A history of the British stalk-eyed crustacea

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BRITISH
STALK-EYED CKUSTACEA.

LONDON :
WOODFALL AND KINDER,

AVOKL COUHT, SKINNKIt STREKT.

TO

PROFESSOR RICHARD OWEN,

THE FAITHFUL AND UNCHANGED FRIEND OF MANY YEARS,

THIS LITTLE WORK IS INSCRIBED

BY

THE AUTHOR,

AS A HUMBLE TOKEN OF HIS LASTING

RESPECT AND AFFECTION.

PREFACE.

I HAVE little to say in this Preface, beyond the ex-
pression of my sincere regret for the delay which has
occurred in the publication of the work. That delay has
arisen from causes which it would not interest the public
to be informed of, and which I have no wish to put
forward for the sake of deprecating the displeasure or
disappointment which it may have excited.

A much more agreeable task is that of acknowledging,
which I do with feelings of sincere gratification and deep
thankfulness, the extensive and valuable assistance which
I have received from so many of my fellow-labourers in
the field of Natural History. Their names are mentioned
in connection with their contributions, in various parts of
the work ; and it would be invidious to particularise them
here, lest, through inadvertence, any should be omitted.
To one and all I beg to offer the tribute of my grateful
thanks.

SELBORNK, HANTS.
July, 1853.

INTRODUCTION.

THE structure of the Crustacea is so little known to
the students of Natural History in this country, and there
are so few works which give even the most superficial
information on the subject, that it appears very desirable
and even necessary to introduce the study of the British
species, by a brief account of the general organization and
physiology of this class of animals. Not only indeed is
the subject itself one of great interest, but without some
such introductory information it would not be possible to
comprehend the descriptions of the different genera and
species ; for it will be found that in scarcely any other
class of animals, is there a greater variety of form and
structure, or more striking apparent anomalies in the
modifications of the typical plan of organization, or in some
cases greater difficulties in ascertaining the true homologies
of the different elements, than in the present.

It is not, indeed, a very easy matter even to express,
in a clear and definite phrase, the characters which, whilst
belonging strictly to all the forms of Crustacea, shall dis-
tinctly exclude those of the approximate ones ; for the
variations which occur in every organ and function, in
the different groups belonging to the crustacean type, are
so considerable, as to render it almost impossible to include
them all within one common and well-defined expression.
The typical characters are so astonishingly modified, in
some cases being totally changed, and in others absolutely
lost, that the inexperienced student examining some aber-

X

INTRODUCTION.

rant form by the test of the known typical characters,
might find it impossible to refer it to its true relations,
without an investigation of the intermediate affinities, and
an acquaintance with the laws which regulate their
variations.

The separation of the true EPIZOA from the Crustacea
has indeed, in some measure, facilitated the arrangement
of the latter class, and enabled the zoologist to restrict
within intelligible limits the characters which belong to
the group.

I shall therefore, in the following sketch, consider the
CRUSTACEA, the EPJZOA, and the CIRRIPEDES, as constituting
three distinct types of form ; with this restriction the
Crustacea may be defined as articulated animals, having
each segment of the external skeleton furnished with ar-
ticulated appendages ; they are all of them free or loco-
motive ; the respiration is branchial, and they are, with
very few exceptions, aquatic in their habits ; the circula-
tion is carried on by means of a complete vascular system,
and is of a mixed character, the blood being received into
an aortic heart, both from the branchiae and from the
system, and circulated in a mixed or partially decarbo-
nized condition. The nervous system resembles, in its
general principles, that of the Insects. It is ganglionic,
longitudinal, and generally distinctly developed. The
sexes are separate.

Such are the general characters by which the Crustacea
proper may be distinguished, and which appear to be
sufficiently defined, as far as our present knowledge ex-
tends. A further insight into the structure of each system
of organs, as existing in the different orders and families
of the class, will show how various and startling are some
of their modifications.

INTRODUCTION. XI

The construction of the skeleton in this class of animals
is for the most part very distinct from that of all others,
although in some of the abnormal forms there is a remark-
able deviation from the typical structure, and a corre-
sponding approximation to that of other classes ; as, for
instance, in the segments of certain Isopoda, which re-
semble, in general character, some forms amongst the
Myriapoda. In the greater number of them, and es-
pecially in the higher forms, the tegumentary skeleton is
formed of a hard, solid, calcareous crust, the earthy por-
tion of which consists of carbonate of lime, with a small
portion of phosphate of the same earth. The colours by
which the crust is, in many cases, very beautifully marked,
depend upon a pigment which pervades different parts of
the substance, and offers various hues, and sometimes
curious and grotesque markings, in different species. The
colouring matter, in these as in most other animals, is
more intense on the upper than on the under surface,
the latter being, in many, nearly pure white, whilst
the former is deeply and brightly coloured. The earthy
matter is deposited upon, and produced by, an organized
vascular membrane or corium. In many of the smaller
Crustacea, even amongst the higher forms, as in most of
the Paltzmonida or prawns, and other allied families, as
well as in most of the lower groups, as the Isopoda, and
others, the crust retains its semi-transparent, elastic, and
flexible nature, resembling thin horn or parchment,
the earthy matter being deposited in very small quan-
tities. Although this difference is not wholly correlative
with the groups in which it principally obtains, — as for
instance, in the genus Palamon, in which the crust of some
species, as the common prawn, has scarcely any earthy
matter, whilst in others, it is almost as solidly calcareous

Xll

INTRODUCTION.

as in the lobster itself, — yet it would appear to bear a
near relation to their habits ; the presence of the cal-
careous substance hardening and solidifying the skeleton,
and thus rendering it an efficient protection against the
rocks and waves of the more exposed parts of the sea, be-
ing found in the greatest proportion in species exposed to
such agents ; whilst the others are either small, active
creatures, swimming with great ease and constancy in
more open and shallow situations, or creeping safely
amongst fuci or under stones, and other protecting sub-
stances, or even attaching themselves to the surface of
different species of fish.

The annulose character, typical of the great group to
which it gives its designation, has, in a great number of
the species composing this class, reached its maximum of
development. The segments which surround the body are
more complete, and more separately movable, whilst they
possess a greater degree of individual solidity than in any
others. They are also furnished with articulated appen-
dages ; each segment, whether remaining distinct or in-
timately united to others, bearing a single pair, in a more
or less developed, or in a merely rudimentary condition.
In numerous instances, from this intimate union or solder-
ing together of two or more segments, the only indi-
cation of their theoretical separate existence is the presence
of the normal number of these appendages ; but with
this aid it rarely happens, in the higher forms of Crus-
tacea, that they cannot be proved to exist.

The true normal number of the segments, taking the
whole class, appears to be twenty-one, of which, accord-
ing to our present knowledge, seven must be considered as
belonging to the head, and an equal number respectively
to the thorax and the abdomen. Now, although it is

INTRODUCTION. Xlll

true that there is not a single known species in which all
these segments are found in a distinct and tangible con-
dition— there being in all the forms, more or fewer of
them so inseparably united together as to offer no other
means by which to predicate their existence, than those
already alluded to — yet, .on the other hand, there is not
one which may not be found distinctly formed in some or
other of the species. The appendages, too, which have
already been slightly mentioned, are no less subject to the
most extraordinary variation both of form and office ;
many of them serving in one case the purposes of loco-
motion, in another the reception and preparation of the
food, in another the attachment of the branchiae, in
another the support and pjotection of the eggs. When,
therefore, we consider the almost endless diversity of
form, under which the species composing this class of
animals appear, the astonishing discrepancy which exists
in the forms and relative proportions of the different
regions of the body, and other parts of their organization,
for the performance of offices and functions equally various,
and see that all these diversities are produced only by mo-
difications of a typical number of parts, we cannot but be
struck by so remarkable and interesting an illustration of
the great economical law, as it may be termed, that
the typical structure of any group being given , the different
habits of its component species or minor groups are provided
for, not by the creation of new organs or the destruction of
others, but by the modification, in form, structure, or place,
of organs typically belonging to the group.

Of this law numerous examples will be exhibited in the
course of this work, in the structural characters of every
order and of every family ; but for the sake of offering
a single comprehensible illustration, the various modifi-

XIV

INTRODUCTION.

cations of the thoracic appendages may be selected. The
typical structure of these may be considered as subserving
the purposes of locomotion. This is the office which they
fulfil, either wholly or in part, in all cases ; and in some
instances the whole of them are thus employed. In the
Isopoda, for instance, the body consists very principally of
the seven thoracic segments, and their appendages consti-
tute seven pairs of true feet. In the Amphipoda the first
or second pairs become modified in the male into strong
holders by the greater development of the hand, and the
movable character of the terminal articulation, and its ap-
plicability to a strong corresponding process from the
penultimate articulation. In several of the Ltemodi/poda
five pairs only of the thoracic appendages are developed
into members, of which the first and second pairs consti-
tute true hands or graspers, and the third and fourth are
destined to a totally different office ; forming respiratory
sacs, to supply the place of the abdominal appendages in
the Isopoda, the abdomen in the present instance being
reduced to a mere rudiment. In the Decapoda there are
only five pairs of true thoracic members, and these answer
to the five posterior segments of the thorax ; but the ap-
pendages to the segments anterior to these are rendered
subservient to mastication, or to the preparation of the
food, in the form of footjaws or pedipalps. I have only
enumerated a few of the more conspicuous modifications
of these organs, for the purpose of conveying at a glance
some idea of the extraordinary aberrations from the typical
structure which will meet us at every step, in the inves-
tigation of these animals, whose habits and requirements
are so varied.

The composition of the segments in the Crustacea,
although modified to a great extent in the different forms,

INTRODUCTION. XV

is yet susceptible of being reduced to a perfect theoretical
idea. Indeed, in many forms, the parts of which each
segment is composed are distinctly appreciable by careful
examination ; and it is found that these parts consist in
two arches, a superior and an inferior, each of which is
formed of two middle and two la-
teral pieces. The superior central
pair, a a, constitute the tergum,
the lateral are called epimera, b b.
Of the inferior arch, the two central pieces form the ster-
num, c c, and to the lateral, d d, the name of episternum
has been applied. As we have already seen, in enume-
rating the segments themselves which compose the different
regions of the body, that some or other of them are always
found to be so intimately combined together that their dis-
tinction is lost, so in the present case also, some or other
of the theoretical elements of the segments are either actu-
ally wanting, or certain of them are so intimately united
that the normal number cannot be distinguished.

It is also necessary, in order to obtain a correct idea of
the actual structure of the skeleton or supporting organs
in the Crustacea, to consider those processes of crustaceous
matter which, in the form of internal lamina, form the
parietes of the cells and canals which are found in the
interior of these animals, and many of which serve the
office of bones, as the solid surfaces to which the muscles
are attached. These have received the name of apodema.
44 They arise in all cases from the junction of two con-
tiguous pieces of one segment, or from the union of two
rings. They are produced by a duplicature of the tegu-
mentary membrane, which dips more or less deeply amongst
the internal organs, and which becomes encrusted with
calcareous matter with the rest of the shell ; they are con-

XVI

INTRODUCTION.

sequently always formed of two layers, soldered, as it
were, together."

Of the various segments composing the three principal
portions of the body, the head, the thorax, and the abdo-
men, some are found always to support similar, or rather
identical, organs. Thus the first cephalic segment or ring
invariably bears the peduncle of the eyes, and the second,
or antennary, as constantly supports a pair of the antennae.
Of those which follow, there are the most extraordinary
and unlooked-for modifications in the different groups ;
and no one who has only formed a theoretical notion of
these parts could recognise in the simple piece of which
the whole cephalic region is composed in the EdriopJithalma,
or in the carapace or shell of the brachyurous Decapoda, as
in the common crab for instance, the mere combination of
two or more of the cephalic segments whi^h in other forms
are found to be distinct. For a full and clear account of
all these modifications, the reader is referred to the admn
rable work of Dr. Milne Edwards, so often quoted and
referred to.

This author has, with great propriety, considered the
genus Squilla as offering the form in which the different
segments before enumerated are most distinctly exhibited ;
but even in this form there are some which are, as it were,
soldered together, and the normal number is consequently
not to be traced. The first cephalic segment, which, as
before observed, is invariably destined to support the
ocular peduncles, and is therefore termed the ophthalmic
segment, is here quite distinct from the second, which is
also very distinctly articulated with the third ; the latter
is, however, confounded with the next, and the following
ones are only to be distinguished by dissection. -f- But the

* Edw. Hist. Nat. des Crust, i. p. 18. f Ib. p. 15.

INTRODUCTION. X\ 11

last eleven are complete and perfectly distinct, and each
of them, without exception, bears its appropriate pair of
members.

Amongst the higher forms of Crustacea, it is in the
Brachyura, where the nervous system is found in the most
concentrated condition, that the condensation of the rings
of which the body is composed, is carried to the greatest
extent. It is indeed somewhat difficult, at first sight, to
determine the homologies of the segments of which the
carapace, as it is termed, is theoretically composed. This
large enveloping buckler in fact covers the whole of the
thorax, and even the abdomen itself is folded underneath
it, so that the whole animal is hidden, when viewed from
above, by this extraordinary development of two of the
cephalic segments ; and although in the Brachyura the
first two segments, the ophthalmic and the antennary, are
soldered to the carapace, yet, as we find that in some
other forms these two are entirely distinct, it would appear
that the carapace is essentially composed of the third and
fourth rings, composing what Dr. Milne Edwards terms
the antenno-maxillary segment.

This remarkable portion of the tegumentary system,
covering, as it does, the whole of the viscera, is found to
be more or less distinctly divided into regions, which are
indicated by elevations, separated from each other by
grooves ; and to these regions have been given names
derived from the different organs which are immediately
covered by them. As reference is frequently made to
these regions in generic and specific descriptions, I here
give an illustration of them.*

* The gastric or stomachal region is marked r s ; the branchial, r b ; the hepatic,
r h ; the genital, r g ; the cardiac r c ; the intestinal, r i.

XV111

INTRODUCTION.

< r A .

The thorax in the Decapods in general is externally

only visible under-
neath, the upper part
being covered by the
carapace, and being in
that part incomplete.
The number of obvi-
ous segments in these
higher forms is five,
and as each segment
bears its proper pair
of appendages, which
here are true ambula-
tory legs, the character of Decapods is thus produced.

The superior surface of the thoracic
segments is limited to the epimera,
the tergum being absolutely wanting.
Upon this upper surface on each side
lie the branchiae, or gills. In this
brief sketch it is only necessary to
refer to the apodemata as consti-
tuting the large cells of the thorax, formed by a dupli-

INTRODUCTION.

cature of the walls dipping into the thoracic cavity, and
filled by the muscles which move the limbs.

The abdomen of the Brachyura is very moderately de-
veloped.* It folds entirely underneath the thorax, against
which it is ordinarily closely applied. It consists, essen-
tially, of seven segments, of which, however, in many
cases, a greater or less number are so united as to be
scarcely distinguishable. In the Macroura* they are far
more extended, and serve the purposes of locomotion,
being elongated, very moveable upon each other, and
furnished at the extremity with a fan-shaped fin, formed
of five pieces, of which the centre is the terminal ab-
dominal segment.

In the lower forms, as the Edriophthalma, the rings of
the body are more similar to each other, and constitute a
nearly regular series of more or less perfect rings. Those
of the head, however, are ordinarily much condensed, and
soldered together ; whilst the thorax consists of seven
very distinct moveable segments, and the abdomen of
either the same number, or nearly so ; as in some cases
the seventh is wanting, and in others the two anterior
ones are united.

Between these two extreme cases, there are numerous
intermediate modifications, which will be seen in the
various families and genera.

The members or appendages to the different segments
or annuli above described, form a very interesting and
important part of the tegumentary system of these ani-
mals. Theoretically speaking, every segment has its pair
of appendages, and, vice versa, each pair of appendages,

* See the figures of the various species.

b 2

XX

INTRODUCTION.

whenever they exist, presupposes a segment or ring to
which they belong. In many cases, where a coalescence
takes place between any of the contiguous segments,
their distinct existence can only be predicated by the
occurrence of the members which belong to them ; thus,
in the Brachyura, the carapace involves not only the third
and fourth rings, enormously developed, but also the first
two, which bear the eyes and antennae, and which are
indissolubly blended with the succeeding ones.

Normally there are twenty-one pairs of appendages or
limbs : generally speaking, even in the higher forms,
twenty only are perceived, as the terminal joint of the
abdomen, which forms the central piece of the fan-like
fin, has none which are perceptible. I have, however,
observed them frequently in the common prawn, Palce-
mon serratus,* in the form of extremely minute points
attached to the very extremity of the segment, and
moveable.

The first pair exist only in the Podophthalma or stalk-
eyed forms, and constitute the peduncles upon which the
eyes are elevated ; they are moveable, and in many cases
are of considerable length, lying, when at rest, in grooves,
or sockets, formed for their reception. The two following
pairs are of great importance, forming, in most cases,
organs of sense. These are the antenna?. One or both
pairs exist in all the forms of true Crustacea ; ordinarily

* I have often separated the whole twenty-one pairs of appendages in this
species, and placed them seriatim on a card. They consist very clearly of the
ocular peduncles, the anterior and posterior antennae, the mandibles, the two pairs
of maxillae, the three pairs of foot-jaws, the five pairs of thoracic legs, the five
pairs of abdominal false feet, the appendages to the sixth abdominal segment
forming the lateral caudal flap, and the two minute rudimentary appendages
above alluded to.

INTRODUCTION. XXI

they are slender, elongated, moveable, and multiarticulate.
They are, however, subject, in some forms even of the
higher orders, to extraordinary modifications ; thus in the
genera Scyllarus and Ibacus, the external pair are de-
veloped into broad, flat organs of natation, and probably
also constitute a pair of shovels for the purpose of burrow-
ing: and in some Amphipoda, they are much elongated,
serving as a pair of swimming or sustaining arms. The
fourth pair always appertain to the mouth, and form man-
ducating organs : these are the mandibles. The two
pairs of jaws, or maxilla?, follow, and are also employed
in the comminution of the food. Theoretically speaking,
the next pair ought to be considered as belonging to the
cephalic division of the body ; these, as well as the pre-
vious and two following pairs, are, in the Decapoda, sub-
servient to nutrition. The eighth and ninth pairs are,
therefore, properly speaking, the first and second thoracic
members, and, with the seventh, constitute the three pairs
of footjaws or pedipalps, leaving, in this particular class,
the five remaining thoracic appendages to serv7e the office
of ambulatory locomotion, or of claws for the apprehen-
sion and tearing of the food, or of weapons of defence.
In most of the Edriophthalma the normal arrangement
obtains, and the thorax bears seven pairs of ambulatory
members. The remaining appendages, which seldom ex-
ceed six pairs, belong to the abdominal portion of the
body, and in the higher forms are very small and slightly
developed, in comparison with those of the thoracic di-
vision. In the female Decapoda they constitute the sup-
port of the eggs, after their exclusion, and as long as they
continue attached to the parent.

In their full development, each of these organs consists

XXH

INTRODUCTION.

of three distinct parts. The Stalk, which constitutes the
essential part, and which is usually multiarticulate ; the
Palp, which is an appendage to the stalk, and ordinarily
arises from its basal segment; and the Lash. It is not in
all cases that these three portions exist, and in the Bra-
chyura, for example, the foot-jaws are the only ones in
which they are all present. The ambulatory thoracic legs
in these are obviously composed only of the stalk, without
either of the other members, and consist of six distinct
joints. In the Macroura, however, the ambulatory feet, in
some genera, have all the three elements ; in others, one
of them is wanting. Their modifications are almost
innumerable, and often it would be impossible to distin-
guish their homologues, without extensive comparative
examination.

It is impossible, in a mere sketch, introductory to a
local Fauna, to enter, at any detail, into the various modi-
fications now merely alluded to, but perhaps there is
scarcely any group of animals in which the homologies
are more recondite, the variations more interesting, and
the relations between those variations and the habits
and requirements of the animals more beautiful and
instructive.

In order to give a general idea of the extent of these
modifications, it may be stated that the ocular peduncles
are the only appendages which are never devoted to
any but their normal objects. The antenna are, as has
been before observed, sometimes modified into locomotive
organs. The cephalic appendages about the mouth, the
mandibles and maxillae, are sometimes rudimentary, at
other times they are modified into mere organs of appre-
hension. The thoracic members are sometimes locomo-

INTRODUCTION. XXlli

tive organs, at others they subserve the nutritive function :
the remaining thoracic members are, in some cases, pre-
hensile, in others ambulatory, in others natatory, in others
partially branchiophorous, and so on. The abdominal
sometimes serve the purpose of swimming, at others of
bearing and protecting the eggs, at others they are
partially converted into branchia3. Besides these modi-
fications, some or other of them are, in many forms,
either wholly wanting or rudimentary.

The digestive system appears under very various phases
in the different groups of the Crustacea. The extremes
of this diversity are found in those two primary divisions,
the food of which is most opposite in its kind. In the
one group, the whole of which are parasitic upon other
animals, and which I have in this Introduction considered
as belonging to a distinct class, the aliment consists of
the juices of the creatures to which they are attached, and
is obtained by suction. In these the normal elements of
the organs for procuring or preparing the food for diges-
tion are either rudimentary or wanting. In the higher
forms of the true Crustacea, on the contrary, which sub-
sist upon solid and often hard substances, and in many
cases on living prey, the organs for pursuing, seizing,
tearing, and comminuting the food, are carried to a high
degree of development, and a corresponding difference is
also found in the digestive organs themselves. The most
elaborate condition of these organs is exhibited in the
Decapoda, and especially in the Brachyura. It has been
already stated that the appendages belonging to certain
of the cephalo- thoracic segments are variously modified to
serve their several offices; and in the latter order they have

XXIV

INTRODUCTION.

been shown to consist of six pairs, of which some are actual
organs of mastication, as the mandibles or the true jaws,
the foot-jaws or pedipalps generally serving to keep the
food in contact with the former, whilst it is being broken
up by them.

The buccal orifice in the Brachyura occupies the in-
ferior face of the cephalic division of the body, and is
bounded anteriorly by a crustaceous lamina of determi-
nate form, which has been termed the upper lip, and pos-
teriorly by another termed the lower lip. The mandibles
occupy the sides of the opening. After these, and ex-
ternal to them, are the first, and then the second pair of
true jaws, followed by the three pairs of pedipalps or
foot-jaws, the last of which, when at rest, close the mouth,
and include the whole of the preceding ones. In the
Macroura, the pedipalps are very different in their forms,
and have the aspect of very simple feet. In the Stoma-
poda they not only have the form, but the office also of
the other locomotive organs, and hence the increased
number of legs which appear to appertain to these, and
especially to the Mysidae. In the Edriophthalma, and the
other lower forms, the parts about the mouth are fewer,
and more simple. At the back of the mouth, a short
O3sophagus opens into the stomach, which is a very ca-
pacious cavity, occupying the whole depth of the body in
the Decapods, and co-extensive with the gastric region of
the carapace, already described. It is pretty distinctly
divided into two portions, a cardiac and a pyloric, the
former occupying the greater portion of the cavity, the
latter of small dimensions.

The means of comminuting the food are not restricted
to the complicated machinery above referred to, for the

INTRODUCTION. XXV

stomach itself contains a very remarkable apparatus, con-
sisting of several hard calcareous pieces, which may be
termed gastric teeth. These are attached to horny or
calcareous levers fixed in the parietes of the stomach ;
they are moved by a complicated system of muscles, and
are admirably adapted to complete the thorough breaking-
down of the aliment, which had already been to a con-
siderable extent effected by the buccal appendages.
These gastric teeth may be readily seen and examined in
the larger species of the Decapoda, as in the large eatable
crab and the lobster; and it will be readily perceived how
perfectly the different pieces are made to act upon each
other, and to grind the food interposed between them.
Analogous structures, but of less complexity, are found
in the Edriophthalma. The single and simple intestine
extends in a direct line from the stomach, and terminates
at the last segment of the abdomen. Immediately from
its origin at the pyloric opening of the stomach, a notable
enlargement is observed, but the rest of the canal is
of uniform size. The enlarged portion is, in some cases,
very short ; in others, it occupies the larger portion of
the total length.

The liver is of considerable volume in most of the
families of Crustacea, and occupies in the Decapoda the
greater portion of the visceral cavity. It consists of a
mass of caecal vesicles, ordinarily more or less elongated,
and pouring the secretion into a system of membranous
canals, the union of which forms ultimately a large trunk
on each side, which opens into the pyloric portion of the
stomach. Such is the structure of this important gland
in the highest forms ; but in the larger Stomapoda its
structure is apparently granular, and it forms two series

INTRODUCTION.

of lobes extending the whole length of the intestine,—
and in the Edriophthalma, according to Prof. M. Ed-
wards, it is reduced to " three pairs of biliary vessels,
running alongside the intestine, the whole length of the
body." There are other tubular appendages connected
with the pyloric portion of the stomach, which are of
considerable size in certain of the larger Decapoda, and
which, from analogy, may with some probability be con-
sidered as pancreatic.

The respiration in this class is, with very few excep-
tions amongst the Isopoda, aquatic. In some of the
lower forms, it would appear that there are no special
organs devoted to this function, but in the higher these
are very varied, and in many cases of a complicated
character. The typical form of Crustacean respiratory
organs may be considered that of lamellar branchiae ; and
this form is found in the Decapoda, and particularly in
the Brachyura ; in the crab it is seen in its most complete
development. The branchiae are placed within a distinct
cavity on each side, protected above by the carapace, and
lying upon the upper surface of the thorax. They con-
sist of a series of elongated pyramidal bodies, each com-
posed of a vast number of plates or lamellae, which are
closely packed, but still admit of the free circulation of
the water between them. The respiratory cavity has an
afferent and an efferent opening, through which the water
is propelled by a mechanism differing in the different
groups. The former opening, through which the water
has access to the cavity, is a long lateral slit, between
the cephalo-thorax and the side of the thorax ; and the
latter is near the buccal cavity, and is covered by the

INTRODUCTION. XXVll

last or flabelliform appendage of the second pair of the
true jaws, which is developed into a broad horny plate,
fixed by a sort of pivot, on which it continually turns,
and thus regulates the efflux of the water. Prof. Milne
Edwards observes, that this action is proved to be es-
sential to the renewal of the water which bathes the
branchiae, as, if its movements be stopped, the animal
becomes soon asphyxiated. The whole of the apparatus
belonging to this function in the higher Crustacea is
exceedingly curious and interesting, but it would be out
of place to enter into the detail in this work.

The branchiae are very differently formed in the dif-
ferent orders of the class, and even vary considerably in
some genera of the same family. In some cases the
abdominal appendages support these organs; in others
they are attached to the basal joint of the thoracic legs;
in some genera, as in Mysis, their distinct existence has
not as yet been demonstrated, although, as I have ob-
served in speaking of that genus in the body of the work,
there appears little doubt that a special organ exercises
their function.

In the terrestrial Isopoda, or the common Millipedes,
as they are termed, the respiration is exclusively atmo-
spheric.

The respiration of the land crabs, which must neces-
sarily be, during the greater part of their lives, atmo-
spheric, is one of the most remarkable phenomena
connected with this subject, and has occupied the atten-
tion of Mons. Audouin and Dr. Milne Edwards, who have
given a most elaborate and interesting memoir on this
subject,* to which the reader is referred. It is well

* Annales des Sciences Naturelles, t. v. p. 85.

XXV111 INTRODUCTION.

known that the lobster will live for a long time out of
water, provided the branchiae are occasionally bathed, so
as to keep them in a humid condition, whilst it will
die very soon on being confined in a small quantity of
water, without access to air.

There has been considerable discrepancy in the state-
ments of different anatomists respecting the circulation in
the Crustacea. Messrs. Audouin and Milne Edwards *
have considered that " no other than the two great bran-
chial veins terminate in the heart, and, consequently, only
pure aerated or arterial blood is propelled by it over the
general system ; the circulation is, in fact, the same as in
the Gasteropodous Mollusca ; the ventricle is exclusively
systemic, and is provided with only two venous aper-
tures." Such is a summary of their opinion. The fact,
however, that the circulation is of a mixed kind was evi-
dently known to Hunter, and has been elaborately demon-
strated by Professor Owen in his more recent researches.f
A reference to the engravings from the Hunterian draw-
ings in the collection of the Royal College of Surgeons,^
to that of the heart of the lobster by Professor Owen in
his lectures above referred to, and to the respective de-
scriptions of these figures, will show " that the heart,
instead of being purely systemic, is partly branchial, and
impels the blood, not through the body only, but also to
the respiratory organs."

* Recherches Anatomises et Physiologiques sur la Circulation dans les
Crustaces. Ann. des Sc. Nat. t. ii.

t Lectures on the Comparative Anatomy and Physiology of the Invertebr.

£ Catalogue of the Physiological Series of Comparative Anatomy contained
in the Museum of the Royal College of Surgeons, vol. ii. Copied in Professor
Rymer Jones's " Animal Kingdom," pp. 333-336.

INTRODUCTION.

" We may trace," says Professor Owen,* " in the heart
of the Crustacea, a gradational series of forms, from the
elongated, median, dorsal vessel, to the short, broad and
compact muscular ventricle in the lobster and the crab.
In all the Crustacea, as in all the other articulate animals,
the heart is situated immediately beneath the skin of the
back, above the intestinal tube, and is retained in situ by
lateral pyramidal muscles. In the lower, elongated, many-
jointed species of the Edriophthalmous Crustacea the heart
presents its vasiform character: it is broadest and most
compact in the crab. In this series we may trace a
general correspondence in the progressive development
of the vascular as of the nervous system, concomitant
with the concentration of the external segments, and
the progressive compactness in the form of the entire
body."

Corresponding with the view which has been taken of
the gradual condensation of the segments of the body
and the centralization of the viscera, is that of the nervous
system as seen in the various forms of Crustacea as they
rise in the scale of organization. An elaborate detailed
description of all the gradations formed the substance of
an admirable essay f by the distinguished naturalists so
often quoted, of whose labours an excellent abstract is
given by my friend Professor Rymer Jones, in his " Ani-
mal Kingdom." J

In Talitrus, where the insectiform arrangement is the
most obvious, and where every pair of ganglia consists of

* L. c. p. 180.

t Messrs. Audouin et Milne Edwards, " Recherches Anatomiques sur le
Systeme Nerveux des Crustaces." Ann. des Sc. Nat. t. xiv.
£ L. c. p. 337.

XXX

INTRODUCTION.

two separate nuclei of nervous substance, united by a
transverse band, with an anterior and posterior nervous
filament uniting each to the antecedent and succeeding
pairs, the number of ganglia (thirteen) coincides with that
of the segments of the body. Proceeding upwards, a
condensation, both lateral and longitudinal, of certain of
the ganglia is found to be coincident with the concentra-
tion of the rings, until in the crab the whole of the abdo-
minal and thoracic ganglia become concentrated into one
mass, from which the nerves radiate in a most beautiful
manner to the parts about the mouth, the limbs, &c.
The conclusions to which their elaborate researches have
conducted Messrs. Audouin and Milne Edwards are thus
given : —

" Le systeme nerveux des Crustaces se compose tou-
jours de noyaux medullaires dont le nombre normal est
egal a celui des membres, et toutes les modifications qu'on
y rencontre dependent principalement de rapprochemens
plus ou moins complets de ces noyaux, agglomeration qui
s'opere des cotes vers la ligne mediane en meme temps
que dans la direction longitudinale, mais peuvent tenir
aussi en partie a un arret de developpement dans un
certain nombre de ces noyaux." *

The organ of hearing is found only in the higher forms
of this class. In the larger Decapoda, and particularly
in the brachyurous group, it is very easily seen, on re-
moving a little crustaceous plate in the basal joint of the
second antennae, and thus exposing a small cavity. This
operculum is pierced by a small oval opening, covered
with a membrane ; and in the Macroura, the whole closure

* Hist. Nat. des Crustaces, t. i. p. 147.

INTRODUCTION. XXXi

is membranous. Within the cavity and immediately be-
hind the little opening before mentioned, is a minute
vesicle filled with fluid, which conveys the vibrations to
a branch of the antennal nerve, which is expanded
upon the vesicle. This is the simple apparatus ; but
it is sufficient to receive and convey to the sensorium
the imperfect sonorous vibrations to which they are
subject.

The visual organ is essentially similar to that of in-
sects. The eyes are compound in all the higher forms,
and those of the Edriophthalma do not differ essentially
from those of the Podophthalma, excepting in the ab-
sence of those movable peduncles by which the eyes of
the latter are distinguished. The optic nerve, the lenses,
the facets of the cornea, the pigment, are alike in all, and
in all resemble generally the same organs in insects.
There is one peculiarity, however, which is found in
certain species which live in such places as are inacces-
sible to light, or to such degrees of it as would render
eyes in any way useful. In Calocaris, for instance, a
little prawn-like animal, inhabiting very deep water, and
ordinarily immersed in mud, the eyes and their peduncles
do not differ in form from those of the other Palaemo-
pidae; but the vision is wanting. There is no pigment,
there are no corneal facets j the organ is evidently rudi-
mentary and merely formal. Mr. Westwood has recently
made known through the Linnean Society a form of
Edriophthalma, inhabiting a deep well, a species in which
there is no external appearance of eyes whatever ; Mr.
Newport has, however, by his accustomed accuracy of
dissection, shewn that in this case also, a rudimentary
visual organ exists underneath the cephalic crust.

XXX11

INTRODUCTION.

The propagation of the Crustacea proper is invariably
oviparous, and the sexes are distinct. The reproductive
organs in either sex are double, the two elements being
perfectly similar, and occupying a corresponding position
on each side of the median line. The two are wholly
independent of each other, having no communication
even to the efferent opening, there being one of them to
each. Dr. Milne Edwards mentions the following curious
fact: — " Cette indepen dance des deux moities de 1'appareil
de generation est si complete qu'on a vu un cas, ou Tun
des cotes etait male et 1'autre femelle, sans que cette
monstruosite eut entraine aucune autre perturbation sen-
sible dans la conformation de ces organes."* They are
very similar in arrangement, position, and general relation
to the other organs in the two sexes.

In most cases the eggs are carried by the female until
they are hatched; but in some they are previously de-
posited in the sand. In different families the eggs are
carried by the mother attached to different parts of the
body. In the Decapoda they are borne on the under
side of the abdomen, attached to the abdominal false
feet. In the genus Mysis, a pouch is formed at the base
of the posterior thoracic legs,f in which the eggs remain
until the young are excluded. In Thymnopoda, another
genus of the Mysidae, they are contained in two oval
purses, depending from the same part.J

Hist, des Crust, t. i. p. 165.

t See p. 336.

See p. 346.

INTRODUCTION. xxxiii

ON EXUVIATION AND THE RESTORATION OF LOST

LIMBS.

The fact that the throwing off of the old integument and
its replacement by a new one during the growth of the
animal, takes place in all the Crustacea as necessarily
and as constantly as in insects during their larva condi-
tion, has long been known, and as long has excited the
admiration of all who take any interest in natural phe-
nomena. That an animal covered by integument of the
hard, solid, almost stony consistence as that of the lobster
and the crab, for example, should have the power of with-
drawing itself from its shell, leaving it, to all appearance,
as perfect as before, with the carapace, the abdomen, the
limbs, the eyes, the antennae, and even the stomachal
teeth, and other internal shelly organs, whole and entire,
and in their former relative situation and condition, is
one of the most interesting, and, at first sight, one of the
most perplexing and inexplicable, of all the phenomena
of voluntary action.

The first clear and satisfactory observations on this
subject were made by Reaumur,* whose unexampled
accuracy and truthfulness is attested by the fact that of
all the observations made by himself alone, far exceeding
those of any other naturalist of past or present times,
and occupying, in their published form, numerous large
quarto volumes, scarcely one has ever been contravened
by subsequent credible observers, whilst they have formed
the substance of half the numerous compilations on in-
sect life, acknowledged or otherwise, which have appeared
since his time.

* Mem. de 1'Acad. des Sc. 1712, p. 226, and 1718, p. 263.

C

XXXIV INTRODUCTION.

The necessity for the process in question is so evident
seeing that, without it, there would be no possible means
of allowing the gradual growth of the animal, that it is
matter of surprise that it should have ever been doubted, as
it appears to have been by a distinguished entomologist,
more especially of late years, when so many conclusive
observations have been made of the fact. There is no
doubt that in many of the higher forms it takes place
annually, with great regularity,* until the growth is com-
pleted, which in many species is not the case before the
animal is many years old. This is proved by the extent
to which the size increases by each moult, compared
with the difference between the young and the old ani-
mal ; and it is evident that after the growth has reached
its maximum the crust ceases to be changed, from the
fact which I have seen in several instances, as in the
common crab, the lobster, and some others, where the
carapace of the still living creature was the seat of bar-
nacles so large, that several years must probably have
been required for attaining their existing size.

The observations of Reaumur to which I have alluded,
and those of subsequent naturalists, and especially of
Mr. Couch, furnish us with the following history of this
curious process.

When the animal by gradual internal increase has
become too large for its existing covering, it ceases for a
time to feed, and retires to a secret and undisturbed situa-
tion, where it may undergo the process in security. If it
be examined at this time, an evident loosening of the

* Some recent observations by Mr. Warrington shew that in the common
prawn, the moult is much more frequent ; he has noticed its occurrence with
much regularity, every twelve clays, in the snmmcr.

INTRODUCTION. XXXV

crust may be perceived, upon pressing it gently in dif-
ferent parts. Shortly afterwards, — and this description
belongs particularly to the river cray-fish, — it appears
uneasy and restless, rubbing its limbs against each other,
and moving the segments of the body in various direc-
tions. It throws itself on its back, and, swelling out its
body, ruptures the membrane which connects the cara-
pace with the abdomen, and raises the former, so as to
loosen it from its attachments. Resting from time to
time after its laborious efforts, it finally detaches the
whole thoraco-abdominal portion, from which it withdraws
itself, having, with much apparent difficulty and pain,
disengaged the legs, and then the antennae, the eyes, and
other appendages. It is impossible to imagine that the
crust of the legs, and especially of the great claws of the
larger species, could be cast off unless it were susceptible
of being longitudinally split; and Reaumur states that
such is actually the case; each of the segments being
composed of two longitudinal pieces, which, after sepa-
rating to allow of the passage of the soft limb, close again
so accurately that it is very difficult, in the cast crust,
to discover the line of division. When the animal has
disembarrassed itself of the crust, the latter is found abso-
lutely entire, and has exactly the form which it possessed
previous to the operation. In a recent interesting ac-
count of the exuviation of a Maia,* Mr. Gosse has, how-
ever, shewn that in this brachyurous form, no such split-
ting of the legs takes place, but that " the animal pulled
first at one and then at another, until they were quite out,
as if from boots. The joints as they came out were a great
deal larger than the cases from which they proceeded. It

* Annals of Nat. Hist. 2nd Ser. vol. x. p. 210.

c 2

XXXVI INTRODUCTION.

was evident that, in this instance, neither were the shells
split to afford a lateral passage for the limbs, nor were the
limbs reduced to tenuity by emaciation." The new in-
tegument is at first soft and membranous, but speedily
becomes encrusted with calcareous matter, and as hard
as the former. The additional size which is gained by
each moult is very striking, and I have often felt, on
seeing a newly-emancipated crab by the side of the shell
which it had just shed, that, were not the fact absolutely
ascertained by observation, it would appear physically im-
possible that the larger body could have so recently been
contained within so small a case. Reaumur supposed
that even the hairs with which the surface is in many
species furnished, were contained within the cast crust;
but Dr. Milne Edwards asserts that such is not the case ;
stating that they are not at first obvious on the surface of
the new shell, but " sont rentres a 1'interieur, comme le
doigt d'un gant qui serait retourne sur lui-meme ! " If we
open, says this author, a Maia a short time before the
commencement of the moult, we find between the exist-
ing shell and the " chorion " a membranous layer, which
resembles condensed cellular tissue, and which becomes
thicker and more solid, as the period of moult approaches;
it is evidently secreted by the chorion, and is moulded
upon the shell which covers it. In the common crab
(Cancer Pagurus], and some others of similar form, it
would appear that the carapace, instead of being cast
entire, divides at the junction of the epimera with the
dorsal piece or tergum ; a fact which I have often seen in
many species, particularly in the larger Grapsidoe, which,
from their form, could not possibly withdraw the body
without such a separation.

INTRODUCTION. XXXvii

In the account of the great crab, p. 62, I have stated
that the male lies in wait for the female previous to and
during her moult, and seizes her as soon as this is ac-
complished, whilst she is still weak and enfeebled by
the process; and I have so commonly seen the male
and female shore-crab (Carcinus Manas) in conjunction
when the latter is still soft, that there can be no doubt
that this is a general, although certainly not a constant
habit.

A no less curious and interesting process than that
above described, is the voluntary casting of the limbs,
and the restoration of such as have been thus lost by the
animal's will, or by accident. Reaumur in this case also
was the first to make any correct and scientific researches
on the subject, and his statements, full of interest, will be
found in the earlier of the two memoirs already quoted.
My friend Mr. Couch has subsequently extended these
observations, which will be found embodied in my account
of the habits of the lobster at page 245.

On this subject an interesting paper was read before
the Wernerian Society of Edinburgh by Mr. H. Goodsir,
in December, 1843 ; and to the details which I have given
in the place above mentioned, I would merely add a short
abstract of Mr. H. Goodsir's paper:*

" It has long been known that the animals belonging to
this class have the power of reproducing parts of their
body which have been accidentally lost. If one of the more
distant phalanges of a limb be torn off, the animal has
the power of throwing the remaining part of the limb off
altogether. This separation is found to take place always
at one spot only, near the basal extremity of the first

* Annals of Nat. Hist. vol. xiii. p. 67.

XXXV111

INTRODUCTION.

phalanx. The author has found that a small glandular-
like body exists at this spot in each of the limbs, which
supplies the germs for future legs. This body completely
fills up the cavity of the shell for the extent of about half
an inch in length. The microscopic structure of this glan-
dular-like body is very peculiar, consisting of a great
number of large nucleated cells, which are interspersed
throughout a fibro-gelatinous mass. A single branch of
each of the great vessels, accompanied by a branch of
nerve, runs through a small foramen near the centre of
this body, but there is no vestige of either muscle or
tendon, the attachments of which are at each extremity.
Tn fact, this body is perfectly defined, and can be turned
out of the shell without being much injured.

" When the limb is thrown off, the blood-vessels and
nerve retract, thus leaving a small cavity in the new-made
surface. Tt is from this cavity that the germ of the future
leg springs, and is at first seen as a nucleated cell. A
cicatrix forms over the raw surface caused by the separa-
tion, which afterwards forms a sheath for the young leg.'

METAMORPHOSIS.

One of the most marked characters by which this class
was long considered as distinguished from that of insects,
was the supposed absence of any such change of form,
during the progress of development after exclusion from
the egg, as is ordinarily understood by the term metamor-
phosis; and Dr. Leach, in his definition of the class,*
formally adopts this character, which has been repeatedly
recognised by others.

* Encycl. Brit., Art. Crustacea.

INTRODUCTION. XXXIX

It was in the year 1823 that Mr. Vaughan Thompson,
whoso name is now identified with the discovery, follow-
ing up an observation made by Slabber, a Dutch natu-
ralist, as long ago as 1768, and published ten years after-
wards, established the remarkable fact that those ano-
malous forms which constituted the genus Zoea of Bosc,
itro nothing more than the early or larva condition of the
higher Crustacea. It will readily be imagined that no
small excitement was produced in the scientific world by
the announcement of a discovery which, followed up, as it
afterwards was, with equal intelligence and perseverance,
and with corresponding success, may claim for its author
a place amongst the few observers who, from a single
pin 'iiomenon, have been led to the establishment of gene-
ralisations and laws of the highest importance.

Notwithstanding, however, the credit is due to Mr.
Thompson of having carried out the suggestion to its full
development, it was undoubtedly to the Dutch naturalist
that he was indebted for the ascertained fact that the
anomalous creatures on which Bosc afterwards founded
his genus Zoea pass by metamorphosis into a different
and a higher form.

Before I proceed with the further history of this dis-
covery, I think it right to show the grounds of Slabber's
claim, which had been wholly overlooked as to its results,
and which, in consequence of an error arising from de-
ficient information, Mr. Thompson himself, in the first
place, much depreciated, without, as far as I am aware,
having afterwards taken any opportunity of correcting
the misapprehension. It was, then, in the year 1778
that Slabber published a small work, in which occurs
a description with figures of a new crustacean animal

xl

INTRODUCTION.

(fig. a,) to which the
name of Zoea Taurus was
afterwards given. Having
taken at sea several spe-
cimens of this singular
creature, he placed one
of them (a) in sea water,
which he constantly re-
newed, for the purpose
of observation, and, "on
the third day, finding its
movement become slower
and its colour paler, he subjected it to the microscope,

Fig. ft.

and found to his surprise
that the anterior part of
the animal had changed
its form, and on the fourth
day it had acquired the
appearance represented
in fig. b} so that, together
with the other individuals
he had taken, it seemed
to have experienced a
complete metamorphosis ;
under this new form the
dorsal spine had disap-
peared, the front spine
had become compara-
tively small, the antennae
were rendered conspi-
cuous, the feet and eves

* V

were apparently more de-

INTRODUCTION. xli

veloped, and the tail had changed from forked to spatu-
late, fringed by a row of thirteen short spines." It would
certainly seem that this plain and simple statement, sup-
ported as it was in many respects by Mr. Thompson's
own subsequent observations, can scarcely justify the
conclusion to which that gentleman is led,* "that Slabber
lost his Zoea, in changing the sea water, and that the
new form came from the added portion." But the truth
of Slabber's statement, and, consequently, the evidence
of the correctness and originality of his discovery, are
very strongly proved by the almost absolute identity of
the second form of his animal with that of several species
subsequently observed ; and particularly of the ditch -
prawn, Pal&mon varians, as figured by Capt. Du Cane.f

It was, however, from this observation of Slabber that
Mr. Thompson, in the year 1823, was induced to carry
out the investigation. In the spring of the previous year,
as he informs us, in the harbour of Cove, he first met with
Zoeas, and that in considerable abundance ; and " in the
year following, at the same season, one of considerable size
occurred, amongst a number of smaller ones, and, judging it
full grown, he considered it a fit subject to keep for the
purpose of witnessing the metamorphosis observed by
Slabber" &c. The metamorphosis was interrupted by
the death of the animal when in the act of undergoing
it ; but it had advanced sufficiently to show that the
animal belonged to the Brachyura, and the portion which
was observed, contained all the five feet on one side,
the anterior foot being furnished with a perfect claw ;
and it appears now more than probable that the form into

* Zool. Researches, p. 8. t Ann. Nat. Hist. vol. ii. pi. 6.

xlii INTRODUCTION.

which it was passing was that of Megalopa, to whic
further reference will be presently made.

Here, then, was the first decided demonstration ; but
any doubt which might be supposed to appertain to an
incomplete fact, was shortly removed by Mr. Thompson's
success in hatching the ova of the common crab, Cancer
Pagurus, the product of which were true Zoeas.

Subsequent observations by Mr. Thompson confirmed
his new views, and he established the truth of a metamor-
photic change in several genera; the results of his re-
searches being given to the world in a subsequent portion
of his Zoological Researches, in the " Entomological Ma-
gazine,"* in " Jameson's Journal," f and particularly in a
paper read before the Royal Society in 1835, and pub-
lished in the " Philosophical Transactions," in which
details are given of the complete changes in Carcinus
Manas, the common shore crab, which establish the fur-
ther interesting and important fact, that while the animal
appears under the aspect of a Zoea on its first exclusion
from the egg, it undergoes a further change into a true
Megalopa before its final assumption of the perfect form :
showing that this supposed genus also, which was formed
by Leach, is, like Zoea, only a phase of a higher type.
Thus, in its progress from the egg to its final development,
the brachyurous crustacean was proved to pass through
two temporary conditions, which had previously been
regarded as types, not of genera only, but of different
families ; and both strikingly dissimilar from the group to
which, in its perfect state, it really belongs.

The new doctrine was not received at once with im-
plicit assent. Mr. Westwood, in a paper read before the

* Vol. iii. pp. 85, 275, 370, 452. f For 1846.

INTRODUCTION. xliii

Royal Society in June, 1835,* not only contests the uni-
versality of the law, which Mr. Thompson had somewhat
too hastily, perhaps, deduced from his facts, but concludes
that that gentleman's views are erroneous, and that " no
exception occurs to the general law of development in the
Crustacea — namely, that they undergo no change of form
sufficiently marked to warrant the application to them of
the term metamorphosis."

This hasty, and, as the result has proved, very pre-
mature condemnation, derived some primd facie supports
from the elaborate investigations of Rathke on the deve-
lopment of the embryo in the ova of the river cray-fish,
Astacus Jluviatilis, and the subsequent observations of
Mr. Brightwell on that of the lobster, which latter, how-
ever, have since been only partially verified by Rathke,
and are, indeed, modified in some particulars by Mr. R.
Couch. To these I shall have occasion to refer more
particularly hereafter ; it is sufficient now to observe, that
in both instances the animal was stated to be perfected by
gradual development, and not by any sudden change of
form. These, if even the statements were fully borne
out, have since been proved to be merely exceptional
cases ; and not only is Mr. Rathke's assumed general
support of Mr. Westwood's objections completely re-
moved, but that distinguished physiologist himself volun-
teers his strong testimony in favour of the opposite views
in a subsequent paper, in which he says that he hastens
the publication of these new researches respecting the
development of several other forms of Crustacea, one of
which is the lobster, " in order, as soon as possible, to
record a testimony to the correctness of Thompson's dis-

* Phil. Trans. 1835, p. 311.

xliv

INTRODUCTION.

covery, that even the Decapods, after they have already
quitted the egg, undergo a very considerable metamor-
phosis;1" and, in conclusion, he adds, " from the notices
which I have here briefly communicated respecting the
development of some Decapods, it results that several of
these animals, as first discovered and described by Thomp-
son, undergo a very considerable and highly remarkable

metamorphosis I, therefore, confess that I

have done Thompson injustice in not putting faith in that
discovery." ( And he then states his intention " next
spring, partially to subject his researches on the cray-fish
to revision."* There is one apparent anomaly, however,
on which Mr. Westwood dwells with some plausible show
of reason, and on which it may be well to offer a few
remarks.

Amongst the specimens of Crustacea, preserved in
spirits, which formed part of the collection of the late
Rev. Lansdown Guilding, and which came into my pos-
session after his death, was one of the abdomen of a
female land crab, Gecarcimts, to which were attached
numerous young, in their perfect form, and very similar,
excepting in size, to the parent. Here, then, was a case
in which, it may at once be granted, no external and
independent metamorphosis, at least, had taken place;
and on this, with the other instances above alluded to,
Mr. Westwood founds his principal argument against the
doctrine enunciated by Mr. Thompson. But may not
this probably be an analogous phenomenon to that of the
land salamanders amongst the amphibia? And, as in
that instance, where the parent has no opportunity

1 Wiegmann's Archiv. part iii. 1840. Translated in Ann. Nat. Hist. vol. vi.
pp. 263-268.

INTRODUCTION. xlv

of depositing her eggs in the water, where, in the more
typical forms, the young undergo the transformations
essential to the whole group, the changes take place in
the oviduct; so may not the young of the land crab,
whose habits require them to be speedily in a condition
to leave the coast where they are hatched, formally un-
dergo the metamorphosis within the egg ? This being
granted, it would be as reasonable to deny the pheno-
menon of transformation in the amphibia generally, be-
cause the young of the salamander are brought forth in
the perfect state, as to deny its occurrence in the Crusta-
cea, on the analogous exceptional case of the terrestrial
Gecarcmus.*

I do not consider it necessary to examine at any detail
the " six arguments" which Mr.Westwood adduces "against
the metamorphosis into crabs which the Zoes are stated
to undergo," since the facts, exactly as related by Mr.
Thompson, have been so fully confirmed by subsequent
observers. Indeed, I prefer referring to the whole of
Mr. Westwood's elaborate examination of the question,
for the information of those who may have the curiosity
to see how much may plausibly be urged against the
truth of a theory, so irrefragably supported by facts. It
is sufficient to say that Mr. Westwood does not attempt
to bring forward a single investigation or observation of
his own in support of his views, with the exception of
that of the land crab, already mentioned.i*

* Mr. Thompson, in the case of Gecarcinus, as in that of some other West-
Indian species, depended for his information upon some specimens of female
crabs with matured ova being sent to him in spirits. The ambiguous character
of such, observations may warrant us in eliminating them at once from the
question.

t I have thought it necessary to examine Mr. Westwood's objections at

Xlvi INTRODUCTION.

But Mr. Westwood was not the only one who demurre

to the correctness of Mr. Thompson's conclusion. In the
first volume of Milne Edwards's admirable "History of Crus-
tacea,"* this author says, " Les Decapodes paraissent tons
naitre avec la serie complete de leurs anneaux et leurs
membres ;" and in a note occurs the following opinion on
the earliest researches of Mr. Thompson. " Suivant M.
Thompson, les Decapodes eprouveraient de veritable me-
tamorphoses, car ce naturaliste regarde I'animal connu
sous le nom de Zoe comme etant le jeune du crabe
commun de nos cotes. Mais cette opinion ii'est pas
etayee d'observations assez precises pour entrainer la
conviction."

It is remarkable that this distinguished naturalist's ulti-
mate convictions were derived from his own observation ;
and it is difficult to account for such a discrepancy when
we consider the high character of the dissentient, and the
means which were placed in his hands for determining the
question ; for in consequence of the interest which it ex-
cited amongst the scientific men of France, Dr. Milne
Edwards was deputed with another naturalist, to repair
to the Isle de Rhe for the express purpose of settling the
disputed point, and he arrived, as we learn, at the conclu-
sion above stated.

some length, on account of that gentleman's deserved eminence as a profound
entomologist, and because I believe that he has never published any recantation
of the opinions stated in his paper. I have, however, before me, a letter from
him to myself, dated Sept., 1844, in which the following passage occurs, showing
that his convictions on this subject had undergone a material change : — " I be-
lieve it will turn out, following the normal rule of development of the embryo,
that at a certain period all the Decapods are Zoese, and that some are born (i. e.
escape from the egg) in that state, but that others are not bom until a late
period of development, that is, when the true legs and claws are disengaged."
* P. 198.

INTRODUCTION. xlvii

Subsequently to the researches above-mentioned, the late
Capt. Du Cane investigated the development of the shore
crab, Carcinus Mcenas, and of the Ditch Prawn, Palemon
varians, with complete success ; establishing in each of
these forms the truth of Mr. Thompson's position. Mr.
H. Goodsir also examined, with similar results, the former
species. But by far the most complete illustration of the
subject and the most extensive proofs of the general
law, are afforded by the researches of my friend, Mr.
Richard Q. Couch, of Penzance, who, dissatisfied with
the uncertainty and contradiction of former testimony,
resolved to investigate the matter for himself; and this
he effected with a degree of acumen and perseverance
which characterise all his researches, and by which the
truth of the doctrine is fully established, as regards
the genera Cancer, ZantJio, Pilumnus, Carcinus, Por-
tunus, Polybiiis, Maia, Galathea, Homarus, and Pali-
-Hurns — a goodly number to have been investigated by
one observer — and of some of these he watched every
change. These results were published in two Memoirs,
read to the Cornwall Polytechnic Society in 1843; in
which the author takes a clear and fair view of the whole
subject, and comes to his decision with a host of evidence
sufficient to set the substantive question entirely at rest.
Unfortunately, the useful local publication in which these
memoirs appeared, is so much confined in its circulation
that it has probably fallen into the hands of but few
naturalists.

I have felt it desirable to give a more extended history
of the discovery, as, with the exception of Mr. R. Couch's
first memoir just referred to, no such digest has ever been
placed at one view before the world. I now proceed to

xlviii INTRODUCTION.

examine the actual results, and to endeavour to reduce the
facts already known to some order.

It will be inferred from the previous account, that there
are considerable variations in the character of the meta-
morphosis of different families, and that in the case of
Astacus JluviatiliSy there appears at present to exist even
an abrupt and isolated exception to the general law. As
this is the only case at present in which such exception
has been established, I refer my readers for further in-
formation on this subject to the work of Mr. Rathke
himself,* which constitutes one of the most complete
and elaborate monographs in existence, illustrated in
the most beautiful and perfect manner; and to the
full and satisfactory analysis of the work by Milne
Edwards in the first volume of his " History of the
Crustacea."

Eliminating, therefore, this exceptional case, it will be
found that the fact of a metamorphosis has been demon-
strated with more or less success in no less than seven-
teen genera of the Brachyurous order of the Decapoda
— in which order the phenomenon is most decided and
obvious — belonging to the families Leptopodiadce,Maiadce,
CanccridcE, PortunidcB, Pinnotheridce, Grapsidtz, and Ge-
carcinida. In the Anomourous order, it has been shown
in the genera Pagurus, Porcellana, and Galathea, and
amongst the Macroura in Homarus, Palinurus, Palemon,
and Crangon.

The facilities which everywhere exist for procuring
the common shore crab, Carcinus Mcenas, have occa-

* Untersuchengen neber die Bildung und Entwickeberg des Flusskrebses, von
Hcinrich Rathke. Folio. Leipzig. 182.0.

INTRODUCTION. xlix

sioned it to be more fully investigated than any other ;
and it may, therefore, be taken as the type of the process
amongst the Brachyura. Thus it was the first form in
which the Megalopoid period was observed by Mr.
Thompson ;* it was four years afterwards described in its
zoeform state by Capt. du Cane, who, it appears, was not
acquainted with Mr. Thompson's paper ; it has occupied
the attention of Mr. H. Goodsir; and it forms the subject
of Mr. R. Couch's elaborate and very complete re-
searches. To the latter of these, as embodying all that
is at present known on the subject, and as being the
result of the personal observation of so intelligent and
acute an observer, I shall have recourse for the general
description of this process in the Brachyura. In the first
place it appears that Mr. Couch met with the young Zoes
already hatched; and even then he had the satisfaction of
finding them pass into the Megalopoid condition described
by Thompson. Afterwards, however, he procured some
specimens of the crab itself laden with ripe ova, just
ready for shedding; and he then proceeds with the
account of his observations: —

" These were transferred to captivity, placed in sepa-
rate basins, and supplied with sea water, and in about
sixteen hours I had the gratification of finding large
numbers of the creatures alluded to above, swimming
about with all the activity of young life. There could be
but little doubt that these creatures were the young of
the captive crabs. In order, however, to secure accuracy
of result, one of the crabs was removed to another
vessel, and supplied with filtered water, that all insects
might be removed ; but in about an hour the same crea-

* Phil. Trans, ut supra.

d

1

INTRODUCTION.

tares were observed swimming about as before,
render the matter, if possible, still more certain, some
of the ova were opened, and the embryos extracted; but
shortly afterwards T had the pleasure of witnessing, be-
neath the microscope, the natural bursting and escape
of one precisely similar in form to those found so abun-
Fl'g- c- dantly in the water. Thus,

then, there is no doubt
that these grotesque-
looking creatures are the
young of the Carcinus
Mcenas ; but how diffe-
rent they are from the
adult need hardly be
pointed out any further
than by referring to the
fig. (c). When they first
escape they rarely exceed
half aline in length. The

body is ovoid, the dorsal shield large and inflated, on its
upper edge and about the middle is a long spine, curved
posteriorly and rather longer than the diameter of the
body, though it varies in length in different specimens ;
it is hollow, and the blood may be seen circulating-
through it. The upper portion of the body is sap-
green, and the lower semi-transparent. The eyes are
large, sessile, and situated in front, and the circum-
ference of the pupil marked with radiating lines. The
lower margin of the shield is waved, and at its posterior
and lateral margin, is a pair of natatory feet. The tail
is extended, longer than the diameter of the shield,
and is composed of five equal annulations, beside the

INTRODUCTION. 11

terminal one; its extremity is forked, and the external
angles long, slender, pointed, and attached to the last
ann ulation by joints. Between the external angles, and
on each side of the median line, are three lesser spines,
also attached to the last ring by joints. Between the
eyes, and from near the edge of the shield, hangs a long,
stout, and somewhat compressed appendage, which, as the
animal moves, is reflexed posteriorly between the claws.
Under each eye there is also another appendage, shorter,
and slightly more compressed. The claws are in three
pairs ; each is composed of three joints, and terminates in
four long, slender, hair-like appendages. These claws are
generally bent on the body, but stand in relief from it.
If the animal be viewed in front, the lower margin of the
dorsal shield will be found to be waved into three semi-
circular festoons, the two external of which are occupied
by the eyes, and between which the middle one inter-
venes ; the general direction of the claws will be seen to
be at right angles to the body. As the young lies en-
closed within the membranes of the egg, the claws are
folded on each other, and the tail is flexed on them so far
as the margin of the shield, and, if long enough, is re-
flected over the front of the shield between the eyes.
The dorsal spine is bent backwards, and lies in contact
with the dorsal shield; for the young, when it escapes
from the egg, is quite soft, but it rapidly hardens and
solidifies by the deposition of calcareous matter, in what
may be called its skin. The progress of this solidifica-
tion may be very beautifully observed by watching the
circulation in the dorsal spine. When the creature has
just effected its liberation from the egg, the blood glo-
bules may be seen ascending to the apex ; but as the

d 2

Hi

INTRODUCTION.

consolidation advances, the circulation becomes more
and more limited in its extent, and is finally confined
to the base. These minute creatures, in this early state
of their existence, are natatory, and wonderfully active.
They are continually swimming from one part of the
vessel to the other, and when observed free in their native
pools, if possible even more active than when in confine-
ment. Their swimming is produced by continued flexions
and extensions of the tail, and by repeated beating mo-
tions of their claws ; this, together with their grotesque-
looking forms, gives them a most extraordinary appear-
ance when under examination. As the shell becomes

Fig. d.

more solid they get less active, and retire to the sand

INTRODUCTION. liii

at the bottom of the vessel, to cast their shells, and
acquire a new form. They are exceedingly delicate, and
require great care and attention to convey them through
the first stage; for unless the water be supplied very
frequently and in great abundance, they soon die. The
second form of transmutation is equally as remarkable as
the first, and quite as distinct from the adult animal (d).
In the species now under consideration this second trans-
formation is marked by the disappearance of the dorsal
spine ; the shield becomes flatter and more depressed,
the anterior portion more horizontal and pointed, the
three festoons having disappeared. The eyes, from being
sessile, are now elevated on footstalks ; the infra-orbital
Appendages become apparently converted into antennae.
The claws undergo an entire revolution; the first pair
become stouter than the others, and are armed with a pair
of nippers," the others being simple ; " but the posterior
pair are branched near the base, and one of the branches
ends in a bushy tuft. The tail is greatly diminished
in its relative size and proportions, and is sometimes
partially bent under the body, but is more commonly
extended. This form is as natatory as the first. They
are frequently found congregating around floating sea-
weed, the buoys and strings of the crab pot marks, and
other floating substances, both near the shore and in
deep water. Their general form somewhat resembles a
Galathea."

Every one will immediately recognise in this descrip-
tion, and in the figure which accompanies it, the creature
typifying the genus Megalopa of Dr. Leach. Here, then,
is the second form of a brachyurous type, and its final
change is seen in the accompanying figure (e). It is

liv

INTRODUCTION.

Fig. e.

unnecessary to follow out the minor distinctions in the
various brachyurous genera. It is sufficient to state that
the investigations of Mr. Couch confirm fully the views of
Thompson, by the establishment of a metamorphosis of
similar character, as regards the first change, in the large
edible crab, Cancer Pa/gurus, in Portunus, and in several
of the Maiadce and Leptopodiadce. There are some minor
differences in the structure and form of the first stage of
these as compared with that of Carrinus, but they do
not involve any important consideration. The curious
little larva of Pinnotheres I have figured at p. 125, after
Thompson, and as I have myself seen it.

Amongst the oxyrhynchous forms there are some rather
curious deviations from the type above described, par-
ticularly in the absence, according to Mr. Couch's figures
in the genus Maia, of the dorsal and frontal spines ; but
these, as I understand Rathke's description, are found
in the corresponding stage of the neighbouring genus
Hyas ; if this be so, it shows that the existence or
absence of these spines is of little importance.

In the Anomoura we have elaborate descriptions of the
young stage of Pagurus, in the paper by Rathke already
referred to, and in one by Dr. Philippi, with a figure.*

* Ann. of Nat. Hist. vol. vi. p. 92, pi. iii. f. 7, 8.

INTRODUCTION. lv

If this figure be correct, we have a remarkable approach
in the general form of this species to that of some of the
smaller Macroura, as observed by Mr. Thompson and
Capt. Du Cane; but the details scarcely agree with the
full and doubtless correct description of the former author.
The researches of Mr. Rathke * are, in fact, of great
value, as affording the only clue we have yet seen, to
the homologies of the members which exist in this early
condition of the animal. It appears from this account,
that the true feet are not represented by the three pairs
of locomotive organs which are observed in the early
stage, but that these are in fact developed into the foot-
jaws of the adult. " Embryos about to escape have only
three pairs of members that can serve for locomotion.
All these six members are not, as might be expected,
true feet in a lower state of development, but the foot-
jaws. Of true legs, and also of branchiae, there does
not yet exist a trace." It is not until a subsequent period
that these organs are formed, and, in fact, the whole
account of the development of the young Paguri, as
given by M. Rathke, is highly interesting, and would
be particularly useful as a guide to those observers who
might have the opportunity of watching the whole pro-
gress of any of these animals from the egg to maturity.
The most remarkable form of the larva amongst the
Anomoura hitherto observed, and, indeed, one of the
most anomalous in the whole Decapod group, is that of
Porcellana platycheles, as described and figured by Mr.
R. Couch, in his second Memoir. There is no appear-
ance of either dorsal or frontal spines, in which respect
it agrees with the Macroura, as it does also in the com-

* Ann. of Nat. Hist. vol. vi. p. 263.

Ivi

INTRODUCTION.

pressed corselet, and the large, sessile eyes. On its
„. , first escape from the egg (fig./"), the

feet are in two pairs, dichotomously
branched and destitute of hairs ;
the tail comparatively short, the
terminal flap somewhat lozenge-
shaped, and armed with long, slen-
der, bristle-like appendages. From
the anterior part of the carapace hang

two long, slender filaments which turn under the thorax.

In a few hours the first exuviation takes place, and the

animal appears under a different aspect (fig. g}. Tl

Fig. g.

branchial members are converted into two pairs of simp]
Fig. Ji. three -jointed tufted feet. The

hairy tufts are appended only to
the last joint. The terminal seg-
ment of the six-jointed tail (fig. h)
is expanded into a large quadran-
gular surface, the inferior mar-
gin of which is fringed with six
pairs of long slender filaments.

INTRODUCTION.

Ivii

But one of the most remarkable peculiarities of this
state of the animal is the existence of an exces-
sively long filament extending from above the eyes
and in front of the corselet : this is rough with minute
spines, and appears, as Mr. Couch says, to be hollow.
Two similar filaments, equally long, are attached to
the posterior part of the corselet above the tail.
From the repeated and careful observations of Mr.
Couch there can be no doubt of their correctness, for
he not only bred them repeatedly in filtered water,
but succeeded in artificially extracting some from the
ova.*

The metamorphosis in the Macroura generally is less
strongly marked than in those forms to which we have
hitherto referred. Of these, the lobster, Homarus, the
spiny lobster, Palinurus, the prawn, Palemon, and the
shrimp, Crangon, have been more or less fully observed.
Mr. Brightwell did not consider the changes which he
observed in the lobster such as to warrant the application
of the term metamorphosis ; but even Mr. Rathke him-
self, whose researches in the river
species have offered the strongest
arguments to the opponents of this
view, in his subsequent Memoir,
adduces this, amongst other spe-
cies, as an attestation of the truth
of Mr. Thompson's theory. Mr. R.
Couch's figure (fig. i) of the young
lobster on its exit from the egg
does not differ materially from that

Fig. i.

* The larva of Galathea is figured at p. 203, in illustration of Mr. R. Couch's
description at the previous page.

Iviii

INTRODUCTION.

of Galathea and Palinurus, excepting that on the superior

rings of the tail in the latter are situated four pairs of

appendages (fig. j). Upon this point Mr. Couch has the

F« . following sensible remarks.

e>* «/*

" There is not certainly the
same difference of configura-
tion between the young and
adult condition of these (the
Macroura), as is found to be
the case with the short-tailed
crabs, simply from the circumstance of the tail being
extended in both states, and the claws also show a
nearer approach to each other. But this similarity is
more apparent than real, for the physiological difference

is nearly as wide in one case as in the other

The form of the shield and the body generally, the
sessile character of the eyes, and the long and slender
filaments on the tail in Palinurus, undergo an entire
change in the transformation. The shield and body
become more depressed and elongated, the eyes be-
come elevated on stout footstalks," &c. The sessile
character of the eyes in the early stage of all the Po-
dophthalma hitherto examined is a very remarkable and
important character.

The changes in the smaller decapod Macroura, repre-
sented by the genus Palemon, were first examined by
Mr. Thompson, and formed the subject of a second
paper read before the Royal Society in 1836. This paper,
as well as that on Carcinus before referred to, appears
not to have been known to the late Capt. du Cane, who
having amused the hours of a long illness by a number
of interesting investigations on subjects of Natural His-

INTRODUCTION.

lix

tory, communicated two papers to the Annals of Natural
History, on the Metamorphosis of Crustacea. To one of
these, on Carcinus Manas, I have already alluded j the
other * contains a brief account of the transformation and
development of the ditch prawn, Palemon varians, in
four stages, accompanied by excellent figures ; and a still
more slight one of the common shrimp, Crangon vul-
garis, in its first stage only. I give that author's figure
of the first stage of the prawn (fig. k)9 in which the
locomotive organs are pro-
bably the homologues of the
foot-jaws, and the rudiments
of some of the true feet ap-
pear under the cephalo-tho-
rax. The eyes are wholly
sessile ; there is not the
slightest appearance of ab-
dominal members ; and the
simple spatulate form of
the tail is remarkably dif-
ferent from the highly de-
veloped and complicated
structure of that organ in
the adult.

The two following figures
exhibit two successive states
of the young animal, gra-
dually approaching more
and more to the adult con-
dition. In Fig /, is seen one of the serratures of the

Ann. Nat. Hist. vol. ii. p. 178, pi. vi. and vii.

Ix

INTRODUCTION.
Fig. /.

Fig. m.

\

carapace, the rostrum is produced, the important change

in the eyes from the
sessile to the pedun-
culate form has now
taken place, the true
feet have become
evolved, developed,
and rudimentary ab-
dominal members are
perceived, and in fig.
m, all these develop-
ments are far more ad-
vanced, and the animal
has nearly approached
its final state.

Such is, as far as it
appeared to me neces-
sary to detail it, the
state of our present
knowledge of this very
interesting phase in the
economy of this class
of animals. I have
entered more into de-

INTRODUCTION. Ixi

tail in the history of the discovery, in order to do
justice to those whose original and independent observa-
tions led them to break through the trammels of precon-
ceived notions, and, notwithstanding much opposition
and some misrepresentation, persevered in prosecuting
the investigation until the truth of the doctrine has been
universally received.*

It has not been my object, in the present Introduction,
to enter into the details of the anatomy and physiology of
the class of animals of which it treats. It has been con-
sidered sufficient for my present purpose to offer a very
slight sketch of the principal organs and their functions,

* During the passage of part of this introduction through the press, I received
a communication from my friend Mr. Couch, containing some new observations
on the development of the lobster. From these observations, and others made
on Caprella and other forms, Mr. Couch comes to the following conclusions,
which are strongly confirmatory of the doctrine of arrested development, and
are, in that point of view, very interesting. The original paper was read at
the Royal Cornwall Polytechnic Society.

" So far as my observation has extended, it appears probable that the meta-
morphosis of the young in their progress to adult growth is not universal in all
Crustaceans ; but, on the contrary, that the families in which the eyes are always
sessile in their adult growth, and which do not exuviate or voluntarily throw off
their limbs, are in the habit of producing their young perfectly formed ; and an
opportunity that has occurred to me of observing the process of early develop-
ment in the common lobster will tend to establish the existence of a law of
Nature as applicable not only to it, but probably also to all the genera of this
extensive family or class — that is, the long-tailed Crustacea — which law is, that
the greatest extent of metamorphosis is in those genera which are of the highest
rank in the series— that is, the short-tailed, or crabs — that, even at their birth,
the long-tailed genera — as the lobster — approach more closely to the ultimate
form of the parent ; and — what is still more extraordinary than all beside — that
so long as the lobster in particular, retains the eyes sessile, the progress of develop-
ment and growth is conformed to what is the perpetual mode of growth of the
permanently sessile-eyed races; and it is only when the crust has become fully
extended and hardened, and thus the exuviation is rendered necessary, that the
eyes become elevated on footstalks, and the adult form and habit are completely
established."

Ixii

INTRODUCTION.

with reference, on the one hand, to the characters which
are given of the different genera and species, in the body
of the work, and, on the other, to their habits and mode
of life. For those who seek for further information, I
beg to refer to the excellent digest contained in Pro-
fessor Rymer Jones's " Outline of the Animal Kingdom,"
to Professor Owen's admirable lectures on the Inver-
tebrata, to Dr. Milne Edwards's article CRUSTACEA in
Dr. Todd's " Cyclopaedia of Anatomy and Physiology," and
above all, to the great general work of the same author
on the natural history of this class of animals.* In the
introductory portion of that invaluable book, and in the
general description of the different groups contained in
the body of the work, will be found an immense fund of
information, great part of which is original and based
upon the actual dissection and observation of that distin-
guished naturalist, and of his no less talented friend and
coadjutor, Mons. Audouin. My obligations to this un-
rivalled monograph will appear in every page of this little
work, and demand my warmest acknowledgments.

* Histoire Naturelle des Crustaces, torn. iii. Paris, 1834.

INDEX.

[The systematic names, including the Latin synonyms, are printed in Italics.]

A.

Aclueus CrancMi, 10.
Alauna rostrata, 330.
Albunea dentata* 159.
Alplieus Caramote, 318.

,, ruLcr, '27 ] .

„ sirado, 312.

,, Spinus, 284.
Antaeus Bamjficus, 208.

„ Bernhardus, 171.

„ Crangon, 256.

,, fluviutiliS) 237.

,, HomaruS) 213.

,, marinus, 242.

„ nitescens, 261.

., Aorveyicus, 25 1 .

„ serratus, 302.

„ squamifer, 1 97.

„ Squilla, 305.

„ strigosus, 200.

„ stcllattis, 223.

Atelecydus heterodou, 1 53.

„ scptcitulcntatuS) 153.
Atlianas nitescens, 261.
Adius stirynckus, 228.

B.

Blastus tetraodon, 22.
Bodotria arenosa, 333.

C.

Callianassa subterranca, 217.
Calocans iMucandrete, 233.
Caneellm marinas, 135.
f'unccr anyulatus, 130.

iiraneuS) 31.

asper, 46.

Astacus, 237.

Bamfficus, 208.

Burnliardus, 171.

liiaculeutus, 27.

J5?^/o, 31.

Cassicdaiinus, 159.

corrugattis, 94.

Cancer denticulatus* 72.
„ Depurator, 101.
„ digitatus, 351.

„ Dorsettensis, 13.

„ Dromia, 369.

„ floridus, 51.

„ fluviatilis, 237.

„ Gammarus, 242.

„ hirtellus, 68.

„ horridus, 165.

„ hydrophilus, 54.

„ inciso-serraiusj 59.

„ incisus, 51.

„ latipeSy 85.

„ longicornis, 193.

„ Afoia, 39, 165.

„ minutuS) 135.

„ Mcenas, 76.

„ Norvegicus, 251.

„ Pagurus, 59.

„ Phalangium, 2.

„ Pistim, 121.

„ Platycheles, 190.

„ puber, 90.

„ restrains^ 2.

„ Scorpio , 13.

„ Spinus, 284.

„ Squilla, 202, 305.

„ Squinado, 39.

„ strigosusj 200.

„ tetraodon, 22.

„ tuberosus, 141.

„ tumefactus, 145.

„ velutinus, 90.
Carcinus Alcenas, 76.
Corystes Cassivelaunus, 159.

„ dentatus, 159.
Crab, angular, ] 30.
„ circular, 153.
,, floating, 135.
„ great, 59.
„ harbour, 77.
„ masked, 159.
„ shore, 77.
Cranyonbispinosus, 268.

„ cataphractus, 261.

„ fasciatus, 259.

„ sculpfat, 263.

Ixiv

INDEX.

Crangon spinostis, 261.

„ trispinosus, 265.

„ vulgaris, 256.
Cray-fish, common, 237.
Cuma Audouiniij 328.

„ Edwardsii, 326.

„ trispinosa, 329.
Cynthia Flemingii, 379.

D.

Dromia Rumphii, 369.
„ vulgaris, 369.

E.

Ebalia Bryerii, 1 45.

„ Cranchii, 148.

„ Pennantiij 141.
Eurynomc aspera, 46.
„ spinosa, 46.

G.

GalatJiea Bamffia, 208.
Galathea, Embleton's, 204.
Galathea nexa, 204.

„ rugosa, 208.
Galathea, scaly, 197.
(,'atathea spinigera, 200.
Galathea, spinous, 200.
Galathea, squamifera, 197.

„ strigosa, 200.

„ deltura, 225.
£efa'a stellata, 223.
Gelasimus Bellii, 130.
Gonoplax angulatus, 1 30.

„ bispinosus, 130.

„ rhomboides, 130.
Grapsus cinereus, 1 35.

„ mimttus, 135.

„ Testudinum, 135.

H.

Hermit-crab, blue-banded, 375.

„ common, 171 .

„ Prideaux's, 175.

„ rough-clawed, 186.

„ smooth, 184.

Hippa septemdentata, 153.
Hippolyte Cranclm, 288.
Hippolyte, Cranch's, 288.
Hippolyte Moorii, 292.

„ Pandaliformis, 294.
„ Prideauxiana^ 292.
Hippolyte, Prideaux's, 292.
Hippolyte Sowerbaei, 284.
Hippolyte, Sowerby's, 284.
Hippolyte Spinus1 284.

„ Thompson^ 290.
Hippolyte, Thompson's, 290.

Hippolyte varians, 286.
Plippolyte, varying, 286.
Ilomarus vulgaris, 242.

araneus, 31.
„ coarctatus, 35.

Inachus araneus, 31.
„ Dorsettensis, 13.
„ DorynohuSy 1 6.
„ leptocliirus, 18.
„ Phalangium, 2.
„ Scorpio, 13.

L.

Leptopodia tenuirostris, 6.
/.if //odes Maia, 165.
Lobster, common, 242.
„ Norway, 251.

M.

Macropodia longirostris, 6.
„ Phalangium, 2.
„ Scorpio, 13.

„ tenuirosfris, 6.

Macropus longirostris, 6.

„ Phalangium^ 2.

Maia aranea, 31.
„ Squinado, 39.
„ tctraodon, 22.
Mantis digitatus, 351.
Munida, long-armed, 208.
Mimida, Rondeletii, 208.

„ rugosa, 208.
Mysis Chamozleon, 336.
„ Grijfithsice, 342.
„ Leachiif 336.
„ rostratus, 342.
„ spinulosus, 336.
„ vulgaris, 339.

N.

Nautilograpsus minutus, 135.
Neplirops Norvegicus, 251.
M'&a canaliculata, 275.

„ Coucliii, 278.

„ edulis, 275.

0.

Ocypoda angulata, 130.

P.

Pagurus Bcrnliardus^ 171.
, Cuanensis, 178.

INDEX.

Ixv

I'ayunis Dillwynii, 377 .
„ fasciatuSi 375.
,, Forbesiiy 186.
„ Hyndinanni, J 82.
Itzvis, 184.
Pndeauxii, 175.
strellonyX) 171.
T/iompsoni, 372.
ulidianus, 180.
Pal&mon Leachi, 307.
„ nitescens, 261.
„ serratus, 302.
„ &7z«'#«, 302, 305.
„ varians, 309.
Palinurus Homarus, 213.
„ quadricorniS) '2 1 3.
„ vulgaris, 213.
I'ai/dalus annul/conn's, 297.
I'aslph&u in-i'irostris, 312.
„ Saviynii, 312.
„ Sivado, 312.
Pea-crab, Pinna, 126.

„ common, 121.
Pen&us Caramote, 318.
„ trisulcatus, 318.
Planes Linn<eanat 135.
Plutycarcinus Pitt/urns, 159.
Pilitmniui hirtcllus, 68.
I'titnothercs C ranch ii, 121.
„ Latreillii, 121.
„ IWontayui, 126.
„ 7^7/wtf, 126.
„ 1'isuin, 1-1.
„ varians, 121.
„ JYATM/H, 126.

Pir'nnda denticultita, 72.
/'«« biaculeata, 27.
„ G-zWsM', 27.
„ ictraodon, 22.
Pisldia lonyicomis, 193.
Platyonicus lalipes^ 85.
Polybius Hunslowii) 116.
Pontophilus bispinosus, 268.
„ spinosus, 261.
„ trispinosus, 265.
Porcelain-crab, hairy, 1 90.

„ minute, 193.
Porcellana Leachii, 193.
„ lonyicornis, 193.
„ platychelesi 190.
Portumnus variegatus, 85.
Portunus arcuatus, 97.
„ corrugatus, 94.
„ Dalyellii, 361.
„ Depurator^ 101.
„ emaryinatus, 97.
„ holsatus, 109.
„ infractus, 361.
„ Uvidus, 109.

Portunus,longipes, 361.

maculatus, 112.

marmoreus, 105.

Mcetias, 76.

plicatus, 101.

puber, 90.

pusillus, 112.

Ronddetii) 97.
Prawn, 303.

Processa canaliculata, 275.
„ edulis, 275.

S.

Shrimp, banded, 259.
„ common, 256.
„ sculptured, 263.
„ spinous, 261.
„ three-spined, 265.
„ two-spined, 268.
Spider-crab, Cranch's, 1 1.
„ four-horned, 22.
„ Gibbs's, 27.
„ long-legged, 2.
„ Scorpion, 13.
„ slender, 6.
„ slender-legged, 19.
„ spinous, 39.
Spiny-lobster, common, 213.
Stjuilla Destiiarcstii, 354.

„ Mantis, 351.
Stenorynclius longirustris^ 6.
„ Phalangium, 2.

„ tenuirostris, 6.

Stone-crab, northern, 1 65.
Swimming-crab, arched, 97.
cleanser, 101.
dwarf, 112.
Henslow's, 116.
livid, 109.
long-legged, 36 1
marbled, 105.
velvet, 90.
„ wrinkled, 94.

T.

TJtemisto brevispinosa, 384.
„ longispinosa., 381.
Tlda polita, 365.
Thysatiopoda Couchii, 346.

X.

Xantho florida, 51.

,, i?iciso-serrata, 51.
,, rivulosa, 54.
,, tuberculata, 359.

BRITISH CEUSTACEA.

DEC APOD A, LEPTOPODIADM.

nilACHYURA.

<JENUS STENORYNCHUS, LAMARCK.

CANCKK, Linn. Penn. Herbet.

INACHLIS, Fabr.

MAIA, Bosc.

MACROPUS, Latr.

MACROPODIA, Leach.

STENORYNCHUS, Lamk. Edwards.

Generic character. External antennce setaceous, the basal joint
narrow, the second * inserted close to the side of the rostrum, very
short ; the third, three times as long as the former. External
pedipalps narrow, the second joint considerably produced internally
at its apex ; the third joint oval. Anterior feet shorter, and much
larger (in the male) than the succeeding ones ; equal ; the hand
somewhat ventricose ; the fingers slightly inflected. The remaining
pairs very long and slender, diminishing in length from the second
to the fifth ; the nails of the second and third pairs long, slender,
and curved only at the apex ; those of the fourth and fifth shorter,
curved at the base and somewhat falciform. Eyes not retractile,
larger than their peduncles, oval, pointed at the apex and setiger-
ous. Carapace triangular ; rostrum taper and bifid. Abdomen
six-jointed, the terminal portion being formed by the union of the
sixth and seventh joints.

* Leach calls this the first joint of the antennas, as he does not reckon the
basal joint, which is fixed, and, as it were, soldered to the parts contiguous, as in
most of the higher forms of Crustacea.

B

LEPTOPODIAD^E.

DECAPODA.
BRACHrURA.

LONG-LEGGED SPIDER-CRAB.

StenoryncJius Phalangium.

Specific character. — Rostrum shorter than the peduncle of the antennae ; a single
minute spine on the epistome, close to the auditory cavity ; no spine behind the
base of the antennae ; arms slightly scabrous, without spines.

Cancer rostratus,

„ Phalangium^
Inachus „

Macropus „
Macropodia „

Stenorynclius „

LIN. Faun. Suec. HERBST. t. xvi. f. 90.

PENN. IV. t. ix. f. xvii.

FABR. Supp. p. 358.

LATR. Hist. Nat. Crust. VI., p. 110.

LEACH, Tr. Linn. Soc., XL, p. 331, Malac. Brit.

t. xxiii. f. 6.
EDW. Hist. Crust. I. p. 279.

THE general form of the carapace in this species is that
of an acute angled triangle, rounded at the posterior angles.
It has several rather prominent spines ; one on each he-

LONG-LEGGED SPIDER-CRAB. 3

patic region, forming, with one on the gastric region, an
equilateral triangle ; there are two small ones on each
branchial region, and one, the largest of all, on the cardiac ;
there are also one or two smaller ones near the latero-
anterior margin. The rostrum is of moderate length,
scarcely reaching to the middle of the third joint of the
peduncle of the antenna?; it has a groove through its
whole length, reaching to the back of the orbit. The ex-
ternal antenna- are long and setaceous, and furnished with
several long hairs; the basal joint is narrow, entirely im-
moveable, and continuous with the epistome ; the move-
able part of the peduncle consists of two joints, of which
the second is three times a^ long as the first. The internal
antenna' are lodged in fossa1, which are separated from
each other by a ridge, which is incomplete at the middle.
The eyes are oval, larger than their peduncles, and pointed
at the apex, where there is a small bristle.* The orbits
are round, and there is a prominent ridge over the upper
margin. The epistome, or that portion of the shell be-
t \\ eeii the mouth and the base of the antenna?, has a very
minute tubercle, just in front of the organ of hearing, but
none at the base of the antenna?, as in St. tenuirostris."^
The first pair of legs in the male are about twice as long
a- the body ; the arm has a line of minute tubercles on
the outer, and another on the inferior surface, which parts
are also hairy ; but there are no spines on its inner margin,
as in St. tenuirostris : the wrist is similarly furnished :
the hand is somewhat ventricose ; it is hairy both on the
outer and inner margin ; the fingers are slightly inflected ;
the moveable one is furnished with a tubercle near its base,

* This curious appendage I have never seen mentioned as appertaining to this
genus.

f This second tubercle is also found in a Mediterranean species St. JEgypffau,

B 2

LEPTOPODIAD^E.

and there is a corresponding excavation in the other. In
the female these feet are altogether much smaller than in
the male. The remaining pairs are very slender and fili-
form ; the second pair is three times and a half the length
of the post-rostral part of the body, and they diminish
regularly to the last pair : the claws of the second and
third pairs are slender, and slightly curved towards the
extremity ; those of the fourth and fifth are shorter, and
somewhat falcate, being curved more abruptly near the
base. The abdomen in both sexes has six joints, the sixth
and seventh being united into one piece. That of the male
is broadest at the base, and again at the union of the third
and fourth joints, and terminates in an obtuse triangle :
each joint is furnished with a tubercle. The abdomen of
the female is very broad, and much curved : the tubercles
pass into a continuous obtuse carina on the three or four
last joints.

These characters belong for the most part to both the
species, excepting where the contrary has been stated ;
the specific difference with those exceptions being rather
in the degree of development than in the existence, or non-
existence of parts.

This is one of the most common species of the Trian-
gular Crabs, being found in considerable numbers on most
parts of the coast. I have obtained it from Wales, the
coast of Cornwall, Devonshire, Dorsetshire, and Sussex,
from Scarborough, and from Orkney. It is also not un-
common on the coast of Ireland. Dr. Leach mentions its
being particularly common at the mouths of rivers, and in
estuaries ; but I have found it in very different localities,
having often dredged it in deep water, and taken it in
crab and lobster pots. Mr. Hailstone states that " it is
very common at Hastings, both among the rocks on the

LONG-LEGGED SPIDER-CRAB. 5

shore, and in deep water, and is occasionally caught in
the trawl-net in vast numbers. Of sixty-eight specimens
brought up at once, the proportion of males to females was
as two to one." Like all the species of the family it is
slow, sluggish, and timid. It generally has small fuci
growing on it, especially on the legs ; and I have some-
times seen the body completely covered and concealed by
a mass of sponge. When taken it moves with very little
energy, and speedily dies after being taken out of the
u ater. Its slow and sluggish habits render it an easy prey
to many fishes ; Mr. W. Thompson says, " On opening a
thornback, fi-aia clavata, about twenty inches in length, I
found the stomach entirely filled with Macropodia Pha-
langium."

\( deposits its spawn during the early spring months.

6

LEPTOPODIADJE.

DEC A POD A.

BRACHYURA.

LEPTOPODIAD&.

SLENDER SPIDER-CRAB.

Stenorynclius tenuirostris.

Specific character. — Rostrum longer than the peduncle of the external antennae,
its two portions being in contact throughout their whole length ; two minute spines
on the epistome, one close to the organ of hearing and another at the base of the
external antennae ; arms spinulose at the inner margin.

Leptopodia tenuirostris,
Macropus longirostris ?
Macropodia „

„ tenuirostris,

Stenorynchus longirostris 1

LEACH, Edinb. Enc. VII., p. 431.
LATH. Hist. Nat. des Crust. VIII., p. 110.
Risso. Hist. Nat. de 1'Eur. Merid. V., p. 27.
LEACH, Trans. Linn. Soc. XI. p. 331. Malac.

Brit. t. XXIII. f. 1-5.
EDW. Hist. Crust. I. p. 280. COUCH, Cornish

Fauna, p. 64.

THIS elegant species may be readily distinguished from
the former by the long attenuated rostrum, by the existence
of a small spine on the epistome, immediately behind the

SLENDER SPIDER-CRAB. 7

basal joint of the external antennae, and by a series of
minute spines on the inner part of the arm. The body is
altogether more elongated, and the spines more acute ;
but, in other respects, the characters are nearly the
same.

" I first observed this species," says Dr. Leach, " amongst
some Crustacea collected at Torquay, in Southern Devon, by
Hooker ; and have since found it a very common inhabi-
tant of all the deep water off the coast of that country,
especially in the Sound of Plymouth." Mr. Couch states
it to be very common in Cornwall, at the depth of from two
to twenty fathoms ; and Mr. Embleton includes it in his
list of the Crustacea of Berwickshire and North Durham.
It does not appear to have been taken in Ireland. I have
taken it in prawn pots at Bognor, and by dredging in
Studland Bay in Dorsetshire.

I have appended a note of doubt to the synonyms of
the Mediterranean species, Macropus longirostris, Latr.,
hitherto considered as identical with this, as I am much
inclined to believe they may be distinct. I am led to this
supposition by a careful examination of specimens of my
own collection on our coast, with some which I had
received from Sicily, and from the Bay of Naples, and
I find that on all those brought from the Mediterranean,
the body is proportionally longer ; the rostrum also longer
and more slender, reaching very much beyond the peduncle
of the antennce. By measurement I find that, in the Mediter-
ranean specimens, the length of the carapace, including the
rostrum, is to its breadth, at the widest part, as five to two ;
whereas, in the British, it is not quite twice as long as broad.
The two portions of the rostrum in the former are a little
separated throughout almost their whole length, and each
is perfectly round ; whereas, in the British specimens, they

8

LEPTOPODIADJE.

are entirely in contact, and flattened above and beneath.
There are a few other differences principally proportional,
but these are the most considerable. These may be mere
accidental variations, but I think it not improbable that
they indicate a specific distinction.

DECAPOD A . LEPTOPODIA DM.

BRACHYURA.

GENUS ACH^US, LEACH.

A(H.v:i >, Leach, Latr. Edwards.

Generic character. External antennae remote, setaceous, the
first articulation united to the front, and extending beyond the
inner canthus of the orbits ; the second articulation inserted at the
side of the rostrum, and entirely exposed from above, and, with
the third, much thicker than the subsequent ones. External pedi-
palps, with the second articulation much longer than broad, and
produced at the interior and anterior angles, the third subtriangular
with the angles rounded. The first pair of feet (in the female)
short, rather slender; the second and third pairs having the ter-
minal joint long and styliform ; that of the fourth and fifth com-
pressed, abruptly curved, and falciform. Carapace somewhat tri-
angular, slightly spinous, the branchial regions elevated and swollen.
Hostrum extremely small, bifid. Eyes not retractile, placed on
long footstalks of equal size, and furnished with a single tubercle
on the fore-part. Abdomen six-jointed in both sexes.

This genus, of which one species only is at present
known, is considered by Dr. Leach as intermediate between
Inaclius and Leptopodia \Macropodia\, and by Milne Ed-
wards it is placed between Stenorynchus (Macropodia Le.)
and Camposcia. Its relation to Eurypodius is also pro-
bable from the character of the feet, whilst the structure of
the eyes and some other points appear to indicate an ap-
proach to some of the Maiadce.

10

LEPTOPODIAD^E.

DEC APOD A.

BRACHYURA.

LEPTOPODIADfll.

CRANCITS SPIDER-CRAB.

AcJiaus CrancJm. Leach.

Specific character. — " Carapace, with two tubercles in the median line, and
with two elevated lines between the eyes." — LEACH.

Acluzus Crancliii, LEACH, Malac. Brit. XXII. C. Ed. 2. LATB. Reg. Anim.

IV. p. 64. EDW. Hist. Crust. I. p. 281.

THE carapace of this interesting species, is triangular,
contracted behind the orbits, then enlarged into a promi-
nent point or tubercle, then again contracted, and finally
enlarged and rounded at the sides of the branchial regions.
Two conspicuous elevations, or tubercles, occur on the
median line, with an inconspicuous one between them ; and
the branchial regions are elevated and rounded. The ros-
trum is extremely small and bifid, as broad as it is long.
The orbits are small and Open above, and the eyes exposed
almost to the insertion of the peduncles, which are long,
cylindrical, furnished with a small rounded tubercle on the
anterior part, about the middle of its length, and standing
directly outwards ; not retractile. The antennae and the

CRANCH'S SPIDER CRAB. 11

feet are very hairy. The hands are earinated longitudinally.
The epistome is quadrate. The abdomen in the female (and,
according to Dr. Milne Edwards, in the male also,) is six-
jointed. In the former it is oval, expanded towards the
posterior part, and earinated through its whole length. The
carapace is about six lines in length.

Colour, pale reddish brown.

Of the occurrence of this beautiful little species on our
coasts, we have, I believe, only two recorded instances.
In the " Malacostraca Podophthalma Britannise," Dr. Leach
first made it known as having been discovered by Mr.
Cranch in dredging off Falmouth. This single specimen, a
female, is now in the British Museum. The second ex-
ample is thus stated by Mr. W. Thompson in his catalogue
of the Crustacea of Ireland. " In the collection of Crustacea
formed by Mr. J. V. Thompson, and now in the possession
of the Eoyal College of Surgeons, Dublin, is a native speci-
men of this crab, which we may presume was obtained on
the Southern coast." This is the sum of the information
we have respecting this species as indigenous to this country.
Dr. Milne Edwards gives as its habitat on the French
coast, " I'embouchure de la Kance, pres Saint- Malo." Of
its habits nothing whatever is recorded, beyond the remark
of Dr. Edwards, that it lives amongst sea-weeds and on
oyster-beds.

DEC APOD A.

BRACHYURA.

LEPTOPODIADM.

GENUS INACHUS, FABB.

CANCER,
INACHUS,
MACROPUS,
MAIA,

Pennant, Herbst.

Fabr. Leach, Latr. Edw.

Latr.

Bosc.

Generic character. — External antennce not more than one-fifth
of the length of the body ; the basal joint forming the inferior
margin of the orbit ; the second inserted by the side of the rostrum.
External pedipalps with the second joint much produced internally ;
the third joint elongate, somewhat triangular, the anterior and
inner angle truncate at the insertion of the palp, which is three-
jointed. The anterior legs, in the male, twice as long as the body,
the arms and the hands subovate, the fingers inflected. The re-
maining pairs very long, diminishing in length from the second to
the fifth ; second pair larger than the succeeding ones ; the terminal
joint long and slightly curved. Carapace subtriangular, nearly as
broad as long, the rostrum short and bifid. Eyes on short foot-
stalks, retractile or capable of being bent backwards and lodged in
the posterior part of the orbit. Abdomen in both sexes, six-jointed
and carinated,

SCORPION SPIDER-CRAB.

13

DEC A POD A.

BRACHYURA.

LEPTOPODIADX,.

SCORPION SPIDER-CRAB.

Inachus Dorsettensis. Leach.

Specific character. — Rostrum very short, emarginate : the gastric region fur-
nished with four small tubercles ranged in a line transversely, and a larger one
behind them.

Cancer Dorsettensis,
„ Scorpio,

„ Dorsettensis,

PENN. Brit. Zool. IV. t. x. f. 1. p. 12.

FABR. Ent. Syst. II. p. 462. HERBST. I. p. 237. No.

130.

LATR. Hist. Nat. Crust. VI. p. 10.9.
FABR. Suppl. 358. DESM. Cons. t. xxiv. f. 1. EDW.

Hist. Crust. I. p. 288. COUCH, Cornish Fauna,

p. 65.
LEACH, Edinb. Encycl. Malac. Brit. t. xxii. f. 1-6.

I HAVE found it necessary to restore to this species the
original specific name given to it by Pennant, who first
described it from specimens in the Portland Cabinet, taken

14 LEPTOPODIAD.E.

at Weymouth, from which locality he designated it Cancer
Dorsettensis. His work was published in 1777; and the
Entomologia Systematica of Fabricius, in which it first re-
ceived the name of C. Scorpio, not until 1793. The Fab-
rician name has recently been adopted by Dr. Milne
Edwards, as it had previously been by Desmarest, probably
from some objection to the local origin of the former name ;
this, however, is quite admissible in the present instance,
as indicating the locality in which it was first discovered.
At all events, it is not more objectionable than the other.

The carapace of this species is triangular, rounded poste-
riorly, and ventricose. The rostrum is very short and
bifid ; the orbits oval, so that the eyes, which are attached
by their peduncles to the anterior portion of the orbit, can
be laid backwards into the posterior portion of that cavity ;
a character which belongs to most of the genera of the
triangular or oxyrynchian families. The eyes are protected
by a spine on the anterior, and a stronger one on the
posterior margin of the orbits, of which the upper margin
is also raised, and the inferior, formed by the basal joint of
the antennae, slightly tuberculated. The external antennas
are short ; the moveable portion not much exceeding twice
the length of the rostrum. There are four small tubercles on
the anterior part of the carapace arranged transversely, and
one much larger behind them, on the centre of the gastric
region; there are two tubercles on each branchial region,
one at the anterior part and another rather larger on the
centre ; there is also a conspicuous one on the cardiac region.
The external pedipalps are elongate, the second joint being
much produced anteriorly at the inner angle ; and the third,
which is somewhat triangular, has the inner and anterior
angle truncated, for the articulation of the terminal portion,
which consists of three joints. The anterior pair of legs in

SCORPION SPIDER-CRAB. 15

tlio male are thick and long, the joints of a somewhat oval
form, and the fingers considerably incurved. Those of the
female are very small. The remaining feet are very long
and slender, the second pair being considerably more than
three times the length of the body, including the rostrum.
They are also much larger than the succeeding one, which
diminish in length and thickness to the last. The abdomen
of the male is rather short and broad, the widest part being
at the union of the third and fourth joints ; that of the
female is remarkably broad. In both sexes it is tuberculo-
carinatcd.

It would appear that this species is more widely distri-
buted than had been supposed. Dr. Loach states that it
i» very plentiful on the coast of Devon ; we have seen that
Pennant's specimens were from \Veymoutli; and I ob-
tained it in Stndland Hay. Dorsetshire, and at Hastings.
Mr. Couch states that in Cornwall it is commonly taken in
crab pots, within a few miles of the shore, at all depths;
and Mr. Kyton informs me that it is found on the oyster-
beds at Rhoscolyn, near Holyhead. In Ireland it has
been found in many places ; in the Harbour of Cove, by
Mr. J. V. Thompson. "It is pretty commonly taken,"
says Mr. W. Thompson, " in the loughs of Strangford and
Belfast, and on the western coast. — Mr. Ball," adds Mr.
Thompson, " finds it in Dublin Bay." It is also recorded
that Captain Beechey, E.N., brought up a specimen of this
species alive in the dredge from a depth of one hundred
and forty fathoms, in the Mull of Galloway. Its habitat
extends far north, Fabricius having found it in the Nor-
wegian Seas.

LEPTOPODIAD^E.

DEC A POD A.

BRACHYURA.

LEPTOPODJADM.

InacJius Dorynchus. Leach.

Specific character. — Rostrum bifid, extending beyond the third joint of the pedun-
cle of the antennae ; gastric region with three spines, two anterior, and the third
much longer, forming a triangle. Second pair of legs not more than three times
the total length of the body.

Inaclius Dorynchus,

LEACH, Edinb. Enc. art. Crust, p. 431. Id. Malac. Brit,
t. xxii. f. 7-8. EDW. Hist. Crust, p. 288. COUCH,
Cornish Fauna, p. 65.

THE general form of this species is very similar to the
former, but it is less globose. The carapace is triangular,
longer than it is broad. The rostrum is short, some-
what hastiform, and in most slightly bifid ; although in
some specimens the division is more considerable. The
antennae, the eyes, and orbits, as well as the external

INACHUS DORYNCHUS. 17

pedipalps, are very similar to those of the former species.
The gastric region of the carapace has three spines, two
small ones distant, and another much stronger placed far-
ther back on the median line, and, with the others, forming
a triangle. There are two tubercles on each hepatic
region, placed as in the former species ; and the cardiac
region, instead of a spine, has only an elevation, on which
are three very small tubercles. The sides of the shell are
destitute of tubercles. The hands are smooth. In other
respects this species resembles the former.

The present species of InacJius was discovered by Dr.
Leach, as he informs us, " whilst cleaning a parcel of /.
Dorsettensis from the Salcombe estuary for examination/1
Mr. Couch states that it is commonly found in crab-pots
in Cornwall. Mr. Hailstone found it at Hastings, where
I have also obtained it. I have taken it by the dredge in
Studland Bay, Dorsetshire, and at Bognor I found several
small specimens amongst the refuse of prawn and lobster
pots. These were of a lighter colour than most which I
have observed from other localities, but this may have
arisen from their being young. In Mr. Embleton^s list of
the Crustacea of Berwickshire and North Durham, it is
stated to occur not uncommonly in Berwick and Embleton
Bays. It is found on the coast of Ireland, though rarely,
having been taken by Dr. Drummond in Belfast Bay.

This species, like all the others of the family, is very
liable to be covered with small fuci and sponges ; hence, as
Dr. Leach has observed, in all probability arose its having
been for so long a time undiscovered, having doubtless been
passed over as /. Dorsettensis; it does riot, however, at
present appear to be so generally distributed as that species.

18

LEPTOPODIAD.E.

DEC A POD A.

BRACHYURA,

LEPTOPODIADJE.

SLENDER-LEGGED SPIDER-CRAB.

Inachus leptochirus. Leach.

Specific character. — Feet slender, anterior pair in the male extending beyond
the penultimate joint of the second pair. Rostrum hastiform. Sternum in the
male with a round polished tubercle.

Inachus leptocMrus,

LEACH, Malac. Brit. t. xxii. B.

(errore leptorinchus) EDW. Hist. Crust. I. p. 289.

THE carapace in this species considerably resembles that
of /. Dorynchus. It is triangular, considerably longer than
it is broad, much narrowed forwards ; the rostrum hasti-
form, bifid at the extremity, and with a slight groove ex-
tending from thence backwards between the eyes. There
is a strong spine on the gastric region, a very small tuber-
cle on each hepatic, a spine on the latero-anterior margin,

SLENDER-LEGGED SPIDER-CRAB. 19

two on each branchial region, the posterior being the
larger, and one on the genital region in a straight line
between the two larger ones on the branchial. The feet
are all very long and slender. The hands in the adult
male are considerably longer than the carapace ; the fingers
curved. The second pair of feet are three times the length
of the carapace. On the sternum, immediately in front of
the apex of the abdomen, when in its usual position applied
against the thorax, is a round or oval prominent and po-
lished tubercle, of a greyish-white colour.

In the adult state this is considerably the largest of the
British species of Inachus. It is also then readily distin-
guished from the others, by the general form, as well as
by the extraordinary length of all the legs, and especially
by the form and length of the first pair. But in the
younger state all these characters are much less conspi-
cuous, and it might almost be mistaken for /. Dorynchus,
but for the remarkable character of the round polished
tubercle on the thorax, which somewhat resembles the
half of a pearl. This is peculiar to the male, and cannot
fail to strike us as offering a very obvious mark of relation
to the Mediterranean species /. Thora-
cicus, on the thorax of which there is
a very curious development of a similar
hard shelly substance, in the form of a
broad, three-lobed plate. This formation is peculiar to the
genus Inachus, and, as far as it is at present known, to
the two species in question.

The InacJius leptocMrus is extremely rare. It was dis-
covered by the ill-fated Mr. Cranch on the western coast
of Devon, or Cornwall, and was afterwards taken by Mr.
Prideaux from a crab-pot in Bigbury Bay. In Mr. W.

Thompson's " Additions to the Fauna of Ireland," is men-

c 2

LEPTOPODIAD^E.

tioned " a specimen dredged in Clifton Bay, Oonneman
by Mr. Forbes and Mr. Hall, and another in Belfast 1
by Mr. Patterson." The latter specimen, through the
kindness of Mr. Thompson, I have now before me. It is
young male. The same gentleman subsequently states that
he had seen specimens from Belfast Bay " in the Ordnance
collection." This is the extent of our knowledge of this
curious species.

Dr. Milne Edwards has misquoted Leach's specific name
as " Leptorinchus" and this error has been copied by Mi
Couch in his " Cornish Fauna."

DEC A POD A.

BRACHYURA.

GENUS PISA.

CANCER, Penn. Herbst, Montagu.

IN.UHUS, Fabr. Risso.

MAIA, Latr. Bosc.

I'I.SA, Leach, Desmar, Edwards.

Generic character. — External antenna beset with club-shaped
nairs; the basal joint longer than broad, extending beyond the
inner canthus of the orbit j but concealed above by the strong spine
which proceeds from the upper margin of the orbit : second joint of
the antennae rather slender, inserted a little behind and on the
outer side of the rostrum. External pedipalps very broad, the
second joint produced at the inner and anterior angle ; the third
triangular, very broad at the outer margin ; the anterior and inner
angle truncate or emarginate. First pair of feet in the adult male
very large, longer than the second pair ; the hand thick and the
fingers meeting only at the outer margin of the points which are
toothed ; those of the female much smaller, the fingers meeting
throughout nearly their whole length ; shorter than the second pair.
The remaining feet moderately long, diminishing regularly from
the second to the fifth, cylindrical, the terminal joint curved,
pectinato-denticulated beneath, naked at the extremity. Eyes
scarcely thicker than their peduncles, capable of being reflected in
the orbits. The orbits oval, directed outwards and downwards ;
their upper margin with a strong triangular spine directed forwards.
Carapace triangular, terminating in a strong bifid rostrum, divari-
cating at the extremity. Abdomen seven-jointed in both sexes.

22

MAIAD^E.

DECAPOD A.
BRACHYURA.

MAIAD&.

FOUR-HORNED SPIDER-CRAB.
Pisa tetmodon. Leach.

Specific character. — Lateral margin with four spines, (exclusive of those above
and behind the orbit.) Posterior portion of the carapace rounded, without spines ;
a small tubercle near the posterior margin.

Cancer tetraodon> PENN, Brit. Zool. IV. t. viii. f. 2. p. 11.

Maia „ Bosc, Hist. Crust. I. 254. LEACH, Edinb. Encycl. VII.

p. 395.

Blastus „ LEACH, 1. c. p. 431.

Pisa „ LEACH, Trans. Linn. Soc. XI. p. 328. Id. Encycl. Brit.

Supp. I. p. 415. Id. Malac. Brit. t. xx. f. 1-4.

EDW. Hist. Crust. I. p. 305. COUCH, Cornish Fauna.

p. 65.

THE general form of the body of this species is trian-
gular, produced anteriorly, and with the posterior angles
much rounded. The rostrum is large, strong, and promi-
nent, about one-third as long as the remainder of the cara-

FOUR-HORNED SPIDER-CRAB. 28

pace ; it is formed of two strong horns, diverging for about
one-third of their length, and slightly deflexed ; the lateral
margin has four spines, exclusive of a very strong one above
the orbit, and a smaller one behind that cavity. There are
numerous tubercles on the carapace, several small ones
on the gastric region, disposed transversely ; one on the
centre of the carapace ; two considerable ones on each
branchial region, one on the centre of the cardiac, and
a small one near the posterior margin. The spines above
the orbit are triangular, very strong and prominent ; di-
rected forwards and a little outwards, and so formed that
the eyes can be deflexed within them, so as to be quite
concealed from above. The external antennae are beset at
their base with long club-shaped hairs. The anterior pair
of feet in the male are exceedingly strong and thick, the
hands especially are nearly as broad as they are long. The
fingers meet at the points ; the outer edge of each being
denticulated, and the moveable one has a small round
tooth. The arms and wrists have several round tubercles.
In the female these feet are very small, and shorter than
the second pair, and in the immature male they are very
similar to those of the female. The remaining feet are of
moderate size and length, the second pair being but little
longer than the carapace, and the fifth pair shorter than
its breadth. There are a few tubercles, and a few small
spines upon the legs, and the nail is furnished beneath with
a regular row of sharp spines arranged like the teeth of a
comb. The abdomen has seven distinct joints in each sex;
that of the male being broadest at the third joint ; the
sixth is broader than the fifth, and the seventh is trian-
gular. Each joint has a central tubercle.

The abdomen of the female is very large and broad, and
has a broad carina. The whole surface of the shell, and

MAIAD.E.

the greater part of the limbs, is covered with a close, shoi
villous coat ; and the antennae, rostrum, and all the tu-
bercles are furnished with tufts of long, curved, club-
shaped hairs. Underneath this covering the shell is po-
lished, and minutely punctured. The colour is a dull red-
dish-brown, becoming bright red by boiling, or by the
action of spirit. The general length of the carapace in a
full-grown male is two inches three lines, breadth one
inch six lines.

The habits of this species, as far as I have had an op-
portunity of observing them, are curious. They are found
concealed under the long hanging fuci which clothe the
rocks at some distance from the shore, in which situation
I have taken them amongst the Bognor rocks. They con-
gregate in vast numbers at the place I have, just mentioned,
in the prawn and lobster pots. I have seen, probably,
thirty amongst the refuse of one of these, attracted no
doubt by the garbage which is placed in them as bait.
These were much larger and finer than any I have seen
elsewhere. Contrary to the comparative sizes of the two
sexes, as figured by Dr. Leach, I found the males larger
than the females, exceeding them in length by about half
an inch. Thus, Leach's figure of the male is not at all
equal in size or apparent strength to those which I found
at Bognor, but that of the female is about the ordinary
size of that sex. Like all the slow moving Crustacea, they
are very liable to be covered with small fuci, so that they
are sometimes completely concealed by a mass of these
marine plants growing upon their surface, where their
roots find a secure hold amongst the villous coat of the
shell and limbs.* This is especially the case with the

* Say supposes that the fuci, which are found covering certain Crustacea, are
merely entangled mechanically in the hooked hairs by which they are covered ;

FOUR-HORNED SPIDER-CRAB. 25

females, which in this, as in many other species, are less
active than the males. Their movements are extremely
slow and measured, and they are very timid, concealing
themselves under the fuci, and remaining for a time almost
motionless. But notwithstanding their timid and lazy
character, they seize the object of their anger by a sudden
and unexpected snap, and nip with great force, holding on
with extraordinary firmness and tenacity, although unable,
from the bluntness of their pincers, to inflict a wound.
The manner of their seizing any object, when from their
slow motion it is least expected, reminded me of the mode
in which 1 have seen the Otolicnus tardigradus seize a bird,
or other small living animal ; and any one who has seen
both, must, I think, be struck with the similarity.

This species of Pisa formed the type of the genus Blas-
tns of Leach, who, however, afterwards reunited the two
forms, which certainly are not sufficiently distinct to war-
rant their separation. It would appear from the paucity
of observations which I have found of the occurrence of
this species, that it is not a common one ; or at least that
it is very local. Mr. Couch says in his " Cornish Fauna"
that it is not common in that county. Dr. Leach gives,
as its localities, " The Isle of Wight, Teignmouth, and
Brighton.91 It is not mentioned by Mr. Hailstone in his
MS. Catalogue of Hastings Crustacea, which he obligingly
sent me, nor do I remember to have found it there. I
have taken many small specimens on the Dorsetshire Coast
by dredging, and, as I before observed, in very large num-
bers at Bognor. The only account of its occurrence as an
Irish species is, that " two examples exist in Mr. Ball's

but there is no doubt that they actually grow upon them, and are attached by
roots. This is evident from the healthy state of the little plants, as well as from
the direction of their branches.

MAIADJ3.

collection which were obtained at Roundstone, Conne-

mara.

It inhabits, also, the Mediterranean ; and I have observed
a remarkable peculiarity in some of the specimens from
that locality. The anterior pair of legs, as I have before
mentioned, do not assume their full size and development
until the animal is quite adult ; but I have seen Mediter-
ranean specimens of a very small size comparatively, with
the full adult development of the feet. In such cases we
might expect to find the reproductive organs fully per-
fected, from some local circumstances favourable to their
development, whilst the general growth of the animal had
been retarded, probably by deficiency of nourishment.

GIBBS 8 SPIDER-CRAB.

DEC A POD A.

BRACHYURA.

MA1ADJE.

J

a

GIBBS-S SPIDER-CRAB.
Pisa Gifibsii. Leach.

Specific character. — No spines on the lateral margin. A strong spine on each
branchial region, and a large prominent tubercle just above the posterior margin of
the carapace.

Cancer biaculcatus^
Pisa „

„ GiUtsii,

MONTAGU, Linn. Trans. XI. t. i. f. 2. p. 2.

LEACH, Edinb. Encycl. VII. p. 431.

Id. Trans. Linn. Soc. XI. p. 327. Malac. Brit. t. xix.

EDW. Hist. Crust. I. p. 307. COUCH, Cornish

Fauna, p. 65.

THE general form of the carapace in Pisa Gibbsii is very
different from that of P. tetraodon. The rostrum is much
longer, being not less than half the length of the rest of
the shell, and its two horns, in the male, are parallel
throughout almost their whole length ; but in the female

MAIAD^E.

they are shorter, and divergent for about one-third of their
length, as in the former species. The lateral margin of
the carapace is without spines, — excepting, in some speci-
mens, a very small one on the hepatic region. The supra-
orbitar spine is smaller than in the other species, not ex-
ceeding one-third the length of the rostrum in the male ;
it is directed outwards and forwards ; the post-orbitar
spine is very small. The regions of the carapace are very
strongly marked and gibbous, particularly the genital and
intestinal, and they are separated by deep furrows. There
is on each branchial region a strong prominent spine which,
with a large round tubercle just above the middle of the
posterior margin, on the intestinal region, form an obtuse
triangle. The antennae, the pedipalps, and the abdomen,
are very similar to those of P. tetraodon. The anterior
pair of feet are of moderate size, not nearly so broad and
massive as those of the other species, and the hands com-
pressed. The remaining feet are tuberculated, excepting
the penultimate joint of the second pair, which is without
tubercles or spines. The whole surface is covered with a
very dense villous coat, much thicker than in P. tetraodon,
and there are a few tufts of longer club-shaped hairs inter-
spersed, with which also the base of the rostrum and that
of the antennae are furnished.

This species is exceedingly liable to the growth of foreign
substances upon the surface, to which the dense villous
covering affords a very ready and firm attachment. I have
a specimen in my collection the form of which is almost
completely concealed by a mass of sponge which has grown
on its back.

Dr. Leach states that it was first noticed by Mr. Gibbs,
who was employed as a collector by Montagu. It was
described and figured by the latter indefatigable naturalist,

GIBBS S SPIDER-CRAB. Z9

in the eleventh volume of the "Transactions of the Linnean
Society," under the name of Cancer Uaculeatus ; and Dr.
Leach afterwards assigned to it its present name after the
discoverer.

According to the same authority it is not an uncommon
species on the southern coast of Devon and Cornwall. In
the latter county Mr. Couch says it is not uncommon, oc-
curring at various depths, from two to twenty fathoms. I
have obtained it at Hastings ; where Mr. Hailstone also
mentions its frequent occurrence ; and Dr. Milne Edwards
mentions it as an inhabitant of the French coast.

It is generally found in deep water, and is taken either
by the trawl net, or by dredging. It spawns in December,
according to the observation of Mr. Hailstone.

DEC A POD A.

BRACHYURA.

WAI ADM.

GENUS HYAS, LEA.II.

CANCER,

MAIA,

INACHUS,

PISA,

HYAS,

Herbst.

Bosc.

Fabricius.

Latr.

Loach, Edwards.

Generic character. — External antennce with the basal portion
slightly narrowed forwards, and separated from the outer portion
of the orbit by a notch ; the second joint dilated externally, longer
than the third. External pedipalps with the third joint notched
at the internal apex. The first pair of legs thicker than the rest,
shorter than the second pair, and equal ; the fingers tapering to
the point, and when closed, meeting throughout nearly their whole
length. The remaining pairs of legs simple, slender, long, almost
cylindrical ; the terminal joint without spines beneath. Carapace
tuberculous, elongate- subtriangular, much rounder at the posterior
margin ; rostrum of moderate length, triangular, depressed ; the
laciniae somewhat converging. The lateral margin with a strong
spear-shaped process immediately behind the orbit. Eyes capable
of being deflexed within the orbits. Abdomen seven-jointed in
both sexes; the terminal joint in the male is transversely oval,
and the corresponding margin of the penultimate joint is broadly
emarginate to receive it.

This genus bears considerable relation to Pisa, from
which it differs, amongst other characters, in the dilated
form of the second joint of the antennae, and the absence of
spines beneath the last joint of the legs.

11YAS AKANEUS.

31

DEC APOD A.
BRACHYUn.l.

MATADM.

Hyas araneus.

Specific cliaracter. — Carapace not contracted behind the post-orbitar hastiform
process.

Cancer araneus,

„ Bufo,
Tnachus araneus,

Hyas

LINN. Syst. Nat. I. 1044.
HERUST, I. t. xvii. f. 59. p. 342.
FABR. Ent. Syst. Suppl. 356.
LEACH, Edinb. Encycl. VII. 394.

Id. 1. c. p. 431. Id. Malac. Brit. t. xxi. A. EDW. Hist.
Crust. I. p. 312. COUCH, Cornish Fauna, p. 66.

THIS is the largest British species of the family with the
exception of Maia Squinado. The carapace is of an elongate-
triangular form, the posterior margin very much rounded,
and the anterior portion considerably narrowed. The ros-
trum is triangular, its two lacinise nearly parallel at their

MATAD.E.

inner edge, converging at the points, somewhat flattened
above, and slightly hollowed beneath. The external an-
tennse are remarkable in this, as in the other species of tlio
genus, for the dilated form of the external margin of the
second joint, which is also considerably longer than the
succeeding one ; the peduncle is nearly as long as the ros-
trum. The eyes are but little larger than the footstalk, and
capable of being retracted within the orbit, which is large
and open, arched above, and protected posteriorly by a
strong hastate process. There are no spines on any part
of the body or limbs ; but the carapace is covered with
low tubercles of various sizes. Of the external pedipalps
the second joint is quadrate, slightly produced at the an-
terior and inner angle ; the third joint of an irregular
form, and somewhat notched at the inner apex for the
articulation of the terminal portion. The abdomen of the
male is of a very peculiar form. The third joint is the
broadest, the fifth and sixth nearly equal, and the latter
excavated in its distal margin to receive the seventh joint,
which is transversely oval, or rather remform, being broad-
ly emarginate at the terminal margin. The abdomen of
the female is broadly oval, and has a broad tuberculated
carina, which is also the case with that of the male.
The body and limbs are partially covered with a villous
coat.

The dimensions of a fine male are as follows :

Length of the carapace

Breadth of do.

Length of the anterior legs

In.
3

2
5

Lines.
6
6
3

1 This species," says Dr. Leach, " is very common on
the coasts of Scotland and Kent. On the shores of Devon-
<liin« it is of rare occurrence." I have received it from

HYAS ABANEUS. 33

Worthing in Sussex, and from the coast of North Wales,
through the kindness, respectively, of my friends Mr.
Dixon and Mr. Eyton. I have obtained it at Hastings,
where it occurs in considerable abundance ; and dredged
it on oyster-beds at Sandgate, of large size, at from ten to
twelve fathoms.

The following particulars respecting the occurrence of
this species on different parts of the coast of Ireland, are
very interesting, and are taken from the Catalogue of Irish
Crustacea, by my friend Mr. W. Thompson.

" Mr. Templeton has noticed this species as taken at
Carrickfergus ; and native specimens are in Mr. J. V.
Thompson's collection. It has been obtained at Youghall
and Dublin by Mr. R. Ball. We take it by dredging in
the loughs of Strangford and Belfast, where, too, it is com-
monly thrown ashore. In the estuary, at little more than
half a mile from Belfast, a number of large specimens of
this Crab were captured in the month of October 1839, on
the hooks attached to hand lines, much to the surprise of
the fishermen, who had never met with them so near the
town before, or in brackish water. The lug-worm (Lum-
bricus marinus) was the bait attacked in this instance by
the Crabs. Hyas araneus was taken in the dredge at Bun-
doran, on the western coast, by our party in July 1840,
and very small living specimens were found under stones,
between tide-marks at Lahinch, on the coast of Clare.
In Mr. Hyndman's cabinet are two Crabs of this species,
with oysters attached to their backs. The oyster (Ostrea
edulis) on the larger Crab is three inches in length, and
five or six years old, and is covered with many large
Balani. The ' shell,1 or carapace of the Crab is but two
inches and a quarter in length, and hence it must, Atlas-
like, have borne a world of weight upon its shoulders.

D

34

MAIADJE.

The presence of this oyster affords interesting evidence that
the Hyas lived several years after attaining its full growth.
Both crahs and oysters, though dead, were brought to Mr.
Hyndman in a fresh state. The hairs on the body and
legs of specimens in my collection are longer in the small
than in the large individual. On the north-east coast of
Ireland, the H. araneus is very much preyed on by the
codfish.

" In January 1840, I saw specimens of this Crab of very
large size on the coast near Edinburgh ; the carapace of
one which I measured was three inches in length, and the
extent from the extremities of the first pair of legs eleven
inches."

Mr. Hailstone states that this Crab spawns in February :
this, however, cannot be universally the case, as I took
several females at Sandgate early in May, in the year
1843, every one of which was carrying her load of spawn,
which is of a rich deep orange colour.

HYAS COARCTATUS.

35

DECAPOD A.

BRACHYURA.

MAIADJE.

Hyas coarctatus. Leach.

-fie diaracler. — Carapace distinctly contracted immediately behind the post-
orbitar process.

Hyas axirctutua, LEACH, Trans. Linn. Soc. XI. p. 329. Id. Malac. Brit. t.

xxi. B. EDW. Hist. Crust. I. p. 312. COUCH, Cornish
Fauna, p. 66.

Tins is a small and elegant species, differing so much in
the contour of the shell from Hyas araneus, as to be dis-
tinguished at a glance from that species, although agreeing
with it in almost all the essential characters. The carapace
is very broad anteriorly, and suddenly contracted at the
sides, both of which characters arise from the extraordinary
breadth of the post-orbitar processes, which are half lyre-
shaped and lamelliform. The rostrum is bifid, triangular,
and each lacinia has a series of minute tubercles along the
middle. The whole carapace is tuberculated. The an-
tennae, the eyes, the orbits, and the pedipalps, are very

D 2

36

MAIADJE.

similar to those of the former species. The first pair of
legs in the male are fully half as long again as the body ;
those of the female, which are slender, about the length
of the body ; the arms, wrists, and hands are tuberculo-
caririated. The remaining legs are slender, shorter and
smaller in proportion, than in H. araneus ; the third joint
with a line of small tubercles above. The abdomen re-
sembles in each sex that of the former species. The colour
of the carapace and legs above is reddish-white, the tu-
bercles a beautiful pink or rose-colour ; the under parts
dirty white. The dimensions of a fine male taken at Sand-
gate by myself, are as follow :

Length of Carapace

Breadth of do.

Length of first pair of legs

In. Lines.
1 3

9
1 9

It is remarkable that in Dr. Leach's plate of this species
the figure of the male is very much smaller than that of
the female. In the specimens which I have taken, the
contrary has been generally the rule, and the males have
been much larger than those figured by him.

This species was discovered by Dr. Leach in the Frith
of Forth, and afterwards found by him on the southern
coast of Devon. I procured it at Hastings. Mr. Eyton
sent it to me from the coast of North Wales ; Mr. Couch
from Cornwall, and Mr. Dixon from Worthing. Dr.
Leach mentions Sandgate as a particular habitat, where
I also obtained several specimens by dredging, in May.
I have received it through the kindness of Mrs. Tate from
Zetland, and from Orkney by Dr. Pollexfen and Dr. Du-
guid. As an Irish species, it has occurred at Youghall,
in Dalkey Sound near Dublin ; in the loughs of Strangford
and Belfast, and at the Giant's Causeway. " Thus," says

HYAS COARCTATL's-. 37

Mr. Thompson, " from the North to the South of Ireland
this species prevails." This extensive range authorises me
to consider it as even more generally distributed on our
coasts than H. araneus. In the young state it is very
difficult to distinguish the two species, as the former has,
in its early age, the spreading form of the post-orbitar pro-
cesses which distinguishes the present species in its perfect
adult condition, and which is gradually lost by the other.
It is said by Mr. Hailstone to spawn in January. Amongst
those which I obtained at Sandgate in the month of May,
were several females, all without spawn.

Mr. Hailstone described in the eighth volume of Lou-
don's Magazine of Natural History, what he considered to
be a distinct species, under the name of Hyas serratus.
There can be no doubt that these were very young speci-
mens of the present species, as was suggested by Mr.
Westwood in some observations on Mr. Hailstone's com-
munication. There were three specimens, which Mr. H.
states were all males ; but as the largest was only a quar-
ter of an inch long, it would be impossible at so early
a period to distinguish the male from the female by the
abdomen.

DEC A POD A.

BRACHYURA.

GENUS MAIA, LAM.

CANCER, Herbst.

INACHUS, Fabr.

MAIA, Lam. Leach, Edwards.

Generic character. — External antennae with the basal portion
very broad, forming a considerable part of the inferior boundary of
the orbit, furnished with two strong spines, the outer one directed
outwards and forwards, the inner curved downwards ; the move-
able portion inserted at the outer and upper angle of the basal por-
tion, where it fills the inner canthus of the orbit. Internal an-
tennce placed in triangular fossae, between the anterior extremity of
which is a strong spine, exactly similar to the inferior spine of the
basal joint of the external antennae, and ranging with them. Eyes
not thicker than their peduncles, which are elongated and slightly
curved. Orbits deep, oval ; their upper boundary, which is arched,
having two fissures. Carapace ovate-subtriangular, convex, cover-
ed with numerous spines or tubercles. Rostrum very strong, bifur-
cate, the horns somewhat divaricate. Anterior legs elongated,
thicker than the others in the adult male, but much smaller in
younger age, and in the female ; the hands and wrists long, the
fingers tapering and pointed, and scarcely toothed. Legs of the
remaining pairs elongate, cylindrical, the terminal joint naked
at the extremity, and without spines beneath. Abdomen seven-
jointed in both sexes.

SPINOUS SPIDER-CRAB.

39

DEC A POD A.

BRACHYURA.

MAIADJE.

SPINOUS SPIDEK.CBAB.

CORWICH.

Maia squinado.

Specific character. — Carapace convex, covered with sharp spines.

Cancer Squinado, HERBST, I. t. xiv. f. 84-85, (jun.) Id. III. t. Ivi.

(adult.)

„ Maia, SOWERB. Brit. Misc. t. xxxix.

Maia Squinado., LATR. Hist. Nat. des Crust. VI. p. 93. Bosc, Hist.

Nat. des Crust. I. p. 257. LEACH, Trans. Linn. Soc.

XI. p. 326. Id. Malac. Brit. t. xviii. EDW. Hist.

Crust. I. p. 327.

THE carapace of this species of Maia is considerably con-
vex, of an ovoid form, but becoming more triangular in
adult age, by the increased narrowing of its anterior por-
tion. The rostrum is strong and prominent, its two horns

MAIADJi.

somewhat diverging, so as to leave a triangular space be-
tween them. The orbit has a strong spine above its outer
angle, and a smaller one at the base of the former; its
superior boundary is arched and rounded. The lateral
margin has five or six very strong sharp spines, the an-
terior of which bounds the outer angle of the orbit. The
upper surface of the carapace is covered with innumerable
spines and tubercles. The under surface of the anterior
portion is furnished with five strong spines, two on each
side on the basal joint of the external antennae, the outer
one directed forwards and outwards, the other curved
downwards, and a single one at the root of the rostrum,
likewise curved downwards. The second and third joints
of the antennae of nearly equal length, and inserted at the
outer angle of the basal joint. Anterior pair of legs in the
adult male nearly twice as long as the carapace, much larger
than the succeeding ones ; the arm and wrist tuberculated ;
the hand scabrous ; the fingers very taper, pointed, the
moveable one slightly curved, scarcely denticulated. The
remaining legs cylindrical, without spines or tubercles ; the
second pair nearly half as long again as the carapace, the
rest diminishing regularly to the fifth ; the last joint very
slightly curved, its extremity naked, abruptly smaller, and
pointed. The abdomen is in each sex seven-jointed. In
the male, the second joint is very narrow at the insertion
of the last pair of legs, the anterior part of it becoming
abruptly much wider ; the sides of the remainder are
nearly parallel, becoming, however, a little narrower, and
the terminal margin is rounded. It has a broad carina
occupying one- third of its breadth. In the female it is
oval.

There are few species of Crustacea in the form of which
age produces so great a change as in this. The younger in-

SPINOUS SPIDER-CRAB. 41

dividual* not only exhibit the more slender and shorter
dimensions of the anterior legs, but the anterior part of the
carapace is much broader in proportion ; a character which
permanently belongs to the Mediterranean species, M. ver-
rucosa.

Pennant's figure of what he terms Cancer mala belongs
to Lithodes arctica, and it is very probable that he, as well
as other*, ha* confounded these two species, before the true
characters of Crustacea were understood, and indeed before
naturalists in general were aware of the value of specific
characters.

There is a species found in the Mediterranean very
nearly allied to this, and which has been supposed to in-
habit our southern coast. It is the Maia verrucosa of
Edwards already alluded to : it is readily distinguished
from this by the absence of spines on the surface, which
are replaced by tubercles ; by the greater extent and de-
velopment of the supra-orbitar arch ; by the breadth of
the anterior portion of the carapace, which remains to the
adult age as broad as in the younger state ; and by the
depressed form of the carapace. I believe M. verrucosa has
not been taken on our shores ; those found in Cornwall,
and considered as such by Mr. Couch, being undoubtedly
the present species.

This Crab is found in great abundance on almost all
parts of our southern and western coast. In Ireland it
occurs also on the southern coast. It is by far the largest
species of the family, and with the exception of the great
Crab, Cancer pagurus, the largest of the British Brachyura.
I have a specimen taken in Plymouth Sound, the carapace
of which is eight inches in length, and nearly six in
breadth, and the length of the anterior feet is fifteen
inches.

MAIADJE.

It is eaten by the poorer classes, though I understand it
is but indifferent food. Like all the other triangular Crus-
tacea, the fishermen inveterately term it " spider ;" and
they appear to have very little idea of any affinity between
these forms, and the Crabs properly so called. I remem-
ber some years since seeing in one of the back streets of
Poole, near the water-side, a little girl standing by a small
table, on which was a plate containing two of these Crabs,
of moderate size, cooked and for sale. On my accosting
her with " Pray do they eat these crabs here ?" She re-
plied with a look of great surprise at my ignorance, " They
ben't crabs, sir, themes spiders ! "

Mr. Richard Couch informs me that in Cornwall several
dozens of " the Corwich " are sold for sixpence, but that
they are more frequently given away to those who ask
for them. Mr. Couch adds, that he never saw a soft one,
or one soon after casting its shell, although they are often
taken "peel," or ready to cast it. This, doubtless, arises
from the extreme secrecy of their retreats when undergoing
this process.

The following account, for which I am indebted to the
gentleman just mentioned, is very interesting, and it affords
another opportunity of confirming the true metamorphosis
of the decapodous Crustacea. " This is the most abundant
of all the Crabs found on our coast, but it does not make
its appearance so early in the season as the Common Crab,
the Lobster, or indeed any other ; it is rarely found earlier
than May, but from that time till the end of the fishery
in August or September, these Crabs make their appear-
ance in vast numbers, to the great vexation of the fisher-
men; for it is found that from the time these begin to
enter the pots, the more valuable kinds considerably de-
crease in number ; and this is supposed to arise from their

SPINOUS SPIDER-CRAB. 43

restless activity. No sooner are they in the crab-pot, than
they are continually in motion, scrambling from one part
to another, and in this way frighten the Crab and Lobster,
and prevent them from entering. In the spring and early
part of the summer they lie concealed beneath the sand,
in deep water. About May they leave their places of con-
cealment, but never come into shallow water, as does the
Common Crab ; the latter is often found in crevices of rock,
or beneath stones left by the receding tide ; but this is
never the case with the Corwich. They shed their spawn
about August or September, at some short distance from
the shore, most probably in the sands. In this, too, they
differ from the Common Crab, for even when the spawn is
quite mature for " casting," they enter the pots as readily
as at any other time ; whilst on the other hand it is a very
rare occurrence to catch the Common Crab with spawn,
unless it be with a dredge-net. It would seem either that
they grow very fast, or that the young differ considerably
in their habits from the larger ones ; for whilst it is very
common to find specimens measuring nine or ten inches in
the length of the carapace, it is very rare indeed to get one
less than three inches ; and a fisherman tells me that after
many years1 fishing he caught one about the size of a half-
crown, which was the smallest he ever saw.

"The ova, when quite ready for shedding, (fig. 1,) are
about the size of a very small mustard-seed, and of a
reddish-brown colour, besprinkled with small dark spots.
After keeping them suspended in sea-water for twenty-four
hours, some of the ova dropped from their attachments,
and soon after the young escaped, and this evidently by
their own exertions, as distinct motions were easily ob-
servable under the microscope while they were yet en-
closed. When they first escape, they are, as it were, rolled

AJAIAD^E.

on themselves, (fig. 2,) the caudal extremity being bent on
the body ; but this is soon changed for the position re-
presented in fig. 3. I could detect no spine on the anterior
part of the carapace, which was quite smooth, but marked
with dots. The eyes are sessile and large ; the claws,
particularly towards the extremity, covered with minute
hairs."

These interesting observations of Mr. Richard Couch af-
ford a fresh confirmation of the truth of the metamorphosis
of the brachyurous Crustacea, and it is to be hoped that
whenever an opportunity occurs to any observer to pre-
serve and examine the embryo, and the subsequent pro-
gress towards the perfect state of any other species, similar
notes may be made, and thus we shall hereafter arrive at
a knowledge of this curious process in most of our native
species.

An ordinary sized Corwich, as Mr. Couch informs me,
bears at one time upwards of seventy-six thousand eggs.

RC.

DEC A POD A. PARTHEXOPIDM.

BRACHTURA.

GENUS EURYNOME, LEACH.

CANCER, Pennant.

EURYNOME, Leach, Risso, Edwards.

Generic character. — External antenna; scarcely longer than the
rostrum ; the basal joint triangular, and perfectly united to the
surrounding parts ; the second inserted at its apex, at the inner
canthus of the orbit, and beneath the rostrum ; second joint larger,
but shorter than the third. External pedipalpa with the third
joint dilated at the outer and emarginate at the inner angle. An-
tcr'nir jK.iir of legs in the male, larger and much longer than the
succeeding ones ; hands long, linear ; fingers inflected. The second
to the fifth pairs of legs linear, diminishing regularly in length.
Carapace irregularly rhomboidal, produced anteriorly, and much
rounded behind, verrucose. Rostrum bifid, the Iacinia3 triangular,
flattened, slightly divaricate. Orbits deep, above strongly arched,
with a single fissure near the external angle. Eyes retractile,
globular, larger than the peduncles,, which are short. Abdomen
seven-jointed in both sexes.

This genus is the only British representative of a highly
interesting and curious, as well as natural family, agreeing
nearly with the genus Parthenope of Fabricius, and com-
prising a number of bizarre forms, which have for the most
part very long arms and rough, rocky-looking bodies. They
form upon the whole, as Milne Edwards has observed, a
passage from the triangular families, to the more typical
CANCERID^E ; and, like many other small osculant or inter-
mediate groups, exhibit many diverse and somewrhat isolat-
ed forms. Of these the present genus, Eurynome, may be
considered as the most nearly related to the MAIAD^E, with
which family it agrees in the union of the basal joint of
the external antennae with the parts surrounding it, as well
as in the general form of the body.

46

PARTHENOPIDJ3.

DEC A POD A.

BRACHYURA.

Eurynome aspera. Leach.

Specific character. — Rostrum less than one-fourth the total length of the body.
Carapace covered with numerous small warty tubercles, regularly disposed.

Cancer aspcr,
Eurynome aspera,

„ spinosa,

PENNANT, Brit. Zool. IV. t. x. f. 3. p. 13.

LEACH, Malac. Brit. t. xvii. EDW. Hist. Crust. I. p.

351.
HAILSTONE in Mag. Nat. Hist. VIII. p. 549.

THE carapace of this very pretty Crab is irregularly rhom-
boidal, the anterior triangle being longer than the posterior,
which latter is somewhat rounded ; the rostrum is less than
one-fourth the whole length of the carapace, bifurcate, the
lacinise somewhat divergent, acute, and flattened. There
is a large triangular laminar tooth at the outer angle of the
orbit, and there are three smaller ones at the lateral mar-
gin of the branchial region. The carapace is covered with
numerous small, round, warty tubercles, which, on a close
examination, are found to be distributed with perfect regu-
larity. The most conspicuous of these are two on each

EURYNOME ASPERA. 47

branchial region, and one on the centre of the cardiac.
The latter, which is smooth and polished, is surrounded by
ten others, which are warty, arranged in an oval form, five
on each side. The external antennae are not longer than
the rostrum. The basal joint, as in the Maiada, is sol-
dered to the surrounding parts ; in which respect it differs
from that of some other genera of the family in which it
is detached ; it is triangular, and the moveable portion is
inserted at its apex, and does not extend beyond the ros-
trum. The second and third joints are oval, and nearly
equal. The external pt-di palps have the second joint
oblong-quadrate ; the third has the outer angle produced,
and the inner angle truncate and emarginatc. The an-
terior legs in the male are nearly twice as long as the body,
and much larger than the succeeding ones, the arms and
hands long, the wrists short, the fingers long and inflected.
In the female they are but little larger, and scarcely
longer than the second pair. The whole are covered
with tubercles. The abdomen in the male is tubercu-
lated and carinated ; the terminal joint triangular. In
the female it is oval, carinated, and the margin broadly
ciliated.

The length of a very fine male specimen is about nine
lines, and its breadth seven lines. Its colour is a light
rose, intermixed with a slight tint of blueish-grey.

The Eurynome aspem, which is one of the rarer of the
British Crustacea, inhabits deep water, having been dredged
in seventy fathoms. It has been taken by dredging, or by
the trawl on the coasts of Cornwall, Devonshire, Dorsetshire,
and Sussex. I find by my own notes that I took a speci-
men in Swanage Bay, in Dorsetshire, some years since, but
it has been lost. It has also been dredged off the Isle of
Man, and in Loch Fyne, by Mr. McAndrew, to whom I

48

PARTHENOPID.*:.

am indebted for specimens from both localities. I have
been favoured with another specimen, also a female, and
loaded with spawn, by Mrs. Griffiths, who took it at Tor-
quay. I cannot doubt that Eu. spinosa of Mr. Hailstone,
described in the eighth volume of the Magazine of Natural
History, is the young of the present species ; it was taken
at Hastings " in a mass of Filipora filigmna"

The following account of its occurrence as an Irish spe-
cies, is taken from Mr, W. Thompson's Catalogue of the
Crustacea of Ireland. " Marked as Irish in Mr. J. V.
Thompson's collection. It is rather a rare species, and an
inhabitant of deep water." In Strangford Lough several
specimens were taken by Mr. Thompson and Mr. Hynd-
man. It has occurred in Belfast Bay, on. the Dublin coast,
and at Roundstone on the western coast. It was obtained
also by Captain Beechey off the Mull of Galloway, at
seventy fathoms. It is found on the coast of France, from
whence I have received specimens through the kindness of
my friend Dr. Milne Edwards.

Being found only in deep water, but little is known of
its habits. The eggs are of a beautiful orange colour; they
are deposited in June, or the early part of July, as I have
a female specimen taken at the latter end of June, in which
the eggs are so fully developed, that the embryo can be
seen through the investing membranes.

When Dr. Leach established this genus, the present was
the only species known. Risso has, however, since that,
described another species, to which he gave the name Eu.
scutellata,* but so imperfect is the description, that Dr. Milne
Edwards found it impossible to judge, with any degree of
certainty, whether it belonged to this genus or not ; and if
so, whether it might not be identical with the present. I

* Risso, Hist. Nat. de 1'Eur. Merid., IV. p. 21.

EURYNOME ASPERA. 49

possess, however, a pair of this beautiful little species from
the Bay of Naples, and find it to be very distinct from ours
in several points, yet bearing a near affinity to it. As a
sufficient distinctive character of it has not yet been given,
for that of Risso is altogether useless, I thought it desirable
to notice it on the present occasion. It differs from the
English species by its longer rostrum, which equals one-
third of the total length, and by the absence of the scat-
tered tubercles by which that is distinguished, instead of
which there are several broad, flat, shield-like elevations.
Risso had not seen the female, of which sex I have a
specimen loaded with eggs of a deep amber colour.

My friend Professor Forbes dredged Eu. aspera at a
depth of thirty fathoms off the Isle of Man, and at seventy
fathoms in the ^Egcan. This evidently shows that the
genus belongs to deep water, an observation which holds
good of all the family of the Partfonopida.

DEC A POD A.

BRACHYVRA.

CANCERIDIE.

GENUS XANTHO, LKA.H

CANCER, Montagu, Ilerbst.
XANTHO, Leach, Edwards.

Generic Character. — External antenna very short, the basal
joint longer than it is broad, in contact with the front only at its
anterior internal angle ; the moveable portion inserted at the inner
canthus of the orbit ; the second joint considerably larger than the
succeeding ones. Internal antennae placed obliquely immediately
under the front. External pedipalps with the third joint quad-
rate, the inner anterior angle truncate and slightly emarginate.
Carapace very broad, slightly convex from before backwards ; the
latero-anterior margins with the front forming a semi-ellipsis ; the
latero-posterior margin nearly straight ; front projecting, divided by
a slight fissure ; orbits, with a fissure beneath, at the external
angle. Anterior legs very large, nearly equal, the fingers pointed.
The posterior pairs short, compressed ; the terminal joint very
short. Abdomen, in the male, five-jointed ; in the female, seven-
jointed.

XAXTHO FLORIDA.

51

DEC A POD A.

BRACHYURA.

CANCERIDJE.

Xantlio florida. Leach .

Specific character. — Carapace deflexed anteriorly ; latero-anterior margin with
four strong obtusely triangular teeth ; fingers black, without grooves ; the second
to the fifth pairs of legs with the third joint only ciliated on the upper edge.

Cancer floridus, MONTAGU, Trans. Linn. Soc. IX. t. ii. f. 1. p. 85.

„ incisus, LEACH, Edinb. Encycl. VII. p. 391.

Xantho iticita, Id. 1. c. p. 430.

„ fiorida, Id. Trans. Linn. Soc. XI. p. 320. Malac. Brit. t. xi.

„ floridus, EDWARDS, Hist. Crust. I. p. 394.

THE carapace of Xantlio florida is about two-thirds as
long as it is broad ; the anterior portion somewhat de-
flexed ; the latero anterior margin with four strong ob-
tusely triangular teeth, and reaching nearly as far back as

E 2

52

CANCERIDJE.

the anterior part of the cardiac region. The surface of
the anterior portion has several broad flattened elevations,
which are separated by grooves, the principal of which are
continuous with the intervals between the lateral teeth ;
the posterior portion nearly smooth. The front is very
slightly waved, and sub-emarginate. Orbit with a fissure
at the inner angle beneath. The anterior legs very large
and strong ; the wrist with a double tubercle above ; the
hand rugous, the fingers without grooves. The remaining
legs short, slightly compressed, the third joint only hairy
on the upper edge, the fourth and fifth joints grooved.
Abdomen in the male five jointed, in the female seven
jointed ; oval, ciliated with long hairs. The colour of this
species is a reddish brown, the claws black.

The male is much larger than the female, and his claws
are very large in proportion to the size of the body. A
full-sized male is more than an inch and a half long, and
nearly two inches and a half broad ; and the anterior legs
of such an individual are nearly four inches long, and the
hand is three-quarters of an inch broad.

This species formed the type of a new genus established
by Dr. Leach, and was at that time the only one known
to him. Since that time, however, many others, some
before known and placed in other genera, and some since
discovered, have been ascertained to belong to it, so that it
now consists of between twenty and thirty species, inhabit-
ing every quarter of the world. Until lately, however, it
has been considered our only indigenous species. It was
first described by Montagu in the " Transactions of the
Linnsean Society," under the name of Cancer floridus ; but,
as Dr. Leach very truly says, he must have been misled in
supposing it to be identical with Linnaeus'1 s species of the
same name. The Cancer floridus of Herbst, which Mon-

XANTHO FLORIDA. 53

tagu quotes also as a synonyme of this species, is a charac-
teristic figure of Zozymus <zneus.

It is found in considerable numbers on the coast of Corn-
wall and Devonshire, and also in Dorsetshire. It has been
observed on several parts of the coast of Ireland. The
female produces a large quantity of eggs, which are of a
reddish brown colour. Of its peculiar habits nothing is
known.

CANCERIDJS.

DEC A POD A.
BRACHYURA.

Xaniho rivulosa.

Specific character. — Carapace nearly horizontal ; latero-anterior margin with
four triangular teeth ; fingers brown, the moveable one grooved above ; the second
to the fifth pairs of legs with all the joints ciliated on the upper edge.

Cancer hydrophttus,
Xaniho florida, var. j8,
„ rivulosus.

HERBST, I. t. xxi. f. 124. p. 266.
LEACH, Trans. Linn. Soc. XI. p. 320.
EDWARDS, Hist. Crust. I. p. 394. Roux, Crust.
Mediterr. t, xxxv. COUCH, Cornish Fauna.

THIS species exceedingly resembles X.florida, and has
been doubtless often confounded with it. There are, how-
ever, numerous well marked distinctive characters, as the
following description will show on a comparison with that
of the former.

The carapace is nearly horizontal, the anterior portion

XANTHO RIVULOSA. 55

being very slightly deflexed ; the front nearly straight,
projecting, the margin minutely beaded. The latero-
anterior margin with four triangular teeth, the posterior of
which reaches scarcely beyond the line of the posterior
edge of the gastric region ; the inequalities of the surface
and the intervening grooves, are not very strongly marked.
The anterior legs are large and strong, the wrist bituber-
culated ; the moveable finger has a distinct groove on the
outer side of the upper surface, extending from the joint
nearly to the extremity. The remaining pairs of legs are
compressed, and the upper edge of all the joints ciliated.

The general colour is yellowish, with red markings ; the
fingers brown, sometimes but little darker than the rest of
the shell. The specimens which I have seen have all been
smaller than the full size of X. florida.

It appears, then, that the present species differs from the
former in the following particulars : — the carapace is much
more horizontal, the inequalities of the surface less con-
spicuous, the lateral teeth more angular, the front less de-
flexed, its margin short and prettily beaded, which is not
the case with those specimens of X. florida which I have
examined. But besides these comparative characters by
which the two species may be distinguished, when ex-
amined together, there are others of a positive kind by
which the present animal may be readily detected. The
moveable finger is grooved ; the whole of the joints of the
legs are ciliated on the upper edge, whereas in X. florida
this is the case only with the third joint. The colour of
the pincers in this species is brown, in the other it is quite
black.

There can be no doubt that this is the Cancer hydrophilus
of Herbst. It is figured also by Savigny in the " Crustacea
of Egypt;" it occurs in Eisso^s " Crustacea of the Neigh-

56

CANCERIDJ5.

bourhood of Nice ;" and Edwards says that it inhabits the
western coast of France. In all probability it is identical
with X.florida, " var. (3 digitis concoloribus" of Leach; but
Mr. Couch of Polperro was the first to detect it as an
English species, and to refer it to its proper name ; and it
was also detected by Captain Portlock as an Irish species,
a specimen having been obtained at Portruch, in the coun-
ty of Antrim. I have been favoured by Mr. Couch with
specimens from Cornwall ; I have also received it from
North Wales, through the kindness of my friend Mr. Ey-
ton. Mr. Couch, writing from Polperro says, " Xantlio
rivulosa is common with us, rather more so than X.florida.
It is found concealed under stones at low-water mark ; is
of rather slow habits, and exuviates much in the same
manner as the common crab." There is indeed but little
difference in this respect amongst all the true brachyurous
forms.

DECAPODA. CANCER1DM.

BRACHYURA.

GENUS CANCER.

CANCER, Linn. Leach, Bell.

PLATYCARCINUS, Latr. Edwards.

Generic Character. — External antennae with the basal joint
very long and thick, filling the hiatus between the inner canthus
of the orbit and the front, and terminating forwards in a strong,
angular, tooth-like projection, directed forwards and slightly in-
wards, reaching a little beyond the frontal line ; the terminal por-
tion is very short and slender, and arises from the internal part
of the basal joint, nearer to the cell of the internal antennae than
to the orbit. Internal antennce directed forwards, placed in longi-
tudinal cells. External pedipalps with the third joint excavated
at the anterior and inner margin. Anterior feet nearly equal,
robust ; the others, more or less hairy, but without spines. Cara-
pace transversely elliptic, somewhat elevated, with the regions
obviously marked ; front trifid ; orbits with a strong tooth over
the inner canthus ; and with two fissures above, and one be-
neath : the latero-anterior margin on each side extends back to
the centre of the cardiac region, and passes off into a sinuous,
granulated ridge, which rises over the latero-posterior margin ;
it is divided into ten lobes, of which the last is very small, and
often obsolete. Eyes placed on short peduncles. Abdomen, in
the male, five-jointed ; in the female, seven-jointed.

This genus is readily distinguished from its immediate
congeners by the form of the basal portion of the external
antennae, by the direction of the internal antennae, and by
the form of the latero-anterior margin of the carapace,
which is, in this genus, uniformly ten-toothed. There is

58

CANCERID^E.

but one species of this genus, as now restricted, native of
the shores of this country, or indeed of Europe, all the
others being South American.

The generic name Cancer was applied by Dr. Leach to
this, the present genus, as restricted by him ; and I have
elsewhere* stated my reasons for restoring it, after La-
treille had, in the French Museum, assigned to it the name
of Platycarcinus, in which he had been followed by Dr.
Milne Edwards. When the characters of the present
genus were first defined, the only known species was the
common large eatable crab of our coasts, the Cancer Pa-
gurus of Linnaeus. Subsequently another species was added
by Say, and since that three others by myself, from the
South American collection of Mr. Cuming. The whole
of these are described in a monograph of the genus just
referred to.

* " Transactions of the Zoological Society," 70! . i. p. 335.

GREAT CRAB.

59

DECAPODA.

BRACHYURA.

CANCERIU^E.

GREAT CRAB.

Cancer Paguriis. Auct.

Specific cluiructer. — Shell ^mnulated ; latero-anterior margin ten-lobed, the lobe*
i tnitiguous, quadrate, entire ; hands smooth.

Payurus,

Platycarcinus

.Tun. Cancer inciso-crenatus,

LINN. Syst. Nat. XII. i. 1044. HKRBST, Krab.

t. ix. f. 59. PENN. Brit. Zool. IV. t. iii. f. 7.

LEACH, Malac. Brit. t. x. BELL, Trans. Zool.

Soc. I. p. 341.

EDWARDS, Hist. Crust, i. p. 413
COUCH, Cornish Fauna, p. 70.

THE carapace is transversely oblong, flattened, slightly
elevated in the middle, somewhat rounded before and be-
hind ; the surface minutely granulated, smooth, with the
regions but slightly marked. The latero-anterior margin
is slightly recurved, divided into ten quadrate lobes, the
sides of which are contiguous, and the margins entire ;

60

CANCERID^E.

the last lobe inconspicuous, and passing into the posterior
marginal line, which terminates immediately anterior to
the posterior marginal ridge. The front trifid, the teeth
nearly equal. The orbits are round, with a strong trian-
gular tooth over the inner canthus, which does not project
as far as the front, and a smaller one between the two
superior fissures. The external antennae have the basal
joint much elongated, and terminating forwards in an ob-
tuse tooth ; the first joint of the moveable portion club-
shaped, the second cylindrical. The internal antenna^
stand forwards, the anterior half being folded directly
backwards when at rest. The sternum minutely punc-
tated, and furnished with small patches and lines of short
scanty hair. The abdomen in the male, has the margin
fringed with short hair, and the surface with numerous
small tufts of short stiff hair; the last joint forming an
equilateral triangle : in the female the sixth joint is very
large, the terminal one triangular, the sides slightly sinu-
ated. The anterior pair of feet large, robust, smooth,
without spines or tubercles, minutely granulated ; the hand
rounded, without any ridge ; the fingers with strong round-
ed teeth. The remaining feet slightly compressed, irre-
gularly angular, and furnished with numerous bundles of
stiff hairs.

The colour above reddish brown, in younger individuals
with a purplish tint ; the legs more red ; the claws black ;
beneath nearly white.

There can be little doubt that this species was the one
known to the Romans by the name of carabus, from
whence our common name crab.* Pliny, in enumerating

* The common name of the wild apple has probably no reference to the animal ;
it is, doubtless, as Skinner has it, from schrabfon, A. s., to scrape, to bite, from the
harsh, rough taste of the fruit.

GREAT CRAB. 61

the different kinds of " cancer" says, — " Cancrorum genera
carabi, astaci, maia?, paguri, heracleotici, icones et alia ig-
nobiliora." It would appear by this passage that the term
Cancer was applied to the whole of the Malacostracous
Crustacea ; for not only are the brachyura and some of
the larger macroura evidently here designated, but the
" alia ignobiliora," in all probability, indicated all the
smaller and less important forms.

The habits of this species have been perhaps more
thoroughly investigated, and are better understood than
those of most other species. Its large size, and the ex-
cellence of its flavour, occasion it to be more sought after
as an article of food than any other of the brachyurous
species ; and hence its habits and the places of its resort
have been necessarily much observed by those whose occu-
pation it is to procure it for the market ; whilst the natu-
ralist has found it a convenient species for his more scien-
tific investigations, whether as it regards its history or its
structure.

It inhabits the whole of our coasts, preferring those parts
which are rocky ; and its usual retreats are amongst the
holes in the rocks, where it generally retires when not
engaged in seeking its food. It is often seen in such
situations, even when the tide has retreated sufficiently to
render the rocks accessible, as, for instance, among those
on the shore at Hastings, where I have often seen them
in the pools and caverns, left by the receding tide. These
are, however, always small individuals, rarely more than
three inches in breadth ; the larger ones remain farther at
sea amongst the rocks in deep water ; and they also bury
themselves in the sand, but always in the immediate neigh-
bourhood of the rocks. The food of this species, like that
of most others, consists principally of animal matter, such

62 CANCERID^E.

as dead fish, and the like ; and it is exceedingly probable
that the crabs discover their food rather by the smell than
by sight, or, at least, by an impression made by the dif-
fusion of odorous particles emanating from it, and diffused
through the water. Thus they detect the bait which is
often placed in such situations that it cannot be seen by
them at any distance, and which consists generally of pieces
of fish, in which decomposition has already commenced.
Mr. Couch, indeed, states in his "Cornish Fauna," that " It
is found that the freshest (bait) only will attract the crab,
whilst for the lobster it is best when hung for several days
to become tainted." And this may doubtless be true to
a certain extent ; but I have often seen crabs taken with
lobsters in pots in which the bait was far from being sweet.
The period of life at which the " Bon crab," as the female
of this species is termed along the western coast, begins to
breed is, according to Mr. Couch, when the carapace is
about three inches across. The male seeks the female at
various seasons ; but it would appear that in this, as in
the case of the Carcinus mtcnas, this often takes place im-
mediately after her exuviation, and that the male watches
for the completion of this process, when the female is in
a soft and unprotected state. My friend Mr. Richard
Couch, thus writes to me on this subject. " When the
female retires for exuviation, she is generally accompanied
by a male ; and when the shell is removed impregnation
takes place. If the male be discovered and removed, an-
other will be found to have taken his place after the
following tide, arid this will be repeated for many times in
succession." The spawn is carried by the parent for a
considerable period, and is deposited "at all seasons of
the year," according to Mr. Couch ; Mr. Hailstone says
in March ; but it is most probable that it occurs during

GREAT CRAB. 63

the spring and summer, as is the case with so many other
species.

It was in the month of June, 1826, that Mr. J. V.
Thompson * " had the good fortune to succeed in hatching
the ova of the common crab," and thus, by perfect and
satisfactory observation, demonstrated the theory which
his investigation of Zoea had already suggested to his
mind, of the true metamorphosis of the Crustacea ; a dis-
covery which may rank amongst the most interesting and
important that have been made within the sphere of the
sciences of observation, not only in the present, but in any
previous age. The extreme difficulty of preserving these
little animals alive, and ensuring them a supply of their
proper food, has prevented the observations of their subse-
quent growth from being so satisfactorily carried out as
could have been wished ; but the doctrine thus established
has been confirmed in so many instances by observations
on other species of Crustacea, that the metamorphosis of
these animals may now be considered as a fixed and
incontrovertible truth.

The fishery for these crabs constitutes an important trade
on many parts of the coast. The numbers which are
annually taken are immense ; and as the occupation of
procuring them is principally carried on by persons who
are past the more laborious and dangerous pursuits of
general fishing, it affords a means of subsistence to many
a poor man who, from age or infirmity, would be unable
without it to keep himself and his family from the work-
house. They are taken in what are termed " crab-pots ;"
a sort of wicker trap, made, by preference, of the twigs
of the golden willow, (Salix vitellina,) at least, in many
parts of the coast, on account, as they say, of its great

* See his " Zoological Researches," No. I. p. 9.

CANCERID^E.

durability and toughness. These pots are formed on the
principle of a common wire mouse-trap, but with the en-
trance at the top ; they are baited with pieces of fish,
generally of some otherwise useless kind, and these are
fixed into the pots by means of a skewer. The pots are
sunk by stones attached to the bottom, and the situation
where they are dropped is indicated, and the means of rais-
ing them provided, by a long line fixed to the creel, or pot,
having a piece of cork attached to the free end of the line :
these float the line, and at the same time serve to designate
the owners of the different pots ; one perhaps having three
corks near together, towards the extremity of the line,
and two distant ones ; another may have one cork fastened
cross-wise ; another two fastened together, and so on. It
is of course for their mutual security that the fishermen
abstain from any poaching on their neighbours property ;
and hence we find that stealing from each other's pots is
a crime almost wholly unknown amongst them. It is at
Bognor, and Hastings, and in Studland and Swanage Bays
in Dorsetshire, that I have principally had opportunities of
personal observation on these points ; and I am also in-
debted to my friend Mr. Richard Couch for some interest-
ing observations on this subject ; in addition to which I
would refer to an excellent account of the crab and lobster
fishery, in the 6th volume of the Penny Magazine.

Mr. Richard Couch informs me that on the coast of
Cornwall " most of these crabs are sold to the lobster
smacks ; but, that when brought on shore for sale, those
measuring six inches across the carapace are sold for two-
pence each ; those of eight or ten inches, threepence, and
the largest from sixpence to eightpence ! " If the crabs
are not immediately wanted on being taken out of the
pots, they are placed in store pots, which are of the same

GREAT CRAB. 65

form and materials as the others, but considerably larger.
They are conveyed to great distances, as far, for instance,
as from the coast of Norway to the Billingsgate Market,
in well boxes, which are of wood, very strongly construct-
ed, and with holes in all the sides to admit of continual
change of water, as the boxes are drawn through the sea,
attached to the vessel.

The male Crabs are esteemed the best for the table ;
they are generally larger than the females, and the claws
are much heavier. They often weigh eight or nine pounds,
and sometimes as much as twelve pounds.

Examples are not few of the occurrence of different spe-
cies of Crustacea in armorial bearings. Prawns, Crayfish,
Lobsters, and Crabs, are occasionally found, and these, not
only as "canting" bearings, or puns upon the name of the
bearers, but often as examples of that emblematical allu-
sion in which the heralds of former times so much delight-
ed. This is not, perhaps, the place to enter into much
serious disquisition on the utility of such a custom ; and
yet one can scarcely read the quaint, but wholesome mo-
ralities, of good old Guillim, and other professors of the
gentle science, without some misgivings that the matter-of-
fact and prosaic scorn of such emblems, which has suc-
ceeded to the more poetical — may we not also say the
happier credulity of olden time, may have given us no
equivalent advantage for the loss of those striking and
epigrammatic maxims. I shall venture, therefore, to in-
dulge an old fondness for this ancient, and really not un-
interesting " science," (I do not use the term in its modern
and critical sense,) by giving some occasional examples of
CRUSTACEAN HERALDRY. And in doing this I cannot but
refer to Mr. Moule's " Heraldry of Fish," as a work not
less interesting in its historical and technical details, than

66

CANCERID^E.

tasteful and elegant in its illustration. We will presume,
and it appears extremely probable, that the Heraldic
Crab is the present universally known and useful spe-
cies. Mr. Moule observes, " The Crab, the emblem of
inconstancy, appears on a shield of Francis I., one of
the finest specimens of art in the collection of armour
at Goodrich Court ; and, according to Sir Samuel Mer-
rick, the Crab was intended as an allusion to the ad-
vancing and retrograde movements of the English army at
Boulogne, under the celebrated Charles Brandon, Duke of
Suffolk, in 1523." A golden Crab, according to the same
authority, was one of the cognizances of the Scrope family,
and is found on the portrait of Henry, Lord Scrope. " The
Crab also appears as a crest on the seals of several mem-
bers of this noble family.1'1*

The families of Bridger of Sussex, Crab of Scotland,
Bythesea of Kent, and some others, also bear this ani-
mal in their coat- armour.

* Moule'8 " Heraldry of Fish," p. 231.

U EC APOD A. CANCER1D&.

BRACHYURA.

CANCER, Linn., Pennant, Herbst.

PILU.MMS, Leach, Edwards.

Generic Character. — External antenna long and setaceous ; the
basal joint not continuous with the surrounding parts, but sepa-
rated by a distinct line, and filling the inner canthus of the orbit ;
second joint nearly as broad as it is long, and moveable with the
remaining portion ; third joint longer than the second. Internal
antennce with the last point of the peduncle club-shaped. Exter-
nal pedipalps with the third joint transversely quadrate, the
antero-internal angle emarginate. Anterior pair of feet unequal,
robust, rounded ; the remaining pairs rounded above, flattened
beneath ; the second pair not longer than the third or fourth.
Carapace convex, the anterior part much curved from before
backwards ; the surface even ; the latero-anterior margin extend-
ing backwards as far as the posterior part of the gastric region ;
front slightly prominent ; orbits elliptical, the inferior margin
spinulose. Abdomen, in each sex, seven-jointed ; in the male,
the third joint the broadest, the succeeding ones diminishing regu-
larly to the apex ; in the female, all the joints sub-equal.

68

CANCERIDJ3.

DEC APOD A.

BRACHYURA.

CANCERIDjE

Pilumnus Jiirtellus. Leach.

Specific character. — Superior margin of the orbit not spinous, but, with the
front, minutely denticulated ; latero-anterior margin armed with four spines (ex-
clusive of the external angle of the orbit) ; hands slightly tuberculated.

Cancer hirtellus, LINN. Syst. Nat. I. 1045. PENN. IV. t. vi. f. 1. p. 9.

Pilumnus „ LEACH, Trans. Linn. Soc. XL p. 321 ; Malac. Brit. t. xii.

EDWARDS, Hist. Crust. I. p. 417.

THE carapace is smooth, anteriorly much incurved ; its
length to its breadth, as seven to ten ; the front broad,
finely toothed, divided in the centre by a deep fissure ;
the latero-anterior margin evenly arched, furnished, ex-
clusive of the outer angle of the orbit, with four strong-
sharp spines, the anterior two being frequently bifid ; the
hinder one the strongest, and in a line with the posterior
part of the gastric region. The upper margin of the orbits
very minutely toothed ; the lower margin spinous, and in
each a small fissure. The anterior pair of legs are remark-

PILUMNUS HIRTELLUS. 69

ably strong, thick, and rounded ; they are somewhat un-
equal, in some the right, in others the left being the larger;
the wrist is tuberculated, and furnished with a single spine,
and is slightly hairy ; the smaller hand is tuberculated on
its upper and outer surface, the larger one almost entirely
smooth ; the moveable finger much curved, the fixed one
triangular, and strongly toothed. The remaining legs are
slightly rounded above, flattened beneath ; they are covered
with numerous hairs, and there are also a few on the wrist
and on the anterior part of the carapace, which is also
covered with short down. The abdomen in the male is
broadest at the proximal margin of the third joint, thence
diminishing regularly to the extremity, the third to the
seventh, thus forming a long acute triangle. The abdomen
of the female is of the form of a long ellipse, with the
proximal portion truncate ; its margin is fringed with long
hair. The colour of most individuals is brownish red, with
obscure yellowish spots ; the anterior legs brownish red,
the fingers light brown ; the remaining legs red, with ob-
scure yellowish bands. In many the brownish red colour
is replaced by a dull purple.

In. Lines.

Length of the carapace . . . . .07

Breadth of do. . . . . . 10

The present species is the only one of the genus found on
our coast, and it may be readily distinguished from all the
foreign species by the absence of spines on the superior
margin of the orbit. The figures in Dr. Leach's great
work are very inferior, and would scarcely serve to dis-
tinguish it, were any of the other species indigenous to this
country with which it might be compared. They must
have been taken from immature specimens ; but even of
such they form but very erroneous representations.

70

CANCER1DJ3.

It is a common species on all the western coast of
England, having been taken in Cornwall, and along the
coast of Devonshire, Dorsetshire, Hampshire, and Sussex.
Dr. Leach mentions it being taken under stones at low
tide, but those which I have obtained have been from deep
water. I have dredged them in Swanage Bay, Dorset-
shire ; but the finest specimens I ever saw, I procured from
prawn and lobster pots at Bognor, in September, 1842.
It is worthy of remark, that amongst twenty or thirty
specimens, I found only one female, a dead and mutilated
one. It would appear from Mr. Thompson's Catalogue
to be widely distributed on the coasts of Ireland, although
occurring in small numbers.

The different species of this genus are very widely dis-
tributed. They inhabit the Mediterranean, the Red Sea,
the East Indies, and other parts of the coast of Asia,
Australia, and both the eastern and western coasts of South
America.

DECAPOD A . CA NCEEIDM.

BRACHYUBA.

GENUS PIBIMELA.

CANCER, Montagu.

PIRIMELA, Leach, Desmarert, Edwards.

Generic Character. — External antennae nearly half the length
of the carapace ; the basal joint short, filling a space at the inner
angle of the orbit ; the moveable portion inserted at its inner
canthus. Internal antennae, lying somewhat obliquely in their
cavities, which open immediately under the margin of the front.
External pedipalps extending forwards beyond the oral cavity,
and covering the epistome ; the third joint sub-quadrate, emargin-
ate at the inner margin, about one third from the anterior angle,
for the articulation of the palpes. Anterior legs small, compressed ;
the remaining pairs of moderate length, much compressed ; the
terminal joint nearly straight. Carapace nearly as long as it is
broad, convex, with numerous strongly-marked elevations ; the
anterior margin arched, the posterior much narrowed ; front tri-
dentate, the middle tooth the longest. Orbits, with two fissures
above. Eyes, not thicker than their peduncles, which are very
thick at the base. Abdomen, in the male, five-jointed ; in the
female, seven-jointed.

Of this genus one species only is at present known. It
differs from all the other Cancerida, in the circumstance
that the external pedipalps, instead of being confined to
the opening of the oral cavity, are advanced over the
epistome to the antennary cavities.

In its affinities this genus probably approaches the Por-
tumdce by the genus Carcinm ; possibly Panop&w may be
intermediate between them.

72

CANCERIDJE,

DEC APOD A.
BRACHYURA.

CANCEEIDJE.

Pirimela denticulata.

Cancer denticulatus,
Pirimela, denticulata^

MONTAGU, Trans. Linn. Soc. IX. p. 87. t. ii. f. 2.
LEACH, Malac. Brit. t. iii. EDWARDS, Hist. Crust.
I. p. 424.

THE general form of this pretty Crab will at once strike
us as differing very greatly from all those which have
preceded it. The carapace is very little broader than it
is long ; the anterior margin is so much arched, as to form
nearly a semicircle, whilst the posterior portion is regularly
and greatly narrowed. The latero-anterior margin is
armed with four prominent teeth, which are triangular,
slightly curved forwards and upwards, and flattened. The
front is tridentate ; the two external teeth are triangular,
flattened, curved a little upwards and inwards, and small ;
I have seen specimens in which they are almost obsolete ;
the middle tooth is spiniform, and considerably longer than
the others. The orbit is also furnished with similar teeth,
of which there are two above, the inner one being the
larger ; one beneath, and one at the external angle. The

PIRIMELA DENTICULATA. /O

surface of the carapace is convex, the regions distinctly
marked, and the anterior half has several rounded eleva-
tions, but the hepatic regions are excavated towards the
margin. The anterior pair of legs are of moderate size,
equal ; the wrist has three carinse, each of which termi-
nates in a small tubercle near its articulation ; the hand
has four distinct carinse, two on the upper, and two on
the outer surface ; the moveable finger has two longitu-
dinal grooves ; and both the fingers are moderately and
evenly toothed. The remaining legs are compressed and
ciliated at the edges, particularly the fifth pair. The ab-
domen of the male has five joints, that of the female seven ;
the latter is of a lanceolate form, and furnished at the
margin with numerous long hairs. The usual length of
the carapace in English specimens, is not more than six
lines, and its breadth nearly seven ; but I have in my
collection specimens from the Mediterranean, of which the
carapace is nine-tenths of an inch in length, and an inch in
breadth.

The colour in some specimens is greenish, in others
purplish and brown mottled.

This must be considered as one of the least common
species belonging to our coasts. It was first described by
the indefatigable Montagu, who states that it was sent to
him by Mr. Boys, " as the produce of the coast of Sand-
wich ;" and he adds, "I have seen a specimen in the cabinet
of Mr. Donovan, which I am assured came from the coast
of Scotland." Leach mentions the latter specimen, and
says that he obtained a fragment from the same locality ;
two other places on the south coast of Devon, Bantham
and Torquay, are also named by that celebrated naturalist
as its habitats. Mr. W. Thompson found three specimens
washed ashore at Compton, in the Isle of Wight. The

/4 CANCERID.E.

same gentleman mentions two localities in Ireland where
it has been found, namely, the coast of Antrim, and La-
hinch on the coast of Clare. Of its habits nothing, I
believe, is known. It would appear not to approach the
shore, as the only living examples on record were obtained
from the refuse of trawl-fishers.

DEC APOD A. PORTUNID^E.

BRACHYURA.

GENUS CARCINUS, Lend.

CANCER, Anct.

CARCINUS, Leach, Edwards.

Generic Character. — External antennce lodged in the inner
canthus of the orbit, the basal joint narrow and sub -cylindrical.
Internal antennce lying obliquely in nearly circular cells. Ex-
ternal pedijxdps with the third joint excavated on the anterior
half of the inner margin, and dilated at the outer side. First pair
of feet somewhat unequal, the wrists with a strong spine on the
inner side, standing forwards ; the hands glabrous on the outer
surface; second, third, and fourth pairs slightly compressed, with
the terminal joint long, styliform, somewhat four-sided ; the ffth
pair more compressed, formed for swimming, the terminal joint
lanceolate. Carapace slightly convex, rather broader than it is
long ; the front somewhat projecting, and forming, with the orbits
and the latero-anterior margin, a nearly regular curve, which ex-
tends back to a line drawn through the middle of the genital
region ; latero-anterior margin strongly toothed. Orbits, oval,
directed forwards, very open above, with a single fissure, both
in the superior and inferior margins. Eyes, smaller than their
peduncles. Abdomen, in the male, five-jointed ; in the female,
seven-jointed.

This genus, of which one species only is at present
known, constitutes the nearest approximation amongst the
swimming Crabs, to the cancerida; the osculant genus in
that family which bears a near affinity to this, is Pano-
paus.

76

PORTUNIDJE.

DEC APOD A.

BRACHYURA.

PORTUNIDM.

COMMON SHORE-CRAB. HARBOUR-CRAB.

Carcinus Manas.

Manas,
Portunus „
Carcinus „

PENN. Brit. Zool. IV. p. 3. t. iii. f. 5.
LEACH, Edinb. Encycl. VII. p. 390.

LEACH, Ib. p. 429. Trans. Linn. Soc. XI. p. 314. Malac.
Podophth. Brit. t. v. f. 1—4. EDW. Hist. Crust. I. p. 434.

THE carapace of this common species is rather broader
than it is long, minutely tuberculated, the regions very
distinct and rather prominent. The front is divided into
three lobes, of which the middle one is rather longer
than the others ; they are distinctly margined and slightly
turned upwards ; the orbits very open above, with a single
fissure in the superior, and one in the inferior margin, and
a strong tooth at the outer, and a smaller one at the

COMMON SHORE-CRAB.

77

inner angle. The latero-anterior margin has four strong
flattened triangular teeth, directed forwards ; the second
and fourth more acute than the others. The latero-pos-
terior margin extends backwards in a straight line, and
the posterior margin has a distinct elevated waved border.
The external antennae are placed in a hiatus at the inner
canthus of the orbit, which they do not entirely fill.
The basal joint is rather narrow, and somewhat round.
The internal antennae are lodged rather obliquely in large
open fossae. The anterior pair of feet nearly equal, the
wrist with a strong but not very prominent tooth at the
upper and anterior angle ; the hand smooth externally,
the upper margin with a double longitudinal carina ;
the fingers toothed. The second, third, and fourth pairs
slightly compressed, the terminal joint very long, styliform,
somewhat four-sided ; the fifth pair more compressed, the
terminal joint broader and flatter than in the others, form-
ing an approximation to the more perfectly natatory form
observed in the other genera of the family. The two last
joints of the second pair, and the three last of the fifth
pair, ciliated on the under edge, and the latter also on the
upper edge of all the joints. The abdomen, in the male,
five-jointed, forming a slightly acute triangle from the
base of the third joint ; in the female, it is seven-jointed,
broad, with rounded and ciliated margins, the terminal
joint rather abruptly smaller than the preceding.

The general colour of this species is a blackish green,
darker anteriorly, and often dull red underneath ; they
vary, however, considerably, both in the hue and in the
intensity of the colour. The young are often mottled with
white, and sometimes almost wholly white, with perhaps
a single black spot on the centre of the carapace.

This is the only known species of the genus, and is

7o PORTUNIDJ3.

undoubtedly the most common Crab of our shores. On
every part of the coast, it is found in numbers ; on sandy
beaches it is constantly left by the receding tide, concealing
itself under stones, and on being disturbed, either runs to
regain its natural shelter in the retiring sea, or hastily
buries itself completely in the soft sand. It is, however,
by no means confined to the sandy shores ; it is often
dredged in rather deep water, though its favourite haunt
is in the former situation. Such habits as these require
a power of remaining for a considerable time out of
water, and we find this to be remarkably the case with this
species ; it cannot, it is true, like the land Crabs, live at a
great distance from the sea, requiring only the moisture of
a humid atmosphere, to preserve their branchiae in a state
fit for respiration, but it will remain active for many hours,
and probably for days together, if it have the opportunity
of burying itself in sand which is wetted with sea-water :
differing in this respect from the more typical forms of the
family, which require constant immersion in deep water.
It will even, as Mr. Couch informs me, survive its im-
mersion in fresh water for several hours.

This Crab is much eaten by the poorer classes on the
coast, and great numbers are also brought to the London
markets, the flavour being very delicate and sweet. On
some parts of the coast, a small black variety is found,
which the fishermen consider as a distinct species, distin-
guishing them as the black and the green crab. This variety
is found in deeper water, and is believed to interfere with
the success of their prawning, by either destroying the
prawns, or frightening them away from the pots. It is
certainly merely a variety.

Its food consists principally of the fry of fish, of shrimps,
and other Crustacea, but it will also feed upon dead

COMMON SHORE-CRAB. 79

fish, and almost any other animal substance. Indeed,
the most common method of taking these Crabs at Poole,
where numbers are caught by the fishermen's children, is
by tying a mass of the intestines of either a fowl or of
any fish to a line, and hanging it over the quay : the
Crabs seize upon this bait, and are drawn up in considera-
ble numbers. Mr. Hailstone states, that they attack
mussels, and that he once saw one carrying about on its
hand a mussel which had closed its shell upon it. They
run with considerable rapidity, and with an awkward
sidelong gait ; and they lurk in pools of water left by the
tide, partially concealed in the sand, but with the anterior
part of the carapace, including the eyes, exposed, so as to
watch for the approach of their small living prey, on
which they spring with great activity. They are, however,
very timid and wary, and will not move if they discover
that they are watched. They simulate death, if disturbed,
as completely as do many coleopterous insects.

The process of exuviation takes place at various parts
of the year, from spring to autumn. I have found the fe-
male carrying spawn as early as April, and as late as Sep-
tember.

The eggs continue to increase in size in this and in the
rest of the Portunida, until the abdomen is forced back-
wards to an obtuse angle with the body. Like most of
the Brachyura, this species buries its ova in the sand ;
and c< when they are disengaged," says Mr. Couch, " the
Crab stands high on the points of its legs, and employs a
couple of them, one on each side, in working the loose ten-
drils to which the ova are attached." For the following
interesting account of the development of this species, I
am indebted to the kindness of the same indefatigable ob-
server. " The ova come to life in about forty-eight hours

80

PORTUNIDJ3.

or less. The following are my notes made at the time
of observation on one that bred in captivity : — ' It seems
clear that each ovum has two investing coats, one proper
to it, the other in which it is enclosed as attached to the
parent. The latter has a thread, a portion of which is
seen attached to the ovum after it has been thrown off.
The ovum bursts on the sides opposite to this thread, and
the creature first protrudes the abdominal portion, or that
which is behind the carapace, and which in the ovum had
been bent underneath ; so that it escapes backwards.
In some it appeared as if the caudal extremity protruded
first ; but in most it was the bent portion, and the legs
were in general bent up under the thorax. They seemed,
however, to find great difficulty in throwing off the loose
membrane of the ovum from the thoracic portion or cara-
pace, and almost all failed in doing this effectually, the
development, perhaps, going on too rapidly, in consequence
of exposure to a warm sun. I suppose, that in the na-
tural state this is effected in the sand, by creeping back-
ward, and thereby rubbing it off. The eyes of these young
Crabs, at their first escape from the ovum, are large and
sessile. In one or two instances, I thought I saw antennae
and branchiae, or, at least, their projecting extremities ;
but I could not decidedly distinguish between them and
the legs. The thoracic portion, or carapace, is somewhat
rounded, or at least ovoid. I could see no chela, and sup-
pose them not developed. The common legs seem bifur-
cate at the second joint from the extremity, and ending
in a fine point; or, perhaps, the bifurcation is at the root.
The abdominal and caudal portion is long and narrow, and
also projecting, much resembling the corresponding por*
tion of the Nebalia Herbstii. A considerable change or
metamorphosis, must take place in these creatures before

COMMON SHORE-CRAB. 81

they assume their final form, thus confirming the views of
Mr. J. V. Thompson on this subject ; though these little
Crabs differ much from the figures of the common edible
Crab (Cancer Pagurus), as given by that gentleman."

This detail will be found remarkably consonant with the
brief description of the Zoea of this species, by Mr. H.
Goodsir,* who, however, gives figures of the more ad-
vanced development of the embryo ; and it is very inter-
esting to observe these consentaneous accounts of the in-
teresting fact, from two observers whose investigations were
carried on at a distance from each other, and without any
intercommunication.

It is remarkable that this Crab, unlike the Cancer
Pagurus, is active and pugnacious, both during the pro-
cess of exuviation, and after it is completed ; and although
in some cases it takes place in concealment, and even, as
Mr. Couch observes, whilst buried in the sand, yet they
certainly appear not to require such precaution, as I have
often found them running about both whilst the old crust is
loosening, and in the soft state immediately subsequent to
exuviation ; and it is not uncommon for the males to seek
the females when the latter are in this condition.

* See Jameson's Journal, xxiii. p. 181.

(r

DEC A POD A.

BRACHYURA.

ORTUNIDM.

GENUS PORTUMNUS.

CANCER, (LATIPES), Planci.

CANCER, Pennant, Herbst.

PORTUMNUS, Leach.

PLATYONYCHUS, Latr. Edwards.

Generic Character. — External antennce inserted at the inner
canthus of the orbit, the basal joint small, not united to the front,
moveable. Internal antenna lying obliquely in their fossae, which
are but incompletely separated from the orbits. External pedi-
palps extending forwards to the antennary fossae ; the third joint
elongated, emarginate at the inner margin a little behind the
apex, for the articulation of the palpal portion, which is three-
jointed. Anterior feet sub- compressed, equal ; second, third, and
fourth pairs with the terminal joint compressed, narrow, lanceo-
late, that of the first rather broader ; the fifth pair with the
penultimate joint broad, rounded, and compressed, the terminal
acutely lanceolate, and broader than that of the other pairs. Cara-
pace^ as long as it is broad ; front, narrow, toothed ; latero-
anterior margin arched ; the posterior half of the carapace gradu-
ally narrowed ; posterior margin truncate. Orbits, with the upper
margin evenly concave, and with a single fissure, the inner canthus
open. Eyes, not larger than their footstalks, which are rather
slender and slightly curved. Abdomen, in the male, five-jointed,
the third and fourth joints much longer than they are broad, the
third being the longest ; in the female, seven-jointed, less than
half as broad as it is long, the second, third, and fourth joints
very short, the fifth transversely quadrate, the sixth and seventh
regularly diminishing to the apex.

PORTUMNUS.

83

I have adopted some characters for this genus which
will imply the necessity of separating from it species which
have been included by Edwards in the genus Platyonychus
of Latreille, which is synonymous with Portumnus of
Leach. The general form and habit of a large and very
handsome species, Platyonychus bipustulatus, Edw., must
at once strike even a casual observer as very distinct from
our species, on which Dr. Leach founded his genus ; and
the details of many important organs will offer no less
striking discrepancies. I will now venture to place before
the reader some of these points in a parallel view, pre-
mising that I propose to consider our species as the type
of the genus Portumnus, and the other as that of a distinct
genus, for which I would retain Dr. Milne Edwards's name
of Platyonychus.

PORTUMM >.

Carapace quite as long as it is broad,
with the latero-anterior margins very
slightly toothed ; the front tridentate.
Orbits with a single fissure in the
upper margin.

Sternum twice as long as it is
broad.

Fifth pair of legs ivith the terminal
joint broad oval, very much rounded.

Abdomen in the male five-jointed ; the
terminal joint not abruptly smaller than
the preceding one.

Abdomen in tJte female seven-jointed ;
nearly three times as long as it is
broad ; the sides parallel, as far as the
fifth joint inclusive ; the terminal joint
not abruptly smaller than the preced-
ing one.

PLATYONYCHUS.

Carapace one fourth broader than it
is long ; the latero-anterior margin very
strongly toothed ; front quadridentate.
Orbits with two fissures in the upper
margin.

Sternum not more than one third
longer than it is broad.

Fifth pair of legs with the terminal
joint acutely lanceolate.

Abdomen in tJie male seven-jointed;
the terminal joint abruptly smaller than
the preceding one.

Abdomen in the female seven-jointed ;
not half as long again as it is broad ;
the fourth, fifth, and sixth joints form-
ing nearly a circle, posteriorly trun-
cated ; the terminal joint only one- third
the breadth of the preceding one.

Such are some of the most important characters in which
these two forms differ, and on which I have thought it
necessary to consider them as generically distinct. In

G 2

PORTUNIDJ3.

many respects the British species more nearly resembles
Polytius Henslowii) than it does Platyonyclius bipustulatus ;
nor can I imagine, if the two in question be reduced to
one generic name, how PolyUus can consistently be con-
sidered as distinct.

It is to be remarked, that Edwards throughout quotes
Leach's genus Portumnus as Portunus, from which it is
of course distinct ; and although it was perhaps undesirable
to give to two genera so nearly allied, names so similarly
spelt, yet I cannot consider this as a sufficient ground for
changing the generic name from Portumnus to Platyony-
cJius, as Latreille has done.

I have not had an opportunity of examining an Ame-
rican species, first described by Herbst, and afterwards by
Say, and referred by Latreille and Edwards to Platyony-
chus, under the name of PL ocellatus, and therefore I am
unable to state positively its relations, particularly as the
abdomen has not been described by either of the naturalists
who have noticed it. But I believe it will be found to
belong to Platyonychus, as I have above restricted that
genus.

PORTUMNUS VARIEGATUS.

85

DECAPOD A.

BKACHYURA

PORTUNIDM.

Portumnus variegatus.

Specific character. — Front tridentate ; carapace heart-shaped, not broader than
it is long ; terminal joint of the fifth pair of legs lanceolate.

Cancer latipes,
Portumnus variegatus,

Platyonyclius latipes,

PENNANT, Brit. Zool. IV. t. i. f. 4. p. 5.

LEACH, Edinb. Encycl. VII. p. 391. Make. Brit-

t. iv.
EDWARDS, Hist. Crust. I. p. 436\

THE carapace of this species is almost evenly convex,
slightly granulated, heart-shaped, as broad as it is long,
the latero-anterior margins with the front almost continu-
ously arched, the latero-posterior margins much contracted.
There are four small teeth on each latero-anterior margin,
exclusive of the external angle of the orbit. The front
has three teeth, of which the middle one is the longest.
The orbits are entire, the superior and the inferior margin
regularly concave, with a strong tooth at the outer, and a
smaller one at the inner angle ; there is a considerable
hiatus at the inner canthus, which is filled with the basal
and second joints of the external antennae. The anterior

86

PORTUNIDJE.

legs are of moderate length and size, rounded on the outer,
and flattened on the inner sides ; the wrist has a distinct
carina on the superior margin, which is ciliated, and ter-
minates anteriorly in a sharp spine ; the hand is carinate
above and beneath, the superior carina being, like that of
the wrist, closely ciliated with short hairs, the inferior con-
tinued along the immoveable finger, which is triangular.
The moveable finger is considerably curved, with a furrow
on the outer side ; both are obtusely toothed. The re-
maining legs are slightly compressed, the terminal joints of
the second, third, and fourth, very narrow lanceolate ; that
of the fifth pair more broadly lanceolate, all acutely
pointed. The abdomen of the male is long and narrow,
the penultimate joint nearly quadrate, the terminal one
triangular. That of the female is but little broader than
that of the male, the sides parallel as far as the fifth joint
inclusive, which is transversely quadrate, the penultimate
and the terminal one diminishing almost regularly to the
apex, which is slightly truncated.

The colour is very pale dull purplish-white, mottled with
a darker hue.

Dr. Leach describes this species, with great truth, as one
of the most beautiful of the British Crabs ; but he is cer-
tainly in error when he calls it " the most common." It is
found along the whole of the western and southern coasts ;
but as far as my own experience goes, and that of others
of whom I have made the inquiry, not in the abundance
alluded to by my lamented friend. Mr. Thompson, in
giving its Irish localities, says very correctly, " It is occa-
sionally found thrown ashore on extensive sandy beaches."
It is one of the more rare and local of the Irish species.
It is taken, according to Dr. Leach, by digging beneath

PORTUMNUS VARIEGATUS.

87

the sand at low water mark ; but there can be no doubt
of its inhabiting also deep water, from the natatory cha-
racter of the legs, all of which are terminated by a true
swimming joint, though less strikingly so than in some of
its congeners.

DEC A POD A.

BRACHYURA.

PORTUNIDJE.

GENUS PORTUNUS, LEACH.

CANCER, Linn. Penn. Herbst.

PORTUNUS, Fabr. Latr. Leach, Edwards.

Generic Character. — External antennce placed in the] inner
canthus of the eyes, separating the orbits from the antennary
fossse, which are open in front. External pedipalps with the
third joint quadrate, and either truncate at the inner and ante-
rior angle, or notched at the inner margin, for the articulation
of the palp. Anterior pair of legs generally somewhat unequal,
and the wrist armed with a strong spine at the superior and
interior angle ; hands slightly incurved, marked with elevated
lines. The second, third, and fourth pairs of legs, with the last
joint long, styliform, slightly curved, and longitudinally grooved ;
fifth pair formed for swimming, the last and penultimate joint,
being very flat, broad, and rounded. Carapace, rather broader than
long ; the latero-anterior margin four or five toothed, flattened,
and thin ; the front, horizontal, projecting. Orbits, above with
two — beneath towards the outer angle, with one fissure. Eyes,
with a short peduncle. Abdomen, in the male, five-jointed, trian-
gular ; in the female, seven -jointed.

The Crabs of this genus are capable of swimming with
great ease, as the thin, expanded, fin-like form of the pos-
terior feet would indicate. They are commonly termed
by the fishermen, swimming and flying Crab ; and, from
the peculiar motion of their hinder feet, fiddlers. Pen-
nant gives the name of cleanser Crab to one species, and
the specific name depurator, given by Linnaeus to a species

PORTUNUS. 89

of Crab presumed by Pennant and by Leach to be the one
in question, would point to the same supposed office. That
they do perform such an office in no very limited degree,
may be concluded from the localities in which they abound,
and the numbers in which they are found congregated.
In the refuse of the prawn and lobster pots, where they
resort for the purpose of feeding on the often half-putrid
garbage which is placed there as bait, and amongst the
mass of miscellaneous filth sometimes brought up by the
dredge, hundreds of these cleansers are frequently taken.

The genus Portunus as established by Fabricius, was
much more extensive than at present, including as it did
the whole of the swimming Crabs belonging to this divi-
sion ; in fact, the whole family of Portunidte, as far as
they were then known, with the exception of Carcinus,
which forms one of the links by which the family of Cance-
rida are united with the present group.

90

PORTUNJDJ2.

DEC A POD A.

BRACHYURA.

PORTUNIDJE.

VELVET SWIMMING-CRAB.

Portunus puber.

Specific diameter. — Hinder feet with a longitudinal elevated line ; body pubes-
cent ; front with numerous small spiny teeth.

Cancer puber, LINN. Syst. Nat. XII. 1046.

„ velutinus, PENN. Brit. Zool. IV. p. 5. t. iv. f. 8.

Portunus puber, LEACH, Malac. Podophth. Brit. t. vi. EDW. Crust. I.

p. 441.

THE carapace of this species is broader than it is long-
in the proportions of four to three. The anterior margin
forms the segment of a circle, and each latero-anterior
portion is furnished with five strong triangular teeth, the
margins of all of which, excepting the last, are minutely
serrated, and the points are directed somewhat forwards ;
the posterior is the narrowest, and finely acuminated.
The orbits are very large and open, both margins minutely

VELVET SWIMMING-CRAB. 91

denticulate, with two rather deep fissures in the upper,
and one in the lower ; a strong denticulated tooth protects
the inner canthus beneath. The eyes are round, placed on
short and broad peduncles. The front is very broad, armed
with a spine on each side of the centre, and a denticulated
triangular tooth at the exterior extremity, between which
are about three small pointed teeth. The posterior por-
tion of the carapace is broad, the surface is granulated,
and covered with a dense, short, villous coat. The first
pair of legs are very robust ; the spines and processes very
strongly marked ; on the wrist are two spines, the outer
one simple and acute, the inner very strong, and furnished
with two additional smaller teeth. The hand is furnished
with a strong spine at the anterior and upper part, pro-
jecting over the joint of the moveable finger : the elevated
portions are covered with large granulations. The fingers
are longitudinally grooved, and furnished with strong ir-
regular tubercular teeth ; the points moderately acute.
The second, third, and fourth pairs of legs are long,
slightly grooved longitudinally, carinated above, and the
terminal joint is long, slender, and pointed. The fifth
pair has the last two joints much flattened ; the last but
one has four, and the terminal one three raised longi-
tudinal lines, which are naked and polished : they are
both furnished with a close firm fringe of hair, and the
last is acuminated. The whole of the legs, as well as the
carapace and thorax, are covered with a villous coat,
excepting on the elevated portions, which are generally
naked. The abdomen in the male forms an acute triangle,
and each joint is slightly carinated transversely ; in the
female, it is broadly ovate.

The colours of this fine species are exceedingly bright
and showy when it is alive, but soon fade after death.

92

PORTUNID.E.

Leach's figure, in his Malacostraca Britannia, is coloured
after life, and exhibits a remarkable assemblage of hues,
the general tint being a reddish brown, and the naked
portions a bright blue.

Its velvety coat has procured for it the English name
of Velvet Crab, and the French one of Crabe a laine.

The Velvet Crab is found in considerable quantities, all
along the south-western coast of England. In Cornwall
and Devonshire it is very common ; I have taken it in
Swanage and Studland Bays, and on the southern coast
of Kent, where, however, it appears to be more rare. Like
some other species, it appears in much greater numbers
during some seasons than in others. Mr. Hailstone has
the following note respecting its occurrence at Hastings.
" In July, 1834, several dozens were taken off Hastings,
to the astonishment of the fishermen, who had rarely seen
them here ; and, since that influx, they have quite dis-
appeared. This advance and retreat is of frequent occur-
rence.'" Mr. Embleton, in his list of the Crustacea found
on the coasts of Berwickshire and North Durham, men-
tions its occurrence as not uncommon. Mr. Thompson
records its existence on all parts of the Irish coast ; and
states, after Dr. Drummond, that it is taken commonly
at Bangor by boys, who find it lurking under stones in
rocky pools at low water. Mr. Couch observes that it
is found in the adult state at a few fathoms' depth, but
that the younger ones are found at low- water mark amongst
stones, under which they conceal themselves. I have cer-
tainly obtained the larger specimens at a considerable dis-
tance from the shore by dredging, as well as in lobster-pots.
The whole of the species of this genus are remarkably
active and pugnacious ; but this is, according to the tes-
timony of Mr. Couch, " the most active and fierce of the

VELVET SWIMMING-CRAB.

93

family, running with great agility on the appearance of
clanger, but stopping and assuming an attitude of defence
when closely pursued. It seizes an enemy suddenly, and
holds him with tenacity."

It is taken with Carcinus Hcenas, and in the same way.
I have occasionally seen it brought to the London market
with that species ; and it is taken in large quantities on
the French coast as an article of food. It is by far the
largest of the family inhabiting the European coasts, being
often two inches and a half to three inches in length.

PORTUNIDJB.

DEC A POD A.

BRACHYURA.

PORTUNID^E.

WRINKLED SWIMMING-CRAB.

Portunus corrugatus. Leach.

Specific character. — Carapace with numerous raised serrato-granular, hairy,
transverse lines ; front three-lobed, the lobes crenulated, the middle one the
largest ; latero-anterior margin on each side five-toothed. Terminal joint of the
posterior feet, with a raised median and marginal line, lanceolate and rnucronate.

Cancer corrugatus,
Portunus „

PENN. Brit. Zool. IV. 5. t. v. f. 9. HERBST, t. vii. f. 50.
LEACH, Edinb. Encycl. VII. p. 390. Trans. Linn.

Soc. XI. p. 315. Malac. Brit. t. vii. f. 1, 2. EDW.

Hist. Nat. Crust. I. p. 443.

THE carapace in Portunus corrugatus, is about four-fifths
as long as it is broad, elevated, with the regions distinct,
and marked with numerous transverse elevated lines ; the
front is three-lobed, the lobes crenulated at the margins,
the middle one the largest ; the latero-anterior margin five-

WRINKLED SWIMMING-CRAB. 95

toothed, the teeth curved, and directed forwards ; the
latero-posterior margin abruptly narrowed behind the pos-
terior lateral tooth. The first pair of feet somewhat un-
equal, the surface rugose ; the wrist with a long sharp
spine at the anterior and superior angle ; the hand with a
sharp carina on the upper side, terminating in a sharp
tooth over the joint of the finger ; claws longitudinally sul-
cate, the superior curved, the margins furnished with nu-
merous tubercular teeth, of which those of the larger claw
are larger and irregular, those of the smaller regular and
small ; the second, third, and fourth pairs of feet hairy
at the upper and lower edge, carinated above, and with
elevated lines along the sides, the terminal joint long,
slender, and styliform ; the posterior feet with elevated
lines on the sides of each joint, the margins of the joint
ciliated, the terminal joint rather narrow, lanceolate, and
mucronate. The sternum is slightly rugose. The abdo-
men in the male is triangular, in the female ovate ; the
first to the fourth joints strongly carinated transversely ;
the terminal joint forming an equilateral triangle.

In. Lines.

Length of the carapace . . . . .15

Breadth ... ..18

The colour is reddish brown, often spotted with a
brighter red.

The characters of P. corrugatus are so strongly marked
as to preclude the possibility of its being confounded with
any other species. It belongs to the same section of the
genus as P. puber, and P. Rondeletii, characterised by ele-
vated lines on the sides of the terminal and penultimate
joints of the fifth pair of feet, a character which, associated
as it is with a narrower form of these parts, would seem
to indicate a somewhat inferior power of swimming.

96

PORTUNID^E.

It must be considered as one of the rarer species of the
genus. Pennant states that it was found " on the shores
of Skye, opposite to Loch Jurn." This is the first account
we have of its occurrence, and Herbsfs figure is copied
from Pennant's. Leach mentions specimens having been
taken by Mr. 0. Prideaux in Plymouth Sound ; and I
have a fine female specimen from the same locality, given
to me by my friend Dr. Miller, R.N. Mr. Couch, to
whose kindness I am also indebted for a specimen, men-
tions it in his u Cornish Fauna" as scarce on that coast. It
has been found by Dr. Johnston in Berwick Bay, but is
rare. It is an Irish species, as appears from the following
notice in Mr. W. Thompson's account of the Crustacea of
Ireland. " The only examples of this species which I
have seen, are some fine examples from Larne and Carrick-
fergus, in the Ordnance Collection, and a single specimen
obtained on the Dublin coast, by Mr. R. Ball. Mr. J. V.
Thompson notices P. corrugatm as inhabiting the harbour
of Cove ; but those so -named in his collection are the
wrinkled variety of P. depurator" These are all the lo-
calities that I am acquainted with in which it has occurred
as a British species ; but it is mentioned by Edwards as
being very common in the Mediterranean, although Risso
does not mention it, unless his P. Leacliii be identical with
it, which is possible, as the short description given of that
species agrees in every respect with P. corrugatus.

ARCHED-FRONTED SWIMMING-CRAB.

97

DECAPOD A.

BRACHYURA.

PORTUNIDJE.

ARCHED-FRONTED SWIMMING-CRAB.

Portunus arcuatus. Leach.

Specific character. — Front entire, arched ; latero-anterior margin five-toothed ;
the penultimate tooth the smallest.

Portunus arcuatus,
„ Rondeletii.

Var. fronte emarginato.
Portunus emarginatus,

LEACH, Malac. Brit. t. vii. f. 5, 6. W. THOMPSON,
Ann. and Mag. Nat. Hist. X. p. 283.

Risso, Hist. Nat. des Crust, de Nice, t. i. f. 3. Id.
Hist. Nat. de 1'Eur. Merid. V. p. 2. EDW. Hist.
Nat. Crust. I. p. 444.

LEACH, 1. c. vii. f. 3, 4.

I HAVE followed Milne Edwards in adopting the sug-
gestion of Leach, that the Portunus emarginatus of the
latter is only a variety of his P. arcuatus. In retaining

98

PORTUNID.E.

Leach's name for the species, in which I have been pre-
ceded by Mr. W. Thompson, of Belfast, I believe that I
follow the strict law of priority ; as the early parts of the
" Malacostraca Britannise " were published in 1815, and
Risso's " Histoire Naturelle des Crustaces des environs de
Nice " not until the following year, The specific name
Rondeletii is retained by Risso in his Natural History of
Southern Europe, which was published in 1826, so that
he was either not aware of Leach's figure, or not satisfied
of its specific identity with his own species. Milne Ed-
wards has also kept Risso's name against the law of
priority of description.

The carapace is four-fifths as long as it is broad ; con-
siderably raised, the regions distinct, the surface granu-
lated ; the anterior portion slightly scabrous ; the anterior
margin describing nearly a semicircular arch, of which the
front forms a continuous portion ; latero-anterior margin
on each side armed with five teeth, including that at the
external canthus of the eye ; the fourth being the smallest,
and the fifth prominent and acute. Front entire, except
in the variety named by Dr. Leach emarginatus, in which
it is slightly excavated, the margin granulated and fringed
with rather long hair ; the posterior portion of the cara-
pace broad, the posterior margin nearly straight ; orbits
with two fissures on the upper margin, and one beneath.
The anterior feet in the male very robust ; the wrist armed
with a single prominent and acute spine ; the hand with
a double carina on the superior edge, each terminating in
a small tubercle ; the fingers strong, armed with numerous
tuberculous teeth, and each having two carinse on the outer
surface, and a carina and a groove on the inner; the re-
maining pairs of feet rather slender ; the third and fourth

ARCHED-FRONTED SWIMMING-CRAB. 99

the longest, and the second shorter ; the fifth pair fringed
with long hair ; the terminal joint lanceolate, very acute.
Abdomen in the male regularly triangular ; in the female
semi-ovate, slightly carinated, the terminal articulation
triangular. The colour of this species is a dull blackish-
brown above, paler beneath, and with a tinge of red ; the
legs paler than the body.

The habits of this species are very similar to those of
the other species of the genus as far as they have hitherto
been observed. They are active, bold, swimming with agi-
lity, and seizing with great sharpness, and pinching severely
with their acute claws. They are gregarious, like most of
their congeners ; and I found them extremely abundant
at Bognor, where they constantly infest the prawn-pots
and, as the fishermen believe, keep the prawns from the bait.

I believe this species will prove, upon further observa-
tion, to be more generally distributed than has hitherto
been supposed. Dr. Leach gives the more northern coasts
of England as its usual habitat ; I have dredged it in
Poole Harbour, and in the neighbouring bays of Studland
and Swanage, and plentifully at Bognor. Mr. Eyton sent
me specimens from the Welsh coast. Mr. Couch does
not, however, give it a place in his " Cornish Fauna ;" nor
does it occur in the late Mr. Hailstone's MS. notes of
Crustacea taken at Hastings. In Ireland, Mr. W. Thomp-
son has taken it " when dredging in deep water in the
loughs of Strangford and Belfast ;" and he adds, " it was
procured by our party when dredging in Killery and
E/oundstone Bays on the Western coast." Mr. Ball also
found it cast on shore at Portmarnock.

I have never found the variety named by Leach P.
etnarginatus. Of the hundreds which I have taken, all

H2

100

PORTUNID.E.

possessed the arched and entire front assigned by him to
his P. arcuatus. The original specimen of his emarginatus
is in the British Museum, and a figure of it is given below.

CLEANSER SWIMMING-CRAB.

101

DEC APOD A.

BRACHYURA.

PORTUNID&.

CLEANSER SWIMMING-CRAB.

Portunus depurator. Leach.

Specific character. — Front armed with three triangular teeth, and a small one on
each side, over the inner angle of the orbit ; latero-anterior margin with five
teeth ; carapace irregularly granulate, scabrous. Terminal joint of the posterior
feet broadly oval, smooth.

Cancer depurator , (?)
„ „ var.

Portunus depurator,

„ plicatus,

LINN. Syst. Nat. XII. 1043, 23.

PENN. Brit. Zool. IV. t iv. fig. 6. A.

LEACH. Edinb. Encycl. VII. p. 390. Trans. Linn.

Soc. XI. p. 317. Malac. Brit. t. ix. f. 1, 2.
Risso, Crust, de Nice. Id. Hist. Nat. de 1'Eur-

Mend. V. p. 3. EDW. Hist. Crust, I. p. 442.

THE carapace of this species is very uneven on the sur-
face, the regions being distinctly marked, and all the
elevated parts scabrous, with unequal raised granules or
points, some round, others elongated. The latero-anterior

102

PORTUNIDvE.

margin on each side armed with five triangular teeth,
slightly curved forwards and sharp pointed. The front
has three projecting flat teeth, of which the middle one is
rather the longest, and a smaller one at the outer side, and
a little posterior to these, over the inner angle of the orbit.
The orbits are large, opening forwards and upwards ; the
eyes large and the peduncles very short. First pair of legs
slightly unequal, elegantly sculptured ; the wrist having the
superior area granular, bounded by raised lines, of which the
outer one is furnished with two or three small teeth, and
the inner terminates anteriorly in a sharp spine ; the hand
has five longitudinal raised lines, which are granular, or
slightly denticulate, and the superior one terminates in a
small sharp spine over the joint of the finger ; the claws are
longitudinally carinated, and furnished with very distinct
rounded tubercles. The second, third, and fourth legs
are long and slender, with a double carina running along
the superior edge, the terminal joint very long, slender,
and sharp pointed. The fifth pair very much flattened,
the joints ciliated at the margin, and sculptured, excepting
the terminal one, which is flat, smooth, and oval. The
abdomen in both sexes has the second and third joints
acutely carinated transversely. That of the male is trian-
gular ; that of the female very broad and ciliated with
long hairs ; the third to the sixth joints broader than the
first two, the seventh abruptly narrower.

The colour is generally a pale reddish brown ; in the
younger ones flesh-coloured.

The sculpture in this species varies greatly in degree.
The specimen figured in Leach's Malacostraca, and which
may be considered as a fair representation of the ordinary
appearance of the adult individual, is comparatively smooth;
whilst a younger one, which I have from the Mediterranean,

CLEANSER SWIMMING-CRAB. 103

is very sharply and elegantly sculptured. There is, in fact,
no species of the genus, and scarcely any of the whole order,
the surface of which is more minutely and beautifully re-
lieved, and this is particularly the case with the hands
and wrists, the inequalities of which are most delicately
picked out.

The early synonymy assigned to this species by Leach
is, to say the least, exceedingly doubtful. The figures to
which Linnaeus refers in his synonymes of Cancer depu-
rator, may be referred to two or three other species, with
quite as great probability as to this. But as Fabricius and
Leach have both appropriated the specific name of depu-
rator to the species, and as there is no proof whatever that
it was originally given to another species, I have preferred
retaining it, to the adoption of the name of plicatus, sub-
sequently assigned to it by Risso, and continued by Ed-
wards.

This is not an unfrequent species on our coasts. In the
north it has been recorded by Mr. Embleton as occasion-
ally brought from deep water in Embleton Bay, adhering
to the nets of the fishermen. Leach states that it is the
most common of all the species of the genus ; but like
many others it is local, although, like them, very numerous
where it does occur. This is confirmed by the observation
of Mr. Ball, quoted by Mr. Thompson in his account of the
Crustacea of Ireland. " We have," says the latter gen-
tleman, " dredged it in Strangford Lough, in the open sea,
off Down, and on the Connaught coast. During some
weeks spent at Bangor, near the entrance of Belfast Bay,
in the autumn of 1835, I found this to be the most com-
mon species of Crab thrown by the waves upon the beach.
Mr. R. Ball mentions that the P. depurator is local, but
abundant where it does occur about Youghal." I have

104

PORTUNID^E.

dredged it in Studland Bay, in Dorsetshire ; but have not
found it on the coasts of Sussex and Kent, where I have
found other species in great plenty. Mr. Hailstone, how-
ever, states that it is frequently caught at Hastings in the
shrimping-net.

The habits of this species are doubtless similar to those
of the rest of the genus. I am not aware of the period of
its spawning in this country, but Eisso states that it occurs
in March and December in the Mediterranean.

MARBLED SWIMMING-CRAB.

105

DECAPOD A.

BRACHYURA.

PORTUNIDJE.

MARBLED SWIMMING-CRAB.

Portunus marmoreus. Leach.

Specific character. — Carapace even, very slightly granulated, without hairs ;
latero-anterior margin armed with five teeth on each side ; front three-toothed,
the teeth rather obtuse, the middle one the longest ; hands with four carinae,
slightly denticulate ; terminal joint of the posterior feet without raised lines,
the apex mucronate.

Portunus marmoreus,

LEACH, Malac. Brit. t. viii. EDW. Hist. Crust. I. p.
442.

THE general form and the whole of the characters of
this elegant species resemble so exceedingly that of P.
holsatus, that I am almost imperatively forced to con-
sider them as varieties of one species The carapace is
somewhat convex, with the regions moderately distinct ; the

106

PORTUNID^E.

surface obsoletely minutely granulated, smooth and naked,
with an arched line of very slightly raised points, separating
the hepatic from the branchial regions, and a sulcus be-
tween the latter and the genital. Latero-anterior margin
with five acute flattened triangular teeth : the points di-
rected forwards, the last being the most acute and the
longest. Posterior margin waved, broad, moderately hol-
lowed at each side. Front with three teeth, the middle
one slightly longer than the others — all rather obtuse.
Anterior feet strong, angular ; the wrist with a rough
irregularly rhomboid area on the upper surface, bounded
by a raised denticulate line; the anterior angle with a
very strong tooth. Hands with four distinct carinse, which
are generally slightly denticulate ; the superior one ter-
minating in a small sharp tooth. Fingers longitudinally
carinated, strongly tuberculated ; the moveable one much
curved. The second, third, and fourth pairs of feet rather
slender, compressed ; the terminal joint curved, hairy on
the inferior edge ; the fifth pair having no raised lines on
the terminal and penultimate joints ; the whole fringed with
hair ; the terminal joint very smooth, ovate and slightly
mucronate. Abdomen in the male, five-jointed, triangular ;
the second and third joints transversely acutely carinated ;
in the female seven-jointed, also triangular, but broader,
and with the second and third joints similarly carinated.

Length of the carapace
Breadth of ditto

In. Lines.
1 3
1 6

The colours of this species are exceedingly varied and
beautiful, particularly in the males. Buff, light-brown, deeper
brown, and brownish red are arranged over the carapace, in
varied but always exactly symmetrical patterns. The only
way in which these beautiful markings can be preserved is,

MARBLED SWIMMING-CRAB. 107

by raising the carapace, taking out the soft parts and dry-
ing the specimens in a shady place in a brisk current of
air. If they are put into spirit, the whole of the beauty
of the colour is lost.

The younger specimens do not possess these markings.
They are, as Dr. Leach has observed, of a plain brown
colour, and much resemble the fry of Portunus depurator,
from which they may be easily separated by their more
considerable convexity. It must be considered as one of
the more local species of the genus, occurring, however, in
considerable numbers in its favourite localities. It was first
discovered by Montagu, who sent specimens to Dr. Leach
for description ; and who appears, from LeaclTs quotation,
to have named it, " Cancer pinnatus marmoreus." It is
not uncommon, according to the latter author, " on the
sandy shores of the southern coast of Devon, from Tor-
cross to the mouth of the river Ex, and is frequently
found entangled in the shore-nets of the fishermen, or
thrown on the shore after heavy gales of wind. It is in-
cluded in Mr. Couch's " Cornish Fauna," but without any
remark. It does not appear to have been hitherto taken on
the coast of Ireland ; and Mr. H. Goodsir mentions it as not
common as a Scottish species. At Hastings, I procured a
single specimen, which I found in a shop where shells, crus-
tacea, and other marine productions were sold, but it was
certainly native at that place ; and at Sandgate, in the
month of May, 1844, I procured by dredging nearly four
hundred specimens at two casts of the dredge, of which
about three-fourths were females. Several of these were
carrying spawn, which is of a rich orange colour.

It is very curious to observe how local these " cleansers"
are. In the former year, at Bognor, I found multitudes
of Portunus Rondeletii, which absolutely swarmed in the

108

PORTUNID/E.

prawn and lobster-pots, but not a specimen of any other
species was obtained there. The place of these is supplied
at Sandgate by the present species, whilst farther to the
west, P. puber, and P. depumtor appear to occupy the
ground and perform the same important office of scaven-
gers of the sea.

There is another fact relative to this species which is
worth recording, and that is, the extent to which they are
infested with a remarkable parasite, occupying the space
between the folded abdomen and the sternum, and hav-
ing the primd facie appearance of a bag of immature eggs.
Both males and females are equally obnoxious to it ; and
from its size and situation it must present an insuperable
barrier to impregnation. It consists principally of a mass
of minute eggs, which are arranged in bundles attached
to filaments, like bunches of grapes ; the alimentary canal
passes directly through the body, the mouth being at-
tached to the intestine of the crab, which it pierces near
its extremity, and from which, in all probability, it derives
its nourishment. The anal opening, which is distinct
and obvious, is visible without removing the parasite from
its position. The whole is of a rounded trihedral form, and
is covered by a tough but thin integument. I have oc-
casionally found it infesting Carcinus mcenas, but never
in such numbers as on the present species.

LIVID SWIMMING-CRATl.

109

DEC APOD A.

BRACHYURA.

PORTUNIDJF..

LIVID SWIMMING-CRAB.

Portunus holsatm. Fabr.

Specific character . — Carapace somewhat depressed, minutely granulated ; latero-
anterior margin with five strong flattened teeth ; front with three nearly equal
teeth ; posterior margin very largely emarginate at the angles for the hinder feet ;
hands with denticulate carinae ; last joint of the fifth pair roundly oval, more than
half as broad as long.

Portumis liolsatus,
„ lividus.

FABR. Suppl. p. 336. (Edw.) EDW. Hist. Nat. Crust.

I. p. 442.
LEACH, Malac. Brit. pi. ix. figs. 3. 4.

IT is extremely difficult to assign any very satisfac-
tory distinctive character to this species. Its great resem-
blance to P. marmoreus, — at least to all the specimens
which I have in my possession, fully justify the belief

110

PORTUNID.E.

that they may be merely varieties ; although there are
certain comparative characters which, as they are pretty
constant, render it necessary that further investigations
should be made before their identity can be fully es-
tablished. Then the whole contour of the animal is
more strongly marked in the present species ; the mar-
ginal teeth are more prominent ; the margins of the
orbit more distinctly granulated ; the latero-posterior mar-
gin much more contracted and more deeply emarginate at
the angles ; the outer carina of the hand, more strongly
denticulate ; and the terminal joint of the posterior feet
rounder and broader in proportion to its length. In other
respects the similarity is so great in the form of all the
parts, as fully to justify Dr. Milne Edwards's remark of
their " extreme resemblance." It is matter of surprise that
Dr. Leach should not have observed this close relation of
these two species ; but that he should, on the contrary, have
stated that P. lividus [holsatus] most nearly resembles P.
depurator, a species from which, in fact, it differs most ob-
viously. It is remarkable that the specimens of P. mar-
moreus in the British Museum, which were collected by Dr.
Leach, differ much more from holsatus, than those which I
have myself procured ; the hand having in all those unarmed
carinse, and the upper margin of the orbit without granula-
tions. The figures in Dr. Leach's beautiful work, also
magnify the distinctions far beyond the truth.

The occurrence of this Crab is extremely rare on our
coasts ; Dr. Leach mentions his having found a single spe-
cimen amongst a number of P. depurator that were taken
in the Frith of Forth at Newhaven, and that he observed
another in the collection of Montagu ; but there is a
fine series in the British collection of the British Museum,
which must have been procured after the " Malacostraca

LIVID SWIMMING-CRAB. Ill

Britannise" was published. It is not mentioned by Mr.
H. Goodsir as occurring1 within his notice on the Scottish
coast ; nor does Mr. Couch give any account of its oc-
currence in Cornwall. In Ireland, however, according to
Mr. W. Thompson's statement, it has occurred repeatedly ;
but as it appears to me that faded specimens of P.
marmoreus might be easily mistaken for this species, it is
always desirable that they should be compared with those
well distinguished specimens which exist in the British
Museum. The following is Mr. Thompson's notice to
which I have referred. " Templeton mentions it as found
by him ' on the shore at Dunfanaghy.' We have dredged
it on more than one occasion in Belfast Bay, and have
obtained it on the beach of Carnlough, county of Antrim.
In Mr. R. Ball's collection, are several specimens which
were dredged in Dublin Bay." It is mentioned by Milne
Edwards as occurring on the French coast.

112

PORTUNIDJE.

DEC A POD A.
BRACHYVRA.

PORTUNIDM.

DWARF SWIMMING-CRAB.

Portunus pusillus.

Specific cliaracter. — Carapace considerably raised, rugose ; front three-lobed,
much advanced ; latero-anterior margin with five teeth.

Portunus pusillus,
„ maculatus,

LEACH, Malac. Brit. t. ix. f. 5 — 8. EDWARDS, Nat.

Hist. Crust. I. p. 444.
Risso, Hist. Nat. Eu. Merid. v. p. 5. Roux, Crust.

Mediter. t. xxxi.

THE carapace of this species is broader than it is long,
considerably elevated, and with the regions remarkably
distinct ; the surface is rugose, and irregularly granulated.
The front is advanced much beyond the orbits, flattened,
and three-lobed, the middle lobe being longer than the
others : the latero-anterior margin has five teeth, (including
the outer angle of the orbit,) of which the posterior one is
the most acute, and the most curved. The posterior
margin is almost straight. The first pair of legs are large
and robust ; the wrist is armed with a very strong spine
on the inner and anterior angle ; the hand has a double

DWARF SWIMMING-CRAB. 113

carina above ; the fingers are strongly tuberculated, and
the moveable one has a shallow longitudinal groove on
the upper and outer margin. The second, third, and
fourth pairs are slightly compressed and grooved. The fifth
pair has the penultimate joint grooved, and the terminal
joint is oval ; they are both ciliated all round.

The abdomen in the male is broadest at the base of
the third joint, the remainder forming a regular acute
angled triangle ; that of the female is ovate-lanceolate and
ciliated at the margin.

The colour is reddish-brown, often with red spots on
the back. In some specimens the colour is lighter, being
of a pale red with darker spots. The legs are usually
annulated with similar colours.

This very pretty species was first described by Dr.
Leach in the eleventh volume of the Transactions of the
Linnean Society, under its present name. Subsequently
to this, Risso described it in his Natural History of South-
ern Europe, giving it the name of P. maculatus, which
Roux very improperly retained in his Crustaces de la
Mediterranee, notwithstanding he was aware of the pri-
ority of Leach's name. It inhabits deep water, and is
common on the coast of Devonshire and Cornwall ; it
occurs all along the southern coast, and is also found
in the Frith of Forth, and I have specimens taken
by Mr. McAndrew off the Isle of Man. On its oc-
currence as an Irish species, Mr. Thompson has the fol-
lowing remarks, " It is ordinarily taken by us when dredg-
ing in the loughs of Strangford and Belfast. At the
Killeries in Connemara, it has similarly occurred, as
well as in Dublin Bay. In the South, too, it has been
taken in the harbour of Cove. I have several times taken
it in the stomach of fishes ; in one instance, in a Triffia

114

PORTUNIDJi!.

Gurnardus, taken in the open sea off Dover." It is found
also in the Mediterranean, and off the coast of France.
It spawns in June, and the eggs are of a reddish orange
colour.

Its ordinary size is about four lines in length ; this is
the size of the figures of Roux, and of those of Leach ;
but it occasionally grows much larger, as one of the
specimens, a male, taken by Mr. Me Andrew off the Isle
of Man, is fully an inch in breadth, by eight-tenths in
length.

DECAPOD A. PORTUNID&.

BRACHYURA.

GENUS POLYBIUS. LEACH.

POLYBIUS. Leach, Edwards.

PLATYONICHUS. Latr.

Generic character. — External antennae with the basal joint
round, detached, moveable, with the remaining portion lodged
in a hiatus at the inner canthus of the orbit, which it does not
fill. Internal antennae in fossae, which are entirely open forwards.
Eyes larger than their peduncles, which are short. External
pedipalps with the third joint subquadrate, longer than broad,
and slightly notched at its inner margin, near the anterior angle.
Carapace nearly orbicular, slightly contracted posteriorly. An-
terior pair of legs equal, the pincers curved. Second, third, and
fourth pairs compressed, the terminal joint flattened, thin, broad,
and lanceolate. The fifth pair with the penultimate joint much
flattened ; the terminal one very large, oval, foliaceous. Cara-
pace much depressed, the anterior margin semicircular. Orbits
with two fissures in the superior, and one in the inferior margin ;
a hiatus at the inner angle, and a small tooth at the outer.
Abdomen of the male, five-jointed, the first, second, and third
joints very short and broad, and transversely carinated ; of the
female, seven- jointed, the sides nearly parallel as far as the
middle of the sixth joint.

The structure "of this genus, of which a single species
only is known, is of a more decidedly natatory character
than any other brachyurous form found on our shores. It
is on this account that it has been with great propriety con-
sidered as generically distinct from Portumnus, with which,
however, it stands in very near relation.

i 2

116

DEC APOD A.

BRACHYURA.

PORTUNIDJi.

PORTUNIDM.

HENSLOW'S SWIMMING-CKAB.

Polybius Hemlowii. Leach.

Polybius Henslowii, LEACH, Malac. Brit. t. ix. B. EDWARDS. Crust. I. p. 439.

THIS species, the only one of the genus at present
known, exhibits the natatory structure to the greatest ex-
tent of any of the British examples of this family. The
carapace is remarkably flat, even in the female, and the
regions are very indistinctly marked ; it is all over minutely
granulated. Its form is nearly orbicular ; the latero-anterior
margins, with the orbits and front, forming a semicircle,
and the latero-posterior margins being but little contracted :
the front is flat, and has five teeth, the external of which
on each side belongs to the orbit : the latero-anterior
margin has five flat teeth, the points directed somewhat
forwards.

HENSLOW'S SWIMMING-CRAB. 11 7

The first pair of legs are nearly equal : the wrist has
two sharp teeth on the anterior margin, of which the
inner is much the more prominent, and a third tooth is
found at the outer and anterior angle, which forms the
commencement of a carina, which extends the whole length
of the wrist. The hand is compressed, and has three low
but sharp longitudinal carinse, the spaces between them
being slightly hollowed : the fingers are much compressed,
somewhat incurved, as long as the hand. The three fol-
lowing pairs are much compressed, particularly the last
two joints ; the terminal one being very thin and lan-
ceolate. The last four joints are ciliated on the inferior
margin. The fifth pair have the last two joints very broad
and flat ; the penultimate being irregularly quadrate, and
the terminal one broadly oval, slightly acuminated at
the apex. The abdomen in the male consists of five joints,
of which the first, second, and the base of the third are
transversely carinated ; the third joint is broadest at the
base, and becomes moderately contracted with a slight
notch ; the fifth is rather acutely triangular. In the fe-
male, the abdomen is seven-jointed ; the first three joints
transversely carinated ; the fifth joint suddenly smaller than
the preceding one, and obtusely triangular.

The colour is a rich reddish-brown, which becomes a
pale salmon-colour in drying. The under parts are pale.

Of this species, which is very local in its distribution, and
probably nowhere existing in great numbers, there is a
specimen in the Banksian collection in the Linnean Society,
which was taken on the coast of Spain. It was first disco-
vered on our shores by Professor Henslow in a herring-net,
on the north coast of Devon, in 1817, and by him com-
municated to Dr. Leach, who named the species after its
discoverer, assigning to it also a new generic appellation.
It was afterwards found by Mr. Prideaux on the south-

118

PORTUNIDJE.

western coast of Devon ; also in herring-nets on the Dorset-
shire coast, amongst the refuse of the nets of fishermen,
by the late Rev. Dr. Goodall. I have also obtained it
at Hastings, and received it, by the kindness of Mr. Couch,
from Cornwall, and by my friend Mr. Dixon, from Worthing.

The following observations on the habits of this species
are from the Cornish Fauna of Mr. Couch ; and as this
gentleman appears to be the only one who has ever ob-
served its habits, I make no apology for quoting his ac-
count entire. " This is, more than any others, a swimming-
crab ; for whilst the other British species of this family are
only able to shoot themselves from one low prominence to
another, the Nipper Crab, as our fishermen term it, mounts
to the surface over the deepest water, in pursuit of its prey ;
among which are numbered the most active fishes, as the
Mackerel and the running Pollock ; the skin of which
it pierces with its sharp pincers, keeping its hold until its
terrified victim becomes exhausted. We are witnesses of
this curious method of obtaining food in the summer only,
at which time the fishermen's nets intercept them and
their prey together ; and it is probable, that in colder
weather, they keep at the bottom in deep water, from
which, however, I have never seen them brought in the
stomachs of fishes. So far as my observation extends, it is
chiefly or only the male that pursues this actively preda-
ceous existence ; but that for a time they also remain
quiet, as appears from the fact that while for the most
part the smooth and flattened carapace is clean, I have
seen it covered with small corallines.11*

This interesting narrative is perfectly consistent with
the remarkable natatory structure of the species, evinced
in the form of the carapace and the structure of the
legs, and with the sharpness and strength of the claws.

* Couch's Cornish Fauna, p. 71.

DEC APOD A. PINNOTHEWDM.

BRACHYURA.

GENUS PINNOTHERES, LATR.

CANCER, Linn. Fabr. Herbst, Penn.

PINNOTHERES, Latr. Leach, Edwards.

Generic character. — External antennce very short, occupying the
inner canthus of the orbit. External pedipalps oblique ; the se-
cond articulation rudimentary, the third large, and forming the
whole valvular portion ; the fourth inserted at the extremity of
the previous one; and the fifth giving attachment to the sixth
at the middle of its anterior margin, resembling the thumb of a
didactyle hand. Anterior legs equal, the remaining pairs some-
what compressed ; the terminal joint acute, curved, and strong.
Eyes inserted on very short peduncles, distant. Orbits nearly
circular. Carapace nearly circular, rounded at the anterior mar-
gin. Front not united to the epistome. Abdomen seven-jointed
in both sexes ; that of the male small, of the female extremely
broad, round, and prominent.

THE species of this genus are very remarkable from the
peculiarity of their being indebted to animals of a very
different class for protection, although not truly parasitic.
They are found always to inhabit the shells of the Bivalve
Mollusca, principally of the genera Mytilus, Modiolus, and
Pinna^ and occasionally also of Ostrea, Cardium, and other
genera ; and this habit, which was well known to the
ancients, gave rise to some interesting and curious hypo-
theses and fables, which will be alluded to hereafter. The
males are always very much smaller than the females, and

120

PJNNOTHERID.fi.

the crust of the former is as- hard as in other brachyurons
forms ; but the female is comparatively very large, almost
globular, and remarkably soft ; the latter character being
doubtless the cause of its requiring the efficient protection
of the shells of Mollusca. In other allied forms a some-
what analogous habit is observed ; the soft body of Ela-
mene and Hymenosoma demanding extrinsic protection,
which they obtain by appropriating to themselves small
single shells of dead acephalous Mollusca, as I have my-
self seen in several instances, — a fact which affords a col-
lateral argument in favour of Milne Edwards^s association
of these different genera in one family.

The species of the present genus even yet require careful
revision ; and I have found it necessary to comprehend the
whole of Dr. Leaches six species in two, — which, how-
ever, I have not done without the most deliberate con-
sideration.

COMMON PEA-CRAB.

121

DEC APOD A.
BRACHYURA.

PINNO THERJDJE.

1 Pinnotheres Latreillii. Leach.
3 Pinnotheres Pisum. Leach.

2 Pinnotheres varians. Leach.
4 Pinnotheres Cranchii. Leach.

COMMON PEA-CRAB.

Pinnotheres Pisum.

Specific character. — Front of the male projecting ; carapace of the female uni-
formly rounded at the anterior margin ; abdomen in the latter sex broader than
it is long.

('«n<-cr Pisum,
Pinnotheres Pisum,

Cranchii,
Latreillii,
varians.

PENNANT, Brit. Zool. IV. t. i. f. i. p. i. HERBST,
I. p. 95, t. 2, f. 21. FABR. Suppl. Ent. 343.

LATR. Hist. Nat. des Crust. VI. p. 83. LEACH,
Mai. Brit. t. xiv. f. 2, 3, (fern.) EDWARDS,
Hist. Nat. des Crust. II. p. 31.

LEACH, 1. c. fig. 4, 5, (fern.)

LEACH, 1. c. f. 6, 7, 8, (mas immat. ?)

LEACH, 1. c. f. 9, 10, 11. (mas.)

THE sexes in call the species of this genus differ so re-
markably, that a separate description is necessary.

MALE. (Figs. 1 and 2.) The carapace is nearly orbicu-

122

P[NNOTHERIDJE.

lar, very slightly narrowed forwards, convex, glabrous, and
solid ; the front projecting, arched, and entire ; the latero-
posterior margin slightly hollowed. The eyes small, round,
and filling the orbits. Sternum large and orbicular. An-
terior feet robust, the hands large, ovate, with two lines of
hairs beneath ; the fingers much curved, the moveable one
with a single tooth. The remaining pairs of legs fringed
with hair both above and below, terminating in a hooked
claw. The abdomen is broadest at the third joint, be-
comes narrower from this to the fifth, the sixth is a very
little broader, and the last abruptly narrower.

FEMALE. (Figs. 3 and 4.) The carapace in this sex is
nearly orbicular, rather broader than it is long, without any
projecting front, or hollows at the latero-posterior margin,
soft and glabrous. The hands are oblong, weak, and fur-
nished beneath with a single line of hairs. The remaining
legs slender, the thighs fringed with a line of hairs on the
upper side only. Abdomen very large, broader than it is
long, almost evenly rounded.

The colour of the male varies ; it is usually of a pale
yellowish grey, with rather darker symmetrical markings.
The female is ordinarily slightly transparent, brown above,
a yellow spot over the front, and an irregular one on
each branchial region ; the abdomen yellow, with a central
large triangular brown spot extending from the base nearly
to the extremity.

In accordance with the opinion of Mr. W. Thompson, I
cannot but believe that the individual figured by Leach
under the name of P. Latreillii, which he considered as an
immature female, in which he is followed by Milne Ed-
wards, is in fact a young male. The form and apparent
consistence of the carapace, the form of the hands, and
the colour, are all in favour of such an opinion. The form

COMMON PEA-CRAB. 123

of the abdomen is not at all at variance with it, as in many
species this part is very similar in the young of the two
sexes.

It is very remarkable that Leach should have failed to
detect the male and female of this very common species as
being specifically identical. They are frequently found
together, and yet he describes the female as one species,
P. Pisum, avowing his ignorance of the male, and the male
as another, P. varians, acknowledging himself similarly
unacquainted with the female, " unless she be P. Pisum"
After a careful examination of the subject, I have come to
the conclusion that the first four species of Leach are all
to be referred to one ; an opinion in conformation with
that of Dr. Edwards.

This species of Pinnotheres is very commonly found in
the common mussel, Mytilus edulis^ on many parts of our
coast ; and especially in those which are found in rather
deep water. On one occasion I dredged great numbers
of these Mollusca on the coast of Dorset, and found
by far the greater number of them with one or two of
these little soft-bodied crabs within their shells ; for the
females are much more common than the males. The
latter sex I have occasionally taken apart from the mussel-
shells, the former never. They also inhabit the shells of
Modiolus vulgaris, and occasionally also the common cockle,
Cardium edule, in which I have now and then found them,
as well as very rarely in the oyster, in which Mr. Ball also
states that he has taken them. The following account of
some circumstances respecting this crab is extracted from
my friend Mr. W. Thompson's observations on the Crus-
tacea of Ireland,* and is too interesting to admit of being
curtailed.

* " Ann. .and Mag. Nat. Hist." vol. x. p. 284.

124

PINNOTHERIDJE.

" The smallest Pinnotheres I have seen was found by
Mr. Hyndman, in a living Cardium exiguum, dredged by
us in Strangford Lough in October, 1834. It is a male ;
the carapace is under a line in length ; the entire breadth
of the crab from the extremities of the outstretched legs is
three lines. The cardium is under three lines in length,
and barely exceeds that admeasurement in breadth ; so
that the crab when in the position just mentioned must
have, on both sides, touched the walls of its chosen prison.
The Pinnotheres likewise inhabits the Cardium edule. Be-
fore me is one of these crabs, of which the carapace is
two lines in breadth, obtained by Mr. Hyndman in a full
grown C. edule from Strangford Lough ; but from the
Sligo coast, where this crab attains an extraordinary large
size, a crab with a carapace four lines in breadth, and
with outstretched legs seven lines across, was once kindly
brought to me by Lord Enniskillen. Mr. R. Ball informs
me that on two occasions he obtained a great number of
the Pinnotheres, and which were all males, from the
Cardium edule taken at Youghal, — about nine out of every
ten cockles contained a crab. On opening oysters in
Tenby, in Wales, he has likewise procured the Pinnotheres.
This crab, like the Pagurus, occupies different species of
shells according to its size, and at every age generally
selects such as with outstretched legs it would fill from
side to side."

It is a point of considerable interest as connected with
this species, that it formed one of the subjects of Mr.
Vaughan Thompson^ investigations on the transformations
of Crustacea, and the description with figures of the Zoea
of Pinnotheres as given in a paper by that gentleman in
the " Entomological Magazine." *

* Vol. iii. p. 85.

COMMON PEA-CRAB.

125

" As the females are found with an amazing group of
ova under their abdominal plate," says this author, " in
spring, summer, and autumn, it is probable that they have
several successive broods. This circumstance renders it no
difficult matter to select a number of females with mature
ova at any convenient time, and to preserve them alive
in sea water for a few days, or until the ova should hatch.

" From several females selected and kept alive after the
above manner, I had the satisfaction to see the ova hatch
in great numbers, under the form of a new kind of Zoe,
differing from all those previously discovered, with the
front and lateral spines deflected, so as to resemble a tripod.
In this stage the minute animals are all like the Zoea,
purely natatory, disperse themselves abroad, probably un-
dergo a further change, and may be supposed to gain an
easy access within the bivalve shells, before they lose their
power of swimming.'*''

I add a copy of Mr. Thompson's figures of this interest-
ing state of the animal, the accuracy of which I can attest
from my own observation.

126

PINNOTHERID^E.

DEC APOD A.
BRACHYURA.

PINNOTHER1DJE.

i. «.

•2. tl.

Pinnotheres veterum. Leach. Male and Female.

PINNA PEA-CRAB.

Pinnotheres veterum.

Specific diameter. — Male. Carapace subquadrate, rounded, the front slightly
emarginate. Female. — Carapace broader than it is long ; abdomen broadly
ovate, longer than it is broad.

Pinnotheres veterum,

„ Pinna,
„ Montagui,

Bosc, Hist. Nat. des Crust. I. 243. LEACH, Malac.

Brit. t. xv. f. 1,2, 3, 4, 5. EDW. Hist des Crust.

II. p. 32.

LEACH, Edinb. Encycl. VII. p. 431. V. THOMP-
SON, Ent. Mag. III. p. 89.
LEACH, Malac. Brit. t. xv. f. 6. EDW. 1. c. p. 32.

THE male of this species has the carapace less solid than
P. Pisum, rather broader than it is long, rounded, slightly
quadrate, with the front slightly emarginate ; the hands
are ovate, with the fingers arched ; the remaining feet very
similar to those of P. Pisum. The abdomen gradually
and evenly decreasing towards the extremities, the last

PINNA PEA-CRAB.

127

joint evenly rounded, nearly semicircular. In the variety
termed P. Montagui by Dr. Leach, this joint is abruptly
broader. In the female the carapace is rounded, broader
than it is long, very minutely punctulate ; the front trans-
verse, slightly arched, scarcely emarginate at the middle.
" The anterior feet with a small spine on the inferior
margin of the hand.11 The abdomen is evenly ovate,
broadest at the fourth and fifth joints, broadly carinate
along the middle, the last joint emarginate.

Colour in both sexes almost uniformly brown.

This species differs sufficiently from the former, in either
sex, to be distinguished at the first glance. Its habits,
however, are perfectly similar, as far as we have an oppor-
tunity of knowing them, but it is much less common than
the other on our coasts. It was first discovered to be an
English species by the indefatigable Montagu, who found
both sexes in Pinna: from the Salcombe Estuary in Devon-
shire ; and it was subsequently taken by Cranch in the
same locality. Vaughan Thompson records its being found
on the Irish coast, " both in Pinna and in Modioli" It
has not, as far as I am informed, been found on any other
part of the English coast but that already mentioned, nor
has it yet been taken in Scotland.

Its favourite haunt justifies the name which Leach first
assigned to it, P. Pinna; although he afterwards very
properly adopted the name previously given to it by Bosc.
It is found in the Pinna ingens, both on our coast and in
the Mediterranean ; it has also been taken in Modioli, and
in the common oyster. There can be no doubt that it was
of this species that the ancients, aware of its peculiar mode
of existence, formed such absurd notions. It is not, in-
deed, wonderful that with such imperfect ideas of the value
and bearing of natural phenomena, and with a love of the

128

P1NNOTHERIDJ5.

marvellous, which no Baconian philosophy then existed to
correct, the relations of these little interesting parasites to
their gigantic hosts should have given rise to legends as
amusing as they were false ; and we find that Cicero and
Pliny and Oppian have, in various degrees, given currency
to the most erroneous notions. Aristotle, indeed, with
his accustomed accuracy, first, and alone amongst the
ancients, offered any correct ideas of their habits: but
even he states that the life of the protecting shell-fish de-
pends for its continuance on that of its little guest. The
absurdities of the other ancient authors whom I have
named, are only worthy of recital as examples of the
danger of trusting to the assertions and conclusions of those
who have no general principles to guide them, — a danger
not even in the present enlightened age, altogether to be
neglected as chimerical.

I have thought it necessary, on the most mature con-
sideration, to merge Pinnotheres Montagui of Leach as a
synonyme of this species, — a result to which I am led by a

careful examination of the single
specimen on which that species
was founded, and which is in
the British Museum. The sole
appreciable distinction between
them is the enlargement of the
last joint of the abdomen in P.
Montagui, a character which
probably depends on age ; the
individual in question is a male, and is a little larger than
the ordinary males of P. veterutn. Milne Edwards speaks
of the " female of P. Montagui ;^ being probably misled
by a cursory observation of the enlarged view of the male
in Leach's plate.

DECAPODA. GONOPLACID&.

BRACHYURA.

GENUS GONOPLAX, LEACH.

CANCER, Fabr. Pennant.

OCYPODA, Bosc, Latr.

GONOPLAX, Leach, Edwards.

Generic character. — External antennce long, slender, setaceous,
the basal joint not notably broader than the following. Internal
antennce lying in transverse cells. External pedipalps with the
third joint transversely subquadrate, the anterior inner angle trun-
cate for the insertion of the palp. Anterior feet equal, extremely
long in the male, nearly cylindrical ; the remaining pairs somewhat
compressed, the fourth pair the longest, then the third, the fifth,
and the second. Carapace quadrate, much broader than it is long,
narrowed behind ; the fronto-orbitar margin extending the whole
breadth. Orbits long, transverse, open, terminating at the external
angle of the carapace. Eyes small, with extremely long pedun-
cles. Abdomen in both sexes seven-jointed.

130

GONOPLACID.E.

DEC APOD A.

BRACHYURA.

GONOPLACID/E.

Cancer angulatus,
Ocypoda angidata,
Gonoplax angulata,

? Gelasimus Bellii,

? Gonoplax rhomboides,

ANGULAR CRAB.
Gonoplax angulata.

FABR. Suppl. p. 341. PENN. Brit. VI. Zool.

IV. p. 7. t. v. fig. 10. HERBST, t. i. f. 13.
Bosc. Hist. Nat. des Crust. I. p. 198. LATR.

Hist. Nat. des Crust. &c., VI. p. 44.
LEACH, Edinb. Encycl. VII. 430. EDWARDS,

Hist. Crust. II. p. 61. COUCH, Cornish

Fauna, p. 72.

LEACH, Malac. Brit. t. xiii.
COUCH, Corn. Faun. p. 73.
Roux, EDWARDS, &c.

THE carapace is half as broad again as it is long, broader
across the anterior margin than at the posterior, rounded
from before backwards, nearly even from side to side ; the
anterior outer angle with a prominent and acute spine,

ANGULAR CRAB. 131

and a smaller one behind it on the lateral margin. Front
entire, incurved, broad; orbits directly transverse, open
directly forwards ; eyes on long peduncles, and protected
by the latero-anterior spines. The anterior legs in the
male four times the length of the carapace ; those of the
female much shorter, as are those of the young male. The
arm cylindrical, curved, armed with a small spine near the
middle of its upper side ; a still smaller spine on the inner
margin of the wrist ; the hand gradually increasing in size
towards the extremity, rounded, somewhat flattened at
the sides ; fingers finely toothed, and with a few larger
tubercles ; in the older individuals separated for nearly
half their length. The remaining feet long, slender ; the
second and third pairs with the last three joints hairy on
the edges. Abdomen of the male triangular from the third
joint to the extremity, the last joint forming nearly an
equilateral triangle ; of the female broadly oval : both
fringed with hair.

Colour dull yellowish red. The moveable finger, in the
male only, blackish.

It was not until this species was obtained by Montagu
in the Estuary of Kingsbridge, Devon, that it was ascer-
tained to be British. Since that period it has been re-
peatedly taken on the southern parts of the coast. I have
received it through the kindness of Mr. Couch from Corn-
wall, and from the coast of Wales, where it was procured
by Mr. Eyton ; but I am not aware of its having been
found on the eastern coast, nor have I heard of its having
been taken in Scotland. In Ireland we have the following
records of its occurrence from Mr. W. Thompson's account
of the Crustacea of that portion of the kingdom. " Mr. J.
V. Thompson's collection contains an Irish specimen of
this Crab, marked 'rare.' Mr. R. Ball has found the

K 2

132

GONOPLACIDJ3.

species in the stomachs of cod-fish, purchased in the mar-
kets of Youghal and Dublin, and commonly in those
brought to the former place : four of these Crabs is the
greatest number he has obtained from the stomach of a
single fish. In the Ordnance Collection is a fine example,
labelled as procured at ' Bangor, January, 1836."1

It is a Mediterranean species, and is found also on the
north-west and southern coasts of France, according to the
observation of Dr. Milne Edwards.

I cannot but believe that the Gonaplax rhomboides of
Roux and other authors, is merely a variety of this species,
in which opinion I concur with Mr. W. Thompson. Should
further observations, however, prove that it is distinct, it
is probable that the Gelasimus Bellii of Couches Cornish
Fauna will prove to be the female, or young male of that
species.

It is found in moderately deep water ; and Leach re-
cords on the authority of Cranch, that " they live in ex-
cavations formed in the hardened mud, and that their
habitations, at the extremities of which they live, are open
at both ends." They appear to constitute a favourite food
of the cod and other fish, as, in addition to the observation
of Mr. Ball quoted above, Mr. Couch states that it is often
taken in their stomachs.

DECAPOD A. GRAPSIDJE.

BRACHYVRA.

GENUS PLANES, LEACH.

CANCER, Herbst, Fabr.

GRAPSUS, Latr. Roux, Leach.

PLANES, Leach, Bowdich.

NAUTILOGRAPSUS, Edwards, Mac Leay, Goodsir.

Generic character. — External antennce lying at the exterior of
the antennary fossae, the basal articulation nearly horizontal, ex-
tending obliquely forwards and outwards, the outer extremity the
narrowest ; its moveable portion very short, setaceous, the joints
rounded. Internal antennae folded transversely in the fossae,
which are covered by the lamellar front, and separated by a broad
process extending from the epistome to the front. External pedi-
palps with the third joint broader than it is long, broadly and not
deeply emarginate at the inner half of the anterior margin. Ante-
rior legs robust, rounded, smooth, the hand inflated, the fingers
somewhat inflected, slightly toothed ; the remaining pairs much
compressed. Carapace depressed, convex, rounded, quadrato-
orbicular. Front broad, lamellar, bent somewhat downwards.
Orbits distant, open above. Abdomen seven-jointed in both sexes ;
in the male acutely triangular ; in the female, nearly orbicular.

THIS genus, the only representative of the family GRAP-
SIDJE known to have been found on our coasts, has hitherto
been but very imperfectly elaborated. The synonymy of
the species is much involved, and it is almost impossible
satisfactorily to disentangle it. I believe there are not
less than three or four species, the whole of which are
found floating about amongst the sargasso or gulf-weed

134

GENUS PLA.NES.

Fucus vagans, or attached to the bodies of the large
marine turtles. The figures of Linnaeus in his " Iter
Westrog." — of Bowdich in the " Excursions in Madeira
and Porto Santo," the descriptions of Say, of Edwards, of
Mac Leay, and others, only tend to show that there are
several species in existence, but do not diminish the diffi-
culty of distinguishing them. It is not intended on this
occasion to attempt their discrimination ; but it would
be very desirable that the task should be undertaken by
some one having the means at hand of comparing a great
number of specimens. There is a good collection of them
in the British Museum, and I have little doubt that I
possess three species in my own collection.

I have thought it right to restore the generic name of
Planes to these Grapsida, because it was not only applied
to them by Leach in his MSS. in the British Museum,
but adopted by Bowdich in his book above referred to.
Whether Leach had ever published any account of the
genus under the name Planes or not, I have not been able
to ascertain ; but it is highly probable that Bowdich
quoted it from some such authority.

FLOATING CRAB.

135

DEC A POD A.

BRACHYURA.

GRAPSID&.

FLOATING CRAB.

Planes Linnaana, Leach.

? Cancellns marinus minimus quadratus,

? Grapsus testudinum,
? Cancer minutus,

? Grapsus, „

? „ cinereus,

? Nautilograpsus minutus

Planes Linnceana,

SLOANE, Nat. Hist. Faun., II. p. 270.

t. ccxlv. fig. 1.

Roux, Crust. Mediterr. t. vi. figs. 1 — 6.
FABR. Syst. Ent. XI. p. 443, ejusd.

Suppl. 343. HERBST, I. t. ii. fig.

32.

LATR. Hist. Nat. Oust. VI. p. G8.
SAY, Journ. Acad. Sc. Phil. p. 99.
EDW. Hist. Crust. II. p. 90.
LEACH, MSS. Brit. Mus.

THE carapace in this species is nearly quadrate, with the
sides somewhat rounded, and slightly contracted posteri-
orly : it is of a generally depressed form ; the surface
smooth but not polished ; and there are on the posterior
part of the branchial region several faint stria3, occupying
the place of those which are so conspicuous in the genus
Grapsus, and some other forms of this family. The front

136

GRAPSIDJE.

is lamellar, broad, projecting, slightly inclining, and entire.
The orbits open above, with a small tooth at the outer
angle, forming the anterior angle of the lateral margin :
immediately behind this tooth is a very slight depression.
The margins are very entire. The external antennae are ex-
tremely small. The antennary fossae are separated from the
orbits only by the basal joint of the external antennae, which
scarcely fills up the hiatus. The anterior legs are robust,
and, ordinarily, nearly equal ; the arm is distinctly denticu-
late on the anterior and slightly so on the inner margin ;
the wrist has a minute tooth on the anterior inner and
outer angles ; the hand is smooth, very slightly granulated
beneath, rounded and inflated ; the fingers somewhat in-
curved, furnished with small tubercular teeth. The re-
maining pair of legs are considerably compressed; the
upper edge of the last three joints fringed with stiff hairs ;
the inferior edge of the last joint, and the last but one,
furnished with sharp spines, of which there are often two
or three also on the upper edge of the last joint near the
point, which terminates in a sharp spine. The abdomen in
the male is triangular, formed of seven smooth joints,
the first of which is transversely carinated ; that of the
female is nearly orbicular and very slightly raised along the
centre.

The colour is very various in different individuals. In
those which are marked in the British Museum as English,
it is of an uniform brownish buff; in others grey, mottled
with brown : but the most beautiful are those in which the
upper parts are mottled with various shades of reddish
brown and rich dark brown, with blotches of yellow or
buff; the legs being marked with obscure bands of similar
colours. These, however, doubtless belong to a distinct
species.

FLOATING CRAB. 137

The carapace in the largest specimens in my possession,
which are from the gulf-weed floating in the Atlantic, is
eight-tenths of an inch long, and the same broad : the
females being smaller than the males. In the British
specimens the length and breadth does not exceed four-
tenths of an inch.

The occasional occurrence of this erratic species on our
southern coast enables me for the first time to give it a
distinct place in our British Fauna. There are in the
British collection of Crustacea, in the British Museum, three
specimens, placed there by Dr. Leach, obtained, as I
believe, from the coast of Devonshire ; and Mr. Couch, in
his Cornish Fauna, has the following notice of another : —
" A species of the genus Grapsus is in the Athenseum at
Plymouth, under the name of G. pelagicus, by Mr.
Prideaux, and known to Dr. Leach. It is understood that
the collection in the Museum of that Institution is con-
fined to specimens taken on the borders of Devon and
Cornwall/1 I have also received from this gentleman,
whose diligence and tact in observing facts in Natural
History is equalled by his kindness and liberality in im-
parting his information, a very young specimen from the
Cornish coast, which is extremely small, being not more
than a line in breadth. It was sent to me with some
other specimens of various very small Crustacea, apparently
taken from sea-weed ; it is quite perfect, although so small,
and is of a very pale grey colour, with small dark dots.
Such is the amount of our knowledge of this species as an
inhabitant of our coasts.

The several species are found in great numbers on the
sargasso or gulf-weed, amongst which they breed, live, and
die. One species is particularly mentioned by Sloane in his
Natural History of Jamaica, as being found on the Sargasso

138

GRAPSIDvE.

and other submarine plants growing on the north side of
that island ; and adds that, " Columbus, finding it alive on
the sargasso floating in the sea, concluded himself not far
from some land, in the first voyage he made, on the dis-
covery of the West Indies." They are, however, found
wherever the gulf-weed floats ; and it is doubtless from
some accidental drifting of this plant towards our own coast,
that we owe the addition of one species to the British
Fauna.

As has been already observed, there are, doubtless, at
least three distinct species of the genus. As the British
specimens have been named by Dr. Leach, and are cer-
tainly distinct from that ordinarily found, I have thought
it right to retain his name ; and shall be glad to find that
the investigation of the genus by some competent person
has led to the adoption of sound specific characters by
which the different species may be distinguished.

DEC APOD A. LEUCOSIADM.

BRACHYURA.

GENUS EBALIA, LEACH.

CANCER, Pennant, Montagu.

LEUCOSIA, Leach.

EIJALIA, Leach, Edwards, &c.

Generic Character. — External antennae extremely minute, in-
serted in the inner canthus of the orbit. Internal antenna; lying
in oblique fossae, which are entirely separated by a small process
of the epistome, and concealed by the front. External pedipalps
elongato-triangular, reaching forwards to the margin of the epi-
stome ; the internal footstalk gradually acuminated, the third joint
internally palpigerous. Anterior legs large, equal, the hand in-
flated, those of the male larger than those of the female ; the other
legs shorter than the first pair, diminishing gradually in length,
terminating in a slightly curved, rather strong claw. Abdomen
seven-jointed, but with several of the middle joints confluent ;
that of the male narrow, gradually diminishing from the third
joint : of the female very broad, the last joint very small, abruptly
narrower than the preceding. Carapace rhomboidal, with the
angles more or less truncated or rounded ; front produced, ele-
vated. Eyes very small. Orbits with two small fissures on the
superior margin.

OF this genus, which forms the English representative
of the family Leucosiada, there are three distinct species
found on our coasts. These are sufficiently distinct in
several very tangible and essential characters ; and I
am surprised to find that Dr. Milne Edwards should con-
sider them merely as varieties. The distinctions will be

140

GENUS EBALIA.

particularly pointed out in the descriptions of the several
species. At present I am not aware that either of them
has been found in any other locality than on our own
coasts ; but Dr. Edwards describes a species existing in
the French Museum, and I 'have specimens from Mr.
Cuming's collection from the western coast of America,
which must be referred to this genus, but belonging to a
new and very remarkable species. The genus was formed
by Dr. Leach, who, with great propriety, separated it
from his genus Leucosia, to which he had at first referred
the species then known.

The family of which this genus forms a part is perfectly
natural and well defined, and contains many very inter-
esting forms, all of them so characteristic as to exhibit
at once their close relation to each other.

PENNANT S EBALIA.

141

DECAPODA. LEUCOSIADjE.

BRACHYURA.

PENNANT'S EBALIA. LEACH.
Ebalia Pennantii.

Specific cliaracter. — Carapace granulated, with an obtuse elevated transverse and
longitudinal ridge, forming a cross ; latero-anterior margin divided into two lobes
by a fissure ; abdomen with the third to the sixth joints united.

Cancer tuberosus, PENNANT, Brit. Zool. IV. t. ix. a, f, 19.

Ebalia Pennantii, LEACH, Malac. Brit. t. xxv. f. 1 — 6. Zool. Miscell.

III. p. 19.

THE carapace in Ebalia Pennantii is rhomboid, rather
broader than it is long, the angles rounded, the latero-
anterior margin slightly sinuous, and divided by a small
fissure ; the posterior margin is rounded ; the front elevated
and emarginate ; the orbits very small, and with two small
fissures above ; the carapace has an elevated cross, formed
by a rounded longitudinal ridge crossed by a transverse
one ; the whole posterior portion is elevated, and the
anterior part slopes suddenly from the obliquely transverse

142

LEUCOSIADJE.

ridge on each side ; the surface is everywhere distinctly
granulated. The first pair of legs are the longest and are
equal ; the arm is trihedrons, the wrist short and slightly
inflated, the hand rounded, inflated, externally carinated,
the fingers furnished with two very minute ridges on the
outer surface ; the whole granulated. The remaining pairs
of feet are slender, the joints rounded, the terminal one
slightly curved. The whole of the parts about the mouth,
particularly the foot-jaws, distinctly granulated, the granu-
lation appearing almost like minute pearls. The abdomen
in the male is triangular and more than twice as long as
it is broad ; the third to the sixth joints united, — in the
female it is much rounded, nearly as broad as it is long,
the terminal articulation abruptly much smaller than the
preceding, to which it is, as it were, a mere appendage.

Colour reddish brown, paler beneath, the abdomen in
either sex often symmetrically spotted with red. I have a
specimen obtained by Mr. Me Andrew, and to whom I am
indebted for it, which is all over of a lovely bright rose
colour.

This species, which is the largest of the genus, is about
five-eighths of an inch long, by two-thirds broad. These
are the dimensions of the carapace of a female specimen
in my cabinet from the coast of Devon ; and Dr. Leach
speaks of female specimens half as large again as his figure,
which would correspond with mine, or perhaps rather ex-
ceed it. It was first described by Pennant, from speci-
mens in the Portland Cabinet, which were probably ob-
tained at Weymouth, a locality in which another species,
E. Bryerii, was also first discovered. It was afterwards
found on the coast of Devonshire, from whence I have
obtained it, through the kindness of my friend Walter
Buchanan, Esq., who procured it at Exmouth. It is men-

PENNANT'S EBALIA. 143

tioned in the following terms by Mr. Embleton, in his
Catalogue of the Poclophthalmous Crustacea of Berwick-
shire and North Durham. " A single specimen, taken at
Redhaugh, Berwickshire, in the collection of Dr. John-
stone, and another in my own, taken in Embleton Bay,
are the only ones which have fallen under my notice. In
both, which are females, the abdominal covering is marked
with two rows of bright scarlet spots, a character not
noticed by Dr. Leach." Its occurrence as an Irish species
is thus detailed by Mr. W. Thompson.* " Although this
species must be considered rare, it is less so than E. Bryerii
and E. Cranchii. A specimen (from Cork ?) is in Mr. J.
V. Thompson's collection. In September, 1836, one was
dredged up from deep water in Belfast Bay, by Mr. Hynd-
man, and subsequently another was similarly obtained
there by Dr. Drummond. Several were procured in the
same locality by the collectors attached to the Ordnance
Survey, who likewise dredged a specimen in Larne Loch.
To Mr. G. J. Allman I am indebted for one which he
found in Dublin Bay. Three examples of the E. Pen-
nantii were brought up alive in the dredge from a depth
of fifty fathoms, off the Mull of Galloway, by Captain
Beechey, R.N."f

Its occurrence on the eastern coast of Scotland is also
well attested, and I have before me an immature female
specimen,! obtained by Mr. H. Goodsir, who notices its
being generally found on stony bottoms, and on fishing-

* 'Ann. and Mag. Nat. Hist.' vol. x. p. 286. f Ibid. vol. x. p. 21.

£ The specimen here alluded to was considered by Mr. Goodsir as belonging
to a distinct species ; but from a careful examination of several specimens, I am
satisfied that it is the present species at an immature age. The form of the ab-
domen is the only character in which it differs, and this has the comparatively
narrowed form which always belongs to this part in the young female in all the
Brachyura.

144

LEUCOSIADJ3.

banks. Professor Forbes informs me that he has repeated-
ly procured it.

The above account of the localities in which this species
has been found, warrants us in believing that it is not so
rare as has been imagined ; and that its unfrequent occur-
rence is to be attributed to its deep-water habits, rather
than to its actual scarcity. As far as I have had oppor-
tunities of judging, females are much more numerous than
males.

EBALIA BRYERII. 145

DEC A POD A . LEUCOSIADM.

BRACHYURA.

BEYER'S EBALIA.
Ebalia Bryerii. LEACH.

diameter. Carapace slightly and minutely granulated ; lateral margin
t-iitire, somewhat re volute at the angles ; two tubercles on the cardiac region,
and one on each of the branchial in the male ; these parts very tumid in the
female. Abdomen in the male with the third to the fifth joints united ; in the
female, the fourth to the sixth. Arm not more than twice as long as it is broad.

(:< nicer tumcfuctiis, MONT. Trans. Linn. Soc. IX. p. 86. t. ii. fig. 3.

(fcem. auct.)
ia Brycrii, LEACH, Mai. Podoph. Brit. t. xxv. figs. 12, 13.

THE carapace in the male is somewhat flattened, de-
pressed in the centre, and transversely hollowed imme-
diately behind the front, which is considerably raised, and
slightly emarginate. The branchial regions and the car-
diac region are raised, the elevations in the male being
distinct, in the female so tumid as to form a general eleva-
tion of the whole of the posterior two-thirds of the cara-
pace, abruptly sloping to the margin, which is turned up
at the sides. The orbits are very small, and the fissures in
their superior margin indistinct. The surface is minutely
and almost obsoletely granulated. The arm in the male
is less than twice as long as it is broad, with a projection
on the inner side, and furnished on each edge with a few

L

146 LEUCOSIAD^E.

minute but distinct tubercles; the hand is somewhat
tumid, robust, and the fingers slightly grooved. The re-
maining feet slender, and little different from those of the
former species. The foot-jaws and other parts about the
mouth, as well as the whole surface, are nearly smooth.
The abdomen in the male is triangular, about twice as
long as it is broad, obsoletely carinated, the third, fourth,
and fifth joints united, the terminal one with a small promi-
nent point directed backwards. In the female the general
form of the abdomen much resembles that in E. Pennantii,
but the fourth, fifth, and sixth joints are united ; it is
distinctly carinated.

Colour reddish white, the anterior margin and a few dots
on the carapace red, with indistinct reddish bands across
the abdomen in the female.

Length half an inch ; breadth very little exceeding the
length.

This species, which appears to be more rare than the
former one, although perhaps less so than E. Cranchii, was
first described and figured by Montagu, who at once ap-
preciated the distinction between it and Pennant's Cancer
tuberosus, and gives those distinctions with great discrimi-
nation. The carapace is more nearly rectangular ; the
whole surface nearly smooth, instead of being, as in the
former case, covered with distinct pearly granulations ;
the three distinct tuberosities of the carapace, so different
from the cruciform elevation in E. Pennantii, the raised
margin, together with the different form and composition
of the abdomen, and the more swollen and uneven cha-
racter of the hands, form altogether an accumulation of
distinctive characters so obvious that it is impossible to
account for the two species being for a moment considered
as mere varieties, as they arc by Dr. Milne Edwards.

BEYER'S EBALIA. 147

The first occurrence of this species on record is that
mentioned by Montagu, who received specimens from
Weymouth, where it was discovered by Mr. Bryer, to
whom Dr. Leach afterwards dedicated it. This distin-
guished zoologist subsequently procured it through Mr.
Prideaux from the Sound of Plymouth ; it is mentioned
by Mr. Couch in his Cornish Fauna as the only species he
had himself taken. I have received both sexes from Ex-
mouth, through the kindness of Mr. Buchanan ; and I
have a fine male specimen from Torquay, and a female
from Tenby ; for both of which I am indebted to Mr.
Bowerbank, by whom they were procured by dredging.
It occurs also in Mr. Bean's collection at Scarborough.
Mr. W. Thompson mentions its rare occurrence as an Irish
species, the only locality in which it has been found there
being Belfast Bay. Captain Beechey dredged it with the
former off the Mull of Galloway, in fifty fathom water.

Nothing is known of the habits of this species, nor in-
deed of either of the others of the genus. Its occurrence,
as far as we have any data, has always been in deep
water.

L 2

148

LEUCOSIADJB.

DEC APOD A.

BRACHYURA.

LEUCOSJADM,

CRANCfFS EBALIA.
Ebalia Cranchii. Leach.

Specific Character. — Carapace distinctly granulated, carinated ; with five tuber-
cles, two near together on the cardiac region, two distant on the branchial regions,
and one on the intestinal region ; latero-anterior margin nearly entire ; arm linear,
three times as long as it is broad.

Ebalia Cranclm, LEACH, Zool. Misc. III. p. 20. Malac. Brit. t. xxv.

f. 7—11. EDW. Hist. Nat. Crust. II. p. 129.

THE carapace in this species is more regularly rhombi
than in either Eb. Pennantii or Bryerii. The surface is
distinctly granulated; there is an obtuse longitudinal carina
extending the whole length, and there are five distinct
tubercles, of which two are very near each other on the
cardiac region, one on each branchial, and a single one,
larger than the others, on the intestinal. The latero-
anterior margin is almost entire, having only a slight sinu-
ation ; the front is emarginate, as is also the posterior
angle. The anterior pair of legs are equal, robust, and in

CRANCH'S EBALIA. 149

the male nearly twice as long as the carapace ; the arm is
somewhat trihedrons, and three times as long as it is
broad ; the wrist ovate, the hand slightly tumid, the fingers
shorter than the hand ; the remaining pairs of legs slender,
the second and third pairs in the male one-third longer
than the carapace. In the female the carapace is. in pro-
portion, a little longer than in the male, and the legs con-
siderably shorter. The abdomen in the male has the third,
fourth, and fifth joints, and the female the fourth, fifth, and
sixth, united ; in the former the penultimate joint is emar-
ginate in the anterior margin to receive an angular projec-
tion in the posterior margin of the terminal joint.

Length of the carapace half an inch. Colour yellowish
red, the female paler.

The male of this species so nearly resembles that of E.
Bryerii, that without very careful examination they may
very readily be mistaken for each other. The principal
distinctive characters are to be found in the form and pro-
portions of the arm, and the size of the granulations on
the surface. The arm in E. Cranchii is three times as long
as it is broad, and without any dilatation or protuberance
on the inner side ; in E. Bryerii the arm is scarcely twice
as long as it is broad, and is furnished with a distinct pro-
jection on the inner side. In E. Cranchii the granulations
which cover the surface of the body and limbs are distinct
and somewhat prominent ; in E. Bryerii they are very
small, and depressed. The female in the present species
very nearly resembles the male ; in E. Bryerii the sexes
are very dissimilar.

This is the most rare of the British species of Ebalia.
It was discovered by the indefatigable and unfortunate
Cranch, in Plymouth Sound, where it was afterwards ob-
served, according to Dr. Leach, in considerable numbers ;

150

CORYSTTD.E.

it occurs in Mr. Bean's collection at Scarborough. In the
Frith of Forth it is mentioned by Mr. Goodsir as being-
very rare. Mr. Thompson records its occurrence as an
Irish species in Round&tone Bay, Connemara ; Mr. Ball
found several on the beach at Portmarnoch after a storm ;
and Captain Portlock obtained it " by deep dredging in
Belfast Bay, in the course of the Ordnance Survey."*

The vignette is an illustration of the sign Cancer, from
a thirteenth century drawing, contained in the Prayer-
book of Queen Mary in the British Museum.

* Thompson, Ann. and Mag. Nat. Hist. vol. x. p. 285.

DEC A POD A . COR YSTID.E.

RRACHYVRA.

GENUS ATELECYCLUS. LEACH.

. CANCER. Herbst.

CANCER (HIPPA). Montagu.

ATELECYCLUS. Leach, Edwards.

Generic Character. — External antenna with the basal articu-
lation very large, united to the floor of the orbit at the outer side,
and to the front above, thus separating the orbit from the anten-
nary fossa : the moveable portion inserted beneath the front, be-
tween the orbit and the antennary fossa. Internal antenna lying
longitudinally in the antennary fossae, which are, as it were, exca-
vated in the front. External pedipalps completely closing the
buccal opening, and advancing forwards to the base of the ex-
ternal antennae ; the third joint much longer than broad, ter-
minating in an oblique line, and giving attachment to the terminal
portion in a notch near the middle of its internal margin. Cara-
pace more or less approaching a circular form, evenly convex ; the
latero-anterior and lateral margins numerously toothed ; the front
moderately projecting, quinquedentate, the exterior tooth forming
the boundary of the orbit ; the hepatic regions small, the bran-
chial very large. Orbits, directed forwards, with a single fissure
beneath, and two above, which form a distinct tooth towards the
outer angle. Anterior legs very large and strong, short, com-
pressed, the hand carinated and ciliated above ; the fingers curved ;
the remaining pairs of moderate length, compressed., the ter-
minal joint long, acute, and nearly straight. Abdomen in the
male, five-jointed, in the female, seven-jointed.

This genus was established by Leach for a species found
by Montagu, and described by him in the eleventh volume
of the Linnsean Transactions, under the name of Cancer

152

GENUS ATELECYCLUS.

(Hippo) septemdentatus. There are now several other
species known, one of which A . cruentatus, is found on the
coast of France, and probably in the Mediterranean. It
appears very nearly to resemble our species, and may pos-
sibly be a variety of it. The group is a very natural one,
and its characters well defined, but its geographical distri-
bution is so extensive as to set all ordinary laws at defi-
ance ; I have a well-marked species, hitherto undescribed,
which was procured on the western coast of South America
by Mr. Cuming.

DEC APOD A.
BRACHYUR.4.

CIRCULAR CRAB,

153

CORYSTIDJE.

CIRCULAR CRAB.

Atelecyclm Jieterodon. Leach.

Specific Character. — Carapace nearly circular, the lateral margins with nine
teeth, alternately larger and smaller ; hairs of the legs very long.

Cancer (kippa) septemdentatus, MONTAGU, Trans. Lin. Soc. XI. t. 1. f. i.
Atelecydus „ LEACH, Edin. Encycl. VII. p. 430. Trans. Lin.

Soc. XL p. 313.
„ hcterodon LEACH, Malac. Brit. t. ii.

THE general form of the carapace of this species is so
nearly circular, as to distinguish it at first sight from all the
other brachyurous Crabs of our coast. The lateral margins
with the front form somewhat more than a semicircle, and
the latero-posterior margins form three sides of a nearly
regular octagon. The whole circumference is fringed with
hair. The lateral margin on each side is furnished with
nine teeth, which are alternately a little smaller and larger;
the front is tridentate, the middle tooth being rather the

154

COHYSTIDJB.

longest ; the whole of the teeth are slightly denticulate.
The carapace is granular, moderately elevated, and the
regions not very distinct. The orbits are open forwards,
and have two fissures in the upper and one in the lower
margin, the two former being the boundaries of a small
projecting tooth. The anterior pair of legs are large and
strong, compressed, and, when at rest, closing accurately
against the under part of the body. The outer and upper
surface of the wrist is furnished with short lines and warts
of minute raised points, and there is a spine on the inner
and anterior angle. The hand, which, with the fingers, is
incurved, has five longitudinal lines of small raised points,
besides similar ones on the superior and inferior margins.
The fingers are compressed, curved, slightly toothed, and
meet only at the points. The remaining legs are slightly
compressed, of moderate length, and the whole are fringed
with long hair. The abdomen in the male is five-jointed,
nearly linear, slightly hollowed on the sides, the terminal
joint triangular : in the female it is seven-jointed, very
slender, being three times as long as it is broad, the ter-
minal joint elongate and somewhat cordate.

The colour is reddish white, with red spots ; the anterior
feet red, the fingers black ; the hair light brown.

The carapace of a full-sized male is about an inch and a
quarter in diameter ; the female considerably smaller.

The credit of the discovery of this species is due to Mon-
tagu, who found it on the coast of Devonshire, where it
has since been found, as Leach observes, in great plenty in
deep water. Mr. Couch, in his Cornish Fauna, observes
that it is " common in the stomachs of fishes, chiefly cod-
fish and rays, from the depth of twenty to fifty fathoms.
They must abound at these depths, as I have found more
than thirty in a single fish, and almost every ray opened

CIRCULAR CRAB. 155

for several days in succession, was found to contain them."
I have obtained it from the Welch coast ; and I find a
very young specimen amongst some rare Crustacea kindly
forwarded to me from Scarborough by Mr. Bean. It has
been found on the coast of Scotland, in the Frith of Forth,
both by Mr. Stephenson of Edinburgh, as stated by Leach,
and by my friend Mr. Harry Goodsir, who, however, states
that it is rare. I have lately received a specimen which
was taken from the stomach of a cod, off the coast of
Zetland, by my friends Mr. M' Andrew and Professor
Forbes. The accuracy and detail which characterize
all the observations of my friend Mr. W. Thompson of
Belfast, induce me to quote at length his account of this
species as belonging to the Fauna of Ireland. " Mr. Tem-
pleton notices a Crab of this species as found by him in the
stomach of a codfish, Jan. 17, 1817. In Mr. J. V.
Thompson's collection is an Irish specimen, probably from
Cork. In January 1839 I obtained a perfect adult male
from the stomach of a brill, (Pleuronectes rhombus,) taken
at Ardglass, County Down ; it somewhat exceeds in size
that figured by Leach, which again is larger than Montagu
represents the species. The circumstance of the species
being found in the stomachs of the cod and brill would in-
dicate its being an inhabitant of deep water. In the
Ordnance collection are examples of this Crab from Mo-
ville (Co. Donegal), Portrush, near the Giants Causeway,
and Carrickfergus. Mr. R. Ball has twice obtained it on
the Dublin coast ; on one occasion many specimens were
found by him on the beech at Portmarnoch after a great
storm."" In confirmation of Montagu's and Leach's obser-
vations of the great prevalence of male specimens — those
observed by the former having been all of that sex, and
the latter stating that two females only were found amongst

156

several hundreds of males, Mr. Thompson informs us that
the several Irish examples which he examined with refer-
ence to their sex were all males.

The testimony which I have given from these different
authors prove that the south-western coast, that of Corn-
wall and south Devon, is the locality in which this species
is most abundant, although it occasionally occurs far to
the North. That it is generally an inhabitant of deep
water, is also evident ; yet an observation of Mr. Thomp-
son's would seem to show that the spawn is deposited,
and that the young continue to reside, in shallower
depths. " In the month of September 1835," he observes,
"• I obtained several small living specimens of Atelecyclus
(carapace about two lines in length) in rock-pools, ac-
cessible at low water." Beyond these observations, we
know nothing of its peculiar habits.

DEC A POD. 1 . CORYSTIDJS.

BRACHYURA.

GENUS CORYSTES. LEACH.

CANCER. Penn., Herbst.

ALBUNEA. Fabr., Bosc.

CORYSTES. Latreille, Leach, Edwards.

Generic Character. — External antennce very much developed,
longer than the carapace, setaceous, ciliated ; the basal joint
thick, nearly cylindrical, inserted immediately beneath the eye in
a hiatus of the orbits ; the second joint also nearly cylindrical,
bending downwards and inwards, approaching its fellow, so that
the third joint is articulated at right angles with it, and stands
forwards in contact with that of the other side — this is cylindrical,
and twice as long as it is broad ; the remaining joints, like the
former, are nearly cylindrical, and fringed with hair. Internal
antennce folded longitudinally. External pedipalps long, narrow,
standing forwards as far as the origin of the internal antennae,
leaving an aperture between themselves and the epistome directed
forwards ; the third joint longer than the second, and terminating
forwards in a narrow and pointed process, extending beyond the
origin of the fourth joint, which is articulated in a notch in the
inner margin. Anterior legs, equal, subcompressed, with the
fingers deflexed ; in the male twice as long, and in the female as
long as the body, the remaining legs of moderate size, compressed,
ciliated ; the terminal articulation very long, straight and acute.
Abdomen in the male five-jointed, in the female seven-jointed; the
first and second joints visible from above, and on nearly the same
plane as the carapace. Carapace much longer than it is broad,
elliptical, with the latero-anterior margins toothed; the rostrum
triangular ; orbits transverse, with two fissures above. Eyes little
thicker than their peduncles, couching outwards and a little down-
wards in the orbits.

158

GENUS CORYSTES.

The present genus forms a very obvious approach to the
division of the Anomoura of Edwards. Its deviations from
the typical Brachyura are numerous and striking, and
consist in the general form of the body, the relations of the
buccal opening, the external pedipalps, the epistome, and
the arrangement of the first joints of the abdomen, and the
posterior pair of legs. There is, at present, but one species
of the genus known ; but it has a very nearly allied repre-
sentative in the new world, the Pseudocorystes armatus of
Edwards, discovered by M. Guy on the coast of Valparaiso,
and found by Mr. Cuming and by Mr. Darwin in the
same locality.

DEC APOD A.

BRACHYURA.

MASKED CRAI3.

159
CORYST1D&.

MASKED CRAB.

Corystes Cassivelaunus.

PENNANT, Brit. Zool. iv. t. vii. p. 6.
HERBST, 1. 1. xii. f. 72. Mas.

„ t. xii. f. 71. Fern.
FABR. Suppl. 398.
LATR. Hist. Nat. des Crust, et Insect. VI. p. 122.

EDW. Hist, des Crust. II. p. 148. COUCH, Corn.

Faun. p. 74.
„ Cassivelaunus, LEACH, Edinb. Encycl. VII. p. 395. Mai. Brit. t. i.

THE carapace in this species is longer than it is broad, in
the proportion of nearly three to two ; convex, with the
regions somewhat distinctly marked, having a groove sur-

Cancer

„ personatus
Albunea dentata,
Corystcs dentatus,

160

CORYSTIDJR.

rounding the cardiac and genital regions, and another short
transverse depression over the intestinal region, forming
altogether, in many specimens, a remarkable similitude to
the features of the human face ; from which circumstance
T have given it the English name of " the Masked Crab.'"1
There are three acute teeth on each side of the carapace,
the first forming the external angle of the orbit ; the second
placed on the margin of the hepatic, and the third, which
is very small, on the margin of the branchial region : the
surface is covered with minute scattered tufts of very short
hair, scarcely distinguishable by the naked eye. The
rostrum is deeply notched. The orbits are minutely granu-
lated on the margin. The external antennoe are very long,
setaceous and doubly ciliated throughout their whole
length, as are also the pedipalps. The anterior feet in the
male are twice as long as the body; the arm nearly cylindrical,
and nearly the same length as the arm ; the wrist about
half as long and furnished with two spines on the inner
side ; the hand gradually enlarging forwards ; the fingers
considerably inflected, and ciliated. In the female these
feet are not longer than the body ; the hand scarcely
longer than the wrist, and somewhat gibbous. The re-
maining pairs of legs are compressed, and doubly ciliated.
The abdomen in the male is five-jointed ; the third becom-
ing abruptly narrower than the second ; and the terminal
one obtuse and rounded. In the female the first two joints
are very broad ; the third abruptly narrower, and, with the
remaining joints, forming an oval : in both sexes this part
is marginated with rather long hair.

The colour is pale red, passing into yellowish white ; the
arms rather deeper red. In the female the colours are
much less bright and clear than in the male.

The sexes of this species differ so much from each other,

MASKED CRAB. 161

particularly in the form and development of the anterior
legs, that Herbst describes them as distinct species, — an
error in which he was at first followed by Latreille, who,
however, afterwards corrected the mistake. It was first
discovered by Pennant, who gave it the name of Cancer
Cassivelaunus, for no very obvious reason. He gives as its
habitat " the deep between Holyhead and Red-wharf,
Anglesea." From the Welch coast I have also received it
from Mr. Eyton ; from Torquay through the kindness of
Mrs. Griffiths ; and it occurs in Mr. Bean's collection
at Scarborough. It is generally rather a deep-sea species ;
and is occasionally thrown on shore " after storms or gales
of wind that have been tending towards shore." In May,
1843, at Saudgate, I took a single specimen with the
dredge, and on the following day ten more in the shrimp,
trawl ; these were all females. I have likewise obtained it
at Hastings, where the late Mr. Hailstone also mentions
having seen it caught by the trawlers. Mr. Couch, in his
Cornish Fauna, mentions it as " scarcely common, which
may be accounted for from its habit of burrowing in the
sand, leaving the extremities of its antennae alone projecting
above the surface. These organs," adds Mr. Couch, " are
of some use beyond their common office of feelers ; perhaps,
as in some other crustaceans, they assist in the process of
excavation ; and, when soiled by labour, I have seen the
crab effect their cleaning by alternately bending the joints
of their stalks, which stand conveniently angular for this
purpose. Each of the long antennae is thus drawn along the
brush that fringes the internal face of the other, until both
are cleared of every particle that adhered to them." As a
Scottish species, it is stated by Mr. H. D. Goodsir to be
rare. In Ireland it has been repeatedly taken. Mr. Wm.
Thompson mentions having dredged a number of very small

M

162

COBYSTIDvE.

specimens from a sandy bottom in the open sea ; and he
states that the antennae in these young individuals are much
longer in proportion to the carapace than in the adult, —
some, with the carapace only three lines in length, having
the antennse six lines long. The habit quoted above from
Mr. Couch, of this species lying buried in the sand, with
the antennse only protruded, was also observed by Dr.
Drummond, and by Mr. Ball of Dublin.

According to Mr. Hailstone"^ observations, the spawn is
shed in April and May. I did not find any spawn attached
to any of the eleven females which I took at Sandgate in
the latter month.

•- ' . r >

DEC A POD A . HOMOLA DM.

ANOMOURA.

GENUS LITHODES. LAIR.

CANCER, Linn. Herbst.

INACHUS. Fabr.

MAIA. Bosc.

LITHODES. Latr. Leach, Edwards.

Generic character. — External antennce placed nearly in a line
with the internal, on the outer side, and a little beneath them ; the
basal joint being, as it were, imbedded between the anterior mar-
gin of the carapace and a process or elongation of the lateral mar-
gin of the buccal opening, which is enclosed only at the sides,
where the margins are nearly straight ; the second joint is fur-
nished with a spine on the outer side, and the third is long and
cylindrical. Internal antennce long, inserted beneath and some-
what external to the eyes ; the first joint nearly cylindrical, thick,
and bent downwards and inwards ; the second and third cylin-
drical, slender, elongated ; the terminal portion consisting of two
short, setaceous, multiarticulate filaments. External pedipalps
pediform, with the second joint short, broad, internally dilated and
toothed. Thorax with the posterior portion free and movable.
Anterior feet unequal, of moderate size, the fingers more or less
spoon-shaped ; the three following pairs very long, cylindrical ; the
fifth pair very small, adactylous, folded backwards beneath the
latero-posterior margin of the carapace. Carapace cordiform, with
the regions very distinct, spinous. Rostrum projecting horizontally.
Eyes not enclosed within orbits, but protected externally by a
strong spine ; the peduncles short, approximate. Abdomen large,
five-jointed.

This very remarkable genus was formerly placed amongst
the Oxyrhynchi on account of the form of the carapace,

M 2

164

GENUS LITHODES.

which greatly resembles many of that group. Its relation
to these, however, is only one of analogy ; and Leach was
the first to point out the discrepancies. The glimpse which
he caught of its true affinities is embodied in the observa-
tion that, "in the form of its pedipalps and external
antennae, and in the position of the eyes, it approaches the
Macrourous Malacostraca." It is, however, to Dr. Milne
Edwards that we owe the full development of its relations,
and its natural location in a group intermediate between
the Brachyurous and the Macrourous forms, and in close
association with Homola.

I have found it necessary to modify the generic charac-
ters previously given of this genus, founded as they were
upon the single species hitherto described. The posses-
sion of a second, discovered by Mr. Cuming on the eastern
coast of America, enables me to state that the membranous
condition of the abdomen is either merely a sexual, or
at most a specific distinction, as the specimen obtained
by Mr. Cuming, to which I have given the name of L.
Australis, is entirely covered with crustaceous matter.

NORTHERN STONE-CRAB.

165

DEC A POD A.

ANOMOURA,

HOMOLAD^E.

NORTHERN STONE-CRAB.
Lithodes Maia. Leach.

Specific character. — Rostrum furnished with eight spines ; one above, one be-
neath, and one on each side at the base, two about the middle, and terminating
in two, which are somewhat divergent. Carapace distinctly margined, with nu-
merous spines longer than those on the disk. Abdomen membranaceous, with
crustaceous patches representing the joints ; the first and last joint entirely
crustaceous.

Cancer Maia, LINN. Syst. Nat. I. 1046, 41. HERBST. I. t. xv. f. 87, p. 219.

„ liorridus, PENN. Brit. IV. t. vii. f. 14, p. 7.
Fnachus Maia, FABR. Suppl. p. 358.
Lithodes arctica, LATR. Gen. Crust. &c. I. p. 40. Emv. Hist, des Crust. II.

p. 186.
„ Maia, LEACH, Trans. Lin. Soc. xi. p. 332. Malac. Brit. t. xxiv.

THE form of the carapace is cordate, longer than it is
broad, exclusive of the rostrum ; the margin somewhat

166

HOMOLADJ3.

recurved all round, and beset with numerous very long and
strong spines, of which those on the latero-anterior margin
are regular, longer than the others, and six in number on
each side, including that immediately at the outer side of
the orbit. The surface is also covered with tubercles and
spines ; the regions distinct and elevated, excepting the
hepatic, which are very slightly developed. Rostrum one-
third as long as the rest of the carapace, projecting for-
wards, furnished with four spines at the base, of which
one is placed above and another (the longest) beneath,
and one on each side ; two other lateral spines near the
middle, and two terminal ones which are divergent. There
are no distinct orbits ; the eyes are contiguous at the
insertion of their peduncles, and stand forwards and out-
wards, being protected above by the rostrum and the
anterior margin of the carapace, between them by the
long inferior spine of the rostrum, and at the outside by
a strong spine. The anterior pair of legs are unequal, in
some cases the right, in others the left being the larger ;
they are covered with strong sharp spines, those on the
inner margin the largest ; the wrist nearly cylindrical ; the
larger hand robust, nearly as broad as it is long; the
fingers somewhat spoon-shaped, and furnished with small
tufts of hair above, the opposing margins tuberculated.
The second to the fourth pair of feet long, cylindrical,
furnished with strong spines ; the terminal joint compressed,
slightly curved and acute ; the fifth pair diminutive and
without spines. The abdomen is coriaceous, with regular
patches of crustaceous matter, representing the segments ;
the first is entirely crustaceous, very short, and extending
quite across the breadth of the abdomen, linear and spinous ;
the second, fourth, and sixth joints are represented each by
a pair of broad oval patches towards the margin ; the

NORTHERN STONE-CRAB. 167

third and fifth by much smaller marginal pieces between
the second and fourth, and the fourth and sixth respective-
ly ; the terminal joint is also nearly oval and entirely
crustaceous.

The colour is yellowish red ; the spines darker, the
under surface paler.

In. Lines.
Length of carapace ....... 5 0

Breadth of carapace ...... 4 0

Length of larger anterior leg . . . . .55

Length of leg of the third pair .... 8 0

This remarkable species must be considered as one of the
rarer of our British Crustacea. It is, strictly speaking, a
northern species, not having yet been found farther south
than the Isle of Man ; with the exception of a specimen in
the Museum of Trinity College, Dublin, recorded to have
been taken on the coast of the County Wexford. I pos-
sess, through the kindness of my friend Mr. McAndrew,
several specimens, of various size, taken by him in dredging
in Loch Fyne ; they have also been dredged between the
Isle of Man and the Mull of Galloway. The Frith of
Forth (Goodwin), the Coast of Ayrshire (Thompson), of
Aberdeen and of Yorkshire (Leach), are localities where
this crab has at different times been obtained ; and I have
a specimen which was taken from the stomach of a cod on
the coast of Orkney. I am uncertain at what period they
cast their spawn. One of Mr. Mc Andrew's specimens,
taken in the month of June, was carrying spawn.

The synonymy of this species has become not a little
involved from some slight resemblance which it bears in its
external characters to the Mam Squinado, and from a very
obvious mistake into which Pennant has fallen in consider-
ing it identical with the Cancer horridus of Linnaeus, the
Parthenope horrida of subsequent naturalists. It is un-

168

HOMOLATXE.

necessary to say that to the latter there is not the slightest
affinity, nor even a remote external resemblance ; whilst to
the former the similarity is confined to the mere figure of
the carapace, and the spiny armature of the body.

DECAPOD A PAGURtDM.

ANOMOURA.

GENUS PAGURUS. FABR.

CANCER, Linn. Herbst.

ASTACUS, Pennant, Degeer.

PAGURUS, Fabr. Bosc. Lam. Latr. Leach, Edwards.

Generic character. — External antennae inserted in the same
line with the peduncles of the eyes, and furnished with a large
moveable spine, which represents the palpus of this organ ; the last
joint of the peduncle long, slender, and cylindrical ; filament com-
posed of many articulations, very long and setaceous. Internal
antenna?, placed immediately above the ocular peduncles ; the first
joint nearly globular ; the second and third elongate and slender,
the terminal portion consisting of two setce, the superior com-
pressed, hairy ; the inferior shorter, filiform. External pedipalps
pediform, having five exserted joints ; the palpus much developed,
nearly as long as the stalk. Anterior feet very unequal, one of the
hands being large and tumid ; the second and third pairs long,
ambulatory, with long curved nails; the fourth and fifth pairs
small, rudimentary, sub-didactyle, the latter more distinctly so than
the former. Cephalo-tkorax membranaceous, shorter than the ab-
dominal portion of the body. Carapace covering only the anterior
and inferior portion of the thorax. Abdomen greatly developed,
elongated, membranous, furnished on the upper surface with rudi-
mentary crustaceous plates. Tail crustaceous, of three joints,
the second joint with appendices on each side.

The family PAGURID^E, and particularly the present genus,
is composed of some of the most curious and anomalous
forms in the whole of the class. Whilst the Birgus, leaving
the water, and even disdaining to crawl on the ground like
the true land-crab, climbs the height of the cocoa-tree, and

170

GENUS PAGURUS.

feasts upon the young fruit, the species of the present genus
clothes its soft and defenceless body in the cast-off cover-
ing of the shelled mollusks, occupying the turbinated shells
of numerous species of gasteropoda, to which they close-
ly attach themselves by means of the hooked appendages
of the abdomen. From this peculiarity they have been
commonly termed Hermit Crabs. Of this genus there have
until lately been only two correctly distinguished species
known as indigenous to this country ; but the examination
by Mr. William Thompson of numerous minute paguri,
occupying various small shells found on the coast of Ire-
land, has led to the clear discrimination of four additional
species; which, with one from the coast of Devonshire,
make altogether no less than seven British species.

COMMON HERMIT CRAB.

171

DEC APOD A

ANOMOURA.

PAGURIDJE.

COMMON HERMIT CRAB.

SOLDIER CRAB.

Paourus Bernhardus.

«/

Specific cliaractcr. — Hands strongly tuberculo-granulated ; terminal joints of
the second and third pairs of legs spinous on the upper side, slightly tortuous.

Cancer Bernliardus,
A stacus „
Pagurits „

LINN. Syst. Nat. 1049.

PENN. Brit. Zool. (ed. 8vo.) IV. t. xviii. p. 30.

FABR. Suppl. 411. EDW. Hist. Nat. Crust. II. p.

215.
LEACH. Malac. Brit. t. xxvi. f. 1 — 4.

„ streblonyx,

The carapace in this species has the anterior margin
hollowed on each side above the insertion of the eye-stalks.

172

PAGURID.E.

forming a short obtuse-angled rostrum. The eye-stalks
are short, thick, armed with a broad, flattened, oval or
lanceolate tooth. The third joint of the internal an-
tenna) scarcely extending beyond the basal portion of the
external ; the second joint of the latter is armed on its
outer side with a sharp tooth ; its palp spiniform, longer
than the eye-stalks, slender, and curved. The anterior
pair of legs very robust, thick, unequal, the right being
ordinarily the larger, — furnished with numerous isolated
tubercles, more or less spinous ; the wrist, which is nearly
as long as the hand, is dilated and spinous at the inner
margin ; the fingers obtuse and strongly tuberculated.
The second and third pairs of feet spinous on the upper
side, the last joint very long, strong, compressed, slightly
twisted, and a little thickened towards the extremity.
Posterior pairs of feet rudimentary, terminating in an
extremely short, flattened pincer. Abdomen in the female
furnished with four ovigerous false feet, each consisting of a
basal joint, which is elongate and cylindrical, and two
terminal laminar branches ; the fourth much the smallest.
In the male there are three false feet, composed of a basal
and a double terminal joint, one finger of which is laminar
and large, the other rudimentary. The terminal joint of
the abdomen is notched.

The general colour is red, passing into yellow ; the abdo-
men brown. Usual length of the adult about five inches.

I have thought it right to follow Dr. Edwards in
resuming for this species its generally received name, as it
is, in all probability, the one which Linnseus assigned to it,
notwithstanding the doubt which led Dr. Leach to reject
it, and to substitute for it the name of Streblonyx, in
allusion to the peculiar tortuosity of the terminal joints of
the ambulatory legs.

COMMON HERMIT CRAB. 1 73

This species is extremely common, inhabiting, in the
course of its growth, almost every species of turbinated
shell existing on our coasts ; but in its adult state requiring
a habitation not smaller than the full-sized whelk, (Bucci-
natum undatum,) in which it is constantly found. Occu-
pying, in the early stages of its growth, the small species
of Litorina, of Natica, of Buccinum, of Murex, &c. When
it becomes too large for its existing dwelling, it leaves it,
and seeks for one not merely large enough for its present
occupation, but sufficiently so to admit of a certain degree
of further increase. Hence we often find individuals in
shells considerably larger than would be sufficient to pro-
tect them.

It is a question of some interest whether the Hermit
Crab always chooses for its habitation a shell already
empty, or whether it actually kills and devours the inha-
bitant of one that suits its size, and then takes possession of
its violated home. The latter I believe to be true, in
many if not in most cases ; certainly, however, not in all,
as we often find the Hermit occupying an old and long-
abandoned shell. But so much more generally is it found
in fresh shells, that it can scarcely be doubted, even on this
ground alone, that it often obtains its habitation by
violence. The fishermen on the coast are fully persuaded
of this ; and an intelligent person of this class at Bognor
assured me that the fact has often been observed by him-
self and others. He stated that the aggressor seizes its
victim — the whelk, for instance, — immediately behind the
head, and thus kills or disables it, then eats it, and finally
creeps into and appropriates its vacant shell. It holds on
with great force and tenacity by means of the terminal
appendages ; and if taken hold of when running about,
which it does with great rapidity with its usurped shell

174

PAGURIDJ3.

attached, it draws itself in with a sudden snap, and then
resists every attempt to pull it out, closing the aperture
with its stout strong legs and pincers, and thus also pro-
tecting the soft membranous abdomen.

The Hermit Crabs are much employed by the fishermen
(who call them " Wigs," or possibly " Whigs,'"1) as bait
for cod ; for which purpose they answer very well for
immediate use, although the original possessors and build-
ers of the house, the whelks, are much preferred for night-
lines, as remaining more firmly on the hook. They are
taken in great numbers in prawn-pots for this purpose.

The species is very widely distributed, and exists in
every part of our coast in great numbers, being continu-
ally taken in the dredge, the keer-drag, and the prawn
and lobster pots.

P1UDEAUX S HERMIT CRAB.

DEC A POD A.

ANOMOURA.

175

PAGUR1D&.

PRIDEAUX'S HERMIT CRAB.

Pagurus Prideauxii. Leach.

Specific Cliaracter. — Hands simply granulated ; internal antennae half as long
again as the eye- stalks ; terminal joints of the second and third pairs of legs
nearly straight, grooved on each side.

Pagurus Prideaux,
„ Prideauxii,

LEACH, Malac, Brit. t. xxvi. f. 5, 6.
EDW. Hist. Nat. Crust. II. p. 216.

THE present species resembles the foregoing in so many
respects, that it had doubtless been mistaken for it by
observers previous to its detection by Leach : it differs,
however, from it in several well-marked characters. The
anterior margin of the carapace has no median projection ;

PAGURID^E.

the lateral portions of the carapace are more exclusively
membranous ; the hands, instead of being strongly tuber-
culated, are merely granulated, and the wrists, on which,
in P. Bernhardus, the tubercles become spinous on the
inner margin, are in this species furnished with small
tubercles ; the hand and wrist are elevated along the
median line of the upper surface. The ambulatory legs
are nearly smooth, and the terminal joint is grooved longi-
tudinally on each side, and is not twisted. The eye-stalks
are short and very thick, and the extremity, where the
eye itself is inserted, is globular. The spiniform palp of
the external antennae is more slender and less curved than
in P. Bernhardus. It is usually of considerably smaller
size, seldom exceeding two inches and a half from the front
to the extremity of the abdomen.

The colour is light reddish-brown.

The discovery of this species is due to Leach, who re-
ceived it from his indefatigable friend Prideaux, by whom
it was taken in considerable numbers in Plvmouth Sound.

w

It has since that been found on several other parts of
the coast. In Loch Fyne it has been taken by my friends
Professor E. Forbes and Mr. Mc Andrew ; and it has
also been taken in Ireland by Mr. W. Thompson and
Mr. Hyndman, " when dredging in Strangford and Bel-
fast Loughs, and in the open sea off Dundrum, county
Down.11 Mr. Thompson notices the very remarkable cir-
cumstance of its being found " in every instance in-
habiting the shell invested by the Adamsia maculata {Ac-
tinia m. Adams).11 And Mr. Thompson proceeds to state,
" among the very numerous specimens of Paguri in my
collection, from all quarters of the Irish coast, and found
inhabiting shells of various species, not a P. Prideauxii oc-
curs except in connexion with the Actinia already named.1

HERMIT CRAB. 177

In a subsequent note on the same subject, Mr. Thompson
quotes Dr. Coldstream, who, in a communication in the
" Edinburgh New Philosophical Journal,11 remarks, in treat-
ing on the Actinia maculata obtained by him " at Torbay,
and in Rothsay and Kames Bays in Bute," that the shell
which it covered was always covered by a variety of the
Hermit Crab." It is also remarkable that " by Duges
the species have been found associated on the coast of
France." Whether this coincidence be accidental or other-
wise, it is difficult to decide without further observation ;
the facts, however, that Dr. Leach makes no mention of
its occurrence, and that Professor Edward Forbes states
that not a single specimen of the Actinia taken by him
in the course of a season was so associated, are much in
favour of their concurrence being fortuitous.

178

PAGURIDJE.

DEC A POD A.

ANOMOURA.

PAGURTDJE.

Pagurus cuanensis. Thompson.

Specific Character. — Anterior feet unequal, hisped, spinous ; the palp of the
external antennae as long as the eye-stalk ; their basal tooth denticulate on the
inner side, half as long as the palp.

Pagurus cuanensis,

THOMPSON, Report on the Fauna of Ireland, (Report of
Brit. Assoc. 1843. p. 267.)

THIS is the largest of four new species of Pagurus,
discovered by Mr. W. Thompson and named by him,
though without any description or specific character, in
his interesting report on the Fauna of Ireland, read before
the British Association for the Advancement of Science
at their session in 1843.

The carapace has the anterior margin slightly waved,
without any rostral projection. The eye-stalks are very long,
exceeding the basal portion of the external antenna? ; the
basal tooth of these half the length of the palp, straight,
acute, denticulate on the inner side ; the palp at least as
long as the eye-stalk, curved, and furnished with long, stiff,
adpressed hairs on the inner side. The anterior legs are un-
equal, the right the larger, covered with long stiff hair, and
furnished with numerous spinous tubercles ; the wrist with
a row of strong short spines on the upper margin ; the

PAGURUS CUANENSIS. 179

hand rather longer than broad, with its sides parallel and
straight, furnished with rows of spines on its upper sur-
face ; the fingers short, curved, robust, strongly tuber-
culated. The ambulatory legs long, compressed, hairy, with
the terminal joint very long, slender, and slightly curved.

Found (principally inhabiting the Triton Erinaceus) at
Portaferry and in Bangor Bay by Mr. Thompson-, and in
Belfast Bay by Dr. Drummond.

N 2

180

DEC APOD A.

ANOMOURA.

Pagurus ulidianus. Thompson.

Specific Cliaracter. — Carapace with a minute rostrum ; internal antennae the
length of the basal portion of the external ; anterior feet nearly equal ; hand
elongate, the sides parallel, roughly granulate ; inner margin of the wrist toothed.

Pagurus ulidice,

W. THOMPSON, 1. c.

THE carapace is smooth and shining ; the anterior mar-
gin hollowed over the insertion of the eye-stalks, having
a very small rostriform projection in the centre. The eye-
stalks thick, reaching nearly to the third basal joint of the
external antennse, with the basal tooth convex, triangular,
incurved at the point. The external antennse with the palp
having a double curve, its inner margin furnished with
three or four very slender long teeth. The internal antennse
about as long as the basal portion of the external. The
first pair of feet somewhat unequal ; the wrist roughly
granular, its inner margin toothed ; the hand with paral-
lel sides, granular, gibbous, slightly carinated on the outer
edge ; moveable finger toothed on the outer edge. The se-
cond and third pairs of feet slightly compressed.

A very small species, so nearly resembling the young

PAGURUS ULIDIANUS. 181

of P. Bernhardus that it is difficult at first sight to dis-
tinguish them, especially as the contortion of the termi-
nal joint of the ambulatory legs in the latter is not evident
in very young individuals. The hand, however, in the
present species is more elongate, its sides more nearly
parallel, and the granulations on its surface more even.
It was found by Mr. Thompson at Portaferry.

182

PAGURID^E.

DEC A POD A.

ANOMOURA.

PAGVRIDM.

Pagurm Hyndmanni. Thompson.

Specific Character. — Anterior legs unequal ; the hand oval, minutely granu-
lated, denticulate on the outer margin ; eye-stalks much shorter than the basal
portion of the external antennae ; internal antennae four times as long as the
eye-stalks.

Pagurus Hyndmanni,

W. THOMPSON, 1. c.

THE carapace in this species is perfectly smooth, its
anterior margin entire. The eye-stalks short and thick,
extending only to the third basal joint of the external
antennae ; the tooth at their base smooth, convex, and
acutely pointed. The external antennae about as long as the
second pair of legs ; the tooth on the outer side of the se-
cond joint smooth, simple, shorter than the third joint ; the
palp extending a little beyond the eye-stalks. The internal
antennas compressed, extremely long, being not less than
four times the length of the eye-stalks. The anterior legs
are very unequal, the right being the larger, granulated ;
the wrist of the larger with a series of small teeth along the
inner margin ; the hand oval, slightly convex, with an ob-

PAGURUS HYNDMANNI. 183

tuse tooth at the base, the outer margin delicately and evenly
denticulate ; the immoveable finger broad, triangular ; the
moveable one carinated, minutely toothed on the outer
margin, somewhat contorted in old individuals. The second
and third pairs of legs slender, the joints hairy on the
anterior edge ; the terminal one curved.

Total length of the only specimen which could be com-
pletely examined, six-tenths of an inch ; another specimen,
dried in its shell, is considerably larger.

This is one of the most interesting and elegant species
of this curious genus ; and the perfect condition of one
of Mr. Thompson's specimens enables me to give a more
satisfactory description of it than of some of the others
discovered by him. The form of the hand, the arrange-
ment of the parts about the ophthalmic and antennary
regions, the unparalleled proportional length of the inter-
nal antennae, distinguish it at a glance from every other
species.

It was found inhabiting Turritella terebra at Portaferry
by Mr. Thompson, and in Belfast Bay by Mr. Drummond.

The figure is enlarged to two diameters and a half.

184

DECAPOD A.

ANOMOURA.

PAGURIDvE.

PAGURIDJE.

SMOOTH HEEMIT CRAB.

Pagurm l<zms. Thompson.

Specific Character. — Carapace with the anterior margin raised ; eye-stalks short
and thick, reaching to the middle of the third joint of the internal antennae j
hand mimitely granulated, polished, with two obsolete teeth at the base towards
the inner side, and a minute tubercle at the outer.

Pagurus

THOMPSON, 1. c.

THE carapace of this pretty species is smooth and po-
lished, somewhat heart-shaped ; the anterior margin waved,
and slightly raised. The external antennse are of mo-
derate length, the basal tooth short, pyriform, acute ; the
palp doubly curved, nearly as long as the basal portion
of the antennse, slightly denticulated. The eye-stalks,
short, thick, extending a little beyond the middle of the
third joint of the internal antennse, which are slender.
The right anterior foot very much larger than the left ;
the wrist rather roughly granulated, denticulated along
the inner margin, which terminates in a tooth, contiguous
to which is a smooth obtuse tubercle ; the hand broadly

PAGURUS LJ2VIS. 185

ovate, convex, slightly granulated, polished, with two
small obsolete approximating tubercles near the base ; the
remaining second and third pairs of feet compressed ; the
joints carinated and slightly spinous above ; the terminal
joint long, slender, and slightly curved.

The general colour is yellowish testaceous, and there is
a distinct red mark extending the whole length of the
hand and bifurcating towards the fingers.

The specimens taken by Mr. Thompson at Portaferry
were very small, and being contracted by drying and
otherwise injured, afforded but little opportunity for a
minute description. Having, however, recently obtained
several large and perfect specimens amongst other Paguri
from Falmouth, through the kindness of Mr. Corks, I am
enabled to give the above description, and to add to the
locality afforded by Mr. Thompson, that of the coast of
Cornwall.

186

DEC APOD A.
BRACHYURA.

PAGURIDsE.

BOUGH-CLAWED HERMIT CRAB.

Pagurus Forbesii. Mihi.

Specific Character. — Eye-stalks club-shaped, as long as the basal portion of
the internal antennse ; hand with irregular depressions, rough and strongly
serrato-denticulate on the inner side.

OF this strongly characterised species, the carapace is
subordinate, smooth. The external antennae longer than
the anterior pair of legs ; the tooth at their second joint,
extending to the extremity of the third joint of the basal
portion ; the palp nearly as long as the basal portion of
the antennse, slightly curved, and fringed with a few long
hairs. The eye-stalks are club-shaped, as long as the
basal portion of the internal antennse. The anterior feet
slightly unequal, the right being the longer ; the wrist
and hand roughly granulated ; the inner margin of the
wrist toothed ; the hand ovate ; the surface of the right
with irregular depressions ; the margins strongly serrato-
denticulate. The second and third pairs of legs are slightly

PAGURUS FORBESII. 187

compressed, the fourth joint spinous on the upper edge ;
the terminal joint hairy, spinous beneath.

The whole of the legs with numerous small reddish
brown spots.

This curious species differs obviously from every other
inhabiting our coasts. I discovered it amongst some
small Paguri, which I received through the kindness of
Mr. Corks, of Falmouth, and which consisted of no less
than four species, all obtained by him on that coast. The
other species with which it was associated, were P. Bern-
hardus, Prideauxii, and lavis. Of the present new one
there was but a single specimen.

I have named this species after my distinguished friend
and colleague, Professor Edward Forbes, to whom I am
indebted for several interesting additions to the objects of
this work.

DEC A POD A.

ANOMOURA.

rORCELLANAD^E.

GENUS PORCELLANA, LAM.

CANCER.
PORCELLANA.
PORCBLLANA PlSIDIA.

Lin. Herbst. Pennant.
Lamarck, Edwards.
Leach, Desmarest.

Generic Character. — External antennae inserted at the outer
side of the eyes; the basal portion formed of three joints, of which
the second is the largest and the longest ; the terminal portion very
long, setaceous. Internal antennce concealed beneath the front,
very small. External pedipalps greatly developed ; the second
joint very large, rounded, with a single tooth on the outer anterior
angle ; the third joint much smaller, irregularly trigonal, and with
the remaining joints fringed with long hair at the edges. Anterior
feet very large, and more or less flattened ; the arm very short ;
the wrist long and dilated on the upper and inner edge, so as to
form a hollow space, in which the hand lies when retracted ; the
hand narrow at its base, becoming very broad forwards ; the
fingers strong and scarcely toothed. Second, third, and fourth
pairs of feet ambulatory, nearly cylindrical ; fifth pair very small,
didactyle, and doubled together at the latero-posterior angle of the
carapace. Carapace suborbicular, depressed. Eyes small, lodged
in an orbit, the parieties of which are imperfect, excepting above.
Abdomen very large, much developed, nearly as long as the cara-
pace, ordinarily closed against the sternum, composed of seven
distinct segments, and terminating in a broad fan-like tail, formed,
as in the MACROURA, of the terminal segment of the abdomen and
the appendices of the penultimate.

IN this genus we find a marked approach to the Ma-
crourous group in the development of the pedipalps and
of the tail, as well as in several other less obvious charac-

GENUS PORCELLANA.

189

ters. The form of the carapace, however, recalls that
of the true BRACHYURA.

After a very careful consideration, I cannot place the
genus ^Eglea in a different family from Galathea, nor the
present genus from jEcjlea ; I have therefore thought it
necessary to form one large family of the two families
Porcellaniens and GalatJieides of Edwards. They differ
in few important particulars, excepting in the comparative
development of the abdomen, and a corresponding differ-
ence in their natatory powers ; and the general form is so
similar when the abdomen of the present genus is displayed,
as to show to the most casual observer how near is the
affinity.

190

DEC APOD A.

ANOMOURA.

PORCELLANADJS.

PORCELLANADJE.

HAIRY PORCELAIN CRAB.

Porcellana platycheles.

Specific Character. — Front with three flattened triangular teeth, the middle one
the longest, and slightly grooved ; hands very large, hairy on the outer edge ;
fingers triangular ; wrist with a denticulated lobe at the base.

Cancer platyclieles,
Porcellana „

PENNANT, Brit. Zool. (8vo.) IV. t. iv. f. 2, p. 9. HERBST.

t. ii. f. 6.

LAM. Anim. sans. Vert. v. p. 230.
LEACH, Diet. des. Sc. Nat. xviii. p. 55.
EDW. Hist. Nat. des. Crust, ii. p. 255.

THE carapace in this species is rather longer than
broad, the front trificl, the middle lobe or tooth rather
longer than the others, and having a slight median groove ;
the surface of the carapace polished, in young specimens
covered with short hair, which is longer at the margin,
where it is permanent ; a considerable depression behind
the genital region of the carapace ; the orbits much arched
above. The external antennae much longer than the cara-

HAIRY PORCELAIN CRAB. 191

pace. The anterior legs are large, flattened above ; the wrist
quadrilateral, the sides nearly parallel, rather longer than
broad, rounded beneath, furnished on the inner margin near
the base with a triangular lobe or tooth, which is slightly
denticulated ; the hand flattened above, the palmar portion
triangular, furnished on the outer side with long close
hairs ; the fingers triangular, slightly incurved, meeting
only at the tips, the moveable one deeply grooved through
its whole length, the inner edges slightly granulated. The
second to the fourth pairs of feet, compressed at the sides,
rounded beneath, hairy ; the terminal joint very short. Ab-
domen with the centre slightly raised.

Colour reddish-brown, paler and yellowish beneath ; the
hairs brown.

Ordinary length of the carapace half an inch ; length
of the anterior pair of legs one inch and three-tenths.

The distribution of this species is extensive, and in some
localities it is also very numerous. I have received speci-
mens from various parts of our coast, from the Orkneys to
the Land's End. It is found also on several parts of the
Irish coast ; and it is plentiful on the coast of France, and
in the Mediterranean. Some of the largest and finest that
have come under my observation, were sent me by Dr.
Duguid from Kirkwall in Orkney. It is a littoral species,
being generally found under stones at low water. It bites
severely, as Dr. Duguid remarks ; and if seized by its
claws, has the power of throwing them off instantly to faci-
litate its escape.

This is a further example of the favourable influence of a
northern climate on the growth and development of parti-
cular animals, the specimens which are ordinarily taken
on the northern part of our coast, and especially those
which I received from Orkney, being much finer than those

192

PORCELLANADJE.

which I have obtained from the Mediterranean. A simi-
lar observation has already been made respecting Pisa
tetraodon, and I have noticed the same difference in several
other species. I have, however, lately received a very
large specimen from the coast of Cornwall, through the
kindness of Mr. Corks of Falmouth.

MINUTE PORCELAIN CRAB.

193

DEC A POD A.

ANOMOURA

PORCELLA NA DJE.

MINUTE PORCELAIN CRAB.

Porcellana longicornis.

Character. — Front three-lobed, the middle lobe with a deep groove ;
hands unequal, long, narrow, and convex.

PENN. Brit. Zool. iv. HERBST, II. t. xlvii. f. !'>.
LBACH, Diet, des Sc. Nat. XVIII. p. 54.
GRAY, Zool. Miscell,
EDW. Hist. Nat. Crust. II. p. 257.

( 'anccr

Pisidia Linnaeanu,
Leach //,
longicornis,

THE carapace is nearly circular, convex, nearly smooth,
with a distinct thin lateral margin ; the front with three
lobes, the middle one so deeply grooved as to appear bifid ;
there are a few obsolete lateral striae over the branchial
regions. The external antennae very long and slender ;
the internal of moderate length. The anterior pair of legs
very unequal, the larger being, in many cases, half as long
again, and nearly twice as broad, as the smaller one : in the
former, the arm is very short, the wrist large and quadrate,
the sides being parallel ; the hand is convex, very slightly

194

PORCELLANADJ3.

and obtusely carinated ; the fingers, in the adult, touching
only at the extremity, slightly tortuous ; the smaller hand
differs from the larger in being much more strongly cari-
nated and grooved ; the fingers are hairy on the inner edge,
and the immovable one bifid at the extremity. The re-
maining feet are slender, and scarcely hairy at* any period.
The abdomen is broad, smooth, and without hair.

The colour of the carapace varies very much ; it is gene-
rally pale red, frequently with irregular markings of dark
reddish brown, in other specimens of bright red.

The ordinary length of the carapace is from two lines to
two and a half.

This is a very pretty and a very common species. It is
found under stones a little beyond low-water mark, and is
very often brought up in great numbers with the oyster
dredge.

I believe that the Cancer longicornis of Pennant, C.
hexapus of Herbst, Pisidia Linnaana of Leach, P. longicor-
nis of the same author, Porcellana Leachii of Gray, and P.
acanthocJieles of Couch, are one and the same species, vary-
ing only according to age and sex.

DECAPODA . I *ORCELLANADJE.

ANOMOURA.

GENUS GALATHEA. FAHH.

CANCER, Linn. Degeer. Herbst.

AST AC us, Pennant.

GALATHEA, Fubr. Latr. Leach, Edwards.

Generic character. — Antennae inserted on the same transverse
line. External antennce longer than the body, the three basa
segments thick, the second not longer than it is broad ; the terminal
filament long and slender. Internal antennce inserted beneath the
eye-stalks, the peduncle elongate ; the last segment acute, multi-
articulate, ciliated beneath. External pedipalps with the last two
articulations neither dilated nor foliaceous. Anterior feet equal,
or nearly so, thicker than the others, the claw well- formed;
second, third, and fourth pairs offset simple, alike in form, with
acute nails ; fifth pair spurious, very slender, doubled above the
others within the branchial cavity, terminating in a rudimentary
hand. Carapace depressed, rather longer than broad, terminating
anteriorly in a sharp, more or less prominent, triangular rostrum,
which covers the base of the eye-stalks. Eyes large and bent
downwards. Abdomen longer and nearly as broad as the thorax,
six-jointed ; all of the joints without spines on the anterior mar-
gin, and terminating in a broad fan-like tail.

THE species of which this genus is composed, are few in
number, although it is probable that some have been con-
founded which are in reality distinct. The genus as it has
hitherto stood, according to Edwards and other late
writers, is composed of the genera Galathea and Munida of
Leach ; I have, however, on what appears to me to be

sufficient grounds, restored Leach's genus Munida ; which

o 2

196

PORCELLANAD^E.

now consists of Galathea rugosa of Fabricius, and a new
species obtained by Mr. Darwin, and through his kindness,
in my possession.

The reasons which have induced me to consider, with
Dr. Leach, that the forms which constitute the two fami-
lies Porcellaniens and Galatheides of Edwards, are properly
one group, have been already stated. Dr. Leach consi-
dered Galathea as the typical form of the family, as we
may conclude from his giving to it the name of GALA-
THEAD^E. I, how.ever, cannot but think that Porcellana
is the typical form, and that Galathea, with Munida,
JEglea, and Grimotea are aberrant, passing off towards the
Macrourous type ; although I cannot agree with Edwards
in considering these latter as true Macroura.

SCALY GALATHEA.

197

DEC A POD A.

ANOMOURA.

PORCELLANAD/E.

SCALY GALATHEA.

Galaihea squamifera. LEACH.

Specific character. — Rostrum short, with one central spine, and four on each
side, the hinder one the smallest ; anterior feet broad,'flattened, covered with
squamiform tubercles ; the hands externally, and the wrists and arms internally
spinous. Third joint of the external pedipalps longer than the second.

Cancer (astacus) squamifer, MONTAGU.

Galatltea squamifera, LEACH, Edinb. Encycl. VII. p. 393. Diet.

des Sc. Nat. XVIII. p. 51. Malac. Podoph.
Brit. t. xxviii. A. — Emv. Hist. Nat. Crust.
II. p. 275.

COUCH, Corn. Faun. p. 77.
THOMPS. Crust. Irel. 1. c. p. 105.

THE carapace, exclusive of the rostrum, is a little longer

198 PORCELLANADJE.

than it is broad, the lateral margins with strong acute
spines directed forwards ; the rostrum short, broad, trian-
gular, terminating in a strong acute spine, and with four
others on each side, of which the posterior is the smallest.
The first joint of the internal antennae short, and enlarged
on the outer side, strongly spined anteriorly ; external an-
tennae as long as the whole of the body from the rostrum to
the tail. External pedipalps longer than the rostrum, the
third joint longer than the second ; the latter trigonous
with a regular row of small teeth on the inner edge ; the
former with a few spines on the outer margin. Anterior
feet broad, flattened, the arm and wrist strongly spined on
the inner edge, without spines on the outer ; the hand with
smaller spines on the outer edge, none on the inner ; the
surface covered with small scale-like tubercles. The se-
cond, third, and fourth pairs of legs with a row of small
regular spines on the anterior margin.

The general colour of this species is a greenish brown ;
but some which I procured at Bognor were tinged with
red.

Length of the body from the rostrum to the end of the
tail, three inches ; such was the length of some of the speci-
mens which I obtained on the Sussex coast, but ordinarily
it is much smaller.

The first distinct account of this species appears to be
that of Montagu, which Leach quotes from his MSS. It
is, however, a common species all along the southern and
western coast. I have specimens from Cornwall, Devon-
shire, Dorsetshire, and Sussex. The largest I have seen
were procured by myself at Bognor, where they are often
taken in considerable numbers in prawn and lobster pots.
It is recorded as the most common Irish species, by Mr.
Thompson, who observes that it is found on all the coasts

SCALY GALATHEA.

199

of Ireland. It appears to be pretty much a littoral species,
occurring, according to both Dr. Leach and Mr. Couch,
under stones at low tide. I have, however, taken it by the
dredge in Swanage Bay, Dorsetshire, and in lobster-pots at
Bognor, and Mr. Thompson mentions its being dredged by
him in Ireland. This would intimate that they resort to
deeper water occasionally, and Dr. Leach particularly men-
tions that such is the case when they are young. Those,
however, which I procured in lobster-pots on the coast of
Sussex were adult and remarkably large.

The vignette below is from a picture by Crome of Nor-
wich, in the possession of Walter Buchanan, Esq.

200

PORCELLANAD.E.

DEC APOD A .
ANOMOURA,

PORCELLANAD/E.

SPINOUS GALATHEA.

Galathea strigosa. FABR.

Specific character. — Rostrum short, with one central spine, and three on each
side ; anterior feet broad, very spinous on both margins ; scarcely longer than
the bodies ; external pedipalps with the second joint longer than the third.

Cancer strigosus^
Astacus „
Galatliea strigosa.

spimgera,

LINN. Syst. Nat. XII. 1053. HERBST, II. p. 50, t. xxvi.

PENN. Brit. Zool. IV. p. 24, t. xv.

FABR. Suppl. 414. LATR. Gen. Crust, et Ins. I. p. 49.

LEACH, Edin. Encyc. VII. p. 398. EDW. Nat. Hist.

Crust. II. p. 273.
LEACH, Malac. Pod. Brit, xxviii. — B.

THIS beautiful species resembles the former, G. squami-
fera, in its general aspect, but may be distinguished from it

SPINOUS GALATHEA. 201

at the first glance when adult, by the size and arrange-
ment of the spines on the anterior feet ; and on a more
careful examination it may be distinguished from it at all
ages, by the relative length of the second and third joints
of the external pedipalps ; in the present species the former,
and in G. squamifera the latter, being the longer. The
carapace is of nearly the same proportions ; the rostrum
has seven spines, three on each side of the central one,
receding from it backwards and outwards. The lateral
margin armed with strong spines. The external antennae,
with the anterior extremity of the first joint furnished with
three long spines ; a large spine above the auditory tu-
bercle. External pedipalps short, scarcely extending beyond
the rostrum when stretched out ; the second joint much
longer than the third. Anterior feet of moderate length,
not much exceeding that of the whole body from the
rostrum to the tail ; depressed, and very spinous on all
sides, excepting the outer margin of the arm. Second,
third, and fourth pairs of feet, also furnished with several
strong spines. Abdomen with the second and third seg-
ment unarmed. Terminal segment (the central part of the
tail) much smaller at the extremity than at the base.

Colour reddish, with some blue transverse lines and
spots.

Length four inches.

I have thought right to follow Dr. Milne-Edwards in
considering this species as identical with Linnaeus'1 s Cancer
strigosus, notwithstanding Leaches decided opinion to the
contrary. It appears to me that the description of that
species, as given by Linnaeus, agrees perfectly well with
our specimens of Leaches G. spinigera.

It is found in nearly similar localities with the former, but
is certainly occasionally met with in deeper water. For

202

PORCELLANAD/E.

the following interesting account of its habits, and of the
earliest stage of its existence, as well as for the drawing of
that stage of its growth from which the vignette is taken,
I am indebted to my kind friend, Mr. Richard Q. Couch
of Penzance, whose investigations in this and many other
subjects of Natural History are well known. " This is a
common species throughout the whole of the south coast of
Cornwall, and I have also found it on our northern shores.
It frequents pools between tide-marks, where there are
loose stones and sand. It is, generally speaking, very
slow in its motions, though it will frequently move with
very great activity, especially when alarmed. From the
great length of its first pair of legs, its motions are always
retrograde. In walking its pace is tardy ; but in swim-
ming it darts from spot to spot with the rapidity of an
arrow. It is never seen in any exposed part of the pool,
but always seeks the shelter of stones, or some hole in
the rock, so that it can retire on the least alarm. 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 ; this I have often seen them do,
and always with precision. They are laden with ova
through the latter part of April and May, and the quantity
they produce seems to be between that of the long and the
short-tailed species. The Galathew are very tender, and
require great care in confinement ; they soon die, and
hence it is not easy to rear the young. I have on many
occasions hatched a very numerous family, but, like those
now before me, they soon die. I can only, therefore, offer
a description of them as they escape from the ovum.* As
they lie in ova, the tail is bent over the thorax, and the
termination rests on the space between the eyes. The tail

* See the figures in the next page.

SPINOUS GA LATHE A.

203

is about as long as the body, slender, and composed of
seven annulations ; it terminates in two diverging plates.
The last two annulations are of equal size and seem almost
blended in one. The terminal plates are armed posteriorly
with six bristles in each ; the external ones are short, stout,
and pointed, the others are long and slender. The cara-
pace is rounded and indented anteriorly, and the eyes are
large, sessile, and placed on a festoon of the shield. The
antennas are short, terminating in a tuft of bristles. The
first pair of natatory claws are three-pointed, and, besides
terminating in a tuft of setae, are armed also along their
anterior and posterior margins. The posterior claws are
in three pairs, the anterior two of which are bifid ; the
third or posterior are small, situated at the posterior mar-
gin of the shield."

204

PORCELLANADJ3.

DEC APOD A.

ANOMOURA.

PORCELLA NA DIE.

EMBLETON'S GALATHEA.

Galathea nexa. EMBLETON.

Specific character. — Hands hairy, without spines ; external pedipalps with the
second joint longer than the third.

(,'<(!< ttliea netra, EMBLETON, in Proceedings of the Berwickshire Club.
,, „ THOMPSON, Annal. Nat. Hist. 1. c. p. 255.

THE characters of this species approach nearly to those
of the two former species, and in some respects are inter-
mediate between them. The principal characters which
distinguish it from those species, are in the armature of
the hands, and the relative proportion of the different
joints of the external pedipalps. Agreeing with G. squa-
mifera in the absence of spines in the hand, being, in fact,
more free from them than that species, and thus more
especially differing from G. strigosa^ it agrees with the

EMBLETON'S GALATHEA. 205

latter in the comparative length of the joints of the ex-
ternal pedipalps or foot-jaws, of which the second joint is
longer than the third ; the spines of the rostrum are more
flattened than in the other species. Mr. Embleton states
that the " ligament of the shell " differs in colour in the
three species, being bright blue in G. strigosa, brown in G.
nexa, and blackish in G. squamifera.

There can be no doubt of the distinctness of this species.
The characters above named are very constant, and the
habitat is essentially different. It is also by far smaller
than either of the others, as I have seen many now from
various localities, none of them exceeding that figured by
Mr. Embleton, and most of them much smaller. I have
one specimen, with spawn, of which the thorax and
abdomen together are not more than an inch in length.

It is doubtless a deep sea species. Mr. Thompson's
specimens which I have before me, were obtained " from
the stomachs of cod-fish brought from the coast of Down
and Antrim to the Belfast market ; and in Dr. Drum-
mond^s collection are specimens which were similarly pro-
cured." I have several specimens which were taken by
Mr. McAndrew in dredging in Loch Fyne at a depth of
from twenty to seventy fathoms, and by that gentleman
and Professor Edward Forbes at Zetland.

DEC APOD A.

ANOMOURA.

PORCELLANAD^E.

GENUS MUNIDA. LEACH.

AST AC us. Pennant.

GALATHEA. Fabr. Latr. Leach, Edwards.

MUNIDA. Leach, Desmar.

Generic Character. — External antennas with the second and
third joints equal, basal joint very large ; the terminal filament
long and slender. Internal antennae, inserted beneath the eye-
stalks, nearly contiguous. Anterior feet long, slender, and some-
what filiform, spinous within and on the upper surface. Carapace
longer than it is broad, spinous at the margins; the rostrum,
forming a long, slender, acute spine, with two smaller ones above
its base, each immediately above the inner angle of the orbit, and
a small spine behind each of these. Abdomen strongly furrowed
transversely, with two or more of the segments furnished with
small spines on the anterior margin ; terminal joint (or central
portion of the tail) nearly as broad at its extremity as at its
base.

THIS genus was founded by Leach for the Galatliea
rugosa of Fabricius, and, as it appears, upon sufficient
grounds. The general habit of the animal, the form of its
rostrum, and the length and slenderness of the hands, with
other characters, appeared to point out a very marked dis-
tinction between this and all other species of Galathea of
Fabricius.

It, however, appears that no subsequent author followed
Leach in considering the generic distinction satisfactory
excepting Desmarest, who, however, merely followed Leach
on this and other occasions. My own impressions, however,

GENUS MUNIDA.

207

in favour of the generic separation of this form, have re-
ceived an interesting confirmation, in the existence of a
new and elegant species which I find among the fine col-
lection of Crustacea procured by my friend Mr. Darwin.
It possesses all the characters which I have recorded above
as generic, and in all of which our own species agrees,
whilst the specific distinctions are striking and obvious. I
have, therefore, thought it right to restore Leach's name
Munida to the genus, which now consists of two very
distinct species.

The vignette, by Mr. C. C. Pyne, represents part of
the coast between Hastings and Winchelsea.

208

PORCELLANAD.E.

DEC APOD A.

ANOMOURA.

PORCELLANADsE.

LONG-ARMED MUNIDA.
Munida Rondeletii. MIHI.

Specific character. — Anterior legs more than twice as long as the body; second
and third segments of the abdomen, the former with six, the latter with four
small spines on the anterior margin ; the other segments without spines.

Astacus Bamfficus, PENN. Brit. Zool. iv. t. xiii.

Cancer Bamfficus, HERBST, II. t. xxvii. f. 3.

Cokdliea rugosa, FABR. Suppl. 415. 2. LATR. Hist. Nat. Crust.

&c. VI. p. 198. LEACH, Malac. Pod. Brit. t.

xxix. EDW. Hist. Nat. Crust. II. p. 274.
„ Bamffia LEACH, Edinb. Encl. VII. p. 398.

iMiudda rugosa, LEACH, Diet, des Sc. Nat. XVIII. p. 52.

THE carapace is slightly elliptical, transversely rugose,
spinous on the lateral margins ; the rostrum formed of a

LONG-ARMED MUNIDA. 209

long styliform spine, nearly half the length of the carapace;
at the base of the spine, and above it, immediately over the
inner angle of the orbit, are two smaller spines, one on each
side, standing directly forwards, and behind each of these
another still smaller. The anterior pair of feet very long,
being nearly four times the length of the cephalo-thorax,
of nearly the same size throughout their length ; the arms
nearly three times as long as the wrist, and, as well as the
wrist, armed with a series of spines on the upper and on the
inner surface ; the hand enlarges towards the extremity ;
the fingers are very slender, and longer than the hand.
The remaining legs are long, slender, and cylindrical. The
whole covered with close, very short hairs. The abdomen
is very convex, the second segment furnished with six, and
the third with four small sharp spines.

The general colour is dull reddish yellow, with redder
markings.

Length of the whole animal, from the rostrum to the tail
inclusive, three inches ; length of the anterior legs, nearly
six inches.

This remarkable species appears to be far from common
on our coasts, although it is probably more numerous than
has been supposed, from its frequenting deep water. It was
found in Plymouth Sound by Mr. Prideaux ; I have re-
ceived it from Falmouth, through the kindness of Mr.
Cocks ; but it is not included in the Cornish Fauna by
Mr. Couch. I have it also from Zetland, where it was
taken by dredging by Mr. Me Andrew and Professor E.
Forbes ; Pennant received it from Bamffshire, and hence
named it A stacus Bamffius. Mr. Thompson, in recording
its repeated occurrence on the coast of Ireland, establishes
its habitat in deep water by stating several instances of its
being found in the stomach of the cod ; and still more re-

p

210

PORCELLANAD^E.

markably, by the fact of its having been " dredged alive in
water from one hundred and ten to one hundred and
forty fathoms in depth, off the Mull of Galloway." These
were all of them very small specimens. It is, in fact, an
inhabitant of deeper water than any other of the family,
not excluding Galaihea nexa.

I have taken upon me, in restoring the genus to which
this species belongs, to change the specific name. The dis-
covery of a second species, as before mentioned, has ren-
dered this necessary, as the latter is far more rugous in
every part than the present species ; and I have ventured
to name it in honour of its first describer.

DECA POD A . PA LlNURIDjE.

MACROURA.

GENUS PALINURUS. FABH.

CANCER, (Astacus). Penn.

PALINURUS. Fabr. Latr. Lam. Leach, Edw.

Generic character. — External antenna very thick and long ;
basal joint very large, and united with its fellow in front of the
mouth, forming a broad epistome ; the three following joints very
large and spinous ; the setae but little flexible, composed of nume-
rous short articulations. Internal antennce long, the basal portion
consisting of three long cylindrical articulations, terminated by
two short multi-articulate setae. External foot-jaws pediform.
Feet wholly monodactyle. The first pair thicker and shorter
than the others, with a spine at the termination of the penulti-
mate joint, constituting the rudiment of a thumb. Carapace sub-
cylindrical, with a strongly marked furrow separating the gastric
from the cardiac and branchial regions ; its anterior margin armed
with two very strong curved spines, standing forwards over the
eyes and the base of the antennae. Abdomen very much de-
veloped, being thick and long : the first segment without appen-
dages ; the four following furnished with false feet, single in the
male, double and hairy in the female. Tail very broad ; the base
only of each portion being crustaceous, the remaining portion
membranaceous.

THIS genus comprises several large esculent species, one
only of which is an inhabitant of our coasts. They are
found principally on rocky shores, and are very widely
extended. It would appear that they were well known

to the ancients, and esteemed as food ; and there is no

p 2

212

GENUS PALINURUS.

doubt that the Palinurus was the /capa/3os of Aristotle,
and the Locusta of Latin authors ; the latter name being
taken up by Belon, Rondeletius, and other writers of the
earlier period of the revival of science.

This genus is the sole generic representative of the family.
The characters are, however, so important and so strongly
marked, as absolutely to require this distinction.

The vignette is a view on the Thames at Chelsea, by
Mr. C. C. Pyne.

COMMON SPINY LOBSTER.

213

DEC APOD A .
MAC HOUR A.

PALINVKIDJE.

COMMON SPINY LOBSTEE.

Palinurus vulgaris. Latr.

Specific CJiaracter. — Lateral spines of the rostrum very large, triangular,
smooth above, strongly dentate on the anterior margin ; a strong spine at the
anterior margin of the carapace beneath the orbit.

Cancer (Astacus) Homarus, PENN. Brit. Zool. IV. t. xi. f. 22, p. 16.
Palinurus quadricornis, FABR. Suppl. 401. — LATR. Hist, des Crust. VI.

t. lii. fig. 3, p. 193.

LEACH, Edinb. Encyc. VII. p. 397. Trans.
Lin. Soc. XI. p. 339.

214

PALINURtD^.

Palinurus vulyaris,

LATR. Ann. du Mus. III. p. 391. Regn. Anim.
Cuv. IV. p. 8. — LEACH, Mai. Pod. Brit. t.
xxx.— EDW. HistNat. Crust. II. p. 292.

THE carapace is entirely covered with spines of various
size ; the sulcus separating the gastric and hepatic regions
from the posterior portion is deep and smooth ; the
central rostral tooth triangular : the lateral spines, which
cover and protect the eyes, are hroad, triangular, the
point sharp, the anterior edge furnished with a few strong
teeth ; at the hase of each is a strong spine : on the
anterior margin of the carapace, below the orbit, is a
very strong triangular spine, standing forwards. The
eyes are large, globose, with a contraction immediately
behind them ; and the peduncle is long, exposed, and
moveable. The external antennae are extremely long ;
the peduncle very thick and strongly spinous ; the basal
joint of each meets its fellow beneath, forming a broad,
smooth epistome, toothed at the anterior margin, its
centre tooth much larger than the others, — at the base
of this joint is placed the organ of hearing, in a tuber-
cle raised above the surface ; the remaining joints very
moveable, nearly cylindrical, with strong spines on the
upper and lower sides ; the setaceous portion very long,
composed of numerous short rings, which are closely
united for the first half of its length. The internal
antennae are long, the peduncle cylindrical, the second
joint nearly as long as the two succeeding ones ; the
setse very short, and composed of several rings. The
external pedipalps are pediforrn, the joints with short
spines, and tufts of short stiff hairs. The first pair of
feet robust in the male, smaller in the female, in both
shorter than the others, monodactyle, but the penul-
timate joint or hand has a strong spine on the inner

COMMON SPINY LOBSTER. 215

side, which forms a rudimentary thumb ; there are strong
spines on the outer margin of the other joints ; the remain-
ing pairs are strictly monodactyle and without spines ;
the last joint furnished with tufts of hairs. The sternum
is covered with tubercles. The abdomen is nearly cy-
lindrical, the segments smooth, terminating at the sides
in a strong, flattened, triangular tooth : the first segment
is without the usual appendages or false feet ; those of the
second, third, fourth, and fifth are simple, oval, and some-
what fleshy in the male ; in the female they are double
and foliaceous ; those of the sixth joint form, as usual,
the lateral laminae of the tail, which are partially covered
with short spines, and are crustaceous only at the outer
part of the base. The central lamina or terminal segment
of the abdomen is also membranaceous at the anterior
part, but the whole surface is covered with numerous
stronger spines.

The length of the body, from the front of the carapace
to the end of the tail, is eighteen inches.

The general colour is purplish brown, with irregular
dull white spots ; the legs reddish white, with reddish
brown irregular longitudinal bands.

This fine species is an inhabitant of our western coasts,
where it occurs in great numbers, and from whence it
is brought in considerable quantities to the London
market. It is much esteemed as an article of food, al-
though certainly of inferior flavour to the lobster. It is
but sparingly found in the north, whether of England or
Ireland, but is equally common on the southern coasts of
both. It inhabits the borders of rocks, where it is often
taken in crab-pots.

Its usual length is about a foot, but it sometimes
reaches eighteen inches. I have taken the foregoing

216

PALINURIDJE.

description from a fine male specimen of the latter size,
which weighs about five pounds ; and I cannot but think
that Dr. Milne-Edwards is greatly mistaken in attributing
to individuals of that size a weight of from twelve to
fifteen pounds.

The vignette is from a sketch by Mr. Coke Smith, and
represents St. Michael's Mount.

DECAPOD A . TH A LASSINADJE.

MACROURA.

GENUS CALLIANASSA. LEACH.

CANCER (Astacus). Montagu.
CALLIANASSA. Leach, Edwards.

Generic Character. — Antenna inserted in nearly the same ho-
rizontal line. External antennae with an elongated peduncle,
and without any moveable scale at the base. Internal antenna
with an elongate, rather thick, cylindrical peduncle, terminating
in two setae scarcely longer than the peduncle itself. External
pedipalps with the second and third joints very broad, consti-
tuting when in contact a broad oval disk, and terminating in a
small seta formed of the last three joints : there is no palp.
Anterior feet very unequal, one, generally the right, being ex-
tremely large ; the first three joints of moderate size ; the arm
furnished with a strong, hooked process on its outer margin j the
wrist and hand enormously developed, the former attached to
the arm by a narrow neck ; these two joints are of nearly the
same dimensions, and united by a straight line : second pair
small, didactyle ; third pair monodactyle, the penultimate joint
much dilated ; fourth pair simple ; fifth pair subdidactyle. Cara-
pace small, without any rostrum. Abdomen very long : the first
five segments broad ; the sixth abruptly narrower ; the seventh
triangular.

THIS genus may be considered as a fair type of the
remarkable family to which it belongs, and which con-
stitutes the true fossorial group of the Macroura. The
whole of them burrow in the mud or sand, and remain
generally concealed in these retreats. They are cha-

218

THALASSINADJE.

racterized by the semi-membranaceons texture ot the
external skeleton, by the remarkable length of the ab-
domen, the compressed form of the carapace, the absence
of any laminar appendage to the external antennae, and
other striking characters. The family is divided into
two distinct groups, according to the structure and situa-
tion of the respiratory organs. All the British species
belong to that division in which the branchiae are wholly
contained within the usual branchial cavity under the
margin and sides of the carapace, and which are with-
out any branchial appendages to the under surface of the
abdomen.

Of the genus Callianassa there is but one British
species.

CALLIANASSA SUBTERKANEA. 21 7

DEC APOD A. THALASS1NADM.

MACROURA.

Callianassa subterranea. Leach.

Specific Character. — Moveablc finger of the larger claw, thick, obtuse ; wrist
.and hand smooth.

Cancer (Astaciis) subterrawus, MoNf. Trans. Lin. Soc. IX. t. iii. f. 1,2, p. 89.
Callianassa subtcrra?iea, LEACH, Edinb. Encycl. VII. p. 400. — ED.

Trans. Lin. Soc. XI, p. 341.— Malac. Brit.

t. xxii.— EDW. Hist. Nat. Crust. II. p. 309.

THE carapace is much flattened at the sides, rounded
above, very smooth ; the rostrum minute. The eyes
very small. The external antennae with a long peduncle :
the terminal and antecedent joints nearly cylindrical ; the
basal joint pyramidal. The internal antennae have the
peduncle as long as the terminal portion, which is double.
The external pedipalps are rather broad, pediform ; the
terminal joint acute, curved. The first pair of feet very
unequal : the larger, which is sometimes the left, some-
times the right, is very large, flattened, polished, ciliated
on the edges ; the arm is furnished, on the inner side

220

THALASSINAD>E.

near its origin, with a broad falciform process, the front
of which is turned forwards ; the wrist is quadrate,
broader than it is long, connected with the arm by a
narrow process, and with the hand by its entire breadth ;
the hand, exclusive of the fingers, is nearly equilateral,
smooth, with a distinct margin at the outer side, the
fingers meeting only at the point, the moveable one
furnished with stiff hairs : the smaller anterior foot is
very slender, the arm becoming somewhat larger at its
junction with the wrist, which also enlarges towards
the hand, each of these parts being longer than broad ;
the hand is small and smooth. The second pair of
feet is didactyle, the pincers robust, and the fingers acute ;
the third pair has the penultimate joint transversely oval
and hairy ; the fourth and fifth pairs nearly filiform and
simple. The abdomen is contracted at each extremity,
smooth, rounded above, compressed at the sides, the
second segment the longest, being as long as it is broad ;
the terminal or caudal segment semi-oval.

The colour of this species is a rather bright red when
living, which colour it loses soon after death.

Length, about two inches.

The discovery of this remarkable species, which may be
considered as the British type of the fossorial form of
Crustacea, is due to Montagu who found it on the coast
of Devon, where it appears to be not uncommon. It
resides, as Leach states, in subterranean passages, similar
to those formed by the Gebia. It has been found on the
coast of France, and in the Mediterranean. Its claim to
be considered as an Irish species is thus stated by Mr.
Thompson : — " March 25th, 1839. On examining the
contents of the stomach of several individuals of the
Platessa Pola, wjiich were taken off Newcastle (County

CALLIANASSA SUBTERRANEA.

221

Down), two of the larger arms of this species, so peculiar
in form, and still retaining their beautiful pink colour, were
detected."*

The vignette below, by Mr. C. C. Pyne, is a view on
the beach at Hastings.

* Annals, I. c.

DECAPOD A.

MACROURA.

THALASSINADM,

GENUS GEBIA. LEACH.

CANCER (Astacus). Penn.

GEBIA. Leach.

Generic Character. — Antennae inserted in nearly the same ho-
rizontal line : external very slender, without any vestige of a
moveable scale at the base ; the seta very long, its joints sub-
elongate : internal very short, the double setae rather longer than
the peduncle, which is dilated on the outer side at the base. Ex-
ternal pedipalps pediform, slender. First pair of feet somewhat
robust, nearly equal, straight, the nrm becoming trigonous for-
wards ; the wrist short, rounded ; the hand elongate, imperfectly
cheliform ; the moveable finger large, turning down to the im-
moveable one, which is not half its length. The remaining pairs
of feet slender, slightly compressed, monodactyle. Carapace
narrowed anteriorly, terminating in a short triangular rostrum.
Abdomen narrowed at each extremity, somewhat depressed.

THE two recorded British species of this genus so nearly
resemble each other, that there is perhaps still some doubt
whether they exhibit more than sexual distinctions.

GEBIA STELLATA. 223

DEC A PO DA . THA LA SSJNA DM.

MACROURA.

Gebia stellata.

Specific Character. — Abdomen wholly crustaceous ; tail with the exterior la-
mella rounded, the interior subacuminate ; hands with granulated hairy lines.

Cancer (Astacus) stellatus, MONT. Trans. Lin. Soc. IX. t. iii. fig. 5, p. 89.
Gebia stellata, LEACH, Edin. Encycl. XI. p. 400. Malac. Brit.

t. xxxi. f. 1— 8.— EDW. Hist. Nat. Crust. II. p.

313.

THE carapace is close at the sides, the gastric region
hairy and sharply scabrous, elongate, triangular, and ter-
minating in a small acute rostrum. External antennae
with the setae about the length of the body. Anterior
legs with the arm elongate, slightly curved, with a small
tooth near the extremity ; wrist very little longer than
it is broad, furnished anteriorly with a sharp spine ;
hand three times as long as it is broad, with the move-
able finger long and slender, extending far beyond the
immoveable one : the second, to the fifth pair of legs, gra-
dually more slender. Abdomen contracted at its ex-
tremities ; the sides, as well as the dorsal portion, crus-
taceous. The tail, with the central lamina, narrowed

224 THALASSINAD^E.

and a little rounded forwards ; the outer lamina rather
longer than broad, the whole ciliated at the margin.

Length, about an inch and a half.

The discovery of this species, according to Leach, is due
to Mr. Gibbs, who found it in the King's-Bridge Estuary.
Montagu says that it was taken with Callianassa subterra-
nea, in a sand-bank at that place ; and he supposes it
to inhabit the burrows formed by the Solenes. It is, how-
ever, not to be doubted that it forms its own burrows ;
and Leach states that " it has been taken on some of the
shores of Plymouth Sound, under the mud of which it
makes long winding horizontal passages, often of a hundred
feet or more in length."

The burrowing of these fossorial species is a subject
which deserves more attention than has hitherto been paid
to it. The means by which it is effected are at present
absolutely unknown ; nor is it yet certain whether they
ever avail themselves of the labours of other animals, or
whether the excavations in which they are found are
wholly the work of their own hands. The account given
above, from Dr. Leach, of the extent of these passages,
appear at first scarcely credible, and may well challenge
a thorough examination of these points in the economy of
these curious animals.

The difference of the depth which the various species of
this fossorial family inhabit is very remarkable ; the pre-
sent species, with Callianassa subterranea, being found in
a sand-bank, when digging for Solenes" whilst Calocalis
Macandrew was dredged from the astonishing depth of
one hundred and eighty fathoms.

GEBIA DELTURA. 225

DEC A POD A . THA LASSINAD^E.

MACROURA.

Gebia deltura.

Specific Character.—" Abdomen, with the back, submembranaceous ; exterior
lamella of the tail with the apex slightly rounded and dilated ; the interior trun-
cated, deltoid ; the hands furnished with hairy lines." — Leach.

Gebia deltura, LEACH, Malac. Podolph. Brit. t. xxxi. fig. 9, 10. — EDW.

Hist. Nat. Crust. II. p. 314.

THIS species, if it be indeed distinct, differs from the
former, G. stellata, in the following particulars : — The
whole animal is very much larger, sometimes not less
than twice the length, and more than proportionally wider.
The carapace is much broader, and more spreading at the
sides. The legs are more robust ; the arm of the first pair
not more than twice as long as it is broad, the wrist even
shorter than broad, the hand thicker, and the fingers more
nearly of equal length. The setae of the external an-
tennae are shorter in proportion, being, according to Leach's

226 THALASSINAD.E.

figure,* not more than half the length of the body. The
abdomen is broader, more spread, and much less firm in
its texture, the sides being almost membranaceous, and
the abdominal false feet larger and more voluminous than
in the other species. The different lamellae of the tail
differ also in some particulars, the exterior being rather
broader than it is long, and the middle one, or terminal
segment of the abdomen, nearly quadrate. •(• In all other
respects the two species very greatly resemble each
other.

Whether the distinctions above enumerated constitute
anything more than sexual characters, I cannot at present
determine, nor have I hitherto had access to a sufficient
number of specimens to enable me to make a satisfactory
comparison ; but I confess I am very doubtful if it will
not prove, upon further investigation, that the two British
forms, and perhaps also G. littoralis of Risso, constitute
but one species. The form and development of the abdo-
men, and the great volume of the abdominal false feet
in G. deltura, are certainly very much like peculiarities
belonging to the female sex, and calculated for the support
and protection of the ova. " This species," says Dr.
Leach, " lives with G. stellata, with which it was con-
founded until the distinctions were discovered by Mr.
J. D. 0. Sowerby."

* In the only specimens I have seen, which are those in the British Museum,
the antennae are somewhat injured.

*h The term " deltoid " appears to be very much misplaced in describing this
part.

DEC A POD A . THA LA SSIXADM.

MACROURA.

GENUS AXIUS. LEACH.

A xi us. Leach, Desmar. Latr. Ed\v.

Generic Character. — External antennce nearly as long as the
body ; the peduncle furnished above with a small moveable spine.
Internal antennce with two setse nearly as long as the carapace.
External pedipalps rather slender, pediform, the joints nearly of
equal length. Anterior feet unequal, compressed, terminated by
a perfect claw ; the second pair compressed, didactyle ; the re-
maining pairs slender, compressed, simple, (the fifth pair the most
slender and most compressed.) Carapace much compressed la-
terally; the rostrum triangular. Abdomen compressed, rounded
above ; the five intermediate joints of nearly equal length ; the
caudal joint elongate-triangular.

ONE species only of this genus is at present known.
The genus is truly fossorial in its form, although in some
respects approaching to the natatory groups of PALJSMO-
ALPHJEAD^E, &c.

Q 2

228

THALASSINAD^.

DEC A POD A.

MACROURA,

THALASS1NADJE.

Axius Stirynchus.

Axius Stirynchus, LEACH, Trans. Lin. Soc. XI. p. 343. Mai. Brit. t. xxxiii.
— DESMAR, Consider, sur les Crust, t. xxxvi. fig. 1, p.
207. — GUER. Icon. Crust, t. xviii. fig. 5. — EDW. Hist.
Nat. Crust. II. p. 311.

THE carapace in this species is nearly semi-cylindrical,
but somewhat compressed at the sides ; the gastric region
punctate, scabrous ; the rostrum short, elongate-trian-
gular, having a raised margin and a raised longitudinal
median line. The first abdominal ring very short, fur-
nished with a pair of rudimentary false feet ; those of the
four succeeding rings are fully developed, natatory, com-
posed of a short and thick peduncle, which bears at its
extremity a small styliform appendage, and two large oval
laminae, having the margins ciliated ; the terminal segment
is elongate-triangular ; and the two pairs of lateral caudal

AX I US STIIIYNCHUS, 229

appendages are broad, rounded, and ciliated at the mar-
gin. The first pair of legs are unequal, robust ; the arm
thicker anteriorly, twice as long as it is broad ; the wrist
broader than Jong, somewhat triangular ; the hand thick,
with nearly parallel sides; the fingers short and strong, cili-
ated with a few stiff hairs. The second pair of feet di-
dactyle, rather small, compressed ; the arm as long as the
wrist and hand ; the fingers weak ; the whole, particularly
the arm, furnished with long hairs at the inner margin.
Of the remaining feet, which are all simple, the third pair
are the thickest, and the fifth the most slender.

The following observations of the two sexes of this
species are from Couches u Cornish Fauna :" — " The male
of what I judge to be the same species differs from the
female in the snout, which, in my specimen of the latter,
was finely notched, and without the well-marked longitudinal
ridge of the former. The outer antennae of the male are fur-
nished with a ridge of firm hair on their inward line, de-
creasing towards the point, which the female is without ;
and the former also has well-marked brushes near the
lateral edges of the abdominal rings.1'1

Total length, three inches three lines.

General colour, pale reddish-brown.

This species, the largest of the family indigenous to this
country, was first discovered by Dr. Leach " at Sidmouth,
where it was taken amongst prawns on the shore. Mon-
tagu afterwards procured, near Plymouth, another speci-
men."" I have received it from Cornwall, through the
kindness of Mr. Couch, who is the only naturalist that
has hitherto given any account of its habits.

" This species," says Mr. Couch, " like those of the
genus Callianassa, has the habit of burrowing in the sand,
from which it rarely emerges, and then it seeks shelter in

230

THALASSINAD^E.

a crevice covered with weeds, for it is sluggish in its mo-
tions, and, if distant from a soft bottom in which to sink,
incapable of escaping an enemy. A female that I ob-
tained, loaded with spawn, was dug out of the sand in
the middle of summer."

It is clear that the occurrence of Dr. LeacVs specimen
amongst prawns must have been purely accidental, as it is
essentially a fossorial species, although, as I before ob-
served, offering some slight deviations from the typical
structure of the group.

I believe it has not been found either in Scotland or
Ireland. I have obtained it from the Mediterranean,
and Dr. Milne-Edwards records its being indigenous to the
French coast.

The subject of the vignette below is Barmouth, North
Wales, by Mr. C. C. Pyne.

DEC A POD A . 1 It A LA SSINA DJE.

MACROURA,

GENUS CALOCARIS. Mini.

Generic Character. — External antennae placed nearly on the
same line with the internal ; the peduncle cylindrical ; the penul-
timate joint the longest ; a large triangular scale reaching to the
end of the first joint. Internal antennce with two setae, more
than half as long as the external ; the peduncle cylindrical, with the
joints of nearly equal length. External pedipalps pediform, elon-
gate, with a long seta. First pair of feet somewhat unequal,
very long, compressed ; the arm slender, twice as long as the
wrist, which is very short, subtriangular, flattened, with the hand
somewhat gibbous* as broad as it is long ; the fingers more than
three times the length of the hand, slender, much flattened ; se-
cond pair of feet didactyle, resembling the former, but much
smaller ; third, fourth, and fifth pairs simple, long, and slender.
Carapace very large, terminating in an acute triangular rostrum,
from which is continued, backwards and outwards, on each side,
a raised line furnished with small acute spines. Eyes rudimentary,
subglobose, without any pigment or cornea1. Abdomen long, coin-
pressed, enlarged at the middle segment, contracted at each ex-
tremity ; the terminal joint, or central lamina of the tail, longer
than broad, rounded.

OF this interesting fossorial form one species only is
known, and it is now described for the first time. Al-
though the structure of the feet in general, and especially
of the anterior pair, together with the presence of a spinous
scale on the outer side of the peduncle of the external
antennae, and some other characters, exhibit an aberration

232

THALASSINAD^E.

from the usual type of the fossorial family, yet its essential
characters shew it to belong to that group. The most
remarkable peculiarity, however, which it exhibits, is the
absence of any colouring pigment and of cornese in the
eyes, to which more particular reference will be made
in the specific description.

CALOCARIS MACANDRE.E.

DEC A POD A.

MACROURA.

233

THALASSINADJE,

Calocaris Macandrea. Mihi.

THE crust of this species is very thin, its texture slight
and flexible. The carapace is large, somewhat cylindrical,
narrowed forwards, and terminating in an acute triangular
rostrum, from which a raised line passes backwards and
outwards, furnished on each side with four sharp flattened
teeth, and inclosing a triangular space over the gastric
region. A small raised medial line extends along the
whole length of the carapace. The anterior feet are
two-thirds the length of the whole body ; the fingers very
long, much compressed, and longitudinally grooved, fur-
nished with a few small tubercles ; the hand, which is
gibbous, has a double carina on the upper side, which

234

THALASS1NADJ3.

terminate each in a small spine above the orgrin of the
moveable finger. The second pair of feet is distinctly
and evenly diclactyle, resembling in general form the
first pair, but very much smaller ; and the remaining
pairs are very slender, and monodactyle. The whole of the
feet, as well as most of the limbs and other appendages,
are hairy. The abdomen is shorter in proportion, and less
cylindrical, than in some other of the fossorial forms.

The general colour is a delicate pink or pale rose,
varying in depth in different parts ; but it soon becomes
white after being placed in spirit.

The total length is about two inches.

This species constitutes one of the most singular and
interesting additions which have, for a long time past,
been made to our list of British Crustacea. Allied as it is
in its essential characters to the Thalasnnada in general, it
exhibits some points of structure so abnormal, that at the
first examination it would scarcely be recognized as belong-
ing to that group. Instead of the thick and clumsy
hands, the imperfect claws, and the short, solid form of
the other limbs, which are exhibited in Gebia and Callia-
nassa, we see in this species a remarkable degree of slender-
ness in the limbs, and an almost normal structure of the
hands, assimilating it in some degree to the ordinary
PalamonidtE or Astacid<z. The absence of all colouring
pigment, as well as of the corneae in the eyes is a very
remarkable, and, as I believe, an unique instance in the
whole of the higher forms of Crustacea. But it is ad-
mirably in keeping with its habits, as will be presently
seen.

In a fine collection of Irish Crustacea, made by my friend
Mr. W. Thompson, and obligingly lent to me by him
some three years since, there occurred a pair of the

CALOCARIS MACANDRE^E. 235

anterior hands of some crustacean which was wholly un-
known to me, and unlike every other form I had ever
seen. The only note which I found appended to them
intimated that they had been taken from the stomach of a
flat-fish, a ground feeder therefore, and in deep water. In
the course of last year (1 845) I received from my friend
Mr. Mc An drew, amongst some other Crustacea dredged
by him in Loch Fyne and the Mull of Galloway, speci-
mens of the present species, an examination of which
at once shewed me that the claws obtained by Mr.
Thompson belonged to the same animal. Mr. McAndrew
and Professor Forbes have since again obtained it, and
have completely established the remarkable fact, that it
occasionally inhabits a depth of no less than one hundred
and eighty fathoms, in which situation it is fossorial in
sandy mud. Now it is clear that at such a depth, and
of fossorial habits too, distinct vision would be useless and
unavailing ; and this at once accounts for the rudimentary
character of the eyes, which are entirely white, and
exhibit the appearance shewn in the vignette.

I have named it after my friend Mr. McAndrew, who
first obtained it, and who has made so many important
additions to our British Marine Fauna.

EVES OF CALOCAUIS.

DEC A POD A.

MACEOURA.

AST ACID JE.

GENUS ASTACUS. Fabr.

CANCER.

CANCER (ASTACUS.)

ASTACUS.

Linn.
Penn.
Fabr, Latr. Leach, Edw.

Generic Character. — External antennas inserted beneath, am
external to the internal ; the peduncle thick ; the second and third
joints subcylindrical, covered by a moveable scale, which is broad
in 'the middle, narrowed at each extremity, and acuminate. In-
ternal antennae with two short setae. External pedipalps with
the second joint very broad and thick ; the terminal portion ra-
ther thick and evenly curved. First pair of feet unequal, tu-
mid ; the wrist short, rounded, and placed in the same line with
the arm ; the hands only slightly tuberculated ; second and third
pairs slender, filiform, didactyle ; fourth and fifth pairs mono-
dactyle. Carapace smooth, with a strong transverse furrow ;
the rostrum short, triangular, depressed, and with not more than
one tooth on each side. Thorax with the last joint moveable.
Abdomen very smooth ; the terminal or caudal segment armed
with a small tooth on each side, near the extremity, which is
rounded.

A FRESHWATER genus, very properly separated by Edwards
from the lobsters.

COMMON RIVER CRAYFISH.

DEC A POD A.

MACROUBA.

237

ASTACIDJE.

COMMON RIVER CRAYFISH.

A stacus fluviatttis. Auct.

Specific Character. — Rostrum as long as the peduncle of the external antennae,
with a slight elevation along the middle, and a small tooth on each side about
one-third from the extremity. Carapace granulated.

Cancer fluviatilis,
A stacus,
Cancer A stacus,
A stacus fluviutilis.

RONDEL, Poiss. II. p. 10.

GESNER, ALDROV. et al. auct.

LINN. Syst. Nat. II. p. 1051.

FABR. Suppl. p. 406. — LATR. Hist. Nat. Crust. V. p.

235. — LEACH, Diet, des c. Nat. — EDW. Hist, des

Crust. II. p. 330.

THIS, the only European species of the genus Astacus,
may be readily known from others by the characters above
given ; although the general aspect of the whole of them is
so similar, that they might at a cursory glance be readily
confounded.

238

ASTAOTD/K.

The carapace in the present species is granulated, tin
surface of the sides being scabrous and coarsely granulated.
The rostrum is of moderate length, with a tooth on each
side, about one-third from the apex : there is a slight ele-
vation along the median line, and the margin is also
distinctly raised. There is a small tooth on each side
of the gastric region, near the base of the rostrum ; and
a spine at the anterior part of the branchial. The anterior
pair of legs are thick and rounded, covered with tubercles,
which become slightly spinous in some parts ; the wrist
denticulated on the inner margin ; the hand shorter than
the fingers, slightly denticulated on the inner margin ; the
fingers curved at the points, and strongly tuberculated
on the inner edge. The second and third pairs of feet
slender, didactyle ; the fourth and fifth monodactyle. The
abdomen is very convex, and rounded above, each seg-
ment terminating at the sides in a sharp triangular pro-
cess. The terminal segment or central lamina of the
tail, evenly rounded at the extremity ; the lateral laminse
fan-shaped, the outer one slightly jointed about one-third
from the extremity.

General length, from three to four inches.

Colour, a dull greenish gray.

Few species are more abundantly diffused than this. It
is found in almost all the rivers and larger streams, not
only of this country, but throughout the greater part
of Europe. It is not unfrequently brought to the London
market as an article of food, but is not very highly
esteemed. It has long possessed a considerable degree of
interest, in consequence of the facilities which it affords
for watching its habits, and continuously tracing its his-
tory ; and it afforded to Reaumur the means of his very
interesting and original investigation into the curious

COMMON RIVER CRAYFISH. 289

subject of the moult of Crustacea ; and to Rathke the
subject of his observations on the growth and development
of the embryo. The general facts thus observed, and their
bearing upon the two interesting subjects to which they
refer, will be found treated of in the Introduction to this
work.

Their food consists of aquatic mollusca, the larvae of
insects, and even of small fish ; and they also do not
refuse any dead animals which may lie within their reach
in the water. They generally appear to require the
continual renewal of the respiratory fluid ; and hence
are generally found inhabiting running streams and
rivers, in which they conceal themselves in holes in the
banks. They change their crust annually, towards the
end of spring, and, like all their congeners, they grow
rapidly for a time after this change, and become fleshy
and full.

My friend, Mr. Ball of Dublin, has favoured me with
the following amusing and graphic account of an indivi-
dual of this species, which he kept in confinement : — " I
once had a domesticated cray-fish, Astacus fluviatilis,
which I kept in a glass pan, in water not more than
an inch and a half deep ; previous experiments having
shewn that in deeper water, probably for want of suffi-
cient aeration, this animal would not live long. By
degrees my prisoner became very bold ; and when I held
my fingers at the edge of the vessel, he assailed them
with promptness and energy. About a year after I had
him, I perceived, as I thought, a second cray-fish with him ;
on examination, I found it to be his old coat, which he had
left in a most perfect state. My friend had now lost his
heroism, and fluttered about in the greatest agitation.
He was quite soft ; and every time I entered the room,

240

ASTACIDJE.

during the next two days, he exhibited the wildest
terror. On the third he appeared to gain confidence,
and ventured to use his nippers, though with some timi-
dity ; and he was not yet quite so hard as he had been.
In about a week, however, he became bolder than ever ;
his weapons were sharper, and he appeared stronger, and
a nip from him was no joke ! He lived in all about two
years, during which time his food was a very few worms, at
very uncertain times ; perhaps he did not get fifty alto-
gether. I presume some person, presuming to poach in
his pond, was pinched by him, and plucked him forth,
and so falling, he came by his death."

Mr. Ball adds elsewhere, " The water was never
changed, but some was occasionally added to supply
the loss by evaporation." The truth is, that many Crus-
tacea will live in the atmosphere, as long as they have
access to water in which to bathe their branchiae, and
thus preserve them in a moist and respirable condition ;
but die from asphyxia when confined beneath a small
quantity of water, from which the air is soon exhausted.

DECAPODA. ASTACIDJE.

MACROURA.

GENUS HOMARUS. EDW.

CANCER. Linn.

CANCER (Astacus.) Penn.

ASTACUS. Fabr. Latr. Leach.

HOMARUS. Edw.

Generic Character. — External antennce placed above and to the
outer side of the internal; the laminar appendage dentiform,
dilated on the inner side, scarcely covering the penultimate joint
of the peduncle. Internal antennce with the peduncle nearly as
long as that of the external. External pedipalps pediform, ex-
tending forwards beyond the peduncles of the antennae. Anterior
legs very robust, unequal; the larger with the fingers strongly
tuberculated on the grasping edge, the smaller merely toothed ;
second and third pairs didactyle; fourth and fifth pairs mono-
dactyle. Carapace nearly cylindrical, the rostrum armed on each
side with three or four teeth. Thorax with the last joint im-
moveably connected with the preceding one. Abdomen nearly
cylindrical, the segments terminating laterally in a large flat
triangular process; terminal segment (or central lamina of the
tail) armed with a tooth on each side near the extremity. Tail,
with the exterior lamina divided transversely, about one-third
from the extremity, with a distinct rnoveable joint.

242

ASTACIDJ3.

DECAPODA .
MACROURA.

ASTACIDM.

LOBSTER.

Homarus vulgaris. Edw.

Specific Character. — Rostrum extending beyond the peduncle of the external
antennae, armed with two or three strong teeth on each side, without teeth on
its under surface.

Cancer gammarus^

Astacus marinus,

»
Homarus vulgaris,

LINN. Faun. Suec. 2033. Syst. Nat. Herbst. II, p. 42, t.

XXV.

FABR. Suppl. 406.— PENN. Brit. Zool. IV. t. x. f. 21.

LATR. Hist. Nat. des Crust. VI. p. 233.

EDW. Hist, des Crust. II. p. 334. — COUCH, Corn. Faun.

THE body is thick and rounded ; the cephalo-thorax
deeper than it is broad, somewhat compressed at the

LOBSTER. 243

sides ; the surface slightly punctated : a furrow separates
the gastric from the posterior regions. The rostrum pro-
jects forwards as far as the peduncle of the external
antennae ; it terminates in a strong point, and has about
four teeth on each side, diminishing in size backwards.
There is a small tooth on each side, just behind the base
of the rostrum. External antennae with the peduncle
nearly cylindrical ; its base armed with a strong tooth.
Eyes globular, smaller than the peduncle. Abdomen semi-
cylindrical. The segments smooth, terminating on each
side in a strong flattened triangular plate. The tail
broad ; the external lamina strongly divided at its anterior
third ; the margin of its posterior portion closely dentated :
two strong teeth at the common peduncle of the two
outer laminae. Anterior legs very large, unequal, the
larger one furnished with very strong tubercles on the
prehensile edge of the fingers, which is irregular ; the
smaller one with the edge of the fingers straight, and hav-
ing numerous small teeth ; the hands with the inner
margin furnished with strong white teeth ; and the wrist
with a few similar ones. The remaining legs filiform
and weak ; the second and third pairs didactyle, the
fourth and fifth monodactyle.

General colour dull pale reddish-yellow, spotted with
bluish-black ; the spots coalescent on the upper parts.

The esteem in which this species is universally held
as a delicate article of food, and the multitudes which
are annually taken and brought to our markets, render
it perhaps the most interesting and important of the
whole class, in a commercial point of view. Lobsters
are taken on various parts of our coast, particularly on
rocky shores. From the southern and western coast of
England a considerable number are constantly sent off

R 2

244

ASTACID.E.

to the London markets, by the South- Western Railway
from Southampton, and by the Great Western from Bris-
tol ; also by steamers from Guernsey and Jersey ; and
again from the coast of Ireland to Liverpool. From
the coast of Scotland and the Orkney and Lewes Islands,
it is computed that not less than 150,000 reach the
market at Billingsgate ; but the principal supply is from
Norway, from whence we derive not less than 600,000.
There is often in the season a supply at Billingsgate
of not less than from 20,000 to 25,000 lobsters in one
day.* If we allow only as many to be eaten in the whole
of England besides as in London, the multitude which are
consumed in the course of every year is enormous.

The period in which this immense sacrifice to crustacean
gastronomy principally takes place is from March to Au-
gust ; but it is a mistake to suppose that the lobster is
only in season during that time. During the latter part of
August and the following month, the lobsters are shedding
their coat, and the new covering is becoming indurated ;
but after that time they feed ravenously, and soon become
plump and firm ; so that in the winter they are probably
in as high flavour, and as solid for food, as during the period
when they are most in request. Mr. Saunders informs
me that he has reason to suppose the lobster to be very
stationary, seldom wandering fifty miles from the spot
of their birth ; and he adds, what one would scarcely
have supposed probable, that " they are as varied in ap-
pearance and character as a white man and an African."
"I could tell by looking at them," says Mr. Saunders, " the
part from whence they are brought." This curious fact is
corroborated by Mr. Couch, who, in his " Cornish Fauna,"

* For these details I am principally indebted to Mr. J. E. Saunders, the
respectable fish-salesman of Thames Street.

LOBSTER. 245

has the following observation : — " Lobsters do not stray
far from their haunts, and hence the discovery of a new
station is a fortunate circumstance for the fisherman ; and
each situation is found to impress its own shade of colour
upon the shell."

Lobsters are frequently caught in pots, similar to those
which are employed for the capture of crabs, and by some-
what similar means ; but in some localities the pots are
differently shaped, being formed of nets, which are held
in a nearly cylindrical form by three hoops, one at each
end, and one in the middle. At one end the trap is
closed ; at the other it is entered by a funnel-shaped pro-
longation of the net inwards, like some rat-traps. Mr.
Thompson informs me of the capture of a lobster by means
of a hook and line, baited with a whelk, which was used
for taking cod. Whether the hook was taken I am not
informed ; but it is perhaps most probable that the lobster
held firmly to the bait itself, and suffered itself to be
dragged out of the water rather than quit its hold.

It is a well-authenticated and indubitable fact, that the
lobster, as well as the common crab (Cancer pagurus),
and several other species of Crustaceans, not only shed
their claws and other limbs in case of severe injury to
them, but voluntarily. On being seized by one of their
limbs, the captive member is left in the possession of the
captor, and the animal escapes, leaving his arms on the
field of battle ; and it is also well known to fishermen and
other practical persons, that the same loss of limbs will
take place in violent thunder-storms. In the words of
the intelligent correspondent to whom I have already
had occasion to express my obligations, Mr. Saunders,
" they shoot their claws, especially after a thunder-storm
or the report of cannon, and whole voyages are destroyed

246

ASTACID^E.

by this means. If time were given new claws would be
formed. It is a voluntary act, and does not injuriously
affect the animal." The following remarks on this sub-
ject, by my observant and accurate friend Mr. Couch,
will be read with much interest, and I need offer no
apology for their extent.

Mr. Couch first speaks of the effects of injuries to the
antennse, and observes that it is an erroneous opinion
that these organs are ordinarily thrown off in consequence
of violence done to them, and afterwards renewed. " I
have not," he proceeds, " found this to be the fact ; but,
subjecting the parts to blows or fracture, both in short
and long-tailed Crustaceans, I have found the creature
suffering acutely from the injury, most so when just
emerged from the water ; but in no case have they re-
jected the whole organ in consequence of the violence.
If, however, it be violently handled, a separation takes
place at the terminal joint of the peduncles, in preference
to any other place ; and from this wound no stream of
blood flows, but a fine membrane quickly forms on the
surface, by which all effusion is prevented. This pre-
servative process resembles that which takes place in
case of the loss of the legs, and for the same purpose ;
for crabs and lobsters soon bleed to death, if the hsemor-
rhage be not restrained. It is only the legs, including
those bearing the chela or nippers, that are readily and
willingly thrown off by the animal ; and in some cases,
as in Porcellana platycheles, this is not only done on the
infliction of violence, but as if to occupy the attention of
some dreaded object, while the timid creature escapes to a
place of safety. The general method of defence is to seize
the object with the pincers, and while these are left attached,
inflicting, by their spasmodic twitchings, all the pain they

LOBSTER. 247

are able to give, the crab, lightened of so great an incum-
brance, has sought shelter in its hiding-place. It is by the
short and quickened muscular action of the limb itself, and
not by any effort of the body or peduncle that this is ef-
fected ; as the convulsion will continue for a considerable
time after the separation, it follows that the twisting off of
the claw, where the animal has seized human flesh for in-
stance, or any other sensible object, is the direct way to in-
crease the violence of the grasp. Any or all the legs may
be thrown off on the receipt of injury, but not with equal
facility in all the species ; for in some, as in the com-
mon crab, if they be crushed or broken without great
violence, they are sometimes retained, and the creature
will in no long time bleed to death. To save the crab
the fishermen proceed to twist off the limb at the pro-
per joint, or give it a smart blow, when it is rejected ;
and in either case the bleeding is stopped. Fracture
of the crust at the extreme points of the legs is not
much regarded ; for, being filled with an insensible cel-
lular membrane, no violent action is excited in the muscu-
lar structure, and the part seems capable of some attempt at
restoration, at least sufficient to render the evil endurable
until the period of a general renewal of the surface.

After the loss of a limb, a considerable time elapses
before any attempt at restoration is visible : but under
some circumstances the process is much accelerated ; and
while it is advancing, it is commonly found that the flesh
of the creature is unusually flaccid and watery. In the
most common species, the first appearance of the new
limb is in the middle of the scar, from whence proceeds
a soft member of minute size, doubled on itself, but with
all the proper proportions, and enclosed in an exceedingly
fine membrane, by which it is bound down. Much of the

248

ASTACID^E.

first stage of the growth of the new limb is accomplished
before it acquires density ; but when the crust is rendered
firm, the nutrition no longer proceeds through the encasing
membrane ; which a slight motion of the limb lacerates, and
the leg extends to its natural position ; but it continues for
a long time of a much smaller size than the corresponding
one of full growth, sometimes also appearing as if dis-
torted, either from deficient nourishment, or from injury
received in its unprotected state."

I have omitted from this interesting detail some specu-
lations of the observant author, and some statements
respecting which he himself speaks doubtfully ; and it
appears to me that it contains by far the most satisfactory
and most simple statements of this interesting fact that
have ever appeared. Although Mr. Couch's observations
were chiefly made upon brachyurous forms, there is no
doubt that the process is precisely similar in all the higher
forms of Crustacea.

The reproduction of the lobster would be multitudinous,
were not the young destined to become, in myriads, the
prey of fish of various descriptions.

The metamorphosis of this species has been examined
with care by several naturalists, and particularly by my
friend Mr. R. Q. Couch. The details, as far as they
belong to the general subject, will be found in the Intro-
duction.

If the following statement, with which I have been fa-
voured by Mr. Peach, be correct, it proves that the at-
tachment of these creatures for their progeny does not
cease on the deposit of their spawn, but continues, in a
very pleasing and interesting manner, much longer than in
many animals of a higher grade of organization.

" I have heard the fishermen of Groran Haven say that

LOBSTER.

249

they have seen in the summer, frequently r, the old Lobsters
with their young ones around them ; some of the young
have been noticed as six inches long. One man noticed the
old Lobster with her head peeping from under a rock, the
young ones playing around her : she appeared to rattle
her claws on the approach of the fisherman, and herself
and young took shelter under the rock ; this rattling, no
doubt, was to give the alarm. I have heard this from
several, some very old men, who all speak to this without
concert, and as a matter of course ; and they are men I can
readily believe"

DEC APOD A.

MACROURA.

ASTACWM,

GENUS NEPHROPS. LEACH.

CANCER. Linn. Herbst.

ASTACUS. Fabr. Penn. Latr.

NEPHROPS. Leach, Edwards.

Generic Character. — External antennae with the scale of the
first joint extending to the extremity of the peduncle. Internal
antennce with the basal joint very broad, triangular, terminating
in two setce, the superior much thicker than the inferior, and
slightly compressed. External pedipalps much elongated, the second
joint the longest. Eyes very large, reniform. First pair of feet
very long, unequal ; the hands quadrangular, the angles carinated
and strongly toothed ; the fingers armed with strong tubercles :
these and the second and third pairs are didactyle; the fourth and
fifth monodactyle. Abdomen semi-cylindrical, sculptured; the
lateral processes of the segments laminar and thin. Carapace
terminating in a long rostrum, strongly dentate on each side.

THIS genus consists but of a single known recent species.
It is nearly allied to Homarus and to Astacus, and may
be considered as in some respects intermediate between
them.

DECAPODA.

MACROURA.

NORWAY LOBSTER.

251

AST ACID JE.

Cancer norvegicus,
Astacus „

Nephrops „

NORWAY LOBSTER.

Nephrops norvegicus. Leach.

LINN, Syst. Nat. I. 1058. — HERBST, II. t. xxvi. f. 3.
FABR. Ent. 418. — PENN. Brit. Zool. (8vo.) IV. t. xiii. f.

1, p. 23.
LEACH, Edinb. Encycl. VII. p. 400. — ID. Trans. Lin.

Soc. XI. p. 344. — Malac. Pod. Brit. t. xxvi. — EDW.

Hist. Nat. Crust. II. p. 336.

THE body of this elegant species is elongated arid sub-
cylindrical ; the cephalo-thorax compressed at the sides ;
the surface slightly pubescent : the gastric region is
armed with seven lines of points, of which the outermost

252

ASTACIDJE.

are not more than three or four in number ; the inner
pair converge towards the rostrum and pass into a
double carina which extends to its extremity. The rostrum
extends beyond the peduncle of the external antennse, and
is armed on each side with three oblong teeth ; it is ciliated
on each side beneath. The posterior portion of the thorax
has three lines of small points: a strongly marked sulcus
runs within the posterior margin. The eyes are remark-
ably large and reniform ; the peduncles very small at
their origin, becoming suddenly much larger. The pe-
duncle of the external antennse is nearly as long as the
rostrum : the first joint has a triangular spine at the outer
side ; from the anterior margin of this joint arises the
broad falciform scale, which extends forwards to the ex-
tremity of the peduncle. The basal joints of the inter-
nal antennae are very broad and laminar. The first pair
of feet are very long, unequal, in some cases the right,
in others the left being the larger : the arm is slender, en-
larging towards its anterior extremity, carinated above and
below, and armed with a few teeth : the wrist, which is
short, is armed above with strong teeth, and is strongly ca-
rinated: the hand is distinctly four-sided, strongly cari-
nated ; the carinse armed with tubercular teeth, the upper
in a single, and the others in a double series ; the interme-
diate spaces concave, and slightly pubescent : the fingers are
armed with strong tubercles, particularly those of the larger
claw, and the moveable one is toothed on its outer mar-
gin. The other legs are filiform, slender, and smooth ;
the second and third pairs being didactyle, the fourth
and fifth monodactyle. The abdomen is long, each seg-
ment being beautifully sculptured ; the raised portions
smooth and polished, the depressions covered with a
short but dense pubescence. The epimeral portion of

NORWAY LOBSTER. 253

the first abdominal segment is small and rudimentary ;
the second is very broad and subquadrate ; the remainder
are acutely triangular. The tail is very broad, and the
outer lamina is slightly divided transversely at its an-
terior third.

The general colour is pale flesh, rather darker in parts ;
the pubescence light brown.

The length of the body from the tail to the rostrum is
from seven to eight inches.

This is certainly one of the most beautiful of the larger
Macroura. It is to be considered generally as a northern
species, but I have received fine specimens from the
Mediterranean. It is found on the coast of Norway in
considerable quantities ; it is also taken on the coast of
Scotland, and is not unfrequently sold in the Edinburgh
and other northern markets. I have occasionally seen it
at the shops of London fishmongers. It is said to be a
very delicate and well-flavoured food.

Although, as I have mentioned above, I have obtained
it from the Mediterranean, (Dr. Milne-Edwards also
records it as being taken in the Adriatic,) yet its general
range is certainly confined to northern limits. Mr. Em-
bleton says that it is not uncommon on the coast of Ber-
wickshire, but is rarely seen farther south. Leach names
only the Frith of Forth as its habitation. Mr. M°An-
drew procured it by dredging in Loch Fyne. On the
Irish coast it has been taken in Belfast Lough, accord-
ing to Mr. Templeton. Mr. Thompson says, " I have
heard of its being taken near Portaferry, about the en-
trance to Strangford Lough, and that it has been pro-
cured in numbers off Dundrum on the Down coast." He
adds, " It is brought in great quantities to Dublin as an
article of food ;" and in a letter recently received from

254

ASTACID.E.

the same gentleman, he mentions its having been found in
the stomach of the cod, " near Donaghadee, county Down,
and also at Dungarvon, county Waterford." According
to Mr. Br. Ball, it is very numerous in Dublin Bay ; and
he has taken it from the stomachs of cod bought at that
place.*

It is not included in the " Cornish Fauna " by Mr.
Couch, nor have I ever heard of its appearance on that part
of the coast. Mr. Thompson states that he has received
specimens from Holyhead by Captain Fayrer, B.N.

* Thompson on the Crustacea of Ireland, 1. c., p. 209.

DECAPODA. CRANGONlDjft.

MACROURA.

GENUS CRANGON.

ASTACUS. Herbst, Penn.

CRANGON. Fabr. Latr. Leach, Edw.

Generic Character. — External antennae situated nearly on the
same line with the internal, on the outer side, and a very little
beneath them. Internal antennce dilated at the base, and having
at the outer side a broad scale ; the peduncle short, and termi-
nating in two filaments. External pedipalps pediform ; the ter-
minal joint obtuse and flattened. First pair of feet subdidactyle,
stronger and thicker than the others ; the hand flattened, the
moveable finger inflexed upon the hand, and meeting a rudi-
mentary thumb : the second and third pairs very slender ; the
second didactyle ; the fourth and fifth shorter and thicker than the
former. Carapace depressed, and with only a rudiment of a ros-
trum. Abdomen large and rounded. Branchice only seven on
each side.

THE family to which this species belongs is distinguished
from all others by the insertion of the two pairs of an-
tennae on the same line, and the subcheliform structure of
the anterior hand. I am inclined to follow Dr. Milne-
Edwards in restoring to this genus Leaches genus Ponot-
pJiilus and Risso's Egeon, separated unnecessarily from
Crangon, which, in fact, constitutes the only known genus
of the family. It may, however, be conveniently divided
into two sections, in one of which the second pair of feet is
as long as the first, in the other it is not much more than
half as long. The first constitutes the genus Crangon of
Leach ; the second Poutophilus of the same author.

256

CRANGONID.E.

DECAPOD A.
MACROURA.

CRANGONIDjE.

COMMON SHRIMP.

Crangon vulgar is. Fabr.

Specific Character. — Carapace and abdomen smooth, excepting a small spine
on the median line of the gastric region, and one on each branchia ; second pair
of feet nearly as long as the third.

Astacus Crangon,
Crangon vulgarin,

HERBST, II. p. 57, t. xxix. fig. 3, 4.— PENN. Brit. Zool.

IV. t. xv. f. 30.
FABR. Suppl. 410. — LATR. Hist. Nat. des Crust. VI. p.

267, t. Iv. f. 1, 2. — LEACH, Malac. Brit. t. xxxvii. B. —

EDW. Hist. Nat. Crust. II. p. 341.

THE carapace in this species is large, rounded, some-
what depressed, particularly towards its anterior part :
there is no rostrum, but a slight elevation on the me-
dian line, between the eyes ; a minute spine directed
forwards over the gastric region, and one a little more
conspicuous on each branchia. The eyes are conspi-

COMMON SHRIMP. 257

cuous, naked, and not very distant. The external an-
tennae have the peduncle about half the length of the
moveable plate, which terminates in a small spine ; its
internal margin dilated and hairy. The internal antennae
are placed very little above the external, and terminate
in two short filaments. The external pedipalps are of
considerable length, extending forward Jbeyond the pe-
duncles of the external antennae ; the terminal joint much
elongated.

The anterior legs are robust and smooth, the hands
furnished with a curved moveable finger, which is in-
flected to meet a small spiniform rudimentary thumb.
The remaining legs filiform, elongated ; the second the
most slender and minutely didactyle ; the others mono-
dactyle. A strong spine on the sternum between the
anterior pair of legs. Abdomen regularly tapering, round-
ed, and smooth. The tail with the middle lamina nar-
row, and pointed at the extremity. Abdominal false feet
very long.

Colour greyish- brown, dotted all over with dark brown.
Unlike most of its congeners, it does not become red by
heat.

Total length from the eyes to the extremity of the tail
two inches and a half.

This is one of the most abundant of the coast species of
Crustacea. It is taken in multitudes for the table on
almost all our sandy shores, ordinarily by means of nets,
which are pushed forwards by the " shrimpers," who wade
nearly to their middle for hours together, raising the net
at intervals, and taking out the shrimps, which are secured
in a bag. In some parts of the coast, as at Poole, this
species is comparatively rare, and is not used as food.
The smaller Palamonidte are here called " shrimps ;" and

s

258

CRANGONIDJi.

when of small size and sold by measure, they are termed
" cup -shrimps." The present species is called the Sand
Shrimp, and the smaller prawns the Rock Shrimp.

In the breeding-season the shrimps approach the estu-
aries, and even ascend the rivers to a considerable dis-
tance.

" Although," says Mr. Thompson, " this species chiefly
frequents sandy shores, I have occasionally seen it brought
up in the dredge from deep water, and at a considerable
distance from land, in the loughs of Strangford and Belfast.
Mr. E. Ball mentions that shrimps, though taken in large
quantities at Youghal, are held in little esteem ; but that the
prawn (Paleemon serratus), caught abundantly at spring-
tides, is much thought of. This latter is called ' shrimp '
there, the former the ' gray shrimp ;' this term is also used
in Smith's ' History of the County of Cork,' written nearly
a century since."

The following observations I have selected from the
late Mr. Hailstone's MS. Notes on the Crustacea of Hast-
ings. " Although in general this species is very whole-
some, yet instances occasionally occur in which it pro-
duces effects similar to those which sometimes follow the
eating of mussels. They swim in the water or lie upon
the sand in shoals, and are taken by a large net with a
semicircular mouth, which the shrimper pushes before him
along the bottom of the sea during the ebb-tide. In colour
they so closely resemble the sand, that, in the pools left
by the tide, they are with difficulty distinguished. They
are in spawn throughout the year, and cast the shell in
March, April, and May."

BANDED SHRIMP.

DEC A POD A.

MACROURA.

259

CRANGONID^E.

BANDED SHRIMP.

Crangon fasciatus. Risso.

Specific Character. — Second pair of feet shorter than the first and third ; abdo-
men smooth, rather suddenly contracted at the posterior third, with a broad
brown band across the fourth abdominal segment : no sternal spine.

Crangon fasciatus ,

Risso, Crust, de Nice, t. iii. f. 5. p. 82. — Hist. Nat. de
1'Eur. Merid. V. p. 64. — EDW. Hist, des Crust. II.
p. 342.

FOR the first time I am enabled to publish this interest-
ing little species as indigenous to our coasts. I found
three specimens amongst some small Crustacea, many of
which were very interesting, sent to me by Mr. Alder, by
whom they were taken in Salcombe Bay, Devonshire, in
the course of his investigations on that coast in search of
the nudi branchiate mollusca, the more immediate results
of which are well known by the splendid work of that
gentleman and Dr. Hancock, published by the Ray Society.

s 2

260

CRANGONIDvE.

This species considerably resembles the common shrimp
in its general aspect ; but, besides being very much smaller,
it differs from it in many particulars. The peduncle of
the internal antennse is proportionally much shorter ; the
spines on the branchial region of the carapace obsolete.
The first pair of feet are robust, the moveable finger much
curved ; the second pair of feet shorter than the first and
third, extremely small, minutely didactyle ; the third pair
very slender. The abdomen is as large as the thorax for
rather more than half its length, and then contracts some-
what suddenly, by which it may be at once distinguished
from young individuals of the other species. There is also
a remarkable brown band across the fourth segment of the
abdomen, and a spot or two of the same colour on the
sides.

Total length six- tenths of an inch.

SPINOUS SHRIMP.

261

DEC A POD A.

MACROURA.

CRANGONIDJE.

SPINOUS SHRIMP.

Crangon spinosus. Leach.

Specific Character. — Carapace armed with five longitudinal series of teeth ;
abdomen nearly smooth ; the third and fourth segments slightly carinated ; the
fifth, sixth, and seventh, channelled.

Crangon spinosus,

PontopMlus „

Crangon cataphractus (in part),

LEACH, Trans. Lin. Soc. XI. p. 346. — LAM.

Hist. Nat. des Anim. sans Verteb. V. p.

202.

LEACH, Mol. Brit. t. xxxvii. A.
EDW. Hist, des Crust. II. p. 243.

THE carapace of this species is armed with five longitudi-
nal series of teeth directed forwards. The laminar appen-
dage of the external antennae about the length of the
peduncle of the same antennae. Internal antennae very
short. First pair of feet strong, the moveable finger
moderately curved ; the second pair extremely small, but
distinctly didactyle ; the third pair very slender and fili-

262 CRANGONIDJ3.

form ; the fourth and fifth stronger. The abdomen is
nearly smooth ; the third and fourth segments obtusely
carinated in the centre ; the fifth with a triangular depres-
sion ; the sixth and seventh distinctly channelled.

Length one inch and a half.

A careful examination of several British specimens of
this species, and of a well marked one of the Mediterra-
nean form, with which, I believe, it has been erroneously
confounded, has led me to reject the alleged synonyms of
Bisso and Roux, which appear to me to belong to a very
distinct species. I am not aware of the grounds upon
which Dr. Milne-Edwards has considered the Egeon lorica-
tus of Risso as the male of the PontopMlus spinosus of
Leach ; but I feel very confident that they belong to dif-
ferent species.

Although the spinous shrimp is to be ranked amongst
the rarer of the small Macroura of this country, it is very
extensive in its range. Leach speaks but of two speci-
mens known to him ; one obtained by Mr. Prideaux in
Plymouth Sound, and the other taken off Falmouth by
the ill-fated Cranch. Mr. Couch states, in his "Cornish
Fauna," that he has obtained it only once, when he found it
in the stomach of a fish taken at a depth of from twelve
to fifteen fathoms. I have a specimen taken by my friends
Professor Forbes and Mr. Mc Andrew, off Shetland.

By the following extract from Mr. William Thompson's
observations on the Crustacea of Ireland, it would appear
that it has been found on the Irish coast. " In Mr. V.
Thompson's collection there is a specimen bearing the
name of PontopMlus spinosus, and marked as Irish."

SCULPTURED SHRIMP.

263

DECAPODA.

MACROURA.

CRANGONIDft.

SCULPTURED SHRIMP.

Crangon sculptus. Mihi.

Specific Character. — Carapace with several raised lines, each armed with two or
three small teeth ; two spines on the median line, one considerably posterior to
the other : second pair of legs much shorter than the first, didactyle : abdomen
distinctly sculptured ; third, fourth, and fifth segments sharply carinated ; sixth
and seventh, channelled.

OF this new species I possess two specimens, which
I found amongst some small Crustacea dredged by Mr.
Bowerbank at Weymouth. Like Egeon loricatus of Risso,
Pontopliilus spinosus of Leach, and Crangon septemcari-
natus of Sabine, it has several denticulated carinse on the
carapace, and might at first sight be supposed the young
of some one of them. It is, however, a very distinctly
marked species.

The carapace is rough, with about five irregular raised
lines, each armed with two or three small teeth, and two
small spines on the median line, one behind the other. The

264

CRANGONID^E.

laminar appendage of the external antennae, a little longer
than their peduncle. The first pair of feet, with the hand,
smooth and rounded, the finger moderately curved ; the
second pair of feet minute. The segments of the abdomen
very distinctly sculptured ; the raised portions polished,
the depressions slightly pubescent : the third, fourth, and
fifth segments with a distinct central carina ; the sixth and
seventh channelled.

Length seven-tenths of an inch.

It differs for C. spinosus in the less regularly longitudi-
nal direction of the lateral raised lines on the carapace, the
less pointed and fewer teeth of this part, the longer propor-
tion of the antennae-scale with relation to the peduncle,
and, strikingly, in the sculpture of the abdominal segments,
and the extent and sharpness of the carina on this part.
Of the two specimens which I possess, one has several ova
attached to the abdominal false feet.

THREE-SPINED SHRIMP. 265

DEC A POD A. CRANGONIDJE.

MACROURA.

THREE-SPINED SHRIMP.

Crangon trispinosus.

Pontophilus trispinosm^ HAILSTONE, Mag. of Nat. Hist. VIII. p. 261, fig. 25.

OF this species I have never seen a specimen ; I there-
fore content myself with copying Mr. Hailstone's descrip-
tion, and Mr. Westwood's observations on the species ;
premising that the characters, as Mr. Westwood very pro-
perly remarks, entirely confirm the correctness of Milne-
Edwards, and other continental carcinologists, in rejecting
the generic separation of Pontophilus from Crangon.

"On March 1st, 1834, several individuals of a species of
Pontophilus were brought to me, which had been caught in
a shrimping-net upon this coast. They had only three
spines on the thorax ; one in the middle, and one on each
side of it. Their colour was much like a shrimp's, but
paler, less clouded, and with a sprinkling of golden blots.
Their length about an inch. They were called by the

266

CRANGONIDJ3.

man who caught them ' pug-shrimps ; ' he said he had
never observed them before this last winter. The females
were with spawn."

Thus far Mr. Hailstone. Mr. Westwood's observations
follow : —

" Of Mr. Hailstone's Crustacea, probably the new Pon-
topJiilus will be regarded as possessing the highest interest,
inasmuch as the propriety of the establishment of the
group, which was at first confined to a single species, is
thereby proved. The character of this genus, as defined
by Dr. Leach, separating it from that of Crangon (of
which the common edible shrimp, Crangon vulgaris, is the
type), consisted in the very small size of the second pair of
legs, and the length and acuteness of the terminal joints of
the external foot-jaws or pedipalpi. These characters,
however, to which that of the spinous shell might be added,
have been deemed by the French crustaceologists insuffi-
cient to warrant the generic separation of the two groups ;
and, on considering the characters of the new species from
Hastings, the correctness of their opinion must, I think, be
admitted ; since it will be seen, that, in several respects,
its characters are quite intermediate between those of the
types of Crangon and PontopTiilus. Thus the shell, instead
of being armed with a double series of lateral and three
rows of dorsal spines, as in the latter, is 3-spinous only,
just as in the common shrimp ; while the terminal joint of
the foot-jaws is scarcely longer than the penultimate joint,
and is broad, flat, and obtuse. The central piece of the
tail is also much longer than in PontopMlus spinosus. Still
the minute size of the second pair of legs corresponds with
PontopMlus ; whence it will, perhaps, be more advisable
to divide the genus Crangon into two sections : first, those
with the second and third legs of equal length, the common

THREE-SPINED SHRIMP.

267

shrimp ; and, secondly, those with the second leg much
shorter than the third, the PontopJiili of Dr. Leach : and
even in the former group, the comparatively delicate and
imperfect structure of the second pair is very evident ; thus
proving, in a natural point of view, the generic identity of
the two groups/' — Mag. of Nat. Hist. vol. viii. pp. 261,
265.

268

DECAPOD A.

MACROURA.

CRANGONIDJ3.

TWO-SPINED SHRIMP.

Crangon bispinosus.

Pontophilus bispinosus, WESTWOOD.

,, ,, HAILSTONE, Mag. Nat. Hist. VIII. pp. 11, 13, f. 30.

THE imperfect description and figure of this species,
given by Mr. Hailstone, prevent my coming to any very
decided opinion as to the distinctness of its specific charac-
ter. It has, certainly, some points of resemblance to C.
sculptus, but it is much smaller, if Mr. Hailstone's linear
admeasurement be that of an adult ; and there is no in-
dication of any sculpture on the abdomen. The follow-
ing is Mr Hailstone's description : —

" Pedipalps with the last joint rather longer than the
preceding one, and bluntish at its termination. First pair
of legs compressed, didactyle, with the thumb very short :
second pair rather shorter than the first, didactyle ; the last
joint half the length of the preceding one, which is com-

TWO-SPINED SHRIMP. 269

pressed : third pair very slender, as long as the first pair,
with a simple claw : fourth pair and fifth pair of equal
length, rather longer than the third, and somewhat thicker
but slender ; claws simple. Thorax, with two prominent
dorsal spines, one considerably behind the other, and on
each side a row of blunt notches. A spine at the outer
edge of the external plates of the tail." — Mag. of Nat.
Hist., vol. viii. p. 273.

Mr. Hailstone states, in his MS. notes, with which he
favoured me some time before his lamented death, that one
specimen only of this species had come into his possession,
which he found at Hastings in a mass of Filipora fili-
grana.

DEC APOD A.

MACTIOURA.

ALPHJEADM.

GENUS ALPHEUS. FABR.

AST AC us, Fabr.

PAL^EMON, Oliv.

CRYPTOTHALMUS, RafRn.

ASPHALIUS, Roux.

ALPHEUS, Fabr., Latr., Leach, Edw.

Generic Character. — External antennce placed beneath, and to
the outer side of the inner ; the lamellar palp of moderate size, some-
times slender and pointed. Internal antennce terminating in two
filaments, of which the superior is rather thicker than the inferior ;
the basal articulation short, and furnished with a spiniform scale.
External pedipalps more or less slender and elongated; terminal
joint broad, and somewhat foliaceous. First pair of legs didac-
tyle, robust, one much larger than the other, and very differently
formed : second pair also didactyle, very slender ; the carpus multi-
articulate : the remaining pairs slender, monodactyle. Carapace
extending forwards so as to form an arched covering to the eyes.
Rostrum small or wanting. Abdomen long, and much developed.

OF this genus, which is chiefly confined to hot climates,
one species only has been found in Britain, and is now
first described.

GENUS ALPHEUS,

DEC APOD A.
MACROURA,

271

ALPHEAD/E.

AlpJieus ruber. Edwards.

Alpheus ruber, Enw. Hist. Crust. II. p. 351.

Specific character. — Rostrum very small. External antennae without a project-
ing spine at the base. Anns with a small spine on the upper edge, at a short
distance from the extremity. Larger hand with four carinae, two on the upper
surface, and two on the outer ; the moveable finger shorter than the other.

THIS is the first instance of any species of Alpheus
occurring on our coast. The only two specimens hitherto
found were obtained by Mr. Cocks of Falmouth, who
procured them from the stomachs of cod fish. They are
unfortunately much damaged by this circumstance, but
enough remains for me to recognise, with scarcely a doubt,
its identity with Alpheus ruler of Edwards.

The carapace in the specimens is so much injured, that
it is impossible to ascertain whether a rostrum existed
or not, but the Mediterranean species is stated to possess
a small pointed one. The arched processes which always
protect the eyes in this genus, and the peculiarities of
which form good specific characters, are also destroyed.

272

ALPHEAD^.

The general form of the body is slender. The external
antennse have no spiniform palp at the base, which is also
a character of A. ruber. The internal antennse have the
general characters of the genus, but the specific distinctions
of this part are deficient. The anterior feet are in tolera-
ble preservation. The arm in both is about three times as
long as it is broad ; and on the upper surface is a small
spine, situated about one-third from the extremity : the
wrist is very short.. The larger hand, which is on the
left side, is short, the sides nearly parallel, flattened, the
upper margin with two carinse ; the outer side also with
two carinae, the inner surface rounded; the immoveable
finger is much curved towards the point, which is acute :
there is a distinct and deep depression about the middle
of its grasping edge, for the reception of a strong tubercle
of the moveable finger ; this finger is shorter than the
other, and becomes broader towards the extremity, where
its outer edge is acutely carinated. The smaller hand
is also bicarinated above : the fingers are slender and
curved, and there is thus a considerable space between
them excepting at the points ; their inner margins are
hairy. The second pair of feet are filiform, minutely
didactyle ; the carpus long and multi-articulate. The
remaining feet are slender and monodactyle.

Such are the characters afforded by the mutilated spe-
cimens before me ; and I trust the description, imperfect
as it is, may be sufficient to enable some more fortunate
observer to compare other and more perfect specimens,
and determine with greater precision the identity of
this with the Mediterranean species to which I have
referred it.

DEC APOD A. ALPHEADM.

MACROURA.

GENUS NIKA. Risso.

PROCESSA. Leach, Latr.

NIKA. Risso, Roux, Edwards.

Generic Character. — External antennce much longer than the
body, with the basal scale terminating in a single tooth at the
outer side; the inner margin hairy. Internal antennce termi-
nating in two filaments, the inner one the longer. External
pedipalps pediform, with four exserted joints, the second very
long, the terminal one pointed. First pair of legs dissimilar ;
that on the right side didactyle, that on the left monodactyle :
second pair more slender, very long, filiform, of unequal length ;
the arm and wrist multi-articulate, the hand minutely didactyle :
the remaining pairs very long, filiform, and monodactyle. Cara-
pace somewhat elongate, smooth, having a small, simple, com-
pressed rostrum. Abdomen a little bent at the third segment ;
the external laminae of the tail transversely divided near the
extremity.

OF this interesting genus the only known specimen for
a long time was a small one on which Leach founded his
genus Processa, and which was found by Montagu on the
southern coast of Devon. Eisso, however, had, a short
time before Leach's publication, given to the genus the
name of Nika, of which Leach was not aware at the time.
Risso's name must, therefore, be retained, on the ground of
priority of publication.

The remarkable peculiarity by which this genus is dis-
tinguished from every other form of crustacean, is the dis-

T

274

GENUS NIKA.

similar character of the anterior feet, one being didactyle,
and the other monodactyle. In every other instance, how-
ever the feet forming a pair may differ in length, in size,
or in structure, they agree in the character of the terminal
portion, and are always both monodactyle or both didac-
tyle ; but in this genus one is invariably and distinctly
didactyle, while the other is as distinctly monodactyle.

There are probably several species of this genus in the
Mediterranean, and I have in my possession two very dis-
tinct species found on our coast, one of which is undoubt-
edly Nika edulis of Bisso, and the other an entirely new
species.

NIKA EDULIS.

DEC APOD A.

MACROURA.

275

ALPHEAD^E.

Nika edulis. Risso.

Specific Cliaracter. — Didactyle hand longer than the wrist ; both straight. Cen-
tral plate of the tail longitudinally channelled.

Nika edulis.

Processa canaliculata,

„ edulis,
Nika canaliculata.

Risso, Crust, de Nice, p. 85 , t. iii. f. 3. — Hist. Nat. de

1'Eur. Merid. V. p. 72.— Roux, Crust, de la Me"dit.

t. xlv. — LAM. Hist, des Anira. sans Vert. V. p. 203.

— DESMAR. Consider, surles Crust, p. 230. — EDW.

Hist, des Crust. II. p. 364.
LEACH, Malac. Brit. t. xli.
LATH. Reg. Anim. de Cuv. (ed. 2nd) IV. p. 95.
DESMAR Consid. sur les Crust, t. xxxix. f. 4.

THE whole of the carapace and abdomen of this species
is even arid glabrous ; the carapace evenly rounded, some-
what compressed, terminating in a short, pointed, slightly
carinated rostrum ; a short acute point above the outer
edge of the orbit. Plate of the external antennae of almost
equal breadth throughout its length ; obliquely truncated at

T 2

276

ALPHEAD^B.

the extremity ; ciliated on the outer margin. Peduncle of
the internal antennae cylindrical; the internal filament
much longer than the external. External pedipalps, with
the last joint but two equalling in length the terminal and
penultimate joints together. Didactyle foot of the first
pair rather thicker than the other ; the hand and wrist
straight : the monodactyle foot terminating in a very small
slightly curved finger. Of the second pair, the right is
much longer than the left. The fourth pair longer than
the third and fifth, the latter being the shortest. The
abdomen is evenly rounded, somewhat compressed, con-
tinuous with the carapace. The middle plate of the tail
channelled throughout its length, and armed with minute
spines.

Length two inches to two inches and a half.

The colour of this beautiful species is described by Risso
and Roux as of a flesh-red, more or less dotted with
yellow and white, and marked along the back with spots
of these colours. The body is said to be so transparent
that the viscera may be seen through the integument. The
female is stated by Roux to be found, at different periods of
the year, bearing eggs of a yellowish-green colour, which
are deposited on algse and fuci.

The same author states that this species constitutes an
ordinary article of food on all the coasts of the Mediter-
ranean. It lives in shoals with various species of the
genera Pala>mon, Hippolyte, Alpheus, &c.

After the most careful examination I have been able to
institute, I have come to the conclusion that the Nika
edulis of Risso and those who follow him, and the Processa
canaliculata of Leach, are identical. It is certainly one of
the rarest of our British species. A small specimen was
obtained by Montagu at Torcross, on the southern coast of

NIKA EDULTS.

277

Devon, and sent by him to Dr. Leach, who founded there-
on his genus Processa, and figured it in his great work.
This specimen is still in the British Museum. That
from which my figure and the ahove description are
given was accidentally found hy myself in a dish of boiled
prawns, on which I was about to breakfast, at Bognor, in
the year 1842. Mr. W. Thompson states that there are
specimens in the collection made in the south of Ireland
by Mr. Vaughan Thompson.

278

ALPHEAD^E,

DECAPOD A.

MACROURA.

ALP HE AD.

Nika CoucJiii. Mihi.

Specific Character. — Didactyle hand shorter than the wrist ; the former slightly,
the latter more considerably curved. Middle plate of the tail attenuated towards
the extremity, not furrowed.

THE distinctive characters of this new and interesting
species are, with the exception of those given above,
mostly comparative. The whole animal is longer in pro-
portion to its other dimensions. The carapace, which
extends a little further backwards over the posterior
thoracic segment at its junction with the abdomen, is
longer and more slender ; the plates of the external an-
tennas are longer, and rather tapering towards the extre-
mity. The legs generally are altogether longer and more
slender ; the didactyle hand and wrist of the first pair are,
however, shorter, and both, but particularly the wrist,

NIKA COUCHII. 279

curved. The fifth pair of legs are quite as long, or a little
longer than the third and fourth. The abdomen is notably
more slender, and the lateral processes of the segments
extend more obliquely backwards ; the sixth segment is
nearly cylindrical, and the seventh, or middle plate of the
tail longer and much narrower, the terminal half being con-
siderably attenuated ; the upper surface has no distinct
furrow, as in N. edulis, and there is on each side a small
spine, about the middle of its length, at the point where it
becomes narrower. The lateral plates of the tail partake
of the general tendency to attenuation, which so remark-
ably characterises the form of the species.

Length nearly three inches.

One specimen only of this species has come under my
notice, and for this I am indebted to Mr. Couch, who sent
it to me about five or six years since. It was taken on the
coast of Cornwall. I have much pleasure in dedicating so
interesting a species to a naturalist who has not only done
much for the local Fauna of his own district, but whose
observations on the habits and physiology of many forms of
marine animals are peculiarly valuable for their truthful-
ness and originality.

That it is quite distinct from N. edulis, the description I
have given above sufficiently proves : and it is equally so
from any of those, whether varieties or species, named by
Risso in his " Crustaces des Environs de Nice." The
characters given by this author are, unfortunately, so
vague, and the figures in the work just named so bad, that
it is frequently impossible to arrive at any tolerable cer-
tainty as to the identity of the species described by him, or
to ascertain whether the distinctions be spe.cific or not.

DEC APOD A.

MACROURA.

ALP HE ADM.

GENUS ATHANAS. LEACH.

A STAC us. Montagu.

PAL^MON. Leach.

ATHANAS. Leach, Latr., Roux, Edw.

Generic Character. — External antennce not longer than the
body; the scale oval; unidentate on the outer side at the apex.
Internal antennce with three filaments, one shorter and thicker
than the others. External pedipalps short and slender. First
pair of feet the largest, unequal, didactyle : second pair very
small, filiform ; the wrist long and multi-articulate ; the hand
minutely didactyle : the remaining pairs simple. Carapace ter-
minating in a simple rostrum. Abdomen even ; the external plates
of the tail transversly divided.

OF this genus one species only is known. It possesses
the peculiarity which is found most strongly marked in the
Astacidse, the transverse division of the external lamina of
the tail ; a character which also obtains in a less marked
degree in Nika, and some other genera of the ALPHEAD^E.
It differs from all others of the family in having three
filaments to the internal antennae, and from the PALJEMO-
NID^E in the simple form of the rostrum and other cha-
racters.

ATHANAS N1TESCENS.

DEC APOD A.

MACROURA.

281
ALPHEADJE.

"Cancer (Astacus) nitescens,
Palcemon „

Athanas „

Athanas nitescens.

MONTAGU, MSS." — LEACH.

LEACH, Edin. EncjTcl. VII. p. 401.

Id., p. 432.— Trans. Lin. Soc. XI. p. 349.—

Encyc. Brit. Suppl. I. p. 421. — Mai. Brit. t.

xliv — EDW. Hist, des Crust. II. p. 366.

THE carapace in this remarkable little creature is very
smooth, narrowed anteriorly ; the rostrum about half its
length, and not extending backwards in a ridge, perfectly
simple and pointed. The external antennae have a cylindri-
cal peduncle about as long as the scale ; the latter is nearly
oval, hairy on the inner and anterior margin, and with a
little tooth on the anterior and outer angle. The internal
antennae have a thick rounded peduncle, terminating in
three filaments, the shortest of which is not much more
than one-third the length of the longest, and much thicker.
The first pair of legs is large and robust in proportion to
the size of the animal, and the hand is particularly so : the
second pair is very slender ; the wrist formed of several
joints ; the hand very minute and didactyle. The remain-

282

ALPHEADJti.

ing pairs are slender and simple. The abdomen is evenly
rounded and smooth. The outer plate of the tail trans-
versely divided about one-third from the extremity. In its
general aspect it resembles a very young Astacus.

The length of Dr. Leach's specimens is rather more than
half an inch.

Colour light buff ?

The discovery of this species is due to Montagu, who
sent it to Dr. Leach, under the name of " Cancer (Astacus)
nitescens" The latter author states that "it is occasion-
ally found in pools left by the tide amongst the rocks on
the coasts of Devon and Cornwall.'" It cannot, however,
be otherwise than rare in that locality, as Mr. Couch does
not introduce it in his " Cornish Fauna." Mr .W. Thomp-
son thus records its occurrence on the Irish coast : — " A
single specimen was found under a stone, between tide-
marks, at Lahinch, county Clare, by Mr. E. Forbes and
myself, in July, 1 840." These are the only authentic notices
of its existence on the British islands that I am acquainted
with. Dr. Milne-Edwards mentions its inhabiting the
coast of France, but gives no particulars.

The following figure represents one of a series of speci-
mens in the British Museum collection, from Plymouth
Sound, remarkable for the large size of the first leg on the
right hand side of the body.

DEC A POD A . PA LMMONLD&.

MACROURA.

GENUS HIPPOLYTE.

CANCER. 0. Fabr.

PAL^EMON. Olivier.

ALPHEUS. Lamarck, Risso, Sabine.

HIPPOLYTE. Leach, Desmar., Roux, Edw.

Generic Character. — External antennce placed beneath the
internal ; the scale externally unidentate. Internal antennce
terminating in two filaments : the superior thick, strongly ciliated,
and excavated beneath ; the inferior slender and setaceous. Ex-
ternal pedipalps slender and pediform. First pair of feet short,
equal, didactyle : second pair long, unequal, minutely didactyle ;
the wrist many-jointed : remaining pairs simple. Carapace fur-
nished with a deep rostrum, the carina of which extends over
a considerable portion of the median line of the carapace. Abdo-
men abruptly bent downwards at the third segment, which is
gibbous, and produced posteriorly.

OF this genus, which was first established by Leach,
there are several species inhabiting our coast. They
may be at once distinguished from all other Palitmonidte
by the peculiar character of one filament of the internal
antennas, which is broad and excavated in its inferior sur-
face. The rostrum is very deep in most species, and the
wrist multi-articulate in all. The abrupt curvature of the
abdomen varies considerably in the different species.

284

PAL.EMONID^E.

DEC A POD A.

MACROURA.

PALJEMONIDJE.

SOWEEBY'S HIPPOLYTE.

Hippolyte spinus.

Specific Character. — Rostrum anteriorly truncate, extending backwards nearly
to the posterior margin of the carapace, deep, many-toothed above ; the teeth, on
the portion situated on the carapace, which are three or four, larger than those on
the exserted portion. Tooth of the scale of the external antennae terminal;
broad filament of the internal antennae bent upwards at right angles to the
peduncle.

Cancer spinus,
Alphetts „

Hippolyte Sowerb&i,

So WERE. Brit. Misc. t. xxi.

LEACH, Edinb. Encyc. VII. 431. — Trans, of Lin. Soc.

XI. p. 347.— Encyc. Brit. Supp. I. 421.
LEACH, Malac. Brit. t. xxxix. — DESMAR. Consid. sur les

Crust, p. 223, t. xxxix. f. 1. — Enw. Hist, des Crust.

II. p. 380.

THE carapace in this species is furnished with a strong
and deep rostrum, the ridge of which rises almost at the
posterior edge, and has about four strong and large teeth
on that portion which belongs to the carapace, and several
smaller ones on the exserted portion, which decrease in
size towards the apex; the exserted portion is very deep,
terminating in a sharp tooth ; the inferior edge with two

SOWERBY^S HIPPOLYTE. 285

teeth, of which the anterior is almost as forward as the
apex, from which it is separated by a hroad notch, which is
minutely toothed. There are also two teeth above each
orbit, and others on the margin of the carapace. The
scale of the external antennae extends beyond the rostrum,
and has a strong tooth on the anterior and outer margin.
Terminal filaments of the internal antennae very short, the
thicker one bent abruptly upwards at right angles to its
peduncle. Anterior feet not extending beyond the scale
of the external antennae ; the hands robust and rounded.
The second pair longer than the third, with the wrist
divided into about six distinct articulations. The abdo-
men is very gibbous, the third segment being strongly
carinated, the carina terminating in a strong posterior
tooth, standing over the middle of the fourth segment.
Middle scale of the tail with four pairs of small spines
above.

Length about one inch and a half.

I have thought it right to restore the specific name
given by Mr. Sowerby to this remarkable species, which
Leach adopted on no less than three occasions, and after-
wards altered without any sufficient reason. It is the
largest of our British species of Hippolyte. It is exclu-
sively a northern species, being found, according to Dr.
Milne-Edwards, in the seas of Iceland and Greenland.
Mr. Sowerby first described it from a specimen found
on the Scottish coast : the one figured by Dr. Leach
was obtained at Newhaven, in the Frith of Forth. I
have two fine and perfect specimens, which were kindly
given to me by Mr. McAndrew, who procured them by
dredging in deep water off the Isle of Man. It is
not yet recorded as having been taken on the Irish
coast.

286

DECAPOD A.

MACROURA.

FALMMONlDjE.

VARYING HIPPOLYTE.

Hippolyte varians. Leach.

Specific C/taracter. — Rostrum straight, acuminate above, with a spine near the
j and another at the apex ; beneath with a sharp two-toothed carina. Anten-
nal scale with the external tooth one-third from the extremity j internal antennae
with the thick filament only slightly curved.

Hippolyte varians, LEACH, Edinb. Encycl. VIII. p. 432. — Trans. Lin. Soc. XI.
p. 347.— Encyc. Brit. Supp. I. p. 421.— Make. Brit. t.
xxxviii.f. 6-16.— ED w. Hist. Crust. II. p. 371.

THE carapace is less gibbous in this than in most other
species, although more so than H. pandaliformis, now
first described ; it is terminated by a straight and elon-
gated rostrum, which has on its upper side a tooth near
the base, and a very small one near the apex ; beneath
there is a short carina, which has two teeth : there is also a
small tooth on each side of the base of the rostrum, just over
the inner edge of the orbit. The scale of the external antennae
is large, and a little longer than the rostrum ; its external
tooth is placed at the distance of about one-third from the

VARYING HIPPOLYTE. 287

extremity. The thicker filament of the internal antennae
is of moderate size, and is but slightly curved, instead of
being abruptly bent at right angles, as in H. spinus and
some other species. The external pedipalps are of mode-
rate length ; the terminal joint short, flattened, rounded,
hairy, and furnished with minute spines on its inner
margin. The first pair of feet very short, rather thick ;
the second pair shorter than the third, and the wrist with
not more than three or four joints. Abdomen less gib-
bous than in some species, as H. Spinus and H. CrancJiii.
Middle plate of the tail with two pairs of small spines.

Length about three-quarters of an inch.

The usual colour is a beautiful clear green ; but, as Dr.
Leach states, "it is very variable in colour, occurring with
every shade of green, and of every tint between reddish
and liver-brown."

This is the most abundant of all our species of Hippolyte,
though probably not the most extensively distributed.
"It is found," says Dr. Leach, " in profusion in pools
amongst the rocks on the south-western coast of Devon
and Cornwall.*1 It is common all along that coast, and as
far as Poole Harbour in Dorsetshire ; and, although it is
not mentioned by Mr. Couch in his Cornish Fauna, I have
received specimens of it from that gentleman from Pol-
perro. It has been found extensively round the Irish
coast. Mr. W. Thompson says, " It has been taken
commonly by Mr. Hyndman and myself in the rock pools
accessible at low-water throughout the Down coast, and
has been dredged by us in deep water on the north-east
coast, and in Killery Bay, Connemara. Mr. R. Ball has
specimens from the shores about Dublin."

It is a beautiful and elegant species, but loses its lovely
green colour soon after death.

288

DEC A POD A.

MACROURA.

PALMMONIDJE.

CRANCITS HIPPOLYTE.

Hippolyte Cmnckii. Leach.

Specific Character. — Rostrum short, incurved at the base, with three teeth
above, the apex emarginate, bidentate, the upper tooth the longer ; beneath
unarmed.

Hippolyte Cranchii,

LEACH, Malac. Brit. t. xxxviii. f. 17-21. — EDW. Hist.
Crust. II. p. 376. — COUCH, Corn. Faun.

THE carapace is short and rounded ; the rostrum short,
raised, and somewhat abruptly incurved at the base,
where it is broad, and armed with three conspicuous teeth ;
the apical portion straight, bifid at the extremity, the
lower tooth shorter than the upper; the inferior edge is
short, and without any tooth ; there is no tooth above the
orbit. The scale of the external antennse extends to more
than half the length of the filaments of the internal, and

CBANCH'S HIPPOLYTE. 289

the marginal tooth is terminal. Internal antennae with
the thicker filament very slightly curved. Anterior feet
extending forwards a little beyond the antennal scale;
second pair with the wrist long, and formed of six articu-
lations. The junction of the thorax and abdomen is
very gibbous, the process on the posterior margin of the
third segment rounded, and but little prominent. The
middle portion of the tail has four pairs of extremely
minute teeth, so small as to be discerned with difficulty.

Length about three-quarters of an inch.

This little species, which is about the size of A. varians,
may be at once distinguished from it by the thicker thorax,
the more gibbous abdomen, the strong line of demarcation
between those two parts, and especially by the form of the
rostrum. It is a widely extended species, and in some
parts abundant. It was taken first by Mr. Cranch, and
afterwards by Mr. Prideaux, in the Kingsbridge estuary ;
it is also admitted into Mr. Couch's Cornish Fauna. I have
received it from Torbay, and from Salcombe Bay, through
the kindness of Mrs. Griffiths and Mr. Alder: it was
dredged at Poole by my relative, Mr. Henry Salter; and
I have specimens taken by Professor Forbes and Mr.
M' Andrew in Loch Fyne. Mr. Wm. Thompson gives it
as an Irish species, only on the authority of a specimen in
the collection of Mr. Vaughan Thompson : it is exceed-
ingly probable, however, that it will be again found on
the coasts of Ireland, as it has so extensive a range on
those of England and Scotland.

u

290

PAL/RMONIDyE.

DEC A POD A.

MACROURA.

PALJEMONIDM.

THOMPSON'S HIPPOLYTE.
Hippolyte Thompsoni. Mihi.

Specific Cliaracter. — Rostrum straight, deep, acute, continuous with a slight
carina, which extends from near the posterior margin of the carapace ; furnished
above with eight teeth, of which four, more distant than the others, are situated
on the carapace ; beneath, with three minute teeth near the apex.

THE carapace is of moderate length, the surface slightly
scabrous : a carina commences at about two- thirds back-
wards, and extends forwards to form the upper portion of
the rostrum, which, with the carina, is furnished with eight
teeth, directed forwards, of which four are situated on the
carapace, and are more distant from each other than those
on the rostrum itself; the inferior portion of the rostrum
has three minute teeth placed towards the apex, which is
acute and simple. The scale of the external antennae ex-
tends to more than half the length of the internal, and the
latter have the filaments slightly curved downwards, and
moderately thick. The anterior pair of feet are of moderate

THOMPSON'S HIPPOLYTE. 291

length ; the hand thicker than the wrist, which is rather
short, and has but few articulations. The abdomen is
remarkably gibbous, and the anterior segments are very
slightly scabrous at the sides.

Length nearly an inch.

Of this new species of Hippolyte I have seen but one
specimen, — a female loaded with extruded ova, which I
received from my friend Mr. W. Thompson of Belfast, the
acute and successful investigator of the zoological treasures
of his own country, by whose labours our knowledge of
the natural history of that part of the United Kingdom
has been so much enriched, and to whose name I dedicate
the species. It was obtained by that gentleman, with
specimens of H. Cmnchii, on the north-west coast of
Ireland.

It differs from H. pandaliformis in the form of the ros-
trum, which is shorter, and toothed throughout its whole
length, as well as in its general figure, which in the present
species has more of the normal aspect of the genus, and
less resemblance to the more typical Pakemonidtz. From
H. Cranckii it differs in the longer, straighter, and more
toothed rostrum, and in the less gibbous form of the thorax
and of the abdomen. With no other species could it be
confounded, even at the first glance.

u 2

292

PAL.EMONIDJE.

DEC APOD A.
MACROURA.

PALJEMONIDJE.

PBIDEAUX'S HIPPOLYTE.

Hippolyte Prideauxiana. Leach.

Specific Character. — Rostrum quite straight, acuminate, above unarmed, beneath
with one or two teeth on the anterior portion.

Hippolyte Prideauonana^

••t •>•>

„ Moom,

LEACH, Mai. Brit. t. xxviii. f. 1.3, 4, 5.
EDW. Hist. des. Crust. II. p. 372.
LEACH, 1. c. f. 2 — EDW. 1. c.

THIS little species very much resembles ff. varians ; it
differs from that species, however, in the form of the ros-
trum, which is of more equal breadth throughout the prin-
cipal part of its length, in the absence of any tooth on
its upper side and of the deep carina on the lower.

I have thought it right to include the animals defined
by Dr. Leach under the above specific names, as one spe-
cies, being unable to find any distinctive characters of
sufficient importance to warrant their separation. I have,
therefore, taken Prideauxiana as the normal form, and as
having the priority in nomenclature ; and have given

PRIDEAUX'S HIPPOLYTE. 293

Moorii merely as a variety — a view which Dr. Edwards
had already taken in his " History of Crustacea," although
it still remains to be proved which of the two forms of
rostrum is, on account of the comparative frequency of
occurrence, to he considered as normal.

The wrist of the second pair of legs has only two short
and one long articulation ; the ahdomen is remarkably bent
at the third segment. The whole animal is smaller than
H. varians, and of a reddish brown colour.

This is certainly a very rare species, and is not mentioned
in Mr. Thompson's Irish Fauna, nor in that of Cornwall
by Mr. Couch. I have received it, however, from the
neighbouring coast of Devonshire.

The vignette below appears to be a representation of the
Common Shrimp (Crangon vulgaris), and was taken from
a tesselated pavement discovered at Cirencester in 1783.
( Vetust. Mon. vol. ii.)

294

DECAPOD A.

MACROURA.

PALJEMONIDM.

Hippolyte pandaliformis. M i hi .

Character. — Kostrum extending beyond the scale of the antennae, nearly
straight, slightly turned upwards, with seven teeth on the upper and three on the
lower edge ; thicker filament of the internal antennae moderately curved.

THE carapace in this species is evenly rounded, with a
slight carina on the anterior third, passing into the ros-
trum, which is nearly straight, but a little turned upwards
towards the extremity, and extending beyond the an-
tennal scale ; it is furnished above with seven acute teeth,
of which three are on the carina of the carapace, and
the remainder on the free portion ; beneath are three
similar teeth, and the apex is bifid, the upper point pro-
jecting beyond the lower. The eyes are remarkably large,
as in Pandalus annulicornis. The external antennae have
the long filament longer than the body ; the scale is rather
narrow, particularly anteriorly, with long cilia on the outer
edge, and externally a small tooth near the extremity.
The thick filament of the internal antenna? is of moderate

HIPPOLYTE PANDALIFORMIS. 295

size and slightly curved ; the external pedipalps slender
and pediform ; the anterior pair of feet about two- thirds
the length of the second ; the wrist of the latter six-jointed,
the third joint about twice the length of each of the
others ; the remaining legs long and slender. The abdo-
men is more slender than in any other species of Hippolyte
with which I am acquainted ; the terminal joint narrow
and acutely pointed.

Total length an inch and a half.

The resemblance of this species to Pandalus annulicornis
is so remarkable, that I have given it a specific name in
accordance with that relation, in order to record its pro-
bable situation as leading from the normal forms of the
genus towards Pandalus. It is strikingly abnormal as
regards its own genus. The general slenderness of the
whole body, the even form of the carapace, the length and
form of the rostrum, the length of the legs and antennae,
all exhibit a marked tendency in the direction alluded to.
It is, however, in all its essential characters, a true Hip-
polyte.

This constitutes another interesting addition to our native
Crustacea, which we owe to the labours of Mr. M' Andrew
and Professor Forbes, by whom it was dredged in Loch
Fyne, at a depth of about twenty fathoms.

I have two specimens, for which I am indebted to those
gentlemen, and this is the only instance in which its
occurrence has been recorded.

DEC APOD A.
MACROURA.

PALMMONIDJE.

GENUS PANDA LUS, LEACH.

A STAC US.

PAL^EMON.

PONTOPHILUS.

PANTDALUS.

Fabr.

Risso.

Id.

Leach, Latr., Edw.

Generic character. — External antenna longer than the body, the
antennal scale unidentate on the outer margin. Internal antennae
with two filaments, the external one thicker; basal joint of the
peduncle hollowed above for the lodgment of the eyes. External
pedipalps slender, pediform. First pair of feet slender, shorter
than the others ; the terminal joint styliform, simple ; second pair
filiform, didactyle, unequal ; one much longer and more slender
than the other, both with the wrist and arm multiarticulate ; third,
fourth, and fifth pairs of feet, slender, slightly diminishing in
length. Carapace armed with a long rostrum, the carina of which
extends half way to the posterior margin of the carapace, the
rostrum curved upwards, and denticulate above and below. Abdo-
men with the third joint gibbous, the upper and posterior margin
produced backwards.

I HAVE always considered this genus as affording a dis-
tinct passage from the genus Hippolyte to Paleemon ; a view
of its relations, which has received an important confirmation
in the discovery of the H. pandaliformis, which may be
considered as the osculant species on that side. Like
Hippolyte it has but two filaments to the internal antennae
and the carpus multi-articulate ; so that, in fact, it resem-
bles that genus in its essential characters even more nearly
than Palamon.

PANDULUS ANNULICORNLS.

297

DEC APOD A.

MACROURA.

PAL^EMONID^E.

Pandalus annulicornis. Leach.

Specific Character. — Rostrum the length of the carapace ; anterior half without
teeth above, excepting a small one close to the apex.

Pandalus annulicornis. LEACH, Malac. Brit. t. xl. — LATR. Encycl. Meth. —

LAM. Anim. sans vert. V. p. 203. — EDW. Hist, des
Crust. II. p. 384.

THE carapace of Pandalus annulicornis resembles strongly
that of the genus Paltemon. The rostrum, as in that genus,
is very long ; it is considerably turned upwards towards its
extremity ; the carina commences about half-way towards
the posterior margin of the carapace, and it is finely toothed
to nearly half of the free portion of the rostrum, the re-
mainder being without teeth above, excepting a minute one
just above the apex ; beneath, it has five distinct teeth.
The eyes are remarkably large. The external antenna?

298

PAJ^EMONIDJE.

have very long filaments, which are marked with alternate
rings of dark and light colour through their whole length ;
the base cylindrical, and the scale diminishing in breadth
forwards, with a small tooth on the exterior margin at the
extremity. The internal antennae have but two filaments,
the external of which is the thicker ; the base is hollowed
to receive the eyes, and there is, at the anterior margin of
this excavation, a fringe of hairs, which covers the inferior
part of the eyes, and affords them protection. The ex-
ternal pedipalps have the basal joint hollowed above the
terminal joint, furnished with stiff hairs and small spines.
The anterior feet are simple, slightly curved, the basal
joint cylindrical, the remainder styliform, and acute at the
termination. The second pair of feet are of very unequal
length and size ; one being very slender, very long, the
wrist and arm multi-articulate, the didactyle hand very
minute ; the other thicker, shorter, likewise didactyle, and
with the arm and wrist multi-articulate ; the remaining
feet nearly of equal length, and simple ; the terminal joint
furnished with a row of spines beneath. The abdomen
resembles that of Hippolyte in the gibbous form of the
third segment ; the centre piece of the tail has three pairs
of small teeth on its anterior half.

The usual length is from two inches to two inches and
a half.

It is of a reddish grey colour, curiously dotted and marked
with deeper red.

At first sight this species may be readily mistaken for a
common prawn ; but a closer examination will shew that
its structural relations are much nearer to Hippolyte than
to Palamon. Its distinction from the prawn appears to
have struck several persons about the same time. It
was first discovered, according to Dr. Leach, by the

PANDALUS ANNULICORNIS. 299

Rev. Dr. Fleming, in Zetland, and in St. Andrew's Bay,
Scotland ; it was also observed by Montagu on the coast
of Devon ; and by Mrs. Dawson Turner, who noticed it at
Yarmouth, and pointed it out to Mr. J. D. C. Sowerby
as distinct from the common prawn. " It is used," says
Dr. Leach, " at Yarmouth as an article of food ; and
is at that place so much esteemed for the table, as to
afford constant employment during the summer season to
several fishermen, who take it in abundance at a consider-
able distance from the shore, and name it from that
circumstance the sea- shrimp."

The extent of the range of this species is very remark-
able. Dr. Milne Edwards mentions its being an inhabitant
of Iceland. We see above that Dr. Fleming obtained it at
Zetland ; I have specimens taken by Mr. M'Andrew and
Professor Forbes about the same locality ; and it is found
commonly on the southern coasts of England. Mr. Couch
admits it into his Cornish Fauna, and gives it the ex-
pressive name of " jiEsop-shrimp " (another proof of its
affinity to Hippolyte). I have specimens from Poole
Harbour, in Dorsetshire, and on the Norfolk coast it is
constantly taken and sold as a " prawn." I have occa-
sionally known it brought to the London markets, where,
however, it is usually seen of small size. As an Irish
species, it is stated to occur in Mr. J. Vaughan Thompson's
collection; and Mr. William Thompson adds, — " It has been
taken commonly by Mr. Hyndman and myself in the rock
pools accessible at low water throughout the Down coast,
and has been dredged by us in deep water on the north-
east coast, and in Killery Bay, Conuemara. Mr. R. Ball
has specimens from the shores about Dublin."

DEC APOD A.
MACROURA.

PALSEMONIDtf.

GENUS PAL/EMON. FABB.

ASTACUS. Pennant.

PAL-EMON. Fabr., Latr., Lam., Leach, Edw.

Generic character. — External antennce placed beneath, and a
little to the outer side of the internal ; the lamelliform palp very
large, nearly oval, rounded and ciliate at the apex and armed with
a spine near the extremity of the outer margin. Internal an-
tennae inserted above the external ; the first joint of the peduncle
very large, depressed, excavated on its upper side to receive the
eyes, and armed on the outer side with a strong spine; the two
following joints large and cylindrical, the last bearing three setse
of which two are very long, and the other very short and curved.
External pedipalps of moderate length, pediform, slender, terminat-
ing in a slightly curved nail. First pair of feet very small and
slender ; hand didactyle : second pair also didactyle, much larger
than the former; the remaining pairs simple, monodactyle. Cara-
pace of moderate size, broad, terminating in a long, laterally flat-
tened rostrum, which extends usually beyond the peduncles of
the antennae. Eyes large and projecting. Abdomen large, dimi-
nishing regularly towards the tail, and rounded on the upper
surface : the terminal segment, which forms the middle portion
of the tail, triangular. Abdominal false feet very large ;
those of the first pair furnished with a large ciliated scale, and
a much smaller one; the others with two scales, which are also
distinctly ciliated.

ALTHOUGH most of the species of this genus are of
moderate size, there are some inhabiting the tropical re-
gions which may almost rival the larger Astacidtc. The

GENUS PALyEMON.

301

Palamon Carcinus, for instance, sometimes reaches to nearly
a foot in length, and P. Jamaicensis is nearly as large.
The common prawn, P. serratus, is the species best known
and most esteemed in our climate ; but a very careful
examination of all the means within my reach, has es-
tablished in my mind, very satisfactorily, the existence of
four distinct British species of Palfemon^ forming one ad-
ditional to those before denned.

302

DEC APOD A.

MACROURA.

PALJBMONIDJB.

COMMON PRAWN.

Palamon serratus.

Specific Character. — Rostrum extending considerably beyond the antennal
scale ; turned upwards anteriorly ; bifid at the extremity ; above, armed with
seven or eight teeth, the anterior third unarmed ; beneath, with five or six
teeth.

PENN. Brit. Zool. IV. t. xvi. f. 28, p. 19.

HEKBST. II. t. xxv. f. 1.

LATR. Gen. Crust. I. p. 54. — LEACH, Edin. Encycl.

VII. 401.

FABR. Supp. p. 604 — LEACH, Trans. Linn. Soc. XI.
348.— Mai. Brit. XXIV. t. xliii. f. 1-10.— EDW.
Hist. Nat. des Crust. II. p. 389.

THE carapace of the common prawn is even, rounded, and
furnished anteriorly with two points, one above and the
other beneath the peduncle of the external antennae ; the
rostrum is of great length, the anterior half ascending ;

Astacus serratus,
Cancer squilla,
Palcemon „

serratus.

PAL.EMON SERRATUS. 303

above armed with seven or eight teeth (usually seven,
rarely six), which are confined to the posterior portion, the
anterior third being slender and unarmed ; the extremity
bifid, the inferior point being the longer ; beneath armed
with four or five teeth (usually five). The eyes are large
and round. Of the three filaments of the internal (supe-
rior) antennae, the shortest scarcely extends to the ex-
tremity of the rostrum ; the others are more than twice
as long. The external antennse are very long, being
half as long again as the animal from the tail to the
extremity of the rostrum ; the scale with the sides nearly
parallel, anteriorly and posteriorly obliquely truncate,
forming a long rhomboid ; the inner edge furnished with
long hairs. The first pair of feet very slender, ordinarily
bent upon itself; the hand and fingers together not nearly
as long as the wrist ; the second pair extend forwards to
the end of the rostrum ; the hand rounded, elongate ; the
fingers slender, as long as the hand ; the hand and fingers
together twice as long as the wrist ; the remaining pairs
slender and simple. The abdominal false feet very long ;
the terminal joint of the abdomen narrowed forwards, with
two long slender terminal teeth, and two pairs of small
teeth on the sides. Caudal laminae furnished with long
hairs on the terminal margin.

Ordinary length upwards of four inches.

Colour bright grey, spotted and lined with darker purplish
grey.

This species, which is so well known as a favourite and
delicate article of food, is found in vast numbers on all the
coasts of this island. It appears from various accounts that
it approaches the shore in its young state, and multitudes
of them are taken in shrimp-nets, and sold as shrimps on
some parts of the coast. I found that at Bognor the

304

fishermen consider them, when young, as a distinct species,
and assert that, at certain seasons, they drive the true
prawns from their ordinary place of resort. The pro-
bability is that at the season when the young ones have
arrived at, a certain size, they separate themselves from the
older ones, which at that period of the year retire further
from the shore. At Poole I have found the young ones of
this species associated with two other species of Palamon,
and the three are ordinarily sold there under the name of
" cup-shrimps," being measured in small cups, instead of
being sold by tale, as they are when larger. When o
middle size they still retain the name of shrimps at that
place, and are only called prawns when they acquire larger
dimensions.

In the adult condition they frequent rocky parts of the
coast, delighting in still transparent water, where they may
be seen in numerous companies, disporting, in the most
elegant and beautiful manner, amongst the long fuel which
wave in the tide.

Prawns are sometimes taken in bag-nets, suspended from
a circular ring of iron, at the end of a pole ; but in many
parts, the finest are caught in pots, resembling lobster-pots,
but smaller, and made of a closer fabric. At Bognor I
found that besides the baited pots or traps, each fisherman
had a store-pot, into which he transferred the prawns, when
he went his round of the baited pots, and kept them there
until they were wanted.

They are found with the ovaries filled with spawn, and
with the abdominal false feet loaded with excluded spawn
at all seasons of the year. They are chiefly obtained
for the London markets off the Isle of Wight and Hamp-
shire coast ; but they are much deteriorated by the time
which elapses after their capture, before they can be pro-
cured in the metropolis.

PAT^MON SQUILLA. 305

DEC APOD A. PALMMONIDM.

MACROURA.

Palamon Squilla. Fabr.

Specific Character. — Rostrum nearly straight ; the apex emarginate ; above with
seven or eight teeth, of which two are on the carapace, and the third immediately
the ocular notch ; beneath with three teeth.

Cancer Squilla, LINN. Syst. Nat. I. 1051.

Axtacus „ FABR. Ent. Syst. II. p. 485.

I\il(£inon „ FABR. Suppl. Ent. Syst. p. 403.— LATR. Hist, des

Crust, et des Ins. VI. p. 257. — LEACH, Edinb. Enc.

VII. p. 432.— Malac. Brit. t. xliii. f. 11-13.— EDW.

Hist, des Crust. IV. p. 390. — COUCH, Corn. Faun.

p. 80. — W. THOMPSON, Crust, of Ireland.

THIS species differs from the former in a few distinct,
but, with one exception, not very tangible characters. The
whole animal is much smaller, being not more than half the
length ; the first pair of feet are shorter in proportion, and
the second pair less robust. But it is in the rostrum that
the principal and most obvious distinctive characters exist.
This part is almost straight, having, however, a very slight
curve upwards towards the extremity ; it has seven or
eight teeth on the upper side, and three on the under ; but

x

306

the number alone, although very constant, scarcely con-
stitutes so true and certain a criterion as the fact that of
the upper teeth two are invariably placed on the median
line of the carapace, posterior to the base of the rostrum,
and the third immediately over the margin of the ocular
notch. The upper teeth are very acute, spiniform, and
directed very much forwards. Those of the under side are
broader at the base, triangular, and the posterior one
slightly falcate. The apex of the rostrum is bifid, the
inferior point being the longer.

Of fourteen specimens examined I found the teeth on
the upper and under side of the rostrum as follows : — Seven
had f, five -3-, one f, and one i, so that the normal number

is i or f .

The total length, from the rostrum to the tail inclusive,
of the largest specimens I have examined, was two inches
one line.

This species is pretty widely distributed along our
coasts. I have obtained it from Ireland through the kind-
ness of Colonel Portlock ; and Mr. W. Thompson records
it as common on the shore of Belfast Lough, in rock pools,
on the Down coast, as well as in deep water. He also
mentions having met with it commonly in rock pools about
Ballantrae, Ayrshire. It occurs on the Cornish and Devon-
shire coast, but Mr. Couch considers it rare in the former
county, although Dr. Leach mentions it as very abundant
in the latter. At Poole, in Dorsetshire, it forms a con-
siderable proportion of the " cup-shrimps," a name given
there to the young prawns of three different species, which
are sold by measure.

PALJBMON LEACHII. 307

DECAPODA. PALMMONIDJE.

MACEOURA.

Palamon Leackii.

Specific character. — Rostrum nearly straight, with five or six teeth above, and
three beneath ; one only of the former situated behind the line of the ocular
notch ; apex generally emarginatc.

AMONGST the smaller Pal&monida found in Poole Har-
bour, to which I have already alluded as being sold there
under the name of " cup-shrimps," there are found a con-
siderable number which differ materially in the form of
the rostrum, as well as in the number of teeth with which
it is furnished, from either of the species hitherto described.
I have thought right to describe it as a distinct species,
which I cannot doubt to be correct. It differs from
P. Squilla in the smaller number of the teeth in the
upper crest of the rostrum, and in the fact that one of those
teeth only is placed posterior to the ocular notch. From
P. varians it is more obviously distinct.

Of twenty specimens taken promiscuously, the number
of teeth on the upper and under edges of the rostrum were
as follows : — ten had f , seven J, two £, and one had only
two teeth beneath. The normal number, therefore, may

be considered as §.

x 2

308

It may perhaps appear, without a careful comparison of
numerous specimens of both species, that the characters
above named are scarcely sufficient to warrant their se-
paration ; but it happens that an additional distinctive
character obtains invariably, associated with the different
number of the rostral teeth. The rostrum in the present
species is covered with innumerable reddish dots, which
continue to be very visible from their opacity, even after
all colour has been removed from long immersion in spirit.
In P. Squilla there are no such coloured dots.

I have given to this species the name of my lamented
friend, the distinguished illustrator of British Carcinology,
the late William Elford Leach.

DEC A POD A

MACROURA

PALJSJVJON VARIANS.

309

1'AL/EMONIDJE

Palfpmon Varians. Leach.

haracter. — Rostrum perfectly straight, the apex entire ; above with four
to six teeth, beneath with two. Scale of the external antennae rounded at
the apex.

Pal&mon varians, LEACH, Edinb. Enc. VII. p. 401. 431. — Id. Trans.

Lin. Soc. XI. p. 349.— Id. Malac. Brit. t. xliii. f.
14-16.— EDW. Hist, des Crust. IV. p. 391.

THE absolute restriction to two teeth on the inferior
crest of the rostrum in this species, would distinguish it
from all other British species of Palamon, even without the
additional characters of the small number of teeth on the
upper crest, and the entire apex. The whole rostrum is
perfectly straight, lanceolate, acute at the apex, as long as
the scale of the external antenna? ; one of the teeth on the
upper crest is always placed a little behind the ocular
notch. These teeth are generally four in number, some-
times five, very rarely six ; beneath there are never more
than two teeth ; I have seen one specimen in which there
was only one. The external antennae are of moderate
length, not much exceeding that of the body ; the scale
anteriorly rounded, in which character it differs from
P. serratus. The hand of the anterior pair of feet is
slightly tumid ; the upper finger hairy.

310

PALJEMONID^E.

This species is less widely distributed, as far as we can
at present judge, than either of the former ones. It is,
however, found on the Devonshire and Dorsetshire coast,
and onwards as far as that of Norfolk. Mr. Couch does
not include it in his Cornish Fauna. Mr. Thompson states
that a few specimens have been taken in Belfast and
Strangford Loughs, and I have received it myself from
Ireland through the kindness of Col. Portlock.

The vignette consists of several variations of the rostrum
in three species of Palsemon. The first three on the left
are of P. Squilla. The three in the middle belong to P.
serratus, and the three on the right to P. Leachii.

DECAPOD A .
MACROURA

GENUS PASIPH^EA. SAV.

ALPHEUS. Risso.

PASIPHAA.. Savigny, Risso, Desmar. Latr. Leach, Edvv.

Generic character. — External antennae placed beneath the in-
ternal ; the basal joint of the peduncle narrower than the succeed-
ing one. Internal antennae with the peduncle slender, and ter-
minated by two filaments, one of which is considerably longer than
the other. External pedipalps very long, slender, and pediform ;
furnished at the base with a lamellar ciliated palp. First and se-
cond pairs of legs didactyle, rather robust, nearly of equal length ;
the fingers slender and curved ; third, fourth, and fifth pairs very
slender, monodactyle, the fourth pair the shortest. Carapace very
much elongated, compressed, narrowed anteriorly. Abdomen very
long, much compressed ; the fifth segment broad and squared at
the lateral margin ; the sixth very long ; the seventh narrow and
wedge-shaped ; the false feet of the first segment with the filaments
rudimentary, the others with two equal.

The history of this remarkable genus has hitherto been
involved in some obscurity. In the description of our
species I have given some reasons for believing that as yet
one species only is known.

3J2

DEC A POD A.

MACROURA

Pasiphaa Sivado,

Specific character.— External caudal laminae longer than the internal, whicl
are longer than the middle one.

? Alpheus Sivado, Risso. Crust, de Nice, t. iii. f. 4. p. 93. — DKSMAR. Con-
sid. sur les Crust, p. 240. — LATH. Regn. Anim. deCur.
IV. p. 99.

? Paidphcea „ Risso, Hist. Nat. de 1'Eur. Merid. V. p. 81. — EDW.

Hist. Nat. des Crust. IV. p. 426. — GUER. Iconog. du
Reg. Anim. (Crust.) t. xxii. f. 3. — THOMPSON, Ann.
Nat Hist. V. p. 256.
LEACH, MSS. in Mus. Brit.— EDW. 1. c. p. 426.

Savignii^

brevirostris, EDW. 1. c. p. 426.

THE general form of this remarkable species distinguishes
it at first sight from every other known Crustacean. The
whole body is exceedingly compressed laterally, and the
carapace elongated and somewhat attenuated forwards.
There is scarcely a perceptible rostrum ; but immediately
behind the anterior margin of the carapace, is a small
triangular tooth, with the point turned forwards, and a
similar, one, but smaller, on each side just above the origin

PASIPHJ^A SIVADO.

313

of the superior or internal antennae. The superior an-
tennse have a cylindrical peduncle, the basal joint of which
is hollowed for the lodgement of the eyes ; the filament is
double. The external or inferior antennae are placed im-
mediately beneath the former ; the peduncle is cylindrical,
terminating in two filaments, one of which is about as long-
as the body, the other extremely short ; the lamina or
scale is narrow-ovate, and ciliated along the inner margin.
The eyes are much larger than their peduncles. The ex-
ternal pedipalps are long, slender, and pediform, each fur-
nished with a long palp which is a little thicker than it
and about half its length. The first pair of feet are rather
more robust than the second, the hand thicker in the mid-
dle, the fingers shorter than the hand, and curved at the
points which are acute, and cross each other when closed ;
the arm is furnished with a series of short remote teeth ;
the second pair are ordinarily rather longer than the first,
more slender, the fingers as long as the hand, and furnished
along their prehensile edge with a dense series of short,
stiff hairs. The third pair is extremely slender, filiform,
and simple ; the fourth pair, by much the shortest, being
not more than half the length of the fifth, the penultimate
joint furnished on its inner margin with a brush of stiff
hairs, and the terminal joint ciliated ; the fifth pair very
long and slender, the terminal joint ovate, furnished with a
lash of hairs of twice its length. The abdomen is very
long and much compressed ; the second segment broad
and rounded ; the fifth broad and squared at the lateral
margin ; the sixth remarkably long and narrowed ; the
seventh or central lamina of the tail very narrow and wedge-
shaped. The external laminse of the tail are longer than
the internal, which are intermediate in length between the
former and the median lamina or seventh abdominal segment.

314

PEN^EAD^E.

The abdominal false feet have two equal filaments, with the
exception of the first pair, of which one of the filaments is
extremely small or rudimentary. The eggs are remarkably
large and not numerous.

The colour of the Mediterranean species described by
Risso, and which I believe to be identical with this, is thus
given by that author: — The body is white, slightly iri-
descent, transparent, banded with red at every articulation ;
the eyes black ; the antennae, pedipalps, and feet red, and
the caudal scales dotted with the same colour.

Total length of specimens from the Bristol Channel about
three inches.

I have already alluded to the obscurity in which this
genus has been involved ; and which has arisen, in great
measure, from the extremely erroneous figure given by
Risso in his " Histoire des Crustaces de Nice," &c. This
figure in fact is so bad, that it affords no ground whatever
for any determination of the species : it is indeed much to
be regretted that in a work in which so many interesting
species were first described, the figures are almost univer-
sally so imperfect as to afford no specific character which
can be at all depended upon. Savigny, in his masterly
" Memoires sur les Animaux sans Vertebres," establishes
the genus by name, but without any description, retaining
the specific name of Sivado after Risso. Leach, who ap-
pears from some other circumstances to have been unac-
quainted with Risso's earlier work, gives to a specimen in
the British Museum the name of P. Samgnii, but he has
not, as far as I am aware, published any account of it.
Milne Edwards, upon the credit of Basso's figure, has con-
sidered the Mediterranean species as distinct from the
British ; and he has added a third species, which he calls
P. brevirostris. I do not think, however, that the cha-

SIVADO. 315

racters by which this eminent carcinologist distinguishes
the latter supposed species can be considered as constant, as
I have seen British specimens which vary considerably in
the degree of ciliation in the parts from which he deduces
his distinctions. It is, finally, very evident that the figure
of Guerin in his " Monographic," imperfect and unsatis-
factory as it is, and which he refers to P. Sivado, belongs
to our British species ; and the result of all these conside-
rations in my mind, is the full conviction that we are at
present acquainted with but one species of this genus : I
have therefore retained E/isso^s original specific name of
Sivado. It now remains that I should state what is known
about this species as a native of Britain. It appears pro-
bable, from the following extract of a letter from Dr. Leach
to Mr. Baker of Bridgewater, that the first British speci-
men known was in the collection of Mr. Sowerby ; and it
also appears from the same passage that Mr. Baker had
himself sent another individual of this species to Dr. Leach
with some other Crustacea and insects. Dr. Leach writes,
" I cannot refrain from noticing two species which give me
the most pleasure. The one is a species of the genus
Pasiphaa of Savigny. I have seen a specimen of this genus
in Mr. Sowerby's collection, and I believe it to be the same
species." Subsequently Mr. Baker obtained several others,
taken, I believe, in the Bristol Channel, which are now,
through his kindness, in my possession, and I have lately
received from Mr. M'Andrew, two individuals, a male
and a female, taken by him in the Irish Channel, the
latter having the ova excluded and attached to the ab-
dominal false feet. It would appear by the following
notice in the fifth vol. of the " Annals of Natural His-
tory," by Mr. W. Thompson, that the specimen in the
British Museum was originally taken on the coast of Ire-

316

PBN^BADJB.

hind. " Pasiphaa Sivado. In the British Museum there is
a specimen so named and labelled 4 Ireland.1 From the
donor, the Rev. James Bulwer, I learned that it was taken
by him in the vicinity of Dublin."

I have, for obvious reasons, dwelt more at large than in
a case of less difficulty would have been necessary, on the
characters as well as the nomenclature of this species. It
is now for others, who may have the opportunity, to com-
pare Mediterranean with British specimens, in order to
ascertain whether I am right in considering them as all
appertaining to one species.

DEC A POD A . PEN MA DM.

MACROURA.

GENUS PEN^US. FABB.

PAL^MON. Oliv.

PKN^EUS. Fabr. Bosc. Latr. Leach, Edw.

Generic character. — External antennae about as long as the
body, the scale slightly decreasing and rounded at the apex, ciliated
on the inner margin. Internal antennae with the first articulation
very broad, hollowed above, forming a cavity for the eyes ; the
outer margin armed with a tooth, and the inner furnished with a
lamellar and ciliated appendage ; the last two joints very short.
The filaments of these antennae are double and generally very short.
External pedipalps long, slender, and pediform, furnished at their
base with a long, curved, ciliated appendage. Feet all with a small
appendage at the base ; the first three pairs didactyle, increasing
in length from the first to the third. Carapace with a prominent
median crest, extending into a long toothed rostrum. Eyes very
large and round. Abdomen large and much compressed ; its pos-
terior half carinated. False feet much enclosed by the lateral
portions of the abdomen, terminating in two unequal ciliated
plates.

One species only of this genus has been found on our
coasts.

318

DEC A POD A.

MACROUBA

PEN1 /HAD

Penceus Caramote. Desmar.

Specific character. — Filaments of the internal antennae shorter than the last two
articulations. Thorax trisulcate posteriorly ; rostrum bent downwards, above
multidentate.

Alphceus caramote
Penceus

trisulcatus

Risso, Crust, de Nice, p. 20.

DESMAR. Consider, surles Crust, p. 225. — Risso, Hist.

Nat. de 1'Eur. Mer. V. p. 57. — EDW. Hist, des

Crust. II. p. 413.
LEACH, Mai. Brit. t. xlii.

THE carapace is large and somewhat ventricose ; the
rostrum extending to the peduncle of the internal antennae,
armed above with numerous (about twelve) rather strong
teeth, and beneath with one or two points only, the latter
placed a little in front of the line of the eyes ; on each
side of the rostrum is a crest, which is continued back-
wards to near the margin of the carapace, thus forming
a deep groove on each side of the median crest of the

PENJ3US CARAMOTE. 319

rostrum, the posterior portion of which is also traversed by
a third longitudinal groove. A strong tooth at the anterior
margin of the carapace, above the insertion of the internal
antennas, and at the outer and upper margin of the orbit,
a smaller tooth at its inner side, and a third very small one
at the posterior termination of a small lateral groove which
passes backwards from the face of the second tooth. The
eyes are round and remarkably large. The inferior or in-
ternal antennae have two extremely short filaments, shorter
than the last two articulations of the peduncle. The scale
of the external antennae is somewhat narrower and evenly
rounded towards the extremity, and ciliated along its
anterior and inner margin. The external pedipalps are
pediform, gradually tapering to the extremity, and ter-
minating in a small acute finger. The first three pairs
of feet didactyle, increasing in length from the first to
the third, which is rather the longest of the five. The
hand of the first pair is the most robust, that of the second
rather the longest : the fourth and fifth pairs are simple.
The abdomen is much compressed, particularly posteriorly,
and rises to an acute carina for the greater part of its length
backwards. The fourth and fifth segments are notched on
each side. The last segment, or medium portion of the
tail, is long, narrow, triangular, acute, longitudinally
grooved, furnished with a strong tooth on each side near
the apex.

The length of the British specimen, figured by Leach,
from the rostrum to the extremity of the tail is not more
than three and a half inches. Risso gives five inches,
and Milne Edwards seven as the length of those of the
Mediterranean.

I have felt compelled, upon careful examination, to con-
sider the British species of Penaus, to which Leach, pro-

320

PEN.EADJE.

bably from not having seen any Mediterranean specimen o
P. caramote, gave the name of P. trisulcatus, as identical
with that to which the former name has been given by
Rondeletius, by Risso and Edwards. In this conclusion
am borne out by the opinion of the last-mentioned distin-
guished naturalist. Like some other of the Mediterra-
nean species found on our shores, it is very rare with us.
Leach mentions but two specimens known to him, nor is it
mentioned in any of the local Faunas either of England or
Ireland. The two specimens known were both taken on
the Welsh coast.

:

DECAPOD A ? CVMADJR 1

MACROURA 9

GENERA CUMA, EDW., ALAUNA AND
BODOTRTA, GOODSIR.

IN the 1 3th volume of the " Annales des Sciences Natu-
relles," Dr. Milne Edwards described a small Crustacean
under the name of Cum a Audouinii ; but in his " Natural
Hist, of Crustacea," he expresses his doubt whether this
little animal be anything more than the larva of a deca-
podous form, and places it amongst other doubtful examples
in an appendix.

In 1843, however, Mr. Harry Goodsir published in the
"Edinburgh New Philosophical Journal," a very full and
clear description of this and two other species of Cuma,
and of two allied species which he considers as the types
of two new genera, to which he gives the names respec-
tively of Alauna and Bodotria. The whole of these I have
ventured to consider provisionally as constituting a small
family, probably belonging to the lower decapods, which
appears also to be Mr. Goodsirs own opinion, though
expressed with doubt, in which doubt I entirely agree.
This author satisfactorily determined that they are per-
fectly developed animals and not mere larvae.

As I have never had an opportunity of seeing the ani-
mals, I take the liberty of giving the whole of Mr. Good-
sirs account of this remarkable family, which is too concise
to require or admit of condensation.

322 CUMA.DJ3.

For the anatomical details I refer to the plates illus-
trating the paper.

"During the summers of 1841 and 1842, I obtained a num-
ber of crustaceous animals, which I arranged promiscuously under
the genus Cuma of M. Edwards, it being my intention to publish
them at that time under this arrangement. I waited, however,
until it could be satisfactorily proved whether they were perfect
animals, or, according to the suspicions of M. Edwards, merely the
larvae of some Decapodous Crustacea. I have now satisfied
myself that they are perfect animals, and at the same time have
discovered the types of two new genera, which places the group
in a still more interesting point of view.

(l I have applied the name Bodotria to one of these genera, and
Alauna to the other ; the former being the ancient name of the
Firth of Forth, at the mouth of which all these animals were got ;
and the latter, the ancient name of the river Forth.

" The latter of these genera (Alauna) may be the genus Condy-
lurus of Latreille, as I have never seen that author's description ;
but whether it be so or not there cannot be any danger in applying
the name Alauna, as Condylurus had been previously used amongst
the Mammalia.

" As I had a greater number of specimens of the Cuma Edwardsii
than of any of the others, I have been enabled to make out the
structure of that species with greater minuteness.

*' These animals are very like small prawns in their general ap-
pearance ; but they bear perhaps in this respect a greater likeness
to the species of the genus Nebalia than to any other known Crus-
taceans.

" The shell is hard and brittle, cracking under pressure. All the
species are of a pale straw colour. The thoracic portion of the
body is large and swollen ; it is composed of six segments ; the
abdomen is longer ; and is composed of seven segments.

" M. Edwards, in his Memoir on the genus Cuma) published in
the 13th vol. of the Ann. des Sc. Nat., considers that the whole of
the first and largest segment of the body constitutes the head. In

GENERA CUM A, ALAUNA, AND BODOTRIA. 323

all the specimens which I have dissected, I have found a suture
running across this segment, immediately before the middle part of
it ; this is observed very distinctly in the Cuma trispinosa, in the
Bodotria arenosa, and also in the genus Alauna. The first of
these parts I consider to be the head ; the second part as the first
thoracic segment. To the first we find attached the rostrum, eyes,
antennae, organs of the mouth, and footjaws four in number. The
second part bears the first pair of true ambulatory legs ; these legs
constituting (according to M, Edwards) the third pair of foot-
jaws.

" The second thoracic segment is quite obsolete in M. Edwards's
species (Cuma Audouinii) ; it is but slightly observed in the (7.
Edwardsii ; in the C. trispinosa, however, it becomes quite ap-
parent, being of considerable breadth at the dorsal portion. In the
Alauna rostrata, also, we find this segment quite developed through-
out its whole extent, and the second pair of thoracic legs arising
from it.

" These two thoracic segments (the first and second) bear the
compound legs in the genera Cuma and Bodotria, in which two
genera the four following segments bear the four pairs of simple
legs. In the genus Alauna, however, we find a different arrange-
ment, there being an equal number of simple and compound legs,
three pairs of each.

" The eyes in this tribe of animals are exceedingly small ; they
are pedunculated, but sessile,* and are placed very close together ;
they are situated near the posterior part of the head, a short dis-
tance behind the rostrum, and on the mesial line. They are covered
by the shell, owing to which, and their proximity to one another,
the animal is at first sight apt to be considered as monoculous. The
rostrum is short and truncated in the genus Cuma ; is almost al-
together awanting in Bodotria, but is well developed in Alauna,
being of considerable length and pointed.

" The antennae undergo considerable changes in the different
genera of this tribe. In Cuma we find the superior antennse con-

* This passage appears to be inconsistent. The two great families of Mala-
costroca are essentially distinguished from each other by the eyes being relatively
pedunculated (Podophthalma) or sessile (EdriopWialma). — T. B.

Y 2

324 CUMADyE.

sisting of a single scale-like joint, armed with a number of strong
spines ; the inferior antennae are five-jointed, being in general very
little longer than the rostrum. In Bodotria the superior antennae
are altogether obsolete, and the inferior antennae are very short. In
Alauna, again, we find the antennae more developed; the superior
consisting of a single-jointed peduncle, and a long multiarticulate
filament which is covered with hairs. The inferior pair are eight
or nine-jointed, and are somewhat larger than the rostrum. The
organs of the mouth consist of one pair of maxillae, three pairs of
mandibles, and two pairs of foot-jaws. These last organs will be
found minutely described under Cuma Edwardsii, the species which
I have been enabled to examine most minutely.

" The true legs may be classed into compound and simple. The
compound legs, as we have already stated, are four in number in
the genera Cuma and Bodotria ; but six in Alauna. The first,
or compound legs, are divided into two parts, the anterior or am-
bulatory, and the posterior or natatory. The simple legs are much
shorter than the compound, and are more adapted for prehension ;
but they are unarmed with claws, and are seldom used for this
purpose.

" The abdomen is moniliform, seven-jointed, in all the genera.
The last joint is very small in the genera Cuma and Bodotria ;
but in Alauna we find this segment very much developed. All
the genera have the sixth abdominal segment armed with a pair
of long bifurcated styles. The genera Cuma and Alauna are quite
free of appendages to the other abdominal segments ; but in £<
dotria we find that all the abdominal segments are armed with
a pair of bifurcated appendages.

" Owing to the opacity of the shell, I have not been able as yet
to make out the minute parts of the anatomy of these animals.
The intestinal canal consists of a long straight tube, considerably
dilated as it passes through the thoracic portion of the body; when
it reaches the abdominal portion it suddenly becomes much nar-
rower.

" The anal aperture is found in the seventh abdominal seg-
ment.

GENERA CUMA, ALAUNA. AND BODOTRIA. 325

" The branchiae are situated on each side of the thorax, imme-
diately above the insertions of the legs, and approach, in their
comb-like appearance, to those of the higher Crustacea. Interiorly,
each of them is connected with the superior foot-jaws, and, except-
ing that connection., lies apparently quite free in a sac formed by
the reflection of a thin transparent membrane, which lines the
internal surface of the thorax. The superior part of the branchiae
consists of one continuous piece, which is bent in a hook-like man-
ner at its posterior extremity ; the branchiae themselves arise from
the inferior edge of this part, and are about sixteen or seventeen
in number ; they are not laminated like those of the higher Crus-
tacea, but consist of one large piece, which is apparently composed
of a great number of cells.

" The organs of generation are not apparent in the male, but in
the female, and, especially when she is loaded with spawn, these
organs are at once perceptible. They are very similar in their
structure and appearance to the same parts in the female Mysis.
They consist of four scales, which arise from the inferior edge of
the thoracic segments. These scales are of an irregular oval shape,
concave internally, and convex externally, and they are overlapped
by one another. The eggs are of considerable size, and of a bright
straw colour. It is from the genus Cuma only that these obser-
vations were taken in regard to the organs of generation.

" When a portion of the skin, or shell rather, is placed under the
microscope, it presents a very beautiful appearance ; it apparently
consists of a great number of nuclei, arranged in some degree of
order. These nuclei are stellated, and here and there larger nuclei
may be observed, the edges of which are quite smooth.

" The structure of these animals is so peculiar, as to render the
assignation (at present) of a proper place in a natural arrangement
of the class, a point of very considerable difficulty. This arises in
a great measure, without doubt, from our very limited knowledge
of the class. I rather think, however, that they should be ranged
among the lower Decapoda macroura.

326

CUMAD^E.

Genus CUMA (Edwards).

Generic Characters. — The superior antennae are single-jointed, and scale-like ; the
inferior antennae are five-jointed. The caudal styles have the double terminal
scales biarticulate, the last of which is always the shortest.

Cuma Edwardsii, mihi.

C. — With the superior antennae rhomboidal ; with the ambulatory division of the
first pair of legs, with the first joint bent at an obtuse angle ; with the thumb-
like process single-jointed, and with the last joints clavate. Length 4 lines.
Hab. Frith of Forth.

Description. — The whole animal is of a fine straw-colour, with a delicate tinge of
pink, which is brighter in certain lights ; the shell is quite rough, which is
caused by the great number of shallow foveae with which the whole surface is
thickly covered. This, and the following species, are perhaps the smallest of
the genus ; at the same time, they are much thicker and stronger in proportion
to their size than the other species. The rostrum is short, thick, and suddenly
truncated obliquely. The antennae are minute ; the first or superior pair are
almost obsolete ; they consist of one joint only, which is rhomboidal : the ex-
tremity of each is armed with several strong but minute hairs or spines ; they
arise from the truncated extremity of the rostrum. The inferior antennae
arise from the inferior surface and base of the rostrum ; they are considerably
larger than the superior pair ; they are five-jointed, the third joint being the
longest, the fifth or last is extremely small, and is armed with three very strong
pointed and articulated spines. These pair of antennae are somewhat longer
than the rostrum. The footjaws are rather powerful, and have a great resem-
blance to the following pairs of feet. The first, or superior pair, are the smallest ;
the first joint is of considerable length, being equal to all the others combined ;
it is rather bent and broad, and is armed at its distal extremity with two
thumb-like processes or tubercles. Two very long and slender spines, which

GENERA CUM A, ALAUNA, AND EODOTRIA. 327

are almost as long as the foot-jaw itself, arise from the middle part of this seg-
ment ; the external spine is free of spinules altogether, but the internal is
armed, on its external edge only, with a great number of articulated spinules.
The second segment of this footjaw is very bhort, and its posterior edge bears
two very short articulated spines of equal length ; these spines are spiniferous.
The third segment is almost equal in length to the first, and, like the second,
also gives rise to nine or ten articulated and spiniferous spines. The fourth
segment is small and rounded, being also armed on its posterior edge with sim-
ple spines. The fifth segment is thumb-like, and spinous on its posterior edge.

The external pair of footjaws are much larger than the internal ; they are five-
jointed, and are armed in the same way as the first pair, except that the ex-
ternal edge of the first segment is armed at regular intervals with small tufts
of very fine hairs ; the extremity of the second segment is also armed with a
very long articulated and spiniferous spine. These two extremities just de-
scribed are in general lying in such a way as to cover the organs of the
mouth.

The first two pairs of legs are constantly concealed beneath the carapace when the
animal is at rest, covering the footjaws and the organs of the mouth, and appear
only to be used when the animal is swimming. The anterior or ambulatory
division is five-jointed ; the first joint is about twice the length of all the others
combined ; it is considerably bent and very broad ; its internal edge is armed
at regular intervals with pennicillated tufts of hair ; the three following seg-
ments are quite free of spines, but the last is anned at its extremity with a
strong claw and two smaller spines. An articulated thumb-like and chelate
joint arises from the extremity of the first segment, immediately internal
to the last four segments. The natatory or posterior division of this leg is
multiarticulate ; the first two segments are longest, being equal in length to
the first segment of the anterior division ; the remaining segments are mi-
nute, about nine or ten in number, each of which gives off a very long spiniferous
setum, which is articulated at its distal half. The second thoracic leg of this
species presents to us one of those beautiful and delicate structures which it is
impossible either to describe or to delineate with even a remote degree of accu-
racy. The ambulatory division is very long and slender, six -jointed ; the first
joint is long and very much flattened, but tapers from the middle towards its
distal extremity, which is armed with a very long and pointed spine ; the fol-
lowing joints are all equal to one another in length, except the last, which is
minute. The natatory division of this leg is seven- or eight-jointed, and is
equal in length to the first segment of the other division. The last five seg-
ments are all armed with long articulated and spiniferous setae, which smaller
spines are again spinulose. The four following pairs of legs are simple, that
is, they are merely ambulatory ; they are all six-jointed, and are very spiny 4
The segments of the body from which they arise are all ovoid, their dorsal edge
being sharp and pointed.

The abdominal portion of the body is long and slender, seven-jointed and moni-
liform ; the last joint is minute, and lies between the caudal styles which arise
from the extremity of the sixth segment ; these styles are of no great length
in this species ; they are composed of three parts ; each style consists of a

328

CUMADJS.

long-jointed peduncle, from the distal extremity of which two biarticulated
scales arise ; these scales lie one above the other. The first segment of the
peduncle is somewhat longer than the sixth abdominal segment ; the first seg-
ments of the scales are about half the length, and the last segment about one-
fourth the length of the peduncle ; the inner edge of the superior scales is armed
with a number of long, pointed, and articulated spines. The spines which arise
from the inner edge of the inferior scales are more numerous ; they are al
bent, their points being turned backwards ; the convex or anterior edges of all
these spines are very much serrated.

I have named this species after M. Edwards, the founder of the genus, and the
leading crustaceologist of the day.

Cuma Audouinii. Edwards.

C. — With the superior antennae very small ; with the first joint of the ambula-
tory division of the first pair of legs almost bent at right angles ; the terminal
joints oval, and the thumb-like process multiarticulate. Long, four lines to five.
Hab. Frith of Forth.

Description. — Under casual observation this species is very apt to be mistaken
for that last described, but by careful examination the difference is found to be
very material. In its general appearance, this species resembles the Cuma
Edwardsii. The first thoracic segment, however, is longer and not so rounded ;
the rostrum is shorter and more pointed, and the eyes are larger ; the flattened
surface on the sides of this species is not so decided. The second thoracic
segment is more hid ; the third is larger, ovoid, and rounded ; the adjoined

GENERA CUMA, ALAUNA, AND BODOTRIA.

329

scale projects backwards ; the fourth segment is of the same shape as the third,
but not nearly so large ; the fifth ends in a sharp point, both superiorly and
inferiorly ; the sixth thoracic segment is clavate. The superior antennae are
very small, and scarcely to be distinguished from the rostrum. The inferior
antennae are very similar to those of the Cuma Edwardsii. The footjaws are
also similar in their structure to those of the last-described species ; the am-
bulatory division of the first leg is five-jointed ; the first joint is very much
bent, and is of considerable breadth ; the two last joints are quite oval, and
the last nonchelate. The internal thumb-like process, instead of being com-
posed of one joint only, as in the last described species, consists of four or five
segments, which are all armed with short spiniferous and pointed spines ; the
natatory portion of this leg is multiarticulate, the extreme joints being very
small, so as to place the long spiniferous setas very close to one another.

The second pair of legs are very short. The last four pairs of legs are similar in
their structure to those of the last described species. The abdomen and caudal
fins also bearing a similar resemblance.

This species is apparently the Cuma Audouinii of M. Edwards, but whether it is
or not I cannot be quite certain.

Cuma trispinosa, mihi.

<7._With the dorsal ridge of the carapace surmounted by three spines, with the
ambulatory division of the first pair of legs extremely short, and with the second
thoracic segment well developed. Long, eight lines. Hab. Frith of Forth.

Description.— This is a most characteristic species, and brings out several points
of material consequence in the character of the genus. This species has the
body quite smooth, and of the same colour as the preceding. It is the largest
of all the species, but is more slender. The thoracic segments are not so deep
as those of the preceding species, and the lateral compression is awanting. The

330

CUMAD.E.

rostrum is sharp-pointed, and bent considerably upwards ; the eyes are small,
and the dorsal ridge immediately behind the eye is surmounted with three
thick short spines. The second thoracic segment is of considerable extent at
its dorsal part, but is quite obsolete at the middle ; it again, however, makes
its appearance at its inferior part, where it supports the second pair of com-
pound legs. The four following segments gradually decrease in size : — the
superior antennae are of considerable size, oblong and spinous. The inferior
antennae are much longer than the rostrum. The ambulatory division of the
first pair of legs is extremely short, and the first joint is of no great breadth.
The natatory division it about the same length as the first joint of the anterior
division.

The second pair of legs are very long and slender ; the first segment is not broader
than the following joints, and is armed internally at its extremity with a very
long spine.

The simple feet are extremely spiny.

The abdominal portion of the body is very long and slender, the fifth segment be-
ing the longest. The caudal styles are long, slender, and pointed ; the internal
scale has the last joint pointed and armed with two spines ; the last segment
of the external scale is more obtuse.

Genus ALAUNA, mihi.

Generic Characters. — The superior antennae are composed of a peduncle and a
multiarticulate filament. The inferior antennae are eight-jointed. The first
three pair of legs are compound. The internal scale of the caudal style is com-
posed of three segments, and the external of one.

Alauna rostrata, mihi.

Description. — The whole animal is of a beautiful bright straw colour, inclining to
yellow. The thoracic portion of the body is very large and swollen. The
first segment or carapace is almost oval. The rostrum is long, pointed, and is
bent upwards at its extremity. The eyes, which are of considerable size, are
situated at the base of the rostrum. The superior pair of antennae are very
slender, consisting of a delicate filament covered with hairs, which arises from
a short peduncle ; these antennae are almost equal in length to the rostrum.

The inferior antennas are much longer, consisting of eight joints slightly spinous ;
the distal extremity of the third is armed with a strong multiarticulate spine.
The footjaws are seen projecting considerably beyond the edge of the carapace ;
they are very spiny, and the last joint but one is armed with a long articulated
spiniferous spine.

The first pair of legs are extremely short ; the thumb-like process at the extre-
mity of the ambulatory division is single-jointed and spiniferous. The second
pair of legs are also short. The ambulatory division of the third pair of legs is
very long and slender, being almost as long as that of the second pair of legs ;
the fifth joint is the longest. The natatory division is as long as the first four
joints of the ambulatory. The simple legs are very spiny on their anterior
edges.

GENERA CUM A, ALAUNA, ANI> BODOTRIA.

331

The abdomen is short and thick, seven-jointed, the last joint being produced into
a long spine which is spiniferous on either edge ; the anal aperture is seen near
the base of this segment. The caudal styles arise from the sixth segment, and
they are much more complicated that those of the foregoing genera. The first
segment is slightly clavate, longer than the seventh abdominal segment, and
armed with a single row of spines on its inner edge. The internal scale consists
of one joint only ; it is very spiny, and is about half the length of the external.
The external scale is composed of three joints, the first two of which are equal
in length to one another ; the third is about twice the length of both of these,
and is very spiny at its extremity. Long, half-an-inch. Hab. Frith of
Forth.

Having only obtained one specimen of Alauna rostrata, and
one also of Bodotria arenosa, I have not been able to examine the
structure of these two genera satisfactorily.

Genus BODOTRIA, mini.

Generic Characters. — The first, second, third, fourth, and fifth abdominal segments
are each armed with a pair of bifurcated finlets. The two terminal scales of the
caudal styles are single-jointed.

332

CUMAD^E.

Bodotria arenosa, mihi

Description. — Tlie carapace is almost oval, rostrum awanting, that part of the
carapace being merely rounded off. The superior antennae are quite obsolete.
The inferior pair are of considerable length, and are terminated by means of
two long spines.

The ambulatory division of the first pair of legs has the first joint of a very great
size, being very much flattened and slightly curved. The four remaining joints,
together with the internal thumb, are very spiny. The natatory division of
the leg is six-jointed, the four last joints giving rise to as many long spiniferous
spines, which are articulated at their distal halves. The external edge of these
spines are spiniferous at the articulated half only. The ambulatory division of
the second pair of legs has the first segment very broad, and tapering gradually
towards its distal extremity, from which arises a very long, articulated, and
spiniferous spine.

The abdominal finlets are five in number. They are composed of two parts, viz.,
the first or pedicle, and the second or bifurcation ; the pedicle is of considerable
length, from the extremity of which there arise two scales, which are armed
on their margins with long spiniferous spines, which are much longer than the
finlet itself.

The first segment of the caudal styles tapers very slightly, and the two terminal
scales are each of them single-jointed, and end by means of very fine points.
The external is armed at its extremity with two spines. Long, five lines.

This genus forms doubtless a link between the Stomopoda of M. Edwards and the
higher Crustacea.

GENERA CUM A, ALAUNA, AND BODOTRIA.

333

" In their habits all these animals seem to agree. I have not
been able to observe anything peculiar in them. They swim with
very great rapidity, and on stopping they fall to the bottom on the
sand or gravel, without attempting to lay hold of anything, as I
have already remarked, seldom using their feet as a means of pre-
hension. They free themselves with great dexterity from any
weight which may happen to fall on them. I have often placed
the point of a needle on their thorax and pressed them down into
the sand ; the animal immediately frees itself with very little ap-
parent trouble, by means of its tail. The extremity of the tail is
placed against the needle with one of the styles on either side of
it, and by pressing upwards in this way, it soon regains its
liberty.

" They frequent sandy banks, and chiefly those where there is a
little sea-weed."

STOMOPODA. MYS1D&.

GENUS MYSIS, LATR.

CANCER. Muller, Otho, Fabr.

MYSIS. Latr. Lam. Leach, Edw.

Generic character. — External antennae inserted beneath the
ternal, the first joint giving attachment to a laminar appendage,
similar to that in the Palcemonidce, which is much elongated and
ciliated on the inner margin ; the two succeeding joints of the pe-
duncle slender and cylindrical, the terminal filament filiform, and
longer than the internal antennas, which are inserted beneath the
eye, near the median line, and have two terminal filaments. Pedi-
palps consisting of two pairs entirely pediform. The first pair short,
composed of three distinct branches ; the internal portion pediform,
of five joints, hairy, and doubled upon itself in front of the mouth;
the middle branch or palp elongated, and composed of numerous
articulations ; the basilar joint very large, with a ciliated strap-
shaped process on each side ; the third or external branch, or fla-
belliform appendage, is represented by a semimembranous scale
directed upwards, and lying under the margin of the carapace.
Second pair of pedipalps of the same form, but wanting the fla-
belliform appendage. Feet of six pairs, composed of corresponding
elements with the external pedipalps and five pairs of feet in the
DECAPODA ; each consisting of two branches, decreasing in length
from before backwards, and formed for swimming ; the first four
pairs have no flabelliform appendage ; the last two are furnished
with it. This part in the male is very small, but in the female it
is greatly developed, and forms on each side a broad plate bent un-
der the sternum, the two thus forming a pouch, in which the eggs
are first deposited, and within which the young are secluded, and
pass the early period of their life. Carapace covering only the

GENUS MYSIS. 335

anterior part of the thorax, the two sides bent downwards and in-
wards so as to be applied against the base of the feet ; anteriorly it
becomes very narrow, and terminates in a short flattened rostrum.
Eyes large, short, with the base hidden under the anterior mar-
gin of the carapace. Abdomen very slender, tapering, elongated,
nearly cylindrical. Tail as in the macrourous DECAPODA.

No distinct branchial apparatus has as yet been observed
in this remarkable genus ; and, as is observed by Dr. Milne
Edwards, " The only appendage which appears to be so
modified in its structure, as to become more adapted than
the rest of the body to serve the purposes of a respiratory
organ, is the lash of the first pair of pedipalps, which in
other respects are similar to those found in numerous spe-
cies possessed of branchiae." It is, however, not at all im-
probable that this may be the true organ of respiration.

The development of the young in this genus, as well as
their anatomy generally, has engaged the attention of the
late Mr. J. Vaughan Thompson, and a very elaborate
monograph of their structure will be found in his " Zoolo-
gical Researches," to which the reader is referred for full
information.

The affinities of the family Mysida are very incorrectly
indicated by the position which Dr. Milne Edwards has
assigned them amongst the Stomopoda. In almost all the
essential points of structure they are certainly more nearly
allied to some of the Decapoda ; but as they are also re-
mote even from these, I have not considered it right to
reduce them to that group, or to attempt to fix their
natural relation to the two groups, particularly as a local
Fauna does not offer the best vehicle for changes in general
arrangement.

My sis cham&leon. J. V. Thomps.

Specific Character. — Middle plate of the tail bifurcate ; rostrum obtuse, not
more than one-third the length of the ocular peduncle.

Mi/sis apinulosus?

Leachii?
Chamceleon,

LEACH, Trans. Lin. Soc. XL p. 350. — DESMAR. Con-
sider, sur les Crust. — EDW. Hist, des Crust. III. p.
457.

J. V. THOMPSON, Zool. Researches, p. 27.

Ib. p. 28, t. ii. fig. 1— 10.— EDW. 1. c. p. 457.

THE general form of this species is much elongated. The
carapace slender, terminating in a very short rostrum, in
some scarcely projecting, in others forming an obtuse tri-
angle, and never extending more than one-third the length
of the ocular peduncle. The internal antennae have the
peduncle somewhat club-shaped, the first joint being elon-
gated, cylindrical, and small, the last two, and particularly
the terminal one, much broader, and both very short ; the
whole peduncle does not extend much more than one-third
the length of the scale of the external antennae : the scale

MYSIS CHAMELEON. 337

becomes a little narrowed forwards, is obliquely truncate at
the apex, with a small tooth on the outer angle, and it is
ciliated with rather long hairs on the inner side and at its
extremity. The middle plate of the tail is bifurcate at the
apex, longitudinally grooved on each side of the median
line, minutely toothed on the sides, and with a stronger
tooth on each apex. The lateral laminae are ciliated on all
sides with long hairs ; the inner is long-lanceolate, and
acute ; the outer is longer, and rounded at the extremity.

It often reaches the length of an inch and a quarter.

" Nothing," says Mr. Vaughan Thompson, " can shew
the fallacy of colour in distinguishing the species, more
clearly than the variety of tints which Mysis chameleon
assumes, as it occurs here in the river Lee and the harbour
of Cove, and which have suggested its trivial name ; in
the upper part of the river, below the city of Cork, it
occurs of different shades of grey, inclining at times to
black, having invariably the greater part of the anterior
scales, inner branch of the inferior antennae and joints of
the outer laminae of the tail, black, and the fringe of the
scales tinged with pink ; lower down amongst the littoral
fuci, it takes various tints of brown ; and those obtained
from sites abounding in Zostera and Ulvae, present us with
green colours of greater or less intensity."

I have quoted the above account of the variation of
colour in this species in the author's words, in order to
shew that difference of colour alone can afford no ground
for considering this species as distinct from the spinulosus
of Leach. And yet Mr. Vaughan Thompson, in his de-
scription of the latter (which he names M. Leachii), gives
colour as the only tangible distinction. I am decidedly
of opinion that they constitute but one species, and I have
retained the name of cham&leon, as spinulosus is equally
applicable to various other species of the genus.

338

MYSIDJE.

This is, perhaps, the most common and the most widely
distributed of our native species. I have received it from
various parts of the coast, both of England and Ireland,
but from no place in such numbers as from Weymouth,
where it sometimes swarms. My late lamented friend,
Mr. William Thompson, informed me that he has taken
this species in numbers from the stomach of Corregonus
Pollan, caught in Lough Neagh, shewing that it occasion-
ally inhabits fresh water.

MYSIS VULGARIS.

STOMOPODA.

339
MYSIDJE.

My sis vulgar is. J. V. Thompson.

Specific Character. — Middle plate of the tail lanceolate, the apex entire ; rostrum
very short, obtusely triangular, extending to about half the length of the ocular
peduncle ; antennal scale nearly as long as the carapace.

Mysis vulgaris, J. V. THOMPSON, Zool. Researches, p. 30, t. i. — ED\V,

Hist, des Crust. III. p. 459.

GENERAL form less robust than in M. chamaleon. The
carapace slender, somewhat cylindrical, slightly constricted
at its anterior third, terminating in a very short, obtusely
triangular rostrum, which scarcely extends to the middle
of the ocular peduncle. The peduncle of the internal
antennae much resembling that in the former species ; scale
of the external antennae not less than four times the length
of the peduncle of the internal ; subulate, obtuse at the
points, ciliated on both sides, and without an apical tooth.
Middle plate of the tail lanceolate, acute, spinulose on the

z 2

340 MYSID^E.

sides ; lateral plates somewhat subulate, ciliated on each
side.

Mr. J. V. Thompson appears to have been the first to
distinguish this species of Mysis, to which he gave the
name vulgaris, probably from its being the most common
species in the locality where he found it. It is, however,
more rare on our coasts, and probably, as it had escaped
detection, also on those of other countries. The specific
name which he assigned to it is always one of doubtful
propriety, and I would fain have assigned to it that of the
distinguished naturalist by whom it was first discovered
and described, but from a disinclination ever to change
specific name excepting under urgent circumstances.

It appears to be a local species, and as far as we are
at present able to say, is principally found on the Irish
coast ; " abounding in the Lee," says Mr. J. V. Thomp-
son, " even up to Cork," and I have specimens collected
by Mr. W. Thompson in Belfast Lough. From the former
species it may be at once distinguished by several promi-
nent characters, particularly the longer antennal scale, and
the simple acute apex of the middle caudal lamina. Its
colour is pale, translucent grey.

The following is Mr. Vaughan Thompson's account of
its habits. " They swim with the body in a horizontal
position, and abound in the Lee, even up to Cork, from
the early part of spring to the approach of winter ; during
the still period of the tide at low water, they repose upon
the mud and stones at the bottom of the river, and as the
tide rises, may be observed forming a wide belt, just within
its margin, the youngest swimming nearest to the shore,
the oldest further out, and in deeper water : they appear
to be mostly females, the males being few in proportion.
This species contributes towards the food of various young

MYSIS VULGARIS. 341

fish, from which they frequently escape, by springing up out
of the water."

Is it not probable that M. integer of Leach (Scoticus
of Thompson), may be identical with this species ? His
description is too imperfect to enable us to ascertain this,
but they agree in such particulars as are known, excepting
in size and colour, both of which are variable characters.

The following is his account of the species.*

" Tail with the middle lamella entire ; length one-third
of an inch. Colour pellucid cinereous, spotted with black
and reddish brown. Eyes black. Females more abun-
dant than males.

" At low tide, near Loch Banza [in the Isle of ArranJ,
the pools were full of this species, swimming with its head
uppermost, and its eyes spread, making a most grotesque
appearance."

* Lin. Trans. XI. p. 350.

.342

STOMOPODA.

MYSIDJE.

MYSID

My sis Griffithsitf. Mihi.

Specific Character. — Middle plate of the tail lanceolate, constricted near tlu
base, apex entire, slightly obtuse ; rostrum lanceolate, extending beyond the
penultimate joint of the peduncle of the internal antennae ; antennal scale scarcely
longer than the rostrum.

Mysis rostratus ? GUER. Iconogr. Crust, t. xxiii. f. 2.

CARAPACE much elongated, and more slender than in
either of the former species, terminating forwards in a
long, acute, lanceolate rostrum, extending beyond the
penultimate joint of the peduncle of the internal antennae,
which is itself longer and more slender than in the former
species. Scale of the external antennae shorter than the
peduncle of the internal, rounded at the apex, with a
small external spine, ciliated only on the inner margin.
Abdomen very slender and tapering; middle plate of the
tail lanceolate, somewhat constricted near the base, the
apex entire, very slightly obtuse, the margins spinulose ;
the inner lateral lamella very narrow, tapering regularly

MYSIS GRIFFITHSLE. 3 13

to the end, fringed on both sides with long hairs ; outer
lamella broader and longer, fringed with long hairs on the
inner margin, and at the apex, and with a few short stiff
hairs only on the anterior third of the outer margin.

Length three quarters of an inch.

I can scarcely persuade myself that this can be the
species figured, but not described, by Guerin under the
name of M. rostratus, although the characters in many
respects agree with his figures. The form of the rostrum,
of the antennal scale, of the peduncles, of the eyes, of the
tail, and indeed of every part figured, although bearing a
general resemblance, differs so much in detail that we are
left in the dilemma either of considering the representa-
tions worthless from their inaccuracy, or of giving a distinct
specific name to ours. As no description exists of M.
Guerillas species, I have adopted the latter alternative, and
have named it in honour of a lady to whom natural history
is greatly indebted, and from whom I received the only
specimens of this species known. Mrs. Griffiths obtained
them at Torquay.

STOMOPODA. MYSIDJE.

GENUS THYSANOPODA, EDW.

Generic character* — External antenna, as in Mysis, inserted
beneath the internal, and furnished with a small antennal scale,
the basal joint broad and almost globular. Internal antennae in-
serted close beneath the eyes ; furnished with two filaments.
Pedipalps two pairs, entirely pediform, perfectly resembling the
legs themselves. Feet similar to each other and to the pedipalps,
excepting the last pair ; the basal joint short and thick ; the stalk
very long, and furnished with long hairs on the inner side ; the
palp short, lamellar, and hairy ; the last pair of legs much shorter,
consisting only of the palp, which is more developed. Carapace as
in Mysis. Abdomen with the lateral processes more developed
than in that genus ; the first five segments furnished with natatory
false feet — the appendages of the sixth segment forming the lateral
caudal laminae, and the seventh constituting the central, slender,
and furnished at the apex with two needle-shaped appendages.
Branchial external, consisting of eight pairs, attached at the base
of the several pairs of thoracic natatory members ; the pedipalps
and true feet increasing in size and development from the first
to the last. They consist of a stem, or stalk, each furnished with
numerous lateral branches. Eggs contained in a pair of oval sacs
dependent from within the base of the posterior feet.

This very remarkable genus of Mysidse was first de-
scribed by Dr. Milne Edwards, in the Anuales des Sciences,
from an Atlantic species which he found in the collection
of Crustacea formed by Mons. Reynaud, and placed in the

* In the engraving at the head of the description of our species, are the detaiL
of all the essential parts ; for the beautiful and accurate delineation of which I
feel greatly indebted to Mr. Westwood's well known care and accuracy.

GENUS THYSANOPODA.

345

Paris Museum. The remarkable peculiarity in the re-
spiratory apparatus distinguishes it at once from every
other form of Crustacea, and notably from its congeners in
the same family ; and the situation of the ova, which I am
enabled to supply from the new species about to be de-
scribed, is not less remarkable.

346

STOMOPODA.

MYSID^E.

MYSW^E.

Thysanopoda CoucMi.

Specific Character. — Branchiae with only one series of leaflets. Middle point
of the trifid apex of the central caudal lamina, not half the length of the lateral
ones.

THE general aspect of this curious species indicates at
once its near relation to Mysis, which the detail of its
organization confirms. The present species differs from
Th. tricuspida, the species on which Dr. Milne Edwards
founded the genus, in several points, — the most striking
of which are the following. In Edwards' s species the bran-
chise, in addition to the primary leaflets ranged in a single
series along the stalk, have very numerous secondary fila-
ments attached to them — a circumstance which I have not

THYSANOPODA COUCHII. 347

observed to exist in a single case of the numbers I have
examined of our present species. Judging from the figures
in Dr. Edwards^s plates, the carapace in the present species
is smaller and more cylindrical ; the cleft in the lower lip
is more hollowed, the palp of the thoracic feet is less
developed, the abdominal false feet are shorter, and very
differently formed ; the middle lamina of the tail also
presents some difference in the relative length of the middle
and lateral points of its tricuspid apex. One of the most
interesting circumstances in the organization of this species
is the form of the ovisacs, which, instead of being mere
pouches closely adherent to the thorax, are dependent from
their attachment by a distinct peduncle. This structure
was unknown until I detected it in a single individual, the
only female amongst a large number of specimens sent to
me by my friend Mr. Couch, who obtained them on the
Cornish coast, from the stomach of a mackerel, which
appeared to have been making a feast of this rare and
interesting little crustacean. The following account has
been kindly furnished to me by that gentleman, and shews
that it can scarcely be considered as an ordinary inhabi-
tant of our coasts. " The mackerel from which the curious
shrimps Thysanopoda were taken, were caught almost at
mid-channel, or almost ten leagues from us ; perhaps seven
or eight south of the Lizard ; and I have not seen any
since, although I am much in the habit of searching the
stomachs of mackerel and other fishes. There were my-
riads in the stomachs of the mackerel at the time when I
obtained those which I sent you." I have dedicated the
species to that indefatigable and acute observer, to whom
we are indebted for so many valuable contributions to
natural science.

The following is a description of the details of the wood-

348

THYSANOPODA COUCHII.

cut ; #, superior antennas ; 5, inferior antennae ; £, lower
lip ; d, first maxilla ; 0, second maxilla ; /, mandible ; #,
one of the thoracic feet, with branchia attached ; /*, a
branchia; i, abdominal false foot; #, middle caudal lamina;
£, lateral caudal laminae.

STOMOPODA . SQ UILLA DJE.

GENUS SQUILLA.

SQUILL A. Rondel.

CANCER. Lin. Herbet.

SQUILLA. Fabr., Latr., Leach, Desmar. Roux, Edw., &c.

Generic character. — Antennary segment moveable, nearly qua-
drilateral. External or inferior antennae inserted on each side the
antennary segment, beneath the anterior margin of the carapace ;
the first and second joints of the peduncle short and thick, the
latter bearing at its extremity a broad, oval scale ; the terminal
filaments slender and short. The internal or superior aniennce
attached to the anterior margin of the antennary segment, and
composed of a tri- articulate peduncle terminating in three filaments
of moderate length. Mouth situated under the posterior third of
the carapace. First pair of thoracic members forming a pair of
robust claws, of which the terminal joint is furnished with long
and sharp teeth, and is capable of being doubled upon the penulti-
mate joint, into a groove of which it is received, forming a power-
ful prehensile implement. The three pairs following the claws are
small, and terminated by a rounded hand, with a single finger,
forming a single claw like that in crangon ; the three posterior
thoracic members much smaller, slender, cylindrical, and furnished
with a styliform appendage attached to the extremity of the ante-
penultimate joint. Carapace longer than broad, divided by longi-
tudinal sulci into three portions; not covering the first two cephalic
nor the last four thoracic segments. Abdomen rounded above, each
segment furnished with a pair of broad natatory false-feet, the
basilary joint quadrilateral, each bearing two lamellar branches,
the exterior of which gives attachment on its posterior face, and
close to the peduncle, to a tufted branchia. The last segment of
the abdomen is very large, forming the middle plate of the tail, the

350 GENUS SQUILLA.

lateral portions of which are formed as usual by the appendages of
the sixth segment ; the basilary joint of these is very robust, and
is prolonged into a long pointed scale, which stretches out beneath
and between the two terminal branches.

It has been observed by Dr. Milne Edwards, that the
distinctness and separation of the normal segments, espe-
cially those of the head and thorax, are carried further in
this family than in any other form amongst the Crustacea ;
and in this view it may be considered as offering the
nearest approach to the typical structure, and the key to
the homologies of the class. Some further allusion to this
circumstance will be found in the introduction, and it will
be sufficient here to refer the reader to the descriptions
given by the excellent author just named, of the characters
of the family, and of the different genera ; and, in connexion
therewith, to the plates in which the details of the external
anatomy are given.* The species of the family are very
widely distributed; and even of the genus Squilla, the
coasts of Europe, Asia, Africa, and America, furnish ex-
amples. Of the three species which are known to inhabit
the Mediterranean, two have now been found upon our
South-western coast, both first discovered by the acute and
indefatigable researches of Mr. Couch.

In the characters given above I have included those
which are most characteristic of the family of Squilladse,
as well as those which are distinctive of the genus, as this
is the only generic representation of the family indigenous
to Britain.

* Hist. Nat. des Crust. II. p. 509 et scq. pi. 1, &c-

SQUILLAD./E.

STOMOPODA.

351
SQUILL A DM.

Squilla mantis, Rondel.

Specific Character- — Prehensile finger with six long teeth ; abdomen with eight
longitudinal crests, the two central ones near together ; posterior margin of the
middle portion of the carapace straight.

Squilla mantis, RONDEL. Poissons II. p. 397.

Cancer (mantis) digitalis, HERBIT. II. t. xxxiii. f. i, p. 92.

•S/W/fa mantis, LATR. Hist, des Crust., &c., VI. t. Iv. f. 3, p. 278. —

Risso, Hist, des Crust, des Env. de Nice, p. 113. —
Hist. Nat. de TEur. Merid. V. p. 85. — EDW. Hist.
Nat. des Crust. II. p. 52.

THE carapace of this species is much narrowed anteriorly,
and the anterior angles are slightly spiniform; the rostral

352 SQUILLA MANTIS.

plate semiovate ; the middle portion of the carapace has a
longitudinal median crest, which bifurcates anteriorly, and it
is separated from the lateral pieces by a deep groove, which
is continued transversely to separate the posterior portion ;
the lateral pieces have on each side two raised lines or
crests, the outermost of which extends back to near the
posterior margin. The claws very long and robust ; the
last joint furnished with six sharp, slightly curved teeth,
inclusive of the extremity ; the next joint with a deep
groove for the reception of the last when closed, and the
inferior margin of the groove is denticulated, and furnished
with three moveable teeth at the base. The three pos-
terior segments of the thorax with four crests. The ab-
domen is very broad and thick, broader and flatter towards
the extremity, and having eight distinct crests, including
the lateral margin of the segments ; the two middle ones
are nearer to each other than the others, and on the sixth
segment terminate each in a sharp spine. The last abdo-
minal segment (middle lobe of the tail) about as long as it
is broad, furnished with a high median crest, terminating in
a tubercle, at a short distance from the margin — the surface
generally marked with a number of impressed points, ar-
ranged in curved lines. The margin is raised and thickened,
and furnished with two pairs of lateral spines or tubercles,
and there are two pairs of sharp strong spines on the ante-
rior portion, with numerous small denticuli between them.
The laminar prolongation of the basilary joint of the ap-
pendages to the sixth segment extends backwards as far as
the external caudal scale, and is furnished with two very
strong pointed horns. The first joint of the outer caudal
lamina is strong and thick, and furnished, on its outer
margin, with several strong spines which appear to be
moveable.

SQUILLA MANTIS.

353

The length of the English specimen, which is a female,
from the frontal plate to the end of the tail, is four inches
and a half. I have a male specimen from the Mediter-
ranean which is no less than six inches.

Mr. Couch, to whom I am indebted for the specimen
above referred to, informs me that " the Squillse? were
brought from the distance of about a couple of leagues,
where the bottom is rocky, with some spots of sand."

A A

354

STOMOPODA.

SQUILLAD.E.

SQUILL AD &.

Squilla Desmarestii, E-isso.

Specific Cliaracter. — Prehensile finger with, five teeth ; abdomen with four
longitudinal crests, the middle portion smooth, excepting the sixth segment,
which has two additional elevations.

Squilla Desmareslii,

Risso, Crust, de Nice, t. ii. fig. 8, p. 114. — Hist. Nat.
de PEur. Merid. V. p. 86. — DESM. Consid. sur les
Crust, p. 251. — LATR. Encycl. X. p. 471. — Roux,
Crust, de la Medit. t. xl. — EDW, Hist. Nat. des
Crust. II. p. 523. — COUCH, Cornish Fauna, p. 81. —
YARRELL, Loud. Mag. VI. p. 230.

THE present species of Squilla differs in many striking
characters from the former. The carapace has nearly the
same general form, but is comparatively rather less narrowed
anteriorly ; sit is less strongly marked, and the grooves and

SQUILLA DESMARESTII. 355

elevations neither so numerous nor so distinct. There is
scarcely any trace of longitudinal crests, and it is wholly
without spines on the anterior portion. The falciform
finger of the claws is armed with five sharp teeth ; the
penultimate joint has the upper margin of the groove most
minutely denticulated. The four exposed thoracic seg-
ments are smooth. The abdomen has on each side two
low longitudinal crests, and the sixth segment two addi-
tional ones near the centre ; the remainder of the surface
is smooth. The terminal segment has a median crest, and
the margin is furnished with six strong teeth, the inter-
spaces being minutely denticulated. The laminar prolonga-
tion of the basilary joint of the appendages of the sixth
segment projects nearly in the same proportion as in
Sq. mantis ; and the lateral caudal scales do not offer any
striking peculiarity.

The length of full-sized specimens is three inches and
a quarter.

This remarkably pretty species was first distinguished by
Risso, who gives a description and an indifferent figure of
it in his " Crustaces des environs de Nice," and repeats the
description in his subsequent work, " LTHistoire Naturelle
de 1'Europe meridional e." A beautiful figure is given by
Roux in his unfortunately unfinished work on the Crustacea
of the Mediterranean. Its first occurrence on our coasts is
recorded by my valued friend Mr. Yarrell in the sixth
volume of London's Magazine, with a figure, which is,
however, very fallacious, from its being taken from a speci-
men which had become corrugated in drying. This
specimen, with another, was taken by Mr. Couch on the
coast of Cornwall, where they were found amongst sea-
weed ; and thus another interesting addition is made to
those which I have already had to record, to the partial

A A 2

356

SQUILLADJE.

identity of the Mediterranean Marine Fauna with that of
our southern coast. The same fact is recorded by Mr.
Couch in his Cornish Fauna.

I am lately informed by Mr. A. G. More of Bembridge,
Isle of Wight, and of Trinity College, Cambridge, that it has
also been taken repeatedly off Bembridge, by the fishermen
of that place, on a muddy bottom grown over with "grass"
(zostera) ; and from a sketch with which that gentleman
has favoured me, and the testimony of the fishermen, it
would appear that it has there attained nearly the size of
those taken in the Mediterranean ; whilst those found on
the coast of Cornwall have not exceeded two inches and
a quarter.

From the authorities already quoted, we learn that this
species abounds amongst the rocks near the coast, in com-
pany with various Palemonidae ; and Roux informs us that
it is commonly eaten fried, with such smaller Macroura.
Its habits are wholly nocturnal, as it hides itself always
during the day. Its eggs are deposited in March and
August.

The colours of this species are described as very pleasing.
The general tint is a yellowish brown ; the pincers white,
with a slight hue of rose. The scales of the antennse
and those of the tail are fringed with long rose-coloured
cilia. Two remarkable varieties are mentioned — one of a
delicate rose-colour, and the other a deep yellow, slightly
varied with brown.

APPENDIX,

CONSISTING OF SPECIES OBTAINED DURING THE
PROGRESS OF THE WORK.

XANTHO TUBERCULATA. 359

DEC APOD A. CANCERID&.

BRACHYURA.

Xantlio tuber culata, R. Q. Couch, in. s.

Specific Character. — Carapace slightly depressed anteriorly ; latero-anterior
margin with four triangular teeth ; hands and wrists tuberculated, rugose ; fingers
nearly black, the raoveable one with three grooves ; third joint of the ambulatory
legs denticulated on the upper edge.

THE carapace is slightly depressed anteriorly, more so
than in X. rivulosa, but somewhat less than in X. florida.
The rostrum slightly waved, minutely emarginate ; the
anterior portion of the carapace somewhat rugose ; the
regional lines of demarcation sharp and distinct, the eleva-
tions slight and flattened ; the latero-anterior margin with
four triangular teeth. The anterior pair of feet robust,
nearly equal ; the hands and wrists somewhat trans-
versely tuberculated and rugose ; the wrist with two dis-
tinct tubercles anteriorly ; the moveable finger has three
grooves, one on the inner and two on the outer side. The
whole of the ambulatory feet have the fourth, fifth, and
sixth joints hairy, with longer cilia on the edges ; the third
joint distinctly denticulated along the upper margin, with
a hairy patch beneath.

360

CANCERID^).

The general colour of " the carapace is light flesh colour
brown ; and the first pair of claws almost transparent
yellow." The fingers are black or very dark brown.

I have no hesitation in adopting the view of my friend,
Mr. R. Q. Couch, in considering this species as distinct,
not only from either of those already described in this
work, but from all others previously known. It differs from
both the former conspicuously in the distinctly tuberculated
hands and wrists, in the entire hairy covering of the three
terminal joints of the ambulatory feet, and in the den-
ticulated upper margin of their third joint. It differs from
X. rwulosa and agrees with X. florida in the depressed
form of the rostrum, — while it agrees with the former and
differs from the latter species in the grooving of the
moveable finger.

For the discovery of this interesting addition to our
British Carcinology, we are indebted to Mr. Richard Q.
Couch, of Penzance, who has kindly sent me the only
specimen I have seen. He informs me that it appears to
prefer deeper water than the other two species, as he
found it repeatedly in the crevices of the Eschara foliacea,
in the deep water off the Runnell Stone, in Mount's Bay,
In the summer it approaches the shore and is found under
stones. It spawns in June.

The name of tuberculata has been given to the species by
its discoverer, from whom and from his father, Mr. Jona-
than Couch, of Polperro, I have had so many claims upon
my acknowledgments for their intelligent and ready as-
sistance in the progress of the present work.

DEC APOD A.
SRACHYURA.

LONG-LEGGED SWIMMING CRAB. 361

PORTUNIDJE.

LONG-LEGGED SWIMMING CRAB.

Portunus longipes. Risso.

Specific Character. — Front slightly four-lobed ; latero-anterior margin much
shorter than the latero-posterior ; legs remarkably long.

Risso, Crust, des Env. de Nice, t. i. f. 5, p. 30; Hist.

Nat. de TEur. Merid. V. p. 4, — LATR. Encycl. X.

p. 192. — Roux, Crust, de la Medit. t. iv. — EDW.

Hist. Nat. des Crust. I. p. 445.
OTTO, Mem. de 1'Acad. de Bonn, XIV. t. xx. f. 1.

S. BATE Annals of Nat. Hist. 1851, p. 320, t. xi.
f. 9.

Portunus longipes,

infractuS)
Datyelii

THE general form of this interesting species is very dif-
ferent from that of the others of the genus. It is altogether
more slight and slender in its proportions. The carapace
is flattened, and, in the male, broader than it is long, in
the proportion of three to two ; in the female the dis-
proportion is not so great. It is divided transversely by a
ridge, which terminates at each side in a long and sharp

362 PORTUNIDJE.

tooth, the posterior of the five which occupy the latero-
anterior margin ; of these teeth the middle one is broader
than the others, and the posterior is much longer ; they
are all somewhat curved forwards. The anterior portion of
the carapace is minutely granulated, and has several slight
elevations ; the front is slightly four-lobed, the division
more strongly marked in the male. The first pair of legs
strong and angular ; the wrist having a strong tooth on
the inner anterior angle ; the hand with two carinse above,
the inner one terminating in a small spine. The moveable
finger with three distinct longitudinal carinse, and deep
intermediate grooves. The three following pairs of feet
long and slender, increasing in length to the fourth, which
is the longest of all ; flattened, the last three joints lon-
gitudinally grooved : the fifth pair slender and weak, the
terminal joint lanceolate and slightly grooved. The ab-
domen, in the male, triangular, the last joint abruptly
narrowed ; in the female, broad and much rounded.

The colour of this species is a rich deep brownish red,
with reddish grey spots; the abdomen yellowish or pinkish
white.

The occurrence of this truly Mediterranean species on
our southern coast is interesting, as affording another in-
stance of the partial identity of the Fauna of the two shores,
to which I have already had occasion so repeatedly to
refer. It had not, I believe, been found on our shores until
it was dredged on the coast of Cornwall in the year 1848,
by my friends Prof. E. Forbes and Mr. M' Andrew, from
whom I received a male specimen, and subsequently,
through the kindness of Mr. Cocks of Plymouth, a female,
which was taken by that gentleman. I also received
a specimen from Mr. R. Q. Couch, of Penzance, during
the year above-mentioned. It is doubtless the species

LONG-LEGGED SWIMMING CRAB. 363

described by Mr. Spence Bate as new, in the " Annals
of Natural History, for 1851, under the name of Portunus
Dalyellii, from a specimen obtained in Oxwich Bay, near
Swansea. The lateral spines are very largely developed
in the figure given by Mr. Bate, but not more so than in
many Mediterranean specimens, and scarcely more than
in Roux's figure. It is at a glance distinguished from all
other species by the character from which the name has
been given, namely, the length and slenderness of the
legs.

DECAPOD A.
BRACHYURA.

CORYSTID^E.

GENUS THIA, LEACH.

CANCER. Herbst.

THIA. Leach, Risso, Latr. Edw.

Generic character. — External antennce of moderate length, in-
serted beneath the front, just at the inner side of the orbits.
Internal antennae, transversely folded beneath the front. External
pedipalps extending forwards to the antennal fossa ; the inner
branch with second joint shorter than it is broad, its anterior inner
angle truncate and submarginate. Orbits extremely small. Eyes
scarcely visible. Carapace somewhat heart-shaped, considerably
narrowed at the posterior portion, nearly horizontal from before
backwards, much arched from side to side ; the front broad, lamel-
liform, entire, bounded by a small notch on each side. Anterior
legs short, and slightly compressed, the fingers deflexed; the
remaining pairs still shorter, each terminating in an acute styli-
form joint. Abdomen in both sexes very narrow ; in the male
with the three middle joints united ; in the female the seven
joints all moveable.

A GENUS established by Leach, in his " Zoological
Miscellany," on a species of which he was ignorant of the
locality.

DECAPODA.
BRACHYURA.

Till A. POLITA.

365
CORYSTID^E

Thia polita, Leach.

Cancer residuus? HERBST, t. xlviii. f. 1.

Thiapolita, LEACH, Zool. Miscell. II. t, ciii. — GUERIN, Icon, du regno

anim. t. iii. f. 3. — EDW. Hist, des Crust. II. p. 144.
Thia DlamriJIii, Risso, Hist. Nat. de 1'Eur. Mend. v. p. 19.

THE carapace in Thia polita is perfectly smooth and
polished ; the circumference is almost entire, excepting a
small notch over each orbit ; its outline is contracted to-
wards the posterior portion, and the posterior margin is
truncated in the male, and slightly hollowed in the female;
it is nearly horizontal from the front to the posterior mar-
gin, and much arched from side to side ; the front is pro-
minent and evenly arched ; the whole of the margin is
ciliated with long hair. The orbits are very small, and
the minute eyes are ordinarily concealed within them.
The anterior pair of legs are robust, the surface polished ;
the hand is rounded, the posterior outer angle obliquely
cut away for the articulation of the wrist ; the fingers are
slightly deflexed, and armed with a few small tubercles.
The remaining legs are shorter than the former, the hinder
ones being the shortest ; the joints, particularly the pen-

366

ultimate, rounded and somewhat gibbous ; the termina
one subulate and acutely pointed, the whole of them
strongly ciliated. The abdomen in the male is five-
jointed, from the soldering of the middle three joints, but
their distinction is still obvious from the transverse groove
not being obliterated ; it is narrow triangular, the last joint
very small : in the female the abdomen is seven-jointed,
and a little broader than in the male ; in both it is fringed
with long hair.

Length, 0*6 of an inch, breadth rather more.

We owe our knowledge of this rare species, as indi-
genous to Britain, to the researches of Dr. Melville, the
learned Professor of Natural History in Queen's College,
Galway. It was found by him buried in the sand, and
three specimens, one male and two females, obligingly for-
warded to me. Both the females were loaded with spawn.
Hitherto this is the only instance of its occurrence as a
native of our coasts.

The species was first figured by Herbst in his great
work, but somewhat imperfectly ; I cannot, however, join
with Dr. Leach and Milne Edwards in doubting that
Herbsfs species is identical with that of the individual on
which Leach founded his Genus Thia. The habitat of that
specimen was unknown ; but Risso has described, under
the name of Th. Blainvillii, what I cannot but believe to
be this species. It is stated by Dr. Milne Edwards to
inhabit " La Manche" and the Mediterranean.

It is right to mention that there is one character in
which the Irish specimen differs from the descriptions
given by Leach and Milne Edwards ; namely, in the
much shorter length of the antennae ; but Guerin's figure,
in the " Iconographie du regne animal," exactly agrees in
this respect with the former.

DEC APOD A. DROMTADjE.

ANOMOURA.

GENUS DROMIA, EDW.

CANCER. Linn. Herbst.

DROMIA. Fabr. Latr. Leach, Edw.

Generic character. — External antennce placed beneath the ocular
peduncle; the auditory tubercle, occupying the base, very large, and
perforated at the external angle ; the next joint large and nearly
cylindrical, forming the inferior boundary of the orbit, and armed
with a strong tooth. Internal antenna with the basal joint nearly
cylindrical ; the antennary fossre longitudinal and distant, and in-
complete at the outer side. Anterior feet very robust, terminating
in a strong claw, the extremities strongly toothed, and spoon-
shaped. The second and third pairs of feet of moderate and nearly
equal length, terminating in a sharp somewhat curved nail j the
basal joint of the third in the female pierced with the opening of
the generative apparatus ; the fourth and fifth pairs very small,
turned over the back of the carapace, against which they are closely
pressed, each terminating in a small but perfect double claw. Ca-
rapace somewhat globular, the regions distinctly marked; the front
inclined and small. Orbits deep. Eyes with short peduncles.

The characters of this remarkable genus are, to a certain
extent, intermediate between the brachyurous and macro-
urous forms. In the young state the great predominance
of the posterior or abdominal regions of the body approxi-
mate it in some measure to the latter ; and the general
form of the cephalo-thoracic portion, especially in the adult
condition, is not less assimilated to the former division of
the class. The characters of the posterior pairs of feet at
once remove it from either of these, and indicate its true

368

place to be amongst those anomalous forms which have
been associated by Dr. Milne Edwards into the interme-
diate group, the ANOMOURA.

The species of this genus are very widely distribute
The Indian and African shores, those of the Red Sea and
of the Mediterranean, the islands of the West Indies, and
the coasts of South America, have furnished various species;
and our own southern coast has of late years been found to
give a place of habitation to one of the most conspicuous
species.

DROMIA VULGARIS.

869

DEC APOD A.

ANOMOURA.

DROMIA D^E.

Dromia vulgar is, Edwards.

Specific Character. — Carapace broader than it is long ; latero-anterior margin
with four strong teeth, the second having a tubercle at its base ; the last joint of
the abdomen in the male broader than it is long.

Cancer dromia,
Dromia Rumphit,

Dromia vulgaris,

" Olivi Zool. Adriat. p. 45" (M. EDW.).

Bosc, Hist, des Crust. I. p. 229. — DESMAR. Consider.

sur les Crnst. p. 137. — BLAINV. Fauna Franc. Crust.

t. vii. fig. !.• — Risso, Hist. Nat. de 1'Eur. Merid. V. p.

32 — EDW. Reg. anim, de Cuv. Edit. 3. Crust. II. f. 1.
EDW. Hist. Nat. des Crust. II. p. 173.

THIS species, which has at length been undoubtedly proved
to inhabit our southern shores, and probably too in consi-
derable numbers, has the carapace strongly knobbed above,
especially at the anterior portion, and very much raised
so as to approach the globular form ; the front with three
teeth, which become less prominent by age ; there is a

B B

370 DROMIADJE.

fissure above the external angle of the orbit, and a tooth
beneath that cavity. The latero-anterior margin has four
strong teeth, the bases of which are long ; the first situ-
ated beneath the line of the orbit, the second furnished
near its base with a tubercle or small secondary tooth, thus
appearing almost as if double ; the third occupying a larger
portion of the margin than either of the others, and the
last the smallest. The latero-posterior margin nearly as
long as the latero-anterior. The first pair of legs are
robust and nodulated ; the hand has several small conical
teeth on its upper and inner edge. The claws are smooth
and polished, strongly denticulated and internally hollowed
at the extremity, the denticles of each finger shutting into
the interspaces of the other ; the moveable finger much
curved on the upper side ; the wrist largely nodulated ; the
second and third pairs of legs much shorter than the first,
terminating in a strong, sharp, curved nail ; the fourth and
fifth pairs are doubled back over the posterior part of the
carapace, flattened, and each terminating in a sharp, tole-
rably perfect, double claw. The abdomen in the male is
much curved longitudinally, and the joints are distinct;
the terminal one broader than it is long. In the female
the abdomen is extremely broad and much curved ; each
joint elevated in the centre, and on each side. The whole
animal, body and limbs, covered with dense short hair,
which in the young state is of a buff colour, and in the
adult dull brown.

Length of the carapace of a full grown male two inches
and a half, breadth three inches.

I have carefully examined the hair with the microscope,
in individuals of various ages, and have not found in any
one instance the club-shaped hair assigned by Dr. Milne
Edwards to this species. The hair is in all cases setaceous,

DROMIA VULGARTS. 371

very acute at the point, and is itself furnished with minute
hairs along its sides.

The first intimation of the present species as a native of
Britain, occurs in an announcement by Mr. John Edward
Gray, at a meeting of the Zoological Club of the Linnsean
Society, as long since as June 22nd, 1824. These were
stated to have been seen by that gentleman in Billingsgate
Market, amongst some oysters, which had been brought
from Whitstable Bay, on the Kentish coast. This fact is
recorded in the " Zoological Journal,11 Vol. I. p. 419. In
the " Zoologist," 1848, p. 2325, occurs a notice of no fewer
than nine full sized specimens having been dredged on the
coast of Sussex. Mr. Newman gives the details of its
occurrence, and a figure of the species, having received
it from Mr. George Jngall. About the same time my
lamented friend Mr. Dixon, of Worthing, sent me three
specimens which had been procured off Selsey Bill. Mr.
Newman alluding to Linnsous's name of an allied species,
cancer u dormia" supposes it to refer to its sedentary and
lethargic habits. Linnseus was, however, too good a
scholar thus to render a derivative from dormio ; it is
plainly a misprint for dromia, from the Greek Agopav, a
little running crab ; and in the " Amomitates Academicse,"
Linnseus himself gives the correct spelling.

I some years since received numerous young specimens
from Sicily, every one of which had the carapace entirely
covered with a sponge which had grown over it, concealing
even the two hinder pairs of legs, which were closely
pressed against the back, and rendered immoveable. It is
a common Mediterranean species.

BB2

372

DECAPODA.

ANOMOURA

PAGURIDJE.

Pagurus Thompson^ inihi.

Specific Character. — The whole of the legs hispid and spinous ; anterior pair
unequal ; the wrist as long as the hand ; eye stalks extending to half the length
of the last joint of the peduncle of the external antennae ; antennal spine curved
outwards, and furnished with a row of small spines on the outer edge.

THE carapace is polished, but sparsely marked with im-
pressed dots ; the front nearly entire. The eye-stalks are
cylindrical, and furnished with a regular longitudinal series
of minute tufts of hair along the upper surface ; they extend
forwards to the middle of the last joint of the peduncle of
the external antennae. The antennal spine is curved out-
wards, spinous and hairy on its outer edge. The internal
antennae are half as long again as the peduncle of the
external. The anterior feet very unequal, bristly, and
spinous ; the larger hand twice as long as it is broad,
hairy, beset with spinous tubercles, of which there is a
stronger series along the outer side ; the moveable finger with

PAGURUS THOMPSONI.

a strong tubercle fitting between two smaller ones on the
other finger when closed ; wrist about as long as the hand,
and equally hairy and spinous, with a row of longer spines
along the inner edge. Smaller anterior leg nearly linear,
the proportions, clothing, and armature somewhat similar
to the larger, but the opposing edges of the fingers with-
out tubercles. Third and fourth pairs of feet very long,
covered with stiff hairs and small spines ; the last joint
armed with a series of strong spines along the inferior
edge, and terminated by a sharp nail.

The general aspect of this species reminds one of P.
Prideauxii, the proportions of the parts being somewhat
similar ; but it differs not only in some proportional cha-
racters, but strikingly in the spinous and hispid clothing
of the whole of the legs. It bears in these latter circum-
stances some relation to P. Cuanensis, but from this it may
be distinguished by the proportions between the wrist and
hand, the form of the wrist, the relative proportions of the
eye stalks and antennal peduncle, and other characters.

I have a melancholy gratification in dedicating this
species by name to a gentleman who for many years was
justly considered as the representative of the Zoology of
Ireland, and whose acute discrimination and persevering
enthusiasm in his favourite pursuit, were only equalled by
the liberal and unselfish feeling with which he placed his
treasures in the hands of his fellow labourers, whenever he
believed the interests of science would be thereby furthered.
The specimen from which the above description is taken,
was placed in my hands by my lamented friend only a very
few days before his untimely death deprived the science of
Ireland of one of its most distinguished ornaments, and
society of as kind and true hearted a man as ever lived.
Mr. Thompson's note given me with the specimen is as

374

PAGURIDJ5.

follows : — " Dredged at fifty fathoms, entrance of Belfast
Bay, by Mr. Hyndman." It was in the shell of the com
mon whelk, Buccinum undatum.

The vignette is from a tesselated Roman pavement dis-
covered at Cirencester in J 783.

BLUE-BANDED HERMIT CRAB. 375

DECAPODA. PAGURID^E.

ANOMOURA.

BLUE-BANDED HERMIT CRAB.

Pagurus fasciatus. Mihi.

Specific Character. — Anterior legs unequal ; hand oval, smooth ; eye-stalks as
long as the penultimate joint of the external, and nearly half as long as the whole
of the internal antennae ; body and legs banded alternately with red and blue.

THE carapace is smooth and even, ovate, rounded in
front, truncated and slightly emarginate behind. External
antennae as long as the whole of the body, the peduncle
cylindrical, the second and last joints of nearly equal
length, and apparently without any spine. The internal
antennae are of moderate length, less than twice as long as
the peduncle of the external. Eye stalks nearly cylindrical,
slightly curved outwards, as long as the penultimate joint

376

PAGURIDJ3.

ar

of the external antennae. The anterior pair of feet
robust, of unequal size; the hand is oval, broader anteriorly,
slightly pointed at the extremity of the fingers ; the move-
able finger fitting the other closely ; the wrist subquadrate,
broader than it is long; the second and third pairs with
the penultimate joint ciliated on the inner edge.

The body is obscurely, and the whole of the legs dis-
tinctly marked with alternate bands of red and blue.

The whole of the above description is given from a
coloured drawing, for which I am indebted to Mr. Cocks,
of Falmouth, and from which also the woodcut is taken.
It was obtained by him at Falmouth. I have never seen
a specimen, but I am confident that Mr. Cocks's accuracy
of delineation may be implicitly relied on.

This species may at once be distinguished from every
other known on our coasts. The only one to which, from
the form of the hands, it bears a primd-facie resemblance,
is P. Hyndmanni, but from this it differs in the form of the
thorax, the comparative length of the internal antennae,
and many less obvious characters. The distinct alternate
bands of blue and red render it one of the most beautiful
of the genus.

DEC APOD A.
ANOMOURA.

PAGURUS DILWYNII.

377

PAGURID&.

li Pagurus Dilwynii" Sp. Bate.*

" CARAPACE smooth and polished. Colour bluish, marked
with brown.

" First pair of feet unequal, the left being much longer
than the right ; smooth to the naked eye, but under a
lens perceived to be minutely granulated. The second and
third joints are armed with teeth, which give the limb an
angular character. The right is very short and covered
with hair.

" The external antenna is about two-thirds the length of
the longest of the first pair of feet, and hairy ; its base as
long as the eye-stalks, which are slender and long. The
basal tooth, with which the antenna of this genus is gene-
rally armed, is wanting.

* Annals of Nat. Hist. 1851, p. 320, pi. x. fig. 11.

S78

PAGURIDJE.

" The false feet in the female are long and feathery, and
divide at the base.

" The most striking difference between this and other
British species of the Pagurida, is exhibited in the form
of the first pair of feet, and the length of the external
antennae.

" Having met with only this solitary specimen, it is im-
possible to say but that the right foot of the first pair,
which is usually the longer, may be in the process of being
reproduced from loss ; although I am inclined, from its
well-developed character, to believe that the left is in this
species the more important of the two. The false feet,
which in the female are generally forked, are so in this
specimen, but very much nearer to the base than in the
common species.

" It burrows very rapidly in the sand. Taken near the
Worms Head, Swansea.

" Mr. Couch has informed me, since this has been in the
hands of the printer, that he has also found the species in
Cornwall.

" The name applied to this species is one long-known to
science, and honoured as the stimulator of natural history
in this locality in the person of L. W. Dillwyn, Esq.,
Sketty Hall."

The foregoing description and figure are copied from
those given by Mr. Spence Bate, in the " Annals of Natural
History," as I have never seen the species.

CYNTHIA FLEMING1I. 379

STOMA PO DA . M I'SIDjE.

GENUS CYNTHIA. J. V. THOMPSON.

Generic character. — " Subabdominal fins composed of two joints,
four last fins with the terminal plume double, with an opake bifur-
cate, and convolute organ rising between each."

Cynthia Flemingii. H. Goodsir.

Specific Character. — " Inferior antennal scale almost twice as long as the pedun-
cle. A thick fringe of strong hairs bordering its edge. Rostrum slender and
finely pointed. Volute organ between the plumose setae of the subabdominal fins
minute ; edges of the middle plate of the tail spined.

" Long, eight lines. Hab. Frith of Forth.

" Description. — The whole body of an opake straw-
colour, with the reticulated portions of the eyes black.
Superior antennae with the peduncle three-jointed, the two
cetaceous portions arising from the second joint of the
peduncle, the last joint ovate, surrounded with a thick
fringe of hairs ; these hairs are bent downwards at their
extremities, so as to form a concavity on the lower surface.
The peduncle is about twice the length of the eyes. The
peduncle of the inferior antennae extends to the origin of
the setaceous portion of the superior antennae ; the two
last joints are slender and clavate. A long, slender, and

380

MYSID^E.

pointed scale arises from the first joint of the peduncle,
above the setaceous portion ; this is twice as long as the
peduncle, and is thickly fringed with long hairs, which are
directed inwardly so as to meet those of the opposite side.
The carapace is not very large, curved at its posterior
edge, and produced at its posterior and inferior angle.

" Abdomen slender, the inferior edge of each segment
considerably produced, and all of them but the last bear-
ing a fin composed of two joints ; the first joint is scale-
like clavate ; the second is multiarticulate and plumose ;
all of them but the first pair double. The bifurcate con-
volute organ, between the double plumes, is very minute.
Middle plate of the tail edged with spines on its sides, and
entire at the extremity. External caudal fins twice as long
as the middle plate, and pointed.

" The bifurcate and convolute organ between the double
plumes of the four last subabdominal fins, together with
the number of joints in these fins, seem to be the most
striking characters of this genus. Mr. Thompson, in the
third memoir of his ' Zoological Researches,' says, ' It is
not in the number of joints alone, however, that they
(subabdominal fins) differ, their form and structure is also
essentially different. In Cynthia the four last of these
members are each composed of a very large bilobate scale,
supporting at its apex two taper articulate fins, strongly
ciliated with plumose setse ; from between these originates
an opake organ which bifurcates, its two extremes of
unequal length being rolled inwards, the one over the
other.'

" Mr. Edwards considers that these last are the branchial
apparatus.

THEMTSTO LONGISPINOSA, 381

STOMAPODA. MYSID/E.

GENUS THEMISTO. H. GOODSIB.

Generic character. — " External antennae armed with a scale.
First, second, and fifth segments of the abdomen bearing fins like
the mysis. Third and fourth with the peduncles bi-articulate,
and each peduncle giving off two branches ; the external branch of
the fourth very long and slender, semi-articulated.

Themisto longispinosa. H. Goodsir.

Specific Character. — " Superior antennal scale of the same length as the termi-
nal joint of its peduncle ; armed at its extremity with a thick tuft of hairs. In-
ferior antennal scale twice as long as its peduncle ; fringe not strong. Third
subabdominal fin with its internal branch mimite. Internal branch of the fourth
with a. few long hairs from the extremity only. External branch reaching from
the extremity of the caudal fins. Internal caudal fin truncated.

"Long, three-quarters of an inch. Hab. Frith of Forth.

" Description. — The whole body of a dark yellowish or
greenish colour. Eyes large, reaching to the extremity of
the peduncle of the inferior antennae. The reticulated
portion black, and produced backwards inferiorly. Rostrum
very short but sharply pointed. First joint of the pedun-
cle of the inferior antennae very strong, the two following
slender ; the setaceous portion of the antennae arising from

382

MYSIDJS.

the extremity of the last. The scale arises from the inner
and superior part of the first joint of the peduncle ; it is
hardly twice the length of the peduncle, slender, and taper-
ing very gradually to the extremity ; it is rather thinly
fringed. The upper surface of the peduncles of the supe-
rior antennae hollowed out, forming a bed for the eyes. A
short ovate scale arises from the inferior part of the last
joint, immediately below the origins of the setaceous por-
tions of the antennae. .A thick bunch of matted hair arises
from its extremity, which gives it the appearance of being
bi-articulated. The inferior edge of the external seta of
the superior antennae bears a thin fringe of very strong
hairs, which are thickest and strongest near the base.
The carapace is not large, leaving two of the thoracic seg-
ments exposed posteriorly ; it is rounded at its anterior
and inferior angle, and considerably produced at its inferior
and posterior angle. A strong bi-articulate and chelate
palpus arises from each side of the mouth. The abdomen
is slender, but the segments are not produced inferiorly.
The branchial subabdominal fins are five in number ; they
arise from all the abdominal segments except the last
[two]. The first, second, and fifth are like those in the
genus Mysis, namely, a single plumose joint ; the third and
fourth are pedunculated, — the peduncles being composed
of two joints. The first joint is minute, the second is of
considerable length ; two branches arise from the extre-
mity of the second joint ; these branches, in the third fin,
are both plumose ; in the fourth one the internal only is
plumose. The external branch of the fourth consists of a
very long six-jointed spine, which reaches beyond the ex-
tremity of the caudal fins ; it is very finely pointed ; the
internal branch about the same as the first joint of the
external branch. The caudal plate is slightly swollen near

THEMISTO LONGISPINOSA. 383

the base ; its edges are serrated, and its extremity bifur-
cated ; the bottom of the fourth being rounded, and the
extremities of the fork also blunted and rounded. The
internal caudal fins are truncated at their extremities ; the
external are paddle-shaped, and rounded at their extremi-
ties. Both of these fins are fringed at their extremities
and inferior edges with long hairs."

384

STOMAPODA,

MYSIDjfl.

Themisto brevispinosa. H. Gooclsir.

Specific Character. — " Superior antennal scale not so long as the peduncle. In-
ferior antennal scale four or five times as long as the peduncle. Internal branch
of the third subabdominal fin minute ; the internal branch of the fourth longer
than the first joint of the external branch ; the external branch extending a little
beyond the base of the caudal fins, ending by means of a dart-like point. The
lateral caudal fin ending in a sharp point superiorly, and rounded inferiorly ; the
internal fin oblong, ovate, and pointed. The lateral edges of the middle plate
bearing a single row of long, sharp, and bent spines, contracted near the base
and the bottom of the fork, forming an acute angle ; prongs pointed.

" Long, one inch. Hab. Frith of Forth.

" Description. — The whole body more robust than that
of the last-described species, and of an opake white colour,
with a single row of black spots along the dorsal mesial
line of the abdominal segments. The first joint of the
peduncle of the inferior antennae very short and almost
circular ; the two following are slender. The scale which
arises from the superior part of the first joint above the
true antennae is very strong at the base, and then tapers
gradually to a fine point. A fringe of long hairs borders
its inferior edge. These hairs are matted at the extremity
so as to give them the appearance of a second joint ; two
or three short strong spines arise from the extremity of the

THEMISTO BREVISPINOSA. 385

scale. The third joint of the peduncle of the superior an-
tennae is considerably produced at its superior angle. The
scale which arises beneath the setaceous portions is strong,
bent upwards at its extremity, and pointed, but not fringed.
The eyes are large ; the reticulated portion circular.

" The rostrum is of considerable length, but it is not
sharp. The internal branch of the third subabdominal
fin is minute ; the external one is long, slender, and finely
pointed ; it is also fringed with very long hairs. The in-
ternal branch of the fourth fin is longer than the first joint
of the external branch ; and it is both more strongly
ringed and more moveable than that of the last-described
species. The external branch extends a little beyond the
base of the caudal fins. The sixth or last joint of this
branch suddenly contracts near the extremity to about half
its original thickness, ending in a dart-like point. The
external caudal fins end in a sharp point inferiorly, and
are rounded inferiorly ; the internal fins are oblong, oval,
and pointed at the extremity. These are both fringed
at their inferior edges and at their extremities. The late-
ral edges of the middle plate armed with a single row of
strong hooked spines. It is contracted near the base,
and the angle formed by its bifurcation is very acute ;
the extremities of the prongs are also sharp-pointed, and
of a black colour."

Amongst the numerous and interesting additions to our
knowledge of the smaller Crustacea, for which we are in-
debted to Mr. H. D. Goodsir, are the three foregoing
species of the family MYSID^E. As I have never seen spe-
cimens of either of them, I have thought it best to give,
verbatim, Mr. Goodsir^s own descriptions, although some-
what diffuse, with copies of his figures.

c o

386

THEMISTO BREVISPINOSA.

In addition to the species included in this Appendix,
I may refer to some which have been described in recent
periodical publications, from the observations of Mr.
Spence Bate, Mr, William Thompson of Weymotith,
and others. I have not transferred these descriptions to
this work, partly because 1 am not in all cases quite
satisfied with the grounds on which the species have
been considered as distinct, and because they may be
readily examined in their original place of publication.
At the same time I am anxious to express my gratifica-
tion at this accession of young intelligent naturalists in
this field of observation, from whose active and continued
labours the most valuable results may be anticipated.

Woodfall and Kinder, Printers, Angel Court, Skinner Street, London.

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