob-
server, Colonel Montagu, at the beginning of the century
found in South Devon a species which in fact possesses
sight, but not unnaturally Montagu did not attempt to
discover the creature’s eye, because he was under the
impression, though an erroneous one, that his solitary
specimen had lost its head. Kréyer, many years later,
happening to meet with various species which are in truth
blind, formed the opinion that all the species were so, and
that eyes had been attributed to some of them under an
illusion. Harry Goodsir, a Scotch naturalist, in 1843
published the remarkable statement that the eyes are
‘pedunculated but sessile.’ He lost his life not long
afterwards in Franklin’s Arctic expedition, and left his
opinion to be for many years doubted, denied, or sup-
ported, without its being in his power to explain that
what he obviously intended to print was that the eyes
were zof pedunculated but sessile. It is probable that
Kréyer was completely mystified by the misprint. ‘ Good-
sir, he says, ‘thought that eyes must be found in the ©

CHARACTERS OF THE CUMACEA 293

creatures, and he therefore found them.’ Some years
earlier Milne-Edwards had indeed described a species as
having two eyes, which almost certainly has but one; so
easily are even the ablest naturalists misled into taking
for granted that what is customary will prevail. A very
few of the Cumacea have two eyes. The majority have a
single median eye, but occasionally the elements of this
compound organ are so arranged as to have the appear-
ance of several distinctly separated ocelli.

The Cumacea are said to leave the egg as maggot-
shaped Nauplii. From the maternal pouch they issue
almost in the adult form, only being as yet without the
last pair of trunk-legs or peraopods, a deficiency which
in two species, Campylaspis nodulosa, Sars, and Leptostylis
manca, Sars, is perhaps persistent. The notion that these
-creatures, which are in truth born almost fully fledged, were
only larval forras, was early disproved by Goodsir and
Kroyer, but was nevertheless still upheld for several years
by three of the most distinguished naturalists of the
century.

In no group of the Malacostraca is the general form
more characteristic than here. This is principally due to
two unvarying features, the narrowness of the pleon and
the prominence of an elongate pair of uropods at its ex-
tremity. A distinct telson may or may not be present ;
of the six preceding segments none is ever wanting, and
of these the fifth, without any trustworthy exception, is
the longest. The front part of the body is always more
bulky than the pleon, and sometimes enormeusly so. ‘The
integument is often stoutly crustaceous, more ready to
break than to bend.

Normally there are five segments of the trunk distinct
behind the carapace, carrying respectively the five pairs of
pereopods. Occasionally, however, the first of these five
segments is absent or rudimentary, and in one genus the
third and fourth segments are coalesced. Sometimes the
carapace overarches one or more of the free segments. More
or less completely sheltered beneath the carapace lie all
the organs from the eyes to the third maxillipeds. There

294, A HISTORY OF RECENT CRUSTACEA

are no chelate limbs to which the terms chelipeds or gnatho-
pods would be applicable.

_The adult males are very strikingly distinguished from
the females in more than one particular. Thus, the females
have the lower antennz of insignificant size, while in the
males they are developed to a great length, though they
are not always very apparent, as they are often securely
tucked away along the sides of the body, an arrangement
which seems to imply that they are of exceptional value, and
possibly also only of exceptional use. Again, the females
never have pleopods, while the males have them, except in a
single genus, throughout six of the eight families. More-
over, in all the families but one the males have well-
developed exopods or swimming-branches attached to all
the first four pairs of perzeopods, whereas the females never
have them on more than three pairs, and sometimes only on
one ortwo. These disparities are connected with the habits
of the animals. For at night-time it is found that the sur-
face-net in suitable localities will secure the males of certain
species in abundance, not intermingled with any females.
The latter sex, on the other hand, is generally found to
preponderate when their settlements in the sand and
mud are invaded. The females are evidently of a less
roving disposition than their mates. Yet their movements
are not destitute of considerable liveliness and energy. ‘To
compensate them, too, for their inferior swimming appara-
tus, they very commonly have the carapace ornamented
with various spines and tubercles, which may be supposed
to form a sort of defensive armour against some of their
foes. The more active males, on the contrary, seem to
find their advantage in having the carapace smooth. ‘To
the student this last distinction is not a little embarrassing,
for much smaller differences than those which here mark
the external appearance of the two sexes have frequently
been allowed specific value.

The upper antenne of the Cumacea are always small,
with two diminutive flagella, of which one is sometimes
evanescent. The upper lip is a single lobe between the
bases of the lower antennae. The lower lip forms two

MANDIBLES AND MAXILLA! 295

lobes with finely ciliated edges. Between the lips the hard
and strong mandibles make their dentate cutting edges
meet. They have no ‘palp.’ The left mandible, and rarely
also the right, has a secondary plate on the inner side.
The molar tubercle is generally a long and strong precess
at right angles to the body of the mandible, with a denti-
culate crown; but in one family, the Campylaspide, the
process is thin and stiliform. Between the cutting edge
and the molar there is usually a row of spines. It is,
however, distinctive of one family, the Leuconide, that this
spine-row is absent, being represented only by a couple of
setze. The first maxille may be roughly described as con-
sisting of an inner and outer plate, each tipped with spines,
and of a backward directed ‘ palp.’. The inner plate is an
expansion of the first joint, and the outer plate an expan-
“sion of the third, the small second joint between them
being very little conspicuous. Close to the base of the
outer plate on its outer side is placed the ‘ palp, which
may be the fourth joint of the endopod turned back to serve
a particular purpose. It is very movably articulated, and
ends in one or two long setz. Its function is reasonably
supposed to be that of clearing the branchial sacs from any
obstructive particles which might be brought in along with
the water introduced by the action of the breathing ap-
paratus. In the genus Paralamprops, however, this ser-
vice must be dispensed with, for there the ‘ palp’ does not
exist.

The second maxilla are analysed by Hansen into four
joints, of which the second is very large, having a row of
setze on the inner margin and a small terminal plate tipped
with sete. The third and fourth joints have also each a
similar small terminal plate, and to the outer rim of the
third joint is attached a thin plate with curved margin,
which is explained to be morphologically a weaker develop-
ment of the fan as it occurs in the Myside.

Upon the next pair of appendages, the first maxilli-
peds, the interest of the Cumacean group is above all con-
centrated, for these present features that are unique among
the Crustacea. The endopod or linb-like portion of the

296 A HISTORY OF RECENT CRUSTACEA

maxilliped is not of exceptional structure. The second
joint is large, usually with a terminal plate having
coupling hooks on its inner margin. The seventh joint is
wanting, and in the genus Campylaspis the fifth and sixth
also, the fourth joint being rudimentary and terminal, and
the second joint in this case not carrying an apical plate.
All the known forms, however, agree in having in con-
nection with the first maxillipeds a remarkable respiratory
apparatus. The hinder part of this, being certainly at-
tached to the first joint, no doubt represents the epipod,
while the front part, though coalesced with the hinder
part, may in reality be derived from the second joint, and
in that case it will, as Sars supposes, represent the exopod.
This latter opinion is sometimes contested, but, however
that may be, it is to Sars that belongs the honour of having
first clearly made known the manner of action of these
structures, as well as of having beautifully delineated the
intricate forms which some of them assume. ‘The epipod
directed backwards into the branchial cavity finds many
parallels, asinthe Mysidee, where likewise its oscillations con-
tribute to maintain a steadily renewed flowing in of water.
But in the Cumacea the epipod is usually furnished with
branchial sacs, sometimes in large numbers and spiraily
arranged. To this there is nothing properly parallel in these
appendages elsewhere. ‘lhe anterior or exopodal portion
of the apparatus is even more singular. The pair of these
plates on the two maxillipeds are sometimes firmly coalesced
together, but in any case they meet and form a tube which
can be projected in front of the head and again withdrawn.
As long as the aninal continues the peculiar twisting
movements which in life it so frequently exhibits, the
branchial apparatus is completely motionless. But when
it is in turn quiescent, the transparent end of the tube is
shot out under the pseudo-rostral end of the carapace
between the bases of the antenne, while the gill-bearing
epipodal plates are set oscillating. When the gill-plates
move forward the water is forcibly expelled through the
end of the tube. When the plates move back, the slit-
like orifice of the tube closes of itself through the elasti-

THE BREATHING APPARATUS 297

city of the membrane, and the expelled water is thus
prevented from returning.
On the other hand, a new
supply of water can now
enter through the openings
at the sides of the maxille,
and these openings in their
turn are then closed by the
forward movement of the
gill-plates. By this means
the gills are kept washed
by a continually fresh cur-
rent of water, of essential
service to the health and
vital energy of the animal,
although it is obvious that
the creature when burying
itself in the sand can for a
time dispense with this mode
of aerating its blood. in
the Epicaridea, a group of
Isopoda, to be mentioned
hereafter, the marsupial
plates of the first gnatho-
pods (second maxillipeds)
have a function similar to
that of the epipods just de-
scribed.

In the egg-bearing fe-
males of the Cumacea, the
second pair of maxillipeds
have at their base a broad
fan directed straight back-
wards within the ventral
body wall. This is formed
by the two epipods, each
represented by a small round
plate armed on its free mar- Fic. 24.—Diastylis stugia, Sars. First max-

: : illiped, with branchial apparatus, female
gin with several long sete. specimen [Sars]. al

298 A HISTORY OF RECENT CRUSTACEA

In the young and the males these plates are rudimen-
tary and without trace of sete. The inference, there-
fore, cannot be avoided that they have to
do with some maternal duty. ‘It will be
found,’ Professor Sars observes, ‘ that they

\é constantly have their place in the front
iy part of the marsupium, and with their
<yi/ long setee work in among the eggs and
he embryos contained in it. Their function

can, therefore, be nothing else than to
) bring about the rotation or movement of
: 4 “ the eggs included in the marsupium, which
is very clearly observable in living speci-
a mens, and which in the Myside and Iso-
ih poda is brought about in a somewhat dif-
| ferent way, by a peculiar rhythmical
BN movement of the plates themselves of
MASSA Which the marsupium is composed.’
F1G.25.—Diastylis Good- The third maxillipeds have a well-
maxi lined. of tear developed exopod or swimming-branch,
LBaeser|: the second joint to which it is attached
being almost always of very considerable size, and more
often than not produced at the outer apex.

Of the five pairs of trunk-legs or pereopods the first is
usually much elongated. In almost all cases the second
joint in these limbs is the longest. It is only rarely that
the terminal joint is of the curved pattern found in the
so-called fingers of many Crustacea. The three hinder
pairs might, it is said, from the habits of the animals,
rather be called digging than walking feet.

The pleopods of the male vary in pattern as well as in
number. They are only fully developed in the adult.
They usually consist of a two-jointed peduncle, and of this
the second and principal joint carries on the upper part of
its inner margin spines converted into coupling hooks. Of
the two branches the outer is two-jointed, the inner one-
jointed. Sometimes there is only a one-jointed outer
branch, and sometimes in place of well-developed pleopods
there are mere rudiments, or a group of sete. In the

BRUSH AND COMB 299

Cumide the inner branch has a little process on the outer
margin carrying the supposed auditory hairs.

The appendages of the sixth pleon-segment, the
uropods, almost always have the peduncle elongate. The
inner branch may consist of one, two, or three joints, while
the outer appears to be always two-jointed. Living
Cumacea will be seen repeatedly to double this caudal fork
back upon the head, some species being in the habit of
folding it dorsally and others ventrally. Hugéne Hesse
remarks that he has frequently seen these animals pass the
different appendages of the body and the mouth-organs
successively between the uropods as if between the teeth
ofacomb. These appendages are often plentifully sup-
plied with spines and hairs, so that they can well fulfil the
functions both of brush and comb in the creature’s toilet.
- Like so many other marine animals, which live in con-
ditions very unpromising for cleanliness, these can pro-
bably keep themselves exquisitely neat when they so desire,
although if they are killed with the mud and slime upon
them, it is extremely difficult for human fingers to cleanse
the specimens without inflicting damage. The tail part in
the Cumacea has the advantage of being very conspicuously
displayed, and the combined characters of the telson and
uropods, or, when there is no articulated telson, the
characters of the uropods alone, will suffice to determine
the genus to which a specimen belongs.

The shape and armature of the carapace are of the
highest importance for specific distinction, but the charac-
ters are not always especially easy to observe, and the
matter is complicated by the differences which prevail not
only between the males and females, but between the forms
of the male at different periods of life. Normally the
antero-lateral angles of the carapace are produced so as to
surround the front of the head, and by meeting above to
form a sort of rostral process. The median fissure of this
quasi-rostrum being continued backwards on either side
gives a kind of trilobed appearance to the head. Occa-
sionally, as in Vaunthompsonia cristata, Spence Bate, the
ocular prominence of the head projects so far that the

300 A HISTORY OF RECENT CRUSTACEA

lateral angles of the carapace close it in only at the sides
and not in front.

The marsupium of the female is formed by the splitting
of the ventral wall of the segments which carry the third
maxillipeds and the first three pairs of pereeopods, the
upper lamina separating the pouch from the general body-
cavity. Only in the aberrant Isopod genus Gnathia
(wrongly called Anceus) has any correspondent arrange-
ment for the marsupium been observed, although there the
ventral wall serves the purpose without being split into
two laminee.

The body contains an oval or spindle-shaped heart, ex-
tending from about the middle of the carapace back
through two or three of the free segments. It has one
pair of lateral venous openings. At the sides of it are two
elongate organs with some excretory function. ‘The liver-
tubes are usually three pairs, but there is only a single
pair in the family Campylaspide. ‘The nervous system
comprises the supracesophageal ganglion or brain, and
sixteen ganglia, of which the first three in close contiguity
innervate the parts of the mouth. ‘The next seven belong
to the trunk and are connected by rather long double
commissures. The remaining six, pertaining to the pleon,
are weakly developed, and their connecting commissures
are very long and slender.

It is a rather singular circumstance that the telson is
large and conspicuous only in two out of the eight families.
In one other family it is distinct, but small and without
spines. In the remaining five families it is entirely want-
ing, except so far as the ventral opening may vouch for its
existence, and a slight prolongation of the sixth pleon-
segment may suggest that it is not wholly lost but
coalesced.

Of the characters given the combination of avery few
will suffice to distinguish the Cumacea from all other
Edriophthalma.

THE CUMID@ 301]

Definition of the sub-order Cumacea.

The carapace covers the segments of the head and all
but the last five segments of the trunk. The antero-lateral
lobes are drawn towards one another usually in advance of
the frontal region. The first maxillipeds carry a respira-
tory organ of which the hinder division almost always is
furnished with branchial sacs, and the front division forms
an exserted tube during respiration for the outflow of
water from the branchize. Of the perzeopods at fewest the
first pair have exopods. Of the pleon-segments the fifth
is the longest. ‘The appendages of the sixth are the only
pair of uropods, :

The eight families included are the Cumide, Vaun-
_ thompsoniidee, Leuconidze, Nannastacidze, Campylaspide,
Pseudocumide, Lampropidz, Diastylide.

The peculiarity of the fifth pleon-segment being the
longest is reproduced in the curious Isopod genus Phrea-
toicus, Chilton, which is otherwise nearer the Amphipoda.

Family 1.—Cumide.

The first antennze are very small, with one of the
flagella rudimentary; the second antennez in the male
have the filiform flagellum composed of many short joints.
The mandibles have the anterior branch produced and
armed with a dense lateral series of spines. The eptpod
of the first maxillipeds is very large, with the branchial
sacs numerous, leaf-like, in a straight series. The third
maxillipeds have some of the joints expanded and laminar.
Only the first pair of pereeopods in either sex have well-
developed exopods. ‘The male has five pairs of pleopods
well developed. ‘The inner branch of the uropods is one-
or two-jointed; the telson is wanting. Five genera are
included in this family.

Cuma, Milne-Edwards, 1828, has the carapace mode-
rately developed, only four segments of the trunk
distinct behind it; the eye well developed; the
third maxillipeds with the second joint apically

302 A HISTORY OF RECENT CRUSTACEA

produced ; the uropods with the peduncle elongate,
and the inner branch generally two-jointed.
Cyclaspis, Sars, 1865, agrees with the above characters
of Cuma, except that the carapace is swollen,
almost globular, the eye is not always present,
the peduncle of the uropods is not greatly elon-
gate, and the inner branch is one-jointed.
Iphinoe, Spence Bate, 1856, has the body slender, com-
pressed, five segments of the trunk distinct
behind the carapace ; the eye distinct ; the second
joint of the third maxillipeds produced ; the second
joint of the inner branch of the uropods elongate.
Cumopsis, Sars, 1879, has five segments of the trunk
distinct behind the carapace; the eye well de-
veloped; the second joint of the third maxilli-
peds not produced. The second and third pairs
of pereeopods have one-jointed setiferous exopods.
Stephanomma, Sars, 1871, is uniquely devoid of the
frontal bifurcating suture ; it has five segments of
the trunk distinct behind the carapace. The eye
(in the type species, Stephanomma Goésu, Sars)
forms a coronet or circlet of eleven ocelli.

Of the genera thus briefly distinguished, Cuma, ‘a
wave, has given its name to the whole sub-order, although
not in fact the earliest named genus in it. Cuma scor-
pioides (Montagu, 1804) is a British species. The cara-
pace is strong and strongly ridged longitudinally. ‘The
inner branch of the uropods is two-jointed. In Bell’s
‘History of the British Crustacea’ a lamentable confusion
is made. It quotes in full Goodsir’s descriptions of his
own Cuma Edwardsii and Milne-Edwards’ Cuma Audouini,
but, as Sars has pointed out, the figures copied under the
heading Cuma Audouwinit belong to Cuma Edwardsii, and
vice versa. As a matter of fact Goodsir’s Cuma Hdwardsu
is a synonym of Cuma scorpioides (Montagu). Bodotria
arenosa, Goodsir, is, I think, a distinct species of Cuma,
separated from the other four species of that genus by
having the inner branch of the uropod single-jointed.

THE VAUNTHOMPSONIIDZ& 303

The minute Cuma pulchella, Sars, has recently been taken
by Mr. Thomas Scott in the Firth of Forth.

Cyclaspis, ‘ with orbed carapace,’ contains seven species,
one of which cornigera, Sars, by the pair of horns on the
sides at the anterior part of the carapace is a very marked
form. Cyclaspis levis, G. M. Thomson, and Cyclaspis pusilla,
Sars, are notable for having the carapace entirely devoid of
spines and sculpturing.

Iphinoe trispinosa (Goodsir) is plentiful in some British
waters. The number of spines or teeth on the central
crest of the carapace is far from being always limited to
three. In the males these teeth are always set away from
the front of the carapace, and sometimes in that sex there
are none, though it is doubtful whether this is so frequently
the case that it can be called the rule. Iphinoe tenella,
Sars, has recently been taken in the Clyde.

Cumopsis contains two species which are both British,
one, Cumopsis Edwardsti (Spence Bate), which was placed
successively in Cuma, Vaunthompsonia, and Bodotria, till
Sars established a new genus for it, and the other, Cumop-
sis longipes (Dohrn), the specific name of which has
priority over lcevis given by Sars.

Family 2.—Vaunthompsoniide.

General form, first antennze and mandibles, pleopods
and absence of telson, are as in the Cumide. ‘The flagel-
lum of the second antennz in the male is composed of
long slender joints. The epipod of the first maxillipeds
in the female is very narrow, with few, finger-like bran-
chial sacs arranged in a semicircle. The third maxillipeds
have the joints scarcely expanded. The first three pairs
of perzeopods in the female and the first four in the male
have well-developed swimming-branches. The inner branch
of the uropods is two-jointed.

There are at present three genera.

Vaunthompsonia, Spence Bate, 1858, has the body not
very slender, scarcely compressed ; the eye distinct; the
second joint of the third maxillipeds not produced; the

304, A HISTORY OF RECENT CRUSTACEA

second pair of peraeopods spinose, with the third joint not
defined ; the fourth pair in the female without any rudi-
ment of the exopods. Vaunthompsonia cristata, Spence
Bate, is British. ‘The only other species, Vaunthompsonia
meridionalis, Sars, is from Kerguelen. Vaunthompsonia
anomala, Sars, is supposed by its author to represent in
all probability another distinct genus.

Leptocima, Sars, 1873, has the body elongate and
much compressed, the eye indistinct, the third joint in the
second pereeopods defined, and the fourth pereeopods in
the female with rudimentary exopods. ‘The single species
is Leptocuma Kinbergii, Sars, taken off the mouth of the
Rio de la Plata.

Heteroctima, Miers, 1879, has the eye well developed,
and the second joint of the third maxillipeds produced.
It has the single species Heterocuma Sarsti, Miers, with a
variety, granulata.

Family 3.—Leuconide.

The form is generally slender with elongate pleon. The
eye is wanting. ‘The first antenna have one of the flagella
small, one-jointed. The anterior branch of the mandibles
is without the usual series of spines, the molar tubercle
is massive. ‘The ‘ palp’ of the first maxille has a single
terminal seta. The epipod of the first maxillipeds has few,
finger-like branchial sacs. ‘The third maxillipeds are
rather short, with some strong sete on the outer margin.
The first three pairs of pereeopods in the female and the
first four in the male have well-developed swimming-
branches. ‘The second pair of perzeopods are only six-
jointed. There are only two pairs of pleopods in the male.
The inner branch of the uropods is two-jointed, spinose,
the outer being setose. The telson is wanting.

The family contains three genera.

Leucon, Kroyer, 1846, has the body slender, the pseudo-
rostral projection distinctly prominent, and the
first antennee not geniculate. There are eleven
species known, of which the oldest Leucon nasica,
Kroyer, has been recorded from British waters.

LEUCONIDA—NANNASTACID © 505

Fudorella, Norman, 1867, is a name substituted for
the preoccupied Hudora, Spence Bate, 1856. It
has an oval orifice between the antero-lateral lobes
of the carapace, the pseudo-rostral projection
wanting, and the first antenne geniculate between
the last two joints. It contains eight species,
among which Kudorella emarginata (Kroyer) and
Kudorella truncatula (Spence Bate) are British.

Hudorellopsis, Sars, 1882, has the body short and stout,
the median lobe of the carapace not excavate, and
the first antennze geniculate between the first two
joints. It contains two species, Hudorellopsis de-
formis (Kroyer) and Eudorellopsis integra, S. I.
Smith.

Family 4.—Nannastacide.

There may be either one eye or two eyes. The first
antennz are alike in both sexes, the flagella very unequal,
the smaller one- or two-jointed. The flagellum of the second
antenne in the male has rather long slender joints.
The mandibles have few spines on the anterior branch.
‘The epipod of the first maxillipeds has the branchial sacs
in the female very slightly developed. The third maxil-
lipeds have the terminal part irregularly flexuous. The
first two pairs of perzeopods in the female and the first
four in the male have well-developed swimming-branches.
The last three pairs of peraeopods are very slender and
end in a curved finger. The pleopods are wanting in
both sexes. The inner branch of the uropods is one-
jointed. The telson is wanting.

Sars calls this family the Cumellide, but Spence
Bate’s name Nannastacidze has clear priority. It contains
three or four genera.

Nannasticus, Spence Bate, 1865, means ‘a dwarf lob-
ster.’ It has two distinct compound eyes. The carapace
is broad in front or with elongate pseudo-rostrum. The
British species, Nannastacus unguiculatus, Spence Bate, and
Nannastacus Suhmi, Sars, from the Philippines, have the

23

06 A HISTORY OF RECENT CRUSTACEA

oy)

peduncles of the uropods very short, but the Mediterranean
Nannastacus longirostris, Sars, has these peduncles tolerably
long. Kossmann has instituted Nannastacus Sarsu from
the Red Sea.

Diops, Paulson, 1875, as its name implies, has two
separate eyes, and may be the same as Nannastacus, but
the species parvulus and spinosus are represented with the
carapace much narrowed in front, and it is difficult to
make them agree with any recognised species of Nan-
NAStacus.

Cumella, Sars, 1865, has but one eye. Of the two
species, pygmea, Sars, and limicola, Sars, the former is
found in British waters.

Spencebatea, Norman, 1879, has the uropods greatly
developed, with the peduncle much longer than the
branches, although the inner of these consists of a long
joint and a greatly developed terminal spine. Canon
Norman informs me by letter that it has an eye. The
single specimen, measuring a sixth of an inch, of the single
species, Spencebatea abyssicola, Norman, was taken in
1,360 fathoms, in lat. 54° 53’ N., long. 10° 56’ W., west
of Donegal Bay.

Family 5.—Campylaspide.

The carapace is strongly arched behind. The first
antenne are alike in both sexes, with one of the flagella
obsolete. ‘The flagellum of the second antennz is com-
posed of long and slender joints. The mandibles have
the anterior branch obliquely truncate and toothed, the
molar process narrow, stiliform. The first maxille are
very large, the second feeble. The terminal part of the
first maxillipeds is obsolete, the narrow epipod has the
branchial sacs arranged in a semicircle. The second
maxillipeds have the penultimate joint swollen. The
third maxillipeds closely resemble the first peraeopods. -
The first two pairs of peraeopods in the female and the
first four in the male have well-developed swimming-
branches. The pleopods are wanting in both sexes. The

—~
y =

CAMPYLASPIDEZ—PSEUDOCUMID® 807

inner branch of the uropods is one-jointed. The telson is
wanting.

The single genus, Campylaspis, Sars, 1865, is well
marked by the enormous development of the carapace,
which usually bulges backward over some of the free
segments of the trunk. Sars has found in this genus the
liver consisting of only a single pair of ceecal tubes instead
of three pairs. Thirteen species have been described,
eleven of them by Sars himself, the other two being
rubicunda (Lilljeborg) and carinata, Hansen. Campylaspis
costata, Sars, has been recorded from the Clyde by Mr.
Thomas Scott, F.L.S.

Fumily 6.—Pseudocumide.

The first antennz have oue of the flagella rudimentary.

_ The flagellum of the second antennz is composed of rather

long slender joints. The anterior branch of the mandibles
has few spines. ‘The epipod of the first mavxillipeds has
only slight traces of branchial sacs. ‘The first two pairs
of perzeopods in the female and the first four in the male
have well-developed swimming-branches. The male has
but a single pair of well-developed pleopods. The inner
branch of the uropods is one-jointed. The telson is dis-
tinct, but very small, and unarmed.

The family contains two genera.

Pseudoctima, Sars, 1865, has an eye; there are two-
jointed rudimentary exopods on the third and fourth pairs
of pereeopods in the female, and in the male rudimentary
pleopods on the second segment of the pleon, and plumose
setee in place of pleopods on the third, fourth, and fifth
segments. Pseudocuma longicornis (Spence Bate) is an
abundant British species, often spoken of as Pseudocuma
cercaria (van Beneden), but Bate’s name is the older. In
speaking of the species as British, it will be understood
that there is no intention to exclude any number of other
localities. Pseudocuma ciliata, Sars, is the only other
species in the genus, and this it would be better to call
ciliatus, since, if the gendér of the generic name is
ettended to, it would rather become ciliatum than ciliata.

308 A HISTORY OF RECENT CRUSTACEA

For Sars’s Petaloméra, 1882, and Petaldpus, 1865, both
preoccupied, I propose Petalosarsia. It has no eye. The
last segment of the trunk is firmly united to the preceding.
The first pereeopods are devoid of the seventh joint and
have the so-called merus or fourth joint like a petal or
leaf, an expansion which is unique. ‘There are no rudi-
mentary exopods on the third and fourth pleopods of the
female, nor rudimentary pleopods on the second to the fifth
pleon-segments of the male. The single species is Petalo-
sarsia declivis, Sars, from the Lofoden Islands and Spitz-
bergen. It has been recently taken in the Firth of Forth.

Strauchia, Czerniavsky, 1869, is described as having
exopods on the second and third perzeopods in the female,
and none on the first, which would require for it the
institution of a separate family, Strauchide. But pro-
bably allowance should be made for some mistake in the
description, as the single specimen of the single species,
Strauchia taurica, Czerniavsky, is said to be about a
twenty-fifth of an inch long! A small distinct telson is
attributed to it, which rather points to its position among
the Pseudocumide, but this species from the Black Sea is
at present involved in obscurity.

Family 7.—Lampropide.

The first antenne have both flagella well developed
and nearly equal. ‘The flagellum of the second antennz
in the male is composed of many short joints. The epipod
of the first maxillipeds has few finger-shaped branchial
sacs. ‘The first two pairs or only the first pair of pereo-
pods in the female and the first four pairs in the male
have well-developed swimming-branches. In the male
there are three pairs of pleopods or none. The branches
of the uropods are very slender, the inner three-jointed.
The telson is distinct, with three or more terminal spines.

There are five genera.

Lamprops, Sars, 1863, meaning ‘ bright-eyed,’ has the
flagellum of the second antenne in the male relatively
short and prehensile; the third and fourth perezeopods in

THE LAMPROPID® 309

the female carry rudimentary exopods in the shape of
two-jointed setiferous appendages; the male has no pleo-
pods. Lamprops fasciata, Sars, is found in Great Britain
as well as Norway. In the female the carapace has three
oblique lateral folds. ‘The telson terminates in five spines.
Lamprops fuscata, Sars, has the carapace smooth in both
sexes. Lamprops quadriplicata, 8. 1. Smith, from the north-
east coast of America, has four lateral folds on the carapace.

Hemilamprops, Sars, 1882, has the flagellum of the
second antennz in the male filiform and as long as the
body ; the third and fourth pereeopods in the female with
rudimentary exopods; and three pairs of pleopods in the
male. Hemilamprops rosea (Norman) is British and Nor-
wegian. It has the telson ending in seven or eight spines.
Hemilamprops cristata, Sars, from the same localities, has
the telson ending in three spines, in which it agrees with
the Norwegian Hemilamprops uniplicata, Sars. The re-
maining species, Hemilamprops assimilis, Sars, has the eye
rudimentary, and the telson ending in six spines.

Paralamprops, Sars, 1887, has no eye. The first maxille
are without ‘ palp,’ this defect being unique in the sub-
order. The third and fourth perzeopods in the female have
rudimentary two-jointed exopods, and the male has three
pairs of pleopods. The single species, Paralamprops ser-
rato-costala, Sars, was obtained by the Challenger at Ker-
guelen Island.

Platyaspis, Sars, 1870, has no eye. Only the first pe-
reeopods in the female have swimming-branches, instead of
the first two pairs as in the preceding genera of this
family. The male has three pairs of pleopods. ‘The single
species 1s Platyaspis typica, Sars.

Chalarostylis, Norman, 1879, has the flagellum of the
second antennee in the male reaching to the end of the
trunk. There are three pairs of pleopods in the male.
The uropods are remarkably long and slender. The telson’
is short, ending in three spines. The female is unknown.
Chalarostylis elegans, Norman, taken by the Poreupine
off Rockall, in 109 fathoms, is the only species. It may
or may not have an eye, but none has yet been perceived.

310 A HISTORY OF RECENT CRUSTACEA

Family 8. —Diastylide.

The first antennze are more or less unlike in the two
sexes, the flagella unequal, the smaller being three-jointed
in the female. The anterior branch of the mandibles has

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of female [ Hansen],

a dense series of lateral spines. The epipod of the first
maxillipeds has the branchial sacs arranged more or less.
spirally. The third maxillipeds have the second joint very
large and curved. The first two pairs of peraecpods in the
female and the first four in the male have well-developed
swimming-branches. ‘There are only two pairs of pleopods
in the male, and of these the second is sometimes imper-
fectly developed. The uropods have the inner branch
‘two- or three-jointed. The telson is distinct, generally
narrowed terminally, with only two spines at the apex.

The family includes three genera.

Diastylis, Say, 1818, is the earliest in date of the
Cumacean genera, and in Lepechin’s Oniscus scorpioides,

THE DIASTYLID/ 3ll

1780, it. possesses the earliest in date of the Cumacean
species, unless the doubtful Gammarus esca, Fabricius,
1779, be allowed precedence. The name is evidently
based on a Greek word meaning ‘ with an interval between
the columns,’ and in this Greek word the penultimate
syllable is long, but the interval referred to is not really
between columns, as implied by the Greek styl, but
between the stilets or slender-branched uropods, to which
the Latin word stili is appropriate. But to pronounce the
name as Diastilis in accordance with this correction would
make a hybrid of it, and it cannot therefore be recommended.
This genus has the second antennz in the male very fully
developed, attaining the length of the body. The third
and fourth pereeopods in the female have no rudimentary
exopods. The genus is widely distributed, and includes
thirty species or more. Several of these are recorded by
Norman, Robertson, and others, from British waters, as:
Diastylis Rathkii (Kroyer), Diastylis cornuta, Boeck, Dia-
stylis insignis, Sars, Diastylis echinatus, Spence Bate, Dia-
stylis biplicata, Sars, Diastylis spinosa, Norman, Diastylis
levis, Norman, Diastylis rugosa, Sars, Diastylis tumida
(Lilljeborg), Diastylis lamellata, Norman.

Leptostylis, Sars, 1869, has the second antenne of the
male less fully developed than in the preceding genus,
and has rudimentary exopods on the third and fourth
pereeopods in the female. The genus includes six species,
of which Leptostylis producta, Norman, is British.

Diastylopsis, S. 1. Smith, 1880, like Diastylis, has no
rudimentary exopods on the third and fourth pereeopods of
the female, but it is distinguished by the unique character
of having the third and fourth free segments of the perzeon
consolidated. To the American species, Diastylopsis Daw-
soni, Smith, must be added Diustylopsis resima (Kroyer),
which is well marked by the upturned nose or pseudo-
rostrum, to which the specific name refers.

By aid of the accompanying table the student will be
able to assign his specimens to their proper families, which
will be found a very useful preliminary to the more dif_i-
cult task of discovering the genus and the species :—

A HISTORY OF RECENT CRUSTACEA

312

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A TABLE FOR STUDENTS 3138

According to the table the family can always be as-
certained by the external characters, except in the case
of the females of the Vaunthompsoniidee and Leuconidee,
and there the eye is generally available, since it is absent
from all the Leuconidze, and indistinct only in one genus,
Leptocima, of the Vaunthompsonide. The Campylaspide,
which in the table are but slightly distinguished from the
Nannastacide, are strongly distinguished externally both
from them and all other Cumacea by the backward bulging
carapece, as also by the stiliform molar process of the
mandibles and internally by the single pair of liver
tubes.

The genealogical relationships of the Cumacea are ob-
scure. ‘l'he second antenne of the male resemble what is
often seen in the Amphipoda. The epipod of the first
-maxillipeds helps the respiration, as in the Myside and
cheliferous Isopods, but with the important addition of
sessile branchial sacs. In the swimming branches on
some of the perzeopods there is a weighty resemblance to
the Mysidz. ‘The mouth-organs make some approaches
to those of the Isopoda, and, as with them, the young are
hatched before the development of the last pair of perzeo-
pods. The pleon recalls’ the paleozoic Phyllocarida and
their existing representative Nebalia.

It will have been seen by the number of genera and
species to which the name of G. O. Sars is attached that
he has made a special study of this sub-order, and this
sketch of it is deeply indebted to his numerous and lum1-
nous works upon the subject, to which, indeed, must be
credited the clearness and accuracy with which this small
but very interesting group is now known.

314 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXI

ISOPODA

Tribes. , Families
{ Apseudidee
| Tanaidee

-- | Anthuridz

Chelifera . hs . : - .

Gnathiide .
4 Cirolanidze
| Corallanide @
, Alcironidee
|{ Flabellifera . ; ‘ e . + Barybrotidze
.- Agide
Cymothoide ,
Serolidz
| Sphzeromidze
-\Limnoriidie
cf Arcturidze
* | Idoteidee

| —f Asellidee ee at
2 Asellota . . : : * *.\ Munnopsidze a

Cymothoid
group

7 Valvifera : ; : E :

| Phreatoicidea. ‘ : : ~~ Phreatoicidse

Microniscidze
~| Cyproniscidee
| Dajidee
jf Epicaridea .. . » +» « ~ +4 Cabiropsidz
[een
Entoniscidas
Bopyridze YOs
~y Ligiidee
SJ Ty lide
Oniscoidea . R ; ; . »™ Helleriidz
| Oniscidee ,
~\ Armadillididas

Suborder 2.—Isopoda.

THE Isopoda form a vast and widely distributed army.
In contrast with the distinctive uniformity of the Cumacea,
they exhibit an extreme diversity of shape. The name was

KEEPING DARK '° 815

formed by Latreille from the Greek words tcos, equal, and
movs, a foot, but, so far from the legs being all alike or
equal as the name would imply, these appendages often
have two or three very different developments in a single
animal. Thereis, to be sure, a typical form of limb which
- prevails very widely, but the exceptional forms are nume-
rous and remarkable. With these Latreille was unac-
quainted, and therefore naturally gives no clue to them in
the name Isopoda, which he himself interprets as signifying
‘tous les pieds simples et uniquement propres a la locomo-
tion ou dla préhension.’ In proportion to their importance
in the economy of the world the Isopoda have hitherto
attracted little of popular notice. They enjoy still less of
popular favour. ‘ihey are all of retiring habits, never
needlessly courting attention, but in general clinging as
‘closely as possible to whatever shelter or holdfast they
have adopted. Amidst enormous disparities of size and
strength and shape and temper, this prudent love of ob-
scurity, the one feature of the moral character which all of
them possess In common, is strong evidence that all of
them must have sprung from a common origin. They
have never tempted mankind to search for them as food.
The services which they doubtless often render as effective
scavengers are In some measure counterbalanced by the
damage which some of them inflict on submarine structures
and the depredations committed by others on the fruits
of the garden. Several of the species treat their fellow-
inhabitants of the sea with little ceremony, and make up for
smallness of size by ferocity of behaviour. It is only to be
hoped, as indeed it may be considered certain, that their
living victims are immeasurably less sensitive to pain than
ourselves.

Normally the members of this sub-order have anelongate
ventrally flattened body, divided into a head of six seg-
ments under a carapace, a trunk or perzeon of seven arti-
culated segments, and a pleon usually limited to six
segments. As in all the Edriophthalma, there is no ap-
preciable ocular segment. The carapace is occasionally
in coalescence with one or two of the segments of the

a

316 A HISTORY OF RECENT CRUSTACEA

pereon. The six segments of the pleon may be all
articulated, or some or all of them fused together. The
seventh segment or telson is scarcely ever free, but its in-
dependent existence is indicated in the peculiar genus
Phreatoicus, and in one tribe, the Flabellifera, its presence
may generally be inferred ‘from the attachment of the
uropods high up on the sides of the terminal segment,
while a few of the genera, as Paranthura, have it distinctly
articulated.

A pair of sessile compound eyes, remote or contiguous,
are usually present, but may be entirely wanting. Occa-
sionally they project from the head, but never on movable
foot-stalks.

The first antennee are never very elongate, and rarely
have a secondary flagellum. The second antennz very
seldom carry an exopod, the articulated scale so common
among the ‘Macrura. The upper lip usually forms a plate
projecting from the top of the oral aperture over the cutting
edges of the mandibles, and may have an inner plate lying
parallel to the outer. ‘The lower lip is bilobed, or forms two
pairs of lobes, of which the inner pair is much the smaller.
The mandibles are very variable, the dentate cutting edge,
secondary plate, spine-row, molar tubercle, and three-jomted
‘palp,’ being sometimes strongly developed, at others, some
or even all of them disappearing. The first maxillee very
rarely have a backward directed ‘palp.’ The second
maxille have neither ‘ palp’ nor exopod ; the outer plate
is divided, the inner undivided. The maxillipeds, of which
the first are in this and the next sub-order the only pair,
often have an epipod on the first jomt. This first joint as
a rule stands free in each maxilliped, the pair not being
fused together. The plate developed from the second
_ joint is provided with coupling spines. For the limbs of
the trunk it is difficult to find any characters that are at
all constant through the sub-order. Dr. Boas in his defi-
nition (1883) says that these seven pairs are strong running-
feet with a spine at the point of the terminal joint; that
the basal joint is always small, the second joint long, the
third in the Tanaidew smaller than those which follow,

STRUCTURE OF THE ISOPODA oie

eisewhere almost of the same size as these. But the ex-
ceptions to this statement are exceedingly numerous.
Occasionally the first pair are opercular ; often they have
the form of gnathopcods, that is to say, they are prebensile
instead of ambulatory. Sometimes they are weak and
slender, and agree in character with the three following
pairs, at others they agree with only the next two pairs.
Rarely the last three pairs are adapted for swimming in-
stead of walking. The comparative lengths of the joints
are also subject to much variation, although the second
joint is scarcely ever shorter than the first or the third, the
seventh pair of legs in Phreatoicus typicus, Chilton, and
the first pair of the male in one or more species of Munna,
offering perhaps rare exceptions. Marsupial plates are de-
veloped in the females in varying number. The pedun-
cles of the pleopods often carry coupling spines. The two
first pairs of the pleopods are often modified in the male
as sexual organs. Usually the inner branch in some of
the pairs is branchial. All the pairs are sometimes want-
ing. The uropods vary greatly both as to shape, function,
and their position on the sixth segment. The liver is said
to consist of four or six backward-directed tubes. The
heart is generally but not always elongate, and usually in
part situated inthe pleon. The ovaries and testes are with-
out a median section. The young usually quit the brood-~
pouch with the last peraeopods still undeveloped.

While in the Cumacea the pleon is in general very
considerably narrower than the trunk, in the Isopoda this
is only rarely the case, and sometimes the pleon even ex-
ceeds the trunk in breadth.

Definiticn of the Sub-order Isopoda.

The cephalon or carapace with rare exceptions leaves
free seven segments of the trunk. There are no branchial
sacs In Gon with the first maxillipeds, although these
occasionally assist the respiration. - Usually some of the
pleopods have a branchial character. None of the last five
pairs of trunk-limbs have natatory exopods. The first

318 A HISTORY OF RECENT CRUSTACEA

three and generally the first five segments of the pleon are
short, whether fused or articulated ; the sixth comprising
the telson is usually the largest, and its appendages con-
stitute the only pair of uropods. The pleopods when
present are almost always closely overlapping.

Instead of being contented with the single genus
Oniscus, as in the first edition of Linneeus’s ‘System of
Nature,’ the Isopoda now occupy seven tribes, several of
which are of great extent. These are named respectively
Chelifera, Flabellifera, Valvifera, Asellota, Phreatoicidea,
Epicaridea, and Oniscoidea.

Tribe 1.—Chelifera.

This first tribe, the ‘claw-bearing’ Isopods, is a com-
paratively small one, but it has many peculiarities and is
controversially interesting. It has to do with narrow,
subdepressed, or subcylindrical animals, in which the head
is united with the first or even the first and second seg-
ments of the perwon. The segments of the pleon are
sometimes fused together, and in that case the pleopods
are wanting. Otherwise these appendages are generally
present, and consist of a two-jointed stem and two un-
jointed branches, but differing from those of the Isopoda
in general in being swimming rather than branchial
organs. In this tribe respiration is carried on by means
of a branchial chamber situated under the sides of the
‘ carapace to the rear. The first maxillee have a backward-
directed ‘palp’ similar to that described in the Cumacea,
and no doubt fulfilling the same function of cleansing the
branchial chamber from obstructions. It is supposed to
be a part of the endopod turned backwards. The maxilli-
peds have also a remarkable structure directed backward
into the branchial chamber. This by its attachment to
the first joint is recognised as the epipod. By its rhyth-
mical movement to and fro within the cavity it maintains
a constant influx of water for the oxygenation of the
animal's blood. In evident connection with this respira-
tory process in the front part of the body is the circum-

ae

ISOPODS WITH FINGER AND THUMB 319

stance that the heart occupies the earlier seements of the
pereeon, whereas in those Isopoda which have branchial
pleopods, the heart is correspondingly situated in and ©
near the pleon. ‘The tribal name refers to the fact that
the first pair of trunk-limbs, or gnathopods (corresponding
to the second maxillipeds of preceding descriptions), are
furnished with a chela, the two terminal joints forming an
opposed thumb and finger as in the familiar chelipeds of
crabs and lobsters, a character not met with in the rest of
the Isopoda. ‘The uropods are slender, the branches often
flagelliform. The eggs are carried in a marsupium of thin
plates, which either form one pair attached to the fourth
free seoment alone, or four pairs attached to four segments.
The tribe includes only two families, the Apseudide
and Tanaide, distinguishable by numerous ¢haracters both

‘external and internal.

Family 1.—Apseudide.

The body is depressed, the carapace generally having
a well-developed rostrum and carinate sides, with pyriform
or spine-like ocular lobes. The segments of the pleon are
well defined, narrower than those of the perzeon.

The first antenne, placed at the front corners of the
carapace, are remarkable in this sub-order by having two
many-jointed flagella. The second antennze with the
bases contiguous are placed between and below the first, —
and are often furnished with an articulated scale, ciliated
all round. ‘The flagellum is many-jointed.

The mandibles have a three-jointed ‘palp.. The first
maxillee have two incisive lobes and a two-jointed back-
ward-directed ‘ palp,’ ending in two or more setz. The
second maxillez are furnished with setze and spines. The
maxillipeds have a large laminar epipod, branchial in
function. The first gnathopods are strong and chelate,
the inner margins of the finger and thumb being usually
tuberculate in the male and serrate in the female. The
second gnathopods are fossorial, having the last three
joints, especially the penultimate or ‘hand,’ flattened, the

320 A HISTORY OF RECENT CRUSTACEA

flattened spines being of use for specific distinctions. One
or both of the pairs have usually small two-jointed exopods.
The pereeopods are slender, with many sete and spines.
~The pleopods have two long setiferous branches, and the
uropods two that are many-jointed and filiform, the inner
elongate.

The small exopods above mentioned, when seen only
in cabinet specimens, might be considered rudimentary or
of little importance. But this would not be a right way
of regarding them. ‘The branchial chamber has two little
openings, one for the entrance, the other for the exit of
the water used in breathing. In front of the latter of
these orifices in the hving animal, M. Yves Delage points
out that the exopods of the first gnathopods with their
terminal sete vibrate so rapidly that the machinery can
with difficulty be seen, while those of the second gnatho-
pods behave in the same manner in front of the entrance
apertures. By this contrivance a lively current of water
is introduced to the branchial chamber, and, when its
virtue has been exhausted, the parting guest is speeded to
a convenient distance. When there is only one pair of
exopods, it is those at the gate of egress which remain,
and it is no doubt of less importance that the entering
current should be rapid than that the used-up water
should be effectively dismissed.

Five genera are at present assigned to this family.
The ocular lobes are not movable, as they were at one
time supposed to be.

Apseudes, Leach, 1814, has six segments of the trunk
free, a well-developed scale on the second antennze, a well-
developed ‘ palp’ on the mandibles, exopods on both pairs
of gnathopods, and five pairs of pleopods, with both
branches usually one-jointed.

Parapseudes, Sars, 1880, has six segments of the trunk
free, the antennal scale rudimentary, the mandibular
‘palp’ very small, exopods on both pairs of gnathopods,
and only four pairs of pleopods, which have one of the
branches two-jointed. The single species is Parapseudes
latifrons (Grube) from the Mediterranean. It was at one

THE APSEUDID 321

time supposed to be without exopods on the first two pairs
of limbs.

Sphyrdapus, Norman and Stebbing (in Sars), 1880, has
only five segments of the trunk free, no antennal scale, -
exopods on the first, and sometimes if not always on the
second, pair of gnathopods, and five pairs of pleopods.

Typhlapseudes, Beddard, 1886, ‘the blind Apseudes,’
shares a want of eyes with the genus Sphyrapus and with
some species of Apseudes. Six segments of the trunk are
free. It has a small antennal scale, but is said to be with-
out exopod on either first or second gnathopods. ‘There
are five pairs of pleopods, in which one of the branches is
two-jointed.

Lewpus, Beddard, 1886, ‘the smooth-footed,’ has six
free segments of the trunk, a rudimentary antennal scale,
a minute three-jointed exopod on the gnathopods of both
pairs, and five pairs of pleopods, in which one of the
branches is two-jointed. The type-species, Lewopus lepto-
dactylus, is described as having three joints to the palp of
the first maxille, but ‘the very short median joint’
seems open to some suspicion.

The earliest known species of this family is Apseudes
talpa (Montagu), first recorded from Devonshire, but also
occurring in the Mediterranean. From Apseudes Latreillia
(Milne-Edwards), also a British species, it may be distin-
guished by the serrate first joint of the first antennee, the
spines on the epistome and on the ventral surface of the
pereeon-segments, and the elongation of the last segment
of the pleon. Other species, such as Apseudes simplici-
rostris, Norman and Stebbing, ‘taken in 1,263 fathoms,
about one hundred miles directly south of Rockall, Porcu-
pine Expedition, 1869,’ and Apseudes grossimanus, Norman,
from 90 fathoms, long. 11° 40’ W. off the south-west
coast of Ireland, may be technically regarded as British,
but these and others in like circumstances seldom come
into the hands of any students but those who will prefer
to consult the original memoirs for their characteristics.
Sphyrapus malledlus, Norman and Stebbing, alludes both
by its generic and its specific name to the hammer-like

24

322 A HISTORY OF RECENT CRUSTACEA

appearance of the first gnathopods, especially in the male,
in which sex the huge hand is set on at right angles to
the preceding handle-like joint. Like Sphyrapus tudes, of
the same authors, it has been taken off the west of Ireland.
From the latter species it is distinguished by the great
extension of the lateral processes on the second segment
of the pleon. .

In both of these species there are exopods on both
pairs of gnathopods, but, according to Sars, they are absent
from the second pair in his species, anomalus and serratus.

Family 2.—Tanaidee.
The body is nearly parallel-sided, the carapace being

truncate in front or with a minute rostrum, with or without
ocular lobes and eyes. The perzeon and pleon are without
spiny armature. ‘The pleon is seldom narrower and some-
times broader than the pereeon. The first antenne are
contiguous, with a single flagellum, which is rudimentary
or sometimes wanting or rarely well developed in the
female, but multiarticulate in the male. The second
antennee are smaller than the first and below them, with-
out scale, and with the flagellum rudimentary or rarely
well developed. The mandibles have no ‘palp.’ The first
maxillee have one incisive lobe and a one-jointed ‘palp’
usually ending in two sete. The second maxille form
minute rudimentary unarmed lobules. The maxillipeds
are fused at the base, and usually have a narrow falci-
form epipod. The masticatory organs are, however, often

evanescent in the adult male. The gnathopods are with- —

out exopods. In the first pair the second joint is large
and tumid, and in the adult male the sixth joint or hand
becomes so much developed that it seems to crowd the
mouth-organs out of existence. The second gnathopods
are ambulatory like the following limbs. The pleopods
have two short setiferous branches, or are rarely absent.
The uropods are either simple or furnished with two fila-
ments, of which the outer is always short, having one, two,
or at most three, joints.

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Within recent years the genera of this family have
become tolerably numerous. Many of the species are
quite microscopic, and in some instances an impatient
observer may be tempted to suppose that the distinguish-
ing features even of the genera have been invented to
match the size of the specimens. But in most cases such
a criticism will be withdrawn upon a more careful in-
spection.

Only a few selected characters can here be offered to
discriminate the fifteen (or rather, the fourteen) genera
that have been established :—

+ Tanais, Audouin and Milne-Edwards, 1829, has eyes,
several setae on the ‘ palp’ of the first maxille, the marsu-
plum of the female consisting of two large plates affixed
to the fourth free segment of the perzeon, only three pairs

‘of pleopods, and the uropods simple, the single branch

being two- or three-jointed.

A Leptochelia, Dana, 1849, has two setz on the ‘ palp’ of
the first maxille, the first gnathopods of the adult male
with very elongate thumb and finger, the marsupium of
the female consisting of a pair of plates on each of the
first four free segments, five pairs of pleopods, and in the
uropods a multiarticulate inner and a one-jointed outer
branch.

4 Heterotanais, Sars, 1880, scarcely differs from Lepto-
chelia, except in the first gnathopods of the male, which
are incompletely chelate, the so-called thumb being very
little instead of enormously produced. In the uropods the
outer branch is little but) two-jointed, the inner filiform,
with four or five joints.

4 Paratanais, Dana, 1852, has eyes, but nae distinct
ocular lobes. The mandibles are strong in the female,
with cylindrical molar process, whereas in the male all the
mouth-organs, except the maxillipeds, are lost. The first
gnathopods are similar in the two sexes. Of the uropods
both branches are two-jointed.

5Pseudotanais, Sars, 1880. The eyes are imperfect or
absent, and there are no ocular lobes. The mandibles
have a stiliform molar. The maxillipeds are fused at the

324 A HISTORY OF RECENT CRUSTACEA

base, a single central plate issuing between the ‘ palps’
from the fused second joints. The marsupium is like that
in Tanais. There are five pairs of pleopods in the male,
and five or none in the female. The uropods have both
branches two-jointed.

6 Typhlotanais, Sars, 1880, is without eyes or ocular
lobes. The mandibles have a thick cylindrical molar in the
female. In the male the mouth-organs disappear as in
Paratanais. The marsupium has the usual four pairs of
plates. There are five pairs of pleopods in both sexes.
Both branches of the uropods are two-jointed, or one or
other of them may be one-jointed..

7 Leptoqnathia, Sars, 1880, has no eyes or ocular lobes.
The mandibles are weak, with a feeble pointed molar in
the female. The mouth-organs of the male and marsu-
pium of the female and the pleopods are as in the preced-
ing genus. Of the uropods the inner branch is two-
jointed in the female, three-jointed in the male, the outer
much smaller, two- or one-jointed, sometimes rudimentary.

¢ Alaotanais, Norman and Stebbing, 1886, has minute
ocular lobes, but no eyes. ‘The mandibles are strong, with
large molar, at least in the female, the full-grown male
being probably content with the maxillipeds for mouth-
organs. ‘The marsupium and pleopods are as in the pre-
ceding genus. The first gnathopods are powerful, espe-
cially in the male, much like those of Leptochelia. Of the
uropods the inner branch is eight- or nine-jomted, the
outer two-jointed.

1 Neotanais, Beddard, 1886, is no doubt the same genus
as the preceding. Both were published by the Zoological
Society of London in the same year. The deseription of
Alaotanais was received Nov. 5, 1884, read Dec. 2, 1884, |
and published in October 1886. Neotanais was, I believe,
received and read considerably later, but actually published
earlier. Mr. Beddard mentions ‘ mandibles with the usual
structure, with a slender extremity and a stout molar
process.’ His only specimens were males, but not perhaps
at the stage when the mandibles would be lost.

Bathytanais, Beddard, 1886, has distinct ocular lobes,

oF a

SOME BLIND GENERA 325

with eyes well developed, and the first and second antennze
four-jointed apparently in the male as well as in the
female. The male is thought to be distinguished chiefly
by a more elongate pleon. The single species is repre-
sented by one small specimen supposed to come from
2,050 fathoms in Mid Pacific, and other specimens from
between 2 and 10 fathoms at Port Jackson in Australia.
1@ Tanaella, Norman and Stebbing, 1886, has no eyes
and no distinct ocular lobes. There are no pleopods in
the female, and the uropods are simple, the single branch
being also single-jointed. ‘The male is unknown.

| Strongylara, Sars, 1880, has no eyes and no distinct
ocular lobes. The mandibles have the molar moderately
large, laminar. There are no pleopods in the female. In
the uropods the inner branch is two-jointed, the outer

. one-jointed.

)A Cryptocdpe, Sars, 1880, like several of the preceding
yenera 18 without eyes. The mandibles have the molar
sublaminar, unarmed, and on the right hand mandible
there is a very prominent secondary plate. The segments
of the perzeon are divided by deep instrictions. The pleo-
pods are well developed in the male, rudimentary in the
female. The uropods in the male are long, with three-
jointed inner, and two-jointed outer, branch; in the
female short, with two-jointed inner, and one-jointed outer,
branch.

'S Haplocdpe, Sars, 1880, agrees nearly with the preced-
ing genus, except that the mandibles have a cylindrical
molar, of which the truncate apex is encircled with teeth,
and the uropods are moderately long with unequal two-
jointed branches.

'Y Anarthrira, Sars, 1880, is distinguished from all the
foregoing genera by having the pleon unsegmented. There
are no eyes. ‘The hands of the first gnathopods are weak.
There are no pleopods. In the uropods the outer branch
is represented by a conical process not disunited from the
peduncle, the inner branch is two-jointed.

Among the earlier authorities on this family the writ-

ings of Kréyer, Lilljeborg, and Fritz Miiller may be men-

326 A HISTORY OF RECENT CRUSTACEA

tioned as of special importance. For more recent infor-
mation the student should consult Sars’s two papers on the
‘Isopoda Chelifera’ published in 1880 and 1886, and that
py Norman and Stebbing on the Isopoda of the [iyhtning,
Porcwpine, and Valorous Expeditions, in the ‘ Transac-
tions of the Zoological Society’ for the latter year. The
Jast-mentioned paper enumerates thirteen genera and
forty-six species of Tanaidz as occurring in the North-
Atlantic and Mediterranean, T'yphlotanais and Leptognathia
being each credited with ten species and Leptochelia with
five.

Tanais tomentosus, Kroyer, 1842, has been identified
with Tanais vittatus (Rathke), 1843. In Devonshire
in timbers washed by the tide it occurs in company
with Limnoria lignorum and Chelura terebrans. In
America the same association is reported of Tanais filum,
Stimpson, which may, however, be a Leptochelia. ‘The
Egyptian species, Tanais Dulongit (Audouin), is by Bate
and Westwood enrolled in the fauna of Devonshire, though
their only specimens came from Polperro, in Cornwall.
They are with some reason doubtful about the identifica-
tion, and the rediscovery of their species in Great Britain
is still awaited. They curiously include in the synonymy
the Tanais Dulongw of Thompson and of White, though
acknowledging in the text that these Irish specimens had
proved to be mutilated Amphipods. They speak of the
third perzeopods, or fifth pair of trunk limbs, in this
species as carrying branchial organs, which would be a
pecuharity of no little importance, were it not practically
certain that the supposed branchize were merely the mar-
supial plates of a female specimen.

The species which Bate and Westwood name Leptochelia
Hidwardsii (Kroyer) should rather be called Leptochelia
Savignyt (Kroyer), as the earlier description belongs to
that name. Kréyer’s Tanais Edwardsii is the male of the
same species. Leptochelia alqicéla, Harger, from New Eng-
land, is, according to Sars, in the female a synonym of this
species. while in the male it is a synonym of Leptochelia

dubia (Kroyer). Fritz Miller, and after him Dr. Dohrn,

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MARRIAGE CUSTOMS 30%

supposed. that in Tanais dubius, Kroyer, there were two
forms of the male, but Sars considers that of the two
supposed forms one is Leptochelia dubia and the other
Heterotanais anomalus, Sars. He has not found any true
dimorphism in the males of any of the Tanaide. The
distinction between Leptochelia Savignyi and Leptochelia
dubia is itself open to some doubt. M. E. Chevreux has
sent me specimens from Villefranche, the males of which
have gnathopods, such as Kroyer attributes to the
Edwardsii and Sars to the Savigny: form, that is, with the
teeth on the thumb very wide apart, but on the other
hand they have the first antenne, such as Sars attributes
to the dubia form, with a curve at the base of the first
joint, and with a flagellum, not indeed of nine joints, but
of eight. These antennz agree with Kréyer’s description
of Hdwardsw and also with the figure and description by
Bate and Westwood, so that, unless Sars has himself for
once made a confusion, the males of dubia and Savignyt
would seem to be undistinguishable in regard to the first
antennz, not necessarily at every stage of existence, but
at some stage. Since the marital Tanaid frequently
sacrifices his mouth-organs to the enormous develop-
ment of his chelipeds, he must, as Norman observes,
either reacquire his feeding apparatus at a subsequent
moult, or else die of inanition. The alternation of form
in the same individual is not improbable. It is, of course,
quite distinct from dimorphism. To Heterotanais Sars
assigns the American species Leptochelia limicola, Harger,
and the New Zealand Paratanais tenuis, Thomson, and
with Heterotanais Orstedi (Kroyer) he identifies T'anais
curculio, Kroyer, 6, Tanais balticus, Fritz Miiller, 2, and
Tanais rhynchites, Fritz Miller, ¢. The species which
Bate and Westwood call Paratanais forcipatus (Lilljeborg)
should be named Paratanais Batei, Sars, and their Para-
tanais rigidus has now become Leptognathia rigida (Bate
and Westwood). Leptognathia laticaudata, Sars, has been
recently taken in the Clyde, and Leptoguathia Lnlljeborgi,
Stebbing, is found in North Devon. The deep-sea species,
Alastanais (or Neotanais) serratispinosus and Alaotanais (or

328 A HISTORY OF RECENT CRUSTACEA —

Neotanais) lcevispinosus and Strongylura arctophijlax, all
of Norman and Stebbing, taken off the coast of Ireland,
may be regarded as British. The last, however, is not
very markedly distinct from the Norwegian species,
Strongylura cylindrata, Sars. The Australian species,
Paratanais linearis, Haswell, should perhaps be transferred
to Anarthrura, hitherto represented only by Anarthrura
simplex, Sars, from Norway.

There are difficulties connected with the study of the
Tanaidee, owing to the differences that often exist between
the two sexes, to the likenesses that sometimes exist be-
tween the females of different species, and to the prevailing
minuteness of size, which descends even to one-twentieth
of aninch. That many of the genera are blind is readily
to be explained in connection with their habit of living
ensconced in the sand. When their little white or
pellucid bodies are discerned amidst the fragments of
crystal, shells, polyzoa, foraminifera, and spines of urchins,
it is seen that these components of the sand often exceed the
Tanaids in size. It is not unlikely, therefore, that many of
the species have been frequently overlooked, and that in the
future those already known will be discovered in many
fresh localities, and that many fresh species will eventually
be brought to light.

There is a still pending dispute whether the Tanaidee
should maintain their position among the Isopoda or be
transferred to the Amphipoda, or be separated from both
and raised to the dignity of an independent sub-order. Of
these plans the least advisable seems to be that which
would mix them up with the Amphipoda, for that enormous
group is at present separated from all other Crustacea by
characters of the branchial organs and the pleon, in which
the Tanaide have no share, while the Tanaide, on their
side, have characters of the mouth-organs foreign to all
the Amphipoda. The form and position of the heart,
extending in the Tanaidz from the first to the last segment
of the perzeon, very nearly as in the Amphipod Corophium,
and the other resemblances in the circulatory apparatus of
the two groups, pointed out by M. Yves Delage, afford the

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AN UNSETTLED QUESTION 829

most important argument for the proposed alliance between
them. But the position of the heart, when considered in
connection with the branchial arrangements, points rather
in the direction of the Cumacea than the Amphipoda, and
although in the Isopoda the heart is usually in the pleon,
there are various genera in which it extends more or less
into the peron, thus establishing a gradation to the
Tanaids in which it is wholly there. From the point of
view of embryology. Bate and Westwood say of T’anais and
Apseudes that ‘the development is after the manner of the
Amphipoda rather than that of the Isopoda,’ but in point
of fact, though the curvature of the embryo in the egg
is inward as in the Amphipoda, the young leave the
mother’s pouch with the last pereeopods undeveloped, as
is customary with the Isopoda.

300 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXII

TRIBE II —FLABELLIFERA

THE name refers to the circumstance that in all the
members of this tribe the terminal segment in conjunction
with the uropods forms a caudal fan as in the Macrura,
although here the telson is often not articulated, but fused
with the preceding segment. The heart is situated chiefly
in the pleon, only penetrating one or two of the terminal
segments of the perwon. Respiration is effected by the
help of pleopods acting as branchiz.

The families included are the Anthuride, Gnathiide,
Cymothoide, Serolide, Spharomide, and Limnoriide.
The term Cymothoide is used comprehensively for a
closely connected group of families, as will be explained
hereafter.

Family 1.—Anthuride.

The body is long and narrow, subcylindrical or
depressed. ‘The head is usually shorter than the following
segment. The perzon has its seven segments distinct.
The first five seoments of the pleon may be all distinct or
completely or partially coalesced; the sixth is sometimes
fused with the linguiform telson. The mouth-organs are
suctorial. ‘The first gnathopods are usually the larger,
subchelate; the second gnathopods and first pereeopods re-
sembling them in general form. The other pereeopods are

ambulatory. There appear to be no separate marsupial -

plates. The first pleopods are large, commonly expanded
to cover the rest. The uropods have a two-jointed inner
branch, and the one-jointed outer branch usually so arti-
culated as to arch more or less over the back of the telson.

Pa
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_—

THE ANTHURIDE * Sag

Some eight genera are included in this family. The
first four to be mentioned agree in having two rounded
lobes to the lower lip, the mandibles with a cutting edge
of two or three blunt teeth and a sort of semicircular saw
in place of molar and spine-row, the ‘ palp’ three-jointed ;
the first maxille are simple, with apical teeth, without

‘palp;’ the second are slightly cleft at the apex; the
maxillipeds have from three to six broad flattened joints
including the basal piece.

Anthiira, Leach, 18i4, has the flagella of both pairs of
antenne few-jointed in fe female, of the first multi-
articulate in the male; the maxillipeds three-jointed ; the
first five pleon-segments fused in the female, partially
distinct in the male. The telson is not coalesced with the
preceding segment.

Cyathiira, Norman and Stebbing, 1886, has the flagella
of both antennz rudimentary, of the first perhaps not
greatly developed in the male; the maxillipeds four-
jointed; the first five pleon-segments fused, at least dor-
sally, in the female.

Anthelira, Norman and Stebbing, 1886, has the flagella
of both antenne multiarticulate, of the first pair brush-
like in the male; the maxillipeds six-jointed; the pleon-
segments distinct, and the telson in the type-species
separate from the sixth segment.

Hysstiiva, Norman and Stebbing, 1886, has the flagella
of both antennz multiarticulate; the maxillipeds six-
jointed ; the seventh segment of the perzeon seemingly de-
void of limbs; the first five pleon-segments distinct, fully
half as long as broad ; the pleopods alike, the first pair not
covering any of the following; the uropods with the outer
branch long and narrow, not arching over the narrow
lanceolate telson. The animal is vermiform.

Hiisothistos, Haswell, 1884, has both antennz very
short in both sexes with few-(8-6) jointed flagella; the
first gnathopods not subchelate, smaller than the following
hmbs; the first five pleon-segments short but distinct;
the first pleopods covering the rest; the uropods with
outer branch narrow, not arching over the broad quadrate

S524 A HISTORY OF RECENT CRUSTACEA

telson. The animal, especially the male, is vermiform.
The mouth-organs have not been described. Mr. Haswell
speaks of the outer branch of the uropods as ‘an appen-
dage which is directly articulated with the posterior border
of the segment,’ a very strange peculiarity.

Haliophasma, Haswell, 1880, would seem to be a
synonym of Anthwra, since the species Haliophasma macu-
lata, Haswell, has been described by Chilton under the name
Anthura affinis, and stated by him to be a true Anthura.

Ptilanthura, Harger, 1878, is probably also a synonym
of Anthwra, the one-jointed mandibular ‘ palp’ being due,
it may be supposed, to a defect of the specimen observed.

The next two genera agree in having the lower lip
bipartite but acuminate; the mandibles without teeth,
lancet-like, lobes at the base forming a channel for the
liquid drawn by the thrust of the lancets; the first maxillee .
spear-like, distally channelled and serrate; the maxillipeds
elongate, consisting of four or five joints, the second of
which is elongate.

Paranthura, Bate and Westwood, 1866. The flagellum
of the first antenne in the male forms a large multi-
articulate brush, in the second it is rudimentary. The
mandibular ‘palp’ is three-jointed. ‘The pleon has six
segments and the telson distinct. The outer branch of
the uropods is short, variable in width.

Calathira, Norman and Stebbing, 1886. The antennz
of both pairs in both sexes have many-jointed flagella,
that of the first pair perhaps not greatly developed in the
male. The pleon has six segments and the telson dis-
tinct. ‘The outer branch of the uropods is short and wide,
overarching.

Crurégens, Chilton, 1882. Both pairs of antenne are
short, few-jointed. ‘T’he second pair have a small exopod.
‘There is no mandibular ‘ palp,’ but otherwise the mouth-
organs bear a general resemblance. to those of the two
preceding genera. ‘The seventh segment of the pereeon is
very short and devoid of limbs. The pleon has six seg-
ments and the telson distinct. The outer branch of the
uropods is narrow, not overarching the squamiform telson.

FLORAL TAILS O00

Anthura gracilis (Montagu) was first found on the
coast of South Devon. <Anthura tenuis (Harger) is a
closely allied species found in the United States. The
New Zealand species Anthura jflagellata, Chilton, was
included in the genus with hesitation, owing to the mis-
description in the ‘ History of the British Sessile-eyed
Crustacea,’ in which the uropods are said to be attached
to the fifth instead of the sixth segment of the pleon.
Paranthura Costana, Bate and Westwood, should be called
Paranthura ngropunctata( Lucas). ‘ Anthuwra gracilis,’ Milne-
Edwards, though agreeing with this species in the shape
of the telson, has the first five segments of the pleon fused
as in Anthura. Calathura brachiata (Stimpson) has been
traced ‘ from the east coast of America, across the Atlantic,
between Shetland and Faroe, off Norway, Scotland, and
Ireland, and between the south of England and the Bay
of Biscay. It has been taken as deep down as 1,360
fathoms. It is well marked by a dorsal impression on the
fourth, fifth, and sixth segments of the pereeon, and by
the great size, attaining a length of one inch and an eighth.
It is the largest known species of the family.

Cyuthura carinata (Kroyer) has been described under
various names from the coasts of the United States, and
from Denmark, but not hitherto from any part of Great
Britain.

Anthelura abyssorum, Norman and Stebbing, dredged
by the Valorous, justifies its name by the depth of 1,750
fathoms from which it was obtained near the entrance of
Davis Strait. Hyssura producta, of the same authors,
refers in the generic name to the spear-shaped telson and
in the specific to the linear form of the animal. Many of
the generic names in this family refer to the peculiar cup-
shaped or calyx-like arrangement of the caudal fan.
Cruregens, ‘leg-wanting,’ alludes to the retention of a
larval character in the absence of the last pair of pereeo-
pods. Cruregens fontanus, Chilton, is the only known
species in this family that is not marine. Mr. Charles
Chilton obtained it from a well of fresh water at Eyreton
in New Zealand, together with four other new subterra-

304 A HISTORY OF RECENT CRUSTACEA

nean species of sessile-eyed Crustaceans. Hisothistos, ‘the
thrust-in one,’ has for its type-species Hisothistos vermi-
formis, Haswell, obtained from about low-water mark at

Fic. 28.—E£isothistos vermiformis, Haswell, Fic. 29.— Lisothistos vermiformis, Haswell,
the me!e [Haswell]. the female [Haswell].

Watson’s Bay in Australia. It is not a little remarkable
for the shape assumed by the male, but still more for the
habitation which it adopts. It occupies the tube of a
Vermilia, one of the Serpulide, and with the policy of the
wolf in the story of ‘ Little Red Ridinghood,’ it not only

PRETENDING TO BE A WORM aou

occupies the tenement, but puts on the guise of the original
tenant. ‘The whole appearance of the animal is singularly
hike that of a small Serpula, the operculum and branchiz
being mimicked by the expanded posterior appendages
and telson, and the hairs representing the parapodial sete,
while the smallness of the limbs and the vermiform shape
of the body, aid in perfecting the resemblance.’ It is a
sufficiently curious instance of mimicry that the head of
one animal should be imitated by the tail of another. The
creatures habit of entering the tube head foremost is
quite in accord with its diminutive antenne and abnor-
mally small front limbs, and that when not in quest of
food it should have the branchial appendages of the tail
near the aperture of ts cave is an obviously convenient
arrangement. Probably the British Anthura gracilis may

“use a similar shelter, since it is undoubtedly dredged up

in company with sheils and stones on which the tubes of
Serpule are abundant. Many of the Edriophthalma
occupy tubes which they themselves construct. This is
apparently the case with Typhlotanais brachyurus, Bed-
dard, the tube of which is ‘ shaped somewhat like the shell
of Dentalium.’ The Indian Amphipod, named Concholestes
dental by Dr. G. M. Giles, forms its tube within a Den-
tulium shell. It seems, however, certainly to belong to the
genus Cerapus, other species of which have the tubes free.

Family 2.—Gnathide.

Though the Gnathiidee have been long contented with
a single genus, the peculiarities of that genus are so great
that at one time they were supposed to suffice for the
institution of two separate families. There are striking
differences that distinguish the sexes from one another and
the adults from the young. Characters common to all are
as follows. Both pairs of antenne are short, with the
flagella clearly marked off from the peduncles; the man-
dibles are abnormal; the first and last segments of the
perzeon are very small, and the last pereeopods are want-
ing; an embryonic character permanenily retained as in
the genera Hyssuwra and Cruregens of the preceding family.

336 A HISTORY OF RECENT CRUSTACEA

The first five seements of the pleon are distinct, carrying
each a pair of pleopods; the sixth segment ends in a
pointed telson and bears inserted at the sides of the base
a pair of two-branched uropods resembling the pleopods
except in being of a firmer texture.

In the adult male the so-called mandibles are powerful
and exserted beyond the front of the quadrate head; the
maxillipeds have a ‘palp’ consisting of four flattened
ciliated joints. The first segment of the perzeon is sepa-
rated from the head only by a suture, and its appendages,
the first gnathopods, are (in Gnathia) two-jointed, oper-
cular, the first joint being a large pyriform plate fringed
with sete on the convex inner margin and containing
three semitransparent calcareous plates, supposed to in-
dicate the same number of original joints. The seventh
segment of the perwon is abruptly narrower than the pre-
ceding, so that it seems to form part of the narrow pleon.
The pleopods with their two one-jointed rami are sometimes
ciliated, and sometimes not. Dr. Dohrn considers that
the so-called mandibles of the adult male are structures
that arise independently of the true mandibles as found in
the young. He considers that these new structures are
not concerned in feeding, but only in attaching the animal
to some object. For feeding purposes he states that the
opercular gnathopods are thrown open, and the maxilli-
peds act as whirling organs, the current of water so
maintained bringing with it small nutritious particles such
as do not require any powerful oral apparatus for their
mastication.

In the adult female the head is subtriangular, with
the eyes (when present) larger and placed further back
than in the male; the mandibles are said to be wholly
lost; the mavxillipeds are reduced. The first gnathopods
with the joints unexpanded or not much expanded lie each
on a delicate membranous plate which may be marsupial.
The first and last segments of the perzon and the pleon
are as in the male, but the fourth, fifth, and often the
sixth segments of the person are fused, the dilated trans-
parent skin affording a view of the young ones within.

THE GNATHIIDZ O07

When the young are ready to escape, the cuticle of the
mother, previously separated from the hypodermis, splits
into scales on the various segments.

In the young the mouth-organs project beyond the

head, and are evidently formed for piercing and for suction;
the mandibles have stiliform ends, and are followed by
two pairs of slender organs, which are considered to be
the two pairs of maxillz; the maxillipeds are also slender
and elongate; and the first gnathopods are elongate,
limb-lhke, with the normal seven segments; the first
perezeon-segment is distinct, the fourth, fifth, and sixth
being perhaps fused in the young female and distinct in
the young male. Dr. Dohrn considers it inappropriate
to speak of the mandibles as without ‘palp;’ rather, he |
says, it is only the ‘ palp’ which appears to be present.
' It is said to be easy to keep the males alive for a year
or two in asmall bowl containing some of their native mud
and some sea-water. As they are active climbers, pre-
cautions must be taken against their escape.

Gnathia, Leach, 1814, has long been the only genus
contained in the family, to which it is entitled to give its
~name, as hinted by Bate and Westwood, and properly
decided by the late Mr. Oscar Harger. For a long time
the name Anceus, Risso, 1816, was used for the males, and
Praniza, Latreille (Leach MS.), for the females and young.
M. Eugéne Hesse has the credit of having definitely esta-
blished the relationship between the two forms, but it
should not be forgotten that Leach had expressed his con-
Viction of it as long ago as 1814. The female had already
been figured and described as a marine Oniscus by Slabber
in 1769. The best known British species is Gnathia mazil-
laris (Montagu) 1804. The ‘mandibles’ of the male dis-
tinguish it from the species Gnathia Halidati (Bate and
Westwood), instituted by those authors in 1866 with an
expression of some doubt as to whether it might not be
the same as Guathia formica (Hesse). The American
species, Gnathia cerina (Stimpson) may likewise be dis-
tinguished by the ‘mandibles.’ M. Hesse has described
seventeen species from the coast of France, and given draw-

25

338 A HISTORY OF RECENT CRUSTACEA

ings of many of them that excite some surprise by the vivid-
ness of the colouring. His Gnathia asciaferus has ‘man-
dibles’ of unusual shape,
their axe-like appearance
being alluded to in the
specific name. Gnathia
stygius (Sars) is more than
half an inch long.
iuneognathia may be
instituted as a new genus
to receive the species
Anceus gigas, Beddard,
from Kerguelen. It is
strikingly distinguished
from Gnathia by having
the first gnathopods in the
male six-jointed. The pleo-
pods have both branches
fringed with long plumose
hairs. The male of Huneo-
qnathia gigas (see Plate
ones eee XIV.) exceeds three-fifths
aR ra ca cae of an inch in length, and
is therefore the largest known member of the family. The
fourth and fifth segments of the pereon are markedly the
widest.

Anceus bathybius, Beddard, dredged from a depth of
900 fathoms, will no doubt require to be transferred to
another new genus, but the species, being founded on a
fragment of a specimen, may wait for a new generic name
till fuller material is obtained.

Anceus Danielii, Hesse, 1884, may also represent a dis-
tinct genus, and probably, whenever the family is mono-
graphed, it will develop as plentiful a harvest of genera as
its neighbours.

Se gigas. 1° Gnathopod.

A FINE FAMILY 309

Family 3.—Cymothoide.

In contrast with the two preceding families the
Cymothoidz, in the comprehensive sense of the term,
would form a truly gigantic group. It is best, therefore,
to accept the arrangement which breaks it up into at least
six families, the animals in which are united in having in
most cases a similar outward facies. These six families
are the Cirolanide, Corallanide, Alcironide, Bary-
brotidee, Aigidee, and Cymothoide. It is common to them
all to have all the segments of the peraon distinct and
well developed; to have a well-developed ‘palp’ but no
proper molar to the mandibles, the maxillipeds with the
epipod short and coalesced to the underside of the head,
and the plate of the second joint short or wanting ; the
_ first joint of the first gnathopods fused with the segment ;
the last four pairs of pereeopods always longer than the
three preceding pairs of limbs, and the pleopods alike in
the two sexes, except for the presence of a stilet on the
second pair of the male. In the young there are six pleon-
seoments distinct, of which the terminal one which includes
the telson is large. The pleopods generally have the
branches fringed with hairs, always excepting the inner
branch of the fifth pair; in the first four pairs there are
couphng-hooks on the broad peduncles. In the gravid
female there are five pairs of marsupial plates on the first
five pairs of limbs of the pereeon, and small'supplementary
plates on the last two pairs; the maxillipeds have fringed
expansions of the epipod and the first two joints, more or
less covered by the front marsupial plates, and evidently de-
signed to promote the steady influx of water upon the eggs.

Considering that in this group a father, mother, and
child might in some cases readily be mistaken for speci-
mens of three separate species, and that among the families
the similarities and dissimilarities are often alike perplexing,
the student has great reason to be grateful to Dr. H. J.
Hansen, of Copenhagen, who in his admirable work on this
subject has provided efficient clues to the labyrinth. The
annexed table is translated from his treatise.

340

Maxillipeds with the ‘ palp’ free,
the margins of the last two
joints more or less setose, never
furnished with hooks

First maxillz with the plate of
the third joint tolerably broad,
at least towards the middle

Maxillipeds with the ‘ palp’ em-
bracing 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 mar-
gin, at least in the males and
the females without eggs, being
furnished with outward curved
hooks

First maxillee with the plate of
the third joint narrow through-
out

A HISTORY OF RECENT CRUSTACEA

SYNOPSIS OF THE

Mandibles with the distal half
stout, very conspicuous, un-
covered, or with only the an-
terior margin concealed; from
the base towards the middle
directed forwards and a little-
outwards

Mandibles with the distal half
narrow, most or all of it con-
cealed by the upper and lower
lips; from the base towards the
apex directed gradually inwards

Distal parts of the mouth-organs
forming a cone directed some-
what forwards

Second maxillz small, feeble, with-
out hooks

Maxillipeds with the fourth and
fifth joints coalesced, forming a
very long joint

Distal parts of the mouth-organs
forming a short subvertical cone

Second maxille large, elongate,
and proportionately broad, with
two apical plates furnished with
hooks

Maxillipeds with the fourth and
fifth joints sometimes coalesced,
never forming a long joint

HANSEN’S TABULAR VIEW BAL

CYMOTHOID GROUP.

‘Mandibles with the rather broad, more or less triden-
tate cutting edges meeting squarely behind the
large upper lip; the secondary plate and peculiar
equivalent for the molar well developed

First maxillz having the plate of the first joint armed
with three spines, that of the third with many

Second maxillie of moderate size, the three free plates
very setose

Maxillipeds with the ‘palp’ rather broad, very setose

Cirolanidse —

Mandibles with the distal part produced into a long

prominent process, the pair much overlapping; the
; secondary plate and molar evanescent

First maxille having the plate of the first joint un-
armed, of the third carrying one very long spine

Second maxille smalland feeble, the free plates almost |
rudimentary, with few setz

Maxillipeds with the ‘ palp’ narrowed, not very setose
(the antepenultimate joint rather elongate)

Corallanidze

First maxille having the plate of the first joint un- \
armed, of the third carrying two spines or only one
Second maxillz feeble, sometimes very small, with one Meena
. plate or none, the setz very few or none
Maxillipeds with the ‘ palp’ rather broad, with no elon-
gate joint

a

. . ° : ° ° . ° . ° . Barybrotide

Mandibles with the secondary plate very often (per-
haps always) visible; the ‘palp’ with no inflated
joint

Maxillipeds commonly seven-jointed, sometimes four-
jointed, the last joint in the latter case rather short,
obtuse

Mandibles with no secondary plate; the ‘palp’ in the

adults with the first joint or beth first and second

joints inflated Cymothoidse
Maxillipeds always four-jointed, the last joint rather

long and narrow, subacute

342 A HISTORY OF RECENT CRUSTACEA

The foregoing table has the special advantage of
enabling a specimen in almost all cases to be referred to
its proper family without dissection.

It may not be superfluous to remark that tables of this
kind are not only dry and fatiguing, but to a great extent
useless and unprofitable reading, until the moment comes
for practical application. With specimens in hand, and
possibly with all the literature relating to the specimens
freely at his command, a naturalist may still be bewildered,
until he lights upon the page, hitherto dull and unread-
able, which briefly states the distinguishing points between
several closely allied families or genera. If the characters
have been skilfully chosen and clearly and accurately de-
scribed, the apparently lifeless record at once becomes
luminous and delightful. It will not indeed be available
as a specimen of style in a book of elegant extracts, nor
should it be selected as a choice morsel for public recita-
tion ; it is rather like a bank-note or a cheque, prosaic in
expression, but the representative of solid value.

Family A.—Cirolanide.

Of the five genera grouped under this heading one
may require to be transferred to an independent family.

Ciroléna, Leach, 1818, has the peduncle of the second
antenne five-jointed; the plete of the second
jomt of the maxilliipeds furnished with hooks;
the first and second pleopods alike, with at least
the inner branch submembranaceous; the uropods
with the inner angle of the peduncle produced.

Coniléra, Leach, 1818, has the same charasters, except
that the first pleopods are opercular, with both
branches hard.

Kurydice, Leach, 1815, has the peduncle of the second
antenneze four-jointed; the plate of the second
joint of the maxillipeds without hooks; the pleo-
pods with both branches submembranaceous ; the
uropods with the inner angle of the peduncle
very little produced. ‘ ; .

UNOBTAINABLY COMMON 343

~ Bathynimus, A. Milne-Edwards, 1879, is distinguished
from the three preceding genera by having supple-
mentary ramified branehize uniquely developed at
the bases of the pleopods.
Anurépus, Beddard, 1886, unlike the four preceding
| genera, is without eyes, and the uropods have snb-
membranaceous branches concealed beneath the
telson.

The genus Cirolana comprehends a very large number
of species. That named Cirolana spinipes by Bate and
Westwood is identified by Hansen with the earlier Cirolana
borealis, Lilljeborg (see Plate XV.). It is a good swimmer,
tenacious of life, a savage devourer of fish, and not to be
held in the human hand with impunity. Another British
species, Cirolana Cranchii, Leach, distinguished from the
preceding by the much less spinose limbs, resembles it in
abundance. Upon one occasion at Anstis Cove, near Torquay,
a fishing-boat drawn up on the beach was swarming with
it. As the boatman had often promised to preserve any
small marine curiosities met with in his fishing, his at-
tention was called to these creatures crawling in such num-
bers over his boat. When asked why he had never brought
any of the kind to the naturalist, his reply was that they
were so common that he could not imagine any one want-
ing them. It isin this way that the efforts of the lands-
man are repeatedly baffled, unless he can fish for himself
in sheltered inlets or has his breast and interior constructed
of oak and triple bronze to qualify him for dredging in the
open. The American Cirolana concharum (Stimpson) feeds
sweetly on the common edible crab, otherwise called the
‘blue-crab,’ of the United States. From a single crab
as many as a hundred and eight specimens of the Cirolana
have been taken.

Conilera thus far is limited to a single species, Conilera
cylindracea (Montag’u), known from various parts of Great
Britain, including the Channel Islands, and from the
Mediterranean. Its piratical behaviour is discussed by
_ Dr. F. Day in his remarks upon a specimen of a Dog-fish,

=

3 14 A HISTORY OF RECENT CRUSTACEA

Acanthias vulgaris, which had been reduced to nothing but
skin and bones by these parasites. They hunt, he says,
in shoals, driving away the congers and other fish, but are
themselves devoured by the bream. (‘ Proceedings of the
Zoological Society, London,’ for 1884, p. 44). In this and
the preceding genus there is little difference between the
sexes, whereas in the next that difference is sometimes,
though not always, considerable.

Kurydice contains nine species, but they are not all well
known. ‘The actively swimming and viciously biting little
Hurydice pulchra, Leach, which should perhaps rather be
called Lurydice achatus (Slabber), is extremely common on
many of the sandy shores of Great Britain. ‘There seems
a sort of conspiracy to deprive Slabber of the credit of his
observations, which for his period were by no means to be
despised. ‘The specific name he chose no doubt refers to
the handsome markings, which, however, are rather stellate
or dendritic than agate-like, and which in this species are
retained even when the animal has been preserved for
many years in spirit. ‘The eyes have a surface facetting.
Eurydice truncata, Norman, from St. Magnus Bay, Shet-
land, is described as having the ‘ superior antenne sud-
denly bent in a remarkable way at a right angle at the
junction of first and second joints of the peduncle.’

Bathynomus has but a single species, but, in contrast
with the small stature prevailing in the species of Hurydice,
the West Indian Bathynomus giganteus, A. Miine-Edwards,
is by far the largest of all known Isopods. ‘The eyes are
said to be placed wholly on the underside of the head, and
each to contain nearly 4,000 squared facets. There is a
tendency in other Cirolanidz for the eyes to adopt some-
thing of a ventral position, so that it is not on this account
necessary to place Bathynomus in a separate family. The
development of accessory branchiz has been no doubt
necessitated by the animal’s great size and its abyssal habi-
tat, to which the specific and generic names respectively
refer. Professor Milne-Edwards says that its pleopods
form ‘a sort of opercular system, beneath which are found
the true organs of respiration, or branchiz. These, re-

THE BRANCHLE OF BATHYNOMUS 845

garded individually, resemble little trees or plumes, arising
from stems, which, by repeated subdivision, produce a
regular bush of hair.’ These branchial trees are connected
by their tubular stem with a network in the ordinary
laminze of the pleopods, and when the blood has been
aerated it is gathered into a marginal vessel, from which it
is transferred in the usual way to the cavity surrounding
the heart.

Anurodpus, with its single species, the large and re-
markable Anuropus branchiatus, Beddard, may have greater
claims to be the type of a distinct family, Anuropide,
since, in addition to the conversion of the uropods into
branchial pleopods, and the absence of eyes, the first an-
tennz have only two joints, and the very short ‘ palp’ of
the maxillipeds consists of a single joint.

As two of the genera of the Cirolanidee have thirty or
forty species between them, while the other three genera
have only a single species apiece, it is not unreasonable to
suppose that there may be many species of this family
either extinct or still undiscovered. Between Hurydice
and Cirolana the late M. Hesse, in 1866, places a new
genus, which he variously called Hucolumba and Lucolom-
ban, with two species named picta and ornatus..

Family B.—Corallanide.

Corallana, Dana, 1852, the single genus, contains some
fifteen or sixteen species from the Atlantic and Pacific.
The male of the species Corallana tricornis, Hansen, from
the West Indies, is ornamented by a large frontal horn
and two other large horns near the back of the head. The
epithet ‘ large,’ however, is comparative, for these horns do
not approach in size the three processes of the head in
Ceratocephaius Grayanus, Woodward, among the Sphzero-
mide. Since the type-species of Corallana, hirticauda,
Dana, was obtained from the coral reefs at Tongatabu, the
origin of Dana’s generic name cannot be misunderstood.
At the same time it chimes in with the sound and com-
position of such names as Oirolana, Conilera, and Rocinela,

346 A HISTORY OF RECENT CRUSTACEA

which Leach is said to have framed without any meaning
or derivation, but simply by placing in various positions
the same four consonants, and interspersing vowels to suit
the requirements of his ear.

— Family C.—Alevronide.

Under this name are grouped three or four genera in
which the limbs of the peraeon never show the expansion
of the joints and fringing with setae which in the preceding
families often adapt those limbs to assist in the operation
ofswimming. ‘The fifth segment of the pleon has its sides
covered by the lateral angles of the fourth.

Alciréna, Hansen, 1890, has the clypeus (the shield-like
plate to which the upper lip is attached) large, crescent-
shaped; the peduncle of the second antenne long; the
first three pairs of limbs of the pereeon with the fifth joint
not produced on the inner side, the last four pairs with the
sixth joint not dilated. Alcirona Krebs and Alcironu
imsularis are described by Hansen.

Lanocira, Hansen, 1890, has the clypeus small; the
peduncle of the second antennz short; the limbs of the
pereon as in the preceding genus, Lanocira Kriyert,
Hansen, is the type.

Tacheea, Schiédte and Meinert, 1879, has the clypeus
small; the peduncle of the second antennz long; the first
three pairs of limbs of the pereeon with the fifth joint very
broad, produced on the inner side, the last four pairs with
the sixth joint dilated. To the type-species, Tachcea cras-
sipes, Hansen adds Tacheea incerta.

Corilana, Kossmann, 1880, is incompletely described,
but is remarkable by having on the very short first pair of
limbs the claw as long as the other joints together. The
type-species, Corilana erythreea, is from the Red Sea, and
was established from a specimen only an eighth of an inck
long.

In addition to the six species of Alcironidae already
mentioned, five or six more may in fact belong to this
family, rather than to the genera Mga, Cuiralana, and

THE AGIDA 347

Corallana, to which they have been assigned, but infirmi-

ties of description have made it impossible for Dr. Hansen

to decide these cases. It is only by degrees beginning to
, be understood that by naming undecipherable species

naturalists increase ‘neither the resources of science nor
‘their own reputation.

Family D.—Barybrotide.

Barybrotes, Schiddte and Meinert, 1879, is the only
genus. ‘The limbs of the perzeon have the seventh joint
in the first three pairs forming a strong hook, and all the
seven pairs by dilatation of the joints or garniture of sete
are auxiliary to swimming. ‘lwo species, /ndus and agilis,
were instituted by the authors of the genus. Hansen finds

- that these are one and the same, and adopts the name agilis
as the most significant, but as Jndus has precedence in the
original authority, it should be retained. Schiddte and
Meinert state that the male has a stiliform appendage on
the inner side of the inner branch of the second, third, and
fourth pleopods, which would be a truly remarkable
feature. But Hansen, who has examined the type-speci-
mens, declares that neither here nor in any other Isoped
does such an appendage occur on the third and fourth
pleopods, it being limited here as elsewhere, to the second.
A noticeable feature in the species is that the seventh
segment of the perzon is almost entirely concealed. The
animals have only been taken in the open sea.

Family H.— Aigide.

To discriminate the young of this family from those of
the Cymothoidee demands careful scrutiny. It has for this
purpose to be noticed that in the Aigidé the last three
pairs of perzeopods have the seventh joint rather shorter
than the sixth, and, though a little curved, not forming a
hook, whereas in the Cymothoide this seventh joint-is not
shorter than the sixth and forms a much curved hook.
When the animals are adult or half-grown the distinction
is easy. In addition to. the character already mentioned,

548 A HISTORY OF RECENT CRUSTACEA

the Aigide have the flagella of both pairs of antennz
markedly distinct from the peduncles, and the earlier
pleopods, the uropods, and the terminal segment of the
pleon ciliated.

4iga, Leach, 1815. The maxillipeds have seven joints,
or at the least six. In the female with eggs, the first pair
of marsupial plates are so large that they cover up all the
parts of the mouth except the clypeus, part of the upper
lip, and about half the ‘ palp’ of the mandible, thus leaving
the animal incapable of taking food. In accordance with
this condition, the ovigerous female, it is said, has never
been taken upon a fish.

Rocinéla, Leach, 1818. The maxillipeds are four-
jointed ; the mandibles have the apex narrow, not denticu-
Jate, and the second joint of the ‘ palp’ not much longer
than the first.

Alitropus, Milne-Edwards, 1840. The maxillipeds are
four-jointed. It is doubtful whether this genus should be
separated from Rocinela. The descriptions of <Alitropus
typus, Milne-Edwards, and of Alitropus foveolatus, Schiédte
and Meinert, do not supply characters for discriminat-
ing it.

: Syscénus, Harger, 1878. The maxillipeds are four-
jointed. The mandibles have the apex flattened and denti-
culate, and the second joint of the ‘ palp’ shorter than the
first. The type-species, Syscenus infelic, Harger, is with-
out eyes.

In the ‘ British Sessile-eyed Crustacea,’ Bate and West-
wood describe four species of Aga. ‘The first is called Aga
bicarinata, Leach, which must yield to the earlier name
Aga rosacea (Risso), a Mediterranean species, for the
occurrence of which in Great Britain there is no definite
authority. It is very like Mga Strimiz, Liitken, but dis-
tinguished from it by much smaller and more widely
separated eyes. It is now known that the specimen men-
tioned by the above-named authors as sent them by the
Rey. A. M. Norman from the coast of the county of Durham,
was in fact an A’ga Strémii with eyes contiguous. The
second species Avga tridens, Leach, has also large eyes,

LIFE IN A SPONGE 319

which are almost contiguous, and is distinguished by the
three apical teeth of the telson. The third species, Aga
psora (Linn.), has the eyes well separated, and the inner
branch of the uropods emarginate on the inner side near
the apex. Because of the latter character Leach called it
emarginata, a name that would be naturally supposed to
apply to the telson, and which fortunately had to make
way to an earliername. ‘The fourth species, A’ga monoph-
thalma, Johnston, is not very happily named, since there
are very conspicuously two large elongate eyes, though
they happen to meet apically. The terminal segment of
the pleon has a central carina. It attains a length of more
than two inches. That which Johnston supposed to be a
variety of this species has been determined by Schiédte
and Meinert to belong to Avga Strémii. Twenty species
‘in all are distinguished by those authors, who point out
that the genera Pterélas, Guérin, and Agacylla, Dana, are
synonyms of Aga. Alga crenulata, Liitken, has been re-
corded from Scotland. The species Aga spongiophila,
Semper, is notable for making its home in the beautiful sili-
cious sponge, Huplectella aspergillum, of the Philippines, in
which it can scarcely be expected to live by sucking the
juices of fish, but it is probably well supplied with food
from the other crustaceans and small marine animals
of various kinds which enter the glass-rope basket by
accident or design, and find themselves entrapped within
it in presence of a dangerous foe. A’ga Schioedteana,
Bovallius, was described in 1885, A’ga Lovéni, Bovallius,
in 1886.

Of Rocinela Schiddte and Meinert distinguish from
various parts of the world nine species, the type being the
British focinela danmoniensis, Leach. Rocinela signata,
Schiddte and Meinert, is found in the West Indies and
Central America. To one or other of these two species,
the other seven are said by Hansen to approach very
closely. He points out that both in Aga and Rocinela the
structure of the maxillipeds is probably adapted to pulling
apart the skin of a fish and clearing a space for the attack
of the mandibles. He considers Alitropus foveolatus from

390 A HISTORY OF RECENT CRUSTACEA

Bengal and Borneo a true focinela, and that the genus
Rocinela may be regarded as a kind of link between the
Aigidee and the next family.

Family F.—Cymothoide.

The members of this family in their advanced stages
are distinguished from the Aigidee by the antennee, which
are nearly always strongly reduced, without clear distinc-
tion between peduncle and flagellum; by tke strongly
hooked fingers of the fifth, sixth, and often also of the
seventh, pairs of limbs of the perzeon; and by the absence
of cilation from the pleopods, from the terminal segment
of the pleon, and almost always from the uropods.

By one very curious character in at least some of the
genera this family is distinguished, so far as at present
known, from all the other families which in its more
comprehensive sense the name Cymothoide includes, as
well as from all other Isopods. At a certain period of its
life the young Cymothoid of some genera is a male,
with three pairs of testes, two rudimentary ovaries
internal to the testes, and a paired copulatory organ into
which the two vasa deferentia open. After a subsequent
shedding of the integument, and when the female glands
have been developed at the expense of the gradually
diminishing male glands, the now developed marsupial
plates become free on the legs of the pereeon, and the
copulatory organs are thrown off. This strange cycle of
events was discovered by Mr. J. F’. Bullar, and confirmed
by Dr. Paul Mayer, the latter showing that self-fertilisation
does not occur. As these animals when adult adopt a
parasitic mode of life, and cannot therefore roam about in
quest of partners, Hansen suggests that the propagation
of the species may be materially assisted by the alternation
of sex in each individual. The peculiarity has been
observed in the genera Cymothoa, Nerocila, and Anilvcra.
It is not to be assumed as belonging to genera in which it
has not been actually remarked, and it is rash to speak of
the Cymothoidz as hermaphrodite on one page, and on
another to assign to this family species of dAvga and

aa

SCHIODTE AND MEINERT 351

Serolis as well as of Cymothoa and Anilocra, without any
warning that so strange a characteristic does not neces-
sarily or even probably appertain to all the miscellaneous
assemblage. It has been suggested that something of the
same kind may occur in some of the Epicaridea.

The Cymothoide, after the exclusion of the five
families already characterised, are still a group of embar-
rassing size, including at least thirty genera, and about
four times as many species. ‘The description of this single
family by Schiddte and Meinert occupies a volume larger
than the present. ‘Twenty of the genera are instituted by
those authors. ‘To say that they give a figure and de-
scription of every species would very inadequately express
the scope of their labour. It must be added that the

. descriptions and figures are repeatedly double, or triple,
and sometimes fourfold. This was necessary on account

of the differences already alluded to between the forms
assumed by the same animal at different periods of life.
The symmetry of the young is often exchanged in the
adult for a more or less distorted shape due to its residence,

_ these animals being found in the mouths, and on or within

the skin, and about the fins of various fishes, in the mouths
of squids, and in other strange situations. It does not
seem proper to follow Schiddte and Meinert in their further
subdivision of this family into three families, which they
name Anilocride, Saophride, and Cymothoide, but, what-
ever view may be taken on such a matter of detail, their
work will be found indispensable to a student of this group.
Even with all the assistance it gives he will not always
find the task of identifying his specimens too easy. Under
the circumstances it is useless to compress into these pages
any brief synopsis of the numerous genera, although one
or two of them may receive a passing mention.

Nerocila, Leach, 1818, contains more than _ thirty
species. ‘The eyes, which are manifest in the larval and
young forms, in the adults as a rule gradually disappear,
this being obviously in connection with the assumption of
a parasitic life, which led Latreille to name the genus
Iehthyophilus, ‘a lover of fish.’ Nerocila depressa, Milne-

26

B02 A HISTORY OF RECENT CRUSTACEA

Edwards, and Nerocila serra, Schiddte and Meinert,
in general appearance somewhat approach the next family,
the Serdlidz, but this is still more the case with Nerocila
Lovéni, Bovallius, 1887 (see Plate XV.), from the coast of
Java, in which the side-plates of the peraecon-segments ‘ are
very long, extremely produced, flattened in the form ot
sabres or flat horns, very sharp;’ those of the seventh
segment reaching nearly to the end of the peduncles of
the uropods. The New England species, Nerocila munda,
Harger, is not mentioned by Schiddte and Meinert.

Invonéca, Leach, 1818, contains twelve species. The
head, which is large in the young, is much smaller in the
adult male, and generally of moderate size in the adult
female. The eyes suffer less diminution with advancing
age than in the preceding genus, with which in regard to
the mouth-organs it is In near agreement. Whereas in
the arrangement by Schiddte and Meinert these two genera
are widely separated, Hansen regards them as closely
connected, and both very near to Rocinela, a genus of the
Aigide. Livoneca Redmanni, Leach, is a variable species,
widely distributed on the east coast of North and South
America; Iivoneca ovalis (Say) is perhaps a synonym of
it. As in other species of this genus the adults are
usually twisted to one side.

Anilocra, Leach, 1818, contains sixteen species, one of
which excels in size all others of the family, this being
Anilocra gigantea (Herklots), for which Herklots instituted
the genus Hpichthys, but without assigning any distin-
guishing character of any importance except the gigantic
size. The length of three inches and a half, though
striking even in this family of large Isopods, is not a
character of generic value. It is remarked, however, that
the young of this species is very different from the young
of neighbouring species, even of those most nearly allied
in the adult forms. Anilocra asilus (Linn.), recorded by
the Rev. A. M. Norman from Herm, is interesting, not
merely as being hitherto the only British representative of
the family, but as being the ancient Pediculus marinus of
Rondelet and Gesner.

— Te:

Pl. xe

~

Ve

I

iy f Hh
i
fy ff]
Hy i ii
V4) \
i A
y |

3% C . borealis

Mandible

C. borealis
Head

GLOSSOBIUS A SYNONYM OF CERATOTHOA 390

Olencira, Leach, 1818, has but one species, but that the
remarkable Olencira preequstator (Latrobe) of America, in
which the first six pairs of feet from before backwards are
successively and gradually longer, but the seventh pair
abruptly much so.

Aigathoa, Dana, 1852, is not mentioned by Schiddte and
Meinert. The definition, Mr. Harger says, is :—‘ Body
elongate oval; pleon not suddenly narrower than the
thorax ; head large, subtriangular; eyes large; legs nearly
alike throughout, with strong curved dactyli; epimera of
moderate size or small; pleon long and large, composed of
six distinct segments ; pleopoda not ciliated ; uropods more
or less distinctly ciliated, rami subequal.’ Mr. Harger
remarks that the large granulated eyes remind one of Avga,
and that the ciliated uropods aiso indicate the approxima-
tion of this genus to the preceding family. The ciliation
is, however, nearly rudimentary in the New England species,
Afgathia loliginea, Harger.

Lobothérax, Bleeker, 1857, is distinguished by the
strong dorsal carination along the first four segments of
the perzeon, and the deep sinuation in the centre of their
hinder margin. The species are Lobothorax typus, Bleeker,
from Batavia, and Lobothorax auritus, (Schiddte and
Meinert) from the Philippines. From what must be con-
sidered a fanciful objection to the formation of the name
Lobothorax, the latter authors thought proper to change it
into Saophra, which they made the leading genus of their
family Saophridee.

[ Glossobiws |, Schiddte and Meinert, 1883, is notable for
the great disparity in size between the male and female.
Of Glossobius linearis (Dana) the two often quoted authors
give five descriptions relating to the adult male and female
and to three stages of the young. The ovigerous female
attains a length of an inch and a half, while the adult male is
content with about two-fifths of an inch at the largest. The
generic name signifies ‘tongue-life,’ and the species men-
tioned infests several kinds of flying-fish in a way that jus-
tifies the name. ‘ ‘I'he female embraces the fish’s tongue,
perforating its lower conjunctive membrane with the very

354 A HISTORY OF RECENT CRUSTACEA

large and curved third pair of claws, and, while with its
ventral surface it covers the top of the tongue, it projects
beyond the apex of it with its first pair of feet, so that
the mouth of the fish can hardly be closed. The ‘male, as
usual, many times smaller than the female, is often found
covered by her tail and ventral surface.’ Though this
species appears to be confined to the Atlantic, Glossobius
laticauda (Milne-Edwards) pays the same ainiable atten-
tions to the flying-fishes of the Pacific, and Glossobius
auritus, Bovallius (see Ceratothoa auritus, Plate XV.), is
reported both from the Atlantic and the ‘Indian Seas.’

Ceratothéa, Dana, 1852, includes twelve species, in
some of which the male is very much smaller than the
female. Ceratothoa Banksw (Leach) is identified with the
Pediculus marinus of Seba. Miers finds that it is also the
same as the Oniscus imbricatus, Fabricius, the type of
which is in the British Museum from the collection of Sir
Joseph Banks. The name Banksi is therefore superseded
by imbricatus. Hansen notes as a singular circumstance
‘that in the second stage of the young of this species the
fifth pleopods carry hooks, which are absent from that
pair in the adults of this whole group. Ceratothoa crassa,
Dana, is, according to Dr. Bovallius, a Glossobius. It is
worth remarking that, though the genus Ceratothoa 1s
accepted as Dana’s, he is not cited as an authority for a
single one of the accepted species. On the other hand, his
Ceratothoa linearis is transferred to Glossobius, and his
Ceratothoa crassa by Schiddte and Meinert is called Glos-
sobius laticauda (Milne-Edwards), and by Bovallius Glos-
sobius crassus (Dana). It would appear, therefore, that
Glossobius is realiy a synonym of Ceratothoa, and that a
new generic name is required for the species that have
been assigned to Ceratuthoa. For this purpose Meinertia
may be fitly proposed.

Cymothoa, Fabricius, 1793, still has seventeen species,
after the successive restrictions to which it has been sub-
jected. Of Cymothoa eremita (Briinnich) the Copenhagen
Museum has specimens still adhering to the tongues of the
fishes on which they were originally taken, showing that

f

A NARROW LODGING © BT

this species agrees in its habits with those of the so-called
Glossobius Cymothow cstrum (Linn.) is also often taken
on the tongues of fishes. It is said to have been once
found within the shell of Strombus gigas. It is reckoned
‘among the largest and noblest of the family of the
Cymothoee.’

Ichihyoxénus, Herklots, 1870, means ‘an enemy of
fish.’ This is more plain speaking than Latreille’s Ichthyo-
philus, but the treatment to which these genera expose
the fish is the same, whether spoken of as love or hate,
Ichthyoxenus Jellinghausii, Herklots, excavates in the under
side of Pontius (Barbodes) maculatus, Bleeker, behind the
ventral fins, a deep hole wherein the male and female live
together. ‘The fish is found in the river Tjikerang, in the
kingdom of Bandong in Java. The two parasites, lodged

- in the invagination of the outer wall of the fish’s abdomen,

become too large when adult to be able to pass through
the orifice of their cell. MM. Giard and Bonnier sug-
gest that two larve enter together, and that one of them
having the more favourable position continues its evolution
beyond the male stage and becomes the female partner.
A second species, Jchthyouenus montanus, Schiddte and
Meinert, comes from a fish taken in the streams of the
Himalayan mountains.

Qurozeuktes, Milne-Edwards, 1840, contains three
species, all from Australia, the original Oweni, Milne-
Edwards, and monacanthi and caudatus, established by
Schiédte and Meinert. In this genus the segments of the
pleon, though distinguishable, are fused together, and that
part of the animal is greatly narrowed, whereas the perezeon
is for the most part very broad. By the widening of some
of the joints the hinder legs, especially the last pair,
assume a very curious appearance.

Harpinyx pranizoides, Sars, 1882, a new genus and
species founded on two specimens each a quarter of an
inch long, is referred rather vaguely to the family of the
Cymothoidee, without explanation of the limits assigned to
that family. ‘The long second antenne suggest that the
animals are not fully adult, though they are too well deve-

356 A HISTORY OF RECENT CRUSTACEA

loped to be regarded as larval forms. It is very singular
that they are devoid of the last pair of pereeopods. Apart
from this extremely distinctive feature it might be sup-

posed that the species belonged to the genus Olencira, with.

the somewhat variable type-species of which it agrees in
having a very small ‘palp’ to the maxillipeds, the hinder
legs very elongate, with long curved nails, and the pleon
narrow, with a subtriangular termination. It differs in
having no eyes.

Cudonophilus, Haswell, 1881, is placed by its author
among the Cymothoidz, in Dana's subfamily A’gathoine,
and the type-species, Codonophilus argus, Haswell, is said
to approach Avgathoa, Dana. ‘The mandibles have the
‘palp’ elongate. The maxillipeds are small, operculiform,
three-jointed, the small basal joint probably not being
reckoned in. ‘The uropods have a single ramus which is
falciform and carries a few scattered cilia. By the single
ramus of the uropods this genus would seem to approach
the family Spheeromide.

Family 4.—Serolide.

The body is strongly depressed ; the broad head is
united, with or without a suture, to the first segment of
the still broader perzeon. The seventh segment of the
perzon is without side-plates, this and sometimes also the
sixth being dorsally fused with the pleon with or without
suture; ventrally also these two segments are more or less
closely united. The side-plates of the sixth segment are
the longest. The pleon consists of three small free seg-
ments and a large terminal composite one. ‘The pair of
eyes are rarely absent. ‘The second pair of antenne are
not greatly longer than the first. The powerful mandibles
have a three-jointed ‘palp;’ the five-jointed maxillipeds
form an operculum over the two delicate pairs of maxille.
The first gnathopods are subchelate. The second are
similar to the first in the male, except that they are
smaller, but in the female they are similar to the following
pereeopods. ‘The last peraopods are smaller than any

se,

AN AFFECTIONATE SQUEEZE BOF

of the six preceding pairs of limbs. The first three pairs
of pleopods are natatory, the fourth and fifth branchial.
The uropods are lateral, and comparatively small. The
marsupium consists of four pairs of plates, formed probably,
as in the Gnathiidee, by the separation of the ventral cuticle
from the hypodermis.

In strong contrast with the preceding family the pre-
sent contains but a single genus. ‘This, however, is a
strikingly well-marked type, which has excited unusual
interest by an external resemblance to the extinct Trilo-
bites. It is disappointing that, except in the general
shape of the body and to a certain extent in the character
of the eyes, nothing has been found to substantiate any
close relationship between the two groups. <A similarity
in their habits is probable, but that might account for
general resemblance apart from relationship. Professor
Studer says of the Serolide that they ‘live by preference
on sandy ground, into which they burrow with their flat
bodies up to the caudal plate. Their nourishment appears
chiefly to consist of the organic materials distributed in
the fine sand, diatomacea and organic detritus. Their
locomotion is carried on less by swimming than by back-
ward movements on the sandy ground, wherein the widely
separated feet are used as the point of support.’ The male
is often but not invariably larger than the female. In
grasping his partner by the front rim of the carapace
with the claws of his second gnathopods, he sometimes,
according to Studer, drives his over-affectionate nails
through the tender chitinous integument of his beloved.

Serolis, Leach, 1818, now contains, besides five doubt-
ful species, seventeen that are well ascertained, nine of
which were instituted by Mr. F. E. Beddard in his Report
on the Isopoda of the Challenger. The first gnathopods
have the sixth joint or hand fringed with very peculiar
spines of two kinds. The type-species is Serolis paradoxa
(Fabricius), at first named Oniscus paradoxus by Fabricius
in 1775, and afterwards transferred by him to his genus
Cymothoa. In 1833 Eights described Brongniartia trilobi-
toides, from Patagonia. By Milne-Edwards and Audouin

098 A HISTORY OF RECENT CRUSTACEA

this was removed from the fossil genus and twice renamed
as Serolis Brongniartiana and as Serolis trilobitoides. Bed-
dard considers it to be perhaps the same as Studer’s Serolis
cornuta from the Crozets and Kerguelen. The distribution
of the genus is rather peculiar, for though the type, first
reported from Tierra del Fuego, is said by Leach to occur
also on the coast of Senegal, and Serolis carinata, Locking-
ton, has been recently described from California, all the
other species belong to the Southern hemisphere. The
shallow-water species do not even extend north of latitude
30° 8., and though some of the deep-water species approach
the equator, none of them pass to the north of it. Serolis
necera, Beddard, was dredged up from a depth of 2,040
fathoms, and WSerolis Bromleyana, v. Willemoes Suhm,
from the slightly smaller depth of 1,975 fathoms. The
latter somewhat exceeds the former species in size, and is
the largest in the genus. The male is more than two
inches long and more than two inches broad, and, if the
length is reckoned not along the central line but from the
rostrum to the end of the greatly produced sixth side-
plate, it exceeds three inches. All the deep-sea species
except Serolis antarctica, Beddard, agree in having these
side-plates greatly produced, especially in the male. The
Australian Serolis minuta, Beddard, only a sixth of an inch
in length and in breadth, is the smallest species known.
Five other species belonging to Australia form a con-
nected group, in which the dorsal portion of the sixth
pereeon-segment is extremely narrow, and that of the
seventh is either absent or fused with the first of the pleon.
In these characters they agree only with Serolis minuta,
and are separated from that by having the side-plates of
the pleon undeveloped. ‘These Australian species are
named australiensis, elongata, pallida, longicaudata, by Bed-
dard, accompanying the earlier tuberculuta of Grube. The
island of Kerguelen, so richly supplied with sessile-eyed
Crustacea, has three species, Serolis cornuta, Studer, Serolis
septemcarinata, Miers, and Serolis latifrons, White.

Mr. Beddard finds that the deep-sea species are distin-
guished in an important manner from those of shallow

EYES OF THE SEROLIDE 359

‘vater by the character of the eyes. ‘The results,’ he says,
‘of my investigations into the minute structure of the eye
in Serolis may be briefly summed up as follows:—(1) The
shallow-water species invariably possess well-developed
eyes which are fundamentally similar to those of other
Tsopoda, but differ in several particulars; the retinulee are
composed of only four cells; the rhabdom is often a highly
complicated structure unlike that of other Crustacea.
Another element unrepresented (?) in the eyes of other
Crustacea is present, consisting of two large hyaline nu-
cleated cells placed below the rhabdom and between the
retinal cells. (2) In the deep-sea species the eyes are
either altogether absent (Serolis antarctica), or, if present,
show signs of structural degeneration; no retinula, at
least nothing comparable to the retinula in the eyes of the
- shallow-water species, is present, but the vitreous body is
represented. ‘The vitreous bodies may be enclosed in a
sheath of pigment (Serolis neera), or there may be no
pigment present (Serolis gracilis, Serolis Bromleyana).’

From examination of the contents of the stomachs
Mr. Beddard has come to the conclusion that these inter-
esting Crustaceans are upon occasion cannibals.

Family 5.—Spheromide.

The body is convex, the head transverse; the pleon is
vaulted over the pleopods, its earlier segments, exclusive
or inclusive of the first, being usually fused into a shorv
segment marked more or less by sutural lines, the terminal
segment being, on the other hand, very large. The eyes
are generally wide apart ; both pairs of antennz have the
flagellum multiarticulate and well marked off from the
peduncle. The mandibles have a three-jointed ‘palp;’
the first maxille have two plates, the second three; the
maxillipeds are seven-jointed, the second joint being pro-
duced into a plate. The limbs of the perazon are slender,
generally with bifid fingers. The first three pairs of pleo-
pods are ciliated, with the outer branches not opercular ;
the second pair in the male have a stilet on the inner

360 A HISTORY OF RECENT CRUSTACEA

branch. The uropods are affixed near the base of the
terminal segments, and have not more than one branch that
is movably articulated.

The family is at present in a state of considerable
confusion. Genera and species have been established on
characters which, it has since been ascertained, are, at
least in some instances, only marks of age or sex. In
recent years various suggestions have been made for can-
celling several of the genera so established, but without
any effective investigation to determine whether there may
not be valid distinctions to take the place of those which
have proved inappropriate. In the very erudite and com-
prehensive work on the Crustacea by Gerstaecker, now in
course of publication in Germany, the reduction of genera
has been carried far beyond what will, I think, be found
eventually tenable. In several of the genera the character
that has attracted earnest attention has been some dorsal
spine developed, now on one, now on another part of the
animal. As a rule, it now appears that these outgrowths
belong to the male, and not to the female, but the attempt
to refuse them all generic value on this account is not
likely to be successful.

Spherdma, Latreille (in Bosc), 1802, has the body
usually contractile into a sphere, as implied by the name ;
the telson is without any apical incision. Neither pair of
antenne is elongate ; the mandibles have a dentate cutting-
edge and strong molar; the first maxillee have denticulate
spines on the outer plate ; the maxillipeds have the ‘ palp’
strongly ciliated. The limbs of the peraeon are all ambu-
latory, not powerful, but with short and thick fingers.

The upper or outer branch of the fourth and fifth pleopods.

is thin and Jaminar, acting as an operculum to the pleated
branchial inner branch. The outer branch in these and
sometimes also in the third pair is unequally divided by
a suture. The free outer branch of the uropods is sub-
equal to the prolongation of the peduncle which represents
the inner branch. The species are numerous, but not all well
ascertained. Of the British species, Sphceroma serratum
(Fabricius) is occasionally found on the shore in large

FAMILY TIES Obl

groups. The specific name refers to the serrate margin of
the movable branch of the uropods. Spheroma curtum,
Leach, is common among seaweeds on the coast of Devon,
but isolated rather than in groups. Sphceroma Prideaux-
aanum, Leach, may be regarded as a synonym of the pre-
ceding, founded on large specimens. Sphoeroma rugicauda,
Leach, is distributed over the coasts of England, Scotland,
and Ireland, frequently where the water is not very
saline, as, for instance, at Barnstaple in North Devon.
The stilets of the second pleopods in the male are very
elongate, apically widened and rounded. Spheroma
Hookeri, Leach, is very similar to the preceding species,
but distinguished by two small longitudinal ridges on the
pleon. Both species have been taken in company on the
coast of Sussex.

Zuzara, Leach, 1818, was established for species differ-
ing from Spheroma by having the outer branch of the
uropods larger than the fixed inner one, and concave above
instead of flat. The species also have the sixth segment
of the perzeon dorsally produced.

Neesa, Leach, 1818 (Nescea, Leach, 1814, preoccupied),
has the sixth segment of the pereon larger than the others,
and produced backwards in a bidentate process. The uro-
pods are affixed not at the base, but near the further end,
of the terminal segment, and, while the fixed inner branch
is directed transversely inward, the movable outer one ex-
tends backwards beyond the end of the segment. In the
British species Nesa bidentata (Adams), the pleon is rugose
with two dorsal tubercles and a terminal excavation. Bate
and Westwood suggest that this species may prove to be
the male of Dynamene Montagui, Leach, in which there
are two dorsal tubercles on the sixth segment of the peraeon
and two on the pleon. It seems not improbable that the
species named Dynamene rubra and Dynamene viridis by
Leach, and Campecopea versicolor by Rathke, may repre-
sent the female, and Dynamene Montagui the young male,
of Neesa bidentata. These forms are all found on British
coasts under similar conditions and with the same varia-
tions of colour—green, or red, or variously mottled; but

362 A HISTORY OF RECENT CRUSTACEA

the Diynamene forms have the pleon not rugose and the
uropods fixed some way up the terminal segment, and the
branches not in any marked manner extending beyond it,
nor separated from one another. The forms rubra and
viridis are also without dorsal tubercles. No one appears
to have ever found the Nesa form or Dynamene Montagus
carrying eggs, and, as they are not at all uncommon, they
may, therefore, be presumed to be of the male sex. The
differences between the female Dynamene and Neesa in the
hinder half of the animal are superficially very great, but
they are bridged over to a certain extent by the inter-
mediate form of Dynamene Montagu. All the three forms
agree in having both branches of the fourth and fifth pleo-
pods furnished with transverse folds or pleats so as to be
fully branchial. Dynamene in 1814 had as yet no species.

Cymodoce, Leach, 1814. It is not easy to understand
why authors have combined not only to adopt a different
form of this name, but to base the alteration on Leach’s
original authority. In this genus the pleon is dorsally
tuberculate, with two apical notches, and the outer branch
of the uropods so placed that it cannot completely close
under the inner, both branches remaining always salient.
The British species are Cymodoce trunceta, Leach, and
Cymodoce emarginata, Leach, the latter of which has not
recently been found. Cymodoce Lamarckii, Leach, from
Sicily, is briefly described, and not im agreement with the
generic definition. M. Eugéne Hesse has persuaded him-
self, not only that Dynamene is the female of Neesa, which
is possible, but that Spheroma is the female of Cymodoce,
which certainly cannot be accepted on such arguments as
he produces. As between British species assigned to the
two genera, there is no resemblance of colouring worth
speaking of, and no community of residence, except that
Cymodoce is cccasionally and very rarely found on some of
the shores that also yield Spheroma. In Spheroma quadri-
dentatum, Say, Mr. Harger has ascertained that neither
sex is a Cymodoce. The curious fact remains that no
ovigerous Cymodoce has yet been recorded. It is, perhaps,
still more singular that the sexual characters in this group

A NEW GENUS, N&ESICOPEA 3865

should have been so little examined, that their relation-
ships are left rather to speculative argument than to any
basis of observed facts. I can, however, myself testify that
Spheroma rugicauda, Leach, need not have recourse to
Cymodoce for a male form. In the character of the pleo-
pods Cymodoce agrees with Spheroma as opposed to Neesa,
although, as to the stilets of the second pair, in Cymodoce
truncata they are apically narrowed.

The species, Cymodoce abyssorum, Beddard, from 1,070
fathoms, off New Guinea, must be transferred to a new
genus, for which I propose the name Neesicopea. ‘The last
seoment of the perzeon is much narrower than the segment
before or the segment behind it, and has the side-plates
rudimentary. There are two median dorsal teeth, one
behind the other, on the pleon. The fourth and fifth
pleopods have both branches fully branchial. ‘The uropods
in the male have the inner branch rudimentary, the outer
greatly prolonged. In the female they are placed higher
up than in the male, with a longer inner branch, and the
outer not much longer than the inner. The name refers
to the combination of characters found in Neesa and in the
genus next to be mentioned.

Campecopea, Leach. 1814, has the sixth seement of the
perzeon produced in the male, but not in the female. The
uropods are inserted high up on the terminal segment,
and have the movable branch, long, curved, and produced
beyond the apex of the segment; while the inner branch,
marked off by a partial suture from the peduncle, is a
mere knob, only distinguishable on the under side. It
can scarcely be doubted that only one British species of
this genus is at present known, Campecopea hirsuta (Mon-
tagu), of which Campecopea Cranchii, Leach, is the female.
The two forms are constantly found in company in the
little blackish or dark green sea-weed, Lichina pygmeea.
In colour they entirely agree, as in almost all other par-
ticulars except the long tooth on the sixth pereeon-segment.
In some specimens this tooth may be seen in various
stages of growth, while others are entirely without it.
All specimens roll themselves up very tightly, so that, in

364

A HISTORY OF RECENT CRUSTACEA

spite of the projecting uropods and even of the perxon-
process, they roll about with great facility. The projections
from the body promote their resemblance to the weed
among which they lve. Campecopea lineata, Hesse,
taken ‘under stones, near Brest,’ seems to be the same
species.
Oiliceear, Leach, 1818, has the front or median part of
the pleon dorsally produced into a long spine in the male,
but not in the female. The apex of the pleon is notched
as in Cymodoce.

Cycloidira, 1 eee 1878 (Cyclura, Stebbing, 1874,

~

preoccupied), h

as the pleon wider than the preceding

part of the animal, a peculiarity which it shares with very
few of the Tsopoda. The large oval branches of the
uropods are of unusually thin texture, and are very salient,
the movable outer branch folding only partially beneath
the fixed inner one. The Australian type-species, Oycloi-
dura venosa, has the seventh segment of the pereeon pro-

FIG.

duced into a large dorsal spine, at least
in the male. A new genus near to Oycloi-
dura may be required for the Californian
species, Sphaeroma amplicauda, Stimpson.

Isoclidus, Miers, 1876, rather closely
resembles the preceding genus, but has
the uropods ‘ subequal, of a shghtly sig-

“= moid shape, and acute at the extremity.’

31, — Ceratocepha-

lus Grayanus, Wood-
ward [Haswell].

The spine of the seventh peraeon-segment
is not developed in the female. The
species, armatus (Milne-Edwards) and
spiniger (Dana), are from New Zealand.
Ceratocephilus, Woodward, 1877, has
the head produced in the male into three
large processes of which the central is
much the longest. Inthe female ‘ faintly
marked projections’ take the place of the
processes. ‘The terminal segment of the
pleon is produced in an obtusely pointed

process beyond the uropeds, which are affixed high up on
the sides of the segment, and have the outer movable branch

healt ;
ES a Ne oe ae

td
SOUTHERN SPHROMIDA 365

quite minute. The second antenne are unusually elongate.
Jt is probable that Bregmocerella tricornis, Haswell, from
Port Jackson, is specifically as well as generically identi-
cal with Ceratocephalus Grayanus, Woodward, from Bass’s
Strait, although the figures given differ in some particulars.

Circeis, Milne-Edwards, 1840. The head and body ~
are comparatively elongate, the segments of the pereeon
little flexible; the first antennz have a very large basal
joint, with the second joint embedded in its apical emargi-
nation ; the uropods have the outer branch longer than the
inner. Both the species are southern, and their names
tridentuta and bidentata refer to the apical notching of the

leon. :
. Amphoroidea, Milne-Edwards, 1840, has the first joint
of the first antennee greatly dilated; the first segment of
the pleon distinct but rudimentary ; both the branches of
the fourth and fifth pairs of pleopods transversely fluted for
branchial purposes. The type-species, Amphoroidea typa,
from Chili, seen from above and by help of the projecting
first joints of the upper antennz, has the outline of a jar
or amphora. Dana names a second species australiensis.
G. M. Thomson describes Amphoroidea falcifer, from New
Zealand, but thinks it may be identical with one or other
of the two species just mentioned.

Cassidina, Milne-Edwards, 1840, has the body greatly
dilated beyond the insertions of the slender legs. The
uropods do not reach the narrow apex of the terminal
segment, and have the outer movable branch much smaller
than the fixed inner one. Cussidina typa, Milne-Edwards,
is only a third of an inch long. The species latistylis,
Dana, is said by Miers to be a synonym of emarginata,
_ Guérin-Méneville. This, according to Studer, reaches a
length of an inch and a quarter and a breadth of more
than four-fifths of an inch in the male, though the female,
which is a little over an inch in length, is only two-fifths
of aninch broad. Studer describes a third species, Caussidina
maculata, which, like emarginata, is found at Kerguelen
Island, and G. M. Thomson describes a fourth species,
Cassidina neo-zealanica, from New Zealand.

27

366 A HISTORY OF RECENT CRUSTACEA

Haswellia, Miers, 1884 (a new name for the pre-
occupied Calyplira, Haswell, 1881), has the last segment
of the pereeon produced into a broad plate or shield over
and beyond the pleon. The pleon has a terminal qua-
drangular notch, with a squarish lobe within it. ‘The first
antenne are broad at the base. The type is Haswellia
carnea (Haswell).

Ancinus, Milne-Edwards, 1840, has the body flattened,
the pleon triangular with a truncate tip; the eyes dorsal
instead of lateral; the first and second gnathopods sub-
chelate with long curved fingers; the uropods with only
one branch, which is long and narrow, and, as in Nesa
and Campecopea, does not hug the telson. ‘The single
species, Ancinus depressus (Leach), exhibits considerable
diversity in the forms of the limbs of the perzeon.

Scutuloidea, Chilton, 1882, has the body not very con-

vex, the pereon much broader than the head, the pleon
broadly triangular, emarginate at the apex, and the
uropods contiguous to it, very salient, single-branched,
consisting of a large squamiform plate. The type is
Scutuloidea maculata, Chilton, from New Zealand. The
second gnathopods are longer than the other limbs of the
pereeon.

Plakarthrium, Chilton, 1882, has the body much de-
pressed, with the side-plates of the perzeon greatly ex-
panded, the first pair produced forward at the sides of the
head, and the seventh pair backwards nearly to the ex-
tremity of the uropods. The two basal joints of the first
antennee and the third and fourth joints of the second are
expanded, enclosing all the front of the head. The pleon
is rectangular, with the uropods sub-terminal, the outer
branch short, apically dilated. Plakarthium typicum,

Chilton, found on the seaweed Hklonia radiata, in Lyttel- |

ton Harbour, New Zealand, ‘afiords a very good example
of protective resemblance, for the body being very flat and
of a brown colour can scarcely be distinguished from the
seaweed, to which it closely adheres.’ Its position among
the Spheeromide is somewhat doubtful, if it be the case

THE MISCHIEVOUS GRIBBLE 367

that the mandibles have no ‘palp’ or only a one-jointed
one. By the antennal joints projecting in front, the
uropods extended behind, and the large side-plates of the
perzon radiating laterally and distally widened, the lead,
the back of the perzeon, and the pleon are completely en-
closed, and the outline becomes an unbroken oval. The
animal, being only one-fifth of an inch long, might, like the
still smaller Campecopea hirsuta, seem to be no fit subject for
protective mimicry. It must be supposed that, minute as
they are, they are found worth eating by creatures highly
enough organised to be guided in their attacks by form
and colour.

Family 6.—Inmnoriide.

The body is sub-depressed ; the pleon has six distinct
segments. ‘The eyes are lateral, wide apart; the antennze
of both pairs are short, the first having a single-jointed
flagellum ; the mandibles have a chisel-like cutting edge,
the molar tubercle obsolete, the ‘palp’ small, three- (or
perhaps sometimes two-) jointed; the first maxilla have
two slender plates, the second have three; in the maxilli-
peds the second joint is produced, the five joints of the
‘palp’ are short, its three middle ones somewhat expanded;
the epipod is elongate; all the limbs of the pereeon are
similar, not prehensile, but with bifid fingers; the five
pairs of branchial pleopods are sheltered in the vaulted
pleon, all ciliated except the fifth pair, which is smaller
than the rest; the second pair in the male have the usual
stilets; the uropods have two single-jointed branches,
koth movable, the outer much shorter than the inner.

Inmnoria, Leach, 1814, is the only genus. The type,
Inmnoria liqgnorum (J. Rathke, 1799), known at Plymouth
as the Gribble, has an evil fame for gnawing submerged
timber. It is widely distributed. Inaccuracies in the
earlier, descriptions of the species have been pointed out by
the late Mr. Oscar Harger with his accustomed care and
acuteness. In New Zealand Mr. C. Chilton has found a
second species, Limnoria seqnis, on the roots of the sea-

368 A HISTORY OF RECENT CRUSTACEA

weed Macrocystis, not burrowing into wood. He believes
that the ‘ palp’ of the mandible is only two-jointed. The
epipod of the maxillipeds is much larger than in Timnoria
lignorum, and is apically widened instead of having an
acute apex.

A BOX OF BRANCHIA 369

CHAPTER XXIII

TRIBE III.—VALVIFERA

Here the uropods undergo a remarkable metamorphosis,
and assume a function distinct from any that they have
elsewhere, for like a pair of folding doors they form a great
part of the ventral surface of the pleon, these valves closing
over the five pairs of branchial pleopods or opening to
admit the water tothem. —

In the ‘ History of the British Sessile-eyed Crustacea,’
vol. 11. pp. 358, 3868, 375, 378, the uropods are successively
spoken of as ‘the first or anterior pair of pleopoda,’ as per-
taining to ‘the first segment of the tail,’ as being absent in
the Idoteide, where there is said to be a ‘conversion of
the fifth pair of pleopoda into a continuous operculum for
the protection of the branchial organs,’ and lastly, in the
genus Idotea, as ‘a strong outer pair (which are the ter-
minal uropoda), forming an operculum’ over the ‘five
pairs of very delicate branchial appendages.’ Of these
four statements the first two are consistent but erroneous,
the last two are inconsistent with the first and with one
another; only the final one is correct. All the four, as it
happens, appeared in the same number of the work, namely,
Part 19, published October 1, 1867, so that the confusion
is difficult to account for, even as an accident of dual
authorship.

The tribe includes two well-separated families, the
Arcturidz and Idoteide.

Family 1.—Arcturide.

The form of the animal is elongate and sometimes
cylindrical ; the segments of the pleon are more or less

370 A HISTORY OF RECENT CRUSTACEA

coalesced. The second antennz are large and long; the
mandibles have a molar tubercle but no ‘ palp;’ the outer
plate of the first maxille and the inner plate of the second
are broad; the maxillipeds have an oval epipod, a broadly
expanded plate to the second joint, and the five joints of
the ‘palp’ not very large; the first four pairs of limbs of the
pereon are directed forwards, slender, ciliated, with the
terminal joint minute; the last three pairs are stouter,
ambulatory, with the terminal joint bifid. The opercular
uropods have the inner branch much shorter than the
peduncle, the outer branch rudimentary or sometimes
entirely wanting. When the valves are closed the branch
of the uropods which is homclogically the outer is shut up
inside, even when present.

Arctirus, Latreille, 1804, has the flagellum of the
second antennee more than four-jointed, the fourth segment
of the perzeon not greatly longer than the others, the mar-
supium of the female composed of four pairs of plates.
The arctic Arcturus Baffini (Sabine) grows to a length of
three inches. Mr. F. E. Beddard has described thirteen
new species brought from various parts of the world by the
Challenger. Others have been described by Miers, Sars,
and Studer. Almost all have a striking appearance from
the armature of spines or tubercles. In their clinging
habit and general appearance they have some resemblance
to the amphipod group, the Caprellidz, some of which are
also very spinose. It is interesting to observe that in —
creatures which are structurally very distinct a similar
mode of life goes with a similar general appearance, so that
the similarity of life may be supposed to have produced the
similarity of look.

Astacilla, Cordiner, 1795 (= Leacia, Johnston, 1825), has
the flagellum of the second antenne not more than four-
jointed, the fourth segment of the pereeon much longer than
any of the others, and the marsupium of the female con-
sisting of two plates affixed to this segment. There is no
reason for discarding Johnston’s Leacia, on the ground that
the different name Leachia was preoccu pied. Itis acommon
and quite justifiable practice to form generic names by

CORDINER’S LITTLE LOBSTER o7l

variations on the same theme, as Darwinia and Darwinella.
Harger points out that Fleming’s reference of Astacilla to
the Rev. Charles Cordiner, 1784, is no proof that it was
eeehed or described at that date. But in a work en-
titled ‘Remarkable Ruins and Romantic Prospects of
North Britain with Ancient Monuments and Singular
Subjects of Natural History by the Rev. Charles Cordiner
of Banff. London, 1795, there is a section headed ‘ Asta-
cillee, Purple Doris, &c.,’ containing the interesting passage
which follows :—

‘One very lively species of little lobsters, which had
taken up their dwelling among these coralines, seemed on
account of its novelty to merit the attention of a particular
drawing.

‘Their general form and appearance in their natural
state, and the size of life, are carefully represented at a, a,
a; an elaborate delineation of the microscope, after a
minute investigation of the particular structure of its
several parts, is inserted above at a. That will more
distinctly express to the curious the peculiarities of the
animal than any specific distinctions which could be nar-
rated. The eye appeared as a regular arrangement of
bright specks, in circular rows, as at the figure I.

‘The diminutive ASTACILL&, of the general name of
lobsters, is applied at present, as a common characteristic,
until one more particularly appropriate may be fixed on to
distinguish it by; for these are a species that do not ap-
pear to have been yet recognized among the varieties of
British insects.’

Seeing that this account is accompanied by an unmis-
takable figure of Astacilla longicornis (Sowerby), it seems
only proper to uphold the priority of Cordiner’s generic
name, and perhaps the name of the family ought to become
Astacillide. The British species are Astacilla longicornis
(Sowerby), Astacilla intermedia (Goodsir), Astacilla gracilis
(Goodsir), Astacilla damnoniensis, Stebbing, Astacilla Des-
hayesti (Lucas), and Astacilla dilatata, Sars. This last
and others of the genus named by the same author are
found on the coasts of Norway. Astacilla granulata, Sars,

O72 A HISTORY OF RECENT CRUSTACEA

occurs in the North Atlantic, Astacilla marionis, Beddard,
in the Southern Ocean. The young of this genus some-
times, if not always, have the fourth segment of the pereeon
not elongate, just as in Arcturus.

Family 2.—Idoteidee.

The body is ovate or oblong, or more or less oblong-
ovate. ‘The mouth-organs and pleon and its appendages
are nearly as in the preceding family, but the maxillipeds
sometimes have the ‘ palp’ become three-jointed by coa-
lescence. The second antenne are not as a rule greatly
elongate; the flagellum may be rudimentary, single-
jointed, or more usually multiarticulate. The limbs of the
pereeon are usually nearly alike, but the first three pairs
are sometimes subchelate, and the last two may be ‘ mul-
tiarticulate.’

Glyptonétus, Eights, 1852, has the maxilliped-‘ palp’
three-jointed, the two terminal joints being fused and also
the two that precede them. The first three pairs of limbs of
the pereeon have the sixth joint dilated and are subchelate.
The pleon has three or four complete sutures; the stilets
on the second pair of pleopods in the male are very
elongate ; the outer branch of the uropods is minute.
Glyptonotus antarcticus, Kights, being ‘ dorsally sculptured,
corresponds with the generic name. It attains a length of
three inches and a half by a breadth of an inch and three-
quarters, and is, therefore, one of the monster Isopods.
The Arctic species, which also occurs in the Baltic and the
depths of the Swedish Lakes, Glyptonotus entomon (Linn.),
is not much smaller than the preceding. Chiridotea,
Harger, 1878, is regarded by Miers as a synonym of
Glyptonotus.

Chetilia, Dana, 1852. Mr. Miers, in his elaborate ‘ Re-
vision of the Idoteidee,’ says: —‘ The multiarticulatecharacter
of the sixth and seventh thoracic legs is probably not a
character of the importance assigned to it by Dana. In
its ovate form, four-segmented postabdomen [pleon], and
elongated antennules, the relationship of Cheetilia to Glyp-

THE IDOTEID® 379

tovotus is obvious ; but the antennules in Chetilia are placed
immediately above the antennez, asin Hdotia. in Cheetilia
ovata, Dana, the sixth pair of legs are described as being
‘twice as long as the entire animal, terminating in a very
long bristle-like extremity, which consists of numerous
joints. The seventh pair has also a multiarticulate ex-
tremity, which is, however, quite short.’ Dana thought a
separate family Cheetiliide necessary for this genus.

Arcturides, Studer, 1882, in general appearance and in
the length of the second antennee approaches Arcturus, but
the short-jointed limbs are all very nearly alike, though the
first are shortest, and the three following pairs a little
more prehensile than those to the rear. In the southern
Arcturides cornutus, Studer, the head has a pair of frontal!
horns, and is not articulated with the first peraeon-segment
though divided from it by a suture.

Idotea, Fabricius, 1798, has the second antennz mode-
rately elongate; the maxilliped-‘ palp’ four-jointed, only
the last two joints being fused; the limbs of the perzeon
all nearly alike, with the sixth joint not or not much ex-
panded, but the seventh prehensile. The uropods have on
the basal plates a raised line near and almost parallel to
the inner margin, and an apical plumose seta, which is
concealed under the terminal plate. The species are very
numerous, and several additional genera have been pro-
posed which Mr. Miers does not think worthy to be
upheld.

Idotea marina (Linn.) is the name he adopts for that
which Bate and Westwood describe as Jdotea tricuspidata,
Desmarest, and Idotea pelagica, Leach, and which has also
been called by a dozen other names. It is very abundant.
Its distribution appears to be almost cosmopolitan. In
size and colour it is extremely variable. Idotea metallica,
Bosc, which seems to have as great a range over the world,
is, however, not recorded from British coasts. IJdotea
emarginata, Fabricius, is common in British waters, but
not like marina on the shore, and the same may be said
of Idotea linearis (Linn.), with which Mr. Miers com-
bines the curiously striped [dotea sealineata of Kroyer.

374 A HISTORY OF RECENT CRUSTACEA

Idotea lacustris, Thomson, from New Zealand, can
make itself at home in fresh water. It has been taken by
Mr. Chilton in Mihiwaka Creek, a mountain stream, at
200 feet or more above the sea-level. The young leave
the marsupium with all the segments developed and their
appendages present, but the second antenne having a
single-jointed instead of a multiarticulate flagellum.

Idotea prismatica (Risso) belongs to a section in which
the pleon is composed of four or five instead of only three
more or less distinct segments, and in which the species
are small, with a few-jointed flagellum to the second
antenne. It has a small outer branch to the uropods.
It is found in North and South Devon, and has been de-
scribed by Bate and Westwood as Idotea parallela. Itisa
question whether a separate genus ought not to be named
for the group of species to which it belongs. Zenobia,
Risso, 1826, in which it was originally placed, is a preoc-
cupied name.

Idotea acuminata (Leach) belongs to a section in which
all the segments of the pleon are dorsally fused and form a
single piece. In Idotea appendiculata (Risso) it has a
synonym, the two different forms of pleon being connected
by numerous gradations. The species is found in North
and South Devon, and in the Clyde as well as in the
Mediterranean. For the group to which it belongs perhaps
the genus Leptosdma, Risso, 1826, should be upheld, with
a substitute for the name which again is preoccupied.
Miers includes in this group the Australian Crabyzos longi=
caudatus, Spence Bate, 1863, although in that species the
head is fused with the first segment of the perzeon.

Edotia, Guérin-Méneville, 1829-44, has the body
rather convex, and the pleon one- or two-jointed. The
second antenne are either short with an obsolete or rudi-
mentary flagellum, or well developed. The limbs of the
pereon have the seventh joint strong, the sixth joint in
the first three pairs not greatly dilated. The uropods have
the basal plates crossed by an oblique line. The Arctic
Edotia bicuspida (Owen) is beautifully coloured. It has
the second antennz well developed. Edotia triléba (Say)

MIERS AND HARGER 375

is an instance of the group in which the flagellum of the
second antenne is rudimentary. Sars remarks that in his
opinion ‘ Harger’s genus Synidotea [1878] should for the
present be retained for the two Arctic species S. bicuspida
and S. nodulosa {(Kréyer)], both differing distinctly from
the form described by Guérin-Méneville—Edotia tuber-
culata—in the well-developed, multiarticulate flagellum on
the second pair of antenne.’

Cleantis, Dana, 1849, is distinguished by the flagellum
of the second antenne being all fused into a single piece,
but even this character is sometimes shared by Jdotea
prismatica. The pleon in Cleantis may consist either of
one, two, three, or five distinct segments. The New
Zealand species, Cleantis tubicola, Thomson, is eleven times
as long as it is broad. Mr. Chilton is disposed to regard
- it as normally not a tube-dweller, though the type-speci-
men was found in a tube. The species with all the seg-
ments of the pleon fused, such as Cleantis filiformis (Say)
from the United States, were referred by Dana and Harger
to a separate genus, Hrichsonia, Dana, 1849.

On this family the work by Miers already mentioned
and Harger’s ‘Report on the Marine Isopoda of New
England and adjacent waters’ are essential to the student
for the groundwork of his inquiries.

376 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXIV
TRIBE IV.—ASELLOTA

THE second pair of antenne are elongate; the maxillipeds
are furnished with an epipod, have the second joint pro-
duced into a plate, and the ‘palp’ consisting of five dis-
tinct joints. The first pleopods in the female are usually
transformed into a single opercular plate, and in the
male are variously modified; the four following pairs are
branchial; the uropods are terminal, or, if lateral, not
remote from the apex of the pleon, one- or two-branched,
or consisting of a single joint. There are two families,
the Asellidze and Munnopsidee.

Family 1.—Asellide.

The mandibles have a denticulate cutting edge, a
molar tubercle, and usually a three-jointed ‘palp.’ The
limbs of the person are prehensile or ambulatory, not
specially modified for swimming. The marsupial pouch is
formed of plates pertaining to the first four, or to the
second, third, and fourth segments of the pereeon. Some
twenty-five genera are included in this family, many of
them exhibiting very striking peculiarities.

Asellus, Geoffroy, 1762, shares with Mancasellus a cha-
racter exceptional in the tribe to which it has given its
name, in that the pleon in both sexes has the first pair of
pleopods quite small, consisting in the female of two un-
jointed oval plates, while the second pair are opercular,
but not fused together in either sex. The female has but
four, the male has five pairs of pleopods. The heart ex- —
tends from the pleon through the pereon. This genus
belongs exclusively to fresh water. Asellus aquaticus

ae

A CAVE ISOPOD Sd

{Linn.) is a species distributed almost all over Europe in
great abundance. ‘The details of its organisation, external
and internal, are explained, with a clearness of language
and drawing which leaves nothing to be desired, in the
‘Histoire naturelle des Crustacés d’eau douce de Norvége’
by G. O. Sars, 1867. M. Dollfus says that aquaticus is
completely displaced in Palestine by his new species,
Asellus coxalis. Harger mentions Asellus communis, Say,
as common in the fresh-water ponds and streams of New
England. For other species, and the bibliography of the
genus, the ‘ Notes on the Family Asellide,’ by Dr. Boval-
lius, should be consulted.

Mancasellus, Harger, 1876, was named to take the
place of Asellopsis, Harger, 1874, preoccupied. This genus
is exceptional in regard to the mandibles which have no

- *palp,’ being otherwise very like Asellus. Mancasellus

tenaxz (S. I. Smith) and Muncasellus brachyurus, Harger,
are found in the fresh waters of North America.

Cecidotea, Packard, 1871, is without eyes, has the
seventh joint of the limbs not bifid, and the uropods elon-
gate, with two unequal branches. ‘The species Ccecidotea
stygia is found in the Mammoth and Wyandotte Caves and
in wells in Indiana. The absence of eyes does not distin-
guish it from Asellus, for some of the species of that genus
are also blind. |

Janira, Leach, 1814, is a marine genus, dorsally not un-

like Asellus, but the second antennz have a small scale or

exopod ; the first limbs of the perzeon have the sixth joint
scarcely expanded; the first pleopods in the female form
a subcircular operculum. The uropods are two-branched.
The only British species is Janira maculosa, Leach. In
regard to the American species, Janira alta (Stimpson),
Harger says of the pleopods in the male :—‘ The thickened
opercular plates are three in number, viz., a pair of semi-
oval plates at the sides, and a more slender median plate
presenting traces of a suture along the middle.’ This
formation is probably characteristic of the genus, and no
doubt, as explained by Hansen for Hurycope, the fused
plates represent the first pleopods, and the semi-oval plates

3/78 A HISTORY OF RECENT CRUSTACEA

the second pleopods. Janthe speciosa, Bovallius, is by
Hansen identified both generically and specifically with
the earlier Janira spinosa, Harger. Janira abyssicola,
Beddard, was obtained among the Fiji Islands, from a

depth of 1,850 fathoms; Janira laciniata, Sars, from —
4.00 fathoms on the west coast of Norway. Janira tricorms

(Kréyer) comes from Greenland.

Trichopleon, Beddard, 1886, has a rudimentary exopod
on the second antenne, the limbs of the pereeon with the
seventh joint simple, the uropods with the outer branch
one-jointed, the inner two-jointed. ‘The type is T’richopleon
ramosum from the Philippines.

Tathrippa, Bovallius, 1886, was instituted to receive the
New Zealand species, Janira longicauda, Chilton, the genus
being distinguished from Janira chiefly by the two
branches of the uropods being long, laminar, and lanceo-
late, instead of narrow and stiliform.

Iais, Bovallius, 1886, is distinguished by having the
terminal joint of the limbs ‘triunguiculate.’ It has two
elongate laminar branches to the uropods. The type is
Iais Hargeri from the Strait of Magellan.

[Acanthoniscus|, Sars, 1879, differs from Janira in
having ‘the first legs not subchelate, the rest with the
seventh joint simple, and the uropods stiliform with very
short branches.’ The type species, Acanthoniscus typhlops,
is blind. Dr. Bovallins having pointed out that the name
Acanthoniscus is preoccupied, it may be changed to Acan-
thaspidia.

Ianthopsis, Beddard, 1886, was instituted to receive
TIanthe Bovallu, Studer, from Kerguelen. It is allied to
the preceding genus, but distinguished from it by having
eyes, a rudimentary flagellum to the first antenne, and
bifid fingers on the limbs of the perzeon. All the limbs
are similar to each other in both sexes. The uropods have
a long peduncle and two branches, of which the inner is
the larger.

Tolanthe, Beddard, 1886, is described as most nearly
allied to the two preceding genera. It has no eyes, and

the lateral margins of the head and the segments of the ~

a

ei laa aaa .

SMALL SPECIES 379

perzon are prolonged into long curved spiny processes. To
save research into classical authorities for the origin of the
name of this genus, it may be mentioned that it was taken
from the title-réle of a popular comic operetta by Gilbert
and Sullivan.

Jeera, Leach, 1814, is distinguished from mary of the
preceding genera by its shorter second antenne, shorter
limbs, and especially by the uropods, which are very short
and have two diminutive branches. ‘There are two British
species, Jera albifrons, Leach, and Jera Nordmann
(Rathke), both very small. The former, which is rather
the larger, has a very extensive northern distribution.
Both are often at home in runlets of fresh water travers-
ing sea-beaches. Jeera Guernei, Dollfus, is an inland river
species of the Azores.

Jeeropsis, Koehler, 1885, is distinguished from Jera by

its very small pairs of antennz, its narrow perzon with

the segments laterally set apart, and other particulars.
The type, Jeropsis brevicornis, was taken at Sark. All the
species are minute. Jeropsis marionis, Beddard, is founded
on a specimen less than a sixth of an inch long. The
length of Jaropsis neo-zelanica, Chilton, is about a tenth
of an inch.

Jamna, Bovallius, 1886, was instituted to receive Jera
longicornis, Lucas, from Algeria, in which the first limbs
are chelate, and the uropods are two-branched, with the
branches longer than the peduncles.

Stenetrium, Haswell, 1881, has the second antennz

long,.and carrying an exopod. The first limbs are chelate

or nearly so. The terminal joint is bifid in the following
pairs. The uropods are two-branched, the branches
narrow. Haswell describes Stenetrium armatum and
Stenetrium iwmerme from Australia, Chilton, Stenetrium
fractum from New Zealand, Beddard, Stenetrium Haswelli,
from South America.

Munna, Kroyer, 1839, has the head large, the pleon
fused into asingle segment ; the eyes extremely prominent,
the second antennz very long, with their bases below the
short first pair. The limbs of the perzeon of the first pair

380 A HISTORY OF RECENT CRUSTACEA

are short, robust, and subprehensile, of the following pairs
ambulatory, very long, with the seventh joint bifid. The
anterior pleopods are arranged as in Janira. The uropods
are minute, seemingly single-jointed. ‘l'wo British species
have been described, Munna Kriyeri, Goodsir, and Munna
Whiteana, Bate and Westwood, but Sars decides that the
former is male, the latter female, of one and the same
species, so that the name Whiiteana must be cancelled.
The type is Munna Boecku, Kroyer. The species are very
small, and the differences such as are not always very easy
to seize when exhibited on so minute a scale. There are
three other Norwegian species, Munna Fabricn, Kroyer,
Munna limicila, Sars, and Munna palmata, Lilljeborg, the
last distinguished by its enormously developed first pair of
feet. Of the Munna Fabric, Sars remarks that Kroyer
himself mixed up several species in his description and
figures under this name. Beddard describes two species
from Kerguelen, Munna pallida and Munna maculata.
Chilton describes Munna neozelanica from New Zealand,
a species in which the first gnathopods of the adult male
have a very remarkable form, with the second joint small,
the third ‘very thick and strong, hollowed anteriorly to
receive the distal end of the limb when bent back ; carpus
expanding distally, mallet-shaped; propodos small and
rounded.’

Paramunna, Sars, 1866, has exceedingly prominent
eyes, the mandibular ‘ palp’ short and thick, three-jointed,
the last three segments of the perzeon narrow and armed
with acute laterai processes. The uropods are very short,
simple, biarticulate. The genus is intermediate between
Munna and Pleurogonium. The type, Paramunna bilobata,
has the head divided in front into two truncate lobes. It
is a sixteenth of an inch long.

Pleurogonium, Sars, 1871, is a change of name from
Pleuracantha, Sars, 1864, said to be preoccupied. It has
some or all of the segments of the perzeon laterally spimi-
ferous, the anterior four being also acuminate. ‘The pleon,
forms a single piece constricted at the base with the apex -
obtusely pointed. There are no eyes. The mandibles

IN THE NEST OF A MOLLUSC 381

have no molar tubercle, and the ‘palp’ is very small,
indistinctly two-jointed. The limbs are nearly as in
Munna. The uropods are very short, two-branched, the
branches simple, unequal. ‘The Norwegian species are
rubicundum, spinosissimum, and inerme, all instituted by
Sars. Beddard has added two species from Kerguelen and
one from Tristan da Cunha.

Acanthomunna, Beddard, 1886, is akin to Munna, but
the first antenne have a long instead of a short flagellum,
and the limbs of the pereeon have the seventh joint simple.
The type is Acanthomunna proteus from New Zealand.

Leptaspidia, Bate and Westwood, 1867, has not been
very fully described. The animal is said to be ‘ pear-
shaped, flattened, but the latter epithet does not well apply.
to the ovigerous female. ‘The pleon is oval, entire and
_ almost acute at the apex. The limbs, except the first pair,
are very slender, but not very short; they have the seventh
joint simple. The uropods are minute, single-jointed,
lateral. ‘The first pleopods are said to ‘shut together in
the form of a flattened pear, divided down the centre.’ The
impression given by the figure is of a pair of valves as in
the tribe valvifera. This may be correct in regard to the
male, but in the female there is a single opercular plate,
slightly carinate down the centre. The type is Leptaspidia
brevipes, from the Clyde, where this microscopic species
was first found by Mr. David Robertson in the strange
fibrous nests of the molluse Lima hians. It has no eyes.

Neasellus, Beddard, 1885, is near to Plewrogonium and
Paramunna in character, and in the articulation of the first
antennee below the lateral extension of the head it re-
calls the appearance of Leptasyidia. ‘The first and second
seoments of the perzeon are dorsally fused in the middle ; the
fourth and seventh segments are narrower than their neigh-
bours. The type is Neasellus kerquelenensis (see Plate XIV.).

Astriirus, Beddard, 1886, is much like Leptaspidia and —
Pleurogonium in appearance. There appear to be traces of .
eyes. ‘The fingers are not bifid. The uropods are rudi-
' mentary, yet perhaps two-jointed. The type is Astrurus
crucicauda from the prolific vicinity of Kerguelen.

28

O82 A HISTORY OF RECENT CRUSTACEA

Nannoniscus, Sars, 1869, has the head produced into a
frontal process, the pleon consisting of a single piece, sub-
triangular, apically rounded or trungate. There are no eyes.
The mandibles have ten spines in the spine-row, the molar
short and narrow, the ‘palp’ short, three-jointed. The
operculum of the pleon is short, armed with a tooth ; the
uropods are very short, two-branched, with the inner branch
the longer, or they are single-branched. The type, Nann-
oniscus oblongus, Sars, a twelfth of an ich long, was
taken at depths between 120 and 250 fathoms. It 1s de-
scribed as having on the short three-jointed first antennee
‘a single ovoid olfactory papilla of portentous size” A
second species, Nannoniscus bicuspis, Sars, has the first
antenns seven-jointed, the second pair forming on the
outer side a large triangular process. ‘This species has the
uropods simple, biarticulate.

Fugerda, Meinert, 1890, has the last three segments of
the perzon longer than the anterior segments, the pleon-
seoments fused into one. The mandibles are without
molar and ‘palp.’ The maxillipeds have the first three
joints of the ‘ palp* broad, the last two narrow and small.
All the limbs of the perzon are long, the first pair more
slender and smooth than the rest. The opercular plate of
the pleon is orbicular; the uropods are moderately long, the
branches single-jointed, the inner the longer. Eugerda
globiceps is the type.

Dendrotion, Sars, 1871, has the head divided into two
ear-like branches, to which the two pairs of antennee are
attached. The first four segments of the pereeon have each
a long spine on either side; the three following segments
are abruptly much narrower. The pleon has all the seg-
ments fused into one. There are no eyes. The mandibles
have a conical molar, the ‘ palp’ three-jointed, The first
limbs of the perzeon are shorter than the others, which are
long and slender. There are no uropods.

Macrostjlis, Sars, 1864, has the first three segments of
the peraeon so closely united as to give an appearance of
fusion, the four following segments being very distinct,
with acute postero-lateral angles. The pleon forms a long

LEGS IN SEVERAL SAMPLES 383

segment, dilated in the middle and ending obtusely. The
first antenne are short, the second long, with the flagellum
shorter than the peduncle. The mandibles are without
‘palp ;’ the maxillipeds have the two terminal joints of
the ‘palp’ very short. The third pair of limbs of the
perzeon are the most robust, while the fourth pair are very
small, and the seventh not much larger. The uropods are
long, slender, simple, two-jointed. ‘The type is the Nor-
wegian Macrostylis spinigera, from a specimen about a six-
teenth of an inch long. Macrostylis latifrons, Beddard,
from 2,050 fathoms in the North Pacific, is a fifth of an
inch long. Vana longiremis, Meinert, 1890, beyond doubt
agrees generically and probably also specifically with the
type of Macrostylis.

Ischnoséma, Sars, 1866, meaning ‘a slender body,’ is,
_ perhaps, the most singular-looking of this family. The
fourth and fifth segments of the perzon are fused, and
combine to form a columnar centre to the animal. The
pleon is constricted at the base. There are no eyes. The
mandibles have a large molar, but no ‘palp.’ The first
limbs of the pereon are short and robust, the others slender
and long. ‘The uropods have a single one-jointed branch.
The type is the Norwegian species, [schnosoma bispinosum,
Sars. The same author has described an Arctic species,
Ischnosoma quadrispinosum. Beddard adds Ischnosoma
spmnosum (see Plate XIV.), from the Azores, Ischnosoma
bacillus, from 50° south latitude, I[schnosoma bacilloides,
from South America, and Ischnosoma Thomsoni, from 2,050
fathoms depth in the North Pacific.

Fanily 2.—Munnopside.

The animal has a bipartite appearance, the anterior
portion consisting of the head and first four segments of
the perzeon, the last three segments of the perzeon and the
consolidated pleon forming the other. There are no eyes.
The first limbs of the pereeon are subprehensile and shorter
than the three following pairs of limbs, which are ambu-
latory and in general very elongate; the next two or the
next three pairs are natatory, having some of the joints

384 A HISTORY OF RECENT CRUSTACEA

flattened and ciliated. The incubatory pouch in the female
is generally under the first four segments of the perzon.

The swimming joints above described resemble those
found on some of the swimming crabs, and differ strikingly
from what is customary among the Isopoda. To this
family, indeed, the title of equal-legged animals is singu-
larly inappropriate.

Munnopsis, Michael Sars, 1861, has the body suddenly
constricted and slender behind the fourth peraeon-segment.
The second antennz are very elongate, with the peduncle
six-jointed. ‘The mandibles are acuminate, with a second-
ary plate on the left, but not on the right mandible, with-
out molar, and with a three-jointed ‘palp.’ The first and
second hmbs of the perzeon are short, rather robust, sub-
prehensile, the two following pairs enormously elongated ;
the three following pairs are natatory, without a seventh
joint. The arrangement of the pleopods corresponds with
that already described in Janira. The uropods are slender,
single-branched. Munnopsis typica, Michael Sars, the type-
species, has a very extended boreal distribution in deep
water on muddy ground. Hansen says that in the second
antennee the long fourth and fifth joints of the peduncle
are immovably fused. In these organs the flagellum is
nearly as long as the peduncle, and the two together are
about five times the length of the body. By the great
elongation of the fifth and sixth joints in the third and
fourth limbs these equal about three times the body’s
length. Munnopsis australig, Beddard, with no ‘ palp’ to
the mandibles, and with the marsupium arising apparently
only from one segment of the perzeon, must probably be
referred to a separate genus.

Hurycope, Sars, 1864, has the body not abruptly con-
stricted. he second antennz are very elongate, with six-
jointed peduncle. ‘The mandibles have a spine-row, molar,
and three-jointed ‘ palp,’ but no secondary plate on either
mandible. The first pair of limbs are rather short, the
next three pairs are long, and the last three pairs are nata-
tory, with an unguiform seventh joint. Thé pleopods
are as in the preceding genus. The uropods are short,

THE MUNNOPSIDZ2 385

two-branched, the branches single-jointed. Hight Nor-
wegian species have been described by G. O. Sars, in some

of which the second, third,
and fourth limbs are ex-
tremely elongate, but in
Hurycope robusta, Harger,
from the Gulf of St.
Lawrence, they are not
much longer than the body.
The three species first de-
scribed, Hurycope cornuta,
phalangium, and mutica,
all of Sars, range in length
between a seventh and a
sixteenth of aninch. Eu-
‘rycope gigantea, Sars, ex-
tensively distributed in
the high north, attains a
length of an inch and a
third, by a breadth of over
half an inch. It is notable
that this species and Mun-
nopsis typica appear inva-
riably to occur together.
Both sexes are known of
both. The first antennze
are shorter in the females
than in the males. In Hu-
rycope gigantea there is,
according to Hansen, a
little triangular plate on
the third jointof thesecond
antenne, which may be re-
garded as a rudimentary
exopod. It would not seem
very rash to conclude from
this that the first two
joints are really one joint

subdivided. The fourth

Fic. 32.—Eurycope gigantea, Sars [Hansen].

386. A HISTORY OF RECENT CRUSTACEA

and fifth joints are, Hansen says, in this species firmly
fused. Of the swimming-feet he observes that the
feathered setze are attached a little within the margin, to
obtain support when displayed for swimming, and to have
a resting-place when folded away between the strokes.
Hight new species are named and described by Beddard
from the Challenger explorations, all from considerable and
some from very great depths.

Ilyarachna, Sars, 1869, ‘ mud-spider, was named in
place of the preoccupied Mesosténus, Sars, 1864, meaning
‘narrow in the middle.’ The body is suboval, but deeply
incised ,behind the fourth segment of the perzeon. ‘The
second antenne are long; the mandibles have a molar
tubercle, and either have a small three-jointed ‘ palp’ or
are without one. The first limbs of the perzeon are not
elongate, the second usually more robust than the rest, the
third and fourth in general very elongate, the fifth and
sixth natatory, with an unguiform seventh joint, the
seventh long and slender, with the joints scarcely flattened,
the nail long and curved. The uropods are simple, lying
close to the pleon. Sars has described five Norwegian
species, of which the first was Ilyarachna longicornis.
Ilyarachna quadrispinosa, Beddard, was brought by the
Challenger from Kerguelen.

Desmoséma, Sars, 1864, ‘a chain-like body,’ has the
segments marked off by constrictions which are commonly
deep; the three hinder segments of the pleon are larger
than those which precede. The second antenne are shorter
than the body, slender in the female, robust in the male.
The mandibles have a dentate ae ee spine-row,
molar, and usually a three-jointed ‘palp,’ ending in a long
unguiform spine. The first four pairs of limbs are short
and robust, the last three natatory, but with the fifth and
sixth joints not greatly expanded, edged with spines that
are flattened but not plumose; the seventh joint is narrow
and stiliform. The uropods are simple, two-jointed, the
last joint being the larger. Sars has described four Nor-
wegian species, Desmosoma lineare, armatum, aculeatum, and
tenuimdnum, of which aculeatum has no mandibular ‘ palp.’

THE TAIL UNIQUE OOT

Acanthocope, Beddard, 1885, has the side-plates of the
perzeon, except the first pair, furnished with long spine-
like processes, and the pleon ending in an elongate spine-
like process. The mandibles have a powerful molar and a
small, three-jointed ‘ palp.’ The hind limbs of the perzeon
have a natatory character. The uropods are simple, long,
and stiliform, from three- to five-jointed. In Acanthocope
spinicauda, taken from a depth of 1,800 fathoms in the
Southern Ocean, the five-jointed uropods present a feature
unique in this tribe. <Acanthocope acutispina, from South
America, has three-jointed uropods, and the first antennee
with a short flagellum instead of a very long one as in the
companion species.

388 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXV
TRIBE V.—PHREATOICIDEA

Family Phreatoicide.

Phreatoicus, Chilton, 1882. The only genus.

The animal is long, subcylindrical, laterally coin-
pressed. The seven segments of the peraon are distinct,
with small distinct side-plates. he pleon has six distinct
segments, the first five laterally produced downwards, the
fifth longer than any of the preceding four, the sixth
dorsally fused with the telson, but distinguished from it
by lateral sutures or setose ridges. The eyes are small.
and Jateral or absent. The first antennze are short, the
flagellum subterminally thickened and carrying olfactory
filaments; the second antenne have a five-jointed peduncle
and a flagellum exceeding it in length. The mandibles
have a dentate cutting edge, accessory plate on the left
mandible only, a long spine-row, strong molar, and three-
jointed ‘palp;’ the lower lip is bilobed; these and the
other mouth-organs agree in all important respects with
those of Asellus, only that in the maxillipeds the fourth
joint is strongly produced on the outer side. The first
limbs of the person are subchelate, of the ‘gnathopod’
form. The rest are ambulatory, the last three pairs facing
those in front as in most of the Gammaridea. All the
pleopods have the outer branch ciliated, the inner and
smaller branchial; the first pair have narrow branches;
the second have in the male the usual stilets, which are
curved and semicylindical, and the outer branch both in
this and ihe following pairs is two-jointed. ‘The uropods

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A NEW TRIBE 389

are infero-lateral in position, with a strong spinigerous
peduncle and two spinigerous branches.

The type-species is Phreatowcus typicus, Chilton, 1882,
from a pump at Hyreton in New Zealand. In this species
the eyes are not visible, the second joint in the limbs of
the pereeon is very slightly expanded, and in the seventh
pair is shorter than the following joint. The pleon is
remarkable for the great length of the fifth segment, a
character not met with elsewhere either in the Isopoda or
Amphipoda, though it is a distinguishing feature of the
Cumacea. In regard to colour the animal is described as
transparent.

Phreatoicus australis, Chilton, 1891, was obtained by
Mr. R. Helms from Mount Kosciusko in Australia. The
specimens were taken, he says, at a place ‘ locally known
- as “Piper’s Creek,” at en elevation of 5,700 feet or
perhaps rather more, on the track from “ Pretty Point”
towards the ‘“‘Ram’s Head.” The creek (or at least a
branch of it) runs here through a, in damp weather,
boggy flat, and at the time (early in March 1889)
was slowly trickling along forming puddles here and
there. In one of these puddles where there was only a
little water covering the black bog mud, perhaps from two
to three inches, | made the find. In turning the stones
(Hat pieces such as frost will split from rocks—not
boulders) I found no difficulty in picking the animals off,
the most of them keeping quiet. They were pretty
numerous under the stones, when at all, and looked
exceedingly like the surrounding earth. Through this
and their quiet habit I did not notice at first that they
were so numerous, but seeing that they were interesting
things (I had not seen anything like it before) I took
pretty well all I could lay hands on; and this is the only
time and place I have collected them although I have
many a time turned stones in the neighbourhood and in
similar localities.’ Mr. Chilton supplies the not unin-
teresting detail that ‘on March 13th at ‘“ Pretty Point”
Mr. Helms found the remains of his tea completely frozen
in his billy.’ This new species is distinguished from the

390 A HISTORY OF RECENT CRUSTACEA

type by having eyes, which are small but distinct, the
second antenne shorter, the second joint in the limbs of
the pereon more dilated, and the pleon furry. In de-
scribing this species Mr. Chilton mentions that the third
pleopods have on the outer margin of the basal portion
‘an ovate appendage which perhaps represents the epipo-
dite. He finds the males distinguished from the females
not only by the special organs at the base of the seventh
pair of limbs, but by rather stronger hands in the first pair,
and a clasping arrangement in the last two joints of the
fourth pair. The female appears to have brood-plates on
the second, third, and fourth segments of the pereeon.

The figures in Plate XVI. are copied from the papers
in which Mr. Chilton describes the two notable species
under discussion.

While the mouth-organs and pleopods make Phreatoicus
an unquestionable Isopod genus, the affinity with the
Amphipoda appears not a little remarkable. The lateral
compression of the body, the downward lateral production
of the pleon-segments, the arrangement of the limbs of
the pereeon, the considerable development of the pleon,
the two-jointed branch in several of the pleopods, the
strong indication of a distinction between the sixth pleon-
segment and the telson, and above all the position and
structure of the uropods, form a group of characters which
bring this genus nearer to the Amphipoda than any other
Isopod can claim to be. In the limbs of the perzeon the
third joint is not very short, as it usually but by no
means always is in the Gammaridea, nor does the fourth
joint in the first pair underride the fifth as is usual in the
enathopods of the Gammaridea. On the other hand the
clasping arrangement of the fourth pair of limbs is
strikingly parallel to what is found in the Orchestide,
and, as Mr. Chilton points out, the expansion of the
second joint of the limbs in Phreatoicus australis is similar
to what is found in so many of the Amphipoda. In his
admirable discussion of all the characters Mr. Chilton is
inclined to disallow the Phreatoicidee any special proximity
to the Amphipoda, and is thus induced to remark that

APPROXIMATE TO THE AMPHIPODA O91

the uropoda ‘present no greater resemblance to the Am-
phipoda than to several of the Isopoda such as Asellus,’
although the position alone would suffice to distinguish
them from those of Asellus, and if disjoined from the
animal there is absolutely nothing about them that would
enable any one to say that they belonged to any Crustacean
except their own or some Amphipod genus. The spine
at the lower end of the peduncle occurs as so often in the
Amphipoda. The genus and its two species are beyond
dispute remarkable, requiring to be placed in a separate
family, and though some may prefer to class this among
the Asellota, | have ventured to think that a separate tribe
Phreatoicidea should be instituted to receive it.

392 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXVI
TRIBE VI.—EPICARIDEA

THis tribe consists of Crustacea which in the adult
state are parasitic upon other Crustacea, to which allusion
is made in the tribal name signifying ‘dwellers upon
shrimps.’ The females become degraded in form and often
very unsymmetrical, while the males, much smaller and
symmetrical, are often free, but usually do not quit their
partners. |

The notion entertained of old by the French fisher-folk,
that the Bopyrt in the prawn were young flat-fish, received
scientific support from M. Deslandes in 1722, but in 1772
was disproved by M. Fougeroux de Bondaroy. For some
sixty or seventy years after his time the knowledge of the
group was but slowly advanced. Remarkable forms were
obscurely described by Cavolini, Montagu, and Risso.
Others were made known later on with clearer definition
by H. Rathke and Kréyer. Duvernoy and Dana contri-
buted new genera ; and by degrees the tribe both gathered
volume and evoked attention. During the last thirty
years Fritz Miiller, R. Kossmann, Paul Fraisse, and
various other writers of eminence have thrown light upon
the subject from several points of view, and in the latter
part of that period the labours of MM. Giard and Bonnier
have introduced order and clearness into its arrangement,
The writings of these last-named observers will not soon
or easily be superseded as the leading authorities on this
tribe. They ascribe to it seven families, the Microniscide,
Cyproniscidze, Dajidze, Cabiropside, Cryptoniscidee, Ento-
niscidee, and Bopyride, for which they propose the follow-
ing phylogenetic table :—

PARASITIC ISOPODS 393
Bopyride

Bopyriens Loniens

hryxiens

P x
Entoniscidze ae

Cryptoniscids

Cabiropsidze
Dajidx

Cy proniscidee

Microniscidse
Microniscidz parasitic on Copepoda.
Cyproniscidze ~ » Ostracoda.
Dajidee ” 5» Schizopoda.
Cabiropsidze 3 », lsopoda and Amphipoda.
Cryptoniscide ,, », Cirripedia (chietly the parasitic),
Entoniscide “i » Brachyura.
Bepyridz ss », Brachyura and Macrura.

The Epicaridea are all, strictly speaking, external para-
sites, although according to position on their host they may
be classified as abdominal, branchial, or visceral. In those
which inhabit the branchial chambers of other crustaceans,
the form of the female becomes obliquely ovate, the convex
side being on the right or the left, according as the animal
occupies the right or left side of its host. In some genera
(Kepon, Gyge, lone), a right-hand female has the marsu-
pial plates of the right side overlapping those of the left,
while the reverse is the case in a left-hand female. The
plates are so imbricated that the last of the five pairs is

O94 A HISTORY OF RECENT CRUSTACEA

outermost. They are attached pair by pair to the first five
segments of the perzeon as in the Cymothoide. Giard
and Bonnier regard them as representing parts of the
exopods of the limbs. ‘This seems to require what they
admit to be a very hypothetical explanation of an Isopod’s
leg, namely, that the fourth and fifth joints are the fifth
subdivided, and that the small first joint is a fusion of
the first and second. By this redistribution the long
second joint becomes the third, and thus matches the long
third joint so frequently found in the third maxillipeds of
the higher Crustacea. But convenient as the hypothesis
may be for attaining this piece of symmetry, other grounds
for it are not as yet forthcoming. However that may be,
the authors show that the structure of these marsupial
plates admits of the view that they are to a considerable
extent branchial, that is, assist in the oxygenation of the
blood. The first pair has a special structure and func-
tion. As examined in the genus Cancricepon the larger
and upper member of the pair is found to be divided into
two portions by a median fold with an outer crest. The
front part covers the base of the maxillipeds, the lower
part 1s covered by the opposite plate and floats freely in the
marsupial cavity. ‘There are two movements affecting this
apparatus, one that alternately lifts and lowers it as a
whole, the other alternately lifting and lowering the front
and back. By this means a current of water is maintained
both to the marsupial plates and to the embryos within
them. Inthe podophthalmous host the water enters at the
back and leaves by the front of the branchial cavity, so that
in the parasite which lies with its head towards the tail of
its host it naturally enters by the upper part and leaves by
the lower. In the Entoniscidz the arrangement is modi-
fied to correspond with their position among the viscera.

In regard to the chance of procuring specimens, the —
authors note that, to obtain ‘the Cryptoniscian stage’ and
the young female of Athelque paguri, the pleon of Pagurt
should be carefully examined in the month of September,
and that these interesting forms will be found much less
rare than is often supposed. Dr. Hoek records that on

A PROTRACTED SEARCH 3995

examining twelve specimens of Mysis oculata he found six
infested with young Dajus mysidis. On the other hand,
at the Neapolitan Marine Station, Salvatore lo Bianco
had opened about 10,000 Brachyura before he came across
a couple of Risso’s Hrgyne cervicornis, and MM. Giard and
Bonnier themselves had to sacrifice tens of thousands to
provide the requisite materials for their ‘Contributions 4
létude des Bopyriens.’

Should any sensitive persons regret this expenditure
of life on a scientific investigation, they must remember
that it is perfectly trivial compared with what is continu-
ally being exacted for the meaner purpose of tickling man’s
palate, trivial also compared with the havoc so frequently
wrought by storms among creatures of this same class, and
further, that against every crustacean destroyed must be
_ set the lives of many others preserved which would else
have been its victims.

According to the authors cited only Portunion Koss-
mann on Platyonichus latipes can be called common. ‘They
opened an enormous number of Porcellana longicornis at
ever so many points of the French coast before meeting
with a specimen of Hntoniscus Miillert at Concarneau.
Both there and at three other places they examined the
Pagurid Clibanarius misanthropus without finding a para-
site, although at Mahon in Minorca Dr. Fraisse found upon
this crustacean a Peltogaster, a Cryptoniscus, an Athelque,
and a Paleevyge. Thousands of Portunus depurator (Linn.)
and Porcellana platycheles had in like manner yielded them
no parasites. ‘They feel ready to affirm that our common
edible shrimp, Crangon vulgaris, is free from Bopyrids,
though they remind us that Crangon munitus, its American
congener, is infested by Argeza. The occurrence of Epica-
ridea may be called, in terms of our present knowledge,
very capricious. It not unfrequently happens that, where
they occur at all, they occur in some profusion, their hosts
suffering as it were from an epidemic attack. One host
may undoubtedly carry several species of parasite, but it is
an axiom with Giard and Bonnier that both among the
Epicecidea and the Rhizocephala no species of parasite has

29

396 A HISTORY OF RECENT CRUSTACEA

more than one host. ‘This, if accepted, makes the distinc-
tion of species particularly easy. It is, however, a rather
wide generalisation. It appears to imply that the larval
forms always settle on the same species as that occupied
by their parents, or perish unless they do. Yet, if the
larvee of a single brood were dispersed upon hosts of nearly
related species, one might expect that to those placed in
slightly novel circumstances, some difference of habit would
result rather than destruction. Still the important point
would remain that in each species of host the parasite is
distinct in character, and in favour of their view that it
is also distinct in species, Giard and Bonnier urge that
‘often among closely related Epicarids there are consider-
able physiological differences, sometimes even morpholo-
gical differences relating solely to the male or the embryo,
differences too important to be attributed simply to the
difference of host.’

In the relations between the Epicaridea and their hosts
a very singular circumstance has recently been brought to
light. Rathke and other observers had commented on the
unexplained peculiarity that the infested prawns and
crabs all appeared to be females, and moreover sterile
females. De Haan, as heretofore remarked, not unfre-
quently records sterile females of a different form from the
fertile females of the same crab. Guard and Bonnier have
shown that an infested female is not always absolutely
sterile; but a few years earlier Professor Giard made the
extremely interesting discovery that the parasites attack
males just as freely as the other sex. Only, under the
influence of the invader the distinguishing characters of
the male are hindered from development, and a sort of
intermediate appearance is permanently retained.

Family 1.—Micromscide.

This includes the least degraded forms, corresponding
in general aspect to the second larval form of the other
families. ‘They are parasitic on Copepoda.

Microniscus, Fritz Miiller, 1870, is the only genus.

Pl. xvii.

a. Microniscus calani (Sars). b-f. Cyproniscus cypridinae (Sars).

IICRONISCIDA—CYPRONISCIDA 397

The type, Microniscus fuscus, found by Miiller on a species
of Calanus on the coast of Brazil, is characterised by
having ‘the third pair of thoracic feet longer than the
others, and terminating in an oval lamella, by which the
animal fixes itself on its host.’ Microniscus calini, Sars,
1882 (see Plate XVII.), with all seven pairs of feet
similar, fastens itself to the back of Calanus finmarchicus,
Gunner, and, according to Sars, also to Pseudocalanus
elongatus, Boeck. It is possible, however, that the para-
sites on the latter Copepod have not been specially ex-
amined to determine their identity with those on the
former. Microniscus calant has the pleopods two-branched,
a character which ‘ is only met with exceptionally in the
cryptoniscian embryo of the Entoniscidee and the Bopyride.,

while it is the rule in the Cryptoniscidee.’

Family 2.—Cyproniscide.

They are parasitic on Ostracoda.

Cypromscus, Kossmann, 1884. The characters of the
family and genus rest on those of a single species, Cypro-
miscus cypridine (Sars), 1882 (see Plate XVII.), which is
thus described :—‘The adult female, deprived of all the
mouth-organs and appendages, with the whole body filled
with eggs, sack-like, curved, the arched middle of the back
divided into six or seven indistinct segments, the ventral
side flattened, the sides slightly expanded, the frontal part
widely cordate, exserted, defined by an emargination on
either side from the lateral parts. The male (? when adult)
like the female devoid of appendages, with the body
spindle-shaped, indistinctly segmented, the anterior ex-
tremity furnished on either side with a long flexuous root-
like process for fixation. An advanced larval stage re-
sembling Cryptothiria pygmcea in form and structure, but a
little more elongate, and quite without eyes.’ Sars found
these queer animals at the Lofoden Isles fixed within the
valves of Cypridina norvegica, Baird, to the hindmost part
of the animal’s back, calmly occupying the space properly
belonging to the eggs of its host. Asa rule he found what

398 A HISTORY OF RECENT CRUSTACEA

appeared to be two males fixed one on each side of the
female.

Family 3.—Dajide.

They are parasitic on Schizopoda. In the adult female
the trunk-feet are only five pairs, and the sides of the
body are folded ventrally so as to form a chief part of the
marsupium, only the last pair of marsupial lamellee re-
taining an important function in closing the pouch from
behind.

Dajus, Kréyer, 1846. The animals of this genus are
attached on the ventral side of the host. In the female,
the first antennz are tuberculiform, three-jointed, the two
terminal joints minute; the second antennz have a large
basal joint, succeeded by about eight slender joints. The
spoon-shaped ends of the mandibles can be projected
through an opening between the upper and lower lips.
Both pairs of maxilla: are rudimentary, tubercular. The
maxillipeds are two-jointed, with an epipod, but no
exopod. Between them is developed a triangular opercu-
liform plate. The sixth and seventh pairs of feet disap-
pear ; the preceding five are all nearly alike. The imbricated
first four pairs of marsupial plates form a movable lid to
the front opening of the marsupium. ‘The large fifth pair
close it behind, in combination with the inner branches
of the first pleopods. The remaining pleopods are rudi-
mentary, the second, third, and fourth being bilobed, but
the fifth consisting of a pair of simple tubercles. The
uropods also are simple, but a little more elongate. The
adult male is placed between the first pleopods of the
female. It has the first segment of the perzeon fused
with the head; the pleon is a single piece without pleo-
pods. The first antenne are four-jointed, the second
eleven-jointed. The mouth-organs consist of strong
mandibles and tubercular first maxillee and maxillipeds.
The male, in the earlier ‘cryptoniscian stage, has seven
distinct segments in the perzeon and six in the pleon, with
appendages to each, those of the pleon being all biramous,
with the branches set wide apart on the broad peduncle.

THE DAJIDA 399

Hoek has stated that the male in this stage is com-
pressed laterally, so as to look like an Amphipod, and that
it is fixed to the body of the female by the aid of a sucker.
Giard and Bonnier remark that the lateral compression
would be very astonishing, since all the Epicarids in the
cryptoniscian stage tend to be flattened. From specimens
sent me by Dr. Fulton of the Scotch Fishery Board, I
should say that these cryptoniscian forms of the male were
decidedly flattened, not compressed, but these specimens
were taken or found apart from females, whereas Dr.
Hoek’s may have been modified by their position as
attached to the female. ‘The suboral circular sucker is a
conspicuous object, which attracted Dr. Fulton’s attention
at once. It appears to have escaped notice that this ring
is shown in the figure of Dajus mysidis, Kroyer, on plate
28, fig. 1a, of the ‘ Voyages en Scandinavie, &c.’ Dr.
Hoek has figured the curious hand-shaped spines on the
sixth joint of the legs. Some of these spines are split as
it were into five fingers and a thumb.

Three species are at present allotted to the genus :—

Dajus mysidis, Kroyer, 1846, on Mysis oculata
(Fabricius).

—— Pajus-mixtus,Giard-and Bonnier, 1889, on-Mysis mixta,

Dajus sirielle, Sars, 1885, on Siriella Thompsonii
(Milne-Edwards).

Aspidophrywus, Sars, 1882. The animals are attached
to the back of the perezon of the host. The female is
much more curved than in Dajus. It has the five pairs
of feet more elongate, the first four pairs of marsupial
plates very small, not overlapping from side to side, the
last pair very elongate, soldered together longitudinally ;
the pleon unsegmented, without appendages. In the male
the pleon has an indication of the segments of which it is
composed, the sixth especially being distinct; the only
appendages are the two-jointed uropods.

Aspidophryxus peltatus, Sars, 1882, on Erythrops ery-
throphthalmus (Goés). Eggs many and small. )

“Aspidophrywus Sarsi, Giard and Bonnier, 1889, on |

4.00 A HISTORY OF RECENT CRUSTACEA

Lirythrops nucrophthalma, Sars. Eggs few and large.
Upon this species Giard and Bonnier have found a para-
sitic Copepod, which thus retaliates upon the Isopods that
are parasitic on Copepoda.

Notophryxus, Sars, 1882. The animals are attached to
the back (or side) of the host. In the female the body is
symmetrical, a little depressed, imperfectly segmented,
the first antenne are laminar, the five pairs of feet are
small, incompletely articulated, and crowded into a narrow
space on either side of the mouth. ‘The pleon is without
appendages. The male has the pereeon clearly segmented,
with the full number of appendages, the pleon unseg-
mented, without appendages.

Notophrycus ovoides, Sars, 1882, on Amblyopsis abbre-
viata, Sars.

Notophryzus clypeatus, Sars (1880), on Pseudomma
roseum, Sars. :

Jotophryxus lateralis, Sars, on Nemtoscelis megalops,
Sars. This is thought likely to become the type of a new
genus.

Notophryzus globularis, Sars, 1885, on Thysanoessa gre-
garia, Sars.

Heterophryxus, Sars, 1885. The animals are attached
to the back of the host. The female has the back pretty
distinctly segmented, the five pairs of feet distant from
one another, and the fifth pair remote from the rest, di-
rected backwards, bifurcate ; the pleon rudimentary, with
the male adhering to this rudiment.

Helerophryxus appendiculatus, Sars, 1885, on Huphausia
pellucida, Dana.

Fanuly 4.—Caliropside.

They are parasitic on Isopoda and Amphipoda.

Cabirops, Kossmann, 1884, for Cabira, Kossmann, 1872,
preoccupied, is described as having ‘ 8-9 distinct segments,
divided by a chitinous lamella into dorsal and ventral
halves; mouth in the ventral part of the first segment;
pouch-like appendages of the single segments filled with
embryos’ (‘ Zool. Record,’ 1872).

CABIROPSIDZ—CRYPTONISCID A 401

Cabirops lerncesdiscoides, Kossmann (1872), was found
in the brood-cavity ofa Bopyrus from the Philippines. To
this genus Giard and Bonnier approximate Cryptothiria (?)
marsupialis, Sars, reported to be parasitic on tuo species,
Eurycope cornuta and Ilyarachna lonjicornis. The female
only of this parasite is known. It is a simple pellucid
broadly bilobed sack, narrowed in front, filled with eggs,
with an ovate oral area, and no appendages.

Podascon, Giard and Bonnier, 1889. ‘ All the body of
the female is, so to speak, transformed into a vast incuba-
tory chamber, enclosed by two lateral plates extending from
the first to the fifth segment of the peraeon and united
along the median line so as merely to leave at either end
an opening for the passage of water.’

Podascon Dellavallei, Giard and Bonnier, 1889, on the
Amphipod Ampelisca diadema (Costa). When first de-
scribed, this was the only known instance of an Isopod
parasitic on an Amphipod. New forms have since been
found by M. Chevreux on three other species of Ampelisca.
Also a Cryptoniscus-form found by Gourret on Leucothoe
spimcarpa in the Ascidian Phallusia gelatinosa, may in the
opinion of MM. Giard and Bonnier prove to belong to
the Cabiropside. A Cryptoniscus-form found by myself
among the eggs of an Onisimus plautus (Kroyer) from the
Arctic regions, closely agrees with the Hemioniscus balam
of Buchholz, which is a member of the next family.

Fanily 5.—Cryptonscide.

They are parasitic on Cirripedes, chiefly on the para-
sitic Rhizocephala. It is reasonable to believe that the
Rhizocephala did not begin their existence as parasites,
but descended from independent Cirripedes. Fritz Miiller
ingeniously suggests that in becoming parasitic they took
with them their own parasites, the Cryptoniscide. Guiard
and Bonnier further suggest that the Entoniscide and
Bopyridee were intreduced to the higher Crustacea by an-
cestors parasitic on Rhizocephala, and that in course of
time they found their advantage in exchanging an indirect
for a direct parasitism.

4.02 A HISTORY OF RECENT CRUSTACEA

In the Cryptoniscidee the first two segments of the
perzeon carry very short feet, sometimes degraded, pro-
vided at the extremity with a strong claw; the pleopods
are two-branched. The adult female, without becoming
unsymmetrical, loses the characteristic shape of an Isopod
and all or most of its appendages.

The Epicaridea in general pass, according to Giard and
Bonnier, from the embryo or first stage of their develop-
ment to a second or cryptoniscian stage, in which they
resemble the males of this family. According to Dr.
Fraisse the free-swimming Cryptoniscide have a quite
peculiar smell, and the female becomes sexually mature
before adopting a parasitic life. Notwithstanding Pro-
fessor Kossmann’s scepticism regarding the latter state-
ment, I believe that it is correct. At all events a minute
specimen taken in the tropical Atlantic, retaining all its
appendages, and of the shape usual in the ‘ cryptoniscian
stage,’ appears to have ovaries crowded with eggs.

Oryptoniscus, Fritz Miiller, 1864. The characters no-
ticed by Fritz Miiller are that the young of Cryptoniscus
are, like most other Isopods, hatched with the last perzeo-
pods undeveloped, and that the penultimate pair are thin
and rod-like, differing much from those which precede them.

Oryptoniscus planarioides, Fritz Miiller, 1864, was found
on Peltogaster purpureus (F. Miiller), together with Phrywus
resupinatus, on a Pagurid, in Southern Brazil. Fritz
Miiller remarks of this species, that, if the eggs and young
did not betray the crustacean character, the female would
almost rather be taken for a flat-worm (a Planarian) than
for an Isopod.

The Peltogaster, it must be understood, is a strangely
metamorphosed Cirripede, which pushes roots into the
body of its Pagurid host. Then comes the Cryptoniscus, —
penetrates the parasite, and draws nourishment to itself
through those piratical roots. Strangely it happens next
that under this infliction the body of the Cirripede, cheated
of its nutriment, dies and falls away, and yet its roots
remain and flourish for the benefit of an alien digestive
apparatus. Crustaceans of three distinct orders are thus

A MEDLEY OF ANIMALS 403

brought together, and, as it were, jumbled up into a sort
of compound animal, so that when the Pagurid devours

a shrimp, its gastronomic exertions are supplyi ing food
Bsach the remnants of a shapeless Cirripede to a degraded
Isopod. This remarkable arrangement on the body of a
hermit-crab, itself occupying the shell of a departed mol-
luse, must be regarded as the result of special creation by
those who still uphold the venerable doctrine of the fixity
of species. What a gasp an intelligent mind must give at
swallowing such an explanation !

Cryptoniscus paguri, Fraisse, 1878, was found on Pelto-
gaster Rodriquez, Fraisse, on Clibanarius misanthropus,
Risso, at Mahon in Minorca. It is described as flat and
worm-like, much resembling the preceding species.

Oryptoniseus lar veformis, Giard, 1874, on Sacculina
carcint.

Danala, Giard, 1887, was substituted for part of
Zeuxo, Kossmann, 1872, preoccupied.

Danalia curvatu (Fraisse), 1878, on Saceulina neglecta,
Fraisse, from the Bay of Naples, is said to be round and
rolled together, very like the Cabirops lernceodiscoides of
Kossmann. Dr. Fraisse says that it is either a simple
parasite on the Sacculina, or placed beside it on the crab
Inachus scorpio, Fabricius, but that in any case it has to
draw its nourishment from the roots of the Sacculina.

Danalia Lobiancoi, Giard and Bonnier, 1890, on Portu-
nascus corrugatus, Giard.

Danalia Dohrni, Giard, 1887, on Grapsisaccus Benedent,
Kossmann. The Zeuxo longicollis of Kossmann, 1880, was
found on the pleon of Chlorodius (Leptodius) exaratus,
Milne-Edwards, in company with but remote from a Sac-
culina.

Inriopsis, Max Schultze, 1859, was substituted for
Inriope, Rathke, 1843, preoccupied.

Liriopsis pyymea (Rathke), 1843, on Peltogaster pagwrt,
Rathke. The first antenne have a very thick bundle of
hairs attached to the outer side of the basal joint in the
male.

Inriopsis monophthalma (Fraisse), 1878, on Peltogaster

4.04, A HISTORY OF RECENT CRUSTACEA

curvatus, Kossmann, is said to have a cylindrical form, and
to be nearly related to the preceding species.

Eumetor, Kossmann, 1872. ‘The male allied to Liriope
(Rathke), but without antenne ; the female much larger,
its segmentation continuing in the mature state.’ (¢ Zool.
Record,’ 1873).

Twmetor liriopides, Kossmann, 1872, in the mantle-
cavity of Sacculina pisiformis, from the Philippines. Dr.
Fraisse, discussing specimens which he supposes to belong
to this genus, from the mantle of Sacculina Denedeni, says
that no brood-cavity is present, the I[sopod being content
to use the mantle of the Sacculina for that purpose. He
also says that the male of Kossmann’s species ‘has no
olfactory setze on the inner antenne.’

Cryptothir, Dana, 1852, on non-parasitic Cirripedes.

Oryptothir minutum, Dana, in the corallidomous barnacle
Creusia, at the Fiji Islands.

Cryptothir balani (Bate), 1861, on Balanus balanordes.
The larval form, as taken with the tow-net in the Clyde,,
has eight teeth on the basal joint of the first antennee ; the
second antennz nine-jointed; the mouth-organs forming
a triangular mass, with the apex pointing backwards ; the
sides of the perzeon, and ina less degree those of the pleon,
digitate ; the first two pairs of trunk-limbs not degraded,
strongly subchelate, the next three pairs slightly so, the
last two pairs simple, with the two terminal joints elongate ;
the five pairs of pleopods and the uropods two-branched,
the branches tipped with sete. According to Bate and
Westwood, the adult sedentary female is a lobate sack-
formed mass without any appendages.

The genus Hemioniscus, Buchholz, 1866, is said to be
a synonym of Cryptothir. But according to Buchholz the
adult female of his Hemioniscus balani retains the front
part of the larval form. This, however, may not be per-
manently the case. Beddard mentions a Bopyrid in the
larval stage attached to Serolis cornuta, Studer, on the dor-
sal surface of some of the anterior segments, and ‘apparently
belonging to the genus Hemioniscus, but this parasite has
not been described.

POCKETED PARASITES 405

Teponiscus, Giard, has the single species Leponiscus
pollicipedis, parasitic, as the name indicates, on a pedun-
culate Cirripede.

Family 6. --Entoniscide.

The animals are parasitic (to appearance) within the
bodies of Brachyura, entering through the branchial into
the visceral cavity. In the females the body is extremely
unsymmetrical, with traces of segmentation when young ;
the head is swollen into a double sphere, the antenne are
metamorphosed into lips; the Jabrum, hypostome and
mandibles forming the oral apparatus. The maxillipeds
are Jamellar, the feet rudimentary, the marsupium formed
of five pairs of plates, with the first pair situated be-
' tween the rest; the ovaries opening at the base of the
fifth pair of feet, and by their prolongations determining
the shape of the perzeon ; the pleon has six segments, fur-
nished with lamellar or sabre-shaped pleopods. In the
minute male there are two rudimentary eyes, the antennz
are evanescent, the mavxillipeds are rudimentary, the
seventh segment of the pereon is without appendages ;
the six segments of the pleon are without pleopods. ‘The
embryo has two eyes, sometimes a nauplian eye, the
second antenne elongate, six pairs of feet, five pairs of
pleopods and even a pair of uropods. In the ‘Crypto-
niscian stage’ there are seven pairs of feet. MM. Giard
and Bonnier give a provisional genealogical tree of the
Entoniscide in connection with their hosts.

Portunion (Portunus)
Entione (Acheus)

Cancrion (Cancer)

Ree

Grapsion (Grapsus)

Entoniscus ( Porcellana)

4.06 A HISTORY OF RECENT CRUSTACEA

These are in reality ectoparasites, though with an ap-
pearance of being endoparasites. The sheath or enveloping
membrane moulded on every detail of their bodies is an
invagination of the hypodermis of the crab in which the
Entoniscid lives.

Entoniscus, Fritz Miiller, 1862. Parasitic on Porcel-
lanide. The female has the marsupium open when adult,
with deeply cnt edges to the component plates, and an
elongate pleon with five pairs of sabre-shaped pleopods.
The male is comparatively large, with the first antennee
elongated, six pairs of trunk-feet reduced to pedicellate
tubercles, and the last segment of the pleon not slit.

Eintoniscus porcellane, Miiller, 1862, on Porcellana sp.

Entoniscus Miilleri, Giard and Bonnier, 1886, on Por-
cellana longicornis (Linn.).

Entoniscus brasiliensis, Miller, 1871, on Porcellana sp.

Entoniseus Creplinii, Giard and Bonnier, 1887, on Por-
cellana (Polyonyx), Creplinii, Miller. Fritz Miiller found
a couple of the Porcellana in almost every tube of the
Cheeptopteri at Desterro. Only three times did he find
the Porcellana solitary, once a female, twice a male. Only
on these three specimens did he find an Hntoniscus. The
parasite makes the animal sterile, and it is inferred that
the infested crabs either could not find or retain partners.
Possibly they did not make the attempt to do either one
or the other.

Entidne, Kossmann, 1881. The male has the last
seoment of the pleon terminally bifid. This genus since
its institution has been much subdivided, and the original
name limited to Entoniscidz parasitic on Oxyrrhyncha.

Hintione acheert, Fritz Miller, on Achceus sp.

Grapsion, Giard and Bonnier, 1886. Parasitic on —
Grapsidee. The female has the marsupium closed when
adult, the ascendant lamella of the first pair of marsupial
plates narrow all along; there are two medio-ventral and
two latero-dorsal ovarian bosses and four dorsal tubercles ;
the pleopods lamellar, little recurved. ‘The male has the
sixth segment of the pleon ending in two recurved hooks.

THE ENTONISCID® 407

The embryo has a nauplian eye, and swims with the sixth
pair of trunk-feet extended.

Grapsion Cavolinii, Giard (1878), on Pachygrapsus mar-
moratus, Fabricius. ‘This species is named after Cavolini,
who in 1792 described an Entoniscid from ‘ Granchio de-
presso,’ which is supposed to be the same as Pachygrapsus
marmoratus.

Cancrion, Giard and Bonnier, 1886. Parasitic on
Cancride. The female has the marsupium closed when
adult, and has four dorsal ovarian bosses. ‘The sheath in
which the animal is enclosed is always covered with thick-
enings of yellow chitin. The male has the pleon clearly
distinct from the perzeon, elongate, without ventral pro-
minences or terminal hooks, the bilobed apex of the sixth
segment being minutely squamose. ‘The embryo has the
_ sixth trunk-feet elongate and carries them extended
laterally.

Cancrion cancrorum (Fritz Miiller, 1864), on several
Brazilian species of Xantho, implying ew hypothesi several
species of parasite under one name. Fritz Miiller states
that the heart in the male is situated in the third segment
of the pleon.

Cancrion miser, Giard and Bonnier, 1886, on Pilumnus
hirtellus (Linn.) Six specimens were found. ‘The crabs
examined were more than 1,800.

Cancrion floridus, Giard and Bonnier, 1886, on Xantho
incisus, Leach, commonly called Xantho floridus (Montagu).
Three specimens were found to about 900 crabs examined.

Portunion, Giard and Bonnier, 1886. Parasitic on
Portunidz. The female has the marsupium closed when
adult, the ascendant lamella of the first pair of plates
regularly widened from the base, much recurved, the
upper edge not cut; there are two medio-ventral and two
latero-dorsal ovarian bosses. The male has medio-ventral
hooks on the pleon, and the sixth segment apically fur-
—nished with a pair of hooks. ‘The embryo is without a
nauplian eye, and swims with the sixth trunk-feet carried
under the pleon.

Portunion menadis, Giard, 1886, on Carcinus mcenas

408 A HISTORY OF RECENT CRUSTACEA

(Pennant) (see Plate XVIII.). The specimens found were
in about one per cent. of the crabs examined.

Portunion Salvatoris (Kossmann, 1881), on Portunus
arcuatus, Leach.

Portunion Moniezit, Giard (1878), on Portunus puber
(Linn.). Excessively rare.

Portunion Fraissei, Giard and Bonnier, 1886, on Por-
tunus holsatus, Fabricius.

Portunion Kossmanni, Giard and Bonnier, 1886 (see
Plate XVIIT.), on Platyonichus latipes (Pennant).

This is the only species that can be called common,
and one which does not necessarily sterilise the host or
hinder the exuviation of its integument. These are pro-
bably the conditions that have allowed it to become
common, since, when the parasite makes the host sterile,
it, so to speak, cunts the ground from under its own feet,
by preventing the propagation of the very animal which
is essential to the existence of the parasites own progeny.

Pinnotherion, Giard and Bonnier, 1889. Parasitic on
Pinnotheres. The first marsupial plate is without a trans-
verse lamella, and its recurrent part is of unusual length.
There are no dorsal ovarian humps, but of the ventral two
the hinder is excessively long and cylindrical, with
vermiform movements, whence the type species is called
Pinnotherion vermiforme.

Family 7.—Bopyride.

The animals are parasitic in the branchial cavity, with
a few exceptions. The females in general have a flattened
appearance with one side longer than the other. Giard
and Bonnier, as already mentioned, subdivide this family
into Phryziens chiefly found on Macrura Anomala, Jomens
on Brachyura, and Bopyriens on regular Macrura. In
the Bopyriens the pleon is very degraded in both sexes, in
the male a single piece without appendages, in the female
shorter than in the Joniens and never carrying ramified
appendages. ‘These latter on the other hand are the rule
in the loniens, of which moreover the males sometimes

TUE POSITION EXPLAINED 4.09

have pleopods or rudiments of them. The Phryziens are
considered to represent the stem out of which the other
two divisions arise as branches.

Phryxus, Rathke, 1843, is preoccupied, but MM.
Giard and Bonnier retain it, though transferring Rathke’s
Phryxus paguri to Athelges.. 'The male has the pleon fused
and without appendages.

Phrywus resupinatus (Miller), 1870, was found on a
Pagurid from Brazil, generally in connection with Pelto-
gaster purpureus and a Cryptoniscus already mentioned.
Dr. Fraisse considers that the name resupinatus, meaning
with the ventral side outwards, does not really refer to a
specific peculiarity, but that the larva places itself under
the Peltogaster, naturally with its ventral side towards it,
and consequently with its dorsal side towards the Pagurid.
When nothing of the Peltoguster is left but its roots, the
Bopyrid, having lost its original point of support, bends
back its claws to clutch the abdomen of the hermit-crab.
That the parasites are not injured by the movement of the
Pagurid within the mollusc shell is explained in this way.
The hermit by its terminal appendages clings firmly to the
twist of the shell, laying its ventral side close to the spindle
of it. The parasites, however, uniformly sit on the lett
side of their host’s back, tolerably near the carapace, just
where the eggs of the healthy female Pagurid are wont to
be attached.

Athelque, Hesse, 1861, isspoken of as Athelqus by Fritz
Mier in 1870. Athelges is the form generally used. It
has a cylindrical pleon and flat laminar branchiz.

Athelque paguri (Rathke), 1843, on Mupagurus bern-
hardus (Linn.). In describing this species under the
name Phryxus paquri, Bate and Westwood suggest that
Athelque fullode, Hesse, 1861, is a synonym.

Athelque Prideauani, Giard and Bonnier, 1890, on
Tupagurus Prideauz (Leach). This species is larger than
the preceding, and the adult female retains a rudimentary
fifth pair of appendages on the pleon, which are transitory
in the former.

Athelque guitarra, Giard and Bonnier, 1890, on Pagurus

“P- 30

410 A HISTORY OF RECENT CRUSTACEA

Athelque intermedia, Hesse, 1877, on Eupagurus cua-
nensis (‘hompson).

Athelque Cardone, Kossmann, on Clibanarius misan-
thropus, Risso.

Athelque lorifera, Hesse, 1877, on Hupagurus cuanensis
(Thompson), tugether with several specimens of Pelto-
gaster.

Athelque cladophora, Hesse, 1861.

Pleurocrypta, Hesse, 1865 The male has the pleon as
in Phiyxus. In the female, it 1s stated, ‘the five segments
of the pleon are provided each, on each side, near the
margin, with a branchia of oval form, filiform, thin, flat,
very contractile.’ ‘The sixth segment has two small ap-
pendages.

Pleurocrypta qalatece, Hesse, 1865, on Galathea squami-
fera, Leach. According to Giard and Bonnier the Phryxus
longibranchiatus of Bate and Westwood is the Phryxus
stage of this Plewrocrypta.

Pleurocrypta porcellane, Hesse, 1877, on Porcellana
longicornis (Linn.).

Pleurocrypta strigosa, Giard and Bonnier, 1890, on
Galathea strigosa, Fabricius.

Pleurocrypta Hendersonii, Giard and Bonnier, 1890, on
Galathea dispersa, Bate, from the Clyde.

Palegyge, Giard and Bonnier, 1888. The male has
the pleon composed of well-separated segments, each on the
ventral side carrying rudiments of pleopods. ‘The authors
in 1890 suggest that it will probably be necessary to
make two sections of the genus, one characterised by the
plates of the pleon in the female being furnished with
warts or tubercles, and including the species parasitic on
Anomala and Thalassinida, the other characterised by the
appendages of the pleon being entirely smooth, and in-
cluding the species parasitic on the Hukyphota (see page
224). or the former division the genus Pseudione, Koss-
mann, seems to be the appropriate name, and for the latter
Palegqyge. As the name implies, this genus is regarded
by its authors as representing an ancestral form of Gyge.

THE BOPYRIDZE 411

Paleeqyge Borrei, Giard and Bonnier, 1888, on the
freshwater species Palemon dispar, von Martens.

Paleegyge Bonniert, Max Weber, 1892, on Palemon lar,
Fabricius.

Paleegyge fluviatilis, Max Weber, 1892, on Palcemon
lampropus, de Man.

Palegyge de Man, Max Weber, 1892, on Palewmon
pilimanus, de Man.

Paleeqyge ajjinis (Sars, 1882), on Pandalus leptorhyn-
chus, Kinahan.

Paleegyge Hoyli, Giard and Bonnier, 1890, on Pandalus
annulicornis (i.e. Montagur), Leach.

Pseudione, Kossmann, 1881, has the ‘ maxillipeds of the
male quite rudimentary.’

Pseudione callianasse, Kossmann, 1881, on Callianassa
_ subterranea (Montagu). Since Giard and Bonnier refer
this species to their Palcegyge, and also, as just observed,
look forward to a subdivision of that genus, questions of
priority will be best arranged by retaining Pseudione for
one of the sections.

Pseudione Hyndmanni (Bate and Westwood, 1867), on
Hupagurus bernhardus (Linn.). This is described in the
‘History of British Sessile-eyed Crustacea’ as Phryaus
Hyndmanm. Moreover, the Phryzxus fusticaudatus of Bate
and Westwood is, according to the often quoted authori-
ties, the phryxoid stage of the same species. By phryxoid
stage is meant the form of the female immediately follow-
ing the cryptoniscian stage.

Pseudione Fraisser (Kossmann, 1886), on Clibanarius
nusanthropus, Risso.

Pseudione Dohrni (Giard and Bonnier, 1890), on Cal-
liunassa ti wncata, Giard and Bonnier. This parasite was in
one instance found on each side of the host.

Pseudione insiqnis (Giard and Bonnier, 1890), on
Munida rugosa (Fabricius).

Pseudione confusa (Norman, 1869), on Galathea dispersa,
Bate. This was erroneously assigned at first to Galathea
wmtermedia, Lilljeborg, and described by Bate and West-
wood as Phryxus galathee, and supposed by them to be

412 A HISTORY OF RECENT CRUSTACEA

the same as Plewrocrypta galathece, Hesse, from which,
however, it is distinguished by the clearly segmented
pleon and rudimentary pleopods.

Gyge, Cornalia and Panceri, 1861. The lateral pro-
longations of the pleon are simple, unless transiently
double in the young female.

Gyge galathee, Bate-and Westwood, 1867, on Galathea
squamifera, Leach, from the Channel Islands.

Gyge branchialis, Cornalia and Panceri, 1861, on
Upogebia stellata (Montagu). In the branchial cavity of
the host the parasite here as in other instances has its back
turned to the host’s body, the ventral side with the mar-
supial plates turned outwards. When the brood is far
developed, it causes a bulging of the host’s carapace, by
which the whole parasitic family is securely retained. At
other times, as Dr. Fraisse observes, the sharp claws, which
would be unable to grasp the smooth carapace, curve back
to clutch the branchie.

Kepon, Duvernoy, 1840. The female has the feet
ending in an inflated joint, without claw. The adhe-
sive processes (supposed in general to represent the exo-
pods) are well developed, papillose, in the first four pairs,
rudimentary on the other three. The appendages of the
pleon are coarsely pinnate.

Kepon typus, Duvernoy, 1840, on an unknown crab in
the Mauritius.

Teidya, Cornalia and Panceri, 1861. The female has
the feet ending in a blunt claw, the adhesive processes
of all seven pairs nearly equal. The appendages of
the pleon form sharp finely-fringed branches. ‘The male
has the first antennee three-jointed, the second seven-
jointed, the pleon segmented, carrying five rudimentary
pleopods and two long appendages on the sixth segment.

Leidya distorta (Leidy, 1855), in Gelasimus pugilator,
Bose.

Grapsicépon, Giard and Bonnier, 1887. The female
has the feet ending in a short sharp claw, the adhesive
processes oval, not warty. The pleon appendages of the

AN OLD NAME REVIVED 413

first four segments are three-branched, of the fifth two-
branched, all coarsely fringed.

Grapsicepon messoris (KKossmann, 1880), in Metopo-
grapsus messor (Forskal).

Grapsicepon Fritz, Giard and Bonnier, 1887, in a
Brazilian Grapsus (Leptograpsus rugqulosus ?).

Grapsicepon Hdwardsi, Giard and Bonnier, in Planes
minutus (Fabricius), found occupying both sides of the
same host.

Cancricépon, Giard and Bonnier, 1857. The female has
the feet ending in a short sharp claw, the adhesive pro-
cesses rudimentary, the ovarian bosses numerous. The first
five segments of the pleon are laterally three-branched,
the dorsal branch tuberculose; the sixth segment carries
two long appendages. The male has the first antenne
three-jointed, the second five-jointed ; the pleon segmented,
carrying very rudimentary pleopods; the sixth segment
has some rough hairs or little wrinkled scales.

Cancricepon elegans, Giard and Bonnier (1886) (see
Plate XVIII.), in Pilumnus hirtellus (Linn.). The Pilum-
nus is abundant at Wimereux among the vast collections
of tubes of Sabellaria alveolata. In about one per cent.
of the times that the parasite was found, it occurred on
both sides of the same crab. The authors once found
this species and Cancrion miser on the same specimen of
Pilumnus. They compare the central prolongation of the
pleon in the embryo with that in the embryos of some
Cirripedes and Merostomata.

Cancricepon pilula, Giard and Bonnier (1886), in
Xantho incisus, Leach.

lirgyne, Risso, 1816. The female has the adhesive
processes strong and muscular, the pleon appendages
fringed, the first five two-branched, the sixth simple. The
male has the maxillipeds rudimentary, the pleon without
distinct segments or appendages.

Hrgyne cervicornis, Risso, 1816, in Portunus arcuatus,
Leach. Giard and Bonnier identify Portwnicepon portuni
(Kkossmann, 1881) with Risso’s species, so that the restora-
tion of Risso’s generic name seems inevitable, little as

Al 4, A HISTORY OF RECENT CRUSTACEA

Risso’s obscure descriptions entitle him to honour or grati-
tude. In the present instance, 1t 1s said, he mistook the
tail of the parasite for its head, and considered the appen-
dages of the pleon to be ramified plumose antennee.
Evidently Latreille was puzzled by the description, for in
1825, under the genus ‘Ichthyophile (Cymothoa, Leach),’
he says, ‘ L’ergina cervicornis.de M. Risso me parait étre
un ichthyophile, ayant accidentellement un corps étranger
(aloue?) aux antennes.’ In this species it is observed
that ‘the colour of the ovary and consequently that of the
largest part of the body is of a brilliant carmine red.’

Gigantione, Kossmann, 1881. The female has an
almost circular outline, all the segments having un-
branched prolongations. ‘The three-jointed first antennee
have the basal joint expanded so as to cover the oral
region, just leaving space for the protrusion of the points
of the mandibles. The tiny feet have a short pointed
nail. The marsupial plates are very large. he first
pleopods form acuminate sacks with sparingly ramified
out-growths on the surface; the following pairs are small,
entirely ramose. The male has the pleon distinctly seg-
mented, with six pairs of oval sack-like pleopods.

Gigantione Moebii, Kossmann, 1881 (see Plate XVIIL.),
in Riippellia impressa, de Haan.

lone, Latreille, 1818. The female has the side-plates
well developed on the head and perzeon, those of the first
five segments of the pleon arborescent, coralloid, the ap-
pendages of the sixth segment simple, cylindrical, recurved
at the extremity. ‘The male has the second antennz seven-
jointed, and the pleon furnished with six pairs of long
cylindrical appendages.

Tone thoracicus (Montagu, 1808), in Caliianassa sub-
terranea (Montagu), was first recorded from Devonshire.

Lone cornutus, Spence Bate, 1864, in Callianassa longi-
mana, Spence Bate.

Tone vicina, Giard and Bonnier, 1890, in Callianassa
truncata, Giard and Bonnier.

Tone gelice, Giard and Bonnier, 1890, in Upogebia stellata
(Montagu).

Portunion menadis

on Carcinus manas

Cigantione Moebi. Dorsal view G. Moebit. Ventral view

AN OLD NAME REJECTED 415

Argeia, Dana, 1852. In the female the side-plates of
the segments are developed into long lobes, but without
adhesive processes. ‘I'he pleopods are short, not ramified.
dn the male the pleon is unsegmented, and without ap-
pendages.

Argeia pugettensis, Dana, 1852, in Crangon munitus.

Argeia depauperata, Stimpson, 1857, in Crangon Fran-
ciscorum, from San Francisco Bay.

Bopyrus, Latreille, 1804. In the female the bound-
aries of the pleon-segments are not visible in the centre of
the back; the pleopods are pairs of simple rudimentary
plates. In the male the pleon has no lateral appendages.
Leach, in the Appendix to his ‘Crustaceology,’ 1814, makes
the strange remark that ‘the genus Bopyrus is to be
altogether rejected from this article, as it belongs to the
- class Vermes.’

Giard and Bonnier give up the old name Bopyrus squil-
larum, Latreille, 1804, on the ground of the inextricable
confusion of the synonymy, Latreille’s squillarum having
been indiscriminately applied to various species, and not
being the oldest name, since the misleading crangorum of
Fabricius dates from 1798, and Latreille himself appears
to have confounded Leander serratus (Pennant) and Leander
squilla (Linn.), so that, to start with, the name of the host
is as uncertain as the name of the parasite.

Bopyrus Hellert, Giard and Bonnier, 1890, in Leander
squilla (Linn.), may, notwithstanding the above arguments,
be thought deserving of the old name squillarum.

Bopyrus Fougerouxi, Giard and Bonnier, 1890, in Lean-
der serratus (Pennant), from which the ‘ Bopyrus squillarum’
of the ‘ British Sessile-eyed Crustacea’ was obtained.

Bopyrus Rathkei, Giard and Bonnier, 1890, in Palemon
rectirostris, Zaddach.

Bopyrus treiliianus, Giard and Bonnier, 1890, in Palc-
mon treillianus, Risso.

Bopyrus xiphias, Giard and Bonnier, 1890, in Palemon
xiphias, Risso.

Bopyrus palemoms, Risso, a doubtful species in Alpheus
sp. (?)

416 A HISTORY OF RECENT CRUSTACEA

Bopyrus (?) alpher, Fritz Miiller, in a Brazilian Al-
pheus sp.

The Zeuxo alphei, Kossmann, 1872, described as an
external parasite on the head of an Alpheus, may be men-
tioned here, and perhaps the Prosthéte cannelée of Hesse,
1861, belongs to this genus.

Probopyrus, Giard and Bonnier, 1888. In the female
the pleon has the boundaries of the segments well marked
all across the back, and has five pairs of two-brancbed
pleopods. In the male the pleon has five pairs of little
tuberculiform pleopods. This freshwater genus is con-
sidered to represent an ancestral less degraded form of
Bopyrus.

Probopyrus ascendens (Semper, 1880), in Palcemon or-
natus, Olivier, which in the Philippines inhabits streams up
to 4,000 feet above the sea-level.

Probopyrus palemoneticéla (Packard), in Palcemonetes
vulgaris, Stimpson, of North America.

Probopyrus Giardi, Max Weber, 1892, on Palemon
placidus, de Man.

Bopyrina, Kossmann, 1881. The first antenne are
relatively strong in both sexes, especially the basal joint,
which in the female works upon the skin of the host. In
the adult the second antennz are reduced to a rudiment.
The pleon in both sexes is feebly segmented, in the female
with short sack-like appendaes, in the male without any.
The first pair of marsupial plates are colossal, the rest
rudimentary.

Bopyrina virbii (Walz), 1881, on ‘ Virbius’ viridis, Otto.

Bopyrina ocellata (Czerniavsky), 1869, on ‘ Virbius’
gracilis, Heller.

Bopyrina nitescens, Giard and Bonnier, 1890,on Athanas
nitescens, Leach. ‘The authors think the species may be-
long to some genus distinct from Bopyrina, and merely
name it to call attention to it.

Bopyrina hippcelytes, Giard and Bonnier, 1890, on Hip-
polyte Cranchit, Leach (?). This species also appears to be
at present only nominal.

With regard to the genus Virbius, the reader may refer

MORE LIGHT IN THE FUTURE 417

back to chapter xvii., page 235. Bopyrina virbii, corre-
sponding with the figure of the young female given by
Kossmann in the ‘ Zeitschrift fiir Wiss. Zool.’ Bd. 35, pl. 34,
fig. 6, 1881, has been found lying across the hind dorsal
margin of the carapace of Hippolyte varians taken at Ilfra-
combe. From the conical mouth-apparatus protrude a pair
of denticulate lancets, the points of the mandibles.

Bopyroides, Stimpson, 1864. Formed for those species
that agree in shape and structure with Bopyrus, but differ
in their branchial features in having merely fleshy ridges
instead of lamine, with the segments of the pleon distinct.
See ‘ History of British Sessile-eyed Crustacea,’ vol. ii. p.
223.

Bopyroides acutimarginatus, Stimpson, 1864, on Hip-
polyte brevirostris. Stimpson also thinks that Bopyrus
- hippolytes, Kroyer, should be placed in this genus. By
Bate and Westwood that is called Gyge hippolytes (Kroyer).
Kréyer’s species was taken on Sippolyte polaris. ‘The
host of the British form is not named.

Hemiarthrus, Giard and Bonnier, 1887. The authors
say, ‘It is impossible to leave in the genus Phryxus the
parasites of the abdomen of Virhius and Hippolyte. These
animals differ much from the Phryzus type, alike in the
female and in the male, which has all the pleon-segments
free and furnished with rudimentary limbs. We have
established for these Bopyrians the genus Hemiarthrus.’
In the promised continuation of their great work on the
Bopyridz, no doubt the obscure relations between this and
some of the preceding genera will be illuminated.

Hemiarthrus typtonis, Giard and Bonnier, 1890, on
Typton spongicola, Costa.

Hemiarthrus philontka, Giard and Bonnier, 1890, on
Nika edilis, Risso.

Hemiarthrus virbii, Giard and Bonnier, 1890, on ‘ Vir-
bius’ viridis, Otto.

Hemiarthrus Cranchii, Giard and Bonnier, 1890, on Hip-
polyte Cranchii, Leach (?). This and the preceding species
auswer to what Walz has called Phryxus abdominalis,
Kroyer. .

418 A HISTORY OF RECENT CRUSTACEA

Hemiarthrus abdominalis (Kroyer), 1840, on Hippolyte
Gaimardu, Milne-Edwards. Kréyer states that he also
found it on Hippolyte Sowerber and another nearly related
species. J. Sp. Schneider assigns it also to Kréyer’s Hip-
polyte turgida and pusiola,and to ) Pandalus Monta: gut, Leach.
Bate and Westwood speak of it as a parasite both of the
Pandalus and of a species of [Hippolyte. The full-grown
female is of remarkable appearance, from her want of
symmetry, her great marsupial plates enclosing a vast
number of eggs, and the condition of her limbs, which form
on one side a little crowded row, while on the other all
have disappeared except the first. Hippolyte Sowerbei or
rather Sowerbar, Leach, is a synonym of Spirontocaris
spinus (8 Sowerby), and stands therefore in the genus to
which the species pusiola and Gaimardw have also been
recently transferred (see pages 235, 236).

Phyllodirus, Stimpson, 1857, is thus described by
Stimpson, in Latin which if not pedantically classical,
has at least the merit of being very easy for English
readers to follow :—‘ Feminee pedes thoracis sat validi, toti
ancorales, unguiculati; appendicibus branchiales carentes.
Appendices abdominis branchiales; superiores laterales,
laminis duabus zquis magnis elongatis; inferiores papilli-
formes. Abdominis segmentus primus setis dorsalibus
unguiculatis instructus.’

Phyllodurus abdominalis, Stimpson, 1857, from between
the abdominal feet of the common Upogebia, Puget Sound.
On the position of this species the recent authorities do
not appear to express any opinion. The other Epicarids of
Upogebia, Lone and Pseudione, are referred to the branchial
cavity.

At the conclusion of this long catalogue it may be
allowable to express a hope that its utility to the student
will be in some measure proportionate to the time and
trouble expended on producing it. It would have been
easy to sacrifice the useful to the ornamental, and instead
of showing the extent of the subject, to dwell only
on the singularities, indulging in a disquisition on the
extremely eccentric and abnormal forms included in this

THE SUBJECT NOT EXHAUSTED 419

sroup. With attention directed to the number of species
actually existing, it is probable that the half-score described
by Bate and Westwood as belonging to the British fauna
will soon prove to be but the nucleus of a far larger com-
pany. By accepting the view that no parasite has more
than one species of host, we may greatly simplify the
otherwise bewildering task of naming specimens, and so
far leave the mind at leisure to grapple with the other
numerous and intricate difficulties connected with this
little-known tribe.

4.20 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXVII
TRIBE VII.—ONISCOIDEA

Tuts tribe consists of the land Isopods, adapted for breath-
ing air, but probably in all cases requiring that the air
should be humid. In general uniformity and regularity
of shape they are strikingly contrasted with the preceding
parasitic tribe. ‘The head is small, the seven segments of
the pereeon are distinct, the pleon is narrower, and usually
has six distinct segments, of which the sixth is the smallest.
The first antenne never have more than three joints, and
may have fewer, or may be wholly wanting. ‘The man-
dibles are without ‘palp. The inner plate of the first
maxille bears either two or three plumose sete. The
second maxille have two plates or only one. The maxilli-
peds are occasionally seven-jointed, but seldom more than
four-jointed. ‘The seven pairs of trunk-feet are similar to
one another; the hinder more or less exceeding in length
those that precede; all are gressorial. The pleopods are
branchial. Of the five pairs rarely the first 1s obsolete ;
the second and sometimes also the first have sexual organs
in the male. The uropods are of variable character, never
powerful organs; tieir branches are single-jointed. Five
families are included in the tribe, the Ligiide, Tylidz,
Helleriide, Oniscidze, and Armadillididee.

Paunily 1.—Inqude.

The pleon consists of six segments, of which the first
two are narrower than the third. The first antennz are
small, three-jointed. ‘The first maxille have three sete
on the inner plate. The second maxille have two plates.

os

THE LIGIIDE 421

In the five pairs of pleopods the outer branch is opercular,
the inner branchial, but sexual in the first two pairs of the
male. The uropods are produced beyond the apex of the
pleon. The young are said to quit the mother with only
six pairs of trunk-feet. The famiity contains seven or
eight genera.

Ingia, Fabricius, 1798, has a multiarticulate flagellum
to the second antenne, the maxillipeds with a small
rounded epipod, and the ‘ palp’ four- to five-jointed. The
uropods have two equal, stiliform, often filiform, branches.
Ingia oceanica (Linn.) is found on rocky shores of Great
Britain and in many parts of northern and western
Europe. The uropods are not unlike these of Asellus
aquaticus. It attains a length of more than an inch,
without including uropods and antennx. In Ligia exotica,
Roux, the second antenne are longer than the animal, the
flagellum haying from twenty-seven to forty-one joints.
Ingia cursor, Dana, from Valparaiso, hints by its specific
name at what is rather a character of the genus, rapidity
of running. Von Siebold says that in Japan on rocky
shores at ebb-tide in summer the Ligiz are sometimes so
abundant that the fishermen sweep them with brooms
into pots, to be used for bait. Budde-Lund in 1885 de-
scribes in all twelve species from the shores of various parts
of the world, and gives the names of five others. Ligua
dilatata, Perty, he renames in 1879, Stymphdalus dilatatus,
and he includes Dana’s Styloniscus, with its three species,
in this family.

Ingidium, Brandt, 1835, has a multiarticulate flagellum
to the second antenne, the ‘palp’ of the maxillipeds
conical, five-joiated, the stem of the uropods obliquely
produced on the inner side, and the inner branch tipped
with two hairs. Five species have been described. Liqi-
dium hypnorum (Cuvier, 1792) has had several names.
In England it has hitherto only been recorded from the
borders of Surrey and Sussex. Budde-Lund supposes
that the Bavarian species Zia paludicéla, Koch, and Zia
melanocephadla, Koch, belong to this genus.

Trichoniscus, Brandt, 1833, has the flagellum of the

422 A HISTORY OF RECENT CRUSTACEA

second antennee from two- to seven-jointed, the ‘ palp’ of
the maxillipeds obscurely two- to three-jointed, the
branches of the uropods subequal or the inner thinner
and rather shorter than the outer. Trichonscus pusillus,
Brandt, is identified with the British Philougria riparia
(IXoch), Trichoniscus vividus, Koch, with the British Phil-
ougria vivida, and Trichoniscus roseus, Koch, with the
Philougria rosea, which not only occurs in many parts of
Kiugland and other European countries, but has been taken
by Mr. Chilton in New Zealand. The first two are little
agile brown species; the third is especially attractive by
its delicate rose colour, a tint so unusual in this tribe.
Budde-Lund describes two other species, and names four
more, one of the latter being the Scyphacella arenicola,
S. I. Smith, of the United States. Dollfus describes four
new species, two being from the Azores, one from Tristan
da Cunha, and one from Valparaiso.

Haplophthalmus, Schobl, 1860, has the flagellum of the
second antenne three-jointed, the legs shorter than in
Trichoniscus, and the pleon less abruptly narrower than
the pereeon. The last character it shares with Smith's
Scyphacella. 'The two species are IHaplophthalmus Mengu
(Zaddach), and Haplophthalmus danicus, Budde-Lund,
both of them white.

Oligoniscus, Dollfus, 1890, is distinguished from T'ri-
choniscus, because, the head being bent forward, the
frontal line encroaches on the facial region, and because
the eyes are simple. The specific name of the type-species,
Oligoniscus monocellatus, from Juan Fernandez, corresponds
inmeaning with Haplophthalmus, the name of the preceding
genus, from which it seems but little remote.

Titanethes, Schiddte, 1849, has no eyes, the flagellum
ot the second antennze multiarticulate, the ‘palp’ of the
maxillipeds three-jointed, the uropods with conical, stili-
form, unequal branches. ‘Yitanethes albus (Soch) is the
type. Five other species have been recorded. The genus
appears to be confined to caverns.

A DOUBTFUL DATE 42

Oo

Family 2.—Tylidee.

The segments of the perzeon, except the first, have the
side-plates marked off by a distinct suture. The pleon
consists of six segments, of which the first two are very
short and narrow. The first antennz are small, adpressed,
one- to two-jointed. The components of the mandibular
Spine-row are numerous. ‘The first maxille have three
seteze on the inner plate. The second have only one plate.
The ‘palp’ of the maxillipeds is two-jointed. The first
pleopods are wanting (or retain a doubtful rudiment in
the male). The second, third, fourth, and fifth pairs are,
according to Budde-Lund, all branchial, single-branched.
Von Ebner, however, says :—‘ The peduncular plates of the
. branchiferous caudal appendages in J'ylos are not essen-
tially different from those of other Oniscoida; they carry
as well the branchial-operculum as the branchial-sack.’
Of the respiratory apparatus in this family, he remarks :—
‘The four developed branchial-opercula all contain rami-
fied air-cavities. These consist essentially of a sack
enclosed between the two leaves of the branchial-oper-
culum, which divides into a number of microscopic cecal
tubes. Quite similarly constructed air-cavities occur also
on the two first, often on all, of the branchial-opercula of
other Oniscoida. These, however, are distinguished from
those of the Tylinz, by the circumstance that it is not
openings of the under surface of the operculum, but cross
slits on its hinder margin, that lead tothem.’ The uropods
of the T'ylidz are something like those of the Valvifera,
but here the folding doors form an operculum not over
the pleopods but over the anal opening of the telson; they
carry a minute single branch, and are completely covered
dorsally by the terminal segment of the pleon.

Tylos, Audouin, 1825? This being the only genus
has the characters of the family. The first verbal descrip-
tion was printed by Audouin in his ‘ Explication sommaire
des planches des Crustacés de lEgypte et de la Syrie.’
He states that T'ylos was a manuscript name given to the

31

424 A HISTORY OF RECENT CRUSTACEA

genus by Latreille, and points out that the figures of the
type-species, Tylos Latreillit, Audouin, in Savigny’s Plate,
show the generic characters.” Latreille in his ‘ Familles
naturelles du Régne Animal,’ p. 567, 1825, merely says,
‘Ajoutez immédiatement aprés le genre lygie, TYLOos
_ (nouveau genre composé d’espéces marines), so that the
information he offers is incorrect. Thus Savigny gave no
name; Latreille gave a name, but did not effectively
publish it; Audouin published the name, with a descrip-
tion; the genus must therefore belong to him. But there
is still a difficulty. In 1826 the name T'ylos was given
by Van Heyden to a genus of Arachnida, and Budde-Lund
assigns Audouin’s ‘ Explication’ to 1827. M. HEugéne
Simon, however, has explained that Van Heyden’s pro-
dromus on the classification of the Acari merely named
without defining the genus, and therefore did not effectively
pre-occupy the name T'ylos. But Audouin’s preface is dated
1825, and it seems possible, therefore, that the Crustacean
genus was really published in advance of the Arachnid.
M. Simon, on the contrary, says that the name 1'ylos
armadillo, Latreille, 1829, was published before the T'ylos
Latreillit of Audouin’s ‘ Explication,’ which can scarcely
be correct. Budde-Lund describes, besides the typical
Mediterranean species, six others, including two made
known by Krauss from South Africa. Tylos spinulosus,
Dana, is mentioned, and Tylos granulatus, Miers, from
Japan, is distinguished from Krauss’s African species of
the same name, as T’'ylos granuliferus.

Family 3.—Hellerude.

The perzeon is as in the preceding family. The pleon
has the first five segments fused, with two pairs of short
lateral sutures marking off the third from the fourth, and
the fourth from the fifth segment. The terminal seoment
is short, subquadrate. The first antennae are wanting.
The spine-row of the mandibles has but two components
on the left mandible, and is reduced to one on the right.
The two pairs of maxilla and the maxillipeds have “the

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Helleria brevicornis,v. Ebner

=e THE HELLERIIDE 425

characters ascribed to them in the preceding family. The
first pleopods are absent or reduced to widely separated
rudiments, of doubtful homology. The pleopods of the
second, third, fourth, and fifth segments are two-branched ;
the second pair have the usual stilets in the male. On each
opercular plate there is a roundish air-cavity placed near
the outer margin, with a single opening in each operculum
of the second pleopods, but two openings in those of the
three following pairs. According to von Ebner, the pe-
duncle in the pleopods forms a part of the branchial sack,
so that the two branches instead of being freely articulated
with it are fastened direct to the segment. The uropods
are similar to those in the Tylide, but are attached at the
front.corner of the outer margin instead of at its centre.
The minute terminal joint is considered to be the oute
branch.

Helleria, Ebner, 1868, is the only genus, and Helleria
brevicorms, Ebner, the only species. It occurs in Italy, and
in the mountain forests of Corsica in damp moss; also M.
Chevreux has recently sent it me from Cap d’Antibes out
of his own garden. In 1879 Budde-Lund changed the
name Helleria to Syspastus, because other genera of Crusta-
ceans have received the name Helleria, but these other
genera, as M. Chevreux has pointed out, were named not
before but after the publication of von Ebner’s genus. It
would be absurd that Dr. Camil Heller should be entirely
deprived of the honour intended him, through the fact that
so many of his friends had separately endeavoured to render
it. Without question von Ebner’s genus must retain its
original name, and, with the cancelling of Syspastus, Budde-
Lund’s family ‘Syspasti’ naturally suffers a corresponding
change into Helleriide. The figures on Plate XIX. are
copied from von Ebner’s paper.

Family 4.—Onscide.

The animal is seldom very convex or capable of easily
assuming a globular form. ‘The head is little broader than
long, and not clearly flanked by the first segment of the

426 A HISTORY OF RECENT CRUSTACEA

perzeon; the face is sloping. ‘The sides of the head are
distinctly marked by a vertical marginal line and an infra-
marginal line. The clypeus is arched.’ The pleon has six
segments, of which the first two are narrower and usually
shorter than the third. The young quit the mother with
the seventh segment of the pereeon still undeveloped.
The first antennze are three-jointed. ‘The second antennze
have the flagellum from two- to four-jointed. The first
maxillz have two plumose sete on the inner plate; the
second maxillee have two plates; the ‘ palp’ of the maxilli-
peds is two-jointed, the epipod oblong, acute. The trunk-
feet are rather long. In the first and second pleopods of
the male the inner branches form long narrow sexual
organs, those of the first pair often coalesced; in the
female the same branches are rudimentary, short, acute.
In the remaining pairs the inner branch is branchial ; in
all the pairs the outer branch is opercular, and often also
tracheal. The uropods are always prolonged beyond the
two terminal segments of the pleon.

Budde-Lund, in his exceedingly valuable work on the
Terrestrial Isopoda, makes a family Onisci, which he divides
into two sections, Armadilloidea and Oniscoidea, but it
seems better to constitute two families, since it is the
almost invariable fate of large sections eventually to be
made independent. For the Oniscide, or second section,
Budde-Lund gives a tantalising ‘Conspectus Generum,’
based on the flagellum of the second antennz, on the
tracheal or non-tracheal character of the pleopods, and on
the uropods.

I. Flagellum 2-jointed.

A. With trachez.
B. Without trachez.

. Porcellio.
. Platyarthrus.

Noe

II. Flagellum 3-jointed.

A. With trachezx. : 3. Scleropactes.
B. Without trachez. 4. Oniscus.
IIL. Flagellum 4-jointed.
A. Uropods short. 5. Armadilloniscus.
B. Uropods elongate. 6. Deto.

Any enjoyment that might be derived from the sweet

_

a

THE ONISCID ; 427

simplicity of this arrangement is rather rudely disturbed,
when it appears that Porcellio has to be divided into seven
genera or sub-genera and Oniscus into five, and in fact with
one or two recent additions the Oniscide contain twenty-
one genera instead of only six. Little more can he done
here than to mention their names.

\ Porcellio, Latreille, 1804. In this genus, after restric-
tion, Budde-Lund describes seventy-one species, besides
giving the names of more than a score recorded without
description or imperfectly described. To this long list
additions have since been made, as lamellatus, Uljanin,
from the Mediterranean and the Azores; cristatus, Dollfus,
from Surinam ; Mariom, Aubert and Dollfus, from Marseilles;
provincialis, Aubert and Dollfus, from Salon, in one of the
districts of Provence, the most arid and remote from human
habitations. Moreover, four or five new species from Syria,
chiefly collected by Dr. Th. Barrois, have been named by
M. Dollfus during the year 1892. Only the following
four species out of this extensive genus have been re-
corded in Great Britain. 1.—Porcellio scaber, Latreille, is
extremely common over the whole of northern and central
Europe and the North of America. It extends to Green-
land, and none of the land Isopoda range further to the
north than this does. It is said also to reach the Cape of
Good Hope and to have been found in Central America.
2.—Porcellio pictus, Brandt, is perhaps the same as the
earlier Porcellio spinicorms, Say. It is distinguished by a
large apical tooth on the second jointof the second antenna,
and by the black and yellow markings of the perzon.
Together with the preceding species it belongs to a section
of the genus in which the last segment is triangularly pro-
duced, with a sharp apex. 3.—Porcellio dilatatus, Brandt,
belongs to a section in which the last sezment is produced
with a rounded apex. It does not appear to be at all
common in Great Britain. 4.—Porcellio levis, Latreille,
belongs to a group distinguished from that which includes
all the other three by having the hind margins of the first
three perzeon-segments less laterally sinuate, the side-
plates less, with the hinder angles in the earlier segments

428 A HISTORY OF RECENT CRUSTACEA

more obtuse, scarcely prolonged backwards, with the
lateral process small, obtuse or none. All the four species
agree with the species found in Syria in belonging to the
division of the genus in which there are two pairs of
tracheze, as distinguished from another division in which
there are five pairs. The extensive distribution of Porcellio
levis is emphasised by Budde-Lund in the words ‘Patria:
Orbis terrarum.’ It was obtained by the Challenger at
Bermudas, the Cape Verde Isles, and at Honolulu. M.
Adrien Dollfus observes that while Porcellio scaber is
abundant in the cold and temperate regions both north and
south, but not in the tropics, Porcellio levis appears to
have followed man all round the world except in the cold
regions of the two hemispheres.

Cylisticus, Schnitzler, 1853, has the body more convex
and contractile than it is in the preceding genus. The
branchial-opercula of all five pairs of pleopods are fur-
nished with trachez. OCylisticus convecus (De Geer) has
priority over the name Porcellio armadilloides, Lereboullet,
used in the ‘ British Sessile-eyed Crustacea.’ Budde-Lund
describes seven species of Cylisticus.

Hemilepistus, Budde-Lund, 1879, is notable for ample
sculpture with spines or coarse granulation on the front
part of the body, of which, however, the young ones are
devoid. Budde-Lund describes ten species, all of which
are found in the sandy deserts of Africa and Asia. One
of them, Hemilepistus ruderalis (Pallas), was described by
Pallas in 1771. The first and second pleopods, and more
rarely the third or all are provided with trachee. |

Metoponorthus, Budde-Lund, 1879, meaning ‘with a
straight front,’ is frequently mis-spelt Metoponorthrus, to
which no intelligible meaning could be assigned. Budde-
Lund gives descriptions of thirty-five species. In this
genus is included Metoponorthus cingendus (Kinahan) found
in the coast regions of England and Brittany, but dis-
tinct from the species so named by Budde-Lund from
the highlands of the South of France, which Dollfus has
therefore renamed Metoponorthus meridionalis. This has
three pairs of tracheee, whereas Kinahan’s species has only

A MOUNTAINEER 429

two pairs. Another British species, which is said to be
cosmopolitan, is Metoponorthus pruinosus (Brandt). It
belongs to the section with two pairs of trachee. Mr.
Whyper found it in Ecuador at a height of 13,500 feet
above the sea, highest soaring of the Isopoda. Dollfus
describes Metoponorthus Barroisi, 1889, from the Azores,
and in 1892 two new species from Palestine.

Rhyscotus, Budde-Lund, 1885, has a single species,
Ethyscotus turgifrons from the West Indies. |

Leptotrichus, Budde-Lund, 1879, ‘with fine hairs,’
receives four species, to which Dollfus doubtfully adds his
Syrian Porcellio pulchellus. He also records Leptotrichus
tauricus, Budde-Lund, from the Mount of Olives.

Bathytripa, Budde-Lund, 1879, ‘with deep haunts,’
has two or three species. |

Ineasius, Kinahan, 1859, is reinstated by M. Eugéne
Simon in 1885, to receive not only the Algerian Por-
cellio myrmecophilus, Lucas, for which it was instituted by
Kinahan, but also three other species, pallidus, tardus,
and pauper, named by Budde-Lund and by him referred to
_ Porcellio. In 1890 Dollfus likewise remarks that Lucasius
ought to be extended to a whole group of the ancient
genus Porcellio, formed of ant-loving species, with charac-
ters morphological and biological near to those of Platy-
arthrus. He describes a new species Lucasius hirtus from
Marseilles, and from the same district records Lwucasius
pallidus (Budde-Lund).

Chavesia, Dollfus, 1889, agrees with the preceding
genera in having the flagellum of the second antennz
two-jointed, but with Armadilloniscus more nearly in the
structure of the uropods. Chavesia costulata, Dollfus, is
from the Azores. By an obvious misprint the description
assigns the two-jointed flagellum to the first antenne.

Platyarthrus, Brandt, 1833, has the body broad and
flattened, no eyes, the flagellum of the second antenne
small, with its first jot imconspicuous. Platyarthrus
Hoffmannseggu, Brandt, appears to be met with almost all
over Europe, but never except in ants’ nests. In addition
to the English localities named by Bate and Westwood,

430 A HISTORY OF RECENT CRUSTACEA

there may be mentioned Tenby, Ventnor, Tunbridge Wells,
and Cissbury Camp near Worthing. Probably the little
white slow-moving woodlouse finds its food in the for-
micarium, and pays for its board and lodging by act-
ing as a scavenger. The ants when disturbed leave
their guests to shift for themselves, and do not carry
them off along with their own helpless larva. There
are two other species of the genus, one of them a cave-
dweller.

Oniseus, Linneeus, 1767, occupies now a humble and
limited position in the sub-order of the Isopoda, the whole
of which it at one time embraced. Oniscus asellus, aucto-
rum, 1s very common throughout Europe and in North
America. There seems no reason to relinquish the
specific name in favour of the later Oniscus murarius of
Cuvier. The other species found in Great Britain, Oniscus
jossor, Koch, is smaller, duller in colour, and more closely
tuberculate. Oniscus Simoni, Budde-Lund, occurs in the
South of France; Oniscus punctatus, G. M. Thomson, in
New Zealand.

Philoscia, Latreille, 1804, to be pronounced Philoskia,
and meaning ‘a lover of shade,’ has a name which would
probably be appropriate to every genus in this sub-order.
Budde-Lund gives the description of twenty species, with
the names of three more. That which he describes as
Philoscia longicornis is in fact Philoscia Couchti, Kinahan,
a maritime species which he elsewhere supposes possibly
to belong to Ingidiwm. Besides inhabiting the coasts of
Deyon and Cornwall, Philoscia Couchii appears to be found
all round the Mediterranean. It runs fast and is very
shy. ‘The body is smooth as in the rest of the genus, and
the integument is not very firm. Philoscia muscorum
(Scopoli) is very common in the South of England and in
many parts of Europe. Budde-Lund says that Leach was
mistaken in saying that it had been found in Sweden.
Philoscia jubescens (Dana) is found in New Zealand.
Philoscia pulchella, Budde-Lund, is identified by Dollfus
with his own earlier described Philoscia elongata. Dollfus
also establishes Philoscia corsica, 1888, inhabiting the

AN ANOMALOUS JOINT 431

mountain forests of Corsica, a ‘ beautiful species, hitherto
the largest of the genus,’ Philoscia celleria, 1884, from
Marseilles, and Philoscia anomala, 1890, a species brought
by the Challenger from Valparaiso and Juan Fernandez, in
which the adult male, perhaps in the marital stage, has
the fifth joint (tarsus) of the fourth pair of feet developed
into an almost circular disc. Dollfus remarks that Oniscus
bucculentus, Nicolet, is really a Philoscia, which also ex-
hibits this apparently anomalous and perhaps temporary
character.

Alloniscus, Dana, 1854, has seven species described by
Budde-Lund, of which the first is Alloniscus perconvexus,
Dana, from California; the last is Alloniscus cornutus,
Budde-Lund, strongly exhibiting the generic character in
having the lateral frontal processes of the head large,
narrow, prominent, subconical, and the middle of the front
very tumid. In addition to the seven species, Rhinoryctes
mirabilis, Staxberg, 1875, from California, is said certainly
to belong to Alloniscus.

Liyprobius, Budde-Lund, 1875, receives three species.

Scyphax, Dana, 1852, has the species setiger, Budde-
Lund, from New Caledonia, and ornatus, Dana, from a
sandy beach of New Zealand.

Deto, Guérin, 1834, is said to be very near Oniscus.
Deto echinata, Guérin, and Deto acinosa, Budde-Lund, are
both African species.

Armadilloniscus, Uljanin, 1875, has the flagellum of the
second antenne four-jointed. Budde-Lund, besides de-
scribing three species, incorporates with them Actoniscus
ellipticus, Harger, and with hesitation also Actcecia euchroa,
Dana, and Actecia Aucklandie, G. M. Thomson, both from
New Zealand. Dollfus adds Armadilloniscus tuberculatus,
1889, from the Azores. In this genus the uropods are
flattened and scarcely produced, the peduncle large, and
the outer branch short, just reaching the apex of the
peduncle.

Scleropactes, Budde-Lund, 1885, has the body very
convex and contractile into a globular form, the opercular
branch in all the pleopods tracheal, and the uropods toler-

4.52 A HISTORY OF RECENT CRUSTACEA

ably produced with a short outer branch. The three
species described by Budde-Lund are from Peru.

Budde-Lund mentions <Acanthoniscus spiniger, White,
from Jamaica, and Ouracherus caudatus, White, of un-
known habitat, but confesses himself unable to determine
their position among the Onisci.

Stenonscus, Aubert and Dollfus, 1890, does not fall into
any of the groups established or recognised by Budde-Lund.
It has a very narrow, hairy body, the hind margin in the
front segments of the pereeon not sinuous, and but little in
the hinder ones, the side-plates distinct in all but the first
segment; the first segment of the pleon not visible, the
others dorsally tubercled, the large rounded terminal seg-
ment completely covering the uropods, which have a broad
short peduncle, the outer branch apical, minute, the inner
longer than the outer, attached high up on the peduncle.
The second antenne are very short, with a two-jointed
flagellum. The single species is Stenoniscus pleonalis,
Aubert and Dollfus, from the sea-coast, Marseilles.

Family 5.—Armadillidide.

The body is very convex, contractile into a globular
form. The head is sometimes broader than long, flanked
by the first segment of the peraeon; the face is nearly
perpendicular. There is no demarcation of the sides of
the head. The clypeus is perpendicular. The young quit
the mother with all seven segments of the perzon
developed. The trunk-feet are rather short. The uropods
are short, flattened, not reaching beyond the postero-lateral
points of the two terminal segments of the pleon. The
foregoing characters distinguish. this family from the
Oniscide, the other characters of which are common to both
families and need not be repeated.

Of the generic names in this family the nearest in age
to the preoccupied Armadillo are Cubaris and Armadilli-
dium. Of these two, which are contemporaries, it seemed
reasonable and convenient, for the sake of old association,
to give the preference to Armadillidiwum in forming the
name of the family.

THE ARMADILLIDIDE 433

Budde-Lund gives in effect the following ‘ Conspectus
Generum :’—

I, Outer branch of the uropods small or minute, rather
smooth.

A. Terminal segment not shorter than the uropods.
a. ‘Terminal segment apically truncate.
1. Cubaris. 2. Eubelum. 3. Pseudarmadillo.
b. Terminal segment apically acuminate.
4, Peryscyphis.
B. Terminal segment shorter than the uropods,
broadly triangular.

5. Spheroniscus. 6. Cylloma.
If. Outer branch of the uropods large, flattened, lamellar.
7. Hluma. 8. Armadillidium.

Cubaris, Brandt, 1833, appears to be the earliest
synonym of Armadillo, Latreille, 1804, which is not only
preoccupied, but has had the type-species removed to
another genus. Under the name Armadillo, Budde-Lund
gives descriptions of thirty-six species, and the names of
some twenty-four more. Only two or three of this host
are found in Kurope, seven belong to South Africa, five to
South America, a great number occur in the islands and
coasts of the Pacific, while from the whole mainland of
Asia not one is known, except Cubaris officinalis (Des-
marest), a species found all round the Mediterranean.
Dollfus adds Armadillo melanurus, 1887, Armadillo java-
nensis, 1889, Armadillo trifolium, 1890, and Armadillo albo-
marginatus, 1892. In this genus the flagellum of the second
antennee is two-jointed.

Hubelum, Budde-Lund, 1885, has the flagellum of the
second antenne three-jointed, the last segment of the pleon
in the middle squarely produced. As in the preceding
genus the opercular branch in all the pleopods is tracheal.
The only species is Hubelum lubricum, from South Africa.

Pseudarmadillo, de Saussure, 1858, has very small, un-

—

4.34 A HISTORY OF RECENT CRUSTACEA

pigmented eyes. ‘The only species is Pseudarmadillo cari-
nulatus from Cuba or Mexico.

Peryscyphis, Gerstaecker, 1875, has three species, Pery-
. scyphis trivialis, Gerstaecker, from an Kast African Lake,
and two others from Egypt, for which at first Budde-Lund
established a new genus Cercocytonus, which he cancels in
the same volume. The meaning of Vercocytonusis obscure.
Probably Cercoxvytinus was intended, meaning with acumi-
nate tail. Peryscyphis was no doubt a misprint for Peri-
scyphis, the name alluding to the convex form of the
animal.

Spheroniscus, Gerstaecker, 1854, has small eyes, the
second antenne short, with a three-jointed flagellum.
The single species is Spheroniscus flavomaculatus, from
New Granada. Budde-Lund thinks that Pyrgoniscus cinc-
tutus, Kinahan, 1859, from Eastern regions, may belong to
this genus.

Cylloma, Budde-Lund, 1879, has very large prominent
eyes, the third joint of the first antenne very long, all the
pleopods with tracheal opercula. The single species Cylloma
oculatum is from New Zealand.

Hlima, Budde-Lund, 1879, has simple, minute eyes, the
flagellum of the second antennee two-jointed, the opercular
branch of the first and second pleopods tracheal, the ter-
minal segment of the pleon subtriangular, the uropods
reaching beyond this, but not beyond the postero-lateral —
angles of the preceding segment ; the outer branch of the
uropods is flattened, laminar. The type is Hluma purpu-
rascens, Budde-Lund, 1879, from Madeira, the Azores,
Algeria, and Portugal. It is possible that this is synony-
mous with the earlier Armadillidiwm ccelatum, Miers, 1877.

Armadiliidium, Brandt, 1833, has the flagellum of the
second antenne two-jointed, the opercular branch of the
first and second pleopods tracheal, the terminal segment of
the pleon with the apex variable, not produced beyond the
angles of the preceding segment, the uropods not reach-
ing beyond the terminal segment. Budde-Lund describes
thirty species, and names eight others attributed to this
genus. Dollfus in 1887 adds five new French species, Simone,

CRANIOLOGY 435

esterelanum, sordidum, alpinum, album, and two others
named Kochi and Davidi. Of all this crowd only one spe-
cies, Armadillidium vulgare (Latreille), appears to be known
in Great Britain, and this species seems to be gradually |
following the track of Europeans all over the world.

From Assinee in West Africa, M. Adrien Dollfus has
just recorded two new genera and four new species of
this family. His Synarmadillo clausus is near to Cubaris,
but distinguished from it by having the terminal segment
of the pleon after the fashion of Armadillidium. His
Mesarmadillo is intermediate between the same two genera,
and with its three species, Alluaudi, marginatus, and
tuberculatus, appears to belong to the section I. B. of
Budde-Lund’s Conspectus. As observed in Alluaudi, the
second maxillz are said to be exceptionally large.

In a paper on the terrestrial Isopoda of “Spain, M.
Dollfus has further added several new species to this and
the preceding family.

It may be useful here to call attention to the remarks
which the same author has recently made as to the head
of a woodlouse. The hinder part or top he calls the
occiput. The anterior part comprehends, first, the vertex,
‘generally forming a right angle or an obtuse angle with
the occiput, from which it is always separated by a more
or less strongly defined ridge;’ secondly, the epistome ;
thirdly, the labrum attached to the epistome. The face is
said to be sloping, when’ the occiput and vertex form an
obtuse angle, perpendicular, when they form a right angle.
Occasionally the occiput itself is bent forwards and then its
front part must not be confounded with the vertex, from
which it is separated by the usual boundary.

436 A HISTORY OF RECENT CRUSTACEA

CHAPTER XXVIII
CONCLUSION

To complete the sketch of the Malacostraca, the sub-order
of the Amphipoda remains to be described. These crusta-
ceans may be defined in a very simple manner as Edrioph-
thalma having branchial sacs or vesicles connected with
some or all of the last six of the seven pairs of limbs
normal to the perzeon or trunk. Of all the divisions of
the sub-order which have been proposed, that which
arranges them in three tribes, the Gammaridea, Caprel-
lidea, and Hyperidea, still seems the most satisfactory.
Chapters describing these tribes for this volume had been
already written, when it appeared that they overflowed
the utmost space that could be allowed. As room for
them could only be found by an unsatisfactory curtailment
of the earlier portions of the work, I have preferred to.
leave over this last section of the Malacostraca, hoping to
engage the reader’s interest in it at no distant future.

For the exclusion of a group so important as the
Amphipoda, and one so obviously within the scope of the
present pages, an apology is doubtless due, but little or
none need be offered for the omission of much else which
the student might desire to know, since the extent of the
subject and the limits of the volume must make it clear
that no other course was possible. It would take a
volume by itself to analyse in an effective manner the long
and valuable disquisitions which have been written on the
circulation, the nervous system, the viscera, the tissues,
the intimate structure of the various organs of the senses,
the connection between fossil and recent forms, and the

THEN AND NOW 437

difficult questions of genealogy. On all these lines of
research knowledge is continually extending. The time
‘may be expected to come when, not from any one of thein
by itself, but from all combined, a final system of classifi-
cation will be established. Apart from all these questions
the simpler groundwork of the student’s knowledge of
recent Crustacea will still be incomplete unless the history
be extended to those other orders mentioned at the outset,
which comprise forms as varied, as strange, as numerous
as those of the Malacostraca.

On the literature of the subject not a little that is
entertaining might be written. That literature was scanty
and unfruitful in classical times. At the restoration of
learning it began, amidst idle tales and inexact observa-
tions, to lay the solid foundations of science. In the
present century it has attained an astonishing develop-
ment, aided no doubt successively by the perfecting of the
microscope, by the extension of marine research, and by
an all-pervading desire to arrive at the truth about the
origin of species. To illustrate the difference between
what was known of the Crustacea at the beginning of the
last century and what is known of them at the close of
the present, one is tempted to contrast the half-dozen
lines which suffice for the whole class in the first edition
of Linnzeus’s ‘Systema Nature’ in 1735, with the four
thousand quarto pages and more than six hundred plates
employed by the Challenger Reports between 1880 and
1888 in the discussion and illustration of a host of crusta-
cean species of which most were previously unknown.
The ‘System of Nature,’ it is true, began in small com-
pass, and was repeatedly expanded in successive editions,
but even in the thirteenth, published in 1788, that part
of it which may fairly be regarded as a manual of all the
Crustacea with which science was at that period acquainted,
is swollen only to the extent of fifty-three octavo pages.
In 1825 the French writer, A. G. Desmarest, could still
confine within the limits of a single volume an able
and meritorious survey of the whole subject, but not
long afterwards the masterly ‘ History of the Crustacea,’

32

458 A HISTORY OF RECENT CRUSTACEA
by Henri Milne-Edwards, completed in 1840, though

perhaps three times as valuable as Desmarest’s, was also
three times as large. . Since that date no work of similar
scope has been carried out with any success in smaller
compass, nor is it likely now that such a feat could be
accomplished. ‘The Jinnee has escaped from the casket,
and no magician can ever again reduce its gigantic expan-
sion to occupy ane narrow receptacle from which it
issued.

a ae

i isi, fel Dl a: <

» ABD

ABDOMEN, alias postacdomen,
tail, or pleon, 32, 45

Abdominalia, an order of Cirri-
pedes, 11

Acanthaspidia (new name) typh-
lops, 378

Acanthephyra, range of, 243;
Agassizii, microphthalma, pur-
purea, 243; pellucida, sica,
244

Acanthephyride, defined, 242

Acanthias vulgaris, devoured by
isopods, 344

Acanthocope,
cauda, 387

Acanthocyclus Gayi, 71

Acanthomunna proteus, 381

Acanthoniscus spiniger (family
Oniscide), 432

Acanthoniscus (preoccupied) ty-
phlops (family Asellide), 378

Acanthoplax, 93

Acanthopus (preoccupied) clavi-
manus, habits of, 98

Acanthosoma, a larval Sergestes,
221

Acetes, 221; indicus, found inthe
Ox-ray, 222

Achzus Cranchii, 106

Acicle, antennal scale or exopod,
146, 149, 155

Actecia, Aucklandiz,
431

Actzomorpha, a doubtful genus,
127

Actoniscus ellipticus, 431

acutispina, spini-

euchroa,

ALT

Adamsia palliata, the hermit-crab’s
associate, 167

Aiga, 348; bicarinata, rosacea,
Stromii, tridens, 348 ; crenulata,
emarginata, Lovéni, monoph-
thalma, psora, Schioedteana,
spongiophila, 349

Aigacylla, 349

Aigathoa loliginea, 353

Aigide, how discriminated, 347

Agassiz, Alex., 29

Aka-oni-gani, 154

Alaotanais, priority of, considered,
324 ; serratispinosus, 327; levi-
spinosus, 328

‘ Albatross,’ U.S.S., 28, 30

Albunea symnista, 152

Albuneide delined, 152

Alcirona, insularis, Krebsii, 346

Alcironide detined, 346

Alcyonium butchered to make a
Maia's finery, 112

Alert,’ H.M.S., 154

Alima, larval Squilla, 290 .

Alimerichthus, larval
290

Alitropus, foveolatus, typus, 347,
348

Alloniscus, cornutus,
perconvexus, 431

Alpheidz defined, 230

Alpheus, 230; affinis, avarus, coma-
tularum, Edwardsii, megacheles,
minus, 231; sivado, 251

Alternating forms of male
Cambaroides, 208;

Squilla,

mirabilis,

in
in Cam-

440

ALT

barus, 209; suggested in Tana-
idee, 327

Alternation of sex in Cymothoide,
350, 355

Amalopenzeus elegans, 219

Amathia (pre-occupied) Carpen-
teri, 119

Amblyops, synonym of Amblyop-
sis, 269

Amblyopsis, abbreviata, crozetii,
269

Amboina, present from king of,
29; species of Gonoplax at, 92

Amorphopus, 102, 103

Amphiplectus, 234, 237

Amphipoda, name of, 8; where
found, 14, 16, 17, 22, 23; sizes
of, 30; place in classification. 8,
291; ‘compared with isopods,
390; isopods parasites on, 400 ;
the suborder briefly defined,
436

Amphoroidea, australiensis, falci-
fer, typa, 365

Anamathia, 119

Anapagurus, 161, 165; chiroacan-
thus, ferrugineus, Hyndmanni,
levis, 161

Anarthrura, 325 ; simplex, linearis
(2), 328

Anaspis, recently discovered genus
of Schizopods, 257

Anceus, synonym of Gnathia, 300,
337, 338

Anchialus, 267;
typicus, 274

Anchistia, migratoria, 248; scripta,
249

Ancinus depressus, 365

Anebocaris, 242

Aniculus, 160

Anilocra, asilus, 352;
29, 352

Ani:locride, 351

Annulosa, 2

Annulus ventralis of Cambarus,
208

Anomala, tribe of Brachyura, de-
fined, 133; tribe of Macrura,
defined, 149

Anomura, position of, 8; apterura,

agilis, pusillus,

gigantea,

A HISTORY OF RECENT CRUSTACEA

ARI

52, 133; pterygura, 146; reason
for discarding, 147

Antenne, first, alias antennules,
35 ; otoliths in, 36, 196, 248

Antenne, second, alias outer,
under, 38; stridulating appara-
tus in, 39

Anthelura, 331; abyssorum, 333

Antnura, 331; flagellata, gracilis,
tenuis, 333

Anthuridz defined, 330

Antilibinia Smithii, tenacity of,
117

Anuropide, suggested new family,
344

Anuropus, 342 ; branchiatus, 345

Aphareus inermis, 212

Apoda, order of Cirripedes, 11

Apodemes, 133

Appendag‘s, a single pair to a
segment, 33, 42; names for the
parts of, 36, 43

Apseudes, 320; grossimanus, Lat-

reillii, simplicirostris, talpa,
321
Apseudide defined, 319

Apterura, meaning of, 133

Apus Newberryi, Jarge Phyllopod,
ol

Arachnida, the class, 3

Arachnomysis, 267 ;
276

Aratus Pisonii, breathing arrange-
ments of, 97

Archer, Surgeon-Major, on ae
at Singapore, 135

Arctomysis (pre-occupied) 267;
Fyllex, 268

Arciopsis, its priority over Pisa
mooted, 116

Arcturidez detined, 369

Areturides cornutus, 373

Arcturus Baffini,370; resemblance
to Caprellide shown in this
genus, 370

Arctus, 194; ursus, 195

Argeia, depauperata, pugettensis,
415

TLeuckartii,

Argis lar, 228
Aristeus antennatus, 219
Aristotle, Carcinus Heracleoticus

INDEX

ARM

of, 77; on the crab with the
Pinna, 100; Carabos of, 195;
on name for the lobster used
by, 203; on a caridion in the
shell of a Pinna, 241

Armadillididz detined, 432

Armadillidium, album, alpinum,
Davidi, esterelanum, Kochi,
Simoni, sordidum, vulgare, 434

Armadilloniscus, ellipticus, tuber-
culatus, 431

Armature, of Oplophorus, 244 ; of
claw and pleon in Squilla, 282 ;
of carapace in female Cumacea,
294; of species of Arcturus, 370

Arms, Miss J. M., on the crusta-
cean labium, 40; on the telson
of Porcellana, 47; on the gait
of a crab, 58

Artemia, the brine-shrimp, a Phyl-

lopod, 14
Arthrobranchiz, 134
Arthropoda, definition of, 2;

classes of, 3

Asaphus tyrannus, a large trilo-
bite, 27

Ascension Island, land-crabs at, 14

Asellidz defined, 376; notes by
Bovallius on, 377

Asellopsis preoccupied, 377

Asellota defined, 376

Asellus, 375; aquaticus, 13, 23,
377 ; communis, coxalis, 377

Aspidophryxus, peltatus, Sarsi,
399; Sarsi, parasitic Copepod
on, 400

Astacidz, discarded as a family
name, 201

Astacidea defined, 199

Astacilla, 370 ; Cordiner’s original
account of, 371 ; damnoniensis,
Deshayesii, dilatata, gracilis,
granulata, intermedia, longi-
cornis, 371; marionis, 372

Astacoides madagascariensis, 209

Astacopsis serratus, large Austra-
-lian crayfish, 28, 210

Astacus, misuse of name, 201;
right use reasserted, 203 ; gam-
marus, americanus, 203

Astrurus crucicauda, 381

441
BAT

Atattut, name of cocoanut crab
in Amboina, 158

Atelecyclus, heterodon, septem-
dentatus, 75

Athanas nitescens, 232

Athelgue, alias Athelgus, Athelges,
409; guitarra, paguri, Prideauxii,
409; Cardone, cladophora, in-
termedia, lorifera, 410

Atya, remarkable hands of, 240;
bisuleata, scabra, serrata, sul-
catipes, 240

Atyephyra, 241

Atyide defined, 239

Atyoida, 240

Atys preoccupied, 240

Auditory apparatus, in first an-
tenne of Macrura, 36; in uro-
pods of Mysidz, 37; in Bra-
chyura, 52

Audouin, Savigny’s plates de-
scribed by, 173; on Tylos La-
treillii, 424

Aurivillius, Dr. C. W. S., on the
manners and customs of the
Oxyrrhyncha, 113, 114; on the
associates of hermit-crabs, 168;
on glands in Lupagurus, 169

Autonomeea, classification of, 253;
Olivii, glaber, 253

Axiide defined, 187

Axius, 187; glyptocerus,
stirynchus, 187

188;

BAcoN, Lord, natural knowledge
ine 5

Beenosome, alias trunk, perzon, 45

Bait for Crustaczans, 21

Balanoglossus, position of, 2

Balanus,improvisus in fresh water,
17; psittacus of great size, 31

Barrois, Dr. Th., on Ozius Ed-
wardsi, 63; on catching crabs,
94; Syrian woodlice collected
by, 427

Barybrotide defined, 347

Barybrotes, agilis, Indus, 347

Basis, alias basipodite, second
joint, 43

Bate, Mr. Spence, on ear-cavity

442
BAT

of lobster, 36; on the telson,
46; on young Pagurids, 164;
on subdivision of Macrura, 180;
on sensory and respiratory ap-
paratus, 181; on the petasma,
215; on classitication of the
Schizopoda, 223; on uniform
nomenclature, 255

Bate and Westwood, on Tanais
and Apseudes, 329; on the
Valvifera, 369

Bathymetrical distribution, 18

Bathynectes, longispina, superbus,
70; longipes, 71

Bathynomus giganteus, 29; eyes
and branchiz of, 344

Bathyplax, 93 ; typhlus, oculiferus,
103

Bathytanais, 324

Bathytropa, 429

Beddard, Mr. F. E., report on the
‘Challenger’ Isopoda by, 357;
on eyes of Serolide, 359

Bell, Thomas, on telson of prawn,
46; on the genus Cancer, 57;
on Vaughan Thompson, 59; on
Milne-Edwards, 60; on Portum-
nus and Platyonichus, 67

Bellia, 72

Bellon, Rondelet’s criticism of, 281

Belt, Mr. T., on wide range of
freshwater species, 23

Beneden, M. P. J. van, finds Nau-
plius of Cerataspis, 220

Benedict, Mr. J., on the genus
Panopeus, 56

Bentheocaris exuens, an abyssal
species, 245

Benthesicymus, deep range of, 19;
pleocanthus, 219; eyestalk of,
220

Bentheuphausia amblyops. 264

Benthoecetes, subdivided sixth
joint in, 219

Benthonectes, subdivided seventh
joint in, 219

Betzeus, 232; zequimanus, malleo-
digitus, microstylus, 233

Beurs-Krabbe, name _ explained,
158

Birgus the cocoa-nut crab, de-

|

A HISTORY OF RECENT CRUSTACEA

BRA

scribed, 156; its names in va-
rious languages, 158 ; its specific
name Jatro originally belonging
to Pagurus, 159

Bithynis, a synonym of Palemon,
246

‘ Blake,’ U.S.S., giant isopod found
by, 29; Pylocheles Agassizii,
taken by, 160

Blepharis, 181

Boas, Dr. J. E. V., on the first an-
tenne, 36, 37; on the position
of the vulve, 139; the euky-
phota of, 224; on the order
‘Squillacea,’ 278; on the legs
of the Isopoda, 316

Boddam-Whetham, Mr. J. W., on
cocoanut crabs, 157

Bodotria arenosa, 302

Boeck, Axel, numbering of leg-
joints by, 43

Bondaroy, Fougeroux de, on Bo-
pyri. 392

Bonnier, M. Jules, on parasites of
Macrura anomala, 174; his key
to species of Galathea, 175: on
Uroptychus rubrovittatus, 178

Bopyri, allusion to, 13, 128, 174

Bopyridz defined, 408

Bopyrina, hippolytes, nitescens,
ocellata, Virbii, 416

Bopyroides, acutimarginatus, 417

Bopyrus, Fougerouxi, Helleri, pa-
lemonis, Rathkei, squillarum,
treillianus, xiphias, 415 ; (?)
alphei, 416

Boreomysis obtusata, deep range
of, 19 ; arctica, scyphops, 268;
range and size of, 269

Boreophausia, synonym of Rhoda,
inermis, Jardineana, Raschii,
263

Bosc, L. A. G., legend accepted
by, 25; on crabs in Carolina,
91

Bovallius, Dr. C., on Thranites,
70; on Glossobius, 354; on Asel-
lidee, 377

Brachycarpus, 247

Brachyura, the suborder, 8; de-
fined, 51; subdivisions of, 53, 54

INDEX

BRA

Brady, Dr. G. 8., on Ostracoda, 31

Brain, the, 33, 48, 299

Branchiz, 4, 45 ; in Ocypode, 87;
Sesarma, 97; distinguishing
names of, 184; in Thalassina,
182; wanting in Mysidz, 267 ;
of the Squillide, 279; of the
Cumacea, 296; in bathynomus,
344; in Tylos, 423; in Helleria,
425

Branchiopoda, order of Entomos-
traca, 9

Branchiura, sub-orderof Branchio-
poda, 10

Breathing apparatus, of Gnatho-
phausia, 259; of Cumacea, 295 ;
of cheliferous isopods, 318, 320;
of Epicaridea, 394

Bregmocerella, synonym of Cerato-
cephalus, tricornis, 365

Brongniartia, synonym of Serolis,
trilobitoides, 357

Brook, Mr. G., on larval Euphau-
siidze, 265

Brooks, Professor W. K., on range
of Squillide, 19, 280; develop-
ment of Penzus, 217; on
characters of Squillide, 281;
on larval Squillide, 288

Browne, Patrick, on West Indian
land-crabs, 80, 83; on the Turtle-
Crab, 95; Oyster-crab, 101:
Mamma Shrimp, 145; Mother
Lobster, 192

Budde-Lund, G., on the terrestrial
Isopoda, 421, 423-426, &c.

Bullar, Mr. J. F., on alternating
sexes in Cymothoide, 350

Burrowing crustaceans, Chelura
terebrans, 17; American Lady-
Crab, 67; the Masked Crab, 72 ;
Thia residuus, 75; American
fiddler-crabs, 90, 91; Sesarma,
97; the mole-like Hippa, 150;
Callianassa, 183 ; Upogebia, 185 ;
Cambarus, 208; Squillide, 280;
Lysiosquilla, 285; Limnoria lig-
norum, 367

Bythocaris, 234; leucopis, nana,
Panschii, Payeri, simplicirostris,
237

443
CAN

Bythotrephes crassicauda, an En
tomostracan, 31

CABIRA preoccupied, 400

Cabirops, 400; lernzodiscoides,
401

Cabiropside, 400

Calanus finmarchicus, parasite of,
397

Calappa, depressa, gallus, granu-
lata, 124

Calappide defined, 123

Calathura, 332

Callianassa, branchize of, 180;
early description of, 183; lari-
cauda, Stimpsoni, subterranea,
183

Callianasside defined, 183

Callianidea, pleopods of, 184

Calliaxis adriatica, 187 ~

Calling Crab, the, 89

Calocaris, larval form of, 186;
Macandree, habits of, 190

Calyptopis, larval stage of Eu-
phausiidz, 266

Calyptura (preoccupied), carnea,
366

Cambaroides accepted as ge-
nus, 208; dauricus, japonicus,
Schrenkii, 208

Cambarus, 207 ; alternating forms
of male in, 209; argillicola,
Bartonii, Diogenes, dubius, pel-
lucidus, 208

Campbell, Lord George, on land-
crabs, 94

Campecopea, hirsuta, mimicry by,
16, 363; Cranchii, 363

Camptoplax, 93

Campylaspide, 295, 313; defined,
306

Campylaspis, nodulosa, last legs
deficient in, 293; carinata, cos-
tata, rubicunda, 307

Cancer, great restriction of the
genus, 57; irroratus, pagurus,
58; borealis, 59; residuus, 75;
ruricola, 80; marmoratus, 94;
dormia, dormitator, 135;caninus,
raniformis, 143; crumenatus,

444

CAN

158; megistos, 162; modestus,
206 ; Boreas, 228

Cancricepon, elegans, pilula, 413

Cancridz defined, 56

Cancrinea defined, 55

Cancrion, cancrorum,
miser, 407

Cancroidea, alias Cyclometopa, 53

Caprellidz, where found, 16, 22

Caprellidea, tribe of Amphipoda,
436; antenne of, 35

Carabos of Aristotle, Bell’s opinion
on, 195

Carapace, origin of, 38

Carcinion of Aristotle, the Pin-
notheres, 242

Carcinology, science of Crustacea,
13

Carcinus, mzenas, 61,65; granu-
latus, 66; heracleoticus, 77

Cardisoma, 79

Caribbee Islands, crabs in, 80

Caricyphide, 239; vaguely de-
fined, 242

Caricyphus, 242

Caridea, the tribe defined, 224

Carides, Sars on larval forms of,
186

Caridina, 224,72 *¢

Caridion, 233; Gordoni, 235

Carpus, alias carpopodite, fifth
joint, wrist, 43; its occasional
subdivision, 44; in the Poly-
carpinea, 228

Cassidina, emarginata, latistylis,
maculata, neo-zealanica, typa,
365

Catapagurus, 165; Sharreri, 168

Catattut, Amboinese name of
cocoanut crab, 158

Catometopa, the tribe defined, 78

Catta, Professor, on distribution,
99

Cenobita rugosa, 159

Cenobitidz detined, 155

Cephalon, 32

Cephalothorax, 32

Cerapus dentalii, an Indian amphi-
pod, 335

Cerataspis monstrosus, one of the
Penzidz, 220

floridus,

A HISTORY OF RECENT CRUSTACEA

CHL

Ceratocarcinus, 120

Ceratocephalus, 364; Grayanus,
365

Ceratolepis hamata, 258

Ceratothoa, misapplication of the
name, 354 ; species properly be-
longing to, auritus, crassa, lati-
cauda, linearis, 353, 354

Cercocytonus, a cancelled generic
name, 434

Cervical groove, 33, 52; absent
from ‘ Ibacus verdi,’ 193

Ceylon, crab-hunting pigs in, 159

Cheeraps, distribution of, 210

Chetilia ovata, 372

Cheetiliidz, the family, rejected
by Miers, 373

Chalaraspis alata, 260

Chalarostylis elegans, 309

‘ Challenger,’ H.M.S8., abyssal &e.
species found by, 18

Chameleon species, a, 235

Charybdis cruciatus, vivid colour-
ing of, 69, its names upheld, 70

Chavesia costulata, 429

Cheiroplatea, telson in, 47; ceno-
bita, 170

Chelate, 45

Chelifera, the Isopod tribe, de-
fined, 318

Chelipeds, 44

Chelura terebrans, a wood-boring
Amphipod, 17 :

Cheramus, 183; its position ques-
tioned, 184

Cheraphilus, bispinosus, nanus,
trispinosus, 226; echinule.tus,
neglectus, 227

Chevreux, M. Ed., many Amphi-
pods on Maia squinado, found
by, 22; on Helleria brevicornis,
425

Chilton, Mr. C, on the Phreatoi-
cide, 388, 390

Chioncecetes opilio, size of, 117

Chiromysis, synonym of Heteromy-
sis, 273

Chitin, 62

Chlorida preoccupied, 287

Chloridella,substitute for Chlorida,
281, 287

INDEX

CHL

Chlorotocus, 237, 238

Chorinus algatectus, 113; aculea-
tus, 115, 116; longispina, 116

Chorismus, 234

Ciliczea, 364

Circeis, bidentata, tridentata, 365

Circulation, 182

Cirolana, 342; borealis, concharum,
Cranchii, spinipes, 243

Cirolanide defined, 341

Cirripedia, alias Thyrostraca, posi-
tion and sub-division of, 11;
their range, 17; large species
of, 31

Cladocera, a sub-order of Branchio-
poda, 9

Cladocopa, a sub-order of Ostra-
coda, 10

Classification, of animals, 1; of
Arthropoda, 3; of Crustacea, 6 ;
of the Anomura, 8, 133, 146; of
the Schizopoda, 223, 256; of
the Tanaide, 328; of the
Phreatoicide, 391

Slaus, Dr. C., on foot-jaws of
Copepoda, 42; development of
Stomatopoda, 288

Cleantis, filiformis, tubicola, 375

Clibanarius, 160

Cocoanut Crab, Birgus latro, man-
ners and nature of, 156

Codonophilus argus, 356

Ceecidotea stygia, a blind cave-
dwelling species, 377

Coelenterata, 1

Collecting, chapter on, 12; the
eatable crab, 65

Colouring, of common shrimp, 16 ;
American Lady Crab, 68 ; Chary-
bdis cruciatus, 69 ; Ocypode, 86 ;
Grapsus pictus, 94; -Lazy Crab,
121; Galathea magnifica, 176;
Upogebia stellata, 185; larvee
of American lobster, 205; Al-
pheus comatularum, 231; Al-
pheus affinis, 231; Hippolyte
varians, 235; Gnathophausia,
260; Euphausia superba, 262;
Squilla empusa, 283 ; Gnathiide,
338 ; Nessa and Dynamene, 361;
Trichoniscus roseus, 422

445

CRA

Columbus, his argument from a
crab, 95

Concheecetes, 135; conchifera, 136

Concholestes dentalii, an Indian
amphipod, 335

Conilera, 342; cylindracea, vora-
city of, 343

Copepoda, an order of Entomos-
traca, 9; where found, 17;
bathymetrical range of, 20;
first antenne of, 35; foot-jaws
of, 42

Corallana, hirticauda,tricornis,3 15

Corallanide defined, 341

Cordiner, Rev. Charles, work by,
371

Corilana erythraa, 346

Coronida, 281; Bradyi, trachurus,
287

Coronis preoccupied, 281],
287

Corophium, position of heart in
the Amphipod, 328

Corystidz, 72

Corystinea defined, 72

Corystes, 74; cassivelaunus, fea-
tures of, 72, 73; supposed rela-
tion of, 145

Corystoidea, 139

Couch, J., on second antennz of
Corystes, 73; on Autonomaxa
Olivii, 253

Corwich, the, 11]

Coxa, alias coxopodite or first

_ joint, 43

Crab’s eyes, 83

Crab-fish, 5

Crab Island, Drake at, 26; land-
crabs at, 80

Crabe enragé, 65

Crabyzos longicaudatus, 373

Crangon, 224, 225; vulgaris, dis-
tribution of, 225; Allmanni,
bispinosus, fasciatus, nanus,
sculptus, trispinosus, 226; cata-
phractus, lar, salebrosus, 228;
munitus, parasite of, 395

Crangonidz defined, 224

Crangoninea defined, 224

Crawfish, 5, 196

284,

| Crayfish, 5; Australian, 210

4.4.6
CRA

‘Crayfish, The, by Huxley, on the
second maxille, 41; on struc-
ture of Crustacea, 48; on ‘ palp’
and ‘ flagellum,’ 192; on Amur-
land Astaci, 208

Crossophorus imperator, a giant
among Ostracoda, 31

Cruregens, 332; fontanus, 333

Cruripeds, 44

Crustacea, alias Crustata, defini-
tions of, 3; meaning of name,
5; subdivision of class, 6

Cryptocheles pygmexa, 237

Cryptocope, 325

Cryptodromia lateralis, 136

Cryptolithodes typicus, 154

Cryptoniscian forms, 394, 397, 398,
401, 405

Cryptoniscide discussed, 401

Cryptoniscus, planarioides, 402;
larveformis, paguri, 403

Cryptopodia, 154

Cryptopus, synonym of Cerataspis,
220

Cryptosoma cristatum, its priority
questioned, 125

Cryptothir, balani, minutum, 404

Cryptothiria, synonym of Crypto-
thir, 401, 404

Cubaris, albomarginatus, javanen-
sis, melanurus, officinalis, tri-
folium, 433

Cuma, 8, 301; arenosa, Audouinii,
Edwardsii, scorpioides, 302;
pulchella, 303

Cumacea, origin of name, 8; dis-
cussion of, 291; suborder de-
fined, 301

Sumella, limicola, pygmea, 306

Cumide defined, 301

Cumopsis, 302; Edwardsii, leevis,
longipes, 303

Cuvier, on the pinna and crab, 100

Cyathura, 331; carinata, 333

Cyclaspis, 302; cornigera, levis,
pusilla, 303

Cyclide, 54

Cyclinea, 71

Cyclodorippe, doubtful position
of, 130

Cycloés granulosa, 125

A HISTORY OF RECENT CRUSTACEA

DEE

Cyclograpsus, respiration of, 97

Cycloidura venosa, 364

Cyclometopa, the tribe defined, 55

Cyclorhynchus preoccupied, 234

Cyclura preoccupied, 364

Cylisticus convexus, 428

Cylloma, 433; oculatum, 434

Cymodoce, emarginata, Lamarckii,
truncata, 362; abyssorum, 363

Cymonomus granulatus, 132

Cymopolia Caronii, 132

Cymothoa, sexes of, 350; eremita,
on tongues of fish, 353 ; cestrum,
354

Cymothoide, as a group, defined,
339; Hansen’s tabular view of,
340

Cymothoide, in restricted sense,
defined, 341; discussed, 350,
351

Cynthia preoccupied, 276

Cynthilia, synonym of Siriella, 276

Cyproniscide, 397

Cyproniscus cypridine, descrip-
tion of, 397

Cyrtomaia, Murrayi, Suhmi, 110

Cyrtopia, larval stage of Euphau-
siidze, 266

Cystisoma, genus of Amphipoda
Hyperidea, 30

Czerniavsky, V., bibliographical
writings of, 174; remarks on
Callianassa by, 183

DACTYLUS, alias Dactylopodite,
finger, nail, or seventh joint, 43-

Dajide defined, 398

Dajus described, 398;
mysidis, siriellz, 399

Danalia, curvata, Dohrni, Lobian-
coi, 403

Darwin, Charles, on inosculant
forms, 93; on Grapsus at St.
Paul’s Rocks, 94; on a crab
allied to Notopus, 143; on the
cocoanut crab, 156

Darwin, Erasmus, on the nature
of flesh, 6

Decapoda, objection to the word,7

Deep-water species, 18, 19, 20,

mixtus,

INDEX

DEF

201, 219, 237, 243, 250, 252, 259,
261, 269, 291, 326, 383, 387

Definition, difficulties of, 5; need
for caution in, 145

De Freminville, inaccurate de
scription by, 144

De Haan, on respiratory arrange-
ments, 41, 140; on ‘spurious
females,’ 109; on the clothing
of Chorinus, 116; on the food
_of various crabs, 124; on the
impropriety of establishing the
suborder Anomura, 146

Delage, M. Yves, on breathing of
Apseudide, 320; on circulatory
apparatus of Tanaidez, 328 :

De Man, Dr. J. G., on Thelphusa,
77; on Porcellanide, 173

Demon-faced Crab, the, 132

Dendrobranchiata, 180, 213

Dendrotion, 382

Dennisia sagittifera, marking of,
249

Deodamia preoccupied, 201

De Paw, description of death of
Drake by, 25

Desmarest, A. G., edition of Bosc’s
Crustacea by, 25; history of
Crustacea by, 437

Desmosoma, aculeatum, armatum,
lineare, tenuimanum, 386

Deto, acin sa, echinata, 431

Development of Cancridz 59, 60;
of the Anomala, 172, 178; of
Norway lobster, 202; of Ameri-
can .obster, 204; of Crayfish,
207; of Euphausiide, 265; of
Squillide, 288; of Gnathiide,
335, 337; of Epicaridea, 396,
397, 402, 404

Diaphoropus, slight foundation for
the genus, 239

Diasty lide defined, 310

Diastylis, 310; discussion of the
name, 311; stygia, 20; Good-
siri, 29, 310; biplicata, cornuta,
echinatus, insignis, levis, lamel-
lata, Rathkii, rugosa, spinosa,
tumida, 311

Diastylopsis, Dawsoni, resima, 311

Dicera preoccupied, 75, 76

447

EBN

Dicerobates eroogoodoo, the huge
fish, 222

Dicranodromia, an
genus, 1357

Diogenes, 160; varians, 161

Diops, parvulus, spinosus, 306

Diptychus preoccupied, 178

Distribution, questions of, 22, 23;
by unconscious human agency,
99; in the deep sea, 153; of Asta-
cidea, 209; by wading birds,
241; of Eucopia, 261; of Sto-
matopoda, 280; of Serolide,
358; of Oniscoidea, 422, 428,
433

Dodecas elongata, one of the Am-
phipoda Caprellidea, 30

Dohrn, Dr. A., on the structure of
the Gnathiide, 336, 337

Dollfus, M. Adrien, on distribu-
tion of Porcellio, 428; on Lu-
casius, 429; on the parts of tie
head in Oniscoidea, 435

Don Diego in ‘t volle harnasch, 158

Dorippe, facchino, 130, 132; ja-
ponica, 131, 132; dorsipes, 132

Dorippide defined, 130

Dorodotes, 237, 238

Doryphorus preoccupied, 233

Dotilla, brevitarsis, fenestrata, 102

Doto preoccupied, 102

Drake, Sir Francis, 25

Dressing, crabs practise, 112, 113,
115

Dromia, 134; origin of the name,
135; Rumphii, vulgaris, 135

Dromidz detined, 134

Drominea defined, 133

Dynamene, Montagui, rubra, ver-
sicolor, viridis, 361, 362

Dynomene, 136

inosculant

EARSTONES, alias otoliths, 36, 37,
182, 196

Ebalia, Bryerii, Cranchii, nux,
Pennantii, tuberosa, tumefacta,
129 ; undecimspinosa, 130

Ebner, Dr. V. von, on respiratory
apparatus of Tylos, 423; on
Helleria, 425

4.48
ECH

Kchidnocerus setimanus,
size of, 154

Echinoplax Moseleyi, 110

Ecphysis, alias exopod, 194

Edible crab, the, good contrivance
for extirpating, 57

Edotia, bicuspida, triloba, 374;
tuberculata, 375

Eriophthalma, 7, 8, 43; defined,
291

Egeon, fasciatus, sculptus, 226

Eggs, of Gecarcinus, 83; often
large in deep-water species, 177,
189; of Squiilidaz, 288; of Cu-
macea, 298

Kiconaxius, acutifrons, parvus, 188

Eisig, Dr.,on behaviour of Inachus,
113

Hisothistos, 331;
mimicry by, 335

Elamene Mathzei, 102

Elaphocaris, a larval Sergestes, 221

Eluma, 433; purpurascens, 434

Endopod, alias endopodite, 36

Endostome, 62

Engeus, distribution of, 210

Entione achzei, 406

Entomostraca, 6, 7; subdivision
of, 9; where met with, 14, 17;
numbers and sizes of, 31; seg-
ments of, 32; mandibular palp
in, 39

Entoniscide defined, 405

Ent niscus, brasiliensis, Creplinii,
Miilleri, porcellane, 406

Ephyra (?) compressa, 241

Ephyrina Benedicti, 244

Epicaridea, discussion of, 392;
phylogenetic table of, 393 ; mar-
supial plates of, 297, 393

Kpichthys giganteus, 352

Epipod, 41, 42; of first maxillipeds
in Eucopia, 260

Epistome, the, 52, 435

Epizoanthus, americanus, paguri-
philus, colonial polyps asso-
ciated with Hermit-crabs, 168

Eretmocaris, 254; longicaulis, eye
of, 35, 255

Ergasticus, Clouei, Naresii, 110

Ergyne cervicornis, 413

great

vermiformis,

A HISTORY OF RECENT CRUSTACEA

EUP

Erichsonia filiformis, 375

Erichthalima, 290

Erichthide, larval Squillide, 281

Erichthus, 289

Eriocheir japonicus, 95

Kriphia, ridges on endostome of,
62

Eryon, a fossil genus, 199; cari-
bensis, 144

Eryontide defined, 199

Erythrops, 267, 275; elegans, ery-
throphthalmus, Goésii, pyg-
meeus, serratus, 275

Kstheria californica, a large Phyl-
lopod, 31

Ethusa, 18, 132; mascarone, 53,
132; granulata, 132

Ethusina, challengeri, 18; abyssi-
cola, 132

Eubelum lubricum, 433

Eucheta glacialis, mandibular
‘palp ’ in, 39

Euchezetomera, tenuis, typica, 267,
276

Eucolomban, ornatus, picta, 345

Eucolumba, ornatus, picta, 345

Eucopia australis, 260; distri-
bution of, 261

Eucopiide defined, 260

Eudora preoccupied, 305

Eudorella, emarginata, truncatula,
305

Eudorellopsis, deformis, resima,
305

Eugerda globiceps, 382

Eukyphota, meaning of, 224;
pods parasitic on, 410

Eumetor liriopides, 404

EKumiersia, synonym of Nemato-
carcinus, 249

Eumunida picta, 177

Euneognathia, new genus, gigas,
338

Eunepbrops Bairdii, 202

Eupagurus, 1L0; Bernhardus, cu-
anensis, excavatus, Prideaux,
pubescens, sculptimanus, 161;
isopods parasitic on, 409, 410,
411

Euphausia, luminosity of, 262;
pellucida, superba, 262

iso-

INDEX

EUP

Euphausiide defined, 261

Euphylax, 71

Euplecteliaaspergillum, Crustacea
living in, 212, 349

Euprognatha rastellifera, abund-
ance of, 111

Eurycope, 384; gigantea, mutica,
sizes of, 29; cornuta, gigantea,
mutica, phalangium, robusta,
385; cornuta, parasite on, 401

Eurydice, 342; achatus, pulchra,
truncata, 344

Eurynome, 120; aspera, boleti-
fera, scutellata, tenuicornis, 121

Euryozius, a sub-genus, 63

Eurypanopeus, 56

Eurythenes gryllus, size and dis-
tribution of the Amphipod, 30

Eurytium, 56

Eutrichocheles modestus, 206

Evatya, 241

Evolution, the theory of, tested,
97; links in the chain of, 103;
exemplified in hermit-crabs,
164; bearing of parasites upon,
403

Eyes, 34, 35; of Ommatocarcinus,
92; of eatable shrimp, 225; of
Acanthephyra microphthalma,
2413; of Eretmocaris, 255; of
Schizopoda, 265, 266, 268, 269,
273, 275; of the Squillidz, 279,
282 ; of the Edriophthalma, 291 ;
of the Cumacea, 292; of the
Apseudidz, 320; of the Sero-
lide, 359

Eye-lash, 181

Eye-stalk, in the Podophthalma,
35; in Panulirus penicillatus,
197; in Polycheles, immovable,
200; in Willemoesia, rudimen-

tary, 201

Exopod, alias exopodite, exc-
egnathite, scale, acicle, outer
branch, 36, 39; sometimes

called the palp, 192
Exuviation, 84, 207

FABRICcIus, J. C., condemnation
of Hill and Renard by, 162

449

GAM

Faro Isles, the, 118, 206

Faxon, Mr. W., on the English
crayfish, 207 ; on Cambarus and
Cambaroides, 208, 209

Fiction, 25, 107, 162

Fiddler crabs, English, 66; Ameri-
can, 89, 91

Fish-lice, Copepoda known as, 17

Fiabellifera, the tribe, defined, 330

Flabellum, or fan, of the second

‘maxille, 41; of the pleon, 46,

146, 330

Flagellum, or lash, of antenne,
35, 36, 37, 38; of an exopod,
192; alternative name for po-
dobranchia, 192

Food, Crustaceans used for, 12, 14,
26, 57, 65, 81, 95, 124, 158, 225,
229, 247, 282

Food of Crustaceans, 21, 25, 86,
94, 124, 151, 201, 248, 285, 315,
336, 342, 357

Fossettes, 51

Fraisse, Dr., on parasitic Crusta-
cea, 109, 402, 404

Fraudulent specimens, 107, 162

Freshwater Crustaceans, 13, 14,
17, 23, 28, 76, 207, 209, 246, 217,
257, 333, 355, 373, 376, 379, 389

Frog-crab, the, 143

‘ Front,’ the, 52

Fulton, Dr.,on Dajus mysidis, 399

Furcilia, larval stage of Euphau-
siidze, 266

GALATHEA, courage of, 15; swim-
ming powers of, 175; dispersa,
intermedia, nexa, squamifera,
strigosa, 175; digiti-distans.
magnifica, 176; gregaria, 177;
development of, 179

Galatheidz, bathymetrical range
of, 175

Galatheinea defined, 174

Galene, 93

Gammaridea, size of, 30; pecu-
liarities in limbs of, 390; the
tribe, 436

Gammarus, pulex, 13, 23; littoral
species of, 16

450

GAS

-Gastric region, 52

Gastroliths, 83

Gastrosaccus, 267, 277; sanctus,
spinifer, 277 ; Normani, 278

Gebia, synonym of Upogebia, 185

CGebios, synonym of Upogebia, 185

Gecarcinidee defined, 78

Gecarcinucus, 79

Gecarcinus, 79; curious particulars
of, 80; ruricola, 80; lagostoma,
84

Gecarcoidea, 79, 80

Gelasimus, 88; arcuatus, 88, 89,
91; pugilator, vocans, 89;
minax, 91

Genders of generic names, discus-
sion of, 75, 120

Genera, protest against multiply-
ing, 227; minute distinctions
of, 323; attempts at reduction
of, 360

Gennadas, bathymetrical range
of, 19; eyestalk of, 220

Geograpsus, 94

Geothelphusa, 76

Gerstaecker, Dr., work on Crus-
tacea by, 360

Geryon, quinquedens, eggs of, 62 ;
doubtful systematic place of,
93; tridens, luminous eyes of,
103

Gesner, on the habits of Pinno-
theres, 100; criticism of Aris-
totle by, 164

Giard, Professor, explanation of
‘spurious females’ by, 109, 396

Giard and Bonnier, on Epicaridea,
392,393, 396, 399, &c.

Gigantione Moebii, 414

Gigantostraca, the sub-class, 6;
rarity of, 10

Glaucothoé, 170!

Globigerina ooze, species taken on,
201

Glossobius, synonym of Cerato-
thoa, 353, 354

Glyphocrangon, distribution of,

A HISTORY OF RECENT CRUSTACEA

GRA

229; large eyes and powerful
telson of, 230; aculea tus, granu-
losis, rimapes, 230

Glyptonotus, antarcticus, entomon,
372

Gnathia, marsupial arrangement
in, 300; cerina, formica, Hali-
daii, maxil'aris, 337 ; asciaferus,
bathybius, Danielii, gigas, 3358

Gnathiide defined, 335

Gna.hophausia, ingens, size of,
28; gigas, Goliath, 29; cha-
racters of the genus, 258; cal-
carata, gracilis, gigas, ingens,
260

Gnathopods, 42

Gnathostoma, a sub-order of Cope-
poda, 10

Gomeza, 76

Gonatonotus, 246

Gonerichthus, larva of Gono-
dactylus, 290

Goniograpsus marmoratus, 94

Goniopsis, manners of, 98

Goniosoma cruciferum, synonym
of Charybdis cruciatus, 70

Gonodactylus, falcatus, chiragra,°
286

Gonoplax, alias Goneplat, Gone-
plax, 91; angulata, rhomb ides,
sinuatifrons, 92; rhomboides,
long-stalked eyes of, 35 _

Goodsir, Harry, eyes of Cumacea
described by, 292; on develop-
ment of Cumacea, 293

Gosse, P. H., on action of fiddler-
crabs, 66

Graeffe, Dr., on the toilette of the
Oxyrrhyncha, 112, 113

Grapsicepon, 412; Edwardsi,
Fritzii, messoris, 413

Grapside defined, 93

Grapsion, 405, 406; Cavolinii, 407 -

Grapsus, respiration of, 87, 97;
habits of, 94; maculatus, 93;
marmoratus, pictus, 94

Grass Crab, the, 75

‘MM. Chevreux and Bouvier have recently confirmed the opinion that the genus
Glaucothoé represents only larval forms, and they argue that these belong rather to the

family Paguride than to the Parapaguride.

INDEX

GRE
Greek, enigmas in, 234, 250,
253

Gribble, the, 367

Grimothea gregaria,
position of, 177

Gurney, Mr., observation of young
hermit-crabs by, 164

Gyge, branchialis, galathee, 412

doubtful

HABITS, of littoral crustaceans,
15: cirripedes, 17; Cancride,
57: of larval forms, 61; of Car-
cinus meenas, 65; Corystes cas-
sivelaunus, 73 ; Cancer ruricola,
80; the calling crab, 8£; Pin-
notheres, 100 ; the Oxyrrhyncha,
112; Ranina, 142; Birgus latro,
156 ; Hermit-crabs, 163; Squil-
lidz, 280, 285; Cumacea, 294,
299; Isopoda, 315; Cymothoa,
Bo4

Hagen, Dr., on Cambarus, 208

Halicarcinus, 101; Mathzi, 102;
planatus, antarctic distribution
of, 102

Haliophasma maculata, 332

Hansen, Dr. H. J., on flabellum
and joints of second maxille,
41, 295; on Schizopoda, 268 ;
on the Cymothoide, 339, &c.

Hansenomysis, new generic name,
Fylz, 268

Hapalogaster, 154

Haplocope, 325

Haplophthalmus, danicus, Mengii,
422

Haplopodinea defined, 253

Haplostylus, erythrzus, Normani,
278

Harger, Oscar, on Astacilla, 371;
on marine Isopoda of New Eng-
land, 375

Harponyx pranizoides, 355

Haswell, Mr. W. A., on Elamene
Mathei, 102; on Paratymolide,
139 ; on Hisothistos vermiformis,
335

Haswellia carnea, 366

Haynes, F. H., Mr., specimens of
Pontonia received from, 241

451
HES

Head, difficulty of defining a, 33

Heart, position of, 48; of Mala-
costraca, 50 ; in Euphausiide,
262; in Stomatopoda, 279; in
Cumacea, 300; in Isopods gene-
rally, 317; in [sopoda chelifera,
319

Hectarthropide, 254

Hectarthropus, meaning of, 254

Hedriophthalma, refinement upon
Edriophthalma, 8

Helice, ‘musical crest’ in, 92

Heller, Dr. Camil, on the genus
Thelphusa, 77 ; proposes the term
loricata, 191; genera named
after, 425

Helleria brevicornis, 425

Helleriidez defined, 424

Helms, Mr. R., Phreatoicus austra-
lis found by, 389

Hemiarthrus, Cranchii, philonika,
typtonis, virbii, 417 ; abdomina-
lis, 418

Hemilamprops, assimilis, cristata,
rosea, uniplicata, 309

Hemilepistus ruderalis, 428

Hersioniscus balani, 404

Hemiplax, 93

Henderson, Dr. J. R, on bathy-
metrical range of Anomura, 19;
report on Challenger Anomura
by, 134; on the habits of Zan-
clifer, 145; on Pagurids and
their dwellings, 169; on Uro-
-ptychus, 178

Hensen, Dr. V., on the auditory
arrangements of Palinurus, 196 ;
of Palzemonetes varians, 248

Hepatic lobes, 48 ; of Cyclome-
topa, 55; of Catometopa, 78;
of Oxyrrhyncha, 104; of Cuma-
cea, 300; of Isopoda, 317

Hepatus princeps, 127

Heracleoticus of Aristotle, identi-
fied with Thelphusa, 77

Herbst, J. F. W., 67, 72, 80, 135,
136, 145

Hermit Crabs, 147, 163

Herring food, 263, 292

Hesse, Enugéne, on habits of Cu-
macea, 299; on the sexes of

452
HET

Gnathia, 337; on the Spheero-
mide, 362

Hetairus, 234; difficulties in the
way of accepting, 235

Heterocarpus, ensifer, 238; cari-
natus, 239

Heterocrypta, Maltzani, Marionis,
122

Heterocuma, Sarsii, var. granulata,
304

Ieteromysis, 267 ; formosa, 273

Heterophryxus appendiculatus,
400 B

Heterotanais, 323; limicola, Or-
stedi, tenuis, 327

Hexapoda, alias Insecta, 3

Hexapus, explanation of the name,
102; relations of, 103

Hieroglyphics, pinna and crab in,
100

Hippa, 149; emeritus, talpoida,
150

Hippidee defined, 149

Hippinea defined, 149

Hippolyte, 234; Gaimardii, var-
ians, 235; Cranchii, fascigera,
Liljeborgi, Mitchelli, pandali-
formis, Prideauxiana, producta,
pusiola, securifrons, spinus,
viridis, Whitei, 236; Thomp-
soni, 237

Hippolytidz defined, 233

Hoek, Dr. P. P. C., on Dajus my-
sidis, 399

Holothuriaphilus, 101

Homaride, reason for discarding
the name, 201

Homarus, a synonym of Astacus,
201

Homola, barbata, Cuvieri, orienta- -

lis, 137

Homolide defined, 137

Homologenus, 138

Homolopsis preoccupied, 138

Horse-shoe Crab, 17

Hoyle, Mr. W. E., on larval stages
of Euphausiide, 265

Huenia, curious derivation of, 107;
elongata, heraldica, proteus,
discussion of, 107, 109

Huxley, Professor, terms used by,

A HISTORY OF RECENT CRUSTACEA

ION

36; on the maxillary fan, 413
on ‘ palp’ and ‘ flagellum,’ 192 ;
on branchiz of Nephrops, 202;
on Amurland Cray-fishes, 208
Hyas, 113; araneus, coarctatus,
small specimen of, 114 ; curious
habits of, 114
Hyatt, Mr. Alpheus,
Guides by, 40
Hyleocarcinus, 79, 80; Humei, 84
Hymenodora, 245
Hymenosoma orbiculare, 101
Hyperidea, tribe of Amphipoda,
436; specimens on jelly-fishes,
22; large species of, 30
Hypoconcha, 135; sabulosa, ex-
amined by Herbst, 136
Hyssura, 331; producta, 333

Science

TAIs Hargeri, 378 -

Ianthe, speciosa, Bovallii, 378

Iantbopsis Bovallii, 378

Jathrippa longicauda, 378

Ibaccus, mis-spelling of Ibacus,
193 ;

Ibacus, incisus, verdi, 193

Ichthyophilus, synonym of Nero-
cila, 351

Ichthyoxenus, Jellinghausii, mon-
tanus, 355

Icotopus, meaning of name, 254

Idotea, emarginata, lacustris,
linearis, marina, metallica,
pelagica, sexlineata, tricuspi-

data, 373 ; acuminata, appendi-
culata, longicaudatus, parallela,
prismatica, 374

Tdoteidz defined, 372

Ilyarachna, longicornis, quadri-
spinosa, 386

Ilyoplax, 93

Inachidee defined, 104

Inachus, dorsettensis, dorynchus,
leptochirus, 106

Insecta, extent of class, at present,
‘3; formerly, 57

Insect, crab spoken of as an, 95

TIolanthe, 378

Ione, cornutus, gebize, thoracicus,
vicina, 414

INDEX

IPH

Iphinoe, 302; tenella, trispinosa,
303
Isea Montagui, amphipod found
on Maia squinado, 22, 111

Ischium, alias ischiopodite, or
third joint, sometimes called
the genu or knee, 43

Ischnosoma, bacillus, bacilloides,
bispinosum, quadrispinosum,
spinosum, Thomsoni, 383

Isea, a doubtful genus, 184

Isocladus, armatus, spiniger, 364

Isopoda, sub-order of Edrioph-
thalma, 8; size attained by, 29;
sub-divisions of, 314; defined,
317

Ives, Mr. J. E., term cruriped
proposed by, 44; on Hippa
emeritus, 150

JRA, albifrons, Guernei, longi-
cornis, Nordmanni, 379

Jzropsis, brevicornis, marionis,
neo-zelanica, 379

Jamaica, Grass Crab of, 75; land
crabs, 80; Oyster Crab, 101;
Mamma Shrimp, 145; Mother
Lobster, 192; isopod, 432

Jamna, longicornis, 379

Janira, alta, maculosa, 377; abys-
sicola, laciniata, longicauda,
spinosa, tricornis, 378

Japan, Crustacea of, 27 ; de Haan’s
work on, 44, 88, 95, 101, 102,
107, 125, 128, 144, 154, 421

Jasus, priority over Palinosytus of,
197

Jaxea nocturna, 187

Jobert, M.,on breathing apparatus
of land crabs, 85

Johnson, Dr. Samuel, on the lan-
guage of natural history, 5

Johnston, G., species of Aga
named by, 349

Jonah’s whale, fish fit to be, 222

KEPON typus, 412
Kerguelen Island, Crustacea from,
243, 338, 358, 378, 380, 381, 386

33

453

LEP

King Crab, the, 27

Kirk, Mr. T. W., on Palinurus
tumidus, 27

Kolga, a fossil genus, 220

Krauss, Dr. F., on South-African
Crustacea, 69, 77, 86, 91, 98, 117

Kroyer, H., Chioncecetes opilio
figured by, 117; on the Cumacea,
292, 293

Kosciusko, Mount, isopod found
high up on, 389

LABIUM, alias lower lip, 40

Labrum, alias upper lip, 40

Lady Crab, the British, 66; the
American, 67 _

Lady in the chair, the, picture of,
48

Lambrus, intermedius, macroche-
los, 121

Lampropide defined, 308

Lamprops. 308 ; fa-ciata, fuscata,
quadriplicata, 309

Land Crabs, 14, 80

Lanocira Kroyeri, 346

Larval forms, 59, 60, 172, 178, 204,
221, 222, 265, 288, 335, 337, 402

Latin, specimen of scientific, 418

Latreille, nomenclature of Crus-
taceans by, 8, 9, 315

Latreillia, deceptive outward form
of, 137; elegans, valida, 137

Latreillopsis bispinosa, 138

Latreutes, 234

Lazy Crab, the, 121

Leach, Dr. W. E., on the way to
take Cancer pagurus, 57; his
name for the Gulf-weed crab,
95; his name for the common
lobster, 203

Leachia preoccupied, 370

Leacia, synonym of Astacilla, 370

Leander, 246; serratus, telson of,
46; Fabricii, Leachii, serratus,
squilla, 247

Leidya distorta, 412

Leiolophus clavimanus, 98

Leiopus leptodactylus, unusual
maxille of, 321

Lepas, compared with Leucifer,

4.54
LEP

223; anatifera, size attained by,
31; fascicularis, larvee of, 205

Leponiscus pollicipedis, 405

Leptaspidia brevipes, curious habi-
tat of, 381

Leptochela, gracilis, robusta, ser-
ratorbita, 252

Leptochelia, 323; algicola, dubia,
Edwardsii, Savignyi, 326; limi-
cola, 327

Leptocuma Kinbergii, 304

Leptognathia, 324; laticaudata,
Lilljeborgi, rigida, 327

Leptomysis, 267; gracilis, ling-
vura, 274

Leptopodia sagittaria, 106; frau-
dulent use of, 107

Leptosoma preoccupied, 374

Leptosquilla, 281 ; Schmeltzii, 288

Leptostylis, 311 ; manca, last lees
deficient in, 298 ; producta, 311

Leptotrichus, pulchellus, tauricus,
429

Lernza abyssicola, a parasitic
copepod, 20

Leucifer, Reynaudii, eyes of, 35;
typus, 222; comparison of, with
Lepas, 223

Leucon nasica, 304

Leuconide defined, 304

Leucosia, australiensis, pulcher-
rima, scabriuscula, splendida,
127; de Haan on respiratory
system of, 41, 142

Leucosiide defined, 127

Leucosiidea, alias Oxystomata, 53

Leydig, Dr. Fr., on olfactory or-
gans, 37

Libinia emarginata, numbers cf,
120

Ligia, cursor, dilatata, exotica,
oceanica, 421

Ligiide defined, 420

Ligidium, hypnorum,
cephala, paludicola, 421

Life, expenditure of, 395

Limbs, 33

Limnoria, lignorum, 367; segnis,
368

Limnoriide defined 367

melano-

A HISTORY OF RECENT CRUSTACEA

LYS

Limulus, polyphemus, 17 ; moluc-
‘canus, 27; use of legs as man-
dibles by, 40

Links in the evolution of species,
55, 103, 137

Linnzus, the genus Cancer of, 57 ;
view of Pinnotheres held by,
100; the genus Oniscus of, 318 ;
Systema Nature of, 437

Linschotten, on man-eating crabs,
26

Liriope preoccupied, 403

Lirivpsis, monophthalma,pygmea,
403

Lisp gnathus Thomsoni, distri-
bution of, 110

Lissa chiragra, appearance and
habits of, 116

Lithodes, camschatica, 28 ; histrix,
Maia, 153; Agassizii, Murrayi,
154

Lithodide, distribution of, 153

Lithodinea defined, 152

Liver, the, 48, 55, 78, 104, 300,
ou,

Livoneca, classification of, 352;
ovalis, Redmanni, 352

Lloyd, W. A., on behaviour of Hu-
pagurus, 164

Lobothorax, auritus, typus, 353

Lobster, the Norway, 202; the
common, 203; the American,
204; little, 371

Lomis dentata, 154

Lophogaster, typicus, 257, 259

Lophogastridz defined, 257

Lophoxanthus, 56

Loricata, alias Scyllaridea, 191

Lucasius, hirtus, myrmecophilus,
pallidus, pauper, tardus, 429

Lucifer preoccupied, 221

Luminosity of Crustacea, 103, 244,
259, 262, 263, 265

Lyprobius, 431

Lyreidus, Bairdi, tridentatus, 144;
ill-defined orbits of, 145

Lysioerichthus, larva of Lysios
squilla, 290

Lysiosquilla, armata, 19, 281; ex-
cavatrix, maculata, scabricauda,
scolopendra, spinosa, 284; burs

INDEX

LYS
rowing procedure of excavatrix,

’ Lysmata seticaudata, 229

MACROCHEIRA Kiampferi, great
size of, 27, 107

Macrocceloma, concava, trispinosa,
119

Macromysis, synonym of Praunus,

eo -wbt, 271.
Macrophthalmus, 92

Macropodia, 105, 113; longiros-
tris, rostratus, 105

Macropsis, 267, 272; Slabberi, re-
markable eyes of, 273

Macropus preoccupied, 105

Macrostylis, 382; latifrons, spini-
gera, 383

M crura, the suborder, 8; defined,
146; tabular view of, 148

Mera, littoral specimens of the
amphipod, 16

Maia, 107, 111; squinado, charac-
ter and habits of, 22, 111; ver-
ruco-a, 112

Maiide defined, 111

Maiinea defined, 104

Maioidea, alias Oxyrrhyncha, 53

Malacostraca, the sub-class, im-
portance of, 6; the name of, 7;
detined, 50

Mamma Shrimp, the West Indian,
145

Mancasellus,
377

Mandibles, 39; in Hippa talpoida,
151; in Paratanais, 323; in the
Gnathiide, 336, 337

Marsupium, 45; inthe Schizopoda,
256, 257, 260, 261, 267; in the
Cumacea, 298, 300; in the Iso-
poda, 319, 337, 339, 357, 370,
376, 393, 398, 405

Masked Crab, the, 53, 73

Mastigobranchiez, 197, 201

Mastigochirus quadrilobatus, 152

Mastigopus preoccupied, 152

Matuta, swimming and digging
powers of, 126; lunaris, victor,
126

brachyurus, tenax,

455
MIL

Matutide defined, 126

Maxille, 41; of Lophogastride,
259; of Cumacea, 295; of Iso-
poda chelifera, 318

Maxillipeds, 42; of Schizopoda,
256; of Squilla mantis, 282; of
Cumacea, 296; of Isopoda, 316

Mayer, Dr. Paul, on development
and auditory apparatus of Palee-
monetes varians, 248; on sexes
of the Cymothoidz, 350

Measurements, abuse of, 232; use
of, 289

Megalopa, larval stage of various
crabs, 61; of Hippa, 151

Meinert, Dr. F., on the Cymo-
thoidee, 351

Meinertia, new genus, imbricatus,
354

Meleagrina margaritifera, Pinno-
theres encysted in, 101

Melita, littoral species of the Am-
phipod, 16

Meningodora, 245

Mergui Archipelago, Crustacea of,
77

Merhippolyte, 234, 237

Merostomata, an order of extinct
Gigantostraca, 10

Merus, alias meropodite, thigh, or
fourth joint, 43

Mesarmadillo, Alluandi, margina-
tus, tuberculatus, 435

Mesorheea, 121

Mesostenus preoccupied, 386

Metanauplius, larval stage of Eu-
phausiide, 266

Metaplax, 92

Metoponorthus, cingendus, meri-
dionalis, 428; Barroisi, pruino-
sus, 429

Microniscidez, 396

Microniscus, 396; calani, fuscus,
397

Miers, Mr. E. J., on Ethusina chal-
lengeri, 18; report on the Chal-
lenger Brachyura by, 55; on
genera near to Xantho, 56; on
Professor A. Milne-Edwards, 63

Miersia, 243

Miersiidz, why discarded, 243

456

MIL

Milne-Edwards, Professor Al-
phonse, definition of Crustacea
by, 4; on aspecies of Ozius, 63 ;
revision of Callianassidze by, 183

Milne-Edwards, Profe sor Henri,
on development of Crustacea,
60; on the respiratory cavity of
Ranina scabra, 140; history of
Crustacea by, 437

Mimicry, by common shrimp and
isopoda, 16; by species of Hbalia,
21; Antilibinia, 117; Parthe-
nope, 121; Alpheus, 231; His»-
thistos, 335, 363; Phreatoicus,
389

Minute species, 29, 232, 255, 275,
308, 328, 355, 379, 380, 382, 383

Mithrax, 120

Mocquard, M. F., on structure of
the Crustacean stomach, 147

Monaco, the Prince of, adventure
with the nipper crab,.68

Monocarpinea defined, 239

Montagu, Colonel, discovery of
Callianassa by, 183; of Upo-
gebia, 185; of a Cumacean, 292

Moresby, Captain, on the cocoanut
crab, 157

Mother Lobster, the, 192

Mouldering, 83

Mound of crabs, 112

Mountaineering Crustacea, in As-
cension Island, 14; in the Great
Andes, 14, 429; in Jap+n, 14,
77; in Tasmania, 257; in Aus-
tralia, 389; in the Philippines,
416

Mouth-organs, 39

Miller, Fritz, on olfactory organs,
37; on respiration in Ocypode,
86; on differences in land-crabs,
96; respiration of Aratus, 97;
development of Penzeus, 217

Munida, Rondeletii, rugosa, 176

Munidopsis, 177

Munna, 379; Boeckii, Fabricii,
Kroyeri, limicola, maculata,
neo-zelanica, pallida, palmata,
Whiteana, 380

Munnopside defined, 383

Munnopsis, australis, typica, 384

A HISTORY OF RECENT CRUSTACEA

NEO

Musical or stridulating apparatus,
39, 64, 85, 92

Myodocopa, a suborder of Ostra- °
coda, 10

Myra, 128; fugax, 127, 128

Myside defined, 266 .

Mysideis, 267 ; insignis, 274

Mysidella, 267; typhlops, typica,
273

Mysidopsis, 267, 273; angusta,
didelphys, gibbosa, hibernica,
274

Mysis, 267, 269; arenosa, chamz-
leon, flexuosus, Helleri, inermis,
Kervillei, Lamornz, neglecta,
ornata, Parkeri, spiritus, 270,271

Mysis-stage, of Penzeus, 217

Myto Gaimardii, larval form of
Sabinea, 228

N2sA bidentata, 361

Neesicopea, hew genus, abyssorum,
363

Nannastacide defined, 305

Nannastacus, Suhmii, unguicula-
tus, 305; longirostris, Sarsii, 306

Nannoniscus, bicuspis, oblongus,
382

Napoleon in Egypt, 173

Nauplius, 213, 217, 222, 265, 279

Nauticaris, 234, 237

Nautilocorystes, 74, 76

Nautilograpsus,synonym of Planes,
minutus, 95

Naxia, hystrix, 116

Neasellus kerguelenensis, 381

Nebalia, a genus of Phyllocarida,
31, 313

Nebaliopsis typica,gize of, 31

Nectocrangon lar, synonym of
Argis lar, 228

Nematocarcinide defined, 249

Nematocarcinus, ensifer, 249; al-
tus, cursor, lanceopes, undula-
tipes, 250

Nematopus (preoccupied), elegans,
Goésii, obesus, 275

Nematoscelis, borealis, megalops,
265

Neomysis, 267 ; vulgaris, 271

INDEX

NEP

Neotanais, 324; serratispinosus,
327 ; levispinosus, 328

Nephrops, norwegicus, Thomsoni,
202

Nephropside defined, 201

Nephropsis, atlantica, Stewarti,
206

Nerocila, depressa, 351; Lovéni,
munda, serra, 352

Nervous system, 2, 48; in Cyclo-
metopa, 55; in Oxyrrhyncha,
104; in Cumacea, 300

Neseea preoccupied, 361

Nika, Couchii, edulis, processa, 229

Nikide defined, 229

Nikoides Danz, 230

Norman, Canon, on distribution,
66; on Axius stirynchus, 187;
on Mysidz, 271; on male Ta-
naids, 327

Norman and Stebbing, on Isopoda
of the Porcupine, &c., 326

Nothocaris, 238

Notophryxus,clypeatus, globularis,
lateralis, ovoides, 400

Notopoides latus, 143

Notopus dorsipes, 145

Notostomus, 245; perlatus, 246

‘Novara,’ the, Crustacea of, 77

Nyctiphanes, australis, Couchii,
norvegica, 263

OCCIPUT, in Oniscoidea, 435

Ocypode, 85; arenaria, ceratoph-
thaimus, rhombea, 86; Fritz
Miiller’s discu-sion of, 87

Ocypodidz defined, 85

Ocypodiidea, alias Catometopa, 53

Oeidia, synonym of Gomeza, 76

(Kthra, 154

Olaus Magnus, pictures from, 25

Old Man’s Face Crab, 75

Olencira pregustator, 353

Oligoniscus monocellatus, 422

Olivi, pile of crabs described by,
ATL

Ommatocarcinus Macgillivrayi, 92

Oniscide defined, 425

Oniscoidea defined, 420

Oniscus, the original genus, 318;

457

OZI

paradoxus, 357 ; asellus, fossor,
murarius, punctatus, . Simonii,
430

Onychophura, a small class of Ar-
thropods, 3

Oodeopide defined, 252

Oodeopus, 252; origin of the name,
253

Opercula‘a, order or suborder of
Cirripedes, 11

Ophthalmic segment, 34

Oplophorus typus, armature of,
24

Oppian, on Pinnotheres, 100; his
ignorance of Squillide, 282

Orbits, 51

Orchestia, littoral species of, 16

Orchestide, short first antennz of
the Amphipod family, 36

Oreophorus, 130

Orithyia, bimaculatus,
laris, 125

Orphania tenuimana, 252

Osachila, 127

Ostracoda, order of Entomostraca,
9; subdivision of, 10; a giant
species of, 31

Ostraconotus, 166

Otoliths, 36, 37, 182, 196

Ouracherus caudatus, 432

Ourozeuktes, caudatus,
canthi, Owenli, 355

Ova, of Corystes cassivelaunus, 74;
of Eupagurus, 164 ; of Munidop-
sis, 177; of Caridea, 224; of
Schizopoda, 256; of Squillide,
288

Ovaries, of the Stomatopoda, 279;
of the Cymothoidz, 350; of the.
Entoniscide, 405; of Ergyne
cervicornis, 414

Oxyrrhyncha defined, 104; spell-
ing of the name, 105; manners
of, 112; lead among Crustacea
taken by, 118

Oxystomata defined, 123

Oyster Crab, the, 101

Oysters, eaten by the Shore Crab,
66; story of Pinnotheresand, 100

Ozius, ridges on endostceme of, 62;
Edwardsi, 63

mammil-

mona-

458

PAC

Pachygrapsus marmoratus, 94;
parasite of, 407

Packard, Dr. A.8.,on size of Phyl-
locarida, 31

Pactolus Boscii, a made-up species,
i06, 107

Paguridz defined, 159

Pagurinea defined, 155

Paguristes, 166

Paguropsis, simply bent pleon of,
169

Pagurus, 159, 160; similimanus,
160; Bernhardus, cuanensis,
Dilwynii, fasciatus, ferrugineus,
Forbesii, Hyndmanni, levis,
Prideaux, striatus, tricarinatus,
Thompsoni, ulidianus, 161; ar-
rosor, megistus, 162; granu-
latus, 163

Palegyge, 410; affinis, Bonnieri,
Borrei, de Mani, fluviatilis,
Hoyli, 411 ;

Palemon, 246; carcinus, 28; Fa-
bricii, heterochirus, jamaicensis,
lar, Leachii, minans, serratus,
squilla, varians, 247

Palemonella, tenuipes, orientalis,
247

Palemonetes,
vulgaris, 248

Palestine, isopods of, 376, 429

Palinosytus, synonym of Jasus,
Hiigelii, Lalandii, 196

Palinurellus, gundlachi, 197; hy-
bridica, 198

Palinuride defined, 195

Palinurus, vulgaris, 27, 195; tu-
midus, 27, 196

‘Palp’ (endopodal joints), of
the mandibles, 39; of the
first maxille, 295, 316, 318;
of the first maxillipeds, 356,
340

Palp, alias exopod, of the third
maxillipeds, 192, 194

Pandalide defined, 237

Pandalopsis, 238

Pandalus, annulicornis. breviros-
tris, Montagui, narwal, 238

Panopeus, Benedict and Rathbun
on the genus, 56

exilipes, varians,

A HISTORY OF RECENT CRUSTACEA

PAU

Pantopoda, alias
sea-spiders, 3
Panulirus, author of, 197; penicil-
latus, 35, 197

Paracrangon, second trunk-legs
obsolete in, 225

Paracyclois,124; Milne-Edwardsii,
125

Paradoxides, genus of Trilobites,
27

Paralamprops,
tata, 309

Paralomis, 154

Paramunna bilobata, 380

Paranephrops, planifrons, zealan-
dicus, 210

Paranthura, 332;
punctata, 333

Parapaguride defined, 166

Parapagurus, 166; pilosimanus,
bathymetrical range of, 167 ; as-
sociates of, 168

Parapasiphaé, 252

Parapseudes latifrons, 320

Parasites, 12, 17,- 109.428 2.Sar.
353, 392

Parastacide defined, 209

Parastacus, 209

Paratanais, 323 ; Batei, forcipatus,
rigidus, 327; linearis, 328

Paratelphusa, 77

Parathanas, decorticus, immatu-
rus, 233

Paratya compressa, 241

Paratymolidz defined by Haswell,
139

Paratymolus, 139

Paraxius, 188

Parerythrops, 267; obesus, 275

Pariambus typicus, amphipod of
tribe Caprellidea, 22

Parthenope horrida, 121

Parthenopide detined, 120

Parthenopinea defined, 120

Pasiphaé, synonym of Pasiphza,
245; princeps, 28

Pasiphea, Savigny’s account of,
251; cristata, sivado, 251; prin-
ceps, tarda, 252

Pasipheeide defined, 251

Paulson, 0, description of thely-

Pycnogonida,

295; serrato-cos-

Costana, nigro-

INDEX

PED

cum by, 216; term loricata used
by, 191

Pediculus marinus, of Rondelet,
352; of Seba, 354

Pedunculata, order or suborder of
Cirripedes, 11

Pelocarcinus, synonym of Gecar-
coidea, 80

Peltogaster, 402, 409; purpureus,
402; paguri, Rodriguezii, 403

Penzidez defined, 213

Penzidea defined, 213

Penzeus, 214; canaliculatus, cara-
mote, monodon, semisulcatus,
215; esculentus, 216; mem-
branaceus, siphonoceras, 217;
the petasma, 215; the thely-
cum, 216; the development, 217

Penguin, Eucopia australis ob-
tained from a, 261

Pentacheles euthrix, 200

Perzeon, afias thorax or trunk, 44

Perzeopods, limbs of the five seg-
ments immediately preceding
the pleon, 44

Pericera cornudo, 119

Periceride defined, 119

Peripatus, genus assigned to the
Myriapoda, or to the Oxycho-
phora, 3

Perrier, Prof. E., 103

Peryscyphis, trivialis, 433; mean-
ing of name, 434

Petalidium, 221

Petalomera pulchra (family Dro-
midz), 136, 140

Petalomera preoccupied, declivis
(family Pseudocumidz), 308

Petalophthalmus, 267; armiger,
268

Petalopus preoccupied, 308

Petalosarsia, new generic name,
declivis, 308

Petasma, in Penzidze and Serges-
tide, 215

Peteinura gubernata, huge tail of,
220

Petiver, name given to Scyllarus
latus by, 192

Petrolisthes Boscii, 173

Philoscia, corsica, Couchii, elon-

459

PLA

gata, longicornis, muscorum,
pubescens, pulchella, 430; ano-
mala, bucculeutus, celleria, 431

Philougria, synonym of Trichonis-
cus, riparia, rosea, vivida, 422

Philyra, 127; pisum, parasites
upon, 128

Phlyxia, connection of, with Eba-
lia, 129; orbicularis, undecim-
spinosa, 130

Phoberus tenuimanus, 206

' Phreatoicidee, 388

Phreatoicidea, a new tribe, 388

Phreatoicus described, 388 ; aus-
tralis, typicus, 389; affinities
discussed, 390

Phryxiens, 393, 408

Phryxus (preoccupied, but hitherto
retained), paguri, resupinatus,
409; longibranchiatus, 410;
fusticaudatus, 411

Phyllobranchiata, 155, 166, 180

Phyllocarida, a suborder of the
Branch‘opoda, 9; paleeozoic, 31

Phyllodurus abdominalis, 418

Phyllopoda, a suborder of the
Branchiopoda, 9; large species
of, 31

Phyllosoma, larval form of Scyl-
laridz and Palinuride, 191, 198

Phymacerite, the ‘tubercle at
base of second antenna, con-
taining external orifice of the
green gland,’ 255

Pigs hunting crabs, 159

Pilumnoplax, 93

Pilumnus, hirtellus,
64

Pinnixa, 103

Pinnophylax, 100

Pinnoteres, 99; meaning of name,
100

Pinnotheres, 99; stories about,100;
ascidiicola, lithodomi, pholadis,
pisum, vetcrum, 101

Pinnotheridez defined, 99

Pinnotherion vermiforme, 408

Pirimela denticulata, 64

Pisa, 113; Gibbsii, tetraodon, tri-
bulus, 116

Plagusia, habits of, 98; chabrus,

xanthoides,

4.60
PLA

depressa, squamosa, tomentosa,
99

Plakarthrium typicum, 36

Planes minutus, the gulfweed
crab, 9a, 89

Plastron, 52

Platyarthrus Hoffmannseggii, in
ants’ nests, 429

Platyaspis typica, 309

Platybema, 233; explanation of
the name, 234; planirostris, ru-
gosum o7 rugosus, 235

Platycopa, a suborder of Ostra-
coda, 10

Platygrapsus, 94

Platymaia Wyville-thomsoni, 110

Platymera, 125

Platyonichus, bipustulatus,
descens, ocellatus, 67

Platysacus, larval form of Ser-
gestes, 221

Pleon, 45

Pleopods, 45

Pleoticus, 218

Plesionika uniproducta, ophthal-
mic segment in, 34

Pleuracantha preoccupied, 380

Pleurobranchiz, 134

Pleurocrypta, galatez, Hender-
sonii, porcellane, strigosa, 410

Pleurogonium, 380; inerme, rubi-
cundum, spinosissimum, 381

Pliny’s opinion about Pinnotheres,
100

Pocock, Mr. R. I., 184, 197

Podascon Dellavallei, 401

Podobranchiz, 134

Podocopa, a suborder of Ostracoda,
10

Podophthalma, the order, 7; de-
fined, 51

Podophthalmide defined, 71

Podophthalmus vigil, battledore
‘front’ of, 71

Peecilostoma, a suborder of Cope-
poda, 10

Polperro, the geographical position
of, 326

Polybius Henslowii, a great abun-
dance of, 68

Polycarpinea defined, 228

iri-

A HISTORY OF RECENT CRUSTACEA

PRO

Polycheles,199 ; baccata, typhlops,
£00

Polyonyx, 171

Pomatocheles, 170

Pontocaris, 228 .
Pontonia, custos, 241; melea-
grinze, 242

Pontoniide defined, 241

Pontophilus spinosus, 226; larval
forms of, 227

Pontostratiotes abyssicola, an
abyssal copepod, 20

Porcellana, 47 ; longicornis, platy-
cheles, 171, 172; Robertsoni,
173; Creplinii, 406

Porcellanella, 171

Porcellanide, 47, 171

Porcellaninea detined, 171

Porcellanides, 171

Porcellio,cristatus, dilatatus, levis,
lamellatus, Marioni, pictus, pro-
vincialis, scaber, spinicornis,
427; levis, scaber, extensive
distribution of, 428

Porcupine, the, Tsopoda of, 321,
326

Portumnus, 66;
tus, 67

Portunide defined, 65

Portunion meznadis, 407 ; Frais-
sei, Kossmanni, Moniezii, Sal-
vatoris, 408

Portunus, arcuatus,

latipes, variega-

corrugatus,

depurator, holsatus, marmoreus,

puber, pusillus, tuberculatus, 66
Potamobia, fluviatilis, pallipes,
torrentium, 207
Potamobiidez defined, 206
Potamonautes, 76
Praniza, synonym of Gnathia, 337
Praunus, 267 ; integer, 270; flexuo-
sus, inermis, neglectus, 271
Preguediou, 282

Priority, recognition of, advo-
cated, 203
Probopyrus, ascendens, Giardi,

palzmoneticola, 416
Procletes, biangulatus, Ellioti, 254
Promysis, 267, ‘O75
Propodus, alias propodite, hand,
_ or sixth joint, 43

INDEX

PRO

Prosthéte cannelée, 416

Protopodite, 36

Protosquilla, elongata, Guerinii,
287; larval form of, 290

Protozoa, 1

Protozoea, 217

Prudden, Mr. T. M., on Gelasimus
minax, 91

Psalistoma, the ‘cutting margin
of the mandible,’ 255

Pseudarmadillo carinulatus, 433

Pseuderichthus, larval form of
Pseudosquilla, 290

Pseudibacus Veranyi, 194

Pseudione, callianas-z, confusa,
Dohrni, Fraissei, Hyndmanni,
insignis, 411

Pseudocalanus elongatus, parasite
on, 397

Pseudocarcinus gigas, 26

Pseudocorystes, 74; armatus, 75

Pseudocuma, cercaria, ciliata, lon-
gicornis, 307

Pseudocumide defined, 307

Pseudo-mandibles of Gnathia, 336

Pseudomma, 267; Sarsii, trunca-
tum, 269

Pseudomysis, 267; abyssi, 274

Pseudorhombila, 93

Pseudosiriella, 267; frontalis, 277

Pseudosquilla ciliata, 286

Pseudotanais, 323

Pseudozius, Mellissi, 62
63

Pterelas, 349 -

Pterygotus, a genus of the Mero-
stomata, 26, 27

Pterygostomian regions, 52

Pterygura, 146; reason for dis-
carding the name, 147

Ptilanthura, 332

Ptychogaster Milne-Edwardsi, 178

Pycnogonida, some peculiarities of
the, 3, 4

Pylocheles, Agassizii, spinosus, 169

Pylochelidz, 169; a synonym of
Parapaguride, 170

Pyrgoniscus cinctutus, 434

; Bouvieri,

QUADRELLA, 65

461

SAB

RACHITIA spinalis, 253

Ranina, scabra, 139 ; dentata, sca-
bra, serrata, 140, 141

Raninidz, 140

Ranininea defined, 139

Raninoides personatus, 143

Rathbun, Miss M, on Panopeus,
56; on the Periceridz, 120

Rathke, H., on the cray-fish, 84,
207

Rathke, J., Cymothoa lignorum of,
367

Réaumur, on exuviation, 207

Red Crab of the devil, 154

Regions of the carapace, 52

Regulus preoccupied, 239

Remipes, 151; adactylus, scutel-
latus, testudinarius, 152

Respiration, see Branchiz and
Breathing apparatus

Rhabdosoma armatum, a slender
species of Amphipoda Hype-
ridea, 30

Rhinoceros-whale, the, 25

Rhinoryctes mirabilis, 431

Rhipidura, or tail-fan, 46, 146

Rhizocephala, an order of Cirri-
pedes, 11

Rhoda, inermis, Jardineana, Ras-
chii, 263

Rhomaleocaris, 242

Rhynchocinetes typus, 228

Rhyscotus een Ons, 429

River Crabs, 7

Robber Crab, 158 5

Robertson, Mr. David, observa-
tions on Corystes cassivelaunus,
74; Cumacea found in the Clyde
by, 292; Leptaspidia bees
found by, 381

Rocinela, 348, 352; dainvonieeens
signata, 349; foveolatns, 350

Rondelet on Squilla mantis, 282

Rumph, or Rumphius, story attri-
buted to, 142; his Cancer cani-
nus, 143; on the cocoanut
crab, 158

SABINEA, 225; septemcarinata,
227; larval form of, 228

462

SAN
Sandhopper, a littoral amphipod,
16

Saophra, 353

Saophridez, 351, 353

Sars, Professor G. O., on the
maxillary fan, 41; description
of Scyramathia Carpenteri, 118;
development of Macrura ano-
mala, 178; of Upogebia, 186;
on the Schizopoda, 257, 272;
Cumacea, 292, 313; Sphyrapus,
322; Leptochelia, 327; Cypro-
niscus cypridinez, 397, &c.

Savart, 38

Savigny, 173, 251

Scalpellum regium, an abyssal
cirripede, 20

Scaphocerite, 38, 188

Scaphognathite, 41

Schiddte and Meinert, great work
on the Cymothoidz by, 351

Schistomysis, 267; arencsa, Hel-
leri, Kervillei, ornata, Parkeri,
spiritus, 271

Schizopoda, a sub-order of Podo-
phthalma, 8; range in size of,
28; Bate’s classification of, 223,
245; defined, 256

Sciacaris, 221

Sclerocrangon, boreas, cataphrac-
tus, salebrosus, 228

Scleropactes, 431

Scopimera, with a pane in the

- leg, 102; globosa, 102

Scutuloidea maculata, 366

Scylla, 68; serrata, habits of, 69

Scyllaride defined, 191

Scyllaridea defined, and choice of
the name explained, 191

Scylarus latus, 192

Scyphacella arenicola, 422

Scyphax, ornatus, setiger, 431

Scyra umbonata, 119

Scyramathia Carpenteri, descrip-
tion of, 118; origin of generic
name, 119

Seal, devoured by small crustacea,
21; stomach of, filled with
shrimps, 227

Sea-spiders, 3

Segments, 2, 32

t

A HISTORY OF RECENT CRUSTACEA

SOL

Sensory filaments, 37

Seraphim, 27

Sergestes, literature of, 221; at-
janticus, 221

Sergestide defined, 221

Serolis, paradoxa, 357 ; antarctica,
australiensis, Bromleyana, Bron-
eniartiana, carinata, cornuta,
elongata, latifrons, longicau-
data, minuta, nezra, pallida,
septemcarinata, trilobitoides,
tuberculata, 358; gracilis, 359;
eyes of, 359

Serolide defined, 356

Sesarma, 96; Pisonii, 97

Sexes, distinction of, 45; of
Corystes cassivelaunus, 72; of
the Oxyrrhyncha, 115; of Ga-
lathea, 175; of Gnathiide, 335;
of Cymothoide, 350; of Sphe-
romide, 362

Shore Crab, the Common, 65

Shore-hopper, the, a littoral amphi-
pod, 16

Sicyonia, branchiz of, 218; cari-
nata, 218

- Siho maneki, meaning of the name,

88

Siphonostoma,
Copepoda, 10

Siriella, 267; Clausii, crassipes,
jaltensis, norvegica, 276; ar-
mata, Brooki, 277

Size, standards of, 24

Skeleton shrimps, 16, 22, 30

Slabber, Martin, on metamorphoses
of Crustacea, 59; on Macropsis,
273; on Eurydice achatus, 344

Sluiter, Dr. C. Ph., on manners of
Oxyrrhyncha, 113

Smith, Professor 8. I., on young of
Caucer irroratus, 61; Platyo-
nichus ocellatus, 67; Ocypode
arenaria, 86; Gelasimus pugila-
tor, 89; Euprognatha rastelli-
fera, 111; Hippa talpoida, 150;
Upogebia affinis, 185; Squilla
mantis, 283, &c.

a sub-order of

Solenocera, Philippii, siphono-
ceras, 217; meaning of the
name, 218

INDEX

SOL

Solenolambrus, 121

Spatuliform, 65, 71

Specimens, on collecting, 12

Spelzophorus, meaning of the
uame, 130

Spencebatea abyssicola, 306

Spermatozoa, in the Squillide,
279

Sphzroma, serratum, 360; cur-
tum, Hookeri, Prideauxianum,
rugicauda, 361

Spheeromide defined, 359

Sphezeroniscus, 433 ; flavomaculatus,
434

Sphyrapus, 321; malleolus, 321;
anomalus, serratus, tudes, 322

Spider Crabs, 105

Spirontocaris, 234, 235; Cranchii,
Gaimardii, pusiola, spinus, 236

Spiropagurus spiriger, 165

Sponge-dwellers, 17, 212, 349

Spongicola venusta, 212

‘Spurious females,’ 109, 126, 128,
396

Squame, alias scale, acicle, sca-
phocerite, exopod of second
antenne, 38, 146, 188, 279, 316,
319, 377, 379

Squilla, 281; mantis, 282; ar-
mata, Desmarestii, empusa, 283;
nepa, scabricauda, 284; larval
forms of, 289

Squillacea, Dr. Boas on, 279

Squillide, range of, 19; sizes, 29;
ophthalmic segment, 34; first
antenne, 38; defined, 279, 281

Stalio, Professor, on Carcinus
meenas, 65; Maia squinado, 112;
Lissa. chiragra, 117; Calappa
granulata, 124

Stenetrium, armatum,
Haswelli, inerme, 379

Stenoniscus pleonalis, 432

Stenopide, 211

Stenopidea defined, 211

Stenopus, hispidus, 211; spinosus,
212

Stenorynchus, spelling of, 105;
Phalangium, tenuirostris, 105

Stephanomma Goésii, unusual eye
of, 302

fractum,

|! Stereomastis,

463

SYS

meaning of the
name, 201; Suhmi, 200

Stiliform, origin of the word, 250,
311

Stilomysis, 267; grandis, 274

Stimpson, distinction of two
species by, 59; Latin descrip-
tion by, 418

Stochasmus, a conjecture rather
than a genus, 250

Stomach, on structure of, Dr. E.
Nauck, 47; M. F. Mooquard, 147

Stomatopoda, a sub-order of the
Podophthalma, 8 ; defined, 279

St. Paul’s Rocks, land crabs at, 94—

St. Peter's Sand, great crabs at,
26

Strauchia taurica, 308

Streets, Dr. T. H., on climbing
crabs, 158

Stridulating apparatus, 39, 64, 8&,
92, 161

Strongylura, 325 ;
cylindrata, 328

Studer, Professor, on habits of
Serolidew, 357

Stylamblys, 199, 255

Stylocerite, 188

Stylocheiron, longicorne, masti-
gophorum, 265

Stylodactylidz defined, 250

Stylodactylus serratus, 250

Styloniscus, 421

Stymphalus dilatatus, 421

Subchelate, 45

Subgenera criticised, 107, 129,
208

Suicide by a crab, alleged, 158

Sweden, marine fauna of lakes in,
23, 272, 372

Swimming appendages, 45, 66,
180, 256, 279, 294, 383

Symbiosis, 168

Sympagurus, 166

Synarmadillo clausus, 435

Synaxes, 191,197; hybridica, 198

Synaxidea, 46, 191

Syscenus infelix, 348

Syspasti, 425

Syspastus, a synonym of Helleria,
425

arctophylax,

464

TAB

TABULAR view, of the class Crus-
tacea, 49; sub-order Brachyura,
54; sub-order Macrura, 148;
larval Squillidz, 290; Cumacean
families, 312; sub-order Iso-
poda, 314; Cymothoid group,
340; families of Epicaridea,
393; genera of Entoniscide,
405; genera of the Oniscide,
426; genera of the Armadilli-
didze, 433

Tacheea, crassipes, incerta, 346

Tail, alias pleon or post-abdomen,
45

Tulisman, the, Crustacea ob-
tained by, 153

Talitrus, a genus of Amphipoda,
16

Talorchestia, or beach-fleas, a
genus of littoral amphipoda, 86

Tanaella, 325

Tanaidz defined, 322; classifica-
tion of, 9, 328

Tanais, 323; Dulongii, Edwardsii,
filum, tomentosus, vittatus, 326;
balticus, curculio, dubius, rhyn-
chites, 327

Tasmania, pitted against Van
Diemen’s Land, 210

Tatos, name ofthe Birgus latro at
Samboangan, 158

Telson, 46; in Cumacea, 300

Testacea, distinguished from Crus-
tacea, 5

Tetradecapoda,
thalma, 7

Tetralia, Paulson on the genus, 65

Thalassina, anomalus, scorpion-
oides, 181

Thalassinide defined, 181

Thalassinidea defined, 180

Thalassocaride defined, 239

Thalassocaris, 259

Thaumastocheles zaleucus, 189;
claws of, 190

Thaumastochelidez defined, 189

Thaumastoplax, 102; last legs de-
ficient in, 103

Thelphusa, 14; chilensis, depressa,
fluviatilis, perlata, 76; dehaanii,
77

alias Edrioph-

A HISTORY OF RECENT CRUSTACEA

TUR

Thelphusidee, 76

Thelphusinea defined, 76

Thelycum, the, 216

Themisto (preoccupied),
spinosa, longispinosa, 271

Thenus orientalis, 193

Thia, polita, residuus, 75

Thompson, Vaughan, on develop-
ment of Crustacea, 59

Thomson, Mr. G. M., describes a
new genus of Schizopoda, 256

Thoracica, an order of Cirripedes,
14

Thoracipoda, 7

Thoracostraca, objection to the
term, 8

Thorax, 7, 32

Turanites velox, 70

Thyrostraca, alias Cirripedia, 6
11, 31

Thysanoessa, borealis, gregaria,
longipes, macrura, neglecta,
264 ; longicaudata, 265

Thysanopoda, Couchii, tricuspida,
263; neglecta, 264

Titanethes albus, 422, 425, 426

Toulouroux, 79

Trachex, 4, 423, 425, 426

Transmutation of species, 103°

Trapezia, 65

Trapeziide defined, 64

Travailleur, th:, Crustacea taken
by, 118, 122

Trichobranchiata, 155, 165, 180,
191

Trichoniscus, 421; pusillus, roseus,
vividus, 422

Trichopleon ramosum, 378

Trilobita, an order of Gigantos-
traca,; 105-41, 27,350

Triticella flava, polyzoon parasitic
on Calocaris, 190

Troglocaris, a cave-shrimp, 241

Tropiocarida, 239, 245

Tropiocaris, 245

Trunk, alias thorax,
pereon, 31

Tubercle, of second antenne, 38;
molar, of mandible, 39

Tubercles, in the Palinuride, 195

Turkish saddle, 138

brevi-

body, or

INDEX

TUR

Turtle Crab, 95
Tylaspis anomala,
species, 19, 166
Tylidz de ned, 423
Tylos, 423 ; armadillo, granulatus,
granuliferus, Latreillii, spinu-
losus, 424

Tympana, 102

Typhlapseudes, 321

Typhlotanais, 324, 326

Typton spongicola, 242

an abyssal

UcA, 79; una, 84

Upogebia, affinis, stellata, 185;
deltdura, littoralis, 186

Uropods, 46

Uroptychus, 177; gracilimanus,
insignis, rubrovittatus, 178

VALVIFERA,
369

Vana longiremis, 383

Varuna litterata, 96

Vaunthompsonia, 303; anomala,
cristata, meridicralis, 304

Vaunthompsoniide defined, 303

Verges, position of, 45, 55, 104,
123, 146

Verrill and Smith, 67, 89, !85

Vertex, in Oniscoidea, 435

Virbius, 235, 236; gracilis, viridis,
416, 417 y

Voracity of Crustacea, 21

Vulvze, position of, 45, 139, 146

the tribe defined,

WALKER, Mr. A.O,o0n Crustacea
from Singapore, 136

Walking, crab’s method of, de-
scribed, 58

Warty Crab, the great broad,
192

Warty Crab, the great, 121

Weber, Professor Max, on fresh-

water decapods of the Pacitic,

23

WelJ-shrimp, character of the am-
phipod, 14

A465

you

Westwood, J. O., on Gecarcinus,
84

White, Adam, genera named by,
197; his authority cited, 203;
species assigned to Hippol) te
by, 235

Whymper, Mr. E., Isopods and
Amphipods found by, 14, 429

Willemoesia leptodactyia, 201

Windows in legs and breast of a
crab, 102

Wood-lice, name applied to isopod
crustaceans, 13

Wood-Mason, Prof. J., on tlie
Gecarcinide, 80; on young of
Paranephrops, 210

Wood's Hole, Massachusetts, 150,
185

Woodward, Dr. H., the term tho-

racipoda proposed by, 7, on

an encysted Pinnotheres, 101;

his Ceratocephalus Grayanus,
364

XANTHO, 56; floridus, hydrophi-
lus, incisus, rivulosa, tubercu-
lata, 62; Bouvieri, 63

Xanthodes, affinity with Xantho
of, 56

Xavier's adventure with a crab,
70

Xiphocephalus, synonym of Rhab-
dosoma, 30

Xiphopeneus, sub-divided joints
of, 219

Xiphosura, an order of Gigantos-
traca, 10

Xyphicéphale, 30

Youne, of Cancer irroratus, 61;
of Corystes cassivelaunus, 74;
of Gecarcinus, 84; of Hippa
talpoida, 150; of Porcellana
longicornis, 172; of Palinuride,
198; of Astacus americanus,
204; of Paranephrops zealandi-
cus, 210; of Squillidz, 280, 288,
of Gnathiidez, 337

4.66 A HISTORY OF RECENT CRUSTACEA

ZAN

Zanclifer caribensis, rediscovered,
144; orbits of, 145

Zenobia preoccupied, 374

Zeuxo preoccupied, 403; alphei,
416

ZUZ

Zia, melanocephala, paludicola, 421

Zoea, a larval form, 59, 60, 61,
101, 150, 172, 204, 222

Zoology, domestic, 13

Zuzara, 361

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