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FEINTED FOH lOlfGlUK, OHlffi.BaoW^^ GREEN. & I.OHGiKNS, Pim-JOTOSTIU, BOW,
Jj-SD JOHlir 1,333,011, -OypEB GOWER STREET,
1840.

CONTENTS.

PART T.

A GENERAL SURVEY OF THE TESTACEOUS MOLLUSCA.

CHAP. I.

Introductory Observations. — The Mollusca in general. — The Characters
and Analogies of the three primary Divisions or Classes ; namely, the
Acrita, the Radiata, and the Testacea — Notes on the Bibliography and
the existing Classifications of the latter - - - Page 1

CHAP. II.

On the Testaceous Mollusca in general, the primary Divisions, and their
Analogies to the Vertebrata and Annulosa - - - 26

CHAP. III.

On the Order of Gasteropoda, its primary Divisions, and the Characters
and Analogies of the Muricidce and the Turbinellids - - 53

CHAP. IV.

The Zoophaga, or Predaceous Shell-fish, continued. — The Family of
Volutida;, or Volutes - - - - - 97

CHAP. V.

The Predaceous Gastropods continued — The Strombidce, or Wing-
Shells - - - - - - -136

CHAP. VI.

On the Phytophagous Tribe of Shell-fish The primary Divisions or

Families — The Helicidffi, or Land and Freshwater Snails - 158

Vlll CONTENTS.

CHAP. VII.

The Phytophagous Gastropods continued. — The TurbidaD, or Marine
Snails - - - ... Page 1V.'>

CHAP. VIII.

The Phytophagous' Gastropods concluded. — The Haliotidae, or Ear-Shells,
and the Naticidie, or Nerits - - . . £28

CHAP. IX.

On the Aberrant Tribes of the Gasteropoda, — namely, the .Scutibranchia,
or Limpets; the Cyclobranchia, or Chitons; and the Pteropoda, or
Crystal Shells - - - - - - 241

CHAP. X.

On the Order Dithyra, or Bivalve Shells — The Affinities and Analogies
of the Unionidas, or River Unios - _ . . 253

PART II.

A NATURAL ARRANGEMENT OF THE UNIVALVE AND BI-
VALVE SHELL-FISH COMPOSING THE ORDERS GASTERO-
PODA AND DITHYRA OF THE CLASS TKSTACEA - 29^

EXPLANATION OF TERMS USED IN DESCRIBING THE SHELLS
OF TESTACEOUS MOLLUSCA - - - 391

APPENDIX - - - - 405

A TREATISE

ON

MALACOLOGY;

OR

SHFTT.S AMD SHFT.T.FTSH

ERRATA.

Page 192. line 3. from bottom, for "LucideUa" read " Lucidula."
193. lines 19. and 36. for " Heraicycla" read " Polygyra."

CHAPTER I.

INTRODUCTORY OBSERVATIONS. THE MOLF.USCA IN GENERAL.

THE CHARACTERS AND ANALOGIES OF THE THREE PRI-
MARY DIVISIONS OR classes; NAMELY, THE ACRITA, THE

RADIATA, AND THE TESTACEA. NOTES ON THE BIBLIOGRAFHY

AND THE EXISTING CLASSIFICATIONS OF THE LATTER.

(l.) In our last volume^ we completed the survey of
those great divisions of animals which, from possessing
a bony skeleton, are called the Vertebrata. Our pre-
sent treatise will he devoted to a far more numerous, hut
less interesting, assemblage, — namely, the Mollusca,
or soft animals. These, with few exceptions, are
either inhabitants of the ocean or of fresh waters. The
majority are little known even to naturalists ; and

B

f

^ SHELLS AND SHELL-FISH. PART I.

hundreds of our readers may pass their lives without
seeing one, save the slugs in their gardens, or the
empty shells they once inhabited. Their aspect to the
ordinary observer is strange and unprepossessing, with-
out either the gracefulness of form, the activity of
motion, or the richness of colouring which ornaments
insects and vertebrated animals. Their manners and
economy scarcely come within our cognisance, for their
actions are carried on in an element we do not in-
habit ; hence they are rarely witnessed, and a few
partial details is all that has yet been gathered to eluci-
date their history. Their soft and slimy bodies cannot
be preserved so as to interest us even by their appear-
ance, or to become objects of beauty or of popular
interest ; they are, in short, almost passed, '' unheeded
and unknown," except by the eye of Science.

(2.) The object of the series of volumes we are now
producing, is, to give to the world what has never yet
been attempted, — a philosophic survey of the works of
nature, based upon the harmonious relations which
every part bears to the whole. Partial systems, ap-
plicable to one branch only, and a crowd of anatomical
facts, have been either omitted, or but slightly touched
upon, as mere accessory helps to the paramount object
of our labours, ^^e have, indeed, got through the
almost herculean task of arranging the whole of the
Vertehrata according to their natural affinities and rela-
tions, even down to the sub-genera ; but to follow up
this plan with the annulose and the molluscous animals,
would not only swell the Cabinet of Natural History to
three times it prescribed limits, but would demand a
knowledge which, individually, would be superhuman.
The great truths, or, rather, the leading one, which the
enlightened reader should have constantly brought before
him is, the unity of plan in the creation : this might
be lost sight of, if the attention was long withdrawn
from such enlarged concei>tions, and occupied by a mul-
tiplicity of small details, fit only for the technical de-
scriber and the anatomical demonstrator.

CHAP. I. PLAN OF THE WORK. S

(3.) Under all these circumstances, we must therefore
treat the molluscous groups with great brevity : the lead-
ing divisions, indeed, of the whole will be briefly stated,
sufficient to guide the researches of those who may be
disposed to adopt our views of natural arrangement, and
to analyse their contents ; but this will be entirely
subordinate to the primary intention of this volume,
which, it will be seen, is almost exclusively confined to
the Testacea. Limited as is our space, we shall
endeavour to fill it in that way which promises to be
of the greatest permanent, as well as practical, advantage
to science. The arrangement of one class of the Mol.
lusca, founded upon analysis, is obviously more valu-
able than a theoretical digest of the w'hole. We are
seeking to place zoology upon a new basis. To discover
and develope, as far as in us lies, the fundamental prin-
ciples of the natural system ; and to exhibit its compo-
nent parts — not as detached portions, as if each had
its own set of laws and its own little system of arrange-
ment, but — as a vast and connected whole, throughout
which the utmost harmony and the most perfect unity
of plan pervades. To do this, how^ever, with any
degree of success, requires a fulness of detail, insepa-
rably connected with the comprehensiveness of the
subject, and the novelty of the design. It is due, not
only to the scientific public, but to the labours of those
great men whose opinions now reign paramount, that
the systems now in use should not be lightly set
aside. Hence a variety of details, unnecessary under
other circumstances, becomes absolutely essential in
these. Now, of the three classes of molluscous animals,
the Testacea, or shell-fish, is that which possesses the
greatest degree of popular, and even of scientific, in-
terest. Their beautiful shelly habitations form some of
the most interesting objects in our public museums
and private collections. And although we should not
consider ourselves bound to make this the only reason
for a neglect of the other classes of the MoUusca, yet,
nnder existing circumstances, we shall so far concede to

B 2

4 SHELLS AXD SllKLL-FISH. PART I.

popular taste^ as to devote our present volume almost
entirely to so favourite a branch. This plan will enable
us to submit nearly the whole of our investigations to
the public ; while we trust to do the same hereafter in re-
gard to the remaining classes in a separate publication.

(4.) The innumerable groups of beings which we
comprehend under the general name of Mollusca, are at
once distinguishable from all other animals^ by having no
internal bones^ like the Vertehrata ; or no joints to their
body and limbs^ like the Annulosa, or insect tribes. In
the first, the skeleton is internal ; in the latter, it is ex-
ternal ; but, in the Mollusca, it is entirely wanting.
We might fill several pages on these anatomical dis-
tinctions ; but simplicity is the soul of instruction ; and
we feel assured, that in following this rule, in the pre-
sent instance, we are saving the unscientific reader a
world of perplexing circumlocution.

(5.) We shall first glance at those characters drawn
from the nervous system, which, it is thought, sepa-
rate the Mollusca irora the Vertehrata and the Annulosa.
On a former occasion *, we have stated that their nerv-
ous system is variable,- and that this variation pointed
out the secondary divisions or classes, under which the
leading zoologists of the age have, almost unanimously,
arranged them. Thus, in the Acrita, or polypes, the
nervous system has been called granular ; these granules,
innumerable and minute, being generally dispersed over
the bodies of these animals, which resemble " masses of
transparent, homogeneous, mobile, and sensible pulp,
and thus impregnating the whole with sensibility ."t In

* Classification of Quadrupeds, p. 37.

f Such, at least, is the definition of the Acrita of MacLeay; but our
recent researches among the Mollusca induce us strongly to doubt the
propriety of placing therein thegreater part of thoseminute animals wJiich
that celebrated naturalist has arranged with the corals. Our present im-
pression is, that the whole, or nearly so, of the true Acrita, are com-
pound zo<)()hytes, or, in other words, plant-like animals; that the Ro.
tifern and Infusoria are only prototypes of the Acrita in the circle of the
lladiatn ; and that theaimulose intestinal worms are the same among the
Annulosa. As for the Parcncliipnnta, it will be seen we have had no
hesitation in placing them as the representatives of this class in the most
aberrant order of the testaceous Mollusca. We feel, in short, more and
more persuaded that the real contents of the order Ct/clobrancli/n cainiot
be determined until the entire class of Acrita has been sufficiently ana-

CHAP. I. PRI3IARY DIVISIONS OF MOLLUSKS. 5

the second class, or the Rauiata, the nerves are ar-
ranged in a radiated or star- like manner ; while in the
testaceous Mollusca, or Testacea, the nervous system
resides in four ganglions, either united in pairs, or
altogether, which are embraced by a medullary collar.

(6.) It would thus appear that the three great divisions
of Mollusca are as much distinguished by their ana-
tomical peculiarities, drawn from their nervous system,
as they are by their external and more obvious cha-
racters. It is by these latter, however, that they are
made intelligible to the generality of readers. Every
one, therefore, will be at no loss to understand the ex-
ternal distinctions of these primary divisions : 1. The
Testacea, or shell mollusks ; 2. The Raihata, or
radiated mollusks ; and, 3. The Acrita, or polypes.
The first being represented by shell-fish ; the second, by
starfish, sea eggs, and medusas ; and the third, by corals,
polypes, and other plant-like animals. We shall now,
in the first place, point out the manner of their con-
nection to the higher classes of animals, with the object
of showing that they form an integral part of that vast
circle which comprehends the whole of the animal
world.

(7.) The primary distinction of vertebrated animals
is, their being possessed both of an internal column, or
back-bone, and of legs or other members which give them
the power of locomotion : it follows, therefore, that if
we found among the soft Mollusca any animals which
really possessed these characters, however slightly de-
veloped, we should consider them as forming the pas-
sage from one class to the other ; that is, from the Ver-
tehrata to the Mollusca. Now, there is a whole tribe
of animals which really present us with such a struc-
ture, and yet, in all other respects, they are so unlike
the Fertehrata, that every writer places them with the

lysed. Between the Doridee and the Branchiopoda, there must be, or have
been, very many intervening forms : and we begin to think th;it Ciivier
may not be very wrong in placing many, if not all, of his nakiiA Acephala
close to the Branchiopoda. But the analysis of the Acrita can alone de-
termine this question.

B 3

6

SHELLS AND SIIELL-FISH. PART I.

Testacea. This tribe is the Cephalopoda, or cuttlefiph.
It is among these only^ out of the whole class of Mol-
lusca, that we find a distinct, and often rigid, back-bone,
— not, indeed, jointed or articulated, but performing the
same office as the vertebrated column of a quadruped
or a bird : others of its class have no limbs whatever ;
but the cuttlefish have immense arms, which are also
used as legs ; by these they crawl with the greatest
facility on the bottom of the sea, swim quickly in the
water, and retain the most forcible hold of such ani-
mals as they prey upon. The eyes of nearly all Mol-
lusca are either small and indistinct, or are entirely
wanting ; in these, however, the eye is large, and as
fully developed as in any vertebrated animal. There
cannot, therefore, be the least doubt of the close ap-
proximation of the Cephalopoda to the Vertehrata ; and
as a large proportion of the fossil species were fur-
nished with spiral shells, it follows that the testaceous
class comes immediately after the Vertehrata. This
affinity being established, we are at no loss to discover
the point of junction between this and the next class,
or the Jcrita. The singular naked animals forming the
Nudihranchia of Cuvier, have been very properly
placed by many authors close to the tunicated polypes
(^Tunicata). Again, on the other side of the circle of
Acrita, we have the genus Zoanthus and the Poli/pes
charnues of the French Avriters, closely connected to the
Radiata by Friapulis and other kindred forms ; while
the last vestige of the radiated structure is seen in the
Cirripeda : these latter animals, however, by their arti-
culated limbs, are yet removed out of the confines of
the Radiata, although they become the first group in
the Annulosa, — thus standing in precisely the same re-
lation as the Cephalopoda do to the Vertehrata. ^Ve
have now traced the chain of affinity into the annulose,
or insect class ; and it only remains to inquire how
these latter are connected to the Vertehrata, or, in other
words, how the animal circle is made out and closed.
On this point, again, the labours of our predecessors

CHAP. I. RANK OF THE TESTACEA. 7

have removed all difficulty^ and even doubt. The Anne-
lides have the joints of their bodies, like the common
earth-worm, disposed in rings, but yet they offer the
extraordinary character of red instead of white blood :
hence^ they are always called red-blooded w^orms.
There is, to be sure, no vestige of any internal support
to the body, such as we have seen in the Cephalopoda ;
but every one must be struck with the resemblance
which exists between a worm and an eel, — the one being,
in form, almost the miniature of the other. This re-
semblance, moreover, is carried much further by certain
eel-shaped fishes, which are destitute, not only of fins,
but of eyes ; while in others^ as the genus Myxine, the
vertebral column, or back-bone, is hardly to be dis-
tinguished. It is impossible, therefore, for this grad-
ation to be more perfect. Every naturalist of the
least repute has viewed the connection of the Anne-
lides to' the fishes in this light ; and thus are all the
classes of the animal kingdom united into one vast
circle.

(8.) Of the three divisions of the Mollusca, — namely,
the Testacea, the Radiata, and the Acrita, — it is obvious
that the latter are the lowest in the scale of animal life;
the superiority of the Testacea to the Radiata must
also be admitted, when we come to compare the or-
ganisation of one with the other. The shells of the
Echinid(B, the most typical group of the radiated animals,
are certainly as beautiful and complicated in their con-
struction— although not, perhaps, in outward appear-
ance — as those of the Testacea ; but we must look to
the animals themselves. The EchinidcE show not the
least indication of that form which belongs to verte-
brated animals : although provided with short tentacula,
which are supposed to assist them in removing from
place to place, they yet move so slowly, that a snail, in
comparison, may be said to run : thus the Echinus, al-
though with tentacula, — which are supposed to perform
the office of feet, — can scarcely remove itself a few
inches; the snail, which has no foot or similar processes,

B 4

8

SHELLS AND SHELL-FISH. PART I.

crawls on its belly, at what, in comparison, is a good
round pace. The typical Testacea are all provided with
eyes, however small, and with feelers ; but the Echinidce
have none, properly so called ; they are, in fact, de-
cidedly lower in the scale of creation than the shell-
fish ; for, while the whole of the Radiata are destitute
of eyes, those of the Testacea, in the pre-eminently
typical division (the Zoophaga), and of the Cephalopoda,
are generally very perfect, and always present. This
accords exactly with what, from theory, we should have
supposed : that the Testacea, being nearest allied to the
typical Vertehrata, would consequently be more perfectly
organised ; while the Radiata, being cut off, as it were,
from the Vertehrata, by the intervention of the Arinu'
losa, become further removed from the great types of
animal perfection, and, consequently, exhibit an inferior
developement. The Testacea are, therefore, the most
perfect of all the Mollusca.

(9-) Having now indicated, although with more
brevity that we could have wished, the relative station
of the testaceous Mollusca, both in regard to other
animals and their own class, we shall direct our chief
attention to the exposition of their natural and circular
arrangement. Although we so far concede to the popular
taste for conchology (as the '' art " of arranging shells
and other testaceous Ijodies is called) as to devote this
volume exclusively to the testaceous Mollusca, we can-
not sacrifice our conviction on the principles upon which
tliese animals should be studied, or fall into the common
method now in use of writing upon shells, independent
of all consideration for the animals by which they are
inhabited. To dignify any pursuit of this kind by the
name of Science, seems to us quite misplaced ; since it
would be hardly more absurd to classify birds by the
colour of their eggs, or beetles by the shape of their
wings, than to projjound an arrangement of shells, with-
out a paramount regard to the animals which they
cover. It is quite right that collectors of these elegant
objectSj who mix up with them shelly cases of insects

CHAP. I. IIEMARKS ON CONCIIOLOGY. y

(Cirripedes) fragments of worms (Annelides), hack-
bones of cuttlefish^ gill covers of sea hares (Aplysia),
Sec, should arrange them in their cabinets upon some
plan_, and give them names ; but no one will maintain
that this amusement deserves to be called science.

(10.) One of the first zoologists of this country, in
speaking of the utter ignorance which exists on the
natural arrangement of the Testacea, and the high
importance that belongs to the inquiry, makes the fol-
lowing remarks : — " At all events, it is not to those
collectors who are solely intent on the external form of
a shell, or the streaks of colour w^hich ornament it, that
the hope of discovering the true arrangement of the Mol-
lusca can be held forth. The study of shells appears,
indeed, to be indispensably necessary to the geologist ;
and, no doubt, the testaceous covering of an animal is
always so intimately connected with its structure, that
it would be unpardonable in the naturalist, who ought
to leave nothing without investigation, to forget shells.
But, on the other hand, when we call to our recollection
the lamentable error committed by Linnaeus and his
disciples, in not following the example of our celebrated
Lister in the arrangement of the Mollusca, we be-
come convinced there was about as much hope of their
ever arriving at the truth by the means they chose to
adopt, as that a collection of the wings of different in-
sects should ever instruct us fully in the natural history
of the animals to which they belong. It is said that
Klein formed an ornithological cabinet, in which the
feet and beaks of birds were only to be seen ; because,
according to his notions, they were all the parts re-
quisite for the proper arrangement of the feathered
creation. He thought that it was possible to be a good
ornithologist, without knowing the least of a bird but its
beak and claw. We may, indeed, laugh at this ; but,
at the same time, we ought to inquire whether similar
ridicule may not, with justice, be extended to those
conchologists, who, having procured a shell, describe and
classify it without deigning to bestow a single thought

10 SHELLS AND SHELL-FISH. PART J.

on the nature of the poor animal which constructed it
for its habitation.* A curious arrangement, as might
have been expected, has come of this method of pro-
ceeding; for we have annulose animals i' (or insects)
united to true Mollusca, merely because they have shells;
and true Mollusca separated from this division, merely
because they have no shells. In some cases, even, as in
the genus Limax, it is sufficient for the shell to be
small, in order to set it wide asunder from animals of
the same family : but it would be endless, as well as
useless, to detail the violations of natural order mani-
fested by Linnaeus in his systematic arrangement of the
mollusks, which have so truly constituted .his stum-
bling block. It cannot, however, be denied, that, could
we adopt his notion as to the nature of the animals, the
principles upon which he arranged their testaceous co-
verings are excellent. To those who admire the splen-
dour of the pencilling, the beauty of the enamel, and
the variety of sculpture, which exist in shells, it might
be depriving them of an innocent amusement, to object
the trivial nature of their study as leading to no general
results ; but it may be as well to remind them, that,
unless they add to their satisfaction and to their know-
ledge by studying the structure of the animals them-
selves, there is no more science in the disposition of
their cabinets, than may appear in the tasteful arrange-

* A modern compiler, who has been at some pains to draw up what he
considers some general observations on the " Principles of Conchology,"
very properly refrains from bestowing upon it the name of a science.
" Conchology," as he observes, " is the art of arranging the protecting
bodies of testaceous " (and he might have added of annulose) " animals,
so as to enal)le us to recognise them promptly and certainly, without giving
any attention to the animals which they have contained, or contain, or, at
least, regarding this part a< a matter of very minor imiiortaiice." Inde-
pendent of the assistance this '' art " bestows to the studies of the geologist,
he further observes, " it may almost be regarded as a study nearly idle and
useless by all true zoologists." Nay, he continues, "it is really to this
cause that conchology, properly so called, owes both the continuance of its
existence, and the daily increasing efforts of enlightened naturalists, who
endeavour to give it sure priMcii)les and rules." He omits to inform us,
however, how these sure principles and rules can be attained in an " art "
which absolutely rejects that solid foundation for them, upon which their
true knowledge depends, — that is, a primary regard to the principles of the
variation in these animals.

f The CirripedeSy or barnacles.

CHAP. I. REMARKS ON CONCIIOLOGY. 11

ment of porcelain on a mantelpiece. Separate the shell
from the animal, and much less acquaintance with the
natural system is to he derived from their inorganic
covering, than Klein obtained of his birds_, by seeing only
their beaks and claws." *

(11.) The above sentiments on the insufficiency of
the shell, in all cases, to determine its place in the
natural system, we are free to confess, were held by
us for many years. But the results of that analysis
now given to the public, have materially modified, if
not altered, this opinion. It is needless, perhaps, to
repeat, that a primary regard must always be had to
the nature of the mollusk itself ; and that, without this
knowledge, there are certain forms of Testacea, of
which neither their natural tribes nor families can be
conjectured, and which, for this reason, should always
be kept apart. There are others, again, belonging
to totally different families, or even orders, which
are so alike in their shells, that conchologists place
them in juxta-position.f But yet, on the other
hand, there are numerous other families, where the
modifications in the form of the shell are just as im-
portant, and even more so, than those of the animal.
The molluscous system of Poll fully establishes this
proposition, even though the innumerable proofs in its
support, hereafter detailed, were rejected. The truth
appears to be, that Nature, on the whole, has diversified
the external aspect of these singular animals, — that is,
their shells, — much more than she has their soft or more
unsightly parts. If, therefore, she has thus bestowed
all her beautiful embellishment upon the habitation
rather than upon the inhabitant, we may at least con-
clude that the one is as essential to develope the plan
she has pursued in her own system, as is the other.
The diversity she has created on the shelly coverings of
the typical Testacea is, beyond all comparison, greater

* Hor. Entom. p 240—244.

f Particularly the prototypes of the Planariilar, as Vitrina, Sigarelus,,
Chcelinotus, &c.

12 SHELLS AND SHELL-FISII. PART I.

than is to be found among their animals ; but these
latter must be well studied, before we can comprehend
the leading types of form prevalent among the former.
When this last discovery, if only in part, has been
made, we shall find that the slightest modification in
the shell is not without its meaning; and that, in nine
instances out of ten, we may pronounce with as much
confidence on its natural station in the scale of nature,
as if we had actually dissected its animal.

(12.) A singular idea appears to be entertained by
some writers, that the "^art" of conchology, popularly
so called, is only really serviceable to science, when
viewed in connection with geology. But it may
fairly be asked, how geology or any other branch of
knowledge can be benefited by any aid which is not, in
itself, built on sound and philosophic principles, which
this '^'^art" confessedly is not. It would be difficult to
answer the question why one branch of zoology is to be
separated from the others, and degraded into the hand-
maiden of another science, — and that, too, of such very
recent formation, that the most opposite opinions as to
its very first principles are continually issuing from the
press. It is not a little singular, also, that, while
geologists appear to attach so much importance to
mineral conchology, as it is termed, no author, as yet,
has specifically written on the subject. In such a state
of things, the attempts that are made to identify certain
strata by the nature of the shells they may contain, should
be ventured upon, in most cases, with very great cau-
tion. We are fully persuaded that many of those fossil
shells termed by conchologists fluviatile, are decidedly
marine ; that the nature of others, from ignorance of
their animals, can never be understood ; and that a
great number, now considered identical with existing
genera, belong to groups altogether extinct. Until,
therefore, all these suspicious points are cleared u}),
geologists will derive but very little comparative benefit
by our modern systems of conchology, and will be fre-
quently led to most erroneous conclusions. The " art,"

CHAP. I. BIBLIOGRAPHY OF MALACOLOGY. 13

in fact^ must merge into the science of Malacology,
in which equal regard is paid both to the animal and
the shell. It is then alone that geology will be really
benefited. Our science will then repose upon a proper
and philosophic basis^ and in that capacity will be ready
to aid those of her sisters who may solicit her services.
(13.) Our notices on the Bibliography of the tes-
taceous Mollusca, must be very brief, and chiefly con-
fined to such as have a practical influence on the present
state of science. This brevity will be the less regretted,
since the subject has been so ably and fully gone
into by Maton and Racket, in the seventh volume of the
Linncean Transactions. The foundation of this and
every branch of zoological science was laid by the im-
mortal Aristotle, who well discriminated all the leading
groups of the typical Testacea, and was not inattentive
to the habits and localities of the animal inhabitants.
He separated the spiral univalves by the name of Mo-
nothyra, while he applied the term of Dithyra to the bi-
valves. It would have been as well if the moderns, in
their multifarious and complicated nomenclature, had
shown some little respect to the designations imposed by
this commanding genius on the leading groups of Xhe Mol-
lusca ; such defence would, at all events, have brought
his name more frequently before us, and reminded the
world how infinitely science was indebted to his labours.
How much superior, also, is the simplicity of genuine
classic names over those compounded in modern times,
will be best seen by comparing those bestowed upon
the bivalves, which are the Dithyra of Aristotle, and
the Malacozoaria Acephalophora of M. de Blainville.
It is too late, perhaps, to restore the entire nomen-
clature of the illustrious Stagyrite ; but in this single
instance we shall certainly prefer his designation of the
bivalve Mollusca in preference to those of the moderns.*

* The term of Acephcila, given by Cuvier, would be by no means objec-
tionable, but that it sets aside the name of antiquity, and include?, more-
over, numerous groups which have nothing in common with the Dithyra
of Aristotle, except the want of a distinct head. To judge, indeed, from
the writings and nomenclature of the French school, it would hardly be
conjectured that such a man as Aristotle had ever existed.

14j shells and shell-fish. part 1.

(14.) Our celebrated countryman. Lister *, was the
first naturalist, after the revival of learning, who made
any decided improvement in this science, since he re-
garded both the animals and the shells ; and his noble
volume will be an imperishable record, both of his
talents and his industry. The excellent figures of
Rumphiust;, published in 1711:> are still valuable, as
are likewise those of Gualtieri :|:, but neither of these
writers can scarcely be said to have benefited the subject
in any other way. D'Argenville's plates, although more
elaborately finished, are very inferior to those of the
last-named works ; and it has been truly said, that what
is really valuable in his book has been taken from
Lister. The conchological labours of Klein, who was
perpetually writing upon every branch of natural his-
tory, partake of the character which belongs to all, — a
total want of genius. It was, in fact, reserved for
Adanson§, the celebrated French traveller and naturalist,
once more to revive malacology from the frivolous state
into which it had been gradually sinking since the days
of Lister : by studying both the animal and its shell,
he prosecuted his researches on sound and philosophic
principles ; and hence it is, that his volume, although
published in 1757:, is highly valuable, while the '^ tes-
taceous " arrangement of Linnaeus is as if it had never
been written, — or it is consulted only, at rare intervals,
to determine a specific name. But Adanson confined
himself to the shell-fish of Senegal ; and it was not sur-
prising that the scientific world, captivated by the sim-
plicity of the Linngean nomenclature, still continued
attached to the plan of considering the Testacea merely
in regard to their shells, of which innumerable species
now began to pour in on the European cabinets. This,

* Lister. Historia, sive Synopsis Metliodica Conchyliorum. London,
one volume, folio ; of which there are two editions, the last in two volumes.
See Prcl. Discourse, p. 24.

t Ku.MPHius, G. E. 'J'hesaurus Imaginum Piscium, Testaceoriim, &c.
Haga; Comilum, 17;)9, folio.

: Nico. GuALTiiRi. Index Testatum Conchyliorum. Flor. 1742, royal
folio. The figures are the most artisticai of any that we remember: the
rotundity of the spiral shells is admirably represented.

\ Hist. Nat. des Coquillages du Senegal. Tans, 1757, 4to.

CHAP. I. BIBLIOGRAPHY OF MALACOLOGY. 15

doubtless, gave rise to the voluminous work of Martini
and Chemnitz, which, although published between
1769 and 1788, and with figures exceedingly ill drawn,
is, nevertheless, the most valuable, as a general work,
we yet possess. It was soon after this time, however,
that George Humphrey*, F.L.S., the chief commercial
conchologist then living, gave to the w-orld a small
pamphlet, wherein he arranged the Testacea upon an
entirely novel and very remarkable plan. As a system
of conchology, this w^as both a sudden and a most
extensive improvement upon everything of the kind
which had hitherto been done. The arrangement,
which wdll be subsequently adverted to^ as far excels
that of Linnaeus, as Lister's exceeds that of Klein.
There can be no doubt, in fact, that this little unpre-
tending pamphlet, published in this country merely
as an exhibition catalogue^ found its way to France, and
served as the main foundation, although unacknow-
ledged, for the subsequent system of Bruguiere, if not
of Lamarck and Cuvier. It was, to write colloquially_,
the first quiet but thorough breaking of the ice, in
which conchologists were bound up by the Linnfean
system ; and those w^ho followed up the reformation,
however justly we may praise them as improvers, can-
not be invested with the more honourable distinction
of leaders. It was, therefore, not in France, but in
England, that the revolution against the meagre concho-
logical school of Linnaus first originated. But, having
said this, w^e can put forth no claims for our countrymen_,
on this head, during a subsequent period of nearly forty
years. Montagu, indeed, must be named with honour,
and Pennant's writings aided much to spread a taste for
collecting shells ; but beyond these, we recollect no others
deserving special record. Meantime, a more correct
knowledge of the molluscous animals was making rapid
progress on the Continent. Those illustrious and ad-
mirable anatomists. Poll in Italy, and Cuvier in France^

* Museum Calonnianum. — Specification of the variouo Articles which
compose the magnificent Museum of Natural History, collected by M. de
Calonne in France. Anonymous. London, May 1. 1797.

10 SHELLS AND SHELL-FISH. PART I.

were prosecuting their researches with indefatigable
industry ; while Bruguiere, and subsequently Lamarck,
were no less occupied in describing and arranging the
Testacea; meantime^ faint attempts, in the shape of In-
troductionSj to keep alive Linnaean conchology, were all
that appeared in England on this subject. The labours
of Bruguiere were unfortunately terminated prematurely
by deaths but those of his illustrious friend Lamarck
were continued up to within these few years. His
masterly and incomparable work, wherein aU his labours
on the invertebrated animals are concentrated, are too
well known to be expatiated upon in this place, since it
is in the hands, or should be, of almost every zoologist
who studies those classes. The investigations of Poli,
even more elaborate than those of Cuvier, have been
given to the world more slowly, and in such an expen-
sive form, as to deprive them of half their utility.*
Not so with those of the celebrated Cuvier. The
Regne Animal, a book accessible to all purchasers, con-
tains the essence of all his labours on the Mollusca,
but, unfortunately, so much abridged, that the student
is frequently more perplexed, than satisfied, on the
point he is searching for. His more detailed memoirs
are scattered through innumerable volumes of foreign
transactions, where they lie completely hidden from
every-day reference, although their intrinsic and per-
manent value would fully warrant their being collected
and printed in a cheap volume.f In estimating the
merits of these three great men, — Poli, Cuvier, and La-
marck,— in regard to their arrangement of the testaceous
Mollusca, it may be stated, that the first confined his
system entirely to the animal, giving to it a difi^erent
name to that of the shell ; so that, if the animals of two
conchological genera (as Avicula and Lima^ were nearly

* Poll Testacea Utriusque Sicilia', eorumque Historia et Anatomia,
2 vols, royal folio. Parma', 1790 — 5.

A Supplement, by Stephaiius della Chiaje, forming another volume,
was published at Naples in 1S.')3.

f A few copies of these 3/e?«o»rs, with their plates, were struck ofT se-
parately, and published in one 4to. volume, Paris, 1817 ; but this is now
become so rare as to be unprocurable, excepting hy chance.

CHAP. I. RECENT WORKS. 17

alike, they were placed, in his system, in one and the
same genus. Cuvier has altogether avoided this strange
mode of procedure ; but an inspection of his system
will bear us out, we think, in our opinion that he has
placed far too great a stress on the modes of respiration,
and paid too little attention to the shell, no less than to
the animal ; while the great error of Lamarck appears to
have been that of giving to the shell, and more espe-
cially the hinge of bivalves, a greater regard than he
bestows upon the animal. The system of M. de Blain-
ville, indeed, professes to remedy these defects ; but we
can discern in it little that is new, beyond innumerable
compound Greek names, proposed for groups already
established by his predecessors, and which are only
calculated to overturn all existing nomenclature, with-
out adding anything practical to the advance of science.
(15.) Whatever may be the cause, certain it is that
nearly all that is now valuable in malacology has
emanated from the Continental naturalists. Besides
those just enumerated, the unwearied zeal of the French
circumnavigating naturalists,, more especially M. Quoy,
has added to this science not merely a host of new
shells, but — what is far more valuable — innumerable
facts, of the highest importance, regarding their animals.
We only regret that the price of these splendid publica-
tions, and the few copies of them yet in this country, have
prevented us, in all instances, from profiting from these
most valuable materials. The only one of our country-
men who has pursued the same path of inquiry, and
on the same philosophic principles, was our late friend,
the Reverend Lansdown Guilding, who, from his
official residence in the West Indies, had the enviable
opportunity of examining, and the rarely united talents
of drawing, dissecting, and describing, the soft MoUusca
of the Caribbean seas. To him is science indebted for
a knowledge of the animals of numerous terrestrial and
many marine shells ; and the institution, on the most
solid basis, of several natural genera. These invaluable
researches, too little appreciated by our conchologists,

G

18 SHELLS AND SHELL-FISII. PART I.

in their zeal for describing new species, and too little
known to the scientific world, from being scattered in
detached papers, or unpublished, are all incorporated
and acknowledged in this volume.* To this accom-
plished zoologist and exquisite artist are we indebted,
among many other things, for the discovery of the
extraordinary genus Herpa ; and for drawings of
the animals of Oliva, Volutella, Marginella, Triton,
and Trochella; as also of several other groups, originally
characterised from the shells alone, but now confinued
by the difference of their animals. The name of
Mr. Lowe, the natural historian of Madeira, deserves
honourable mention in this place, as connected with
the illustration of many interesting facts on the Mollusca
of that island. A most magnificent, but extravagantly
expensive, work on the land and freshwater shells, was
commenced, several years ago, by the late baron de
Ferussac.t As it was patronised by Royalty, some hopes
were entertained of its completion, notwithstanding the
grand scale it set out upon ; but the undertaking was
evidently too vast for the very moderate abilities of its
projector ; the parts came out less and less regularly,
until, after it had cost the subscribers near 50/., it
was (virtually) given up, and the author died. This
striking example is surely sufficient to convince any
sober judging person of the utter impracticability of
completing a General Conchology, or of carrying it
on beyond a few numbers. It is, in fact, a physical
impossibility for any one or five men to accomplish
such a work in the ordinary term of human life ; and
even if brought to a termination, unless conducted on
the most economic scale, would involve an outlay to
the projectors, and an expense to the public, which
the latter, at least, would never incur. We are, in
truth, heartily set against all these magnificent under-
takings : they are absolutely detrimental to science ;

* A large collection of highly finished drawings, and several MSS., are
now in the possession of Mr. Guilding's late widow.

t I'ERUssAc Hist. Nat. gC'ntralc et particulierc dcs MoUusques Ter-
restres et Fluviatiles, 27 parts, published, Paris, 1819 — 3J.

CHAP. I. SYSTEMS AND ARRANGEMENTS. I9

for they confine the materials of knowledge and of
study within the narrow limits of the select few (gene-
rally wealthy amateurs)^ to the exclusion of all who
cannot expend 400/. or 500/. upon a zoological library.
We cannot but admire the zeal of their projectors_, —
for such works never produce profit, and generally bring
a heavy loss, — but we think it a zeal misplaced. What
is now most wanted, is a collection of plates of shells,
to supply the deficiencies of the series in the Tableau
Encyclopedique et Metliodique *, and printed uniformly.
The series in question contains nearly 300 plates, and
is the very best which the naturalist can possess. We
have constantly referred to it, as being more within the
pecuniary reach of the student, and as being far more
accurate in the figures, although uncoloured, than that
of Martini and Chemnitz ; and these latter are there-
fore only quoted for species not contained in the other.
The figures in Wood's Catalogue are often very good ;
but the arrangement is so confused, and often so erro-
neous, that the nomenclature, in its present state, can
seldom be quoted as an authority.

(l6.) In regard to systems and arrangejients of
the testaceous animals, the only attempt that has ever
yet been made towards the natural disposition of this
extensive class, is that indicated in the Horce Ento-
mologies. The ingenious author, however, candidly
acknowledges his inability even to point out the primary
divisions; although he has ventured, and, as we think,
has partially succeeded, in tracing the links of affinity
by which the testaceous Mollusca are connected, on one
side, to the Aerita, or polypes, and, on the other, to
the vertebrated animals, by means of the Cephalopoda.
Of arrangements made without any ulterior object of
illustrating the general harmonies of nature, and there-
fore artificial t, there are several ; the best being those

* With these plates, and Lamarck's volumes of the Hist. Nat. des Ant-
maux sans Vertibres, the conchologist will be at no loss to arrange an
ordinary collection of shells, and name by far the greater portion of the
species. The excellent Manuel de I'Hist. Nat. des Moliusques of M. Sander
Rang should also be procured, on account of the valuable notices it con-
tains on the structure of the animals.

t See Geography and Classification of Animals, p. 125.

c 2

20

SHELLS AND SHELL-FISH.

PART I.

of Humphrey, Lamarck, and Cuvier. The two first
of these will therefore be exhibited in their details ;
the latter having already been placed before the reader
in a former volume. Although that of Lamarck, by
common consent, has been preferred by nearly all zoo-
logists, it is but justice to the distinguished author of
the Regne Animal, to designate his early Memoires
upon these animals as fully entitling him to the high
reputation his anatomical talents have so justly acquired
for him in other departments. They are materials upon
which all true knowledge of the Testacea must repose.
(17-) The conchological arrangement of Humphrey,
already spoken of, will now be detailed, so far, at least,
as regards the names of the genera ; since their de-
finitions were never published. To show how intimately
very many of these accord with those of Lamarck, we
have, in almost every instance, added the corresponding
genus of the latter. The ingenious author had such a
conviction that the fluviatileand terrestrial genera should
be kept distinct from the marine, that he places them
in separate divisions.*

Class TESTACEA.
Order I. MARINE.

Division

I. Univalves.

Conus L.

Serpula Linn.

Melo.

Broderip.

Dentalium L.

Valuta L.

Patella L.

Musica.

Voluta Lam.

Larva.

Fissurella Lam.

Harpa.

La 771.

Crypta.

Crepidula Lain.

Dolium.

La7n.

Calyptra.

Idem Lam.

Casida.

Lam.

Galerus.

Calyptrffia Lam.

Haliotis L.

Pedum.

Spirula Lant.

Haliotoidea.

Stomatia Lam.

Nautilus L.

Auris Veneris.

Sigaretus Lam.

Argonauta L.
Bulla L.

Neritoidea.

i; lanthina, &c.
(. Lam. •

Licium.

Ovula Lam.

Uber. ;
Lunatus. ',\

Natica Lam.

Cypraea L.

Dactylus.

Marginella Lam.

Nerita L.

Oliva L.

Auris Mustela;.

Tornatella La7H.

* The author, with that modesty which was his peculiar characteristic,
thus expresses himself: — " I'he editor hopes that his confession of being
but little acquainted with the learned languages will be received as an
apology for such improprieties in the generic orspecific names as he fears
will be found."— Museum Calon/ieanum, pref. p. v.

CfHAP. I.

SYSTEM OF HUMPHREY.

21

Turbo L.

Strombus.

Pterocera. Lam.

Eutropia.

PhasianellaLflw.

Triplex. ' >
Purpura..'

Scala.

Scalaria Lam.

Mtirex Lmn.

Terebra.

Lam.

Rheda.

Hyalia Lam.

Obeliscus.

Trochus Linn.

Cochlus.

■ Cidaris Sw.
I Marmarostoma.

Div. IL

Bivalves.

Pinna L.

€enectus.

SV3.

Mytilus L.

Blench us.

Sw.

Solen L,

Physeter.

Solarium Lam.

Margaritifera.

Avicula Lam,

Apiculum.

Trochus Lam.

Vulsella.

Lam.

Trochulus. 7
Trochus- 3

Placuna.

Lam.

Monodon Lam.

^ M «-• ^.z v« ■ m b4 ^

Cepa.

Anomia Linn.

Sol.

Tubicanthus Sw.

Lampus.

Terebratula Lam

Onustus.

Sw.

Mactra L. 7
Trigonella.3

PygmEea.

Columbella Lam.

Mactra Linn,

Pyrum.

Pyrula Lam.

Tellina L.

Haustrum.

Purpura Lam.

Cuneus.

Donax Linn.

Hystrlx.

Ricinula Lam.

Pectunculus.

Venus Linn.

Bulbus.

Rapella Stv.

Cardium L.

Acus.

Terebra Lam.

Trapezium.

Chama Lhtn.

Clava.

Cerithium Lam.

Tridacna.

Lam.

Cassidula. ' '
Ficus.

Pyrula Lam.

Glycymeris.
Area L.

Lam.

Rhombus.

Fusus, &c. Lam.

Pecten.

Lam.

Rana.

Ranella Lam.

Ostrea L.

Buccinum.

Triton, &c. Lam.

Lacinia.

Chama Lam,

Turris.

Turritella Lam.

Spondylus L.

Colus. 7
Fusus. 3

Fusus Lam.

Div. III. MuLTivALVEs.

Cuma.

'Fusus Lam.
( . Fasciolaria lb.

Pholas L.

Lepas L.

Mitra.

Lam.

Cornucopia.

Lepas Linn.

Murex.

Scolymus Sw.

Balanus.

Rapum.

Turbinella La7n.

Chiton L.

Alatus.

Strombus Linn.

Order II. FLUVIATILE.

Div. T.

Univalves.

Div.

II.

Bivalves.

Catillus. ■
Neritella. ,

Barbata.

Unio Lam.

Neritella Lam.

Scapha.

Iridina? Lam.

Pomus.

Ampullaria Lam,.

Mya.

Unio Lam.

Vesica.

'Lymnia.
'. Melania Lam.

Nux.
Capsa.

Cyclas Lam.

?

Ligula. 7
Turricula. 3

Melania Lam.

Order IIL T

ERRESTRIAL.

Sylvicola.

Cyclostoma Lam.

Otis.

Auricula Lam

Helix L.

Chersina.

Achatina Lam

Lituus.
Cistula.

Cyclostoma?Za7«.
Cyclostoma.

Lendix. '
Pupa. J'

Pupa Lam.

,Bombyx.

?

22

SHELLS AND SHELL-FISH. PARTI.

(18.) As a purely conchological system, this was un-
questionably the best and the most original of any that
had appeared since the revival of learning. It was pub-
lished in 1797, nearly twenty years before the first of
Lamarck's volumes appeared. * That it was well known
to the latter can hardly be doubted, when we see no less
than ten genera similarly named by both ; and that
almost every genus of Lamarck's univalves are found in
this list, under different, but less classical, names. Of
univalves, Humphrey has 87, contained in the single
collection of which his book is a catalogue. How many
more he had determined to name, does not, of course,
appear ; but the total number of Lamarck's is but Q6,
for the whole of the testaceous gastropods.

(19.) Lamarck's system, so far as regards the animals
now before us, may be thus briefly stated. He arranges
the whole group under the two classes of — I. Con-
chifera; and, IL Mollusca. The first contains the
bivalve shell-fish, and is again divided into two orders :
one of these is called Conchiferes dimyaires, the in-
terior of the shells presenting two muscular impressions,
separated and lateral ; while in those of the second
order, or ConcJuferes monompaires, there is but one
muscular impression, placed nearly in the centre, — the
muscle itself being single, and which appears to run
through the body of the animal. Each of these great
divisions of bivalves contains several others, denominated
sections, chiefly differing in the structure of their feet.

Order I. CONCHIFITRES DIMYAIRES.

Section 1.

Mya.

Amphidesma.

Aspergiliuin.

Anatina.

Corbula.

Clavagella.

Pandora.

Fistularia.

Sect.

TI.

Saxicava.

Septaria.

Conch, tenuipedes.

Petricola.

Teredina.

Lutraria.

Venerirupis.

Pholas.

Mactra.

Sanguinolaria.

Gastrochaena.

Crassalella.

Psammobia.

Solen.

Erycina.

Psammota;a.

Panopa?a.

Ungulina.

Tellina.

Glycimeris.

Solenimya.

Tellinides.

* The first volume of the Hist. Nat. des Animaux sans Verthbres bears
the date of March, 1815.

CHAP. I.

■

SYSTE3I OF

LA3IARCK. ^

Corbis.

Cytberea.

Trigonia.

Lucina.

Venus.

Castalia.

Donax.

Venericardia

Unio.

Capsa.

Cardium.

Hyria.

Crassina,

Cardita.
Cypricardia.

Anodon.
Iridina.

Sect.

III.

Hiatella.

Conch, lamellipedes.

Isocardia.

Sect. IV.

Cyclas.

Cuculzea.

Conch, ambigus.

Cyrena.

Area.

Diceras.

Galathea.

Pectunculus.

■ Chama.

Cyprina.

Nucula.

•

Etheria.

Order II. CONCH.

MONOMYAIRES.

Section I.

Sect.

II.

Sect. III.

Tridacna.

Pedum.

Branchiopoda Cuv,

Hippopus.

Lima.

Sphserulites.

Modiola.

Plagiostoma.

Radiolites.

Mytilis.

Pecten.

Calceola.

Pinna.

Plicatula.

Birostrites.

Crenatula.

Spondylus.

Discina.

Perna.

Podopsis.

Crania.

Malleus.

Grypheea.

Orbicula.

Avicula.

Ostrea.

n^prphratula.

Meleagrina.

Vulsella.
Placuna.
Anonica.

Lingula.

23

(20.) To his second great division^ Lamarck restricts
the title oi Mollusca : these he again subdivides into the
five following orders : — 1 . The Pteropoda, which forms
a part of our Cephalopoda. 2. The Hydrohranchia^
which includes the JVudibranchia, Scutihranchia, and
Tectibranchia of Cuvier ; together with the genera On-
chidium, ParmaceUa, Limax, Testacellus, and Vitrina :
these genera he places in his section Pneumobranchia,
and makes them the passage to his tlm^d order, or the
Trachelipodes, in which all the univalve shells are placed.
The foiu'th order is composed of the Cephalopoda, or
cuttlefish ; and the fifth contains the Heteropoda.
The genera belonging to each of these orders are as
follows : —

Order I. PTEROPODA.

Hyalaea.
Ciio.

Cleodora.
Limacina.

4

Cymbulia.
Pneuraodermon.

5J*

SHELLS AND SHELL-

-FISH. PART I

Order H. GASTEROPODES.

Section I.

Pleurobranchus.

Bulla.

Glaucus.

Umbrella.

Aplysia.

Eolis.

Parmophora.

Dolabella.

Tritonia.

Emarginula.

Scyllaea.

Fissurella.

Sect. II.

Tethys.

Pileopsis.

Onchidium.

Doris.

Calyptraa.

Parmacella.

Phyllidia.

Crepidula.

Limax.

Chitonellus.

Ancylus.

Testacella.

Chiton.

Acera.

Vithna.

Patella.

BuUaea.

Order HI. TRACHELIPODES.

Section I.

Haliotis.

Triton.

Les Phytiphages. Tornatella.

Rostellaria.

Helix.

Pyramidella.

Pteroceras.

Carocolla.

"Vermetus. ^

Strombus.

Anastoma.

Scalaria.

Cassidaria.

Helicina.

Delphinula.

Cassis.

Pupa.

Solarium.

Ricinula.

Clausilia.

Rotella.

Purpura.

Bulimus.

Trochus.

Monoceros.

Achatina.

Moiiodonta.

Concholepas.

Cyclostoma.

Turbo.

Harpa.

Planorbis.

Planaxis.

Dolium.

Physa.

Phasianella.

Buccinum.

Lymneea.

Turritella.

Eburna.

Melania.

Terebra.

Melanopsis.

SECT.:n.

Columbella.

Pirena.

L.es Zoophages.

Mitra.

Valvata.

Cerithium.

Voluta.

Paludina.

Pleurotoma.

Marginella.

Ampullaria.

Turbinella.

Volvaria.

Navicella.

Cancellaria.

Ovula.

Neritina

Fasciolaria.

Cypraea.

Natica.

Fusus.

Terebellum. ;

lanthina.

Pyrula.

Ancillaria.

Sigeretus.

Struthiolaria.

Oliva.

Stomatella.

Ranella.

Conus.

Stomatia.

Murex.

Order IV. CEPHALOPODES.

Section I.

Spirula.

Melania.

Testaceous Cephalo- Spirolina.

Rotelia.

poda.

Lituola.

Lenticulina.

*

Belemnites.

Renulina.

Placentula.

Orthocera.

Christcllaria.

Discorbis.

Nodosaria.

Orbiculina.

Siderolites.

Hippiirites.
Conilites.

Miliola.
Gyrogona.

Polystomella.
Vorticialis.

CHAP. I. SYSTEM OF CUVIER. 25

NummuUtes. Baculites. Sect. III.
Nautilus. (^epf^- Cepiaria.

Ammonites. Sect. II. Octopus.

Orbiculites. Ceph. Monothalama. Loligopsis.

Ammonoceras. Argonauta. Loligo.

Turrilites. Sepia.

; Order V. HETEROPODA.

Carinaria. Pterotrachia. Phylliroe.

(21.) The system of M. Cuvier difFers, in many re-
spects^ from the above. The Mollusca form the second
great division into which this admirable anatomist divides
the animal kingdom. These he distributes under six
principal classes : 1 . Cephalopoda, or cuttlefish ; 2.
Pteropoda, or clios ; 3. Gasteropoda, an immense and
heterogeneous assemblage, which we shall presently
notice in detail ; 4. Acephala, or bivalve Testacea, at
the end of which he introduces the tunicated Mollusca
{Tanicata Sav.) ; 5. Branchiopoda, or anomian shells ;
6. Cirripedes, or barnacles. The great variety of ani-
mals brought together in the third order, Gasteropoda,
obhges our author to divide it into others, the names and
contents of which are as follows : — 1. Pulmonia, con-
tains the slugs and snails, both terrestrial and fluviatile.

2. NuDiBRANCHiA, iucludes all the naked marine Tes-
tacea without shells, — as Triton, Doris, Thethys, &c.

3. Inferobranchia, consists but of two genera, Phyl-
lidia and Diphyllidia. 4. Tectibranchia, compre-
hends the Bulla family and the Aphjsia. 5. Hetero-
PODA, embraces the Firoles and the CariiiaricE. 6. Pec-
TiNiBRANCHiA : Under this order, arranged in sections,
are placed the whole of the Trochus and Turbo families,
together with the greatest part of the marine univalve
Testacea. 7- Tubulibranchta, is limited to the genera
Vermetus, Magilis, and Siliquaria. 8. Scutibranchia,
contains Haliotis, Fissurella, and Emarginula : while
the 9th and last order, Cyclobranchia, consists but
of Patella and Chiton. To go into further detail will
be needless, since the student will at once arrive at a
general idea on the contents of these groups, by the indi-
cations already given.

26

SHELLS AND SHELL-FISH. PART I.

(22.) In both these latter methods of classifymg the
Testacea, there is much to approve and much to dissent
from. It is clear that neither of these naturalists^ how-
ever great their merits undoubtedly are in other respects,
have paid any attention to the difference between analogy
and affinity : nor have they aimed at anything beyond
producing a simple scale or line of connection from one
group to another. Now, as no such simple series exists
in nature, — whose relations of affinity are always
double, and generally treble, and whose analogies are
interminable, — it follows, as a matter of course, that
both have completely failed in laying down a simple
graduated scale of the objects before them. Hence, as
the groundwork of both systems is founded in error,
no apology is necessary for rejecting them, particularly
when the object sought for is the discovery of the na-
tural arrangement. It is time, however, to leave the
systems of others, and to lay before the naturalist some
details of that here proposed.

CHAP. II.

ON THE TESTACEOUS MOLLUSCA IN GENERAL, THE PRIMARY
DIVISIONS, AND THEIR ANALOGIES TO THE VERTEBRATA AND
ANNULOSA.

(23.) The testaceous mollusks, or shell-fish, with few
exceptions *, are all marine, or, at least, aquatic animals,
soft and slimy in their nature, and without articulated
limbs, so that such as can move about, crawl upon
their belly, or swim in the water by means of the fin-
shaped lobes of their mantle. Independent of their
peculiar anatomical structure, and merely looking to
external characters, the most perfect of the testaceous

* Some of the parasitic groups, and the land shells, or slugs.

CHAP. ir. TESTACEOUS MOLLUSKS GENERALLY. 27

tribes are at once known^ either by being covered with
a hard shelly or^ if without this protection, by having
white blood, and being destitute of any processes which
perform the office of feet. Many, indeed, are fixed to
the surface of rocks, and other substances, where they
remain during life ; while others bore for themselves
internal cavities, or cells, in which they take up their per-
manent habitation; while the least organised are parasitic.
The similarity of some of the naked Testacea to XheAnne-
lides, or sea-worms, is so great, that the older naturalists
classed them together ; and even to this day we find a
whole division mixed up with the annulose Vermes, or
true intestinal worms. Let the student, however, bear
in mind that the animals of which we are now speaking
have neither joints to their bodies or limbs, nor any pro-
cesses, by which they can crawl ; and that their blood
is white, and not, as in the Annelides, red. Further-
more, the testaceous Mollusca never assume the shape
of the polypes ; nor do they possess that radiated form
and arrangement of filaments, which give such a pecu-
liar aspect to the Radiata. By these circumstances,
therefore, the observer may discriminate, in ordinary
cases, the characteristic marks of even the aberrant or
less perfect Testacea ; while he can be in no doubt as
to those which constitute the types. The perfection of
the class is seen in those animals whose body is pro-
tected by a hard calcareous covering, or shell, either in
the form of a twisted or convoluted cone, variously
modified, or composed of two principal valves or
pieces, more or less flattened, and united by a cartila-
ginous hinge. These shells are generally ornamented
with a variety of colours, and are frequently polished,
on their external surface, in the most beautiful and
perfect manner, by the animals themselves. The single
shells are called Univalves, and such is the periwinkle
and snail ; while the double are termed Bivalves, and
are exemplified in the oyster and the cockle. As
nature, however, proceeds from one to the other of
these groups by gradations of structure, we consequently

28 SHELLS AND SHELL-FISH. PART I.

find a few bivalves which assume the appearance of
univalves ; and others which, from the valves being
more than two, were called by Linnaeus Multivalve
shells. This term the great Swede applied not only to
those animals which really belonged to the Testacea, but
to the Cirripedes, or barnacles, which have nothing to
do with shells, properly so called. The term, there-
fore, is altogether objectionable, and will not here be
employed.

(24.) Such are the leading external distinctions of the
class of animals now before us. Their typical characters
are three ; two positive, the other negative. The first is
that of crawling upon their belly, yet without feet;
the second is their being covered with a beautiful calca-
reous shell, which is their constant habitation, and
which they have the power of enlarging, to suit the
progressive growth of their soft bodies ; the third is,
that, if deprived of this covering, they have not the
least vestige of rings or joints on their bodies : the
mouth, indeed, may be circular, and even the branchia,
but this is the only analogy they have to the Radiata.
In proportion as nature recedes from this typical
eminence, the structure of the shell becomes imperfect,
until, in the aberrant groups, the animal is either naked,
or is but partially protected by such a covering.

(25.) The Testacea, considered anatomically, may
be described as soft inarticulate animals, almost always
breathing by branchia, or lungs, which vary, however,
in the most singular diversity of ways both as to form
and situation ; this variation, moreover, takes place in
groups so closely related to each other in all other re-
spects, that it is perfectly clear no natural arrangement
can be founded upon the organs of respiration. The
least organised, in fact, such as the PlanaricB, &c., have
no branchia whatever ; so that they only possess two of
the characters of the class, — namely, a flattened disk or
disks, which act as a foot, and a total absence of joints
in their body. Their blood is white, and its circulation,
observes Cuvier, is always double ; that is, their pul-

CHAP. IT. TESTACEOUS MOLLUSKS GENERALLY. 2Q

monary circulation describes a separate and distinct
circle. As for their manner of reproduction, it is even
more variable and diversified than their mode of re-
spiration. In some, as with Gasteropoda, there is a
head with tentacula and eyes, either slightly or very
fully developed ; while in the Dithyra, or bivalves, all
these parts are wanting. Nearly all, however, have a
developement of the skin which covers their body, which
bears more or less resemblance to a mantle : but even
this assumes innumerable shapes; — sometimes it is di-
lated in the form of wing-like fins ; in others, as the car-
nivorous Gasteropoda, it becomes a syphon by which the
animal breathes. In the naked Testacea, the mantle is
simply membranaceous, coriaceous, or fleshy. It is, in
fact, utterly impossible to give such a general detail of
this diversified class, either in respect to external or
internal anatomy, as will not be subject to innumerable
exceptions at every step. All the modes of mastication
and deglutition, as Cuvier says, are found among these
animals ; their stomachs are sometimes simple, some-
times multiple. They also present examples of all the
modes of generation ; and the same learned anatomist
confesses that " these varieties of the digestive and ge-
nerative processes are found in the same order, and
sometimes in the same family." * Hence it inevi-
tably follows, that any system founded solely on any
one or more of these anatomical considerations, is sure
to be not only unnatural, but perfectly unintelligible
to the great bulk of naturalists, who are referred to the
soft parts of an animal which they never saw, and
cannot procure. In regard to the nervous system,
Mr. MacLeay has well observed, that " the most ge-
neral notion we can form, at present, of the nervous
system of the Molhisca, is, that the medullary collar, in
the more typical groups, must always, in its circum-
ference, contain four ganglions, which may either be
united two and two, as it is probable they are in the

* Griff. Cuv. p. 4.

30 SHELLS AND SHELL-FISH. PART I.

AcephaJa (Dithyra), or all four together, as in Tritonia.
The brain is always composed of two of these lobes,
which are generally connected, as in Aplysia, or some-
times separate, as in Haliotis and Patella : the remaining
two ganglions of the collar send off nerves to the or-
gans of respiration, &c., and are either united together,
as in the common slug and Patella, or are separate, as
in Aplysia." It is time, however, to quit these ge-
neralities, and enter into more definite details.

(26.) A rapid survey of the general peculiarities of the
class will not, how^ever, be here misplaced. We have said
that these animals have no distinct feet, or any organs
which, by forming appendages to their body, supply their
want. It is, however, customary — although the appella-
tion is certainly incorrect — to call that part of the body
which is next to the ground, and which is generally smooth
and flattened, the foot, when, in fact, it is merely the
belly, assuming only the office of a foot, and the shape
of a sucker : by alternately contracting and extending
this part, the animal moves forward, — slowly, indeed,
but very surely. The aquatic species are able to crawl
on marine rocks, even when the sea is greatly agitated ;
and every one knows the tenacity with ^vhich a slug
will adhere to the substance from wdiich we attempt to
remove it. This is at once explained by the smooth
disc of the belly acting as a sucker, like the tail of the
leech. This mode of progression is almost universal
among the Gasteropoda, or univalve shell-fish ; but, in
the bivalves, the body of the animal is frequently length-
ened behind, so as to assume a much more analogous
appearance of a foot than what we find in others. The
common cockle is one of the best, as it is one of the
most familiar, instances of this structure. Those who
have watched these animals at the ebb of tide, know
that they leap very frequently ; but on their method of
doing this two opinions have been given : some main-
tain that the foot, which, when protruded, forms a
sharp angle, is the chief organ made use of; while
others assert that this motion is caused by the sudden

CHAP. ir. TESTACEOUS MOLLUSKS GENERALLY. 31

shutting of the shelly valves, which produces a jerk.
In some very few instances among the typical Testacea,
as in the genus lanthina, or oceanic snail;, the animal
has a cellular organ attached to the belly, by which it
floats on the surface of the ocean, or sinks to the bottom,
at its own pleasm-e. The power of swimming, how-
ever, is chiefly found among the aberrant groups, such
as the cuttlefish (^Cephalopoda), the tritons {JVudi-
hranchia), and the Tectibranchia : the first of these
may really be said to possess Jins ; while the naked tri-
tons, no doubt, use the appendages of the body for the
same purpose. The power of adhesion is also diflferently
bestowed : in the cuttlefish and Planar ice, it resides in
the innumerable suckers which terminate the arms of
one, and are placed on the under side of the other. In
the limpet {Patella), the ear-shell (Haliotis), and the
chiton, it originates in the excessive breadth of the
disk upon the belly, which covers a surface equal to that
of the whole animal and its shell : so firmly, indeed,
do these genera adhere to the rocks or other substances
upon which they are found, that they can only be sepa-
rated by great force. It is among the limpets that we
find the power of locomotion at its lowest ebb ; for they
seldom remove far from the spot on which they were
born ; and many, from the shape of the shell corre-
sponding to the surface of the rock, appear never to
have done this : finally, in the genus Hipponix, we
arrive at a positive certainty that the animal is fixed,
because it adheres by a separate distinct plate, which
thus, in point of fact, renders it a bivalve shell. At-
tachment, however, is much more prevalent among the
bivalves, where we have entire families fixed to marine
substances, either by one of these valves, as the oysters,
or by a packet of strong fibrous threads. The attached
genera are much less numerous than the others, and are
affixed in different ways. Some, like the muscles {My-
tilus), are merely connected into little bunches or fa-
milies, by slender and scattered threads, strong enough
to keep them together ; others, as the Pinna', or wing-

32 SHELLS AND SHELL-FISH. PART I.

shells, are provided with a thick tuft of silky hairs,
called a byssus, which issues from one side only of the
shell, the other end being firmly attached to m.arine
bodies. In both these families, however, there is still
some slight locomotive power left; for, although the
animal does not, and probably cannot, quit the spot by
disengaging its byssus, and mooring itself to another
station, still it is not rendered absolutely motionless :
the waves can move the shell backwards and forwards,
and the fish may be compared to a horse or other
animal fastened by a very short rope, which, neverthe-
less, permits him to move his body and limbs. In the
Pholas, we have the next step towards an absolute ex-
tinction of the power of moving. These shell-fish have
no byssus, nor are they affixed by any other method ;
yet, soon after birth, they perforate the substance upon
which they have been deposited by the parent, and ex-
cavate for themselves deep burrows, or caves, exactly of
the circumference of their own shells ; and in these
hollows they take up their permanent residence. It is
not absolutely ascertained, indeed, that these boring
Testacea cannot quit their first habitation for another ;
but there are many reasons to authorise the supposition
that they live and die in the same which they excavated
when young, and which they have the power of en-
larging as they increase in size. A\^ithin such a narrow
compass, it is obvious that the Pholas is more a prisoner
than the Pinna or the Terehratula, because the walls
of its habitation keep it immoveable, so that even the
agitation of the waves cannot give it that undulating
motion enjoyed by the byssiferous families. Finally,
we come to such as are absolutely cemented by one of
their valves to rocks or stones^ or to each other : many
of the oysters are of this description ; but the most con-
spicuous are the different species of Chama and spon-
dyles ; several of which have the entire surface of one
valve fastened by a calcareous deposition to rocks, pieces
of floating timber, and to the bottoms of ships. It is,
consequently, in these families, and in the worm-shells.

CHAP. II. TESTACEOUS ANIMALS IN GENERAL. 33

that we have the most perfect examples of the sedentary
Testacea.

(27.) Although the head, where it exists, of the Tes-
tacea, is very different from that of vertebrated and
annulose animals, — inasmuch as it is not separated,
from the body by a neck, — it is yet to be distinguished,
in many groups, by the presence of tentacula, or feelers,
and by two or four black dots, which are generally con-
sidered to be the organs of sight : in proportion as we
advance from the PlanaricE on one side, and from the
chitons on the other, towards the cuttlefish, we find
the head and the eyes gradually assuming that definite
shape and structure which are so characteristic of the
vertebrated animals. Some of the tritons (^Nudi-
branchia), and all the bivalve shell-fish (^Dithyra), have
no indication of eyes, nor have the latter any obvious
head ; but in the Gasteropoda, or univalves, both begin
to appear. We see this in the garden snail, and in all
the freshwater and marine animals of this tribe. In
the StromhidcB and the Volutidcp, the eye is nearly as
perfect as that of the cuttlefish. From this group,
however, nature again recedes ; and in the Pteropoda,
although the general form is preserved, the head is once
more confounded with the body, and the eyes disap-
pear.

(28.) On the habits, food, and geographic distribu-
tion of the Testacea we can say but little w^hich is
applicable to all. The great majority are aquatic and
marine ; but two or three extensive families are found
only in fresh water. The land shells are exceed-
ingly abundant in species, and the gastropod worms
are parasitic in or upon other animals. It may be here
remarked, that all the bivalves (Dithyra) are aquatic,
but that the univalves inhabit the different situations
just enumerated. The food of all these creatures varies
according to their own particular races. A large num-
ber (forming the phytophagous gastropods) feed almost
only upon living vegetables, either terrestrial or aquatic,
— as the snail of our gardens, and the periwinkle of our

D

34 SHELLS AND SHELL-FISH. PART I.

coasts ; but a still greater assemblage are carnivorous, —
devouring not only living, but dead, animals, and even
attacking other tribes of their own class. It Avould be
interesting to know in what manner nature has pro-
vided for the sustenance of such as are permanently
affixed to one spot. Some of these have divers me-
thods of exciting little currents in the water, by Avhicli
means fresh portions of it are brought to the mouth,
along with which such minute animals or fragments of
vegetables as are adapted for food are secured. The
branchipodous bivalves, like the TerehratulcB, although
sedentary, are provided with long fringed processes,
which are, no doubt, employed to capture their prey,
in a similar manner to the arms of the Cirripedes, or
barnacles; while the cuttlefish (C6';^//«/o/)06?a) and the
Tritonia swim about in search of marine animals
weaker than themselves. In regard to their geographic
distribution, much might be said, did we not fear
being drawn into longer details than our space would
permit. It will be only necessary to observe in this
place, that the geographic range of the Testacea is not
so wide or uncircumscribed as the generality of authors
assert. Tropical latitudes, as usual, display a greater
variety of species, and a larger number of individuals,
than those seas which lie under temperate or frigid
skies. The Testacea of Europe are as distinct from
those of America, as the latter are from those of Aus-
tralia, Africa, or Asia. We have already illustrated
this fact in that part of our series devoted to the geo-
graphic distribution of animals ; and it may be safely
asserted that the grand features of zoological geography
are as conspicuous in this class of animals, as in any
other.

(29.) The great natural divisions of the testaceous
Mollusca appear to us to be these : — The first, or
pre-eminently typical, are unquestionably the Gastero-
poda, or spiral univalves, whether we consider the
comparative perfection of their internal or their external
structure. The second, or sub-typical class, is com-

CHAP. II. PRIMARY DIVISIONS OF TESTACEA. 35

posed of the Dithyra of Aristotle^ or the bivalves_,
whose structure is less perfect^ but which are in like
manner protected by a regularly formed, and often
richly coloured, bivalve shell. The third, or aberrant
group, as usual, comprehends three : 1 . The Nudibran-
CHiA of jVI. Cuvier, or the naked Gasteropoda ; 2. The
Pa renchymata, or intestinal Testacea; and, S.TheCE-
PHALOPODA, or cuttlefish. We shall first slightly glance
at the leading characters of each of these classes, and
then endeavour to trace their analogies to other animals.
(30.) Under the name of Gasteropoda, we retain
the greater number of Cuvier's divisions*; but the most
typical consists of the univalve or spiral Testacea, whose
body is protected and generally coveredt by a calcareous
shell : the head, although not assuming a very decided
shape, is always present, and is, in almost all instances,
at once distinguished by having two or more tentacula,
assuming the appearance of the antennse and the palpi
of insects. All the true Gasteropoda possess the rudi-
ments of eyes ; in the generality, these organs appear
in the form of black specks, either at the tips of the
longest pair of tentacula, as in the common snail, or at
their base. "We thus find that the true Gasteropoda
possess four primary characters, — the power of crawling
upon their belly, the possession of a head and eyes,
and, finally, the protection of a shell. Those which
are most remote from the point of perfection, and
which form the links of connection to other classes (as
the Tectihranchia on one side, and the Nudihranchia
on the other), have some one, or, perhaps, two, of these
characters either lost, or but very imperfectly developed;
these, in short, are the aberrant groups, and must never
be looked to for the right understanding of the class to
which they belong. The slug, for instance, has no
shell, or merely the rudiments of one ; yet it crawls
upon its belly, it is furnished with a distinct head and
even jaws, it has four tentacula, and a pair of rudi-

* As the Heteropoda, Cydobranchia, Scutibranchia, and Pulsnonaria.
t Except in Limax, Sec.

D 2

36 SHELLS AND SHELL-FISH. PART I.

mentary eyes ; it presents us, in fact, with all the cha-
racters of a testaceous gastropod, except one, — that of
being covered by a shell. In the Tectihrunchia, again,
v/e have a group still more remote from the typical
structure ; for many of these have the mere rudiments of
a shell covering a small part of their body, and they swim
as much as they crawl. Yet their evident connection to
the VolutidcB (by means of the Cyprcfidcp) on one side,
and to the chitons on the other, points them out as truly
belonging to this order.

(31.) The DiTHYRA of Aristotle, or bivalve shells,
form the next, or sub-typical division. This comprises
animals destitute of an apparent head, but still inclosed
in a shell, and still moving on the belly. There is not,
however, in this latter part, any flattened disk ; and the
shell, instead of being spiral, is generally composed of
• two pieces, or valves, joined together by a horny liga-
ment. The Dithyra, moreover, are further distin-
guished by having neither tentacula, nor the least
vestige of eyes. We meet with some, indeed, as the
Chelisom(jP, which have no external shelly covering ;
and others, where the bivalve shell is inclosed in a
tube, as the family of TuhuUhranchia, — thus assuming
the disguise of a univalve. But these remarkable de-
viations are few, and point out, as we have just men-
tioned, the extreme limits of the tribe.

(32.) The NuDiBRANCHiA, or tritons (part of the
naked Gasteropoda of i\I. Cuvier), form the third of
our principal divisions, and are all no less strongly cha-
racterised. Destitute of any covering, and presenting
a marked peculiarity in their external branchia, their
appearance is so very different, that every unprejudiced
observer cannot but wonder they should, up to this day,
have been mixed up with the true gastropod shell-fish.
These animals, in fact, are entirely flattened, naked,
soft, and gt^nerally ornamented with beautiful colours ;
they move about by means of their foot, or concave
imderside of their beUy, in the depths of the ocean ;
on the sides, and often on the upper part of their

CHAP. II. PRIMARY DIVISIONS OF TESTACEA. S/

bodies, they are provided with processes like filaments ;
and there are generally two very short tentacula, at the
teimination of which are two black dots, representing
the eyes ; in this respect they certainly show a relation
to the Gasteropoda, but then their respiratory organs are
totally different. The Nudihranchia, in short, as their
name implies, have these organs arranged on the upper
part of their body, in the form of a rosette, so as
exactly to resemble a bunch of vine leaves, whose stalks
form a common centre. One, out of the three great
characters of the typical Testacea, is yet retained, — for
the animal crawls upon its belly; but has lost the other
two, — since they have neither a distinct head nor shell.
The tritons and^ dories have the additional power of
swimming and crawling on the surface of the sea, with
their foot uppermost : in the former case, they are pro-
pelled both by their branchia and the thin sides of their
body, which act in the manner of fins.

(SS.^ Our next group is composed of those simply
constructed Testacea, which represent the Acrita in this
class, and which have hitherto been arranged among
that heterogeneous assemblage of animals, named Intes-
tina by Cuvier. Having now arrived at the most re-
mote limits of the Testacea, we find, in the order before
us, nothing more than faint indications, or, in other
words, the elements, of that organisation which belongs
to the typical tribes. The flattened disk-like form,
indeed, of the dories and the tritons is fully preserved
in the Planarice, and even in some of the Fasciolce ;
but the branchia, hitherto so variable, now become less
and less apparent, and finally disappear. Some of these
animals inhabit the water, but others are internal or
external parasites ; and this change of habit takes place
in groups so intimately connected in all other respects,
that we become convinced of the propriety of retaining
them in one and the same assemblage. Hence, without
venturing to determine the precise limits of the animals
which really belong to this class, we feel no hesitation in
considering a large portion of Cuvier's Parexchymata,

D 3

38 SHELLS AXD SHELL-FISH. PART I.

or intestinal worms, as truly belonging to this class.
Our reasons for this will be again adverted to. At
present, it will be sufficient to state, that these animals
are totally distinct from the true Vermes, where the
body is composed of articulations more or less developed,
and which consequently form the corresponding group
in the annulose circle. Nearly all of these imperfect
and obscurely known animals, however, partake of
the general character of the Testacea, in crawling or
adhering by their belly, beneath which, — as in the
Fasciolce, — there are cup-shaped disks, or suckers.
Analogous, in every respect, to these, are the arms of
the next tribe.

(34.) In this manner, then, are we conducted to
the fifth and last tribe of the testaceous Mollusca,
— namely, the Cephalopoda, or cuttlefish. But
this is done by the intervention of a group of ani-
mals, almost as simple in their organisation as the
intestinal tribe last mentioned. Some of the Ptero-
poda, in fact, like the Parenchymata, are without head,
branchia, eyes, or any external members ; even the fin,
so universal among the Firolce, is wanting in such
genera as Timorenia and Monojjliora : but these, or
any of the Hetei'opoda, are not the animals to which
we must look for the typical characters of the group
before us. The types of the Cephalopoda, in fact, are
the most highly organised, and, therefore, the most
perfect, of all the Testacea. The appearance of these
animals is strange and grotesque in the extreme.
Their body is soft and pulpy, having the limbs ar-
ranged in a circle round the mouth ; these limbs per-
form all the offices of feet, arms, and tentacula, and,
in many genera, they are used also as fins. The head,
which, in all the other Testacea, is either wanting or
but slightly developed, is here large and conspicuous ;
while the eyes are so clear and distinct, that they re-
semble those of a vertebrated animal ; the mouth, from
the arrangement of the limbs, or, as we shall term
them, the arms, is consequently in the centre, like that

CHAP. II. THE CEPHALOPODA. 3Q

of a radiated animal ; and the sides of the body are
either slightly dilated into a distinct fin-shaped mem-
brane, or are so thin that it can be vised for the same
purpose. In size, the cuttlefish are by far the largest
of all the testaceous Mollusca ; they are, indeed, the
giants of invertebrated animals ; for, if the accounts of
the old Indian voyagers are true, there are some of
such enormous dimensions, that they seize upon the
divers, entangle them in the folds of their serpent-like
arms, and finally devour them. These stories are, no
doubt, exaggerated ; but we have, ourselves, seen many
of such a size, caught on the shores of Sicily, that two
would be a good load, — their arms being as thick as
those of a man. Most of these animals now in exist-
ence are naked; but in the former aeras of the world,
there appears, unquestionably, to have been a most
numerous and gigantic race, which had a part of their
body protected by a spiral shell, rolled in the form of
a disk. Ancient revolutions of our globe, however,
have swept away nearly the whole of these testaceous
monsters, leaving in the Nautilus almost the only
genus hitherto found in a recent state. It is among
the existing genera that we find a horny or calcareous
plate, which supports the body, and is altogether in-
ternal. This, as before remarked, is the first indication
of the vertebrated structure among molluscous animals ;
and hence, nearly all zoologists place these animals
immediately in junction with the Vertehrata : or what
is the same thing, consider them the last in the series
of the Mollusca. It thus appears, on a general view of
the whole of the testaceous Mollusca, that they may be
thus concisely described : — The typical and sub-typical
divisions crawl, and are covered with calcareous shells ;
of which the first is univalve, and generally spiral,
while that of the other is bivalve and simple. The
aberrant group, on the contrary, have no calcareous
covering, but are externally naked, and they have the
faculty of swimming added to that of crawling. Thus,
we cannot but adm.ire the simplicity and beauty of the

D 4

40 SHELLS AND SHELL-FISH. PART I.

distinctions which nature has thus stamped upon the
primary groups^ infinitely diversified as they are in all
other respects.

(35.) Our next object is, to show upon what grounds
our conviction rests, that these orders form a circular
group, more or less perfect. It is hardly necessary to
apprise the zoologist, that in this class of animals, above
all others, the effects of those revolutions in our globe,
which have nearly exterminated so many races of animals,
are most apparent. It appears, at first, difficult to say
whether this destruction has been most extensive
among those whose hard vestiges yet remain in a fossil
state, or among such as, being entirely soft, have alto-
gether disappeared, and " left not a wreck behind."
Our own opinion, however, is decidedly in favour of
the latter supposition. Four fifths of the testaceous
Cephalopoda have certainly disappeared ; yet their shelly
portions, abounding in incalculable quantities in all the
older formations, are yet sufficient, with the aid of the
few species now existing, to give us some general idea
of the chain of continuity : but, among the Nudihran-
chia and the Branchiopoda, whole families seem to have
disappeared : such of the latter, indeed, as possessed a
hard covering may be judged of by their shells; but
in what way their union was effected with the existing
races of Dithyra it is altogether impossible to judge.
The Nndibranchia, again, are allowed by all naturalists
to constitute a distinct tribe ; and yet it does not con-
tain more individuals, or a greater diversity of structure,
than may be met with in any one of the numerous
families of the gastropod Testacea. Now, it must be
remembered that these are all soft, and often sub-
gelatinous, animals, without any hard or durable parts
whatsoever ; so that all that have only existed in former
periods of our globe, have been exterminated both in
life and substance, no indication whatever remaining
that they ever had existence. Upon what ground,
then, it may be asked, do we take for granted that they
have ever been among the things that were ? and what

CHAP. II. ON EXTINCT ANIMALS. 41

reason is there to suppose any one has heen abstracted
from the living races ? To this we would simply re-
ply^ that such a conclusion is home out by every prin-
ciple of analogical reasoning. Throughout the whole
of the vertebrated classes^ it is solely in groups where
congenial forms have been found in a fossil state that
we find the gradations in the living series broken and
interrupted. Very few such interruptions^ for instance,
occur in the class of birds, and they are so slight as
hardly to merit such a term : this fact, in our esti-
mation, at once accounts for the extreme rarity of the
remains of birds in a fossil state; scarcely any having
been exterminated. The living series is, consequently,
almost perfect. Not so, however, among the reptiles.
In that class there is an entire order (the Elaniosaures)
which has been so absolutely exterminated that .not a
living example remains ; hence, but for the fossil bones
of the Ichthyosaurus, Plesiosaurus, &c., there would not
merely be a wide and violent disruption of the reptile
series, but an absolute impossibility of forming even a
rational conjecture as to its course ; at least, in that
dissevered portion which these extinct reptiles actually
fill up. But we will bring this theory more home to
our present purpose. There is no circular series of living
Testacea, wherein is found every modification of form
necessary for unquestionable connection, more perfect
than that of the predaceous shell-fish {^Gasteropoda
Zoophaga): hence the extinct fossil species are not only
rare, but they nearly all belong to genera now living, and
therefore termed recent. Any one family in this group,
in short, contains more species and genera than are now
known in. the entire tribe of Nudihranchia, or in the
family of Branchiopoda. What, then, are the legitimate
deductions from these facts ? We must take our choice
of these two : — Either we are to suppose that Nature at
first made these latter groups as imperfect as they now
are, while all others, abundant in recent species and
forms, are perfect ; or that she has removed from the
creation most of those links which would fill up the

42 SHELLS AND SHELL-FISH. PART I.

intervals between the existing races^ and which^ were
they now living, would render all her groups equally
perfect. All analogy, drawn from theory or from facts,
compels us to embrace this latter conclusion. Perfec-
tion in all His works is one of the attributes of the
Creator; it is therefore clear that nothing imperfect
could have entered into the plan of the creation.

{36.) An attentive consideration of the vertebrated
classes of animals, both collectively and separately, will
convince the philosophic inquirer, that in every instance
nature begins, as it were, from a small rudimentary
group, — a point, so to speak, in existence, — which
seems to contain such animals as have the very least
affinity to those which, standing at the head, exhibit
the typical structure ; they possess only the rudiments
of the perfection to which they gradually, but ulti-
mately, lead ; and their structure is often so exceed-
ingly simple, that, in such as may be termed the germ,
even these rudiments are scarcely perceptible. One such,
or at most two, are all we can expect to find. Hence
it follows, that such imperfectly formed beings, although
found in every large division of animals, must neces-
sarily possess a strong resemblance to each other ; al-
though, in reality, they belong to classes widely distinct,
when we trace them up to their full developement.
This theory, although in some respects not new, — for it
has been tacitly or indirectly admitted in a general way,
— has never received that attention it deserves. It has
consequently resulted, that nearly all those authors who
overlook the important differences between analogy and
affinity, have naturally supposed these rudimentary
animals, as they may be called, were closely connected
to each other hy affinity, and have accordingly classed
them as such. This seems to be the true cause why we
have such a heterogeneous assemblage of animals under
Cuvier's class of Intcstina, and even in those of Mac-
Leay's Acrita and Vermes. They agree, indeed, in one
respect, — that is, of being the most simple of all others
in structure ; but this is altogether more a negative

CHAP. II. OX RUDIMENTARY TYPES. 4S

than a positive character, and altogether fails of that
accuracy, to he desired. Besides, it is quite evident,
that, if the several threads of affinity — collected together
in the above-mentioned groups — had been followed
up, each would have been found leading to totally dif-
ferent divisions of the animal kingdom. The Acrita,
in fact, as at present constructed, is such an ill-defined
group, that some writers think they are bound to bring
"within its limits the Medusas, and many of the most
perfect radiated animals ; so that, if this is allowable,
there is no reason whatever for excluding the annulose
Vermes, the cephalopodous Foraminata, and the mol-
luscous Parenchymata. It may be thought somewhat
premature to state these objections, seeing that we have
not yet attempted to substitute any other arrangement
of the Acrita * for that which we hold to be a false one,
although proposed by the very founder of the class. But
we are all aware, that the perception of an error, and
the power of rectifying it, are not inseparable. Our
researches may have proceeded quite far enough to
satisfy us on the former, and yet may not have extended,
or have been sufficiently matured, to accomplish the
latter. It is precisely in this predicament that we now
stand. Our researches in the true Acrita, the Radiata,
and the Annulosa, — have advanced sufficiently far to
convince us of the fundamental truth of what we have
just advanced. The subject, however, is of such vast
importance to the first principles of natural arrange-
ment, that we may well devote to it a few additional
remarks.

(37.) If we look to the vertebrated circle of animals,
■we find that many of the amphibians are the most
simply constructed of all the Vertehrata ; the Amphiuma
are worm-like salamanders, having the body excessively

* We trust this investigation may be taken up by the only naturalist
of this country who has devoted himself to the study of the soft Mollusca,
and from whose talents, experience, and zeal, we may expect so much —
Dr. Johnson. It is a serious loss and inconvenience to science, that the
numerous and truly valuable memoirs of this accomplished malacologist
are now scattered in periodicals and magazines, almost hid in a mass of
temporary and trivial articles.

4-4 SHELLS AND SHELL-FISH. PART I.

lengthened, and the legs and feet so small as to be rudi-
mentary ; while the Ccecilia have neither feet nor bran-
chia, and sometimes are without eyes. This group,
therefore, among the Vertebrata, is precisely the sort of
point or nucleus from which diverge two distinct series
of animals : the one leads to the serpents, or reptiles ;
the other branches out, in an opposite direction, to the
fishes ; but both these ultimately meet in the ostrich,
which exhibits a union of the bird and the quadruped.'
Each of the five divisions of the vertebrated circle afford
parallel instances ; so that we invariably find the most
aberrant group is always that which is the least or-
ganised ; just as is the class ^cnto in the whole animal
kingdom. The annulose Vermes, as the tape-worms,
and other intestinal creatures stiU more simple, forming
the Tcenioides of Cuvier, are, in the annulose circle,
precisely what the amphibians become in the Vertebrata,
They exhibit the first simple outlines /3f that structure
which terminates in the painted butterfly and the sa-
gacious bee ; and, when nature has reached these points
of perfection, she returns, by slow degrees, through the
Annelides, or red-blooded worms, to the same point,
although by a different route. Such, also, will be
found her course in the testaceous class. The Paren-
chymata, or parasitic Mollusca, may be considered the
first indistinct and incipient developement of the Tes-
tacea, — the point from which nature diverges towards
the phytophagous gastropods on one side, and to the car-
nivorous gastropods on the other, until both these series
meet together, and form a perfect circle in the family
of Turhklce. It will subsequently appear that this re-
markable principle of variation is not merely confined
to the first great circle formed by the Testacea ; it is
abundantly evident in its primary divisions — nay, in
some instances, even in its families. Among the Ce-
phalopoda it is particularly strong. All waiters who
have mentioned the Foraminifera, so admirably and
beautifully investigated by D'Orbigny, hesitate not to
place these microscopic atoms in that order, although it

CHAP. II. ON THE TYPES OF ACRITA. 45

contains the most perfect Mollusca in existence. And
yet the organisation of these beings is so very simple,
that, if no regard be paid to the difference of analogy
and affinity, they might be placed next to the animalcule?
in the class Acrita. The chitons among our Gasteropoda,
and the genus Chelisoma in the circle of the Dithyra,
are further instances : both are the most simple and
slightly organised of their separate groups ; and both,
in this respect, as well as in the shape of their bodies,
are prototypes of the PlanaridcB and Fasciolce, among
the parasitic Testacea. But the universally confessed
affinities of the naked slugs to the testaceous snails brings
this theory home to the personal cognisance of every
naturalist. Some of these creatures are so small, ge-
latinous, and so little organised, that, but for their in-
disputable and immediate affinity with the beautiful
land shells of the Helix race, no one would think of
placing them in the same order, much less in the same
family ; and yet every zoologist sees that such is their
natural situation. Hence these naked slugs become
nothing more than prototypes of the PlanaricB and
Fascioltp ; related, ilideed, to them by analogy, but
without any connection whatever in regard to affinity.
The extraordinary genus Herpa, one of the splendid
discoveries of Guilding (which will be subsequently
noticed), carries this analogical resemblance to the highest
pitch ; so that, but for the discriminating acumen of
that profound observer, we should have been tempted,
without seeing the animal, to consider it was an actual
type of Planaria, in the disguise, only, of a Limax. On
these, and numerous other similar facts resulting from
the analysis of this class, we hesitate not to place a por-
tion of Cuvier's intestinal worms as the most aberrant
order of the testaceous Mollusca. We wish to follow
nature, and nature only ; perfectly satisfied, from past
experience, that, however various and conflicting may
be the comments of her interpreters, she has pursued but
one course, and but one plan, in her system of animal
variation.

46 SHELLS AND SHELL-FISH. PART I.

(38.) We may noAv'^ commence a rapid survey of
the course by which the class before us resolves itself
into one great circle, the furtner details of which will
be noticed under the several chapters devoted to the
chief divisions. We have already expressed our con-
viction that the germs of the Testacea exist among the
various discordant animals comprising Cuvier's Paren-
chymata, but it is by no means clear which is the pre-
cise point where the very first indication of this struc-
ture is seen ; this cannot be cleared up until the Acrita
and the Radiata, not to mention the annulose Vermes,
have been sufficiently analysed. Without speculating,
therefore, on the probability or possibility of such
genera as Echinorynchus and Herula being the rudi-
mentary type, we may safely point to the Tremadotes
of Rudolphi, and the, whole of the second family of
Cuvier's Parenchymata, as containing the vermiform or
most aberrant types of the class before us. These, in
fact, are nothing more, in one sense, than naked gas-
teropod Mollusca, crawling upon their bellies, or ad-
hering by means of cup-shaped suckers, which are
analogous to, and perform the same office as, the single
disk of the more perfect testaceous gastropods. Some
of these, like the FasciolcB of Linnaeus, are feeders on
the internal parts of animals, and adhere, by means of
these suckers, to the viscera of quadrupeds, birds, and
fish ; others, as Cyclocotyles of Otto, are external para-
sites ; while the true PlanaridcE are entirely free^ and
swim about in the water. Now, it is from these
animals that nature throws out, as it were, two lateral
branches. One of these, emanating from the Planaridce,
conducts us, in the most beautiful and graduated man-
ner, to the NudibranchUi ; the other, departing from
the Fasciola, leads us, by means of such genera as
Menostoma of Blainville, and Hectocotylcs of Cuvier, to
the no less vermiform animals among the Ftrolcp and
other finless Hetcropoda. This latter branch, however,
we shall leave after this indioation, and pursue the for-
mer. Commencing, then, with the Planarida', we see a

CHAP. II. GREAT CIRCLE OF THE TESTACEA. 47

family as much diversified as any of the naked Testacea,
but which, at present, remains almost as a genus. In
it are found representations of nearly all the onisciform
Molluscttj as Sigaretus, Chelisoma, Chelinotus, Chiton,
and numerous others : the interesting genus Tristorna
of Cuvier, contains the first rudiments of branchia, — for
such do we consider that ^' ramified circular vessel in
the parenchyma of the body/' the nature of which, as
that learned anatomist conceives, " it is difficult to
determine." * This, together with the many beautiful
and interesting forms discovered and figured by Riip-
pell, establishes the union of the PlanaridcB and the
DoridcE — in other words, the two orders of Parenchy-
wm^a and Nudihranclua — in the most perfect manner.
^Ve pass, then, from these latter, to the Branchiopoda, the
first tribe in the order of bivalves. From this point our
course is plain : Anomia connects them with the Ostrcea
and other Dithyra without siphons ; while these latter
are connected to the more typical bivalves, where these
organs are fully developed, by means of Chama and
Hippopus. We quit the perfect bivalves for such as
are tubular, and hence almost univalve shells, through
the Myadce and Solenidcp, and thus reach the Teredince.
By this latter family, the path is smoothed to the
terminal series of the Dithyi'a, — namely, the Tuhiili-
hranchia of Cuvier, — where we have the singular union
of a gastropod mollusk inhabiting a tubular shell.
The two typical orders being thus united, we enter^ at
once, among the spiral or testaceous Ga^Ye/'opocfa, — that
group, in short, which stands at the head of the entire
class. Beginning with the Scutihranchia or Patellides,
as the least organised of these univalve animals, we see a
gradual developementof the spire take place in the Halio-
tidce, Trochidce, and HelicidcB ; until, in the Tiirhidce,
we have a union of the phytophagous and the zoophagous
gastropods. The old genera of Melania in one, and
Cerithium in the other, effects this union, and conducts
us at once to the StromhidcFy MuricidcB, and, finally, to

* Griff. Cuv. xii. 473.

48 SHELLS AND SHELL-FISH. PART I.

the Volutida. The transition from these to the CyprmdcB
is no less clear than that from the Cyprceidce to the BuUcBj
— the latter being the most perfect of the TectihruncMa.
In some of these half naked gastropods, the foot-like
disk of the belly is reduced to very small dimensions,
while the two lobes of the mantle become so dilated
that they are used as fins. In this manner does nature
leave the Gasteropoda, and unites them to the swim-
ming order of Cephalopoda, — the first tribe of which is
the Pteropoda. The straight cylindrical case of some of
these singular animals, few in number, but highly in-
teresting, prepares us for that extinct tribe of cuttle-
fish of which the fossil Belemnites, in all probability,
formed the type : from these to the spiral Cephalopoda,
the passage is so easy, that it can be traced by the
shells alone; and then, with the assistance of Argonauta
and C{irinaria, we at once reach the Heteropoda. The
affinity between some of these simply constructed
animals and the aberrant Parenchymata has already
been intimated. Thus we find that the two lateral
series which branch off from the Planaridce meet toge-
ther in the Turhidce, and complete the circle of the
whole class.

{39-^ Ii'i thus tracing the course of the circle of the
Testacea, the zoologist, versed in the circular theory,
will perceive we have taken no notice of the most aber-
rant groups in each order, — and this, because it would
have incumbered, without necessity, the simple ex-
position of the union of the orders themselves. He will
also be aware that it is by these particular groups that
each order forms a circle of itself. This important pro-
perty will, of course, be adverted to when we come to
treat of each order separately. In the mean time, we
shall now compare the orders of the Testacea with such
other groups of the animal kingdom as appear calculated
to render their analogies more comprehensible to the
ordinary reader. Our first comparison will consequently
be with the vertebrated anhnals.

CHAP. II. ANALOGIES OF THE TESTACEA. 49

Analogies of the Testacea to the Vertebrata.

:^ Orders of the Testacea. Circ\e oC the rerfebrata.

Gasteropoda. Qiiaorupeus.

DiTllYRi. JilRDS.

NlJDlBRANCHIA. REPTILES.

Parenchvmata. A:mphibians.

Cephalopoda. Fishes.

(40.) The reader will bear in mind that, hitherto, we
have spoken of relations of affinity ; but our present
business is with analogies, or mutual representations.
Setting aside, therefore, all we have already advanced,
we accordingly find that the best modern zoologists place
the Dithgra, or bivalve shell-fish, close to the Gaste-
ropoda, or univalves, upon the same principle as the
birds, in the other column, follow the quadrupeds.
This arrangement, at the very first, seems to carry with
it an appearance of being natural, because we thus find
that both the Dithgra and the Ai'es are the sub- typical
divisions of their own circles. But this parallelism,
although highly satisfactory, is not of itself sufficient ;
we must look further, and inquire whether these groups
actually agree in any particular circumstance of struc-
ture, common to both. Now, every one knows that,
among the many things in which quadrupeds differ
from birds, their mode of feeding is altogether dissi-
milar. Quadrupeds are provided with jaws bearing
teeth, with which the food is masticated before it enters
the stomach : birds, on the contrary, have the jaws
dilated into a snout-shaped bill, and teeth are alto-
gether wanting. The rapacious birds (Raptores), in-
deed, which typify the quadrupeds, may be said, in some
degree, to masticate their food ; but by all others it is
sucked into the mouth, the effects of mastication being
supplied by the stomach. If we inquire into the modes
in which the typical Gasteropoda and the Dithyra take
their food, we find that it is precisely conformable to the
above variation. The most typical of the spiral shell-
fish (^Gasteropoda), like quadrupeds, are provided with
fleshy lips and corneous jaws, varied, as M. Cuvier truly
observes, into numerous modifications ; while in many
genera (on the same authority), the inside of the cheeks

E

50 SHELLS AND SHELL-FISH. PART 1.

are provided with reflected teeth^ to aid deglutition.
On turning to the Dithyra, however^ we find a totally
different structure : the mouth has neither lips^ jaws^
nor teeth, but is " a simple aperture" entering into the
stomach ; the food, in short, is sucked in, and is
swallowed entire, as it is by birds : so that, strange as
it may appear, the two most perfect groups of the
testaceous Mollusca exhibit, generally speaking, the
same mode of feeding as the two most perfect groups
of vertebrated animals. It seems hardly necessary to
strengthen analogies so beautiful ; yet we cannot omit,
in this place, that there are not wanting indications, even
in the structure of the bivalve shell-fish, to remind us of
the peculiar, character of birds : in these latter, the sides
of the body are enveloped by two broad and expansive
wings ; in like manner is the body of an acephalous
bivalve enveloped on its sides by the ample folds of its
cloak or mantle. Yet neither of these appendages occur
among the typical quadrupeds and the typical gastro-
pods.* But it is time to pass on to the Nudibranchia
and the reptiles. Do these represent each other .f* and
in what manner ? We will set aside that forbidding
appearance which these reptile-looking Mollusca possess ;
and which indicates, at first sight, some analogy to the
true reptiles, because this is a mere m.atter of opinion :
not so, however, is the circumstance that both these
classes crawl upon their belly, and are destitute of any
limbs. The tritons, in fact, have no real feet ; and
the serpents, standing at the head of the ReptUia, are
eminently distinguished in the very same way. The
analogies of the Parenchymata, in general, have been
sufficiently explained ; it is, therefore, only necessary
to observe in this place, that the Amphibia are the most
imperfect of the vertebrated animals, just as the Paren-
chymata are the most simply constructed, and the fur-
thest removed from the typical Testacea. Their short,
thick, and broad form reminds us again of the onisci-
form type of annulose animals. We have now only to

[* Except in such as are aberrant in their ovv-n circles, as the Volutidce, &c.

CHAP. II. THE TESTACEA AND ANNULOSA. 5\

compare the two last groups in our table^ — namely^ the
Cephalopoda and the true fishes. These agree in con-
taining the largest individuals of their respective circles,

— except, indeed, the fish-quadrupeds, or whales. Both
swim by means of their fins, which in both groups
represent the arms and feet of other animals : the eyes
of both are almost perfectly the same : the old natu-
ralists, indeed, who were more led by general appear-
ance than by anatomical peculiarities, considered the
cuttlefish and Loligo as true fishes. It may, therefore,
safely be said, that, if we are to decide which division
of the Testacea bears the greatest resemblance to fishes,

— whether as regarding outward form or internal or-
ganisation,— no one would hesitate to name the Cepha-
lopoda as that group.

(41.) In further confirmation of this arrangement,
we will take a slight glance at the classes of annulose
animals (which are to form the next volume of our
series), and compare them with those of the Testacea.
It is scarcely necessary to dwell upon the two typical
groups of each, — the Gasteropoda and the Ptilota,
which stand as the pre-eminent ; and the Aptera and
Dlthyra, as the suh-typical classes : when, however,
we proceed to the aberrant groups, we find the analogies,
as in all other instances, much stronger. How beauti-
ful, for instance, do the Annelides, or red-blooded worms,
put on the very aspect and form of the Nudibranchia ;
a naturalist, looking to the outward appearance of these
creatures, — their naked body, often covered with tufts
of plumed or ramose appendages, assuming sometimes
the likeness of horns, filaments, or tentacula, — would
even entertain a suspicion that they really belonged to
the same class of animals. No wonder, therefore,
that the older naturalists, and even Linnaeus, mixed
them together ; since the circumstance of one having
red, and the other white, blood, was not, in those days,
considered a matter of much importance. Now, this
analogy, which is perhaps one of the most striking in
the whole of the animal creation, is highly important

E 2

52 SHELLS AND SHELL-FISH. PART I.

when viewed in reference to any doubts which may
hang over this group^ from its isolated situation on one
side of its own circle. The strong analogy between the
Parenchymata and the annulose Vermes has induced
all writers to blend them together^ even up to this
day ; the one being the most imperfect of all the Tes-
tacea, as the other is of the Annulosa. Passing on to
the relationship between the cuttlefish {Cephalopoda)
and the barnacles {Cin'ipeda), we are struck with a
resemblance much stronger than would be supposed
to result from a mere relation of analogy. In both
these tribes, the mouth is surrounded by long slender
arms, employed to catch their prey : both contain ani-
mals whose softer parts are protected by shells. Never-
theless the Cirripedeshsive no more to do with MoUusca,
than the latter have with those crabs, which, like the
genus Cyclops, are naturally enveloped in bivalve shells.
To the Radiata, again, the analogy of these tribes is no
less apparent ; for, as both have the organs of motion
arranged around, or rather radiating from, their mouth,
which thus becomes the common centre, they have, to
all outward appearance, the essential characters of ra-
diated mollusks.

(42.) Assembling all the groups thus brought into
comparison in the following table, we shall see, at one
glance, the mutual relations they present in their com-
ponent parts.

Analogies of the Test acrovs Mollusca to the Annulosa.

Analogical Characters.
"Typical, the most hif;hly organised;'

Tribes of ,« 7 • ? /-.i j Classes of the

-r „/^^,^ Analogical Characters. j., ,. ; ^

festacea. ^ Annulosa.

rTypical, the most hif;hly organised ;T
Gasteropoda. < head distinct, with long antennae or >Ptilota.
t tentacula. j

rHead indistinct, confounded with theT
DiTHYRA. -j thorax, or altogether wanting; no>APTERA.

C antennte or tentacula. J

M.Tn,T,DAi«r'«ii yCiskof the belly flattened, and often 7 4^,„^,,„^,
NUDIBRANCHIA. ^ performing the olhcc of a foot. j Annelides.

TThe most simple in their organisation, 1
Parenchymata. •< naked, and crawl upon tiieir belly ;> Vermes.

C no perceptible branchia. j

f Mouth surrounded by long tentacula,^
Cbphalopoda. < or arms ; soft parts of the body ge- ^Cirripeoa.

C. ncrally protected by a shell. j

CHAP. 111. THE ORDER GASTEROPODA. $3

So singularly do the Aptera represent the Dithyra
by the head (as in spiders and scorpions) being con-
founded with the trunk, that they might even, without
any violation of propriety, be termed acephalous in-
sects. But we presume enough has now been said on
this set of analogies, to satisfy the unprejudiced reader.
And having now sufficiently dwelt upon our arrange-
ment of the Testacea as a class, we may at once pro-
ceed to the details of the tribes in which the whole
are here arranged.

CHAP. III.

ON THE ORDER OF GASTEROPODA, ITS PRIMARY DIVISIONS, AND
THE CHARACTERS AND ANALOGIES OF THE MlIRICIDjE AND
THE TURBINELLID^.

(43.) The gastropod shell-fish, as we have already
shown in the preceding pages, stand at the head of the
testaceous Mollusca, — a station which both Cuvier and
Lamarck have also assigned to them. This has now been
confirmed by the theoretical and analogical tests with
which our last chapter was concluded. Bnt as our ar-
rangement of these aninials will be in many respects
very different from that of preceding writers, it will be
proper, before submitting its details to the reader, that
we should take a short review of the group as it at pre-
sent stands in existing systems.

(44.) On referring to the definitions given in the
Itegne Animal of the order Gasteropoda*, and to the
animals composing it, we find it embraces more than
nine tenths of the whole of the Mollusca inhabiting
univalve shells, and by far the greater part of such as
are naked. The inevitable consequence of thus includ-
ing a multitude of groups, differing from each other in

* Griffith's Cuvier, xii. 21.
E 3

54' SHELLS AND SHELL-FISH. FART I.

almost every thing, has been this_, — that the reader is
at a loss to know by what other principle they are
united, even according to the system of the learned au-
thor. Some crawl on their belly, others do not ; some
have shells, others none ; many have a distinct head,
but many have not ; the eyes are present, or they are
wanting : all the organs, in short, of respiration, deglu-
tition, and reproduction, are admitted to vary ; and this,
in such an extraordinary manner, and in species so ob-
viously allied to each other, that they have no claim to
a primary consideration. True it is, that all these ani-
mals possess an aortic heart ; but this, properly speak-
ing, is more the universal character of the testaceous
Mollusca as a class, than one by which such an immense
number of animals, totally different in all other respects,
can be distinguished. The order, as it noAv stands, may
be said to embrace the whole of the Mollusca, except the
Dithyra, or bivalves, and the Cephalopoda, or cuttlefish.
" There is. no doubt, some great error," observes jNJr.
MacLeay, " yet undetected in the principles upon which
we are accustomed to arrange the 3Iollusca, and that
we shall never arrive at the truth, by looking, like M. de
Blainville, solely to the position and structure of the
organs of respiration ; or, like M. Cuvier, to the method
of reproduction, as when he unites the Cyclohranches to
the Acpphala or Dithyra.

(45.) Rejecting, therefore, all those animals from the
true gastropods, which have neither a distinct head, as
the Tubulibranchia, or whose branchia are naked, as in
Doris, we shall retain an assemblage of mollusks, nearly
all of which are furnished with univalve shells*; and
whose head, distinguished from their body, is provided
with tentacula and eyes ; the flattened part of the belly
serving them as a foot. Thus restricted, we shall find
that nearly all the remaining divisions of M. Cuvier,
under certain modifications, indicate so many natural
groups. It is clear, however, that when M. Cuvier

* Excppt in Chiton, where the valves are separate and dorsal only, and
some of the Tectibrancliia.

CHAP. III. TRIBES OF THE GASTEROPODA. 55

places such genera as Planorhis and Ampullaria in two
different orders, merely on account of a difference in their
organs of respiration, he falls into as great an error as
that he has elsewhere committed in uniting the Cyclo-
.hranchia to his Acephala. The order Piihnonaria, there-
fore, must be clearly abolished. This, indeed, has been
already done by Lamarck, whose authority on all ques-
tions of natural affinity must, in general, be regarded as
superior to that of Cuvier.

(46.) ^\^ith the foregoing restrictions, the primary
divisions of the order before us wuU be found to consist
of the five following tribes: — 1. The Zoophaga of
Lamarck, or the carnivorous shell-fish (corresponding to
the Pectinibranchia Cuv.); 2. The Phytophaga of the
same author, which live chiefly on vegetables, as the
snails and slugs; 3. The Scutibranchia Cuv., or lim-
pets ; 4. The Cyclobranchia Cuv., or chitons ; and, 5.
The Tectibranchia Cuv., or buUas, whose univalve
shells, where they exist, are all hid in the flesh of the
animal, while their mantle is dilated into two fin-Hke
lobes, with which they can swim. We shall now state a
few general particulars of these tribes, and then proceed
to determine their analogies.

(47.) The Zoophaga are the most pre-eminently
typical of the whole of the testaceous Mollusca ; and
this holds good, whether we regard the organisation of
the animal, or the symmetry and beauty of their ex-
ternal shell, wdth which, in every instance, they are
provided. They have only two tentacula ; and the eyes,
which are always conspicuous, are sometimes (as in the
Stromhid(E) highly developed- The edge of the mantle
is almost always provided with a siphon, or tube for
respiration, and by which the animal can breathe without
protruding its head and foot from the aperture of its
shell : this siphon is protected by a corresponding canal,
either long or short, at the base of its habitation ; and its
presence, in all these Mollusca, constitutes one of their
most essential characters. The mouth, also, is very re-
markable, — resembling more or less, as Cuvier well

E 4

56

SHELI.S AND SHKLIi-FISIl. PARTI.

observes, "an elongated proboscis. Their tongue/' he
continues, " is armed with little hooks, which, by slow
and repeated rubbings, act upon the hardest bodies/'
It is by this process that they perforate, with the
smoothness and precision of an auger, the shells of.
other animals, which they then destroy and suck the
juices of. The sexes are always separate; and the
aperture of the shell, in most instances, is closed by an
operculum. The various modern genera formed out
of the Linna^an Murex, Biiccinum, Conns, Voluta, &c.,
are included in this tribe, the shells of which are
always spiral, and furnished with a notch or emargin-
ation at the base.

(48.) The Phytophaga, as the name implies, are
feeders upon plants ; for although several, like the
slugs, will devour animal substances, they more habitu-
ally live upon vegetables. They are, besides, eminently
distinguished from the carnivorous race by two cha-
racters : their mouth does not form a proboscis ; and the
aperture of their shell is entire, — in other words, without
the notch or canal for the passage of the siphon (when
it exists), so universal in the last group. In all but
one or two genera, as the slugs and the marine Onchid^B,
they are more or less covered with shells, which,
in however small a degree, are always spiral. By far
the greater part of them have the sexes separate ; but in
regard to all the other organs connected with respiration,
they may be said to vary in every possible way, — a clear
proof that such variations, in groups naturally and
closely allied, cannot be taken in an arbitrary sense.
Many of these animals have their branchia as in the
Zoophaya; some few, as Cyclostoma and Helicina, even
according to M. Cuvier's admission (who places them,
nevertheless, with his Pectin ibrajichia), '' have instead of
gills, a vascular network covering the top of a cavity
that is otherwise similar ; and they respire, like the
Limax, the natural air." The whole of the terrestrial
slugs and snails, again, breathe through an open perfo-
ration under the edge of the reflected mantle, which

CHAP. III. TRIBES OF THE GASTEROPODA. 57

they can dilate or contract at pleasure : hence they
have no gills, " but merely a network of pulmonary
vessels, which spread over the parietes and the roof of
their respiratory cavity." The tentacula, in such as
inhabit fresh water, are generally only two ; but in the
land and amphibious groups, as Helijo, Ampidlaria, Pla-
norbis, &c., they are four. Their food, notwithstand-
ing all these variations, is always essentially vegetable.
Their mouth is uniformly the same, and their shell is
always spiral ; this latter circumstance, it should be
remembered, carries with it an important character in
the form of their body, which is of much consequence,
and separates them from the next tribe. The whole
of the land shells, as well as the marine families of
Neritinw, Turbidce, TrochidcE, &c., are comprised in
this division ; the HaUotidcp, or ear-shells, being the
connecting link to the next.

(49.) The ScuTiBRANciiiA have the same system of
respiration, according to Cuvier, as hh PectinibrancMa ;
but they differ not only in their mode of reproduction,
but most remarkably in the form of their body. They
are all attached to their shelly covering by an amazing
strong muscle, which fills the centre, and gives them
such an adhesive power, that they affix themselves im-
moveably to other substances, from which they can
only be separated by the sudden insertion of some sharp
instrument. They are, in fact, affixed Testacea ; for
although the animals can move about, they cannot live
but upon a substance where they can instantaneously
fix themselves. In their internal structure, we find the
heart, according to Cuvier, " traversed by the rectum,
and receiving the blood from two auricles, as is the case
in the greater number of bivalves." * The form of
the shell is no less peculiar ; its general shape is that of
a low, broad-based pyramid, or, if viewed inside, of a
very wide but shallow funnel. The common limpet,
in short, appears to us the most typical of the whole ;

* It is by this group, in fact, as will subsequently be shown, tliat we
consider the Gasteropoda and the Di(/ii/ia are united.

58 SHELLS AND SHELL-PISH. PART 1.

for although this genus has heen excluded by some
writers, and separated from Fissurella, Sec, in a dis-
tinct tribe, yet this is evidently doing a violation to
nature. None of the genera in our present group pos-
sess spiral shells ; for although Haliotis is obviously
intermediate between the Phytophaga and the Scuti-
hranchia, its preponderating character, both as regards
the animal and the shell, appears to us in favour of its
being placed as the last of the turbinated families, rather
than as the first of the present group. Thus restricted,
the Scutihranchia will contain Patella, Siphonaria,
Fissurella, E7nargmula, Parmophorus, Capulis, Sec,
together with the singular genus Hijiponyi-, of which
we shall have occasion to speak hereafter. Magilis
and Siliqiiaria evidently disturb this series, yet open a
direct path to the Dithyra, or bivalves.

(50.) The Cyclobranchia, according to Cuvier, '^'have
the branchia resembling small lamella, or little pyra-
mids, forming a cordon more or less complete under the
borders of the mantle, very nearly the same as the In-
ferohranchia," from which, however, he separates them
on account of their different system of reproduction :
" the heart," he continues, " does not embrace the
rectum, but its situation varies ; the stomach is mem-
branaceous, and the intestines very long." The only
genera placed by Cuvier in this group, are Patella and
Chiton. The first, however, is so evidently connected
to the Scutihranchia in all other points of organisation,
setting aside the shell, that we have no hesitation in
adopting the theory of Lamarck, who unites the genera
Phyllidia and Diphyllidia to Chiton, particularly as this
arrangement at once opens a direct passage to the Tcc-
tihranchia. The shells of the chitons, which thus
become the types of the Cyclobranchia, are boat-shaped
and multivalve, the valves being disposed transversely
upon the back of the animal, and folding over each
other like a coat of mail.

(51.) TheTECTiBRANCHrA,to which we are conducted
by Lamarck, form a most natural group. It is peculiarly

CHAP. III. TRIBES OF THE GASTEROPODA. 59

interesting^ because it contains those diverging genera
which connect it not only with the chitons^ but with
the Gasteropoda on one side, and the Cephalopoda, on
the other. They may be described as thick, fleshy,
soft mollusks, generally possessing a distinct head
furnished with a pair of ear-shaped tentacula, and with
the mantle usually dilated into two lobes resembling
fins : the branchia are folliculated on the right side or
on the back, and are generally covered by a small
bulla-shaped shell concealed in the folds of the body.
They have the power both of crawling by means of a
narrow disk on their belly, and of swimming by their
fins. JNIany of the species are very large, and when
taken out of the water they appear like great oval
masses of flesh. They are the only swimming gas-
tropods possessed of a univalve shell, and are con-
nected to the Cephalopoda by the singular genus Gas-
teropteron Meek., which thus brings us at once to the
Pteropoda ; while the connection of the Bullce to the
CypraidcR is obvious to every one.

(52.) The union of the Phytophaga and the Zoophaga,
or the typical divisions, is so perfect, that the only ap-
parent difliculty seems to be where one terminates and
the other begins : thus, if we look to the possession of a
siphon as a primary distinction of the Zoophaga, we
find this organ fully developed in the sub-aquatic genus
Ampullaria, which is nevertheless so closely united in
its other characters to the Phytophaga, that we cannot
separate it from its obvious allies : the mouth of the
shell, in fact, is as entire, or rather as destitute of any
notch or canal, as that of the garden snail ; while PlO'
naxis and Melanopsis, both of which are most inti-
mately related to Melania, have a deeply notched
aperture. If we look to the relations afforded by the
animals themselves, the same interchange of characters
takes place. As these two groups follow each other in
afl5nity, we may pass on to the HelicidcE, or land snails,
and the marine Trochidce, until we reach the Scuti-
hranchia by means of such genera as Trochella, which

60

SHELLS AND SHELL-FISII. PART I.

unites the essential character of a turbinated Trochus
with those of the patelliform Calyptrtra, Capulis, &c.
By following this clue, we arrive at once among the
limpets, while the NaticidcB branch off and unite again
with the TurhidcB. It is quite indifferent to our
present purpose_, whether Haliotis is retained in the
Scutibranchia, or within the confines of the Phytophoga ;
but we may here anticipate our subsequent analysis,
by stating that it truly belongs to the latter, where it
forms a particular family, representing the limpets.
Having arrived, therefore, among these latter shells, the
most simple of all the univalve Testacea, nature returns
to the carnivorous gastropods through the Cyclohranchia
and the Tectibranchia ; so that the junction of the latter
with the CyprcBidce, as before remarked, completes as
perfect a circle as any, perhaps, in the entire animal
kingdom. From this disposition of the groups results
the following table of analogies : —

Analogies of the Ti'ibes of Gasteropoda to the Orders

of the Testacea.

Tribes of t , ■ , nu u Orders of the

/^„ /,,. «„^« Analogical Characters. T^.y,, .^,

Gasteropoda. ° lestacea.

r Pre-eminently typical; mantle^
ZoopHAGA. ■< formed into one or two long tu- > Gasteropoda,

C bular siphons. j

Phytophaga. Siphons entirely wanting. Dithyra.*

'Animal oval, greatly depressed;'
o 1 thebranchia, in the typical di- 1 x-

SCUTIBRANCHIA. < „;„:„„. f.. :„„,') „.,,, .■:iL.„,, >- N UniBRANCHIA.

Lnimal oval, greatly depressed ; '\
thebranchia, in the typical di- f^
visions fringed, and placed on i
the back. J

^ ("Tentacula none; body broad, 7 r>.

Cyclobranchia. J oval, onisciform. ' j Parenchymata.

Sliell, when present, protecting')
only a part of the body, con- f .
cealed ; mantle dilated into fin- 1'
like lobes. J

Tectibranchia. ■{ ^^J^^ ; mantle dilate.l into fin' ^ Cephalopoda

It is not a little extraordinary that these two series of
animals, which in their external aspect are so very dis-
similar, should yet present such strong analogies to each
other ; the Scutibranchia, in fact, may be called A''i(di-
branchia provided with shells _; and, in the same way,

* The sub-typical group, of course, is the one here compared, and there
the animals have no siphon.

CHAP. III. THE CARNIVOROUS TRIBE. , 6l

the PlanaridcE among the Parenchymata are naked
chitons (^Cijclohranchia). The Cephalopoda, in hke
manner, are as perfectly represented by the swimming
tribe of the Tectihranchia ; and like them, also, have
their shell internal. Adverting, again, to the two first
analogies, we find the primary types, the Zoophaga and
the Dithyra, furnished with long siphons^ or tubes,
which are totally wanting in the secondary types. To
this table^ however, w^e may hereafter return ; and, in
the mean time^ w^e shall enter at once on the most
typical families of the entire class.

\5S.^ The tribe of the Zoophaga, or rapacious shell-
fish, is distinguished by a tubular or proboscis-like
mouth, a respiratory siphon, and two tentacula, upon the
sides or near the base of which are the eyes. In some
few, as in the cowries (^Cypr(Ea\ the mantle is ex-
ternal, and almost envelopes the shell ; and this, we sus-
pect, is likewise the case in some of the Volutidcs, or
volutes ; but in general it is internal, and of ordinary
dimensions. Nearly all are provided with a horny oper-
culum for closing the aperture of their shell ; but in the
Cones and ColumheUirKe this is reduced to a mere
vestige ; while in the Cypraidce, and such as have the
lobes of the mantle very much developed, it is unneces-
sary, and therefore does not exist. All these variations,
however, in the operculum are slight and trivial, in com-
parison to those exhibited in the form of the animal
and the construction of the shell. Here the greatest
variety, and the most regular constancy in the variation
of natural groups, is everywhere discernible. Hence it
is, that while our primary attention must be directed to
the variation of the animal, we must still have a suf-
ficient regard to its testaceous covering. It is the abuse,
and not the judicious use, of a regard to the shell, which
is to be condemned. A system built only on the vari-
ation of the animal, would be as useless and insufficient
for all practical or philosophic purposes, as another
would be detrimental to sound principles of classifi-
cation, if it w^as framed entirely on the form of the

62 SHELLS AND SHELL-FISH. PART I.

shell. The first would include^ like the old systems,
all manner of spiral shells,, under the generic name of
Buccinum ; while the other would p^ace Parmophorus,
Fissurella, and Umbrella in the same group as the
limpet, merely because they had similar shaped shells.
"While, therefore, we make this and all our other chief
divisions to repose on a primary consideration of the
soft parts of the body, we regard the construction of the
shell as much a part and parcel of the animal itself, as
are the wings of an insect or the hard covering of the
chelonian reptiles. The shell of testaceous animals, in
fact, is precisely analogous to the covering of the
tortoises, and are to be considered in the same light,
• — that is, furnishing a secondary, although a very im-
portant, set of characters for the determination of the
minor groups. It is not a little remarkable that, as the
tribe before us is the most completely organised, and
therefore the most typical of the whole of the Testacea,
so do we find their testaceous coverings are the most
complicated, and by far the most beautiful of all the
spiral univalves. The gradual transitions of form which
they present, even when there is little or no variation in
the animal, or, at least, none that has yet been detected,
is a clear proof, if any other was wanting, that all our
secondary characters taken from the shell, are those
which nature herself has employed to designate the sub-
ordinate groups. The definitions, therefore, of the
families in which we shall now arrange this tribe, will
be mainly taken from the shell, at the same time intro-
ducing all such information regarding the soft parts of
the inhabitant as appear of primary consequence.

(54.) The five leading divisions of the Zoophaga may
be thus named and defined: — 1. The MuRiciDiE, or
murexes, having the respiratory siphon in general very
much developed, and its corresponding canal at the base
of the shell always straight. 2. The Turbinellid^,
or turnip -shells, where the base of the shell is straight
and lengthened, and the pillar strongly plaited. In both
these, the mantle of the animal is never dilated, but is

CHAP. III. FAMILIES OF THE ZOOPHAGA. 63

of ordinary dimensions, and drawn back into the shell
with the animal. 3. The Volutid.^, or volutes, having
the mantle much developed in the typical species : the
column of the shell is always marked by regular and
well-defined plaits, nearly the same as in the last; but
the base of the aperture is obtuse, truncate, and notched.
4. The Cypr^id^, or cowries, whose shells are without
any spire ; the last whorl enveloping all the others, as in
the bullas. 5. The Strombid^e, or wing-shells ; the
only division where the outer side or lip of the aperture
is considerably dilated. The two first of these are the
typical and sub-typical groups ; the three latter form-
ing the aberrant circle. The whole are marine.

{55.) The MuRiciDiE, or whelks, are resolvable again
into the following sub-families, each of which contains
genera and sub-genera : ] . The Muricince, or murexes * ;
2. The Cassinw, or helmets ; 3. The Buccinincp, or
whelks ; 4. The PurpurincE, or purpuras ; and, 5. The
NassincB. These we shall now enter upon in the above
order of arrangement.

(56.) The MuRiciN^ is a very diversified and (from*
the little yet knowni of the animals) a very difficult
group to arrange. Generally speaking, they are strong
shells, of a rough exterior, without any plaits or teeth
either upon the pillar or outer lip : the different periods
of their growth, or rather of their enlargement by the
anim.al, are marked by thickened transverse ribs called
varices, which are differently disposed in the genera : the
canal is generally short, or of moderate length, but always
present, and usually a little bent on one side. The aper-
ture is oval; and the spire nearly as long as the body- whorl.
They chiefly abound in the shallow waters of temperate
seas; and are either covered with an epidermis of their
owai, or by extraneous marine substances. The typical
genus is MureJc, where we find some of the most beau-
tifully coloured shells, and certainly the most elaborate
in structure, among the whole of the spiral univalves.

* Sometimes called rock-shells, from the roughness and irregularity of
their surface.

64

SHELLS AND SHELL-FISH.

PART I.

This and Ranella appear to be the two typical genera ;
but of the three aberrant divisions^ Triton is the only
one that has been yet named or defined. The foliated
varices of Ranella, and the sharp tubercles on the whole
shell, joined to the additional canal at the upper part of
the aperture, indicate that this group is naturally con-
nected to Miirex ; but the species are very few, and
, present no very marked deviation from the typical form.
In Triton, however, the case is far otherwise. The
species are not only more numerous, but exhibit in their
structure so many different modifications, that there is no
one generic character to which there are not exceptions
in some of the species. The most usual is that of having
but few varices, and these placed alternately ; whereas
in Ranella they are so united as to form a continuous
ridge on each side the shell, when it is placed with the
aperture downwards. But this character is by no means
constant. The animal {fig. 1.) is here represented from

an unpublished drawing by Guilding ; the tentacula
are short, and the eyes at their base. This remarkable
diversity in the genus Triton is easily accounted for, on
the ground that this group contains representations of
all others in the family, besides aberrant forms leading
to the more proximate genera. The two other aber-
rant types, which we consider as completing the circle
of the Muricince, we name Vitulina and Muricidea.
The first is advancing towards Murex, and is repre-
sented by the Mureoc Vitulinus of authors, and is dis-
tinguished by having the varices nearly obsolete, and
the piJlar smooth, broad, and flattened, like a purpura.

CHAP. III. THE GASSING, OR HELMETS. 65

The type of Muricidea, is the harp-like Mureoc Magel-
lanicus* Where, as in very many other of the small
murexes, the progressive growth of the shell is marked
by longitudinal ridges, either foliated or spined, some-
times as close together, and nearly as regular, as those
upon the harp-shells. The outer lip is quite smooth,
and the inner Hp thin : there is no internal groove ; and
the basal canal is almost always closed over, so as to
form an internal tube, open only at the two ends. The
connection of this group of Murices to the true genus
Murex is so close, that they have never, until now, been
separated ; so that, being connected to Triton by means
of Vitulina, also a Lamarckian murex, we find the whole
forming a circular group of themselves.

(57.) Ill the Cassin.e, or helmet-shells, the first cha-
racter which strikes us is their large and often gigantic
size : the spire is remarkably short; and the base, instead
of being prolonged, as in the Muricince, is either truncated
so as merely to present a wide notch, or is very short,
and turned back on the body-whorl. These are the
typical characters of the sub- family, but much remains
to designate the genera. Our attention has been more
especially called to this group, not merely from^ the size
and beauty of the shells, but from the great reluctance
some conchologists have manifested to adopt the genus
CyprcEcassis, proposed by j\Ir. Stuchbury, whose valuable
Essay upon the growth of corals has rendered his
name familiar to naturalists. That Cyprcecassis pos-
sessed a decided relation, either by affinity or analogy,
to Cyprcea, we had long been persuaded. But vre
freely confess, that previous to, and even for some time
after, its being proposed as a genus, we looked upon it
only as a subordinate type of Cassis. Anxious, never-
theless, to arrive at some definite conclusion on this
point, we were induced to re-examine the whole of the
Lamarckian genus Cassis; the result of which has con-
vinced us that our first impression was erroneous, and
that Cyprcecassis is as truly a natural genus as any in

* Ency. Method, pi. 414. fig. 4. a, b.
F

66

SHELLS AND SIIELL-FISH.

PART I.

the whole circle of the Testacea. It will be needless in
this place to enter into the definitions of this and the
other four genera^ since they will be found in our sys-
tematic arrangement ; but they may shortly be cha-
racterised in the folio-wing manner : — In Cassidea and
Dolium, the aperture of the shell is always wdde, rarely
with distinct varices^ and the outer lip never dilated into
a marginal rim over the body- whorl; but in the first, the
inner lip is reflected, thickly marginated, and generally
toothed, while in the last it is always thin : these will
be found, upon analysis, to be the two typical genera.
In the harps {Harpa), which obviously follow the tuns
(^Doliimi), the whole shell is marked by varices, which
assume the form of ribs. Now, the ample information
given by M. Quoy on the animal of this genus, not
only fixes its station in the present circle, but demon-
strates it to be a representation of the volutes, with
•which that admirable malacologist compares it. This im-
portant point being determined upon such high authority
and unpremeditated testimony, we arrive, by induction,
at the station of the two remaining types. Cyprce-
cassis, consequently, intervenes between Harpa and
Cassis; and this latter fills up the interval between Cy-
prcEcassis and Cassidea. Thus, the Cassince, like the
MuricincB, form a circle of affinity among themselves,
and present one of the most beautiful set of analogies
to be found among the families of Testacea.

Analogies oftheCASSiyiM to theFamiUes q/* Gasteropoda.

Genera of the

CASSINiB.

Cassidea.

DOLIliM.

Harpa.

CyPRj1?CASSIS.

CTypical ;
X straight.

Analogies.

basal cliannel never '

{

Cassis.

Sub-typical.

Font of the animal enormously

large ; mantle dilated ; tcnta-

cula short.

r Aperture of the shell linear ; both")
lips regularly toothed, the in- |
ner spreading, but never pro- )■
minent ; aperture with a ciian- |
L nel at each extremity. J

Outer lip gibbous or angulated ^
above, considerably dilated on f
ts margin ; eyes of the animal T
ghly developed. j

rOutc
3 ab(
1 its
C hit

Families of
Gasteropoda.

muricidj!.

TuUBINELLIDiE.
VOLUTIDJE.

CVPR.EID.C

STROMBID.E.

CHAP. III. ANALOGIES OF THE MVRICIN^, Gj

As no very tangible analogies exist between the shells
of the two first groups in each column^ we may fairly
presume that they exist only in these hitherto not well
defined animals^ particularly as it is only by this means
that the resemblance of Harpa to the ]\Ielons^ or typical
volutes^ has been established ; and yet, when we look at
a harp-shelly we cannot assimilate it to any other than a
coronated volute. The analogy between Cypr(Ecassis
and the cowries is too strong to be insisted upon ; and
in this view it is quite unimportant whether the former
has or has not an operculum^ for the relation, in either
case, is clearly one of analogy, and not of affinity :
we are disposed to consider the common C. testiculus as
the type, simply because it puts on more the aspect of
a cowry than any other species we have seen ; it is less
nodulous, and its slender longitudinal ribs accord more
with those of Oniscia and other cyprseform types.
Cassis, itself, is indubitably a prototype not only of the
Sti'omhidcE, but of the NassincE, to which it at once
leads through the intervention of Cassidaria.

(58.) It is not a little remarkable that while the
genera of the Cassince represent the families of the car-
nivorous gastropods, those of the pre-eminently typical
Muricince have a more especial reference to the sub-
families, as will be seen by the following exposition : —

Analogies of the Muricin^ to the Sub-families.

Genera of j^^;„„-^<. Sub-families of

MuRiciN^. Analogies. Muricid^.

Murex. Typicalofthtir respective groups. Cassincz.

Ranella. Sub-typical. Muricin<s.

r Spire generally longer than the"!
Triton. \ aperture ; base short, nearly > Buccinince.

C truncate, straight. j

r-., ,. „ ■ f Inner lip broad, smooth, and flat- 7 „

Jduhna. ^ tened ; basal channel narrow, j Purpurm<e.

Muricidea. Base of the shell slightly produced. 'Nassimc.

Here, again, insufficient acquaintance with the animals
very much lessens the interest of these comparisons :
and yet there can be no doubt that Murex vitiilinus of

F 2

6s SHELLS AND SHELL-FISH. PART I.

authors is more a miirex than a purpura, — that Triton
passes into Bnccinuni, and therefore represents it, — and
that, of all the carnivorous gastropods out of the CassincF,
Murex JMagellanicus and its alUes have the greatest
similarity to the harp-shells. This is all we would
maintain. For the rest, there is such an extreme regu-
larity in all the existing species of Harpa, that we may
fairly conclude the aberrant examples have become
extinct, or have possibly not been discovered. One
species, however, of Muricidea, with the ridges of
31. Magellanka, but with a truncated base, would con-
nect the two groups ; and when we consider that, in
Triton, the comparative length of the channel is only
used to designate the species, we may fairly conclude
there is no violation of nature in supposing that Harpa
and 3Iuric'idea pass into each other. As for the analogy
between the latter and yassa, we have at this moment
a species of Muricidea before us, whose canal is
reflected backwards precisely as in the common ^'i. ar-
cularia.

(59.) The typical distinction of the Nassje lies in
a very thick deposition of enamel which encircles the
aperture, and not only spreads far beyond the inner lip,
but forms a vitreous mass all over the under part of
the body-whorl. The only other genus of predaceous
Testacea having a shell thus constructed, is Cassis, and
a few tritons, w^hich are probably its representatives.
Nevertheless, there are many Kassce which have this
peculiarity but slightly developed, and others in which
it is not at all apparent ; in all, however, there is a pro-
minent internal ridge at the base of the pillar, and a
small transverse tooth on the upper part of the inner
lip. These shells are all of a small size, and abound
in the shallow waters of Southern Europe and the East.
Among the unpublished researches of Guilding*, is a
highly finished drawing of a species from St. Vincent's
{fiy.2.), which throws an important light on the animal :

* Now in the possession of his widow.

CHAP. III.

Tin: NASSIXiE.

69

from this, it does not appear to have a probosciform
mouth ; but the anterior part of the foot is prolonged into
a subulate point on each side, and the hinder jmrt termi-
nates in two little
tail-like appendages.
Now this has much
of the character of
our genus Leiodo-
nius *, figured by
Quoy and Gaimard ;
and, although both
they and their shells are too dissimilar to be placed
in the same group, they may be considered analogous.

(60.) The broad, spreading, and dilated inner lip of
Cassis prepares us at once for the sub-family of Nassin^e,
which is entered by the genus Cassidaria of Lamarck.
These shells differ from all those we have just left, by
having the basal canal considerably more lengthened,
and only slightly turned backv/ards, without reposing on
the shell itself : they are of an intermediate size be-
tween the largest Nassce and the smaller helmets ; and
thus the gradation even of size is preserved. The typi-
cal genus Nassa then succeeds : the species, although
all of them small, are much varied in shape, and in the
degree in which the inner lip is developed; but the
twisted ridge at the base of the pillar, the striated aper-
ture, and the tuberculated tooth at the top of the aper-
ture, are so constant, that they must remain as they now
are in our systems, until their sub-genera are worked
out. There is one form, however, so very remarkable,
that we have placed it as the genus Cyclonassa *: it is
the only snail-shaped flattened shell in this tribe ; and
the animal, when known, will no doubt be very curious.
Our next genus, Vexilla, opens the passage to the
Pm'purbife, which it perfectly resembles in general
form, and in its broad depressed inner lip ; but the outer

* Bucc. agath^ Quoy, Voy. Astrol. pi. 31. fig. 17.

+ Cyclops of Montford ; but this is a long established genus of crabs.

F 3

70

SHELLS AND SHELL-FISH.

PART I.

one is slightly inflected, and distinctly toothed. There
is still wanting another genus possessing some of the
characters both of Vexilla and Cassidaria: this genus
is Oniscia Sow., where the inner lip is still more in-
flected and toothed, and the spire much shorter than in
Vejcilla, but yet with something of the protruding basal
channel and general aspect of Cassidaria. As INIr,
Sowerby has judiciously alluded to this affinity, we need
not defend its existence. The circle of the Nassince
thus becomes closed ; since we have returned to Cas-
sidaria, or to that genus with which we began.

(61.) We shall now see how beautifully this na-
tural series coincides with that of the Cassince, and
rightly estimate the additional value attached to the
genus CyprcEcassiSy without which an important link
would be altogether wanting.

Analogies of the NASsiNiE and the CASsiNiE.

Genera of

Nassa.

Cyclonassa.
Vexilla.

Oniscia.
Cassidaria.

Analogical Characters.

fTypical ; inner lip much develop-"]
I ed ; spire not depressed ; base |
<{ of the pillar internally cari- }>
I nated ; the basal canal reflected |
l_ backwards. j

Spire very short, more or less de-
pressed ; the basal canal trun-
cated.

5 Aperture very effuse; outer lip?
X_ often crenated. 3

r Ovate; inner lip spreading, but"
\ not margined ; outer lip thick, (
"i inflexed ; both lips striated and (
i, toothed.

Vciitricose ; generally tubercu-
lated ; basal canal curvcdback-
wards.

{

H

{

Genera of

CASSI.NiB.

Cassidea.

Dolium.
Harpa.

Cyprcecassis.
Cassis.

To dilate upon this table, would be almost implying
that our conchological readers were purblind. And yet,
for those who are not scientific, we may advert to the
intimate resemblance which some species of N'assa bear
to the small helmet-shells in Cassidea ; so that, but for
their size, a superficial tyro would mistake one for the

CHAP. III. THE PURPURIN^. 71

Other. VexUla represents^ in outward form, and most
perfectly in colour_, Harpula vexillum, just as Harpa
typifies the crowned volutes. Oniscia and Cyprcecmsis
are perfect counterparts of each other; while Cassidaria
and Cassis complete this system of analogies. If any
doubt existed as to the absolute union of Oniscia and
Cassidaria in regard to affinity, it is set aside by a re-
markable shell obligingly sent me by ^Irs. Stuchbury,
where the characters of both are united. This is of
much additional importance, because it shows that Cas-
sidaria does not form one of the five types of the Cas-
sirne, but merely leads to them from the Nas since.
These, therefore, are the grounds upon which we have
adopted ]\Ir. Stuchbury's genus Cyprcecassis. And while
we return his opponents our best thanks for stimulating
our attention to the subject, and thus detecting a mate-
rial error of our ow^n, w'e sincerely trust that he himself
will prosecute his researches with the same ability and
w^th the same success ; to the true advancement of our
favourite science of Malacology.*

(62.) The PuRPURix^E form the next sub-family
in our arrangement. They include shells whose general
form closely resembles the BucciniiKe, or whelks, but
with this difference, — that the pillar, without being ele-
vated round the margin, is very much thickened, yet
always more or less flattened and depressed — not, as in
the generality of shells, convex. This, in truth, is the
only character seen in the shells, by which this assem-
blage is in any way linked together. For the rest, the
spire is almost always very short; the aperture large and
wide; the inner lip not otherwise developed than by a
transparent polish spread over it, wdiich is sometimes

* I cannot pass over this opportunity of publicly expressing my obliga-
tions to his worthy brother, Mr. S. Stuchbury, of Theobald's Road, one of
the tirst commercial naturalists in I.,ondon, for the free use he has always
given me of any interesting shells in his collection, without the necessity
of purchasing them ; a liberality not always met with. With him, I have
named a series of types of the greater part of the new genera here defined,
and 1 feel assured he will supply them to collectors on the most fair and
moderate terms.

F 4

72 SHELLS AND SIIELL-FISH. PART 1.

thickened in the middle, so as to form a slight elevation;
and in one genus (Rici)iula), both lips being toothed
renders the aperture very narrow : they are all heavy,
thick, and rough shells, often armed with tubercles and
spines, but never with varices ; there is generally an in-
ternal groove at the top of the aperture. The true type
of the whole sub-family, which is a representation of the
Cyclohranchia, is Concholepas, — a most singular-formed
shell, which was long classed as Patella : next to this
follows Monoceros, having a basal spine at the aperture
much developed. Following these, we place certain
shells where the basal notch is so small as to be nearly
obsolete. Of all the different modifications in the genus
Purpura, as it now stands, we think these point out the
third sub-genus, since they are evident representations
of Cerithuni, Melania, and other half-emarginate groups:
the spire is very short, and the pillar curves inwards.
Following these, which we distinguish by the name of
Microtoma, come the ordinary PurpurcB; and these
blend imperceptibly into Riciyiula, by means of P. coin-
mellaris, and Ricinula aspera and morus.*

(QS.^ Ricinula is a most remarkable genus of small
prickly shells, with a very short spire, and the mouth,
in the typical species, so beset on both sides with tooth-
like projections, that the aperture itself becomes remark-
ably narrow ; but these teeth are only developed at the
matured age of the animal, and even in some species
they are very small ; nevertheless the pillar is almost
always flattened. The gradual developement, and some-
times the digitated outer margin, of the external lip,
shows a strong analogy to the Stronibidte, while the
toothed aperture instantly reminds us both of Cohunhella
and Cassis : all these relations will be still more deter-
minate, if the circle of the Purpiirince is tested on the
same principles as those last examined. It is this group,
in fact, which unites the Purpurince with the NassincSy
by means of Vexilla, where we see in the toothed outer

* Ency. Meth. pi. 317. tig. 4. 6. t Ibid. pi. 317. fig. 5.

CHAP. III.

THE BUCCININ^ffi;.

73

lip the last indication of Ricinula. The connection^
again, of these singular shells to Concholepas seems to be
effected by our Ricinula planospira\, which has the
spire nearly obsolete. This, as we believe, is the true
course of the circle, the contents of which find their re-
presentatives in the sub-families. It really seems ad-
visable that the sub-genera of Ricinula, Nassa, Triton,
and such varied groups, should be characterised when
the science is somewhat more advanced.

(64.) There is one set of analogies, however, result-
ing from this disposition of the PurpuriniB, which we
cannot omit, because it illustrates that sub-family by
which they are represented in the circle of the Turhi-
nellidcE, — namely, the PyruUncE. This will also save
much useless repetition when we come to speak of the
latter group.

Analogies of the PuRPURiNiE and the Pyrulin^.

Genera of the

PURPt'RlN.E.

Pillar flattened.

Concholepas.

Monoceros.

Microtoma.

Purpura.
Ricinula.

Analogical Characters.

r Shell smooth; spire excessively T
-5 small, scarcely projecting; aper- V
c ture very efifuse. j

Spire more lengthened, conic,
r Shell smooth ; spire small ; aper
■5 ture very effuse ; the basal ca
C nal narrow and almost obsolete.

Shell ponderous, rough, often
spired ; basal canal wide, and
fully developed.

Pillar, or inner lip, toothed.

{

^

Genera of the

Pyrlltn^..
Pillar convex.

Ficula.

Pyrula.

Rapella.

Myristica.
Cuma.

Considering that these sub-families belong to two supe-
rior divisions, of which each is the most aberrant type,
the coincidence of each agreeing in their details, is not
a little remarkable.

{Q5.') The BucciNiN^, or whelks, form the fifth and
last division of this family : they are known from the
murexes by having no varices, and from the PurpurincB
by the pillar not being flattened : they are generally re-
cognised by the abrupt termination of the base, v^'hich
is deeply notched. They are nearly all smooth shells,

74f SHELLS AND SHELL-FISH. PART I.

or at least without spines^ or very prominent nodules.
The typical genus is Terebra, — the longest spired group
of all the carnivorous gastropods^, but so closely resem-
bling TurrUella, that the difference in their apertures
alone distinguishes the shells. In the genus Bucciiium,
the spire is much shorter^ and the body-whorl more
ventricose. These seem to be the typical groups. The
three aberrant will be now described. The first, which
appears to us to make the nearest approximation to the
wide-mouthed genus Microtoma, is Leiodomus, founded
upon two shells, the animals of which have been beauti-
fully figured* by M. Quoy. One of these is the Bucci-
num Icevigatum of authors; the other, XheB.Achatinum.f
Both these have the foot of an immense size, so that it
spreads over a circumference near three times as large
as the shell, and is sufficient to envelope it entirely. In
other respects there are some slight points of variation
between the two; but they do not strike us, at present,
of sufficient moment to sanction the formation of sepa-
rate genera. To these we add the Terebra vittata j,
and three or four other species, apparently undescribed.
The vittata, however, appears aberrant, and leads im-
mediately to Terehra. We are disposed to consider,
also, as the type of another genus ( Trochia), the species
of Purpura of that name, — since its characters will
not agree with those of Purpura, while the striated
inner lip leads to the conjecture that it is a prototype or
Oniscia and similar shells. Lastly, we have, in Tri-
tonidea §, a remarkably varied group of small shells,
some of which resemble Triton, and others Buccinum;
the base, however, is always contracted, and even slightly
produced ; the pillar marked at the base with elevated
granulations, or short obsolete plaits ; and a distinct canal
at the top of the aperture. The connection of this group
to Buccinum is very obvious, while its union to Triton

* Encv. Mcth. j)l. 400. fig. 1.

f Ibid. pi. 400. tig. 4. J Ibid. pi. 402. fi?. 4.

^ I have since learned that this genus is the same as Po/li'n Gray. — a
name 1 should gladly liave adopted, had it not previously been given to a
genus of European Lcpidoptcra.

CHAP. III. THE TURBlNELLIDiE. 75

is even more so. Triton ckmdestinum has the obsolete
plaits and the mternal channel of Tritonidea ; while its
thickened outer lip and more produced channel is suffi-
cient to give it a place within the limits of Triton. The
circle of the MuricidcB is thus complete ; but whether
Leiodomus is a sub-genus of Terebi-a, or really that type
which passes into Microtoma, is a matter of doubt ; its
analogy, however, to Harpa, as shown in the animal, is
a weighty consideration, although we have no interme-
diate links by which it is connected to Trochia.

(66.) The TuBBiNELLiDiE form our next great di-
vision of the predatory sheU-fish. As the Muricidce
are chiefly distinguished by the general shortness of the
testaceous canal which receives the respiratory siphon, or
by its total absence; so may the great majority of the
TurhinellidcB be known by this canal being considerably
lengthened.* The animals, unfortunately, of nearly all
the typical genera are as yet quite unknown f; so that
we have only a few detached land-marks, as it were, to
assist us in the arrangement of their shells. Looking,
therefore, to such characters, we observe that the Tiir-
hinellida, as a whole, are remarkable for the length of
the basal canal ; and that the two typical sub-families
have the pillar plaited, — a character never met with in
the Muricidce. The volutes, indeed, possess it ; but the
total absence of a canal in those shells serves at once to
distinguish them. We shall now arrange the whole
under the following families: — 1. TuRBiNELLiNiB,
having a large, very heavy, and smooth shell, the canal
nmch lengthened, and the spire generally papillary. 2.
ScoLYMiNiE, equally strong and ponderous with the last,
but the shell is rough, with foliated spines or tubercles,
as in Murex, and the canal short. These two are the
typical groups ; the first representing the Cassintr, the
second the Muricince of the last family ; and both are

* Except in the Eburnidce, and some of the aberrant ScohjmincE.

t Guilding has ascertained that oi Scolymus, and Quoy those oi Eburna
and Strutheolaria : the former has not a probosci^brm mouth, but the two
latter have this structure highly developed.

76 SHELLS AND SHELL-FISH. PART I.

furnished with distinct plaits on the pillar. 3. The
Eburninje, where the base of the shell is truncate and
notched^ the pillar smooth, and the inner lip considerably
thickened and spreading. 4. The Pyrulin^e, or pear-
shells, having the spire short, the pillar smooth and con-
vex, and the canal moderate. 5. and lastly. The Fusin^e,
or spindle-shells, slender and delicate, having the canal,
as well as the spire, remarkably long, and generally of
nearly equal length. As it will subsequently appear
that these groups are of the same rank and value as those
of the CassincB, we have given them the same termin-
ation in ince, although their contents are by no means so
numerous as their prototypes.

(67.) The TuRBiNELLiN^ are remarkable in their
typical genus,— which is Turhmella, — for the excessive
heaviness and even the size of their shells, for in this
latter respect they almost equal any others of the family.
Their surface, although usually smooth, is generally
covered with an epidermis : the outer lip is rather thin
and simple, but the inner is frequently thickened and
margined at its basal half : there are three or four very
strong transverse plaits on the pillar, placed nearer to
the top than to the bottom of the aperture ; but the
uppermost is always largest — not, as in the Volutidce,
the smallest. Like these latter shells, also, the tip of
the spire is almost always papillary ; but this part is
small, and assumes a very different appearance to that of
of the true volutes. The next genus we shall notice —
(there being an hiatus in this part of the series, which
we shall subsequently advert to) — is Fasciolaria, where
the spire is so much lengthened, as to be longer than
the canal, — thus reversing the proportion between these
parts as seen in Turbinel/a. The plaits on the pillar
are small, placed close to the bottom of the aperture,
and generally not more than two ; the last being by
far the largest. Some of these large shells are smooth,
but a few are corrugated or wrinkled; thus preparing us
for the ScolymincB, to which they directly lead. Two
other genera, however, enter into this circle: one of

CHAP. III. THE TURBIXELLIN^. 77

these we designated^ on a former occasion*, as the
Pyrella spinlla : it so completely represents Pyrula in
this group, that no one can mistake the analogy ; while
it differs from the old TurhinellcBi by having no other
indication of teeth hut a sharp ridge along the bottom
of the aperture. Following this, we assemble nearly all
the fossil TiirhinellcB under the name of ClavaUthes:
they form, in our estimation, one of the best defined
and most natural groups in malacology ; and our only
surprise is, that they never should have been so defined
by Lamarck. The species, we believe, are all found in
the plastic clay formations. They have hitherto been
confounded with Fusus, but they clearly hold an in-
termediate station between that genus, or rather sub-
family, and the typical TurhineU(F, close to which we
now arrange them. The ClavaUthes, in short, are
Turhinellce, without plaits on their pillar, and with a
more lengthened spire, but the tip of which is also pa-
pillary : the smoothness of the inner lip, and the fusi-
form shape of the shell, has probably induced authors
to place them with Fusus ; but the great size of the
body-whorl, the papillary spire, and the thickness and
general habit of all these shells, bring them much
nearer to Turh'melki. Several species occur among the
fossils of the Paris basin; and one or two of gigantic
size are found at Hordwell Cliff, in Hampshire. We
have now indicated four of the types of form or ge-
nera, Avhich compose the natural series of the Turbi-
NELLiN^ : but there is a hiatus between Turhinella
and FascioJaria ; and this cannot be filled up by any
shells which, so far as we are aware, have yet been
published. As this form, according to our theory,
should represent Scoli/mus and Murex, we should
expect it would have the general shape, and plaits on
the pillars, of Turhinella, but with the rugosity and
perhaps the spines of a Scolymus or Murex, Now, such
a recent shell we have a distinct recollection of see-
ing, many years ago, in the hands of a dealer ; and we

* Zool. 111. series i.

78 SHELLS AND SHELL- FISH. PART I.

remember, at the time^ being completely puzzled as to
what genus it should be placed in. This, of course,
was when we were entirely ignorant of those prin-
ciples of variation in the MoUusca here developed ;
but we made a memorandum of the occurrence at the
time, conjecturing that it might hereafter be useful.
Such we now think it, inasmuch as it realises the very
form which is requisite to complete the circle we are
now upon. Finally, the long spire of Clavalithes is
continued to TurbineUa Scolymus*, which differs only
in this respect from T. rapa.f

(68.) The ScolymincB, as already remarked, are
rough, blunt-spined shells, having the aspect of many
of the Linnsean murexes : but the canal, although short,
is straight; the pillar is furnished with distinct plaits,
generally central ; while the spire is always pointed.
The animal we can fortunately describe from the un-
published drawings of our late friend Guilding : the
foot of Scolymus is a little longer than the aperture, the
the breadth measuring one half the length ; the oper-
culum semicircular, and tolerably large, as in Fascio-
laria; the peduncles of the eyes very long, the eyes
themselves being placed more than half way from the
base to the tip ; the anterior part of the foot is truncate,
with the angles rounded ; the hinder part is also rounded ;
the mouth is not probosciform ; and the respiratory
siphon is rather short. We cannot make use of this
information to the extent that could be wished ; but it
will become doubly valuable for comparison, so soon as
the animals of TurbineUa and of the neighbouring
genera are made known. The first form which pre-
sents itself in this division, after leaving Fasciolaria, is
our genus FlicatcUa, — an extensive group of small shells
hitherto confounded with Fasciolaria and Sco/i/nins.
From the first, they are known by the little plaits upon
the pillar being almost transverse (as in Scoli/miis), and
not oblique, as in Fasciolaria; these plaits are likewise

* Ency. Mcth. pi. 431. bis, fig. 2. + Ibul. fig. 1.

CHAP. III. THE SCOLYMIN^. 79

much less distinct, and of the same thickness, without
the last being manifestly larger; they are always situated
across that part of the pillar which forms the lowest
part of the aperture, and not, as in Scolymus, higher up
towards the middle ; the situation of these plaits, in
short, removes the genus from Scolymus, while their
form and direction separate it from Fasciolaria. The
variation in the shape of the shells is precisely what
may be expected from this intermediate position. In
such as approximate to Fasciolaria, the canal is nearly
as long as the spire; while in those wliich lead to Scoly-
mus, it is shorter : many of the species, again, put on
the aspect of the spindle-shells (Fusus), and hence have
been arranged among them"; while others have the exte-
rior aspect of Murex. They are all of a m.oderate or
small size; and may be known from the Muricidtp by
the distinctness of their transverse plaits, the absence of
internal tubercular teeth on the inner lip, and their
longer channel : they are united to the next genus by
Scolymus (or Plicatelki) capitellum, — a shell which may
be placed in either group without any violation of na-
ture : its predominant characters, however, appear to
us to be those of the last, inasmuch as the three plates
are nearly of equal thickness; whereas, in Scolymus, the
lower are generally much smaller than the upper, and
their situation is much higher. This last-named genus
is a very striking one, and, being now disencumbered of
Plicatella, admits of a much more precise definition than
we originally gave it*: the shells are short, excessively
heavy; the spire acute, and almost turbinate: the pillar
short; the canal straight, and longer than the spire;
while the whorls are rugged, and beset with blunt,
simply folliculated, or plaited spines. All the species
are from warm countries.

(69-) There is strong evidence to believe that the
natural situation of Cancellaria is immediately after
that of Scolymus; for, although the two genera, in their
typical chaiacters, are very different, v^^e once possessed

* Elements of Conchology, p. 21,

80 SHELLS AND SIIELL-FISH. PART I.

certain species which exhibited so many intermediate
characters, that, but for the pecuHarly small and incurved
channel of Cancellaria, we should have been at a loss
where to place them : one, we more particularly remem-
ber, had an exceedingly wide umbilicus, nearly as
large as the Scolymus iimbilicaris* , with a very simi-
lar shaped shell; and it is not a little remarkable that,
in the figure of this very Scolymus, the base of the
pillar, instead of being straight, as in all the other
species, is represented as curved inwards, and with an
exceedingly small notch, — two characters which are
absolutely peculiar, in this group, to Cancellaria.

(70.) The fourth genus, Rhinedomus, is typically
represented by the Cancellaria senticosus of Lamarck,
but of which there are several species. It retains suf-
ficient of the characters of CancellaricB to show its true
affinity to them, for the exterior surface is longitudinally
ribbed, and rough with little points, and there are two
distinct folds, or rather one deep groove, at the base of
the pillar : but in all essential respects the true cha-
racters of Rhinedomus are remarkably different : the
basal canal is fully developed, being deeply notched ;
and, what is very unusual, there is a distinct, though
not a very deep, sinus close to the base of the outer
lip. The animal, made known to us by the valuable
researches of MM. Quoy and Gaimard, is most remark-
able ; but, until we are acquainted with that of Cancel-
laria, it furnishes no comparison with them. The other
species of Rhinedomus have the spire less elongated,
and thus open a passage to our new genus Polytropa,
examples of which will be found in two well-known
British shells, the Purpura lapillus and imbricatus of
Lamarck : this genus agrees, indeed, with Purpura, in
common with many other of its prototypes, in having
the inner lip flattened ; but the base of the shell, in-
stead of being truncate, forms a short straight channel;
the spire is always as long (generally much longer) as

* Ency. Mt'thod. pi. 431. bis, fig. 1.

CHAP, 111. THE EBURNIX^. 81

the aperture ; there is also no internal canal : the inner
lip sometimes has a row of tubercles. The most typical
species^ however, is the Polytropa crispata.* As we re-
cede from this genus, and approach to Plicatella, we
find the spire increasing in length ; the numerous
crisp undulations give place to small nodules and Uttle
tubercles at the base of the inner lip, so that the two
genera became united : the circle of the ScolymincB
is closed ; and this, without the deficiency of a single
link in the chain of connection which binds all the five
genera together,

(71.) The next sub-family, EburnirKP, is one of very
great interest, since it brings together certain genera
whose station has hitherto perplexed us all. For-
tunately, how^ever, Mr. Gray has characterized the re-
markable little genus Cyllene ; and the possession of
other species, joined with those of Rhinedomus, before
alluded to, have prevented us falhng into some errors :
the discovery of the basal sinus, also, on the outer lip of
Rhinedomus, at once opens a passage to Cyllene, which
still retains a costated and somewhat cancellated exterior,
with the basal sinus of the last genus. It deserves es-
pecial notice, that the species described by Mr, Gray
has a distinct channel round the suture, but the other
we possess has not. Now, this variation is precisely
what is met with in the genus Ebiirna, the types of
which are channeled, the others not. The slight striae
at the base of the pillar in Cyllene, are explained by
its analogy to Oliva, just as its obsolete notch typifies
its reference to Stromhus. Other species will no doubt
soon come to light ,• so that, with these facts before us,
we have no hesitation in placing Ehurna as the next
type. Between this last, and Striithiolano. there exists
the most intimate relationship in regard to their animals ;
both have a comparatively small foot, but a probosci-
diform mouth of excessive length, particularly that of
Struthiolaria, which, when fully protruded t, is more

* Chemnetz, 187. fig. 1802, 1805. Ency. Meth. pi. 419. fig. 2.

f See the animal of Strutk. crenata. Voy. d'Astrolobe, pi. 31. figs. 8, 9.

6

82

SHELLS AND SHELL-FISH.

PART I.

than equal to the entire length of the shell, while the
operculum is only rudimentary. A singular unde-
scribed shelly, just communicated to us by Mr. Stuch-
bury, is evidently intermediate between the shape of
the shells of Ehiirna and Struthiolaria ; so that this
part of our series is definite. We must now return to
Cyllene, for the purpose of showing its close approxi-
mation to the fourth genus^ Pseudoliva, the type of
which is the Buccinum plumheum of Linnsean authors.
The very aspect of this {^fig. 3. a) is quite sufficient to
show its proximity to
Cyllene, and its abso-
lute connection with
the VolutidfB by means
of Olivillahiplicata (&).
Last of all, as forming
a passage to the Py-
rulcBy we have Lati-
axis MawcB* (Sw.),
where thechannelround
the whorls is so broad that they become almost discon-
nected. At first sight, this shell would appear a mon-
strosity, did w^e not remember its prototype, Scalaria
pretiosa, not to mention the tribe of Tuhulihranchia.
We consider it therefore as perfect in its kind, related to
aU the types we have noticed by its channeled suture, to
Ehurna by its large umbilicus, and to Rapella (the first
genus of the PyrulhKv) by something, very difficult to de-
scribe, in its general shape. The whole sub-family may
therefore be defined as shells whose base is truncate, having
a channel more or less developed round the whorls, an
aperture contracted at its base, and generally either
emarginate as in Ehurna, or very slightly notched as
in Struthiolaria and Latiaxis : the inner lip is much
developed and spreading, without having a defined
margin. The following table will also exhibit some of
its analogies ; the group, as a whole, being evidently a
representation of the NassincB in the neighbouring
family of the Muricidce.

* Griff. Cuv. pi. 25. figs. 3, 4.

CHAP. III. THE PYRULIN^. 83

Analogies of the Eburnix^.

Genera of the 4..„;^„;„„7 r'A„..„^/^v„ Families of the

Eburmnj^.. Analogical Characters. Zoopkaga.

Struthiolaria. Shell nodulous or muricated. MuRiciDiE.

Eburm. I ^'deUbped.' ' '^^ "'"'' ^'^ """'^ ] Turbixellid^.

Cyllene. P Uncfsinus.''"*" ''^ '''^^ ^ ^''' ] StROmbid^.

Pseudoliva. Oval, smooth. Cypr^id^,

r^/,-^.-» f Spire excessively short and irre-^-tr^, r,^,

Lahazis. I 'g^i^^. jhg ^^^J^^ sub-coronated, j Volutid^.

This comparison explains the relation which Sti'uthio-
laria has been thought to have, by some writers, to
the murexes : the smoothness of all the Ehm'nirKx is
remarkable, and is no doubt an indication of their re-
lation to the typical TurhineUidcE. The lobe of Cyllene,
again, is borrowed, as it were, from the Stromhidte, in
order to show the analogy of both. The excessive short
spire of the two next is explained on the same ground ;
while the irregular spire of Latiaxis is to be found in
no other shells of the zoophagous tribe, than those of
the typical volutes or melons.

(72.) In the Fyridince, or the fourth division of the
family, we place the greatest part of those exceedingly
diversified shells forming the genus Pyrula of modern
writers. They are so designated from their generally
being pear-shaped ; the basal portion representing the
stalk end of that fruit, and the spire and w^horls the
other. This comparison, indeed, is so far apt, that it
gives a very good idea of the shape most prevalent
among them, notwithstanding the great differences they
present, in other respects, among themselves. This is
one of the few natural groups in malacology, of which
we shall endeavour to give as complete an analysis as
a long and protracted investigation of their relations
will permit. We have invariably found, that where
natural assemblages such as this, in any division of
the animal kingdom, contain a great number of subor-

G 2

84 SHELLS AND SHELL-FISH. PART I.

dinate variations, such groups are the best calculated
for discovering the true principles of variation. The
interchange of characters between one division and
another is better marked — the gradations more gentle
— the links more perfect ; and hence, by carefully
tracing the transitions from one form to another, we have
a better chance of correcting our previous errors, and
of discovering the fallacy of any preconceived theory,
than if the hnks were so wide apart as to leave the
imagination to till them up, by supposing that they have
existed, or that they are not yet discovered. The
complete analysis of any one group, where these defi-
ciencies do not occur, is far more worthy the attention
of the scientific, and even the general, reader, than
numberless others whose links are incomplete.

(73.) The most striking characteristic of the shells
composing this sub-family, next to their pear-shaped
form, is that belonging to the inner lip and the colu-
mella, or pillar. It will be remembered, that in the Pu7'-
puriiKT, the inner lip, properly speaking, is merely a
thin glazing spread over that part of the pillar which
forms the left-hand side of the aperture : in this respect
they differ not from the shells now before us ; but the
pillar, instead of being broad, flat, and even concave, as
in all the Purpurce, is invariably rounded, and conse-
quently very convex : the shape of the Pyrulce, also,
necessarily renders the base of the shell much narrower,
and the canal much longer, than in their prototypes ;
although the degree of length of this channel, as well as
that of the spire, cannot enter into the general defini-
tion, since it will be seen that these are subordinate cha-
racters. The five principal modifications of form under
which we arrange all the species, are these: — 1. Pi/rula,
where the shells are strong and solid ; the whorls ge-
nerally muricated ; the spire short, yet elevated, well
defined, and often slightly papillary ; the inner lip en-
tirely wanting; and the canal considerably lengthened.
The Pyrula perversa may be taken as the type of this
genus, all of which are strong, solid, and muricated spe-

CHAP. III. THE PYRULIN^. 85

cies. 2, Ficula, where the great elongation of the canal
is still preserved^ but the shell is differently formed,
and its substance very thin. The body-whorl is nnore
or less ventricose, and without any spines or protube-
rances; the spire also is so small and depressed, that the
shell has very much the appearance of a Bulla, length-
ened out at the base; and there is little or no indica-
tion of even the thin glazing which forms the inner lip:
such, at least, are the characters of the typical species *,
which are few and easily recognised. In P. caudataj,
a new modification of form begins to be developed, —
slightly, indeed, but quite sufficient to leave us in no
doubt as to the characters of the next genus : this
species has the general form of Ficula, but the spire is
somewhat more elevated, and the inner lip is so much
developed that it begins to have a defined margin at its
lower part ; the body-whorl loses nothing of its ventri-
cose or inflated aspect ; and the shell is remarkably
thin and brittle. It is a fact highly interesting to our
present purpose, that there is a shell in almost all re-
spects similar to the Ficula caudata (of which it has
been described as a variety), but which has a decidedly
short canal. Here, then, is the point of junction so
desirable to be established between Ficula and our new
genus Rapella, typically represented by the Ficus rapa
of authors.;]; The spire, although pointed, is still re-
markably short, and almost turbinated ; the body-whorl
equally ventricose with the last, but the lower portion
is no longer lengthened — it becomes very short, and,
by the more sudden contraction of the aperture at the
basal point, the canal becomes so very small as almost
to be obsolete. From the absence of the inner lip in
the last two genera, the shells have no umbilicus, but in
Rapella both these characters are apparent ; the umbi-
licus is usually very large, while the base of the inner
lip is partially or entirely reflected over it. The sub-
stance of these shells varies according to the species, and

* Pyrulaficus Lam. Ency. Meth. pi. 431. fig. 1.; fig. 2. is another species,
t Ency. Meth. pi. 436. fig 1. c. X Ibid. pi. 434. fig. 1.

G 3

86

SHELLS AND SHELL-FISH. PART I.

each presents a graduated link between the thin and
brittle Ficula papyracea and the strength and solidity of
the other types. The whole of the Ficula are smooth,
except one species *, which has some very slight tubercles ;
but in Rapella, these tubercles, where they exist, begin
to put on that foliated structure so prevalent in the next
genus ; and in others there are indications of longitu-
dinal plaits upon the body whorl : the outer lip, how-
ever, is still very thin, and the whole may be described
as a group of generally smooth shells : in one or two
species, the inner lip is so much developed at its base, as
actually to fill up and cover the umbilicus. Yet, in all
the variations we have enumerated, the chief generic
characters are constant, and the basal canal is always
small.

(74.) We now come to the fourth type, or the genus
Myristica, — a name we exalt from a specific to a generic
signification for the shell now known as the Pyrula my-
ristica, and which we shall here call Myristica coronata.
These are the most dissimilar from the typical groups
we have yet noticed : the form indeed, somewhat pear-
shaped, — inasmuch as the spire is not longer than the
contracted part of the aperture, from which the canal
may be said to commence ; but they have nothing of
the lightness or the basal elongation of Pyrula and
Ficula, or of the effuse aperture and contracted chan-
nel of Rapella. They may thus be described as very
short, strong, fusiform shells _; the umbilicus either
entirely or partially concealed ; the outer surface armed
with muricated and semi-foliaceous spines, and marked
with transverse striae ; the inner lip vitreous, but thin ;
the outer lip with an ascending channel above, and a
wide and distinct one at the base. Now, between this
and the last group there is a series of connecting links
which unite them in the most perfect manner to each
other ; few of them, however, are figured in the more
general conchological works. We may here remark,
that the P. hippocastanum and lineatai of Lamarck are

* See Sowerby's Genera. f Ency. Meth. pi. 432. fig. 4, 5. .

CHAP. Ill, THE PYRULIX^. 8/

typical examples of Myristicn; while the well-known Pij^
Tula melongina, from having a much wider aperture^ puts
on something of the characters of Rapella. There are,
in fact, many other species ; but of our last genus Cuma

there is only one that we are yet
acquainted with, which can be
termed truly typical : this we have
named C. sulcata {Jig. 4.). Its
characters may be simply de-
scribed as shorter, but more gra-
dually fusiform, than the last, —
the middle of the pillar being
crossed by a single transverse and
very prominent fold : this cha-
racter is altogether without pa-
rallel in this sub-family ; and dis-
tinguishes this type, at the first glance, from all the
others : the form of the shell is much more slender
at its two extremities than any of the Myristicce, and,
although much shorter, its aspect at once reminds us
both of Fusus and of Plicatella. Nevertheless, although
this shell, from having a distinct plait upon the pillar,
seems to us the true type of the connecting genus be-
tween Pyrida and Fusus; it is quite evident that
the common Pyrula carnaria *, and the more rare P.
canaliculata Sw. t, so closely agree wdth the foregoing
definition, that but for their smooth pillar, and the
greater elongation of their base, they would both enter
into the same genus. In one point of view, it may be
said that these very characters, which preclude their ad-
mission into Cuma, may yet bring them wathin the con-
fines oi Pyrula; so that, being followed by such shells as
P. carica ^, Sec, we come again to the typical genus with
which we began the series ; and yet, on the other hand,
we may suppose these dubious species, to form the first
genus of the FusincB, connecting that sub-family with
the PyrulcB by means of Cuma. In either way, however,

* Ency. Meth. pi. 424. fig. 3. t Ibid. pi. 424. fig. 2.

X Ibid. pi. 433. fig. 3.

G 4

88 SHELLS AND SHELL-FISH. PART I.

there is abundant evidence, even if these species are
omitted, that the PyruUnce form a circular group, in
which scarcely a link is wanting. This will be more
evident upon arranging the whole of the genera in a
tabular form, and placing the few species we have
already named in the natural series of their succes-
sion.

Genera of the Pyrulinje.

List of the Species, sJiowing the progressive Change of one Genus to the

other.

"tuba. Ency. Meth. pi. 426. fig. 2,
perversa. lb. fig. 4.

candelabrum. lb. pi. 437. fig. 3. ; pi. 438, fig. 3.
Pyrula <| carina. lb. pi. 433. fig. 3.

canaliculata. lb. pi. 436. fig. 3.
spirata. lb. pi. 433. fig. 2.
_Burdigalensis. Sowerby's Genera, fig. 2.

rtricarinata. lb. fig. 3.
T?,r„T A 3 fi«^"s- Ency. Meth. pi. 432. fig. 1.

ricuLA ■) reticulata ia?«. lb. pi. 432. fig. 2.

tcaudata lb. pi. 436.

Rapella

Tpapyracea. lb. pi. 436. fig. 1.

3 abbreviata. lb. pi. 426. fig. 2.

ieffusa Sw. lb. pi. 434. fig. 1. {Pyrula Rapa.)

C nerito'ides. lb. pi. 435. fig. 2.

Smelongina. lb. pi. 435. fig. 3. a. — d.
lineata. lb. pi. 432. fig. 5.
coronata Siv. lb. pi. 432. fig. 3. a, b.
hippocastanum. lb. pi. 432. fig. 4.

CuMA sulcata Siv. — followed by Pyrula tuba. Sec.

(75.) The strong resemblance of the Pyrulince to
the PurpurincB is a constant subject of remark among
conchological writers, and is so strong as to be often
exceedingly perplexing. We now allude only to the
latter group, as left by Lamarck ; but many of these are
so like our genus Myristica, that it is only upon close
inspection their distinguishing characters are detected.
Now, this strong resemblance can be accounted for in
two ways : first, by supposing that the two groups re-
present each other generally in their own respective
circles ; and secondly, that this strong analogy actually
extends to the particular genera of each sub-family.

CHAP. III.

THE FUSINiE.

89

The best way, therefore, of testing this theory, is to
place these groups in separate columns^ and to examine
the result.

Analogies of the Turbinellid^ and the C^ssid^e.

Sub-families of
Turbine llidcE.

TURBINELLIN^.

SCOLYMIN^.

FUSININ^.

Py RULING.

Eburnin^.

Analogical Characters.

f Shell large, ponderous, heavy, and \
I mostly smooth. j

f Shelis rough, muricated, and ge- 1
t nerally spined. J

("Body of the animal, and spire of?
i the shell, excessively long. J

Spire always shorter than the
aperture; the pillar straight and
smooth.

Base and canal very short ; inner "^
lip generally formed by a thick ^
enamel. 3

1

I

Sub-families of
MuricidcB,

CASSINJi.
MURICIN^.

buccinin*.
purpurin^.

Nassin^.

(76.) Without enlarging upon the evident traces of
a systematic series of analogies, running through the dif-
ferent groups here brought into juxtaposition, it is at
once seen that the PyrulincB and the PiwpurincE actually
come opposite each other : and having already shown
(73.) how intimately their genera correspond, we may
pass into the next division.

(77.) The Fusing are our last sub-family, and
are composed of those numerous shells arranged in the
genus Fusus of Lamarck, and are the most elegant and
delicate we have yet noticed. Their general form is
that of a spindle, tapering very much at both extremi-
ties : hence the spire is very long ; and as this contains
the body of the animal, the circumstance forms a ge-
neric character, both for the moUusk and its shell. The
canal is almost invariably long, and generally equals
the spire, while the basal volution is typically small :
the pillar is constantly destitute of any appearance either
of plaits or teeth, and the tip of the spire is acute :
this latter character, more especially, separates them
from the Turhinellince, where there are, in the aberrant

90 SHELLS AND SHELL-FISH. PART I.

genus Clavalithes Sw .* , several shells of an equally fusi-
form shape^ but having the tip of the spire papillary.
The shape of the FusincF, and the elongation of the body^
render them very distinct from the PyruUncB, excepting
at that point of junction where the two groups are
united. Nothing satisfactory is known^ so far as we can
discover, of the general nature of the animals.

(78.) The Fusinm being thus defined as a whole, we
may now proceed to the series of the genera, and their
peculiarities. — 1. In the first or typical genus Fusus,
the spire and channel are both very much lengthened_,
and remarkably slender ; the outer lip generally cre-
nated, — the indentations corresponding with the internal
striae, — 2. Chrysodomus, distinguished from the last by
the comparative shortness of the basal channel_, and the
ventricose or enlarged shape of the body-whorl. The
beautiful orange mouthed wilk of England is a typical
example ; and the few others^ now known^ are all of a
large size, and chiefly found in northern seas_, where they
represent the more elegant Fusci of tropical latitudes :
the outer lip is always thin and smooth. — 3. Leiostonms,
where the body -whorl is still larger than the last, while
the spire, although remarkably short, is acutely pointed ;
the inner lip is highly polished, and the contracted base
of the shell is equal, or rather longer than the aperture ;
the outer lip, like that of Chrysodomus, is thin and
sharp, but thickened within. All the species of this
form we have yet seen are fossil, of which the Fusus
bulbiformisf is one of the best and most common types:
the outside and the mouth of these shells are always
smooth ; hence their generic name. — 4. The next genus
we have named Strepsidura, from the twisted shape of
its tail or channel : the form of these shells is very much
like the last, but the base or channel is equal with the
spire, and is turned in an oblique direction; the outside

* We had originally called this genus ClnveUa ; but as this name may be
thought too closely resenihling, in sound, those of ClavagcUa and Clavalula
(Lamarck), we now substitute another, — more appropriate, indeed, as all
the species we have yet seen are fossil.

t Ency. Mcth. pi. 428. fig. 3.

CHAP. III. THE FUSING. Q\

also is marked by distinct longitudinal ribs^ and has a
coronated row of little mucronate spines^ much like
those of the harps : the type is the Fusus ficulneus, a
fossil of Grignon.* — 5. and lastly^ we come to those large
species represented by Fusus colossus, coronatus, 3forio,
Szc, which we have arranged in the genvis Hemif us us j
they are^ indeed^ only half fusiform_, as the spire is
shorter than the aperture : they are also distinguished
by an internal canal^ and the whorls are coronated with
compressed spines : it is easy to perceive, by the very
aspect of these shells, that they form the passage to the
Purpurce ; and their relation is so close, that, until we
know something of these animals, we feel somewhat
uncertain as to the station of such species as carnaria
and Cochlidium. Hemifusus, thus standing betAveen
Strepsidura and Chrysostomus, completes the circle of
the FusincB.

(79-) Upon taking a general view of these shells,
w^e cannot but observe, notwithstanding all their modi-
fications, that the predominant characters of the group,
more or less, are preserved. In all of them we find
shells more or less — equally or unequally — fusiform ;
that is, their thickest part is in the middle, and their
two extremities attenuated to a point. No teeth, either
marginal or internal, are ever seen on the outer lip,
while the inner is invariably smooth : the spire, except in
one type, is always longer than the basal canal; whereas,
in the PyrulmcB, the very reverse of this takes place.
It has often been remarked by our leading zoologists,
— and we have repeatedly illustrated the truth of the
position, — that no groups, whether generic or otherwise,
are so natural and so demonstrable as those which are
linked to others by mtervening gradations of form.
This is, indeed, completely opposed to the old opinion
formerly entertained, that no such divisions should be
tolerated in systems, but such as were distinctly separated
from each other; or, in other words, that, so soon as the

* The Fusus heptagonus (Ency. Mdth. pi. 428. fig. 7.) probably belongs
also to this genus, — although as an aberrant species.

92

SHELLS AND SHELL-FISH.

PART I.

links which connected two genera were discovered, the
two should be thrown into one. Experience, however,
setting aside all other considerations, has long ago con-
signed this dogma to oblivion, and has even obliged its
warmest advocates to renounce it. Ever^ day, almost,
is bringing before us, — particularly in the invertebrate
animals, — not only forms altogether new, but such modi-
fications of those we already have in our collections,
that in a few years we may fairly anticipate not one in
ten of the testaceous genera, now apparently isolated,
will remain so ; the links which unite them to others
will be discovered ; and thus, had we continued to unite
one geims to another in the fashion above adverted to,
we should be now fast approaching that simplicity of
nomenclature which would class all shells under one
genus, — the genus Testacea. It is only by following
out a theory of this sort, and seeing to what it would
lead in a general and extended application, that we can
judge of its philosophic soundness or of its practical
utility.

(80.) All the types of the FusirKP, as will now be
shown, have their representatives in the PyruUiKE.

Analogies of the Fusing and the Pyrulin^e.

Genera of the

Fusing.

Hemifusus.

Fusus.

Chrt/folomus.

Leiostomjis.

Strepsidura.

Analogies.

C Trapeziform, or sub-fusiform;?
t channel short. j

C Channel remarkably long; the 7
\ whorls generally angulated. j

Channel moderate.

f Spire very short ; the basal whorl")
I large and ventncose. 3

The base of the pillar slightly'^
turned outward, the exterior >
rougli and mucronate. j

I

Genera of the
Pyrulin^.

Cu7na.

Pyrula.

Ficula.

Rapella.

Myristica.

The first of these resemblances, or that between
Hemifusus and Cuma, is obviously an affinity, since the
most inexperienced student can perceive that these two
groups pass into each other. The greatest elongation

CHAP. III. ANALOGIES OF THE FUSING. QS

of the basal channel takes place among the Fusince in
Fusus, and the like character among the Pyrida in the
opposite column ; while in Chrysodomus and Ficula
this part is but of moderate length. Strepsidura is
the only genus in the first column^ which, by its lon-
gitudinal plaits and prickly tubercles, corresponds to
Myristica ; while the inflated shape of Leiostomus im-
mediately reminds us of Rapella — its prototype among
the PyruUnce.

(81.) Before taking leave of the Fusince, it will be
interesting to ascertain how far the genera put on the
aspect of those composing the TurhinellincB, more par-
ticularly as, the former being the last, and the latter —
TiirhineUincB — the first with w^hich we commenced,
it foUows, as a necessary consequence of the circularity
of the whole family, that these two divisions join, and
blend into each other. This, we think, will be very
evident, upon examining the following table : —

Analogies of the Turbinellin^ and the FusiNiE.

i Genera of the . ^^„;„„.„ Genera of the

TuRBiNELLii. Analogies. Fusing.

Turbmella IjaTa. Typical of their respective groups. Fusus.

? Sub-typical. Chrysodomus.

i-^-.^,-,/ „ T ovv, CTrapeziform; the whorls turreted: 7 rr -^

Fasciolaria l.a.m. y canal moderate. j Hetmfusus. .

X,,, ,. fPyriform ; the canal long; the base7 o, j

Pyrella. ^ of the pillar turned inward. j Strepsidura.

r Remarkably smooth ; the spireT
Clavalithes. < and aperture of equal length ; >■ Leiostomus.

L the pillar straight. 3

(82.) It would hardly be necessary to repeat, in this
place, the fact we have so often adverted to and illustrated
in former volumes, regarding the analogies of typical
gi'oups, were it not highly probable that they have not
met the eye of our conchological readers. It is there-
fore, perhaps, necessary to apprise them, that the re-
semblances between the typical divisions of two groups,
when thus brought into comparison, are almost always

^4* SHELLS AND SHELL-FISH. PART I.

more remote and faint than those which relate to the
aberrant divisions^ — and for this simple reason; — the
typical groups are furthest apart from each other ;
while the aberrant ones, by which they are connected,
are consequently nearer. In this branch of science,
moreover, the difficulty of discovering the analogies
of typical groups is still further increased, when, as in
the present instance, we are without that precise in-
formation on the animals, which might furnish us with
some analogical points of resemblance. Besides, it
must always be borne in remembrance, that our ar-
rangement is not built upon these analogical compa-
risons, but upon absolute or presumed affinities, the
result of minute analysis. Whatever coincidences,
therefore, arise on comparing the different groups, are
more properly the result than the cause of their ar-
rangement. Analogy is thought to be of the highest
importance for the verification of a natural group, but
it must always be subordinate to affinity. Applying
these general remarks to the two typical groups which
stand first upon our list, it will be remembered that
one, intervening between Turbinella and Fasciolaria,
has never been made known. Passing these, however,
and comparing Fasciolaria and Hemifusus, we find
they are almost precisely of the same shape and pro-
portions ; and that the shells can only be distinguished by
one having the pillar plaited, and the other smooth.
The very name of ficulneus, given by authors to the
type of Strepsidura, shows its analogy to Pyrella, and
consequently to Fyrula ; it is, in fact, completely a pear-
shaped shell. The resemblance of Clavalithes and
Leiostomvs is equally striking : both are remarkably
smooth shells ; with the channel lengthened, and the
basal volution more or less enlarged ; both are fossil
genera of the same strata; and although Clavalithes in
general possess very small plaits on the pillar, and a
papillary spire (without which, in fact, the genus could
not be clearly defined), yet there are one or two species
having the pillar, as in Leiostomus, perfectly smooth.

CHAP. III. MURICID^ AND TURBINELLID^. 9^

If the reader turn to the figures of Clavalithes longcevus,
clavellatus, scalaris, Noce^ and rugosus*, and to that of
Leiostomiis hulhiformis f, he will at once perceive their
mutual affinity much better than from our description.
(83.) Having now supplied all the details in our
power respecting the two great families of the Zoophaga,
or predacious shell-fish, — and which, in fact, stand at
the head of the entire class of Test ace a, — we shall
lay before our readers the following diagram, which
will explain, more distinctly than our usual tables, the
circular affinities of each of these families, and the cor-
responding analogies of their sub-families.

1 M,iricinw/6- =^-^\ -/- <>sTurbinina! \

2 Casshvt^ j\- 'Cj Scolymincs 2

4 Purpurincei

3 Nassin^O^^^ ^^^^hurnirue 3

The analogies of the two typical sub- families (Land
2.) of the circles are very remarkable. We thus find that
the MuricincE stand opposite to the TurhinincB, and the
Cassince to the ScoIymirKe. These resemblances repose
on the relative developement of that portion of the
shell which protects the respiratory siphon (which
must of course be modified in unison with its covering
or sheath) : thus, in the MuricincE and the Turhinince,
the basal canal is considerably longer than in the Cassinm
and the Scolymince, where, in effect, this part is either
short, or absolutely wanting. Thus it is, that we may
often overlook, or be ignorant of, some one character,
which, when discovered, serves as a common bond of
analogy between two groups, in all other respects to-
tally different.

* Ency. Meth. pi. 425. f Ibid. pi. 428. fig. 1. a, b.

()6 SHELLS AND SHELL-FISH. PART I.

(84.) The genus Buccinum andthe aberrant genera of
Fusus are so much ahke, that they can only be distin-
guished by the latter, as Chrysodomus, having the basal
canal slightly produced instead of truncated. These two
divisions are further remarkable for containing those
genera which, by the length of their spire, contain the
longest-bodied Testacea in the whole tribe. But for
its elongated canal, Fusus colus and its allies would
become TerehrcB ; while, but for their truncated base,
these latter would be placed among the Fusince. The
remarkable analogies between the PurpurincB and the
Pyrulincp. (4. 4.), having already been so much enlarged
upon, need not be again repeated. The only remaining
comparison concerns the EburninfS and the Nassince,
— 'two groups so closely related to each other in their
typical examples, that even Lamarck, mistaking ana-
logy for affinity, actually places them following each
other : both, in fact, have the base of the shell obtuse,
without any elongation ; the inner lip very thick, and a
strong internal groove within the aperture. But it is
needless to insist upon an analogy so indisputable : we
may, therefore, presume, that in these two comprehensive
groups we have made good all our propositions on the
laws of the natural system * ; and we shall now endea-
vour to do the same in the succeeding families of the
Gasteropoda.

* The Geography and Classification of Animals^ Part iii. On the First
Principles of natural .Classification, p. ,221. Vol. LXVl. of the Cabinet

CvCLOPJiDlA.

97

CHAP. IV.

THE ZOOPHAGA, OR PREI>ACEOUS SHELL-FISH, CONTIN'UEn. THE

FAMILY OF VOLUTIDiE, OR VOLUTES.

{85.) We now come to one of the most interesting
and beautiful families of the spiral Testacea; whether in
regard to the elegance of the shells themselves, or as
exhibiting a principle of variation in their structure
which can hardly be excelled. Our knowledge of the
animals themselves has been much increased, of late
years, by the French naturalists, and by the exquisite
drawings of Guilding. To generalise these discoveries,
however, so as to assign some undeviating character to
the whole, is almost impossible. The only peculiarity
appears to' be the absence of any operculum : in the ma-
jority, the eyes are sessile, placed at the base of two
short tentaeula, and as much developed, in the typical
volutes, as they are in the Stromhidcs : the mouth is
probosciform and extensile ; and the foot, in the typical
group, of enormous size.

(86.) The shells, however, present us with more
tangible characters. The base is never prolonged ;
although in some mitres {Tiara) it is contracted: in
all others it is truncated, as in the BuccinincB, and
deeply notched. The truncated base at once separates
this family from the Turhinellince, as there is no in-
stance of a volute with an elongated channel. The
plaits upon the pillar, again, are always at the base —
not in the m.iddle only — of the aperture ; although, in
the aberrant groups of Oliva, Ancillaria, and Marginella,
they assume peculiar modifications. The proportion of
the spire to the aperture varies in almost every genus ;

H

9S

SHELLS AND SHELL-FISH.

PART I.

and is, therefore, but a subordinate character. Nume-
rous as is this family, nearly all the species are confined
to warm latitudes, particularly those of the tropics. It
is hardly necessary to add, that the whole are predaceous,
and consequently carnivorous.

(87.) The VoLUTiD*: arrange themselves into five
primary groups. — 1. The Volutins, or typical vo-
lutes, having a short spire more or less papillary, and
the lower plaits upon the pillar largest ; the foot is
excessively large, and envelopes the sides of the shell.
2. The Mitring, or mitres, where the spire is always
acute, generally longer than the aperture, and the lower
plaits smallest ; the foot small, not dilated on the sides,
and the siphon (a) rather long, as in Mitra sanguisuga.

(Jig. 5.) The first is the typical, and the second sub-
typical. The three aberrant sub-families are, — 3. The
CJLiviNiE, or olives : cylindrical in shape ; the aperture
linear, and the pillar thickeijed and confusedly plaited.
4. Ancillaria : the aperture wide, and the base of the
pillar alone thickened and striated. 5. The Marginel-
jAtiJE, or date-shells, having plaits upon the pillar, and
crenated teeth on the thickened outer lip ; the foot

CHAP. IV. PRIMARY DIVISIONS, THEIR ANALOGIES. 99

very large, but the mantle not lobed or reflected.

{fig^ 6.)*

(88.) These primary divisions having long been ad-
mitted by all writers, we shall at once compare them
with those of the predaceous Zoophaga.

Analogy of the Volutid.e and the Zoophaga

Analogies.

Sub-families of the
Voiutidte.

Families of the
Zoophaga.

VOLUTINA.

MlTRIX^.
OLIVINiE.

Ancillarin^,
Marginellin^.

[

Foot of the animal excessively
large ; base of the shell trun
cate,

{Volutince and Cassin^.)

■•}

Foot small, not so long as the'J
shell, the base of which is con- r
tracted. J

{Mitrttus and Scolymus.)

f Spire very short ; tip papillary j 1
X pillar plaited. J

Spire nearly or quite concealed.
Outer lip detached and thick-

{

ened.

]

Muricidce.

Turbinellidis.

I'olutid^.

Ci/prceidee.

Strombidce.

Thus, the truncated and wide-mouthed helmet-shells,
among the MuricidcE, find their prototypes in the melon
volutes ; and the muricated mitres, in the sub- typical
Turhinellida;, with which they also agree in their fu-
siform shape. The Olivines correspond to the typical
volutes, in having their foot excessively large. The ani-
mal of Ancillaria is unknown ; but, from the high polish
of the shells, we may suppose it is analogous to the
cowries. Lastly, the 3Iarginellincp are clearly proto-
types of the Stromhid<T, as they are the only volutes
which have the top of the outer lip detached from the
body-whorl,

(89-) The weakest point in the foregoing table is
that, perhaps, which relates to the Ancillarice ; but, by
comparing the family with the Cassidce, the station of
this group will be more clearly shown.

* The annexed cut is from one of the unpublished drawings of Guildinj:
the shell is jiure white.

H 2

100

SHELLS AND SHELL-FISH.

PART J.

Analogies of the Volutid^ and the Cassid^e.

Suh-iamilies of

VoLirrii)-E.
Tyjjical Genera.

VOLUTA.
MlTRi.

OUVA.
AjfCILLiRIA.

Marginella.

Analogical Characters.

Smooth; spire short ; base truncate.
f Rough ; spire longer j base atte- 1
X nuated. i

f Foot very large ; no distinct plaits >
X on the pillar. 3

Aperture very wide ; the base of
the i)illar oftea thickened and
striated.

J" A thick deposition surrounding
t the anerture of the shell.

i

Sub-families of

CASsin^.
Typical Genera.

Cassis.

MUREX.

buccinum.

Purpura.

Nassa.

This table illustrates what has been often shown
among the vertebrated animals, — that, to establish the
analogies of two given groups, they must often be traced
through the medium of other groups : thus, the Ancil-
larice, in one respect, are prototypes of the Cyprcece; and
in another, by their wide aperture and striated base, are
equally so to the Parpum. Again, if it was asked, —
Vyhat shells among the volutes have a marked resem-
blance to Concholepas and Monocerob- ? every natural-
ist would point to Ancillaria ; for all three have a very
wide aperture, and a distinct prominent tooth at the base
of the outer lip. This is conclusive evidence ; and it
therefore follows that the analogy betw^een AncUkiriii
and Ci/pr(va, however obscure in a direct Avay, is ren-
dered plain by being traced through the medium of the
Furpurince. The other analogies in the table are so
palpable to the zoologist, that they require no illustra-
tion. Hence it follows, as a natural result of this com-
parison, that the Volutidcp, in like manner, represent
all other of the circular groups in the zoophagous
tribe.

(90.) Our next object is to show that the Volutidcp.
as a whole, form a circle of affinity. It is clear that the
pre-eminently typical volutes, or melon-shells, branch
off into two separate series ; — one leading to Scaphelhi,
through F. magiiifica, falgetruni, papillaris, and fuai^

CHAP. IV.

CIRCLE OF VOLTJTID^.

101

form is ; the other to Cymbiola, or the muricated volutes.
From this latter, therefore, we shall begin to trace our
circle ; because, even here, we have evidently a repeti-
tion of the analogy between the smooth helmets and
the spined murexes. After the Cymhiolce, or muricated
volutes, succeed such as have the spire elongated, and
the plaits upon the pillar numerous : among them is the
Valuta lyriformis ; and this brings us at once into the
sub-family of the mitres : from these the passage to the
olives is rendered so gradual, by Mitvplla in one, and
Olivella in the other, that the mere systematist will
hardly admit these genera, because they blend into each
other. Hiatula is in the same predicament : by its wide
mouth, and the thickened base of its pillar, it is all but
an Ancillaria; so that the junction is here also complete.
There remains, then, only the MarginellcE, which are so
like some of the AnciUarice, that we may safely place
them as next in the series. What group then succeeds }
The illustrious Lamarck considered the well-known
/'^"A ^'^oluta Zebra (Jig. ?• «) of
/'Pf ^ our catalogues to be so like a

(wmM\ Marglnella, that he has actually

mim^ placed it

in that genus : and
l>\' i the affinity between this shell
and Scaphella maculata (6) is
immediate : we thus pass to the
S. fulgetrum, and again reach
the typical volutes. Thus, by
a different route, we return to
the point from which we started, without a link in the
chain being wanting.

(91.) We have thus shown that the VolutidtT form
a perfect circle of affinity ; and that the divisions we
have thrown them into are strictly natural, because they
are prototypes of all the others in the zoophagous tribe.
Each of these primary groups, or sub-families, will now
be examined in detail, in the order in which they na-
turally follow j viz., the Volutins, the Mitring, the
Olivine, the AxciLLARiisriE, and the Marginellin^..

H .3

a/^\S\

102

SHELLS AND SHELL-FISH.

PART I.

(92.) The VoLUTiNJE, or volutes, are immediately
distinguished from the mitres by being more ventricose
shells, with a much shorter spire (as in Voluta Ollu,
fig. 8.), the apex or point of which is
more or less thick and papillary. These
characters are developed in their highest
perfection in the smooth and coronated
melon-shells, to which, as being the
pre-eminent types of the whole family,
we are compelled to retain the sub-generic
r\dimeoi Voluta. Nevertheless, these cha-
racters are greatly modified in the five
leading genera, which we characterised
and illustrated several years ago ; and time has only con-
firmed us in the views we then took on the subject. We
accordingly arrange the whole of the Lamarckian volutes
under five leading genera. 1 . Voluta, — having the spire
excessively short, thick, and invariably smooth ; the
suture of the body-whorl being generally covered with
a vitreous deposition or glazing, never seen in the next
genus. 2. Cymbiola, — having the body-whorl less ven-
tricose, and the spire longer ; the apex not near so thick ;
while, in all those species which are coronated, the whorls
are marked with tubercles. In both these groups, the
plaits are almost invariably four, — the upper ones very
thin and small, while the lowest is nearly double their
thickness. This structure of the plaits, it may be here
observed, belongs alone to these two typical genera. The
third genus is Harpula, where the plaits upon the
pillar are very numerous, — the upper ones remarkably
slender, but gradually increasing in size and thickness,
until the last, or the two last, which suddenly become
smaller : the terminal whorls of the spire, although
still papillary, are much more slender. The form of
the spire, however, undergoes a change in this group,
and is therefore of secondary importance. This gra-
dual diminution of one of the typical peculiarities of
the Volutince prepares us for the fourtli genus, Volii-
tilithes, where the apex is perfectly regulai" and acute.

CHAP. rv. CHARACTERS OF THE GENERA. 103

This is one of the most natural, and, at the same time,
interesting groups ; for no recent species has yet been
found. The upper and finer plaits upon the pillar,
so characteristic of Harpula, now disappear, and leave
only one or two, or perhaps three, of the larger ones
at the base : the number of these plaits, iti fact, varies
according to the proximity or the remoteness of the
species to Harpula. The general shape is fusiform, the
whorls being strongly coronated with spines, and often
marked with transverse elevated ribs. The fifth and
last genus is Scaphella, where the upper plaits of the
pillar are as large as, or even larger than, the lower ; the
outer lip, also, is thickened within, and the suture of
the whorls is covered by a glazing of enamel. All the
species yet discovered are smooth ; and from the high
polish with which many are covered, there is every rea-
son to believe the animal has a strong affinity to that of
Mnrginella: this, indeed, is so obvious in the shells them-
selves, that Lamarck, as we before observed, has placed
the Scaphella Zebra (^jig. ?• «) ii^ that group. The form-
ation of the spire in general is conic, obtuse, but hardly
papillary ; but in certain aberrant shells, as S. fusifor-
mis and papillaris, the apex becomes thickened, and
assumes all the characters of the true volutes, and thus
unite with the melons by means of V. magnifica.

(93.) By these typical characters, it appears to us
that the natural and primary divisions of the La-
marckian volutes are regulated. In this, and all similar
investigations, we have found it necessary to discard all
theoretical notions as to what should be the primary
types. No ordinary degree of impartiality is necessary
for accomplishing this ; because every naturalist, more
or less, is prone to form certain preconceived notions as
to what he thinks should he the types of any particular
family ; and thus, prejudiced in favour of some hypo-
thesis, he sits down to his task, exactly in that frame of
mind the most un suited for the investigation of truth.
We candidly confess that many years ago, when this

H 4

04

SHELLS AND SHELL-FISH.

PART r.

family first engaged our attention^ we imbibed a notion
that the formation of the spire was the chief, if not the
only, character upon which they should be arranged : we
soon, however, threw aside this, and fancied the same
importance attached to the number of plaits : equally dis-
satisfied with this theory, we finally resolved to combine
all these characters, without giving to any one a para-
mount importance : having done this, we soon perceived
that these groups turned out to be representations of all
those in the entire family ; and this discovery prevented
our falling into many errors, which would otherwise
have been inevitable. We may now consider each of
these genera in further detail.

(94.) The pre-eminent types of the genus Voluta, for
reasons subsequently stated, are such shell-fish as have the
spire small, and so slightly developed, as to be all but
obsolete. This Ave see more especially in Voluta Nep-
tuni, Porcina, and Cymbium {fig. 9* ^) where nearly the

whole shell being enveloped, as it were, in the body-whorl,
gives to it, in all but the plaited pillar, the perfect ap-
pearance of a Bulla. The very slight elevation of the
spire is, therefore, one of the typical characters of this
genus ; but it is not the only one : the spiral whorls,
which end in the apex, whenever they are developed,
are remarkably thick, and are always perfectly smooth,
although the body-whorl may be coronated ; whereas in
the next genus, Cymhiola (C. vespertilio, fig. 9- ^)» these
spiral whorls are always plaited (c). There is a solitary

CHAP. IV. TYPES OF THE GENUS VOLUTA. 105

exception to this form in the true volutes, which is seen
in Voliita angulata, where the spire is absolutely pointed:
this exception, however, is a necessary one, for other-
wise there would be no species which would represent
VolutiUthes. The exterior of all these shells, so far as
we yet know, is covered with a thin epidermis, except,
perhaps, P. prohoscidalis ; so that, notwithstanding the
enormous foot of the animal, it does not appear that any
part of the shell is covered by that member. The chief
variations among those shells are as follows: — First, the
melons, whether smooth or coronated. Secondly, the
horned volutes, where the form is less ventricose, and
the body-whorl armed with long spines, as in imperialis
and chrysostoma *, both being connected to the coronated
melons by Broderipia and marmorata. The third
type is the V. Scaplia, having the outer lip, as in the
Stromhidce, considerably angulated and dilated. The
fourth type is the V. angulata, whose aperture is very ef-
fuse ; and the spire very short, but pointed. Lastly comes
the Voluta magnificaandfulgetrum '[, where we once more
have the egg-shaped and inflated form of the melons,
together with their very thick apex, totally different
from that of the Voluta ancilla, Sec, with which authors
have hitherto placed it. The Voluta olla and ruhiginosa
follow this type, and blend it, in the most perfect manner,
with those we first enumerated.

(95.) The passage from Voluta to our next
genus, Cymbiola, is opened by the rare V. mitis of
Lamarck ; which, by its general smoothness, its thick
spire, and a slight separation of the top of its outer lip
from the adjoining whorl, evinces a close affinity with
V. ScapJia. The volutes now before us differ from the
former, in being stronger, less ventricose, and having
their spire much more lengthened : their whorls are
angulated, and are mostly armed with acute spines, or

* Exotic Conchology.

f " In size and form this shell approaches nearly to V. magnifica." —
Tank. Cat. p. 28.

10b' SHELLS AND SHELL- FISH. "PART I.

small tubercles. Their great distinction, liowever,
lies in the apex of their sj)ire, which always exhibits
the incipient developement, in the shape of tubercles, of
those spines which may be on the body- whorl. The com-
mon Cymhiola vespertilio(^fig. 9- h) is the type of the whole
genus. From these to the next division, represented by
Cym. pacifica, gracilis, &c., the gradation is easy and
natural. Nevertheless, these Australian shells constitute
a distinct division ; for they are known at once by the
greater prolongation of their spire, which is nearly equal
to their aperture, and by the majority being only tuber-
culated : the apex is always obtuse and slightly papil-
lary. Whether we should con-
sider the V. ancilla (Jig. 10.)
as a distinct type of form, is
uncertain, but it possesses a
peculiarity of aspect, which
seems to detach it from those last alluded to : the very
slender shape of its apex, however, smooths the passage
to the V. hraziliana of Solander, ■ — remarkable not only
for its pointed spire, and its ventricose shape, but from
possessing, like V. anguhta, only three plaits to the
pillar. It is clear that this, as well as C. mitis, are aber-
rant forms.

(96.) In the next genus, Harpula, the form of the
apex, which is the main character of Voluta, became
somewhat variable in Cymhiola ; but in this genus it
is so uncertain, that it must be regarded only as of se-
condary importance. The numerous plaits, which ex-
tend the whole length of the pillar, are the most certain
distinction of Harpula, which is also a more numerous
genus than the last. Of the two primary types, one is
seen in H. vexillum, which is smooth, with a papil-
lary spire j the other, seen in H. hehrcea (fig. 12. b, in
p. 108.), is muricated, with the tip of the spire obtuse, re-
gular, conical, and hardly enlarged. There are, however,
other shells, obviously belonging to this group, which
will not arrange with either of these two divisions. One,

CHAP. IV.

HARPULA, VOLUTILITHES, SCAPHELLA.

107

the Harpula fulminata, has much the shape of a Fascio-
laria, but with the top of the outer lip slightly angulated
and dilated, something in the same way as Valuta
Scapha and Cym. mitis. The enlarged, knob-like form
of its apex immediately reminds us of Voliita papillaris ;
while in its markings, and in the thickness of the outer
lip, internally, it perfectly resembles Scaph. undidata.
The numerous plaits, however, clearly show it is a Har-
pula. Another, our H. lyriformis, is the only recent
volute whose spire is longer than the aperture ; and a
third aberrant type, the H. hullata, stands at the con-
fines of this genus, and forms a passage to the next.

(97.) VoLUTiLiTHEs, SO far as is yet known, is a
genus found only in a fossil state ; unless, indeed, Vo-
luta nucleus Lam., peculiar to the Australian seas, be
considered as coming within its limits : it exhibits
none of the delicate plaits on the pillar of Harpula ; so
that one half of its characters belong to that genus, and
the other half to this. The typical characters of Volu-
tilitlies have already been detailed (92.) ; and as we shall
particularly notice the subordinate types hereafter, we
may pass onward to the next group.

{9^'^ The last of the primary divisions is the Aus-
tralian genus ScAPHELLA ; the best known type being
the Scaphella undulata {fig. 11. a). All of these hitherto
discovered, are natives of the South Pacific Ocean.

We are not aware that any of these shells have an epi-
dermis, and their uniform smoothness leads us to con-
clude they are partly covered by the dilated lobes of the

108

SHELLS AND SHELL-FISH.

PART I.

mantle, as in the Olhnn(P. This, in fact, is the only genus
which is neither spinecl, muricated, nor tuherculated.
The spire (6) is conic and somewhat short ; the whorls of
the apex are scarcely papillose ; while the inner margin
of the lip is considerably thickened. The plaits on the
pillar, as to number, are by no means constant, even in
the same species ; in general, there are four, but the last
is always the smallest. Sometimes, however, the pillar,
at this part of the aperture, is thickened, and there are
five or even six plaits confused and irregular*, as in S,
papillaris (Jig. 12. «). This latter type is remarkable for

its apex, which is suddenly enlarged into a thick nipple-
like form (6), similar to Harpula falminata, and very
much like the published figure of Voluta fulgetrum.
From this, it is clear that we have again arrived, almost
unconsciously, among the aberrant forms of the melon
volutes ; ^or fulgetrum connects papillaris to magnifica,
which, with the form oi fulgetrum, assumes, as it were,
that particularly large spire which is the chief character
of the genus Foluta. Scaphella papillaris, on the other
hand, is closely connected to our S. fusiformis, which
thus unites it also to S. nndulata.

(99') Here we close our remarks on the affinities of
these magnificent shells ; but, before we enter upon the
consequences of this distribution, we shall endeavour to
meet some objections which may possibly be raised

* This deviation is not uncommon in Scaphella vndulafa : four is the
usual number of the plaits ; but sometimes, as Lamarck observes, there are
two smaller and supernumerary ones. (Lam. St/st.v'n. i. 'i^").) The same
variation is seen in Scaph. Jttnonio.

CHAP. IV. RT^MARKS ON VOLUTA ANGULATA. 1 Oy

against it. First, it may be urged, that, although the
series between the smooth melons and such shells as Va-
luta Scapha is sufficiently obvious, still, that the Volutd
angulata can never follow Scapha. This objection seems
well grounded, and certainly deserves attention. We
admit that angulata has a spire totally different from
that structure which we maintain is typical of the
group, wherein we have, nevertheless, placed it. But
is there anything extraordinary in this arrangement ?
Does there exist, in any one class of the animal king-
dom, a natural group, wherein all the species exhibit
the whole of the typical characters ? Every naturalist,
every systematist, knows full well that no such group is
to be found. It has been well said, by one of the
most distinguished naturalists that this country has
produced, that if a species possesses two out of the three
characters of the genus in which it is placed, this is all
we can expect ; and the reason of this is obvious : if
all the species possessed all such characters, then there
would be no gradation of structure — no links in the
chain of affinity — no loss of one structure — and there-
fore no taking up that of another. Now, all this is
diametrically opposed to facts ; for the whole creation is
but one connected chain of such graduated progressions,
— unequal, indeed, yet still graduated. The affinity of
Scapha to angulata is not so intimate and direct as
many others in the series ; but this is nothing to the
purpose, — because, as we have just said, affinities may,
and do, vary in degree : the question is, whether, be-
tween these two shells, there is a sufficient resemblance to
constitute any degree of affinity ? AFhen we compare
the angulated apertures, the form and proportion of their
plaits*, and the thick enamel spread over their spire,
we see an affinity which to us is unquestionable. If
angulata, in short, had a papillary spire, instead of a
pointed one, it would be of the same type or sub-genus
as Scapha ! the pointed spire, therefore, was necessary

* Not tlieir number, for in angulata there is one less.

110 SHELLS AND SHELL-FISH. FART 1.

in two respects; — first, to show that this shell was the
prototype of the genus Volutilithes ; and, secondly, to se-
parate it from V. Scapha. The next type we place after
angulataisfulgetrum, with which, also, comes magnifica.
Now, the complete glazing of angulata (which shows
the great size of the animal's mantle) is partially car-
ried on to fulgetrum, which Mr. Sowerby thus describes :
— " The left lobe of the mantle of the animal must have
been very large, since the columella lip is extended so as
to cover half of the lower volution." And that this
shell exhibits a further affinity to the slender spire and
angulated body-whorl of angulata, is evident on the
same testimony.* Evidence of this sort, from an un-
prejudiced writer, is the very best that can be produced,
since it is given without any idea of the use it may be
applied to.

(100.) Our arrangement of the Lamarckian volutes,
being thus founded solely upon affinity, would seem to
require no additional corroboration ; but beneath the sur-
face of this beautiful chain of relationship, lies another,
even more interesting, which can be only brought to
light by comparing the analogies, which all these vari-
ations in form present among themselves. These re-
semblances are so remarkable, that we shall now enter
upon them very fully. To do this in all cases, even
were it possible, might be tedious ; but in the present
instance it is almost unavoidable, inasmuch as we desire
that our theory on the laws of representation among the
Testacea should stand or fall according to the success
or failure which may attend their exposition in this and
the two preceding families.

(101.) The principles of natural classification, so fully
explained in the second volume of this series, and the
innumerable proofs taken from every class of vetebrated
animals that have been brought forward in the succeed-

* y\ Julgetriim "is easily distinguished by its acuminated papillose
spire, and by the obtuse angle on the upper part of the last volution.'' —
Sow., in Tankervillc Cat. p. 29.

CHAP. IV

ANALOGIES OF THE VOLUTIDiE.

Ill

ing treatises, are so well known to the majority of our
readers, that it would be superfluous again to repeat them.
But before we apply this theory to the group before us,
a previous question must be first disposed of, — namely,
upon what grounds we determine that the melon volutes
are the pre-eminent types of the whole family ? Now,
we do not regard this as a matter of speculative opinion ;
it must be determined, in fact, by the analogies which
the group possesses, as a whole, to other groups. The
following table appears to us to decide this question : —

Analogies of the Zoophagous and Phytophagous

Gasteropoda.

Families of the
Zoophaga.

MURICID^.
TURBINELLID^.

VOLUTID^

Cyprsidje.

STROiVIBID^.

Analogical Characters.

Typical.

Sub-typical.

fFoot of the animal excessivelyl
I large ; tentacula very short ; eyes |
<j sessile ; shell with an enormous )-
I body-whorl, and a short, nearly |
(^obsolete spire. J

f Shell smooth, glossy, partly cover- 7
X ed by the animal's mantle. 3

Animal with a respiratory siphon.

Families of the
Phytophaga.

Helicid^.
Trochid^.

Haliotid*.

Katicip.e.
Turbid^.

Now, as the ear- shells are at the head of the Halio-
tidce, it consequently follows that the melons have the
same rank among the Folufidce. The perfect ana-
logy of the two families is equally remarkable, whether
we look to the animals or to their shells : nay, it might
be carried still further ; for as there are coronated and
smooth melon volutes, so are there among the ear-
shells, — one division of the latter having their per-
forations smooth, the other having them elevated or
coronated.

(102.) We may now at once compare the five genera
of the VolutincB with the five primary divisions of th(^
whole family.

112

SHELLS AND SHELL-FISH.

PART I.

Analogies of the Genera of the Volutin.e to the Volu-

TID^.

Genera of the
Volutins.

Valuta.

Cymbiola.

Harpula.

Volutilithes .
ScapheUa.

Analogical Characters.

f Shell ventricose, smooth; spire 7
X excessively short. j

Shellmuricated; spire lengthened.
C The whole pillar covered with 7
\ slender plaits. 3

f Aperture very effuse ; spire acute ; 1
t base of the pillar alone plaited. J

{

Spire very short ; outer lip sinu-

ated or detached above,
thickened internally.

and

}

Sub-families of the

' V0LUTID.ffi.

Volutin*.

Mitring.

Olivine.

ancellarin&
Marginellinj;.

So completely are the five sub-families of the Volu-
tid(E thus represented by all the Lamarckian volutes, that
the analogical characters, or those common to both^
will almost serve to distinguish each, when joined to
the peculiar one which separates the two series. It
will be as well, however, to apprise the conchologist,
that the real type of the MitrincB is our genus Ttara^
and not that of Mitra, as formerly supposed.

(103.) Having bestowed no ordinary labour in our
attempt to work out the natural affinities of the Muri-
cidce, we were curious to ascertain how that arrange-
ment would tally with the present. The result will
be seen from the following table: —

Analogies of the Volutid^ and the Muricid^.

Sub-families of the

VOLUTlNiE.

Valuta.

Cymbiola.

Harpula.

Volutilithes.

ScapheUa.

Analogical Characters.

("Shell ventricose; spire remarkably 1
X short. 3

f Shell muricated with spines or tu- 7
( bercles , si)ire more lengthened, j

Spire often excessively lengthened.

C Aperture very effuse ; base of the 7
\ pillar grooved or plaited. J

r Outer lobe of the mantle much di- y
< lated ; rc})resenting Marginclla, >
C. and consequently Nassa. j

Sub-families of the

CASS1D£.

Cassincs.

Muricina:.
Buccininit.
Fwpuri7i(e.

Nassiiitc.

In this and the last set of analogies, we again have

CHAP. IV. VOLUTA TYPES OF FORM. 113

an instance of that inequality in analogical relations,
which, in our former volumes, we have so frequently ad-
verted to. This inequality, strangely enough, has been
somewhere urged as an objection to the theory of repre-
sentation. Such reasoners seem to suppose that, unless
all groups possess the same degree of resemblance to
each other, the evidence is inconclusive. On this plan,
an eagle and a lion may perhaps be admitted as analo-
gotis ; but a carnivorous insect and a carnivorous beast
cannot be so, because the analogy is remote or obscure.
But if there are any analogical resemblances in nature,
it follows, as a necessary consequence, that such resem-
blances are strong or faint, near or remote, according
to the proximity or distance, the similarity or the dis-
similarity, of the objects compared. Thus it is in the
present instance : the groups being remote, their analo-
gies are not strong ; nevertheless they are substantially
true, — because they are perfectly verified through the
medium of other or intervening groups, which, from being
more alike, render the analogies, in the same proportion,
more obvious or direct.

(104.) We may now proceed a step further, and
apply the same description of proof to the sub-genera,
or types of form, of the typical genus Voluta, upon the
affinities of which we have already said so much. We
leave it to be determined by others, whether these types
of form should be designated as simple divisions, or as
sub-genera, and therefore to be distinguished by a pa-
tronymic name. That this will ultimately be done, we
have no doubt ; because they are of the same rank as
the sub-genera of the other families. The shells which
we view as types of form in the restricted genus Voluta,
are as follows : — Voluta Neptmii, V. imperialism V.
Scapha, V. angulata, and V. magnifica. We shall now
place these in one column, the two extremes of which,
as we have already shown, meet, and form a circle :
the next column is composed of the genera of the La-
marckian volutes, which also form another circle. Now,
if the contents of one represent the contents of the other,

I

114

SHELLS AND SHELL-FISH.

PART 1.

without any variation in the order in which each divi-
sion respectively stands in regard to affinity, then all
the verification that analogies can possibly give, will have
been attained.

Analogies of the Sub- generic Types in the Genus

VoLUTA.

Typical Species.

/'. Neptuni.

V. hnperialis.

y. Scapha.
y. angulata.

V. magnifica.

]

Analogical Characters.

fVentricose ; egg-sliaped ; spire"?
\ very short, or none. j

Sub-ventricose ; spire more pro-
duced ; the body-whorl and
spire coronated.

f Upper angle of the outer lip ad- >
i vancing up the first spiral whorl. 5

(" Spire with the apex acute, and not V
I papillary. 3

r Columella lip thin and mucho
■< spread ; shell sub-fusiform ; >
t spire short. 3

Genera of the
J'ulutincc Sw. or
VoLUTA Lam.

Valuta.

Cymhiola.

Harpula.
Voltitilithes.

Scaphella.

Four out of the five analogies of this table are so clear
and definite, that they scarcely require further illustra-
tion. We thus see how imperialis represents the bat
volutes ; angulata, again, puts on the pointed spire of
Volutilithes ; while magnifica connects Scaphella with
the melons. The analogy between Scapha and Harpula
(the heavy tuberculated species of the latter being the
true types), although less apparent on a cursory view,
is still very remarkable. The strong resemblance which
V. Scapha bears to a Stromhus, must, indeed, strike the
most casual observer ; but, we confess, it was some time
before we discovered the singular character so prevalent
in all the HarpulcB, or music volutes, where the outer
lip is extended up the first spiral whorl, — a structure so
universal among the Strombidrp, or wing-shells, and
which is not found in any other group of the volutes.
To put this analogy, however, in a clearer light, we shall
now compare the types with the great circle of the Zoo-
phaga.

Genera

Families

of the

Analogies.

of the

YOLVTINJE.

Zuopfiaga.

CHAP. IV. VOLUTA TYPES OF FORJU. 115

Analogies of the Types of Voluta to the Zoophagous

Trihe.

Types of
yoluia.

T • 1- ^ J- 7 ("Spines often largeand acute: 7 Af„„. .^:^

Impenahs. Cyynbwla. \ ^pi^e muricated. 'JMuRiciDf.

vi . . ir ■ . f Spire vervshort, smooth; apex 7 Ti..„„,„„, .„_

Neptuni. yoluta. { %iiiary ; plaits distinct, j TuRBiNELLiDiE.

Magnifica. ScapheUa. Mantle very large. Volutid^.

Angulata. VolutiUthes. { '^^^^^^^^^ '*'"" '°''^'^'^ ^'^*^ ] Cvpr^id*.

... TT > f Outer lip strongly angulated 7 o... _

Scapha. Harpula. J or elevated on the spire. j Strombid^.

This table brings out two remarkable facts. — The first
relates to the analogies of Voliita Scapha and of Har-
pula to the StromhidcB — all which^ by placing these three
groups in separate columns, fall in precisely opposite to
each other. The second relates to the analogy between
the Muricidcd and the coronated volutes : these are all
the most spiny or muricated of all univalves. The
same principle of variation holds good between the
smooth melons and the typical Turhinellidce : both are
remarkably smooth shells ; both have very short papil-
lary spires ; and both have three or four well-defined
plaits on their pillar. But the snh-typical group of the
TurbinellidcB are composed of those rough, spiny, and
often coronated shells, forming our genus Scolymus:
these, therefore, are analogous to the sub-typical genus
Cymhiola ; and, consequently, to all such forms or types
as represent them, as Voluta imperialism Harpula hehrcea,
VolutiUthes musicalis, &c. It seems to be one of the
laws of variation in the structure of the zoophagous
shells, that every one of the families * should contain
two prominent groups ; one remarkable for having
smooth, and the other rough, or spiny, shells. It
would even seem that Nature, so to speak, is so tena-
cious of this law, that she adheres to it in the very
smallest of her groups, — that is, in the variations of sub-
genera. Among the most common instances, the reader

* Except the CyprccidiB, where it is obvious, from the little variation in
the shells, that the analogies must be traced from the animitls cnly.

I 2

Il6 SHELLS AND SHELL-FISH. PART I.

will call to mind the smooth and the coronated helmets
(Cassidea and Dolium), the smooth TurhinellcE, and
the murex-like ScolymincB, the tuberculated Stromhi,
and the smooth Cones. The same principle, again, is often
carried into the variation of each : thus, although the
Cones, as a whole, are smooth shells, yet one division has
coronated tubercles. Some of the melon volutes are
smooth, as V. Neptuni; while others (which are sub-
typical) are coronated. Every division, in short, large
or small, in the entire family of volutes, exhibits these
differences. The reader will of course understand we
are now speaking only of the typical and the sub-typical
types ; the variation of the aberrant forms being regu-
lated by other circumstances, which, in the present state
of our inquiries, it would be premature to venture upon.
(105.) If the foregoing arrangement of the sub-ge-
neric types of Voluta be really natural, it follows that all
the melon volutes form but one sub-genus. Break them
up into other sub-genera, and give to each the same
rank as attaches to the four other types, and the whole
harmony and beauty of the theory w^ould obviously be de-
stroyed ; their arrangement would then, in fact, become
an arbitrary matter of nomenclature. Had our obj ect been
to have formed an artificial classification of the Testacea,
we should, without hesitation, have adopted the views
of others on this subject. The divisions of the smooth
and the coronated melons are excellent, because they are
natural : but all we have now stated shows that they
are two sections only of a sub-genus. It will be evi-
dent to those zoologists who may be conversant wnth
the vertebrated animals, that all groups pre-eminently
typical contain a greater number of forms than any other,
as if Nature intended to show us, at the onset, the rudi-
ments of all those variations which were to characterise
the surrounding groups. Lawrence, long ago, observed
of the Caucasian race of man, — the most pre-eminently
typical, — that it contained more numerous variations
than any other ; and we have shown how strictly
applicable this assertion to the vertebrated animals.

CHAP. IV. RANK OF THE MELON VOLUTES. 117

Now, the melon-shells, forming our genus Voluta, are of
this description ; they stand at the head of the whole
family ; and we accordingly fmd their subordinate types
are not only the most varied, but the most numerous.
Vol. imperialism Scapha, anguhita, and magnifica enter,
indeed, into their circle; but they do not form the highest
point of perfection. This is seen only in the melons,
strictly so termed ; yet, even here, how great is the
diversity of forms ! We have some with a spire alto-
gether hid, and the shell devoid of colour, as in Nep-
tiini; others with the indication only of a mis-shaped
spire, as in V. Cymhium, yet with marbled variegations :
another little assemblage has coronated and vaulted
spines ; and even among these, the spire is so varied,
that in one, V. tessellata, they are compressed, as it were,
over an extremely short spire, which they almost hide ;
or, as in diadema, they are long, and directed forwards :
finally, there is one (F". Broderipia) which deviates so
much in its general shape and habits from all others,
that it will not strictly arrange with these coronated
melons, or with the next type, F. imperialis. Now, all
these variations absolutely occur in the compass of a
single sub-genus : and we may explain this diversity by
supposing that the coronated melons typify the genus
Cymhiola and V. imperialis; that the smooth melons
are the true representatives of the whole ; and that the
V. Broderipia is an aberrant form connecting the coro-
nated melons with Voluta imperialis. That such shells
as Voluta JEthiopica are much more perfect (abstractedly)
in structure than Neptuyii and its allies, is unquestion-
able : but this does not imply typical perfection ; for it
frequently happens in aberrant groups (as the Volutidct
is among the Zoophaga), that the typical character rests
on very different considerations.

(1 06.) It will be needless to go into all the details of
the next genus, Cymhiola. Yet it will be satisfactory
to see how intimately the types represent those of the
Voluta, — at least, in their main characteristics. In the
following table, therefore, we have selected those species

I 3

118 SHELLS AND SHELL-FISH. PART I.

which have been already alluded to ; premising only
that some doubts hang over the true nature of the type
which intervenes between the bat volutes (C. vespertilio)
and C. tuherculata, chiefly arising from our not having
these shells immediately before us. This point, there-
fore,, must for the present be left open to doubt.*

Analogies of Voluta and Cy3Ibiola with the Genera.

„ . ~ c ■ c Genera

^^'':Zf Analogies. l^Zl?.l .of the

Voluta. ^nu^u^cc,. Cymbiola.

VOLUTINiE.

»T s ■ f Body-whorl ventricose : shell 7 4, /;„ -ir-^,.,^.

Neptum. i sijJooth c Anctlla. Voluta.

r ■ ,■ C Shell not ventricose ; whorls 7 7' „ ^„ ,,■/•„ n,,,,,,,^. .

Impermhs. J coronated and spined. \l espe^tUio. Cymbiola.

Scapha. Smooth ; outer lip angulated. Mitis. Harpula.

Angulata. Aperture effuse; spire pointed. Braziliensis. Volutilithes-
Magnifica. [ '^"^'."Jfil^^'";"'"^ ' ^P^^^^^^^oth, j y,,^„.,„^„,„. Scaphella.

Cymbiola tuherculata t^ from having a greater number
of plaits than any other of its genus, seems to connect
Cymbiola with Harpula, through the medium of H. ful-
getrum; and at the same time to pass into Cymbiola
Braziliensis % ; which last, by its effuse aperture, the acu-
minated apex of its spire, and its possessing only three
plaits, is a perfect representation of Voluta angulata.

(107.) The genus Harpula commences with the
Harpula fulminata§, one of the most interesting forms
in the whole family. Its shape is that of a Fasciolaria,
the base being produced; while the apex is so papillary
that it forms a large knob, almost completely round : it
is, in fact, the first, or terminal, whorl which is thus
inflated ; and the little turn which this whorl makes is
not on the top, but on the side. Now, this formation is
only seen in Scaphella papillosa, but it is indicated in

* A full investigation of the animals of the Pacific volutes will claim
our first attention, after the settlement we intend making on the romantic
and ])rolific shores of New Zealand.

f Exotic Conch.

t Chemnitz, pi. 176. figs. 1695, 1696. The Vo/ufa rud's, of which a figure
has been published in Gr{ff'. Ci/v. pi. SO. fig. 1., seems to me a typical melon
volute ; but nothing further is said about it, than that it is " clay-coloured
mixed with white."

^ Ency. Meth. pi. 381. fig. 2.

CHAP. IV. TYPES OP HARPULA. ] 19

H. hullata, and a very near approach to it may be
traced in Harpula vejcillum. We thus have three
resemblances ; one of which only we shall at present
regard. The numerous plaits of fiilminata evince its
proximity to vexillum and Lapponica. To these succeed
the pre-eminently typical forms composed of Harpula
hehrcEa, musica, polyzonalis, sulcata, Sec, all of which
are thick, muricated, or spined. By these a passage is
formed to those slender-ribbed species where the two
last plaits are decidedly the thickest, and the upper ones
either very slender, as in Harpula lyriformis"^; or nearly
obsolete, as m Harpula costataf ; or perfectly wanting, as
in Harpula nucleus.^ In the apex of these shells^ how-
ever, here is a marked difference, plainly indicating a
gradation of structure : thus, in costata and multi-
costata §, the apex, although obtuse, is not swelled, and
the volutions appear to be graduated equally, as in Har-
pula polyzonata. In nucleus, the apex seems almost
acute II ; but in H. lyriformis the second volution is
swelled and papillary : it is by this shell, therefore,
that we may pass to the next type of form, represented
by our Harpula hullata^, where the shell retains the
same shape as H. nucleus, and, like that, has only two
distinct plaits ; the whole shell is quite smooth ;
the spire is not only very obtuse, but the terminal volu-
tion is enlarged, even in the worn individual, which is the
only one we have yet seen; and its last turn is placed
on the side, not at the apex. For this form, however,
we have been prepared by the Harpula lyrifornns, so
that we return again to the singular-shaped spine of
Harpula fulminata. Between H. hullata and H. ful-

* Zool. Journ. iii. pi. 3. Zool. Illust, first series, pi. 54.

t Brand's Journal, xvii. p. 33.

X Mawe's Conchology, frontisp. fig. 2.

\ Broderip, in Zool. Journ. iii. pi. 3. fig. 2.

II I am not positive on this, not having a perfect example at this time
before me.

IF The only specimen I have yet seen of this shell is figured in Zool. III.
2d series, pi. 15. ; nor am I aware of any other, at least in the London cabi-
nets. Papillary spires are always remarkably thick ; and as it was evident
this specimen had been beaten and battered on the sea beach, it is highly
probable that the apex was originally much more thick and inflated than it
was on coming to my hands. It is now in the British Museum.

I 4

120 SHELLS AND SHELL-FISH. PART I.

minata we are disposed to place a most singular volute,
described with Mr. Broderip's usual accuracy, which
partakes both of one and the other. It has, in fact,
almost precisely the same elongated shape as a young
specimen of fulminata, before the outer lip has been
formed; while the number of its plaits are only two, thus
agreeing with bidlata. Divest the fulminata* of its outer
lip, and it would have the same " fig-like" appearance
as Mr. Broderip's R. duhia.\ That the plaits on the
pillar of some of these shells increase with age, is proved
by a young Ho vexillum, now before us, which has only
four, instead of eight.

(108.) In this manner, as it appears, the genus
Harpula forms a circular group, which, by commencing
with H. fulminata, passes onward to Lapponica and vex-
illum, and from thence to hebrtea : polyzonata conducts
us to costata ; and lyriformis to nucleus and hullata ;
while dubia brings us again to fulminata. We may
now compare the contents of this circle with the last.

Analogies of the Genus Harpula.

Sub-generic Genera Sub-generic

Types of Analogies. of the Types of

Harpula. Volutins. Voldta.

H.fulminata. Lower plaits ofthe pillar small. Scaphella. Magtiifica.
vexillum. Shells smooth. Voluta. Neptuni.

f Shells niuricated or nodulous; ^
heb7-cea. ^ apex obtuse, but not much vCymbiola. Imperialis.

L enlarged. 3

„. , CPlaits numerous, the lowers ii.o„.,. . Q^^^h^

costata. ■{ 1 1 -1,1 t Harpula. bcapna.

I largest ; apex variable. i ^

bnllata. Plaits on the pillar very few. Volutilithes. Angvlata.

* I have recently come to a knowledge of the habitat of this shell, which
is Java.

f As Mr. Broderip's observations on this shell will be much more valu-
able than my own, the reader will be better pleased by perusing that acute
naturalist's own words. " This shell is one of those forms which convince
us ofthe vanity of our artificial distinctions. When viewed from above, it
seems as if the spire of a Voluta were placed on the body-whorl of one of
those Pyrnlce which are commonly known by the name of Figs. Turn it,
and the difficulty of classing the shell is rather increased ; for the aperture
is still fig-like, and it requires an accurate examination to detect the two
almost imperceptible plaits on the columella. Tiie apex, indeed, uncouth
as it is, shows more like that of a J'oluta than of any other sliell, and it is
utterly different from that of a Pyrula. Place it among the volutes, and
it will be found to approach nearest to V. rupestris; though one cannot but
suspect that there are yet, in the bosom of the deep, many gradations of
form between them. There is, I believe, one specimen in the cabinet of
prince Massina." — Brod., in Zool. Journ. iii. p. 81. pi. 3. lig 1.

CHAP. IV. VOLUTILITHES TYPES OF FORM. 121

Of the resemblance between the three firsts or ful-
minata, Scaphella, and magnifica, we shall have to
speak hereafter. The group which contains Harpula
veocillum and Lapponica, as clearly represent the smooth
melons_, as hehrcea does the bat volutes {Cymhiola).
There is a circumstance^ also^ regarding H. vejcillum
and Lapponica, apparently trivial, but of peculiar in-
terest to those who delight in analogical researches :
they are the types of the genus Harpula, which, as a
whole, we have shown to correspond with the Stro7nbidce ;
and, in proof of this, we remarked that the major part
presented the analogous character of the outer lip being
carried upwards towards the spire. But this is not the
only analogy : at the base of the outer lip, in fine and
uninjured specimens of vexillum and Lapponica, is a
slight but very distinct sinus*, rudimentary, as it were,
of the distinct lobe in the genuine Strombi : this is not
seen in the next division, represented by H. hehrcea ;
but then, again, these latter shells have the top of the
outer lip much more advanced on the spire. Costata
not only represents, but is actually one of, the HarpulcB ;
while Folutilithes, with its few plaits, is equally repre-
sented by hullata or nucleus.

(109.) The types of form in Volutilithes will now
be inquired into. Throughout all the species we have
seen, or which have been figured, the typical structure,
in regard to the paucity of plaits and the acuteness of
the spire, seems almost universal. The first group which
unites these sharp-pointed volutes with //. lyriformis,
seems to be such shells as V. costariaf, which, by a
series of other species furnished with distinct convex
ribs, like those of H. lyriformis, lead us, by means of
muricina\, to musicalis and spinosa § (Jig. 12. c, in
p. 123.) : a third type is represented by the crenulata and
hicorona \\ Lam. ; a fourth by his rarispina ; and the

* This is precisely analogous to the corresponding prototypes, Rhinedo-
mus and Cyllene.
t Ency. Meth. pi. 383. fig. 9.
X Ibid. pi. 383. fig. 1. a, and pi. 381 fig. 3.
§ Ibid. pi. 392. figs. 4, 5. (| Ibid. pi. 384. figs. 5, 6.

122

SHELLS AND SHELL-FISH.

PART I.

fifth, which so singularly represents Voluta angulata
and Cymhiola Braziliensis (no less than the Fyrulce), is
seen in F.cithera*, this latter being the second type of
the genus.

(110.) That there exists mutual resemblances be-
tween these presumed types^ and those of the three
preceding genera, will be evident from the following
comparison : —

Analogies of the Genus Volutilithes.

Sub-generic

Types of
Volutilithes.

Analogical Charactejs.

Spinosa.-f
Crenulata.

Costaria.

Cithera.

Ra7-ispina.

f Shell partially or wholly 7
/ smooth. J J

Shell entirely muricated.
Spire much lengthened; ")
outer lip well developed
apex sometimes slightly
enlarged.^

Ventricose ; spire very short,

' Analogous to the Stromhidie;
outer lip sinuated at the
base, and often detached
above.

Types of
Harpula.

Genera of the
Voluti.NjE.

Vexillum.

Voluta.

Hebrcea.

Cymbium.

Lyrifonnis.

Harplla.

Bui lata.

Volutilithes

Fuhm'naia.

SCAPHELLA.

Perhaps it may eventually turn out that the V. musi-
calis II — a species we do not possess in perfection — is
one of the typical forms, and that spinosa is the other :
but the very singular-grooved suture of costaria and
bicorona appears to indicate that a peculiarity of structure
existed in the animal, of more importance than the mere
form of the shell. The analogy, or rather the affinity,
between costaria and the HarpulcB must be apparent to
every one, no less than that between Voluta angulata,
Cymbiola Braziliensis, and Volutilithes cithera. Of

* Ency. Meth. pi. 384. fig. 1.

f It is not a little remarkable, that, in well-preserved specimens of the
fossil species from France, the body-whorl is marked by transverse orange
lines, completely analogous to H. vexillum.

I If, as may be suspected, the Voluta labrella (Ency. Meth. pi. 384. fig. 3.)
is the true type of this division, then its analogy to the smooth melons
would be perfect, inasmuch as this fossil is entirely without the muricated
spines of spinosa : 1 do not, however, feel at all satisfied that I have cor-
rectly indicated this and the next type.

(j As in the two species here compared.

II Ency. M^th. pi. 392. fig 4.

CHAP. IV.

SCAPHELLA

TYPES OF FORM.

123

V. rarispina we can only form our conclusions from
the figure in Ency. Mtth. 384. fig. 2. It would seem
from this, that there is a very distinct sinus at the base
of the outer lip, while the wide-spread deposition of
enamel on the inner lip reminds us both of the genus
Marginella and of Voluta Scapha : it is, in short_, the
strombiform type.

(111.) We now come to the last genus, Scaphella.
Although these shells are readily distinguished by the
experienced malacologist at the first glance, it is not so
easy to define them by words. Their true characters,
we apprehend, will be found in the animal. They
differ from all other known volutes, by being always
without sculpture, and generally polished like the Mar-
ginellce. The apex of the spire varies precisely in the
same way as in the genus Harpula : in the chief type,
represented by S. undulata, it is small, and obtusely
pointed. In fusiformis, it is decidedly thick ; and
in papulosa, it becomes exceedingly large and round.
A shelly deposition is often formed in mature age, at
that part of the outer lip which joins the spire, and
also on the pillar side of the aperture : there is a con-
stant propensity, in short, to this thickening of the
pillar, even in shells which usually have their plaits
distinct. The first advance to this structure, after
leaving the last genus, is by a very singular fossil shell,
described by Lamarck as the Buccinum strombio'ides.

11

( fig. 12. a, b.) Mr. G. B. Sowerby, in adopting this name,
justly observes, that, but for the absence of folds on the

124 SHELLS AND SHELL-FISH. PART I.

pillar, its characters are more like those of a volute than
a Stromhus. One circumstance, however, not noticed by
either of these writers, must be here mentioned : the
whole shell is covered with a thin coat of shining enamel,
as in some of the recent Scaphellce, particularly thick
at the top of the outer lip. This is always apparent ;
while, in old ones, there is also a thick deposition on
the upper part of the inner lip, which spreads over all
the under side of the body- whorl. This, in fact, is but
a slighter developement of that greater thickening of
enamel seen in the last shell we spoke of, — namely, the
Volutilithes rarispina ; and is precisely what might
be expected in any type which was to connect it with
the genus Scaphella, The absence of plaits on the
pillar of this interesting shell (which for the present we
shall call Scaphella strombo'ides) will not be at all incon-
gruous, — because, in the whole of the Volutilithes, these
appendages are small, and frequently almost evanescent ;
while the detachment of the upper part of the outer
lip from the spire plainly shows it is the strombiform
type of this genus, as F. rarispina is of the last.

(112.) Scaphella being thus connected to Volutilithes,
we may pass over the two chief types, represented by
S. undulata and fusiformis, and recall the reader's
attention to the next in the series, — namely, Scaphella
papulosa, formerly alluded to. Now, there are two
other shells which more especially possess this kind of
nipple-like apex, and in the same high developement, —
the Harpula fulminata, and the Voluta fulgetrum : the
question, therefore, is, to which of these is it mostly
allied? On this point we reply, — to the latter by affinity,
and to the former by analogy. It thus follows that we
have traced the series of the volutes once more up to
the typical genus, which we enter again by means of
Voluta fulgetrum and magnifica.

(113.) The four types of Scaphella, which are all
we at present know, will thus find their respective ana-
logies.

CHAP. IV.

SCAPHELLA TYPES OF FORM.

125

Types of

SCAPHELLA.

Undulata.
Fus'formis.
Papulosa.
?

Strombdides.

Analogies of the Genus Scaphella.

Analogical Characters.

("Shell very smooth; suture >
\ enamelled ; spire small. 5
Sub-ventricose ; spire thick.

("Tip of the spire thick and 7
\ mammillary. J

?
Inner lip thickened and gib-
near the spire
igular and prom

! Inner lip thickened and gib-"^
hoiis near the spire ; outer f
lip angular and prominent T
al ove. J

Types of

/OLUIILITHES.

Types of

VoLUTA.

Crenidata.

Cymbiola.

Labrella ?

Neptuni.

Costaria.

Magnifica,

Cithara.

Angulata.

Rarispina.

Scapha.

(114.) This is the proper place for remarking a pe-
culiarity in Volutilithes costaria, which we have not ob-
served in its allies; the apex, although pointed, has one
of the volutions thickened, — so that, in its own circle,
it becomes exactly what papillosa is among the Sca-
phellce.

(115.) The peculiarly strong resemblance, however,
between Scaphella papillosa and Harpula fulminata, is
too remarkable to be termed a simple analogy. This
brings us to another peculiarity of the natural system, of
which full explanations and numerous proofs have been
adduced in our former volumes.* The study of the
different classes of the vertebrated animals, however, is
quite out of the province of the malacologist, and we
cannot suppose that he will assent to so novel a theory,
unless it be proved in his own particular walk. We
therefore lay before him, as a case in point, the aberrant
groups of the Volutince, — wa.m.e\y , Harpula, Volutilithes,
and Scaphella. The series in which we have placed
these, commences with Harpula fulminata, and termi-
nates with Scaphella papillosa. Is there not sufficient
evidence that these two extremes meet ? and that Sca-
phella papillosa is as nearly related to H. fulminata as
to Voluta fulgens ? If so, our series forms a circle.
Thus, we find the whole family — as we began with
assuming — constitutes one circular group, primarily

* Geography and Classification of Animals, p. 226,

126 SHELLS AND SHELL-FISH. PARI I.

divided into three other circles, — the first of which,
Valuta, is typical ; the second, Cymbiola, is sub-typical ;
and the third, which contains Harpula, Folutilithes, and
Scaphella, constitutes the aberrant circle. This, in fact,
is only in conformity with all other natural groups in
the Vertebrata ; so that, if the principles upon which
we have now arranged the VolutincB are radically de-
fective, so also are those in the innumerable groups
that have been thus tested and verified in ornithology,
ichthyology, &c. : for it is logically certain, that unity of
plan cannot exist in the animal world, if one and the
same principle of variation is not fundamental, and does
not pervade all its parts,

(1X6.) The Mitring, or mitres, no less than the
volutes, are characterised, in the great majority of the
species, by very distinct and tangible characters ; but
so soon as we reach the extreme limits of each, and
look for those marks by which we have been accustomed
to separate, with ease, the two groups, we find some
of them gradually disappear, and others so modified
and interchanged as to render it very difficult for an
ordinary naturalist to draw any positive line of demarc-
ation, — at least, on those principles of absolute division
insisted upon by some writers. It has, for instance,
been thought that a shell having the spire papillary,
and the lower plaits upon the pillar largest, was un-
questionably a volute: and yet we have, in Folutilithes,
a whole assemblage of shells whose apex is acute ; and
in another group, Scaphella, the lower plait is always
the smallest. Among the mitres, on the other hand,
we shall find more than one with a papillary spire, and
others where the lower plaits are as large as the upper.
Hence it follows, that if no groups are to receive ge-
neric or family names, but such as are distinctly sepa-
rated, and are destitute of these intervening links, the
old genera of Valuta and Mitra must again be united.
Nor should we stop here : Mitrella so connects the
mitres with the olives, that those, too, must be ab-
sorbed in this gathering conchological snowball ; and

CHAF. IV. THE MITRiiS GENERALLY. 127

with OHva must follow Ancillaria : in this way we
might go on until we have but one genus, Voluta, It is
only by thus following out such a theory of nomencla-
ture, that we see the full results to which it must, of
necessity, lead. We have, indeed, already spoken on
this subject ; but we think it desirable to place it more
especially before our readers in this place, where the
opposite plan has been so prominently brought forward.
(117.) The whole of the Mitring, or Lamarckian
mitres, were considered but as one genus until about
twenty years ago, when we ventured to detach from
them a small group by the name of Conoshelioc. Nearly
as great opposition was manifested to this innovation,
as has recently been made in respect to Cyprcpcassis ,
but this, of course, was to be expected from those
conchologists who looked only for " well-marked and
absolute divisions :" the group, however, was soon taken
up by the Continental naturahsts, and is now generally
adopted. Having always had a peculiar fondness —
almost a passion — for these elegant shells, we continued
their study, until, in 1827;, our investigations had pro-
ceeded so far that we ventured to characterise the five
leading divisions, or genera. The great number of new
species discovered by Mr. Cummin, added to others con-
tinually coming before us, naturally led to a still more
close analysis of the whole. The result of this, in re-
gard to the theory of variation, was communicated to the
Zoological Society in 1835.* This theory is now found
to pervade the whole class of Testacea ; while, in our
Systematic Arrangement, will be found all the well-
known and clearly described species, distributed under
their several minor groups. The MitrincE, in comparison
to the volutes, with two or three exceptions, are much
smaller shells, chiefly distinguished by the smaller size
of the foot, as in Mitra episcopalis {fig. 13.), where the
proboscis is excessively long ; and by the greater length
of their spire, the tip of which is never papillary, f The

* Proceedings of the Zool. Society, part iii. p. 197

+ Except in two or three species of Mitreola, which blend into Harjmla.

128

SHELLS AND SHELL-FISH.

PART 1.

upper plaits of the pillar, in almost all, are larger than
the lower ; and the general form of the shell is equally
or unequally fusiform. It is almost impossible to esti-

mate the number of species, as new ones are constantly
coming to light ; but there probably exists already, in our
cabinets, about two hundred and fifty, of which more
than forty were brought home by Mr. Cummin from
the western coast of Tropical America. We suspect,
from these data, that, in a few years, the increase of
known species will come near to 300, leaving out those
that belong to the three aberrant genera — Mitre/la,
Conabhelijr, and Mitreola. Nearly all these are excluded
from the European seas ; and, what is still more extra-
ordinary, not more than half a dozen can be called com-
mon shells. This scarcity of mitres certainly does not
originate from the difficulty of gaining access to their
haunts ; for, although some are known to live at great
depths*, yet both MM. Stuchbury and Cummin inform
us that they generally found these shell-fish in shallow
water, near coral reefs. Hence we conjecture that their
chief metropolis must be the great Pacific Ocean, where,
among the countless numbers of existing islands, and
the coral foundations of others, the number of species
now unknown may be nearly equal to those already
described. The animals of a very few have been pub-
lished by M. Quoy, in the invaluable plates of his
voyage; for the particulars of which we have not suffi-
cient space.

(118.) The primary divisions of the whole of the
family, as already intimated, correspond with those of

* As Mitra zonnia, which, Dr. Leach says, was fished up out of veiy
deep water near Nice.

CHAP. IV.

DIVISIONS OF THE MITRES.

129

genera of the volutes _; and they may be thus briefly

characterised from their
,^Ssa^^*^^:'.-6^^^ shells. The most typi-
cal is — 1 . Mitra,v;here
the basal whorl is some-
what ventricose, and the
aperture has no inter-
nal groove. 2. Tiara
(fig. 14.) J having the
basal whorl contracted,
and the internal groove distinct; — this is the sub-typical
genus. The 3d, or next, Mitrella, resembles the olives
in being smooth, and in having the base of the pillar
thickened, with the plaits very much projecting. In
the 4th, or Conoehelijc, the spire is very short, the plaits
numerous, and sometimes indistinct: whereas, in the 5th,
or Mitreola, the upper plaits are smallest, the outer lip
inflected and sometimes toothed, and the spire slightly
papillary. As all these peculiarities will be detailed in
the next division of our volume, we shall here only make
a few general observations on the contents of the genera ;
and first, with regard to

The Analogies of the Volutins and the Mitring.

Genera of the
MitrincB.

MiTRA.

Tiara.

Mitreola.

CONfEHELIX.

Mitrella.

■\

Analogical Characters.

rBody-wliorl never contracted at
< the base ; the whorls never tur
C retedor anguiated.

fShell turreted; body-whorl con-~|
I traded in the middle; the]
<{ whorls nodulous or sub-coro- J*
I nated, or carinated, larely |
L smooth. J

rThe upper plaits on the pillar^
-5 smaller than those in the mid- v
C die ; spire sometimes papillary. J
Spire very short; plaits very slen- ^
der, sometimes obsolete ; sur- f
face generally reticulated or f
striated. 3

r Smooth, generally polished; the"^
-< lower plaits smaller than the >
C upper. 3

Genera of the
Volutince.

V GLUT a.

Cymbiola.

Harpula.

Volutilithes.

SCAPHELI.A.

K

130

SHELLS AND SHELL-FISH.

PART I.

We shall make no other commentary upon this table,
than as regards the rank of the groups in each column,
which are thus shown to he genera. The sub-genera.
of the Volutince, it will be remembered, we have indi-
cated, but not named, because the species they contain
are so few, and these so well known, that it might be
thought a needless multiplication of names. But in the
present family the case is widely different : as not one
third of the mitres are figured, and the descriptions of
most of the remainder are too vague to admit of deter-
mination, it becomes absolutely necessary, not only to
characterise, but to name, the sub-genera. This we have
accordingly done, — confining ourselves, however, to the
two typical genera, which, as in all such groups, con-
tain the great majority of the species. The foregoing
table shows that Mitra and Tiara are the two groups
in question; and, as the definitions of their sub-genera
wiU be hereafter detailed, we shall at once lay before
the reader the exposition of their analogies.

Analogies of the Genera Mitra and Tiara.

Sub- gen era of

Mitra.
Internal canal
wanting ; aper-
ture smooth.

Mitra.

Tiarella.
Scabricola.
Nebularia.
Strigatella.

Analogical Characters.

Sub-genera of

Thiara.

With an internal

canal ; aperture

striated.

f Spire and aperture of equallength, "i

< unequally fusiform ; body- >
t whorl obtuse. j

("Shell with distinctly coronated, 7
X acute, or obtuse tubercles. j

f Shell with numerous elevated ribs, f

< longitudinal in one, transverse V
C in the other. j

("Shell reticulated or cancellated ; 7

X the base of the aperture effuse. 3

Size very small ; outer lip thick

ened, and generally gibbous

within.

\

}

Costellaria.

Tiara.

Calliihca.

Cancilla.

Pusia.

It thus appears that each of the divisions, or sub-
genera, of Mitra finds its representative in Tiara ; and
that, without a due regard to the essential characters
which distinguish these two genera, it will be impossible

CHAF. IV. SUB-GENERA OF MITRA AND TIARA. 131

to know to which of them a Lamarckian Mitra really
belongs. We are sorry, indeed, to impose so much trou-
ble upon collectors; but the blame, if any, must be
laid upon Nature — not us: for we merely endeavour to
trace her steps. But she does not stop here. Into each
of these sub-genera, which happen to be full of species,
she actually carries the same principles of variation ; so
that, if aU the shells really belonging to our sub-genus
Mitra, even as now restricted, were spread before the
naturalist, he would find not very incipient characters
of every one of the sub-genera just enumerated ; and
this, to such an extent as to justify our reaching this
conclusion, — that if the whole of the species that hare
been created were known, every Mitra would have its
counterpart, or prototype, in the circle of Tiara.
Any naturalist may convince himself of this, by look-
ing to the five sectional types of the sub-genus Mitra,
for instance, as episcopalis, riiffina, punctata, lactea. and
zojiata. The second represents Tiandla by its crenated
suture ; the third shov/s us the roughness of Sca'oricola ;
the fourth the effuse aperture of Nehularia; and the
fifth the dingy colour and thick epidermis of Strigatella.
The Mitra terebralis and the Tiara terebralis*' are
counterparts of each other, and are only prototypes,
under a different form, of the genera Terebra and Tur-
ritella. We regret exceedingly that we cannot give as
full an exposition of the mitres as we have done of the
volutes: half a volume would hardly be sufficient. It
seemed preferable fully to detail our analysis of the
first, as being the typical group ; and because, from the
comparative paucity of the species, the natural series be-
came more difficult to demonstrate than that of the
mitres. Now, as the principle of variation in each is
precisely the same, we have given only the results of

* Of this shell, Mr. Broderip justly observes, " It is one of the most slen-
der of its genus, and has very much the general character and form of a
Terebra : this resemblance is increased by the circumstance of its having
one spiral groove more deeply impressed than the others, placed at about
one third of the length of each volution before the suture." — Froc. Zool.
Soc. part iii. ISoo, p. li:'6.

K 2

132

SHELLS AND SHELL-FISH.

PART I.

our investigation in the mitres. Whether we view the
family Volatidce as a whole, or contemplate separately
each of its divisions, whether large or small, we shall
find their variation uniformly harmonising with what
has been seen in \he MuricidcB and the Turhinellidce, —
a fact which every one will perceive, on investigating
the following table, which is also sufficient to furnish the
clue even to the analogies of the sub-genera.

General Analogies of the Volutid^.

Families

Sub-families

Genera

Genera

Sub-families

Sub-families

of the

of the

of the

of the

of the

of the

ZOOPHAGA.

Volutidce.

Volutince.

MUriJiu:.

Muricldce.

Turbinellidce-

TUKBINELLII)^

VOLUTIN^E.

Volula.

Mitra.

Cassfn.^.

TURBINELLIXK

MUR1CID.C

MlTRIV^.

Cymbiola.

Tiara.

MURICI-VJE.

SCOLYMIN^.

VOLUTID^.

OLIVlNiE.

Harpula.

Mitreola.

BuCCININiE.

Fusing.

Cyprjside.

Ancillarine.

Volutilithes.

Con te helix.

PURPURIN,!:.

Pyrulin.e.

Stkombid^.

Marginelli.v^.

ScaphcUa.

Mitrella.

NASSIN.E.

Eburnin.e.

(119.) The three aberrant divisions of the volutes,
namely, the Olivine, the ANciLLARiNyE, and the Mar-
gelling, must be dismissed in a few words. The minor
variations in each are very few, and will be found in
the systematic arrangement. The genus Mitrella leads
us immediately from the mitres to the olives ; where,
as in Harpula, the plaits upon the pillar cover the whole
length of the inner lip : the foot of the animal is ex-
cessively large, and sufficiently dilated to fold over the
greater part of the shell ; but the mantle is not lobed.
The first genus is Lamprodoma* , which chiefly differs
from Mitrella in having the channeled suture so uni-
versal among the olives. This leads to the typical
genus Oliva, wherein the majority of the species are still
arranged. Scaphula, by its thick undefined spire and
ventricose body-whorl, is a complete prototype of the
melon volutes, and prepares us for Hiatula, in which the
characters of Oliva, Scaphula, and Ancillaria are com-
bined. The circle is then closed by those small species
arranged under the genus Olivella, wherein the base of

* Lamp. Oiiudla, Zool. 111. ii. pi. 40. fig. I.

CHAP. IV. ANCILLARIA. MARGINELLA. 133

the aperture is only effuse^ and the spire as much length-
ened^ as in Lamprodoma : the plaits on the pillar, like
those on VolutiUthes, are reduced to their minimum; the
two last are the strongest, the others nearly obsolete.
It is by this particular group that the Volutid^ and
the TuRBiNELLiD^ are united ; the direct passage being
marked by Olivella hiplicata Sw. in one, and Pseudoliva
plumbea Sw. in the other, {fig. 3. at p. 82.) The
olives are among the best known, the most polished, and
the most variable shells in this family. They swarm in
the seas of tropical climates, more especially in the
East, but seem altogether excluded from the European
coasts.

(120.) The forms, or variations, among the Ancil-
LARiN^ are as yet too few to render it necessary to
create sub-divisions : the beautiful analogy which this
group bears to the Pur purines, by the prominent little
tooth on the outer lip, as well as by the width of its
aperture, must not be overlooked ; while the high polish
of all the species, the general shortness of the spire, and
the unusual thickness of the base of the inner lip, are
so many points of resemblance to the Cyprceidce.

(121.) Finally, the MARGiNELLiDiE are the smallest
shells, as to size, in the whole family : they are at
once distinguished by their thickened outer lip ; but they
all vary in the absence or developement of the spire
and of the inner lip, as well as in the plaits of the
pillar: hence their genera may be sufficiently defined.
Their union with the Volutince, by means of Scaphella
Zebra*, is clearly shown by our genus Glabella, where
the inner lip is either entirely wanting or but slightly
developed: these latter conduct to To/^^eZ/a, which, by its
obsolete spire, preserves a strong analogy to the melons.
In Persicola we have a prototype of Comehelijc ; while
the typical form, Marginella, has the inner lip so much
developed, as to form a thickened deposition all round
the aperture. On the fifth type we feel some uncer-

* Placed among the Marginellce by Lamarck.
K 3

134 SHELLS AND SHELL-FISH. PART I.

tainty ; but we think it is represented by those species
which have the outer lip gibbous above, analogous to
Voluta Scapha and other strombiform types ; or it may
possibly be Lamarck's fossil genus Volvaria. It is easy
to perceive, however, how strikingly this sub-family,
as a whole, represents the Nassince. the Ehurnince, and
the ColumbellincB, all which are prototypes of the
Stro7nbid(T.

(122.) We shall conclude our exposition of this
interesting family by what may be called a continu-
ation of the last diagram, for the purpose of illustrating
certain analogies in regard to the animals.

Analogies of the Volutid^ to Vertehrated and Annulose

Animals.

Genera Sub-families Families Tribes of the Classes of Classes of

i^f Af° S T^j°! Y Dithyra. Aniynals. Insects.

Volutmcc. Murtcidce. Phitophaga. ^

Voluta. Cassince. Trochidcc. Atrachia. Mammalia. Aptera.

Cymbiola. Muriclnte. HelicidcB. Macrotrachia. Aves. Ptilota.

Harpula. Buccinirue. Turbidxe. Tubulibranchia. Reptilia. Annelides.
Volutilithes. Purpurince. Naticidce. Chelisoma. Amphibia. Vermes.

Scaphella. Nassince. Haliotidce. Branchiopoda. Pisces. Cirripedes.

It is chiefly with reference to the fifth set of types,
which contains the longest-bodied animals in all these
circles, that we have drawn up this table. A pecu-
liarity is of course shown in the Testacea, by the pro-
longation of the spiral whorls : hence we find the
longest-spired volutes are in the genus Harpula. The
BiiccinincB contains Terebra ; and the genus Turritella
is the type of the Turbidce. Continuing this analogy
on to the bivalves (Dithyra), we have the long tubular
snake-like shells of the Tubulibranchia, representing
the real serpents among vertehrated animals, and the
Annelides among the annulose or insect tribes. The
excessive developement of the organs of locomotion, or
foot, as shown in the first set of analogies, is most re-
markable. But as a chapter would be insufficient to
illustrate the innumerable analogies concentrated in this

CHAP. IV. CYPR/EIDiE, OR COWRIES. 135

table, we must leave it, as a fruitful and untrodden
field to those who wish to prosecute its study.

(123.) The passage to the Cypr^id^e is so well
marked by those JfarginelUncB which have the spire com-
pletely hidden, as to leave no doubt of the cowries follow-
ing the volutes. We must, for want of space, omit the
accounts of the animals of the two typical divisions,
Cyprcea and Ovula, now well known by the excellent
descriptions of MM. Quoy and Gaimard : suffice it to
observe, they have some things in common with the
volutes; — the foot is very large, and the tentacula short :
the mantle is dilated into two large lobes, almost sufficient
to cover the shell entirely, — their junction being marked
by a pale line down the back, where the colour often
appears as if faded. The Cyprmnce, or cowries, form
the typical, and the OvulincE, or egg-shells, the sub-
typical, group. The former are well known as among
the most elegant and richly coloured of the Te^tocm;
always having the spire concealed, and generally onisci-
form, — that is, oval, and flattened beneath. The
species are particularly numerous in tropical latitudes,
and several are among the most common shells in our
collections: they have been very ably investigated by ]Mr.
Gray, who has judiciously characterised and named some
of the types ; for they were all left by Lamarck in one
genus. The OvulincB resemble in general form the cow-
ries ; but the extremities of the aperture are generally
produced, and there are no teeth on the inner lip. Not
having yet investigated this division, we shall for the
present leave it as it is, and merely notice those which
seem to be the aberrant genera, connecting this family,
on one side, to the VolutidcB, and, on the other, to the
Stromhidce. The first we conjecture to be the fossil
genus Volvaria, as well defined by Mr. Sowerby *; while
the latter union appears to be affected by Erato, where
the general shape is that of a Columhella, but with the
dorsal sulcated line of Trivea : between this we are dis-
posed to place, under the name of Cylindrella, two or three

* Genera of Shells.
K 4

136 SHELLS AND SHELL-FISH. PART I.

small shells resembling Folvaria in form^ but destitute
of any plaits upon the inner lip. The Cyprceidoi will
thus form a group far less perfect in its contents than
the Volutidce, yet sufficiently marked to constitute it
circular.

CHAP. V.

THE PREDACEOUS GASTROPODS CONTINUED. THE STROMBID^,

OR WING-SHELLS.

(124.) The Strombid^ is one of the most varied of
the predaceous families^ not so much in the structure
of the animals, as in their shells. The typical group,
indeed, is very peculiar in both respects ; but the
animals of the rest, with which we are as yet acquainted,
have a much greater sameness than would have been
expected from the marked difference in their habitations.
In regard to the first, the most prevalent character
appears to be the pedunculated nature of the eyes,
which are generally situated about midway upon the
tentacula — never at their base, or at their tips. In
the typical Stronibi, these organs are so much de-
veloped, that the iris is richly coloured ; and the eyes
of some of the large species have been described to us
as particularly beautiful. The shells present every
variety of the spiral form, excepting that they are never
depressed ; yet, throughout the whole, one character
may be traced : the outer lip is either enlarged, thick-
ened, or expanded ; or, if not so, the upper part is
detached from the spiral whorl, so as to form a wing-
like or angular projection; hence their common name of
wing-shelh : all are furnished with a small operculum,
and are strictly external shells. In the Lamarckian
genera Strombus, Conus, Columbella, Pleurotoinu, and
Cerithium, the student will see the five principal types.

CHAP. V. STR03IBID^. 13?

(125.) The rank of the group bemg that of a family,
its tirst divisions, just mentioned, become sub-families.
1. The StrombiniB, or true wing. shells, having the outer
lip greatly dilated, with a lobe at the base, and often on
the summit also, of the outer Up ; the spire being always
more or less elevated. 2. The Conince, or Cones, w^here
the spire is so depressed as to be turbinated, and scarcely
raised above the body-whorl : the aperture is always
smooth ; the outer lip without any lobe, and only
slightly detached above. 3. The Colmnbellince, or dove-
shells, small in size, and with short-pointed spires ;
the outer lip is thick, turned inwards, more or less
toothed on its edge, and gibbous above ; there are also
tuberculated teeth at the base of the inner lip, but no
regular plaits. 4. The PJeui'otomhKP, or slit-shells, —
so called from a deep lobe, or slit, at the top of the
outer lip : the spire, in general, is very long, and the
shells themselves often spindle-shaped. 5. The CeH-
thincB, called club-shells, from their clavate form : the
body- whorl is not much larger than the one which
precedes it ; but the outer lip is slightly detached
above, and then much dilated ; the basal canal, which
is always very short, is generally more or less turned
backwards.

(126.) These primary divisions appear to form a
circular series, and to be united in the following man-
ner : — Commencing with the StrombincE, we pass from
them to the Cerithince, by means of that well-known
shell the S. pes-pelicani of Linnseus, which, in its im-
mature state, before its lip has expanded, might easily
be mistaken for a young Cerithium. Next to these
latter, Lamarck places the Pleurotomince ; their junc-
tion being formed by his Clavatula, and the genus
Potomis : with these, again, a union is rendered abso-
lutely perfect with the Columhince, by means of certain
genera now defined for the first time : others of the
ColiimhirifB so strikingly resemble small cones, that but
for a close inspection, they could not be distinguished.
From the cones we pass to the singular genus TereheUum,

138 SHELLS AND SHELL-FISH. PART I.

which brings us once more to the Strombincp ; and ter-
minates the series. We shall now take each of these
sub-families in succession, and lay before the reader
the result of the closest analysis we have been able to
give them.

(127-) The Strombin^e, or true wing-shells, are obvi-
ously the pre-eminent typical group ; and consequently
stand at the head of the family. The great expansion
of the outer lip in all the genera, save one (^Strombidea*),
which connects them to Terehellum, is their best, and,
indeed^ their only general, distinction. The genera are
five : StromhuSy Sti'ombidea, Rostellaria, Aporrhais, and
Pterocera ; all of which are easily recognised. The
most typical, perhaps, is Pterocera, where the outer lip
is expanded, in mature age, into very long claw-like
processes, which gives them something the appearance
of scorpions, with the legs, on one side, stretched out,
and those of the other concealed ; but their chief cha-
racters seem to rest on the basal lobe of the outer lip
being turned inwards, and generally toothed. This
character, hitherto overlooked, has caused two of the
sub-generic types to be placed with the Lamarckian
Strombi ; and hence the latter has been overburdened
with shells which, we think, do not naturally belong to
it. The first, or typical, form is seen in P. lanibis, where
the processes of the lip are all pointed in one direction ;
and the basal canal, which is considerably lengthened,
is curved only on its terminal half. The second is the
P. millipeda, — differing from the last, not only in the
greater number of the processes, but in those adjoining
the spire being more united together at their base ; or,
in other words, the divisions are not so deeply cleft.
This type prepares us for the third, which has all the
characters of Pterocera, except that the lateral pro-
cesses are wanting, and the upper are only indicated by
deep lobes : the only example yet known, is the shell
we formerly figured under the name of Sty'ombus sinii-

* Represented by Str. urceus and its allies.

CHAP. V. PTEROCERA. STR03IBUS. 139

atus, but which we now remove to the present genus.
This we also do with the Strombus latissimus of authors,
which constitutes our fourth type. This remarkable
shell immediately follows the Pterocera sinuata ; and
although the digitations no longer appear, they are
slightly indicated by little folds : the side of the outer
lip, as in all the other types, is broadly reflected inwards.
In the fifth and last form, as seen in P. chiragra, the
digitations are again developed ; but they are fewer in
number, and of nearly equal length. In this type, also,
the basal channel is recurved outward ; and the sinus
on the lip is so remote from the base, as to admit of an
intervening process.

(128.) The restricted genus Strombus follows that
of Pterocera ; it is distinguished by the outer lip being
entire, much dilated, and always furnished with sinu-
osities, or lobes, both above and below : the base is
short, and slightly turned upwards. In this genus there
are five distinct modifications. The Pterocera sinuata
leads us immediately to the first type, which is com-
posed of S.melanostomus, pacificus, Auris-Dianw hinn.,
and Lamarckii* In all these, we trace the last rem-
nant of the character oi Pterocera, — namely, the folding
back of the outer lip, which is particularly conspicuous
in our ^S". melanostomus and Pacificus : the upper part,
also, is prolonged into a lengthened process. As a group,
it is at once known by the basal canal being turned
back, as in the Cerithince, or rabbit-shells. From these,
by means of S. tricornis and Gallus, we are brought
to the beautiful pink-mouthed S. gigas, and the rare
iS". Goliathus, where the lip may be said to have attained
its majcimum. In Acclpiter and Canai'um, it assumes
the shorter and more wing-like form of the type which
succeeds this : all these, with Strombus granulatus, &c.,
and, finally, Epidi'omus, seem, to us, to constitute a
second type of form, w^herein the outer lip is particularly
large and spreading, yet without that short sinus, or

* I know not who has affixed this name to what was considered the
smooth variety of Auris-Diarue.

140

SHELLS AND SHELL-FISH. PAKT 1.

lobe^ which is so prevalent in the next group. This
lobe is most conspicuous in S. lentiginosiis, where, in
fact;, there are two ; as is the case, also, in our S. Gallus
and tuherculntns ; but in minimus, variabilis, &c., the
lobe is less apparent. Yet, in all these, the outer lip,
although large, is not reflected, but takes a curve in-
wards. The fourth type is seen in ^S". gibherulns, which
is remarkable for the shortness and distortion of the
spiral whorls, and the very slight expansion of the outer
lip : it is chiefly remarkable, however, for a thickened
deposition of enamel at the top of the inner lip, analo-
gous to that in Nassa, Oliva, &c. These are connected
to the last by Lulmanus, which has the distorted
spire, but not the other characters, of gihherulus. The
fifth and last type is seen in the Stromhus succinctus,
remarkable for the prolongation of the lip, very high
upon the spire, so that it becomes a perfect represent-
ation, in this group, of Rostellaria.

(129.) The next genus is Stromhidea, — a name we
give to all those small shells, which, like S. urceus and
its congeners, have the outer lip merely lobed at the
base, without being detached, or dilated above. We
take some blame to ourselves, for not having long ago
perceived that these shells were not true Strombi ; but
we had then only analysed the family in part ; and, as
usual in such cases, we subsequently found that we
were in error.* The Strombidea, in short, are proto-
types of the ColumbellincB ; and so strong is this
analogy, that our S. crassilabis was sent to us as a
Columbella.

(130.) The genus Rostellaria contains some few
of the most elegant and costly, if not the most beautiful,
shells in this family : it is, therefore, very interesting,
even to the conchologist ; but it is particularly so with
reference to its types. The primary distinction of all
these shells, — few in number, but singularly varied, —
is a slender channel, thickened on each side, which

* 1 allude to the article regarding the Sirombidcc in the second series of
the Zoological Illustration)!.

CHAP. V. ROSTELLARIA. APORRHAIS. 141

ascends from the aperture nearly to the top of the spire :
the shell has much of the shape of a typical Pleurotoma ;
the basal channel being more or less lengthened. To this
genus we are led by the Stromhidea tridentata, — the only
Stromhus Avhich gives us at once the outer lip of Ros-
tellaria cwvirostris, with all the other characters of our
genus Stromhidea, The first type of Rostellaria is seen
in those elegant shells, R. curvirostris and rectirostris,
where the siphon is moderate : the outer lip is hardly
dilated, since its margin is merely divided into short
processes. The rectirostris is of great rarity ; but of
still greater value is that which forms the second type ;
indeed, it seems to be known only by the figure of Chem-
nitz, and has been altogether omitted by Lamarck : it
is channeled to the tip of the spire ; while the outer lip,
without being much dilated, is divided into a number
of short spine-like processes. In the third type, Ros-
tellaria macroptera, the upper siphon is equally long ;
but the lip, instead of being cleft, is entire, semicircular,
and dilated to an enormous size. In these two last tvpes,
in fact, we have the greatest developement of the lip; and
hence we may expect a declension in the succeeding forms.
Such is accordingly seen in Rostellaria columbata, where
the lip, although dilated and very broad, does not extend
more than half way up the spire, although it is rather
lengthened into the same sort of lobe as that in Strombus
pacificus. There is still a great difference between R.
columbata and the first type we noticed ; but our fifth
brings them together : this is formed of the small species,
four or five in number, among which the elegant little
Grignon fossil, Rostellaria fissurella Lam., is the best
known. In these shells, the lip is no longer dilated, nor
is it extended up the spire ; they lose, in short, one half
of the characters of their own genus, and in the same pro-
portion assume those of Strombus, — thus becoming the
most aberrant type of the sub-family; while their station
between R. curvirostris and columbata is apparent to the
most unscientific eye.

(131.) The last genus is that of I)a Costa's Apor-

142

SHELLS ANI> SHELL-FISH.

PART I.

rhais, and the only example yet known is the pes-peli-
cani, or pelican's-foot strombus. That it has a close
affinity to Rostellaria colinnhata is evident from the outer
lip being dilated ; but then it has four lobes, or rather
flattened and digitated processes, something similar to
Fteroceras chiragra ; and it deserves attention, that
these are the only two in the family which have the
basal channel assuming precisely the form, size, and
structure of the other processes of the outer lip : on the
other hand, it has no distinct lobe at the base, its mar-
gin is not inflected, and the upper part advances upon
the first spiral whorls ; — in all which it shows an affinity
to Rostellaria. In its young state, however, {fig. 15. a) it

has quite a different appear-
ance; for its form is then so
much like that of a young
Cerithium (b), that none
but a scientific observer
could detect the diff^erence.
Equally related in this man-
ner to three different ge-
nera, we look upon this
type as connected to Ros-
tellaria on one side, Pte-
rocera on another, and to
the Cerithince on a third.
All these affinities are more peculiarly apparent in its
three different stages of growth; so that, when quite
young, it is a Cerithium ; when the outer lip is half
expanded, it is a Rostellaria ; and, in adult age. it puts
on the very aspect of a Pterocera. Here we close our
evidence on the affinities and natural arrangement of
this family,

(132.) Having now gone through the affinities, we
turn to the analogies of the Stromhinci'. They are ob-
viously the typical division of the whole family; and, as
such, should represent within their own circle all the
other divisions : this will be apparent in the following
tabic : —

CHAP. V.

ANALOGIES OF THE STROMBIN^.

143

Genera of
Strombin^.

Pterocera.
Strombus.

Strombidea.
Rostellaria.

Aporrhais.

Analogies of the Genej'a of the ^trombi^: je.

Analogies.

Sub-families of the
Strombid^.

Outer lip greatly dilated, andlobed. Strombin^.

rOuter lip detached above, and en- 7 rQ»Tj^„
I tire. j

rOuterlipnot detached, but gib- '^

•< bous ; both lips thickened, and >CoLUMBELLiN5i.

C. generally striated. j

vShell long, slender, fusiform. Pleurotomin^e.

'Shell club-shaped when young;
channel very short, and
sted on one side.

r Shell c
< the
C. twist

Ijc

ERITHIN^.

These variations take place in precisely the same or-
der as that in which the relations of affinity occur ; for
each of these columns is a circular group, — the genus
Aporrhais being as much connected to Pterocera as to
Rostellaria. Turning to the other group, we perceive
the very same affinity between Cerithium and Strombus,
through the medium of Aporrhais, as between Cerithium
and Pleurotoma. The resemblance between Strombidea
and the typical ColumheUincE, again, cannot be mistaken ;
for the outer lip of both forms a sort of angle or gib-
bosity, altogether peculiar to these two groups. This
remarkable thickening, in short, of the lips in Strombidea,
renders the genus a prototype of the Colunibellince, as

well as of the Mar -
ginellince. Rostella-
ria and the Pleuro-
tomincE are the only
fusiform groups in
the whole family ;
while the likeness
of a young Apor-
rhais to the Ceri-
thincB need not be
dwelt upon. The
resemblance between such shells as Strombus Luhuanus
{fig. 1(). a), when young (6), and Conns amadis (c),
and others, is so great, that an unpractised eye can
hardly tell the difference.

144

SHELLS AND SHELL-FISH.

PART I.

(133.) Our next comparison will be between the
types of form in the genus Pterocera, and the genera
of the StromhincB.

Analogy of the Types of Form, in the Genus Pterocera.

Types of
Pterocera.

Lambis.
MilHpeda.

Sinuata.
Latissimus.

Chimsra.

Analogies.

Basal canal greatly lengthened.

Basal canal short.
f Outer lip thickened, and inflected 7
(_ inwards ; basal canal truncate. J

f Outer !ip extending to the apex >
X of the spire, and entire. J

1

Canal resembling the digitated 'J
processes of the lip, and turned >
on one side. j

Genera of
Strombin.e.

Pterocera.
Strombus.

Strombidea.

RosTELLiVRIA.

Aporriiais.

In such small groups as these, we cannot expect the
analogies to be very strong; a faint resemblance is all
that exists — and all, indeed, that is necessary. Yet it is
remarkable how perfectly P. latisslmns corresponds to
the RosteUaria macroptera in its excessively large outer
lip, which, in both shells, runs up to the top, and even
spreads far beyond the apex of the spire.

(134.) The analogies of the genus Stromhns are nume-
rous, and, in some measure, too complicated to be here
introduced : it will be sufficient to remark, that, besides
the five leading divisions or types of form, there may be
discerned indications of another set of secondary types ;
so, that, if such groups were better understood (as no
doubt they will be hereafter), some cf them may be
found to contain representations of the primary genera
of the St7'otiibin(e, no less than of its leading divisions.
The time, however, is not yet come for such an elaborate
study of analogies as this implies ; and we shall, there-
fore, merely place before our readers the five divisions
of the genus, which, as already specified, seem to be
represented by the five following shells: — Sfromh7<s
Atiris-Dkinrp, yiyas, lentig'mosus, gihhernhis, and suc-
cinvius. All these are among the most common species.

CHAP. V.

CONINE, OR CONES.

145

and, as such, may be readily procured by every student
who feels interested in these inquiries.

Analogies of Types of the Genus Strombus.

Species of
Strombus.

S. Auris-Diarus.
gigas.
lentiginosus.

gibberulus.

succinctus-

Analogies.

f Channel bent ; inner lip spread- 1
\ ing on the spire. J

Outer lip reflected, entire.

5 Outer lip inflected, divided above; 1

f Outer lip slightly or not at all7
X expanded. _)

fA long siphon running up the 7
i spire. j

Divisions of the
Stroynbince.

Aporrhais.

Strombus.

Pterocera.

Strombidea.

rostellaria.

By arranging the intermediate species between each
of these types, the whole would exhibit another set of
relations^ as well as a series of connecting links ; thus
Auris-DiancB is followed by a little group composed of
tricornis, gallus, and Peruvianus, which connect the for-
mer shell with S. gigas : but the student, after these
hints, will find no great difficulty in following up the
theory himself.

(135.) The next genus, Rostellaria, is particularly
interesting to the lover of analogies, inasmuch as all the
types are not only existing, but are of that definite
character which leaves no doubt of their true import.

Analogies of the RosTELLARiiE.

Species of
Rostellaria .

Serrata Sw.*

Macroptera.
Columbata.

Rectirostris.
Fissurella-

\

\

Analogies.

Outer lip reaching to the tip of
the spire, and divided into pro-
cesses.

Outer lip very large, and entire.

'Outer lip hardly attached to the 7

spire, and dilated into a lobe. 5
■ Outer lip not dilated at the top, }

and not extending on the spire. 3
Outer lip hardly dilated, but the"

siphon ascending to the apex I

of the spire ; the margin \vith-(

out teeth-like processes.

Genera of
Stromb/ncc.

Pterocera.

Strombus.
Aporrhais.

Strombidea.
Rostellaria.

* Figured in Chemnitz, pi. 195 A. fig. 1869.
L

146 SHELLS AND SHELL-FISH. PART I.

It thus appears that each type of the Rostellarice, as
arranged according to their affinities, turns out to be a
representation of one of the genera of the Strombince :
and these analogies are so perfect, that it appears to us
absolutely impossible they could be more complete — at
least, in regard to the shells ; although they would be
even more beautiful, when accompanied by a corre-
sponding relation in the animals. R. rectirostris is the
fourth type, and not the common curvirostris ; because
this latter is intermediate in structure between the
former and R. fissurella.

(136.) We feel persuaded, that if the concluding
volumes of the elaborate work of Lamarck had not been
finished ^^ under the eyes of another," because their
celebrated author had become blind, we never should
have seen our Rostellaria cancellata and canalis placed
in his genus Strombus. No species, in fact, either of
Strombus or of Pterocera, so far as we know, occur in
a fossil state. It appears hardly necessary, in so limited
a group, to impose sub-generic names of these types ;
for if one is named, all should be so. Such designations
are not necessary to facilitate research, when the whole
genus contains not more than, perhaps, a dozen species.
With the mitres, the cones, and the land snails, &c., the
case is very different : such groups contain hundreds of
species ; and by designating their sub-genera under
patronymic names, most material help is afforded, in all
ways, to minute research, or to general views.

(137-) The connection of the Conine, or cones, with
the StrombincE, is effected by our new genus Strombidea
in the latter, and Terehellum in the former. The affini-
ties of these two genera we pointed out many years ago,
by the publication of a shell which actually unites the
characters of both *; and Lamarck entertains no doubt
of the close connection of Terebellum to Conus. Tere-
helium, in short, merely represents the olives in this
circle, without having any real affinity with them ; but

* strombus dubius. See Taylor's Phil. Mag. 61. No. 301. May, 1823. This
will now be our Strombidea dubia. Specimens are in the rich collection
of Mr. StanJord.

CHAP. V.

CONINiE, OR CONES.

147

of their animals, nothing, we believe, is yet known.
The true cones, from their beauty, are the favourite
shells of conchologists. Nearly all are natives of tro-
pical climates, where they constitute one of the most
extensive races of the carnivorous shell-fish. The mouth

is a short proboscis (^fig. l6. a),
which in one genus (^Coronaxis
Sw.) has the margin simply cir-
cular, while in the other (Conns
Linn.) it is laciniated, or divided into
a circular fringe of little points,
analogous to the lips of the Trochi-
dce. In both these genera, the ten-
tacula {h) are short, cylindrical, and
nearly obtuse, with the eyes small,
and but slightly developed, placed
half way on their external side :
the foot is small, rather broad, trun-
cate in front, and rounded behind,
where it bears a small oblong oper-
culum, sufficient only to close the
detached part of the top of the outer
lip. The respiratory siphon (c) is well developed, but
its form seems to vary in the sub-genera : in some, it is
thickest at the base (as in C. bandanus*) ; in others
(C. arenatus), it is uniformly cylindrical. t Lamarck
describes no less than 181 species, besides nine fossil;
but we question if there are not more than 230, or
perhaps 250, species already in collections. Such an
immense assemblage of mere species, as they now stand,
fully justifies us in giving patronymic names to the
sub-genera, and arranging them in distinct groups ,• a
plan long ago recommended \, but never yet acted upon.
By separating the coronated from the smooth species,
nothing material is gained ; for although they constitute,
in reality, two genera, the internal relations subsisting
between them are passed over ; and these, in our opinion,

* Voy. d' Astrolabe, pi. 52. fig. 7., here copied^"'. 16.

t Ibid. pi. 52. fig. 8. X Sow. Genera of Shells, article Comts.

L 2

148 SHELLS AND SHELL-FISH. PART I-

are the most important object to be illustrated ; while
the mere collector has no additional help to the no-
menclature of the specieSj more than he now has.
Long and procrastinated attention to these beautiful
shells, together with the invaluable delineations of their
animals by M. Quoy, has now enabled us to give the
following exposition of the genera and sub-genera.*

Analogies and Characters of the Sub-genera o/" Con us

and CoRONAxis.

C0Nt;S. CORONAXIS.

Shell not coronated. Shell coronated.

C. litteratus. f Shell ponderous ; basal whorl not ^ nandanus

Virgo. \ contracted near the suture; \ marmoreus

generates. ( spire in general flattened. J

striatus. f Shell ponderous ; basal whorl con- T jij-cnntus
stercus-mnscarum. < tracted near the suture; spire > cedo-nulli

ammeralis. C short, pointed. j

bullata. r Shell light; basal whorl ventri- i

textile. 3 cose ; aperture eS'use ; the base { Tulina

auratus. j hardly notched ; spire short, C

aulicus. C pointed, concave. }

nussatella. C Shell sub-conic, cylindrical, trans- 1

glans. < versely grooved; spire elevated, >^sp^r?

terebra. C thick, convex, generally obtuse, j

amadis. f Shell conic, light, often trans- ^

gramiis ^ versely striated; spire concave f ^..„^

duplicatus. j elevated, and ponited ; outer (

australis. C lip deeply sinuated above. j

This, perhaps, is one of the most remarkable instances
of analogy yet brought before the reader ; inasmuch as
the characters used as analogies are those only by which
the shells of each group, or sub-genus, of Conns and
Coronaxis, can be defined. Nothing additional, in fact,
can be added to separate, for instance, the sub-genus of
Conus, whose type is C. litteratus. from its represent-
ative, C. marmoratus, in the genus Coronaxis : so per-
fect are these resemblances, that we do not actually
know where the two groups join and unite. As to the
circularity of each, there cannot, we apprehend, be the
least doubt ; for the intervening shades of difference are
so gentle, that we hardly know where one type ends,

* The names of the types are in Italic ; those of the annectant species in
Iloman.

CHAP. V. GENERA OF THE CONINE. 149

and the next begins.* Such only are natural and per-
fect groups : they are the delight of the philosophic
naturalist^ and the torment of the mere nomenclator. As
Conus is the most numerous in species, so it is the most
perfect in these gradations^ by which its five sub-genera
are blended into one circle. The superior heaviness
which belongs to the two typical divisions in each, is
very singular, and may, probably, be owing to the
internal volutions of their shells not being so much ab-
sorbed as in the other types : a simple section, however,
will, no doubt, explain the cause.

(138.) Whether Conus dormitor, and other fossil
species, really constitute the analogous genus in this
circle to the PleurotomcB, cannot be determined, as no
recent species, that we know of, have been discovered :
we shall, however, regard them in this light under the
generic name of Conorbis. The only remaining genus
is that of Conella, hitherto overlooked among the di-
versified shells placed in Columhella by Lamarck, where
they continue to the present day. They are all very
small, and perfectly resemble Cones in their shape ; but
they may be easily known by the outer lip, which ad-
vances upwards on the spire, and is marked internally
by distinct elevated striae. This is a most interesting
group ; for it not only connects this and the succeeding
sub-family of Columbellims in the most satisfactory
manner, but, at the same time, it preserves an affinity,
on the other hand, to Conorbis.

(139.) The Conine, thus arranged, form themselves
into the five following genera, analogous to the primary
divisions of the Strombidce. The genus Conella (^ fig. 17. «.)
€onnects this and the last sub-family.

* There is one rule, however, which we have found quite sufficient for
this purpose. If, of three characters of a given type, a species possesses
only one, and that but slightly developed, the probability is, that it really
belongs to the next type ; or the question may be decided by the law of re.
presentation. Every natural and perfect group, of whatsoever value, con-
tains representations of all the other four groups of its own value in that
circle which unites them all. Thus, it will not be difficult for the natural-
ist to discover, in that sub-genus which includes Conus striatus, represent-
ations (among the species) of all the other four.

L 3

150 SHELLS AND SHELL-FISH. PART I.

Analogies of the Conine, or Cones.

Genera of the 4„nir,ci^<i Sub-families ol

Conine. Analogies. Strombin*.

CoNUs. Spire short, smooth. Typical. Conin,^.

CoRONAXis. Spire coronated or nodulous. Strombin^.

Terebellum. ? Cerithin^.

CONORB.S. [ ^tSuSip" ^^^" '' ^'^ '"' "1 P— OTOMI...

CoNELLA. Outer lip striated internally. Columbellin^.

The third analogy, not heing apparent in the shells,
probably may be traced in the animals. But this is not
very material, since the whole arrangement is founded
upon affinities, and all the other analogies are perfect.

(140.) The C0LUMBELLIN.E, or dove-shells, although
of a small size, rather smooth, and without any dilation
of the outer lip, have, nevertheless, very much the
aspect of little wing-shells ; this impression originates
in the thickened angle or hump on the upper part of
the outer lip ; a character which is seen in no other
group but that of Strombidea, and in certain MarginellcB,
— both which, in fact, are legitimate representatives of
Columbella. According to Guilding, the animals of
this group, like that of ConuSy have the operculum so
very small as often to escape detection.

(141.) The result of an attentive analysis leads us
to arrange the whole of these shells under the five fol-
lowing genera : — 1. We retain the name of Columbella
to the C, mercatoria, and the other European species,
where the crenated teeth of the reflected inner lip ex-
tend its whole length, and are regularly graduated,
those on the inner being but slightly developed. 2. In
Pusiostoma, the teeth on both sides of the aperture are
much more developed ; those on the outer lip are
crowded, very thick, and only occupy the middle por- .
tion. Both these, but particularly the last genus, have
the top of the lip so gibbous, as to form a prominent and
even projecting angle : they constitute the sub-typical
and the typical groups, and consequently exhibit the

CHAP. V,

GENERA OF THE COLUMBELLIN^.

151

characters of the ColumbellhuB in the highest perfection.
The three aberrant genera are more diversified. Thus,
Conidea {fig. 17. h) has the general form of a short fusi-
form mitre (like Mitra contracta*), or that of a cone
with the spire as long, or longer, than the body -whorl,
but still with the volutions thickened at the suture, and
the aperture narrow : there are a few tooth-like stria? on
the inner part of the outer lip ; but it is not thickened
in the middle : the inner lip forms an elevated ridge at
the base ; parallel to which is a longitudinal elevated

17

fold slightly crenated ; but the tuberculated teeth on the
pillar are entirely wanting. In some species the spire is
rather lengthened, with the aperture widened : and this
change brings us to the 4th genus, Nitidella (c), where
the inner lip and its fold totally disappear ; the upper
part of the pillar, or rather that side of the whorl which
forms the apertm-e, is flattened, as if pared down arti-
ficially (as in Purpura) ; the base is finely striated, as
in Ancillaria, and is terminated by a distinct plait
(sometimes two), such as is seen in Volutilithes. All
these resemblances point to one type of structure, and
intimate this to be the most aberrant sub-genus of the
Columbellince. There are many species, but all small ;
the most common of which is the Columbella nitida of
Lamarck t, a little "lYest Indian shell, in almost every
collection : the outer lip is either smooth or slightly
striated within; but although the edge is slightly
thickened, it is never contracted in the middle — nor
is the margin, although inclining inwards, decidedly

* Zool. \\\. 1st Series.

f Nitidella Tnarmorata.Sv!. {fig. 17. c.)
L 4

152 SHELLS AND SHELL-FISH. PART I.

inflected : hence these shells, on a cursory glance, much
more resemble the Buccinints than the Columhellince :
they are almost always smooth, and generally shining.
The 5th and last genus is Crassispira. {fig. !?• d-)
These are also small shells, having the outer lip, externally,
almost as thick as in Pusiostoma, but with a distinct
notch at the top ; this notch is in the same position, but
not near so deep, as in the club-shaped Pleurotomince :
like them, also, the spire is rather long, and the base
very short ; so that at first sight they remind us of very
small Cerithince : the aperture is contracted both above
and below, but wide in the middle ; thus being precisely
the reverse to that of Pusiostoma, which is contracted in
the middle, and wider at the extremities. These shells,
of which there are several species, are known at once
from the PleurotomirKs, to which, however, they lead,
by the outer lip being inflexed and much thickened,
and by the sinus not extending beyond the margin. In
such species as unite with Pusiostoma, the aperture is
slightly toothed, and much contracted ; while in those,
on the other hand, which pass into Nitidella, the shell
is more fusiform, the mouth more effuse, and the
outer lip thin. These variations, which would otherwise
be unaccountable, are fully explained by the relations
that this singular little genus bears to the two adjoining
groups of the Columhellince, and render it one of the
most natural in the whole family.

Analogies of the Genera of the CoLUMBELLiNja.

Genera Typical Genera

of the Analogies. of the

ColimihcUina:. Stro7nbidce.

Columbclla. Sub-typical ; shell coniform. CoNUS.

TThe outer lip often forming a si-T

Nitidella. \ nus at the upper part ; aper- > Pleurotoma.

C. ture effuse. J

„ ., ("Aperture very narrow; whorls 7 tvt .w,^. .,,.,. .

Contdea. { ihickencd at their suture. 5 Marginella.

This table is drawn up for the especial purpose of

CHAP. V. ANALOGIES OF THE COLUMBELLINiE. 153

explaining the singular mixture of characters concen-
trated in this suh-family ; for the only one by which
all its genera are bound together, consists in the outer
lip being invariably inflexed, and either striated or
toothed. Some of the analogies are weak, others strong ;
but as they follow each other in the same series as that
of the primary divisions of the family, this regularity,
of itself, is quite sufficient for our purpose. The sin-
gular tuberculated tooth at the bottom of the aperture,
in several of the NitidellcB, their flattened pillar ter-
minated by an internal fold, the absence of a definite
inner lip, and the effuseness of the aperture, are all
explained, by the following table.

Analogies of the Genera of the Columbellin^.

Genera Sub-families Genera Sub-families

of the Analogies. of the of the of the

COLUMBELLIN^. VoLUTIN.E. VOLUTINS. MuRICID^.

Columbella. Sub-typical, Mitra, Cymbiola. Muricin^.

Pusiostoma. Typical. Voluta. Voluta. Cassin^e.

r Outer lip much "i
Crassispira. < thickened, and > Marginella, Scaphella. Buccinin^s.

C notched above. 3

fObsolete plaits at")

I the base of the |

Nitidella. \ ^mf/o' ^'^t^^l^I^ f> Ancillaria. Volutilithes. PiniPURiN;E.

times with an in- j

l^ ternal tooth. J

r Spire short; inner T

Ccmidea. < lip much deve- >Oliva. Harpui.a. Nassin^.

C loped. J

(142.) But the ColumbellincE possess other resem-
blances, among which that to the mitres has been thought
so strong, as to induce the early reformers of conchology
to place them both in the same genus ; hence it was
taken as a resemblance of affinity. We have seen, how-
ever, by the analysis of the Folutidcp, that this idea is
erroneous. The impression undoubtedly originated in
the strong resemblance between the strombiform division
of the mitres, forming our genus Harpella, and the
typical Columhell(S. Yet even this, although a striking
instance of relationship, is only analogical, as will be
seen more clearly by the following table : —

154 SHELLS AND SHELL-FISH. PART I.

Analogies of the Strojibid^ and the Mitring.

Families of the ^ ; • j /^j, j Genera of the

STROMBID.E. Analogical Characters. Mitiunze.

Stkombus. Shell generally rugged. Tiara.

CoNus. (■Shellsmooth, destitute of protuO ^.

t berances on the body whorl. 3

CO.UMB..... [ ^^S;J'P,;-^ Tnated.^'^'""'' ] "^rpella.

Pleuroto.ma. [ Often coniform ; tip of the outer] Cona^kelu.

I lip sinuated. 3 lutw-^n .

Ceiutuium. ? Miirella.

(143.) Without going further into particulars, we
may observe that these tables afford strong collateral
evidence that the strombiform structure — at least, in this
order — is one of the primary types of form, which is
repeated and represented, under every possible modifi-
cation, in almost all the groups hitherto noticed.

(144.) The Pleurotomin^ is our next sub- family.
The perfect gradation of forms which connects this
remarkable group with the cones, wiU, it is presumed,
remove all doubts as to its supposed affinity with the
FusincB. Nothing, indeed, short of the evidence here
adduced would have satisfied us that Lamarck was in
error in approximating Pleurotoma to Fusiis : so strong
are early impressions and preconceived opinions. The
discovery, however, of the genus Crassispira brings
into this group, by means of the new genus Brachytoma,
a small group of shells, having the aspect of some
Lamarckian Fusmce, but with the basal canal longer,
and the spire shorter, than Crassispira. One of the most
typical has been aptly named Stromhiformis* ; it is tur-
reted and nodulous, with the notch at the top of the
outer lip short, and nearly semicircular, — hardly more
developed, in fact, than it is in Crassispira. There are
several other species, mostly nodulous, and having the
general appearance of such shells as Fusus Syracusensis.
We next come to the typical genus Pleurotoma, where
the channel is so much lengthened as to be little shorter
than the spire. These appear to be succeeded by a group

* Sow. .Manual, fig. 381.

CHAP. V. GENERA OF THE PLEUROTOMIN^. 155

to which we have retained Lamarck's original name of
Clavatula ; it has the long narrow slit oi Pleurotoma, but
with a very short canal. Following this comes Clavi-
cantha, having the canal equally short ; but the sinus, or
notch^ instead of being linear and long, is short and
wide, the surface is rough, and the whorls either coro-
nated with prickles or with compressed nodules resem-
bling spines. The last genus is Tomella, w^hich has the
spire and canal nearly equally fusiform ; but the former
is of very few whorls^ and the inner lip is considerably
thickened within, where it joins the outer lip. In these
five genera, all the varied species of this group will
arrange themselves : the two typical are recognised by
the length and narrowness of the sinus, which, in the
three aberrant genera, is short and wide. Clavicantka
is a very remarkable form, inasmuch as it seems pro-
bable that echinata and auricultfera * are fluviatile shells,
Lamarck describes them as PleurotomcB ; and not having
seen them, we take his authority for the fact ; but we
might almost question whether they do not belong to
Potomis, which is the first genus in the Cerithince, —
so intimately do these sub-families appear connected.
Nearly the whole of these shells^ like the mitres, are
scarce ; and yet the species are numerous. They chiefly
come from the Indian seas, and other warm latitudes.

(145.) The situation and the genera of the Pleuro^
tomincB, thus determined by analysis, offer some very
curious analogies which merit our special notice. The
sinus, which gives them the appearance of having the
outer lip ddated, although it is really not so, is only a
modification, as we believe, of the wider sinus nearly
in the same part of the outer lip in Stroinbus; and
these, again, are but different modifications of the same
part in the typical cowries, where the outer lip forms a
sinus before it joins the umbilicus or depression of the
spire. That this fissure is intended to admit the 'pro-
trusion of some particular organ of the animal, is un-

* Ency. Meth. pi. 439. figs. 8. 10.

156

SHELLS AND SHELL-FISH. PART I.

questionable; but^ until we know what the structure of
this animal really is, nothing further can be determined.
A similar notch is found in the genera lanthina, Scicu-
rella, and Pleurotomaria, among the phytophagous fami-
lies ; and the slit, in certain Emarginulce, may probably
be analogous. By disposing the genera in the order they
have here been placed, some interesting analogies will
come to light.

Analogies of theVhi^VROTOMiNJE and the Strombid^e.

Genera of the yi i ■ ? m . Genera of the

Pleurotomin^. Analogical Characters. Strombid^.

Brachitoma. [ Outer lip gibbous and ascending ; ^ strombidea.

i inner generally thickened. J

Pleurotoma. [Typical; canal considerably j Pterocera.

i lengthened, as long as the spire. J

Clavatula. Sub-typical ; canal short. Strombus.

Clavicantha. Canal very slight. Aporrhais.

ToMELLA. Inner lip considerably thickened. Rostellaria.

(146.) We now turn to the Cerithin^, or club- shells,
the last division of the family. They merit this name,
not merely from their shape, but from having the whorls
encircled, either with obtuse spines, nodules, or granu-
lations. To M. Quoy we are indebted for a knowledge
of the animals of three of the genera, each of which has
some marked and peculiar character, — more so, even,
than their shells. Hitherto, with the exception of
Potomis and Pirena, they have been placed in one
genus. These two, from being covered with a strong
epidermis, are presumed to be fluviatile, or, at least,
living in the estuaries of rivers ; the rest are found in
marine but generally shallow depths, and often in pools
left by the tide. The species are numerous, both in a
recent and fossil state, particularly in the newest form-
ations, where some are stated to occur precisely simi-
lar to those now living. The whole of these shells have
a very long spire, a small body-whorl, and the outer
lip considerably dilated. The first genus is T5rongniart's
Potomis, which may be called the coronated type, be-
ing encircled with obtuse spines and granulated points ;

CHAP. V. GENERA OF THE CERITHIN^. 157

the basal canal is scarcely developed^ so that it merely
forms a sinus ; the epidermis is strong, and of a rich
fulvous brown, beneath which the shell is white. The
typical genus Cerithium appears to follow next, chiefly
disting-uished by its short and nearly straight canal :
the operculum is oblong and ear-shaped, and the pillar
smooth. These almost insensibly glide into Rhino-
clavis — well distinguished, however, by the shell having
a distinct plait on the pillar ; the basal canal fully de-
veloped, and turned backwards ; and by the operculum
being perfectly circular. These are very elegantly
marked shells : the colour is generally white ; and the
surface is often reticulated into little asperities, some-
thing like those on a file. To these succeed Terehralia,
generally of a black colour (as representing the Mela-
niancp), of a large size, and having the outer lip so
much developed, that in almost all, when fully grown,
it actually joins the other, and leaves only a circular
opening for the respiratory siphon of the animal : this
siphon, as shown in the admirable figures of M. Quoy,
assumes the shape of a radiated star, which occupies
the perforation, but does not protrude beyond it : the
tentacula are very long ; and here, for the first time,
we begin to see the commencement of that high deve-
lopement of the eyes, for which the next groups, or the
PterocercB and the Stromhi, are so much distinguished :
the operculum, as in Rhinoclavis, is round ; but there is
no plait upon the pillar, and the basal canal hardly pro-
jects. The genus Pirena * completes the circle, by
showing us a truncated based Cerithium, with the sinus
of a Pleurotoma. These shells, like Potomis, are flu-
viatile ; and thus we return to the point from whence
we began : the variations, however, are so few_, that the
analogies are not striking.

(147-) That the Cerithince pass into the StromhincE ,
by means o{ Aporrhais, we have, individually, no doubt :
we ground this belief more upon the similarity

* Ferussac has most unaccountably joined this very beautiful and dis-
tinct type with Melanopsis.

158 SHELLS AND SHELL-FISH. PART I.

of their animals_, than of their shells ; and yet, when
we look to the young shells of Aporrhais, and of certain
Terebralicp, they might very readily be placed in the
same genus : the cuts (^fig. 15.) already given at p. 142.
will bring this fact more prominently before the reader.
We are not so confident,, however, in regard to the abso-
lute affinities of certain species of Potomis, which have
the aperture oval, and the basal channel almost oblite-
rated : they may, indeed, be the connecting links between
Pol. muricata and the genus Clavicantha ; but until La-
marck's Pleurotoma echinata and auriculifera are better
known, some doubt must hang over them : on the other
hand, this is the point of union between the two great
tribes of the Zoophaga and the Phytophaga ; so that the
very first genus which we should have to notice, if we
followed the thread of affinity in this direction, would
be that of Melania, in the family of the Turhidce, — be-
ing precisely that to which these aberrant species of
Potomis^ with an oval aperture, would seem to belong.

CHAP. VI.

ON THE PHYTOPHAGOUS TRIBE OF SHELL-FISH. THE PRIMARY

DIVISIONS OR FAMILIES. THE HELICID,^, OR LAND AND FRESH-
WATER SNAILS.

(148.) The second great tribe of the gastropod shell-
fish is that to which, after the illustrious Lamarck, we
apply the name oi Phytophaga, since they not only sub-
sist upon animal, but also vegetable, substances : they
are easily known from the truly carnivorous tribe, by
being destitute of the respiratory siphon, and in the
mouth not being retractile, or prcboscidiform. In
regard to the shells, the differences are equally well
defined. From the absence of the respiratory tube, the
aperture is round and entire, or at most is only slightly
notched in such genera as unite the two groups. The

CHAP. VI. THE PHYTOPHAGA GENERALLY. 159

whole are regular spiral shells, — a character by which
they are separated from the Scutihranchia, or limpets.
The great majority are external shells, and all but one
small group — the slugs and their representatives, — have
their habitation sufficiently large to contain the entire
body. Their modes of breathing and propagation are
various, and greatly diversified even in genera close to
each other ; so that nothing can yet be determined of
a general nature on these points. Although the greater
part of the Helicidce, or snails, live upon land, and
therefore breathe differently, a portion of the same
family live in fresh water ; and even some of the slugs
appear to be found only on the sea shore : the rest of
the tribe, excepting the Melaniance, are all marine.

(149.) The secondary divisions or families are first
distinguished by the formation of their animals, and
secondly, by the nature of the shells : this latter mode,
however, will lead to great confusion, if not regulated
by the former ; since there are many genera in different
families, Avhose shells are nearly of the same form,
although inhabited by very different mollusks. As this
will become evident when we enter into their details,
we shall at once characterise the chief divisions. The
first, or the most typical, are the Helicidcs, which in-
cludes the testaceous land snails, the naked slugs, and
the pulmonary fluviatile shells.* The second, or Tro-
chidce, are entirely marine : the shell is almost always
perlaceous ; the body of the animal is furnished with
lateral filaments, and its mouth with lips, as in the
last ; and the shells of both are turbinated and spiral.
The third, or Haliotidce, are known by their flat ear-
shaped shells, having only the rudiment of a spire, and
without any pillar ; hence they may be even called
spiral limpets. The fourth is the Naticidfe, or nerits,
where the spire also is very small, but the pillar is
always thick ; the exposed part, or inner lip, often very
broad; and the animal slug-shaped. The fifth, or

* This group corresponds with a few trifling exceptions, to the Pulmo-
naria of the Eegne Animal..

160

SHELLS AND SHELL-FISH.

PART I.

TurbidcB, can only be characterised effectually by their
animals : they bear a close resemblance^ in their eyes,
tentacula, and mouth, to the Zoophaga, and several of
the genera, as Turbo, Ampullaria, &c., are provided
with the same sort of siphon : the shells themselves are
all more or less spiral, and exhibit some of the most
elongated forms in the whole tribe.

(150.) The slight degree of analogy between the
families of this tribe and the zoophagous Gasteropoda
will, no doubt, be strengthened hereafter, when the
animals of each are better understood.

Analogies of the Phytophagous and Zoophagous Gas-
teropoda.

Families of the
Phytophaga.

Helicid^.
Tbochid-e.

Haliotid^.
Naticid.e.

TURBID/E.

Analogical Characters.

Families of the
Zoophaga.

MURICID^.
TURBTNELLID.E.

Typical.

Sub typical.
TFoot enormously large ; tentacula i
< very short ; spire of the shell > Volutid^e.
C very small. 3

f Shell highly polished, partly or 7
i entirely covered by the animal. 3

Cypr^id.b.

r Animal carnivorous; mouth pro-T

\ bosciform, with a respiratory ?■ Strombid.e.

t sir ^

siphon.

Without dwelling upon *these points, therefore, we
shall take a detailed survey of each of the families.

(151.) The Helicid^e is one of the most remarkable
families in the whole order of the Gasteropoda, in as
much as it is the only one of the truly testaceous divi-
sions, wherein we find moUusks entirely naked closely
and intimately united to others which have perfectly
formed shells. To separate the naked slugs from such
as begin to have the rudiments of a shell, and these
latter, again, from others, like the garden-snails, whose
habitation is sufficiently large to contain them, would
be such a violation of nature as no writer has yet at-
tempted ; we must, therefore, include them in the same
family. We may account for this apparent anomaly,
by supposing that, as this is the pre-eminent type of the
\thyto\i}\digo\xs Gasteropoda, nature, so to speak, has, more

€HAP. VI. HELICID^, OR SNAILS. l6l

distinctly than in any others^ pointed out the mode
which she pursues in the development of all her
groups. Commencing from the most simple form, she
gives us the first germ of the limaciform structure in
the extraordinary genus Herpa, hereafter noticed. From
this point, as it were, she makes two diverging series ;
the one to the right hand, through the terrestrial slugs ;
the other to the left, through the semi-aquatic slugs
and the freshwater snails : and these two series, after
passing through numerous links, finally meet in the
pupaceous-formed shells, constituting the genera of
Pupa and Clausilia. It is by this theory we account
for the actual presence of naked mollusks among the
Helkidd'; and in this manner do we consider that the
whole form a circular group, the particulars of which
will be more clearly stated hereafter.

(152.) The Helicid^ are the only animals of the
Testacea which breathe atmospheric air. From this
circumstance they have been considered, by some, in
the light of a distinct order ; but their close and inti-
mate connection with the Turhidce on one hand, and
even with the Trochido' on the other, clearly shows
their situation to be intermediate, and that they, there-
fore, only constitute a family group. The respiratory
organs of these animals simply consist of a moderate-
sized oval aperture, placed under the reflected edge of
the mantle, which can be dilated or contracted at plea-
sure ; hence there are no branchia, but merely, ac-
cording to Cuvier, " a network of pulmonary/ vessels,
which spread over the parietes and pulmonary cavity."
The number of tentacula is variable, according to the
different groups ; but they are usually four, — two long
and two very short ; the former bear the eyes at their
extremities, but these organs are only so far developed
as to appear like black points. So far as we yet know,
the greatest uniformity pervades the animals of all the
HeliciiKS, or turbinated land-snails, so that the minor
Uvisions rest entirely on the structure of their shells ;
but in the spiral snails (or the sub-family AchatintF)

M

162

SHELLS AND SHELL-FISH.

PART I.

both the animals and the shells are more diversified.
Hence, while scarcely any thing has yet been done in
determining the genera and sub-genera of the Helicino',,
nearly all those of the Achat'uKB have been named and
defined. It is time, however, to quit these general
remarks, and proceed to the sub-divisions of the family.
(153.) We arrange the whole of this group under
the five following families, which may be thus de-
fined: — 1. the Heliciuip, or testaceous snails, having
perfect turbinated shells more or less depressed ; the
aperture entire, but without teeth. 2. The Achatinee,
or spiral snails, the spire of whose shells is elongated
and conic. 3. The LimnacinKB, or river-snails, having
only two depressed or flattened tentacula, and no oper-
culum. 4. the Limacinrp, or slugs, having either no
shell, or one much too small to contain the body. And
5. the Lucernince, or terrestrial volutes, where the shell
is orbicular, depressed, or flattened, and the aperture
furnished with distinct teeth.* That the foregoing
series is probably the natural one, may be inferred from
the following table of analogies : —

Analogies of the HELiciDiE.

Sub-families

of
Helicidcs.

Analogical Characters.

Families
of tile
Phytophaga.

Helicin.e.
achatin^e.

LiMNAClNJL.
LlMACIN,E.

LUCERNIN^.

C Spire most generally with the > helicid.e.
i whorls depressed. J

Spire mostly produced. Trochid^.

Outer lip considerably dilated. Turbid.e.

Animal mu(;ii larger than its

Naticid.c

shell, the sides of which, (
where it exists, are enve-(
loped in its mantle.
Depressed, or the spire very ^
small; aperture furnished vHahotid^.
L with plaits. J

These analogies are, of course, only appl
types of each, and are intended to be so

Families

of the

Zoophaga.

TURBIXELLID^.

MuRICIDyli.
StROMBID/E.

CYPR.EID.E.
VOLUTin^.

i cable to the
understood :

* The injustice of the attempt made by M. de Feru>sac to substitute a
new and artilivial nomenclature of his own for X\\q Ihiicidie, antl so tu
cancel the previous generic names of Lamarck, Draparnau(i,and of all his
predecessors, is without jtarallcl in this or perhaps any deiiartment of zoo-
Jogy, and can only be e<iualled by the confusion it has caused.

CHAP. VI. THK HELICIN.E. 1 63

we have stated them merely as a preliminary step, to
show the general, not the particular, resemblance of
the primary groups. The extreme difficulty attending
such an analysis of the Helicincs and the Lucernince, as
is necessary to determine the sub-generic types, will
prevent us, for the present, from entering into the de-
tails of these two groups so fully as we shall do in regard
to the others. We commence with the Helicin^, as
the most typical group ; but, from the above cause, its
analysis will be less minute than that of the other
divisions.

(154.) The typical sub-family of Helicin^, although
more numerous, perhaps, than any of the land -shells,
has received less attention, in regard to its natural di-
visions, than any group of the same rank. This has
probably originated in two causes ; the entire similitude
that runs through the animals, and the little variation,
of a decided and very prominent nature, observable in
the shells. Nevertheless, a closer attention leads to the
belief that this group, within itself, will be found as
diversified in its modifications as any, — less obtrusive,
indeed, but promising the same results, when thoroughly
analysed, as in all natural groups. As a whole they
are immediately known from the Lucernince, or land-
volutes, by never exhibiting a discoid shell furnished
with plaits or teeth : the aperture of one division, indeed
(^Pupa), has these appendages ; but then the form of
all the shells is spiral and elongated, and cannot there-
fore be confounded with the Lucernino'. The Helicid<^,
perhaps, are best distinguished by the aperture being
without teeth and transversely oval, — a shape which re-
sults from the depressed form of the body-whorl, which^
in the Achatiiife, is always oblong ; and this character is
the more important, because it is preserved even in such
genera as Geotrochus, whose spire is often as conical and as
much produced as that of the Bulimi. It is also to be ob-
served that, with very few exceptions, these half-spiral
snails have the tips of the spires very obtuse and even flat-
tened; whereas, in thQAchathife, they are always pointed

31 2

164

SHELLS AND SHELL-FISH. PART I.

and comparatively slender. Our analysis of the Helicincp
not havinj^ been yet completed, we are only acquainted
with the four following genera ; the fifth, which should
intervene between Helicella and Pupa, being yet unde-
termined. In the first, or Helix proper, we have the
great proportion of shells usually so called, of which
the Helix hortensis is a good example ; they are strictly
turbinated shells, the spire being very slightly elevated ;
the body-whorl ventricose ; the aperture without teeth ;
and the base of the pillar never separated from the outer
lip : this is the typical genus. The second, or sub-
typical, is Geotrochus, where the spire is always elevated,
and composed of more than four whorls *, generally of
five, and sometimes of six: the typical species are trochi-
form ; but the sub- genus Pithohelix puts on the aspect
of a Bulimus or Achatina. The third is Pupa, where the
spire reaches its full development, and the aperture
becomes nearly circular : by this character Pupa may
be readily distinguished from Clausilia and all its sub-
ordinate types. Our fourth genus is composed of the
remaining portion of Ferussac's HeliceUcs, typically
represented by those disk-like shells which are destitute
of a pillar ; the spire very short, and often sunk below the
level of the margins (as in Planorhis) ; the body- whorl
ventricose ; and the outer lip considerably thickened :
this group has no indications whatever of the incipient
teeth seen in Hemiodon, and yet it connects the land-
volutes and the present sub-family of HelicincB in the
most perfect manner. We shall not in this place offer
any conjectures regarding the fifth type, but proceed
at once to give our analysis of the two typical genera.
Helix and Geotrochus, so far as it has yet extended.

(155.) The sub-genera of Helix appear to us to be
as follows : — The first, on leaving Hclicrlla, is Hemi-
cychi, distinguished from Helix proper by the broad and
flattened margin of its outer lip, and by the absence of
the inner, except occasionally a little tubercle, sufficient
to point out its analogy to the Lucernina' ; but there

* The last, or body-whorl, being excluded.

CHAP. VI.

SUB-GENERA OF HELIX, ETC.

165

are never any on the outer lip. In the second, or Helix
proper, the spire is more elevated, the shell more globose,
the umbilicus covered, and the outer lip more or less
reflected : these obviously lead to Zonites, which chiefly
differs in the outer lip being always thin, the spire more
depressed, and the umbilicus more or less open. By
degrees, however, the spire becomes more
and more elevated, until, in that sin-
gular shell Epistylia conica* {Jig. 18. «),
we have a. Pupa and a Helix combined in
one form. The last is a very beautiful
type, already characterised as a sub-
genus by Mr. Gray, under the appro-
priate name of Strepsaxis, while its
obvious affinity to Hemicycla brings us
again to the point whence we commenced,
(156.) The genus Geotrochus, in like manner,
seems to take the following course, corresponding to
that of Helix. Vie give the name of
Hemitrochus to certain trochiform shells,
{jig. 1 9- )' ^^^^^^S ^^^ spire nearly as elevated
as in Epistylia, but less thick ; the whorls
much fewer, and the inner lip margined
internally ; the basal whorl is not angu-
iated, so that, if the spire were not conic, and the inner
lip not thickened within, they might be arranged with
Zonites. These shells at once bring us to the typical
sub-genus Geotrochus '^xo^er, where the body- whorl in its
widest circumference is more or less carinated, and the
spire gradually tapering to a pointed cone ; it is, in fact,
just the shape seen in the marine Trochuses : in some
few species, chiefly small and European, the margin
of the lip is thin, but in the more typical ones from
tropical America it is thickened, dilated, and almost re-
flected. Our next sub-genus, Pithohelix is as spiral as the
last ; the spire, however, is obtuse at the top, the body
whorl not angulated, and the aperture, consequently,
rather higher than broad : such as have the spire

* Helix epistyliiim of authors,
M 3

166

SHELLS AXD SHELL-FISH.

PART I.

more than usually produced^ resemble Bulimi, but with
this difference, that the whorls are more ventricose
and the top of the spire more obtuse ; in some the
base of the pillar forms a small sinus or notch before
it joins the thickened outer lip, analogous to the Acha-
tince ; but in that the margin is always thin, and
the spire more contracted and pointed : something of this
form belongs to our next sub-genus Geomitra {fig. 20.),

founded upon a most extraordi-
nary little shell discovered by
Mr. Lowe in Madeira, and exhi-
biting the only instance of coro-
nated nodules on the whorls we are acquainted with in
this family. The form is that of the last type ; but the
mouth is thin and completely circular, like that of a
Pupa, to which genus we consider it
leads. As connecting Geomitra with He-
mitrochus, we here place the fifth sub-
genus Gon}domus (^fig. 21.), which, in
the distortion of its whorls, is a com-
plete prototype of Strepsaxis. The ge-
nera Helix and Geotrochus would thus
appear to form two circles, whose sub-
ordinate types may be thus stated.

Analogies of the Genera Helix and Geotrochus.

Analogical Characters.

Sub-genera of
Helix.

Helix.
Zoniles.

Epistylia.

Strepsaxis.
Hemicycla.

f Body. whorl large, ventricose
X umbilicus none.

f Body-whorl depressed, narrow ; )
\ umbilicus open. _>

f Spire elevated, oStuse ; body
■s whorl depressed, the margi
C convex.

Spire and whorls distorted.

f Aperture or outer lip perfectly >
X round. J

ns >

Sub-genera of
Geotrochus.

Pithohelix.
Geotrochus.

Hemitrochus.

Gonidomus.
Geomitra.

These sub-genera agree sufficiently well to render any
additional illustration unnecessary. "\\^e shall therefore

CHAP. VI. SUB-GENERA OF PUPA. iGj

at once proceed to the genus Pupa, the passage to which
has been opened by Geomitra.

(157.) The genus Pupa we shall restrict to those
maggot-shaped cylindrical shells whose body- whorl is
larger than the others, whose spire is thickened in the
middle, and which have no teeth on the inner lip ; the
aperture also, in three out of the five sub-genera, is
always round, but in the two others it is oval, on account
of their blending into the genus ClausUia. Having
analysed both these remarkable genera, we feel much
more confidence in stating the types than in what has
been said regarding those of Helix and Geotrochiis. The
type of this present group is that extraordinary and
rare shell the Megaspira of Lea, of which a noble spe-
cimen, containing no less than twenty-two whorls, is in
our cabinet. The outer lip is thin, and the inner want-
ing ; but there are four sharp plates close together at
the base of the pillar, and a central one on the inner side
of the body-whorl : it must be remarked that this shell,
although of such excessive length, does not lose the
apex of its spire, which is obtuse almost to its very tip :
this is an important character, because it is carried on
to our sub-genus Gonospira, where this part is the
same, but even more obtuse : the volutions, however,
are only seven, yet the shell has the same form as the
last, so that the spiral whorls are nearly of equal thick-
ness ; the aperture is more that of Pupa, being oval ; it
is thickened all round, and there is a tooth at the upper
angles. This leads at once to the sub-genus of Pupa
proper, distinguished from both the foregoing by the
suddenly-pointed shape of the apex, and the increased
thickness of the two lips^ which, as in Gonospira, are
united : all the typical species in like manner have a
tooth ; but this disappears in such species as pass into
Plicadomus , where the inner lip is entirely wanting, the
aperture having a dilated margin, and perfectly entire,
while the apex of the spire, no longer suddenly con-
tracted, is obtuse : it is by this sub-genus, as we think,
that the whole group is united to Geomitra ; and it may

M 4

}68

SHELLS AND SHELL-FISH.

PART 1.

be observed, that in the strongly sculptured ridges of
most of the species, a nearer approach is made to the
coronated Geomitra {fig, 20.), than to any other land
shell. The last sub-genus to be noticed was long
ago characterised by the masterly pen and pencil of
Guilding, but seemingly overlooked by our concholo-
gists ; it is his Siphonostotna *, and is distinguished at
once both by the animal and its shell (S. cosfata Guild.,
fig. 22.). The foot is remarkably short, while the

spire of the shell is deci-

duous, i. e. falling off soon
after it has reached matu-
rity ; sometimes, indeed, the
animal has been captured
before this process takes
place : the shell is then re-
markably beautiful, exhibiting as many whorls as 3/rtcro-
spira, but with this difference, that the upper portion is
gradually attenuated to a fine point : this type is thus
separated from Macrospira, not only by its decidu-
ous spire, but by its round aperture and its thickened
lips, which gives it all the aspect of a Cgclostoma,
except that the margin of the lips, in some species, is
even detached from the body-whorl. That there will
be intervening modifications between each of these sub-
genera, so that they may be blended more harmoniously
together, can admit of little doubt : our only regret is,
at present, that they are too strongly marked and dis-
tinct ; nevertheless, we may feel confident, after studying
the annexed table, that these forms follow each other in
the order in which they are now placed. We insert in
this place the series of the ClausilicB, which represent
Fiipa, in order to show the intimate relations of the
two groups ; but we shall subsequently return to that
genus, because it forms part of the sub-fiimily Acha-
tince.

* Guilding imposed this name after he bad discovered ihat Brachipits
had been used by us to designate a group of birds.

CHAP. VI. ANALOGIES OF PUPA. 16Q

Analogies of the Genera Pupa and Clausilia.

Sub-genera Sub-genera Genera

of Analogical Characters. of of the

Pupa. Clausilia. Helicin-e.

r Sub-typical; whorls nume-^
Megasplra. ^ rous, all persistent ; \ivab'\->Balea. Helix.

t. Heated. j

r Typical; spire deciduous;'!
Si'pkonostoma . < lips generally detached from > Clausilia. Geotrochus.

C the body-whorl. J

r Outer lip with the n:argin, ^
Plicadomus. \ considerably dilated, and ^ Macrodontes. Pupa,

C the edge reflected. j

Pupa. [^Sr'?'''' ^'^^ """"'^'""'jp^pf/to. ?

Gonospira. pP'reo^t^few whorls, and very j , Helicella.

The resemblances between the sub-genera of Pupa
and those of Clausilia are too obvious to be dwelt
upon ; but those between the first column and the last
require some explanation. The spire of Helix is al-
ways obtuse^ so is that of Megaspira ; in Geotrochus
and Siphonostoma, on the contrary, the terminal por-
tion of the whorls is acutely conic ; and this form is
carried to such an extent in the deciduous portion of
some species^ that they actually put on the appearance
of being long-spired trochiform shells, instead of a
portion only of that to which they really belong. He-
licella and Gonospira agree in the paucity of their
whorls; while the fifth type, w^hich should represent
Pupa, has not been determined. If we wished to carry
our analogies into the zoophagous tribes, it is clear that
the strombiform type is the third, and the volutiform
the fifth, of the above series.

(158.) We feel unprepared to offer any definite opi-
nion on the extent or the subordinate types of the genus
Helicella ; it stands at the confines of the Helicin^ and
the LucERNiN^, and therefore may be supposed to par-
take in the characters of both. We even think that
several of the perfectly discoid shells, now arranged
with Cyclostoma, such as Cy. planorbula*, will event-

* Ency. Meth. 431. fig. 3.

170

SHELLS AND SHELL-FISH.

PART I.

ually prove the real types of this group^ which repre-
sents Cyclostoma among the Helicin-s;.

(159.) The AcHATiN^, as we have already shown,
constitute the sub-typical group, representing in their
own family the zoophagous tribe. This analogy is seen
in two ways : first, they are the most spiral of all the
Helicidce, just as the Zoophaga are the most spiral of
all the Testacea ; secondly, they are the only ones where
the indication of a basal channel is seen, as if to pre-
pare us for the full development of that character in the
next great tribe which succeeds this. But setting aside
all these considerations, at least for the present, we will
at once proceed to characterise the five genera into
which they appear to divide themselves. 1. In Achatina,
properly so called (^A.marginata^^w.Jig. 23.), the basal

extremity of the pillar is trun-
cated, so as to present a distinct
separation between it and the
outer lip ; this lip also is always
thin and sharp-edged at every
period of age. 2. In BuUmus,
on the contrary, the outer lip
is more or less thickened and
reflected backward ; while the
inner lip — always absent in
Achatina — forms either a little
fold just below or near to the
umbilicus, or is continued up,
and spreads a polish over the
left side of the aperture : the general shape of the shell
in the typical sub-genera of both this and the last is
obovate, having the body-whorl much the largest, and the
aperture without teeth, except in the sub-genus Auri-
cula. This leads to the next or 8d genus, Clausilia : in
these the spire is excessively long in proportion to the
aperture, the basal or body-whorl being hardly larger than
the others ; and the aperture, moreover, is furnished
with various folds, or toothlike process. The ^th,
Helicina {Jig. 18. b), is distinguished at first sight by its

CHAP. VI. THE SUB-GENERA OF ACHATINA. 171

rather depressed form, but still more by its semicircular
aperture, always closed by a horny operculum : the typical
species are also peculiar from having a narrow notch,
or rather slit, at the base of the outer lip. The 5th
and last genus is Cyclostoma, distinguished by its mouth
and operculum being perfectly circular ; the margin of
the lip is also more or less dilated into a fringe or
thickened rim. We shall now take each of these genera,
and describe what appear to us the types of form or
sub-genera in each.

(160.) The first and typical genus, Achatina Z<am.,
includes the largest sized shells of all those inhabiting
the land : they are chiefly found in Africa, where the
natives use them as food, and expose them for sale in
the markets. The inside of the mouth is sometimes of
a brilliant rose-colour, and the outsides of nearly all are
elegantly marbled with white ; but, as the epidermis is
very tenacious, the ground colour appears olive. The
body-whorl of these typical species is large and ventri-
cose, the outer lip simple, and the whole shell solid :
but in the next type, or Cochlicopa of Ferussac*, the
body-whorl is more slender and cylindrical, and the
shell is placed very much towards the end of the disk
or foot of the animal, which makes this part appear very
short : by degrees, however, the spire becomes length-
ened, and the body- whorl proportionably smaller ; and
in these aberrant species, nearly all of which are longi-
tudinally striated, the margin of the outer lip is more
sinuated. This elongation of the spire prepares us for
the sub-genus Macrospira Guild,, where the spire
becomes excessively long and cylindrical ; yet the lip is
still very thin, and the pillar is truncated, or notched at
the base, precisely as in all the other types. In one or
two species we observe, for the first time, a thickened
fold in the middle of the pillar, analogous to what is
seen in some of the Auriculce and the Pupce, Now,

* We adopt M. Fenissac's names whenever they have a right of priority
and are classical ; this group has been called by the strange appellation of
Polyphemus, as if the animal had not two eyes, but one only !

172 SHELLS AND SHELL-FISH. PART I.

this same thickening of the pillar into a central fold is
observable in Leucoatoma, — a name by which we now
designate a remarkable little shell (^fig. 24.) of the
^ same shape as the more elongated
AchatinellcEy but with the addition
of a thick gibbous mass of white
enamel placed on the top of the
aperture within, where the outer
lip joins the body-whorl : this
little pad, in short, is exactly the same as what is seen
in Melanopds, — the base is distinctly emarginate, and
the outer lip thin ; but then the substance is more
like that of a marine than a land shell, and both the
interior of the aperture, and the outside of the whorls,
are transversely striated : the space between the upper
pad and the commencement of the plait on the pillar
is without; enamel, and is so short that it has the ap-
pearance of a deep notch : that this shell, hoAvever,
either by affinity or analogy, has a strong relation to
the types where we now place it, admits of little doubt ;
our difficulty lies in determining bet%veen these two
relations. If not a marine, it may be an amphibious
species ; in this respect it seems to have a relation of
analogy to Melanopsis, as well as one, more near, to
PlancLvis. Achatenilla is our fifth and last type. These
little shells are remarkable for the beauty of their colours;
they are all inhabitants of the Pacific Islands, where
they are used as bead-like ornaments. They are at
once known by the thickened rim on the internal part of
the outer lip : were this rim external, nothing but the
truncated pillar would prevent these shells being placed
with the CyclostomcB. With. Achatinella, in fact, the
circle is closed. Its connection to Achatina proper, with
which our survey began, is effected by that well-known
shell, the A. viryinea, which is almost an aberrant
Achatinella : in this well-known species, the aperture
is very oblique, as in Achatinella pica, and the pillar,
like that shell, considerably turned inward. The thick-
ening on the inner margin of the outer lip is not

CHAP. VI.

ANALOGIES OF THE ACHATIN.E.

173

observed in young shells ; and even in those which
are adult it is very slight^ yet it is distinguishable.
In the typical Achatina, on the contrary^ the base of
the pillar is turned outwards^ the mouth is not ob-
lique, and the whole of the outer lip is so thin and
fragile, that it breaks on the slightest touch : a more
intimate union, in short, cannot possibly exist.

(161.) Having now, to all appearance, closed the
circle of Achatina, we may compare it with the primary
divisions or genera of this sub-family.

Analogies of the suh-genera o/'Achatina.

Sub-genera.
Achatina.
Cochlicopa.

Macrospira.

Leucostoma ?.
Achatinella.

Analofiical Characters.

f Large ; ventricose ; strictly typi-
l cal.

fBodV-whorl more contracted
X spire more lengthened.

"Shell cylindric ; spire exces-
sively long ; the body-vhor
small ; aperture short, nearly
round.
rOuter lip with a distinct notch at
^ the base; inner lip not thick-
C ened internally.
f Lip thickened ; aperture nearly 7
\ round. 3

]
J

1

Genera of the
AchatintB.

Achatina.

BULIMUS.

Clausiua.

Helicina.
Cyclostoma.

This result of following the course of affinities is im-
portant, as showing that the modifications of the spiral
snails are regulated on a uniform and a very simple
system. The more experienced zoologist need hardly be
reminded, that, in comparing Cochlicopa with Bulimus,
we institute the comparison with that division of the
latter genus which is sub-typical, because Cochlicopa
is also sub-typical : in both these the spire is as long,
and generally longer, than the body-whorl ; whereas in
the pre-eminently typical Achatmce and Bulimi, the
body-whorl is ventricose, and the four whorls of the sVue
short. So beautifully do the greater part of these xive
sub-genera of Achatina blend and pass into each other,
that it is no easy matter to detemiine where one ends

174 SHELLS AND SHELL-FISH. PART I.

and the other begins. Leucostoma, however, is an
exception ; it is more isolated, and consequently its pre-
sent position is very doubtful. There is also a hiatus
between Leucostoma and Achatinella; but then this last
is so perfectly connected to Achatina, that nothing can
separate them. Thus we have four lifths of a circle ab-
solutely perfect; so that, if Leucostoma had been undis-
covered, and the fifth type entirely wanting, still this
deficiency would not affect the general principles of our
arrangement, — we should still have four of the sub-
genera intimately representing four of the genera ; and
we should conclude, by inductive reasoning, that the
fifth of the former, when discovered, would represent
the fifth of the latter.

(l6i}.) The most numerous in species, and hence
the most varied in their forms, of all these sub-genera,
is that of Achatina proper. In consequence of this va-
riation, the species, as is usual, assume the forms of
the genera and families which surround them ; so that
they might be called sectional types. An instance of this
we have already shown in Achatina virginea, which, with
its allies, obviously represents Achatinella ; then comes
Achatina Zebra,, &c. as the pre-eminent types of all :
following this, we have such shells as A. elongata Sw.*
&c., with their longer spire, and thus assuming one of
the chief characters of Cochlicopa ; while A. crenata t,
and perversa j, &c., by their still more produced
spire, immediately remind us of Macrospira : the de-
pressed form of Ach. Sultana ^ finds its prototype in the
unusually depressed Helicince ; and thus we have, in
this single sub-genus, indications of all the genera of
the sub-family. This is sufficient to show the neces-
sity of rigid analysis, before we can determine what is
the rank of a particular division, whether it be sec-
tional, sub-generic, or even generic : the same may be
said of higher assemblages ; for it is impossible to know,
a priori, what groups are of the rank of sub-families or

* Chem. pi. 11!». f 1124, 1125. f Zool. Illustrations, 1st Series.
J Exotic Conch.

CHAP. VI.

ANALOGIES OF THE ACHATINiE.

175

families^ before the whole tribe has undergone a careful
examination.

(163.) The foregoing series, constituting the sec-
tional types of our sub-genus Achatina, will be ren-
dered more plain to the general reader, if thrown into
a table in the following manner : —

Analogies of the Species in the Sub-genus Achatina,

Sectional
Division of
the Species,

A. Zebra.

A. elongata.

A. perversa.
A. Sultana.
A. virginea.

Analogical Characters.

Sub-genera Genera
of of the

Achatina. Achatina.

'X

dchatina. Achatina.

BULIMUS.

r Ovate; ventricose; spire

< short ; outer lip simple
L not binuated.

rOvale; aperture nearly or

< quite entire; spire more ^Cochlicopa
t lengthened. j

f Spire lengthened and attenu- } ^acrn-imra
\ ated; body. whorl short. ^ ^^^acrospira.

f Spire rather depressed; base > r v s tt„

\ deeply notched. jie«co5^ow«.? Helicina.

C Aperture nearly round; lip ^ < 7 ,. „ ^

I margined. j ^chatmella. C\clostoma.

Clausilia.

Now, this is the smallest group which can be made
out, next to the actual species which come under each
section ; and yet every conchologist who possesses an
extensive series of these shells, or even of those we have
named, must perceive that no other divisions, or sec-
tions, can be formed with any degree of propriety ,• that
is to say, if he were asked to single out the most diver-
sified forms from the sub-genus Achatina, the above are
those he would probably fix upon. Now, this series,
small as it is, turns out to have a circular succession ;
and not only that, but likewise to represent all the
sub-genera and genera of the family. Hence it would
seem that the essential character of this sub-genus is to
have the contour of the aperture simple — not sinuated
or dilated, as in the next sub-genus, Cochlicopa. The
Cochlicopa maculata thus seems to be neither an Achatina,
nor a distinct sub-genus, as some have imagined, for we
do not believe it is a marine mollusk.

(164.) The preceding analysis of Achatina inci-

176

SHELLS AND SHELL-FISH. PART I.

dentally explains the essential characters of Cochlicopa.
Quoy and Gaimard have figured the animal of the last
sub-genus, and M. Ferussac of this, which is distin-.
guished by the very backward position of the shell ; but
the typical form of Cochlicopa appears to be oblong
ovate, the spire and aperture nearly equal, the whole
shell distinctly striated longitudinally, and the outer lip
forming a sinuated curve near its base ; the substance is
almost always very thin ; and the colour is light fawn,
never marbled or banded transversely, but sometimes
longitudinally : those species which pass into Macro-
spira have such a long spire, that, but for the oval
aperture and regular strife, they would not be known.
The species appear confined to the tropical latitudes of
the Old and the New World. On the remaining sub-
genera, viz. Macrosjnra Guild., Leucostoma, and Acha-
tinella, nothing more can here be said.

(16.5.) The next genus, Bulimus, is a most exten-
sive and varied one. It represents the typical Helices,
or snails ; and has, consequently, the aperture perfectly
entire, the end of the pillar being blended with the
outer lip : except in one of the sub-genera. Auricula,
the pillar has neither teeth, folds, nor plaits ; and even
in this solitary group, the largeness of the body-whorl,
the shortness of the spire, and the thickened margin of
the outer lip, are all certain indications of its belonging
to the genus Bulimus. The Bulimi, in fact, possess
all the characters of the genuine Auriculcp, but without
their folds. There is no perceptible difference in the
animals of the two typical sub-genera ; and that of two
of the others are unknown.

(166.) We shall connnence the survey of this ex-
tensive group at that point where it joins Achatina.
This union is effected by our new sub-genus Lepto-
spira, which, as its name implies, has the spire exces-
sively long and slender ; their form, in fact, is precisely
like that of the Macrospira, but the aperture is entire,
and the outer lip thickened. A remarkable shell in our
cabinet, once the property of the duchess of Portland,

CHAP. VI. HELICID^. BULIMUS. 177

exhibits the typical perfection of this form : but there
are others, much smaller, where the outer lip is thin ;
and these are the connecting links between this and
Macrospira. The well-known Helix decollatus Linn,
seems to belong to this sub-genus, and conducts us im-
mediately to Biilimiilus of Leach. We now come to
shells of the ordinary shape ; the outer lip is rather thin
or scarcely reflected, and the inner so little developed
that it merely forms a thin plate over the umbilicus,
where this latter exists. Before we had sufficiently
analysed this family, we were little disposed to adopt
this sub-genus. Its characters are so very slight, and
the greater or lesser reflection of the outer lip is so
variable, that we did not think such considerations alone
were sufficient to authorise the separation of these shells
from Bulimiis: more particularly as the exquisite draw-
ings of Guilding did not show any outward difl?erence in
their animals. But no sooner had it become evident to
us that BuUmulus, in fact, was the representative not
only of Zonites, but of Achatina, than the full value of
the distinction became manifest. There are not many
sectional forms among these shells, which are all rather
of a small size; but some, as the BuUmulus undulatus,
Antiguensis, and Proteus Guild., are very elegant. The
third sub-genus, or Bulimus proper, is a very numerous
one. The fact is, that, being the pre-eminent type of
all these sub-genera, it contains representations of all,
and under more modifications than are found in Acha-
tina proper. As we shall return to these
shells subsequently, we may now pass
on to Auricula, the fourth sub-genus,
which, with the general form of Buli-
mus, although less ventricose, unites the
peculiar character of having one, or
sometimes two, plaits on the pillar near
the base of the aperture. The next
genus, hitherto overlooked, is Gonyo-
stonia {fig. 25.), represented by the Bu-
limus of that name. The length of its spire, and the

* N

178

SHELLS AND SHELL-FISH.

PART I.

distorted aspect of its mouthy — although quite unique
in this group, — are not its only characters; for at the
base of the aperture is a little emargination or notch,
analogous to what is seen in Helicina, Leucostoma, and
Anastoma. By the length of its spire, it evinces such
an affinity to Leptospb'a, that we insensibly find we have
returned to the group we commenced with. The sub-
genera of Biilimus thus form a circle, without the absence
of a single link in the chain of continuity.

(167.) The sub-genera Bulimus and Auricula are
the only two which will require further illustration.
The first, from being pre-eminently typical, contains,
Vike Achatina, sectional types, representing the five prin-
cipal forms in this family. The Bulimus hcBmastomus
(Jig. '2,6.) is the chief of these, and is an exact counterpart

of the Achatina ])erdijc Lam. of
the opposite circle. It is a
large ventricose shell, with a
spire much shorter than the
body-whorl, and of only four
volutions. In the next type,
Bulimus interruptus* of La-
marck, these proportions are
not preserved ; the form is
more slender, the body-whorl
less ventricose, the spire more
lengthened, and the whole aspect
reminds us of Achatina regi-
na t and its allies. These are followed by such shells as
Bui. /M7>;-icM.9 Lam., having very much the cylindrical form
of Pupa; the outer lip is nearly round, but there is no
inner lip, or any tooth in the pillar. In the third mo-
dification we see a complete prototype of the sub-genus
Goniostoma, in that singular shell the Bulimus Lyonc-
tianus, where the aperture protrudes on one side, and
appears distorted. Last of all comes those small Pa-
cific species (mistakingly separated as a genus, under

Chemnitz, pi. 101. fig. 938, 939.

+ Zool. 111. 1st Series.

CHAP. VI. TYPES OP THE SUB-GENUS BULIMUS. 179

the name of Partula), where the margin of the aperture^
instead of being completely reflected^ as in all the other
types, is only very much dilated or spread out. This
peculiar character brings us, of course, to the confines
of the sub-genus Bulimulus ; and by such shells as the
Bulimus melanostomus of Brazil (which will completely
answer to the characters given of Partula*) we return
again to B. hcemastomus. By arranging these species
in a column, as sectional divisions, they will be found
to represent the primary types of the spiral land shells
in the following manner : —

Analogies of the Sectional Types of the Sub-genus Bu-
limus.

Genera

of the
Achat ince.

Bulimus,

ACHATINA.

Sectional
Types or Species.

Analogical
Characters.

Sub-genera
of the
Bulimi.

f Shell vontricose;^
I spire short ; )
Hamastomus. <; aperture in the |> Bulimus.
I typical species ]
[_ always rosy. J

Interiuptus
Lara.

Clausilia. Lubricus.

Helicina. Lyotietianus.

Ctclostoma. Australis.

Shell more slen
der; spire e
vated.

;n-l

le- > Bulimulus.

fSpire lengthened;"!
I basal volution J
■{ smaller or very )■ Leptospira.
I little larger |
L than the next. J

r Aperture distort
3 ed, with a dis-
i tincl notch at
t the base.

\

Sub-genera

of the
AchatincE.

ACHATINA.

COCHLICOPA.

Macrospira

GONIOSTOMA. LeUCOSTOMA ?

fOuter lip thick-1

I enedmoretlian J

\ usual; a slight i.

1 fold on the pil- J" auricula.

I lar; aperture I
L ear-shaped. J

ACHATINELLA.

* " Partula. Conical, smooth, spire equal to aperture in length, con-
sisting of few whorls; aperture auriform ; outer lip reflected, broad ; inner
lip reflected, with a slight prominence on the columella." — iSoiverbt/'s Ma-
nual, p. 77. if the student turn to the figure of B. melanosto/nus Zool. 111.
1st Series, he will find this description perfectly applicable ; yet this latter
has been arranged as a Bulimus, and placed in a different family.

N 2

180 SHELLS AND SHELL-FISH. PART I.

The variations in the forms of the species are thus seen
to be a primary character in all these groups^ whether
we look to the primary divisions or genera^ or to their
sub-genera. It is singular how very closely some of
the little shells of Ferussac's Partula put on^ as it Avere,
the very colours of the Achatinellce, which they are to
represent ; and even the " slight prominence on the
columella" is analogous to the thickened fold-like ter-
mination of that part in some Aohatince: both^ more-
over, are chiefly found in the Pacific islands ; and both,
by having the broadest lips of their respective congeners,
aptly represent the Cyclostomce.

(168.) The sub-genus Auricula is no less interesting
than the last ; because, although few in species, its re-
lations are unusually complicated. We shall first notice
those types upon which there can be few or no doubts,
and then advert to such as are questionable. The know-
ledge which Guilding's drawings of the Auricula un-
dulata* has given us of the animal, clearly shows its
close approximation to that of Bulimus hcemastomus, also
figured by the same exquisite artist. This fact goes to es-
tablish Auricula as a division of the Bulimi, and we have
to consider what other shells showaclose similarity to this.
The species we may thus select, are the Auricula Dombey-
ana, Auris-Leporis, Sileni, and JBovina ; and the whole
group may be described as shells with the aperture rather
larger than the spire, the whorls of the latter few and
produced, the pillar one or two plaited, and the outer
lip (except in Dombeyana +) thickened and reflected on
he external edge. This latter definition would exclude
Auricula midce, and those other dubious terrestrial spe-
cies whose spire, although much shorter, is composed of
more whorls. We suspect, indeed, that these latter shells
are nearly allied (through Pedipes and Melampus^ to
Tournatella ; in which case both them and the sub-genus
Scarabus must be removed from the Helicidce, a.i\d placed

* Plecocheilus iinilulatiis Guikling, Zool. 111. Cd Series, pi. 10'3.
t I apprelierui, however, that in perfectly adult specimens, this species
has a similar outer lip to A. Silent.

CHAP. VI.

AURICULA.

BULIMUS.

181

with the Turbidw. Certain it is, that these animals (made
known by the excellent figures of the French voyagers)
are very diiFerent from the Auricula undulata; they have
only two short and depressed tentacula with basal eyes,
as in Pedipes*, instead of the usual structure of these
organs common alike to Auricula undulata and Bulimtis
hcemastomus. On these reasons do we restrict the sub-
genus Auricula to the characters above
stated — at least, until further inform-
ation leads to a different conclusion. Of
aU the species of Auricula here named,
the Auris-Leporis (fig. 27.) is the most
remarkable ; the plait on the pillar is not
real, inasmuch as it is not solid, but
formed by a sharp angle of the body-
whorl round the umbilicus; the aperture
is large, and so oblique as to appear dis-
torted. It is by this shell that we pass to the sub-
genus Goniostoma already mentioned (fig. 25.). The
five sub-genera of Bulimus will thus form a circle, and
present us with the following analogies : —

Analogies of the Sub-Genera o/'Bultmus.

Genera Sub-genera
of the of

Turbidte. Bulimus.

Analogical
Characters.

Genera

of

AchatincE,

Turbo.

Bulimus

'Body-whorl large,'

itricose; spire J-BuuMUS.

f Body-
•< vent
L shor

TuRRiTELLA. Bulimulus

ScALARiA. Leptospi

hort. " " 5
Body, whorl more "J
slender; outer lip f a p„,T,,„.
thin, or veryf'^'^"^^"^^-
slightlyreflected. J
f Spire excessively T
ira. < long: body-whorl J- Clausilia.

Sub-genera

of
AchatiniS.

Achatiniz.

CochUcopa.

Macrospira.

ScissuRELLA. Goiiyostoma

Melampus. Auricula.

Helicina.

Leucostoma ?

small. J

A slight notch or"

channel at the(

base of the aper- 4

ture. 3

r Outer lip dilated;'

4 the margin J- Cyclostoma. Achalinella.

L spreading.

s

inM

* See an admirable memoir upon this genus by Mr. Lowe, in the Zoologi-
cal Journal, No. xix, p. 28U.

N 3

182 SHELLS AND SHELL-FISH. PART I

If, therefore, the Auricula Midce* and JudcB belong
to the division of which Melampus is the type, they can
be so arranged, without any detriment to the above table.
The same may be said of Scarabus. We have, indeed,
formed this arrangement in conformity with the struc-
ture of the animals, rather than of their shells ; and
resting upon this principle, we deem it preferable to err
on the safe side, rather than to follow previous authori-
ties on the subject.

(169.) The next genus, Clausilia, has hitherto been
thought to form a part of the Pupa; the two, indeed,
are united, yet they appear to form distinct groups. The
present is distinguished by having the aperture ovate
and ear-shaped; while in Pupa it is almost, if not quite,
circular. The Clausilice, as a whole, possess the follow-
ing characters : — the spire is invariably longer than the
aperture, which is defended in all but one instance (^Ba-
lia Gray) with little ridged teeth, usually placed upon
feo^Alips; they are all small and slender shells; and inhabit
temperate rather than tropical climates. We arrange
them as follows: — 1. Clausilia, where the thickest or
largest whorls are generally in the middle of the spire,
the tip of which usually falls off when the animal has
added new whorls toitsshell, — a wise provision of nature,
observes Guilding, " since, its foot being short, it would
not have the power of drawing along so heavy a shell :"
the aperture is usually sinistral, but in the aberrant
species it is on the right side ; it is very small, much
contracted above, and is generally beset with teeth on
both its sides. In Balia, however, these teeth disappear,
and the mouth is dextral. The third, Macrodontes Sw.,
is a new and most interesting type, uniting the com-
pressed teeth of Clausilia, with the form and size of
Auricula. The few species we have yet seen of these

* The representations of the animal of Auricula Midee, given by M.
Lesson's Atlas (pi. 9. fig. 1.), are totally different from that of M. Quoy's :
the former has the teiitacula and eyes of a Helix, the latter those of Sca-
rabus— There must be some great error in one of these ! Is M. Lesson's
design correct ?

CHAP. VI. SUB-GENERA OF CLAUSILIA. ' 183

rare and remarkable shells are all from Brazil; and they
establish, in the clearest manner, the passage between the
European Clausili(S and the South American Auriculce.
We have now arrived at that particular sub- genus which
is to connect the present group with the genuine Piipte.
This union is effected by those small European shells^
hitherto placed in the latter genus, which we have sepa-
rated under the name of Pupella. This sub-genus, in
fact, may be looked upon as the common point of union
where the sub-families Bulimince and Achatmcs are
united. They are at once distinguished by having both
sides of the aperture toothed ; and not, as in Pupa, the
inner lip only. Some uncertainty hangs over what shells
are the true types intervening between Pupella and Balia.
The passage, indeed, is very easy, if we suppose it to be
made by certain little shells of Europe (as the P. mus-
corum, fragilis, dolium, and umhilicata of Drap.) which
have no teeth on the outer lip, but sometimes one on
the inner ; while the shortness of their spires would
distinguish them from Balia : or this, perhaps, is the
place where some of the smaller shells, analogous to our
Gonospira, should be placed ; at all events, we have in
Pupella such a close approximation to Balia, that the
circle of the genus Clausilia may be considered almost
perfect : at all events, we cannot consider either Alee or
Vertego as sub-generic types, merely because they differ
from our Pupella by the position of their aperture; while
Azeca of Leach, as a sub-genus, is equally questionable.
We presume, therefore, that the types here mentioned
form the circle of Clausilia. We have already com-
pared them with those of the PupcE, in conjunction
with the genera of the Helicin^, we shall now, how-
ever, bring the sub-genera of Pupa and Clausilia more
immediately and exclusively together ; when it will be
more readily perceived that the hiatus between Balia
and Pupella might be filled up by some of the shells
just mentioned.

N 4

184.

SHELLS AND SHELL-FISH.

PART 1.

Analogies of the Genera Clausilia and Pupa.

Sub-genera of
Pupa.

Sipho7iostoma.
Megaspira.

Gonospira.

Analogies.

f Spire exceedingly long, the upper >
\ portion deciduous. J

f Spire greatly lengthened, the up- 7
/ per portion persistent. J

Spire moderate, with few whorls, 'J
the tip thick and obtuse; thef
aperture generally without f
teeth. 3

"Spire moderate, but with manyT

Sub-genera of
Clausilia.

Clausilia.

Balia.*

rbpire moiierate, out witn manyT
Pupa. -^ wliorls of nearly equal thick. > Pupella.

L ness 3

PUcadotnus.

r Whorls few ; the outer lip dilated 7
t and broadly margined. J

Macrodontes.

(170.) Our next genus is Helicina, — a group of
remarkable shells^ of which, as near forty species are now
known, the sub-genera may be advantageously charac-
terised. This will be done in our systematic arrange-
ment, and in the mean time a few general remarks is all
that we can here insert. Tfiey are small helix-formed
shells, distinguished by their semilunate aperture, which
is closed by an operculum. We have not seen, as yet_,
any intermediate form which renders the passage between
them and the last genus sufficiently clear. The animal,
as seen in H.occidentalis (fig. 28.), has been well drawn
by Guilding; it has only two tentacula, with the eyes

at the base. In this respect the Helicince, as Cuvier
observes, have a close affinity with the Cyclostomes,
many of which are also turbinated shells, and all are

* I should conceive, theoretically and analogically, that Bal/a would
represent Gonospira by its toothless aperture ; and that the prototype of
Megaspira would be perfectly like Clausilia, but without any teeth or
folds, and the spire (probably) persistent.

CHAP. VI. SUB-GENEBA OF CYCLOSTOMA. 185

furnished with an operculum. Nothing, perhaps,
can better exemplify the artificial nature of Cuvier's
Pectinihranchia, than his placing Helicina between the
two fluviatile genera Ampullaria and Melania, and Cyclo-
stoma between Scalaria and Valvata ; in both instances
thrusting in a group of land-shells between two others
which only inhabit water. This is the more inexcusable,
because it did not originate in an ignorance of the ani-
mals j and yet he observes that the Helicince, ^'^ judging
by the shell, are Ampullaricp, in which the margin of the
aperture is reflected." * The only reason assigned for
placing Cyclostoma after Scalaria, is '^ because the aper-
ture is entire, nearly or quite round, and operculated." +
This is quite true, but every student will readily per-
ceive that this is merely a remote analogy.

(171 •) The genus Cyclostoma, like the last, has
the sexes distinct ; but this is the only one character
in which they differ from the other pulmoniferous land
and river snails. The passage between this and the last
group is rendered unquestionable by such shells as Heli-
cina'elegans Gray, which has the characters of both
united. The typical Cyclostomce are spiral shells, the
last whorl being but little larger than that which
precedes it. The orifice of the mouth is circular,
and is closed by a horny operculum. The pillar is
often wanting ; but this variation occurs in species
so close to each other, that it cannot be considered
a sub-generic character. They are usually found in
dry arid situations: the island of Malta abounds with
them, where thousands may be gathered on the scanty
herbage of the rocks ; and many elegant species oc-
cur in the mountains of Jamaica. On coming to the
aberrant sub-genera, we find great diversity in the form,
although none in the aperture. In Cyclophora, the shells

* Cuvier further remarks that tlie organs of respiration are arranged as
in the Cyclostomce, and, like the latter, they can live out of water. That
these two genera are naturally united, both by the animal and the shell, is
thus admitted, while we can only say that they are both as terrestrial as
the garden snail ; they cannot, in fact, live out of the air, as we always
killed the animals of our specimens by plunging them into water.

t GrifF. Cuv. xii. p. 58.

186

SHELLS AND SHELL-FISH.

PART I.

are turbinated, and resemble those of Helix, although
the tip of the spire is acutely conical, and not, as in the
common snail, depressed. These obviously lead to the
typical sub-genus Cyclostoma ; and these latter, again, to
the singular 9,\ih-geT\\\s Megalomastoma, — another ad-
mirable group, detected and beautifully illustrated by
Guild ing ; it is the representative of Pupa, from which
it is distinguished by possessing a horny operculum.
Cyclotus of the same accurate zoologist is another
remarkable type : it is so much depressed, that it almost
resembles a Planorhis, and, from not having any pillar,
the umbilicus is open to the terminal whorl : the oper-
culum is shelly ; and although the aperture is round
and thickened, the inner lip is carried upwards in the
form of a little siphon : this is very remarkable in a
species we possess from India, and in another from the
West Indies. We are disposed, indeed, to consider
this and Cyclophora to be the two typical forms of the
whole group which represent Planorhis, just as the
LucernincB do in the entire family of Helicidce.
Guilding founded his group upon one species (C.'fus-
cescens), which he found " with the spire corroded," in
the woods of St. Vincent ; and, unfortunately, all the
specimens found by him afterwards were dead shells, so

that the animal is still unknown.
3Iegalomastoma appears immedi-
ately to follow Cyclostoma, because
the M. suspensitm Guild., in its
shell, is a Cyclostoma ; but the
M. hrunnea Guild., which is ob-
viously the type, is so elongated as
to resemble, at first sight, a Pupa.
The animal of M. suspensum is
often found suspended by glutinous
threads (fg. 29-); it has the mouth
rather elongated, proboscis-like, but
deeply cleft ; the two ten taenia
rather long, and the eyes at their
base. Having now concluded the survey of the four

CHAP. VI.

THE LIMNACIN^.

187

great divisions of the Helicid^, which include all the
land-shells and slugs, we may enter upon the fifth and
last, which are aquatic.

(172.) TheLiMNAciN^is that sub-family which con-
tains the whole of those spiral fluviatile shells which,
like all the Helicidce, respire by a lateral perforation.
It is difficult for the student to distinguish these river
shells from those of the fluviatile genera in the next
family ; but they are in general much thinner, and in
no instance have the Limnacinw even the vestige of an
operculum. Like the Cyclostomce, these animals have
but two tentacula ; but they are, in general, very short
and broad, having the eyes at their base : their shells are
all very thin, devoid of any bright colour, and the aper-
ture is always simple, — that is, without any thickened
margin. They appear to arrange themselves
into the following genera : — 1 . Planorbis,
where the shell is disk-shaped, and with-
out any pillar, as in our common P. cor-
neus. (fig. 30.) 2. Limnceus, having a
very large and wide aperture on the right
side, and the basal whorl so large as to
contain the whole animal. 3. Physa, where
the aperture is much smaller, the base contracted, and
the mantle so large that its two lobes fold over the
shell. In the fourth sub-genus Potomophila, the shell
very much resembles the last, but the pillar is marked

with a distinct plait or fold in
the middle ; the only species we
are yet acquainted with, istheCo-
novulus buHmo'ides * of Lamarck.
{fig. 31.) In this, as in innu-
merable instances, analogy has
been mistaken for affinity. It
is clear there is a resemblance between this and the
sub-genera Auricula and Conovidus ; but we think
there is no doubt that this is a fluviatile shell, and, but

* Ency. Meth. pi. 459. fig. 7-

188

SHELLS AND SHELL-FISH.

PART I.

for this fold on the pillar, it could not be distinguished
from a Limnceus. The fifth and last type is Ancylus,
composed of the freshwater limpets (^fig. 32.), not even

mentioned by Cuvier, but con-
stituting one of the most re-
markable divisions of the whole
group.

(173.) The five genera,
placed opposite to those of the
genera of AchatincB, and the
sub-families of the Helicidce,
will be found to represent each
other thus : —

Genera
of the

I.imnacince.

Planorbis.

Ancylus.

Pototnophila.

Physa.

Limrueus.

Analogies of the Limnacin^.

Analogies.

Sub-families Genera
of the of the

Helicidce. Achatina.

r Shell depressed disk-like ; | Lucernin^. Cyclostoma.
l_ aperture round. 3

f Shell fragile, much smaller 7 Lt^.^^iNiE. Helicina.
(_ than the animal. y

} Shell thin ; aperture large ; ) Lj^n^cin^. ClausUm.
i pillar plaited. 3

(•Outer lip thin; last whorl 7 ^^„^^,^^
i contracted. 3

Outer lip reflected ; basal

Achatina.

{

whorl very large.

i«

ELiciN.£. Bulimus.

The general analogies of the whole group may be
first slightly touched upon. The LimnacincE occupy
that station in the circle of the Helicidce, which corre-
sponds to that of the Cephalopoda in the great tribe of
Testacea. Hence they are all aquatic animals ; and if
this analogy is correct, it follows that Planoi-his is the
typical group, because, in their flat discoid shells, they
perfectly agree with the equally depressed and convo-
luted Nautili. We have seen, also, that in Ci/rlotus
a strong approach is made to this very same structure.
The little shells of several of the slugs (Limacincp), if
no regard be paid to the animals, might very well be

CHAP. VI. THE LIMACIN^, OR NAKED SLUGS. 189

taken for freshwater limpets ; so that the analogy is
most complete. Potomophila, again^ is the only type
having any fold upon the pillar ; and Clausilia is the
only genus so distinguished among the Achatince. It is
the excessive enlargement of the body-whorl which
gives such a peculiar character to the turbinated snails ;
and this renders them distinct from the Achatince : and
the very same disproportion is observed in all the
typical examples of Limncpus, of which the common
L. stagnalis is a familiar example. The near approxi-
mation of the amphibious genus Succinia to the group
we have now gone through^ is abundantly obvious.
While, from possessing four tentaeula, with the eyes
pedunculated, it cannot be brought within the limits of
the freshwater shells ; it is, in short, as Cuvier has
happily expressed it, ''^ a Testacella, with a very large
shell." As the systematic definitions will be here-
after given, we need not dwell longer upon this sub-
family.

(174.) The sub-family of Limacina; which contain
the naked slugs, is admitted to be such a natural group^
that this part of our survey may be considerably abridged.
The first of the typical genera appears to be Limcijc,
where the tentacula are four, and, in general, the
vestige of a shell is placed near the extremity of the
body. The second is typically represented by the
genus Herpa of Guilding, in which the tentacula are
either entirely wanting, or, as in the sub-genus On-
chidium, they are only two in number, and very short.
The determination of Herpa, as connected to Li max,
is one of the most important discoveries in mala-
cology that has been made for many years, not merely
as to the fact itself, but to the inferences to which it
leads : it may be considered, in short, as the germ,
or first incipient developement of this immense family,
from which all its innumerable modifications branch
off. Its analogy to Planaria among the Pareiichymata
is abundantly obvious ; a relation well understood by
its learned and acute discoverer, who thoroughly un-

190 SHELLS AND SHELL-FISH. PART I.

derstood the difference between analogy and affinity*,
so lamentably confounded by so many other naturalists^
even of the greatest reputation. The analogy, again,
which the large coriaceous mantle, or shield, of Onchi-
dium has to the Chitons need hardly be adverted to.
The three aberrant genera, Vitrina Drap., Stenopus
Guild., and Succinea Drap., have turbinate shells, nearly
or quite sufficient to include their bodies ; but these
coverings are generally thin and semi-transparent, with
a wide aperture, a very short or small spire, and, ge-
nerally, with only the vestige of a pillar. For the dis-
covery of the singular animal of Stenopus cruentatus t
(^fig. SS.\ science is likewise indebted to the lamented

Guilding: it seems intermediate between Vitrina and
Succinea, and will thus stand as the most aberrant of
the whole. The connection of this sub-family to the
freshwater snails is obviously effected by Succinea;
while Vitrina leads immediately to Leiostoma, among the
land volutes. The sub-genera not having yet been
determined, we shall pass at once to the fifth division,
which closes the circle of the Helicidcp.

( 1 75.) The terrestrial volutes, or lamp-snails, Lucer-
NiN^, were named by Humphreys, — a name we retain
for the whole group, which, as we have already seen,
constitute a sub-family.:}; They are well distinguished
from the typical HelicincE by three characters, any two

* " Genus Planariis facie quam plurimutn analogiim, ut Limacides re-
spirationis modo, locis, moribusque omnino affinc." — Guildin<^ MSS.

f See figures and description in Zuol. Journal, iii. pi. l5. figs. 1 — 5.

X Lamarck suhsequently used the name Caracolla, which Ferussac
wished to set aside for that of llclicodonta, a name which, even had it the
priority, implies two errors ; — first, that they belong to the typical Helices;
and secondly, that they all have teeth : we consequently cannot adopt the
innovation.

CHAP. VI. THE LUCERNIN^. IQl

of which, in doubtful cases, will almost always he a
sufficient guide : — 1 . The very marked depression of their
whole form, and the great number of the spiral whorls.
2. The possession of teeth either on one or on both sides
of the aperture : and, 3. The granulated, or distinctly
striated, surface of the shell. As our analysis has not
been carried down to the location of all the sub-genera,
we shall merely, in this place, enumerate the primary
groups or genera, with some few of the sub-genera, leaving
the rest for the more systematic department of the vo-
lume.

(176.) The groups which appear to rank as genera,
and which are therefore the first divisions, are the fol-
lowing : — 1 . Lucerna, having the shell flattened and
orbicular, the margin always carinated, and generally
sharp ; the whorls numerous ; the surface granulated,
but never striated ; and the aperture usually toothed, but
the teeth confined to the inner lip.* 2. Lucernella,
equally depressed with the preceding, but the margin of
the body-whorl is rounded and convex ; the outer lip
is always toothed, and there are opposite teeth on the
inner lip. These appear the two typical divisions. The
three aberrant are, the broad-lipped species of Ferussac's
sub-genus Helicella, having the body-whorl unusually
large in proportion to those of the spire, which is flat-
tened ; the umbilicus deep ; the outer lip spreading,
and diflPuse, but rarely provided with any toothlike pro-
jection : these form our genus Hemiodon. The next,
or most aberrant type, is composed of a part of Ferus-
sac's Helicogena, where the shell is granulated, the spire
depressed, and the outer lip marked at its base with
toothlike notches ; the spire is very small, and hardly
makes three volutions : this is our genus Thelidonius.
The wide aperture of these prepare us for Leiostoma,
having the aperture remarkably large and particularly
smooth and glossy, while the glazing of the inner lip is
extended very much beyond its usual circumference.

* Except in Anastoma, which represents Pupa and ClausUta.

192 SHELLS AND SHELL-FISH. PART 1.

This latter character is highly important, as showing the
analogy of Leioatoma to the LimnacincB, and its affinity
to the half-testaceous slugs, or the Limacince.

(177-) Looking to the above genera, with reference
to their analogy, they appear to represent the following
divisions in their own family, and in t^e tribe of the
Zoophaga : —

Analogies of the Lucernin^, or Land Volutes.

Genera of the Analogical Characters. ^"'"'SvJ'lwLf^ ^^^

Lucerntnce. " Helicidce.

LUCERNA. [ ^^'^?.T:1T ^^'' ''°"'' ' ''''°'"^' \ ACHATIN^.

TII^FR^^RIIA J" Spire depressed; the margins? Helioivt

1.UCEKNELLA. ^ convex ; whorls few. j helicinje.

Hemiodon. Shell discoid ; the spire depressed. LuceRiMN^.

Thelidomus. Spire of very lew whorls. LiMAciNiE.

T ^.^ ^^,. ("Aperture very effuse; inner lip7 t,,.x,.^.»,^

Leiostoma. y Spreading. ] Lim^acin^.

(178.) The typical genus Lucerna has one peculiar
character, — that although its outer lip is in general
toothed or plaited, these plaits are never seen upon the
inner lip, or that part of the body-whorl which forms
the opposite side of the aperture. They are the largest
shells of this sub-family, and are particularly abundant
in the West India islands. Although decidedly de-
pressed shells, their spiral whorls are numerous, and are
very progressively graduated. We separate them into
the five following sub-genera: — In Dismdoma, the cir-
cumference is carinated, the aperture angular, and without
teeth ; and the edge of the outer lip but slightly, if at all,
reflected. In Lucerna, the teeth on the edge, or within
the outer lip, are very evident. In Anqstoma, they are
extended all round the aperture, which is likewise
turned, so as to be nearly on the same plane as the spire.
Leaving these, we have an analogous form to Thelidomus
in several small toothless Helices L. (our Lnridella), but
which evidently, by their spire, belong to this group.
Caracotla completes the circle by uniting to Discodoma,

CHAP. VI. THK LUCEBNELLiE. 19-^

from which it is nevertheless separated by its circular
aperture, analogous in this group, to Cydostonia. As
this is the European type, we have preferred retaining to
it the sub-generic name of Caracolla, that the nomen-
clature of such well-known species should not be dis-
turbed. The whole group is composed of granulated
shells.

(179-) Ii^ the second, or sub- typical group, we shall
find five sub-genera agreeing with those of the last. As
a general character, the Lucernellce vt\?Ly be known by the
inner lip, no less than the outer, being provided Avith
teeth : those on the former are either one or (very rarely)
two, placed almost transversely, as if to guard the en-
trance to the shell by rendering the aperture remarkably
narrow ; the teeth on the outer lip are situated at its in-
ner edge, and have no corresponding indented grooves (as
in Lucerna) on the outer surface. All the Lucernellce,
likewise, are convex on their sides, not carinated. It is
only in the sub-genera Heniiq/chi and LuckleUa that the
inner teeth disappear ; but the union of the first of these
two with Cyclodoma is so obvious, that they cannot be
placed in different genera. The first form on quitting
Anastoma is Polydontes, of which the type is that sin-
gular shell P. imperaior oi Montfort; it is remarkable for
its aperture being surrounded by nodulous teeth, obtuse,
and resembling large granules, while those of Anastoma
are more properly folds or plaits : following this comes
Lucernella , where the form of the shell is often globose,
the umbilicus closed, and the teeth very complicated: these
lead to the greatly depressed form of Cyclodoma, where
the shape is sometimes as discoid as in the well-known
genus Pktno7-his. These shells are almost always striated;
and, although small, are highly interesting. A great
number of species inhabit the mountains of North Ame-
rica and Madeira, but probably not one half of those
that exist have yet been discovered. In Hemicycfa, the
internal or left-hand tooth either entirely disappears, or
is reduced to a little tubercle ; the cuter lip makes a bold
and dilated semicircle, the margin of which is broad and

o

194) SHELLS AND SHELL-FISH. PART I.

flattened, without being absolutely reflected backwards.
Lastly, we venture to place a few small shells, having
something the aspect of Helicince* , as a fifth type, under
the name of Lucidella; they differ from the last by the
comparative smallness of the aperture, which has one or
two small teeth on the outer lip, but none on the inner :
these appear to pass into Thelidonta ; and in this man-
ner do we conceive the whole form a circle. Not
having yet completed our analysis of the three aberrant
genera, Piis'wdon, Tlielidomus, and Leiostoma, we shall
not at present attempt to designate their sub-genera. De
Ferussac has adopted a modification of Humphrey's
name of Lucerna (which he writes Lucena) for that
group, part of which we here call Leiostoma ; but how
far he is correct in placing the richly-coloured shells
upon his plates 12, 13, and 14. with that which we de-
signate as the type — may well be questioned. The dis-
torted body- whorl of Thelidomus, and its serrated outer
lip, render it analogous to Lucidella, from which it differs
altogether in the few and unequal volutions of its spire.
The most interesting genus, however, is that of Hemio-
don, which has a large dilated aperture, the spire scarcely
raised, and a gibbous prominence more or less developed
at the base of the outer lip. This is the last remnant
of the toothed aperture so common in this sub-family ;
and accordingly prepares us for the true Helicellce, which
compose the first genus among the HeUciu<v. Thus do
the LucERNiNyE foHu their circle of affinity, connected
on one side to the slugs by Leiostoma, which passes
into Vitrina, and on the other to the land helixes^
as just stated.

* Such as Helicina aureola, Zool. Journ. i. p. Ifi. f. 13.

195

CHAP. VII.

THE PHYTOPHAGOUS GASTROPODS CONTINUED. THE TUREID-«,

OR MARINE SNAILS.

(180.) The family of Turbid^ succeeds the last,
and, like them, is composed of spiral shells, destitute
of any pearly lustre, with the aperture closed by an
operculum * : the differences, however, are so slight,
that the two families can scarcely be distinguished by
their shells alone. The animals of the Turbidce, hov/-
ever, are remarkably dissimilar from those of the
Helicidcp : they breathe by gills, like all the zoopha-
gous families ; and, like them, the mouth of the major
part is furnished with a respiratory siphon, and even
a probosciform mouth : the tentacula are only two ;
and the eyes are either basal, or on the sides of the
tentacula. The animals, in short, often exhibit the
carnivorous structure of the Zoophaga, while their shells
are completely those of the phytophagous tribe : it is
thus that the two groups are connected. The whole of
this assemblage are comprised in the following sub-fami-
lies : — The first is uncertain. 2. The AmpullarincB, or
apple-snails. 3. The Melaniance, or black snails. 4. The
Turhince, or winkles. 5. The lantltincE, or Oceanic
snails. A general analysis of these will now be given ;
this investigation we were, in a manner, forced into,
from the impossibility of discovering any bond of union
or of affinity between the heterogeneous genera of the
Turbidce, as they now stand in our conchological
systems.

(181.) The first primary division by which this
family may be united to the fluviatile Limnacince, is

* Except in Melampus, and probably lanthina,

o 2

196 SHELLS AND SHELL-FISH. PART I.

somewhat uncertain. There are several fossil genera,
as Enomphalus Sow., Orhis, and Planaria* of Lea, of
a discoid shape, whose animals are quite unknown, and
will ever be so, if no recent species are discovered.
Their shells, indeed, are intermediate between those of
the Ampullarince and the Limnacince ; but then this dis-
coid shape is found in so many different families, that
their location here would be entirely conjectural. On
the other hand, we have our choice of Valvata and
'Thalliceraj: the first appears to us more like one of the
genera of the AmpuUarina ; while the extraordinary
animal of the latter, and the singidarity of the shell,
leads us to view it, with ^M. Deshayes, more as the
representative of a sub-family than of a genus. May
this, again, be the natural station of the semi-aquatic
genera Melampus, Scarahus, Sec, whose animals have
certainly a strong resemblance to those of the LimnacincE ?
Into these theoretical questions we dare not enter ;
difficulties are opposed to the adoption of each of these
theories ; and we shall, therefore, choose that which
appears to us, upon the whole, least liable to objection,
— namely, the supposition that Thallicera stands inter-
mediate between the AnipuUarincB and the Limnacince,
The animal of Thallicera, like the Limnacince, is her-
maphrodite : the head is large, flat, cleft in two lobes,
which bear the two sessile eyes ; but these are without
any appearance of tentacula ; the oper-
culum is horny; and the animal is ma-
rine. Such is the substance of the in-
teresting facts made known by ?J. Quoy,
who found the T. Avellana {fig. o-i.)
in abundance on the coasts of New
Zealand. That it is thus allied both
to the operculated marine Pectinibranchia by its shell

» This name cannot be retained, having been long ago applied to a well-
known genus among the ParcncUymata of Cuvier, and of this work

t M. Qiioy, among his other brilliant oiscoveries in malacology, has the
honour of making known the animal of Ampullaccrn I trust he will
excuse my proposing Thallicera, as a name not liable, like the above, to be
confounded with Anipullaria.

CHAP. VII. THALLICERA. AMPULLARIN^.

197

and its habitat, and to the puhnonary fluviatile Lim-
nacince by its animal, there can be no doubt.

(182.) The shape of the AmpullarincB is most like
the garden snails ; they are generally globose, the spire
very short, and the body-whorl enormous. ISIany of
them are very large, and none are of a small size. They
abound in the rivers of tropical countries, both of the
New and the Old World. Guilding has admirably de-
lineated the animal of this and the sub-genus Ceratodes,
and has thus determined the latter to be a representa-
tive only of PlanorUs. TheanimalSj in fact (^fig. 35.),

of the present group are furnished with a respiratory
siphon (a) ; and are, no doubt, carnivorous, as well as
herbaceous. Most of them have the operculum horny,
but in some it is shelly ; and this, joined to the thin-
ness or thickness of the outer lip, may serve to dis-
tinguish the sub-genera. The genus Paludina seems
to represent the last in the rivers of Europe, and is
well distinguished by the greater length of the spire, as
seen in our native P. vivipara; but there are many
exotic species : the aperture is narrowed above, and
generally protected by a horny operculum. Nematura
appears a sub-genus whose operculum is shelly, and
the aperture still more contracted. With this genus

o a

198

SHELLS AND SHELL-FISH.

PART I.

we also place the European
P. impura Lam.^ and the
West Indian P. parmda of
Guilding (^^.36.), the ani-
mal of which, according to
his drawings, has the tenta-
cula unequal, — that nearest
the pillar being almost twice
the length of the other. It
is as a sub-genus, also, of
Paludina, that we are dis-
posed to regard Valvata.
The shells of this last remarkable type are mostly of the
same form as many of the helix-like Cyclostomce ; the
aperture is also round, and closed with an operculum.
The animal, which we have not seen, is described by
Midler as having the branchia, or gills, pectinated, and
projecting from under the mantle, floating externally,
and vibrating every time the animal breathes : on the
right side of the body is a filament, which resembles
a third tentaculum.

(183.) Our third sub-family, Melanian^, is com-
posed of those long-spired fluviatile shells which form
the genera il/e/anm and Melanopsis, together with that of
Planascis, as the most aberrant, and two others now first
designated as Paludomus and Ccrithidea. This, which
we think is the typical sub-family of the Turbidce, is
so numerous, that it becomes necessary to characterise
the sub-genera ; for without this, the theory of their re-
presentation could not be rendered intelligible. The
animals of these shells are well distinguished from the
last, by having their eyes more developed, and placed in
the middle of the tentacula, while the mouth is elongated
in the form of a proboscis. The genus which makes the
nearest approach to the AmpnUarino', in the globular
form of the shell, the short spire, and the rotundity of
the aperture, is that of Paludomus Sw., formed to re-
ceive those short-spired shells which at present are placed
in that of Melania. The American species form the sub-

CHAP. Vir. MELANIANiE. THE GENERA.

199

gemis J ncu/osa of Say {fig.^l-a)* , and almost resemble
nerits. Notwithstanding the thickness of these shells^ the
outer lip is unusually thin, and the inner is like that of a

Purpura, being broad and flat-
tened. One or two species now
before us are so like young ma-
rine turbos, that none but a
practised eye would' distinguish
them. They are,however,strictly
fluviatile shells, having a horny
operculum ; and are abundant in the Ohio. The next sub-
genus is Pahidomus proper (6) : they differ from Anculosa
in being sub-spiral like the Bulimi, and in having both
lips thickened, although not margined by a rim ; the
outer one is slightly reflected and crenated, and the in-
ner perfect and convex : these seem peculiar to the Indian
rivers. In the next sub-genus, Hemimitra, the general
form of Pahidomus is preserved, but the whorls are
coronated by spines. The whole are readily distinguished
from the next genus, by not having the outer lip dilated
at its base, the inner lip complete, the aperture wide, and
the spire always shorter than the body-v*'horl,t

(184.) The true genus Melania comes next. Amid
the great diversities of forms it contains, even as we
now intend to restrict it, there may be detected four, if
not five, types or sub-genera; yet, with one exception |,
they are all possessed of an entire aperture, and are more
or less spiral. The animal, according to Cuvier, has a
proboscis-like inouth, and the tw^o tentacula bear the eyes
half way on their external side ; the aperture is always
oval, the outer lip thin, and is generally much dilated at
the base. The five types of form, or sub-genera, appear
to be these: — 1. Melacantha ; 2. Melania; S. Po-
tadoma ; 4. Hemisinus ; and, 5. Melanella.

(185.) The first type which meets us after quitting
Paludomus is Melacantha, of which the well-known

* I consider this, however, as a form between Paludinn and Paludomus.
t 'Melanin conicii, globulosa, and retusa, of Mr. Gray, Griff. Cuv. pi. 14.,
belong to this group.

X Tlie sub-genus Hemisinus.

0 4

200 SHELLS AND SHELL-FISH. PART I.

Melania amarida and setosa are typical examples. The
spire is short, and the volutions coronated ; the inner lip
is merely a thin glazing ; and the base of the pillar is flat-
tened. It will be remembered that Hemimitra is the
coronated type of Paludomus, and is so like Melacan-
tha on a superficial glance, that, but for the difference in
their apertures, they might be taken for species of the
same genus.' From these we are gradually led to the
typical division of Blelania, w^hose spire is often as long
as in Turritella. These shells are much lighter than
those of the next group, Potadoma, which are more solid
in their substance; the base of the pillar is not depressed
or broad, but convex and comparatively thin ; it is like-
wise, in most of the species, much straighter, while the
base of the outer lip is more dilated. All the species we
have yet seen of this sub-genus are decollated. We
regard, as the most typical character, a slight thickening
of the inner lip, particularly at its upper part, because
this is never seen in the last group. Our next sub-genus,
Hcmisinus, has hitherto been placed with Melanopsis, as
the base of the aperture is notched : the type is the 3Ie-
lania lineata *; in its general form, indeed, it resembles
the preceding shells ; but the body-whorl, although more
ventricose, is yet contracted at its base, the outer lip but
slightly dilated; and the inner lip (now for the first time
clearly developed) is complete, — that is, it extends from
one extremity of the aperture to the other. The lip of
the columella, or pillar, instead of turning inw^ard, turns
outwards ; that part which is covered by the inner lip
being straight ; while the sinus, or notch, at the base,
is even wider than in Melanopsis, to which this type
obviously leads. But before we cross the threshold thus
opened to us, we must notice MeJanella, — another type
resembling Hemisiiius in shape, but having the aperture
perfectly entire; the inner lip is much developed, and its
upper angle has a callosity precisely like that oi Planaxis.
So remarkably, indeed, does one of these Melanellcr re-

* Gray, in Griff. Ciiv. pi. 13. fig. 4.

CHAP. VII. MELANIA. THE SUB-GENERA. 201

semble the Planaxis mollis in size^ shape, and colour *, that
none but a keen-eyed naturalist would know at first which
was which. Both are of the same size and shape — both
are white — and both are covered with a pale fawn-
coloured epidermis ; the only difference between them
being the presence or absence of the minute notch at the
base of the pillar. We thus find the sub-genera of
Melania not merely to form a circle, but to represent,
in no unintelligible manner, the chief genera of the
sub-family.

Analogies of the Sub-genera 0/ Melania.

Sub-geiiera of < , • , /^. . Genera of the

Melania. Analogical Characters. Melanianj^.

Melacantha. Spire remarkably short. Paludomus,

Melania. Spire persistent, acute. Typical. Melania.

Potadoma. [ Spire obtuse ; shell often car'-nated 7 Melanopsis.

i at the suture. Sub-typical. J

r Body-whorl veniricose ; spireo
Hemisinus. < long ; base with a wide but not >- Cerithidea.

C a deep notch. j

tr t 77 ("Inner lip thickened above; spire > t>, .»,.„„

Melanella. J short or moderate, pointed. j PLA>fAXis.

These remarkable analogies result from the breaking up
of the old genus Jfe/aw my and this is the best apology,
if any were needed, that we can make for so many new
divisions.

(186.) The next genus, Melanopsis, is no less diver-
sified in its minor types, so that we may detect all those
which, under a different modification, exist in the last
genus. AVe enter this group by Melafusus — a name by
which we designate a remarkable fluviatile shell, having
the shape of a Fusus blended with that of a Melania ;
it differs from Hemisinus in having the base more pro-
duced, while the spire is shorter. Following this ap-
pears the typical sub-genus J/e?a«i«, — at once recognised
by its acutely pointed spire being longer than the aper-
ture, the thick enamel at the top of the inner lip, and
the inward curve of the pillar : the manner in which
the whorls are disposed on this and the next sub-

* Sowerby's Genera, art. Planaxis, fig. £.

202 SHELLS AXD SHELL-FISH. PART I.

genus deserves attention ; they are so far imbricate
that one overlaps the other to full one half of theii
length, so that the suture of the basal whorl extends
half way up that which precedes it, and gives the ap-
pearance of the outer lip ascending on the spire. But
among the fossils figured by De Ferussac, there are some
which have an aspect altogether different : the spire,
instead of being acutely pointed, is obtuse, and so short
as to consist of only three whorls ; the aperture is also
represented as much shorter than in any of the recent
species, and the base more effuse. Again, there are two
species *, which perfectly resemble the sub-genera Me-
lacantha and HemimUra, being short, broad, and coro-
nated with a single row of short spines, — the tip of the
spire being acute. Now, as these two types obviously
accord with Potndoma and MelacantJia in the adjoin-
ing circle of the Melanicp, we have not scrupled to
designate them as sub-genera, — distinguishing the first
as Melanithes, as being yet only known in a fossil state,
and the second as Canthidomus, from its little spines.
The confidence we repose in the accuracy of Ferussac's
beautiful but costly plates, induces us to do this without
having ourselves seen any of these shells : but the cha-
racters we have stated cannot be doubted ; and the links
by which these two presumed types are connected with
the recent sub-genus Me/miopsis are so perfect, that they
have every indication of being natural sub-genera, t We
must now notice a fifth type, which unites something
of the characters of those two very opposite sub-genera,
Canthidomus and Melafusus ; this is our sub-genus
Melatoma, founded upon a remarkable Ohio shell sent us
many years ago by our old friend professor Rafinesque.
It has the general form of a Pleurotoma and of JMela-
fusus, with a well-defined sinus or cleft near the top of
the outer lip ; while the inner, though thin, is somewhat

* Plate MelanopsiiUc, fig. Ifi. 7. Plate <2. figs. 9, 10.

t 'I'hus the species at pi. 2. fig. VI. plainly connects Melanttfies \v\th Can-
thidoDius ; while those on pi. I fig. 14, 15. seem to be aberrant to the last
sub-genus, leading to the long-si)ired Cerithidia. Fig. 6. pl.i2. is dearly
a Pirena, and fig. 8. a Cerithiujn.

CH. VII. SUB- GENERA OF MELANOPSIS. ANALOGIES. 203

thickened above ; the pillar is straight^ and the notch
at the base nearly as wide as that of an ordinary Pleu-
rotoma ; the whole shell is marked with regular longi-
tudinal plaits, and coronated on the suture by a row of
tubercles. Our specimen, although in bad condition, is
still partially covered with a brown epidermis, beneath
which the shell is of a livid colour : the aberrant
species of Canthidomus , as C. costatus and Owenii, pass
into Melatoma, and complete the circle.

Analogies of the Sub-genera o/Melanopsis.

Sub-genora Sub-genera Genera

of Analogical Characters. of of the

Melanopsis. . Melania. Melani4N^.

Melafusus. P^^V^'^^rTffir "''''^'''' ] ^--«-- Cekithxoe..
Melanopsis. Baseof the aperturecontracted. Potadoma. Melanopsis.
Melanithes. Tip of the spire obtuse. Melania. Melania.

Cantkiaomus. [ ^'^V^ort or n^od^ra^tf ' ' } ^lelacantlra. Pal.bom.s.
Melato^na. [^^^^.^^S^^^.^^;""- '^]Melanella. Pla.axis.

I

The use of the last, or additional column, which con-
tains the genera of the entire sub-family, is chiefly
for the purpose of showing that Melatoma, while it
preserves its analogy to Pleurotoma, agrees also with
Planaxis in having the base notched, and with Mela-
nella by its thickened inner lip.

(187.) The next genus is that of Cerithidea. We
have now come to the cyclostiform type, which, with
the elongate form of Scalaria, has an effuse and circular
aperture, with the outer lip dilated into a broad fringe,
and a very short notch at the base. The lightness of
these shells would seem to indicate that they were flu-
viatile ; but as they are slightly variegated, and have
no epidermis, we should not be surprised at their being
found in the sea, — more particularly as this appears to
be the point where the series of fluviatile Testacea
terminates, and the marine commences. Nevertheless,
the great change from Melanopsis to Cerithidea is not

204

SHELLS AND SHELL-FISH.

PART I.

sudden; for it is here we shall insert, as an intervening
form, our sub-genus Ceriphasia {fig. 38.), founded upon

certain Ohio shells resembling Ce-
rithidea, but whose outer lip is thin
and sharp. Unfortunately, we can
find no account of the animal, nor
are we acquainted with any shells
which wiU connect these with 3Ie-
lanopsis on one side, and. with Ce-
rithidea on the other. Until our
path, therefore, is better marked,
we must leave their precise situation as doubtful.
There are evidently three or four sub-genera un-
discovered or uncharacterised, which belong to this
genus. One of these, we suspect, will be found in
certain small species, figured as Melanopsides by
M. Ferussac : their spire is unusually lengthened ;
and the whorls are strongly and longitudinally plaited.
As our last genus, we introduce Plancijcis, — the animal
of which, having been fully investigated and de-
scribed by M. Quoy, proves that their shell must be
arranged with the Melaniancs. It is difficult to conceive
why this eminent malacologist should have introduced
it near to Buccinum, when he expressly says that in the
structure of the animal it comes close to Melanin. If
Planaxis was to be arranged from its shell alone, it
should be placed next to the Purpurince, since it has
the pillar-lip very broad and flattened ; it is, in fact, a
Purpura among the MelaniancE, and, like them, the
eyes of the animal are placed on short peduncles, close
to the base of its two long and slender tentacula. Some
of these, like the common species, P. suhsulcata, has a
very short spire; but another, the P. decoUata, dis-
covered by M. Quoy, has the spire of a Melanin, while
its name seems to imply that the terminal whorls are
deciduous.

(188.) Having now, as far as possible, analysed this
sub-family, a few general remarks may follow. The
Melauiance may be viewed as that group of the Tur-

CHAP. VII. MELANIAN^. GENERAL RE3IARKS. 205

hidce which stand upon the very confines of the phyto-
phagous circle, yet still within its limits : it therefore
partakes much more of the tribe which Nature is about
to enter upon, than of that she is on the point of quitting;
and, consequently, not only the animal, but even the
shell, is so fashioned as to exhibit this preponderance to
the first rather than to the last group. On this broad
principle do w^e account for the indication of a basal
channel seen in all the sub-genera of Melanopsis, in Pla-
naxis, and in Cerithidea. Nay, to such a refined point
is this principle of gradual developement carried, that
we hardly know, at present, where to draw a line of
demarcation between the TurhidcB and the Stromhidcp ;
not, of course, in their pre-eminent types, but in those
which are aberrant. Cerifhiion is in one, and Ceri-
thidea in the other. Their typical forms are easily dis-
tinguished. But in which of these are we to place the
apparently anomalous sub-genus Cerlphasia ? and how
delicate and refined are the characters by which this is
proposed to be detached from the fiuviatile PotomidcB of
Brongniart ! It is here, then, rather than among any
other of the Melaniance, that we should say the tw^o
tribes actually unite. All modern writers, indeed, have
perceived this ; and some have gone so far as to unite
all the sub-genera of Melania and Melanopsis, and
many of the CerithincE, into one genus. It is quite
clear, however, that if this principle be acted upon, the
greater our knowledge of the Testacea is enlarged, the
more must the number of our genera or divisions — call
them what we will — be reduced. New species bring
new modifications of forms ; and these, filling up inter-
vals, and softening down differences, wnll so blend groups
which are noAv in some degree detached, that the whole,
in process of time, will present but one continued chain
of gentle gradations. No " well-marked divisions," in
the sense which the term has been used in, could by
any possibility exist. Our tribes and families, genera
and sub-genera, v/ould melt, one after the other, into
the general mass — they would be abolished — and our

206 SHELLS AND SHELL-FISH. PART I.

divisions would be species, and species only. We may
be pardoned, perhaps, for alluding to this great error in
our nomenclature more than once, because it appears to
us to be fraught with more inconveniences — not to say
evils — than those of an opposite nature ; and because, in
the group now before us, we have been obliged to name
and define so many new divisions. These divisions, in
fact, will show more forcibly than any general argu-
ments, the perfect confusion in which we must have
exhibited this portion of the Testacea,if we had left them
under the three or four genera where they now stand in
the latest systems of conchology.

(189-) That the TarhincB follow the Melaniance is
evident from the close connection of Cerithidea Sw.
with Scalar ia Lam. : the little basal channel of the former
gradually lessens in the aberrant species, until, in one we
possess from Florida, it is a mere vestige. This affinity
fixes the station of the sub-family before us better than all
theoretical reasons. The Turbince are all marine shells,
and possess a perfectly entire aperture. Their typical
genus, Turritella, is subulate, or awl-shaped, so as to have
the spire very long. All the TurhincB have their aper-
ture closed by an operculum, and their substance is never
perlaceous. From overlooking this very obvious differ-
ence, even in the shells, all conchologists, excepting Hum-
phrey, have blended them with the Trocliidce. Cuvier, at
least, from the know^ledge he had of the difference of the
animals, should have not fallen into this error : the con-
fusion has been still further increased by M. Ferussac ; for
he has given to the Turbines of Humphrey the new name
of Littorina, and transfers that of Turbo* io Humphrey's
Senectus. We do not usually trouble the reader with these
misnomers, but we shall correct them as they occur. Our
genus Turbo, therefore, is that of Linmcus and Hum-
phrey, the last of whom we also follow in placing all the
perlaceous ones in that of Senectus. There are so few
variations or sub- genera in the Turbine, that we shall

* The common winkle, Turbo Uttoreus Linn., is the type.

CHAP. VII. GENERA OF THE TURBINiE. 207

here chiefly confine our notices to the five leading genera :
these appear to be Scalaria Lam., Turritella Lam., Turbo
Humph., Melampus Mont., and Scissurella D'Orbigny.
(190') The genus Scalaria, as the circular-mouthed
group, represents Cyclostoma : the typical form seen in
the common wentletrap (^S". pretiosa Lam.) has no pillar,
although it is a long spiral shell. These lead obviously to
Turritella, where the shell is even more attenuated, so that
the whorls are fully as numerous as in Terehra, which it thus
represents. Turbo (^pulchra,fig. 39.) is the next genus,

differing chiefly, as regards the shell,
in the inner lip being broad and flat-
tened, and the spire often very short,
or not longer than the aperture.
There is certainly a resemblance be-
tween many of these shells and the
more globose Trochida;, particularly
the sub-genera Pagodella and Echi-
nella, which are not perlaceous ; but
the great thickness and depression
of the pillar in Turbo, its perfectly round aperture, and
the convexity of the body-w^horl, are sure marks of dis-
tinction. In the invaluable plates of M. Quoy, there is
a figure of the animal of a species of Turbo (under the
name of Littorirui), which shows it to have almost a
zoophagous structure, — so totally different indeed from
that of Trochus, that they have even no analogy to each
other. The same may be said of PhasianeUa, which is
only a long-spired Trochus, analogous, indeed, to Tur-
ritella, but with the short mouth and lateral filaments of
the TrochidcB.

(191-) The next genus, Melampus Montf., is one of
particular interest. It was originally proposed by Lamarck;
but upon being told that they were land shells, he aban-
doned his name ofConovulus, and incorporated the species
in his genus Auricula. This was clearly a retrograde
movement ; for, even had his information been correct, the
difference of these two genera on one hand, and the close
resemblance between Tornatella smd Melampus, is too ob-

208 SHELLS AND SHELL- FISH. PART I.

vious to be overlooked. From the MS. notes of Guildifg,
it appears that these little shells are not more terrestrial
than the other marine TurhincB. In regard to amphibious
Testacea, or such as live both in and out of water, the
following valuable remarks are taken from the Guilding
MSS. " The genus Melampus commonly inhabits the
shallow parts of the coasts, but I have receiNedi Melaynpus
coniformis } from stagnant fresh waters on the shores of
Tortola, which only communicate with the sea occasion-
ally during heavy rains, when the accumulated water is
discharged with it. They are found creeping on the
mangrove roots ; and, like manyof the NeritidcB and Tur~
hinidce, are perfectly amphibious, and very tenacious of
life. The latter, indeed, though they descend to feed at
night, are often seen on the trees of the coasts, and on the
dark black rocks elevated above the surface at high water ;
they remain stationary on the latter during the hottest
hours, even when it is painful to walk on them from
their great heat. The difference of the waters inhabited
by testaceous Mollusca does not, as was once supposed,
offer a certain guide for the division of genera. Many
of the JVeritince, for instance, dwell in the fresh waters
of rivers, while I have dredged up others in the bays and
shallows of the ocean." *

( 1 92.) This genus, as far as we Cvin at present judge,
seems to be composed of the following groups : — Geo-
vula Sw., Melampus Montf., Rhodostoma Sw., Pedipes
Adanson, and Scarabus Montf. All these are clearly
separated from the sub-genera of Turbo by the total
want of an operculum ; while from Auricula they are
still further removed by the branchia being pectinated,
by having two tentacula, with the eyes at the base, or
sessile, and in the shells being more solid. The highly
interesting and valuable essay by Mr. Lowe on Pedipes
and Melampus t, satisfactorily proves that these cannot
belong to the Pulmonaria of Cuvier, and are therefore
excluded from the lanl shells, or HcUcidce. But
whether the genera Geovula and Scarabus have their

« Guilding's MSS. f Zool. Jourii No. xix. p.281.

CHAP. VII. MELAMPUS. — SCISSURELLA. 209

branchia also pectiniform, we have no means of knowing.
The aspect of their shells, however, induces me to place
them for the present in the same group, more especially
since we have already shown they would altogether dis-
turb what we think is the natural series of Auricula and
Clausilia. We do not attach any importance to the fact
of Geovula having an epidermis, because, although the
excellent zoologist just named thought otherwise, we
possess several specimens of a typical West Indian Me-
lampus, where a thin brown epidermis is over the whole
shell ; and this also is common to the sub-genus Rhodo-
stoma. The peculiar depression of the numerous whorls
of the spire in Geovula, Scarahus, Melampus, and Rho-
dostoma, strikingly contrasts again with the few and
produced volutions of the true Auriculce ; and the whole
are separated from Tornatella, by the animal of the latter
having an operculum, and being differently formed. Tor-
natella, in fact, seems to represent the sub-genus 3fe-
lampus ; while Truncatella of Lowe, probably^ does the
same in the circle of Turritella. The whole of this
sub-family, however, requires much more attention than
we have yet been able to give it.

(193.) We place the genus Scissurella as the only
type of our last division, from a belief that it is analogous
to lanthina. It was first characterised by M. D'Orbigny,
one of the most eminent naturalists of France, who found
his specimens among sea sand. It is very minute, and
the animal is unknown : its general shape is that of Si-
gnretus or Vitrina, but there is the same sort of long
narrow slit in the outer lip as is seen in the Pleuroto-
mince, m Plevrotoivaria, and m lanthina; thus we have
numerous analogies, while in affinity we consider this
genus to be the patelliform type of the TurhincE. The
very beautiful figures in Mr. Sowerby's Genera, is all
we yet know of Scissurella; but we possess two or three
similar shaped shells, which appear closely connected to
this type, and probably enter into the same genus.

(194.) We shall now take a rapid view of the five
genera which appear to compose the sub-family before us.

p

210 SHELLS AND SHELL-FISH. PART I.

These and their analogies may be arranged in the fol-
lowing table : —

Analogies of the Turbine.

Genera Sub-families Genera

of the Analogies. of the of the

TuRBiN^E. Turbid^. Melanianje.

TORBO. [^P^hl^rhlTpe'^rrL^''"^"] AMPULLARiN*:. Melanopsis.

TtiRRiTELLA. Spire excessively long. Melanian^. Melania.

ScALARiA. Mouth circular, margined. Turbinje. Cerithidea.

ScissuRELLA. f^P^':'"'',^ ^'^^^ ^^""'^ '■'\u^Tm^M. Plumxis.

(3i^iaavK.cM,ua.. ^ outer lip sinuated. 3

Melampus. {^sh^rt^^"''"'^' '^"^ ''^•"^JThallicera. Paludomus.

We introduce two series of analogies in this table,
because one will better illustrate what may be thought
obscure in the other. The two first set of analogies.
Turbo and Turritella, are particularly strong; for we thus
find the needle-like Melanianje represented by Turritella,
and Turbo by Ampullaria, both equally ventricose and
turbinate. The thick or margined aperture, again, of
Scalaria and Cerithidea exist in no other groups. It
must be remembered, also, that the Turbidte, as a family,
is the cyclostiform or circular-mouthed group of the
phytophagous tribe ; and this character runs through the
whole group, with the exception of Melampus : Scis-
surella and lanthina have the strongest analogy ; and
these, with Planaxis, have the most effuse apertures of
all their congeners. AVe must confess, indeed, that, but
for the discovery of Scissurella, we had long imagined
that Planaxis formed the most aberrant genus of the
Tnrbince. The last set of analogies is those between
Melampus, Thallicera, and Paludomus: it is not very
strong ; yet, as they are the only shells with plaits on
the pillar, they represent the volutes and the land Auri-
culae; while it seems that JMr. Say has discovered an
Anculosa, whose pillar bears a plate or fold precisely
analogous to that in Thallicera.

(195.) Of the next sub-family, represented by the
beautiful and delicate lanthince, or oceanic snails, little

CHAP. VII. TURBINE. TROCHIDiE. 211

can be said. The only two genera we can venture to
place in it are lanthina of Lamarck and Trichopodus of
Sowerby. The first consists of those pretty but fragile
violet and white snails which so much resemble the He-
licidcE : the animal has been described by Cuvicr, and is
so very peculiar, that it cannot be arranged in any of
the foregoing divisions, and yet it occupies that place in
the Regne Animal precisely where we should have placed
it, — that is, immediately after Melampits. " Theanimal,"
observes Cuvier*, "has no operculum; but the under sur-
face of its foot is furnished with a vesicular organ, resem-
bling a bubble of foam, but composed of a solid substance,
which prevents the animal from crawling, yet allows it
to float on the surface of the water. The head, a cylin-
drical proboscis, terminated by a vertically cleft moutli,
and armed wdth little hooks, has a bifurcated tentaculum
on each side." Nothing, unluckily, is here said of the
position of the eyes; but it is sufficiently clear from this
short account, and also from the shell, that the lanthince
belong to the family before us. We follow Lesson in
placing the singular genus TricJiopodus as intermediate
between this and the last division, yet coming much
nearer to lanthina than to Turbo. This brings us to the
end of the series; and if, as w^e believe, ThaUicera stands
between lanthina aLndAmpuUaria, we reach again the
point from whence we commenced our survey, and
thus complete the entire circle of the Turbid^.

(196.) The TrochidjE, as a family, are distin-
guished from all the phytophagous Testaoea, both by
their animals and their shells ; although much more
by the former than by the latter. The invaluable re-
searches prosecuted by the French voyagers, more es-
pecially by MM, Quoy and Gaimard, joined to the
scattered notices in other authors, have so far afforded
information on the animals of the Trochid^, as to
detach them from the Turbidcp, with which concho-
logists have hitherto mixed them. The following

* Griff. Cuv. xii. 63.

p 2

212 SHELLS AND SHELL-FISH. PART 1.

analysis may, therefore, be interesting, as the most
perfect we have been able to lay before the reader.

(197.) The animals of the present family widely
differ, both in habits, shape, and anatomy, from those
inhabiting the TnrbidfP. In the first place, their mouth
is mor& like that of the slugs and snails (^Helicidcp),
being composed of two short lips, — the upper, and some-
times the under, of which is cleft and fringed ; the
eyes, instead of being supported, as in the Turbid fP, half
^vay on the tentacula, are seated on two short but very
thick tubercles ; while the long and slender tentacula
are nearly cylindrical, and of equal breadth throughout :
the Avhole structure, in short, is intermediate between
the animals of the ear-shells (^Haliotidce) and the
? lails (^Helicidce^ ; further, the generality have three
long slender filaments on each side of the foot, as long
as the tentacula, but the use of which is unknown. In
one of the typical groups, and in PhasmiieUa, the
aperture is closed by a strong, and often very thick,
shelly operculum ; but in the Trochidce, this covering
is horny, except in that particular group which con-
nects them with the Senectince : in the Rofellince, again,
the operculum is horny.

(198.) The shells, in their typical examples, may in
general be recognised both by their pyramidical shape,
and by theh- substance being perlaceous, — a fact always
indicated by the rich pearly hue of the aperture. As
this is the most prevalent, it is perhaps the best cha-
racter for the mere conchologist to go by : and yet this
will not serve in all cases, because the pheasant -snails
(^Phasiianella Lam.) and the carriers (Onustiis Hump.)
are not pearly ; and even the most aberrant sub-genera
in Senectus, Trorhtis, and Monodonta, which represent
the carriers, are equally destitute of this substance.
Nevertheless, all these, excepting the first, have their
basal whorl so much depressed or flattened, and their
shape so trochiform, that a little attention will soon
make the student familiar with them.

(199-) ^^ e think the following groups are the pri-

CHAP. VII. TROCHIDyE. PRIMARY DIVISIONS. 21

n

mary divisions^ and hold the rank of sub-families :
— 1. The Phasianellin^, Lam., where the shell is
spiral and obovate, and shaped like a Butimus ; the
outside is polished, and the operculum shelly. 2. The
Senectin^*, or sea snails, resembling the garden snail
in form, but perlaceous, and furnished with a thick,
round, shelly operculum. 3. The Trochin^, or tro-
chuses, having the shape more pyramidical, the body-
whorl flattened, and the aperture closed by a horny
operculum. 4. The Rotellin^, or wheel-shells,
which are also perlaceous, and nearly discoid in shape,
with a thickened mass over the inner lip. 5. Pleuro-
TOMARiA Tief., — a fossil trochiform shell, having a
slit on the outer lip, as in the genus Pleurotoma
of Lamarck. Such are the primary forms, which
seem to belong to the TROcniDiE. Our information
on the animals is partial ; but there is enough to
guide us in three of the chief groups. Thus the ques-
tion whether Phasianella belongs to this family or the
TurhidcB has been set at rest by M. Quoy, among
whose beautiful figures is the animal of the typical
species : the same eminent zoologist has also decided
the relations of Senectus to the TrochincB, by figuring
the Turbo sarmaticus, — thus showing its affinity to
the animal of Trochus. The gradual chain of con-
nection between Trochus, Solarium, and Rotella, leaves
us in no doubt that these also form part of the family ;
but whether Pleurotomaria is merely a genus of the
latter group, or the representative of a sub-family,
must still remain a disputed point. We insert it, how-
ever, under the latter supposition, because it will appear
by the following analysis, that it can in no wise be in-
corporated elsewhere.

(200.) The Phasianellinj=;, or pheasant-snails,
form one of the most isolated genera in the whole of
the Testacea. That they represent the TurbidcE, is
obvious ; for Lamarck and his followers have mixed

* Senectus of Humphrey, Marmarostoyna (pars) Sw., Turba of Cu-
vier, &c.

p 3

^I4f SHELLS AND SHELL-FISH. PARTI.

them together. Their exterior is the most beautiful of
all the Trochidce, not merely by the richness and end-
less variety of their colours, but from their exterior
being almost as highly polished as the olives. The
mouth has two cleft and crenated lips ; the tentacula are
long, slender, and of equal thickness throughout, while
on each side of the body are three lengthened filaments.
The PhasianellcB are nearly all natives of the Pacific
Ocean, and have an oval-shaped operculum. One
species, of a small size, is found in Britain. This is
obviously the long-spired group of the Trochidcp, re-
presenting in this family the Turhidce, the Buccinidcs
(wherein is Terebra), and the CerithincB.

(201.) The Senectin^, or snake-shells, were sepa-
rated by Humphrey from the Linnsean genus Turbo
near forty years ago ; but conchologists have continued,
up to this day, to confound the two, or, rather, to mis-
apply their names. This most natural group contains
nearly all the largest and the most splendid shells of
the family, — all of which we believe, possess a circular
and very strong stony operculum.* The body-whorl
is always ventricose, and is not depressed, like that of
the TrochincB ; it is produced at its base, in the typical
examples, into an obtuse lobe, analogous to the prolong-
ation of the base of the zoophagous gastropods, yet
without any channel. Thus we perceive, at every step,
how completely Nature preserves her uniform principles
of representation ; for it is clear that these Senectmce
represent the zoophagous or channeled tribe, just as
Trochus represents the Phytophnga. The snake-shells
form themselves into very natural genera. The first, to
which we retain the sub-family name of Senectus, is
known by the spire, although small and short, being
always ventricose and pointed, the body-whorl very
large, the base produced into a lobe, and the umbilicus
altogether wanting. The most gigantic, elegant, and
magnificent shells of the whole family enter into this
group, which are chiefly natives of the southern hemi-

* Excepting, perhaps, that type which corresponds to Onustus Huinph.

CHAP. VII. TROCHID^, SENECTIN^. 215

sphere. The ventricose form of the body-whorl of,
course, modifies the shape of the aperture, which is thus
always circular, and but seldom oblique. Before we
had sufficiently studied this family, we included the
foregoing in our genus Marmarostoma ; but we intend
to limit that name to the umbilicated division of Hum-
phrey's Senectus, represented by the M. versicolor* , —
the passage from one to the other group being made by
our Senectus co?'onatus.f The umbilicus in these is,
indeed, small, but very deep ; the spire is ahnost perfectly
flattened, the tip obtuse, and the base even more pro-
duced than in Senectus. It is quite clear to us, that
more than one species is confounded by conchologists
under the specific name of coronatus; since some have
an umbilicus, and others not. In all the Marmaro-
stomce, however, the pillar is present ; but on entering
upon Lamarck's Delphinula, the umbilicus is open to
the terminal spiral whorl, and there is no pillar : the
Turbo torquatus of the old conchologists is, therefore,
a true Delphinula, connecting this genus with the last.
Of the fossil shells referred to Delphinula we shaU not
speak ; judging from their figures, and from a few speci-
mens we possess, they appear to require a thorough
revision, and to contain types very different from those
which are recent. Our next genus, if it be really one,
contains, at present, but two species, differing in being
very slightly perlaceous ; they may be compared to
Delphinulce without an umbihcus. The name of Cyclo-
cantha may explain their round form, and the circle of
spines on the body- whorl. Cidaris is the last genus,
and contains those Senecti which have the base desti-
tute of any lobe, the aperture more oblique, the apex
of the spire obtuse, and the outer surface almost always
smooth;}:; the aperture is quite circular, and closed by
a thick calcareous operculum. There are many species,
of which the beautiful Cidaris sarmaticus may be

* Turbo versicolor Martini, pi. 176. fig. ITIO, 1741.
t Ency. Meth. 448. fig. 2.

% Except in our S. coronata, which connects this sub-family with the.
next.

P 4

2l6 SHELLS AND SHELL-FISH. PARTI.

selected as the most typical. By simply following the
line of affinity, we thus return to our first genus, Se--
nectus; for it is easy to perceive that Cidaris pethiolatus
has the spire and general aspect of Senectus, with the
truncated base and smooth surface of Cidaris. The
circle, in short, is complete.

(202.) The TRocniNiE naturally follows the last
division. The body-whorl, which in the snake-shells
is ventricose, is here depressed, and often flattened
beneath ; and this modifies the aperture, which thus
becomes broader than it is high, or transversely
oval. It is by these latter characters, also, that the
TrochidcB are separated from the Turbidce, -where the
aperture is invariably either round or longitudinally
oval. In the last genus of the Senectince, nature
has begun to indicate the change from a round to a
transverse aperture. The operculum of all the more
typical forms of the Trochida is horny ; but this change
is eflfected gradually. The first genus, consequently,
of the Ti'OchiniE combines the characters of both sub-
families, Canthorhis, in fact, has the depressed aper-
ture of the TrochincE, with the shelly operculum of the
Senectina. Canthorhis is a remarkably diversified group :
it contains the largest of the Trochi, properly so called,
as distinguished from Senectus ; but in all the shell is
Highly perlaceous, the aperture transversely oval, and
the operculum shelly.* The five types of form, or sub-
genera, are all recent; and as their characters will
subsequently be given, we shall only, in this place, il-
lustrate them by general observations. All the large,
spinous, nodulous, and long-spired Troehi belong to
this genus, in which there are very few having a smooth
surface. It is connected to Cidaris by Riigosus and
Cookii; to Onustus by the sun-shells ; and to the typical
Troehi by our sub-genus Carinidea, into which, as we
suspect, will enter the Troehus Niloticus of Linnaeus, —

* If, as Sowerby mentions, the operculum of the Troehus NilotiaiS is
hornv. instead of shHly, it will be the osculant species connecting Can-
ihorbis to our genus Troehus.

CHAP. VII. TROCHIN^. THE GENERA. 21?

a very remarkable shell : out of hundreds, we have
never yet seen a specimen, however large, which had a
perfectly formed mouth, so that we feel somewhat un-
decided as to its precise station. In a young state, the
basal volution is often perfectly flat, and even concave ;
and this gives the margin precisely the same carinated
edge as belongs to Carinidm ; but when more advanced
it becomes convex, as in the genuine TrocM, — thus
uniting, at different periods of its growth, the characters
of the two groups between which it appears to stand.

(203.) Having now shown, by the foregoing details,
the union of the Senectince and the TrochincB, we
shall briefly characterise the remaining genera of the
sub-family we are now upon, and then notice their sub-
genera. Canthorbis has already been defined : following
this is Trochus, properly so called, where the umbil-
icus, if it exists, is never toothed, and very rarely
channeled. In Monodonta, these characters are reversed;
the umbilicus, if present, is always either toothed or
channeled, and the aperture striated. The fourth genus
is Solarium, where the umbilicus is so large as to reach
to the apex, the pillar is absent, the shell nearly dis-
coid, and the aperture without any defined lip. The
last genus is Onustus, long ago separated by Humphrey,
to include those singular and half-formed shells, called
by collectors. Carriers. Of the animals by which these
are formed, we as yet know nothing ; but their shells are
composed partly of the usual calcareous substance, and
partly of little stones or fragments of other shells,
which the animal gathers up and incorporates on the
outer surface of its own habitation. A gradual series
of intervening forms unites this group on one hand to
Solarium, and on the other to Canthorbis ; so that the
whole of the TrochincB, being united into one circle,
constitute a natural and perfect group. We shall now
notice each of these genera in detail.

(204.) Having already spoken of Canthorbis, we
pass to the second genus, Trochus. Were we to
make this an artificial group, its definition would be very

218

SHELLS AND SHELL-FISH. PART I.

easy, for it might then be formed to contain all those
small or moderately sized trochuses, which are without
a distinct tooth at the end of the pillar, and have a horny
operculum. But this definition would break up the
natural series. The group, in fact, is so difficult to cha-
racterise in general terms, that we suspect its funda-
mental difference from that of Monodonta lies in certain
peculiarities of the animals, with which at present we are
unacquainted ; but if, to the foregoing characters of
Trochus, we add that one of its sub-genera has a promi-
nent tooth, but no umbilicus, and that another is not per-
laceous, we shall then name the only exceptions. The
whole genus, then, divides itself into the following five
sub-genera: — 1. Chlorostoma, where the basal volution is
either perfectly flat or concave, the margin carinated, and
the outer lip so oblique that it extends half way round
the circumference of the shell ; the umbilicus is very
deep, and is bordered on one side by the inner lip,
which is suddenly truncate as soon as it reaches half
way round the umbilicus : this leads to Troclius, or the
typical sub-genus. All our British species, excepting
T. zizyphinus, come into this division ; the umbilicus
is more or less deep, and the aperture either entire or
with a very slight angle at the piUar : by degrees,
however, this angle is so much developed, that it assumes
the appearance of a tooth : thus we are led into the sub-
genus Trochidon, nearly all of which are natives of the
southern hemisphere. Some have the tooth as distinct
as in Monodonta ; but they may at once be known by
having no umbilicus, even although the inner lip may
have a slight marginal groove. But here, as nature has
reached the highest point of developement, she again re-
cedes ; the spire gradually lengthens, the tooth becomes
a simple angle, and we enter on the smooth division of
the group, forming our sub-genus CaUiofitoma. The
Trochus zizyphinus of British writers will give a very
good idea of these shells ,• they are nearly all either per-
fectly smooth or slightly granulated, of a light and ele-
gant form, a long and pointed spire, and no umbilicus :

CHAP. VII. MONODONTA. THE SUB-GENERA. 219

several species, but little known *, are found in the Medi-
terranean ; and these are the most trochiform, — that is,
the basal whorl is unusually flattened, which renders the
aperture narrow : those from the Pacific, on the contrary,
are more ventricose, — thus representing Cidaris and the
SenectincB. This modification of form is to constitute
the passage which here takes place between the five types
of Trochus and those of Monodonta. The last sub-genus,
Pagodella, is the only one containing shells that are not
perlaceous. The student, at first sight, would think this
was a most heterogenous group, for it contains species of
very different forms: some are so like European Callio-
stonice, that they might be strictly arranged as such, if
the substance (tf their shell was not regarded ; others
are equally conic, but instead of being smooth, are beset
with nodulous granules ; while others, again, are formed
precisely the same as our first type, Chlorostoma, but yet
have no umbilicus. But this is at once explained by
the situation of Pagodella, which is intermediate between
CalUostoma and Chlorostoma. So exquisitely, also, has
nature blended this genus with the last-named group,
that there is one species, the Trochus Merula of La-
marck, w^hich unites in itself still more closely the cha-
racters of Chlorostoma and Pagodella ; it has the shape,
colour, and pearly substance of the first, and the flat-
tened imperforate lip of the last ; it may, in fact, be
called either a perlaceous Pagodella or an imperforate
Chlorostoma. Having now gone through the genus
Trochus, we proceed to the next, or sub-typical group.
(205.) On entering the genus Monodonta, we must
refer to what has been just said on the Oceanic f spe-
cies of CalUostoma, the greater convexity of whose basal
whorl cannot fail to have been remarked ; thus we are con-
ducted to Elenchus, the first sub-genus of the present
group, and found only in the same latitudes. These

* It is of these, we believe, that the genus Margarita has been pro-
posed, to include such as have " the operculum of few whorls."

t The Continental naturalists employ this term to designate the pro-
ductions of those countries or seas lying in the Great Pacific Ocean.

220

SHELLS AND SHELL-FISH.

PART I.

splendid shells, although mostly of a small size, have a
brilliancy in the emerald green of their apertures, which is
perfectly unrivalled in this family (^^.40.) like the Callio-
6-tomcB, the basal whorl is convex, — more so, indeed, than
40 ^-««a^*p''?r^ ..^..^ ill any other of this ge-

nus, except that to which
it leads ; the spire is also
generally more produced,
and in one species (a) is
so long that it resembles
a small Turritella. It is among these shells that the
most prevalent character of Monodonta appears. The
base of the pillar in some forms an angle, and in others
a small but very distinct tooth : their exterior is always
smooth.* Next to these we place a small group of
equally ventricose shells, to which we retain Lamarck's
name oi Monodonta ; they have, in fact, almost the form
of Senecti, but they are small, and the pillar is both
umbilicated and toothed : in some, these characters are
very slightly developed ; in others, they are very strong ;
and this variation takes place in species otherwise
so much alike, that they might almost be taken for
the same at different periods of growth. They are
mostly finely granulated, and sometimes striated within ;
but their ventricose aspect is altogether peculiar ; the
umbilicus is always smooth round its edges, but varies
in its size. In the next sub-genus, Fragella, the
basal tooth is so large, that its projection, joined with
the teeth on the inner margin of the outer lip, gives the
aperture an appearance of being distorted. The well-
known little shell called the strawberry trochus, is the
type ; and, by its depressed form, pointed spire, and
large umbilicus, reminds us immediately of a genuine
Trochus : the surface of nearly all is beautifully granu-
lated. In our fourth group, or Monilea, the umbilicus
and its singular marginal rim are precisely the same as
in Chloroatoma, except that the umbilicus is wider, the

* This beautiful group was well known to Humphrey, whose name, im-
posed near forty years ago, we have of course retained, instead of bome
others recently given by the French nomenclators.

CHAP. VII. SOLARIUM. ONUSTUS. 221

shape more depressed and trochiform, and the surface of
the shell often granulated ; the only remnant of the tooth
is shown by one or two small tubercles or notches at the
base of the outer lip. Several species^ mostly of a small
size, are now before us, all of which are natives of warm
climates or of the Pacific Ocean. Lastly, we find in
this genus, as well as in Trochus, one division which
have not perlaceous shells, but which, possesses a
well-defined tooth. These species we include under the
name of Echinella. The most typical is that figured
in the Ency. Meth. (pi. 417- fig. 6.) as Monodonta coro-
naria, — a shell which is a perfect prototype of our Pa-
godella echinata : the species yet known are few; but of
these we possess the connecting link to Elenclms, in our
E. gramdata. We are thus brought back to Elenchus,
where we commenced our survey of Monodonta. The
naturalist will not fail to perceive, that in thus resting
our arrangement upon affinity, we have indicated strong
relations of analogy between Trochus and Mono-
donta : to these we shall presently return.

(206.) The two remaining genera. Solarium and
Onustus, do not comprise more than a few recent species,
although it is highly probable that many of the imper-
fectly preserved fossil discoid shells belong to the first,
and some few also appertain to the last. On receding
from the typical species of Solarium, the spire becomes
more prominent, and the edge of the body- whorl dilated
to form a sharp edge, so thin as easily to be broken off ;
the crenated margin of the umbilicus of these shells, how-
ever, indicates their affinity to the singular genus Onustus.
From certain slight and irregular indentations on the
preliminary whorls of the spire, we suspect that, at an
early age, many of these animals gather small fragments,
and fasten them upon their shells ; but that, when older,
these extraneous substances either fall off, or are volun-
tarily discharged; just as if the animal, having acquired
its full powers by age, was able to fabricate its own ha-
bitation without calling in other assistance. Now, the
same advance which we have thus stated as taking place

222 SHELLS AND SHELL-FISH. PART I.

from Solarium to Onustus on one side, can also be dis-
covered on the other side from Canthorbis. The gra-
dation, in fact, is equally perfect on both sides : the
two extremities of the column of the Trochin^, com-
mencing with the sub-umbilicated species of Canthoi'his,
and ending with the sharp-edged Onustus, meet to-
gether in the Onustus agglutinans*, which thus closes
the circle of the five genera of the TRocHiNiE.

(207.) The two aberrant types of this family are as
remarkable for the paucity of their forms, as the typi-
cal Trochin^e are otherwise. Of the RotelUnce, in fact,
we can only enumerate two genera ; and one of these not
so effectually as we could wish. We think the Turbo Ni-
cobaricus is the type of a sub-genus (^Chrysostoma Sw.)
much more related by its shell to Rotella than to
Senectus, even if its operculum should prove to be
shelly. It differs from all other Trochidcs, in having
a very thick deposition of shelly matter spreading over
the umbilicus, which it almost conceals : it does not,
however, extend near so far as in Rotella; and yet both
shells are evidently highly polished by their animals.
On this account, therefore, and in the absence of all
knowledge of the animal, we place it as the represent-
ative, among the RotelUnce, of Senectus and Monodonta.
Of the fossil genus Pleurotomaria very little can be
said : it obviously enters into our present family, from
the trochiform shape of its shell ; and the foregoing
analysis renders its station in any other group highly
improbable ; we place it, therefore, between Rotella
and Phasianella, as the type of a sub-family, the other
members of which cannot now be distinctly ascertained.
The truth is, that in this and numerous other instances,
the study of fossil conchology is impeded by insur-
mountable difficulties, which must always exist. How
many genera are in our systems, belonging to the older

* It is somewhat remarkable, that, from Lamarck's description of this
shell, it would seem to have the umbilicus open when young, but closed
when it has reached maturity. In two fine specimens now on the table, it
is completely covered ; and yet there is a fossil species from Hordwell,
where it is perfectly open, although not large.

CHAP. VII. TROCHID.E. TURBID^.

ANALOGIES.

223

geological beds, which we only know from casts and
mutilated fragments ! and how many others, even in
the newer formations, which it is impossible to arrange
with precision, from ignorance of the animal ! These are
the true reasons which lead us to say as little as pos-
sible upon all those fossil genera whose affinities are
doubtful ; since, from the peculiar nature of the object
we have in view, we would rather incur the imputation
of overstrained caution, than the opposite extreme.

(208.) We have hitherto considered only the affini-
ties of the TrochidcB ; let us now turn to their analogies.
Our first table will be of the primary divisions, or sub-
families, which represent those of the Turh'idcR in the
following manner : —

Analogies of the Sub-families of the Trochid^ and the

Turbid^.

Sub-families of

TrockidiZ.
Typical Genera.

Senectus.

Trochus.

ROTELLA.

Pleurotomaria.
Phasianella.

Analogical Characters.

c (1. Sub-typical.)

•J Shell globose ; operculum shelly
c spire short, obtuse, ventricose
(2. Typical.)
Spire pointed; whorls more nu-
merous ; operculum horny.
(3. Aberrant.)
Shell depressed ; inner lip thick
ened.

C Trochiform ; the outer lip with a
X marginal slit or sinus.

f Spire greatly lengthened
X culum shelly.

Sub-families of the

Turbidai.

Typical Genera.

Ampillaria.

\

\

Melania. 3

Thallicera.

Ianthina.

^ ^' i TURRITELLA.

Whatever may be the rank of Pleurotomaria, it is
certainly the prototype of Ianthina. These latter shells
are so excessively brittle, that not one in five hundred
are perfect j but the sinus, although neither so long nor
so narrow as in Pleurotomaria, is nevertheless fully de-
veloped in the perfect shells, but more especially in our
/. gJohosa.* The long-spined Turritellce represent
Phasianella, and both have a shelly operculum. The
other analogies are not so striking,— excepting, perhaps.

• Zool. 111. 1st Series.

224

SHELLS AND SHELL-FISH.

PART I.

that of Senectus to Ampullaria; both being large globose
shells, and the latter sometimes closed with a shelly
operculum. The curious reader, who may be desirous
of prosecuting these analogies further, may compare
them, at his leisure, with many others in the volume.

(209.) We shall now bring together the genera of
the two sub-families.

Analogies of the Senectin^ and the Trochin^.

Genera of the
Senectin^.

Senectus.

Marmarostoma.

Delphinula.
Cyclocantha ?

CiDARIS.

Analogical Characters.

CTypiral of their respective circles; 7
\ volutions convex. j

f Sub-typical ; umbilicus with a ba- 7
\ sal groove. 5

f Nearly discoid; umbilicus very 7
X deep ; pillar none. 3

Shell not perlaceous ; trochiform.
f Aperture oblique ; operculum 7
I shelly. 3

Genera of the
Trochi\.«.

Trochus.

monodonta.

scalaria.
Onustus.
Canthorbis.

Our only doubt relates to what is the true type
between Delphinula and Cidat-is. It is either the shells
we have before mentioned, or those of which Turbo
pagodus is the type, where the operculum is horny.
We may now turn to the

Analogies of the Sub-genera 0/ Canthorbis.

Sub-genera of
Canthorbis.

Tuhicanthus.

Canthorbis.
Pyramidea.
Lamprostoma.

Carinidea.

Analogical Characters.

C Apertu re obliquely round or oval ; 7
I smooth. 5

f Greatly depressed ; the sides ca- 7
(_ rinated ; umbilicus small. j

Aperture thin, sharp, brittle.

("Aperture strongly toothed or tu- 7
X berrulated ; striated within. 3
("Aperture nearly entire, slightly")
X angulated ; smooth within. 3

Genera of the
Trochinje.

Canthorbis.

Onustus.

solartum.

Monodonta.

Trochus.

The re^'.ults of this table will explain why we have
thought it expedient to characterise as sub-genera the
types of such a small group as Canthorbis ; for the shells
it contains are so remarkably varied, that, without some

CHAP. VII. TROCHID^. — CANTHORBTS. 225

clue to the meaning of this variation^ it might appear a
questionable group. The only one of these analogies
on which we have any doubts^ is that between Carini-
dea and Trochus : we are, in fact, at a loss to know
whether Trochus Niloticus and Turho Pica are the real
types of Carinidea, in which case they would open a
passage from the large Canthorbi to the small and
moderate-sized shells of our genus Trochus: the strong
and unquestionable affinity, however, of Carinidea con-
cavus* to our sub-genus Chlorostornus, although the
one is a large and the other a small shell, cannot be
disturbed. But, on the other hand, even if the passage
from Canthorhis to Trochus is made by Niloticus and
Pica, the difference is one of very inferior moment.
Two things are certain : one, that Canthorhis is the
intermediate group, which connects the TrochincB to
the SenectincB ; the other, that it equally connects our
genera Trochus dinA Onustus: for every conchologist will
perceive that Tubicanthus runs into Cidaris by means
of C. rugosus and Cookii. There is, however, another
analogy belonging to Canthorhis, too remarkable to be
passed over : it is, in its own group, what Cerithium
is in the circle of the StrombidcB: this is shown in its
twisted and outwardly-curved pillar, as well as the
numerous volutions, and the consequent length of the
spire. According to this view, Pyramidea and Lam-
prostoma would be the types, — since they are the most
conical and elevated of all the others.

(210.) We now come to the sub-genera of the two
typical groups, Trochus and Monodonta. It has been
seen that each forms a circular group ; and the pre-
ceding observations will, in some measure, have pre-
pared the reader for the following general exposition
of their sub-genera. The genus Margarita of Leach
appears to us a purely artificial group, partly composed
of our umbilicated Trochi, and of the true Calliostomce ;
we have therefore not adopted it.

* Our specimen, fortunately, possesses its operculum, and has never been
cleaned.

226

SHELLS AND SHELL- FISH.

PART I.

Analogies of the Sub-genera oyTRocHus and Monodonta.

Sub-gencra of
Trochus.

Trochus.
TrochUicm.

Calliostoma.

Pagodella.

Chlorostoma.

]

Analogical Characters.

More or less umbilicated, but the
umbilicus always smooth.

Base of tlie pillar forming a pro- 1
minent tootii. J

Imperforate, smooth, or slightly "J
granulated ; basal whorl some- {
times ventricose ; spire long, f
pointed. j

Shell not perlaceous, pyramidical.

Deeply umbilicated; the inner ^
lip thickened and truncate >
half way round the margin, j

Sub-genera of

Mo.NODOiV.

Monodonta.
Fragella.

Elenchus.

Echinella.
Monilea.

These analogical resemblances are so close, that, but
for the former explanations, an incautious conchologist
might easily mistake one for the other. Unfortunately,
we are in total ignorance of the animals of all these,
Trochus excepted. Whether they have each a peculiar
modification of form, or whether Nature has confined
herself to tracing out these variations by the shells
alone, are questions which time alone will develope.

(211.) "A natural arrangement," as an eminent en-
tomologist has more than once observed, "^ will stand any
test." We have now placed it in the reader's power to
act upon this hint, by applying all those " tests " which
our preceding diagrams have supplied, to our arrange-
ment of this family. There is one, however, which,
from its singularity, may here be mentioned.

Analogies of the Tbochid^ to the AcHAxiNiE,

Sub- families of

TllOCllIU/E.

Senectin-e.

Trochin*.

kotellin.e.

Pleurotomin^.

FilASIANELLIN£.

Analogical Characters.

("Ventricose ; sjiire short ; aperture \
X always entire. J

C Spire conic, inore developed ; base \
X of the pillar notched or toothed. 3
Nearly discoid.

r Outer lip, either above or below,7
X with a slit. j

Spire very much produced.

Genera of the

ACH.\T1N^.

Bllimls.

achatina.

Cyclostoma.

Helicina.

CLAL'SILIA.

CHAP. VII. TROCHIDiE. ACHATIX^. 227

These analogies, of course, are much more rem.ote
than those we have been tracing, because the groups
themselves are much more remote; and yet the same mode
of variation is preserved in two different families — one
marine, the other terrestrial. The RotellcB in one, and
the Cyclostomcd in the other, are the most discoid shells
in their respective families ; while, at the opposite side
of the circle, we find the long-spired Phasianellce repre-
senting the still longer-spired ClausilicB. Some of the
Helicince have a deep narrow slit at the base of their aper-
ture, precisely similar to that on the outer lip in Pleu-
rotomaria ; and in both instances this structure is only a
repetition of what is seen in lanthina, Scissurella, and
Pleurotoma. The two first analogies equally hold good,
so that the two groups mutually test each other.

(212.) We have placed the Trochidce next to the
Helicidcp, under the belief that they followed each other,
although the links of connection were wanting. It is
clear, that of all the types of the Trochidce, Rotella is
that which by its general form makes the nearest ap-
proach to Helix ; while the thickening of the inner lip,
which spreads over the umbilicus, is found also, but in
a less degree, in many of the land volutes, Lucernince.
But a singular discovery, recently made, has thrown an
entirely new light upon this interesting question. Among
a considerable number of freshwater Planorbi, all of one
species, which were sent us from Brazil, we picked out
two helix-looking shells, so precisely of the same oiiva
brown colour, and of the same size, as the others, that
none but a conchologist would have been led to examine
them. They appeared, in fact, like two little land-snails
of the sub-genus Zonites, that had fallen into the water
where the Planorhi had been found, — their outside being
discoloured, and covered with little particles of dirt and
sand. On placing them, however, under the magnifier,
a conchologist can alone judge of our astonishment at
finding that the whole of the shell was actually com-
posed of little stones and grains of sand only, agglutinated
together, yet with so much skill, by the animal, that the

Q 2

228 SHELLS AND SHELL-FISH. PART I.

regular turns of the volutions of the spire^ and the form
of the umbilicus, was most accurately preserved : they
were, in short, freshwater carriers — absolute counter-
parts of their marine brethren, Onustus. As we can
find no notice, or even allusion, to such an extraordinary
genus of shells in any writer, we have considered it new,
and affixed to it the name of Thelidomus. In regard to
its affinity, we suspect that it fills the same situation
among the Rotellince which Onustus does among the
Trochintp : this will make it the most aberrant type, and
consequently that which comes nearest to the HelicidfB,
whose form it actually possesses. The annexed figures
{fig. 41.) are taken from the only two
specimens in our cabinet which we have
either seen or heard of ; the line denotes
their natural size. Thus, there is ground
for supposing that the passage from the
marine TrochidcB to the terrestrial snails
is marked by one or more fluviatile types,
just as is the passage on the other side of
the Helicidcp, marked by the Limnacince. The accidental
discovery, also, of this extraordinary shell, will probably
induce naturalists to a more accurate examination of the
fossil turbinated univalves than they have received ,• for
it is clear, that, although Thelidomus opens the path to
the Helicidce, there must be several other forms between
the two, either extinct or undiscovered.

CHAP. VIII.

THE PHYTOPHAGOUS GASTROPODS CONCLUDED. THE HALIOTIDj«,

OR EAR-SHELLS, AND THE NA71CID^, OR NERITS.

(213.) The Haliotid.^, or ear-shells, follow the
TrochidfE, and, like them, in their typical examples, are
of a rich pearly and iridescent substance. They have

CHAP. VIII. haliotida: generally. 229

been confounded, even by Cuvier, with the true Scuti-
branchia, merely because, like them and the Tuhuli-
branchia, their mode of generation is the same. If this
latter consideration is of such importance, all these three
should form one group ; and not only so, but they should
be united to the Dythera, or bivalves, — since they also are
fecundated in a similar manner. The fact, however,
appears to come out, by analysis, that the Haliotidcs are
the representatives of the limpets (^Scutihranchia) in the
great circle of the phytophagous gastropods, just as the
naked dorises (N'lidibranchia) represent the limpets
(^Scutihrancliia) in the entire class of shell-fish (^Testa-
cea). And thus, no less a naturalist than Cuvier, from
not attending to the two sorts of relationships, — analogy
and affinity, — has mistaken the one for the other in both
instances, and obscured one of the most beautiful tran-
sitions in nature. To this most accurate anatomist,
however, we are indebted for the first knowledge of the
animal of Haliotis, and to M. Quoy for that of Stomatia.*
Without entering into the details, we may simply state
that the structure of the first evinces an analogy to that
of the Patellida, or limpets; while the animal of Stoma-
tia still more closely resembles that of the Trochidce,
and more especially of Phasianella and Cidaris. The
determination of these two facts are of the highest im-
portance, since it enables us to discern the two typical
groups ; while a beautiful delineation of the ^S". Chinensis,
among the unpublished drawings of Guilding, and of the
animal of a Sigaretus by M. Quoy, makes us actually
acquainted with the inhabitants of four out of the five
genera which compose the family.

(214.) In regard to the shells of the Haliotidcs, they
are easily and certainly recognised : they may be called,
indeed, turbinated or spiral limpets, inasmuch as nearly
the whole have some slight developement of a spire ;
but an indication of the pillar is only seen in that genus
which comes nearest to the Ti'ochidcs, — namely, Calyp-

* Stomatella tacheMe, Vov. d' Astrolabe, pi. Qo. bis.
Q 3

I

230 SHELLS AND SHELL-FISH. PART I.

trcea* The whole may, therefore, be characterised as
patelliform shells, always possessing either a small spire
of two or more volutions, or some internal support within,
although the pillar is wanting. They are, in fact, the dis-
coid type of the phytophagous Gasteropoda; representing
on one side the testaceous Cephalopoda, and on the other
the Scutibranchia, or limpets. Like the Volutidcp, they
have no operculum, and both represent each other in
the extreme shortness of their spire. In comparison
to those we have already noticed, this is a very small
family, — so small, indeed, that its primary divisions
are only of the rank of genera. They are, in a manner,
fixed or sedentary shell-fish ; for, although some are
capable of locomotion, they must move but very little,
since the obvious construction of their shells t is mani-
festly for the purpose of adhesion. Hence they are
found closely affixed to rocks or other substances near
or within the sea. The round holes in the perforated
ear-shells (many species of which are of a large size and
splendidly iridescent) are for the passage of slender
filaments which the animal can protrude at pleasure :
these, of course, do not exist in those ear-shells which
are without perforations ; but in both the mantle of the
animal is highly ornamented, — being in Stomatia regu-
larly cut into numerous points, like the teeth of a saw ;
and these, in Haliotis, assume the more lengthened shape
of filaments. Both these, which constitute the two
typical genera, enjoy the free power of locomotion, for
we do not observe that the contour of the shell of in-
dividuals of the same species ever varies, — a clear proof
that they never take the form of that substance they
may happen to be attached to. In Calyptreea and Cre-
piduln, however, the case is different. We have no
doubt that the greater part, at least, of these shell-fish

* Cuvier, indeed, admits these and similar patelliform shells approxi-
mate in their animals to the Trochidie, and yet he places them widely
apart from Stojuatia, whose structure in its soft parts is still more like
that of Trochus.

t Except, of course, Sigaretus, which has its shell enveloped on its
back, as representing the Tectibranchia.

CHAP. VIII. STOMATIA_, THE TYPES. 231

live and die on the very spot where they were originally
born ; for the circumference of almost every individual
presents a different contour, according to the surface of
the substance on which it adhered. Like the TrocMdcp,
we find that the two typical divisions alone are per-
laceous. One species of Haliotis is found on our
south-western coasts ; but the greater part of these
splendid shells, as well as Stomatia, come from warm
latitudes.

(215.) The five primary divisions of the family are
only genera, — Haliotis and Stomatia being the most
typical j then follow Calyptrcea, Sigaretus, and Cre-
pidula. The whole of these constitute a circular group,
connected by the third type to the Trochidce, and by
the fifth to the NeritidcE by means of Navicella. The
scientific reader will find all these groups sufficiently
characterised in our arrangement; but a few general
remarks appear called for in this place. It is singular
that, if any modification in the structure of the animals
in Haliotis exist, they are not conspicuously* shown in
these shells, with the exception of one, the Haliotis
asinma, or ass's ear ; while in Stomatia (of which
Quoy has figured the animal of the typical species), the
variations in the shell are so many, that there can be
little doubt of their being accompanied by a corre-
sponding variation in their animals. As we are some-
what undecided whether these should all receive sub-
generic names (as in the instance of Stomatella), we
shall here only mention what appear to be the five
types, t >S'. planulata obviously unites Stomatella to
Haliotis, by means of its prototype H. asinina. In both,
the spire is very short, the form oblong, and the outer
surface smooth. S, auricula seems to be the next type,
where the spire is sufficiently developed to be elevated
above the surface of the body-whorl ; then comes the

* Perhaps, however, conchologists have paid too little attention to the
Haliotis in the variations of their form.

t It is curious that Mr. Sowerby, unaware of our views, should have hit
upon all these, and urged this variation as :\ reason for not adopting
Lamarck's Stomatella : see his Genera of Sheds.

a 4

232

SHELLS AND SHELL-FISH.

PART I.

typical form in Stotnatia imbricata and sulcifera, which
appear to have from two to three distinct spiral whorls*,
but Still without any ridges or angles, although the
outer surface is finely imbricated. In duplicata the
spire is still more developed, angulated, and marked
with granulated tubercles ; so that, in fact, it much
more resembles one of the SenectincB, and particularly
Cidaris, than a Stomatia, while its angulated shape and
tubercles remind us of Delphinula. Lastly, we have a
form, in ^S". phimotis, very distinct from all these : the
spire is again shorter, more like that of planvlata and
auricula, but it is irregularly formed ; the outside of the
shell is rough and angulated, as in duplicata, so that it
unites the form of all these three ; we have an indis-
tinct recollection, also, that the substance of this shell is
not perlaceous, like all the preceding species. Now, the
reader, if he turns to our distribution of the Trochidce,
and of the types therein contained, cannot fail to be
struck with the singidar coincidence of these five spe-
cies agreeing with the variations there pointed out.
This will be seen more clearly by throwing them into
a tabular form.

Analogies of the Types of Stomatia.

Types of
Stomatia.

S. planulata.

phimotis, or
obscurata Lam.

duplicata.

Auricula.

imbricata.

Analogies.

\ Spire flattened ; outer surface 7
) smooth. 3

rShell and spire irregular; sub-T
■< stance not perlaceous ; outer >
C surface rough, carinated. J

f Spire elevated ; the whorls angu- 7
I lated and coronated. J

f Spire short, raised above the body- 7 c^„^^/,„
\ whorl ; perlaceous. j ^enectus.

I

Spire more elevated and developed, ^
but without any angles or tu- >
bercles. J

TROCHID.E.

Types.

Jiutella,
Cidaris.

Onustits.

Delphinula,
Canthorbis.

Trochus.

We are unacquainted with any of the fossil species,
but we have no doubt, after this exposition, that they

* Sowerby's Genera, art. Stomatia, figs. 1 and 2.

CHAP. VIII. CALYPTR^A. 233

will arrange themselves under one or other of these
types. Without enlarging further upon these analogies,
we may briefly state that they are in perfect uniformity
with that principle of variation which runs through
the whole of the animal kingdom. It was long ago
announced by one of the most philosophic naturalists
of the age, that when Nature^ so to speak, is about
entering a large assemblage, she gives, as it were, in
the onset, a sketch of the five leading forms she
intends to adhere to, although under innumerable mo-
difications. Thus, in the class of Acrita, as MacLeay
observes, she typifies the five great classes of animals ;
and thus again, in the very first group of the spiral
univalves, she presents us with indications of the five
great families of the phytophagous and zoophagous
Gasteropoda, all concentrated in the limits of a single
genus.

(21 6.) The station of Lamarck's genus Calyp-
tr^a is fully determined by the structure of his Sto-
matella duplicata, since both form an obvious passage
to the Trochidcp, by showing the first developement of
a central pillar. Lamarck's observations upon this
interesting group, which contains many natural sub-
genera, appear to us characteristic of that accurate per-
ception, almost intuitive, of natural afl!inities and
relations which characterised all his writings before his
unfortunate blindness, — a rare talent of discrimination,
which, as it has been justly observed by others, places
him, in this respect, far above even the author of the
Regne Animal. Although he had not the advantage
of being acquainted with the animal, made known to
us by the unpublished drawings of Guilding* (of
which the annexed cut is a copy, fig. 42.), he con-
sidered this genus, not related (by affinity) to Patella,
but that its incipient spire and pillar indicated a struc-
ture approaching to that of Trochus. He erred, appa-
rently, in carrying this theory too far, by supposing

* The typical form is probably C. Chinensis, the species here figured.

234

SHELLS AND SHELL-FISH.

PART I.

that his C. trocMformis would he hetter placed in that
family. But even the errors of such a man are as
lights to others ; for when douhts exist as to the limits
of a genus, we may be perfectly sure of the passage,
and that both genera are natural. On the other hand,
if we look to the resemblance between Patella and
CalyptrcBa as analogical, these conflicting opinions are
at once reconciled : both are cup-shaped, pyramidical,
and with the apex almost central ; and that both stand
opposite to each other in their respective circles, the
intelligent reader will perceive if he brings these fa-
milies into comparison.

(217.) The next group, which, from a consideration
of the animal, we have here named Cheltnotus, cor-
responds, in some measure, to Sigaretus of authors.
We find it impossible, however, to understand this
group. It has been customary to place in Sigaretus
nearly all those ear-shaped shells of the same form as
Stomatia, but which are not perlaceous, without a
knowledge of their animals, or, even when that was
obtained, without a due regard to the differences they
exhibited. We mention this, not as conveying censure,
but as the probable reason why we cannot unravel this
exceedingly intricate question. This has partly arisen,
strange as it may appear, from the new light thrown
upon the JVaticce by Guilding. The beautiful delinea-
tions he has made of the animal of a typical species,
shows that it is almost an internal shell, or at least

CHAP> VIII. SIGARETUS, AND ITS PROTOTYPES. 235

SO far as that its circumference is fitted into a fleshy
rim. The aspect of Quoy's Cryptostoma again, and of
Blainville's, are much the same ; and neither of these
agree with the delineation of the animals of De Blain-
ville's Sigaretus, Vetulina, or Coriocella. In the pre-
sent difficulties, in short, which surround this question,
we shall leave it for the investigation of others : our
impression is, that part of the Sigareti of authors be-
long to the Naticidce, and part to this group ; and
that these can only be determined by the structure of
their animals. In the meantime we have no great hesita-
tion in considering De Blainville's Coriocella and Velutina,
in conjunction with Quoy's iS'/^are^ de Tonga, as sub-ge-
nera of that genus which intervenes between Calyptrfjea
and Crepidula, and which we provisionally call Cheli-
NOTus, from the resemblance which the typical forms bear
to the back of the tortoise. The animals of all these have
two short, thick, cylindrical tentacula ; the eyes being
at their base, and either sessile, as in Coriocella, or at
the tip of short peduncles (which are united to the ten-
tacula), as in Chelinotus* We believe, also (judging
only from his figure), that De Blainville's Sigaretus con-
vea:usf belongs also to this group, since the animal
merely differs from the Coriocella and Chelinotus in not
having the anterior part of its mantle forked, and being
very little larger than its shell, which thus becomes
external. As for the shells themselves of these genera,
they seem to be all of one form, precisely like that of
Vitrina, which they obviously represent : hence they
are not of primary importance in determining the ques-
tion. As for the Sigareti of Lamarck, Sowerby, &c.,
we suspect that when their animals become known, they
will turn out to belong to the NaticidcE, since, so far
as the shells are concerned, we have a most perfect
series by which they seem to be connected with the
Natica mamilla of authors ; while Cryptostoma may
possibly be the tectibranchian type of that family, just

* Si'garet de Tonga, Quoy, Voy. d'Astrolabe, pi. 66. bfs, figs. 4 — 8.
+ Manuel, pi. xlii. fig. 2. 2 a.

236

SHELLS AND SHELL-FISH. PART I.

as Chelinotus is of this : such, at least, are our present
impressions on the relations of these perplexing forms.
Our object, in all cases where we cannot analyse, is to
state difficulties, not to smooth them. The present
instance is one of the few groups we are compelled,
from this cause, to leave in uncertitude. The reader
will remember that the same difficulty has occurred in
regarding the Bailee. Now, both of these are analogous
groups, and, with the NaticcB, are all representatives of
the naked order Tectibranchia. This will be ap-
parent on looking to the opposite columns, the contents
of which follow each other perpendicularly, while the
analogies are expressed horizontally.

(218.) A chapter would be scarcely sufficient for the
full explanation of the innumerable relations implied in
this table ; we must therefore confine our attention to
that line which contains the analogical representations of
the Tectibranchia. All these turn out to be slug-like
animals, with shells either larger than their bodies, or
more or less capable of being concealed by the mantle :
they are all free, that is, they have the full power of
locomotion ; their shells have few, if any, voluties ; of
a thin and delicate substance in most, but rarely sculp-
tured ; never rough, and generally smooth and polished.
But what, perhaps, is the most remarkable feature
running through the majority, is the striking resemblance
they bear to tortoises, not merely in the oval depressed
form, and often coriaceous covering of their back, but
that this part should often be divided into angular or
hexagonal plates, precisely analogous to those reptiles.
Hence the expressive name of Chelisoma, given by
Mr. Broderip to the type which represents the Cyclo-
branchia, while the back of our Chelinotus seems as
if it was entirely covered with a shell divided into regular
series of hexagonal plates. Even the shells, if such
they may be called, of the typical Tectibranchia (as
Aplysia, &c.) resemble the thin horny layers on those
of tortoises ; while the BuUcf, if they really belong to
the Cyprcea, so perfectly resemble these sea-slugs, that

CBAP. VIII.

ANALOGIES OF TECTIBRANCHIA.

237

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238 SHELLS AND SHELL-FISH. PART I.

we know not^ at present, the limits between the two.
We could extend these analogies into the vertebrated
animals ; for they are not only manifested among the
reptiles by the Clielonides or turtles, but by the arma-
dillos, in the order of ruminating quadrupeds, the Cas-
sidcB, or tortoise beetles, among the coleopterous insects ;
and, in short, throughout the whole animal kingdom.

(219.) Leaving, therefore, the true affinities of the
Sigareti of authors undetermined, we may proceed to
the genus d'epidula as the last we place in the present
family. \^e know not by what form, if any, it is con-
nected to Chelinotus, but its affinity on one side to Na-
vicella, and consequently to the nerits, has been long ad-
mitted ; while to Haliotis it is as obviously connected by
means of Crep, aculeata, and such other ear- shaped spe-
cies as have defined spiral whorls placed on one side of
the shell, as in the HaliotidcB. Hence it follows that Cre-
pidida stands at one side of the circle of the Haliotidce,
connecting them with the Naticidce, and Cnlyptrcea at the
other, connecting them with the Trochidcs ; it .'follows,
therefore, that they cannot be united by affilnity, except
indeed on our theory, that the three aberrant groups
always form a circle of their own.

(220.) Our fifth and last family is that of the
JVaticidcB, or nerits, consisting of those genera whose in-
habitants are not furnished, like the Turbidce,y,viih a pro-
boscis-formed mouth, and eyes placed upon their antennae,
but whose mouth is like that of the generality of shell-
fish belonging to this tribe, and whose eyes, where they
exist, are at the base of their tentacula. The animal of
one of the typical Naticidce has been beautifully drawn
by Guilding, and is here copied (Jig. 43.) ; it is a most
extraordinary looking creature. The whole family differs
from the Trochidce, moreover, in having no lateral fila-
ments; and in the form of their lips, eyes, &c. ; and from
the HaliotidcB, in all that respects the animals, as well as
their shell. For reasons, however, which we have just
before this detailed, this is the only family whose analysis
we find it impossible to complete ; this originates in the

CHAP. VIII.

THE NATICID.E, OR NERITS.

239

incertitude regarding the many earlike shells belonging
or related to the genus Sigaretus of authors^ but of whose
animals we know little or nothing. The reader will,
therefore, understand that the only groups we consider
to be natural in the following arrangement, are those of
the NeritincB and the NaticincE; the three others being
merely conjectural. If the animal of Cuvier's Sigaretus
is like that of De Blainville's, we should thus refer it to
the group which contains Chelinotus ; but we strongly
suspect that the shells of the Sigareti figured by Sowerby*
all belong to, and form the typical group of, the present
family : Lamarck's Natica constitutes the second ; and
the Linnaean nerits the third : the other two may pro-
bably be represented by the CryptostonifV of Blainville
and Quoy ; and the fifth, which forms the passage to the
TurhidcB, either by Lacuna, Turton, or more probably
by such long-spired types as Truncatella, Lowe. Of all
these, as shells, it may be said generally, that they are
globose and turbinate ; the spire being always very slightly
developed, the aperture large and semilunar, and the
operculum, where it exists, either shelly or horny. They
are moderate-sized shells, mostly marine, and are never
perlaceous. In the NeritincE, which approach nearest
to the Haliotida, the spire is sometimes nearly or quite
obsolete ; but in the NaticincB it is more developed and
ventricose. The JVerilincs, by the teeth on their pillar,
and excessively short spire, represent the Volutidce ; and
Cryptostoma, the Limacince, or terrestrial slugs. What

* Genera of Shells.

240

SHELLS AND SHELL-FISH.

PART I.

the shells of these latter really are, we know not ; but we
have two, very thin and hardly opaque, which, judging
from his figures, we suspect are of Quoy's Cryptostoma :
they are as brittle as those of Vitrina, but are of that
semitransparent whiteness which shows they must be
internal shells, and they have no sculpture whatever.
As to the Sigaretus cancellatus of Lamarck, it is mani-
fest nothing can be advanced beyond mere conjecture
until the animal is known. Of all these, therefore, the
NaticincB and the Neritince are the only sub-families
which can safely be relied upon as unquestionable ; yet
even their genera cannot be demonstrated with that pre-
cision that could be wished.

(221.) The intimate connection between this family
and the Turhidce is too evident to require any demon-
stration. Thus, then, do we return to the latter group,
and the great circle of the phytophagous Gasteropoda is
rendered complete. On looking to its component parts
or families, and to those of the zoophagous or carnivo-
rous tribe, we find them representing each other in this
manner : —

Analogies of the Phytophagous and Carnivorous

Gasteropoda.

Families of the
Phytophaga.

Helicid*;.
Trochidje.

Haliotid^.

Naticid^.

TuRBIDIDjE.

■1

Analogies.

Typical of their respective tribes.

Sub-typical.

Tentacula very short, sessile;
shell with the body-whorl ex-
cessively large; the spire very!
short, and scarcely raised.

Animal, when crawling, larger"
than its shell, which is smooth, (
and generally polished; spire (
nearly or quite obsolete.

Animal with a proboscis-formed")
mouth, and a resj>iratory si- f
phon; eyes placed on the sides 1
of the tentacula. j

Families of the
Zoophaga.

MURICID^
TURBlNELLIDi;.

V0LUTID;E.

CypRJiiD^.

Strombid*.

There is every reason to suppose, from the three last
analogies, that the two first will rest also upon the struc-
ture of the animals, and not upon their shells ; but it un-
luckily happens we are totally ignorant of that inhabiting

CHAF. IX. SCUTIBRANCniA^ OR LIMPETS. 241

the typical Turhinellidce, so that it is impossible to de-
termine what are its relations to the TrocMdce. In the
present state of malacology, our only surprise should be
that so much may be effected, and so many land-marks
planted, with such very scanty materials.

CHAP. IX.

ON THE ABERRANT TRIBES OF THE GASTEROPODA, NAMELY,

THE SCUTIBRANCHIA, OR LIMPETS ; THE CYCLOBRANCHIA, OR
CHITONS ; AND THE PTEROPODA, OR CRYSTAL-SHELLS.

(222.) The immense superiority in extent and multi-
plicity of types, which the phytophagous and carnivorous
gastropods possess over all the other Testacea, not to
mention the superior interest attached to them by con-
chologists and collectors, have induced us to devote the
greater part of our volume to their illustration. Our
space being limited, we have therefore no other resource
but to abridge our remaining survey as much as possible.
(223.) The first of our aberrant tribes is composed
of the ScuTiBRANCHiA, Or limpets ; in extent, it is little
larger than one of the least families of the spiral shell-
fish: they may be almost termed sedentary or fixed ; for
although some have the power of locomotion, it is so
limited that their shell often assumes the contour of the
spot where they have remained. In the arrangement of
their branchia, and the form of their bodies, they may
almost be called testaceous DoridtE, at least so far as the
typical species are concerned. The passage to this tribe,
from the Haliotidcp, or ear-shells, is rendered perfectly
easy and natural, whether we regard the want of a spire in
Crepidulaor the patelliform shape oi Calijptrcea. We have
now arrived at the last division of univalve shells, where
the structure is so simple that the sheUy part of these

B

24-2 SHELLS AND SHELL-FISH. PART I.

animals merely consists of a cup-shaped protection, with-
out the least vestige of a spire, a whorl, or any internal
support. The peculiarities of the animals have already
been stated, and as those of the shells will be subsequently
defined, Ave may at once proceed to a short statement
of their relations and analogies. The whole are consti-
tuted of the following divisions, which may be termed
genera. 1. Fiss urella, h&\mg an oval perforation on
the apex or summit of the shell. 2. Emarginula, where
the perforation is a narrow slit. 3. Hipponyx, with the
shell entire, but reposing on a spurious flattened valve.
4. Pedicularia, an entirely new genus. And, 5. Patella,
having a simple cup-shaped shell, without any aperture
or basal support. The three last are sedentary, and
constitute the aberrant genera, the two former being the
typical. A very rapid survey of these groups is all that
we can give to them.

(224.) The genus Fissurella has the perforation on
the top of the shell very much resembling a keyhole.
This aperture is for the purposes of respiration, as the
water thus communicates to the branchial cavity, which
is placed, something like that of Doris, on the fore part
of the back. The eyes, the mouth, and tentacula are
very like those of the Haliotidce ; and the margin of the
foot is also edged with short filaments. The shell, ac-
cording to Cuvier and Lesson, is placed in the middle
of the back, but does not cover it ; so that we can scarcely
suppose it is fixed to rocks, like the limpets. The mus-
cular impressions in some of these shells, joined to their
outward differences, intimate the existence of sub-genera,
some of which we have ventured to characterise ; Ave
should not, perhaps, have done this, as the species are so
few, had not most of those in the adjoining genus been
already named.

(225.) The Emarginula, from the very slight notice
given of them by Cuvier, do not appear to differ more in
their animal, than iii their shell, from the last. This
difference, hoAv-ver, is quite sufficient to constitute them
a genus. Thj aperture in the shell (which is more

CHAP. IX. SCUTIBRANCaiA, OR LIMPETS. 243

conic) is not oval, but forms a very narrow slit or cleft,
the position of which indicates the particular situation
of the branchial cavity. In the typical species, this slit
is at the base ; in the sub-genus Cemaria Leach, it is
in the apex ; while in Rimiila it is central between the
apex and the margin. The most aberrant type is Par-
mophoriis, where, as in all the tectibranchial types, the
animal is much larger than the shell, which thus be-
comes partly internal ; hence there is only a slight
emargination on the margin. Our new sub-genus He-
mitonia opens the passage between this and Emarginula ;
and thus the whole form a circle. The animal, like that
of Fissurella, has the margin of the foot fringed with
filaments, and the eyes pedunculated, but at the base of
the tentacula. Cuvier says the mantle envelopes and
covers a great part of the shell ; and this is shown by
Riippell to be the case also in Parmophorus, but to a
greater extent.

(226.) HippoNYx is one of the most remarkable of
the patelliform shells : it is cup-shaped, like Emar
ginida, but has no fissure : it may be almost termed a
bivalve, since it forms a flat, thin, calcareous plate, which
covers that part of the rock on which the upper valve,
or true shell, reposes ; this latter so much resembles a
limpet, that it can only be known by its horseshoe
muscular impression : the common species are small,
and generally whitish. The animal figured by Mr.
Quoy has the mouth shaped like a short proboscis, to-
tally different from that of the Trochidce, near to which
some authors approximate it ; the mantle is not fringed,
and the eyes and tentacula are like those of Einarginula.
Several recent species from warm countries are now
known, and a few fossil ones. The sub-genus Capulis,
which has not this basal valve, seems to connect Hip-
ponyx with Emarginula, — which latter it resembles in
the cup-shaped form of its shell. The analogy of this
genus, in their shells, to the bivalve Branchiopoda, is
particularly remarkable.

(227.) The genus Patella stands at the opposite

B 2

244 SHELLS AND SHELL-FISH. PART I.

side of the circle we are now tracing, and consists of all
those simple cup-shaped shells which have a defined apex
or top, but without any basal or internal support. They
adhere to rocks, and by their broad and fleshy foot retain
such a firm hold as not to be separated without great
art or violence. The animal very much resembles that
oi Hipponyx ; for Cuvier says it has a short and thick
snout, two distinct and pointed tentacula, and the eyes
placed at the base. The most important sub-genus
yet determined is Siphonana Sow., which, with that
inconsistency and violation of all natural affinities which
pervades the greater part of this class, as exhibited in
the Regne Animal, is actually placed in a different order,
between Calyptrcea and Sigaretus ! Every one accus-
tomed to contemplate the beautiful order and gradation
of nature, must be shocked at such a violation of natural
affinity as this arrangement exhibits. It is the more
inexcusable, because it is neither sanctioned by any re-
semblance whatever between the shells or their animals
of the genera thus confusedly mixed. Slphonaria, in
short, is that link which connects the Scutihrunchia
with the Cyclobranchia ; for, like these latter, according to
Cuvier's own showing, " the tentacula seem to be want-
ing, the head being merely furnished with a narrow
veil ;" so that, if these organs really exist, they must be
but mere vestiges. Here, then, is probably the last
form of the Scutihranchia ; and it occurs exactly at that
point of the circle which, from theory, could be next to
the Cyclobranchia.

(228.) But there is yet another form to be added :
this is our new genus Pedicularia (^(jt. 44.), which
appears never to have been described by any writer. In
its somewhat patelliform shape it resembles a Patella ;
yet, although always oval, its form is irregular, since
its circumference is adapted to the inequalities of the
substance to which the animal adheres : hence, to an
inexperienced eye, the margin would appear broken : its
substance, however, is strong, like that of a Hip-
ponyx, from which and from Patella it essentially

CHAP. IX. SCUTIBRANCHlAj OR LIMPETS.

245

differs in having a callous prominent rim placed longi-
tudinally on one side only of the inner surface, and

to which the principal muscle is pro-
bably attached : there is no regular
apex, but merely a rudimentary indi-
cation of one, — one side of the shell
being more gibbous than the other ;
so that, if this faint indication of a vo-
lution had formed an apex, it would
have been longitudinal, or on the late-
ral sides of the shell, — and not central, as in Patella. The
annexed figures will illustrate this description, and show
the irregularity of form in one and the same species. We
found all these adhering to coral fished up on the coast of
Sicily, so far back as 1 807 ', and a few specimens, if we
mistake not, were given to our friend Dr. Leach, for the
British Museum. It is perfectly analogous to the parasitic
genus Coccus among insects; and, indeed, much more
resembles them, or the internal shell of some unknown
tectibranchian moUusk, than any thing else. An approxi-
mation is made to this genus by certain small limpets,
whose apex, from being lateral, makes them also inequi-
lateral shells : of course, we know nothing of the animal ;
but, from the nature of the shell, it must be perfectly
sedentary, as it embraced the coral most closely.

(229.) The Cyclobranchia, or Chitones, are known
at once by their shells. They differ from all the gastro-
pods yet noticed *, in being quite destitute of tentacula,
— these organs being supplied by a membranaceous veil
round the mouth : the mantle, also, unlike that of the
Patellce, is always exposed, and forms the circumference
of that part by which the animal adheres : it is therefore
externally coriaceous, and is covered for its protection
by minute scales resembling shagreen, and often with
spines or setaceous hairs ; and on each side, underneath,
are the lamellar branchia : this arrangement of the or-
gans of breathing gives the name to the tribe. The

* Except Herpa among the Limachue, which is the cyclobranchian type
of the HelicidiE.

B 3

246 SHELLS AND SHELL-FISH, PART I.

testaceous part of the animal consists of a row of sym-
metrical scales^ generally imbricate, or reposing on each
other transversely along the middle of the back ; but
sometimes_, as in Chitonellus, these valves are widely
separated. The only naturalist who has effectually in-
vestigated these shell-fish, is our late regretted friend
Guilding ; and to his admirable paper upon them, we
are indebted both for their natural arrangement, and the
following notes on their manners when living : — "These
animals frequent the rocks and stones of the sea coast,
and are distributed nearly over the whole globe. Many
species are constantly under water ; while others ascend
even above high water mark, spending the day exposed
to the hottest sun, or resting in spots occasionally
moistened by the rude and restless surf. In Chitonellus
and Cryptoconchus, there are certain minute organs on
the zone, which bear a strong resemblance to the spi-
racula of annulose animals. They seem to feed en-
tirely by night. Though they remain stationary during
the day, yet when disturbed they will often creep away
with a slow and equal pace ; sometimes sliding sideways,
and creeping under rocks or stones for concealment.
If accidentally reversed, they soon recover their posi-
tion by violently contorting and undulating; and for
defence, they sometimes roll themselves up, like the
woodlice."* Although only two or three small species
are found in Europe, there are numerous large ones
from the tropical latitudes, particularly the coasts of
Chili and Peru.

(230.) The Tectibranchia constitute the last group
in our arrangement of the Gasteropoda. In it we in-
clude all those naked testaceous mollusks, whose shell,
when it exists, is either rudimentary or partly con-
cealed by the lobes of the mantle; and whose branchia,
in the form of leaves, are arranged either on one or
both sides of the body, or on the back, but in all cases
concealed or covered either by the edge of the mantle
or by a thin shell. We do not think that these animals

* Zoological Journal, v. 29.

CHAP. IX. CYCLOBRANCHIA. TECTIBRANCHIA. 247

have any degree of affinity with the IVudibranchia,
whose gills are invariably exposed, and arranged sym-
metrically. All are marine, and crawl on their belly ;
but the major part, from having the lobes of the mantle
dilated, are likewise capable of swimming. Nevertheless,
they are thick, unsightly creatures, — resembling, when
caught, shapeless lumps of flesh ; for the tentacula,
where they exist, are short ; the shell (if present) is
hid in the mantle ; and it is difficult to know, at first, at
which extremity the head is placed. They cannot be
preserved effectually in spirits ; but by being placed in
sea water, when first caught, they soon begin to crawl,
and exhibit their true form. The annexed sketch of our
Aplysia Sicula {Jig. 45.), taken from the living animal.

wiU give a good idea of that genus : it has the power,
like many other species, of emitting a copious black or
purple fluid when caught, like some of their prototypes
the Cephalopoda, for the purpose of discolouring the
water, and eluding their enemies.

(231.) The Tectibbanchia, even from the little
yet known of them, appear to form a most natural
group, in which the circular succession of the five
types, and the analogies they bear to the conterminous
tribes, may be distinctly traced. The variation in the
form and position of the branchia, although quite in-
sufficient to remove the aberrant types from Aplysia, is
yet of much importance in determining the primary
divisions. Thus, in the Bullince and the Aplysiance, the

H. 4

248 SHELLS AND SHELL-FISH. PART I.

gills are on the back, with long pectinations on one
side : in the first they are covered by an oviform shell,
and in the latter by a convex plate, resembling half a
bivalve. In the three aberrant divisions, however, the
branchia are lateral. Phyllidea has them on both sides ;
Pleurobranchus and Gasteropteron, on the right only ;
and, as Cuvier says that this latter genus " appears to
be an Akera with the foot developed into broad wings,"
we consequently return again to the Bullince. If we
look, on the other hand, to the presence or absence of
the testaceous covering, the same circular course of the
groups can be demonstrated. The pre-eminent type,
seen in the genus Bulla, has the shell so perfect as
sometimes to be capable of receiving the greater part of
the animal, and it is always more or less convolute. In
the sea hares or Aphysiance, however, it is a mere ru-
diment, like one half of a bivalve shell; while in the
three aberrant types, even this vestige is totally wanting.
Some of Cuvier's genus Akera, he observes, have no
shell whatever, or only a vestige of one, yet with the
mantle of Bulla ; and as he insists, in another place, on
this genus being the closest to Gasferopteron, we come
to the same results as by studying the variation of the
branchia. The argumentum ad verecundiam may thus
be advantageously employed, though we generally prefer
resting our theory on the simple facts brought before
the reader.

(232.) And yet, although there is evidently a cir-
cular disposition among the Tecti branchia, and a strong
affinity to the Cyclohraiichia on one side, and to the
Pte?'opoda on the other, their affinity with the Gas-
teropoda is not so evident, — at least, if we consider the
BullcB as standing at the head of the tribe. This
point, however, cannot be well decided, until we know
the animals of such shells as Bulla 7^aucum, Aplustra
pulchella* , Sec. There can be no doubt, that between an
animal which can recede entirely within its shell, and one
which envelopes it (as Akera, &c.), there must be many

* Bulla aplustrc Linn.

CHAP. IX. TECTIBRANCHIA. 24<9

essential differences. Lamarck has judiciously sepa-
rated these into two groups^ to the first only of which
he retains the old name of Bulla : some of these may,
possibly, be connected to the aberrant VolutidiE ; while
others, by uniting with Akera, will open a passage to
the Cephalapoda by means of G aster opteron. At all
events, the situation of the Tectibranchia is clearly
intermediate between the Gasteropoda and the Ce-
phalopoda,

(233.) The Phyllidin^e, as Lamarck has already
shown, evidently connects the Cyclohranchia to the
Aplysia, or sea-hares ; hence its general form is that of
a Chiton, being oblong oval, but without any testaceous
covering. The mantle does not appear divided, but
covers the back like a shell, and is usually of a strong
coriaceous substance : there are two small tentacula,
shaped as in Doris, on the upper surface ; and two
others, still smaller, beneath, on the sides of the mouth,
which Cuvier says "is a small proboscis;" but this
does not appear in Riippell's figure of P. pustulosa * ,
which was taken from the life. The branchia are in the
form of two long leaves or pectinated processes, placed
on each side of the body, under the edge of the mantle,
for its whole length. The anus is on the hind part,
and the genital orifice forward, under the right side.
In the sub-genus Diphyllidea, the branchia are the
same; but the anterior part is more narrowed, and the
second pair of tentacula are reduced to tubercles.
These animals are not numerous, and are almost con-
fined to the Eastern Ocean.

(234.) In Aplysia t, the typical characters already
mentioned begin to appear. These animals have the
appearance of a neck. The upper tentacula are shaped
exactly like those of a hare, whence the common name
of Sea-hares, given to these animals in most countries

* Ruppell, Atlas i. pi. 11. fig. 1.

t A very costly work by M. Sander Rang and DeF^rus.sac on this group
has been published ; but, as it is out of the reach of ordinary naturalists, we
do not possess it, and therefore cannot consult it. This is one out of the
numerous evils of these ouvrages de luxe.

250 SHELLS AND SHELL-FISH. PART I.

by the fishermen. The head and lips are much like those
of a slug ; and the lower tentaeula, which are flattened,
are small, and placed on the edge of the lower lip_,
while the eyes are situated above them ; the branchia
are composed of complicated lamellae, placed on the
back, but covered by a small membraneous mantle, in
which is a thin, convex, and horny plate, hardly to be
called a shell, since it more resembles an operculum.
The edges of the foot, which is enormous, forms around
it a prominent margin or crest, so dilated that they can
be thrown over the back, just like the mantle of the
cowries and the Bullce ; and with these processes the
animal occasionally swims. " An enormous mem-
braneous crop," observes Cuvier, " leads to a muscular
gizzard, armed internally with cartilaginous and pyra-
midical processes, which is followed by a third stomach,
provided with sharp hooks ; and this again by a fourth,
in the form of a ccecum." These animals appear to
feed only on sea-weed, and are oviparous. Such are
the characters of the typical Aplysiance, but there are
several exceptions. In the genus Aplysia Linn., the
body is excessively thick, and the lobes so large that
they can be used for swimming : but in T/iallepus*
Sw., the form is much more slender, the lobes shorter,
" the eyes not visible," and the lower pair of tentacula
wanting. Dolabella, according to the published figures,
is pear-shaped ; the broadest part, which is rounded,
being posterior, where there is an oblique disk, and a
hatchet-shaped shell which covers the branchia. The
next genus, Bursatella, is still shorter, so as to become
nearly globular ; and the edges of the mantle are united
over the back, so that there is merely a passage for the
water to pass to the gills. The fifth genus, Notarchus,

* Thalleptis ornatus Sw. A most beautiful figure of a species to which
I give this name, is among Guilding's drawings, but without any descrip-
tion ; it was evidently finished from the living animal. Thegeneral colour
is sea green, covered with minute black and white dots ; the edges or crests
of the reflected mantle have a brosd edging of the richest orange, bordered
on their outer edge with a line of deep black ; the tentacida are also
orange, and formed like those of Ap/t/si'a. Total length about Sh in. The
only memorandum on the drawing is, " eyes not visible :" whether this had
any covering over the branchia I have no means of judging.

CHAP. IX.

APLYSIA. BULLA.

251

closely resembles the last in its mantle, but is remark-
able for the body being beset with large, flat, irregular-
shaped and palmated membranes, as if it was overgrown
by sea weeds ; the tentacula are only two, and these
also are covered with similar processes as long as them-
selves ; there is no shell ; and the mouth, resembling a
small longitudinal slit, is placed beneath.* We have,
no doubt that all these, hereafter, will be found to con-
tain sub-genera, some of which we may subsequently
characterise.

(235.) In regard to the Bulling, we have already

stated our difficulties, as they
now stand in Lamarck's and
Cuvier's arrangements. Some
have external, some internal,
shells, thin or strong, horny or
calcareous, coloured or hyaline ;
in all these, however, the ovi-
form or bulla-shape is uniformly
preserved. The annexed cut
from Guilding's drawings of a
species allied to B. aperta, will
show how nearly the animal is
related to the AplysiancB, while
it gives a correct idea of the
general character of such types
as have their shell concealed.
In the genus Doridium f of Mecken, the shell almost
disappears ; according to M. Rang ^ , the two lateral lobes
of the animal are so much developed that they can be
used as fins. Many of the BiiUinee have the gizzard
composed of bonv pieces ; the tentacula assume the ap-
pearance of large, fleshy, angulated processes, under
which are very minute sessile eyes.

* See Riippell's admirable figure of jVo/arcAM5Mc/w/c/ws, Atlas, i. pi. 7.
fig. 2.

f Akera Cuv.

t Manuel de L' Hist. Nat. des MoHusques, p. 146. The reader will find
a great deal of original and valuable information in this unpretending but
excellent little volume.

252 SHELLS AND SHELL-FISH. PART I.

{9,36.) The two next types are Gasteropteron and
Pleiirohranclms. The first is a most interesting form,
since it connects the tribe with the Cephalopoda. Cu-
vier, however, with his usual infelicity (wherever na-
tural affinities are concerned), simply remarks, that it
" appears to be an Akera, the margin of whose foot is
developed into broad wings for swimming, which it per-
forms on its back. It has no shell or stony armature to
the stomach ; a slight fold of the skin is the only ves-
tige of a branchial operculum that is visible." * A much
better account, however, is given by M. Rang f, who ob-
serves, that this '' highly interesting " animal was first
made known by M. Delia Chiaje, the learned anatomist
of Naples, who considers it so clearly a Fteropoda, that
he has named it Clio Amati.

(237-) The last genus, or rather sub-family, is the
PLEUROBRANCHiNiE, distinguished from all others by
their broad, flattened, and oval bodies ; but especially by
the feather-like structure of their gills, which are placed
on the right side of the body, j ust under the edge of the
mantle. Here, again, we recognise the cheloniform type
so frequently developed among the Testacea, and of which
Chelisoma, Chelinotus, Parmophorus, Chiton, &c. are
such striking examples. The bodies of aU the animals
now before us are shaped like those of tortoises ; and in
some, as Pleurohranchus Cuv., this resemblance is car-
ried so far, that the foot represents the under plate of
those reptiles ; so that, to use the words of Cuvier, " the
body is equally overlapped by the mantle and by the
foot, as if it were between two shields." The mantle,
in some genera, contains a calcareous plate, which in
Lamarck's Umbrella is so very large and strong as to
resemble a limpet, but is immediately known by the
sharp edge of its circumference. The idea that this shell
could by any possibility have ever been nntundlii attached
to Xhe foot of the animal (whence the name Gastroplax),
is too preposterous to require further notice. Vie here

♦ Griff. Cuv. xii. 46. f Rang, Manuel, p. 148.

CHAP. X, BIVALVE SHELL-FISH GENERALLY. 253

close our survey of the TectihrancMa, and with it the
whole of the pre-eminently typical Testacea. The
little space now left_, will therefore be devoted to the sub-
typical order.

CHAP. X.

ON THE ORDER DITHYRA, OR BIVALVE SHELLS. THE AFFINITIES

AND ANALOGIES OF THE UNIONID^, OR RIVER UNIOS.

(238.) Our survey of the gastropod shell-fish has so
much exceeded the limits we originally intended, that
we can do little more than bestow a hasty glance en the
remaining Testacea. Comparatively so few of the forms
among the Gasteropoda had been defined by our pre-
decessors, that it was absolutely necessary to treat that
order in much detail : but this is not t'le case with the
DiTHYRA ; nearly the whole of the genera and sub-genera
have been defined; with the single exception of thellNio-
NiD^, to the illustration of which we have consequently
devoted the greatest part of this chapter. A few remarks
on the remaining families, with an exposition of their
analogies, is all that our space will admit. We could,
indeed, have easily made this single order alone the sub-
ject of another volume; but as nearly all the genera may
be said to be established, and their technical distinctions
are given in the systematic arrangement, the reader must
be satisfied with the results rather than with the detaih
of our analysis.

(239.) The DiTHYRA *, or bivalve shell-fish, are ani-
mals whose general structure resembles that of the oyster.
They are without any distinct head, and are inclosed in
two shelly valves, which, by means of certain muscles

* Comprising the first order of Cuvier's Acephala, the seventh order of
his Gasteropoda, and the fifth class of his MoUusca.

254 SHELLS AND SHELL-FISH. PART 1.

running through the body, and of a cartilaginous hga-
ment, can be opened and shut like the covers of a book.
Upon opening these, the mantle is seen to form a thin
covering over all the interior surface of the shell ; upon
this being raised, four thin lobes, much smaller, will be
discerned, called by Cuvier the " branchial leaflets ;"
these, again, envelope the internal parts, as the heart,
foot, &c. " On the sides of the mouth are four trian-
gular leaflets," which, according to Cuvier, '' are the
extremities of the two lips, and serve as tentacula ;" the
foot is a mere fleshy mass, and is moved about '^'^by a me-
chanism analogous to that of the tongue in quadrupeds."
The animal is attached to its shell either by a strong cen-
tral muscle, as in the oyster; or by two transverse ones,
which cross from one to the other valve, and leave round-
ish indentations, generally called muscular impressions.
These muscles, however, are of secondary importance,
when compared to the remarkable modifications of the
animal. In the most typical Ditliijra, form.ing our
Macrotrachia, the mantle is so united and prolonged
as to form one or two long siphons or tubes by which the
food is imbibed; while in the next tribe, Atrachia, these
siphons are entirely wanting. The latter animals are
also distinguished by a considerable number of the genera
having the power of forming a bunch of cartilaginous
threads called a hyssus, which they protrude from a small
opening between the valves, for the purpose of affixing
themselves to marine substances : the whole are herma-
phrodites. Such are the two chief or typical tribes of
the Dithyra. The three which are aberrant, lose several
of these characters, and possess others. In the Tubuli-
branchia, which connect the Dithyra and the Gastero-
poda, the structure of the animal is a singular compound
of both tribes ; while its tubular shell reminds us of a
Teredo fixed on other substances externally instead of
internally. The Cheliosomid^, instead of a testaceous,
has a coriaceous covering, analogous to the chitons and
the tortoises; while the Branciiiopoda, although bivalve
shells, are attached by a fleshy peduncle or a strong liga-

CHAP. X.

DITHYRA.

ANALOGIES.

255

ment, which passes through the apex or summit of one
of the valves : ^' hke the other bivalves/' as Cuvier ob-
serves, " they have a bilobed mantle, which," as in the
oysters, " is always open : instead of feet, they have two
fleshy arms, furnished with numerous filaments, which
are protruded or withdrawn at pleasure." Nearly all of
them possess (like their prototypes, the Cephalopoda and
the Tectibranchia) an internal bony support, which in
these consists of a sort of framework closely resembling
an internal skeleton, and rather complicated. Although
innumerable fossil shells of the Branchiopoda abound in
the older formations, very few occur in a recent state.
Our arrangement of the entire order will thus be in the
following tribes: — 1. The Macrotrachia, where there
are either one or two siphons ; 2. The Atrachia, hav-
ing none ; S. The Tubulibranchia, or tubular shell-
fish, having an indistinct head, and an operculum to
their shell ; 4. The Cheliosomid^, with a cartilaginous
covering and two orifices; and, 5. The Branchiopoda,
or anomian bivalves. The whole of these, it will now
appear, have their prototypes in the Gasteropoda,

Analogies of the Orders Dithyra and the Gasteropoda.

Tribes of the
Bithyra.

Macrotrachia.

Atrachia.
Branchiopoua.

Cheliosomid^.
Tubulibranchia.

Analogies,

r Animal with the mantle formed'^
\ into an elongated siphon, sim- >
C pie or double. J

Mantle free, and without a siphon.
C Reciprocally representing the Ce- 1
X pkalopoda. J

rBody cheloniform, oval, covered'^
■< with testaceous or coriaceous >
C. plates. 3

Animal of the gastropod .struc-
ture, furnished with an obtuse
head.

Tribes of the
Gasteropoda. ]

zoophaga.

Phytophaga.
Tectibranchia.

Cyclobranchia.
Scutibranchia.

This table is important, were it only to prove that
the usual divisions of the more typical bivalves accord-
ing to the number of their muscles, whether one or
two, is not a natural arrangement ; because it destroys

256

SHELLS AND SHELL-FISH. PART I.

the beautiful analogy which is found to exist in the
two typical tribes of the Dithyra and the Gasteropoda,
and is not borne out by the details of their analysis.

(240.) The Macrotrachia and the Atrachia com-
prise by far the greater number, and the most perfect,
of all the bivalves : and that they each form a circular
group, will be apparent from the following consider-
ations. The Macrotrachia may be said to have their
first developement in the family oi PhoUdcp, — several
of which, as Teredo, Clavagella, &c,, assume the form
of the Tahulihranchia. By means of Pholas and its
sub-genera, there is a direct passage to the Myad^
through Solen : these semitubular shells are succeeded
by Mya and Mactra, where all appearance of the
gaping peculiarity of the Myadce ceases. Vi,^e enter
the Tellinidce by means of the river genera allied to
Cyclas; and thus, through Venus, reach the TeJMncp,
where the two siphons of the animal are of enormous
length. Cardissa Sw. and Pleurorynchus of Phillips
open the passage to the Chamid^, where we see the
siphons much reduced, and almost obsolete in Hippopus
and Tridacna. The aberrant genera of Cardita and
Chama unite with Cypricardia, and lead to the perfo-
rating family of the Saxicavid^, into which also
enter Petricola, Saxicava, Coralophaga, and Thracia.
Finally, all these are as evidently connected to Gale-
omma, as Galeomma is to Gastrochina. Thus we
again arrive among the Pholadcp, and the circle of
the Macrotrachia is closed.

(241.) The course of the Atrachia is precisely
similar. Cuvier has already pointed out the connection
of the ChamidcE to the Unionidcp; while the genus
Iridina in the latter, and Nucula in the Arcadje, show
that the two families follow each other. The passage
from these to the AvicuLin^ is still more perfect,upon
looking to the genera Byssourca and Mod'wla: then
follow Crenatula, Malleus, Avicula, and Pinna, which,
uniting to Modlolii, completes this group. Avicula
opens the passag? to the Ostreid.*;, which are entered

CHAP. X. MACROTRACHIA AND ATRACHIA. 257

by means of Lima and Pecten. Finally, in order to
close this circle, we have the Etherid^, which, with
Mulleria, " is remarkable as a group possessing in
itself both the character of being intermediate between
Etheria and Ostrea, and as apparently connecting the
regular freshwater bivalves with the regular marine
bivalves, as Ostrea.* The sinus at the posterior ex-
tremity of the hgament of 3fuUeria resembles the
Unionidce and the Etheria; while in its single mus-
cular impression, as well as its general form, it ap-
proaches to Ostrea." This obvious affinity at once
closes the circle of the Atrachia, by the series re-
turning to the Unionidcp. The following table will
consequently exhibit the mutual relations of both these
tribes: —

Analogies of the Macrotrachia and the Atrachia.

Families of the A„r,JnaiPi Families of the

Macrotrachice. Analogies. Atrachia.

rrr^.^.^r.r.^ fShells veiv compact, the valves 7 .

Tellimd/e. ^ ^1^3^^ 0- F > j Arcaid^e.

Mtad^. Valves gaping at one extremity. Aviculid^.

TJ„^r.T>™, C Animals affixed to, or living with- > ^

Pholid^. ] in, other substances. j Ostreid^.

SAXiCAViDiE. Shells irregular, without teeth. Etherid^.

^ r Lateral teeth long, linear, only on 7 r^

Chamid^. J one side of the bosses. j I^nionid^.

(242.) It will be seen, by the subsequent arrangement
of the genera, that they follow each other precisely in the
same way, so as to represent the families. To follow
out this exposition, however, in the present tribe, as
we have already done in that of the Gasteropoda, is
manifestly impossible ; but, as we state this fact as the
result of a careful analysis of the whole, the reader,
knowing the general principle, may apply it to any
particular group, whose analogies he wishes to trace.
As we shall enter into a full investigation of the Unio-
nidce, or river pearl-shells, our remaining space will

* Sowerby's Genera of Shells, art. Mulleria.

258 SHELLS AND SHELL-FISH. PART I.

barely be sufficient for a few general remarks on the
other families ; and these will be confined to the forms
most characteristic of the primary types of bivalves.

(243.) The Tuhulihranchia, or tubular tribe, may
be traced in almost every one of the above families :
it is shown by an unusual elongation of the shell, which
is at the same time very narrow, a ad inclined to be
cylindrical. The whole of the Solens have this
analogy, as well as the genus Anatina, in the Myadce.
Psammobia and Donax are modifications of the same ;
and so also is Cardissa: most of these also have the
anterior side remarkably short, precisely as in all the
PholadcE. Coralophaga is another example ; and it is
even apparent in one of the sub-genera of Cardium.
This type of form is equally, and even more strongly,
developed in the order Atbachia : thus, we detect it in
Jridina, Byssoarca, Lithophaga, and Avicula; all of"
which are the most elongated in general shape, and the
most abbreviated at their anterior extremity. In an-
other type, which evidently runs through the whole, it
is characterised either by the absence of all teeth to the
valves, or by there being but two, placed in the centre,
and resembling the letter V reversed. This is almost
always found in that division of a group which is most
aberrant in its own circle, as the Saxicavidce and the
EtheridcB; the Anodontince among the river bivalves ;
as well as the genera Pholadomya, Thracia, Acardo,
Loripes, Pinna, Placuna, Plicatula, Trigonia, Pan-
dora, &c. A third type of form is evidently intended
to represent the Branchiopoda ; its chief distinction
being that of having an internal cartilage — not, indeed,
protruding through an opening in the valves, but
situated between the cardinal teeth. This is well
known to be the predominant characteristic of all the
MactridcE, and of their prototypes scattered in other
groups, as Gnafhodon, Erycina, Niicula, UnguUna ,
Pecten, Pedum, &c. Now, it is a remarkable fact, that,
on comparing our analysis of the whole of these circular
groups, we almost invariably found that these three

CHAP. X. UNIONIDJS, GENERALLY. 259

types always followed each other^ and that they consti-
tuted the aberrant divisions. On looking to the typical
and the sub-typical divisions of the larger groups, we
find that the first are the most perfectly closed bivalves,
or the most highly finished and ornamented ; while the
latter seem not to have so much the power of free
motion, and usually gape a Uttle at one extremity, — a
sure sign that their inhabitants live in the ground, and
do not roam from place to place. In the tribe oiMacro-
trachia, we thus have the pre-eminent type in the
Tellinidce, and the sub-typical in the MyadcE ; the
former being represented again by the Arcidce; and the
latter by the Aviculidce. We must, however, quit this
inviting train of generalisations, and proceed at once
to the only family of the Dithyra which stands in need
of a more detailed examination.

(244.) The Unionidje, as before observed, are en-
tirely fluviatile, and are the only river shell-fish in
this tribe; except indeed the Etherirnr, by which they are
connected to the marine oysters. As they form that
particular family which unites the Atrachia to the
Macrotrachia, we naturally supposed, that when they
were better known, some trace of the siphons so cha-
racteristic of the latter tribe would be found in one of
the aberrant groups ; and in this expectation we have
not been disappointed. M. Deshayes, it appears, has
announced the fact, that the animal of Iridina pos-
sesses these tubes ; and it further appears that the major
part of the family, although really without these organs
in a permanent state, have yet the power of forming
two temporary tubes, with the posterior edge of the
mantle, which is fringed with cilia, serving to deter-
mine the direction of the water which flows into the
branchia.* Thus, whether we regard the shell or its
animal, we find that the natural station of the Unionida'
is determined by nature ; they are the last of the Atra-
chia as the ChamidcB are the first of the Macrotrachia.

* Lea's Synopsis, p. 5.

s 2

260 SHELLS AND SHELL-FISH. PART 1,

(245.) As the whole of these shell-fish are inhabit-
ants of fresh waters, and chiefly of rivers, so are they
most abundant in those countries whose lofty mountains
supply copious and never-failing supplies of their fa-
vourite element. The mighty rivers of the New "World
are no less remarkable for their innumerable rami-
fications, than for the almost endless number of these
shell-fish which live in them. The American spe-
cies, in fact, comprise more than seven tenths of the
whole number yet made known ; five or six are alone
found in Europe ; about the same number occur
in Australia, a few more in Asia, and we have as yet
seen none from Africa. Why the immense rivers of
the East should be so destitute of Unionidcp, is a ques-
tion we know not how to solve. One reason may pro-
bably be, that they have not been sufficiently examined.
Before the researches of Spix and Martins in Brazil,
scarcely five were known from South America, — so that
nearly all that they found were new, and others will no
doubt be soon brought to light. It is difficult, indeed,
to assign any reason why the tropical rivers of the New
World should not produce these shell- fish at least as
plentifully as the more temperate waters, such as the
Ohio and its tributary streams. The UnionidxB almost
always have their bosses more or less rubbed and in-
jured, occasioned by the friction of stones and other
substances carried onward by the stream. Although
generally of an olive brown colour, occasionally varied with
obscure rays on their outer surface, the interior of these
shells are often particularly brilliant, and their sub-
stance is always perlaceous. Hence they are now manu-
factured in America into pearl buttons and other orna-
ments. Ileal pearls, also, are occasionally found in some
of the species. We once took from a small specimen of
U. circulus, a beautiful little pearl, half the size of a small
pea, which is now in the possession of our friend Mrs.
Corrie of Birmingham. The Mya margurUifera Linn.,
still found in some of our own rivers, produced those
pearls for which Britain was so famous in the time of the

CHAP. X. UNIOXID^, PRIMARY CIRCLE. 26 1

Romans. Some of the American species are remarkably
thick^ particularly at their bosses, which^ in proportion as
they are rubbed, the animal thickens internally; and this
is very remarkable in old shells. In regard to the ana-
tomy of the animals, we must refer the reader to Poll's
account of the European species, and to the scattered
notices of the American in various other publications.

(246.) The natural arrangement of this family, or
rather the principle of its variation, in regard to the shell,
is precisely the same as in all the other groups of the
DiTHYRA. The most typical groups are those two
which stand between the elongated and the cuneated
types ; the most aberrant being intermediate with the
two latter, and having no teeth. The typical groups,
consequently, possess the two sorts of teeth^ cardinal and
lateral, in the highest perfection ; while, in the three
aberrant divisions, only one of these sorts is apparent,
or none. As a whole, this is the most perfect family,
perhaps, of the bivalve Testacea. Like the Psittacid<E
and the Picidce among scansorial birds, the shells of the
Unionidce have such a stamp of identity upon them,
that they cannot possibly be confounded with those of
any other family ; while their amazing diversity, on the
other hand, offers the very best facilities for determining
the natural succession of their forms. Under the beUef
that this would long ago have been done by those Ame-
rican conchologists who have especially studied this
portion of their native fauna, we suspended our labours
towards this object some years ago ; but as nothing has
yet been done to supercede our own views, they will
here be detailed with as much brevity as the subject
will admit.

(247.) Presuming that the station of the Unionid<B,
as a family, has been determined ; and that Tridin.ce,
from possessing true siphons, is that aberrant group
which comes nearest to the Chamadce in the tribe of
Macrotrachia, we thus get a sure point from which to
start : our first object is to show that the whole family
form a circular group, with no chasm, hiatus, or inter-

s 3

262 SHELLS AND SHELL-FISH. PART I.

ruption so great as to cast a doubt on the truth of this
proposition, or to admit the introduction of any shell-
fish that have been arranged in other families. On this
ground, and not for its typical perfection, we commence
our survey with Iridina, where the transverse or tubuli-
form structure of shell is so conspicuous : here the
cardinal teeth are wanting, being absorbed in one single
lateral tooth which occupies the whole length of the
hinge margin ; this lateral tooth being tuberculated or
crenated. Now, the only other examples where the car-
dinal teeth put on the aspect of lateral teeth, and are
also crenated, is in such shells as Hyria avicularis Lam.,
where, in fact, the cardinal teeth * are so far removed
towards the side as to assume the aspect of lateral teeth ;
the interval between those on the other side of the shell
being occupied by a few irregular crenations, similar to
those, in short, of Iridina : on coming to Hyria corru-
gata Lam., these crenations disappear, the cardinal teeth
assume their true position immediately under the bosses,
and the passage thus becomes opened to Lamarck's Cas-
talia. The Indian Unio corrugata Lam. then succeeds,
and from standing at the confines of Hyria, connects
that group, in conjunction with other species more elon-
gated, with Mysca ovata of Turton. This brings us at
once to the genus Unio of Lamarck, where the chain of
aflUnity passes on from Mysca nasuta Sw. to the Unio
ossidens. The pre-eminent types of the whole then
succeed, as shown in U. cuneatus and the Mytiloides of
Raf. By means of U. JEsopus, we pass to Lamarck's
sinuosa, Unio gioas Sw., and so enter Say's Alasmodon
by the well-known Unio margaritifera of Europe.
From this point even the cardinal teeth begin to dis-
appear ; for A. undulatus and calceolus bring us close to,
and rugoftus within, the confines of Anodon : all that
now remains of the teeth is a slight elevation beneath
the hinge margin, as in Dipsus Leach ; and even this
finally disappears, as in the typical anodons. Gradu-

* True cardinal teeth are placed immediately beneath the bosses, and
not on one side, as in Hyria avicularis.

CHAP. X. UNIONID^, PRIMARY CIRCLE. 26S

ally, however, the shell becomes stronger, more elon-
gated, and the hinge margin again thickened : this is
particularly observable in a species from the Nile *,
placed by some writers as an anodon, and by others as
an Iridina ; but to which it really belongs is not, at
present, material. Suffice it, that thus the series of the
Unionidoe returns into itself, and forms as perfect a
circle as any, perhaps, contained in this volume.

(248.) The proportion which the three aberrant di-
visions bear to the pre-eminently typical, is nearly the
same in this as in all natural groups of the animal
kingdom. By far the most numerous in forms and
species is the typical genus Unio, which contains, in
fact, more than all the rest put together ; the few^est,
perhaps, are in Hyria and Iridina : hence it naturally
results, that the interval between the species, in these
two latter, are wider than in the former. But these little
intervals, more or less, occur in every group in nature ;
and provided that no animals are found in other groups,
which appear to fill up these chasms, we may be quite
sure our series is correct. In the Unionidcp, this per-
plexity can never happen ; their general structure is so
peculiar, that no intervals among them can be filled up
by shell-fish of other groups : hence we may feel per-
fectly sure that the break in the line of continuity ori-
ginates either from a few links having not yet been
discovered, or that they exist only in a fossil state.
The proximity, for instance, between Iridina and Ano-
don is so close, that there is not the slightest link
wanting ; but between Iridina and Hyria the difference
is more marked. Are we, then, to conclude from this,
that these two are not also connected } Certainly not.
We know that Hyria is im.perceptibly united to Unio,
on one side ; and if, on the other, it approaches nearer
to Iridina than does any other genus, we have induc-
tive proof that they follow each other, although one or
two of the links may appear wanting.

• This may possibly be the A. rubens Lam.

s 4

264

SHELLS AND SHELL-FISH.

PART I.

(249.) The primary divisions of this family^ as we
stated some years ago, are typically represented by the
following genera: — Unio, Hyria, Iridina, Anodon of
Lamarck, and Alasmodon of Say.* Having shown that
these form a circular group, it follows, that these divi-
sions are sub-families, to which we give the usual ter-
mination in ina. Their secondary groups are conse-
quently genera, and their third are sub-genera. We shall
now take a rapid survey of each in their natural order
of succession.

(250.) The Unionin^ stand at the head of the
family ; and their typical characters may be thus briefly
stated : — The form is various, but the two cardinal
teeth t and the anterior lateral teeth are always present;
the umbones, or bosses, are sometimes wrinkled longitu-
dinally, but never sulcated transversely, — this latter
character being peculiar to Hyria. Thus detached by
the most simple and definite characters furnished by
the shell, we find the whole of the species will arrange
themselves under one or other of the following genera :
— In Unio pre-eminently so called, the umbones, or
bosses, are very large, thick, and prominent; and the car-
dinal teeth (^jig. 4?. «)
either in an obliquely
perpendicular line with
the base of the shell, or
receding in a contrary
direction, to the ante-
rior margin. The
form is various ; but
the hinge margin, al-

* Mr. Lea, in his valuable paper on Unionidce (Am. Tr.), observes that I
have stated" difficulties in adopting these genera." I am not conscious of
ever having done so, and have taken every occasion of expressing my be-
lief that they are perfectly natural. As I entirely dissent from the views
of this gentleman, both in his divisions, in his genera, and even in many of
his species, I am anxious not to be misunderstood, as having in any way
changed my opinion on this family. Mr. Lea has, however, added many
interesting and beautiful species, for which hedeserves the thanks of everj
naturalist ; we only regret that all his arrangements of them aj>pear to us so
very artificial and perplexing.

f I consider these teeth as two ; not as one, cl^t into two.

CHAP. X.

SUB-FAMILY OP UNIONIxXJE.

265

though sometimes angulated, in the most aberrant groups,
is never connate ; nor is the shape of the shell properly
cuneate. In the next genus, Mglia Sw. {h), the car-
dinal teeth are lengthened, compressed, and take a di-
rection precisely opposite to the above ; they diverge,
in fact, from the apex towards the anterior margin
instead of from it : the inner tooth is smallest, and not,
as in Unio, the largest. The shell is generally cuneate
and the bosses prominent. None of the types are con-
nate or tuberculated. In Mysca the shells are more or
less transversely elongated, much thinner, and the bosses
much smaller than in the two preceding genera; and
the cardinal teeth differ essentially from both : they are
much compressed, irregularly crenated, and placed as
nearly as possible on a parallel line with the anterior
margin; they are also sometimes so thin and slightly

divided, that they ap-
pear almost blended into
one : hence they are
rarely obtuse, nor is the
shell winged or tubercu-
lated. In Lymnadia alata
{jig. 48.), the posterior
part of the hinge margin
is greatly elevated, and
the shell is strictly con-
nate ; while in Megado-
mus, of which our M.
gigas is the type, the cardinal teeth are like those of
Unto, but there is only one lateral tooth in each valve.

(251.) To these gTOups we shall presently return ;
in the mean time it will be as well in this place to show
how perfectly they represent the five primary divisions
of the whole family. It is immaterial to our present
object, whether the genus Mysca contains a portion of
those shells we have arranged under the name of Poto-
mida, since none of these latter can be looked upon as
typical examples of Mysca.

266

SHELLS AND SHELL-FISH.

PART I.

Analogies of the Genera q/" UNiONiNi«.

Genera of the
Unionince.

Unto.
Mglia.

My sea.

Lymnadia.
Megadomus.

Analogical Characters.

Cardinal teeth thick, short
f Cardinal teeth compressed, )
I lengthened; shell cuneate. J
r Shell lengthened; cardinal teeth')
■J crenated, almost on a linewith >
t the lateral teeth. " j

f Shell thin, winged; umbones")
(_ small. 3

C Lateral teeth imperfect, one or
t none.

Types of the

Sub-families of die

Unionida.

Unio.
Hyria.

]

Iridina.

Anodon.
Alasmodox.

These analogies are very remarkable, particularly
when we confine our attention to the types of each of the
groups thus brought into comparison. Mglia ovata Sw.

(Unio ovatus of Say)
(fig.4fQ.), like Hyria, has
the cardinal teeth as-
suming the shape and
the position of lateral
teeth ; and both have
merely two or three tu-
bercles immediately be-
neath the bosses. The
elongated form of all the species of Mysca reminds us
of Iridina, no less than the crenated edge and mar-
ginal direction of the cardinal teeth, li Lymnadia, again,
had no cardinal teeth, it would be a Dipsus of Leach ;
and both these have the very aspect of Anodon. Mega-
domus is the only type in which the lateral teeth are
imperfect ; hence a truer prototype of Alasmodon,
where both those teeth are entirely wanting, could
scarcely be found ; particularly as the cardinal teeth
are precisely like those of the typical genus Unio. Our
limits, and, indeed, our materials of specific nomen-
clature *, will not permit us to analyse the whole of

♦ The specific descriptions of Lamarck are scarcely less unsatisfactory
than many of those recently published in America ; I have seen totally

CHAP. X.

UNIONIN^^ ANALOGIES.

267

these genera. Two, however, where the natural series
appear to us very strikingly marked, will be now
noticed : the first regards the sub-genera of our genus
Unio, and the circular succession of the types of form
in two of them.

(252.) The genus Unio, separated by its cardinal
teeth from tEglia, as already shown (JigAl-b), contains
five distinct types of form, which, from the multiplicity
of species, and for the greater facility of nomenclature,
we shall designate under the following sub-generic
names: — 1. Unio: the bosses or umbones prominent
and tumid, the circumference and the posterior hinge mar-
gin never angulated, and both thecardinal teeth very much
receding from the anterior margin, as in U. Mytilo'ides
Raf., and all such species or varieties. 2. Cunicula, where
the umbones are even larger, but not tumid, being, as it
were, compressed or flattened : the shell is generally
oval, or angulated at the base of the posterior side ; —
examples, C. planulata, cuneata, purpurata, Lam., &c. :
the outer cardinal tooth slightly diverges from the base

of the inner. S. Ligumia : the
form is particularly long, like
that of Iridina, the umbones
small and retuse, and the car-
dinal teeth close to the ante-
rior end ; as in U. recta Lam.
4. Theliderma : the form is
various, but the posterior hinge
margin is generally elevated
and angulated, and the outside
of the valves tuberculated or
granulated, — a character not

distinct species sent from that country, evidently labelled by the same hand,
yet bearing the same specific name. Mr. Lea's Synopsis leaves this part
of the subject almost as obsure as ever, because he merely cites the name,
without giving any reference to the works of the authors he quotes. By
his plan, as novel as it is detrimental to science and all critical inquiry,
the author (no doubt, unintentionally) imposes an effectual bar to the ve-
rification of his own nomenclature, no one here being acquainted with all
the detached papers on these shells printed in America.

268

SHELLS AND SHELL-FISH.

PART I.

found in any other of these groups* (T. metanevra
Ra.f. Jig. 50.). 5. Potomida : the shell rather short
and oval ; the umbones prominent, but not so large as
in Unio ; the outer surface smooth ; the cardinal teeth
thick, perpendicular, but the outer one diverging. These
are mostly European shells, and are represented by U. si-
niiata Lam., and our P. corrugata {fig. 51.). Between

51 these sub-genera are in-
tervening species, or
rather types of form,
which blend the whole
into a continuous chain
of affinity ; thus P. si-
nuala is so like some of
the typical Unios, that
the direction of the outer
cardinal tooth and the comparative smallness of the bosses
alone distinguish them. Leaving, however, these inter-
vening or connectant species, and looking only to the
types, we shall see by the following table that they
have a resemblance to the primary divisions of the
whole family, and to the genera of the UnionincB.

Sub-genera
of
Unio.

Unio.

Cunicula.
Ligumea.
Thelider7na.

Potomida.

Analogies of the Sub-genera of Unio.

Analogies.

Sub-families
of
Unionidce.

f Shell ovate; cardinal teeth 7 TTxr,^.„„^
I not diverging. jUNiONmiE.

f Shell more oval, wedge- 7 u,.„.„ ^
I shaped, and angulated. JH^RIN^.

Shell very much lengthened. Iridin^.
f Posterior hinge margin gene- 7 *
I rally winged. j Anodonin^.

r General form oval, oblong ; T

< cardinal teeth obtuse, di- 5- Alasmodonin.e. Megadomus.

C verging, sometimes erect. J

Genera

of

UnioninzB.

Unio.

^GLIA.

Mysca.
Lymnadia.

The analogy of the last three groups is not so satis-
factory as the others, and this excites a suspicion that

* Except U. cornuius and ^sopus. U. nodosa. Wood's Conch, nl. 22. fig.
1, 2., seems to belong to this group.

CHAP. X.

SUBGENERA OF UNIO.

^69

our Megadomus fills up the interval between such spe-
cies as Lamarck's Peruvianus and Msopus ; but this
would exclude the European Unio sinuata, littoralis,
Szc, which seem closely united to the typical or Ame-
rican group by their short, oval shape, and the thickness
of their cardinal teeth. On the other hand, we feel

persuaded ihat our Po-
tomidcB must be kept
distinct from the sub-
genus Unio; and this
will be apparent to every
one who looks to the
annexed cut of the car-
dinal teeth of Unio My-
tilo'ides (fig. 52.), and
those of Potomida corrugata (^fig 51.).

{9,5S.) Two of these sub-genera, being more than
usually perfect in their types of form, or, in other
words, in the diversity of their species, will next be
glanced at, for the purpose of showing there is but one
principle of variation throughout the entire family.
We shall first take the sub-genus Unio as here re-
stricted. The types of this are seen in those inequi-
lateral shells which have been sent to us from America,
as the U. Mytilo'ides Raf. and the undatus of Barnes.
Next follow those which are nearly round and equilateral,
such as U. Torsus Raf. Our U. truncatus, very much
elongated, is the third type of form. The fourth, which
represents Thelider'ma, is perhaps the cornutus of Barnes ;
while the fifth, which unites the last to the first type,
is an American species, formed like ohliqua Lea, but
with small scattered tubercles down the middle. * This
unites with JEsopus, and again brings us back to the
undatus. Thus, in the confines of a single sub-genus,
are types of ^glia, in U. Torsus ; Iridina, in U. trun-
catus ; Anodon, (through Theliderima), in U. nodosa ;

* I pretend not to enter upon specific names, for nearly all those which
belong to species unfigured appear to me one mass of confusion.

270

SHELLS AND SHELL-FISH.

PART I.

and probably of Alasmodon, in the species mentioned
above. We say probably, because, as there is no es-
pecial evidence to prove the fact, we only infer it from
this shell having a structure intermediate between no-
dosa and JEsopus ; hence, it occupies the same station
in its own circle, as Alasmodon does in that of the
whole family.

(254.) So astonishingly variable, however, are the
shells of this family, that we may even carry our ana-
lysis still further ; and by following the series of spe-
cies which arrange with Unio Mytilo'ides, we shall detect
the same analogies as are apparent in the last inves-
tigation. Thus, some of the species or varieties of
Mytilo'ides (as gibbosus) are almost equilateral ; others
pass into Ellipsis and sulcatus of Lea, thus assuming the
long shape of truncata and Iridina ; next follows
c/yrnutus, as a prototype of nodosa and Theliderma ;
and finally, Msopus brings us again to such shells as
U. obliqua, and the inequilateral varieties of Lea's gib-
bosus. Beyond this point, it is utterly impossible to
push analysis, except it be carried into the principle
by which the varieties of each species are regulated; and
this, we firmly believe, is in conformity with the very
same laws. We have seen, in fact, four varieties of
the Mytilo'ides, which assume four out of these primary
forms. Some are inequilateral {Jig. 53.), some trigonal,
others are oval, and another oblong : whether there is
any one with small nodules to represent cornutus and

its prototypes, we know
not, but we have no doubt
that such a variety will
be found.* Mytilo'ides,
therefore, we consider
the most typical

as

species of the whole fa-
mily, concentrating, in
its own variations, pro-

* Since writing the above, we have seen a variety of My/j7o»rf« perfectly
answering our theoretical description, in the hands of Mr. Stuchbury.

CHAP. X.

UNIONINiE. — THELODERM A.

271

totypes of all the natural divisions^ large or small, of the
Unionid^e.

(255.) The other sub-genus, which contains sec-
tional types, is Theliderma ; and this we shall now
briefly notice. It will be remembered that we have
placed this sub-genus immediately after Ligumia, the
type of which is the Unio recta of Lamarck. Nearly
all these shells have their posterior margin dilated
and angulated, and thus represent the genus Ano-
don of Lam. Although the species are remarkably va-
ried, they are all known by the external surface being
covered by numerous tubercles of different shapes, which
stud every part of the sheU. Where we find a cha-
racter, however trivial it may appear, pervading a whole
group, we may be perfectly assured that it is a natural
character, although it may not be the only one.

(256.) Now, let the conchologist place before him
the following shells (fig. 54!.); — 1. Irrorata {a); 2.

Metanevra (6); 3. Cylmdrica (c) ; 4. Pustulata*
Sw. (<Z); and, 5. Plicata (e); — and he will then have
what we consider the sectional types of Theliderma.
It is obvious that the two first have the greatest resem-
blance to each other ; both are nearly circular, and tu-
berculated ; but irrorata is not winged, like metanevra.
Now, this difference, trivial as it seems, is accompanied

• We merely use this name provisionally, until we know that by which
it has been distinguished in America,

272 SHELLS AND SHELL-FISH. PART I.

by a peculiarity in the construction of the animals^ first
ascertained, we believe, by Mr. Lea. Here, then, we
have two obvious modifications of semicircular warted
shells — the one winged, the other not. This rounded
shape, however, begins to be lost in succeeding species,
and we are thus conducted to that singular shell the
Unto cylindricus of Say (c). Notwithstanding its un-
common length, it yet preserves, in every other part of
its outward appearance, such a close affinity to metanevra
(h), that, without knowing why^ a conchologist would
at once place them together. On turning to 2^iicata
we see another modification : this species is neither semi-
circular, like metanevra, nor elongated, like cylindrica;
it is broadly oval; and, instead of being tuberculated, has
merely two or three deep oblique furrows : it exhibits,
in short, but one out of the three typical characters,
— namely, the winged elevation of the posterior angle.
We believe more than two or three species pass under
the name of plicata. In one of these, kindly sent us
by our liberal friend Mr. Cooper, of New York, and
labelled as " a very old specimen," there is but one
lateral tooth on the right valve, instead of two ; so that
this species or variety actually puts on the very cha-
racter of our Megadomus gigas*, and renders both proto-
types of Alasmodon. But has Nature no method in these
remarkable variations } Can it be supposed that the devi-
ation of species, or of races of the same species, are
regulated by no fixed principles, while all the rest of
creation, inconceivably diversified, has been created on
one and the same plan ? Every analogy of reasoning,
every ascertained fact, is against the supposition.
Whence, then, does the species before us put on the very
aspect of another genus ? Simply for this reason, — that
plicata, and its immediate allies, represent the genus
Alasmodon, and that Nature adopts this mode of in-
structing us in her favourite theory of representation.
With plicata must be associated our Unio rugosus,

* It is this fact which so strongly loads me to suspect that there may be
some error in our location oi FotomUia.

CHAP X. UNIONIX^. THELIDERMA. 273

where the form of the shell is nearly semicircular, so that
we again return to irrorata, from whence we first set
out. Four types of the group are now disposed of, but
another is obviously wanting ; because, although there
are representations of four genera of the UnionidcB, we
have not yet noticed the prototype of Anodon. Now,
this type is in the ^Manchester Museum, and was sent to
us, many years ago, by our friend professor Rafinesque,
without a name. By the annexed figure (rf), the con-
chologist wiU perceive that, in its outward appearance,
no one would suspect it was really different froni the
Alasmodon riigosa of Barnes ; yet, on opening the valves,
we find the perfect cardinal and lateral teeth of Theli-
derma. The anodons are remarkable for the smallness
and the depression of their summits ; and this is the
only shell of its own group which possesses this cha-
racter, Avhile its form is exactly intermediate between
cylindrica and plicata. Condensing the results of these
remarks, we find the sectional types of this sub-genus
will represent all those of the entire family, — and in the
following manner : —

Analogies of the Sectional Types of Theliderma.

Sectional
Types.

Genera Genera

Analogical Characters. of of

TJninnidcE. Unto.

Irrorata. Semicircular, but not winged. Unco. Unio.

Metanevra. Semicircular, and winged. Hyria. ^-Eglia.

Cylindrica. \ ^'^^^^^SlS!"^^^'^"'' ' } I—' ^^-^

T, . , . C Oval ; winged ; summits very 7 \„ ^, x

Pustulata. < small •' J Anodon. Lymnadiv.

„,. . f Lateral teeth and cardinal 7 \, „ „„ r>

Pli'^ata. ^ teeih variable. j Alasmodon. Potomida.

Thus we find that every thing apparently anomalous
in T. cylindrica is at once explained by its being the
link between Ligumia and Theliderma; for if a shell so
formed had not been discovered, this link would have
been wanting. It has been stated that the crassidens,
Peruviana, and rariplicata of Lamarck, the undulatus

T

274 SHELLS AND SHELL-FISH. PART I.

and crassus of Barnes^ and the undulafa and Domheyana
of Valenciennes, are varieties of Le Sueur's plicatus;
but as no proofs, so far as we know of, have been brought
forward for this opinion, we must withhold our belief
from it, — more especially as the same author esteems the
Unio sinuata of Lamarck the same as the Mya marga-
ritifera of Linnaeus, and the Alasmodonta arcuata of
Barnes. These three shells are now before us ; and we
consider them not only of difierent species, but actually
of different genera : the first is a Unio, and one of the
types of Potomida; the two latter are distinct species
of Alasmodon. Furthermore, Lamarck has not given
the name of sinuata to the margaritifera of Linnaeus ;
for he expressly calls the latter shell, which, we believe,
is peculiar to England, Unio elongata. We are not fond
of adverting to errors ; but where they have been com-
mitted by writers who, on many points, deserve honour-
able mention, it is absolutely necessary to show the
fallacy of the principles of arrangement from which
they have originated. -^

(257.) On the remaining sub-genera of Unio — namely,
Cunicula, Ligumia, and Megadomns, our remarks must
be very brief. The first is at once distinguished by the
compression of the summits or bosses, and by being
always more or less angulated on the posterior slope :
planulata, cuncata, and ruhiginosa are typical examples,
having the lower lateral tooth remarkably thick, — the
singular /o/mcm of Say obviously representing the Unio
corn at US ; LRxnarck' s pu7'j)urata seems to lead imme-
diately to the sub-genus Ligumia, where the general
form of the shell is nearly as much elongated as any of
the Iridin^. We consider Lamarck's recta (fig. 55.)
as the type, although we think this is also the place for
the gihho.m and other elongated species, whose outer car-
dinal tooth is not erect, and both teeth more in unison
with those of Cunicula and Unio. In all these the shape
and direction of the cardinal teeth are quite different from

* Lea on the Genus Unio, Am. Trans vol. iii. N, S. 1829.

CHAP. X.

UNIONINiE. .EGLIA.

275

MyscAj which they nevertheless represent by their pod-
like form. The remarkable T. cylindrica, already noticed,
unites to this form the tubercles of the sub-genus The-
LiDERMA, which has just been analysed.

(258.) There seems strong evidence for believing that
our Unio gigas follows Theliderma ; in which case it
may be regarded as the type of a distinct sub-genus,
which, for the present, we shall name Megadomus. It
diflPers from the T. Peruviana and its allies, by having
only one lateral tooth in each valve ; and the bosses are
remarkably small and compressed. We have already
alluded to the disappearance of one of the cardinal teeth
in an aberrant species of Theliderma ; and we can now
notice a second gradation in an enormous large and very
old shell, intimately resembling plicata, but having the
second lateral tooth in one valve reduced to a mere
vestige. The question is, whether this deficiency is
accidental or permanent : all such deviations from the
typical characters of the UNioNiNiE, particularly in their
teeth, we regard as prototypes of the Alasmodontin^ ;
but their natural location is very difficult, particularly
until the question regarding Potomidea being a genus,
or a sub-genus, is decided.

(259.) -^GLiA, the second genus, is the represent-
ative of Hyria : this is apparent in the general form of
their shells, and in the structure of the cardinal teeth.
The posterior half is very thick and truncated, so as to
form a carinated angle; the bosses approach towards
the centre, and are very prominent; the form is thus
almost equilateral, and consequently the lateral teeth are

T 2

276 SHELLS AND SHELL-FISH. PART I.

unusually short; the cardinal teeth are also very peculiar^
as already explained (^fig. 47. 6) ; the groove between
them diverges from the beak in precisely an opposite
direction to that which separates the lateral teeth,
— in other words, it is obliquely parallel to the mar-
gin of the shell, instead of receding from it. In the
comparative size of these teeth there is also a de-
cided difference : in lEglia, the inner cardinal tooth
is the smallest, while in Unio it is the largest. The
typical examples are JE. ovata {fig. 49.)^ cuneata Sw.,
and occidens Lea. Unfortunately, however, the genus
is not so rich in forms as the last, and hence the links
between the sub- generic types are not so beautifully
graduated ; but the three species above named are
certainly typical, and by means of ventricosa, ater, and
siliqiioides, lead us to the confines of the group, where
we find such species as M. Say's cariosiis and ochra-
ceus, among which, and some kindred species, there
is at present much confusion : these, however, conduct
us to the U. radiatus of the American conchologists.
This is a very remarkable shell, because it seems the point
of junction between JEglia and the next sub-genus (J/>/*-
ca) ; the form of the teeth are consequently very variable:
hence we find that, in some varieties of this species, the
teeth are like those of ochraceus; in others, the cardinal
teeth are nearly equal, as in Mysca ; and in a very old
specimen now before me, the inner tooth is actually the
largest. These are all natural variations, and are account-
ed for upon the principle that osculent groups or forms
vary according to the characters of those other forms
which they connect. Lastly, we have a beautiful pro-
totype of Theliderma in Canthyria, the type of which is
the U. spinosus of Lea. This, and Naidea, are the only
sub-genera we shall venture to characterise ; the other
two requiring much m^ore study than we have yet been
able to give them.

(260.) The sub-genus Mysca follows next, and ob-
viously blends into the last. Mysca is the representation
of Iridina ; and we consequently find that nearly all the

CHAP. X.

UNIONIN^.

MYSCA.

277

species are unusually long and narrow^ while their in-
terior lustre is by far more brilliant and iridescent than
in either of the preceding groups. The cardinal teeth,
although in some respects like those of JEglia, neverthe-
less deserve much attention, because they not only differ
from those of Unio and JEglia, but bear a remote analogy
to Iridina. They are the most crenated of all those
in the Unionin^, precisely as those of Iridina are the
most crenated in the entire family : they are likewise the
most parallel to the anterior margin; and although in
general distinctly divided, they yet have a propensity,
even in individuals of the same species, to unite, and run,
as it were, into each other ; so that in some specimens
of our Mysca ovata (Jig. 66.), these two teeth will be

perfectly divided ; while in others of a younger age, from
the same pond, the division will be only marked by an
indentation on the ridge, — the groove itself being almost
obsolete. Now, this is precisely in unison wdth shells
intended to represent Iridina, where the lateral and
cardinal teeth are united into a crenated line. This vari-
ation in shells of the same species is not only perplexing
to young conchologists, but to more experienced ones :
in general, however, we may consider it as a rule that no
Unio belongs to this group, which has the cardinal teeth
thick and obtuse ; nor does it comprise any in which one
of the cardinal teeth is not immediately beneath the
bosses. These positive and negative characters render
the discrimination of Mysca comparatively easy. Very

T 3

278 SHELLS AND SHELL-FISH. PART I.

fortunately, the group^ although not so extensive as the
firstj is yet rich in subordinate types ; we shall, there-
fore make some approximation to the natural series of
the species, by looking to the following table, wherein
each subordinate type is indicated by its most prominent
example.

Analogies of the Sub-generic Ti/pes of My sc a.

rr, 4 1- Genera of

^yP''' Analogies. Unionidcc.

Mv«caovata f Both cardinal teeth presentj-^hort, 7 ^1*10

Myscaovata. ^ and jaggedjoue in the left valve, j ^^''^•

^„ . i-T CTwo nearly equal cardinal teeth 7 «..„,»

marginahs. J in the left valve. j "^^'^•

nasufa I" ^"^^"^ cardinal tooth nearly erect, ) TR,nivA

nasuta. ^ pointed, somewhat conical. j iridina.

Nilotira ("Oval; hinge sub-connate; poste- 7 Anodox

JNllotica. ^ rior angle winged. j anodox.

f. .,. ' f Hinge sub-connate: eardinalteeth 7 a,.,,,^„^„
fragihs. I infperfect. j ALAbMODON.

(261.) Among the longest species of Mysca generally
known are our two British species, ovata and pictorum,
which may consequently be considered typical; and these
also have the most crenated cardinal teeth. Following
these we have a type from India, represented by the mar-
ginalis of Lamarck, where the outer cardinal tooth is long
and slender, as in Hyria; and the other similarly formed,
but much shorter : these shells are also remarkable for
having two distinct cardinal teeth, almost alike, in the
other or left hand valve, — a structure which is quite
different from that of ovata, and indeed of all other
Unionidce. Let the malacologist examine the Hyria
avicularia and the Unio marginata of Lamarck ; and
so far as regards the cardinal teeth, he will find they are
formed precisely on the same model : nothing, there-
fore, can be more perfect.* Marginalis agrees also with
Iridina, in being, without exception, the most iridescent

• We even question whether this may not be a relation of affinity, and
thus Lamarck's marginata may be the anodontine type in Hyria.

CHAP. X. UNIONIN^. MYSCA. 279

of the group : with mnrginalis must be joined three or
four other species, all of which are from China and
India. One of these now before us, bears such a close
resemblance to the Unio nasutus of Say. that, if the teeth
are not examined, it would be impossible to define their
difference. Nasutus, however, represents another type,
which at present is almost exclusively confined to North
America. Here the cardinal teeth greatly resemble those
of Say's cario^rt and radiata (which come into the circle of
jSIglia) ; for the outer one is somewhat conic and erect,
while there is only a single defined tooth in the left valve.
From nasuta we pass, by several intervening species,
into the next type, represented by onr M.Nilotica, shaped
like a small Anodon, but with the teeth of Mysca. We
possess three other species, all from the river Nile, and
believe there are many others. Finally, we have from
America the Unio fragilis, figured very accurately in our
Zool. Illust. 1st Series, pi. 17 1^ I'ut which the Ameri-
can conchologists do not appear to understand : it truly
belongs to their genus Unio, because the two lateral teeth
are well defined, although the cardinal are but slightly
developed. Our figure, nevertheless, was drawn from a
very old specimen, which did not exhibit the elevated and
angulated posterior margin. Now, of all the UnionidcB
so constructed, this makes the nearest approach to the
well-known Unio alata of Lamarck ; while, in the imper-
fection of its teeth, it clearly represents Alasmodon.
We are thus brought round to the group with which we
commenced ; and were it necessary to point out the
precise point where the circle is closed, Ave could expa-
tiate upon the structure of our M.Mexicana, — an unde-
scribed species, and standing intermediate between the
first type and the last. It must not be supposed that the
modifications of form represented by the five species
named in the last table, are merely confined to one or two
examples ; even our own collection of specimens and of
drawings can produce several, Ovata, for instance,
represents a little group of eight species ; marginalis,
another of four; nasuta, seven; JVilotica, four; and

T 4

280 SHELLS AND SIIELL-FISH. PART I.

fragiUs, two. Now^ when we reflect how many more may
be in cabinets^ and the probability of still greater num-
bers being midiscovered^ we should be fully waranted in
designating these sections as sub-genera ; but so long as
any doubts remain regarding the true affinities of our
sub-genus Potomida, this plan may be suspended.

(2()2.) The Lymnadia alata is one of the most re-
markable shells of this sub-family ; not so much on ac-
count of its beauty^ but as holding a more isolated station
than any yet noticed. That it has a strong resemblance
to Anodon, is indisputable ; but that it has a much
stronger one to the Unionince, cannot be questioned. —
Now, every one who draws the distinction between
analogy and affinity^ immediately perceives that the first
of these resemblances is purely analogical; w'hile the
other, as Lamarck, Say, and Barnes have correctly
judged, is one of absolute aflSnity : it is needless, there-
fore, to discuss this matter further. At present, Lym-
nadia alata (fig. 48.) stands almost alone as the repre-
sentative of that sub-genus which typifies the anodons.
In conformity with this analogy^ we find the posterior
dorsal margin remarkably elevated, dilated, and winged.
The ligament also is connate, — that is, entirely covered
by a prolongation of the testaceous substance of the valves:
the bosses small, and the shell itself oval and depressed.
The cardinal teeth are very peculiar : they are compressed
and crenated like those of Mysca ; but the inner one is
generally the largest; and the direction of the groove which
separates them, is either perpendicular, or diverges from
the anterior margin of the shell. It is clear that our Unio
fragilis* either enters in this group or is at the confines of
the last: the next question is, what others can be arranged
in the same genus with Lymnadia ? We entertain little
doubt that the Symphynota compressa of ]\Ir. Lea is one of
these. f In this curious type, the cardinal and the lateral
teeth are perfect, and it has the complete external aspect of

• Zool. 111. 1st Series, pi. 171.

f We only know this from the very excellent description and figure in
Mr. Lea's paper.

CHAP. X.

UNIONIN^.

LYMNADIA.

281

Anodon : it is also so perfectly connate^ that Mr. Lea, look-
ing only to that circumstance, actually places it close to
L. alata. It is nevertheless a distinct type, and seems to
represent Anodon in this sub-genus : the cardinal teeth,
in short, strengthen us in the belief that Pofomida suc-
ceeds to Lyynnadia. We shall therefore introduce it here,
leaving its natural affinities still open to future inquiry.
(263.) In regard to the shells provisionally placed in
the genus Potomida, we have some doubts. We feel al-
most convinced that the types do not belong to the genus
Myfica ; and yet some of the aberrant species approach
so closely to such shells as M. pictorum and ovata, that
the gradation, to ordinary eyes, appears perfect. We have
one or two species from Brazil, and others from North
America, but most of the types seem to be European
These present us with the following distinguishing charac-
ters : the form, of course, is variable in the species ; but
it is never so long and attenuated a.s 3fysca; the breadth,
also, is greater, and the extremities more obtuse. The ty-
pical species, P. corrugata
( ^^.57.):'isnearly asround
as the generality of the
Venus -shells : the cardinal
teeth are always two, — not
thin, lengthened, and com-
pressed as in Mysca, but
thick, short, and strong, so
as to resemble the true
American unios ; like these latter, also, the inner cardinal
tooth is decidedly the largest — but then they are divided
like those of Mysca and ^glia. The size of the teeth,
with the general shape, and robustness of the shell, in-
duce us to think that Potomida is not naturally associated
with either Mysca or Unio. The littoralis of Lamarck,
common in the rivers of France, w411 show all these cha-
racters ; but in another Continental species, the Unio
sinuata Lam,, the form is more lengthened ; and by the
direction of the cardinal cleft, this shell seems to approxi-
mate still more to the typical Unios. Next we have the

282

SHELLS AND SHELL-FISH.

PART I.

Unio hatava of the same country^ where the teeth begin to
resemble those of My. sea; but they are still short, strong,
thick, and distinctly separated. Proceeding thus in the
natural series, without caring to circumscribe our groups

by arbitrary characters,
we come to P. Sicula
{fig. 58.), a new spe-
cies, found by us in the
lakes of Leontini in
Sicily : here we have a
still nearer approach to
Mysca than what is made
by Batata : the form of
the shell, indeed, is that of Mysca ovata; but the teeth
are still thick, and the inner one still preserves the typi-
cal character of being thicker than the other. The P.
elongata, also from Sicily, would seem to complete the
union of this sub-genus with Mysca. Whether we are
to look to this as the union of the three aberrant genera
of the UnionincB into one circle, or to take it as pre-
sumptive evidence that these shells form only a division
of Mysca, is uncertain. The question is, are they really
distinct types } If we merely look to Mysca pictoruni or
ovata, and Potomida litoralis or corrugata, the differ-
ence is very remarkable ; but on placing between them
Potomida Batava, Sicula, and elongata, the extreme
differences are softened down, and we become doubtful
as to the limits of the group.* There are several North
American shells which we suspect will clear up this point,
and hereafter enable us to discover the true typical cha-
racters.

(264.) The HyRiNiE constitute a small but very
distinct sub-family, remarkable both for its characters

* Our collection of Unionid(e, upon which these remarks were founded,
has unfortunately passed into the hands of others, and prevents us from
again investigating this (|uestion. We shall feel particularly iiidchted to
those conchologists of America who study the Unionidcv, for specimens, ac-
curately named, from their " Western Waters," of all the species they can
part with, promising to return others in exchange, from \ow Ze.iland.
Letters and parcels should be directed to us, to the care of John Willis,
Esq., Liverpool.

CHAP. X. HYRIN^. 283

and its geographic distribution. All the species yet
known^ are from the rivers of Tropical America and
Australia, — not one having been found north of the
line. Indeed, it may be almost said that the range of
the genus Unio is bounded by the same latitudes ; for
of all the UNioNiNiE we have yet seen, not more than
two have been brought from South America, and these
do not belong to the most typical groups. The Hv-
R1N.E are distinguished by the angulated or wedge-
shaped form of the shell, and the winglike projection
of its hinge or dorsal extremities. The second cha-
racter is in the narrow linear form of the cardinal
teeth, w^hich are on one side of the bosses, not beneath
them : these teeth also diverge to the anterior edge,
and are always more or less linear. The third cha-
racter is so very simple and constant, that it may be
recognised by the merest tyro ; the bosses or summits
of the valves are wrinkled or grooved transversely ; that
is, in a line from the apex to the basal margin. This
singular peculiarity, which pervades nearly all the types
we have yet seen of the Hyrin^, is directly opposed to
the characters of the Unionin^, where, if the summits
are wrinkled, the wrinkles are placed longitudinally, or
in a direction from the anterior to the posterior ex-
tremities. In what way this may be connected with
the natural habits of the animals, is totally unknown.

(265.) The passage from the UiSioNiNiE to the Hy-
RiN^ is through Mysca in the former, and Iridea in
the latter. The gradation from one to the other is
beautifully perfect. Iridea has the strongest possible
affinity to Mysca^ in the general shape of the shell, and
in the structure of the cardinal teeth : the form, how-
ever, is more oval than elongated ; the ends more
obtuse ; the posterior end of the hinge margin more
elevated, and the summits smaller. These, however,
are points of inferior moment. The chief distinction
is in the length and narrowness of the outer cardinal
tooth, and the almost total absence of the other : hence
it is, that in such shells there are always two distinct

28-i

SHELLS AND SHELL-FISH.

PART I.

cardinal teeth in the left valve ; whereas, in the Unio-
-sisM, this valve has scarcely ever more than one.
When, however, both are present in the right valve,
the inner one is always under, and not on the same
line or on the side of the outer tooth. The most
aberrant species of Mysca have something of this ap-
pearance, not very apparent to young conchologists.
But there is another and a more easy discrimination.
Of thirteen species of Iridea now before us, each and all
have the bosses or umhones wrinkled transversely, as
in Hyria. We cannot, indeed, expect that every species
will be so marked, for then there would be an absolute
line of demarcation between Iridea and Mysca, which
is contrary to nature ; but the facts now stated will
enable any one to discriminate the two types. The
next sub-genus is Lamarck's Castalia, of which but
one species is generally known. Reasoning from ana-
logy, it follows Iridea ; but if so, the minor types of
connection are wanting. It is a cockle-shaped shell,

nearly equilateral, and
59 bears a strong resem-
blance to JEglia cune-
ata. From this rare
and somewhat isolated
type the transition to
Hyria (fig. 5^.) is ren-
dered easy and natural
by means of Hyria cor-
rugata Lam. ; and Hy-
ria elongata indicates a passage to that elongated form
which has not yet been discovered, and which must
represent either Alasmodon or Iridina^ Such a shell
we remember to have once seen at King's Auction-
rooms, but by some accident neglected to take notes, or
to secure the specimen. In the sub-genus Na'ia, which
we arrange under Castalia, we have a form connecting
the C. cordata* with Iridea. AV^e have before us six

* I use the prior specific name of Ilumplircy rather than Lamarck's
ambigua, which throws an unnecessary tioubt on its being a species.

CHAP. X. HYRIN^ AND UNIONINiE. Og^

species, four of which are from India_, and two from
Australia. They are short, roundly oval shells, with
the umbones well defined, and placed tow^ards the
middle: from this results their peculiar character. The
lateral teeth are short, and not a great deal longer than
the cardinal teeth ; these latter being strong and thick,
without being short : they are much crenated, yet
without any ridge ; so that they have the appearance of
being broken off. Their immediate affinity to Tridea
is proved by the Na'ia elongata, from New Holland,
having the form of one type, and the teeth of the other.
This interesting species, once the property of admiral
Bligh, was purchased by us at his sale. The pecu-
liarities of Lamarck's Unio Australis (^Hyridella Sw.),
and its affinity to Iridea, lead us to arrange it as the
anodontine type of the Hyrian^, although it may pos-
sibly be an aberiant example of Iridea : the bosses, how-
ever, are not striated, and the wdiole shell has very much
the aspect of an Anodon. Of the fifth type, connecting
this sub-family to the next, we know nothing more than
what has been already stated. As the remaining genera
of the Unionidce are neither rich in the number of their
forms, nor abundant in their species, we shall mention
them wath more conciseness.

(266.) According to the views here taken of the
Hyrin^, we may thus compare the four genera, just
defined, with the circle of the Unionin^.

Analogies of the Hyrin.e and the Unionin^.

Genera of the j„„7^„,-„o Genera of the

HyriiiLe. *' Lnioni/ue.

r^.om.T.. CShell trigonal: posterior side^ zc^t..

Castalia. J truncate and short. j ^^«"^-

Hyria. Posterior side lengthened. Unio.

. ? POTOMIDA,

TT ^ ("Compressed, broad: bosses not7 t, ..........

Hyridella. I striated, retuse ; teeth slender.] Lymnadia.

C Lengthened oblong ; bosses small; "i

Iridea. < inner cardinal teeth very small, > Mysci,
C. almost obsolete. J

286

SHELLS AND SHELL-FISH.

PART I.

The type which we consider unknown, is that which
leads immediately to Iridina, and would consequently
be deficient in some of the teeth. The other four are
such obvious representations of their prototypes among
the Unionin^, that we need not detain the reader by
any additional remarks.

(267.) Of the iRiDiNiE, only three typical species have
been yet discovered ; and these, we believe, are all from

the river Nile. (/. elongata,
fig. 60.) The form of the
whole group has been before
stated ; the shell is almost of
equal breadth throughout,
with the posterior end nearly,
if not quite, as broad as the
anterior. This great elongation of the shell must extend,
of course, to the animal; and for this reason we admit
into the genus Iridina a singular shell from the same
river {Iridina Nilotica Fer.), but which has the hinge
line only '^^ slightly crenulated at the umbones."* Here
it is that Nature, as it were, is hovering between the
confines of this type and the Anodontince, and plainly
intimates to us which will be her succeeding group.

(268.) The ANODONTiNiB form a more numerous
sub-family than the two last. Tropical America ap-
pears richer in these shells, than any other part of the
world. Although one of the sub-genera is peculiar to
Asia, the typical form (represented by our common
Anodon anatinus) occurs both in Europe, Asia, and
North America, but under different modifications, which
will render it necessary to distinguish them as sub-ge-
nera. We arrange the whole under the five principal
genera of Lamproscapha Sw., Symphynota Lea, Anodon
Lam., Hemiodon Sw., and Patularia Sw. The first of
these contains such shells as the A. ensiformis, siliquo-
sum, &c.f , which have the shape of Iridina, but are

• Zool. Journ. i. 55. The name of Pleodon cannot be substituted for that
of Iridina, as applied to the typical species.

+ From Brazil, figured in Spix and Martius's Testacca Fhiviatilia, SjC^
published in 1827.

CHAP. X. IBIDIN^. — ANODONTIN^. 287

destitute of any crenations^ or plate, below the hinge mar-
gin. These obviously lead io Symphynota, where the form
is oval and winged ; while a slender lamellar tooth ex-
tends the whole length of the shell. Following this we
have the typical genus Anodon, where the plate in ques-
tion is entirely wanting. There are many striking mo-
difications, however, in the form of these shells, which
may hereafter point out the sub-genera: — in Anodon
proper, the form is transversely oval or oblong, and the
bosses very small and compressed; Patularia has the um-
bones remarkably swollen, or ventricose ; and the shell
almost round: lastly, the genus Hemiodon includes those
which have a slight tubercle, or indication of the car-
dinal teeth; thus leading to the Alasmodontiiv^.

(269.) Assembling these types in a tabular form, we
shall find they possess the usual analogies.

Analogies of the Genera of the Anodontin^.

Genera of the a„^i„ -^r. Sub-fatnilies of

AnodontincE.

Analogies. Unionida.

Anodo\. Pre-eminently typical. Unionin^.

Symphynota. Hinge margin or tetth lamellar. Hyrian^e.

T „„„.„„ (■ Boat-shaped, and very long, no7T„

Lamproscapha. < teeth j o > i Iridinan^.

Patularia. ' Shell nearly round ; no teeth. Anodonin^.

Vr' „^„ f Hinge plate sinuated or tubercu- 7 . ,

Hemiodon. < lated I ALASMODONiNiE.

Not having carried our analysis into the sub-genera,
we shall not venture to name those which have the
aspect of being such. It is plain, however, that there are
aberrant species, if not sub-genera, in Symphynota and
Anodon. These two are probably connected by Anodon
rubra, which has a distinct elevated ridge, analogous to
the lamellar tooth of Symphynota. The bosses, again,
of our common Anodon are small and compressed; while
those of A. trapezialis Lam., and other large species,
are remarkably ventricose. The Anodon purpurascens* ,

* Zool. 111. pi. i. 260.

288

SHELLS AND SHELL-FISH.

PART I.

again^ has the rudiments of a very thin and short lateral
plate. It may be proper to observe in this place, that
Dipsas was the original name imposed by Dr. Leach to
this sub-genus ; but Larentini, so far back as 1768, had
given this name to a genus of reptiles : and as this is
an insuperable bar to its repetition, we gladly adopt that
of Symphynota Lea, under the restrictions here men-
tioned.

(270.) The last sub-family is that of the Alasmo-
DONTiNiE, the typical species of which are all from the
rivers of America. They are connected to the anodons,
in the most graduated and perfect manner, by our genus
Hemidon; and the first type is probably represented by
the Unio calceola of Lea : then follows the typical form,

as seen in Say's original
Alasmodon undulata
{Jig. 61.); our genus
Uniopsis appears to suc-
ceed this , then we have
the elongated form in
Schumacher's Margari-
tana; and, finally, the
anodoniform, or most
aberrant type, is seen in
our Complanai'ia gigas and rugosa* The whole of these
constitute one of the most natural divisions in the family.
Typically considered, they are without any distinct lateral
teeth ; the hinge-plate being either long and merely con-
vex, as in Margaritana ; or short, flattened, and obliquely
grooved, as in Complanaria. The cardinal teeth are
always present, but vary in each type ; hence they fur-
nish an admirable clue to the analogies of the genera.
Nothing appears known of the animal; but this is not
material to our present purpose, since the variation of
the shell is quite sufficient to guide us in their natural

* Mr. Lea, in his artificial arrangement, i)laces these two shells in widely
different divisions, because one, he says, is " syniphynote," and' the other
'• 7to«-synii)hynote:i" they are the Alasrnodonta coniplanata and rugosa of
American writers, and are most naturally connected.

CHAP. X.

ALASMODONTIN^.

289

arrangement. The ex-
ceedingly oblique teeth
of our Uniopsis radiata*
(Jig. 62.) show it is the
prototype of Unio, and
might have been there
placed, but for the want
of lateral teeth. The
triangular and cuneated
shape of Alasmodon un.
dulata reminds us of
^glia. The single cardinal tooth of Calceola t7'uncataf
accords with the tubercles of Hemiodon; while the
compressed bosses and dilated posterior side of Compla-
naria preserves the analogy between this sub-genus and
its prototypes Lymnadia, T^heliderma, and Anodon.
Finally, we come to Margaritana, which, every one
must perceive, puts on the aspect of Mysca, Ligumia,
Potomida, and the Iridince. Wliether the whole of
the shells retained by us in this last genus really enter
into the circle we are at present tracing, or that such
as have an obsolete lateral tooth should naturally be
arranged with the Potomida Uttoralis^ &c., cannot, of
course, be yet determined ; nor do we feel certain that
Calceola is the connecting type with the AnodontincB.
And yet, as all these find their representatives in the lead-
ing divisions of the Unionid^, they become absolutely
types of genera, equivalent in rank, although not in
numbers, to the genera of the sub-family Unionin^.
This will be further apparent from the following expo-
sition : —

* I suppose, from the name, that this is the Margaritana radiata of
Lea's Synopsis, but, as no reference is made to where the shell is described,
or any information beyond its being " non-symphynote and smooth," I
affix this name at a venture, merely for my present purpose; the real name,
if described, can always be made out from the figure here given. Since
writing the above, my kind friend Mrs. Corrie (who has a noble series of
Unionidce in her fine collection) has sent me a specimen of this type under
the name of Alasmodon inflata ; the teeth are not near so oblique as in that
here figured.

t Under the common name of XJnio calciolus, we have received three
distinct species from America.

U

290

SHELLS AND SHELL-FISH.

PART I.

Analogies of the Genera of the ALASMODONTiNiE.

Genera.

Analogical
Characters.

f Inequilateral ;"|
I the cardinal |
teeth reced- [

Sub-families

of the

Unionidcc.

Genera Sub-genera
of of

Unionince. Unio. ^

Uniopsis. ^ ing'from^he ^ ^^■"^^''^^- ^^^^- ^"'''•

j anterior j
L margin. J

rCuneate, andT
Alas7?iodon. < nearly equi- ^ Hyrin^. JEglja. Cunicula.

C. lateral. J

Calceola. ? Alasmodoninjs. Potomida. Megadomus.

Winged ; the"
Complanaria. -{ !?2!f ^® l™^u /> ANOooNTiNa;. Lymi^ Am\. Theliderma

S Winged ; the")
bosses small (
and much T ^
compressed. 3
f Oblong oval,-!
Margaritana. ] greatly Mridin^.

C lengthened. J

MyscA. Ligumia.

(271.) Having brought our rapid exposition of this
family to a close, we may now offer a few general re-
marks upon the whole. The Unionidcs, of all the groups
of the DiTHYRA, is that which contains the greatest
modifications of form ; insomuch that it becomes
almost impossible, in some of its minor divisions, to
determine which are species, and which varieties.
Hence has originated the idea, entertained by several
conchologists, that they constitute but a single genus ;
while others have gone so far as to suspect that there
is in reality but one species of Unio, and " perhaps of
the whole family : " such, at least, were the sentiments
entertained some years ago, although we believe they
'no longer exist. Upon this principle, the equally ex-
tensive and varied family of HelicidfE should form but
one genus, or rather but one species, which might be
called Helix or Limax terrestris, because it lived upon
land.* It is useless to prove, that by this false and
vicious sort of generalisation, we should return back to

* The naked slugs and the land snails pass into each other by such gra-
duated shades, that no " well-marked and absolute characters" can be
found to separate them.

CHAP. X. ALASMODONTINiE. 291

the dark ages of zoology, and produce the same sort of
confusion and ignorance which then reigned. But, then,
it may be asked, how can genera be retained in our
systems, which actually blend into each other, and
whose distinctions thus become lost ? This objection
has been repeatedly answered. Genera which are really
natural, are always thus united, because they show us
all the connecting links of nature. But genera which
contain only well-defined and isolated characters, so
that no ordinary person can confound them, are not
perfect, because their connecting links to others are
wanting : they are fragments of the chain, having its
gradations disturbed, dissevered, broken ; — hence such
groups are fragments only of what has been, or may be,
a natural assemblage. Our divisions of sub-families,
genera, sub-genera, and sections, are mere conventional
terms employed to denote groups of different sizes, pos-
sessing, in the majority, certain primary characters which
are termed typical. It matters not upon what cha-
racters these divisions are founded in the Unionidce
and the HelicidcB, provided none can be drawn from
the animal ; but it is most essential that disruptions of
kindred species should not be made, — for then the
harmony of nature is destroyed. Now, this leads us
again to advert to the different sorts of resemblances
natural objects bear to each other. The confounding
of analogy and affinity, which has led to the greatest
confusion in every branch of zoology, has been particu-
larly conspicuous in this : every conchologist, for in-
stance, perceives that Ligumia recta, Mysca ovata and
nasuta, Iridina elongata, and Alasmodon margaritifera ,
have a very strong resemblance to each other. Now, if
this resemblance were one of affinity, it naturally would
follow that all these shells belonged to the same natural
group : they possess one character in common, — that of
being particularly long, pod-like shells ; yet if any me-
thodist, looking to this only, and disregarding all other
characters, make them into a genus, he would commit
a palpable outrage on natural classification. So, in like

w 2

292 SHELLS AND SHELL-FISH. PART I.

manner, if he took all the winged or connate shells,
and, holding as trivial their other characters, proceeded
to place them in a separate genus, he would be doing
the same thing, — he would be confounding objects
which merely represented each other analogically, or, as
it were, allegorically, under the belief that they were
bond fide connected by affinity, and followed each other
in the scale of nature.

(272.) But if all this be admitted, the difficulty of
separating species from varieties still remains : a species,
it has been said, is the only absolute division in nature ;
and did we look to the vertebrated, and even the annu-
lose, animals, we might be tempted to adopt this as an
axiom ; but in regard to the present family, at least, it
cannot be maintained, for it receives a direct contradic-
tion. The mode of generation in the whole of the
Dithyra precludes the theory of promiscuous intercourse,
and the consequent production of hybrids.* The vari-
ations, therefore, are spontaneous, and lie beyond our in-
vestigation. We have seen, however, in the case of the
Unio MytU'iodes, that while Nature appears to disregard
all her usual bounds, and to indulge in almost endless
diversity, she nevertheless strictly confines herself to the
same plan she has pursued in all other groups. Her vari-
ations are upon the same system as that which pervades
the animal world. She creates, in short, a type, all the
variations of which have a reference to, and often the
very aspect of, those particular forms which mark the
primary divisions of the whole family. This theory,
borne out in almost every group here laid before the
reader, will materially, if not absolutely, guide us in
determining the limits of species, and consequently of
varieties. We trust the rising school of American ma-
lacologists will confirm this by a renewed investigation of
the inexhaustible profusion of Unionidce with which
their noble rivers abound. Having seen but very few of

* On all anatomical facts, we look to the illustrious Cuvier as a para-
mount authority ; he expressly says all the DiUnjra are hermaphrodites.
Mr. Lea, however, mentions male and female shell-tish of the same spe-
cies. Is there no error in this ?

CHAP. X.

BRANCHIOPODA

•CHELYOSOMA.

293

the valuable Essays, &c. published in their own country on
the species, we have not ventured to carry our analysis
so far : our object for the last twenty-three years has
been to discover the fundamental principles of their
natural arrangement. How far we have done this, time
alone will show. iVIuch uncertainty, indeed, hangs over
the location of one or two genera ; but this, however
desirable to be cleared up, affects not the principle itself,
— for that coincides with all we know of the universal
laws of animal variation.

(^2,73.) Our remaining space is now so contracted,
that we can do no more than merely glance at the two
remaining tribes of the Dithyra. The Branchiojjoda,
indeed, have already been slightly noticed (238); while
the annexed cut (Jig. 63.) of Mr. Broderip's Chelyosoma

will give a good idea of this most extraordinary animal.
According to that very able naturalist, it adheres to
stones by coiiacious processes from the lower part. It
must be observed, however, that on this lower or cup-
shaped part, there are slight traces of separation into
plates, but without internal muscular fibre. The upper
surface is flat, and consists of eight coriaceous, some-
what horny angular plates, which are so disposed that
the branchial orifice (a) is surrounded by three plates,
and the anal orifice (b) by four : each of the plates are
marked by elevated stria?, as in the tortoises. The valves
of the orifices are opened and closed by muscles, adhering
at one end to the inner surface of the tunic (not of the
mantle), and on the other to a small papillary process on

u 3

£94 SHELLS AND SHELL-FISH. PART I.

the valves themselves. Besides this set of muscles^ and
within them, is another set, which passes laterally from
one papilla to another. Other muscles enable the ani-
mal to contract or dilate itself. The ovaries, viscera,
&c., were in too decayed a state for examination ; but
the mantle appears to adhere only to the orifices, each of
which has six valves.* Wherever this animal is placed,
its extraordinary analogy to the CydohraiicMa and the
other cheloniform types, will still be the same; and our
present impression is, that it represents the chitons in
this division of the order rather than in that of the Tu-
nicata.

(274.) Having now completed our exposition of the
two great typical divisions of the Testacea, in which
are included the whole of the univalve and bivalve shell-
fish t, we must reluctantly close this part of our volume.
The whole of the aberrant orders, as the Cephalopoda, the
Parencliymata, and the Nudihranchki, together with the
radiated and the coralline MoUusks, will therefore re-
main open to future investigators of the natural system,
and they may possibly form hereafter the subject of
another volume supplementary to this.

* Abridged from Zool. Journal, vol. v. p. 46.

f Excepting those of the Cephalopoda or Nautilus order.

PART II.

A NATURAL ARRANGEMENT

OF THE UNIVALVE AND BIVALVE SHELL-FISH, COMPOSING

THE OBDICRS

GASTEROPODA AND DITHYRA

OF THE CLASS

TESTACEA.

Chief Abbreviations.

Bligh Cat. Catalogue of the Bligh Mart, or Mar. Martini.

Shells. Sow. Gen. or S. Gen. Sowerbi/'s
Chem. or Ch. Chemnitz. Genera of Shells.

Ency. Meth. or En. M. Encyclo- Sow. Man. Sowerby's Manual of

pedie Methodique. Conchology.

Lam. System of Invertebrated ani- Tank. C. Tankerville Catalog^(e.

mats ; the No. refers to his series Zool. 111. i. & ii. Zoological fllus-

of species in the original edition. trations. First and Second Series.

Order GASTEROPODA.
Tribe ZOOPHAGA. Carnhwous Gastropods.

Family 1. MURICIDiE. Murexes and Whelks.

Pillar never plaited ; shell spiral, the base narrowed,
and either truncate or slightly produced.

SuB-FAM. 1. MURICIN^. Murexes.

Spire as long as the aperture ; exterior rough ; the
whorls marked with varices ; aperture wide.

MuREx Lin. Varices from three to five on each whorl ;

u 4

296

SHELLS AND SHELL-FISH. PART II.

inner lip smooth ; the spire much shorter than the
aperture ; an internal groove at the upper angle of
the aperture.

Mureoc Lin. Canal very long ; shell armed with acute,
cylindrical_, tooth-like spines, mostly arranged in three
varices.

tenuispina. Sow. Gen. f. 2. cornutus. Mart. 114. f. 1057.

crassispina. Mart. f. 1052-4. brandaris. lb. f. 1050. 1058.

Haustellaria Sw. Canal excessively long ; shell with-
out spines ; the varices tuberculated.

erythrostoma Sw. Sow. Gen. f. 1. (Murex haustellum L. )

Phyllonotus Sw. Canal moderate ; varices foliated, la-
ciniated, compressed, or resembling leaves (^fig.QQ.d).

inflatus. Mart. 102. f. 980. endeva. lb. 107. f. 107,108.
eurystomus. Zool. 111. ii. 100. (Aberrant.)

imperialis. lb. pi. 109. adustus. lb. f. 990, 991.

cervicornis. Sow. Gen. f.4. trunculus. lb. f. 1018, 1019.

Scorpio. lb. f. 3. saxatilis. lb. f. 1011, 1012.

ealcitrapa. Mart. 102. f. 982. palmaroScE. Lister. 946. f. 41.

brevifrons. lb. f. 983. capucinus. Chem. 192. 1849.
axicornis. Mart. 105. f. 989.

Muricanthus Sw.* Varices numerous, foliated ; spire
short ; margin of the outer lip with a prominent
tooth near the base.

radix Siv. Zool. 111. 2d series, melanomathus. En. Meth.
pi. 113. 418. f. 2.

Pteronotus Sw. Varices three, compressed, fin-shaped ;
canal moderate, generally closed by the union of the
two lips at their base.

pinnatus. Zool. 111. ii. pi. 112. tricarinatus. En. INI. 418. f. 5.

tripteroides. En. M. 417. f. 3. phyllopterus. Sow. Gen. f. 5.

trigonularis. Mart. f. 1031. gibbosus. En. M. 418. f. 1.

hemitripterus. En. M. 418. acanthopterus. lb. 417. f. 2.

f. 4. uncinarius. Mart. f. 1034-5.

MuRiciDEA Sw. Spire more produced, as long or

* This type was originally called Ccntronotus; but .is that name had been
previously given to a genus of fishes, we substitute the above.

PART II.

MURICIN^.-

•GASSING.

297

longer than the body whorl ; varices numerous ; no in-
ternal channel at the top of the aperture, (^fig. Q5. c.)

lamellosa. Chem. f. 1823-4. scaber. En. Meth. 419. f. 6.

magellanica. En. M.419. f.4. hexagona. lb. 418. f. 3.

peruviana. lb. f. 5. erinacea. Mart. f. 1026.
senticosa. lb. f. 3.

ViTULARiA Sw. General habit of Muricidea, but the
inner lip is depressed and flattened as in the Pur-
purincB; varices simple, nearly obsolete (^fig. Q5. e.)
tuberculata Sw. En. M. 419. f. 1. {Afurex vitulinus Auct.)

Triton * Lam. The varices few^ and placed -'^^ ^
alternately, (fig. 64.)

australis. Sow. Gen. f. 1. ^^^^^^^

lotorium. lb. f. 1. (Jig. 66. e) '— "°^

anus. lb. f. 2. clavator. f. 3,
variegatum. (Jig. 65. d)

Ranella Lam. Varices forming a ridge on
both sides of the shell ; channel short.

marginata.
caudisata.

Sow. Gen. f. 2.
lb. f. 1.

spinosa. En. M. 421. 5-
crumena. lb. 421.3.

SuB-FAM. 2. CASSINtE.
SheU large, ventricose, generally smooth ; spire very

* This is the only character by which this group, as a genus, can be dis-
tinguished; and this is exceptionable, because there are some species, like
T.clandestinuni {fig. Q^-), which have the outer lip thickened, and are with-

298

SHELLS AND SHELL-FISH.

PART II.

short ; the base truncate and emarginate, or with a
short recurved channel ; inner lip toothed or plaited.*

Harpa Lam. Varices numerous and regular^ forming
longitudinal ribs, coronated near the suture ; aperture
and lips highly polished ; base truncate {fig. Q5. b^c).
muhicostata. Sow. Gen. f.l. crenata Sw. Bligh, Cat.

CypRiECASsis Stuclibury. Shell oblong, oval, ventri-
cose, without varices ; spire very small ; aperture
cypraeiform ; outer lip thickened, convex, and ad-
vancing on the spire ; inner margin regularly toothed ;
inner lip thickened, convex, and spreading on the
body-whorl, without being detached ; pillar angu-
lated internally, and crossed by uniformly slender
plaits ; canal very short, reposing on the body- whorl;
aperture very narrow, with a recurved channel above.

testiculus. Mart. f. 375. ? crumena. Mart. 37. f. 379.

rufa. lb. 32. f. .341. harpjBformis. Lam. No. 26.t

Cassis Lam, Shell ponderous, marked with varices ;

out any varices. There is, in fact, every modification of shape among the
Tritons as they now stand ; some have the aperture wide, others narrow:
the channel is either very long or truncate ; the spire greatly lengtliened
or greatly depressed ; the pillar toothed or smooth ; the varices cither alter-
nate or none. But, the suh-genera not having been determined, I leave

the group in this confused state. These facts, better than any theoretical
arguments, show the absolute necessity of defining the sub-genera.

* Except in Dolium and Harpa.

f Uniting this genus to Harpa.

PART II. CASSINiE. NASSINJE. 299

outer lip (typically) considerably dilated, with a pro-
minentj callous, and detached rim ; inner lip inflected,
broad, flattened, dilated in the middle, and toothed ;
aperture narrow, irregular, {fig. 65. «.)
cornuta (type). Chem. pi. flammea.En. Meth. 406. f. 3.

184, 185. (Jfiff. 65. a.) (Aberrant.)

tuberosa. Mart. 38. f. 382. fasclata. Mart. 37. f. 384.

Cassidea Sw. Aperture wide ; outer lip never broad
or flattened, but sometimes slightly inflected ; inner
lip spreading, but never dilated or detached beyond
the base into a prominent rim. (fig. 66. a.)

glauca. Sow. Gen. f. 1. zelanica. lb. 18.

plicaria. Chem. f. 1459-60. sulcosa. Seba. 68. f. 14, 15.

areola. En. M, 407. f. 3. granulosa. Mart. f. 344-5.

Zebra. Chem. f. 1457-8. Saburon. Gualt. 39. g.

decussata. Mart. f. 360-1. semigranosa. Lam. No. 23.

ringens Sw. Bligh, Cat. vibex. Mart. 35. f. 364-6.

achatina. En. Meth. 407. f. 1. erinaceus. lb. 35. fig. 363.
pyrmn. Lam. No. 17.

DoLiUM Lam. Shell ventricose, inflated, smooth ; spire
very short ; outer lip thin, not inflected ; base ge-
nerally truncate and emarginate. {fig. 66. 6.)
D. olearium. Sow, Gen. f. 1. fimbriatum. lb. f. 2.

SuB-FAM. 3. NASSINiE.

Generally small ; the spire longer than the aperture * ;
the base either truncate, or with a short recurved
channel ; inner lip often dilated and spreading ; some-
times granulated, but never toothed ; a prominent ridge
or fold at the base of the pillar; outer lip crenated within.

Cassidarea Zflw. Ventricose; spire short; inner lip
spreading, and detached at the base ; outer lip thick-
ened within ; canal slightly lengthened, and turning
upwards ; representing Cassis.
echinophora. Ency. M. 405. f. 3. Thyrrena. lb. 405. f. 1.

Oniscidia Sow. General shape of Cyprcecassis, but less
ventricose, the base more attenuated, and the canal

* But in the aberrant genera it is shorter.

300

SHELLS AND SHELL-FISH.

PART II.

truncated ; spire very short ; both lips thickened^
the inner granulated, the outer inflected and toothed ;
aperture narrow, (^fig. QQ. c.)
oniscus. Chem. 1872-3. cancellata. Sow. Gen. f. 1 — 3.

Vexilla Sw. General shape of ^ ^^

Purpura ; the inner lip flat-
tened and depressed; the outer,
when adult, thickened, in-
flectedj and toothed ; aperture
wide.

picta Sw. Chem. pi. 157. f. 1504-5. {fig. 61.)

Nassa Layji. Small ; spire longer than the

aperture ; the inner lip, in the typical

forms, greatly dilated, thickened, and often

with a prominent margin ; outer lip simple,

crenated ; aperture wide, with a groove above ;

pillar with a basal ridge; base truncate, {fig. 68.)

N. arcularia. Ency. M. 394. f. 1. clathrata. lb. f. 4.
papillosa. Sow. Gen. f. 5.

Cyclonassa* Sw. Shell small, depressed, neritiform,
nearly round ; inner lip forming a vitreous, spreading
mass ; no internal canal or tubercle on the inner
lip ; basal notch nearly obsolete ; outer lip smooth,
entire, thickened.

C. neritea. Ency. M. 394. f. 9. Sow. Gen. f. 3.

SuB-FAM. 4. PURPURIN^.
Oval; spire much shorter than the aperture, which is very
wide ; inner lip not defined, but vitreous ; pillar broad
and flattened ; outer lip rarely thickened or inflexed,

RiciNULA Lam. {fig. 71. rf.) Outer lip dilated, and often

forming digitated processes externally, but the margin

broad, much reflected, and toothed internally ; inner

lip flat, broad, generally toothed ; spire very small. \

planospira. En. M. 397.5. digitata. Sow. Gen. f. 3, 4.
horrida. Sow. Gen. f, 1. morus. lb. f. 2.

* The fanciful and inapplicable name of Cyclops, given to this type by
De Moiitford, designates a well-known genus of Crustacea.
+ Except in those species, like R. ■»iunis, which lead to Purpura.

PART II.

PURPURIN^.

•BUGGING.

301

CoNCHOLEPAS Lam. Patelliform ; spire lateral, nearly-
obsolete ; pillar none.

C. Peruviana. Sow. Gen. {fig- 71. a.)

MoNCGEROs Lam. Spire moderate ; a

strong tooth-like process^at the base of

the outer lip. (^fig. 6^. )

M. imbricatum. Sow. Gen. f. 1.
cinffulatum. lb. fisr. 4.

MicROTOJiA Sw. Pillar very broad and
curving inwards ; aperture effuse ;
the notch at the base small^ and nearly-
obsolete ; spire very short.

patula. Mart. 69. f. 758, 759. persica. En. Meth. 397. f. 1.

unicolor 5'u\ Cheni. f. 1449.

Purpura Lam. Spire more prominent ;
inner lip flattened ; the basal notch
wide and distinct.* {fig- 10, 11. h.)

coronata. En. Meth. 397. f. 1.
succincta. lb. 398. f. 1.

SuB-FAM. 5. BUCCININ.E.
Spire always as long as the aperture, and

» United to Ricinula by P. columellaris., Ency. Meth. 598. fig. 3., and
Ricinuia morus, Ency. Meth. 395. fig. 6.

302 SHELLS AND SHELL-FISH. PART II.

typically of great length ; base truncated, deeply notched;
inner lip smooth, convex.

Leiodomus Sw. Shell very smooth, nearly polished ;
spire acute, slender, lengthened; of few whorls;
aperture effuse; inner lip thickened and spreading;
base of the pillar curving inwards. 8 species.

Achatinum. En. M. 400. f.4. Quoyii^w;. Voy. d'Astrol.
vittata. En. Meth. 402. f. 4. 31. f. 17.

Terebba Lam.* Shell subulate; spire excessively
long, and of numerous whorls ; pillar straight ; the
base curving outwards {Jig. 71. e).
maculata. En. M. 402. f. 4. Babylonica. lb. 402. f. 5.

BucciNvisi Linn. Shell pyriform ; spine moderate; body-
whorl ventricose ; base obtuse, emarginate ; hps
smooth {fig. 11. c).

undatum. En. M. 399. f. 1. lineatum. lb. 400. f. 8.
? leevigatum. lb. 400. f. 1 . t papillosum. lb. 400. f. 2.

Trochia Sw. Shape intermediate between Purpura
and Bucciniim ; whorls separated by a deep groove ;
inner lip, when young, depressed, when adult, thick-
ened, convex, and striated ; basal canal very small,
sulcata. En. M^th. 422. f. 4.

Tritonidea X Sw. Shell bucciniform, but the basal half
is narrowed, and the middle more or less ventricose ;
spire and aperture equal. Pillar at the base with
two or three obtuse and very transverse plaits, not
well defined ; outer lip internally crenated, and with

* By this group, the Muricid^ are connected with the Strombid^ by
means of the Ccriiliince.

t Probably an aberrant species of Leiodomus.

% Mr. Gray has the merit of first publishing this intricate, but most natu-
ral genus, which I had many years ago also determined. 1 should gladly
have adopted his name, were it not that Pollia has been already given by
Hiihner and Trcitsch to a genus of lepidopterous insects. Mr. Gray has very
happily determined what is certainly its true station in the natural system,
— that is, intermediate between Triton and Biiccinmn. It is connected to
rritun by T. clandcsfinum. Ency. Meth. 433. fig. 1. [Jig. C4. p. 297.), which
thus completes the circle of this family.

PART II.

TURBINELLID^.

303

a superior siphon ; inner lip wanting, or rudi-
mentary.

undosa. En. M^th, 422. f. 5. (Aberrant.)

torulosa. lb. 428. f. 3.
maculosa. lb. 400. f. 7.

aculeiformis. lb. 426. f. 3.
articulata. En. M. 426. f. 1.

Family 2. TURBINELLIDiE.

Base of the shell produced into along channel ; the spire
generally short ; the pillar often toothed ; outer lip thin.

SuB-FAM. 1. TURBINELLIN^.

Spire short, the tip papillary ; middle or base of the
inner lip plaited ; channel lengthened.

TuRBiNELLA Lum. Shell ponderous, smooth, or
slightly nodulous ; spire short, papillary ; pillar with
strong plaits in the middle, (^fig. 72. a.)

rapa. En. Meth. 431.62s, f. 1. pyrum. Chem. f. 1697, 1698.

Fasciolaria Lam. Fusiform, ventricose ; spire and
aperture of equal length, the former attenuated and

304} SHELLS AND SHELL-FISH. PART II.

acute ; outer lip crenated ; base of the pillar with
one or two sharp folds. {Jig. 72. d.)
F. tulipa. En.Meth. 431. f. 2. trapezium. lb. 431. f. 3.

Pyrella Sw. Pyriform ; spire very shorty papillary ;
channel lengthened; inner lip flattened, elevated^
smooth ; pillar with a single sharp fold at the base.

P. spirilla. Zool. 111. 1st series. En. Meth. 437. f. 4.

Clavilithes Sw. Unequally fusiform, the body-whorl
and spire being conic, and the canal suddenly con-
tracted and attenuated ; terminal whorls papillary ;
inner lip thick; pillar smooth. Fossil only. {Jig. 72. b.)

longfevus. En. M. 425. f. 3. Noa?. En. Meth. 425. f. 5.
clavellatus. lb. f. 2. ponderosus Sw. lb. f. 4.

SuB-FAM. 2. SCOLYMIN^.

Spire more produced, the tip always acute; surface
rough ; canal short ; pillar plaited.

Plicatella* Sw. Fusiform ; the spire produced ; pil-
lar with two or three obtuse, basal, transverse folds.

polyzona. En. M. 423. f. 1. rustica. Mart. 120. f. 1104.

cingulifera. lb. 429. f. 1. triserialis. Lam. No. 21.

earinifera. lb. 423. f. 3. ocellata. Mart. 124. f. 1 160.

infundibulum. lb. 424. f. 2. variolosa. Lam. No. 22.

craticulata. lb. 429. f. 3. tuberculata. Grif.Cuv.30.f.3.

lineata. lb. 429. f. 4. turbinelloides. lb. 25. f. 1.

nassatula. Lam. No. 20. filosa. En. Meth. 429. f. 5.

ScoLYMus Sw. Sub-fusiform, armed with foliated
spires ; spire shorter ; pillar with distinct plaits in
the middle.

cornigerus. Chem. f. 1725-6. capitellum. En. Meth. 431.
pugellaris. En.M.401. 6is*,3. bis *, f. 4.

globulus. lb. f, 2. umbilicaris. lb. f. 1. a — c.

rhinoceros. Chem. f. 1407-8. mitis. Lam. No. 10. p. 106.
ceramica. Mart. 99. f. 943.

* rolygonum of some writers; but that is a common and well-known
botanical genus of Linnaeus, and cannot thereiore be again applied.

PART II. SCOLYMIN^. EBURNIN^. 305

Cancellaria Lam. Shell turbinate, scabrous, generally
reticulated ; body-whorl ventricose ; spire and aper-
ture nearly equal ; base obtuse ; pillar with distinct
basal plaits ; aperture rather eflPuse j the canal almost
obsolete.
C. reticulata. En. Meth. 375. f. 3. lobata Sw. (Jig. 72. /. )

Rhinodomus Sw. No internal groove ; shell clavate ;
the spire longer than, or equal with, the aperture ; the
whorls with ridges or longitudinal varices, and ren-
dered hispid by transverse grooves ; inner lip want-
ing ; pillar with a terminal fold ; aperture striated ;
outer lip with a basal sinus.*

R. senticosus. Chem, tab. 193. f. 1864—1866.

PoLYTROPA Sw. "j" Bucciniform ; but the base narrowed,
and ending in a straight and contracted, but rather
short, channel ; spire longer or as long as the aper-
ture ; exterior folliculated or tuberculated ; inner lip
flattened, as in Purpura; basal notch small, oblique ;
no internal channel.

crispata. En. Meth. 41 9 f. 2. imbricata. Mart. 1 22. f. 1 1 24.

Chem. 187. f. 1802. ? ruj?osa. Chem. f. 1473-4.

lapilla. Pennant, pi. 72. f. 89.

'o^

SuB-FAM. 3. EBURNIN^.

Shell generally grooved round the suture ; body-whorl
ventricose ; spire rather longer than the aperture ; the
base obtuse, and almost entire ; inner lip much thick-
ened ; outer lip sinuated.

Cyllene Gray. Small; shape of Harpa and Harpula;
shell longitudinally ribbed^ and sub-coronated with

* Analogous to Nassa; but the inner lip is not developed, and there is not
a superior or internal canal ; it likewise represents Leiodo??ius by its animal,
Scalaria by its varices, and Terebra by it spire. There are several species
with shorter spires than senticosus.

t This is an obvious representationof P?/rjDwra and Fyrula in this circle,
and is connected to Plicatella by such aberrant species as have two or three
obsolete tubercles at the base of the inner lip, and a row of others, more
distinct, on the opposite side ; but even in these the pillar is always de-
pressed, and the channel short. These species are chiefly from the Northern
and Southern Oceans. They are at once distinguished from the FurjmrcE
by having no internal channel at the top of the aperture,

X

306

SHELLS AND SHELL-FISH. PART 11.

tubercles, sometimes cancellated ; aperture striated
within, rather effuse, longer than the spire, which is
acute ; inner lip large, vitreous, spreading ; the base
finely striated ; outer lip with a slight sinus at the
base, as in Rhinodomus ; no internal groove ; the
suture sometimes channeled and polished.
C. Owenii. GrifF. Cuv. p. 41. f. 2.

Struthiolaria Lam. Spire turreted ; outer lip con-
siderably sinuated ; inner lip thick, spreading ; the
pillar turned inwards ; the basal notch nearly obso-
lete,
nodulosa. En. M. 431. f. 1. crenulata. Astrol. pi. 31. f. 8,9.

Eburna Lam. Smooth; sutures gene- ,«^^ '^

rally grooved ; spire and aperture about
equal ; inner lip very thick, partly con-
cealing the umbilicus, and with an up-
per internal groove ; outer lip thin,
slightly sinuated ; basal notch oblique,
small, {jig. 73.)

E.spirata. En.Meth.401.f.2. pacifica. En. Moth. 401. f. 4.

PsEUDOLivA Sw. Shell thick, oval, oliviform, ventricose;
spire very short, acute ; base with two parallel
grooves, one of which forms a notch at the base of
the outer lip ; suture slightly channeled ; inner lip
very thick, and turning inwards ; aperture with an
internal canal. Connects the Turbinellid^ with
the VoLUTiD^.
P. plumbea. Chem. 188. f. 1806, 1807. {fig. 5. p. 82.)

Latiaxis Sw. Shell sub-pyriform, turbinate, and
the whorls detached, as if distorted ; but the spire
flattened at the summit ; whorls angiJated, and cari-
nated, with a fimbriated undulate ridge ; pillar none ;
umbilicus excessively large and deep ; aperture an-
gular ; the basal notch nearly obsolete.*
P. Mawcx. Grift: Cuv. pi. 25. f. 4.

* This singular shell I regard as the representation of Scalnria, Verme-
ius, &c. in the present group, and as opening a passage to the Pyruliua by

PART II.

PYRULINiE. S07

SUB-FAM. 4. PYRULINiE.

Shell pyriform ; the base more or less produced ; the
spire short and typically flattened ; inner lip convex,
and perfectly smooth. * '

Rapella Sw. Shell ventricose, generally thin, almost
globose ; the base suddenly contracted, and forming
a short canal, the channel almost obsolete ; umbilicus
large, partly concealed by the inner lip.

R. papyracia. En. Meth. 436. f. 1.

FicuLA Sw. Shell thin, pyriform ; the

base lengthened into an elongated

channel ; the upper part ventricose ;

spire very small, depressed ; inner lip

wanting, {^fig. 74.)

ficus. En. M6th.431. caudata. En. Meth.
f. 1. 436.f.l.6,c.

Pyrula Lam. Shell strong, pyriform,

solid, coronated wiih spines or tubercles ; the base

lengthened into a long channel ; spire very short,

but a little elevated and pointed ; inner lip wanting.
P. perversa. En. Meth. 433. f. 4.

CuMA Humphrey. Sub-fusiform ; spire and base
equal in length ; inner lip with a central fold.
C. sulcata Sw. (See Jig. 4. p. 87.)

Myristica Sw. Sub-pyriform ; spire strong, spiny,
or tuber culated, nearly as long as the base ; um-
bilicus either partially or entirely concealed ; inner
lip vitreous, thin ; the outer with an internal and
ascending canal ; the basal channel wide.

hippocastanea. En. M. 432. melongena. En. Meth. 435.

f. 4. f. 3.

lineata. lb. f. 5. nodosa. Chem. 1 564-5.

means of Rapella. I know it, however, only from the figures above quoted.
Mr. Gray's description is confined to these words: " Shell deformed, white j
from China." It is obviously related to Rapella ; while, in its large umbili-
cus and nearly obsolete notch, it has a greater resemblance to Eburna than
to any other genus I am acquainted with.
* Except in Cuma, where there is a central fold.

X 2

308

SHELLS AND SHELL-FISH.

lART II.

SuB-FAM. 5. FUSl'N IE. — Spindle- Shells.

Shells generally fusiform and slender ; the base elon-
gated ; the spire lengthened and acute ; pillar smooth ;
outer lip thin.

Hemifusus Sw. Unequally fusiform^ the spire being
shorter than the aperture ; shell ponderous^ coronated
with compressed spines ; an internal and ascending
canal at the top of the aperture.

colossus. En. M^th. 427. f. 2. morio. En. M^th. 430. f.3,4.
pyrulaceus. lb. 429. f. 6. carnaria. lb. 434. f. 3.

coronatus. lb. 430. f. 2. cochlidium. lb. 434. f. 2.

Chrysodomus Sw. Bucciniform, but the base pro-
duced into a channel shorter than the spire ; whorls
ventricose ; smooth_, or nearly so ; outer lip thin ;
inner lip obsolete.

dispectus. Ency. M. 26. f. 4. sulcatus. En. Meth. 424. f. 3.
argyrostomus. Ib.426.f.5. lignarius. lb. 424. f. 6.

Fusus Lam, Shell long, slender ; both extremities
much produced : spire attenuated, turreted, and of
nearly equal length with the aperture.

Syracusanus. En. M.423. f.6. tuberculatus. En. M. 423.f.'4.
torulosus. lb. f. 4. aciculatus. lb. 425. f. 8.

incrassatus. lb. 5. longicauda. lb. 423. f. 2.

Leiostoma Sw. Equally fusiform, but ventricose in the
middle ; shell entirely smooth, almost polished ; in-
ner lip thickened and vitreous ; base
of the pillar very straight. Fossil
only. (fig. 75.)
L. bulbiformis. En. Meth. 428. f. 1.

Strepsidura Sw. Equally fusiform,
but the basal portion of the pillar
turned outAvardly, with a sharp fold
at the base of the aperture ; shell
costated and sub-coronated ; body-
whorl ventricose. Fossil only.
S. costata. Sw. En. Meth. 428. f. 2. (Fusus ^culneus ham.)

PART II.

STROMBIN^.

309

Family 3. STROMBID^. Wing-Shells.

Outer lip dilated^ or thickened internally^, or detached
from the preceding whorl by a sinus ; operculum small.

SuBFAM. 1. STROMBIN^.

Outer lip considerably dilated, but never toothed ; spire
rarely longer than the aperture, with a sinus near the
base.

Aphorrais Da Co5^a. (fig.'jG, a.) Spire, longer than

76

the aperture ; outer lip dilated into finger- like pro-
cesses ; base produced, compressed, with a slender
grooved channel in the middle, but no distinct lobe,
A. pes-pelicani. Mart, 85. f. 848 — 850.

Pteroceras Lafn. (fig. 'J'J.) Spire
short ; outer lip considerably di-
lated, ascending and attached to the
spire, in general divided into linear
processes ; basal lobe inflexed,
toothed ; channel long.

P. truncatus. Chem. latissimus Sw.

Mart. 83. f.
835.
purpuratus 5*?^;.
Chem. 157. f.
1494, 1495.
X 3

pl. 159.
laciniatus. Ex.
Conch. 46.
Chem. 158. f.
1506, 1507.

.'^lO

SHELLS AND SHELL -FISH.

PART II.

Strombus Linn. (^fig. 76. b) Outer lip entire ; the mar-
gin not inflected, with a deep sinus near the base, and
the upper part not ascending to the top of the spire ;
basal lobe rarely inflexed, and never toothed.

tricornis. En. Meth. 401. f. 1.
Gallus. Mart. f. 841, 842.
Goliathus. Chem. 195. B.
inermis Sw. Bligh, Cat.
gigas. Mart. 80. f. 824.
accipitrinus. lb. 81. f. 829.

Pacificus Sw. Chem. f. 1485,
I486. Ex. Conch, pi. 17.

melanostomus Sw. lb. f.
1487-8. lb. pi. 17.

Auris- Dianae. Mart. f. 838-9.

Lamarckii. Gray ?

Strombidea Sw. Outer lip angulated, but not dilated,
or detached from the preceding whorl ; upper sinus
obsolete, or entirely wanting ; the lower distinct.

urceus. Mart. 78. f. 803. tridentata. Chem. f. 1503.

plicata. En. M. 408. f. 2. erythrostoma. lb. f. 1874.

mutabilis. Mart. 78. f. 807. dubia S'w. P. Mag.61. p.377.

RosTELLARiA Lam. [fig. 76. c, d, e.) An ascending
siphon, formed by a groove thickened on each side,
which extends upwards on the spire ; outer lip
various, but not sinuated at the base,
curvirostris. En. Meth. 411. columbata. En. Meth. 411.

f.l.(Jig.76.c.)
rectirostris. Nat. G. pi. 2. f.2.
serrata Sw. Chem. 195. A.

f. 1869.
macroptera. Brander, f. 76.

f. 2. (Jig. 76. c.)
fissurella. lb. f, 3. (Jig. 76. d. )
cancellata. lb. 408. f. 5.
canalis. lb. 409. f. 4.
decussata. Sow. Gen. f. 8.

SuB-FAM. 2. CONINiE. Cones.

Shell coniform; the spire very short,
pyramidical or truncate ; outer lip
slightly detached above, but without
a basal sinus.

Terebellum Lam. Cylindrical,
smooth ; aperture effuse at the
base ; outer lip with an obsolete
sinus ; spire either short or con-
cealed.

T. subulatum. En. Meth. 360. fig. 1
(Jig. 78.)

PART II.

CONINA;.

311

CoRONAxis Sw. Shell conical ; the summits of the
whorls crowned with a single row of tubercles ; mouth
of the animal entire.

Coronaxis Sw. Spire truncate^ scarcely raised above the
margin of the body-whorl, which is not convex.
Bandanus Lam. Voy. d' Astrol. pi. 53. f. 7.

Puncticulis Sw. Spire slightly elevated ; body-whorl
convex near the upper margin ; aperture linear ;
base deeply notched.

P. arenatus Lam. Voy. d' Astrol. pi. 52. f. 8.

TaUparia Sw. Body- whorl ventricose j the aperture
effuse,
nebulosa Siv. Ency. M. 322. f. 11. (Conus tulipa L.)

CylindreUa Sw. Conic-cylindrical; spire elevated_, and
only slightly coronated on the upper whorls j shell
generally grooved.

Asper. Chem. 181. f. 1745-7.

ConUithes Sw. Conic; spire considerably elevated; the
aperture linear.

C. antediluvianiis. Sow. Gen. f. 1.

CoNus Linn. Shell conic ; the summit of the whorls
smooth ; mouth of the animal laciniated.

Conus Linn. Spire generally truncate, or only pointed
at the summit ; margin of the body-
whorl carinate.

C. millepunctatus. En. Meth. 323. f. 5.
litteratus. lb. 323. f. 1. {Jig. 79.)
eburneus. lb. 324. f. 1,2.
nobilis. lb. 339. f. 7.
virgo. lb. 326. f. 5.
miles. lb. 329. f. 7.
capitaneus. lb. 327. f. 2.
vulpinus. lb. 326. f. 6.
maldivus. lb. 325. f. 6.
generalis. lb. 325. f. 2. 4.
monile. Chem. 140. f. 1301 — 1303.

Dendroconiis Sw. Shell heavy ; spire lightly elevated ;

X 4

312 SHELLS AND SHELL-FISH. PART II.

body whorl convex near the margin ; aperture
linear.

betulinus. En. Meth. 338. franciscanus. E. M. 337. f. 5.

f. 7. striatus. lb. S40. f. 1.

figulinus. lb. 332. f. 2. gubernator. lb. 340. f. 5.

quercinus. lb. 332. f. 6. nimbosus. lb. 341. f. 5.

Teoctilia Sw. Spire elevated, concave ; body-whorl

ventricose ; the aperture effuse at the base ; shell

always smooth.

communis. En. M. 346. f. ammlralis. E. M.325. f. 1 — 9.

1 — 5. bullatus. Chem. f. 1315 — 6.

auratus. lb. 343. f. 1. pyramidalis. En. Meth. 347.
rubiginosus. lb. 344. f. 1,2. f. 5.

Theliconus Sw. Shell narrow, nearly cylindrical, gene-
rally grooved transversely ; spire elevated, thick,
convex, obtuse ; aperture linear,
nussatella. Sow, Gen. f. 7. Terebra. Sow. Gen. f. 6.

Leptoconus Sw. Shell light, conic, sometimes striated ;

spire elevated, acute, concave ; the basal whorl cari-

nated, detached, and sinuated above, and contracted

near the suture.

grandis. Sow. Gen. f. 2. duplicatus. Sow. Gen. f, 5.

amadis. Chem. f. 1322-3. Austrabs. lb. f. 4.*

CoNELLA Sw. Shell small, conic; spire elevated, smooth;
the outer lip advancing a little up the spire ; aperture
linear ; inner lip smooth ; outer lip striated within,
picata Sw. {fig. 17, a, p. 151.)

CoNORBis Sw. Conic, but resembling a Pleurotoma :
spire conic, considerably elevated; outer lip with a
deep sinus above.

C, Dormiter, Sow. Gen. f. 8.

SuB-FAM. 3. COLUMBELLIN^,

Shell small ; outer lip considerably thickened within,
where the margin is invariably either toothed or striated ;
the top gibbous, the margin generally in flexed ; inner

* Passing into Nussatdla.

PART II. COLUJIBELLIN^. 313

lip doubly toothed^ i. e. internally and externally ;
aperture narrow, generally ringent ; operculum minute.

CoNiDEA Sw. Mitra-shaped, fusiform ; spire equal or
longer than the aperture; the whorls tumid ; outer
lip slightly gibbous above, contracted below ; margin
not inflected ; striated within ; inner lip terminating
in an elevated ridge, but with the teeth obsolete.

C. semipunctata. (Columhella Lam.) Mart. 44. f. 465,466.

CoLUMBELLA Lum. Subfusiform ; spire shorter than
the aperture ; outer lip gibbous, inflected, sinuated,
broad, and thickest in the middle, crenated or toothed
its entire length ; aperture contracted ; inner lip with
granular teeth.

C. mercatoria. Mart. pi. 44. 452 — 458.

PusiosTOMA Sw. General form of Columhella ; but the
outer lip is only toothed in the middle, where it is
greatly thickened ; inner lip convex between the gra-
nular teeth, (fg, 72. g, h.)

punctata. En. M. 374. f. 4. fulgurans. Lam.*
mendicaria. lb. 375. f. 10. turturina. En. M. 384. f. 2.

Crassispira Sw. Small, subclavate, tuberculated : spire
thick, lengthened ; outer lip with a slight sinus
above, and thickened internally at the top and bottom ;
top of the inner lip with a thick pad ; basal channel
but slightly defined, (fig. 17. a.)

Pleurotoma Bottas Auct. C. fasciata Sw. {fig. 17. d, p. 151.)

NiTiDELLA Sw. Bucciniform ; small, ovate, smooth,
glassy ; aperture effuse ; outer lip slightly thickened,
faintly inflexed, and generally striated internally ;
inner lip somewhat flattened above ; base of the pillar
with one or two slight internal folds, or a single an-
gular projection, (fig. 17- e.)

Columbella nitida Lam. (fig. 17. c, p. 151.)

* Lamarck erroneously cites the Ency. Meth. 574. fig. 7. for this species,
as that represents one of his Mitres.

314 SHELLS AND SHELL-FISH. PART II.

SuB-FAM. 4. PLEUROTOMINiE.

Shell turreted, subfusiform ; the base channeled, and
often much produced ; outer lip never thickened, but
detached at the top from the whorl by a slit or sinus.*

Brachytoma "f Sw. Subfusiform ; resembling a small
Stromhus or Fusus ; spire and aperture of equal
length ; channel short ; outer lip slightly ascending,
and forming a short canal ; sinus very small, and
nearly semi-circular ; inner lip thickened above.

strombiformis. Sow. Man. castanea Sw. Chem. f. 1831,
f. 381. 14S2.

Pleurotoma Lam. Fusiform, turreted ; channel
lengthened, and nearly as long as the spire ; the slit
long and narrow ; inner lip wanting.

P. virgo. En. Meth. 439. Babylonica. lb. f. 1.
f. 2. ^ Javanica. lb. f. 3.

Clavatula Sw. Spire clavate, very long, turreted ;
channel short ; inner lip wanting.

sulcata Sw. Chem. 190. f. 1829.

Clavicantha Sw. Thick, sub-fusiform ; the surface
rugose, and the whorls sub-coronated ; channel short ;
slit assuming the form of a short broad sinus.

C. imperialis. En. Meth. conica. E. M. 439. f. 9.
440. echinata. lb. 439. f. 8.

spirata. lb. 440. f. 5. auriculifera. lb. f. 10.

Tomella Sw. Fusiform, smooth ; the spire of very
few whorls, and not longer than the channel ; inner
lip with a thick callosity at the top ; the slit short and
wide.

lineata. En. Meth. 440. f. 2. filosa. En. Meth. 440. f. 6.
clavicularis. lb. f. 4. lineolata. lb. f. 11.

* In the two typical groups, the'notch is a long slit ; in the three aberrant
genera, it forms a wide but short sinus.

+ The aberrant species of this genus connects the sub-family with the
Columbellince by means of Crassispira. They are mostly small and rare
shells.

PART II.

CERITHIXiE.

315

SuB-FAM. 5. CERITHIN^.

Shell clavate^ generally mucronate ; the spire very long :
the outer lip considerably dilated ; the base either trun-
catCj or forming a short recurved channel.

PoTOMis Brong. Fluviatile ? covered with a brown
epidermis : whorls coronated^, and armed with spines ;
aperture almost entire, the notch being slightly de-
veloped ; top of the outer lip with an obsolete sinus,
muricata. Sow. Man. 377.*

granulata. En. M. 442. f.4.

PiRENA Lam, Fluviatile ; smooth ; outer lip ^.
much dilated, with a deep narrow slit on the /3
upper part; base widely notched; inner lip
entire and thickened. f

P. terebrans. Sow. Man. f. 316. {fig. 80.)

^Terebralia Sw. Outer lip much dilated,
generally uniting at its base to the inner
lip, leaving a round perforation at the base
of the pillar ; channel truncate ; operculum
round.

80

palustre. Mart. f. 1472.
sulcatum. En. M.442. f. 2.
Ebenium. lb. 442. f. 1.

heteroclites. Lam. No. 24.
telescopium. Voy. Ast. pi. 55.
f. 4—6.

lineatum.

Rhinoclavis Sw. Channel curved backwards in an
erect position ; inner lip very thick, with a tumid
margin ; pillar generally with a central plait ; oper-
culum ear-shaped.

obeliscus. En. Meth. 443.f. 4.
aluco. lb. f. 5. (Aberrant.)
semi-granosum. lb. 443. f. 1.
asperum. Mart. 157. f. 1483.

Cerithium Lam. Channel short, nearly straight ; pillar
smooth ; inner lip thickened only at the top, where

En. M. 443. f. 3.
lb. f. 2.
subulatum. Lam. No. 23.
fasciatum. Mart. 157. f. 1481.

vertagus

* Connecting this with the last sub-family by means of Clavicantha.
f Representing Pleurotoma.

316

SHELLS AND SHELL-FISH.

PART II.

it forms a short internal channel ; operculum ear -

shaped.

nodulosum. En. Mdth. 442, tuberculatum. Mart. 157.
f. 3. f. 1490.

Family 4. VOLUTID^.

Shell destitute of a channel ; the base truncated and
notched ; the piUar marked with folds or plaits ; oper-
culum none.

SuB-FAM. 1. VOLUTINiE. True Volutes.

Spire shorter than the aperture^ which is never striated;
pillar with distinct plaits^ the upper ones the shortest ;
tip of the spire papillary.* {fig. 81.)

Voluta Linn. Shell large, ventricose ; the spire ex-
tremely short, very obtuse, and papillary ; the ter-
minal whorls, where they exist, being smooth and
unsculptured.
1. Turbinelliform type. Shell melon-shaped; spire very

* Except in Volutiliihes, •which wants the three last characters, — the
plaits.being faint, the tip of the spire acute, and the lower plaits the longest.

PART II.

VOLUTINS.

317

short, sometimes nearly
obsolete. {Jig- 81. 6.)

diadema. En. M. 388. f. 2.

armata. lb. 388. f. 1.

tessellata. Mart. f. 781.

^thiopica. En. M. 388. f. 3.

melo. lb. 389. f. 1.

Neptmii. lb. 386. f. 1.

Cymbium. lb. f. 3.

proboscidalis. lb. 389. f. 2.

Olla. lb. 385. f. 2.

rubiginosa. Ex. Conch. 28.

porcina. En. M. 386. f. 2.

2. Muriciform type. Shell
heavy, less ventricose, co-
ronated with cylindrical
or vaulted spines ; spire
more produced.

marmorata. Ex. Conch, pi. l.
chrysostoma. lb. pi. 45.
imperialis. En. Meth. 382. 1.

3. Strombiform type. Outer
lip dilated, and angulated
above.

scapha. En. Meth. 391.
Exotic Conchology, pi. 48.

4. Ancilliform type. Aper-
ture very wide ; spire
pointed.

angulata Sw. Ex. Conch,
pi. 3, 4.

5. Marginellifomi type.
Shell partially polished ;
ventricose.

magnifica. Chem. 174, 175.
fulgetrum. Sow. Tank. C.

Cymbiola Sw. Spire more produced;, but not more
than half as long as the aperture ; the terminal whorls
regular and sculptured ; plaits on the pillar four.
{fig. 81. «.)

1. Type 9 Ancilla. En. Meth.

385. f. 3.
magellanica. lb. f. 1.

2. Vespertilio. En. M^th.

378. f. 2.
nivosa. Ex. Conch, pi. 5.

pacifica. Chem. 178. f. 1713,
1714. Ex. Conch, pi. 14.
festiva. ? Lam. No. 42.

3. Mitis. Ex. Conch, pi. 40.

4. Braziliana. Chem. 176.

f. 1695, 1696.

Harpula Sw. Spire developed as in
the last^ but the tip is generally more
slender, and the plaits are numerous.

1, Vexillum. En. Meth. 331. f. 1. {fig. 82.)
Lapponica. lb. 381. f. 3.

2. Hebrcea. En. Meth. 380. f. 2.
musica. lb. 380. f. 1.
thiarella. lb. 380. f. 2.
carneolata. Mart. 96. 930.
Guiniaca. Chem. 178. f. fulva. En. Meth. 382. f. 3.

1717, 1718. sulcata. Chem. 149. f. 1403.

Isevigata. En. Me'th. 379.f. 2. nodulosa. Lam. No. 31.
polyzonalis. lb. 379. f. 1.

318

SHELLS AND SHELL-FISH.

PART II.

3. fulminata. En. M. 381. f. 2. 5. Lyriformis. Zool. 111. i. 54.

4. bullata. Zool. 111. ii. pi. 15. concinna. Brod. Z. P. iv. 43.

nucleus. Lam. No. 44.

mitraeformis. Lam. No. 43.

VoLUTiLiTHES Sw. Spire acutely pointed ; plates gene-
rally faint^ sometimes obsolete, {fig. 81. e.)

1. spinosa. En. M. 392. f. 6. 4. Cithara. En. M. 384. f. 1.

5. bicorona. En. M. 384. f. 6.
crenulata. lb. f. 5.
costaria. lb. 383. f.
lyra. lb. f. 6.

2.musicalis. En. M. 392.f. 4
muricina. lb. 383. f. 1.

3. rarispina. En. M. 384. f. 2
labrella. lb. 384. f. 3.

ScAPHELLA Sw. Shell smooth, almost polished; outer lip
thickened internally ; suture enamelled ; lower plaits
the smallest; apex of the spire various, {fig. 81. e.)

1 . fuslformis S'w. Bligh, Cat. Junonia. Ex. Conch, pl.33.

2. undulata. Ex. Conch, pi. 27. 3. stromboides. (fiff. 12. a,
volvacia. Chem. f. 1339. b. p. 123.)

Zebra Sw. (fig. 81. c.) 5. papillosa Siv. Sow. Gen.

SuB-FAM. 2. MITRAN^.

Spire produced, acute, generally as long* or longer
than the aperture ; plaits 4 — 5, the lower smallest.t

MiTRA. No internal channel or groove at the upper
extremity of the aperture ; outer lip curved from its
two extremities ; the base of the aperture S3
not contracted, the interior always smooth ;
spire lengthened, acute ; shell without co-
ronating tubercles, but not polished. Re-
presenting the Volutes and TurbinellidcB.

Mitra Sw. Shell entirely smooth, or with
the sutures very slightly crenated ; aper-
ture very effuse at the base. {fig. 83.)

episcopalis. En. M. 369. f. 2.
pertusa. lb. 369. f. 1. 3.
versicolor. Martyn, 1. f. 23.
nivosa Sw. Bligh, Cat.

ambigua

Zool. 111. ii. 30. f. 2.
fulva. lb. f. 3.
Terebralis. En. M. 369. f. 5.
lactea. lb. -371. f. 2.

* Except in ConceheUx.

+ Except in some MitreolcF.

PART II. MITRINvE. 519

Thiarella Sw. Shell smooth, with the whorls coro-
nated ; the hody-whorl less ventricose.

papalis. En. Meth. 370. 1. millepora. En. M. 370. f. 5.

pontificalis Lam. lb. f. 2. diadema Sw. Bligh, Cat. pi. 66.

puncticulata. Lam. No. 4. lugubris. Zool. III. i.
coronata. En. M. 371. f. 6.

Scahricola Sw. Shell rough, with transverse elevated
ridges, and longitudinal striae; suture not coronated;
aperture effuse ; outer lip crenated.

serpentina. En. M. 370. f. 3. filosa. Lam. No. 33.

scabriuscula. lb. 371. f. 5. granulosa. En. Meth. 370.
crenifera. lb. 370. f. 4. f. 6.

leucostoma Sw, Tank. Cat. texturata. lb. 372. f. 2.

granatina. En. M. 371.f. 4. ? terebralis. Lam. No. 11.

Nehularia Sw. Shell generally marked with transverse
grooves ; outer lip contracted above, effuse below ; the
margin smooth ; base of the body-whorl narrowed,
contracta. Zool. 111. i. pi. 18. Ancillides. Zool. Proc. iii. 1 93.

Strigatella Sw. Size very small ; spire thick, obtuse ;

outer lip thickened, and often reflected in the middle;

aperture smooth.

Zebra. En. M. 372. f 8. acuminata. Zool. 111. ii. 128.

llneata Sw. lb. 372. f. 7. f. 3.

Tiara Sw. Aperture narrow, linear, or of equal
breadth throughout ; outer lip and base of the body-
whorl contracted, the former generally striated; an
internal canal at the upper part of the aperture ; shell
(typically) turreted, and equally fusiform : repre-
senting the MuricidcB and Cynibiola. (fig. 84.)

Tiara Sw. Shell turreted, fusiform, costated, and
semi-coronated ; spire and aperture of equal length ;
internal striae slight or obsolete, {fig. 84. c.) ;

virgo Linn, unfigured. * nodosa Sw. lb. 373. f. 2.

Regina. Chem. 151. f. 1444. plicaria. En. M. 373. f. 6.

vittata. Zool. 111. i. lyrata. lb. 373. f. 1.

ta;niata. En. M. 373. f. 7. CafFra. lb. 373. f. 4.

corrugata. lb. f.8. (/^.84.c.) simplicata. lb. 373. f. 9.

costellaris. lb. f.3. (/9 84.5f.) melongina. lb. 373. f. 9.

vulpicula. lb. 373. f. 5. foraminata. Zool. P. iii. 194.

* I have once seen this beautiful shell, the rarest and most slender of
this genus.

320

SHELLS AND SHELL-FISH.

PART II.

Costellaria Sw. Unequally fusiform ; the spire longer
than the aperture ; body- whorl slightly ventricose,
but suddenly contracted near the base ; internal striae
distinct ; whorls convex, rarely angulated j the ribs
reaching to the suture, {^fig. 84. 6?.)

C. rigida. Zool. 111. 1st Series, pi. 29.

Callithea Sw. Spire and aperture of nearly equal length ;
internal channel nearly obsolete ; shell with longi-
tudinal linear ribs, crossed with transverse striae and
bands ; base contracted, {fig. 84. e.)

sanguisuga. En.Meth. 373.
f. 10.

stigmataria. Chem. 151. f. 1442,
1443.

Cancilla Sw. General shape of the last ; but the whorls
crossed by transverse linear ribs, or elevated ridges ;
internal canal wanting ; plaits very oblique ; form
slender ; outer lip thin. {fig. 84. h.)
Isabella. Zool. 111. ii. pi. 50. sulcata. lb. pi. 50. f. 2.

Pusia Sw. Size very small ; spire thick, obtuse ;
outer lip thickened, and often reflected ; aperture
striated, with an internal canal.

microzonis. En. Meth. 374. f. 8.

MiTREOLA Sw. Small ; unequally fusiform ; the base
obtuse ; inner lip, typically, thickened, inflected, and
either toothed or tuberculated ; plaits on the pillar
distinct, the inferior largest ; tip of the spire some-

PART II.

OLIVIX.^.

321

times papillary ; aperture without either striae or
groove.

monodonta. Zool. 111. ii. 128. f. 1. terebellum. lb. f. 2.

CoN(ELix Sw. Small ; cylindrical or conic ; spire ge-
nerally short and thick ; plaits on the pillar nu-
merous ; exterior often decussated.

C. conulus. En. Meth. 382. f. 2.

MiTRELLA Sw* Rather small; olive-shaped;
unequally fusiform ; always smooth and
polished^ and sometimes covered with an
epidermis ; base obtuse and effuse ; spire
nearly or quite equal to the aperture ;
plaits of the pillar few_, oblique^ and ex-
tending beyond the aperture^ which is
smooth internally. (M. bicolor, ^^. 85.)

ocellata. Zl. 111. v. pi. 54. f. 2. olivaeformis. Zool. 111. i,
fissurata. En. M. 371. f. 1. ii . 54. f. 3.

casta. Zool. 111. i. pi. 48. fusca. lb. ii. pi. 54. f.

bicolor. Ib.ii. 19. f.2. (Jig. 85.) dactylus. En. M. 372
olivaria. En. M. 371. f. 2.

pi. 48.

1.
. f. 5.

SuB-FAM. 3. OLIVINiE. Olives.

Shell smooth^ highly polished ; spire very short ; the
suture channeled ; inner lip much thickened ; plaits
numerous, crowded, extending, in the typical genus,
the whole length of the aperture, (fig. 86, 87.)

Lamprodoma Sw. Mitriform ; spire pro-
duced, conic; resembling^jTzYreZ/a in shape,
but the suture is channelled ; the aperture
effuse at the base, contracted above ; lower
half of the pillar with 6-7 plaits,
volutella. Zool. 111. ii. series, pi. 40. f. 1. (fig.86.)

Oliva Lam. Cylindrical ; spire very short,

pointed; pillar with numerous slender plaits ; aperture
narrow; the base not effuse, {fig. 87. c.)
O. maura. Sow. Man. f. 457.

322

SHELLS AND SHELL-FISH.

87

PART II.

ScAPHULA Sw, (fig. 87- &.) Spire very short, thick, ob-
tuse, and not defined ; aperture very wide, with only
two or three obhque plaits at the base.

S. patula Sow. Tank. Cat. 2331. (6.)

HiATULA Sw. {fig. 87. «.) General shape of Oliva ; but
the upper part of the pillar is not thickened ; the
lower tumid, and marked with a few oblique plaits ;
the aperture wide, the base effuse.

Lamarckii. Zl.Il. ii. p.78.f. 1. maculosa. lb. 78. f. 3.
pallida. lb. 78. f. 2. ? striata. lb. pi. 40. f. 2.

O liveijI. A Sw.* (fig. 87- e.) Oliviform; spire (typically)
rather produced ; the tip acute ; inner lip not thick-
ened ; outer lip straight ; base of the pillar curved in-
wards, and marked by two strong plaits ; upper plaits
obsolete or wanting ; aperture effused at the base only.

biplicata. Tank. Cat. 2332. eburnea. Zool. 111. ii. 58. f. 2.
purpurata. Zl. 111. ii.. 58. f, 1. conoidalis La7n. No. 57.
mutabilis Sai/. oryza Lam. No. 62.

SuB-FAM. 4. ANCILLARINiE.

Shell oliviform, highly polished ; aperture very effuse ;
suture concealed by enamel ; base with one or two

* The union of the VolutidcB and the TtcrbinellidiB is so intimately
effected by Olii'clla biplicnla and Pseudoltvn plumhea {see Jig. '3. p. Si?.), that
the two plaits on the pillar of the former shell alone separate the two
families.

PART II.

MARGINELLINiE.

323

strong grooves, which form a little tooth
at the edge of the outer lip ; inner lip
wanting ; base of the pillar thick, vitreous,
obliquely striated, and turned outwards.

Ancillaria Lam. The characters, at
present, are those of the sub-family, as
the genera have not been worked out.
A. glabrata Sw. {fig. 88.)

SuB-FAM. 5. MARGINELLIN^E.

Shell small; oval; spire short or concealed; outer lip,
and often the inner, very much thickened and inflexed,
with the inner margin tcrenated ; pillar with distinct
plaits ; the base with a wdde, but not a deeply cleft
notch.

VoLUTELLA Sw, BulHform ; ovate oblong ;
spire either entirely or almost concealed ;
pillar with four oblique plaits at the
base ; aperture not striated ; outer lip
smooth, thickened; inner lip w^anting.

{fig- m

V. bullata. Chemn. 150.- f. 1409-10.
oblonga, Zool. 111. ii. pi. 44. f. 1
guttata. lb. £ 2.

Persicola Schiim. General form of Volutella ; but
the spire always concealed ; plaitsnumerous,
and extending nearly over the whole of the
pillar; the aperture striated; inner lip thick
ened, spreading.

avellana. En. M. 377. f. 5. lineata. En.M. 377.
maculata Sw. lb. f. 3. f. 4. {fig. 90.)

Gibber ULA Sw. Sub-oval ; spire slightly prominent ;
top of the outer lip dilated and gibbous ; base of the
inner lip with plaits ; inner lip broad, spreading.
G. zonata. En. Meth. 374. f. 6.

Marginella Lam. Oval ; spire slightly prominent ;

Y 2

324 SHELLS AND SHELL-FISH. PART II.

inner lip very much developed^ and forming a tumid
rim all round the aperture.

M. lactea Sio. Sow. Gen. f. 3.

Glabella Sw. Volutiform ; the spire more
or less conic, and well developed ; pillar
with basal plaits ; inner lip obsolete ; outer
lip thick_, toothed, or crenated ; rarely
smooth.* (^fig. 91.)

P. ruffina Sw. En. Meth. nubicola. En. M. 377. f. 2.
377. f. 6. bifasciata. lb. f. 8.

Goodalli. Tan. Cat. 2151 a. limbata. lb. 376. f. 3.
If aba. En. Meth. 377. f. 1. casrulescens. lb. 376. f. 8.

Family 5. CYPR^ID^. Cowries.

Oval ; polished ; spire entirely concealed ; aperture as
long as the shell, narrow, and open at each end ; outer
lip generally thickened and inflected.

SUB-FAM. 1. CYPR.^IN^.

Inner lip striated or toothed.

Cypb^a Linn. Shell always entirely

smooth ; the extremities of the aperture

obtuse ; the teeth marginal, and not

extending over the circumference of the

lips.

C. Arabica. Sow. Man. f. 445, 446.
caput-serpentis Lam. {Jig. 92. )

PusTULARiA Sw. Shell generally marked by elevated
pustules ; aperture very narrow, and linear ; the ex-
tremities more or hss produced ; the teeth continued
beyond, and frequently forming elevated striae across,
the lips.

P. cicercula. En. Meth. 355. globulus. (Aberrant.) En.
f. 1. ^ Meth. 356. f. 2.

* M. ccei'ulescens Lam. {prunum Linn.) unites this type to Volutella.

PART II. OVITLIN.I:. 325

Trivea Grai/. Shell marked with transverse, unin-
terrupted, elevated lines, uniting with the teeth ; the
aperture wide, and the extremities obtuse ; inner
lip with a thickened protuberance ; pillar concave
within,
coccinella. En. M. 356. f. 1. Pediculus Aiict.

Cypr^dia Sw. Cypraeform ; the base contracted ;
the body-whorl not flattened beneath ; shell cancel-
lated ; aperture of equal breadth throughout ; a few
thickened, short teeth on the pillar ; lip at the base,
which is not internally concave,*

C. cancellata Siv. Sp. Nov.

CypK^ovAt Gray. Cyprgeform ;'teeth of the inner lip
wanting, being represented by fine raised lines con-
tinued on the back of the shell ; aperture rather
effuse ; top of the outer lip much projecting.
C. capensis. Sow. Man. f. algoensis Gray. (Aberrant. )
444. Sow. Man, f. 447.

SuB-FAM. 2. OVULTN^

Oviform ; smooth, polished ; the extremities of the
aperture more or less produced ; inner lip without teeth.

Cypr^lla Sw. Cyprseform ; inner lip thickened
above into a point as long as the outer lip, the mar-
ginal teeth of which are very regular ; a circular de-
pressed line at each extremity.

C. verrucosa! En. Meth. 357. f. 5.

OvuLA Lam. Oviform ; top of the outer lip elevated
and produced beyond that of the inner, which is
turned and much thickened ; both lips equal at their
base, and slightly produced.

O. ovum. En. Meth. 358. f. 1.
BiROSTRA Sw. The two ends of the aperture suddenly

*' Fossil only ; differing from Trivea in its contracted base, in the equa-
lity of its aperture, and the equal convexity of the inner lip within,
f Abbreviated from Cyprcsovulum. This seems the strombiforra type,

Y 3

326

SHELLS AND SHELL-FISH.

PART II.

contracted and produced into two long beak-like pro-
cesses ; aperture effuse ; the outer lip inflected^ but
not toothed.

B. volva. En. Meth. 357. f, 3.

Carinea Sw. Oblong ; the extremities not
produced ; aperture nearly straight, almost
central, contracted above, and very effuse
below ; lips equal ; the outer slightly
toothed.

C. gibbosa. En. Meth. 357. f. 4. (Jig. 93.)

VoLVARiA Lam. Cylindrical ; lengthened ; the ex-
tremities obtuse ; the surface sculptured ; base of the
pillar with 3 — 5 distinct plaits ; outer lip crenated ;
aperture linear ; fossil.

V. concinna. Sow. Man. f. 439. (/^. 94. a.)

04.
Oylindrella Sw. Cylindrical, narrow, and

obtuse, as in Volvaria ; but the surface

and outer lip are smooth, and there are

no plaits on the pillar.

C. alba Sw. {fig. 94. I. )

Erato Risso. Ovate, more or less angulated, smooth
or granulated, with a dorsal scar, short spire, and
large, angulated, emarginated aperture ; pillar slightly
crenated ; outer lip reflected, and denticulated on the
inner edge ; sutures covered with enamel.*

E. Maugeri.

A,

Sow. Man. 43. f. 454.

Order PHYTOPHAGA.

Family 1. HELICIDiE. Snails.

Animal pulmonary ; breathing by a lateral opening ;
shell light, turbinated, or spiral ; the aperture always

* I have not seen this curious little genus. Mr. Sowerby, in addition to the
above, adds, " it resembles Marginclla, but has no folds on the pillar. Hav-
ing a groove down the back, he considers it intermediate between Margi-
nella and Cyprcea,'" (or rather Trivea), The circle of the Cyprceidce is
thus closed, and its union with the Volutidce at once established.

PART II.

LIMACIN^.

327

entire, rarely closed by an operculum_, and sometimes
only rudimentary.

SuBFAM. 1. LIMACIN^. Slugs.

Shell very thin, often rudimentary, and generally too
small to contain the entire animal ; tentacula, when
present, cylindrical, and bearing the eyes at their tip.

Herpa. Tentacula two, or none ; shell none ; jaws
none, or not discernible.

Herpa Guild. Linear, fusiform, anterior greatly at-
tenuated ; eyes very small, sessile ; tentacula none.
H. gigas. See App. '-~ /^

Onchidium Buch. (fig. 95.) Tentacula

two ; mantle very large, tuberculated,

almost covering the body ; mouth

with two triangular flattened lobes.

; Typhoe Buck. Lin. Tr. v. 132.

LiMAx Linn. Tentacula four ; shell
rudimentary, or none.

Limax Linn. Orifice near the pos-
terior part of the mantle ; shell
very small.

L. variegatus. GrifF. Cuv. pi. 35. f. 2.

Avion Fer. Orifice near the anterior end of the man-
tle ; shell none.

A. empiricorum. GrifF. Cuv. pi. 35. f. 1.

Vaginula Fer. Mantle large, covering the whole body ;
no shell.

V. Taunaysii. Griff. Cuv. p]. 35. f. 7.

Parmacella Lam. Mantle moderate, membranaceous,
placed on the middle of the back ; the edges loose ;
shell oblong, flat ; spire minute.

P Olivieri. Griff. Cuv. pi. 35. f. 5.

Testacella Lam. Mantle very small, and placed at the
posterior extremity of the body ; shell small.
T. haliotoidea. Griff. Cuv. pi. 35. f. 4.
Y 4

328 SHELLS AND SHELL-FISH. PART 11.

ViTRiNA Drap* Mantle with a double border ; the
upper one lobed, and folded back upon the shell ;
posterior part of the body obtuse, truncate ; shell
slightly turbinate, thin, ear-shaped, polished ; too
small, in general, to contain the animal.
V. pellucida, Drap, Moll.

Stenopus Guilding. Body linear, long ; the disk very
narrow, superior ; tentacula thickened, clavate ; shell
thin, nearly discoid, nearly equal to the animal.
S. cruentatus Guild. Zool. Journ. iii. pi. 15. f. 1 — 5.

SucciNEA DrapA Shell nearly equal
to the animal ; oblong, thin ; spire
short, pillar none ; aperture very
large.

S. amphibia. Sow. Man. f. 265. {jig. 96.)

SuB-FAM. 2. LUCERNIN^E. Land Volutes, or Lamp Snails.

Shell discoid ; the spire scarcely raised ; the substance
solid ; surface either granulated or striated ; aperture
generally toothed.

Leiostoma Sw. Shell patulous; the aperture very
large and wide ; spire of only two or three small
whorls ; outer lip reflected.

Leiostoma Sw. Surface granulated ; a transparent
glazing extending far beyond the inner lip.

gigantea. Fer. 15. f. 5, 6,7. vesicalis. Chem. 208. f. 2051,
Jamaicensis. lb. 14. f. 6—8. 2052.

LucERNA Humph. Shell discoid, of several graduated
whorls ; the surface granulated ; the spire slightly
elevated ; circumference carinated ; teeth, Avhen pre-
sent, on the outer lip only.

Caracolla Lam. Aperture circular ; the two lips united;
teeth none ; umbilicus open,
lapicida. Chem. f. 1107. tectiformis. Zool. J. i. pi. 3. f. 6.

* The sub-genera remain to be determined,
f The same remark.

PART II.

LUCERXIN^. 329

Discodoma Sw. Teeth none ; aperture angulated ;
the inner lip nearly obsolete, the outer only slightly
thickened ; margin carinated.
albilabris. Chem. 125,f. 1090, Gualteriana. Chem, 5. vig.

1091. 44. a—c.

inflata. lb. 126. f. 1 100, 1. marginata. lb. 102. f. 1095.
gigas. lb. f. 2044, 5. angistoma. lb. 125. f. 1092.

Lucerna Humph. Outer lip with teeth, either mar-
ginal or internal ; the outer lip thick and reflected ;
circumference carinated.
acutissima. Zool. 111. ^ ii. fasciata Guild. Bow. Conch.

pi. 96.* ' 7. f. 23.

lanx. En. Meth. 462. f. 2. fulgurata Sow.\
lychnuchus. Ch. 126. f. 1108. sinuata. Chem. 126. f. 1110

— 1102. (Aberrant.)

Anastoma Lam. Aperture turned upwards, furnished
with plaited teeth on both sides.

A. depressa. Chem. 109. f. 919, 920.

LucAdula Sw. Aperture transverse ; both lips much
thickened and united ; the outer with marginal obso-
lete teeth at the base ; umbilicus closed.

' Barbadensis Lam. No. 49. p. 78. Fer. Moll. pi. 47. 2, 3, 4.

LucERNELLA Sw. Teeth on both sides of the aper-
ture ; surface regularly and distinctly striated. Cir-
cumference convex.:}:

Polydontes Montf. Aperture nearly circular, sur-
rounded with obtuse tubercular teeth.
P. imperator. Bowdich, Elem. of Conch, pi. 7. f. 21.

Lyrostoma Sw. Aperture lyre-shaped, very contracted
near the body-whorl, widened beyond.

L. labyrintha. Chem. pi. 208. f. 2048. Lam. p. 46.

* The original figure of the shell and animal given in Zool. 111. is
copied by Feriissac, Guerin, and numerous others, but so badly, that the
shell appears to be a totally different species.

f Mr. Sowerby has published a very beautiful detached plate of this
species, first described by himself.

X Some slight variation has been made in the arrangement of this group
from that previously stated at p. 193. Cyclodoma is here united to Lucer-
nella, and the new sub-genus Lyriostoma proposed.

330 SHELLS AND SHELL-FISH. PART II.

Lucernella Sw. Shell small, striated ; outer lip with
marginal, not internal, teeth ; inner lip with an ele-
vated toothlike plate; umbilicus generally pervious.
L. hippocastaneum. Chem. 209. f. 2055, 2056.

Polygyra* Shell completely discoid ; no pillar ; aper-
ture angulated and margined ; a small tooth on the
inner lip.

P. septemvolvus. Sow. Man. carabinata. Bow. Conch,
f. 275, 276. pi. 7. f. 1 9.

Lucidella Sw. Sub-trochiform ; spire conic, and sud-
denly pointed ; outer lip with marginal tuberculated
teeth, f

L. aureola. Zool. Journ. i. pi. 6. f. 15.

PusiODON Sw. Shell flattened, smooth ; the body-
whorl large, and much dilated at the aperture ; spire
small, flat, of three or four contracted whorls ; aper-
ture very oblique, sinuated, or obsoletely toothed at
the base of the outer lip, which is spreading and sub-
reflected ; inner lip obsolete ; umbilicus open,
zonaria. Chem. 132. f. 1188. auriculata. Zool. 111. i. pi, 6.

f J*"'>2 Thelidomus Sw. Shell coarsely granulated ; body-
"^ whorl and spire as in the last genus ; but the former
is more ventricose, and the latter more raised, and
somewhat distorted ; outer lip thickened and reflected ;
the base broad and flattened, sometimes with granu-
lated marginal teeth ; umbilicus none.
T. (Helix) striolata Guild, also Fer. Moll. 44. f. 1-4.

SuB-FAM. 3. HELICIN^. Common Land Snails.

Shell ventricose, turbinated ; the aperture transversely
oval, never toothed ; the body- whorl large and ven-
tricose. J

Helix. Linn. Shell globose, turbinate ; body-whorl
ventricose ; spire slightly raised, obtuse.

* I find this name as above quoted, but no mention is made in the text of
whose genus it is.

f I have been obliged to designate what seem to be the types of this ge-
nus, in order to show more clearly its union, on one side witii Cvclostoma,
and on theotherwith Claiisilia, or the toothed division of the Achatin^e .
Mr. Gray's valuable paper may be consulted with much advantage

t Except in Pupa, which has teeth, and a small body-whorl.

PART II. HELICIN^. 331

HemicycJa Sw. Shell discoid ; spire rather flattened,
but not small, and of four whorls ; outer lip semicir-
cular, dilated into a broad, flat margin, but not re-
flected ; inner lip nearly obsolete, but sometimes
with a small obsolete tooth ; umbilicus none ; sur-
face distinctly striated.

H. plicaria. En. Meth. 462. f. 3.

Helix And. Body- whorl ventricose ; spire more or less
conic, but always shorter than the aperture ; umbili-
cus almost always closed, or not existing ; outer lip
reflected or thickened.

pomatia. Chem. 128. f. 1138. hoemastoma. Ch. 130. f.ll50.
aspera. Penn. pi. 87. f. 3. melanotragus. En. Meth.

lactea. Chem. 1 20. f. 1 1 6 1 . 462. f. 4.

Zonites Montf. Shell sub-ventricose, but the body-
whorl depressed, the margins convex ; spire often of
many whorls ; outer lip thin ; umbilicus open,
unizonalis. En. M. 462. f. 6. citrina. Chem. 131. f. 1177.

Epistyla Sw. Shell very thick, conic, and obtuse ; the
whorls very numerous ; body-whorl and aperture
small ; outer lip thin.

E. conica Sw. Sow. Man. f. 281.

Streptaxis Gray. Heliciform ; but the pillar or axis
not perpendicular, which gives the body-whorl a dis-
torted appearance ; umbilicus small, open ; spire of
six whorls ; outer lip thickened.

S. contusa Gray. Sow. Man. f. 269, 270.

Geotrochus Sw. Shell somewhat spiral; the spire
being conical, often trochiform, and always longer
than the aperture, which is transverse and without
teeth.

Hemitrochus Sw. Whorls convex ; spire conic, obtuse,
not longer than the aperture ; outer lip having a
thickened rim inside the margin, which is acute ;
umbilicus closed.

H. hoemastomus Sw. {See Jig. 19. p. 165.)

332 SHELLS AND SHELL-FISH. PART II.

Geotrochus Sw. Trochiform ; the body- whorl more or

less carinated ; the spire pointed and acute ; outer

lip thickened and reflected, inner almost obsolete ;

umbilicus almost obsolete.

pileus Zool. 111. ii. pi. 91. Ferussacii Lesson, Voy. 8. f. 5.

Pythohelije Sw. Sub-spiral ; body-whorl large, ven-
tricose, and hardly angulated ; spire convex and ob-
tuse ; outer lip thickened and reflected, generally
separated from the pillar by a sinus ; umbilicus none;
aperture nearly round.

P. castanea Sw. Bow. Conch, pi. 8. f. 27.

Geomitra Sw. Conic, thick, obtuse ; the whorls stri-
ated, and coronated with tubercles ; body- whorl small ;
aperture very small, circular ; lips united, the outer
one thin ; umbilicus small,
bicarinata. Zool. Journ. i. pi. 3. f. 7. {fig- 20. p. 166.)

Gonidomus Sw. Conic, thick, obtuse ; the spiral
whorls distorted ; body-whorl contracted ; aperture
oval, perpendicular ; the lips thickened ; umbilicus
open, but not deep.*
? pagodus. Lesson, Voy, pi. 8. f. 6. (fig. 21. p. 166.)

Pupa. Shell cylindrical; the spire much produced;
the middle whorls thicker than the body-whorl ;
teeth generally on the pillar, but none on the outer
lip ; aperture mostly round.

Plicadomus Sw. Spire moderate, regular, and thick,
but gradually conic ; the tip obtuse ; aperture perpen-
dicular ; inner lip wanting ; outer lip semicircular ;
the margin dilated and reflected.

P. sulcata. Chem. J 35. f. 1231, 1232.
Pupa Lam. Spire thickest towards the middle ; the
tip abruptly pointed ; aperture oval ; the lips con-
siderably thickened and united ; a single plait gene-
rally on the pillar.

P. mumia. Mart. 153. f. 1439.
* This seems to represent Streptaxls.

PART II.

HELICIX.E.

333

Gonospira Sw. Spire perfectly cylindrical, of equal
thickness, the tip obtuse, with the whorls large ; aper-
ture oval ; lips thickened ; pillar with or without a
plait.

G. polanga Desk. Lesson, Voy. pi. 8. f. 8.

Megaspira Lea. Spire excessively long, of more than

twenty volutions, and of nearly equal thickness ; the

tip persistent, and slightly pointed; aperture rounded;

outer lip thin ; pillar and inner lip with sharp plaits.

M. elatior Spix. Test. Braz. 15. f. 1.

Siphonostoma Guild. Spire excessively long, pointed,

but the upper portion deciduous ; aperture circular,

spreading ; the lips united, and detached from the

adjoining whorl, (^fig. 97. c. d.)

S. costata Guild, [jig. 97. c, d.}
fasciata. En. Meth. 461. f. 7.

Helicella Feruss. Shell discoid,
but the body- whorl thick and
ventricose ; the spire very small
and sunk ; pillar none ; aperture
semicircular ; outer lip thickened ;
umbilicus very wide. (^^. 98.)

pellis-serpentis (_^^. 98.); also Fer.
MoUus. pi. 66. 73. 75. 77.

S34> SHELLS AND SHELL-FISH. PART II.

SuB-FAM. 4. ACHATIN^.

Shell spiral ; aperture oblong or oval, always equal, and
generally shorter than the spire.*

Clausilia Drap. Aperture oblong, with teeth on both
sides t ; shell cylindrical.

Pupella Sw. X Spire moderate, obtuse ; the whorls of
equal thickness ; basal whorl and aperture small ;
the latter with teeth on both sides ; the lips not
thickened.

frumentum. Drap. 3.f.51,52. vertigo. Bow. Conch. 8.
variabilis. lb. f. 55, 56. f. 35.

Eruca Sw. General habit of the last ; but the tip of
the spire is thicker, and there is only one, or no
plate, upon the inner lip only.

muscorum. Drap. 3. f. 36-38. dolium. Drap. 3. f. 43.
fragilis. lb. 4. f. 4. umbilicata. lb. 3. f. 39,]40.

Balia Gray. Spire very long, of numerous persistent
whorls ; aperture simple, without teeth or folds.
B. fragilis. Drap. pi. iv. ventricosa. Zool. Journ. i. pi.
f. 4. 5, 6.

Clausilia Drap. Spire very long, but the upper portion
deciduous ; aperture oblong, ear-shaped, with teeth
on both sides ; the lips united, and their edges
spreading,
papillaris. Drap. 4. f. 13. plicatula. lb. 4. f. 17,18.

Macrodontes Sw, Size larger; bulimiform ; spire longer
than the aperture, which is surrounded with large
teeth ; lips united ; the outer large, dilated, and the
edge reflected. Tropical America only.

M. Sowerbeyii Sw. Zool. Journ. i. pi. 5. f. 2.

2. BuLiMus. Basal whorl ventricosc ; outer lip mar-

* Except in Helicina and the turbinated Cych'^omce.

f Except in Balia, which has no teeth.

X Including the European Pupu;, f'ertigo, and A!<e.

PART II. ACHATIN^. 335

gined and reflected; aperture without teeth^ rarely

with a single fold.*
Aui'icula Lam. Body-whorl sub-ventricose ; spire

short ; the whorls few ; pillar with one or two plaits ;

outer lip margined and reflected.
Sileni. En. Meth. 460. f. 4. leporis. Lam. {fig. 27. p. 181.)

Bulimus Lam. Outer lip thickened and reflected ;
spire short ; pillar smooth,
melanostomus. Zool. 111. i. 4. Australis. Bow. C. 8. f, 30.

Bulimulus Leach. Outer lip thin, or sub-reflected ;
spire equal or rarely longer than the aperture.

undulatus Guild. Zool. J. iv. 169. Antiguensis. lb.
stramineus. lb. iv. 170. Proteus. lb.

Leptospira Sw. Spire excessively long, sub-cylindrical;
body-whorl largest ; outer lip thickened ; aperture
oval ; no teeth,
striata Sw. Chem. 135. f. 1226. signata Sw. {fig. 97. a,h.)

Goniostoma Sw. Spire elongated, of few whorls ; aper-
ture contracted at each end ; lips margined ; the
pillar curving inwards ; the base slightly notched.
T. erubescens Sw. Zool. Journ. i. pi. 5. f. 2. t

3. AcHATiNA. Outer lip always thin ; base of the
piUar truncated, or sinuated, before it joins the outer
lip.

Macrospira GuUd.J Spire excessively long, sub-
cylindrical ; body-whorl largest ; outer lip thin ;
aperture oval.
M. octona. (Helix octona Auct.^ aperta Guild, (fig. 97. e,f.)

Cochlycopa\ Fer. Oblong; body-whorl slender; sur-
face striated ; spire variable ; outer lip with a promi-
nent lobe near the base.

C.glans. Chem. 117. f. 1009, 1010.

* Only in Auricula.

f The singular lateral position of the aperture is not expressed in this
figure. See^^. 25. p. 177.
X Subsequently named, inadvertently, Chionella, by Mr. Jeffreys.
§ Very properly substituted by Ferussac for Polyphe7nus.

.336

SHELLS AND SHELL-FISH. PART II.

Achatina Lam. Oblong ; body-whorl ventricose ; sur-
face smooth ; spire variable ; outer lip without any
lobe. {fig. 23. p. 170.)

A. marginata Sw. Zool. 111. 1st Series, pi. 30.

Achatinella Sw. Small ; sub-trochiform ; spire obtuse ;
outer lip with a thickened internal margin.
A. pica. Zool. 111. ii. Series, pi. 99.

Leucostoma Sw. General shape of the last, but the
upper lip has a thick pad at the top, and another
over the base ; affinities doubtful.

L. variegata Sw. {fig. 24. p. 172.)

Cyclostoma. Aperture circular, and closed by an oper-
culum j the margins of both lips united.

Cyclophora Montf. Turbinate ; the spire very short,
and generally pointed _; umbilicus very large ; aper-
ture entire.

unicarinata. En. M. 461. f. 1. involvula. Sow. Man. f. 304.

volvula. lb. f. 5. articulata. Griff. Cuv. 28. f. 1.

lincina. lb. f, 2. pulchra. lb. f. 3.

pulchra. Sow. Gen. f. 2. Madagascariensis. lb. f. 4.

ligatuni. lb. f. 4. auricularis. lb. f. 5.

Cyclostoma Drap. Spiral ; spire sub-cylindrical and
obtuse ; pillar sometimes wanting ; umbilicus small,
or closed.

C. labio. En. Meth. 461. f. 4.

Cydotus Guild. Nearly discoid ; pillar none ; spire
scarcely raised, and the tip obtuse ; a small siphon
at the top part of the aperture.

planorbulus. En. M. 461. f. 3. variegatus Sw. Sow. Gen. f. 1.

Megalomastoma Guild. Cylindrical, resembling Pupa,
but has a horny operculum ,• spire not thickened ;
teeth or fold on the pillar none, {fig, 97- g^ h, i.)

flavula Sw En. Meth. 461. f. 6. brunnea Guild. (fig.93.g, h, i. )

Heltcina Lam. Shell turbinate ; outer lip thickened,
and reflected ; inner lip thick, and spreading over
the umbilicus ; aperture semicircular, or lunate.

PART 11. LIMNACINiE. 337

Helicina Lara. Heliciform ; aperture with an open

slit^ or narrow fissure at the base.

major Gray. Zool. Journ. i. sub-marginata. lb. pi. 6. f. 11.
68. pi. 6. f. 10.

Pachytoma Sw. Aperture entire ; the inner lip very

thick ; the spiral whorls hardly convex.

occidentalis. Zool. J. iii. 15. viridls. Zool. Journ. i. pi. 6.
f. 6—10. {fig. 28. p. 184.) f. 7.

Oligyra Say. Aperture entire ; the base of the pillar
produced beyond,
rhodostoma. Zool. Journ. i. pi. 6. f. 9. orbiculata Say.

Trochatella Sw, Trochiform ; spire elevated^ acute •
inner lip very thin ; outer lip spreading : represent-
ing Cyclophora.

T. pulchella. Zool. Journ. i. pi. 6. f. 1.

SuB-FAM. 5. LIMNACIN^. River Snails.

Animal pulmoniferous ; tentacula two, often flat ; the
eyes basal {fig. 100. e) ; shell very thin; operculum
none.

Planorbis. Shell discoid, both surfaces nearly alike ;
pillar none ; aperture oblique ; aperture reversed.

Planorbis Drap. Spiral whorls few ; body-whorl ven-
tricose.
P. corneas. Drap. 1. f. 42 — 44. Sow. Man. f. 311.

Spirorhis Sw. Shell greatly depressed ; the whorls
very numerous.

S. vulgaris. Drap. 2. f. 6, 7.

Helisoma Sw. Shell ventricose, the spire sunk below
the body-whorl ; whorls hardly three.
H. bicarinata. Sow. Gen. f. 4.

Segmentaria Flem.* Shell greatly depressed ; the
whorls very few ; the internal cavity divided, by

* It is not a little extraordinary, that no writer, that I am aware of, Bri-
tish or Continental, has adopted this, the most remarkable t3'pe among the
aquatic Pulmonaria. Dr. Fleming deserves much credit for being the first
who characterised it.

338

SHELLS AND SHELL-FISH.

PART II.

transverse testaceous partitions, into'chambers, which
communicate with each other by triradiated apertures.
Representing the Cephalopoda.

S. lacustris Flem.

LiMNEA Lam. Very thin spiral ; the spire
variable in length, but always pointed ;
aperture large, effuse ; outer lip, typically,
much dilated and rounded.

L. stagnalis. Sow. Man. f. 308. (Jig. 99.)
aserta. lb. f, 309.

LeptoUmnea Sw. Nearly cylindical; spire
thick, lengthened, longer than the aper-
ture; which latter is small.

L. elongata. Sow. Gen. f. 6.

Physa Drap.* Shell generally reversed, smooth, and

polished; aperture oval, not dilated, {^fig. 100.)

rivalis. {Jig. 100. 6.) fontinalis. lb. f. 9. (Jig. 100. a.)
GuUdingii Sw. (jig. 100. c, d, e.)

100

^"

PoTOMOPHiLA Sw. Shell resembling a Limnea, but with
a distinct fold on' the pillar.
P. bulimoides. En. Meth. 459. f. 7. (Jig. 31. p. 187.)

Ancylus Lam. Shell thin, patelliform ; resembling a
limpet.

A. fluviatilis. Sow. Man. f. 246.

Family TURBID^E.

Shell solid, but not perlaceous, spiral ; aperture entire,
closed by an operculum.

* Between the shells of Physa and Lymnca there is no great difference ;
but their animals are too distinct to be united in any system of malacology.

PART II.

AMPULLA RlNiG.

339-

SuB-FAM. ? THALLICERA.

Th ALLicERA Q,uoy. Shell globose ; spire depressed ;
outer lip thin^ with a sinus above ; inner lip thick-
ened, with a prominent plait near the base.
T. avellana. {Jig. 34. p. 196.) Chem. 188. f. 1919-20.

SuB-FAM. AMPULLARIN^.

Animal with a respiratory siphon; shell globular or
turbinate.

Valvata Drap* Shell turbinate, sometimes nearly dis-
coid; spire very short; the whorls convex; aperture
circular ; operculum spiral ; umbilicus pervious.
V, piscinalis. Sow. Man. f. 322.

Ampullaria Lam. Shell glo-
bose, rarely discoid, turbinate ;
spire very short ; aperture ob-
long, pointed above, rounded
below.

Ampullaria Lam. Outer lip thin ;
operculum horny.

fasciata Lam. {fig. 101. a.)

Pachylabra.f Outer lip thick-
ened; operculum shelly,
globosa^'w. Zool. 111. i. pi. 119.

Lanites Montf. Shell reversed ;

the body- whorl ventricose only in the middle ; outer
lip generally thin.

L. Guinaica. Sow. Man. f. 319.

Ceratodes Guild. Shell discoid ; body-whorl higher
than the spiral whorls ; outer lip thin ; operculum
horny.

C. Cornu-Arietis. Sow. Man, f. 320.

Paludina. Spiral; spire equal, or longer than the
aperture ; lips thin.

* Affinities uncertain.

t Pachystotna Guild., already used in Ichthyology.

z 2

340 SHELLS AND SHELL-FISH. PART 11.

Paludina Lam. Whorls inflated ; umbilicus open ;
operculum horny ; aperture ovately round,
elongata. Zool. 111. i. p\. 98. (Jiff. 101. b.) unicolor. lb. (c.)

Nematura Benson.* Whorls slightly convex; aperture
small, oblique, contracted ; operculum spiral, horny.
Sow. Man. f. 305.

Meladomus Sw. Spire pointed; aperture oval, re-
versed, pointed, and contracted above ; umbilicus

none ; operculum }

M. bulimoides. f Sw. Sp. Nov.

SuB-FAM. MELANIAN^.

Shell spiral ; the spire always as long as, and generally
much longer than, the aperture ; body-whorl small.;}:

Paludomus Sw. Shell oblong-globose, strong; spire
shorter than the aperture ; inner lip very thick.

Paludomus. Shell smooth ; outer lip slightly spreading,
the margin crenated ; inner lip very thick and ena-
meled. India.

P. globulosa. GrifF. Cuv, xii. conica. GrifF. Cuv. f. 5.
pi. 14. f. 6. retiisa. lb. f. 9.

Anculosa Say. Spire very short ; outer lip sinuated,
thin ; top of the inner lip thickened internally ; but
obsolete in the middle, and flat at the base. America.
pra^rosa and monodontoides Say. Sow. Man. 314.

Hemimitra Sw. Resembling Paludomus ; but the
whorls are coronated. India.

H. retusa. Sw. Sp. Nov.

Melania. Shell elongated, spiral; the aperture oval,
entire ; the outer lip dilated at its base.

• I do not know this type.

+ Entirely brownish black. The shape and size similar to Bulimus
ciirinus ; but the outer lip thin. Inhabits China ?

X Except in Paludomus, which blends into Melado?nus, and thus unites
this with the last sub-family.

PART II.

MELANIANiE.

341

Melacantha Sw. Spire and aperture

nearly of equal length ; the whorls

coronated with spines ; inner lip

very thin.

M. amarula Sw. Zool. 111. ii. pi. 29.
f. 1. {fig. 102. «.)
setosa Sw. lb. ii. f. 2.

Melania Lam. Subulate and elon-
gated; inner lip wanting, {^fig. 102. 6.)

M. quadriseriata. GrifF. Cuv. 14. f. 3.

Potadoma Sw.* General characters of Melania; but the
outer lip is hardly dilated, and the top of the inner
lip is internally thickened,
P. Frethii. GrifF. Cuv. 14. f. 2. l^vis. lb. 14 f. 8.

Hemisinus Sw. General shape of Melania ; but the
base of the aperture is contracted and emarginate ;
outer lip crenated.

H. lineolata. GrifF. Cuv. xii. pi. 13. f. 4.

Melanella Sw Obovate ; spire scarcely longer than
the aperture, which is entire ; inner ,''p much thick-
ened its whole extent. t

Melanopsis Lam. General form of Melania; but the
spire shorter, and the base of the aperture notched.

Melafusus Sw. Sub-fusiform ; the base contracted,
and the aperture and spire nearly equal.
1 Species, America.

Melanopsis Lam. Obovate ; the base obtuse ; io3 A
spire pointed, acute ; inner lip greatly thick-
ened, particularly at its upper part, and in-
ternally ; suture compressed and flattened,
buccinoides Lam. {fig. 103.)

Melanithes Sw. Habit of Melania ; but the spire is
obtuse, and the suture prominent.
Ferus. Moll. Melanop. pi. 2. f. 1 1, 12, 13., pi. 1. f. 5. 7. 16.

* I suspect that the true distinction of this second type oi Melania will
rest on tlie deciduous nature of the spire.

+ This type, which represents Planaxis, unites on the other side to Me-
lacantha. I have a small species, but know not whether it is described.,

z 3

342 SHELLS AND SHELL-FISH. PART II.

Canthidomus Sw. Spire generally short ; whorls co-
ronated with spines, or marked with longitudinal ribs;
base obtuse.

F^rus. Moll. Melanop. pi. 2. costata. Sow. Gen. f. 3.
f. 9. 10.,pl. 1. 13,14,15.

Melatoma Sw. Fusiform ; longitudinally
ribbed ; a deep sinus at the top of the
outer lip ; base contracted, channel wide.*
M. costata Sw. {Jig. 104.)

Cerithidea. Clavate ; cerithiform ; aper-
ture sub-emarginate.

Triphorus Desh. Shell small, slender, sub-
cylindrical ; spire long, of numerous
whorls ; aperture sinistral ; outer lip re-
flected over and united to the inner, but
leaving a circular opening.

T. costata. Sow. Gen. f. 375.

Cerithidea Sw. Shell light ; decollated ; outer lip semi-
circular, dilated by a flattened border ; aperture
emarginate.
C. lineolata. Griff. Cuv. 14. f. 4. fragilis, lb. 32. f. 12.

Ceriphasia Sw. Cerithiform ; outer lip thin, dilated at
the base ; aperture small, slightly emarginate, without
any internal groove ; inner lip thin.

C. sulcata Sw. (Jig. 38. p. 204.)

Planaxis. Animal marine ; shell obovate ; inner lip
much thickened above ; pUlar flattened ; the base
with a small notch or sinus.

P. semisulcatus Lam. Sow. Gen. f. 3.

SuB-FAM. TURBIN.E.

Animal marine ; shell solid, spiral ; aperture round or
oval, entire, sometimes toothed.t

* Representing P/^M>-o<owrt, and united to Melafusus.
f Except certain types of Me/ampus, which appear amphibious ; and
others which have plaits and teeth on the aperture.

PART II. TURBINE. 343

ScALARiA Lam, Shell turreted, marked with longi-
tudinal ribs ; aperture circular, entire,
pretiosa. En. Meth. 481. f. 1.

TuRRiTELLA. Shell turreted ; spire subulate_, very

long ; umbilicus none.
Rissoa Fremonville. Spire moderate, perpendicular,

acute ; outer lip thickened ; aperture oval.
R. reticulata. Sow. Man. 346.

Turritella Lam. Aperture round, entire ; outer lip thin.
T. duplicata. En. Meth. 449. f. 1.

Eulima Desh. Shell smooth, polished ; spire distorted,
acute ; outer lip thin, dilated in the middle.
E. labiosa. Sow. Man. f. 347. marmorata. lb. f. 348.

Pyramidella Lam. Shell smooth, polished ; outer lip
thin ; base of the pillar produced, and marked with
distinct plaits.

P. terebellum. Sow. Man. f. 342.

Truncatella Risso. Cylindrical ; turreted ; the apex

very obtuse ; aperture oval, small, entire ; the lips

united.

T. leevigata Risso. Drap. costulata. Zool. 111. pi. 13.
pi. 1. f. 31. f. 13—18.

Turbo Linn.* Shell turbinate ; spire short, generally
pointed, not longer than the aperture ; inner lip
flattened, broad,
littoreus (the common winkle). Sow, Man. 363. {fig. 109. e.)

Tornatelldf Lam. Animal marine ; shell solid ; body-
whorl cylindrical ; spire pyramidical, pointed ; aper-
ture contracted above; effuse beneath ; base of the
pillar with two strong plaits ; outer lip very thin.
T. fasciata. En. Meth. 452. f. 3.

Melampus. Amphibious Volutes, Obovate, or oval ;
the spire generally short, and never longer than the

* Tuba, Assimt'nea, and Monatifrma, which may probably be sub-genera,
lam not acquainted with : and, as their animals appear unknown, I am
fearful of locating them incorrectly.

f This sub-genus possibly unites Turbo to Melatnpus ; it is the only one
which has that sort of colouring peculiar to marine shells.

z 4

344 SHELLS AND SHELL-FISH. PART II.

aperture ; outer lip thin, but thickened on the in-
ternal margin ; one or both lips with distinct teeth
or plaits ; animal with two tentacula, sessile eyes,
but no operculum.

Geovula Sw. Oval ; spire very short, tur- ^^^''

binated, cancellated, of many whorls ; ff^'^s.

apex obtuse : outer lip thickened inter- wM'-'MV\

nally; inner lip with a strong plait near p-JW Mi

the base. (Jig. 105.) |\v# ml 1

G. Midje. Griff: Cuv. 27. f. 8. W J^i /

Pedipes Adans. Shell small, turbinate or \ i£/ J
sub-spiral ; body-whorl ventricose ; aper- ^£1/
ture on both sides defended by several teeth and plaits.
P. afra. Lowe, in Zool. Journ, v. pi. 12. f. 8 — 12.

Scarabus Montf. Shell depressed ; spire as long as the
aperture ; umbilicus partly open ; both lips with
plaits, and tuberculous teeth.

S. imbrium. Sow. Man. f. 299.

Melampus Montf. Oval, sub-coniform ; spire very
short, obtuse ; aperture narrow ; inner lip thin, and
striated internally ; pillar plaited,
fasciatus. Gr. Cuv. 27. f. 13. exxguns Lew. Z. J. v. 12. f. 6,7.

Rhodostoma Sw. General form of Melampus and
Tornatella ; but the aperture is not striated, and the
inner margin of the lip is broad, considerably thick-
ened, and distinctly notched towards the top.

coffea. Chem. 120. f. 1043. nucleus. Fer. Tab. Sys. 105.
fabula. Fer. Tab. S>s. 1 05. 24. 26.

ScissuRELLA J)'Or&?^, Shell very small or minute; he-
liciform ; spire depressed ; aperture effuse ; outer lip
with a narrow fissure or slit ; umbilicus open.

S. elatior. Sow. Man. f. 340.

Family NATICID^.

Shell globose, generally smooth ; spire minute, scarcely
raised ; aperture large, semicircular.

PART II. NATICIN^. 345

SuB-FAM. 1. NATICINiE. Sea Snails.

Shell globose ; * inner lip smooth^ not depressed.

Natica Lam. Operculum shelly ; shell globose ;
ventricose ; umbilicus open^ with a central gibbous
ridge, or prominence.

N. lineata. Mart. 186. f. millepunctata. lb. 186. f.
1864, 1865. 1862, 1863.

Naticella Guild. Operculum horny _; shell globose,
but generally depressed ; umbilicus nearly filled up
with a vitreous deposition of the inner lip ; spire ob-
tuse.

? N. aurantia. Mart. 189. f. 1934, 1935.

Glohularia Sw.-j- Shell not depressed, but the aperture

very effuse ; base of the body-whorl

with a thickened belt; apex of the ""

spire acute ; recent and fossil, {^fig,

106.)

sigaretina Lajn. Coq. Foss. 13. f, 1.

patula. lb. f. 2.

depressa. lb. f. 3.

acuminata. lb. f. 4. spirata. Coq. Foss. 13. f. 7,

fluctuata. Griff. Cuv. 1. f. 4. crossitana. lb. f. 8.

Mamillaria Sw. Shell oval, heavy ; spire very small,

pointed ; inner lip considerably thickened at the top,

and filling up a large umbilicus, placed near the base

of the aperture ; aperture effuse.

M. lactea Sw. Mart. 189. tumida Sw. lb. 189. f. 1928
f. 1922, 1923. —1931.

Sigaretus Auct. Oval, flattened, ear- shaped ; inner
lip almost wanting ; umbilicus none.

T. concavus. Lam. Hist. Nat. vi. 2. p. 208.

* The arrangement of this group, from ignorance of the animals of the
major part, is purely artificial, being founde cnly on the shells.
t Globulus Sow. : altered, th:. the specific names may not be changed.

34<6

SHELLS AND SHELL-FISH. PART II.

Naticaria Sw.* Oval ; convex above ;

umbilicus small, open, placed very

near the top of the aperture ; inner

lip reflected^ small, {^fig. 107.)

N. melanostoma. Mart, 189. f. 1926, 1927.
cancellata Sw. lb. 189. f. 1939.
bifasciata. GrifF. Cuv. 1. f. 2.

Lacuna Turton. Turbinate ; thin ; spire very small,
of two whorls ; the general shape
is like JVatica, but the base is
contracted; umbilicus close to
the top of the aperture, with a
groove running on the margin of the pillar, which is
oblique ; operculum horny ; aperture effuse, semicir-
cular. (Jig. 108.)

L. ^aWidula Turton. (fig. 108.)

Leucotis Sw. Form of the shell intermediate between
Sigaretus and Lacuna ; but there is no pillar ; umbi-
licus large,, pervious ; inner lip thin^ slightly reflected
at the top I surface sculptured.

Sigaretus cancellatus. Lam. Sys. vi. 2. p. 207. Chem.
165. f. 1596. 1597,

SuB-FAM. ? NERITINiE. Nerits.

Globose ; spire very small ; pillar oblique ; inner lip
very broad, depressed, more or less flattened, and gene-
rally toothed ; aperture semicircular.

Nerita Linn, Shell solid ; inner lip toothed or gra-
nulated.

N. peloronta. Mart. 192. f. pollta. Mart. 193. f. 2002,
1977—1981. 2003.

Neritopsis Gray. Aperture sub-orbicular ; pillar lip
thickened above and below, with a wide notch in the
middle, f

N. granosa. Sow. Man. f. 331.

♦ These are probably aberrant species, connecting Sigaretus with Ma-
millaria; but, until the whole are better understood, I think it advisable
they should be kept distinct.

t Apparently related, by the shell, to Leucotis.

PART II,

TROCHID^.

34.7

Neritina Lam, General shape of Nerita ; but the
outer lip is thin and smooth, the inner one rather
convex and crenated ; surface smooth.

N. meleagris. Chem. 124. f. 1088. a — i.

Clitlion Montf. Leach. General shape of Neritina;
but there is an obtuse lobe on the inner lip, the
outer is dilated at its origin, and the whorls are armed
with spires.

C. corona. Chem. 124. f. 1083, 1084.

Velotes Mont. Nearly orbicular ; depressed ; above
convex ; beneath flat ; spire nearly obsolete ; inner
lip toothed, as large as the aperture, which is semi-
circular.

V. perversa. Sow. Man. f. 326.

Pileolus Cookson. Shell above patelHform ; spire in-
ternal ; aperture beneath small, semilunar; outer lip
margined ; inner crenated.

P. plicatus. Sow. Man. f. 332.

Naviceila Lam. Somewhat patelliform ; oval ; convex
above ; flat beneath ; aperture large ; inner hp nar-
row, thin, assuming the form of a plate across one
end of the under surface ; operculum shelly. *
N. elliptica. Sow. Man. f. 323.

Family TROCHID^.

109 ,^^ c d

* Unites the Naticidts to the Haliotidce, by Crepidula.

348

SHELLS AND SHELL-FISH,

PART II.

Shell turbinate, mostly trochiform *, the substance almost
always perlaceous ; outer lip never thickened ; aperture
entire, closed by a shelly or horny operculum.

SuB-FAM. SENECTIN^. Snake Shells.

Operculum round ; calcareous ; shell turbinate ; the
basal whorl ventricose ; pillar always smooth ; aperture
round, rarely oblique.

^ENECTvs Humph. Imperforate; the base
produced into a broad flat lobe ; spire
rather elevated and pointed ; the
whorls convex ; aperture perfectly
round ; not more oblique than Helix ;
inner lip entirely wanting, {fig. 110.)

imperialis. Mart. 1 80. f. 1 7 90.
marmoratus. E. M. 448. f. 1.
pethiolatus. Mart. f. 1777-8.
cornutus. lb. 179. f. 1779-80.
setosus. En. Meth. 448. f. 4.
argyrostomus. Mart. f. 1766.
chrysostomus. lb. f. 1766.

radiatus. Mart. f. 1788-9.
margaritaceus. lb. f. 1762.
Sprenglerianus. lb. f. 1801-2.
crenulatus. lb. f. 1811-12.
hippocastanum. lb. f. 1807-10
coronatus. En. M. 448. f. 2.
angulatus Sw. Sow. Gen. f. 8.

Marmarostoma Sw. Umbilicus deep ; spire of few
whorls, much depressed, and obtuse; inner lip ob-
solete ; base even more produced than in Senectus,
but never distinctly channeled.

M. versicolor. Mart. 176. undulata. Chem. 169. f.
f. 1740, 1741. 1640, 1641.

Delphinula Lam. Turbinate ; spire depressed, the tip
obtuse ; pillar almost entirely wanting ; the umbili-
cus being large and pervious ; exterior of the shell
rough with tubercles or lamellar plates, (^fig. IO9. h.)

torquata. Mart. Conch. 2.f. 71. laciniata. En. Meth. 451.
lamellosa. Zool. J. v. p. 331. f. 1.

CYCLOGANTHAt Sw. Sub- depressed, trochiforra ; im-

* Except Phasianella.

t Resembles Tuhicanthus, but the aperture is hardly perlaceous, the
body-whorl not flattened beneath, or the mouth oblique.

PART II. TROCHIN\(E. 349

perforate ; both sides compressed ; substance of the
shell not perlaceous, but convex ; mouth slightly ob-
lique ; lips united ; base not produced : doubtful type,
stellaris. Mart. 164. f. 1553-4. calcar. En. M^th. 451. f. 2.

CiDARis Sw. Perlaceous ; turbinate ; generally smooth ;
the base not produced; the inner Hp not concave;
always imperforate ; aperture round, but oblique ;
operculum very thick : representing Calliostomus.

sarmaticus. Mart. 179. pethiolatus. Mart. 183. f.

f. 1777, 1778. 1826.

smaragdus. En. M. 448. f. 3. pictus Sw. En. Meth. 448.

E. coronatus. 5*2^. Chem. 165. f. 5.

f. 1585, 1586. ater Sw.* Sow. Gen. f. 7.

SuB-FAM. TROCHINiE. Trochus, or Top.

Shell trochiform ; the body-whorl more or less wide^
and flattened beneath; the spire conical or pyramidical;
aperture oval, wider than it is high ; operculum horny, t

Canthorbis. Operculum shelly; aperture very oblique,
broad_, and narrow ; the basal whorl much flattened ;
pillar, in the typical examples, twisted : representing
Cei'ithium.

Tuhicanthus Sw. Turbinate; aperture oval, effuse;

very oblique ; inner lip broad, concave, spreading,

united to the outer lip ; base of the pillar simple,

blended with the circumference of the aperture. :|:

rugosus. Mart. 180. f. Tuber. Mart. 165. f. 1373.

1782—1785. Cookii. lb. 163. f. 1540.

ceelatus. lb. 162. f. 1536. imbricatus. Id. 162. f. 1531.

Canthorbis Sw. Suns. Nearly disk-shaped : spire but
slightly raised ; the margin of the body-whorl flat-
tened, and serrated with flat spines ; inner lip united
to the outer ; pillar and aperture as in the last.
C. imperialis. Mart. 173. f. 1714.

* Is this the Turbo lugubr is? Zool. Journ. v. 345.

f Except in the first genus, which connects this sub-family and the
Senectin/e, and in T. Niloticus (as it is said), which connects Canthorbis
with Trochus.

X Connected to Cidaris by C. rugosus.

350 SHELLS AND SHELL-FISH. PART II.

Pyramidea Sw. Imperforate ; spire much elevated,
pyramidical, acute ; basal whorl beneath much flat-
tened, and scarcely convex ; pillar spiral, the base
very short, turning inwards, and then outwards, but
smooth ; outer lip thin ; inner wanting.* (^fig. IO9. c.)
obalisca. Mart. 160. f. Nilotica. Mart. 168. f. 1614.

1511, 1512. virgata. lb. 160. f. 1514.

foveolata Gm. Mart. 161. f. marmorata. lb. 167. f. 1606.
1516, 1517. Mauritiana. lb. 163. f. 1547.

Lamprostoma Sw. Umbilicated ; pyramidical, spire
elevated, acute ; basal whorl much flattened beneath,
slightly convex ; pillar spiral ; the base short, and
marked by distinct plaits ; aperture striated ; inner
lip wanting.

L. maculata. Mart. 168. f. 1515, 1516.

Carinidea Sw. Imperforate ; spire pyramidical, acute;
basal whorl concave beneath, and carinated round its
circumference ; aperture oval, entire, slightly angu-
lated at the base of the pillar, which turns inwards.

C. concavus. Mart. 168. f. brevisplnus. ? Sow. Gen.
1620, 1621. (Turbo.) f. 1.

Trochus Linn. Operculum horny ; shell trochiform ;
the basal whorl broad ; aperture oval ; sometimes an-
gulated by the union of the pillar and the outer lip,
but rarely toothed or striated.f

Chlorostoma Sw. Deeply umbilicated almost to the
top of the spire ; inner lip forming a semi-margin to
the umbilicus ; outer lip angulated at the base, with
one or two tubercles ; body-whorl almost flat be-
neath, and nearly carinated at its edge ; aperture
remarkably oblique : representing Monilea.X

C. argyrostoma. Mart. 165. f. 1362, 1363.
umbilicaris. lb. 171. f. 1666.

* Troch. Niloticus is probably esculent between this and Lamprostoma ;
but I have not seen a thorouglily full-grown specimen, with the mouth
quite formed : the operculum is said to be horny ; but this may be
doubted.

f Except in Trochidon, which represents Monodonta Lam. in this circle.

% Troch. mcrula Lam. connects this sub-genus with Pa^odella.

PART II. TROCHIN^. ] 351

Trochus Linn. Umbilicus either very open or small^
but always apparent ; base of the outer ^^^^^^
lip sinuated where it unites with the ^^^^SfJ^
pillar ; inner lip generally spreading^ ^K\t"^^S^!)
flattened, and concave ; body-whorl ^^^^^^
convex beneath, rounded on the sides ; \(^£<x^
aperture obliquely round ; spire short, \^^^^^

depressed, pointed, (^fig. 111.) lU ^■^-^_/

T. pica. Mart. 176. f. 1750. cinerarius Linn. Mart. 171.
magus. lb. 171. f. 1656. f. 1686.

Pagodella Sw. Trochiform ; generally thin, and always
not perlaceous ; aperture and pillar perfectly united
and entire ; operculum horny.

P. major. Mart. 163. f. 1541, 1542.
tectum-persica. lb. f. 1543, 1544.

Trochidon Sw. Trochiform ; spire more elevated than
in the last; but the base of the pillar either angulated,
umbilicus none, or forming a tooth more or less deve-
loped, often with a lateral, depressed groove, but no
umbilicus ; margin of the outer lip thin, the inside
rarely striated, {fig. IO9. d.)

T. labeo. En. Meth. 447. viridis. lb. 447. f 2.
f. 1. canalifera. lb. f. 5.

Calliostoma Sw. Imperforate : spire elevated, acute ;
aperture broader than high, transversely ovate, hardly
sinuated at the base, and slightly oblique; shells
always smooth, and often polished : representing
Cidaris.

zizyphina. Pen. Zool. pi. 80. annulata. Ch. 165. f. 1551-2.

f. 103. doliata. lb. f. 1579 — 1583.

conuloides. Lara. No. 47. granatina. Mart. 170. f.
conula. Mart. 166. f. 1588. 1654, 1655.

erythroleuca.Ib.l62.f,1529. Australis. Zool. Jour. v. 331.

MoNODONTA Lam. Base of the piUar forming a distinct
tooth ; umbilicus deep*, with a deep groove below ;
aperture striated ; outer lip not thin at the margin.

Elenchus Humph. Shell smooth ; spire considerably

* Except in Elenchus and Echinidea.

352 SHELLS AND SHELL-FISH. PART II.

lengthened; body -whorl comparatively smaller ; base
of the pillar with a slight angle, or an obsolete tooth ;
aperture smooth, very brilliant; passing into Calli-
ostomus.

E. Iris. Mart. 161. f. 1652, splendidulus. Sw. Sp. Nov.*
1653. {fig. 109. a.)

Echinella Sw. Shell imperforate, granulated, not per-
laceous ; spire considerably lengthened; pyramidical ;
base of the pillar with a distinct tooth ; aperture
striated : representing Pagodella.
E. granulata. Sw. Sp. Nov. coronaria. En.Meth.447. f.6.

Monodonta Lam. Turbinated ; in general umbilicated,
having a groove below, and a tooth at the base of the
pillar ; aperture nearly round, striated within ; um-
bilicus never toothed ; representing Senecus and Tro-
chidon.

M. retusa. En. Meth. 447. f. 4.

Fragella Sw. Trochiform ; umbilicus deep, always
open, and toothed round its margin ; base of the
pillar twisted, and forming a tooth -like process at its
tip : representing Trochidon.

Pharaonis. En. M. 447. f. 7. Sowerbyana. Stv. Sow. Gen.
undata. lb. 447. f. 3. f. 9. 11. ( Trochus.)

Monilea Sw. Umbilicus deep and wide, but the edges
quite smooth, with a thickened half margin, formed
by the inner lip, which terminates abruptly ; base of
the outer lip with one or two tubercles, or obsolete
teeth ; margin of the whorls concave ; inner lip
often striated : representing Chlorostoma.
M. callifera ? Lam. Sys. 27. No. 59.

Solarium Lam. Shell nearly^discoid, not perlaceous ;
spire none ; aperture angulated, smooth within ; the
edge acute ; the lips wanting, {fig. 109- i, k.)
S. perspectivum. En. Meth. 446. f. 1.

Onustus Humph. Shell trochiform ; the surface irre-
gular, and often covered with extraneous bodies

* Small, entirely fawn colour, or light brown ; aperture of the most
brilliant purple and emerald green. Australia.

PART II.

ROTELLIN^.

353

cemented and incorporated with the calcareous sub-
stance of the shell ; the under part of the body-whorl
flattened or concave, umbilicate.

O. Solaris. Mart. 173. f. 1700, 1701.
Indicus. lb. 172. f. 1697, 1698.

SuB-FAM. ROTELLIN^.

Substance perlaceous ; shell depressed^ smooth, and
highly polished ; mouth thin ; umbilicus closed.*

Chrysostoma Sw. Shell turbinate ;
the whorls few and convex ;
aperture effuse, round ; inner
lip thickened, just over and
almost concealing the umbilicus.
Nicobaricus. Mart. 182. f. 1822-1825. (Jig. 109.)

RoTELLA Lam. Shell flattened, nearly discoid, polished ;
inner lip very thick, and spreading over half of the
under surface ; aperture small, angulated ; operculum
horny. {Jig. lOQ. f,g.)

R. lineotata Lam. Mart. 166. f. 1601. e, f, g

Thelidomus Sw. {Jig. 113.) Turbi- ^^^^ ii3
nate, sub-trochiform ; umbilicus large, '^" '*
open ; the whole shell entirely com-
posed of grains of sand.

Braziliensis Sw. {Jig. 113.)

SuB-FAM. PLEUROTOMARI^.

Trochiform ; the aperture with a slit or
fissure. Fossil only.

Pleurotomaria Defrance. Spire more or less elevated.
Being only found in an imperfect or fossil state, nothing
has been determined as to the umbilicus, substance,
operculum, &c.

P. reticulata. Sow. Gen. 1. i.

J 1

* These have probably no operculum, and Rotella may be an internal
shell.

A A

354 SHELLS AND SHELL-FISH. PART II.

SuB-FAM. PHASIANELLIN^.

Obovate^ spiral, polished ; aperture oval ; spire longer
tharij or equal to, the aperture ; operculum shelly.

Phasianella Lam. Umbilicus none, {fig- IO9. h.)
P. bulimoides. En. Meth. 449. f. 1 . a—c.

Family HALIOTID^. The Ear-Shells.

Shell disk-shaped entire ; the spire nearly obsolete, de-
pressed, convolute, mostly lateral, and of only two or three
minute whorls ; pillar none ; operculum none.

Haliotis Linn. Iridescent ; ear-shaped ; a row of per-
forated holes on the thickest side of the aperture.
The sub-genera remain to be determined.

Stomatia Lam. Oval or oblong ; the shell resembling
Haliotis, but without perforations.
The types of form are enumerated at page 232.

('ALYPTRiEA Lam. Shell not perlaceous ; patelliform,
but with the first rudiments of an internal support,
and often of a spire.

Bicatillus Sw. Shell patelliform ; spire or whorls
none ; a cup-shaped appendage within, more or less
complete

B. extinctorium Sw. Sow. Gen. f, 3. deformis. lb. f. 1.

CalyptrcEa Lam. Patelliform ; internal appendage half
funnel-shaped, but open in front.

C. equestris Lam. Sow. Man. f. 2.34. Sow. Gen. f. 2.

Haliotidea Sw. Spire prominent, formed of two whorls,
and placed laterally ; umbilicus open,
sigaretoides. * Sic. dilatata ? Sow. Gen. f. 9. (Cali/ptrcpa.)

* This sub-genus seems to form, with certain VetuUnce, the passage to
our Chelinotus, or the Sigarcti of authors.

PART II. CHELINOTUS. SCUTIBBANCHIA. 355

TrochiUa Sw. Shell conical, patelliform ; spire central,

of two or more whorls ; umbilicus closed.
T. auriculata. Sow. Man. f. 236. pileus. lb. f. 237, 238.

Biconia Sw. Patelliform, conical ; internal appendage
forming a funnel-shaped fold, not open in front ;
apex central, sometimes with the vestige of a whorl.
Humph. Conch, f. 11. and 12.

Chelinotus Sw. Animal cheloniform, broad ; de-
pressed ; the mantle much larger than the shell,
lobed in front ; tentacula two, short, obtuse ; eyes
basal ; mouth circular ; shell ear-shaped, thin, fragile,
imperforate ; pillar none.

Velutina Lam. Animal — } fragile ; shell with the two
spiral whorls raised, so as to resemble a Lymnia; no
pillar ; epidermis thin, horny.

laevigata. Sow. Man. f. 337.

Chelinotus Sw. Shell thin, diaphanous, white, entirely
concealed in the back of the animal, which is marked
with hexagonal partitions.

Sigaret de Tonga. Quoy, Voy. d' Astrolabe.

Coriocella Blainville. Animal broad oval, with the
anterior lobes not prolonged, or the back divided as
in the last ; shell thin, flexible, membranaceous.*
C. niger De Blainville. Man. de Malac. pi. 42. f. 1 .

Crepidula Lam. Shell boat-shaped; the apex or spire
at the narrowest extremity : half of the internal cavity
covered by a testaceous plate.
C. fornicata. Sow. Gen. f. 1. aculata, lb. f. 5.

Tribe 3. SCUTIBRANCHIA. The Limpets.

Shell pateUiform or cup-shaped ; without any spire or
internal support.

Fissurella Lamarck. An oval aperture at the apex,
or highest part of the shell.

* GrifF. Cuv. xii. 68.
A A 2

556

SHELLS AND SHELL-FISH. PART II.

Fissurella. Apex nearly central ; aperture large, oval
simple.
F. picta. Sow. Gen. f. 1. gigas. Sw. Sp. Nov.

MachrocMsma Sw. Aperture very large, oblong, placed
closed to the margin.

M. hiatula Sw. Sow. Gen. f. 5.

Clypidella Sw. One extremity of the shell, near the
perforation, slightly raised, truncated, and sub-emar-
ginate.

C. pustula. Sow. Gen. f. 3.

Fissuridea Sw. Sub-conical, cap-shaped ; the summit
close to the posterior margin ; the perforation narrow.
T. pileus. Sw. Sp. Nov.

Emarginula Lam. Either patelliform or cap-shaped ;
the apex near the posterior end ; the anterior margin
or summit with a very narrow slit or fissure.

Emarginula Lam. Cap-shaped ; fissure on the an-
terior margin.

E, reticulata. Sow. Gen. fissura. Sow, Man. f. 241.
f. 5. elegans. lb. f. 4.

Cemoria Leach. Cap-shaped ; fissure down the centre
of the apex.

C. Flemingii. Sow. Man. f. 244.

Rimula Def. Cap-shaped ; fissure long, in the middle
of the shell ; margin entire.

R. Blainvillii. Sow. Gen. f. 243.

Parmophorus Lam. Patelliform ; fissure assuming the
form of an anterior sinus, scarcely perceptible on
the anterior margin.
P. elongatus. Sow. Gen. f. 1, breviculus. Sow. Gen. f. 2.

Hemitoma Sw. Patelliform ; the fissure not cut through
the shell, but merely forming an internal groove.
H. tricostata Sw. Sow. Gen. f. 6.

HipPONYX. Shell cap-shaped; the apex sometimes

PART II. CYCLOBRANCHIA. 357

produced and slightly curved inwards ; muscular im-
pression semi-circular.

Hipponyx De Fr. Cap-shaped or patelliform ; strong ;
the margins thick_, and reposing upon a thin, flat-
tened ; testaceous plate, forming a second valve,
cornucopia. Sow. Man. f. 199.

P'deopsis Lam. Shell cap-shaped ; thin ; the apex
much produced and incurved ; no basal support or
internal appendage.

P. Hungaricus. Sow. Man. f. 240.

Pedicularia Sw. Shell irregular, sub-patelliform ;
a thick, large, obsolete apex on one of the longest
sides, and an internal callous rim within, on one
side only ; circumference undulated, irregular.
P. Sicula Sw. {Jig. 44. )

Patella Linn. Shell entire, simple, cup-shaped or
patelliform ; apex pointed, entire.*

P. miniata. Sow. Gen. f. 2.

Siphonaria Sow. One side more dilated than the other,
and marked by an internal groove.

S. Sipho. Sow. Gen. f. 1.

Tribe 4. CYCLOBRANCFJIA. The Chitons. \

Animal patelliform, oval ; the mantle coriaceous ; the
back covered with imbricate shelly plates ; no tentacula.

Chiton Lin. Back with large transverse plate ; zone,
or mantle, wide, covered with small scales, either
imbricate or reticulate.

C. squamosus. Sow. Gen. f. 2.

Canthapleura Guild. Plates as in Chiton ; the

* The fresh-water genus Ancylus has the same shaped shell, but the
animal shows it belongs to the Limnn'iancs.

t Not having analysed this tribe, I have adopted the genera and arrange-
ment of Guilding, see Zool. Journ. xvii. p. 27., especially as they thus form
a circular group.

A A 3

358 SHELLS AND SHELL-FISH. PART II.

mantle rough, with moveable spines, prickles, setace-
ous hairs, or granules.

C. spinosus. Sow. Gen. f. 1.

Phakellopleura Guild. Plates moderate ; the mantle
ornamented with a single series of tufts of radiating
hairs.

P. fascicularis. Sow. Gen. f. 3.

Chitonellus Lam. Body larvseform ; plates small,
detached ; mantle naked ; sides with punctures, re-
sembling spiracles.
C. larviformis Burrows, latus Guild. Z. J. xvii. p. 78.

Cryptoconchus Blainv. Plates moderate, entirely co-
vered with the soft down of the zone, each plate
having two lateral and tabular pores, and four on the
anterior plate.

C. porosus Burrows.

Tribe 5. TECTIBRANCHIA. The Sea Slugs.

Body naked ; branchia generally covered by a coriaceous
or testaceous plate, or oviform shell, which is more or
less concealed in the mantle, or its lobes ; eyes sessile,
minute.

SuB-FAM. 1. PHYLLIDINiE.

Shell none ; body shaped as in Chiton ; mantle coria-
ceous ; branchia folliculated, placed on both sides of the
body, under the edges of the mantle ; tentacula small,
short, two or four.

Phyllidea Cuv. Shape oval ; tentacula four, the
upper pair cylindrical and pointed, the under very
small, inferior, and placed on the side of a small
mouth.

P. pustulosa. Riipp. Atlas, i. pi. 7. f. 1.

Diphyllidea Cuv. Posterior end narrowed ; tentacula
two, the inferior pair represented by two tubercles.

D. lineata Otto.

PART II. APLYSIAN^. 359

SuB-FAM. 2. APLYSIANI^. Sea Hares.

Mantle dilated, undulated at its edges and thrown
on the back ; branchia dorsal, pectinated, generally
covered with a convex, irregular, horny, or calcareous
plate ; tentacula two or four, ear-shaped.

Aplysia Linn. Animal with a short neck ; tentacula
four, the upper and large pair flat, and folded so as
to resemble the ears of a hare ; mantle very large,
and sufficiently dilated for swimming,
fasciata. Rang. Ap. pi. 6, 7. Argus. Riipp. Atl. i. pi. 7.

Thallepus Sw. Body more slender and fusiform ;
the lobes of the mantle short, and incapable of being
used for swimming ; tentacula two, large, ear-shaped ;
eyes not visible.

T. ornatus Sw. Sp, Nov. See page 250.

DoLABELLA Lam. Body pyriform, very broad behind ;
the lobes compactly folded on a hatched-shaped cal-
careous shell, which covers the branchia.

D. Rumphii Lam. Blainv. Man. pi. 43. f. 5.

BuRSATELLA BMuv. Body nearly globular; the dor-
sal edges of the mantle united together, but leaving
a short opening for the passage of the water to the
branchia, which have no covering.

B. Leachii Blainv. Man. pi. 43. f. 6.

NoTARCHUs Cuv. Body shaped much like that of Aply-
sia, covered with flat palmated lobes or membranes;
tentacula two, large and palmated ; mantle and
branchia as in Bursatella.

N. laciniatus. Riipp. Atl. i, pi. 7. f. 2.

SuB-FAM. 3. BULLING. The Bullas.

Animal without apparent tentacula ; body oblong ; both
extremities obtuse ; eyes vertical, very minute ; bran-
chia dorsal, covered by a convolute shell, destitute of

A A 4

360

SHELLS AND SHELL-FISH. PART II.

any spire ; the base widest : this in the typical species,
is covered by the lobes of the mantle ; in others the
whole animal is contained in the shell.*

BullcB Lam. Shell internal, oval, colourless ; inner
lip thin ; apex umbilicated ; animal oblong, without
tentacula.
aperta. Sow. Man. f. 248. ? Guildingii Sw. {See Jig. 46.)

Bulla. Animal furnished with two connected bony
plates ; shell obovate ; contracted above, and effuse
at the base.

B, Lignaria. Sow. Man,, f. 251.

Vesica Sw. Animal unknown ? probably contained
within the shell ; shell oval, solid ; apex umbi-
licated ; aperture entire ; contracted above,
ampulla. Sow. Man. f. 252. Naucum. Sow. Man. f. 250.

Aplustra Schum. Animal } shell solid, but thin ;

furnished with a distinct but depressed spire.
A. fascidta. Sow. Man. f. 249.

Bullinula Beck. General shape of the last ; but the
spire is slightly produced and conic : a doubtful
type }

B. lineata. Sow. Man. f. 253.

Vitrella Sw. Animal ? shell internal, hyaline,

or sub-transparent ; convolute ; the apex carinated ;
the substance elastic.

V. fragilis. Sow. Man. f. 247.

DoRiDiuM Mecken. Animal with the lobes dilated into
fin-like processes, but without a shell.
D. carnosa. Cuv. Mem.

SuB-FAM. 4. GASTEROPTERID^.

Gasteropteron Meek. Animal short, ovate, natatorial ;
the margins of the foot dilated into broad wing-like

• The arrangement of this sub-family, founded chiefly upon the shell,
is purely artificial, no knowledge having been gained of the greater part of
the animals. Such genera as Cryptellay Sec, founded merely upon the
branchial covering of some unknown animal, can never be admitted into
Malacology.

PART II. PLEUROBRANCHINiE. S6l

lobes ; shell none ; branchia naked, placed on the
right side of the body.

G. Meckelii. Blainv. Man. de Malacol. pi. 45. f. 3.

SuB-FAM. 5. PLEUROBRANCHIN^.

Animal cheloniform, branchia pectinated, placed on
the right side under the edge of the mantle which
sometimes covers a calcareous shell.

Umbrella hsLxn. Animal large and circular; anus tu-
bular, placed behind the branchia; tentacula two,
short, as in the next genus ; with eyes at the in-
ternal base, between which is a proboscis. Shell
resembling a limpet ; but the middle is thickest, and
the edges very sharp.

U. Indica. Blainv. Man. pi. 44. f. 1.

Pleurobranchus Cuv. Animal cheloniform ; body
overlapped by the mantle and the foot ; the former
sometimes contains a small oval plate, either horny
or calcareous ; mouth small, probosciform ; ten-
tacula two, tubular, and short,
oitrinus. Riipp. Atl. i. 5. f. 1. Forskalii. lb. pi 5. f. 2.

Pleurobranch^na Meckel. Anus above the bran-
chia ; tentacula four, short, remote ; shell none ;
branchia and genital orifices as in the last.

Meckelii. Leve. Dissert. Griff. Cuv. xii. 43.

Order DITHYRA. Bivalve Shells.

Tribe 1. TUBULIBRANCHIA Cuv.

Animal inhabiting a tubular shell affixed to other sub-
stances and somewhat spiral at its tip ; tail turned un-
der the body and terminated by a thin operculum ;
head obtuse, with two short tentacula with sessile eyes ;
mouth a vertical orifice with two filaments beneath be-
longing to the foot; hermaphrodite.*

* The animal of Magilis being unknown, I am afraid of including it in
this group.

362

SHELLS AND SHELL-FISH.

PART II.

Vermetus. Shell tubular, contorted ; the terminal
whorls spiral.

G. lumbricalis. Sow. Man. f. 345.

Vermillia Lam. The terminal whorls not spiral.
V. triquetra. Sow. Man. f. 7.

Siliquaria Brug. Terminal whorls spiral ; a narrow
punctured fissure on one side of the shell.
S. anguina. Sow. Man. f. 1.

Tribe 2. MACROTRACHI^.

Animal with one or two long respiratory siphons^ either
distinct or united ; the margins often furnished with
little teeth.

Family 1. PHOLID^.

Shell bivalve, sedentary, generally perforating, opening
at one or both ends ; the valves often prolonged into a
shelly tube, sometimes of great length : representing the
Tubulibranchia.

11-1

Aspergillium. Animal living in sand, and not fixed
on or upon any other substance : inhabiting a calca-
reous tube.

Aspergillium Lam. Shell tubular, nearly straight, one

PART II. PHOLID^. 363

extremity open, at the other closed by a plate which
is perforated with small holes, near to which are the
bosses : lives in sandy shores. {Jig. 1 J 4. /^ g.)

A. vaginiferum Lam. Sow. Gen. f. 1. 2.

Clavagella Lam. Two irregular valves placed within
a short shelly tube, dilated at its open extremity, and
to which one valve is fixed or soldered at the other :
perforates stones, &c. (^fig. 114. «, A.)
C. aperta. Sow. Gen. f. 1 — 4.

Fistiilana Lam. Animal not perforating ; tube purse-
shaped, straight, the narrow extremity open, the other
closed; a transverse septum crosses the tube, and
incloses at its largest end a bivalve shell, which is
elongated, solen-shaped, gaping widely at the basal
margin, and united by a ligament, i^fig. 114. w.)

F. clava. Sow. Gen. f. 1 — 4.

Gastrochixa Lam. Animal perforating or parasitic ;
tube calcareous, clavate, nearly divided longitudinally
for half its length by an internal ridge, which forms
a double aperture; the other or thick extremity en-
closes an ovate bivalve shell, gaping very wide ante-
riorly ; hinge linear and marginal ; teeth none. {^fig.
114. 6, c,d)

G. modiolina. Sow. Gen. f. 1.*

Pholadomya Sow. Shell 115

not tubular, pholas-
shaped, perlaceous,

slightly gaping, no ac-
cessary valves ; ligament
short ; external hinge
with a small elongated pit somewhat triangular, and
a marginal plate on each valve ; umbones very close.

P. Candida. Sow. Gen. Man. f. 57. {fig. 115.)

Pholas Linn. Animal perforating but not tubular ;

* I consider the perforating species to be types of a different sub-genus ;
and probably those which are parasitic upon other shells should likewise be
separated.

364

SHELLS AND SHELL-FISH. PART II.

shell free^ oblong-ovate^ thin, with an internal com-
pressed tooth in each valve and accessary pieces.

Pholas Linn. Shell gaping at both extremities over the
umbones ; ligament none. (^ Jig. 122. f.)

P. dactylus. Sow. Gen. f. 1.

PholidcEa Leach. Resembling Pholas, but the anterior
end is closed by a thin calcareous prolongation of each
valve, and the posterior end has a cup-shaped ap-
pendage, {fig, 122. g.)

T. papyracea. Sow. Gen. f. 3. Man. f. 56.

Martesia Leach. General characters of Pholas, but
both extremities are closed.

M. clavata Auct. (fig. 122. ^. )

Xylophaga Sow. Habit of Pholas ; but the shell is
orbicular, widely gaping anteriorly, and with ac-
cessary valves ; each valve with an incurved tooth,
and an internal transverse rib.

dorsalis. Sow. Man. f. 50, 51.

Teredo Linn. Shell tubular, irregular ; the valves
pholas- shaped, short and nearly orbicular.

Teredo Linn. Valves resembling Xylophaga; placed
at the thickest extremity of a long, irregular tube,
'' which is open at both ends, the anterior end di-
vided into two apertures furnished with two oper-
cula."* {fig. 114<.k,l.)

T. navalis. Sow. Gen. Man. f. 48, 49.

Teredina. Tube clavate, irregular, nearly divided into
two, by a projection on each side within, thus form-
ing a double opening at the smallest extremity;
valves as in Teredo, but wholly external, incrustated
with the tube, and having accessary valves.

T. personata. Sow. Gen. Man. f. 46, 47. {fig. 114. i.)

* I have not leisure to look into these characters, and have therefore
adopted Mr. Sowerby's account of this and the next genus.

PART II,

M Y AD^. SOLENINjE.

365

Family 2. MYAD^. Gaping Bivalves.

Shells regular^ always with defined cardinal teeth ;
valves more or less gaping at one or both extremities.

SuB-FAM. SOLENIN.E. Salens.

Shells generally linear, and always open at both extre-
mities ; cardinal teeth distinct.

SoLEN Linn. Shell very straight, broad, linear, and of
equal length throughout ; umbones very small, ter-
minal ; cardinal teeth small ; ligament long, exter-
nal.

truncatus. Sow. Gen. f. 1. vagina. lb. f. 2. (Jiff. 116. b.)

Ensatella Sw. Shell slightly curved.

E. Eiu'opea Stv. {Solen Ensis Auct. )

NovAcuLiNA Benson. Straight, of equal length
throughout ; the extremities rounded ; umbones
towards the middle ; cardinal teeth ^ ; dorsal margin
slightly thickened.

N. Gangetica. Sow. Man. f. 63.

366

SHELLS AND SHELL-FISH. PART II.

Lepton Turton. Small, nearly round ; umbones cen-
tral ; teeth ? The cardiform type.

L. squamosus. Sow. Man. f. 62.

SoLENocuRTis. Shell depressed, thin, transverse, oblong
ovate ; the valves slightly gaping at one extremity ;
cardinal teeth and umbones nearly central.

Solenella Sow^. Oval, compressed ; epidermis glossy ;
hinge margin nearly straight; cardinal teeth wanting ;
posterior lateral teeth numerous, sharp ; anterior end
somewhat truncated : representing Nucula.
S. Norisii. Sow. Man. f. 138.

Solenocurtis Blainv. Oblong-ovate, nearly linear ;
umbones small, nearly central, with a thickened in-
ternal transverse ridge; ligamental margin much
thickened, (^fig, ll6. e.)
S. radiata. Sow. Man. f. 61. Blainv. Man. pi. 80. f. 1.

Sanguinolaria Lam. Ovate, compressed ; posterior
end sub-rostrated ; anterior rounded ; cardinal teeth
small, %. {fig. Il6. d.)

S. rosea. Sow. Man. f. 98.

Glauconome Gray.* Obovate, not gaping, sub-ventri-
cose, and rounded anteriorly, narrowed and com-
pressed posteriorly ; cardinal teeth ^, some of which
are bifid ; ligament oblong ; external epidermis ex-
tending over the margin ; fluviatile : apparently re-
presenting Mactra in this genus,

G. chinensis Gray. Sow. Man. f. 64.

Solenymia Lam. Shape of Solenocurtis, but some-
what cylindrical ; umbones very small, and placed
laterally ; hinge margin straight ; valves gaping on
their anterior end ; cardinal teeth i, dilated and
compressed, with a callous ridge between ; ligament

* I have not seen this shell, which, from the figure quoted, has exactly
the shape of Unio uvala.

PART II.

SOLENIN^. MY A.

367

internal and external : representing Pandora and
Glycymeris. Epidermis thin, shining, dilated.
S. Mediterranea. Sow. Gen. f. 112. (/^. 116. a.)

My A Linn. Shell thick, ventricose, ovate, transverse,
one end truncated and gaping ; umbones generally
nearly central and prominent ; cardinal tooth gene-
rally large ,• spatulate valves often gaping.

117

Anatina Lam. Hyaline, thin ; cardinal tooth spoon-
shaped, sometimes with a transverse internal append-
age, or plate, like an additional tooth, (^fig. 11 6./.)

M. subrostrata. En. M^th. 228. f. 3.

Mya Linn. Shell thick, strong ; cardinal tooth spatu-
late ; both extremities gaping * ; cardinal teeth ^.
M. truncata. En. Meth. 229. f. 2. {fig. 117. h,c.)

Panopia Lam. Resembling Mya ; cardinal teeth -i,
acute ; ligamental margin greatly thickened ; liga-
ment external. (/(/, ll6. c.)

P. Aldrovandi. Sow. Man. f. 65.

Corhula. Inequivalve, ovate ; umbones central, one
more prominent than the other ; valves not gaping ;
cardinal teeth \, bearing the ligament : leading to
Mactra. (117. e,/.)
'Sulcata. En. Meth. 230. f. 1. C. nucleus. Sow. Man. 89.

* Connected to Anatina by Anaiina rupicola Lam,

368

SHELLS AND SHELL-FISH.

PART II*

Pandora Lam. Inequivalve, thin, rostrated, perlaceousj

one valve flat, the other convex ; ligament internal ;

umbones small; cardinal teeth 5, lamellar, sagittate, or

like aV reversed: connected to ^na^ma.(^^. 1 l'7.g,h.)

P. rostrata. En. Meth. 251. f. 1.

Mactra Linn. Equivalve ; the valves slightly gaping
on one side ; ligament internal and external ; cardi-
nal teeth complicated.

Lutraria Lam. Shell thin, transversely oval or oblong;
cardinal teeth ^, angular, followed by a spoon-shaped
lobe containing the cartilage ; lateral teeth none.
(^^. 118. &.)
L. compressa. En. M. 257. f. 4. papyracea. Sow, Gen. f. 2.

Mactra Linn.* Transversely oval or sub-trigonal ; um-
bones prominent ; cardinal teeth %, angular, some-

times with additional laminte ; cartilage entirely in-
ternal, nearly central; lateral teeth i. {fig. 118. c.)

Neapolitana. roll. Test, stultorum. En. M. 265. f. 2.
pi. 18. f. 1—5. turgida. Sow. Gen. f. 2.

Schizodesma Gray. General character of Mactra ; but

* Including Mactra bicolor, &c., Auct.

PART II. MACROTRACHIA. — TRLLIiVID^. 36^

the umbones are remote ; the ligament placed in an
external slit ; the lateral teeth very short and small,
and the cardinal teeth nearly obsolete.

S. Sprengleri. En. Meth. 252. f. 3.

Hemimactra Sw. General form of Mactra ; but the
cardinal teeth entirely wanting ; cartilage internal,
central, in a large triangular cavity ; lateral teeth \,
distinct, lamellar, striated : connected to the Glycu-
neri.
H. gigantea. Lam. v. 472. No. 1. grandis Sw. Sp. Nov.

Crassatella Lam. Shell solid, heavy, not gaping, more
or less rostrated ; hinge very thick ; cardinal teeth |-
sub-angTilar, striated, and placed on one side ; imme-
diately beneath the umbones is a triangular cartilage;
lateral teeth obsolete: representing Pa wrfora, Trigonia,
Placuna, Szc.
C Kingicola Lam {fig. 1 18. a.) rostrata. Sow. Man. f. 84.

Glycimeris Lam. Oblong, transverse ; both extre-
mities gaping ; cardinal and lateral teeth entirely
wanting ; but the hinge margin very thick ; ligament
large, external : representing Solenimya, and con-
nected to Solen by Novaculina.*

G. Siliqua. Sow. Gen, {fig. 118. 6, c.)

Family TELLINIDiE. Solid and dose Bivalves.

Shell never gaping t ; equivalve ; the margins thickened
and solid ; rarely covered with an epidermis ; cardinal
and lateral teeth well developed.

SUB-FAM. 1. CYCLING.

Animal generally fluviatile ; shells covered by an epi-
dermis.

CyclasJ Lam. Shell thin, transversely ovate, equila-

* The four other sub-genera are unknown. f Except in Psammobia.
X Including PisiduTn.

B B

570

SHELLS AND SHELL-FISH.

PART II.

teral ; cardinal teeth small; lateral teeth ^^ long,
compressed; ligament external, {fig. II9. &.)
C. rivicola. Sow. Man. f. 111.

Cyrena Lam. Shell thick, transversely ovate, nearly
equilateral ; cardinal teeth 4- ; lateral teeth 4, short,
thick, obtuse ; fluviatile and marine. {fig.W^.n.^
C. Siimatrensis. Sow. Gen. 1 — 4.

Megadesma Bowdich.* Shell thick, trigonal, nearly
equilateral ; cardinal teeth 4t ', lateral teeth obsolete ;
hinge very thick ; ligament external. (^fig.llQ. d.)
M. radiata. Sow. Man. f. 115.

Gnathodon Gray. Shell transversely obovate, in-
equilateral ; bosses thick, prominent, remote ; car-
dinal teeth i ; lateral ", ; cartilage internal, placed
by the side of the cardinal teeth.

G. cuneatus. Sow. Man. f. 83.

CuMiNGiA Sow. Shell transversely obovate ; hinge
with a spatulate cavity filled by the cartilage ; car-
dinal teeth \, very small ; lateral teeth -| ; marine :
leading to Erycina, and representing Amphidesma.
C. mutica. Sow. Man. f. 87.

EBYCiNAf Lam. Shell always transverse, generally

cuneate, but rarely equilateral ; both valves closing ;

cardinal teeth ^, between which is the ligament ;

lateral teeth ^y one of which is lengthened.

striata. Sow. Gen. f. 2. plebeja. lb. f. 3.

(/5r. 118. d,e.)

* Gttlathcea of Lam.

t This name should be chanjjed, havinjj been previously applied by
Fabricius to a large family of lepidopterous insects. Eiijx may be used, a&
preserving the same mythological idea.

PART II. MACROTROCHIA. TELLININ^. 371

SuB-FAM. TELLININ^.

Animal marine ; the siphons excessively long. Shell
rather thin^ more or less compressed ; bosses small.

PsAMMOBiA.* Lam. (fg.llS.i.) Shell transverse, oval
or oblong, angulated, gapingatone or both ends ;
ligament external ; cardinal teeth -|,

rugosa Sow, Chem. 9. f. 79 — 82. ferroensis. Penn. 47. f. 31.
vespertina. Chem, 7. f. 59. Poll, i. pi. 15. f. 19.

Tellina Linn. Shell transverse, greatly compressed,
nearly equilateral ; the valves on the inferior liga-
mental, or anterior side, sinuated and angulated ;
cardinal teeth |^, or -| ; lateral teeth -2, remote from
the cardinal, (fig. 120. a.)
radiata. En. Meth. 289. f. 3. latirostra. Zool. 17. I. pi. 20.

Ltjcina Lam. Shell generally round or orbicular,
equilateral, the outer surface sculptured ; ligament
external ; cardinal and lateral teeth distinct, but va-
riable in their number ; anterior muscular impression
very long and narrow, (fig. 120, c.)
L. punctata. Sow. Gen. f. 1. Pennsylvanica. f. 4.

UnguUna f Lam. Shell irregularly orbicular ; bosses
central ; cardinal teeth -i, bifid ; lateral teeth none ;
ligament both internal and external ; impression of
the mantle entire.

transversa Lam. Sow. Man, f. 88. {fig. 117. d. )

Amphidesma Lam. Shell resembling Lucina in shape;
the posterior side sometimes flexuose, and slightly
gaping; cardinal teeth ^ or %, with a cartilige between ;
ligament external.
A. variegata. En. Meth. 291, f. 3. lucinalis. lb. 286, f.

LoRiPEs Poli. Shell orbicular, equilateral ; cardinal,
teeth obsolete ; lateral teeth none,

L. lactea, Poli, i. pi, 25, f, 28, 29.

* Representing the So/ens.

f JJngulina Lam. seems to be merely an aberrant Lucin&.

B E 2

372

SHELLS AND SHELL-FISfll.

T-ART H-

SuB-FAM. VENERINyE.

Animal with the two siphons shorter, and sometimes
united ; shell thick, strong, and ventricose ; bosses pro-
minent.

c^>

CoRBis Lam. Shell transversely roundish ; bosses curved
in different directions ; cardinal teeth ^ ; lateral re-
mote, short, -|.

C. fimbriata. Sow. Gen. {fg. 120. h,i.)

Venus Z/mw. Animal with the two siphons shorter than
its shell ; shell nearly round, or oval ; lateral teeth
close to the cardinal teeth, 4 , lateral teeth approxi-
mate, and diverging from the summit of the bosses ;
surface often rough, {fig. 119- ^0
V. purpura. En. Meth. 278. f. 1 . rugosa. lb. 27S. f. 4.

Crassina Lam.* Shell solid, suborbicular; bosses nearly
central. Cardinal teeth 4? unequal in one valve ;
lateral teeth none.

C. Danmoniensis. {fig. 120. e.)

* The other subgenera of Tellina, Venus, Cytherea, and Dotiax, are not
■worked out.

i»ART II. MACROTRACHIA. VENERINiE. 37^

CvTHEREA Lam. Animal with the siphons entirely
united ; foot large, tongue-shaped ; shell generally
smooth and glossy ; cardinal teeth 4 ; lateral tooth \,
placed on the anterior side. (^ Jig .'19,0. d, y.)
C. Chione. Poll. ii. pi. 20. f. 1 . niaculata. En. Meth, 265. f. 4.

DoNAx Linn. Shell cuneate, or wedge-shaped, the an-
terior side very short and truncate ; teeth variable in
the sub-genera, (^jig. 120. A.)

D. scorotum. En. Meth. 260. f. 2.

Capsa Lam. Shell transverse, nearly equilateral ; car-
dinal teeth -^ ; lateral teeth ^ ; ligament external.
C. Braziliensis. Sow. Gen. f. 1. {fig. 120./".)

Cardissa Sw. Shell heart-shaped, excessively com-
pressed ; the anterior side truncate, and often concave ;
the posterior rounded.

spinosa Sw. En. Meth. 293. f. 3.

Cardium Linn. Shell ventricose, cordate, or longitudi-
nally oval ; umbones prominent; cardinal teeth -| ;
lateral teeth ^, remote.

Cardium Linn. Shell ventricose, equilateral ; cordate, with
costated ribs ; often armed with spines. Typical.

costatuni. Wood, General Conch, edula. Wood, Conch.

i. pi. 56. f. 1. pi. 55. f. 4.

tuberculatum, Sow. G. f. 3-

Lcevicardium Sw. Shell longitudinally oval, inequila-
teral, the surface neither ribbed nor spired. Sub-
typical.

Europeum. Wood, Con. pi. flavum. Wood, pi. 54. £ 2.

54. f. 1. oblongum. lb. 55. f. 1.

citrinum. lb. 54. f. 3. ^olicum. lb. 51. f. 1.

Hemicardium Sw. Half heart-shaped ; the anterior side
abruptly truncated, and very short : representing
Donux, &c.

H. unedo. Wood, Conch, pi. fragrum. Wood, Conch, pi.
58. f. 3. 58. f. 1, 2.

retusum. lb. 58. f. 4, 5. lasvum Sw. lb. 57. £ 7, 8,

B B 3

374> SHELLS AND SHELL-FISH. PART II.

Acardo Sw. Hinge almost without teeth : representing
the SaocacavidcE.

Card, edentulum. Auct.

Papyridea Sw. Shell heart-shaped, or transversely oval;

inequilateral ; the anterior side almost always gaping *

representing the Pholidce.

P. Soleniforme. Wood, transversum. Sow. Conch-

Conch, pi. 56. f. 3. f. 4. *

ai^ertum. lb. 56. f. 2, ringens. Wood, pi. 53. f. 1, 2.

Family CHAMIDiE.

Animal marine ; shell often attached, irregular, not per-
laceous, with or without short siphons ; lateral teeth on
the posterior side of the shell only ; cardinal teeth variable.

Hippopus Lam. Cuneate ; both valves closed ; bosses
nearly central ; cardinal teeth small ; lateral teeth
long, posterior.
C. maculatus. Sow. Gen. f. 1. En. Meth. 236. f. 2.

Pleurorynchus Phillips. Anterior end abruptly trun-
cate, as in Hemicardium ; the hinge margin elongated
into earlike processes. Fossil only,
elongatum. Sow. Min. Con. avicularis. Sow. Gen. f. 2.

Chama Linn. Shell irregular, attached by the lower
valve ; a single lengtliened tooth in one valve, and a
corresponding groove in the other.
C. Damaecornis. Sow. Gen. f. 1 . arcinella. Sow. Gen. f. 2.

Isocardia Lam. Shell heart shaped, regular, ventricose ;
bosses remote, receding, turbinate ; cardinal teeth
lamellar.

I. cor. En. Meth. 232. f. 1.

Tridacna Lam. Animal affixed by a byssus, which
passes through a large opening on the anterior side ;
cardinal teeth -|.
glgas. En. M6th. 235. f. 1. elongata. Sow. Man. f. 51.

* This species, by uniting Papyridea and Cardium, completes the circu-
lar succession of the sub-generic types.

PART II.

MACROTUACHIA.

SAXICAVlDiE.

375

Cleidoth(P7'us Stuchbury. Shell resembling Chama, but
somewhat pearly ; hinge with an " internal, testa-
'ceous, curved appendage," inserted in a depression
within each of the bosses.

C. chamoides. Sow. Man. f. 75.

Diceras Lam. Somewhat resembling Isocardia ; but
the bosses are excessively produced and turned dif-
ferent ways. Fossil only.

D. arietinum. Sow. Gen. f. 1.

Myochama * Stuchbury. Shell irregular, smooth, at-
tached by the lower valve ; umbones central ; cardinal
teeth small, -, between Avhich is an internal shelly
appendage, attached to a horny cartilage.
M. anomiodes. Sov/. Man. f. 73.

Cardita t Lam. Shell
free, cardiform, or
sub-transverse, rib-
bed ; cardinal teeth
^ or ^, lateral 1 ; re-
presenting Cardium.
{fig. 121.)

C. sulcatus. Sow. Gen. f. 3. imbricatus. lb. f. 4.
calyculatus. lb. f. 1,2. oblonga. lb.

FA3IILY SAXICAVID^.

Animal perforating ; shell often irregular ; lateral teeth

none ', cardinal teeth variable or obsolete.

Saxicava Lam. Shell transversely oval, irregular,

gaping at one or both ends ; ligament external ; teeth

obsolete, {fig. 122. a, e.)

S. rugosa. Sow. Gen. f. 1 — 4.

Fetricola Lam. Shell transversely oval or oblong ; the

valves gaping ; cardinal teeth variable, but always

present ; lateral teeth none {fig. 122. b, c, d.)

P. dactylus. Sow. Gen. f. 3. ochroleuca. lb. f. 4. (6.)

* Affinities uncertain.

f Including Venericordia and Cypricardia Lara. ifig. 121.), the latter
seems an aberrant Cardita. passing into Coralliophaga.

B B 4

37.6"

SHELLS AND SHELL-FISH.

PART II.

CoralUophaga Blainv. Transversely cylindrical ; the
bosses placed close to the anterior margin ; cardinal
teeth ^, one being bifid ; lateral teeth obsolete. A
doubtful type^ but connected to Cardita.

C. carditoidea. Sow. Man. f. 92.

Thracia Leach.* Shell transversely oval^ posterior side
truncate ; bosses central ; lateral hinge margin thick-
ened ; ligament external ; no teeth } ; affinities and
rank uncertain.

T. corbuloidea. Sow. Man. f. 93.

Galeomma Turton.^" Thin^ oval^ equilateral ; the ven-
tral margin considerably gaping ; cardinal teeth ^ ;
ligament internal and external.

G. Turtoni. Sow. Gen. f 1 — 3. Maiiritiana. lb. f. 4, 5.

Venerupes ij: Lam. Animal perforating, analogous to
that of the Solejis ; shell transverse ; the anterior side

* I have not seen this shell ; the figure, but not the definition, being in
So\verl)y's Mnnual. Splnciiiii, 'J'urton, seetns to be an aberrant species of
Saxicava, with the thickened liinjie margin of Thracia.

f Passes into Gastrochie/ia, luul thus completes the circle of this tribe.

t Judiciously contracted from J't'nrn'riipfs. These perforating animals
have no connection whatever with Pullastra. See Poli, vol. ii.

PART II.

UNIONID^. UNIONIW^.

377

very short, the posterior gaping ; cardinal teeth ^
or -I, small and nearly parallel ; ligament external.
V. irus. Poll, i. pi. 10. f. 1,2. ; and ii. pi. 19. f. 25, 26. .

Tribe 3. ATRACHIA.
Animal without siphons.

Family 1. UNIONID^^. River Muscles, or Uriios.

Animal fluviatile ; shell solid, perlaceous ; generally with
cardinal and lateral teeth.

I *
/

SuB-FAM. 1. UNTONIN.E.

One valve, with two cardinal and tw^o lateral teeth ; car-
dinal teeth short ; the mnbones, or bosses, smooth or
longitudinally undulated.

Unio Lam. Cardinal teeth short, oblique, receding from
the anterior margin of the shell, {^jig, 123. //.)

JJnio. Oval or round, but never wdnged _; bosses very
prominent j cardinal teeth very thick.

U. Mytiloides Rafinesque. sulcata. Lea. Am. Tr. iii.
circula. Lea. Am. Tr. pi. 8. f. 12.

iii. pi. 9. 14. cornuta Barnes.
torsa Rafinesque.

378 SHELLS AND SHELL-FISH. PART II.

Cunicula Sw. Ovate oblong ; bosses thick, but de-
pressed ; cardinal teeth moderate.

C. planulata. Lea. Am. rubiginosa. lb. pi. 8. f. 10.

Tr. iii. pi. 9. f. 13. secura. lb. pi. 2. f.l7.

patula. lb. p. f. purpurascens. Lam. vi. 1.

20. p. 73.

Ligumia Sw. Very long and pod-shaped ; bosses de-
pressed ; cardinal teeth moderate.

S. recta. Lam. vi. 1. p. 74.

Theliderma Sw. Posterior hinge margin elevated and

winged ; surface of the valves tuberculated ; cardinal

and lateral teeth perfect.

T. metanerva Raf. nodulosa Wood. Gen. Conch,

lachrymosa Lea. verrucosa Barnes.

pustulosa Lea. Peruviana Lam. En. Meth,
irrorata Lea. 248. f. 7.

Megadomus Sw. Only one lateral tooth in each valve ;
cardinal teeth two ; posterior hinge margin winged.

M. gigas Sw.

Mglia Sw. Shell generally cuneate; bosses moderate ;
cardinal teeth short, compressed, diverging towards
the anterior margin.

JEglia Sw. Shell cuneate ; bosses prominent ; cardinal
teeth much compressed, placed on one side of the
bosses.
M. ovata Saij. Occidens Lea. Am. Tr. iii. pi. 10.

Naidea Sw. Shell ovate ; bosses depressed ; cardinal
teeth short, thick, obtuse, placed immediately beneath
the bosses.

N. ater Lea. Am. Tr. iii. pi. 7.

Canthyria Sw. Shell ovate ; cardinal teeth long, com-
pressed ; surface of the shell spinous.

C. spinosa ( U. spinosa Lea). Syn. frontisp.

Mysca Turton. Shell elongated, oblong-ovate ; car-

PART II. ATRACHIA. — HYRIAN^. 379

dinal teeth compressed and crenated; the outer sharp^
and almost parallel with the anterior margin.
M. pictorum * LinJi. En. Batava Larn. En, Meth. 248.
Meth. 248. f. 4. f. 3.

ovata SiL\ {Jig. 56.) ' '" marginalis, lb. 247. f. 1.

Potomida Sw. Oval ; cardinal teeth short, thick, the

outer one diverging towards the anterior margin.

P. sinuata Za?w, En. Meth. corrugata Sw. (fig. 51.)

pi. 248. f. a, h. littoralis. En. M. 248. f. 2.

Lymnadea Sw. Posterior hinge margin elevated and

winged ; the valves connate ; the surface smooth.

L. alata Sw. Ex. Conch. ? compressa Lea. Am. Tr. iii.
{fig. 48.) pi. 12. f. 22.

fragilis Sw. Zool. 111.

SuB-FAM. 2. HYRIANiE.

Bosses longitudinally sulcated ; cardinal teeth long, com-
pressed, placed on one side of the bosses ; hinge margin
winged, {^fig. 123. g.)

Iridea Siv. Oblong ovate ; bosses small, depressed,
sulcated ; inner cardinal tooth placed beneath the
outer.

I. granosa Lmji. En. Meth. 248. f. 9.t

Castalia Lam. Oval or trigonal, nearly equilateral ;
bosses prominent ; cardinal teeth short, thick ; the
outer largest and crested.

Naia Sw. Oval ; cardinal teeth beneath the bosses,
and deeply sulcated.

C. corrugata Lam. En. picta Sw. En. Meth. 248.
Meth. 248. f. 8. f. 6.

Castalia Lam. Trigonal, nearly heart-shaped.

C. cordata ^ Sw. Sow. Man, pectinata SpLv. Braz. Test,
f. 140. pi. 25. f. 3, 4.

* And of all the British writers who have not confounded it with the
British Ovata, as Lamarck has done.

f This is not a typical species, but it is the only one, out of tenor twelve,
which I believe is figured.

J Castalia amhigua Lam. A name quite inadmissible to a decided
species ; it is the Cordata of Humphrey,

380

SHELLS AND SHELL-FISH.

PAKT II.

Hyria Lam. Hinge margin straight ; both extre-
mities elevated and winged ; cardinal teeth very
long, and resembling lateral teeth. {ji(j, 124.)

syrmatophora Gmelin, 3222. corrugata. En. Meth. pi. 247.
elongata ^«;. Ex. Conch. f. 2.

pi. 24.

HvridellaSw. Transversely oval; bosses not sulcated;
posterior margin elevated and winged ; one cardinal
and one lateral tooth in each valve.

H. australis. Lam. Sys. vi. 1. p. 80.

SUB-FAM. 3. IRIDININ^.

Narrow and greatly elongated ; hinge margin without
teeth, but sometimes granulated, {fig. 123. e, f.)

Iridina Lam. Hinge margin granulated.

I. striata Sw. Monog. En. ovata Sio. Monog.

Meth. 204. bisl.* elongata 5'o<f. (^private plate).

Calliscapha Sw. Hinge margin smooth.

C. Nilotica Sow. Zool. Journ. i. pi. 2.

Mycetopus D' Orb. Pod-shaped ; hinge margin straight,
smooth ; the extremities obtusely rounded, or sub-
truncated ; considerably gaping ; animal perforating

Solenoides, Sow. Man. f. \5l.

* The figure reinesents this as an "arcuate" shell, very diifereiU from
that figured by the late Mr. Sowerby.

PART II. ATRACHIA. ANODONTINiE. 381

SuB-FAM. 4. ANODONTINiE.

Cardinal teeth none ; lateral tooth extending along the
hinge or entirely wanting ; hinge margin generally
winged.

Lamproscapha Sw. Shell not winged, elongate pod-
shaped ; teeth none ; hosses near the anterior ex-
tremity. Tropical America only?

L.? elongata Sw. Zool. 111. i. 176. siliquosa. Braz. Test,
ensiforme Spix. Braz. Test. pygmea. IF).

SympJiynota^ Lea. A single or double lamellar tooth
extending the whole length of the hinge margin ;
valves generally winged and connate, {fig. 123. ?.)

plicata Leac/i. Zool. Miss f ? tenuissima. Am. Tr. iii.

lavissima Lea. Am.Tr. iii. pi. 11. f. 21.j:

pi. 13. f. 23. rubens. En. Meth. 201. f. 1.
bialataZert. lb. pi. 14.f. 24.

Anodon Lam. Doubly winged ; no lamellar or other

teeth.

A. cataracta Lam. vi. 1. cygnea Lam. Gualt. pi. 7.
p. 85. ' f. F.

Hemiodon Sw. Shell ovate ; tubercles or undulations

on the hinge margin^ representing cardinal teeth.

H. undulatus. {An. rugosus purpurascens Zool. 111. i. 160.
Zool. 111. i. 96.) areolata. Id. ii. 18.

Patulavia Sw. Shell nearly equilateral, round or cor-
date ; no teeth.
T. ovata Sw. Ex. Conch, pi. 36. rotundatus, lb. pi. 137.

SuB-rA3i. 5. ALASMODONTIN^.

Lateral teeth entirely wanting ; cardinal teeth one or
two.

* Dipsus Leach.

f Differs from bialata by having oblique depressions towards the bosses
or beaks, which latter also are not marked with "concentric undulations."

X Seems to form the passage to Anodon. Specimens labelled by Mr. Lea,
were totally different from my Hem. purpurascens. ^

382

SHELLS AXD SHELL -FISH. PART IT.

Calceola Sw.* Shell ovate ; posterior hinge margin
angulated ; one cardinal tooth, and generally a small
single lateral tooth in each valve.

C. angulata Sio. Am. Tr. 1827, pi. 3. f. 1.

Alasmodon Say. Trigonal ; nearly equilateral ; bosses
large, prominent ; two cardinal teeth.
A. undulata Say.

Uniopsifi Sw. Oval ; bosses prominent ; cardinal teeth
two, irregular, receding from the anterior margin.
U. Mytiloides. (Jig. 62. )f

Margaritana Schum. Elongated, and somewhat ar-
cuated ', bosses small ; posterior hinge plate long,
convex, sometimes with the rudiments of a tooth ;
cardinal teeth two or one, small, obtuse.
M. elongata Lam.\ arcuata Barnes.

Complanaria Sw. Shell winged ; the valves connate ;

the bosses very small and depressed ; cardinal teeth

two or three ; lateral teeth represented by irregular

grooves.

gigas Sw. Sow. Gen. f. 141. rugosa Sw. {Al. rugosa) Barnes.

Family 2. ARCADE. Arch-Shells,

Marine; hinge margin furnished with numerous small
well-defined teeth, without any distinction of cardinal
and lateral ; umbones generally remote, mostly covered
with an epidermis.

NucuLA Lam. Perlaceous ; shape various ; beneath the
umbones, a spatulate enlargement or pit containing
the cartilage ; teeth small, numerous, prominent, and
pectinate : marine and fluviatile. (fg. 125. f, g.)
margaritacea. Sow. Gen. f. 7.

* The situation of tliis type seems doubtful, but as I have more than one
species of the same form, but without the small lateral tooth, I conjecture
they all stand between Alasmodon and Anodo?i.

t See note at p. 28a

X This is the true ^fl/a marf^aritifcra of British'authors, for which La-
marck only quotes the fiffures of Pennant and Da Costa; and as he was the
first to distinguish it as dittercnt from the other European species, I think
his specific name has every right of priority.

PART II.

ATRACBIA. - AVICULIDiE.

383

Pectunculus Lam. Orbicular : the bosses central ;
hinge margin curved, with a line of small oblique
teeth diverging on each side, {^fig- 125. a.)
P. pilosus. Sow. Man. f. 134.

Arc A. Shell of various shapes, either equivalve or in-
equivalve, but the valves closing all round ; the bosses
very prominent ; hinge margin always straight ; the
teeth small.* {fig. 19,5. b,d.)

A. antiquata. Sow. Man. f. 131.

Byssoarca f Stv. Shell always transversely oblong or
oval, generally angulated ; hinge margin straight,
often auriculated ; the teeth minute ; valves gaping
on the basal margin, {fig. 125. c, e.)
B. Zebra. Zool. 111. ii. pi. 113. No®. Sow. Gen. f. 132.

Trigonia Lam. Shell perlaceous, sub-cardiform, one
extremity rounded, the other truncated and com-
pressed ; cardinal teeth -, sagittate, compressed, and
regularly grooved : intermediate between Byssoarca
and Nucula, and representing Cardiiim, Pandora,
and all the other cardiform types.

T. pectinata. Sow. Gen. Man. f. 139.

* The sub-genera require to be made out : one of these is Cucullaia.
t The above remark is also applicable to this group.

584

SHELLS AND SHELL -FISH.

PART II.

Family 3. AVICULIDiE. Muscles and Pearl Oysters.

Animal attached, byssiferous ; shells lamellar, internally
perlaceous; the valves generally gaping, {fig. 126.)

Mytilus Linn. Oblong, transverse ; the bosses small,
close to the anterior margin ; both extremities rounded ;
hinge margin straight, and generally forming an angle ;
valves not always gaping ; teeth (except in Bi-achi-
dontes) none.

Brachidontes Sw. Umbones prominent, not terminal ;
valves corrugated ; hinge margin considerably angu
lated ; teeth many, small, and crenate.
sulcata. En. Meth. 220. f. 2.

Modinla Lam. Resembling the last, but the hinge
without teeth, and the shell smooth ; valves slightly
gaping, {fig. 126. h.)

M. tulipa. Sow. Gen. f. 160.

Lithodomus Cuv. Animal perforating ; shell oblong,
ventricose, nearly cylindrical ; the hinge margin not

PART II. ATRACHIA. AVICULID^. 385

elevated ; umbones terminal ; the posterior end some-
times rostrated. (Jig, 126, «.)

L. dactylus. Sow. Man. f. 161.

Mytilus Linn. Shell transverse, somewhat triangular,
from the straightness and elevation of the hinge mar-
gin ; umbones minute, terminal, sometimes with an
obsolete tooth.

M. achatinus. Sow. Man. f. 158.

Lanistes Humph. Shell oval, transversely cardiform,
ventricose ; umbones prominent, with diverging ele-
vated striae ; hinge margin not elevated or angulated;
teeth none : the cardiform type.

discors. En. Meth. ^04. f. 5.

Pern A. Shells sometimes irregular, inequi valve,
oyster-shaped, greatly compressed ; the margins
brittle ; hinge plate broad, with numerous teeth, se-
parated by parallel grooves containing the ligament,
and gaping near the umbones.

Gervillia Def. General form of Modiola; hinge long,
straight, with small, irregular, transverse grooves.
Fossil only.

G. avicularis. Sow. Man. f. 169.

Crenatula Lam, Irregularly oval, compressed; hinge
margin straight, with a few semicircular excavations,
containing theligament; umbones terminal..(^^.126.«.)
C. Mytiloides. Sow. Man. f. 168.

Perna Lam. Shape various; valves always equally flat-
tened; but the hinge margin always straight, not pro-
longed; the plate marked with numerous transverse
regular grooves.

P. Ephippium. Sow. Gen. f. 166.

Pulvinites Def. Valves unequal, — one being flat, the
other convex ; hinge short, grooved, as in the last :
representing Corhula, &c.

P. Adansoni, Sow. Man. f. 170.
c c

386

SHELLS AND SHELL-FISH.

PART II.

Inoceramus Sow. Cardiform^ thick ; umbones lateral,
rather prominent, and incurved ; hinge short, formed
of a series of short transverse grooves : the cardifornm

type.

I. Lamarck ii. Sow. Man. f. 167.

Malleus. Shell very irregular, more or less hammer-
shaped ; the hinge margin being straight, and often
greater prolonged ; the valves gaping to near the
umbones.

Malleus Lam. Hinge margin excessively long, and
forming two auricles ; umbones minute, depressed,
with a small disk for the liga-
ment, and an external groove for
the cartilage.

M. vulgaris. Sow, Man. 167.

Reniella Sw. Shell transversely ^
and irregularly orbicular ; sub- "^
ventricose near the umbones,
which are very small, termi-
nal, and remote; between them
is a deep triangular concave pit,
lined by the ligament ; the mar-
gin of this pit forms a semicircle,
to the edge of which is attached
a narrow cartilage.

R. dilatata Sw. {fig. 127.)

Vulsella Lam. Shell tongue-
shaped, longitudinally elon-
gated, compressed, without
auricles ; umbones minute,
curved, approximating ;
hinge plate thick, diluted
into a semicircular solid pit
for the cartilage.

V. lingulata. Sow. Man.' f. 185. (fig.128.)

Avicula. Shell regular, foliaceous, unequally auricu-
lated ; hinge margin straight, much lengthened ;

PART II.

ATRACHIA-

•OSTRAClDiE.

387

umbones lateral or sublateral ; byssus protruded near
the umbones.
Margarita Leach. (I8I7.) Shell more or less rounded;
auricles small ; umbones sub-lateral ; the hinge mar-
gin straight, but not lengthened ; teeth small, tuber-
culated, nearly obsolete, {fig. 126. e.)
crocata. Zool. 111. ii. pi. 55.

Aviciila Lam. Shell obliquely oval ; the hinge margin
very much lengthened, and forming unequal auricles ;
teeth tuberculous, nearly or quite obsolete, {^fig. 1'2,1.
h, c, c?.)
A. heteroptera. Sow. Gen. f. 1. aculeata. lb. f. 2.

PiiNNA. Shell equivalve, wedge-shaped or triangular ;
umbones terminal ; the other extremity widely gaping ;
hinge margin straight ; teeth none ; anterior margin
slightly gaping.* {fig. 19.6. f, g.)
P. serrata. Sow. Gen.

Family 4. OSTRACTD^. Oysters.

Animal sedentary, generally affixed by their under valve ;
shell foliaceous, rarely pearly, {fig. 129.)

Peoten Linn. Shell regular, depressed, nearly orbicular,
auriculated ; umbones central ; ligament small ; in-
ternal hinge margin short ; teeth straight.

* This genus, by coining close to Mytilus corapletes the circle of thi»
family.

c c 2

^

388 SHELLS AND SHELL-FISH. PART II.

Lima Linn. Longitudinally oval ; valves gaping on
one side near the umbones; animal similar to avicula,
connecting this family with the last.

L. squamosa. Sow. Man. 174.

Pecten Brug. Shell generally free_, sometimes slightly
attached by a byssus ; orbicular or ovate ; auricles
nearly equal ; umbones central ; valves closing all
round ; hinge margin straight ; no teeth ; ligament
triangular, internal.

Decadopecten Riippell. General form of Pecten, but
with plicated teeth of the hinge : analogous to Nucula.
D. plicata Sow. Man. f. 172.

Pleuronectia Sw. General form of Pecten, but the
valves very much compressed and gaping at their
edges.

P. Icevigata Sw. En. Meth. 208. f. 3.

Hinnites Def. Animal attached ; shell pectiniform, but
irregular.

H. pusio. Sow. Man. f. 173.

Spondylus. Shell inequivalve, attached by its under
valve ; rough, with spines and plates ; umbones
central, remote, separated by a triangular disk.

Plagiostoma Sow. Shell free, inequilateral, oblique ; um-
bones remote ; sub-auriculated on one side ; hinge
straight in one valve, with a triangular notch in the
other ; surface spinous or smooth. Fossil only.
P. spinosum. Sow. Man. f. 176.

Spondylus Lam. Shell attached ; spinous and foliaceous
externally; auriculated hinge^ with two teeth locking
into cavities (Jig. 129. a.)

S. Americanus. Sow. Man. f. 177.

Dianchora Sow. Shell attached, obliquely pectiniform,
the attached valve having an opening at the boss,
the other auriculated with an obtuse boss ; teeth
none : passing into Ostrea by Pedum.
D. striata. Sow, Man. f. 175.

PART II. ATBACHIA. OSTRACID^. 389

OsTREA Linn. Shell foliaceous^ irregular, generally
attached by the under valve ; hinge usually without
teeth.

Pedum Brug. Shell hatchet-shaped, depressed ; in-
equivalve, slightly auriculate ; umbones small, re-
mote ; sides of the lower valve turned upwards, with
a deep sinus for the passage of the substance by
which it adheres ; a small, central, spatulate tooth in
each valve bears the cartilage, and a transverse cen-
tral furrow between the umbones holds the ligament,
which spreads also between the umbones.

P. spondyloideuin. Sow. Gen. f. 1 — 5.

Dendrostran Sw. Shell irregular, equivalve, attached

by its lower valve by extraneous processes ; the

margins solid and plicated.

D. folium. Sow. Gen. f. 3. crista-galli. Sow. Gen. f. 2.
carinata, lb. f. 1 .

Ostrcea Linn. Shell irregular, round or oval, inequi-
valve ; the margins thin and brittle ; no teeth ; um-
bones central.

O. edulis. Sow. Gen. f. 2, cingulata. lb. f. 1.
Virginica. lb. f. 1.

Gryph(jea Lam, Shell regular,
inequivalve ; one valve con-
vex, with the umbo recurved,
the other smaller, and nearly
flat; margin of the valves not
foliaceous.
G. incurva {fig.l'HO.) Sow. Gen. f. 2. dilatata. lb. f 3.

PUcatula Lam. Shell irregularly ovate, plicated, in-
equivalve ; one valve more convex than the other ;
cardinal teeth ^ sagittate ; the sides strongly, regu-
larly, and transversely grooved ; between the teeth is
the internal ligament, (^fig. I29. e.)

P. gibbosa. Sow. Gen. f. 1, 2.

Anomia Linn. Shell thin, perlaceous, very irregular,
inequivalve ; attached by a calcareous mass, which

c c 3

SQO SHELLS AND SHELL-FISH. PART II.

passes through an opening near the umbo of the
lower or smaller valve, which is flat; the other is
convex. (fig.Ug.f.)

A. Ephippium. Sow. Man. f. 186.

Placuna Brug. Shell very much compressed^ per-
laceous^ with two internal lamellar, sagittate, cardinal
teeth in one valve, {fig. 129- h, c.)

Placunomia.* Shell attached, with the form and gene-
ral structure of Anomia, but with two sagittate car-
dinal teeth.

Cumingii. Sow. Man. f. 189.

Placuna Brug. Shell not attached, foliaceous, roundish ;
the valves equally flattened : united to Pecten by
Pleuronecta.

P. placenta. En. M^th. 173. f. 2.

Family 5. ETHERID.iE. River Oysters.

Irregular, inequivalve, foliaceous ; pearly within ; epi-
dermis olive green ; ligament partly internal and partly
external.

Etheria Lam. Muscular impressions two ; shell irre-
gular ; teeth none.

E. semilunata. Sow. Man. f. 155.

MuLLERiA De Per. Muscular impression single ; shell
sub-quadrate ; hinge irregular ; teeth none.
M. lobata. Sow. Man. f. 192.

Abridged from Placunanomia Sow.

391

EXPLANATION OF TERMS

USED IN DESCRIBING THE SHELLS OP TESTACEOUS

MOLLUSCA.

Accessary Valves. Small additional valves placed near
the umbones or bosses of the genus Pholas among
shells, and on the edges of the pedunculated bar-
nacles, among annulose animals.

Acephalous. Mollusca without an apparent head,
comprehending the bivalves of conchologists.

Acuminated. Ending in a graduated and often acute
point.

Adductor muscle. That which closes the two pieces of
a bivalve together, the base or insertion of which is
indicated by an irregular depression in each valve,
these being called the muscular impressions.

Anterior, when applied to the sizes of bivalve shells,
is that in which the ligament is not placed.

Apex, The point or nucleus of a shell ; hence the
bosses of bivalves, the points or top of limpets, or
of univalve shells, are so called.

Aperture, or mouth of univalve shells, is the cavity
from which the head of the animal is protruded.

Arcuated. Curved or arched.

Auriculated, or eared. A term given to a few bivalves
which have a flat angulated projection on one or
both sides of the umbones, or bosses : these processes
are most developed in the Pectens, and are merely

c c 4

392 SHELLS AND SHELL-FISH.

an incipient modification of the angular dilation of
the hinge margin in Byssoarca, and several other
genera.

Auriform, or ear-shaped^ as in Haliotis.

Base. This term in regard to shells is variously applied :
generally speakings it is used in opposition to the
apex or end of univalve shells, although, correctly
speaking, it is at this part where the head of the
animal protrudes. In such hivalves as adhere to
other substances by one of their valves, as in Spon-
dylus, Anomia, Sec. that valve is termed the basal.
In unattached bivalves the terra cannot be properly
employed. In reference to the whorls of spiral
shells, the last or largest is termed the basal w^horl.

Bivalve. Shells of the order Dithyra, having tAvo valves.
Bifid. Cleft, or double.

Byssus. A bunch of silk-like fibres, by which many
bivalves adhere to other substances, without the shell
itself being deprived of motion. The PinncE, or
wing-shells, are the most typical examples ; but
many other genera, as the Pearl and Hammer oysters
and even some of the muscles are thus provided.
When dried, the byssus of the large Neapolitan
Pinna is sometimes fabricated into gloves, but only
as objects of curiosity, since, as w^e know by per-
sonal inquiry, it is a most tedious and difficult
process.

Callous. When there is a thickening of enamel upon
any particular part of a shell, resembling a tumour, it
is termed callous, or a callosity : this is observed
among spiral shells, in the inner lip of the Olives,
Natica?, and many others, and is very common near
the hinge of certain bivalves.

Canal. A groove or gutter observable in different
parts of certain spiral shells, belonging to the Zoo-
phaga, or carnivorous tribe. In these the canal is
either lengthened, as in Murex, short as in Ha)-pa,

EXPLANATION OF TERMS, 393

or truncate as in Buccinum ; in the two latter it
thus gives place to a notch, but in all these instances
it is that part fitted for the protrusion of the long
cylindrical siphon possessed by all these animals.
This part, also, constitutes the base of the shell. Be-
sides this, there is in many of the mitres, Stromhi,
and other predaceous genera, another channel or
groove, placed in the interior of the upper part of the
aperture, the use of which has not been fully ascer-
tained.
Cancellated, When the surface is marked by striae or
lines, which cross each other at right angles.

Cardinal teeth of bivalves, are those placed immediately
beneath tbe bosses, and between the lateral teeth
where such exist, as in the common cockle.

Carinated, or keeled. Furnished with an elevated, and
often a sharp ridge, either on the surface or margin
of the shell.

Chambered. Divided internally into compartments, as
in the testaceous Cephalopoda, or Nautilus.

Clavate, club-shaped. One extremity being slender and
pointed, the other thick and obtuse. Many of the
zoophagous genera, as Cerithium, &c. are peculiarly
strong examples.

Columella, or Pillar. The internal support of most
spiral shells, round which the whorls convolute : it
is not present in Solarium, Delphinula, the typical
Scalar ia, and a few other genera ; all of which, in
consequence, have the umbilicus so deep, that it ex-
tends to the apex or top of the shell. The basal
portion of the columella generally forms the support
of the inner lip, and always that around which the
plaits are disposed, as in the Volutes ; it is some-
times greatly thickened, as in Ancillaria, and all the
Olives.

Concentric. Stripes, grooves, or other external marks
indicating the progressive enlargement or growth of
the shell : hence those indented stripes or striae in

394* SHELLS AND SHELL-FISH.

bivalves^ which run parallel to the margin, are termed
concentric. Among spiral shells these indications are
less common, but the Wentletrap is a good example.

Corneous. Resembling the colour or substance of horn :
the epidermis of some, and the operculum of other
spiral shells, often present this appearance.

Coronated, or crowned. Spiral shells which have their
whorls more or less surmounted by a row of spines,
or tubercles, are termed coronated. The typical Vo-
lutes, or melon shells, several cones, mitres, &c. are
thus ornamented.

Crenated. Small indentations, generally sharp and re-
gular, often placed on the outer lip of spiral shells,
particularly on many of the typical mitres, as M. pa-
palis, episcopalis, &c. Harpa crenata is also a good
example : in bivalves fewer examples occur, and these
only in the teeth, as Byssoarca and Iridina.

Cuniform. Wedge-shaped, as Donax : this shape,
comng bivalves, is analogous to that of clavate uni-
valves.

Deciduous. Any part which falls off in a more ad-
vanced stage of growth, as the terminal whorls of the
pupaform land-shells, to which, indeed, this pecu-
liarity is almost confined.

Dextral. When the mouth or aperture of a spiral
shell is on the right hand ; when on the left, it is
sinistral or reversed. The great majority of spiral
shells are dextral, but frequently in the very same
species (as in Bulimus), individuals occur whose aper-
ture is reversed. This, by the way, shows the in-
sufficiency of making such deviations the ground of
generic distinctions. In some genera, on the other
hand, as Physa, all the species are reversed.

Digitated. The expansion of any particular part, as in
the outer lip of the scorpion Stromhi, into finger-
shaped processes.

Discoid, or discoidal. Circular or disk-shaped, and
much flattened. The freshwater genus Planorbis, and

EXPLANATION OF TERMS. 395

i

many of the Helicidce, or land-shells, are of this
form.
Dorsal. All shells are dorsal^ because they are all
placed upon the back of the animal : the term^ there-
fore^ is only applicable to the valves of bivalves, and
merely serves to distinguish that part of their cir-
cumference on which the bosses are placed, in oppo-
sition to that which, when the animal is crawl-
ing, is nearest the belly. The upper part of a spiral
shell, when the mouth is downward, may be termed
its back, or dorsal surface.

Emarginate. A small notch, or fissure, wherever it may
occur : thus the base of most predacous Testacea, not
provided with a canal, are emarginate ; so also is one
extremity of Parmophorus , although in a very slight
degree, while, in the genus Emarginnla, the notch
becomes a deep slit.

Epidermis. A name generally applied to the outer
rough coating of shells, over which it spreads as a
fibrous horny skin, although not really such, being
destitute of sensation.

Entire. Immarginate, or uninterrupted, in opposition to
emarginate.

Equilateral. When both sides of a bivalve are equals
the umbones or bosses being nearly, or quite, in the
middle : this is nearly the case with the common
cockle.

Equivalve. The two valves of equal size and depth, as
in the generality of bivalves.

Fibrous. Resembling fibres ; applied to the substance
of a shell it indicates those, like the Pinna, whose
fracture presents perpendicular fibres.

Fimbriated. Thin elevated processes, somewhat re-
sembling fins, possessed by many of the Murices, as
Murejc fimbriata, &c., and sometimes placed round
the aperture of cyclostomous land shells.

S96

SHELLS AND SHELL-FISH.

Foliated. Resembling leaves. As used for the external
surface of shells, the varices, or spines, on many of
the Murices are foliated, or divided at their margins
into leaf-like segments, as in the rosebush Murex ;
but applied to the substance, it indicates those bivalves
which are composed of thin flat plates, very fragile,
and lying upon each other, as in the common and
pearl oysters. Sometimes the spines of bivalves are
partly foliated, as in the genus Spondylus.

Front. The front of a shell is obviously that near
to which the head of the animal protrudes : but this
term, however objectionable, is given to the under
surface of spiral shells, or that where the aperture is
placed, in contra-distinction to the back.

Fusiform, or spindle-shaped ; thickest in the middle,
and attenuated or tapering to the extremities. Fusus,
Fasciolaria, and many mitres, are more or less of this
form.

Gaping, A bivalve is called gaping, when any part of
the margins do not touch.

Gibbous, or humped. Any part of a shell more par-
ticularly elevated above the surface, or unusually so in
comparison to other species, is termed gibbous, as
Strombus gibbosus.

Granulated, or grained. Marked by elevated, close set,
and regular dots, resembling grains : this appearance
is very common at the base of the predaceous spiral
genera.

Hinge margin in bivalves, see Dorsal margin. The
hinge is composed of the ligament, the cartilage, and
the teeth.

Hyaline. Of a glassy, thin, and semi-transparent sub-
stance.

Imbricated. Plates or folds laid over each other, like
tiles on the roof of a house.

EXPLANATION OF TERMS. 397

Incrassated. Any part more thickened than usual, or
than the surrounding surface. The inner lip of
Oliva and the hinge of Glijcimeris are good examples
among the spiral and acephalous tribes.

Incurved. The point turned inwards.

Indented. A term of very comprehensive meaning : it
is used, generally, to express any thing depressed or
sunk beneath the surrounding surface, whether they
are lines, dots, irregular cavities, or tooth-like depres-
sions. Many shells are marked by indented strise.
The suture of others is also indented.

Inequivalve. One valve smaller than the other, as in
Anomia and Terebratula,

Inferior valve of adherent bivalves, is that by which the
shell is united to other substances.

InHated. See Ventricose.

Irregular bivalves. Such as, from being influenced
in their growth by the substances in which they re-
side, do not present a uniformity of shape in the in-
dividuals of the same species. This variation is
almost confined to the perforating groups ; among
which, however, as in Lithodomus, this deviation
from a uniform specific shape is not found.

Lamellated. Shells whose substance is composed of
very thin plates or lamellae, which do not present a
solid surface, as in the pearl oysters.

Lateral. Any thing on the sides of a shell. Thus the
lateral teeth of bivalves, where they exist, are on one
or both sides of the cardinal teeth, which are always
central.

Length of shells. Spiral shells are measured from the
tip of the spire to the base, and therefore perpen-
dicularly : but the length of bivalves is taken hori-
zontally ; thus the Soleus are the longest shells of
this tribe, the length being taken from the anterior
to the posterior margin.

398 SHELLS AND SHELL-FISH.

Ligament, An exteranl substance, by which the two
valves of acephalous Testacea are united, and which,
in fact, is the true hinge. The internal part is gene-
rally composed of another substance, called the car-
tilage, of a compact fibrous structure, which is elastic
when moistened, but very hard and solid when dry.
This is generally placed close to the bosses, and is
often continued between the teeth, so as to form a
second or internal ligament.

Lips. The two sides of the aperture of spiral shells are
termed the lips. That which joins, and generally
folds over, the lower part of the columella, is called
the inner lip, while that part of the circumference
opposite is the outer. The latter, of course, is found
in all shells, because it is the termination of the last
whorl ; but the inner lip is frequently absent, or only
indicated by a thin, whitish, almost transparent
enamel': sometimes, however, it is highly developed,
as in Nassa, the typical Cassides, or helmet-shells,
and several others.

Lobed. A broad obtuse division, as in many of the
Strombi and Pleurotomince.

Longitudinal. The meaning of this term, as used and
understood by all the best conchologists, is " length-
wise ;" hence it means any stripes which run in a
perpendicular direction from the apex to the base of
spiral shells, while such as are in a contrary direc-
tion— that is, parallel to the suture of the whorls,
are transverse. Great confusion, therefore, is likely
to be introduced by reversing these definitions.*
However objectionable they may be thought by fas-
tidious persons, we always have and shall continue
to designate the direction of stripes, bands, or other
peculiarities, as longitudinal when they run in the
direction of the length of a spiral shell, and ti'ansverse
when they cross its breadth. The latter term, how-
ever, is not applicable to bivalves, because such marks

* As is done in the Conchological Manual.

EXPLANATION OF TER3IS 399

always spring from the bosses^ and, widening as they
approach the ventral margin, become radiated.

Lunate, or lunulate, assuming the form of a crescent o.
half-moon. Tiie aperture of the nerits is of this de«
scription, as well as the muscular impressions of
most bivalves.

Mamillary, or mamillated. Smooth, thick, and obtuse,
like a teat. The apex of the typical volutes, as
Voluta olla, Diadema &c. are strictly of this de-
scription, as also those of Harpula fulgetrum, Sea-
phella papulosa, and other volutes : but C. vesperiilio
is not so, for the spire is distinctly plaited^ and even
rough with obsolete spines.

Measurement, see Length.

Multivalve. The oiily multivalve Testacea, properly
so called, are the chitons and the perforating genera
belonging or closely allied to Teredo and Pholas. The
Cirripedes are annulose animals or insects_, and have
no place whatever among the molluscous tribes, any
more than beetles or butterflies.

Muscular Impressio7is : those indented marks in ace-
phalous bivalves, indicating the insertion of those
muscles by which the animal is attached to its shell.
Of these there are three principal sorts, — lateral,
central, and paUial. 1 . The lateral impressions indicate
the animal to have two adductor muscles, as in Unio
Cardium, and aU the most typical bivalves. 2. A
central impression shows us the presence of but
one adductor muscle, which is generally in the middle
of the shell, as in the common oyster. AU these
shells, however, are furnished with the third or pal-
lial muscle, which is indicated by a depressed line,
often sinuated, running parallel with the ventral
margin.

Obsolete. This term, in conchology, is more properly
restricted to implying a faint indication of par-
ticular characters. Thus, very slight and partially

400 SHELLS AND SHELL-FISH.

indistinct stria upon a shell are called obsolete strice,
not because they are worn off' by accident, but be-
cause they are only rudimentary, or very slightly
developed.

Operculum. The hard lid, either corneous or cal-
careous_, which closes the mouth of many spiral
shells, and is carried on the posterior part of the
belly of the animal. It generally fits the aperture
of the shell, but is sometimes smaller, in which case
it is drawn inside until the animal adjusts it to the
diminished circumference of the whorl. Nearly all
the predaceous tribes have this protection ; but it is
never found among such as envelop their shell in the
lobes of their mantle.

Ovate. Not oval, but egg-shaped ; one extremity being
thicker and more obtuse than the other.

Patelliform. Dish shaped, as the limpets.

Pectinated. Processes resembling in form and arrange-
ment the teeth of a comb, as are the spines of some
species of Murex.

Perforated. As if bored or indented by an awl : the
holes or perforations in the ear-shells are of this de-
scription.

Plicated. Applied to any part of a shell which has
plaits or folds, either upon the pillar or the external
surface: the concentric ridges so common in the
genus Venus are also of this description.

Posterior margin. This term is confined to acephalous
bivalves, and is that side of the bosses which contains
the ligament.

Ramose. Spines upon shells which send out others in
a lateral direction, are termed ramose or branched.

Recurved. Turned backwards, in contra-distinction to
incurved. The canal of some Strombi and Cerithiinn
are remarkably recurved. The apex of all the patelli-

EXPLANATION OF TERMS. 401

form shells, however, are not always incurved, the top
bending downwards or being erect.

Reflected. Turned or folded backwards, as is the thick-
ened outer lip of the common garden, and many other
of the terrestrial, snails.

Reverse Shells, are such as have the aperture opening
on the left side when it is placed in front of the spec-
tator.

Sinuated, or waved. Any part whose margin has one
or more undulations : this appearance is produced by
a projecting lobe being followed by a notch or hoUow
more or less deep. The outer lip of Struth'wlaria and
several of the Stromhi are sinuated, but the latter so
much so as to form abrupt lobes and corresponding
notches.

Sessile. Destitute of any support or peduncle, as in the
shell of the Anomia. Those of Terebratula, on the
contrary, are elevated in some degree, on a pedunclcj
and are termed pedunculated.

Siphon. A sucker: a fleshy process, generally long,
cylindrical, and hollow ; protruded by the carnivorous
and testaceous animals from the base or channel of
their shells. The same term is given to the slender
shelly tube which connects the chambers of cephalo-
pod shells, or the Nautili.

Spire. Those volutions of a spiral shell which are
above the lowest or body- whorl, collectively form the
spire of the shell, M'hatever shape it may assume.
The variations in the form of this part are num.erous.
In some it is excessively lengthened; in others it is not
even raised above the body- whorl. In Plcmorhis the
spire is sunk, while in CyprcBa it is so small as
only to be seen when the shell is young, after which
it is covered over by the enlargement of the body-
whorl or principal volution.

Squamose. Having the appearance of scales.

D D

402 SHELLS AND SHELL-FISH.

Striated. Marked with lines, either elevated or raised,,
at parallel and nearly equal distances. Such marks
are termed striae only when they are very slender^
not much exceeding the breadth of a hair, or at most
of the human nail : when they are deeper and in-
dented, they are termed grooves ; or, if elevated,
ridges. Sometimes the striae are formed by a series
of punctures, as in Mitra cardinalis, &c. ; while in
other instances they are elevated and granulated, as
Mitra granulosa. In bivalve shells they are almost
always concentric, or following parallel to the outer
margin. All these variations have been found of
great importance in the determination of species, and
hence require the closest attention.

Suh. Nearly or partially, as sub-striate, sub-fusi-
form, &c.

Subulate. Awl-shaped, long, slender, and acutely
pointed, as Terebra, Tu7'ritella, &c.

Sulcated. Broad grooves, sunk beneath the surround-
ing surface.

Suture. A term applied to the line of junction in the
whorls of spiral shells^ or that where two parts join
or fit into each other.

Symmetrical. Where the two sides of a shell are alike.

Terebrating Testacea are such as take up their habi-
tations in other substances, as Pholas, &c.

Tessellated. Divided into squares or chequers, either
by a division of the colours, or by the crossing of the
stris.

Transverse. A line drawn across the breadth of a sliell.
Thus the coronations of the Volutes are transverse,
so also are the bands on the AcJiatince, and all those
upon bivalve shells which radiate from the bosses.

Trigonal or triangular. Having three equal or unequal

sides, as Donax, Hyria, Cardissa, &c.
Trilobate. Divided into three obtuse divisions or lobes.

EXPLANATION OF TERMS. 403

Tricuspidate. When these divisions end in points.

Truncated. Ending abruptly^ as if cut off, as in the
extremities of the typical Soleus, Mya truncata, 8cc.
The same term may be applied to the termination of
the spire in several land-sheUs, which seem as if
they had been broken off.

Tuhivalves. Such bivalves, like Teredo, as are pro-
vided also with a tube.

Turbinated. Turban or top-shaped j the whorls con
vex, and generally but very little raised. The garden
snails are good examples, but not the TrocM, thai
form being pyramidical.

Umbilicus. A hollow opening, more or less wide,
on the side of the inner lip of spiral shells : in some,
as Scalaria and Sollarium, it is so deep as to ex-
tend to the apex of the shell ; in others, as Tro-
chus, it is small ; in Bulimus it becomes nearly
obsolete ; and in N'atica it is often entirely con-
cealed by the spreading of the inner lip. In all
these variations, however, the umbilicus is caused by
the inner edges of the whorls not touching each other.
Instances occur in certain land-shells which are
deeply umbilicated when young, but not at all when
old.

Undulated. Waved ; nearly synonymous with sinuated,
but more particularly applied to the colouring of
shells. Scapella undulata and many other volutes
are marked in this way.

Valves. The two ordinary or principal pieces which
comprise the covering of acephalous Testacea, or
bivalves.

Varix. Those strong elevated ridges which cross
the whorls of several of the predaceous genera,
as Murex, Triton, &c. : they mark the progressive
enlargement of the sheU, being the remnants of
former apertures, beyond which the animal, when

D u 2

404< SHELLS AND SHELL-FISH.

grown, forms another aperture. Sometimes, as in
Murex, these varices are irregular, and are either
spined or foliated ; but in the harp-shells they are
smooth and at equal distances. In Ranella they are
united, so as to form two lateral ridges ; while in
Triton they are detached and remote from each other.
In Cassis they are also alternate ; and, in the aberrant
species, none whatever are perceived.

Volution. Synonymous with whorl.

Whorl. Each complete turn of the spire in a spiral shell
is termed a whorl : th€ last, which terminates with the
aperture, is the body or basal whorl ; the rest are
the spiral whorls.

APPENDIX.

S-u. r /f,4r ■"

The following note on the extraordinary genus Herpa, from
the Guilding MSS., and referred to in the text, is too valu-
able to be omitted.

HERPA Guilding.

Animal terrestre, pulmoniferum. Corpus moUe, subgelati-
aosum, mucrone obductum, elongatum, contractile, depressum,
antice praesertim attenuatum. Os apicale, minutissimum,
obscurum. Fades contracta, emarginata. Tentacula nulla.
Scxttum nullum. Oculi cervicales. Solea magnitudine corporis,
nee distincta. Glandules plurimae ventrales mucorem ab ore
transverse eflfuadentes, unica majore centrali, equa viscus lo-
batum, moUe, plicatile, parvulum, rare protruditur.

Genus valde distinctum, et inusitatae formae. Corpore fere
toto erecto Herpa more serpentum prolabitur, viam mucore
superillinens, et tentaculis carens cervice longo valde attenuate
vestigia diriget. Genus Planariis facie quam plurimum analo-
gum, ut Limacibus respirationis modo, locis, moribusque
omnino affine.

In the 8th number of the Zool. Journ. p. 443. a short notice
of this genus was given, drawn from a single specimen which
must now be struck out. The capture of many of them has
enabled me materially to improve the description. They are
very singular animals, and in their external characters have a
remarkable resemblance to the Planarice, which, however, as
Cuvier observes, inhabit only salt or fresh water, and therefore
can have no relation of aflBnity with Herpa. Probably, the PL
ierrestris and Candida of Gmelin may resemble them in their
economyo I have found the Herpes on the decayed fronds of

D D 3

406

APPENDIX.

palms, on the summits of high mountains, and on the dry lands
within a few yards of the sea ; these always seeking cool places
for concealment during the day, but never approaching the water,
which upon being thrown into, they instantly quit." The
largest of the three species discovered by our author, was Her-
pa gigas, black above, dirty and paler beneath. It was from
six to seven inches long, and was found creeping across a damp
forest path ; but from the strange power it possesses of contrac-
ting its body, it escaped through a small crevice of the box it
was deposited in, before it could be more accurately examined.

INDEX.

*** The page references are to the Author''s remarks : to avoid a multipUcUy
of figures, the reader is referred to the occasional tables for the classifica-
tion of genera.

AcARDO, 373.

Acephala, the naked, 5. n. The bi-
valve Testacea, 25.

Achatinse, snails with elongated
spiral shells, 1G2. 174. 179. 334.
Sub-typical, 170. 335, oSQ. A.
marginata, 170. Sub-genera and
analogies, 173. 175. 179. 5oQ.
Point of union with the Bulimi-
r\dz. 183.

Achatinellffi, 172. 338.

Acrita, their nervous system gra-
nular, 4. n. Probably consists of
polypes, corals, and plant-like
animals, 5. The group seems to
to be ill-definedby naturalists, 43.

Adanson, on the shell-fish of Sene-
gal, 14.

Adhesion, power of, often by in-
numerable suckers, 30, 31. Of
the Patella to rocks, 244.

iEglia, genus, 265. 378. Represents
Hyria, 275.

Affinity, theory of, 5. 7. 94. 189.
291. Of Testacea, form a conti-
nuous circle, 41. et passitn.

Akera, 249.

Alee, 183.

Alasmodon, 263, 264. 273. 381.
A. undulatus and calceolus, 263.
288, 289. A . rugosus, 273.

Alasmodontinffi, the, 276. 287. 381.
Connection with Anodons, 288.
Analogies of the genera, 290.

Amphibia, allusions to, 50.

Amphidesma, 371.

Amphiuma, worm-like salaman-
ders. 43.

Ampullaria, genus, 55. 339. Siphon

• of, 160.

Ampullarinse, or apple-snails, 1P5.
339. Guilding's drawing of, Jbi7.

Analogies, in Malacology, different
from athnities, 42. 183. 291. Con-
sist of mutual representations, 49.
Of Annelides with Nudibranchia,
51. Of Parenchymata with annu-
lose Vermes, 52. Ofzoophagous
and phytophagous Gaste.opoda,
111. See various classes and ge-
nera.

Analogy, averification subordinate
to that by affinity, 94.

Anastoma, sub-genus, 192. 329.

Ancillaria, aberrant group, 97, 98.
132. 323. Resemblance to Con-
cholepas and Monoceros, 100.

Ancillarinae, sub-.^amily, Itil. 133.
322.

Anculosa, fluviatile, 199. 210. 340.

Ancylus, freshwater limpets, 188.
338.

Annnal kingdom, links of compa-
rison and resemblance betwixt
various classes of the, 5. 7. 40. 42.

AnimalculcK, classification of, 45.

Aimelides, ring-jointed, and hav-
ing red blood, 7. Resemblances
of, to fishes, 7. ; and to Testacea,
27. 51. Analogy with Nudibran-
chia, 51.

Annulcsa, the, or insect tribes, 2. 4.
Circle or group of, 38. 51. Ana-
logies of, 52.

Anodon, genus, 263. 287. Small
depressed summit of, 273. A. ana-
tinus, 286. Various other spe-
cies of, 286, 287.

Anodontinffi, the, 259. 286. 381.
Analogies of, 287.

Anomia, 47- 389.

Aphorrais, 138. 141. 157. 309. Its

D D 4<

40o

INDEX.

resemblance to Cerithium, 142. ;
to Rostellaria,il42. ; to Pterocera,
142.

Aplustra, 360. A. pulchella, 24P.

Aplysia, sea hares, 25. 30. 238. 248.
Typical characters of, 250. 359.

Aplysianae, sub-family, 359.

Aptera, a sub-typical class, 51. 55.

Area, genus, 383.

Arcidai, or arch-shells, 260. 382.

Argonauta, 48.

Aristotle, the acknowledged leader
of zoological science, 13.

Arrangement, natural, 295.

Aspergillium, the animal lives in
sand, 362.

Atrachia, tribe of, 255, 256. 377.
Circle of, perfected, 258. Analo-
gies of, 258.

Auricula, 171. 209. 337. Genuine,
176. 178. Sub-genus, 180. Spe-
cies of, 180.

Aves, circle of, perfectly developed,
41. Certain analogies with typi-
cal Gasteropoda, &c., 49.

Avicula, description of, 257. 386.

Aviculidae, the, 257. Muscles and
pearl oysters, 383.

Azeca, sub-genus, 183.

B,

Balia, 182, 3.34.

Barnacles, classification of, 25. 28.

Their analogy with cuttlefish, 52.
Belemnites, fossil, 48.
Bibliography of the testaceous

MoUusca. notice of the, 13, et seq.
Bicatillus, 354.
Biconia, 355.
Birostra, form of, 325.
Bivalves, Aristotle's designations

of the molluscous, 13. 21. Ace-

phala, 25. Double shells, as the

oyster and cockle, 27. All

aquatic, 33. Sub-typical, S5.
'• Devoid of eyes and tentacula, 36.

Some analogy of, with Aves, 50.

Order of Dithyra, 254. 361. Flu-

viatjle, 259.
Blainville, M. de, system of, 17,

His nomenclature objectionable,

13. 17.
Brachidontes, 383.
Brachytoma, new genus, 154. 314.
Branchiopoda, of Cuvier, 23. 47.

Anomian shells, 25. 47. 256.
Buccininas, or whelks, 63. 71. Base

abrupt and notched, 73. 97. 301.
Buccinum, genus, 62. 96. 302,

B. Achatinum, 74. B. la^vigatum,

74. B. plumbeum, 82. B. strom-

bioides, 123.
Bulimus, description of, 170. 176.

oflB. B. proper, 177. Sub-genus,

178. Analogies of its sectional

types, 179.
Bulimi, conical spire of the, 163.

177. Sub-genera of, 178. Circle

of, 181.
Bulimulus undulatus, antiquensis,

and proteus, 177. 335.
Bulla, conformation of, 25. 55. .360.

Connected with the Cvpraeidae,

59. 238. B. naucum, 249. B.

aperta, 252.
Bullinas, sub-family of, 248. 251.

3.59.
BuUinula, of Beck, 360.
Bursatella, structure of, 251. 359.

Calceola, 382. C. truncata, 289.

Calliostoma, sub-genus, 218, 219.
351.

Callithea, conformation of, 320.

Calliscapha, 380.

Calyptrea, 230, 231. 354. Natural
station of, 233. C. chinensis, 234.

Cancellaria, small incurved chan-
nel of, 79. 305.

Cancilla, described, 320.

Canthapleura, 357-

Canthella, 202.

Canthidomus, 342.

Canthorbis, diversified sub-genera,
216. 349. Sub-genera and ana-
logies of, 224

Canthyria, 276. 378.

Capsa, 373.

Capulis, 244.

Caracolla, 328.

Cardissa, 257. 259. 373.

Cardita, 375.

Cardium, 373.

Carinea, 326.

Carinaria, 48.

Carinidea, sub-genus, 216. 350.

Carrier shells, 212. 217. 228.

Cassida?, analogies of, 89. 100.

Cassidaria, of Lamarck, 69. 71. 299

Cassidea, 66. Form, and species of,
299.

Ca.ssinaD, or helmet-shells, 63. 65.
297. Separate circle of affinity,
66. 95. Analogies to the Gaste-
ropoda, 66.

Cassis, genus, 65. 68. 71. Species
of, 298.

Castalia, of Lamarck, 284. 379. C.

- cordata, 284.

Cemaria, of Leach, 243. 356.

Cephalopoda, jirovided with a back-
bone, form an order connected
alike with the Vertebrata and
Mollusca, 5, et srq. Perfection
of sight of, 8. Lamarck's table

INDEX.

409

of, 24, Cuvier's classification of,
25. Swimming, and fins of, 31.
Search for its prey, 34. High
organisation of, 38. Vestiges of
testaceous, 40. Affinities of, 48.
Extinct or fossil genera of, 48.
Their analogy with fishes, 51 ;

■' and with barnacles, 52.

Ceratodes, sub-genus, 197. 339.

Ceriphrasia, siib-genus, 204. Ano-
malous, 205. 342.

Cerithidea, 198. 203. 342.

Cerithins, or club-shells, 137. 139.
156. Characters of, 315.

Cerithium, affinities of, 47. 136. 142.
205. Typical genus, 157. 315.

Chama, how cemented or affixed to
rocks, &c.,32. 47. 374.

Chamidffi, the, 257. 374.

Chelidomus, analogies of, 192.

Chelinotus, group of, 234. S55.

Chelosomje, 36. Organisation of,
45. 238. 255, 256.

Chiton, of Linnaeus, 357.

Chitonellus, 246. 358.

Chitones, or Cyclobranchia, 25. 55.
238. 360. Their organisation, 45.
Boat-shaped shells of, 58. Struc-
ture of, 246.

Chlorostoma, formation of, 218.
350.

Chrysodomus, characters of, 90. 308.

Chrysostoma, description of, 353.

Cidaris, characters of the genus, 215.
349.

Circle connecting Testacea, theory
of a, 40. 95. Circle of existing
birds, 41. Of extant and of ex-
tinct Reptilia, 41. Of the entire
class of Testacea, traced, 46. 48.
Of the entire Animal Kingdom,
49.

Cirripeda, articulated limbs of the,
6. First group of Annulosa, 6.
Barnacles, 25. 28. Relationship
between Cephalopoda and, 52.

Clausilia, genus, 161. Characters
of, 182. 334. Analogies of, 184.
209.

Clavagella, 363.

Clavalithes, fossils of the Turbi-
nell£B, 77. 94. Characters of, 304.

Clavatula, of Lamarck, 137. 155.
314.

Clavicantha, 155. 314. C. echinata
and auriculifera, fluviatile, 155.

Cleidothasrus, 374.

Clithon, 347.

Clypidella, 356.

Cochlicopa, 171. 173. 335.

Cockle, the, 27. What called its
foot, 30.

CoDcilia, 44.

Columbella, 135. 313. C. merca-
toria, 150. C. nitida, 151.

Columbellinje, 61. 134. Conform-
ation of the dove-shells, 1S7. 150.
The typical, 143. 312. Operculum
of, 150. The genera of, 152. Ana-
logies of, 153.

Complanaria gigas, 288, 290. 382.
C. rugosa, 288.

Conchifera, of Lamarck, 22.

Concholepas, 73. 100. 301.

Conchology, definition of, 10. The
interests of geology require that
shells should be scientifically stu-
died, 12. Advantage of a genuine
classical nomenclature, 13. In-
feriority of modern compound
names, 13. The Linnjean no-
menclature, 14. System of Lin-
neeus, 15, 16. Plates by D'Ar-
genville and others, 14. Merits
of the chief modern writers on,
15, 16. e( passim. Great difficulty
of completing a general and illu-
minated work on, IS. Theory of
a perfect circular group of all
the Testacea, 40. 46. Knowledge
of the animals increased, 97.
Mr. Cuming's discoveries, 127.
Theory of variation, 127. Sys-
tematic arrangement of, 127. 295.
Glossary, 391.

Conella, 312.

Cones, smooth shells of the, 61. 116.
311. With coronated tubercles,
116. The Coninae described,
137. 310. Their genera, 150. 311.
Their connection with the Strom-
bina?, 146. Analogies and cha-
racters of the sub-genera of, 148.
150.

Conidea, characters of, 151. 153. 313.

Conilithes antediluvianus, 311.

Concehelix, remarks on, 127. 129.
321.

Concelix, characters of, 321.

Conorbis dormiter, 312.

Conus amadis, 143. C. bandanus,
147. C. arenatus, 147. Types of
the sub-genera, 148. 311. C. dor-
miter, fossil, 149.

Coralliophaga, 259. 376.

Corals, growth of, 65.

Corbis, Lam., 371.

Corbula, 367.

Coriocella, 235. 355.

Coronaxis, 147. 311. Types of the
sub-genera of, 148.

Costellaria, form of, 320.

Cowries, 61. 63. 324. Analogy of
Cyprfficassis to, ^67. The Cyprse-
inae, typical, 135, 324.

Crabs, with bivalve shells, 52.

Crassatella, 369.

Crassina, Lam,, 372.

Crassispira, characters of, 152. 313.

Creator, works of the, perfect, 42.

410

INDEX.

Crenatula, 385.

Crepidula, 230, 231. Natural sta-
tion of, 239. 355.

Cryptoconchus, zone of, 247. 358.

Cryptostoma, 235.

Cuma sulcata, 87. 307.

Cumingia, 370.

Cunicula planeata, cuneata, and
purpurata, 268. 378.

Cuttlefish, description of the, 5.
Eyes of the, 8. Mode of swim-
ming, 31. Food of, 34. Organ!,
sation of, 38. Extinct tribe of,
fossil, 4S.

Cuvier, baron, character of his
Jtegne Animal with regard to the

. Mollusca, 16. His Memuires on
the Testacea, 20. System of, 25.
35. 54. 211. Definitions in Grif-
fith's, 53.

Cyclas, 257. 3fi9.

Cyclinae, sub-family, 369.

Cyclobranchia, comprehend Patella
and Chiton, 25. 55. United by
Cuvier to Dithyra, 54, Con-
struction of, 58. 246. 357.

Cvclocantha, with a circle of spines,
215. 348.

Cyclocotyles, external parasites, 46.

Cyclonassa, genus, 69. 300.

Cyclophora, 186. ooQ.

Cyclops, a genus of crabs, 52.

Cyclostoma, 56. 171. 198. 336. Its
analogy to Pupa, 169. Mouth,
characters of, 185. 207. Discoid
form of, 227.

Cyclotus, of Guilding, 186. 336.

Cylindrella, description of, 135.326.

Cyllene, the genus characterised,
81. 305. Approximates to Pseud-
oliva, 82,

Cymbiola, muricated, 101. 105. 317.
Sub-typical, 126. Types of this
genus represent those of Voluta,
117. Tableof analogies, 118. C.
ve.spertilio, 106. 318. C tubercu-
lata, 118. C. Braziliensis, 118.

Cymbium, 104. 117.

Cyprffia, of Linnteus, 61. 100. 324.

Cyprfecassis, C)5. Analogy to cow-
ries, 67. ; and to the Nassina?, 70.
Characters of, 298.

CyprzEidc-c, affinities of, 59. 61. Shell
described, 63. Analogies to be
traced from the animals only,
115. n. 1.35. Family of, 324.

Cyprseinte, typical forms, 1-35. 324.

Cyprajlla, structure of, 325.

Cypraaova, 525.

Cypricardia, 257.

Cyrena, 370.

Cytherca, 372.

Decadopecten, 388.

Delphinula, 215. 348.

Diagram of the athnitics of Muri-
cida? and Turbinellidse, 95.

Dianchora, 388.

Diceras, 375.

Dipsas, of Leach, 263. 288.

Discodoma, its circumference cari-
nated, 192. 329.

Dithyra, the Aristotelian term for
bivalves, 13. Considered ana-
tomically, 29. No apparent head
or eyes in, 53. All bivalves are
marine or fluviatile, 33. Food of,
53. Sub-typical, 35, 36. Circle
of, 45. Analogies of, 49. 256.
Survey of the order, 254. Gene-
ralisation, 290. Arrangement of
the order, ,361.

Dolabella, 251. 359.

Dolium, e,6. 299.

Donax, 259. 373.

Doridium, 252. 360.

Doris, 24, 25. 37. 250. Has naked
branchia, 54.

Dove shells, 137.

E.

Ear-shells,"see Haliotis.

Earth-worms, their body disposed
in rings, 7. Resemblances of, to
the eel, 7.

Eburna, types of, 81, 82. structure,
306.

Eburninte, base truncated and
notched, 76. Sub-family of, 81.
Genera and analogies of, 83. Af-
finities of, 95, 96. Definition of,
305.

Echinella, sub-genus of Trochus,
207. 221.352.

Echinidaj, shells of the, 7. Ten-
tacula lof, 7. Slow locomotion
of, 7.

Echinorynchus, 46.

Echinus, the, its conformation, 7.

Elenchus, 219, 220. 351.

Emarginula, 58. 240. Characters
of, 243, 244. 356.

Enomphalus, fossil, 196.

Ensatella, 365.

Epistyia conica, 165. 331.

Erato, 135. 326. Unites the Cypras-
idiB and Volutida?, 326. n.

Eruca, Sid., .334.

Erycina, 259. The name pre-occu-
pied, 370.

Eryx, instead of Erycina, 371.

Ethcria, 237. 390.

Etheridie, family of, 390. Remark-
able affinities of this group, 257.

INDEX.

411

Eulima, 343.

Eyes, of the Testacea, 8. 53. 97.
Of the Cephalopoda, 8.

Fasciolje, 37. Cup-shaped 'suckers
of the, 38. Food of, 46. "

Fasciolaria, 76. P4. Characters, 303.

Ferussac, baron de, his work on
the terrestrial Mollusca, IS. 171. n.

Ficula, characters of, 85. 307. F.
caudata, 85. F. rapa, 85.

Firula, 46.

Fishes, the Cephalopoda, among the
Mollusca, bear greatest resem-
blance to, 51.

Fissurella, 58. 62. 240. Description
of, 243. 555, 356.

Fistulana, 363.

Foot or belly of molluscous animals,
30. 134.

Foraminata, cephalopodous, 43.
.Foraminifera, investigated by the
microscope, 44. Organisation of,
45.

Fossils, arguments founded on
those of testaceous genera now
extinct, 40. Those of the larger
reptiles, 41 . Of Cephalopoda, 48.
Of Turbinellins, 77. Of Cones,
149. Snails, 196.

Fragella.'Sw., 352.

Freshwater and fluviatile Testacea,

ctct

Fusing, or spindle-shells, 76. 87. 90.
154. Delicate and elegant, 89.
Analogies of Pyrulinffi:;to, 92. ; of
Turbellinfe to, 93. Sub-genera
of, 308.

Fusus, the typical genus, 87. 90.
308. Fossil, 77. F. bulbiformis,
90. F. ficulneus, colossus, coro-
natus, 91. F. col us, 96. Affinities

; of this group, 154. F. strombi-
formis, typical, 154. F. Syracu-
sensis, 154.

G.

Galeomma, 257. 376.

Gasteropoda, of Lamarck, 24. Of
Cuvier, 25. Anatomy of the, 29.
Progression of, 30. Eyes and
head of, o3. Phytophagous, 33.
The spiral univalves eminently
typical, 34. 47. Developement
of the perfect spire, gradual, 47.
Analogies with the rest of the
animal kingdom, 49. Primary
divisions, 53. Analogies of the
Muricin£e and Turbinellidfe, 53.
Of Gasteropoda and Testacea, 60.

Of the zoophagous and phyto-
phagous classes. 111. 160. 195.228.
Aberrant tribes of, 2-39. Analogies
of phytophagous and carnivorous,
242.

Gasteropteron,_248. 252.362.

Gastrochina, 2o/. 363.

Generation of Mollusks, 29. 292.

Generalisation, remarks on, 290.

Geographic distribution of Tes-
tacea, 34.

Geology, its relations with con-
chology, 9. 12. Fossils of the
Paris basin, 77. Of Hordwell
Cliff, 77.

Geomitra, Terrestrial, 166. 332.

Geotrochus, conical spire of, 165.
331, 332. Sub-genera of, 166.

Geovula, group of, 208. 344.

Gervillia, 385.

Gibberula, Sw., 323.

Glabella, 133. 324.

Glauconome, 366.

Globularia, 345.

Glycimeris, 369.

Gnathodon, 370.

Gonidomus,166. 332.

Gonospira, 168. 333.

Goniostoma, 177- 181. 535.

Gryphffia, 389.

Guilding, Rev. Lansdown, on the
Mollusca of the Caribbean Seas,
17. 182. Drawings by, 18. n. ISO.
Discoveryof Herpaby, 45. Draw-
ing of a species of Nassa, 69.

H.

Haliotidffi, the, 111. 556, 354. Con-
formation of, 159. 228. Circular
group of the, 231.

Haliotidea, Stv., 354.

Haliotis, or ear-shell, 25. 30. Cha-
racters of. 111. 230. 354. The
animal, 229. H. asinina, 231-

Harpa. the harp-shells. 66. 298.

Harpiila, genus, 102. 134 317. H.
vexillum, 71.106.119. H.hebrsea,
106. H. fulminata, 107, 108. 119.
12.5. H. bullata, 107. 119. H. ly-
riformis, 107- 119. H. costata,

119. H. nucleus, 119. H. poly-
zonata, 119. H. musica, 119. H.
sulcata, 119. H. Lapponica, 120.
Mr. Broderip's Observations on
H. dubia, 120. n. Sub-generic
types, 120. 122. Analogies of,

120. 122.

Harpula costata and multicostata,

119. 121.
Haustellaria, 296.
Hectocotyles, of Cuvier, 46.
Helicell^, 164. 194. Their disk-like

shells, 16-1. 333. Broad-lipped, 191.

412

INDEX.

Helicidffi, analogies of, 111. Land
and freshwater snails, 158. Prin-
ciples of investigating this tribe,

160. 291. The only division of
Testacea breathing atmo.'^pheric
air, 161. Circular group of, 161.
Network of pulmonary vessels in,

161. Tentacula of, 161. Chief
families described, 162. 186. Ana-
logies of, 162. 227. Sub-families
of, 162. Classification of, 326.

Helicinje, or testaceous snails, 56.

162. 330. 336. Are typical, 163.
Group extensive, 184. 194.

Helicogena, of Ferussac, 191.
Helisoma, 337.

Helix proper, description, 164, 165.
227. 330. H. hortensis, 164. Ana-
logies of, 166. Sub-genera of, 166.
Hemicardium,373.
Hemicycla, 164. 193.
Hemidbnta, 288. 381.
Hemifusus, 91. 94.
Hemimactra, 369.
Hemimitra, 199. '342.
Hemiodon, genus, 191. 330. Toothed

aperture of, 164. 194.
Hemisinus, 200. 341.
Hemitoma, sub-genus, 244. 356.
Hemitrochus, with elevated spire,

165. 331.
Herpa, genus of soft MoUusca, dis-
covered by Guilding, 18. 45. 161.
189. 327. App. 405.
Heteropoda, divided into Cari-
naria, Pterotrachia, and Phylli-
roe, 25. By Cuvier, into Firoles
and the Carinariae, 25. 48.
Hiatula, 101. 132. 322.
Hinnites, 388.

Hipponyx, 31. 58. 240. 244. 357.
Hippopus, 47. 257. 374.
Horce Entomologicce, notes on the

Testacea in the, 19.
Humphrey, George, F.L.S., system
of conch ology by, 15. His ar-
; rangement compared tabularly
with Lamarck's, 20. Order I.,
Marine Testacea, 20. Order II.,
Fluviatile, 21. Order III., Ter-
restrial, 21. His enumeration of
univalves, 22.
Hybrids, non-production of, 292.
Hyria, its connection with Unio,

264. 285. 380.
Hyria avicularis, 263. 278. H. cor-

rugata, 263. 284.
Hyridella, 380.

Hyrina?, sub-family of, 282. 378.
.Analogies of, 285.

lanthina, or oceanic snail, '31. 195.

Inferobranchia, of Cuvier, 25.

Infusoria, 4.

Inoceramus, 385.

Intestina, heterogeneous class of,
37. 45.

Iridea, its affinity to Mysca, 283.

. Remarks on, 284. 379.

Iridinina, 257. 262. 380. Prox-
imate to Anodon, 264. Typical
species of, 286. I. Nilotica, 286.
I. elongata, 291.

Iridinina;, sub-faraily, 286. 380.

Isocardia, 374.

J.

Johnson, Dr., of Edinburgh, his
valuable labours on the soft Mol-
lusca, 43. n.

K.

Klein, 'his ornithological cabinet,
9. 11. Conchological labours of,
14.

L,

Lacuna, 241.

Lffivicardium, 373.

Lamarck, his arrangement of the
Testacea, 15, 16. 26. Compara-
tive Tables, 20. First Order of
Lamarck : Conchiferes dimyaires,
22.; tenuipedes, 22.; lamelli-
pedes, 23. ; ambigus, 23. His se-
cond order : Conchiferes mono,
myaires, 23. : Branchiopoda, 23.
His division of MoHusca into five
orders, 23. ; Pteropoda, 23. ;
Gasteropoda, 24. ; Trachelipodes,
24 ; Cephalopodes, 24. ; Hetero-
poda, 25.

Lamprodoma, 132. 225. 321.

Lamproscapha, genus, 287. 381.

Lamprostoma, 350.

Lanistes, 384.

Lanites, 339.

Latiaxis, 82. 306.

Ligumia recta, 291."

Leiodomus, 69. 74. 302.

Leiostoma, analogies of, 192. Cha-
racters of, 308. 328.

Leiostomus, 90. 94.

Leptolimnea, 338.

Leptoconus, 312.

INDEX.

413

Lepton, of Turton, 366.

Leptospira, 176. 337.

Leucostoma, 173. 336.

Ligumia, 2t;8. 274. 378.

Lima, 257. 387.

LimaciiiEB, 162. 329. Sub-family,

189.
Limax, the genus, 10. 45. 189. 327.

Food of, S3. Respiration, 56.

160. First germ of limaciform

structure, 161. Arrangement, 327-
LimnEea, Sec, see Limninse.
Limnjeus, description of, 187. L.

stagnalis, 189.
Liianinee, spiral fluviatile shells,

162. 187. 337. Analogies of, 162.

188. 339.
Limpets, the structure and habits

of, 25. 30, 31. 60. 239. 355. Fresh-

water, 188.
Linnajus, error of, 9. Simplicity

of his nomenclature, 14. System

of, 15. On multivalves, 28.
Lister's Conchology, 14.
Lithodomus, 384.
Littorina, or Turbines, 206.
Loligo, 51.
Loripes, of Poli, 371.
Lowe, of the Mollusca of Madeira,

18.
Lucernellfe, 191. 193. 329, 330.
Lucerninae, or lamp-snails, 163. 186.

190. 328. Circle of affinity of

the, 194.
Lucerninte, or terrestrial volutes,

162.
Lucidella, 192. 194. 330.
Lucidula, 329.
Lucina, 371.

Lucternin®, analogies of, 192.
Lutraria, 368.
Lymnadia alata, 280. Genus, 266.

267. 280. 379.
Lyrostoma, 329.

M.

Macrodontes, 182. 334.

Macrospira, 168. 171. 335.

Macrotrachia, typical, 255,256. 362.
Analogies of, 258.

Mactra, 257. 368.

Mactridffl. 259.

Malacology treats both of shells and
their inhabitants, 13. Recent in-
quiries as to the nature of the
animals, 97. Theory, 292. Glos-
sary, 391.

Malleus, 385.

Mamillaria, .345.

Man, the Caucasian race said to be
the typical form of, 116.

Margafitana, 288, 289. 3S2.

Marginalis, 278, 279.

Marginella, 97. 323. '
Marginellinffi, or date-shells 98..10L

OJ. OZ.J.

Martesia, 364.

Medusse, the, appertains to the Ra-
diata, 5.

Megadesma, 370.

Megadomus, cardinal teeth of, 266.
269. 378. M. gigas, 266. 275.

Megalomastoma, 186. 336,

Melacantha, 341.

Meladomus, 340.

Melafusus, 202. 341.

Melampus, 182. Semi-aquatic, 196.
Guiiding's remarks upon, 208.
Amphibious volutes, 34.3,344.

Melania, 47. 59. 158. 341. The true,
199. Sub-genera : Melacantha,
Potadoma, Hemisinus, Melanella,
199. 340, 341. M. lineata, 200.
Analogies of, 201.

Melanianee, or black snails, 157. 159.
195. 340. Genera of, 201. 203.
210.

Melanithes, fossil, 202.341.

Melanopsis, 59. 198. 200. 341. Minor
types diversified, 201. Analogies
of sub-genera of, 203.

Melanopsides. of Ferussac, 204.

Melatoma, 202. 342.

Melons, or typical volutes, 67. 99.
105. 111. Considered as a sub-
genus, 116, 117.

Menostoma, of Blainville, 46.

Microtoma, 74. 301.

Mitra, the mitre-shells, 97, 98. Ty-
pical, 126. 129. 318. Analogies,
130. M. sanguisuga, 98. M. epis-
copalis,127,128. M.zonata, 128. n.
M. terebrans, 131. M. rutiina
punctata, 131. M. lactea, 131.

Mitranze, sub-family, 31S. Spire
acute in, 98. Characteristics of,
99. 101. 126. Real type of, 112.
Analogies of, 129. ; to the Strom-
bidte, 154.

Mitrella, 101. 128, 129. 321.

Mitreola, 127. n. 129. 320.

Modiola, bivalve, 257. 384.

Mollusca, the, or soft animals, 1.
Their appearance unprepossess-
ing, 2. Division of the groups of,
3. Devoid of internal bone, 4.
Nervous system of, variable, 4.
Their three divisions character-
ised, 7. Their arrangement in
respect to the circle of affinities,
8. Lister's arrangement of, 9.
Mistakes in recognising the true,
10. On the testaceous, 26, ei seq. ,
see Testacea. The parasitic, 44.
The Cephalopoda most resemble
fishes, 51. Analogies of testaceous
Mollusca to Annulosa, 52. Gas-
teropoda possess an aortic heart,

4U

INDEX.

54. General principles of inves-
tigating, 54. 97. Naked mollusks
among the Helicidffi, 161.

Monilea, 220. 352.

Monoceros, 100. Tooth-like pro-
cess of, 301.

Monodonta, 212. 217—219. 362.
Analogies' of, 226. Characters of,
220.

Monophora, 38.

Monothyra, of Aristotle, 13.

Mulleria, 257.

Multi valve shells, 21. 28. 399.

Murex, the, 63. 295. Vitulinus, 64.
68. Magellanicus, harp-like, 65.
68.

Muricanthus, structure of, 296.

Muricidse, 64. 295. Sub-families,
89. 99. Diagram of affinities of,
95. Analogies of, 112.

Muricinae, or whelks, 63. Circle of
the, 64. 89. Sub-families of, 67.
Shortness of their canal, 75. Cha-
racters of, 295.

Muricidea, 296.

Muscle, the, or Mytilus, 31. 383.

Mva, 257. 367. M. margaritifera,
261.

Myadae, family of, 257- 260. 367.

IMycetopus, 380.

Myocliama, 375.

Myristica, 307. M. coronata, 8S.

Mysca, sub-genus, 276. 283. 378.
Analogies of types of, 278. M.
nasuta, 2&3. M. ovata, 263. 277.
292. Structure of, 266. M. [lic-
torum, 278. 282. Aberrant spe-
cies of, 285.

Mytilus, 31.383.

N.

Na'ia, sub-genus, 284. 379. N. elon-
gata, 286.

Naidea, 276.

Nassa, typical distinction of, 68.
300.

Nassiiiae, sub-family of, 63. 69. 299.
Circle of. 70. Analogies of, 70.
112. Affinities, 95, 96.

Natica, 234. 241. 345.

Nattcaria, 346.

Naticella, animal of, 249. 345.

NaticidiB, family of, 60. 235. 344.
Analogies of, 111. Structure of
the nerits, 159.

Naticinas, sub-family, 241. 345.

Nature, on the works, provisions,
and devices of, 41. Her ascend-
ing scale from imperfection to
perfection, 42. 44. Great circle
of the system of, 3. 40. 49, et seq.
Tenacious of her laws, 115.
Modes of (levelopement of animal
forms, 161. 293.

Nautilus, the, 39.
Navicella, 347.
Nebularia, 319.
Nematura, 197.340.
Nerita, 346.
Neritinae, 347-
Neritopsis, 346.

Nervous system of shell-fish, 29.
Nitidella, 151. 153. 313.
Nomenclature, remarks on, 92. 291.
Notarchus,'.251. 359.
Novaculina, S65.
Nucula, 257. 259. 382.
Nudibranchia, naked animals so
termed, 6. 25. 35. Description,

36. 50. Respiratory organs of,

37. The tribe distinct, 40.

O.

Oligyra, 337.

Oliva, 97. 132. 321.

Olivella, 324. O. biplicata, 82. 132.

322. n.
OlivincE, 98.132.321.
Onchid«, marine, 56.
Onchidium, 190. 327.
Oniscia, 67- 70. 299.
Onustus, or carriers, 212. 217- 221.

355. O. agglutinans, 222.
Orbis, fossil, 196.
Ostrffia, affinities of the, 47. 257.

387—389.
Ostridffi, the, 257. 385.
Ovula, 135. 325.

OvuliuEe, or egg-shells, 135. 325.
Oyster, the, 27. 387. The river

oysters, 369.

Pachylabra, 339.

Pachvtoma, 337-

Pagodella, 2u7. 219. 351.

Paludina, genus, 197. 339.
para, 197. P. impura,
parvula, 198.

Paludomus, 198.

Pandora, 3o8.

Pa!,o])ia, 367.

Papyridea, 374.

Parenchyniata, affinitie-s of the,
4. n. Intestinal Testacea, 35. ;
and worms, 38. Parasitic Mol-
lusca, 44. Cuvier's second fa-
mily; habits and food, 46. Ana-
logy with annulose Vermes, 52.

Parmophorus, 58. 62. 243. 356.

Partula, of Ferussac. 179. n.

Parella, or limpet, 25. 30. 47- 58.
357. Nearly stationary, 31. 234.
240. Adhesion to rocks, 244.

Patularia, 287. 381.

P. vivi-
198. P.

Proper, 199. 340.

1.3

INDEX.

415

Pecteii, 257. 259. 387, 388.

Pectinibranchia, comprehend Tro-
chus, Turbo, and many univalve
marine Testacea, 25. 55. 185.

Pectunculus, 383.

Pedipes, 2C8. 344.

Pedicularia, 240. 245. 357.

Pedum, 388.

Periwinkle, 27- Food of the, 33.

Perna, 385.

Persicola, 133. 323. •'

Petricola, 257. 376.

Phakellopleura, 358.

Phasianella, 207.213. 354.

Pholadomya, 365.

Pholas, its residence, 32. Power of
enlargingtheir cave in rocks, &c.,
32. 257. Of LinncBus, 36:3.

Pholidffi, 257. 362.

Pholida?a, 36i.

PhvUidea and Diphyllidea, 25, 58.
248. 250. 358.

PhyllidiniE, sub-family, 249. 358.

Phyllonotus, 296.

Physa, 187. 338.

Phytophaga, Lamarck's subdivi-
sions of, 24. Food of phyto-
phagous gastropods, 33. 55. Or-
ganisation of, 56. Sexes, 56. Re-
spiration, 56. Confines of, with
the Zoophaga, 59. Point of union
with Zoophaga, 158. Primary
divisions of the phytophagous
shell-fish, 158. Families of, 160.

Picidae, 262.

Pileolus, 347.

Pileopsis, 357.

Pinnfe, or wing-shells, 31. 387.
Byssus. or silken tuft of, 32.

Pirena, 156, 157.

Pithohelix, 16i, 165.

Placuna, 389, 390.

Placunomia, 390

Plagiostoma, 388.

Planarite, the, possess no branchia,
28. Form of, 37. Analogy of
naked slugs with, 4.5. Fossil, 196.

PlanaridEe, true, swim freely, 46.

Planaxis, 59. 198. 342. Animal of,
204.

Planorbis, 55. 164. 186. 227. 337.
P. covneus, 187. I

Plant-like animals, 4. n. 5.

Pleurobrancliaana, 361.

Pleurobranchinje, sub-family, 361.

Pleurobranchus, 248. 252. 361.

Pleuronectia, 388.

Pleurotoraa, 136. 154. 314.

PleurotomariEe, 213. 223. 353.

PleurotoraiuEe, or slit-shells, 137.
152.314. Affinities of, 154 Cu-
rious analogies of, 155, 156.

Plicadomus, 352.

Pli'-atella, 78. 304.

Plicatula, 389.

Poll, investigations of, 16.

Polvdontes, 329.

Polygyra, 330.

Polypes, or Arcita, 4. Polypes char-
nues, 6. Tunicated, 6.

Polytropa, 80. P. crispata, 81.
Structure described, 305.

Porcina, 104.

Potadoma, 199. 200. 341.

Potomida, genus, 137. 276. 281. 316.

^379. P. corrugata, 281, 282. P.
elongata, 282. P. littoralis, 282.
289. P. Batava and Sicula, 282.

Potomis, 156. 158. 315.

Potomophila, 188. 338.

Priapulis, 6.

Processes for capturing prey, 34.
Of the Xudibranchia, 37.

Progression or locomotion of shell-
fish, 30. 134

Psammobia, 259. 370.

Pseudoliva, 82. 306. Ps. plumbea,
loo.

Psittacidffi, 262.

Pterocera, typical of the Strom-
binae, 1,38. 310. P. lambis, 138.
P. millipeda, 138. P. sinuata, 138.
Analogy of the types of form of
the genus, 144. P.'latissimus, 144.

Pteronotus, 296.

Pteropoda, of Lamarck, 23. Of
Cuvier, 25. No apparent head
or eyes, 33. First tribe of Cepha-
lopoda, 48.

Ptilota, eminently typical, 51.

Pulmonaria. 25. 55. 208.

Pulvinites, SS5.

Puncticulis, 311.

Pupa, inquiry into pupaceous shells,
161. 163. Description of, 164. Cy.
lindrical, maggot-shaped, 167. 183.
332. The sub-genera, 168. Ana-
logy of Cyclostoma to, 169. j of
Clausilia with, 184.

Pupella, 183. .334.

Purpura, 63. 74 204. P. lapillus,
and imbricatus, 80. P. coronata,
301.

Purpurinse, or purpuras, 63. 300.
How far resembling Buccininje,
71. Analogies of Pyrulinas and,
73. Affinities, 95. 204.

Pusia, 320.

Pusiodon, Sw , 330.

Pusiostoma, 150. 152. 220. 313. ;

Pustularia, 324.

Pyramidea, 225. 350.

Pyramidella, 343.

Pyrella spirilla, 77. 304.

Pyrena, 315.

Pyrula of modern authors, 83. Its
shape, 84. P. perversa, 84. P.
myristica, 86. P. hippocastanum,

86. P. lineata, 86. P. carnaria,

87. Characters of, 307.

416

INDEX.

Pyrulinse, genera described, 73. 88.
307. Characteristics of the pear-
shells, 76. 83. Resemblances to
Purpurinas, 88. ; to Fusinje, 92.

Quadrupeds, analogical ' compari-
sons of Gasteropoda^with, 49.

Quoy, M., new[shells discovered by,
17- 196. His researches in testa-
ceous animals, 17. 156. 204. Leio-
domus of, 69. His plates valuable,

, 128.

Radiata, the second class of Mol.
lusoa, 5. Nerves of, radiated, 5.
Destitute of eyes, 8. Analogies
of, 52.

Ranella, 64. 297.

Rapella, 82. 307.

Reniella, 386.

Reproduction, modes of testaceous,
29. 54.

Reptilia, analogy of Nudibranchia
with, 50.

Respiration of Testacea, &c., 29. 55.
Siphonic organ of, 55. 111.

Rhinoclavis, 157. 315.

Rhinodomus, 80. 305.

Rhodostoma, 208. 346.

Ricinula, 72. Planospira, 73. Cha-
racters of, 300.

Rimula, 243. 356. Z

Rissoa, 343.

Rostellaria, 138. 310. Elegance of
their form, 140. R. rectirostris, of
great rarity, 141. 146. R. curvi-
rostris, 141. R. fissurella, 141.
R. columbata, 141. R. raacro-
ptera, 144. R. cancellatus, 146.
R. canalis, 146. Analogies of the
group, 145. Species of, 145.

Rotella, 213. 222. 227. 353.

RotelliuEe, 213. 222. 353.

Rotifera, are prototypes of the Ra-
diata, 4. n.

Sanguinolaria, 366.

Saxicava, 376.

Saxicavidae, 257. 259. 375.

Scabricola, 319.

Scalaria pretiosa, 82. 185. 343. Cir-
cular mouth of, 207.

Scaphella, genus, 100. Types of,
12.J. 318. Connection with V' olu-
tilithes, 124. Forms a circular

group, 125. S. maculata, 101. S.
fulgetrum,' 101. S. fusiformis,
103. 108. 123. S. papillaris, 103.
108. S.undulata, 107. 123. S. pa-
pulosa, 108. 123.:

Scaphula, 132. 322.

Scarabus, 196. 208, 209. 344.

Schizodesma, 368.

Scissurella, 209. 344. Sowerby's fi-
gures of, 209.

Scolyminffi, 75. 78. The circle of,
perfect, 81. 95. Classification of
the genera, 304.

Scolymus, 77. 115. S. umbilicaris,
80. Characters and species of,
304.

Scorpions, observation on, .53.

Scutibranchia, of Cuvier, 25. 47.
358. Respiration of the, 57. In-
ternal structure, 57. 60. 239.
Divisions of, 240. Circle of, 245.

Sea eggs, or Echinida, 5.

Senectinee, or snake.shells,212. 214.
3i8. Analogies of, 224.

Senectus, 206. 213. Species of, 215.
348.

Shells and shell-fish, 2, f^se^.^tudy
of, important to geology, 9.
Science looks to the animal rather
than its shelly domicile, 10. On
what principle cabinets should be
arranged, 10. Modifications of
the forms of, 11. New shells im-
ported, 17. Habits of the animals
investigated, 17. Desiderata as
to plates representing, 19. Divi-
sions and analogies of, 26. Struc-
ture of, 27. Locomotion of, 30.
Permanent habitat of, 32. River,
33. Land, 33. 56. Gastropod, 53.
Spiral, 62. The Helicidas de-
scribed, 160. Marine, 195. 206.
River bivalves, 259. et passim.
Systematic arrangement of, 295.
Explanation of terms, 391.

Sigaretus, animal of the, 229. 234.
241. 345. Sigaret of Tonga, 235.

Siliquaria, 362.

Siphonaria, 58. 245. 357.

Siphonostoma, 333.

Skin, of Testacea, resembles a man-
tle, 29.
Slugs, terrestrial and fluviatile, fi5.
SO. Description of, 35. 45. 55.
Mantle of, 56. Respiration of, 5&.
Structure of, 162. Oceanic, 238.
Classification of, 327.
Snails, account of, 25. 55. 164. Uni-
valve, 27. Head and eyes of, 3.3.
Food of, 33. Minute testaceous,
described, 45. Respiratory per-
foration in the mantle, 56. Land
and fresliwatcr, 59. 1.58. The
pre-eminent type of phytopha-
gous Gasteropoda, 160. Families

INDEX.

417

arranged, 162. See Helix and
Helicidje. The lamp snails, 190.
Oceanic, 31. 195.210, etseq. Clas-
sification of, 326. 328.

Solarium, 213. 217. 221. 352.

Solan, 365.

Solenella, 366.

Soleninse, sub-family, 365.

Solenocurtis, 366.

Solenymia, 366.

Spiders, observation on, 53.

Spirorbis, 337.

Spondylus, 32. 388.

Starfish, of the class Radiata, 5.

Stenopsis, of Guildiiig, 328.

Stenopus, 190. The animal figured
190.

Stomatella, 231. S. duplicata, 233.

Stomatia, 229. Description of, 230.
354. Types of, 231. Analogies
of, 232. 234.

Streptaxis, 165 331.

Strepsidura, 90. 94. 308.

Strigatella, 131. 319.

Strombidffi, have fully developed
eyes, 33. 47. 55. Wing-shells,
63. Respiratory siphon of. 111.
Predacious, 136. Sub-families
of, 143. Typical genera of, 152.
156. 309. Analogies of, 154.

Strombidea, 138. 140. 146. 310.

Strombinae, true wing-shells, 138.
309. Genera of, 138, 139. 145.
Affinities of, 138. 142. Analo-
gies of, 140. 143.

Strombus, tuberculated, 116. Lobe
of the genuine, 121. 123. Typical
of the class, 136. S. pes-pelicani,
137. 141. S. sinuatus, 138. S.
latissimus, 138. S. melanosto-
mus, 139. S. pacificus, 139. S.
gigas, pink-mouthed, 139. 144.
S. granulatus, 139. S. goliathus,
the largest lip of the genus, 1,39.
S. gibberulus, 140. 144. S. Lu-

. huanus, 140. 143. S. Auris-
Dianffi, 139. 144, 145. S. sue-
cinctus, 144. S. lentiginosus, 139.
144. Analogies of the types of
the genus, 145. The strombi-
form structure, a primary type,
154. 310.

Struthiolaria, 81. Relation to Mu-
rex, 83. Characters of, 306.

Stuchbury, Mr., 71. n.

Succinea, 190. 189. 328.

Sun-shells, 216.

Swimming of molluscous animals,
31.

Symphynota compressa, 280. 287.

Systematic and natural arrange-
ment; forming Part II. of this
work, 295.

Tzenio'ides of Cuvier, compr.ehended
in the annulose circle, 44.

Tape-worms, 44.

Tectibranchia, comprehend Bulla
and Aplysia, 25. 35. Form and
habits of, 36. Shells hid in the
flesh, 55. Natural group of, 58.

247. Naked order of, 236. Ana-
logies of, 237. Representations
of, 238. Circular succession and
analogies of, clearly developed,

248. Classification of, 361.
Tellina, 371.

Tellinidse, 260. 369.

Tellininfe, sub-family, 370.

Terebellum, 137. 146. 310.

Terebra, 302. Long spire of the
group, 74. 131. T. vittata, 74.
T. maculata, 302.

Terebralia, 157. 315.

Terebratulfe, 32. Processes of, to
capture prey, 34.

Teredina, 364.

Teredo, 257. 364.

Terms used in conchology, 391.

Testacea, the, 3. Are a popularly
interesting class of molluscous
animals, 3. The typical Testacea
provided with eyes, 8. The most
perfect of the Mollusca, 8. Ar-
rangement of species of, 9. Groups
of the typical, as discriminated
by Aristotle, 13. Arrangement of,
by various modern naturalists, 41,
cl seq. Of the Caribbean seas,
17. Difference of the animals
confirms the recognised charac-
teristics of their shells, 18. Na-
tural disposition of the class, 19.
Table of, 20. Order I., the Ma-
rine, 20. Order 11., the Fluvi-
atile, 21. Order III., Terrestrial,
21 Merits of Lamarck and Cu-
Tier's classifications of, 26. Ana-
logies of, 26. Typical character,
istics of, 27. ; positive and ne-
gative, 28. Considered anato-
mically,28. Blood white, 28. ; its
circulation double, 29. Respir-
ation, 29. 55. Reproduction, 29.
54, Deglutition, 29. Operculum,
97. Nervous system of, 29. Mode
of progression of, 30. Power of
saltation, 30. Adhesion, 31. De-
fect of power of locomotion, 32.
Perforation of a permanent re-
sidence, 27. 32. Some cemented
to fixed or floating substances, 32.
Head, eyes, and tentacula of, 33.
Habits, food, and geographic dis-
tribution, 33, -34. 97. Primary
divisions of, 35. Gigantic genera
of, known only from tradition, 39.

E E

418

INDEX.

Great circle of, 44. 46. Orders
of, 49. Analogies of, 52. A single
grand genus, Testacea, imagined,
92. Families of exquisite spiral,
97. Series of fluviatile, 204. &c.

Testacella, 327.

Tethys, 24, 25.

Textilia 312.

Thallepus, 251. 359. T. ornatus,
251.*n.

Thallicera, 196. 339. T. avellana,
196. Analogies of, 210.

Theliconus, 312.

Theliderma, 268. 272. 377. T.
irrorata, nodosa, ' cylindrica,
pustulata, plicata, 272. T. cylin-
drica, 274. T. Peruviana, 276.
Analogies of the sectional types
of, 273.

Thelidomus, 191. 194. Description
of, 228. 332. 353.

Thelidonta, 193, 194.

Thracia, 376.

Tiara, typical form, 97. 319. 322.
Real type of Mitrina, 112. 129.
Analogies of, 130. 319. T. tere-
brans, 131. Sub-genera of, 320.

Tiarella, 131. 319.

Timorenla, 38.

Tomella, 155. 314.

Tornatella, 207. 343.

Trachelipoda, of Lamarck, 24.

Tremadotes of Rudolphi, 46.

Trichopodus, 211.

Tridacna, 257. 374.

Trigonia, 383.

Triphorus, 342.

Triton, genus, 24, 25. The naked,
31. Swims in search of its prey,
34. Description of, 36. 50. 64.
297. T. clandestinum, 75.

Tritonidea, 74. Remarks upon cha-
racters of, 74. 302.

Trivea, 135. 325.

Trochatella, 337.

Trochella, 59.355.

Trochia, 74. 302.

Trochidae, are marine, 159. 211.
Genera of, 207. Habits of, 212.
Shells perlaccous, 212. Pyra-
midal, 212. Sub-families of, 213.
Analogies with those of Turbi-
dae, 223. ; with the Achatinse,
226. Family of, 347.

Trochidon, 351.

Trochin«, described, 213. Oper-
culum horny, 216. Genera and
analogies of, 224. Sub-family,
349.

Trochus, of LinnjEus, 25. 350, 351.
Spiral, 47. Horny onorculum of,
213. T. Niloticus, 216. T. zizy-
phinu?, 218. T. merula, 219.
Strawberry, 220. Analogies of,
226.

Tropics, the, Testacea of, 34. 1 47.

Truncatella, analogies of, 209. 343.'

Tubicanthus, 349.

Tubulibranchia, comprehend Ver-
metus, Magilis, and Sihquaria,
25. Structure of, 36. 47. 54. 134.

? 256. Characters of the tribe, 258.
Systematic arrangement of, 361.

Tuliparia, 311.

Turbidee, family and circle of, 44.
341. The animals alone offer the
characters of, 160. Shells spiral,
with an operculum, and without
pearly lustre, 195. Typical ge-
nera of, 223.

Turbinffi, or winkles, 195. Analo-
gies of, 210. Characters of the
genera, 342.

Turbinelia, tyi)ical genus, 76. 94.
303. Fossil Clavalithes, 77. T.
Scolymus, 78. T. rapa, 78.

Turbinellidae, characteristics of
shell of, 75. 303. Sub-families of,
75. 243. Sub-typical group, spiny
and coronated, 115. Analogies
to the Cassidffi, 89. Affinities to
the Muricidffl, 95.

Turbinellinfe, 'smooth and heavy
shells of, 75. Analogies of Fusinae
and, 93. Arrangement, &c.,303.

Turbo, of Linnfeus, animal of, 25.
207. 345. Phytophagous and also
zoophagous, 47. Possesses a si-
phon, 160. 206. Figure of, 207.
T. sarmaticus, 213. .T. Nicoba-
ricus, 222.

Turritella, resemblance with Tere-
bra, 74. 131. A typical genus,
206. Long-spired, 223. Charac-
ters of, 343.

U.

Umbrella, 62. 253. 361.

Ungulina, 259.371. ^

Unio circulus, 261. U. gigas, 26^. ^

275. U. margaritifera, 263. U.
ciuieatus, 263. U. Esopus, 263.
271. U. mytiloides, 268. 270, 271.
292. U. torsus, 270. U. recta,
268. 272. U. cylindricus, 273.

276. U. alata, 279. U. nasutus,
279. U. truncatus, 270. U. no-
dosa, 270. U. obliqua, 270. U.
rugosus, 273. U. elongata, 275.
U. radiatus, 276. U. marginata,
278. U. frat;ilis, 279. U. Austra-
lis, 285. The typical, 264. Its
umbones, or bosses, 265. Distinct
types of, 268. 377. Analogies of
sub-genera of, 269. 274. Climate
inhabited by, 283.

Unionidae, the, 257. 260. 264. 282. n.
Primary divisions of, 264. 377.

INDEX.

419

Principle of variation in these
shells, 262. Modifications of, 290.
Station of the family of, 262.
Analogies of the genera of, 267.
Inexhaustible profusion of, 292.

Unionins, the, 265. Characters of,
275. 377. Analogies of, 285.

Uniopsis, figure of, 288. 382. U. ra-
diata, 289.

Univalve sheli-fish, 21. 27. 30. Spi-
ral, 34. et passim.

Valvata, 185. 196. 198. 339.

Velotes, 347.

Velutina, 235. 355.

Veneriuce, sub-family, 371.

"Venerupes, 376.

Venus, 372.

Vermes, annulose or intestinal, 27.
44. 52. True, completely articu-
lated, 38.

Vermetus, 362.

Vermillia, 362.

Vertebrata, allusions to the, 1. 2. 4.
116. Connecting link of the Mol-
lusca with the Cephalopoda, or
cuttlefish, 5, 6. 33. Theory re-
specting the, 42 — 44. 50. Circle
of the, 49.

Vertego, 183.

Vesica, 360.

Vexilla, 69. 300.

Vitrella, 360.

Vitrina, 190. 328.

Vitularia, 297.

Voluta, of Linnaeus, 316. V. zebra,
101. V. olla, 102. V. Neptuni,
104. 113. 116. V. angulata, 105.
V. magnifica, 105. V. mitis, 105.
V.ancilla, 106. V. scapha, 105.
V. fulgetrum, 108. 124. Generic
character, a large spire, 108. Af-
finities and distribution, 101 — 111.
Generic types of this genus, 113.
316. Circles of, 113. Analogies
of, 114. V. imperialis, and bat
volutes, 114. Coronated volutes,
115. Melons, or typical volutes,
67. t9. 105. ni. 117. V. Brode-
ripia remarks upon, 105. 117. V.
Cymbium, 104. 117. V. ^thi-
opica, 117. V. musicalis, 122. V.
fulgens, 125. The terrestrial vo-
lutes, 162. 190. 192.
Volutella, 323.

Volutidse, or volutes, 6.3. 76. Pri-
mary groups of, 98. 112. Analogy

to Zoophaga, 99. 117. ; and Cas-
sida;, 100. Circle of affinity per.
feet, 101. Analogy of Volutince

_ with, 112. ; of the Muricidce with,
112. General analogies of, 132. ;
to vertebrated and annulose ani-
mals, 134. Classification of, 316.

Volutilithes, genus, 105. 112. 318.
Typical conformation of, 121. V.
musicata, 115. V. costaria, 121.
125. V. angulata, 122. V. ci-
thera, 122. V. rafispina, 123, 124.
Analogies of, 122. Sub-generic
types of, 122. 318.

Volutins, are the typical volutes,
98. 316. Genera of, 112. Ana-
logies of, 112. 122. 129.

Volvaria, 134. 326.

Vulsella, 386.

w. ■

Wentle-trap, common, 207.

West Indies, Testacea, &c. of the,
17. 45. 180. 182. 192. 209.

Wheel-shells, 213.

Winkles, or Turbinse, 195.

Wood's Catalogue, 19.

Worms, red-blooded, 7, 44. Gas-
tropod, 33.

Xylophaga, 364.

Z.

Zoanthus, a genus connected with
Radiata, 6.

Zonites, 177. 227. 331.

Zoology, arranged on a new basis, 3.
Aristotle established the first prin-
ciples of, 13.

Zoophaga, the, perfection of sight
of, 8. Table of, 24. Carnivorous
shell-fish, 55. Respiratory siphon
of, 55. Eyes and tentacula, 55.
Mouth, 55. Tongue, 56. Sexes,
56. Operculum, 56. Genera of,
56. Distinctions of, 59. 61. Di-
visions of, 62. 83. 97. Analogies
of, 99. Point of union with the
tribe Phytophaga, 1.58. Families
of, 160. The tribe arranged, 295.

Zoophytes, the true Acritaare con-
sidered as compound, 4. n.

THE END.

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