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BRITISH
§STALK-EYED CRUSTACEA.
fe A HISTORY
INVERTEBRA tee. op THE
YOOLOGY
Crustaces BRITISH
STALK-EYED CRUSTACEA.
BY
THOMAS BELL, Src. R.S., F.G.S., F.Z.5.,
PRESIDENT OF THE LINNEAN SOCIETY ;
MEMBER OF THE PHILOMATHIC AND NATURAL HISTORY SOCIETIES OF PARIS;
OF THE IMPERIAL ACADEMY CHSAR, LEOPOLD. NATURA CURIOSORUM; OF THE
ACADEMY OF SCIENCES OF PHILADELPHIA; OF THE NATURAL HISTORY
SOCIETY OF NEW YORK; HONORARY MEMBER OF THE ROYAL
ZOOLOGICAL SOCIETY OF DUBLIN, ETC., ETC,
PROFESSOR OF ZOOLOGY IN KING’S COLLEGE, LONDON.
ILLUSTRATED BY 174 WOOD-ENGRAVINGS.
LONDON:
JOHN VAN VOORST, 1, PATERNOSTER RQ —-™
= Sqn SOMIAN STH
M.DCCC.LIILI.
he. F2RUGE |
x Aug2d WAP x)
Na HOwaL ar seuss /
: LONDON: ;
WOODFALL AND KINDER,
ANGEL COURT, SKINNER STREET,
Be i
—
TO
PROFESSOR RICHARD OWEN,
THE FAITHFUL AND UNCHANGED FRIEND OF MANY YEARS,
THIS LITTLE WORK IS INSCRIBED
THE AUTHOR,
AS A HUMBLE TOKEN OF HIS LASTING
RESPECT AND AFFECTION.
fe
Ol
a
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.
SELBORNE, Hanrs.
July, 1853.
INTRODUCTION.
Tuer 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-
xX 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 Eprzoa 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 Erszoa, and the Crrrivepes, 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 branchiz 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. Xl
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 Lsopoda, 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 coriwm. In many of the smaller
Crustacea, even amongst the higher forms, as in most of
the Palemonide or prawns, and other allied families, as
well as in most of the lower groups, as the Lsopoda, 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 Palemon, 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
Xil 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. Xiil
trne 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 branchiz, in
another the support and protection 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-
X1V 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 Lamodipoda
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- ————5 ibe
A ° Yo a a \ b
teral pieces. The superior central <<“ SS
pair, @ a, constitute the tergum, IN r , Le
the lateral are called epimera, 6 6. Sia oa
Of the inferior arch, the two central pieces form the ster-
num, cc, and to the lateral, dd, 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.
‘* 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 antenne.
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 Hdriophthalma,
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 which iu other forms
are found to be distinct. For a full and clear account of
all these modifications, the reader is referred to the admi-
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.- But the
* Edw. Hist. Nat. des Crust. i. p. 18. Tf Deapelios
INTRODUCTION. XVI
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 rs ; the branchial, rb; the hepatic,
rh; the genital, rg ; the cardiac rc; the intestinal, ri.
XVill
INTRODUCTION,
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 branchiz, or gills. In this
brief sketch it is only n@gessary to
refer to the apodemata as consti-
tuting the large cells of the thorax, formed by a dupli-
INTRODUCTION. X1X
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 versd, each pair of appendages,
* See the figures of the various species.
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 antennz, 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, Pale-
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 antenne. 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 ona card. They consist very clearly of the
ocular peduncles, the anterior and posterior antenne, the mandibles, the two pairs
of maxilla, 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. XX1
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 maxille, 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 serve 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
XXll 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 antenne are, as has
been before observed, sometimes modified into locomotive
organs. The cephalic appendages about the mouth, the
mandibles and maxill, are sometimes rudimentary, at
other times they are modified into mere organs of appre-
hension. The thoracic members are sometimes locomo-
INTRODUCTION. XXill
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 branchiw. 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 mm 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 Myside. 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
cesophagus 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
ereater portion of the visceral cavity. It consists of a
mass of cecal 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
XXVl INTRODUCTION.
of lobes extending the whole length of the intestine,—
and in the Edriophthalma, according to Prof. M. Kd-
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 branchie ; 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 branchie 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 lamelle, 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. XXVli
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
branchie, 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 branchiz 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. vy. p. 85.
XXVill INTRODUCTION.
known that the lobster will live for a long time out of
water, provided the branchiz 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 aérated 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.t
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 Anatomiques et Physiologiques sur la Circulation dans les
Crustacés. Ann. des Sc. Nat. t. ii.
+ 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. TXLX
“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 t+ 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.” f¢
In Talitrus, where the insectiform arrangement is the
most obvious, and where every pair of ganglia consists of
elie. pe lo:
+ Messrs. Audouin et Milne Edwards, “ Recherches Anatomiques sur le
Systeme Nerveux des Crustacés.” Ann, des Sc. Nat. t. xiv.
Dec. ps do.
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 systéme nerveux des Crustacés se compose tou-
jours de noyaux médullaires dont le nombre normal est
égal a celui des membres, et toutes les modifications qu’on
y rencontre dépendent principalement de rapprochemens
plus ou moins complets de ces noyaux, agglomeration qui
s’opére des cotés vers la ligne médiane en méme temps
que dans la direction longitudinale, mais peuvent tenir
aussi en partie a un arrét de développement 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 antenne, 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 Crustacés, t. i. p. 147.
INTRODUCTION. XXXl1
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 Culocaris, 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 Palemo-
pid; but the vision is wanting. ‘There is no pigment,
there are no corneal facets; 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.
XXXil 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 indépendance des deux moitiés de l’appareil
de génération est si compléte qu’on a vu un cas, ot l'un
des cétés était male et lautre femelle, sans que cette
monstruosité ett entrainé 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, in which the eggs remain
until the young are excluded. In Thysanopoda, another
genus of the Mysidx, they are contained in two oval
purses, depending from the same part.{
* Hist. des Crust. t. i. p. 165. + See p. 336. See p. 346.
INTRODUCTION. XXXill
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 antenna, 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 Réaumur,* 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 lAcad. des Se. 1712, p. 226, and 1718, p. 263.
Cc
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 Réaumur 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 days, in the summer.
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 antenne, 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.
XXXV1 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. Réaumur 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 rentrés a Vintérieur, comme le
doigt @un gant qui serait retourné sur lui-méme!” 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 Grapsid, which,
from their form, could not possibly withdraw the body
without such a separation.
INTRODUCTION. XXXV11
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 Menas) 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. Réaumur 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.
XXXVill 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
aninchin 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. .
=o ar)
INTRODUCTION. lxi
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 exuyiate or voluntarily throw off
their limbs, are in the habit of producing their young perfectly formed ; and an
opportuyity 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.”
lxii 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 “ Cyclopedia 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 Crustacés, tom. iii. Paris, 1834.
[ The systematic names, including the Latin synonyms, are printed in J¢alics.]
A.
Acheus Cranchii, 10.
Alauna rostrata, 330.
Albunea dentata, 159.
Alpheus Caramote, 318.
aan Tubers Dil.
» stvado, 312.
» Spinus, 284.
Astacus Bamfficus, 208
» Bernhardus, 171.
» Crangon, 256.
» fluviatilis, 237.
> Homarus, 213.
5 marinus, 242.
5 nitescens, 261.
» Norvegicus, 251.
» serratus, 302.
5, squamifer, 197.
» Squilla, 305.
» strigosus, 200.
» stellatus, 223.
subtewraneus, 217.
Atelecyclus heterodon, 153.
os septemdentatus, 153.
A thanas nitescens, 261.
Awxius stirynchus, 226.
B.
Blastus tetraodon, 22.
Bodotria arenosa, 333.
C.
Callianassa subterranea, 217.
Calocaris Macandree, 533,
Cancellus marinus, 135.
Cancer angulatus, 130.
>» araneus, 31.
» casper, 46.
» Astacus, 237.
» Bamfficus, 208.
» Bernhardus, 171.
» biaculeatus, 2
BB UjO. 3)l\<
> Cassivelaunus, 159.
» corrugatus, 94,
INDEX.
Cancer denticulatus, 72.
» Depurator, 101,
» digitatus, 351.
» LDorsettensis, 13.
» Dromia, 369.
» jloridus, 51.
» fluviatilis, 237.
» Gammarus, 242,
» irtellus, 68.
horridus, 165.
» hydrophilus, 54.
» netso-serratus, 59.
5 meisus, 51.
» latipes, 85.
» longicornis, 193.
» Maia, 39, 165.
5 minutus, 135.
9 Menas, 76.
» Norvegicus, 251.
» Pagurus, 59.
» Phalangium, 2.
» Lisum, 121.
» Platycheles, 190.
» puber, 90.
» rostratus, 2.
» Scorpio, 13.
» Spinus, 284.
» Squilla, 202, 305.
» Squinado, 39.
» strigosus, 200.
» tetraodon, 22.
» tuberosus, 141.
» tumefactus, 145.
» velutinus, 90.
Carcinus Meenas, 76.
Corystes Cassivelaunus, 159.
» dentatus, 159.
Crab, angular, 130.
a ecincilarse lose
5 floating, 135.
» great, 59.
» harbour, 77.
5 masked, 159.
shore, ae.
C; vate yon bispinosus, 268.
» CEU Ee 261,
» fasciatus, 259.
35 se ulptus, 263.
lxiv
Crangon spinosus, 261.
» trispinosus, 265,
» vulgaris, 256.
Cray-fish, common, 237.
Cuma Audouinii, 328.
» Edwardsii, 326.
» trispinosa, 329.
Cynthia Flemingii, 379.
D.
Dromia Rumphii, 369.
» vulgaris, 369.
EK.
Ebalia Bryerii, 145.
> Cranchit, 148.
» Pennantii, 141.
Eurynome aspera, 46.
>» Spinosa, 46.
G.
Galathea Bamffia, 208.
Galathea, Embleton’s, 204.
Galathea neaa, 204.
ax rugosa, 208.
Galathea, scaly, 197.
Galathea spinigera, 200.
Galathea, spinous, 200.
Galathea squamifera, 197.
5 strigosa, 200,
» adeltura, 225.
Gebia stellata, 223.
Gelasimus Bellii, 130.
Gonoplax angulatus, 120.
is bispinosus, 130.
“a rhomboides, 130.
Grapsus cinereus, 135.
3 minutus, 135.
» Lestudinum, 135.
H.
Hermit-crab, blue-banded, 375.
ss common, 17].
‘a Prideaux’s, 175.
os rough-clawed, 186.
‘a smooth, 184.
Hippa septemdentata, 153.
Hippolyte Cranchit, 288.
Hippolyte, Cranch’s, 288.
Hippolyte Moorii, 292.
» Pandaliformis, 294.
p Prideauxiana, 292.
Hippolyte, Prideaux’s, 292.
Fippolyte Sowerbai, 284,
Hippolyte, Sowerby’s, 284,
Hippolyte Spinus, 284.
. Thompsont, 290.
Hippolyte, Thompson’s, 290.
INDEX.
Hippolyte varians, 286.
Hippolyte, varying, 286.
Homarus vulgaris, 242.
Hyas araneus, 31.
5, coarctatus, 35.
Inachus araneus, 31.
» Dorsettensis, 13.
> Dorynchus, 16.
» leptochirus, 18.
>» Phalangium, 2.
» Scorpio, 13.
L.
Leptopodia tenuirosiris, 6.
Lithodes Maia, 165.
Lobster, common, 242.
» Norway, 251.
M.
Macropodia longirostris, 6.
fo Phalangium, 2.
& Scorpio, 13.
os tenuirostris, 6.
Macropus longirostris, 6.
3 Phalangium, 2.
Maia aranea, 31.
5 Sguinado, 39.
» tetraodon, 22.
Mantis digitatus, 351.
Munida, long-armed, 208.
Munida Rondeletii, 208.
» rugosa, 208.
Mysis Chameleon, 336.
» Griffithsie, 342.
» Leachii, 336.
» rostratus, 342.
> spinulosus, 336.
» vulgaris, 339.
N.
Nautilograpsus minutus, 135.
Nephrops Norvegicus, 251.
Nika eanaliculata, 275.
Couchii, 278.
edulis, 275.
ted
”°
O.
Ocypoda angulata, 130.
IE
Pagurus Bernhardus, 171.
4» Cuanensis, 178.
|
|
Pagurus Dillwynit, 377.
» fusciatus, 375.
» orbesii, 186.
e Hyndmanni, 182.
» levis, 184.
» Prideauwii, 175.
» streblonyx, 171.
»5 Thompsoni, 372.
ulidianus, 180.
Palen Leachi, 307.
i; nitescens, 261.
95 serratus, 302.
5 Squilla, 302, 305.
VATLANS, 309.
Polinurus Homarus, 213.
a quadricornis, 213.
5 vulgaris, 213.
Pandalus annulicornis, 297.
Pasiphea brevirostris, 312.
eS Savignii, 312.
-p Sivado, 312.
Pea-crab, Pinna, 126.
+» common, 121].
Peneus Caramote, 318.
» trisulcatus, 318.
Planes Linneana, 135.
Platycarcinus Pagurus, 159.
Pilumnus hirtellus, 68.
Pinnotheres Cranchit, 121.
i Latreillii, 121.
os Montagui, 126.
os Pinne, 126.
os Pisum, 121.
. varians, 121.
9 Veterum, 126.
Pirimela denticulata, 72.
Pisa biaculeata, 27.
9 Gibbsii, 27.
» tetraodon, 22.
Pisidia longicornis, 193.
Platyonicus latipes, 85.
Polybius Henslowii, 116.
Pontophilus bispinosus, 268.
5 spinosus, 261.
- trispinosus, 205.
Porcelain-crab, hairy, 190.
9 minute, 193.
Porcelluna Leachii, 193.
oS longicornis, 193.
a platycheles, 190.
Portumnus variegatus, 85.
Portunus arcuatus, 97.
a5 corrugatus, 94.
5 Dalyell, 361.
3 Depurator, 101.
Sy emarginatus, 97,
~ holsatus, 109.
9 infractus, 361.
oF lividus, 109.
INDEX. Ixv
Portunus, longipes, 361.
5 maculatus, 112.
os marmoreus, 105.
- Menas, 76.
» Pplicatus, 101.
» puber, 90.
» pusillus, 112.
Rondeletii, 97.
Prawn, 303.
Processa canaliculata, 275.
3 edulis, 275.
Ss.
Shrimp, banded, 259
3 common, 256.
5 sculptured, 263.
» spinous, 261.
>» three- Pete en
two-spined, 2
Spider- -crab, Cranch’s, a
a four-horned, 22.
es Gibbs's, 27.
3 long-legged, 2.
- Scorpion, 13.
- slender, 6.
55 slender-legged, 19.
spinous, 39.
Spiny- “lobster, common, 213.
Squilla Desmarestit, 354.
» Mantis, 351.
Stenorynchus longirostris, 6.
7) Phalangium, 2.
a tenuirostris, 6.
Stone-crab, northern, 165.
Swimming-crab, arched, 97.
PS cleanser, 101.
p dwarf, 112.
= Henslow’s, 116.
= livid, 109.
long-legged, 361,
5 marbled, 105.
e velvet, 90.
> wrinkled, 94.
T.
Themisto brevispinosa, 364.
» longispinosa, 381,
Thia polita, 365.
Thysanopoda Couchii, 346.
Kk
Xantho florida, bills
inciso-serrati, 51.
?
», revulosa, 54,
» tuberculata, 359.
BRITISH CRUSTACEA.
DECAPODA. LEPTOPODIAD.
BRACHYURA,
GENUS STENORYNCHUS, Lamarcr.
CANCER, Linn. Penn. Herbet.
INACHUS, Fabr.
Mara, Bose.
Macropus, Latr.
Macropopia, Leach.
STENORYNCHUS, Lamk. Edwards.
Generic character. External antenne 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. Earterna/
pedipalps narrow, the second joint considerably produced internally
at its apex; the third jomt oval. Anterior Jeet 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 faiciform. Hyves 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 antenna, 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
2, LEPTOPODIADA.
DECAPODA. LEPTOPODIAD.
BRACHYURA.
LONG-LEGGED SPIDER-CRAB.
Stenorynchus Phalangium.
Specific character.—Rostrum shorter than the peduncle of the antenne ; a single
minute spine on the epistome, close to the auditory cavity ; no spine behind the
base of the antenn ; arms slightly scabrous, without spines.
Cancer rostratus, Lin. Faun. Suec. Hergsst. t. xvi. f. 90.
5 Phalangium, PEnn. IV. t. ix. f. xvii.
Inachus 5 Fapr. Supp. p. 358.
Macropus i Latr. Hist. Nat. Crust. VI., p. 110.
Macropodia ,, Lxacu, Tr. Linn. Soc., XI., p. 33], Malac. Brit.
Uh 2o-obie 15 (ip
Stenorynchus 4, Epw. Hist. Crust. I. p. 279.
Tue 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 margm. The rostrum is of moderate length,
scarcely reaching to the middle of the third joint of the
peduncle of the antenne; it has a groove through its
whole length, reaching to the back of the orbit. The ex-
ternal antennz are long and setaceous, and furnished with
several long hairs; the basal jomt 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 as long as the first. The internal
antennz are lodged in fosse, 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-
tween the mouth and the base of the antenne, has a very
minute tubercle, just in front of the organ of hearing, but
none at the base of the antenne, as in S¢. tenuirostris.+
The first pair of legs in the male are about twice as long
as 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. tenwirostris: 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.
+ This second tubercle is also found in a Mediterranean species S#. Afgyptius.
B 2
4. LEPTOPODIAD &.
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 faleate, 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, bemg 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
amass of sponge. When taken it moves with very little
energy, and speedily dies after bemg taken out of the
water. Its slow and sluggish habits render it an easy prey
to many fishes; Mr. W. Thompson says, ‘* On opening a
thornback, Raia clavata, about twenty inches in length, [
found the stomach entirely filled with Macropodia Pha-
langium.”
It deposits its spawn during the early spring months.
oO
6 LEPTOPODIAD&.
DECAPODA. LEPTOPODIAD.
BRACHYURA.
SLENDER SPIDER-CRAB.
Stenorynchus tenuirostris.
Specific character.—Rostrum longer than the peduncle of the external antenna,
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 antennz ; arms spinulose at the inner margin.
Leptopodia tenuirostris, Leacu, Edinb. Enc. VII., p. 43].
Macropus longirostris ? Latr. Hist. Nat. des Crust. VIII., p. 110.
Macropodia ,, Risso. Hist. Nat. de l’Eur. Merid. V., p. 27.
2 tenuirostris, Leacu, Trans. Linn. Soc. XI. p. 331. Malac.
Brit. t. XXIII. f. 1-5.
Stenorynchus longirostris ? Epw. Hist. Crust. I. p. 280. Covucn, Cornish
Fauna, p. 64.
Tuts 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. i
basal joint of the external antenne, 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,
“T 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 antenne. 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, inthe 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 LEPTOPODIAD &.
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.
DECAPODA. LEPTOPODIA Di,
BRACHYURA.
GENUS ACHZEUS, Leacn.
ACH&US, Leach, Latr. Edwards.
Generic character. External antenne 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. Eaternal 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.
Rostrum 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
Inachus and Leptopodia | Macropodia], and by Milne Ed-
wards it is placed between Stenorynchus (Macropodia Le.)
and Camposcia. Its relation to Hurypodius 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 Maiade.
10 LEPTOPODIAD A.
DECAPODA. LEPTOPODIAD.
BRACHYURA.
CRANCH’S SPIDER-CRAB.
Achaus Cranchii. each.
Specific character—* Carapace, with two tubercles in the median line, and
} pace,
with two elevated lines between the eyes.”—LEACH.
Acheus Cranchii, Leacu, Malac. Brit. XXII. C. Ed. 2. Larr. Reg. Anim.
IV. p. 64. Epw. Hist. Crust. I. p. 281.
Tue 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 antenne and the
ee ee ee ee ee
CRANCH’S SPIDER CRAB. 11
feet are very hairy. The hands are carmated 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 carinated 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 Britanniz,” Dr. Leach
first made it known as haying 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 Royal 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, ‘“‘l’embouchure de la Rance, prés 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.
DECAPODA. LEPTOPODIADA.
BRACHYURA.
GENUS INACHUS, Fanr.
CANCER, Pennant, Herbst.
INACHUS, Fabr. Leach, Latr. Edw.
Macrorus, Latr.
Malia, Bose.
Generic character. — External antenne 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. Cavapace 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. Addomen in both sexes, six-jointed
and carinated.
ae
SCORPION SPIDER-CRAB.
DECAPODA.
15
BRACHYURA.
LEPTOPODIADé.
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, Penn. Brit. Zool. IV. t. x. f. 1. p. 12.
» Scorpio,
Fasr. Ent. Syst. Il. p. 462. Huresr. I. p. 237. No
130.
Macropus ,,
Larr. Hist. Nat. Crust. VI. p. 109.
Tnachus 55 Fase. Suppl. 358. Dersm. Cons. t. xxiv. f. 1. Epw
Hist. Crust. I. p. 288.
p: 65.
5 Dorsettensis,
Coucu, Cornish Fauna,
Leacu, Edinb. Encycl.
Malac. Brit. t. xxii. f. 1-6.
I nave 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&.
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 yentricose. 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 antennee, slightly tuberculated. The external antenne
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
the 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 jomts; that of the
female is remarkably broad. In both sexes it is tuberculo-
carinated.
It would appear that this species is more widely distri-
buted than had been supposed. Dr. Leach states that it
is very plentiful on the coast of Devon; we have seen that
Pennant’s specimens were from Weymouth; and I ob-
tained it in Studland Bay, 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. Eyton 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.
5
Thompson, “finds it in Dublin Bay.” It is also recorded
that Captain Beechey, R.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.
—
16 LEPTOPODIAD.
DECAPODA, LEPTOPODIADA.
BRACHYURA.
Inachus Dorynchus. each.
Specific character.— Rostrum bifid, extending beyond the third joint of the pedun-
cle of the antennze ; gastrie 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.
Inachus Dorynchus, Leacu, Edinb. Ene. art. Crust. p. 431. Id. Malac. Brit.
t. xxii, f. 7-8. Epw. Hist. Crust. p. 288. Coucn,
Cornish Fauna, p. 65.
Tue 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
antenne, the eyes, and orbits, as well as the external
— ea
INACHUS DORYNCHUS. J fi
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 spme, 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 Jnachus was discovered by Dr.
Leach, as he informs us, “ whilst cleanig a parcel of J.
Dorsettensis from the Salcombe estuary for examination.”
Mr. Couch states that it is commonly found m 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 bemg 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, im all probability arose its having
been for so long a time undiscovered, having doubtless been
passed over as J. Dorsettensis; it does not, however, at
present appear to be so generally distributed as that species.
18 LEPTOPODIADE.
DECAPODA. LEPTOPODIAD..
BRACHYURA.
Y
Y
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 leptochirus, Leacu, Malac. Brit. t. xxii. B.
(errore leptorinchus) Epw. Hist. Crust. I, p. 289.
Tue carapace in this species considerably resembles that
of I. 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 beimg 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 Znachus. 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 J. 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 J. 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 Jnachus, and, as far as it is at present known, to
the two species in question.
The Znachus leptochirus 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-
co 2
+“
20 LEPTOPODIAD 4.
tioned ‘‘a specimen dredged in Clifton Bay, Connemara,
by Mr. Forbes and Mr. Hall, and another in Belfast Bay
by Mr. Patterson.” The latter specimen, through the
kindness of Mr. Thompson, I have now before me. It isa
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 Mr.
Couch in his ** Cornish Fauna.”
DECAPODA, MAIAD 48,
BRACHYURA.
GENUS PISA.
Cancer, Penn. Herbst, Montagu,
Inacnus, Fabr. Risso.
Mata, Latr. Bose.
Pisa, Leach, Desmar, Edwards.
Generic character.—External antenne beset with club-shaped
nairs; the basal joint longer than broad, extending beyond the
inner canthus of the orbit ; but concealed above by the strong spine
which proceeds from the upper margin of the orbit: second joint of
the antenne rather slender, inserted a little behind and on the
outer side of the rostrum. L2ternal pedipalps very broad, the
second jomt produced at the imner and anterior angle ; the third
triangular, very broad at the outer margin; the anterior and inner
angle truncate or emarginate. Fst 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 jomt curved,
pectinato-denticulated beneath, naked at the extremity. yes
searcely 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. dddomen seven-jointed in both sexes,
———
2») MAIAD&.
DECAPODA. MAIADE.,
BRACHYURA.
FOUR-HORNED SPIDER-CRAB.
Pisa tetraodon. Leach.
Speerfie character.—Lateral margin with four spines, (exclusive of those aboye
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 A Bosc, Hist. Crust. I. 254. Leacu, Edinb. Encycl. VII.
p. 395.
Blastus x Leacu, l.c. p. 431.
Pisa 5 Leacu, Trans. Linn. Soc. XI. p. 328. Id. Encycl. Brit.
Supp. I. p. 415. Id. Malac. Brit. t. xx. f. 1-4,
Epw. Hist. Crust. I. p. 805. Coucu, Cornish Fauna.
p. 65.
Tue 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-
ae a ee EE
ee i
FOUR-HORNED SPIDER-CRAB. 23
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 antenne 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
oo ae ee oe
——— i ae
24 MAIAD&.
the greater part of the limbs, is covered with a close, short,
villous coat ; and the antenns, 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 I have seen the Ofolicnus 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-
tus 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.” 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.
26 MAIAD&.
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’S SPIDER-CRAB. pif
DECAPODA, MAIADA.
BRACHYURA.
GIBBS’S SPIDER-CRAB.
Pisa Gibbsit. 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.
‘ancer biaculeatus, Monracu, Linn. Trans. XI. t. i. f. 2. p. 2.
Pisa oH Leracu, Edinb. Encycl. VII. p. 431.
» Gibbsit, Id. Trans. Linn. Soc. XI. p. 327. Malac. Brit. t. xix.
Epw. Hist. Crust. I. p. 307. Coucu, Cornish
Fauna, p. 65,
Tue 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
28 MAIADA.
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 spme which,
with a large round tubercle just above the middle of the
posterior margin, on the intestinal region, form an obtuse
triangle. The antennz, 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 antennz 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,
ee
GIBBS S SPIDER-CRAB. 29
in the eleventh volume of the “Transactions of the Linnean
Society,” under the name of Cancer biaculeatus; 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.
DECAPODA. MAIADE.
BRACHYURA.
GENUS HYAS, Liacn.
CANCER, Herbst.
Mara, Bose.
INACHUS, Fabricius.
PIsA, Latr.
Hyas, Leach, Edwards.
Generic character.—External antenne 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. Lzternal 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
lacinia 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 antenne, and the absence of
spines beneath the last joint of the legs.
—_
HYAS ARANEUS. 31
DECAPODA. MATAD A.
BRACHYURA.
yas araneus.
Specific character.—Carapace not contracted behind the post-orbitar hastiform
process.
Cancer arancus, Linn. Syst. Nat. I. 1044.
SoU; Os Hersst, I. t. xvii. f. 59. p. 342.
Inachus araneus, Fapr. Ent. Syst. Suppl. 356.
Maia ~ Leacu, Edinb. Encycl. VII. 394.
Hyas 55 Id. l.c. p.431. Id. Malac. Brit. t. xxi. A. Epw. Hist.
Crust. I. p. 812. Coucu, Cornish Fauna, p. 66.
Tus 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 lacinie nearly parallel at their
32 MATADA.
inner edge, converging at the points, somewhat flattened
above, and slightly hollowed beneath. The external an-
tenne are remarkable in this, as in the other species of the
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 imner apex for the
articulation of the terminal portion. The abdomen of the
male is of a very peculiar form. he 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 reniform, 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 :
In. Lines.
Length of the carapace. : : . 3 6
Breadth of do. . : : : 2 6
Length of the anterior legs : ; a 3 3
“This species,” says Dr. Leach, “is very common on
the coasts of Scotland and Kent. On the shores of Devon-
shire it is of rare occurrence.” I have received it from
HYAS ARANEUS. 33
Worthing in Sussex, and from the coast of North Wales,
through the kindness, respectively, of my friends Mr. Dick-
son and Mr. Kyton. 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 imteresting, 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 mches in length, and
five or six years old, and is covered with many large
Balani. The ‘shell, or carapace of the crab is but two
inches and a quarter in length, and hence it must, A tlas-
like, have borne a world of weight upon its shoulders.
D
34 MAIADA.
The presence of this oyster affords interesting evidence that
the Hyas lived several years after attaining its full growth.
Both crabs 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
1845, every one of which was carrying her load of spawn,
which is of a rich deep orange colour.
HYAS COARCTATUS. 35
DECAPODA. MATIADE,
BRACHYURA.
Hyas coarctatus. Leach.
Specific character.—Carapace distinctly contracted immediately behind the post-
orbitar process.
yas coarctatus, Leacu, Trans. Linn. Soc. XI, p. 8329. Id. Malac. Brit. t.
xxi. B. Epw. Hist. Crust. I. p. 312. Coucu, Cornish
Fauna, p. 66.
Turs 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-
tenn, the eyes, the orbits, and the pedipalps, are very
Die
36 MAIADAR.
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-
carinated. 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 follows :
In. Lines.
Length of Carapace : F é 1 3
Breadth of do. : 5 . 5 9
Length of first pair of legs . : : 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 COARCTATUS. Si
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.
DECAPODA. MATIADE.
BRACHYURA.
GENUS MAIA, Lam.
CANCER, Herbst.
INACHUS, Fabr.
Mata, Lam. Leach, Edwards.
Generic character—External antenncee with the basal portion
very broad, forming a considerable part of the inferior boundary of
the orbit, fwmnished 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-
tennee placed in triangular fossee, between the anterior extremity of
which is a strong spine, exactly similar to the inferior spine of the
basal joint of the external antennz 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. Casapace ovate-subtriangular, convex, cover-
ed with numerous spines or tubercles. Rostrwm 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 wnists 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
DECAPODA. MATADE.
BRACHYURA.
SPINOUS SPIDER-CRAB.
CORWICH.
Maia squinado.
Specific character.—Carapace conyex, covered with sharp spines.
Cancer Squinado, Hersst, I. t. xiv. f. 84-85, (jun.) Id. III. t. lvi.
(adult. )
» Maia, Sowers. Brit. Misc. t. xxxix.
Maia Squinado, Later. Hist. Nat. des Crust. VI. p. 93. Bosc, Hist.
Nat. des Crust. I. p. 257. Luacu, Trans. Linn. Soe,
XI. p. 326. Id. Malac. Brit. t. xviii Epw. Hist.
Crust. I. p. 327.
Tue 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
40 MATADA.
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 antenne, 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 antenne 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 jomt very
slightly curved, its extremity naked, abruptly smaller, and
pointed. The abdomen is in each sex seven-jomted. 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, becommg, 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
dividuals 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, J/. ver-
rUucosa.
Pennant’s figure of what he terms Cancer maia, belongs
to Lithodes arctica, and it is very probable that he, as well
as others, has 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
Kdwards 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 MZ. 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 m length, and nearly six in
breadth, and the length of the anterior feet is fifteen
inches.
42 MAIAD®.
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 contaming 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, them’s 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 thei 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 nuinber ; 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 years 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
44, MAIAD A.
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.
JF
S a)
0 < thecal
fi" ce
of Ee
RC,
DECAPODA. PARTHENOPID EE.
BRACHYURA.
GENUS EURYNOME, Leacu.
CANCER, Pennant.
EURYNOME, Leach, Risso, Edwards.
Generic character.—External antennee 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 pedipalps with the third
joint dilated at the outer and emarginate at the inner angle. dzn-
terior pair 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. Rostrwm bifid, the lacinize triangular,
flattened, slightly divaricate. Orbits deep, above strongly arched,
with a single fissure near the external angle. yes 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
Cancerip#; and, like many other small osculant or inter-
mediate groups, exhibit many diverse and somewhat isolat-
ed forms. Of these the present genus, Murynome, may be
considered as the most nearly related to the Marana, with
which family it agrees in the union of the basal joint of
the external antennee with the parts surrounding it, as well
as in the general form of the body.
46 PARTHENOPID Ab.
DECAPODA. PARTHENOPID.
BRACHYURA.
Eurynome aspera. each.
Specific character.—Rostrum less than one fourth the total length of the body.
Carapace covered with numerous small warty tubercles, regularly disposed.
Cancer asper, PENNANT, Brit. Zool. IV. t. x. f. 3. p. 13.
Eurynome aspera, Leacu, Malac. Brit. t. xvii. Epw. Hist. Crust. I. p.
Bolle
as spinosa, Hatisrone in Mag. Nat. Hist. VIII. p-. 549.
Tue 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
lacinix 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 antenne are not longer than
the rostrum. The basal joint, as in the Maiade, 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 pedipalps have the second joint
oblong-quadrate ; the third has the outer angle produced,
and the inner angle truncate and emarginate. 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, carmated, 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 Hurynome aspera, 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 Lu. 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 Pilipora filigrana.”
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 Hw.
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 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 Hw. aspera at a
depth of thirty fathoms off the Isle of Man, and at seventy
fathoms in the A®gean. This evidently shows that the
genus belongs to deep water, an observation which holds
good of all the family of the Parthenopide.
DECAPODA, CANCERID.
BRACHYURA,
GENUS XANTHO, Leacn.
CANCER, Montagu, Herbst.
XANTHO, Leach, Edwards.
Generic Character.—External antenne 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 antenne placed obliquely immediately
under the front. LHaternal 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.
XANTHO FLORIDA. 5l
DECAPODA. CANCERID,
BRACHYURA,
Nantho 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.
+ ncisus, Leacu, Edinb. Encycl. VII. p. 391.
Xantho incisa, Id. 1. c. p. 480.
» florida, Id. Trans. Linn. Soc. XI. p. 320. Malac. Brit. t. xi.
» floridus, Epwarps, Hist. Crust. I. p, 394.
Tue carapace of Vantho 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 CANCERID2&.
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. » lividus, Leacu, Malac. Brit. pl. ix. figs. 3. 4.
Ir 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 PORTUNIDA.
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
carine, 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. aL
Britanniz” was published. It is not mentioned by Mr.
H. Goodsir as occurring 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 followmg 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.
1 BY PORTUNID®.
DECAPODA. PORTUNID.
BRACHYURA.
DWARF SWIMMING-CRAB.
Portunus pusillus.
Specific character.—Carapace considerably raised, rugose ; front three-lobed,
much advanced ; latero-anterior margin with five teeth.
Portunus pusillus, Leacu, Malac. Brit. t. ix. f. 5—8. Epwarps, Nat.
Hist. Crust. I. p. 444.
= maculatus, Risso, Hist. Nat. Eu. Mérid. v. p. 5. Roux, Crust.
Mediter. t. xxxi.
Tue 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 imner and anterior angle; the hand has a double
DWARF SWIMMING-CRAB. Nels
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, bemg
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 m his Crustacés de la
Méditerranée, notwithstanding he was aware of the pri-
ority of Leach’s name. It mhabits 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 7 rigla
I
114 PORTUNIDA.
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.
DECAPODA. PORTUNIDE.
BRACHYURA,
GENUS POLYBIUS. Weacu.
PoLyBIvs. Leach, Edwards.
PLaTyONIcHus. Latr.
Generic character. — External antennce 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 antennce in fossee, which are entirely open forwards.
Eyes larger than their peduncles, which are short. E2ternal
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 jot 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 Portwmnus, with which,
however, it stands in very near relation.
116 PORTUNIDA.
DECAPODA. PORTUNID.
BRACHYURA.
HENSLOW’S SWIMMING-CRAB.
Polybius Henslowii. Leach.
Polybius Henslowti, | Leacu, Malac. Brit. t. ix. B. Epwarps. Crust. I. p. 439.
Tuts 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 if
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 carine, 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 PORTUNID ©.
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 faras 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.” *
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.
DECAPODA. PINNOTHERID&,
BRACHYURA.
GENUS PINNOTHERES, Larr.
CANCER, Linn, Fabr. Herbst, Penn.
PINNOTHERES, Latr. Leach, Edwards.
Generic character.—External antenne 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. Addomen seven-jointed
in both sexes; that of the male small, of the female extremely
broad, round, and prominent.
Tue 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 PINNOTHERID-E.
the crust of the former is as hard as in other brachyurous
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 Hla-
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. Leach’s six species in two,—which, how-
ever, I have not done without the most deliberate con-
sideration.
COMMON PEA-CRAB. 121
DECAPODA. PINNOTHERID&.
BRACHYURA.
1 Pinnotheres Latreillii, Leach. 2 Pinnotheres varians. Leach.
3 Pinnotheres Pisum. 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.
Cancer Pisum, PENNANT, Brit. Zool. IV. t. i. f. i. p. i. Heresr,
I. p. 95, t. 2,f.21. Fasr. Suppl. Ent. 343.
Pinnotheres Pisum, Latr. Hist. Nat. des Crust. VI. p. 83. Leacu,
Mal. Brit. t. xiv. f. 2, 3, (fem.)° Epwarps,
Hist. Nat. des Crust. II. p. 31.
» Cranchii, Leracug, |. ¢. fig. 4, 5, (fem.)
» Latreillii, Leach, l. c. f. 6, 7, 8, (mas immat. ?)
3 «varians, Lracu, l.c. f. 9, 10, 11. (mas.)
Tne sexes in all the species of this genus differ so re-
markably, that a separate description is necessary.
Mate. (Figs. 1 and 2.) The carapace is nearly orbicu-
J
At
129 PINNOTHERID®.
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 enrved, 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.
Femate. (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 1s
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 iregular 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
a
COMMON PEA-CRAB. 28
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, M/ytilus 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 PINNOTHERID-%.
“The smallest Pinnotheres I have seen was found by
Mr. Hyndman, in a living Cardium exiquum, 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’s investigations on the transformations
of Crustacea, and the description with figures of the Zoéa
of Pinnotheres as given in a paper by that gentleman in
the ‘* Entomological Magazine.”*
= Vols isps.ops
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 Zoé,
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 imterest-
ing state of the animal, the accuracy of which I can attest
from my own observation.
ey, 5)
“a Sy
KGRSS
126 PINNOTHERID 2.
DECAPODA. PINNOTHERID.
BRACHYURA.
Pinnotheres veterum. Leach. Male and Female.
PINNA PEA-CRAB.
Pinnotheres veterum.
Specific character.— Male. Carapace subquadrate, rounded, the front slightly
emarginate. Memale.—Carapace broader than it is long; abdomen broadly
ovate, longer than it is broad.
Pinnotheres veterum, Bosc, Hist. Nat. des Crust. I. 243. Leacu, Malac.
Brit. t. xy. f. 1, 2, 3, 4, 5. Epw. Hist. des Crust.
II. p. 32.
~ Pinna, Leacu, Edinb. Encycl. VII. p. 431. V. THomp-
son, Ent. Mag. III. p. 89.
op Montagui, Lracu, Malac. Brit. t. xv. f. 6. Epw.1.c. p. 32.
Tue 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. i 7
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.” 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 Pinne 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 Trish coast, ‘‘ both in Pinne 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. Pinne; although he afterwards very
properly adopted the name previously given to it by Bose.
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 PINNOTHERID.E.
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. veterwm. Milne Edwards speaks
of the ‘female of P. Montagui ;” bemg probably misled
by a cursory observation of the enlarged view of the male
in Leach’s plate.
DECAPODA. GONOPLACID#.
BRACHYURA.
GENUS GONOPLAX, Leacu.
CANCER, Fabr. Pennant.
OcyPopa, Bose, Latr.
GONOPLAX, Leach, Edwards.
Generic character.—External antenne long, slender, setaceous,
the basal joint not notably broader than the following. Internal
antenne 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. Cavapace quadrate, much broader than it is long,
narrowed behind ; the fronto-orbitar margin extending the whole
breadth. Ordits 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 &.
DECAPODA. GONOPLACIDE.
BRACHYURA.
ANGULAR CRAB.
Gonoplax angulata.
Cancer angulatus, Fasr. Suppl. p. 341. Prnn. Brit. VI. Zool.
IV. p. 7. t- v. fig. 10. Hzersst, t. i. f. 13.
Ocypoda angulata, Bosc. Hist. Nat. des Crust. I. p. 198. Larr.
Hist. Nat. des Crust. &c., VI. p. 44.
Gonoplax angulata, Leacu, Edinb. Encycl. VII. 480. Epwarps,
Hist. Crust. II. p. 61. Covcn, Cornish
Fauna, p. 72.
» bispinosa, Leacu, Malac. Brit. t. xiii.
? Gelasimus Bellii, Coucu, Corn. Faun. p. 73.
? Gonoplax rhomboides, Roux, Epwarps, &c.
Tue 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, imcurved, 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 obtamed 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
P32 GONOPLACIDA,
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.”
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 Bellia of Couch’s 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.
DECAPODA. GRAPSID.
BRACHYURA.
GENUS PLANES, Leacn.
CANCER, Herbst, Fabr.
GRAPSUS, Latr. Roux, Leach.
PLANES, Leach, Bowdich.
Nauritograpsus, Edwards, Mac Leay, Goodsir.
Generic character.— External antenne lying at the exterior of
the antennary fosse, 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 antenne folded transversely in the fosse,
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. Font 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.
Tus genus, the only representative of the family Grap-
sip“ 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 PLANES.
Fucus vagans, or attached to the bodies of the large
marine turtles. The figures of Linneus 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
DECAPODA. GRAPSIDE.
BRACHYURA.
FLOATING CRAB.
Planes Linneana, Leach.
2 Cancellus marinus minimus quadratus, SLOANE, Nat. Hist. Faun., II. p. 270.
t. cexlv. fig. 1.
? Grapsus testudinum, Roux, Crust. Mediterr. t. vi. figs. 1—6.
? Cancer minutus, Fapr. Syst. Ent. XI. p. 443, ejusd.
Suppl. 343. Heres, I. t. ii. fig.
32.
? Grapsus, 55 Latr. Hist. Nat. Crust. VI. p. 68.
? 9 «—(CiMeT EUS, Say, Journ. Acad. Sc. Phil. p. 99.
? Nautilograpsus minutus Epw. Hist. Crust. II. p. 90.
Planes Linneana, Lracu, MSS. Brit. Mus.
Tue 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 stria, occupying
the place of those which are so conspicuous in the genus
Grapsus, and some other forms of this family. The front
136 GRAPSID 2.
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 antenne are ex-
tremely small. The antennary fosse are separated from the
orbits only by the basal joint of the external antenne, 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
distmet 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 Atheneum 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.” 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 avery 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 GRAPSIDA.
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.
DECAPODA. LEUCOSTAD /E.
BRACHYURA,
GENUS EBALIA, Leacu.
CANCER, Pennant, Montagu.
LEucosIA, Leach.
EBALIA, Leach, Edwards, &e.
Generie Character.—External antenne extremely minute, in-
serted in the inner canthus of the orbit. Internal antenne lying
in oblique fossee, 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 ep7-
stome ; the internal footstalk gradually acuminated, the third joint
internally palpigerous. Azterior 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.
Or 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. Mine 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.
PENNANTS EBALIA. 141
DECAPODA., LEUCOSIAD,
BRACHYURA.
PENNANT’S EBALIA. Leacu.
Kbalia Pennantii.
Specific character.
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, Leacu, Malac. Brit. t. xxv. f. 1—6. Zool. Miscell.
Te palo:
Tue carapace in Lbalia 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 LEUCOSIAD.2.
ridge on each side; the surface is everywhere distinctly
granulated. The first pair of legs are the longest and are
equal ; the arm is trihedrous, 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 jomts 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. McAndrew, 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-
PENNANTS EBALIA. 143
tioned in the following terms by Mr. Embleton, in his
Catalogue of the Podophthalmous 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 HL. Bryerii
and #. 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 #. 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.” +
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. + 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 LEUCOSIAD A.
’
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
DECAPODA. LEUCOSIAD.
BRACHYURA.
BRYER’S EBALIA.
Ebalia Bryerii. Lracn.
Specific character. Carapace slightly and minutely granulated ; lateral margin
entire, somewhat revolute 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.
‘ancer tumefuctus, Mont. Trans. Linn. Soc. IX. p. 86. t, ii. fig. 3.
(fcem. auct.)
Ebalia Bryerii, Leacu, Mal. Podoph. Brit. t. xxv. figs. 12, 13.
Tue 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 mner side, and furnished on each edge with a few
L
146 LEUCOSIAD&.
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 #. 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 £. 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 H. 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 bemg for a moment considered
as mere varicties, as they are by Dr. Milne Edwards.
BRYER’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.
148 LEUCOSIADA.
DECAPODA. LEUCOSIAD A!
BRACHYURA.
CRANCH’S EBALIA.
Ebalia Cranchii. each.
Specific Chavacter.—Carapace distinetly 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 Cranchit, Leacu, Zool. Misc. III. p. 20. Malac. Brit. t. xxv.
f.7—ll. Epw. Hist. Nat. Crust. II. p. 129.
Tue carapace in this species is more regularly rhombic
than in either Lb. Pennantii or Bryer. ‘The surface is
distinctly granulated; there isan obtuse longitudinal cara
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 nargin 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 trihedrous, 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 /.
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 #. Cranchii is three times as long
as it is broad, and without any dilatation or protuberance
on the inner side; in L. 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 /. Cranchit the granulations
which cover the surface of the body and limbs are distinct
and somewhat prominent; in 7. Bryerit they are very
small, and depressed. The female in the present species
very nearly resembles the male; in KL. Bryerit 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 CORYSTID.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 Roundstone 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.
DECAPODA., CORYSTID&.
BRACHYURA,
GENUS ATELECYCLUS. Leacu.
CANCER, Herbst.
Cancer (Hira). Montagu.
ATELECYCLUS, Leach, Edwards.
Generic Character.—External antenne 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 antenne lying
longitudinally in the antennary fossa, which are, as it were, exca-
vated in the front. LKaternal pedipalps completely closing the
buccal opening, and advancing forwards to the base of the ex-
ternal antennae; the third jot 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.- Aédomen 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 Linnean Transactions, under the name of Cancer
152 GENUS ATELECYCLUS.
(Tippa) septemdentatus. ‘There are now several other
species known, one of which A. erucntatus, 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.
CIRCULAR CRAR. 158
DECAPODA. CORYSTID&.
BRACHYURA.
CIRCULAR CRAB.
Atelecyclus heterodon. each.
Specific Character.—Carapace nearly circular, the lateral margins with nine
teeth, alternately larger and smaller; hairs of the legs very long.
Cancer (hippa) septemdentatus, Montacu, Trans. Lin, Soc. XI. t. 1. f. 1.
Atelecyclus op Leacu, Edin. Encycl. VII. p. 430. Trans, Lin,
Soc. XI. p. 313.
Px heterodon Leacu, Malac. Brit. t. ii.
Tue 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 CORYSTID.®.
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. Gouch, 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 Giant’s 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 CORYSTID.®.
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,
‘“T obtained several small living specimens of clvieleis sys! (LL
Gray’s Bard and Elegy.............-- 14
Greg and Lettsom’s British Mineralogy 8
Griffith & Henfrey’s Micrographie Dict. 9
Harvey’s British Marine Alge .,..... Be
— Nereis Boreali-Americana........ 6
ea SIGepBbOOkKg- gece? cisielselviecicte 11
Henfrey’s Botanical Diagrams ........ 6
— Elementary Course of Botany .... 5
——= Rudiments of Botany «s/c sess 10
Translation of Mohl...,.........- 5
— Vegetation of Europe........... - 5
— & Griffith’s Micrographie Dict. .. 9
Hewitson’s Birds’ Eggs ....-.eeeeeeee 1
— Exotic Butterflies......-..eseeeee 5
Ibbetson’s Geology of Isle of Wight.... 12
Page
Instrumenta Ecclesiastica ............ 13
Jenyns’s Observations in Meteorology. . 9
== Observations i in Nat. History...... 9
Jesse’s Angler’s Rambles ......... Gata
Johnston’s British Zoophytes....... see 4
—— Introduction to Conchology ...... 3
— Terra Lindisfarnensis ............ 6
Jones’s Aquarian Naturalist .......... 8
—— Animal Kingdom........... SB500 8)
—— Natural History of ‘Animals Reteteieie aie)
Knox’s (A. E.) Rambles in Sussex .... IV
Knox (Dr.), Great Artists & Great Anat. 9
Latham’s Descriptive Ethnology ...... 10
Ethnology of British Colonies .... 10
—— Ethnology of British Islands..... =u
—— Ethnology of Europe ....... celstere 170)
—— Man and his Migrations.......... 10
—— Varieties of Man :. 22... cs... cen = LO
Leach’s Synopsis of British Mollusca .. 3
Letters /Of RUSHCUS \s:<.ciaeyon cvs wee 10
Lowe’s Faunz et Flore Mader ...... 6
— Manual Flora of Madeira ........ 6
Malan’s Catalogue of Eggs............ 1
Martin’s Cat. of Privately Printed Books. 14
Memoirs of Hugh E. Strickland ...... 8
Micrographic Dictionary ........ Achowcice i)
Mohl on the Vegetable Cell........... 405
Moule’s Heraldry of Fish ............ 2
Newman’s British Ferns........... PRS
— History of Insects...........+050- 4
—— Letters of Rusticus .............. 10
Northcote & Church’s Chem. Analysis. 7
Owen’s British Fossil Mammals ..... ae)
on Skeleton of Extinct Sloth..... ns
Paley’s Gothic Moldings............. . 14
Manual of Gothie Architecture.... 13
POOWATHSt ie itacs eee a [atofeletetetetele sisisieje,, 12
Prescott on) Tobacco. .5. joer. escola 12
Prestwich’s Geological Inquiry ........ 8
Ground beneath us ............. See ef
Samuelson’s Humble Creatures ...... 8
Sclater?s.Tanaeens: < .xjctetcriseicciciese ne os a
Selby’s British Forest Trees ......... > 16
Shakspeare’s Seven Ages of Man ...... 13
Sharpe’s Decorated Windows.......... 13
Shield’s Hints on Moths and Butterflies 4
Siebold on True Parthenogenesis ...... 4
Smith’s British Diatomacez ......... 7
Sowerby’s Thesaurus Conchyliorum .. 3
Spratt’s (and Forbes’s) Travels in Lycia ll
Stainton’s Butterflies and Moths ..... a7)
Histonyion the! Mend tajat ale etateteree 5
Strickland’s Ornithological Synonyms... 2
and Melville on the Dodo ...,.... 2
Sunday-Book for the Young .......... 12
Tugwell’s Sea-Anemones ............ 4
Vicar of Wakefield, Ilustr. by siren 14
Watts’s Songs, Illustrated by Cope.... 14
Ward (Dr.) on Healthy Respiration.... 11
Ward (N. B.) on the Growth of Plants... 6
Wihite’?s'Selborne 25. She ace ce oes 11
Wilkinson’s Weeds and Wild Flowers. . a
Williams’s Chemical Manipulation .... 7
Wollaston’s Insecta Maderensia ..... ub
on Variation of Species ....... --- 10
Woodward on Polarized Light ........ 9
Varrell’s BuitishiBirdss\ecsesciebilleens atk
—— British Fishes scscussceccseseciee) 2
—— on the Salmon .rcecsssrscscessee BF
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