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BRITISH CONCHOLOGY,

OR AN" ACCOUIfT OF

THE MOLLUSCA

WHICH NOW INHABIT THE BEITISH ISLES AND THE

SUREOUNDINO SEAS.

VOLUME L

LAND AND PEESHWATER SHELLS.

By JOHN GWYN JEFFREYS, F.R.S., F.G.S., &c.

■ O come hither, and behold the works of the Lord ! " — PsAL^i xIti. 8.

LONDON:
JOHN VA.^ VOORST, PATERNOSTER ROW.

MDCCCLXH.
[The right of Translation is reserved.]

PRINTED BY TAYLOR AND T R A N 1 1 S,
KED LION COURT, FLEET STREET.

TO THE MEMOEY

OF

MANY DISTINGUISHED NATURALISTS
AND VALUED FRIENDS,

WHO ARE NOW NO MORE,

AND IN GRATEFUL ACKNOWLEDGMENT OF THE
KIND SYMPATHY OF

THOSE WHO STILL HAPPILY SURVIVE,

FROM ALL OF WHOM I HAVE RECEIVED

MUCH ASSISTANCE

IN THESE CONCHOLOGICAL STUDIES,

I DEDICATE

THE PRESENT WORK.

PREFACE.

The question whether another book on the British
Mollusca is wanted by the scientific world, when there is
at present a complete history of the subject by the late
Professor Edward Forbes and Mr. Hanley, is answered by
the notoriety of the fact that the price of that admirable
work puts it beyond the reach of most naturalists ; and
the enterprising publisher of those, as well as the present,
volumes was so fully impressed with the necessity of
another work at a more moderate price, that he in\dted
me to undertake the task, which I fear I have inefficiently
performed. In doing this, however, I have endeavoured
to make the present work quite distinct from its
predecessor, as may be seen by comparing the two;
and those who are not fortunate enough to possess a
copy of *^A History of British Mollusca and their
Shells,^'' and who can afibrd the money for its purchase,
will not regret the expenditure.

With regard to the animals or soft parts of the
Mollusca described in this volume, I have been greatly

VI PREFACE.

indebted to the invaluable work of Moquin-Tandon,
entitled " Histoire naturelle des Mollusques terrestres
et fluviatiles de France/^ in which the physiology and
anatomy of the land and freshwater Mollusca have been
treated in a far more able and exhaustive manner than
had been previously done by any author.

My old and esteemed friend, Mr. Alder, has most
kindly promised to assist me with a notice of the Nudi-
branchsj so as to make that part of the subject as com-
plete as possible ; and the value of such cooperation will
be fully appreciated by all naturalists.

A volume of supplementary plates will probably be
published, to contain figures of every species and well-
marked variety. The figures now given illustrate the
genera ; but the cost and price of the work would have
been greatly increased by the other mode of illustration,
except by resorting to the inartistic and unsatisfactory
substitute of woodcuts.

In the prosecution of this task I have been actuated
by what I trust mil not be deemed a selfish consideration.
The study of our native Mollusca has been to me fi'om
childhood such an inexhaustible source of pleasant and
innocent occupation, it has given me so many happy
hours, and it has taken away or alleviated the sting of
so many sorrows, that I am desirous to assist in making
it more an object of general cultivation than it has
hitherto been. This field of research has by no means
been exhausted ; and whether regarded in a zoological

. PREFACE. Vll

or geological point of view^ or as tending to increase our
imperfect knowledge of tlie habits and instincts of these
humble works of our Common Creator, very much yet
remains to be done. No lover of nature need share in
Alexander's sigh, or regret that he has no more work to
do in any department to which he chooses to devote
himself. ^^ Nulla dies sine linea^' was the favourite
maxim of the great Linne ; and our days are too few for
the accomplishment of all that we propose to do, let our
aspirations be ever so modest.

A few explanatory remarks as to the scope of this
work may be here introduced.

It was at first my intention to give, in an Intro-
duction, a general outline of the subject, and to treat at
considerable length some of the principal topics which
are more especially interesting to naturalists and geolo-
gists. But the space which is necessarily occupied by
the body of the work (although the synonymy has been
compressed within the shortest limits and the descrip-
tive characters have been printed in small type) will not
admit of justice being done to this part of the subject,
without making the volume too bulky ; and I must there-
fore content myself with oflPering in the proper place a
few observations, so as to elicit further discussion.

In describing the dimensions of shells, I have taken
the measurements from average and adult specimens,
dividing inches into decimal and centesimal parts ac^
cording to the size of each species. This mode of

Vlll PREFACE.

admeasurement I have considered preferable to stating
the largest dimensions to which each species attains,
which would not give a fair idea of the usual size, or to
adopting the method used by some Continental authors
of giving the range or extreme limits of such dimensions.
Any extraordinary diflference of size presented by speci-
mens or varieties will be noticed. In giving the ad-
measurement of bivalve shells, I have considered the
length to correspond with the line of growth (viz. from
the apex or beak to the front margin), and the breadth
from one side of each valve to the other. In the case of
univalve shells I have adopted the same rule, viz. taking
the line of gi'owth for the length (the apex or point of
the spire representing each beak of the bivalve) , and the
widest part of the shell, or its greatest diameter, for the
breadth.

At the end of the work I propose to give some prac-
tical hints to collectors.

For the benefit of such of my lady readers as have not
added a knowledge of the classics to their other accom-
plishments, I have marked the accentuation of all the
names of genera and species described in this work. One
word of frequent occun^ence I have noticed to be too
often mispronounced by many who ought to know better,
and that is the specific name of our common eatable
oyster, mussel, and cockle. This word [edidis] has the
middle syllable long, as is evident by remembering one
of the various gastronomic maxims of Catius, "Vinea

PREFACE. IX

submittit capreas non semper edules." My late friend,
the Rev. Dr. Goodall, when he was Provost of Eton,
impressed on my memory a rule of pronunciation, which
it may be here useful to repeat. It is, that in words
which end in inus, .and are derived from the names of
animals, the last syllable but one is generally long (as in
Neritina and anatinus), while in those words which have
a similar termination, but are derived from vegetable or
mineral names (such as lanthina and crystallinus) , the
penultimate syllable is generally short. The first are
Latin, and the last are Greek forms. I have also
endeavoured to render as literally as possible the
English meaning of all generic and specific names,
although the barbarisms are nearly as frequent in the
nomenclature of natural history as they are in the
materia medica.

The way in which the name of the great Swedish
naturalist and founder of scientific classification ought
to be spelt has been long the subject of controversy. It
was originally Linnmus ; but on his receiving a patent
of nobility, he assumed the name of Linne. The latter
name is given in the twelfth (and most perfect) edi-
tion of the " Systema Naturse;^^ and in aU his subse-
quent works and correspondence he always used this
title of distinction. The learned Society which bears
his name in this country is Linnean and not Linnsean,
as appears by their charter and Transactions. Under
these circumstances, I have adopted the name which he

a 5

X PREFACE.

himself preferred, and which is prefixed to the work by
which he is best kno^vii as a conchologist.

A parting word to the critics ! When a mere youth,
I was encouraged by my lamented friend, Mr. Dillwyn,
to commit to print what little I then knew of the subject
comprised in the present volume ; and my first essay,
entitled " A Synopsis of the Testaceous Pneumono-
branchous MoUusca of Great Britain,^^ was honoured
by the Linnean Society by publication in their Trans-
actions. Now, in mature years, I have become still
more bold, and venture to appeal to the public. But,
although I cannot hope to be exempt from the fate of all
authors — criticism (and indeed, for the sake of science
and the elucidation of truth, I would rather in\dte it,
instead of considering it a calamity) , I cannot send forth
this little work without a mixture of the same feeling
of hope and doubt, which made the ancient poet thus
apostrophize his book : —

" Paucis ostendi gemis, et communia laudas,
Non ita nutritus. Fuge, quo descendere gestis :
Json erit emisso reditus tibi."

25 Devonshire Place, London,
24 May, 18G2.

INTKODUCTION.

CHAPTER I.

CLASSIFICATION.

DEFINITION OP THE TEEM ''CONCHOLOGY." CONFORMITY OF

SHELLS WITH THEIR INHABITANTS. CEPHALIC MOLLUSKS OR

UNIVALVES. ACEPHALA OR BIVALVES. TUNICATA. SPE-
CIES. VARIETIES. MONSTROSITIES. REVERSED SHELLS.

SYNONYMY. NOMENCLATURE.

Definition of the term " Conchology .'^ — Conchology ^,
as a branch of Natiu'al History, treats of the Molhisca
or that great division of invertebrate animals which have
soft bodies and an organization superior to that of
insects and only inferior to that of fishes. It properly
comprises the study, not only of the shell or outer cover-
ing of the moUusk, but also of the whole animal, — al-
though it has sometimes been used in a more limited
sense, in contradistinction to the term "malacology/^
which has exclusive reference to the soft parts of the
animal. Linne included the Mollusca in his great class
Vermes — some of them as Vermes Mollusca and others
as Vermes Testacea ; but as the first of these divisions
comprised a very heterogeneous assemblage of inver-
tebrate animals, and as the testaceous Annelids were
united with the latter, the classification proposed by him

* Compounded of two Greek words, Koyxri, a shellfish, and Xdyo?, a
treatise.

75032

Xii INTRODUCTION. [CH.

has not been adopted by modern naturalists. Cuvier was
the first to restrict the term " Mollusca^^ to its present
meaning. Nearly all the MoUusca have a shelly cover-
ing, which protects either the whole of their bodies or
the more important organs. Even the Nudibranchs or
Sea-slugs, in their embryonic state, are provided with
a unispiral shell; and the Limacida or Land-slugs
possess a shelly plate, which is imbedded in the shield
or mantle. The term ^^ Conchology '' may be therefore
considered sufficiently appropriate to express the nature
of this science, especially when the original meaning of
the word is taken into account. I do not profess to be
conversant with the anatomy and morphology of the
MoUusca; and I must refer those who wish to studv
this part of the subject to the admirable treatises of
Cuvier, Milne-Edwards, Quatrefages, Troschel, Von Sie-
bold, Vrolik, and other Continental writers, as well as to
those of our own equally eminent countrymen, Owen,
Gray, Huxley, and Hancock. A complete knowledge of
the MoUusca is of course unattainable mthout such
study; but I must content myself with having made
such progress as time and opportunities have permitted.

" Est quadam prodire tenus, si non datur ultra."

Conformity of shells with their inhabitants. — The im-
portance of studying all the parts of the MoUusca is
undeniable, and especially for the pui^oose of arranging
them in generic and higher groups ; but the distinctive
characters afforded by the soft parts alone, which have
been erroneously termed by some writers the " animal,"
cannot be much relied on in making out species. Phi-
hppi has completely demonstrated the insufficiency of
such characters in the case of the genus Rissoa ; and a
careful comparison of the descriptions given in the fol-
lowing pages of our Land and Freshwater MoUusca

I.] INTRODUCTION.

XUl

ought to satisfy any naturalist, who is inclined to con-
sider the question in an unprejudiced spirit, that the
body or soft parts of the moUusk, taken without re-
ference to the shell, offers an extremely shght and
variable criterion of specific difference. The shell of
itself generally enables the conchologist to distinguish
one species from another, without regard to the soft
parts ; and as the latter are seldom observable, the con-
venience of such a mode of distinction is obvious. It
would be rather difficult for a malacologist to describe
any particular kind of testaceous moUusk without no-
ticing the shell ; and for the same reason a crab or sea-
egg would not be easily recognized by the description,
if all mention of the carapace or test were omitted. The
shell of the mollusk may be in some respects considered
as a pseudo-skeleton, serving not only to protect the
soft and tender body, but also to keep the whole frame
together, like the true skeleton of any vertebrate animal.
Tliere is, besides, an intimate connexion between the
shell and the tissues of the body, which is only dissolved
by death or violence. The shell is (to use the words of
Mr. Searles Wood) "part and parcel of the animal itself."
I am aware that this opinion has been controverted by
high authority, and especially by Dr. Gray, whose valu-
able contributions to the science of zoology, in many of
its branches, are famihar to all. He, at one time, dis-
turbed the minds of geologists as well as students not a
little, by a statement that some shells which were per-
fectly ahke were inhabited by animals so extremely
dissimilar as to be referable to very different orders of
MoUusca"^. This statement, however, he afterwards quali-
fied to a considerable extent by admitting that, " in the
distinction of the larger and smaller groups of MoUusca,

* Phil. Trans. 1834, p. 302.

xiv INTRODUCTION. [CH.

the characters derived from the animal, the shell, and the
operculum, which all have a mutual relation to each
other, are of equal value and constancy;" and he ob-
served "how thoroughly they depend on each other,
and what excellent and permanent characters they afford,
both separately and in combination with each other^."
Dr. Gray seems now to be quite sensible of the value
of conchological characters, as nearly the whole of his
numerous genera of MoUusca have no other foundation
than the shell. I believe that the form and structure of
the shell will be invariably found to correspond with the
habits and wants of the animal which produces it. The
mechanical principles involved in the construction of
shells, and the adaptability of these habitations to the
uses of their builders, have been admirably explained by
the Rev. Canon Moseley, in an essay "On the Geometri-
cal Form of Turbinated and Discoid Shells," which was
published in the ^Philosophical Transactions^ for 1838,
and to which I would invite the attention of my readers.
The uniformity of the laws which are here so ably ex-
pounded, and the correlation which exists between the
mollusk and its shell, exhibit in no small degree the in-
finite wisdom of the Creator of all things, thus

"dimly seen

In these thy lowest works ; yet these declare

Thy goodness beyond thought, and power divine ! "

Cephalic Mollusks or Univalves. — The Mollusca may
be considered in a general point of view as divided into
Cephalic and Acephalous, and their shells into Univalves
and Bivalves. The former arrangement was proposed
by Lamarck, and the latter by his predecessor, Linne,
who also added a third division — viz. that of Multi valves,
which would almost be warranted by the anomalous
* Ann. & Mag. Nat. Hist. Sept. 1855, p. 425.

I.] INTRODUCTION. XV

organization of Teredo and Chiton, All these divisions,
however,, are clearly artificial. The Cephalic or Cephalo-
phorous MoUusks have a distinct head, and usually ten-
tacles or horns, with eyes at their tips or base, and a
foot or muscular disk for crawHng or floating. A few of
them have arms for swimming. Some inhabit the land,
and others the water. The Snail, Whelk, and Cuttle-
fish are instances of this kind of Mollusca.

Acephala or Bivalves. — Although the bivalve Mollusca
have no heads as a distinct part of their bodies, they are
not deficient in those organs of outward sense which cha-
racterize other Mollusca, and their brain is as largely
developed. Many of them have numerous eyes for
seeing, otolites or ear- stones for hearing, filaments for
touching, lips for tasting, a mouth for taking in their
food, and (according to some physiologists) also an organ
of smell. The fry of the Oyster, Terebratula, and other
bivalves, which, in their adult state, are permanently
attached to other substances, swim about freely, and are
provided with distinct eyes, which afterwards disappear.
All the Acephala are aquatic, and respire by means of
gills, like fishes. The Oyster, Mussel, and Cockle are
familiar examples of this kind of Mollusca.

Tunicata. — The Tunicata or Ascidians can scarcely
be said to belong to the Mollusca, from which they difi'er,
according to Milne-Edwards, in many essential par-
ticulars, especially as regards their circulation and re-
production. They appear to have a considerable afiinity
to the Polyzoa (or what are generally called " Polypes "),
and may with them constitute the great and separate
class of Molluscoidea. Each division of the animal
kingdom has so many points of resemblance to others,
and the network of organization is so closely inter-
woven, that it would be very difiicult to define any one

Xvi INTRODUCTION. [CH.

class by characters which others do not share in common
with it. Mr. Alder is at present occupied with the sub-
ject of the British Tunicata ; and it will doubtless re-
ceive from that talented and experienced naturalist the
same elucidation as was bestowed on his celebrated
Monograph of our native Nudibranchs.

Species. — I now venture to offer a few remarks on a
very diflBcult and perhaps insoluble problem, \iz. the
nature of species. The difficulty of this investigation is
greater in the study of the Mollusca and other Inver-
tebrata than in that of more highly organized animals,
because one characteristic element, from the nature of
their reproductive system, is here wanting or beyond the
reach of observation. Nearly all the land Mollusca,
the habits of which it is comparatively easy to study,
have both sexes united in the same individual ; and not
even the aquarium will enable us to make those experi-
ments as to the fertility or sterility of hybrids to which
such importance is attached in the discussion of this
question in the case of vertebrate animals.

The forms of some shells appear to be more perma-
nent or capable of being reproduced without any modi-
fication than others. The Silurian Lingula, which claims
the precedence of all Mollusca in point of antiquity, is
said to be undistinguishable from an existing species;
and its mould must therefore have been continued from
the womb of time to the present day without the slight-
est change. The secondary strata contain many well-
known instances of a similar persistence of form, espe-
cially those of Terebratula caput-serpentis and some
Foraminifera, which are considered by competent autho-
rities not to differ from species which now live in the
adjacent seas. A large proportion of the fossil shells
found in the lowermost of the Pliocene strata (or

I.] INTRODUCTION. Xvii

" Coralline Crag ^^) are precisely similar in every respect
to the recent shells of species which bear the same names
and still survive; and it is impossible for the most critical
species-maker to distinguish one from the other. Even
their varieties and monstrosities or abnormal forms are
still repeated. The opinion of the late Professor D^Or-
bigny_, which has been adopted by Agassiz_, that all tertiary
species became extinct, and that they are only repre-
sented at present by analogous forms, evidently resulted
from a preconceived theory, against which a concordance
of fossil with recent species would have militated.

Without, however, entering into an abstruse (and
perhaps useless) inquiry into the origin of species, or
how far they have been modified during any period of
time, however vast, by external circumstances or condi-
tions, it is undeniable that certain definite forms, called
" species," exist, and that they constitute more or less
extensive groups of individuals, which resemble each
other as well as their parents and offspring, to the same
extent that we observe in the case of our own kind.
These groups, to deserve the name of species, must
be distinct from others ; because if any of them are so
intimately blended together by intermediate links as to
make the line of separation too critical, the test fails, and
a subordinate group, or what is called a "variety," is
the result. For this reason it is indispensably necessary
to compare as great a number of individuals as possible,
and especially a series of different ages and sizes com-
mencing ab ovo, as well as specimens collected from
various localities. The study of abnormal or monstrous
forms is also important in order to ascertain the range
of variation in growth. By such investigations a crying
abuse of the present school of natural history (an ex-
cessive multiplication of species) would be avoided.

Xviii INTRODUCTION. [CH.

juster views would prevail as to the distinction of spe-
cies^ and the well- deserved reproach of those philo-
sophers who are confirmed in their denial that species
have any real existence in nature by the notorious dis-
agreement of naturalists as to their limits would thus
cease. There is no judge or ^' arbiter specierum ; ^^ and
every naturalist is at perfect liberty to follow the bent
of his own discretion or inclination in the extension or
reduction of species^ subject only to the opinion of his
scientific compeers. He is amenable to no other autho-
rity. Hence arises that great and continual diversity of
opinion as to the determination of certain species among
natui'alists, whose opportunities or experience are more
or less great J or whose minds are differently constituted —
the nature of some being rather analytical and of others
synthetical. The same remark of course applies to the
distribution of species into genera^ and of these, again,
into families and higher groups or sections. To a cer-
tain extent all classification is artificial and arbitrary;
but the necessity for some arrangement of the kind is
obvious, considering the immense number and variety
of objects to which some name or symbol of distinction
must be given for the sake of those who pursue or study
any branch of natural history. Systems of classification
are as indispensable to a naturalist as tools to a work-
man. This necessity of science equally applies to the
discussion of the interesting question as to the origin
and mutability of species, which in the absence of such
data could not be satisfactorily conducted.

Varieties. — Besides species, and holding a subordinate
rank to them in the great host of Nature's works, are
certain forms called " varieties,^' which are not less defi-
nite, but more difiicult to separate from the typical or
specific forms. They are offshoots of species, and origi-

I.] INTRODUCTION. xix

nate in some peculiarity of climate, situation, composition
of the soil or water which they inhabit, the nature or
supply of food, and various other conditions. The cha-
racters by which they usually differ from species consist
of size, comparative proportions of different parts, colour,
and degree of sculpture ; and the investigation of forms
thus changed or modified is often extremely perplexing.
Some species are more liable than others to variation ;
and, as might be expected, the tendency to variation is
greater in those species which most abound in individuals,
by reason of their offering a wider scope of observation
to the naturalist. Varieties are of two kinds, perma-
nent and local. The former are called "races,^^ and
have many of the characters of true or typical species,
with which they associate. Great experience and good
faith are essential to the investigation of this experi-
mentum crucis ; and the only reliable test of distinction
between species and races appears to be the discovery
of intermediate forms. In the absence of such discovery
we may proceed to classify, — although after all we must
not lose sight of the great probability that all species,
and even higher groups, may have originally descended
from races or permanent varieties, and these again from
local varieties. The latter are more readily distinguished
from species and are never found associated with them.
I believe it may be now considered a well-established
rule, that all distinct groups of individuals living toge-
ther and having a common feeding-ground, and which
are not connected or blended with each other by insen-
sible gradations, are prima facie entitled to the rank of
species. A contrary opinion used formerly to be enter-
tained by some naturalists; and it was not unusual
to found a claim to specific distinction on the fact that
the specimens thus distinguished did not occur with the

XX INTRODUCTION. [CH.

species from wliicli it was proposed to separate them.
They apparently forgot that the very difference of locality
or habitat^ with its accompanying conditions, caused the
variation in question.

Monstrosities. — These abnormal forms of shells are
frequently repeated, and even appear to be hereditary ;
and it is not easy at first to distinguish them from varie-
ties. Both are probably owing to an irregularity, or an
excessive or defective power, of secretion in. the mantle
of the animal. The monstrosity seldom, if ever, occurs
in the first stage of growth ; and the examination of the
top whorls or apex of a univalve, or of one of the beaks
of a bivalve (being in each case the nucleus of the shell) ,
offers a good criterion to distinguish monstrosities from
species. The normal or regular form becomes distorted
at a subsequent stage of growth, instead of pursuing the
usual course of formation.

Reversed shells. — Among the numerous cases of mon-
strosity to which the MoUusca are liable, by reason of
their comparatively simple organization, none is more
remarkable than the reversed turn and position which the
spire of univalve shells and the valves of some Acephala
not unfrequently assume. The twist of the spire in
univalves is, with a few exceptions, dextral or from left
to right, the shell being placed with its spire towards
the observer and its mouth downwards. If the shell is
held in this position before a mirror, the spire will of
course appear to be sinistral or turning from right to
left, which is termed "reversed.^^ This phenomenon
occurs in most species of Mollusca which have spiral
shells ; but it is more rare in some than in others. In
certain genera the shell is naturally reversed; and a
dextral spire becomes the exception or monstrosity. In
a few species the spire is as frequently sinistral as dex-

I,] INTRODUCTION. XXi

tral. The direction of the spire is attended by a corre-
sponding change in the position of those organs of the
animal which are usually placed on one particular side ;
and it may be compared to the case of a man ha\ing
his heart on the right and his lungs on the left side of
his body. The structure of a mollusk is, however, not
so complicated ; and the consequence of such a reversal
in the position of its organs is probably not very import-
ant to its economy. One curious case of this kind of
malformation is worth noticing. During the deposit of
that part of our upper tertiary strata which is called the
"Red Crag/^ nearly all the specimens of the almond
whelk (Fusus antiquus) appear to have been sinistral or
reversed, dextral specimens being comparatively very
scarce in this formation. The same species still exists
and is common in our seas ^ but the proportion of dex-
tral to sinistral specimens is at present exactly the con-
trary to what it was in the Crag epoch — the former being
now the rule and the latter the exception. A reversed spe-
cimen in a recent or fresh state is worth half a sovereign ;
while dextral specimens may be had at any street stall
(with the fish) at the rate of four for a penny. A few
bivalve species, which have one valve larger than the
other and are therefore called inequivalve, have also
their shells occasionally reversed, — their right or left
valve being the largest, contrary to the usual rule in
these species.

In the prosecution of any inquiry into the nature of
species or varieties, or as to whether there have been
any special or successive creations since this world was
called into existence by the fiat of its Great Creator, I do
not believe that it can have any irreligious or sceptical
tendency. Holy Scripture is not a work of natural his-
tory, and it is silent on the subject of this investigation.

Xxii INTRODUCTION. [cH.

As Dr. Carpenter has well observed, in his Researches
on the Foraminifera *j "The creation of any organism
seems to me just as much to require the exertion of
Divine Power when it takes place in the ordinary course
of generation, as it would do if that organism were to
be called into existence de novo ; the question being in
reality whether such exertion takes place in the way of
continuous exercise according to a settled and compre^
hensive plan, or by a series of disconnected efforts."

Synonymy. — Although the prevalent habit of multi-
plying species is much to be deprecated, an equal amount
of injury has been done to the cause of science by the
unnecessary addition, from time to time, of fresh names
for species which had been previously described; the
consequence of which is that, an overgrown mass of
nomenclature encumbers most works on natural history.
For our common Cockle and its varieties no less than
sixteen, and for the Oyster fourteen different names
have been given by British and Continental writers ; a
genus of minute shells [Odostomia] has received from
various conchologists twenty different names ; and in an
essay of M. Bourguignat on the species of Pisidium (a
small freshwater bivalve) the synonymy of P. amnicum
comprises eighty specific names and extends over more
than five octavo pages. The student may well stand
aghast at this fearful array of names, which bewilder him
and obstruct his entrance into the portals of the edifice
of natural history ! This redundancy of names for the
same object has partly arisen from the want of inter-
com'se which naturalists of this and other countries
experienced formerly, and especially during that chronic
state of international warfare which so long debarred us
from any communication with foreigners. Such an

* Phil. Trans, vol. cl. p. 570.

I.] INTRODUCTION. Xxiii

unfortunate state of things certainly retarded scientific
progress in Great Britain to a very great extent; and
the friendly sympathy which now exists between the
naturalists of all countries cannot be sufficiently ap-
preciated. In one sense the multiplication of species
and addition of synonyms are convertible terms ; and
that is^ where local varieties have been described and
raised to the rank of species. This evil it is impossible
to prevent ; but as science does not march '' pede claudOy"
but regularly and steadily, it is to be hoped that each
succeeding year will bring with further discoveries the
occasional publication of monographs by experienced na-
turalists, so as gradually to rectify this crying evil. The
introduction to the ^ Flora Indica/ by Drs. Hooker and
Thomson, contains a valuable remark which deserves the
attention of zoologists as well as botanists, viz., " The
discovery of a form uniting two others, previously thought
distinct, is much more important than that of a totally
new species, inasmuch as the coiTcction of an error is a
greater boon to science than a step in advance.^^

Nomenclature. — Very often the longest and most un-
pronounceable names have been bestowed on minute
and almost microscopic species. When the student meets
with such names as Cerithiopsis tubercularis and Omalo-
gyra nitidisslma, he is scarcely prepared to find that one
of the objects designated by these more than sesqui-
pedalian words is scarcely more than a quarter of an
inch in length, and that the other is only about one-
fifteenth of an inch in diameter ! There is, however, no
way of preventing this abuse of language for scientific
purposes, except by making a new coinage; and this
would be attended with more inconvenience to naturalists
in the substitution of new for old and familiar names,
than in the retention of a few long words.

Xxiv INTRODUCTION. [CH.

The general rule is not to alter the name which has
been first given to any species, in order to establish a con-
ventional right of priority and to prevent confusion. But
this rule is not without an exception — especially where
the original name has been accidentally misspelt, either
by the author or printer. Thus " Suediense '' has been
properly changed to Suecicum ; and " Syndosmya ^^ ought
to be replaced by Syndesmia. Such trivial corrections
are necessary in the works of our best authors ; and in
those which have largely benefited the cause of science,

" non ego paucis

Offendar maculis, quas aut incuria fudit
Aut humaua parum cavit natura."

CHAPTER II.

ORGAJ^IZATION AND HABITS.

REPEODLTTIVE system. FECUNDITY. HYBRIDISM. PROGRESSIVE

DEVELOPMENT. ORGANS OF SIGHT HEARING SMELL LOCO-
MOTION. FOOD. SIZE. HABITAT. CARE OF YOUNG. SOCIA-
BILITY. ESTIVATION AND HIBERNATION. NESTS. MODES OF

ATTACK AND DEFENCE. RENEWAL OF PARTS, PHOSPHORES-
CENCE. PERFORATING POAVERS. OCCASIONAL APPEARANCE AND

DISAPPEARANCE. TENACITY OF LIFE. AGE. RESUME.

Reproductive system. — The modes of propagation
among the Mollusca are various. In the case of uni-
valves, many of them (e. g. the Whelk tribe) have distinct
sexes, and are what botanists term " dioecious f' w^hile
most of the land-snails are nearlv " monoecious,^^ each
indiA'idual being at the same time male and female, but
incapable of fertilizing itself. Some of these even change
their sex at diff'erent periods, — the ValvatidcB being at

II.] INTRODUCTION. XXV

first male and afterwards becoming female. In the case
of the Conchifera or bivalves, they are probably all
strictly '^ monoecious '' and fertilize themselves. It was
at one time supposed that the Oyster and freshwater
Mussel were exceptions to this rule, and that some in-
dividuals were male and others female; but the re-
searches of Davaine, Moquin-Tandon, and other able
physiologists have disproved this idea*. The external
organization of the Conchifera, as well as the complete
isolation of the Teredines and many other kinds from all
intercourse with each other during the whole of their
lives, would make it very unlikely that they are of dif-
ferent sexes. Some of the MoUusca are ovoviviparous,
the eggs being hatched within the body and the fry ex-
cluded in a perfect form. This is the case not only with
" monoecious '^ kinds (such as Anodonta and Kellia) , but
also with some snails [Helix rupestris and Pupa umbili-
cata) and even with " dioecious ^^ kinds, such as Paludina
and certain species of Littorina. Some particulars will be
found in the following pages T\4th regard to the amours
of the land and freshwater snails ; and much more might
be said on this curious subject. The tender passion
seems to take up much of their time and attention. M.
Turpin has observed a pair of the common garden-snail
[Helix aspersa) engaged in love-making for the space of
more than ten hours !

Fecundity. — The extreme fertility of some moUusks is
not exceeded by that of fish. It has been estimated that
the oyster spawns annually at least three millions. Ac-
cording to C. Pfeifi*er the gills of a freshwater mussel of
moderate size contain at least 400,000 eggs ; and Jacob-
son has given a much higher figure (two millions) for the

* See also Hancock " On the Organization of the Brackiopoda,^^ Phil.
Trans, vol. cxlviii. p. 816.

b

XXvi INTRODUCTION. [CH.

product of a large individual of this kind. If this rate
of increase were unchecked, our seas and rivers would in
a comparatively short time (reckoning geologically) be
filled up with the remains of shell- fish.

Hybridism. — Although many surmises have from time
to time been hazarded as to the production of abnormal
forms of Mollusca by means of an unnatural union be-
tween individuals of different species, the only direct
experiments or observations that appear to have been
published on the subject have been made by French
naturalists. M. Gassies, in his descriptive Catalogue of
the Land and Freshwater Mollusca found near Agen,
mentioned several cases of what he called " accouple-
ments adulterins/^ which he had observed between in-
dividuals of Helioo virgata and H. Pisana, as well as
between those species and Bulimus decollatus. M. Gassies
enclosed the snails during a thunderstorm in a vessel
covered ^^At\\ metallic gauze ; and he believed that the
electricity with which the air was then charged induced
the unnatural union. Great care appears to have been
taken to prevent any error in the result, by selecting
individuals which had not been previously fertilized and
keeping them after fecundation separate from any others.
The product of these unions was as follows. The young
of H. Pisana had perfectly white shells, — their mother
li^ving the usual coloured bands ; and the young of H.
virgata had shells of a darker colour than that of their
mother. In the other case, the product of the Helices
which had been coupled with the Bulimus was various.
Many had shells which were almost scalariform ; the
shells of others were pyramidal ; but the greater part of
them had shells exactly like that of their mother. The
product of the Bulimus did not differ from their maternal
form. M. Gassies had also observed the product of a

II.] INTRODUCTION. XXvii

union between Helix nemoralis and H. hortensiSy in which
the colour of the lips of their shells in each case varied
indifferently from bro^Ti or rose-colour to milk-white.
Professor Lecoq and M. Miergue have celebrated the
voluntary nuptials between individuals of Helix nemo-
ralis and H. aspersa, as well as between Pupa cinerea
and Clausilia papillaris ; but these unions do not seem
to have been blessed with any offspring. The fact,
however^ of such unions having taken place in a state of
nature, and not under forced or accidental conditions,
is remarkable, and the more so because the individuals
belonged to what are considered different genera.

Progressive development. — The researches of geolo-
gists have established by positive evidence,, that the
organization of many animal and vegetable types has not
become more specialized or rendered more perfect since
the period to which we ascribe their creation, and that,
notwithstanding the enormous lapse of time which is
indicated by the accumulation of fossiliferous strata, the
modification or change which these types have under-
gone has been remarkably slight. There is abundant
evidence of variation, but none of what is usually under-
stood as progression*. The theory of ^'^progressive de-
velopment '^ appears to have been very hastily advanced,
and is by no means borne out by geological facts. It is
a cmious circumstance in the history of the growth of
certain land and freshwater Mollusca, that the young of
some species of Pupa resemble those of Helix, the young
of the latter those of Zonites, and the young of the last
those of Vitrina, These genera are enumerated in the
order of their organization, Pupa being the most, and
Vitrina the least perfect of them.

* See Professor Huxley's Address delivered at the Anniversary Meeting
of the Geological Society, 21st February, 1862.

62

XXviii INTRODUCTION. [CH.

Organs of sight. — The eyes of a Cuttle are more perfect
than those of many kinds of fish ; but the so-called eyes
of land-snails are supposed to be only organs of touch
and not of vision, although endued with a greater sensi-
bility than the tentacles which support them. The
coloured bulbs which fringe the mantle of a Scallop are
also called eyes; but their structure is very simple.
According to Mr. Lea, several kinds of Unto are sensi-
tive to light. These organs are entirely wanting in many
of the Mollusca, and even in some species of genera which
usually have eyes.

Hearing. — In the Pectinibranch Mollusca the contents
of the auditory capsules consist of spherical ear- stones,
which in every respect but that of form are similar to
the otolites of fishes. In the Pulmonobranch Mollusca
they are called octoconia and consist of a chalky pulp,
which is separable into minute elliptical granules. Frey
has observed organs of hearing in many of the land
and freshwater Mollusca, both univalve and bivalve. He
counted as many as 200 otolites of different sizes in one of
the auditory vessels (of which there were two) in an adult
snail. In Sphcerium (or Cyclas) each individual appears
to have never more than a single otolite. He believes
that these bodies are formed by a subcrystaUization of
the liquid contained in the auditory vessels.

Smell. — In the Helicidce, or land-snails, this sense is
supposed to lie in the bulbs which surmount their ten-
tacles. It is probable that the carnivorous or zoophagous
Mollusks have the power of scenting out their prey or
food. Quantities of the common "almond-whelk^^ of
dealers in shell-fish (Fusus antiquus) are procured on
the Cheshire coast by the fishermen placing a dead dog
on the sands at low-water mark during spring tides.
The bait is then completely covered with stones, which

II.] INTRODUCTION. xxix

f

are piled up like a cairn, partly to prevent the carcase
being carried away by the tide, and also because the
fishermen have a scruple about eating shell-fish which
have been fed on such carrion. On the next turn of
the tide the heap of stones is visited and the whelks are
found on the surface in great numbers, having been
apparently attracted by the smell of the bait, but unable
to get at it.

Locomotion. — The methods by which MoUusca move
from place to place are exceedingly varied. Most uni-
valves crawl on the lower part or disk of a large fleshy
organ, which is the homologue of a foot and supports
the body. The Melampus uses this organ in an unusual
way, by first planting the front half, like a caterpillar,
and then drawing up to it the other half, and repeating
this alternate movement in a fashion called " looping/'
The celebrated French naturalist, Adanson, gave that
genus the name of Pedipes on account of this peculiarity.
Many of the aquatic univalves can swim, or rather creep
underneath the surface of the water, the position of their
bodies being reversed, with the point of the shell down-
wards. A few of the bivalves {e. g. species of Lepton
and Galeomma) sometimes walk about with their valves
spread out like the cover of a book when left on the
table by an untidy person. The Cuttles and Pteropods
swim as rapidly as fishes, but in a different manner —
viz. by taking in and expelling by means of their mantle
successive volumes of water, so as continually to propel
th^m onwards. One kind of Cuttle is said even to pos-
sess the faculty of flying, and to dart for a considerable
distance out of the water through the air like a flying-
fish. Most of the Acephala or bivalves have a tongue-
shaped organ of progression, which is muscular and
extremely flexible. By means of this kind of foot the

XXX

INTRODUCTION. [cH.

Cockle^ Razor-fish {Solen), and other kinds burrow in
sand and mud. The Scallop and Lima fill their bodies
with water, and then, suddenly collapsing and closing
their valves, execute a series of leaps or jerks, by which
they can traverse a considerable distance, although in
an irregular course. Certain small bivalves [Sphcerium
and Kellid), while floating on the surface of the water,
spin filaments which serve to moor them and prevent
their being drifted about. Several kinds of slug secrete
glutinous threads by which they suspend themselves
from trees and either remove from one branch to another
or drop safely to the ground. Thus it will be seen that
the Mollusca partake of all the modes of locomotion pos-
sessed by other animals — that they can walk like quadru-
peds, fly like birds, crawl like serpents, swim like fishes,
and even spin threads like spiders.

The action of creeping in a snail is performed by the
close appression of its foot to the substance over which
it moves, as well as by muscular force. Any unevenness
in the surface to be traversed is filled up by folds of the
foot, which is extremely flexible. This action may be
compared to the application of one piece of flat glass to
another. Musical sounds, resembling those which are
given out by the Eolian harp, may be observed on a dry
summer evening by putting a garden-snail to crawl out-
side a window; and this phenomenon has frightened
many a timid or superstitious person, who could not
imagine whence these mysterious sounds proceeded. A
curious calculation was made by Mr. Thomas, an Ameri-
can conchologist, as to the rate of a snaiFs pace. He
found that it takes 16 days and 14 hours for a moderately
fast snail to do a mile.

Food, — By far the greater part of the MoUusca are
zoophagous or animal- eaters. The food of the Acephala

II.] INTRODUCTION. XXXi

consists of Infusoria and other animalcules^ which are
conveyed to their mouths, by an action analogous to
that of suction, through the inhalant tube or the outer
folds of their mantle. The Buccinwn or whelk tribe prey
upon other moUusks (especially bivalves) by drilling
holes in their shells with their proboscis, which is armed
with a formidable apparatus of teeth. The whelks are
also very troublesome to fishermen, being often found
sucking and sticking to the bait when the lines are taken
up. Numbers of them may be caught in lobster-pots
baited with fish or meat, if laid down on a sandy instead
of a rocky ground. Most of the littoral univalves feed
on sea- weed. The common Limpet forms by means of
its foot a shallow excavation in the rock. When the
tide returns it goes out to its pasture, browsing like an
herbivorous quadruped ; and it returns to its hole when
the tide retires. The track left by its grazing on the
submarine vegetation which clothes the adjoining rock
is very perceptible and is sometimes tortuous or maze-
like. Land and freshwater snails, as well as slugs, are
for the most part herbivorous, as gardeners know to
their cost in the former case; but some of them also
devour animal matter, and a few are cannibals. The
food of the Testacella consists almost exclusively of
living earthworms ; and a fall account of its carnivorous
and voracious propensities mil be found in this volume.
Snails have been taken with insects in their mouths,
which they were swallowing by degrees ; and, accord-
ing to M. Bonnafoux, the Helix aspersa has been known
to perforate birds^ eggs in deserted nests, in order
to feed on their contents. The number of curved si-
liceous teeth which arm the tongues or lingual plates
of snails is prodigious (amounting in some species to
many thousands), being arranged in several rows. Some

XXxii INTRODUCTION. [CH.

of the marine Mollusca are parasitic, or live upon the
secretions of other animals. Among the bivalves Mon-
tacuta substriata, and among the univalves Stylifer Tur-
toni, are instances of these parasitic habits.

Size. — This appears to depend on the supply of food ;
and it is probable that, owing to the vast shoals of mol-
lusk- eating fish which abound in the northern seas, the
shell-fish there are thinned to such an extent that the
fortunate sur\TLVors have a proportionally larger share of
food than those which inhabit southern seas, where both
species and individuals are more numerous. Northern
Mollusca are generally larger than those of the same
species from the South ■^. The same law is observable
with regard to cultivated fruits, — thinning being resorted
to for the purpose of reducing the number and in-
creasing the size of those which are allowed to remain.

Habitat. — There is probably not a square foot of land,
either in a cultivated or uncultivated state, or co-
vered with fresh, brackish, or salt water, that is not
inhabited by Mollusca of various kinds. Trees, herbage,
and sea-weeds are the chosen stations of many sorts,
for the sake of the shelter or food which they afibrd ;
and even our cellars and kitchens are not free from
them. Some live only in the ocean, and never approach
land unless when driven on shore by the winds and
waves. These are called " pelagic.^' Among them are
the lanthinaj or " blue-snaiV and a few small Ptero-
pods, which are occasionally found in our seas. The
former is provided with a cellular apparatus, by wliich

* See also Draparnaud (Tabl. Moll. p. 35) as to the comparative size
of land shells inhabiting the North and South of France. " Le cHmat
influe beaucoup sur la grandeur des individus. Chez les MoUusques,
comme chez les Mousses et un grand nombre d'autres plantes, la meme
espece acquiert un volume d'autant moindre, qu'elle habite dans un pays
plus chaud."

II.] INTRODUCTION. XXxiii

it is enabled to keep always in a floating position on the
surface of the water, with the point or spire of its shell
downwards, and which apparatus also serves as a nidus
for its spawn. A description of this curious appendage
or " float," as well as of the equally remarkable habits of
the lanthina, will be found in its proper place. The
Pteropods have feet like wings, and flutter through the
water like butterflies. They have conical, and some-
times spiral, shells as fragile and transparent as the
finest blown glass.

Care of young. — Many of the bivalve Mollusca, inha-
biting the sea as well as fresh water (e. g. Teredo and
Anodonta), retain for some time their fry, after being
excluded from the egg, in the folds of their mantle, this
being in some degree an analogous provision to that
which is possessed by the marsupial quadrupeds. The
common Limpet and some kinds of Pupa (small land-
snails) have also been observed to carry about their
young, the former within the folds of its foot, and the
latter attached to the shells of their mother. These
cases of Molluscan a-ropyrj are nearly as wonderful as
any which have been adduced in accounts of much more
highly organized animals.

Sociability. — Although many of the Mollusca are gre-
garious and assemble together on the same feeding-
grounds, it does not appear that they ever associate for
a common object, like bees or ants. Each Pholas and
Teredo makes a hole for itself; and although the com-
mon garden-snail often fastens itself to the shell of its
companion, when they hibernate and form clusters, a
smooth stone or any other object is used for the same
purpose.

Estivation and Hibernation. — Many animals in a state
of nature have their periodical seasons of repose, espe-

65

XXxiv INTRODUCTION. [CH.

cially in the winter when there is a deficiency of food.
For this reason it may be supposed that all the Mol-
Insca hibernate ; and we know that the land- snails in
this country have such a habit. Most of them bury
themselves in the ground^ or nestle in the crevices of
rocks, under the bark of trees, or even in the hollow
stems of the larger umbelliferous plants. They also
cover the mouths of their shells with a calcareous plate
of various degrees of thickness, which they secrete, in the
same way as the shells, by means of their mantle. This
plate is called an " epiphrag-m,^' and in the apple-snail
[Helisc pomatia) is of considerable thickness. But in
dry weather and during the heat of summer they form
another and slighter kind of epiphragm, in order to keep
their bodies always moist and lubricated, as without such
protection thfe tissues would soon dry up and the snails
perish. The E,ev. H. B. Tristram, in his account of the
Great Sahara, says that the snail-shells which he found
there were much thicker than those of the same species
from more temperate parts of Europe, apparently as an
additional means of preventing evaporation in so dry a
climate. The simile in the 58th Psalm (verse 8) which
is rendered in our translation for the ^ Common Praver/
" consume away like a snail,^^ may have had reference
to the inability of these Mollusca to endure exposure
to the great heat of the sun in an Eastern climate.
None of the naked Slugs occur in the lists of land
Mollusca collected by Professor Roth in Palestine,
and by Dr. Schliifli and M. Mousson in the East.
The circulation of land-snails is affected to a great
extent by the temperature. In some kinds the rate
of pulsation varies from 30 to 110 per minute during
summer ; and it ceases altogether in winter. Although
the temperature of the sea is nearly the same in summer

II.] INTRODUCTION. XXXV

and winter^ except at its surface, the circumstance that
most sea- weeds are annual would lead us to conclude
that the marine phytophagous MoUusca also retire into
winter quarters, and that, as these are preyed upon by the
zoophagous kinds, the habit of hibernating is common to
all shell-fish. In shallow seas near the land, the number
of marine animals is perceptibly diminished during cold
and inclement seasons ; and this was noticed by several
naturalists to have been the case in the wet year of 1860.
The period of hibernation differs among the MoUusca.
Some retire earlier or emerge later than others. Ac-
cording to M. Drouet the Anodontce or freshwater mus-
sels hibernate before the close of autumn, and bury
themselves deep in the mud until the middle of spring,
when the water begins to get warmer.

Nests. — A few marine bivalves, which do not spin a
byssus or bundle of threads with which they can moor
themselves to rocks, or which have not the power of exca-
vating for themselves a place of residence in stone, wood,
the tunic of Ascidians, or other substances, form a kind of
rude nest out of broken shells and zoophytes, which they
cement and line internally with a slimy exudation from
their bodies ; and thus they remain snugly ensconced
and protected from their natural enemies. Among these
nest-builders are the Modiola radiata, Lima Loscombii,
and the northern form of L. hians. So little is known
of the habits of the marine MoUusca, that I am not pre-
pared to say whether these are proper nests and used
for the protection of the young, as in the case of stickle-
backs and other small fishes, or are constructed solely
for the use of the adult shell- fish.

Modes of attack and defence. — Some aquatic moUusks
have the faculty of emitting from their bodies a purple
or dark fluids apparently for the purpose of securing

XXXvi INTRODUCTION. [CH.

their prey or concealing tliemselves from fishes or other
predaceous animals. The inky cloud which the Cuttle
ejects is of a glutinous or viscous nature, and does not
readily mix with the water. It seems to be better
adapted for entangling small fishes than to cover the
retreat of the Cuttle, which is extremely rapid in its
movements. The Aplysia, or sea-hare, gives out a
purple dye which is also glutinous and has an ofi'ensive
smell. As this mollusk crawls but slowly, it may use
the dye to obfuscate some more active animal which it
may have taken a fancy to make a meal of, all the Nudi-
branchs being said to be carnivorous. Several kinds
of Planorbis (freshwater snails) yield, on being irritated,
a quantity of their own purple blood. These are vege-
table-eaters; and we can therefore conceive no other
object in this volmitary blood-letting than to elude ob-
servation. A few land-snails (e. g. Bulimus obscurus and
Pupa secale) in their young state, as well as some small
freshwater bivalves belonging to the genus Pisidium,
have their shells covered with mud and other extraneous
matter ; but it is difficult to say whether this is the re-
sult of design or acyident. One might suppose that the
sharp eyes of a bird or a frog would easily detect their
prey through this feeble disguis.e. Some marine bivalves
(as Lyonsia Norvegica and species of Necera) are covered
with a coat of sand, which may to some extent answer
the purpose of concealment. If the safety of these
animals is ensured by such means, how great must be
our admiration of that wonderful yet varied plan of con-
trivance which makes the humble Mollusk, as well as
Man, the object of Divine care !

Renewal of parts. — Some Mollusca, which had been
accidentally deprived of theu' feet, tentacles, eyes, and
even of their entire heads, have been known to repro-

II.] INTRODUCTION. XXXvii

duce them. Nearly a century ago, the experiment of
decapitating unfortunate slugs and snails was con-
ducted on a wholesale scale on the Continent, and every
philosopher was anxious to cut off a head. Even the
great Voltaire followed the universal fashion ; and his
experiences were pubHshed in the " Questions sur FEn-
cyclopedie.^^ In these he mentions having operated on
twenty brown slugs and a dozen snails ; and he after-
wards records with great pride and satisfaction "mes
Limaces '''' and " mes Escargots " showing their budding
heads and horns, and doing as well as might be expected
under the circumstances.

Phosphorescence. — Although a great many animals,
from the highest order of fishes to the imperfectly orga-
nized Noctiluca miliaris, as well as several of the Tuni-
cata, emit or exhibit a phosphorescent Hght, I am not
aware that any of the MoUusca possess the same property,
except some kinds of Pholas ; and it is possible that the
phenomenon in their case may be owing to animalcula
which infest them or are found in their holes. The
eggs of a common slug {Arion hortensis) are said to be
luminous for the first fifteen days after they have been
laid. But both the nature and object of this common
phenomenon requires further investigation.

Perforating powers. — Many shell-fish, and especially
bivalves, burrow in sand or mud for protection against
their natural enemies ; but some of them excavate wood,
peat, or stone of various degrees of hardness, for the
same purpose. The process of burrowing is undoubtedly
performed by the foot of the Mollusk. It is exemphfied
by the case of the common Cockle, which uses its tongue-
shaped and flexible foot in the same way as a gardener
uses his dibble, and, having thrust it into the sand and
expanded it, thus makes a hole large enough to contain

XXXviii INTRODUCTION. * [CH.

the shell. The limpet [Patella vulgata) slightly perforates
calcareous rocks by the muscular action of its sucker-
like foot or disk, which occupies all the lower part of the
body. The shell exactly fits the space thus excavated,
so as to prevent the limpet being easily dislodged by a
bird or a crab. The common garden-snail excavates
hard limestone rocks for the purpose of hibernation ; and
as its shell is covered with a delicate epidermis, which
remains on specimens having just emerged from their
winter quarters, it may be safely inferred that the shell
is not the instrument of perforation in this case. But
with respect to the Teredo or ship-worm (which tunnels
through wood), the Pholas (which pierces wood, peat,
clay, and chalk), the Gastrochcena (which penetrates
hard sandstone, chalk, and limestone, as well as old
oyster- shells), and the Saxicava (which perforates the
hardest calcareous rocks), it is not so easy to form a
definite conclusion. This volume would scarcely con-
tain all that might be said on the subject. Forbes and
Hanleyhave given an excellent account of the discussion
which had taken place up to the time of publishing their
work ; and I will content myself with stating briefly the
result of their investigation and adding a few remarks
suggested by my own inquiries.

The opinions which had been expressed on this subject
when the ^ History of the British Mollusca ' was pub-
lished, were classed by its authors, when treating of the
Pholas, under five conclusions, which are as follows : —

" 1 . That the boring Mollusca perforate by means of
the rotation of the valves of their shells, which serve as
augers. 2. That the holes are made by rasping, effected
by siliceous particles studding the substance of certain
parts of the animals. 3. That currents of water, set in
action by the motion of vibratile cilia, are the agents.

II.] INTRODUCTION. XXxix

4. Tliat the animal secretes a chemical solvent — an
acid which dissolves the substance into which it bores.

5. That the combined action of a secreted solvent and
rasping by the valves effects the perforations*.^-'

The first of these views is advocated by Forbes and
Hanley; and the other naturalists to whom they have
referred as having expressed an opinion on the subject
are as follows_, taking the several views in their order
of succession: — 1. Dr. Gray, Dr. Fleming, Mr. Osier.
2. Mr. Hancock. 3. Mr. Garner. 4. Dr. Gray, Dr.
Drummond, M. Deshayes, M. CaiUiaud. 5. Mr. Thomp-
son, M. Necker.

As I believe that all these different views, except the
first, have been successfully refuted by the arguments of
Forbes and Hanley, it only remains for me to adopt
their view, or to substitute another for it.

If we only consider the shell of PholaSy with respect
to its efficiency as an instrument of mechanical perfora-
tion, there might be sufficient reason for supposing that
it can by this mode drill a hole in peat, submerged wood,
clay, or even in chalk when softened by the continual
contact of water. The shell is certainly harder than
any of these substances j and the animal is provided with
muscles of unusual strength for efiecting the rotatory
motion which would be necessary for such an operation.
But we must also consider the cases of other perforating
mollusks whose shells are not so hard. The shell of
Gastrochcena is more fragile than that of the oyster into
which it bores, and very much more so than the lime-
stone in which it not unfrequently lodges itself. The
helmet-shaped valves of Teredo could only be used to
rasp the sides of the tube which this moUusk forms in
wood; and they are not adapted for excavating the con*
•* ' British Mollusca,' vol. i. p. 104.

xl INTRODUCTION. [CH.

cave end of the tube. The shell of Saxicava is coated
with a dehcate epidermis, which would unquestionably
be scraped away in perforating the solid limestone rock,
if the theory advocated by Forbes and Hanley is appli-
cable to this case. And, to take the case of other
marine animals which excavate rocks and shells for the
same purpose as the Mollusca, we know that the boring
Annelids or sea-worms have no hard substance in their
composition. For these reasons, I do not think that
the mechanical theory (viz. that the shell is the sole
instrument of perforation) has been established.

Since the publication of Forbes and Hanley^'s work, the
controversy has been continued with unabated ardour ;
and to the list of naturalists who have taken a part in
it, other names may be added as supporters of the under-
mentioned theories.

Mechanical. Mr. Robertson and M. Fischer.

Chemical. Dr. Mantell, M. Thorent, and Mr. Reeve.

M. Cailliaud now contends that both methods of per-
foration are adopted by the same kind of mollusk ac-
cording to the material acted upon ; and M. Bouchard-
Chantereaux, who was at first in favour of the mechani-
cal theory, is now strongly of opinion that a corrosive
secretion of the animal is the agent of perforation.

But there is another point of view in which the ques-
tion may be considered, and which does not appear to
have received any attention, although in my humble
judgment fully deserving it.

Nearly 130 years ago, a very learned but eccentric
Dutch philosopher, named Sellius, wrote and published,
for the benefit of his country, an elaborate monograph on
the Teredo. In this remarkable production he discussed
at great length, and in the most exhaustive style, all
the various theories which had been propounded up to

II.] INTRODUCTION. xU

that time as to the means by which the ship-worm bores
into wood. He showed conclusively that their shells
could not be the instruments of perforation ; and he
asked how it was possible that the extremely tender
shell of the young Teredo (in fact a mere film) could
make a hole in solid oak, a material ten times harder
than itself. Besides, as he justly remarked, the form of
the tube is evidently not the result of an auger-like in-
strument, because it is broader at the bottom than at
the top and sides. The conclusion he formed, after a
most laborious and impartial investigation, was that the
Teredo perforates by suction, aided by continual mace-
ration and softening of the wood. One of his numerous
quotations from the ancient poets, in support of his
argument, may be here appropriately repeated. It is
from his favourite, Ovid : —

" Quid magis est durum saxo? quid moUius unda?
Dura tamen molli saxa cavantur aqua."

I profess myself to be a follower of Sellius ; and I
am convinced that the sole instrument of perforation by
the Mollusca of stone, wood, and other substances, is in
every case their foot or muscular disk, which is closely
applied to the concave end of the hole and is constantly
suppHed with moisture through the glandular tissues of
the body. The strength of this organ may be easily
tested by any one who tries to remove a limpet from its
native rock, after having touched it and thus given it
due notice of his intention. By this simple, yet gradual,
process the fibres of wood or grains of sandstone may
easily be detached or disintegrated, time and patience
being allowed for the operation. When it is considered
that the hole made by an adult Pholas or Saocicava is
only a few inches deep, and that an aged Patella scarcely
penetrates a quarter of an inch into a limestone rock.

xlii INTRODUCTION. [CH.

there can scarcely be a question that these moUusks
have abundance of time to effect their purpose. It is
said that even the hardest marble is not proof against the
softest impressions, and that the big toe of St. Peter's
statue in the Vatican has been nearly worn away by the
lips of fair devotees. The osculatory process is not un-
like that of suction.

Occasional appearance and disappearance. — Both sea
and land furnish instances (some of which are difficult
to explain) of the periodical appearance and disappear-
ance of certain species of Mollusca in particular places.
Their arrival and departure are often sudden and seem-
ingly capricious. In the case of marine species, this
phenomenon is probably the result of changes in the
course of tidal and other currents, as well as of the
migratory habits of fish. These currents, by accumu-
lating or removing deposits of mud, sand, and gravel,
wliich afford shelter and food to Mollusca, conduce
greatly to their congregation or dispersal. When such
deposits are rapidly formed, the shell-bed becomes co-
vered up or silted; and the Mollusca are entombed
alive for the benefit of future geologists. When their
chief enemies, the fish, desert their former quarters and
migrate to another feeding- ground, the Mollusca then
increase and multiply, being unthinned except by the
tigers of their own kind, or occasionally by the curious
conchologist, or by all-devouring death. The destruc-
tion of shell-beds by marine currents may account for
the prevalent notion that some parts of our sea-coast
(as for example South Devon), which used to yield such
regular and plentiful harvests of shells to collectors,
are now scarcely worth searching, — -it being said that
the shells have " deserted" the coast. The unexpected
occurrence of some kinds of land and freshwater Mol-

II.] INTRODUCTION. xHu

lusca in places where they had not been previously
noticed is not nnfrequent. Many a wonderful tale of a
'' shower of snails^^ has helped to fill the pages of country
newspapers^ arising out of the sudden appearance in a
limited area of Helix virgata and Bulimus acutus, which
are abundant on most of our sandy downs and plains.
This has been sometimes caused by a mere change of
wind to the south-west^ in consequence of which the air
has become charged with moisture, and tempted all the
snails to leave their retreat at the roots of grass during
the night, and to present themselves in the morning to
the eyes of astonished rustics. It is not, however, so
easy to account for some kinds of freshwater snails (e. g.
Limn(Ba glutinosa) being found in the same spots so
abundantly some years, and scarcely at all in others, as
has been noticed by Mr. Bridgman of Norwich. This
is one of the minor, but numerous, problems in the pre-
sent branch of Natural History which still remains to be
worked out, and the solution of which will reward the
diligent and observant conchologist.

Tenacity of life. — Many of the Mollusca, as before
remarked, pass the winter in a state of torpidity, their
vital functions being apparently suspended during hiber-
nation. But some of the land-snails have been known
to live many years shut up in boxes and drawers, or
affixed to tablets as specimens. This capability of sub-
sisting for a long period without food is probably owing
to the snail being able to close its shell by an epiphragm,
which not only prevents the evaporation of its natural
moisture, but also produces a kind of protracted hiber-
nation. Miiller relates that some snails, from which he
had cut off their heads, lived more than a year in this
state without food, crawling about, and at the usual
time forming their winter epiphragms. Some marine

xliv INTRODUCTION. [CH.

Mollusca, both univalve and bivalve, possess also a cer-
tain power of endurance under altered conditions. Thus
Trochus lineatus, which inhabits rocks only uncovered
at low water, can live in a warm room for a fortnight ;
and specimens of Mya arenaria, which burrows into
muddy gravel in the sublittoral zone, have been noticed
by Mr. Rich (an intelligent collector and dealer) to sur-
vive their captivity for three weeks, being all that time
in apparently a healthy state (evidenced by the with-
drawal of their tubes when touched), at the end of which
period they were killed for commercial purposes. No
sea- water was supplied in any of the above cases. The
gills must have been kept moist by the fluid contained
within the mantle — a provision nearly similar to that by
which the camel is able to endure the heat and fatigue of
a journey across the desert after having filled its paunch
with a stock of water. M. Joly observed with respect to
some freshwater mollusca (^/iof/ow/a cygnea and Paludina
vivipara), that they maybe frozen up, and kept for some
time enclosed in ice, without being killed. Some of the
Paludincs even produced young after being thawed *.

Age. — Little or nothing is known with respect to the
duration of life in the Mollusca. According to Sir
Emerson Tennent, the pearl oysters of Ceylon only live
seven or eight years ; and it is said that snails do not
attain a greater age. This is not improbable as regards
the latter, because most of them become adult at the
end of their first year. Whether the numerous laminae
of old oyster-shells afford the same indication of an-
nual growth as the rings of a forest tree is another
question.

Resume. — In concluding this chapter, I cannot do
better than quote the resume given by M. Moquin-Tandon
* Comptes Rendus, 1843, xvi. p. 460.

III.] INTRODUCTION. xlv

of his admirable observations on the land and freshwater
Mollusca of France : —

^' Les Mollusques ont des ruses et des industries, des
sympathies et des inimities, des guerres acharnees et
des amours bizarres. Beaucoup sont a la fois male et
femelle, et par suite pere et mere .... Malgre leur
apathie apparente, les Mollusques sont des etres qui ne
manquent pas d^intelligence. Leur vie privee et leur
vie commune nous montrent des details extremement
curieux.^^

CHAPTER III.

SHELLS.

FORMATION. COMPOSITION. SHAPE. NIJCLErS. GROWTH.

COLOFR. DECOLLATION. EROSION. OPERCULUM. EPIDERMIS.

Formation. — The shells of Mollusca are formed by a
secretion from glands of the mantle or cloak. In uni-
valves this part of the body only covers the front, and in
most cases surrounds the head like a loose collar ; but
it is very flexible, and it can be withdrawn or folded
back nearly to the top of the spire to repair a fracture
of the shell in that part. In bivalves it is double, like
the cover of a book.

Composition. — Carbonate of lime is the main ingre-
dient ; and the sheUs of Mollusca difi'er from the bones
of vertebrate animals, as well as from the shells of crabs,
sea-eggs, and birds^ eggs, in the absence of phosphate of
lime. In all these cases, however, the mineral ingre-
dients are cemented together by an animal gluten.
According to M. Delacroix, the shell of a Helix pomatia

Xlvi INTRODUCTION. [CH.

is composed of the following materials, in every 100

parts : —

Organic matter 18*64

Carbonate of lime 64*96

Other mineral substances, undetermined... 16 -40/

10000

The structure of some shells is fibrous, and of others
crystalline; and they differ considerably in the degree
of compactness. Nearly all the secrets of this wonderfid
laboratory have been made known through the researches
of Mr. Hatchett, Dr. Carpenter, and others; but no
philosopher has been able to explain why this process of
formation has continued from generation to generation
in the same uniform mould, according to the nature of
each species, or how the newly-born MoUusk works out,
with unerring and undeviating instinct, the pattern
which was originally designed by its Creator. Humboldt
justly observed that there are mysteries beyond our com-
prehension ; and it might be good for us that some check
should be put on the overweening pride of intelligence
in the " audax lapeti genus.'"

Shape. — All shells assume the form of a cone. Uni-
valves are generally spiral, so as to accommodate the folds
of the body. Even the common limpet {Patella vulgata)
has a distinct spire in its embryonic state, resembling
that of Fissurella or Emarginula. The Chitons are in
some respects abnormal, having several testaceous joints,
which overlap each other, like the plates of ancient ar-
mour or the scales of a fish; but all these joints taken
together may be considered as forming a depressed cone
of greater length than that of a Patella, the lines of
growth on each side of the apex (which is compound in
Chiton) being equally symmetrical in both cases. Bi-
valves offer no exception to this conical law of growth,

III.] INTRODUCTION. xlvii

the apex or nucleus of each valve being analogous to the
same part in a spiral shell ; but in bivalves the deposit
of shelly layers is formed on both sides, in consequence
of the mantle or organ of secretion being double. Every
part of the shell, whether univalve or bivalve, enlarges by
growth in the same relative proportion.

Nucleus. — This part of the shell furnishes the concho-
logist with an important character of distinction. Odo-
stomia, Nassa, Cerithiopsis, lanthina, and many other
genera of univalve shells have the apex of their spire
differently formed. In the adult Cyprcea (or Cowry),
the whole of the spire, including the apex or nucleus,
is covered and concealed by an extraneous deposit of
shelly matter; and the same process, although to a
partial extent only, takes place with regard to the genus
Marginella. In many spiral shells the upper whorls
(which originally formed the nucleus) are deserted by
the animal, in consequence of the volume of its body
having increased so rapidly that these whorls were too
small to receive any part of it, and they therefore became
unnecessary.

Growth. — Owing to the difficulty which exists in keep-
ing and observing Mollusks in a state of confinement for
any length of time, and especially those which live in the
open sea, very little is known as to the mode and rate
of their increase. Some interesting experiments on the
growth of land-shells were, however, made by Mr. E. J.
Lowe and communicated to the Royal Society in 1854 *.
The result of his observations is as follows : — 1st, The
shells of Helicidce increase but little for a considerable
period, never arriving at maturity before the animal has
once become dormant (or hibernated). 2nd, Shells do
not grow whilst the animal remains dormant. 3rd, The

* Proceedings, vol. vii. p, 8.

Xlviii INTRODUCTION. [CH.

growth of shells is very rapid when it does take place.
4th, Most species bury themselves in the ground to
increase the dimensions of their shells. Helix pomatia
and many other shells retreat for that purpose in summer,
ha^dng their heads and the mouths of their shells down-
wards (this position being reversed during hibernation) ;
H. rotundata burrows into decayed wood for the same
purpose; while Pupa umbilicata, Clausilia nigricans [C.
ruyosa) , and Bulimus obscurus bury their heads only while
the increase takes place. With regard to marine shells
it may be observed that sea-water does not everywhere
contain the same relative proportion of mineral and
chemical ingredients, and that the admixture of fresh
water has a material effect on the substance, texture, and
composition of sea-shells. In estuaries, where the water
is brackish, oyster- shells are smaller and thinner than
usual, owing to the deficiency of calcareous salts ; while
the shells of oysters procured from considerable depths
in the open sea and at some distance from the land are
remarkably large, thick, and heavy.

Colour. — The dye by which the outer layer of shells
is stained, and which often forms bands, streaks, spots,
and other markings of the most beautiful and varied
hues, is secreted by special glands of the mantle. Owing,
however, to some defect in this organ of secretion, the
colouring-matter is occasionally wanting ; and nearly
every kind of shell, which is usually tinted, has what is
termed an " albino " or white variety. This is the case
with resrard both to land and marine Testacea.

The late Professor Forbes, in a paper which was
published in the ^ Proceedings ' of the Royal Society *,
entitled '^ Note on an indication of depth of Primseval
Seas, afforded by the remains of colour in fossil Tes-

» Vol. vii. p. 21.

III.] INTRODUCTION. xlix

tacea/^ observed that^ ^^ in our own seas, Testacea, taken
from below 100 fathoms, even when they were indivi-
duals of species vividly striped or banded in shallower
zones, were quite white or colourless ; that between 60
and 80 fathoms striping and banding were rarely pre-
sented by our own shells, especially in the northern
provinces ; but from 50 fathoms shallow-wards, colours
and patterns were well marked/'

I cannot help thinking that there must have been
some mistake as to the first and second of these obser-
vations. At least, my own experience induces me to
form a different conclusion.

Instances of depths exceeding 100 fathoms in our seas
are very rare. I only know of two. One of them is
a submarine trough off the Mull of Galloway, called
" Beaufort's Dyke,'' where the depth is 145 fathoms ; and
the other is a pit in the Sound or Sleat of Skye. The
results of dredging in Beaufort's Dyke are recorded in
the ^ Annals of Natural History"^.' Although shells
usually inhabiting comparatively shallow water, and
distinctly striped or banded [Tapes virginea and Venus
ovata), were obtained alive from this remarkable depth,
no deficiency of colour or markings is noticed in the
account of these results. In the other case, I can state
from my own knowledge that the shells were as highly
coloured and the markings quite as vivid as in specimens
found at a depth of 30 fathoms in another part of the
Sleat of Skye. Soundings were taken with Massey's
patent log, and living Testacea were brought up in the
dredge from 118 fathoms. On this occasion Captain
Otter was with me, and I had the benefit of his great ex-
perience in such matters. Last year I dredged for some
weeks off the Shetland Isles at depths between 60 and

* Vol. X., Sept. 1842, p. 21.

J INTRODUCTION. [CH.

80 fathoms ; and not only were live shells which I pro-
cured from those depths as brightly coloured and marked
with as distinct patterns as shells of the same species [e.g.
of Trochus ziziphinus), taken at low- water mark, but
colourless or white varieties of such species were found
in the same spots. The Star-fishes lately got by Dr.
Wallich in the Arctic Sea from a depth of 1260 fathoms
still retain their former colours ; and, during the recent
expedition of Torell and other Swedish naturalists to
Spitzbergen, a portion of the sea-bottom was brought up
from a depth of 1400 fathoms, when, among other ani-
mals of different types, a Crustacean of bright colours is
said to have made its appearance. The extent to which
light penetrates into the abysses of the ocean, as well as
the mode of its transmission, does not seem to be known.

Decollation, — Some univalve Mollusca, both terrestrial
and aquatic, the shells of which have a long and slowly
enlarging spire, desert the first or top whorls, and get
rid of them by a process called decollation or truncature.
The suture, or point of junction between this part of the
spire and the rest of the shell, is usually very slight ;
and the animal effects the process of decollation by
])urying itself in the earth if a land- snail, or rubbing
its shell against a stone or other hard substance if a
freshwater or marine species, in order to disengage itself
from the empty and useless whorls. Before doing this,
however, it reconstructs the top of its spire by forming
a hemispherical plate of shelly matter between that part
of the shell Avhich is to be retained and the empty top.
Among land-snails Bulimus decollatus is a well-known
instance of this peculiarity, among freshwater snails
Limnaa glabra, and among the marine univalves Trun-
catella truncatula.

Erosion. — The outer layers of the shells of aquatic

III.] INTRODUCTION. li

Mollusca, as well bivalve as univalve^ are frequently ex-
coriated or decorticated, and sometimes to a considerable
depth when the shell is thick, as in Unio margaritifer,
or the pearl-mussel. Several marine species, especially
those oiAstarte, Mytilus, and Littorina, are also affected
in the same way. Various theories have been put for-
ward to account for this erosion. In the case of fresh-
water shells, many naturalists have supposed that it is
caused by gaseous action, some have attributed it to the
attacks of Myriapodous insects, a few to excavation by
the eggs of Neritina fluviatilis, MM. de Saulcy and Fis-
cher, as well as Mr. Bland, to other Mollusca eating away
the calcareous matter for the purpose of constructing
and repairing their own shells, and MM. Cuigneau and
Lespinasse to parasitic Confervse and other hydrophytes.
But as this phenomenon is not confined to freshwater
shells, some other explanation must be sought for. It
is very probable that the former class of cases may be
attributable to chemical action, and especially that of
sulphuretted hydrogen ; but in the other, and perhaps
all the cases, the effect may be produced by another
cause. Mr. Grove suggests that it may be owing to the
want of homogeneity in the substance of the shell, and
that the slightest and almost imperceptible inequality in
the surface would result in an electrolytic action of the
water, which would gradually dissolve portions of the
shell. Sea-water is more likely to produce this effect
than fresh water, by reason of the stronger galvanic pro-
perty of the former. Corrosion of metals by water or
moisture may be due to the same cause. As the sub-
ject does not appear to have received much attention in
a chemical point of view, I trust the following remarks,
from so great an authority as Mr. Grove, wiU help to
throw some light upon it. The shells which I submitted

c2

lii INTRODUCTION. [CH.

to his examination were those of Littorina litorea, or the
common periwinkle.

" March 26, 1862.

^' Dear Jeffreys, — As you wish me to put on paper
the suggested explanation of your difficulty, viz. why
it is that substances apparently homogeneous are cor-
roded in patches or irregular hollows, I endeavour to do
so, premising that it is only theoretical and may be
found not to accord with all vour facts.

" If a plate of pure zinc be immersed in dilute sul-
phuric acid, little or no chemical action takes place ;
but keep in contact with the zinc another metal, say an
iron nail, and the zinc is rapidly oxidated and dissolved,
hydrogen being evolved from the surface of the iron. The
action is most rapid at the points most proximate to the
iron ; so that, if the nail be laid upon the zinc, both being
immersed in the liquid, the iron would seem to eat its
way into the zinc. If a few iron filings be placed upon
the zinc, the action will be similar, but Avill begin more
slowly and increase as the points of iron are exposed,
these latter Ijeing protected to a great extent by their
being negative and coated T\ith hydrogen. If an in-
finitesimal quantity of copper be dissohed in the acid, it
will be precipitated in a metallic state on the negative
points and make these permanent centres of action. So,
if no iron be made to touch the zinc, after a time some
want of absolute homogeneity is sure to determine a
chemical action ; and as any trace of metal existing in
the solution will by this chemical (or, rather, electrolytic)
action be deposited on the negative points, or those
least attacked, the action will continually increase, and,
instead of being uniform, mil be in patches around the
negative centres. Thus a piece of common zinc of com-
merce which contains small portions of iron and tin will

III.] INTRODUCTION. " liii

be corroded in pits or holes. With imperfectly con-
ducting bodies the action is similar; at very short di-
stances they conduct^ and the action spreads or extends
from a point to the surrounding points. Sometimes^, in-
stead of forming a patch, the chemical action eats its
way in a dendritic form, pursuing the ramifications of
either the more oxidable portion of the substances or
of the more accessible negative points. The slightest
superficial change will produce a corresponding corro-
sion : thus, if you were to breathe on a polished plate of
iron and wipe away the condensed moisture from half
the plate, leaving that on the other half to evaporate,
the iron would subsequently rust in a dififerent manner
on the two parts. If you electrify a plate of glass having
letters cut in paper on it, and subsequently expose it
without the paper to hydrofluoric acid, the parts pre-
viously uncovered will be attacked ; and so, if you simply
allow the paper letters to remain on the ^lass for some
time (say a day or two), and then blow them off" by
breathing on the glass, or by the vapour of hydrofluoric
acid, the letters will be made manifest. You may easily
imagine a number of other instances. The efiects all pro-
ceed from a want of perfect homogeneity, either original
or impressed by some very trifling circumstance, and
from the fact that, points of action having once been
established, the corrosion is increased by the eff'ects it
itself produces and the deposits it forms. A dentist, to
cure a carious tooth, scrapes out all the diseased parts,
&c. Another cause of localized destructive agency is that
of crystallization : if a plate of common earthenware
has been used to contain saline solutions and is then
allowed to dry and is put aside, it will efi^loresce in spots
and a sort of vegetation will sprout up here and there,
disintegrating the plate in patches. I have now in my

liv INTRODUCTION. [CH.

laboratory a piece of earthenware, which was used merely
to hold a small voltaic battery and catch the chance
spillings of sulphate of zinc from the cells, which is
here and there eaten out in deep pits, and in other places
pockmarked with small spots. If this dish had been
exposed to alternations of sea-water and air, a similar
effect would have taken place ; and yet there was no per-
ceptible want of homogeneity in the dish at first.

" The tree-like corrosions between the object-lenses of
old telescopes are probably due to the same causes, or one
of them. The old experiments of the zinc and silver
tree are instances of the same sort of action. Wet a
glass plate with nitrate of silver and hold the point of a
pin in it, the acid leaves the silver for the copper ; but
the silver is not deposited in a uniform circle, but in a
beautiful arborescent form. Old wine-bottles are fre-
quently found corroded, some in spots, others in tree-
like figures.

" I believe the above will help to solve the problem
you are investigating ; at all events, I can offer no better
solution. (' Ever yours,

"W. R. Grove /^

I may add that limestone rocks are fretted in the
same way as the shells of Purpura lapillus and a stunted
variety of Mytilus edulis which are found on these rocks,
all having the same calcareous basis. The erosion of
bivalves is greater at their beaks, where the connexion
between the animal and the shell is weaker than in other
parts. This is also the case with the points of univalves.
The action appears to be prevented by the epidermis.

Operculum. — The horny or shelly plate (" pot-lid ^^)
by which many univalve Mollusca close the mouths of
their shells is attached by a strong muscle to the back
or upper surface of the foot ; and it serves to protect the

III.] INTRODUCTION. Iv,

moUusk from the attacks or intrusion of other animals.
It is often formed on the same plan as the spire of the
shell, but it differs from the latter in being nearly always
compressed instead of tubular. The only exception to
this rule of which I am aware, as far as regards European
MoUusca, is that of Zanclea, where the operculum is
pyramidal. It has, indeed, been stated that the opercu-
lum o^Adeorbis siibcarinata is cellular ; but the supposed
operculum of this rather common shell belongs to the
Foraminifera and is the Spirillina perforata of William-
son. The mistake arose from the shells and Forami-
nifera having been found by the late Mr. William Clark
in the same parcel of dredged sand; and as the latter
exactly fitted the mouths of the former, he concluded
that the Foraminifera were the opercula of the shells.
The original specimens are now in my collection. A few
of our native MoUusca, as well land as freshwater and
marine {e. g. species of Cyclostoma, Neritina, Bythinia,
and Phasianella), have calcareous or shelly opercula.
The opercula of other kinds are horny and usually thin.
The operculum of Neritina and Jeffreysia is furnished
with an excentric process, or apophysis, which enables
it to fit more closely into the shell, like the bolt of a lock
into the box. In most cases the operculum is spiral;
but in Paludina, Phasianella, and a few other genera it
is concentric. The whorls on some of the horny opercula
nearly correspond in number with those of the shell,
being multispiral in Trochus and paucispiral in Littorina ;
but this rule is not universal. There is a difference of
opinion among physiologists as to the mode in which the
operculum is formed. Some consider the mantle as the
organ of secretion, others the foot, while according to a
few it is formed by the glands of a special organ called
the operculigerous lobe. Adanson and lately Dr. Gray

Ivi INTRODUCTION. [CH.

have likened the operculum to the second valve of bivalve
shells ; but these do not appear to be homologous organs,
although equally serving to cover the body of the mollusk.
Calcareous processes, which answer the purjDOse of oper-
cula, occur in a genus of land snails [Clausilia), as well
as in marine bivalves belonging to the genus Teredo.
In the former case this process consists of a t^Wsted plate,
which is not attached to the animal, but acts like a spring-
door in closing the interior of the shell ; and in Teredo
there are two such processes, each shaped like a spatula,
and attached to the body by strong muscles. Specimens
of Buccinum undatum and Fusus antiquus are sometimes
bioperculate ; and occasionally one of these opercula is
divided into two, or even three laminse, which are piled
upon each other, so as to give the specimen the appear-
ance of having three or four opercula. In some cases of
this malformation in Buccinum undatum, the two oper-
cula are too large to be contained within the shell, and
overlap each other ; but in others they are abortive and
widely separate from each other. They are found in
individuals of all ages ; and they appear to be congenital,
and not the result of accidental loss and renewal. In
one instance of malformation connected with this subject,
which fell under my observation, a deficiency, instead
of a redundancy, of opercular formation occurred, and
may have been caused by disease. A living specimen of
Fusus gracilis, which I procured last year in the Shetland
Isles, had no operculum or even the scar or trace of any
such process. The back of the foot, where the oper-
culum was placed in other specimens of the same kind,
was merely hardened by exposure. In Buccinum Hum-
phrey sianum the operculum is very small, and only covers
part of the aperture or mouth of the shell when the animal
withdraws itself. In some species of the genus Mangelia

III.] INTRODUCTION. Ivii

it is entirely wanting. M. nivalis has a distinct operculum ;
while M. Ginnaniana (which belongs to the same section
of this genus and is found in company with M. nivalis
in our northern sea) has not the slightest vestige of an
operculum. Exceptional instances of the same kind occur
in the tropical genera Valuta, Conus, and Oliva. But a
remarkable peculiarity is presented by some species of
lanthina. which are furnished in their embryonic state
with perfect opercula. These processes afterwards dis-
appear, being probably absorbed by the animal when the
shell becomes too large to be thus closed. Sars, Van
Beneden, and Vogt have shown tha-t the fry of many
Nudibranchs, as well as of that anomalous moliusk
Elysia viridis, have Nautiliform and operculated shells.
The fry of Dolium jjerdix, which has also an operculated
shell in this stage of grow^th only, is so unlike the adult,
that the late Professor Forbes constituted for it a new
genus of another order, under the name oi Macgillivrayia.
The fry of a curious land moUusk {Parmacella), which
partakes more of the nature of a slug than a snail, is said
to be enclosed in an operculated shell. In the adult this
shell becomes more rudimentary and only covers a small
part of the body. This is a case of retrogressive, rather
than of " progressive development.^^

Epidermis. — Most shells have an outer horny covering,
called an " epidermis '* or " periostracon," which appears
to be analogous to the periosteum of bones in vertebrate
animals. Its office is probably to protect the shell from
the chemical action of the air or water inhabited by the
moUusk. It is formed simultaneously with the shell, and
probably by the same organ of secretion. It is usually
glossy, and sometimes resembles a coat of varnish. In
Astarte (a genus of marine bivalves) it is thick and
strong. In some of the whelks and land snails it re-

c5

Ivili INTRODUCTION. [CH.

sembles the pile of cloth, and is occasionally produced
into bristles or hairs ; but in most cases it is very thin
and only forms a delicate film. It exists also in shells
which are internal, as those of Limax and Lamellaria, but
not in Cyprcea or the cowry, which is constantly being
lubricated by the mantle. In its nature it appears to
be persistent and almost indestructible, being not unfre-
quently found still adhering to shells in upper tertiary
strata.

CHAPTER IV.

EXTEENAL EELATIONS.

ENEMIES or MOLLrsCA. PARASITES. USES TO MAN : VIZ. FOOD,

MEDICINE, OENAMENT, AND ECONOMY. INJURIES TO MAN.

STUDY OE CONCHOLOGY. PLEASURES AND DRAWBACKS. INCI-
DENTS OP THE PURSUIT.

Enemies of Mollusca. — These soft creatures are the
favourite food of many animals. Man is not the only
one that finds them savoury and digestible, and that
hunts them down with insatiable voracity. The slow-
ness of their movements makes them an easy prey ; and
their shells afford them no protection against their
larger enemies. On land, hedgehogs (and it is said the
fox also), rats, thrushes, ducks and other birds, snakes,
lizards, toads, zoophagous beetles and centipedes pursue
them and greatly thin their numbers. An insect (the
Cochhoctonus vorax) lays an egg in the body of dif-
ferent species of snails, which, when hatched, eats up by
slow degrees the whole of its unwilling host, and then
curls itself up in the spire of the empty shell, until it is
turned into a chrysalis. The Mollusca which live iii
fresh water are devoured by "wild ducks and other birds
of that class, frogs, fishes, leeches, and the larvae of the

IV.] INTRODUCTION. lix

dragon-fly. The innumerable host of marine Mollusca
afford a constant supply of food to sea-fowl of various
sorts, fish (especially the cod, haddock, mullet, gurnard,
halibut, and sole), crabs and other Crustacea, star-fishes,
sea-cucumbers, and Actiniae. No less than 35,000 spe-
cimens of a small bivalve [Turtonia minuta) were esti-
mated by Mr. Hyndman to be contained in the stomach
of a single mullet which had been taken in Lame Lough.
They are not even spared by their own kind. M. Des-
hayes fed some pet snails with chopped-up morsels of
one of their companions, which appeared to be unhealthy
and not likely to survive. Many instances of such
cannibal propensities in the land and freshwater Mollusca
will be found in this volume. Bulla lignaria is a great
tyrant among the smaller marine shell-fish, and uses the
strong plates of its singular gizzard to crush them. All
the whelk-tribe, as well as the Naticce, enfold their testa-
ceous prey in their large feet, and drill holes in the shells,
as before observed, in order to feed on their contents.
The great strength of the shells possessed by some whelks
does not save them from becoming victims in their turn.
I have been informed by intelligent fishermen, that,,jf
their lobster-pots (in which the Buccinum undatum is
often caught) are left a few hours longer than usual, the
shells of the whelks are found cracked ^' like nuts,"
having been cleared out by the lobsters and crabs while
they were fellow-prisoners. Quantities of this kind of
whelk are caught on the Dogger-bank as bait for the cod-
fisheries of Iceland and Greenland. The way in which
gold-fish contrive to extract the animals from fresh-
water shells is curious. When the shell is too large to
be swallowed, the fish puts its mouth to it, and then,
sucking it for some minutes, lets it go. After a while
the snail recovers and withdraws itself from its shell,

Ix INTRODUCTION. [CH.

when the fish again seizes and sucks it, repeating this
operation for hours and sometimes for days, until its
victim is exhausted. Whether the fish kills its prey by
means of any poisonous injection is a question which
might be answered by some observant naturalist who
not only has an aquarium but makes good use of it. In
consequence of this continual and internecine warfare,
an excessive increase in the number of molkisks, both
on land and in water, is checked.

Parasites. — Very little appears to be knoAvn with re-
spect to the animal and vegetable parasites which are
nourished by the juices or excretions of living ^loUusca.
On land, several kinds of slug are infested by a small
white mite [Philodromus limacum, Jenyns), which may
often be seen in considerable numbers running actively
over their bodies, but apparently not doing the slugs any
harm, except, perhaps, in sHghtly lessening or interfering
with their secretion of slime, on which these insects pro-
bably feed. The Rev. Leonard Jenyns says that the
most striking feature in the history of this kind of para-
sitic mite is " the circumstance of its not confining its
abode to the external surface of the slug, but often re-
tiring within the body of that animal — effecting its en-
trance by means of the lateral foramen which leads to
the cavity of the lungs.^^ And he observes, " Indeed
I am inclined to think that tliis ca^dty is its principal
residence, whence it only comes forth occasionally to
ramble about the surface of the body. In one instance
I confined in a close box a slug which, to all appearance,
was free from parasites. On opening the box a day or
two afterwards, I observed very many crawling about the
slug externally, all of which would seem to have pro-
ceeded from the pulmonary cavity. On another occa-
sion I observed these insects running in and out of the

IV.] INTRODUCTION. Ixi

cavity at pleasure ; and some which I saw retire into it
never reappeared, although I watched the slug narrowly
for a considerable time. It is remarkable that the slug
appears to suffer no particular inconvenience from these
parasites, and even allows them to run in and out of the
lateral orifice without betraying the slightest symptoms
of irritation.^-' M. Barthelemy has noticed in the eggs of
one kind of slug numbers of a small Nematoid worm,
which he has named Ascarioides limacis. These worms
are present in the e^^ at the moment of its being laid,
having been previously deposited by the parent worm
while living in the ovary of the slug. The young worms
must therefore have been introduced into the q^^ while
it was being formed. They appear to adopt the same
course as the parasitic larvse of the Ichneumon when
they are deposited in the body of a grub, and to spare the
vital parts of the embryo on which they feed, until the
period has arrived for their own development. In fresh
water, the pond-mussel (Anodonta) constantly entertains
a large party of parasites, consisting of another kind of
mite {At ax ypsilophora, Buntz), which are so tenacious of
life, that after their host has been put into boiling water
and killed they survive and crawl about as if nothing
had happened to them. A kind of hair-worm [Gordius
inquilinuSy Miiller) attaches itself in clusters to Limncea
stagnalis and many other freshwater snails. In all pro-
bability, however, these are not true parasites, and only
attach themselves to the Mollusca for the sake of the
shelter afforded by their shells or mantles, obtaining
their food from the water and not from the snails, be-
cause their heads are always seen outside and in active
motion when the snails are crawling. Each genus, if
not every species, of freshwater snail may have its own
pseudoparasite. Limncea, Planoy^bis, Physa, Ancylus,

l.xii INTRODUCTION. [CH.

and Bythinia are similarly infested ; but they are of
various sizes, and some of them have different habitats.
In the sea, a small kind of pea-crab {Pinnoteres vete-
rum) is frequently found inside the mantle of Cyprina
Islandica, Modiola modiolus (or the great horse-mussel),
and Phina pectinata, taking up its abode in these snug
quarters for parasitic purposes, and not (as was imagined
by the too credulous Pliny) in order to warn the Pinna of
the approach of its foes, like a faithful friend or watch-
dog. Professor Kolliker has lately noticed in the shells
of several kinds of Mollusca, both univalve and bivalve,
certain vegetable parasites, which he regards as unicellular
^ fungi. They form minute tubes, which run straight
through the pores or fibres of the shell. He thought
it probable that these vegetable parasites dissolve the car-
bonate of lime contained in the shell by means of an acid
which they may have the power of secreting. But the pro-
cess by which shells are perforated by vegetable as well
as animal organisms does not seem to be understood, and
requires much elucidation in a chemical point of view.

Uses to Man. — {Food.) — We naturally consider our-
selves (as the " lords of the creation ^^) the sole pivot round
which all other creatures turn, without much sympathy
with them or regard for their wants and feelings. But
the countless and complicated links of the chainwork in
which all Nature is involved are so closely and wonder-
fully connected together, that not one of them can be
broken or displaced without interfering with the eco-
nomy of the whole. Much of the animal food which we
consume has been nourished at the expense of other
creatures, which in their turn have subsisted upon smaller
organisms ; and this process of destruction is repeated
until the bottom of the scale of animal life has been
reached. Then the varied and inexhaustible stores of

IV.] INTRODUCTION. Ixiii

inorganic substances are called into requisition, and
these again are supplied and renewed from decayed par-
ticles of once living matter. Thus a never-ending cycle
of waste and renewal takes place^ in accordance with the
beneficent design of the Author of all things !

The principal use which the MoUusca subserve^ so
far as man is concerned, is to supply him, directly and
indirectly, with an abundance of food. It is true that this
kind of food is not so grateful to us in a civilized as in
an uncivilized state ; but one of our most favourite lux-
uries is derived from this source, and the oyster, fortu-
nately, inhabits those regions where civilization has
attained its present height of perfection. Many other
kinds of shell-fish, such as scallops and cockles, are not
less wholesome than the king of the Mollusks, and are
by no means to be despised ; and the ormer (Haliotis
tuberculata) is reckoned a delicacy in the Channel Isles,
when properly cooked. The salt flavour which is so
much relished by a maritime population is imparted by
all the marine MoUusca. The quantity (amounting to
many hundreds of tons) of whelks, mussels, and peri-
winkles which is every year disposed of in Billingsgate
market alone is almost incredible ; and there is no
seaport or adjoining tract of country, especially in the
manufacturing and mining districts, but has a consider-
able traffic carried on within it by a numerous and in-
dustrious class of itinerant dealers in such wares. On
many parts of the Scotch and Irish coasts shell-fish form
a considerable portion of the food of the poorer inha-
bitants; and in a few of our more remote and almost
inaccessible islets (such as Fair Isle and some of the
Western Hebrides) positive starvation would ensue in
winter, if it were not for these unfailing and easy sup-
plies. In an indirect way, the MoUusca contribute still

Ixiv INTRODUCTION. [CH.

more to the sustenance of man, by supporting the innu-
merable shoals of cod, Img, haddock, halibut, and various
other sorts of fish which abound in our seas and pro\ide
a constant livelihood for a hardy race, and through them
for a great part of our population, who, both from neces-
sity and choice, are fish-eaters. Our Continental neigh-
bours, not being so well supplied as we are with sea-fish,
do not disdain any ^^frutti del mare/^ The date-shell
(Lithodomus dactylus), which is extracted with much
labour from the solid rock on the coasts of the Mediter-
ranean, is reckoned a dish fit for an emperor; and M.
Recluz says of a kind of cockle [Cardium l(svigatum)y
" Sa chair est savoureuse et prisee du gourmet/'

The Romans had their oyster-beds, as well as their
Cochlearia or snail-preserves; and Varro, in his 3rd
Book (" De viUaticis pastionibus^'), describes fully the
method adopted by his countrymen for improving the
difiierent breeds of oysters by crossing. The improve-
ment of the breed of oysters, as well as their preserva-
tion, ranks in France as a science, and has received the
name of " huitreculture,'' its professor being M. Coste.
We can, but (alas !) do not, manage these things so
well. Even land- snails are pressed into the service of
the French, and enter rather largely into their cookery.
No one can have traversed the streets of Paris, or of the
larger towns in France, without seeing dishes of Helix
pomatia temptingly displayed in the shops of restaurants,
like kidneys and white-bait in the windows of London
eating-houses. The list of eatable snails in France is
very considerable and comprises some comparatively
small species. " Chacun a son gout !"

[Medicine,) — In our pharmacopoeia of former times a
decoction of snails was much esteemed as a remedy in
pulmonary complaints ; and great numbers of them were

IV.] INTRODUCTION. IxV

unmercifully pounded alive for that purpose. Even in
the present day snail-broth is said to be serviceable as a
lenitive. In France an extract from snails, called ' He-
licine/ is used in similar cases. The spongy plate of
the common cuttle [Sepia officinalis), calcined oyster-
shells, and the Limacella of the large slug [Limax maxi-
mus), as well as "crabs^-eyes^^ (or the concretions of
calcareous matter found in the stomach of the eatable
crab), were used during the last century in the prepara-
tion of certain medicines.

[Ornament.) — When the Romans were the masters of
these islands they ransacked not only our seas and estu-
aries for oysters (those from the Mediterranean being
very scarce and inferior in quality) but also our northern
rivers for pearls, which were extracted from the Unio
margaritifer. This shell, with its accompanying product,
is represented in the Frontispiece to the present volume.
The search for native pearls continued until a compara-
tively modern period, when it was superseded by the
successful prosecution of the true pearl-fishery in Eastern
seas, the valuable and lustrous produce of which threw
into the shade our comparatively worthless and dull
jewel. Other species of freshwater mussel, as well as
the oyster, ormer, sea- mussel, and cockle, and even the
periwinkle, occasionally yield pearls, but of an unservice-
able kind. It is evident, from an examination of the
shells in which such excrescences are formed, that they
are o\ving to an irregular and partial secretion by the
mantle of the nacreous and lamellar substance which
lines the inside of the shell. In all probability the
proximate cause is some extraneous body, and not dis-
ease as was formerly supposed. In freshwater bivalves
the irritating tenacity of parasitic insects and worms
[Limnochares Anodontce and Distoma duplicatum), and

Ixvi INTRODUCTION. [CH.

in marine bivalves the attacks of perforating annelids,
would be sufficient inducements for the shell-fish endea-
vouring to smother or keep out its assailants by secre-
ting an extra quantity of nacreous matter. The nucleus
of many pearls reveals the origin of their formation. A
communication made by Signor Antonio Villa in 1860
to the Literary and Scientific Athenseum at Milan (en-
titled " SulP origine delle perle^^), and another by Mr.
Robert Garner to the Linnean Society in December 1861
(^'^Note on the formation of pearls ^''), will well repay a
perusal by those who are interested in this curious sub-
ject. The unsuccessful experiments made a century ago
by Linne for the artificial production of pearls by the
Unio margaritifer in the rivers of Sweden (and for which
he took out a patent), and the ingenious process invented
by the Chinese, of putting little josses or images of some
incorrodible metal between the mantle and shell of an-
other freshwater mussel, so as to have them coated over
with several layers of pearly matter, are now well known.
Great quantities of the Mytilus edulis are said to have
been collected a few years ago in the estuary of the
Conway, as well as in the North of Ireland, and exported
on account of the Jews, for the purpose of fabricating
mock pearls out of their nacreous linings.

Another testaceous article of commerce in this coun-
try for ornamental purposes is the ^^ ormer " or ear- shell
(Haliotis tuberculata) , which is found abundantly in the
Channel Isles. Many tons of these sheUs are annually
gathered for the Birmingham market ; and their inner
coats of mother-of-pearl are sufficiently thick to make
buttons and studs, or for inlaying.

Shells of various kinds are collected wholesale from
the famous beach of the islet of Herm, and sent to
England for fancy-work. The Romans used shells for

IV.] INTRODUCTION. Ixvii

ornamenting their dwellings. GelFs ' Pompeiana^ (vol.i.
pp. 1.95, 196) contains an interesting description of the
celebrated ^^ Fountain of Shells," which appears to have
been decorated with the Tyrian murex and pilgrim scal-
lop ; and these shells are stated to have been " neither
calcined by the heat of the eruption nor changed by the
lapse of so many centuries." Cicero is said to have also
used shells in decorating a fountain at his Formian villa.
In our own country it was once the fashion to ornament
grottos in the same way.

Among other ornamental uses may be mentioned the
purple dye which is yielded by many shell -fish. The
Greeks and Komans extracted it from Murex trun-
culus and other species which we do not possess ; and
the process of dyeing constituted one of their most
important manufactures. An excellent article on this
subject, considered in a scientific and artistic point of
view, and entitled " Natural History of the Purple of the
Ancients," by Professor Duthiers of Lille, will be found
in the '^Proceedings of the Royal Society' for 1860*.
Dr. Bizio, a distinguished chemist, has also investigated
the nature and properties of these dyes ; and a learned
Scotch divine, the Rev. James Smith, has given, in the
' Zoologist ' for 1849, a classical and elaborate disqui-
sition on the same subject. The common dog-whelk
[Purpura lapillus) of our own rocky coasts, as well as
Murex erinaceus, Scalaria communis , and lanthina com-
munis produce the same colouring-matter, but in a
smaller quantity and of a much less vivid hue -, and it
has never been turned to any account. More than a cen-
tury ago, Borlase, in his ^ Natural History of Cornwall,^
mentions "The purple-marking whelke." He says, "the
juice which marks is in a separate bag, of a yellowish-

* Vol. X. p. 579.

lx\dii INTRODUCTION. [CH.

green when first drawn npon linen, grows a little ruddy
afterwards, till it comes to a faint purple ; when diy,
and the linen washed, it is of a good purple, and rather
betters by age and frequent washing/^ A cambric
handkerchief, which I stained more than twenty years
ago ^vith the dye from the purpuriferous gland of a
dog- whelk, still retains its ^-iolet hue. The pillar lip of
this shell often exhibits the same tinge of colour.
Nearly two centuries ago Lister tried, but in yain, to
fix the purple dye which is yielded in such quantity by
the Planorbis corneus, a freshwater snail.

{Economy .) — Other uses to which the shells of Moi-
lusca are sometimes applied in this country are numerous
and varied, although not very important. The valves
of the great pond-mussel [Anodonta cygnea) make here,
as well as in the North of France, excellent ere am -
skimmers. The mussels are procured by means of a
long pointed stick, which is inserted between the gaping
valves when the animal is feeding, and these closing on
the stick allow it to be drawn up out of the water. The
shell of the almond-whelk [Fusus antiquus) serves our
northern fishermen for a lamp, being suspended from a
nail in the wall or ceiling of their hut by a piece of
string, which is fastened round the shell in a triangular
fashion. The inside is filled with fish-oil, and a wick of
cotton or tOAv is put into the canal at the extremity of
the mouth. This I have seen prepared and used in the
Shetland Isles ; and I doubt whether any antique lamp
could excel it in elegance of shape. In the palmy days
of the Italian and Flemish schools, valves of a freshwater
mussel (named for this reason Unio pictorum) were used
by the gi'cat masters to hold their colom's. Although
they have been superseded by palettes for this purpose,
they are sold by many artists^ -colourmen in London,

IV.]' INTRODUCTION. Ixix

containing a preparation of gold or silver leaf for em-
blazoning. The valves of Pecten maximus and P. oper-
cularis make an ornamental as well as a usefal little
dish for scalloped oysters. Ormers are used in Guernsey
by farmers to frighten away small birds from the standing
corn^ two or three of these shells being strung together
and suspended by a string from the end of a long stick,
so as to make a clattering noise when moved by the
wind. Among other services which the Mollusca render
to man is their indicating an approach of rain or a
change of temperature. Several interesting facts with
respect to this hygrometrical property have been recorded
by Mr. B. Thomas of Cincinnati, U.S., in Dingler^s
^ Polvtechnisches Journal : " and as I am not aware that
similar observations have been made or published in
Great Britain, I venture to direct the attention of
naturalists who live in the countrv to this curious
inquiry. Mr. Thomas states that snails are more
reliable than leaves as natural barometers ; that, in con-
sequence of their never drinking, all the moistm^e they
receive is by absorption of rain, mist, or dew through the
tissues of their bodies, and this thev afterwards exude
at regular intervals, until they obtain a fresh supply
that the colour of certain kinds of snail varies according
to the quantity of moisture retained ; that tAvo days
before rain is about to fall they climb trees, which they
never do on other occasions : and that when thev are
observed to leave the herbage and get on rocks, it is a
certain prognostication of wet weather. Not many
years ago some wonderful stories were afloat as to the
galvanic nature of snails, which it was proposed to
turn to account as a medium of communication between
distant friends ; but this mystery has been eclipsed by
that of spirit-rapping, with Which the molluscan phe-

IXX INTRODUCTION. [CH.

nomenon may perhaps be classed. I have no doubt
that both of these mysteries ^^dll in due time become
equally obsolete and superseded by some other preter-
natural manifestation.

Injuries to Man, — The sum total of the mischief in-
flicted by the Mollusca upon Man is easily told and
reckoned; and it by no means counterbalances the
benefit he derives from them. At sea^ the damage done
to the woodwork of our piers by some kinds of ship-
Avorm {Teredo)) as well as by species of an allied genus
[Xylophaga], is indeed not inconsiderable ; and, before
copper or yellow-metal sheathing was used for protect-
ing the bottoms of our outward-bound vessels, these
marine scourges used to be justly dreaded. The noble
breakwater at Plymouth has also suffered^ although not
to any extent, from the excavations made in its more
exposed parts by a small bivalve {Saa:icava rugosd) ; and,
on some parts of the coast, beds of clay, which served as
natural barriers to w^ard off the action of tidal weaves on
our harbours, have disappeared in consequence of Pho-
lades having chosen to take up their abode in them. On
land, our molluscan foes are more troublesome than
formidable. Turnips and cabbages occasionally suffer
from the partiality of slugs to such succulent food ; and
of course we cannot help sympathizing with the gentle
florist who sees her pet carnation nipped in the bud and
ruined, in consequence of its having been selected by a
hungry or dainty snail for its supper. But the wire-
worm, fly, and grub are far more formidable pests to the
farmer and gardener, and no mollusk has been known
to attach itself parasitically to Man ; so that we may
safely challenge the entomologist in favour of the com-
paratively harmless subjects of this inquiry. Various
remedies have been proposed for preventing the ravages

IV.l INTRODUCTION. Ixxi

of slugs and snails in gardens. The application of lime
has only -a temporary effect ; and it may do as much
harm as good by overstimulating the chemical ingredients
of some soils. An ingenious method has been proposed
for protecting flowers by surrounding the bed with cop-
per and zinc wire, the former being outermost. The
wire should be laid on the ground and kept clear of
dirt, or fixed in such a way that the snails and slugs
must crawl over it to reach the flower-bed. In attempt-
ing to do this, they receive an electric shock, and they find
the sensation so uncomfortable or unusual, that they
never venture to transgress the forbidden boundary. Pro-
fessor Wheatstone assures me that he has no doubt such
a galvanic battery, or " slug-shocker,^^ would answer the
desired purpose.

Study of ConcJiology. — As Wordsworth nobly says^

" Know that pride.

Howe'er disguised in its own majesty,

Is littleness ; that he who feels contempt

For any living tiling, hath faculties

Wliich he has never used ; that thought with him

Is in its infancy."

Besides the interest which belongs to the studv of anv
branch of Natural History for its own sake, Conchology
has other claims on our attention in consequence of its
important relation to Geology. The first consideration
leads us to admire (if our limited sphere of mental vision
does not enable us to fully comprehend) the infinite
wisdom, harmony, and variety of that wonderful scheme
of creation which connects us with all our fellow- creatures
in one common bond of sympathy ; and it also teaches
us a lesson of humility, by showing that all our phy-
sical, and perhaps even our mental, faculties are shared
with us by other animals, far indeed inferior to us in
organization, but equally enjoying the prescient and

Ixxii INTRODUCTION. [CH.

beneficent care of Him through whom ^' we all live and
move and have our being." The second consideration
discloses to us the ancient history of the globe which
we inhabit; and, by reason of the durable nature of
molluscous shells, which is capable of resisting the
action of many forces that destroy other organisms, we
can apply our knowledge of their living structure and
habits to the elucidation of some of those difficult pro-
blems which are necessarily involved in the study of
Geology. For this reason, shells have been aptly called
the " Medals of Creation ; " and they are as important
to this science as coins are for making us acquainted
with the history of past nations. The advantages and
pleasures of the fascinating pursuit of Natural history
have been so often and so forcibly expatiated upon by
popular writers on the subject, that I can hardly hope
to add anything to promote its interest. As a branch
of education, the benefit of such studies is incalcu-
lable. They impart and inculcate, in the most agree-
able form, the faculty of sound reasoning, the continual
exercise of memory, a love of order, habits of observation,
♦ and, above all, the necessity of truth. No one can hope
to be a naturalist who is wanting in accuracy. As a
source of intellectual gratification, no pursuit of any
other kind can excel it. It is entitled to bear equal
rank with the pleasures of " Hope," " Memory," " Ima-
gination," and " Literature," all of which have had able
poets and writers to celebrate their praises ; and, although
the great orator of ancient days had letters especially in
his view, his admirable remarks Avill apply with equal
force to the study and love of Natural science. After
premising that such pursuits are most worthy of the
dignity of a thinking being, as well as most humanizing
and li])eral in their tendency, he says, ^' Other mental

IV.] INTRODUCTION. Ixxiii

occupations are not suited either to every time, or to
every age or place : these studies, however, foster our
earlier years and impart pleasure to our declining ones ;
they adorn our prosperity, and afford a refuge and solace
in adversity ; they delight us at home, but do not hinder
us in the discharge of our public duties; they are our
companions in the evening, abroad, and in the country "^/^
We are, I fear, too prone to indulge in a patriotic
boast, that our naturalists are more painstaking and
numerous than those of other nations ; but, with regard
to conchology, I must admit that we are far excelled by
the French. Moquin-Tandon stands preeminent in the
elucidation of the anatomy, physiology, and habits of his
native land and freshwater Mollusca ; and the number
of his countrymen to whose works on the subject of con-
chology he has refen^ed in his admirable ' Histoire Natu-
relle des Mollusques terrestres et fluviatiles de France '
is no less than 168. Can we show any work at all equal
to his as regards knowledge or labour on our own land
and freshwater Mollusca, or one-half of the above num-
ber as British writers on conchology, from Lister to
the present time? It is true that the marine fauna
of France has not been studied with equal assiduity and
success ; but our superiority in this respect may be owing
to the greater extent and variety of sea-coast which we
possess, as well as to our habits as a maritime people,
evidenced by the fleet of yachts and pleasure-boats which
crowd many of our harbours. In the thinly populated
and comparatively isolated region of Scandinavia, but
where opportunities of marine investigation are peculiarly
favourable, we find a host of able and zealous concholo-
gists (such as Nilsson, Loven, Sars, Hisinger, Steen-
strup, Oersted, Moller, Morch, Asbjornsen,Malm, Torell,
* Cicero, Or. pro Arch. poet. (ed. Anth.) p. 158.

d

Ixxiv INTRODUCTION. [CH.

and Bergh), who are not far, if at all, behind us in the
race, and are worthy successors of the great Linne,
Miiller, and Fabricius. Nor are the conchologists in
Germany, Italy, and other parts of the European con-
tinent few or unknown, as may be seen by reference to
the list of authors which is appended to this volume.

Pleasures and drawbacks. — In the pursuit of this as
well as of other branches of Natural History, not the
least part of our enjoyment is derived from sympathy
with other naturalists, or from what may be, perhaps
not inappropriately, termed *^^the freemasonry of the
craft/^ In my occasional visits to the Continent, I have
invariably experienced the greatest kindness from many
who were only known to me by name; nor is such
good-fellowship less hearty at home than it is abroad.
On one occasion my hobby of snail -hunting perhaps
saved me from some trouble or annoyance. In the spring
of 1850 1 was travelling mth my wife through Lombardy,
when, during a mid-day halt at Ro\dgo to bait the horses,
I could not resist taking a walk outside the barriers,
accompanied by our courier, who had been previously
useful to me in assisting to collect shells. At the end
of an hour or so we returned, but found at the barrier-
gate an Austrian official who demanded our passports.
This was at first a poser, as I had left in the carriage at
Rovigo the document which was at that time so indis-
pensable for passing through the North of Italy. All
explanations appeared to be unavailing, when the courier
pulled out of his pocket a collecting-box full of live snails,
and at once satisfied the smiling official by allowing this
proof of our innocence with the remark, " Ecco, Signore,
i nostri passaporti \"

The reminiscences and association of ideas arising out
of the work of collection are often very pleasant, but

IV.] INTRODUCTION. IxXV

occasionally not unfranglit with sadness. A specimen
will in after days bring back to our minds many an in-
cident, which else had been forgotten, of woodland and
seaside rambles, of nautical adventure, of excursions in
foreign lands, and (above all) the companionship of be-
loved but lost friends, who have, alas ! left this fair world
and us. The bitter drop will arise from the midst of
the sweet and bubbling spring of pleasure, and give us
pain even among the encircling flowers. It is still the
same as when Lucretius wrote —

" coronse, serta parantur ;

Nequicquam : quoniam medio de fonte leporum
Surgit amari aliquid, quod in ipsis floribus angat."

Incidents of the pursuit. — It is not always easy to
enlist fishermen in the cause of science. Most of them
readily promise, but seldom keep their word ; and they
do not seem to comprehend how any sensible person can
take an interest in such pursuits, as they regard all the
products of the sea, which are not fish, as " trash." In
the Shetlands, however, I have received much assistance
from the long-line fishermen, who brought me all the
whelks (or " buckles ") which were caught sticking to
the bait on the deep-sea (or " haaf ") fishing-banks ; and
they did this regularly and for several weeks together.
M. Drouet complained bitterly of the difficulty which he
experienced in inducing the native fishermen at the
Azores to bring him any shells, even although he offered
to pay them liberally for their trouble. They told him
they did not choose to alter their habits ; and one of them,
after seeing the French conchologist very busy collecting
some small land-shells, said to his muleteer one day in
confidence, " C^est bien dommage, mais ce seigneur
frangais est pris de la!" and, while saying this, he sig-
nificantly touched his forehead. How far some persons,

^2

Ixxvi INTRODUCTION. [CH.

who affect to consider themselves as more enlightened
than the poor fisherman, may share in his remark, I will
not pretend to inquire, — although it is by no means
certain that, by their so doing, they are not themselves
gi'eater objects of pity than the crazy naturalist.

A curious question may be raised as to the right of
any person to collect and appropriate shells or other ob-
jects of Natural history. According' to the strict inter-
pretation of the law, all trespasses upon private lands
without the consent of the occupier are unjustifiable;
and it makes no difference whether the trespasser is a
naturalist in pursuit of his amusement, or whether he
is simply taking a walk for the sake of exercise. For-
tunately for scientific research, great forbearance is
almost invariably shoA\Ti to naturalists by the proprietors
or occupiers of land, even although the latter may take
no interest in such pursuits; and the instance to the
contrary, of which the gifted Hugh Miller complained,
in his " Cruise of the Betsey,^^ was probably owing to his
not having exercised the common courtesy of requesting,
from a sectarian opponent, permission to collect fossils
on his land. I could also very well imagine that the
owner of a "neat villa^^ might have a decided objection
to his favourite fish-pond being invaded by a party of
conchologists or entomologists armed with ladles or nets,
especially if they considered it quite unnecessary to go
through the ceremony of asking leave. In the case of
manorial wastes or commons, over which the lord and
his tenants have certain and well-defined rights, not ex-
tending to such things as objects of Natural history, no
question of this kind is ever likely to arise ; and the
legal maxim, "de minimis non curat lex,^^ would pro-
bably apply to this case. The majesty of the law would
iiot condescend to notice such trifles as a few shells, in-

IV.] INTRODUCTION. Ixxvii

sectSj or plants. The same rule would, in all probability,
hold good in the case of researches for Natural-history
purposes on those parts of the sea- shore which lie be-
tween high and low-water mark, and especially if they
were made exclusively in the pursuit of science and not
for commercial gain. In a seigniory or honour, com-
prising several manors, which has an extensive frontage
to the sea, on the coast of Gower in South Wales, the
lord is entitled to receive small annual sums, varying
from sixpence to half- a- crown, by way of acknowledg-
ment of his rights, for the privilege of gathering cockles,
mussels, lobsters, and crabs, as well as ore-weed or wrack
which is used as manure in that part of the country ;
and distinct licenses are granted for these privileges.
With respect to the vast tracts of the sea-bottom which
extend beyond the low-water mark of spring tides, the
right of the public to explore them with the dredge or
any other device for scientific purposes has never yet been
questioned. Even in France, where the garde-marine
have strict orders not to allow any net or similar imple-
ment to be on board of a vessel or boat on that coast
when oysters are out of season, I have found no difficulty
in obtaining the requisite permission to use my dredge, and
it was granted readily and with the utmost courtesy.

In a commercial point of view, British shells do not
fetch high prices, compared with what is given by col-
lectors for some exotic rarities. The late Dr. Turton
stated, in his useful but unsystematic little book called
' A Conchological Dictionary of the British Islands,^
that a complete collection of our native shells had
been estimated to be worth its weight in silver. This
was certainly a singular mode of valuing such property,
considering that many of our minute shells, which are so
light that hundreds of them would scarcely balance the

Ixxviii INTRODUCTION. [cH.

smallest weight used by apothecaries, are among our
greatest treasures. As is not uncommon in such cases,
beauty of form or brilliancy of colour does not always
represent the same value as rarity and the consequent
difficulty of acquisition. As much as £S has been given
for a single specimen of Panopma Norvegicay which
would be considered by all but conchologists as a very
ugly and coarse shell. Some of our scarcer kinds of
Fusus also command good prices ; and it is said that the
magnificent specimen of Buccinum acuminatum, which
once belonged to Lord Kilcoursie and is now in our
National Museum, cost the Trustees (or rather the
country) no less than £\2. Mr. Damon of Weymouth,
as well as Mr. Rich, Mr. Sowerby, and Mr. Wright, all
of Great Russell Street, London, are the principal dealers
in this line ; and a priced list of British shells may be
had of the first-named enterprising person.

CHAPTER V.

DISTRIBUTION.

EXTENT. ORIGIN OF BRITISH MOLLUSCA. FOSSILS. GULF-
STREAM.

Extent, — It has long been notorious that distinct
groups of MoUusca, as well as of other animals and of
plants, occupy more or less extensive areas of the earth^s
surface. This distribution is generally more limited with
regard to terrestrial kinds than to those which have an
aquatic habitat. The temperature of the sea at certain
depths is constantly the same everywhere, and it does not
appear to be affected by that of the surface. One species

v.] INTRODUCTION. IxXlX

of the marine Testacea [Saxicava arctica or rugosa) is said
to be almost " cosmopolite/^ being diffused over all seas
from Baffin^s Bay to that which washes the shores of
Australia. It has also a wide range of habitat in the
same seas, extending from low-water mark down to a
depth of 100 fathoms and upwards. The distribution of
Terebratula caputserpentis is nearly as extensive in re-
spect of area and depth of water. This is spread not
only over all the European seas, but also (although under
other names, viz. septentrionalis and Japonica) over a
great part of the North and South Atlantic, Pacific, and
Indian Oceans. In both of these instances the variation
of form and sculpture is very considerable, being coinci-
dent with, and probably caused by, the extent of habitat.
Philine aperta is fomid in every part of the seas of
Europe, as well as in Simon^s Bay at the Cape of Good
Hope, and in the Australian seas. Saxicava, Terebra-
tula, and Philine represent three different orders of Mol-
lusca ; and I have cited them, for that reason, as exam-
ples of the extent of what is termed " geographical distri-
bution.^^ The limits within which some other kinds of
Mollusca occur are' also very wide ; and the Gulf-stream
transports to great distances pelagic or floating kinds,
such as Hyalcea, lanthina, and Spirula. But, considering
all these to be exceptions, it may be assumed as a
general rule, that there is no specific conformity between
the marine products of the temperate and tropical
regions, especially between the Mollusca which inhabit
that part of the North Atlantic Ocean which confines
the coasts of Europe, on the one hand, and the rest of
the Atlantic Ocean, as well as the Pacific, Indian, and
great Southern Oceans, on the other hand. No authen-
ticated case has been recorded of any marine West
Indian species having been found living in the European

IXXX INTRODUCTION. [CH.

seas^ or vice versa. The most striking diflPerence appears
to be with respect to those species called '^^ littoral/''
which are more subject to climatal influence than the
inhabitants of deep "water. In the case of freshwater
shells^ the same rule and exceptions seem to prevail.
The common pond-snail {Limn(Ea peregra) is diffused
over the whole of Eui'ope, as well as over considerable
tracts of North America and Northern Asia ; and it is
only by calling them " representative " species and gi^'ing
them other names that any pretence can be made for
distinguishing certain British species of Limncea, Physttj
and Pisidium from those which are brought from very
distant parts of the world. This diffusion of freshwater
shells has been attributed to the chance transport by
birds ; but I am inclined to believe that it had a different
and very remote origin_, and that it took place long before
the present distribution of land and water. Land-shells
are much more restricted in their range ; and with the
exception of two minute species {Helios pulchella and
Cochlicopa lubrica), besides a few other snails which
have been introduced^ and as it were domesticated, by
Man, T am not aware of any kinds which are common
to both hemispheres. In Thibet and Cashmir, indeed,
many of the land-shells are said to belong to the same
species as inhabit Great Britain ; but these are probably
the descendants of ancient immigrants during the Gla-
cial epoch from more northern latitudes. The mode by
which the Mollusca have become distributed throughout
the different and remote areas in which they are now
found living or in a fossil state has in all probability
been the same from the time of their creation. Their
natural tendency is to disperse either in search of food
or from a migratory instinct ; and, although the pace
of a snail is proverbially slow, time and the action

v.] INTRODUCTION. IXXXI

of marine currents will effect for tlieir countless race
and generations that which is denied to animals of
greater locomotive powers but of less number. A small
tribe of gigantic animals would be far more easily ex-
terminated than a host of puny shell-fish. When the
Mollusca have, in the course of ages, become thus spread
over a certain space, their further progress is arrested
by some geological convulsion or change. The land or
sea-bed, which they inhabited or roamed over, is either
suddenly or gradually covered with water or dried up ;
plains are raised and converted into mountains; trees
and succulent vegetation disappear; deserts become
swamps, and rivers estuaries ; the sea-shore sinks many
fathoms deep ; the climate of the land and the tempera-
ture of the sea are altered ; and conditions unfavourable
to molluscan life succeed. By some of these means
many species are entirely destroyed within the area
which is the scene of such a convulsion or change ;
others are reduced in number and dwindle away ; while
a few of a more hardy nature survive and continue to
flourish. Frequent alterations in the relative level of
sea and land, accompanying the alternate elevation or
depression of more or less extensive districts, will doubt-
less account in a great measure for the irregular distri-
bution of some species and groups of Mollusca. But
shell-fish do not " retire " or " retreat," as has been
conjectured by some naturalists. Their instinctive im-
pulse is to advance only. When aquatic mollusks sud-
denly and unwillingly find themselves on dry land, or
snails are immersed in a sea-bath for a long time, they
have no alternative but to die at their posts like brave
soldiers ; while their comrades are starved to death, owing
to the failure of the commissariat.
With respect to the distribution of the marine Mol-

c?5

Ixxxii INTRODUCTION. [CH.

lusca in the European seas, many theories have been
from time to time advanced, each of which would divide
this great area into several distinct parts, or what are
called "provinces/' Professor Milne -Edwards, in the
' Annales des Sciences Naturelles' for 1838, proposed
the following division — 1. Scandinavian, 2. Celtic, 3.
Mediterranean. Mr. S. P. Woodward, in his verv useful
little treatise, entitled ' Manual of the Mollusca ' (the
last edition of which was published in 1856), considered
that there are four provinces, viz. 1. Arctic, 2. Boreal,
3. Celtic, 4. Lusitanian; and these, according to this
writer, were "framed upon the widest possible basis.''
In a posthumous work of the late Professor Edward
Forbes, which was most ably continued and edited by
Mr. Godwin- Austen in 1859, under the title of ' The
Natural History of the European Seas,' a fifth province
(the "Mediterranean") has been added to those above
enumerated. The latter scheme of distribution has been
recently adopted by Mr. M ^Andrew in the ^ Annals of
Natural History' for December 1861.

Now, although such a division into "provinces" or
separate areas of distribution is very plausible, and pos-
sibly may be maintainable in the same sense as the divi-
sion of Mankind into distinct races, a definite principle
seems to be wanting in their construction. If we com-
pare any one of these schemes with another, a very
material discrepancy is observable as to the relative
limits of the proAdnces. For instance (not to travel far
from home), Milne-Edwards considered that the Celtic
province had its southern boundary in the Straits of
Gibraltar ; Woodward restricted the same limit of this
province to our own coasts ; while Forbes advocated its
extension " from the Bay of Biscay to the Baltic Sea."

The principle of definition, as well as of construction.

v.] INTRODUCTION. Ixxxiii

has been also left in an unsettled and unsatisfactory
state. Woodward lays it down as a rule, that, ^' in order
to constitute a distinct province, it is considered neces-
sary that at least one-half the species should be peculiar,
a rule which applies equally to plants and animals/^
On the other hand, M ^Andrew, after admitting that a
considerable portion of the species of Mollusca inhabiting
any one zoological province may be found in other pro-
viiices, says, "It is not by a simple comparison of the
list of species that we can determine the similarity or
divergence of the fauna of separate localities, as the differ-
ence between them may consist in a few characteristic
forms, which may be especially developed in each.^^ This
wide divergence of opinion as to the rule or "law^' of
distribution, between two such able and experienced
naturalists, renders further inquiry into the facts of the
case indispensable, especially when it is considered that
so many of the " species ^^ referred to by Woodward and
of the " forms ^^ (by which it is presumed genera are
meant) indicated by M 'Andrew are questionable or still
sub judice. That genera-makers may be found who will
separate such forms as Trivia from Cyprceaf Erato from
Marginella, and Admete from Cancellaria, cannot be
helped, — although most naturalists deprecate and disavow
such trifling distinctions. But until a complete concord-
ance has been established and recognized between all the
forms, whether generic or specific, of the Mollusca which
inhabit any one area, a solid and reliable foundation
cannot be obtained for erecting the superstructure of
distribution. No conchologist, whose mind is free from
prejudice, either as regards the authority of names or of
theories on the subject in question, can detect any greater
difference between specimens of Mitra Groenlandica from
Spitzbergen and Mitra ebenus from Naples, than he can

Ixxxiv INTRODUCTION. [CH.

between recent shells of Natica clausa from the North
Cape and fossil shells of the same species from Palermo.
14; is an indisputable fact that whenever the Mollusca of
any part of the European sea-coast have been carefully
examined, the species which are there found exhibit a
greater conformity than had been previously supposed
with the species inhabiting more remote parts, the
general area being thus widened and every portion of it
brought into closer relation to the others. The former
test of percentage is in that case fallacious and no longer
to be depended upon. Thus we find that in Philippics
invaluable work on the Sicilian Mollusca, w^hich was
completed in 1844, 513 species of marine Testacea are
described. After making a small deduction for dupli-
cates [e. g. six out of eight species oi Anomia, and some
Rissoce), about 500 species may be regarded as distinct.
The treatise appended to the last volume of that work
contains a table of comparison between the Mollusca of
the Mediterranean and those of the British seas ; and
in this table 127 out of the above number of 500 are set
down as belonging to our fauna. This gives a rate of
only about 25 per cent. The result of my own exami-
nation of the marine Testacea of another part of the
Mediterranean * is very different from that of Philippi —
especially when it is taken into account that my exami-
nation only occupied three or four weeks, while Philippi
was engaged for many years in a continuous investiga-
tion. The total number of species which I found or ex-
amined on the Piedmontese coast in 1855 was 375 ; and
of this number I identified no less than 205 as British.
This gives a rate of nearly 55 per cent. ; and taking

* " On the Marine Testacea of the Piedmontese Coast," Ann. & Mag.
N.H., February 1S56, p. 155-188. An Italian translation by Professor
Capellini has been published at Genoa.

v.] INTRODUCTION. IxXXV

Philippics number of 500 as the standard of comparison
it is 41 per cent., after making some allowance on the
one hand for species unnoticed by Philippi but included
in my list, and on the other hand for species described
by him but not observed by me, although many of the
latter are unquestionably British. The discrepancy in
these results is the more remarkable when it is con-
sidered that only twelve years elapsed between the pub-
lication by Philippi and myself of our respective re-
searches. When the number and extent of similar in-
vestigations have been increased, and sufficient attention
has been paid to the discrimination of species, in order
to their identification with the names imposed upon
them by different authors, it is highly probable that a
still further correspondence will be found to exist between
the Testacea of the Mediterranean and British seas than
has been imperfectly indicated by me. One great diffi-
culty in making such a concordance has arisen from the
habit of merely collating the names given by authors, in-
stead of examining and comparing the specimens described
by them ; and I believe that many an unsuspected link
in the chain of specific identity would be detected by
pursuing the latter com'se of investigation. It was only
by mere accident, while I was lately looking over the
excellent collections of French sea-shells belonging to
M. Petit de la Saussaye at Paris and to Dr. Baudon
at Mouy, that I recognized, among some specimens
which they had received from M. Martin of Martigues,
and which he had procured by dredging in a deep part
of the Mediterranean off the coast of Provence, not only
the Buccinum Humphrey sianum of our northern sea
(under the name of B. Fusiforme, Kiener), but also the
Rissoa abyssicola of Forbes, which had hitherto been
supposed to be exclusively confined to the Hebridean

Ixxxvi INTRODUCTION. [CH.

channel. This last was called " Rissoa scabra/' although
it was not the species so named and described by Philippi.
Bulla Cranchii and other "northern " forms also occurred
among these Mediterranean shells, but under names
distinct from those which British conchologists have
given to them. If we can divest our minds of the popular
or received impression, that the diversity between species
which inhabit the extreme northern and southern por-
tions of the European seas is both general and well-
marked, we shall not be surprised at the discovery that
many species of Mollusca which at present bear different
names (such as Mitra Grcenlandica and M. ebenus) are
really the same or undistinguishable from each other, or
that even the Astarte incrassata of the Mediterranean is
only a variety of that polymorphous and northern species,
A. sulcata.

The testaceous Mollusca of our own seas have been
separated by Forbes and Hanley into no less than nine
different types — viz. Lusitanian, South British, Euro-
pean, Celtic, British, Atlantic, Oceanic, Boreal, and
Arctic. The limits of these so-called types have not
been defined mth any degree of precision ; and, although
the proposed division is highly ingenious, it can scarcely
be considered as justified by the present state of our
information on the subject. It seems to me, after a
long and careful study of the question, that no more
than tw^o groups (which are apparently distinct from
each other) can be recognized in a geographical point
of view ; and for these I would suggest the general, but
not inappropriate, names of "Northern" or North-
European, and " Southern " or South-European. It is
extremely difl&cult to fix the limits of even these com-
paratively wide areas of distribution ; but the " facies "
of each group is manifest to some extent in the lit-

v.] INTRODUCTION. IxXXvii

toral or shallow-water species, and especially in sucli
conspicuous and striking forms as those of Trichotro-
pis and Neara in our northern seas and Haliotis and
Galeomma on our southern coast. Taking the wider
basis of the European seas, I am not aware that any
species of Conus or Ringicula is found living in the
North, or that any species of Margarita or Lacuna in-
habits the South. It is, however, not unlikely that when
the sphere of our observation has been enlarged, and
a complete concordance obtained between the species of
Testacea from different parts of Europe, the exceptions
from a general distribution will become fewer and at
last disappear, and perhaps that only one common area
may be hereafter recognized. The distribution which at
present exists must be referred to a past state of things.
There can be no doubt that the area of diffusion was
formerly much more extensive than it is at present, and
that it has been restricted by subsequent causes.

Keverting, however, to the proposed scheme of distri-
bution by Forbes and Hanley, as well as to the sugges-
tion now advanced by me, our marine Testacea may be
classed as follows : — -

1. Northern;

2. Southern;

3. Oceanic, or occasional visitants.

The first of these divisions corresponds with the '^^Arctic^^
and "BoreaP^ types of Forbes and Hanley, and the
second to their '^ Atlantic " and " Lusitanian ^' types.
Their "South British," "European," "Celtic," and
" British " types indicate mixed or neutral ground, and
partake both of northern and southern characters. The
third division answers to their " oceanic " type," but it
can hardly be regarded as indigenous to the British
seas.

IxXXviii INTRODUCTION. [CH.

The same basis of classification may be adopted for our
land and freshwater shells. These have been separated
by Forbes and Hanley into only three types, viz. North
European, Central European, and South European. The
third division of the foregoing category (viz. Oceanic) is
of course inapplicable to this group ; but in other re-
spects the principles which regulate their distribution
are nearly the same as in the case of their marine ana-
logues. The difference of aspect between these and
marine species, so far as regards their distribution, is very
noticeable, although, in this point of view, many of the
land and freshwater shells exhibit a greater resem-
blance to littoral species than to those which inhabit
deeper water, by reason of their external conditions.
Temperature or climate is one of the principal agents
in regulating the diffusion of land and freshwater Mol-
lusca ; and their limits are often sharply defined by a
strait of the sea or a mountain-range. Some conspi-
cuous land-shells (as Helix fruticum and H. incarnata)
live in the North of France, although they have never
been found in this country unless in a subfossil state
and as the relics of a past state of things. Some of our
common snails do not pass the Grampian Hills. In
Zetland the Helix aspersa is a total stranger, fortunately
for the poor gardens of the natives ; and only a scanty
remnant of the tribe have succeeded in crossing the
Pentland Firth or maintaining their existence in these
barren isles. Freshwater shells are not so restricted in
their distribution, although one of our native species
(Limncea involutd) has hitherto been discovered in only
one locality — assuming that this species is distinct from
L. glutinosa, which does not appear to have been found
in the same district. A table of distribution of the
land and freshwater shells which inhabit the British

v.] ' INTRODUCTION. Ixxxix

Isles, with reference to other countries and to our upper
tertiary deposits, will be subjoined to this volume; and
I propose to give in the succeeding volumes similar
tables to show also the distribution of our marine
Testacea.

Origin of British Mollusca. — As regards the '' history"
or proximate origin of the British Mollusca, I fully agree
with Forbes and Hanley, w4io stated in the Introduction
to their work (vol. i. p. xxxv), that " the true source of
our Molluscan fauna was first manifested by the assem-
blage of Testacea preserved in the deposit called Coralline
Crag," although my investigation of the Crag shells has
not led me to form the same conclusion that they did,
viz. that most of these ancestors of our living shell-fish
are " of those forms which we regard as Southern types."
The opportunities afforded by a study of the Crag strata
are far superior to any, that we at present possess, for the
investigation of our marine Mollusca. We can explore
the ancient sea-bottom for many miles on dry land, and
as leisurely as if the bed of the present ocean were un-
covered and laid dry by some violent convulsion of
nature ; and this examination can be extended not only
superficially, but also by making sections of the bed to
a depth of thirty feet, so as to have the whole of its con-
tents exposed to view. In attempting a similar explora-
tion of the present sea-bottom, we are only able, at con-
siderable expense, with some personal discomfort, and
in such weather as we too frequently meet with in this
climate, to scrape up with the dredge a few bagfuls of
sand or mud mixed with shells ; nor can we hope to
examine in this way more than a very few inches in
depth. Many deep-burrowing shell-fish altogether escape
our observation, or are only procured by chance.

In order to ascertain the exact nature of the relations

XC INTRODUCTION. [CH.

which exist between this ancient Molluscan fauna and
that which at present inhabits our seas and coasts^ I have
not only examined the Crag strata in company with
Mr.Prestwich^ whose experience in this important branch
of geological science is so w ell known, but I have also
carefully gone over the extensive collection of Crag shells
made by Mr. Searles Wood and presented by him to
the British Museum. In pursuing the latter examina-
tion, I compared the collection with the valuable and
elaborate work of Mr. Wood, published by the Palseon-
tographical Society, in which the specimens were de-
scribed and figured, as well as with Mr. Davidson's
memoir on the Tertiary Brachiopoda in the same series
of publications ; and I afterwards collated the result of
this examination with a great many books and special
treatises on the recent conchology of Europe and the
Arctic regions. I likewise derived no small assistance
in the investigation from the opportunity I had of
consulting the large collection of recent shells in our
National Museum, and for which I would here return
my best thanks to Dr. Baird, the courteous and able
Curator of this department. This examination has satis-
fied me that, out of 386 species of marine shells belong-
ing to the Coralline Crag formation, no less than 167 are
identical with those which still live in the British seas.
Of the remaining 119 species, 7 are said to be exclusively
Northern, and 19 Southern forms, while 93 appear to
be extinct or are as yet unascertained to be existing.
This gives a proportion of very nearly 60 per cent, for
those marine species of the Coralline Crag which at pre-
sent inhabit our seas. Out of the 167 species which I
have recognized as British, 27 have been described or
recorded by different authors as Northern, and only 24
as Southern forms, — taking the Arctic circle as the

v.] INTRODUCTION. XCi

southern limit of the one^ and the Bay of Biscay as the
northern limit of the other area. The greater part are
common to the North and South. In considering the
Crag Mollusca^ the percentage of existing or recent spe-
cies would be very much larger if we were to include
the Bed Crag and the Mammaliferous or Norwich beds,
and especially if we were to add the pleistocene or post-
pliocene strata which immediately overlie those beds —
in fact the whole of our upper tertiaries. It is highly
probable that all the Mollusca which lived during the
periods represented by the newer strata still survive in
some part or other of those vast tracts of sea-bed which
lie between the North Pole and the Pillars of Hercules.
The discovery which is continually being made of missing
links, as well as the increase of experience which results
from a more extensive and perfect knowledge of the Mol-
lusca, must tend to alter the rate of percentage as between
recent and fossil forms. I am aware that the late Pro-
fessor D^Orbigny (in his ^ Paleontologie Fran9aise^), Pro-
fessor Agassiz (in his ^ Essay on Classification^), as well
as Hall, Pictet, and others, have contended that there
is no specific identity between any of the Tertiary and
recent Mollusca ; but the peculiar views which some of
those naturalists entertained and advocated, as to the
successive creation of species, may have influenced their
judgment. At all events, he must be a bold species-
maker who can pretend to distinguish Crag specimens of
the common European cowry, and of many other species,
from those which now live in the adjacent seas ; and their
varieties and monstrosities also, both in a fossil and recent
state, coincide in the most minute particulars, the only
difierence being that the latter are glossy and compara-
tively transparent, while the former are dull and opaque.
Even the lAngula of the Wenlock Silurians could not be

Xcii INTRODUCTION. [CH.

distinguished by Mr. DaAddson (who has especially and so
thoroughly studied the fossil Brachiopoda) from a living
species (L. anatina) by any characters which he could
recognize as constituting a valid specific difference.

These considerations^ however, involve the difficult
question of the origin of species ; and I will not pursue
them further, except by suggesting the very great proba-
bility that all existing species have descended by modi-
fication from primeval forms, but at the same time not
admitting the hypothesis of Mr. Darwin that such forms
were very few or perhaps unique. In those strata which
contain our earliest records of the world^s history, as
great a diversity of form is exhibited in the groups which
we call genera and species as in the existing fauna ; and
it seems evident that the plan of the Creator, so far as
we can comprehend it, has not been that of progressive
development.

Nor will I here venture to touch upon the equally
abstruse, and more speculative, hypothesis as to the
radiation of species from several centres of creation.

But I am digressing. For the reasons above stated
with regard to the connexion between the Coralline
Crag and British shells, I am inclined to regard this
formation as the starting-point, and as it were the
cradle of our moUuscan race. The fauna of Europe,
Northern Asia, the Cis- Atlantic zone of Africa, and a
great part of North America appears to have been
closely related at a comparatively recent epoch, and
to constitute only one area of origin. Many species of
Mollusca once existed at both extremities of this vast
district. Mya truncata, Cyprina Islandica, and Bucci-
num undatum live in the Arctic and North Atlantic as
well as in our own seas, and their remains or shells
are found in Sicily. Cancellaria costellifera occurs in

v.] INTRODUCTION. XCiii

our Coralline Crag beds ; and it survives in the North
Atlantic under the name of C. Couthouyi. The Cardita
senilis of the same beds is the C. sulcata of the Medi-
terranean; and the Crag C. scalaris is the C. borealis
of Conrad and inhabits the coast of Massachusetts and
the Arctic Sea. Many other instances of a similar kind
might be given. Some species appear to be more hardy
than others and have consequently resisted considerable,
and perhaps frequent, changes of temperature or climate.
Littoral or shallow- water species are of course the most
liable to be exterminated or affected by such changes,
and the instances above given are of that kind. Many
of the Thibetan and Algerian land-shells belong to
European species ; and thus the chain of relationship to
which I have referred is complete.

Our upper Tertiary fossils offer tolerable evidence that
the climate of this country was, previously to or at the
time of their being deposited, of a Glacial or Arctic
character, as will be seen by referring to the table of
distribution of our land and freshwater MoUusca at the
end of this volume. Nearly all the land-shells which
occur in the pleistocene strata, but are not now living
in Great Britain [e. g. Helix fruticum, H. incarnata, and
H. ruder ata) , are decidedly Northern species, inhabiting
Finland and Scandinavia ; and even the Alpine variety
of H, arbustorum appears to be the only form of that
species which has been found in our Tertiaries. Among
the freshwater shells in this same formation, Corbicula
(or Cyrena) flwninalis presents, however, an apparent
but remarkable exception from the above indication of
our ancient climate having been so severe, if the habits
of that species have not undergone any change. The
Corbicula is only known to live at present in Asia. But
it may be observed that a common European freshwater

XCiv INTRODUCTION. [CH.

shell [Physa acuta) inhabits the West Indies^ and that
such MoUusca seem to have a greater aptitude for dif-
fusion, or a greater capability of endui'ing different
climates, than land Mollusca, being (as some naturalists
would call it) more " mundane/^

Fossils. — It is sometimes very dif&cult, if not impos-
sible, to distinguish what are called "fossil" from "re-
cent " shells of marine species, if they are " dead " or
found in an empty state. When the shells in question
belong to species which are not known to inhabit the
locality where they occur, this difficulty may give rise to
some interesting questions. In most cases, the nature
of these shells is manifest from their dull appearance
and greater opacity, contrasted with fresh shells of the
same species ; and it does not require much experience
to determine whether single valves of Pecten Islandicus,
which are not unfrequently taken at comparatively great
depths in our northern seas, are fossil or recent, although
they occasionally retain their coloured markings. This
species is abundant in the Arctic regions, and during
the Glacial epoch appears to have been diffused over a
large tract of the European sea-bed; but I am not
aware that it is now found in a living state south of the
Bohuslan district of the Swedish coast. But a perplex-
ing case has occurred with respect to some shells which
were taken by the dredge in the Irish Sea off the coast
of Antrim. The locality is a submarine deposit called
the "Turbot bank," lying about five miles south of
Lame and having a depth of about 20 fathoms at low
water. This bank was repeatedly and diligently explored
during several successive years by Mr. Waller, Mr.
Hyndman, and other naturalists ; and I had the advan-
tage of not only examining the produce of their labours,
but of taking part in an expedition which was made in the

v.] INTRODUCTION. - XCV

autumn of 1859 for the express purpose of endeavouring
to ascertain the nature of this submarine deposit. The
result of these researches was recorded by Mr. Hyndman
in the ' Reports of the British Association^ for 1857 and
1858; and some observations on the same subject by
Mr. Waller wiU be found in the ' Journal of the Royal
Dublin Society^ for 1858 (vol. ii. p. 29-34), as well as by
myself in the ' Annals and Magazine of Natural History^
for August 1858 and February and September 1859. The
association or collection in the same spot of forms which
have been usually regarded as Northern and Southern is
one of the most peculiar features of this inquiry. Colum-
bella Holbollii, Scalaria (?) Eschrichti, Natica clausa,
Margarita cinereaj and Trophon Scalariformis (all of
which are decidedly ^' Arctic ^^ species), Crania anomala,
Trichotropis borealis, and Puncturella Noachina (which
were regarded by Forbes and Hanley as " boreal '^ types),
Terebratula caputserpentis, Lima subauriculata, and Fis-
surella reticulata (being, according to the same authors,
''^ Atlantic ^^), Argiope cistellula, Trochus Montagui, and
Pecten tigrinus C^*^ British ^^), Astarte sulcata, Buccinum
undatum, and Venus Casina (" Celtic "), Artemis lincta,
Corbula nucleus, and Trochus cinerarius {" European ^^),
together with Rissoa striatula ("Lusitanian^^), aU of
them in the same fresh and apparently recent condition
and (with the exception of those included in the first and
last categories) in a living state, were congregated to-
gether in this locality, as if on purpose to refute certain
theories of geographical distribution. With respect to
those species which were not taken there in a living
state, it was surmised that they were fossil, or had been
carried to the spot by marine currents. Some of the
specimens in question I submitted to Dr. Carpenter,
whose researches on the microscopical structure of mol-

XCvi INTRODUCTION. [CH.

luscous shells entitle his opinion to the greatest possible
weight ; and he professed that he was unable to detect
any apparent difference between the texture of these
specimens and of others (which were unquestionably
recent) belonging to the same species and placed with
them for the sake of comparison. No chemical or other
test seems to be known, by which the texture of shells
called fossil, and certainly of very remote antiquity, can
be distinguished from that of recent shells. The gloss
and the greater or less transparency of the latter, con-
trasted with the dull aspect and opacity of the former,
afford the only criteria of distinction; but it is not
known how far the continued submersion of shells for
many ages in the sea, where they are placed beyond the
reach of atmospheric influence, may have prevented any
change in their external appearance. The shells of Mol-
lusca would seem to be nearly indestructible by the
ordinary action of air and water, and especially when
their structure is crystalline and compact. The term
'^ recent '^ is, of course, comparative in point of time. But
a few of the shells from the Turbot bank, belonging as
well to some of the species in question as to other species
which are undoubtedly indigenous and exist there in a
living state, have every sign of being fossil, and are pre-
cisely similar in appearance to the shells which are found
in the Clyde and other beds of a pleistocene formation.
Some of these beds occur in the neighbourhood of the
Turbot bank, and contain Yoldia lanceolata, Leda pyg-
mcea, Hypothyris jjsittacea, and other shells of a decidedly
Arctic character ; but only one of these species (viz. Leda
pygnKBO) has been observed in the Turbot- bank dredgings,
and of this species Mr. Waller found a living specimen.
Columbella Holbollii, Scalaria (?) Eschrichti, and Mar-
garita cinerea (being three out of the five Arctic species

v.] INTRODUCTION. XCVll

which have been taken on the bank) have not^ so far as
I am aware, ever been detected in any of our Tertiary
strata. The two other Arctic species (Nalica clausa
and Trophon Scalay^iformis) inhabit the upper coasts of
Norway, as well as more northern seas. The first-named
species has a range, according to M ^Andrew and Barrett,
from the shore to 150 fathoms. It occurs in the Eed
Crag, as well as in almost every pleistocene bed which
has been examined in this country ; and I noticed it in
the collection of Dr. Van Geuns at Utrecht, among some
shells which he had found in the Subapennine deposit
of Palermo. This species is not included in Philippi's
list of Sicilian fossils. The distribution of the other
species appears to have been equally extensive; and I
have a fresh specimen, recently inhabited by a hermit
crab, which was dredged fr-om deep water oflP the Aber-
deen coast and obligingly presented to me by the late
Professor Macgillivray. It is quite possible that a plei-
stocene bed may have formerly existed in the spot which
is now occupied by the Tui-bot bank, and that the con-
tents of this bed may, by the action of the tide or marine
currents, have become mixed up with the existing pro-
ducts of the adjacent sea-bed ; and the appearance of
some of the shells to which I have refen^ed might
warrant such a conclusion. But, inasmuch as many
relics of the Glacial epoch, such as Leda pygmaa and
Area raridentata, still survive in a few and widely sepa-
rated parts of that extensive area which was once sub-
ject to Arctic conditions, it will not be surprising if all
the species I have thus mentioned as doubtful inha-
bitants of our seas should also have lingered on in their
old quarters and be really British. The conjecture that
these shells may have been accidentally transported by
sul^marine currents from the Arctic Sea to the Irish

XCviii INTRODUCTION. [CH.

coast does not rest upon any foundation. I was satisfied,
by information which I obtained on the spot and in the
course of my di'edging-operations, that no submarine
cun'ent sets in that direction, nor any which could have
brought the shells from a distance ; and the same con-
viction is entertained l)y tlie able and zealous naturalists
who have so carefully and during several years in suc-
cession explored many square leagues of this remarkable
sea-bed.

Gulf -stream. — This " deus ex machina" seems al-
ways to be called into requisition, in order to explain
any apparent anomaly in the distribution of marine
Mollusca. In the minds of many persons it ranks with
the comet in its mysterious effects. It is quite true that
the scientific world, and indeed all who take any interest
in the works of Nature, are under the greatest obliga-
tions to Commodore Maury for the lucid account he
has given, in his ^ Physical Geography of the Sea,^ of
this really wonderful phenomenon. But with regard to
the subject of the present inquiry, I cannot help express-
ing a doubt whether the effects of this great '' river in
the ocean '' have not been much overrated.

The partial glimpse which we have hitherto been able
to obtain of the results from the recent expedition of
Otto Torell and other Swedish naturalists to Spitz-
bergen shows that the Gulf-stream was found not to
exert any influence on animal life in that region, it ap-
pearing to be entirely of a glacial nature *. From careful
inquiries which I made in several parts of the eastern
coast of Zetland last year, I was satisfied that the Gulf-

* While tliis last sheet is passing through the press (22 May, 18G2),
Professor Forchhamraer has read before the Royal Society a valuable paper
on the composition and density of sea-water. His observations as to the
Gulf-stream tend to sliow that it cannot affect the distribution of animal
life in the lower zones of the sea.

VI.] INTRODUCTION.

XCIX

stream does not set upon any part of that coast. All
the driftwood that was washed ashore was of Norway
fir, and came from the opposite coast. Dr. Lukis in-
forms me that the Gulf- stream has now been ascer-
tained not to impinge on any part of the Channel Isles,
although the Sargasso weed and the seeds of tropical
plants are occasionally thrown up on those shores, after
having been deflected and drifted by marine currents.
Much evidently remains to be done in defining its exact
course in northern latitudes, and in making accurate
observations as to its influence on the fauna and flora,
as well as on the temperature, of different parts of
Europe.

CHAPTEK VI.

HABITAT.

STATIONS. ZONES. ABUNDANCE OF MOLLUSCAN LIFE. GEOLOGI-
CAL RELATIONS. CHANNEL ISLES. EXOTIC AND SPURIOUS SPE-
CIES. SEA-SIDE SKETCH.

Stations. — The subject of this chapter is closely con-
nected with that of the last ; but it seems more conve-
nient to divide it. Having considered the British Mol-
lusca with reference to their European and general
distribution, I now propose to give a short account of
their native habitats and to take a home view of the
matter.

The MoUusca may be divided into land, freshwater, and
marine. Their respiratory organization mainly results
from the nature of their habitat, or, as botanists would
term it, their " station.^^ All land-snails breathe the free

e.2

C INTRODUCTION. [CH.

air^ by means of lung-like ca\dties or pouches which they
possess. Some kinds of freshwater snails have a similar
apparatus; but they are also enabled to extract occa-
sional supplies of oxygen from the water, and are thus not
entirely dependent on their air-pouches. Others of this
kind are furnished only with gills, which they use like
iishes. In the genus Valvata the gill is external and
shaped like a feather; and the animal has also an au-
xiliaiy branchial organ, which resembles another ten-
tacle. The respiratory system of the marine Mollusca,
with the exception of a very few littoral species, is bran-
chial ; and in some kinds the gills are external. Bivalves
have usually two leaf-like gills, which are arranged sym-
metrically, one on each side of the body. In the Bra-
chiopoda, however, the brachial organs (according to
Mr. Hancock) subserve the function of gills, although
in one genus (Lingula) the lobes of the mantle may, to
a certain extent, be considered specialized breathing -
organs.

There are some peculiarities with respect to habitat that
are interesting to geologists. Some kinds of freshwater
univalves, both those called Pulmonobranch [i.e. respiring
by means of lung-like pouches), and Pectinibranch (i. e.
respiring by means of comb-like gills), have the faculty
of enduring a partial change or difference in their usual
habitat, which would be fatal to other kinds. The
Swedish naturalist Nilsson relates that two species of
JAmjKBa described by him, as well as Neritina fluviatilis,
live in the Baltic, adhering to sea-weeds, and sometimes
at a distance from the mouth of any river. With these
live certain marine Mollusca, such as the common mussel
and cockle, Mya arenaria and Tellina Balthica (or soli-
dula)^ all of which, however, are of a dwarf size. Lim-
noia is Pulmonobranch, and Neritina is Pectinibranch.

VI.] INTRODUCTION. ci

The same peculiarity _, but not of so permanent a cha-
racter, has been observed in the case of a freshwater
bivalve. The common pond-mussel [Anodonta cygnea)
is said to live in the river Trent at Bottesford in Lincoln-
shire, which is salt at high water. The fresh water,
being lighter, forms the upper stratum ; while the sea-
water covers the bed of the river inhabited by the Ano-
donta. A small Pectinibranch univalve (Hydrobia ulva)
inhabits indifferentlv salt and brackish water ; another
(H. ventrosa) frequents only the latter ; while a third
{H. similis) lives, in company with Bythinia tentaculata
and other freshwater univalves, in water which is nearly
fresh. The usual habitat of the genus Melampus (which
is Pulmonobranch) is the sea-shore ; but one species
occurs high up in estuaries, where the water is more
fresh than salt. M. Marcel de Serres is of opinion that
the habitat of Dreissena polymorpha (a kind of mussel
which abounds in many of our rivers and canals) was
originally marine, from the circumstance of the shells
being found in tertiary strata of marine formation. The
Russian traveller, Pallas, who first discovered or made
known this species, described one variety of it as marine
and the other as inhabiting fresh water. Many of the
marine Mollusca which live on the sea-shore (some of
them even beyond the reach of the tide) pass the greater
part of their time out of water ; and the same remark
applies to some freshwater snails, such as Limn^a
peregra and Ancylus fluviatilis, which are as often found
on dry land as in their natural element. Succinea putris
(a land-snail) appears to be almost amphibious. Many
genera of bivalve Mollusca contain certain species which
are marine and others which have a freshwater habitat.
Even Teredo, Pholas, and Area are in this category. The
smaller Crustaceans seem also to be very indifferent to the

cii INTRODUCTION. [CH.

nature of their habitat in this respect. Mr. Spence Bate,
who has so diligently and successfully studied our native
shrimps, informs me that Gammarus locusta, which only
inhabits the sea, is scarcely distinguishable from G. flu-
viatilis, which would be instantly killed by being put
into salt water. Professor Lilljeborg has discovered in
some of the inland freshwater lakes of Denmark several
Arctic species of marine Crustacea, which appear to have
survived the Glacial epoch, and to have adopted from
necessity a new habitat, in consequence of the gradual
elevation of the land. And the result of the researches
made by Dr. E. von Martens on the occurrence of
marine animal forms in fresh water, which was published
in ^ Wiegmann's Archiv^ for 1857, shows that 10 out of
44 divisions or groups of Crustacea, and 6 out of 52
divisions of Mollusca, are common to the sea and fresh
water. Fish have no less than 23 out of 55 divisions
similarly circumstanced as to habitat ; but some of these
are well known to migrate annually from the sea to
rivers that flow into it, for the purpose of depositing
their spawn. Such peculiarities of habitat form one of
the stumblingblocks of geology ; and it is fortunate that
the cultivators of this science are not obliged to place
their sole reliance on the palseontological contents of the
strata which they wish to investigate, as they have also
the mineral composition, as well as the relative juxtaposi-
tion, of those strata to guide them in the investigation.
Zones. — It had long been known that different parts
of the sea-bed w^ere inhabited by special forms of animal
life; but Risso, the celebrated naturalist of Nice, was
the first who proposed its distribution into zones of
depth. His theory was derived from observations on the
Mediterranean fishes. The late Professor Edward Forbes
added much to our knowledge of such distribution ; and

VI.] INTRODUCTION, ciii

his valuable researches on the Invertebrata of the ^Egean
and our own Seas enabled him to define these zones
with considerable precision. Professors Loven and
Sars, as well as Oersted, have made us acquainted with
the range and limits of marine life in the Scandinavian
seas.

In framing any scheme for dividing the sea-bed into
separate areas of molluscan habitability, according to
their depth_, it must be borne in mind that the extent
and produce of these areas vary greatly, and depend upon
the inclination and mineral nature of the coast. That
part of our sea-bed which is circumscribed by the line
of soundings may be divided into four distinct areas or
zones, of different width and depth ; and I will endeavour
to define briefly their limits, nature, and contents.

The first is the Littoral zone, or the shore, which
fringes every part of our coast and lies between tide-
marks, being laid bare when the tide retires. Wherever
the coast is steep and rocky, this zone is very narrow.
Where it shelves gradually and is sandy (each of these
conditions being probably consequent on the other), the
strand frequently extends seaward for a mile or even
further. Where it is composed of cliffs, such as chalk or
boulder- clay, the beach is pebbly, and its width is
usually intermediate between that of the two other cases
I have mentioned. The pebbles are derived from the
wearing-away of the cliffs, either in the course of their
original elevation above the sea-level (which in many
cases appears to have been slow and gradual), or else by
the combined action of the atmosphere, rain and frosty
or of the tide and waves. This pebbly beach is sometimes
succeeded by a belt of larger stones or boulders, and
that again by a strip of sand, mud, or clay, as we advance
to meet the tide. In each of these cases the nature of

civ INTRODUCTION. • [cH.

the shore^ strand, or beach depends on the composition
of the strata which form that part of the land which is
opposed to the sea. The rocks lying between tide-
marks are clothed with sea^veed, which supports a
numerous and peculiar group of Mollusca. Among
those on our OAvn coasts may be enumerated various
species of Littorina (or periwinkle), Lacuna, Trochus,
Rissoa, Chiton, Patella (or limpet), Furpura lapillus (or
dogs^-whelk), and a stunted variety or form of the com-
mon mussel. In the small rock-pools, which are left
by the receding tide, and are generally lined with Coral-
Una officinalis and other small seaweeds, as well as under
loose stones, will be found many small shells of various
sorts, including Poronia rubra, Modiola discors, Skenea
planorbis, Rissoa parva, Cerithium reticulatum, and the
fry of other species. The highest part of this zone,
which the sea does not cover for more than two or three
hours out of every twelve, is inhabited by two kinds of
Melampus (M. bidentatus and a variety of M. myosotis),
Otina otis, Assiminia littorea, Truncatella truncatula,
a variety of the common limpet, Littorina Neritoides,
and some of the numerous varieties of L. rudis. The
first three of the above species are Pulmonobranch.
That part of the littoral zone which consists of sand,
gravel, or mud is frequented by various genera of bi-
valve Mollusca, such as Mya, Solen, Tellina, Donax,
Mactra and Tapes, as well as by Mytilus edulis. Within
this zone submarine peat, chalk, and trias or new red
sandstone, harbour several kinds of Pholas ; Scrobicu-
laria piperata burrows into clay ; calcareous rocks are
perforated by Saxicava rugosa ; and fixed wood is drilled
in every direction by the destructive Teredines or ship-
worms. Wherever a river or stream empties itself into
the sea, a strong reflux is caused by the advancing tide.

VI.] INTRODUCTION. CV

which has the effect of casting on the shore a collection
of spolia marina, dislodged by the ground-swell from
considerable depths^ as well as of many land and fresh-
water shells, which have been washed down by the river
or stream and thus become mixed with those from the
sea. This phenomenon frequently occurs in some of our
upper tertiary and more recent deposits, and shows the
regularity with which such physical operations have been
repeated dui'ing periods of the duration of which we can
form no conception. In the same zone are also com-
prised estuaries, which form deep but narrow indenta-
tions of the sea- coast, and are the channels, as well as
the outlet, of tidal rivers. The water of these estuaries
is always more or less brackish. They are inhabited by
peculiar MoUusca, viz. Assiminia Grayana, Melampus
myosotis, and the several species of Hydrobia above men-
tioned. The few pelagic mollusks which occasionally, but
unwillingly, \4sit our seas, are also met with in the littoral
zone, being cast on shore generally after a continuance
of westerly gales. These consist of species oi lanthina,
Spirula Peronii, and a few Pteropods, some of which
have but a doubtful claim to be considered indigenous
productions of our seas. The present zone has been
subdivided by Forbes and Hanley into four intermediate
lines or strips, each of which is said to be inhabited by
its own peculiar set of Mollusca ; but the great variety
exhibited by our seaboard, as well as its geological for-
mation, seems scarcely to warrant such a subdivision.
For instance, Trochus umbilicatus and T. lineatus, which
are assigned by these authors to the fourth or lower-
most line, in which they usually occur on our western
and south-western coasts, inhabit the second line on the
shores of the Bristol Channel, as well as those of the
north-west of Ireland.

Cvi INTRODUCTION. [CH.

The second zone is called the Laminarian, from the
belt of that kind of seaweed which girds all the rocky
parts of our coast-line. It is seldom laid bare^ except at
very low spring-tides ; and it is generally much narrower
than the littoral zone, in consequence of the rocks, to
which the Laminaria or tangle is attached, dipping sea-
ward and being covered with sand beyond the direct and
more immediate influence of the tide. This zone may
be said to extend from low- water mark to 10 fathoms.
The mollusca which inhabit it chiefly belong to Patella,
Acmcea, Trochus, Lacuna, Rissoa, and Jeffreysia, all of
which are phytophagous or vegetable-eaters, as well as
the Nudibranchs or sea-slugs, which are mostly zoopha-
gous. Where the coast is sandy, this zone is entirely
wanting and is merged into the one above or below it,
so far as regards its zoological contents. The extent of
each zone mainly depends on its capability as a feeding-
ground; and the same species are frequently common
to every zone, when their nature is alike and they are
not prevented by an intervening barrier of sand or rock
from spreading from one zone to another. To this cause
is probably owing the great variation in the depth to
which many species attain. The common mussel, which
is usually found within tide-marks, has been recorded by
Dr. Walker as living in the North Sea at a depth of
140 fathoms or 840 feet. Cyprina Islandica, which in
most seas inhabits depths of from 30 to 140 fathoms,
occurs on the coast of South Wales at low- water mark ;
and our little cowry {CyprcBa Europcea) has a range from
low-water mark to 100 fathoms.

The third zone has received the name of ^^ Coralline,^'
from the quantity of nullipore [Melobesia polymorpha) ,
which is a stony coral-like plant, and in many places
covers large tracts of the sea-bed. Its width varies con-

VI.] INTRODUCTION. CVli

siderably ; but its vertical range may be stated as ex-
tending from 10 to 50 fathoms. As a general rule^ rocks
do not occur in this zone^ especially in the deeper part
of it — stones, gravel and sand (sometimes mixed with
mud) being its chief characteristics. These mineral
conditions to some extent regulate the nature of the
Mollusca which are here found. The whelk-tribe, as
well as many Nudibranchs, frequent the stony or, as it
is called, " hard '' ground ; and different sorts of bivalves
take up their quarters in the other, or ^' soft," ground.
Seaweeds are scarce in this zone and are generally
absent from its lower regions ; so that most of the Mol-
lusca which inhabit it are animal- eaters, — some being
sarcophagous, others zoophagous, and many of them
preying on each other.

The fourth and last is called the Deep-sea zone, and
reaches from 50 fathoms to the greatest depth comprised
within the line of soundings. Both this and the last-
mentioned zone contain our most productive fishing-
banks ; and the floor of these submarine areas is exceed-
ingly uneven, and diversified by many an unseen hill and
dale. The deep-sea zone appears to have nearly always
a soft bottom, consisting of a much finer sediment than
that which covers the bed of the coralline zone. The
only vegetable organisms which are found in it are tiny
and almost microscopic Diatoms. It is inhabited by
various kinds of Mollusca, all of which are, probably
from necessity, animal-eaters. They appear to exceed in
number, as well as in variety, the inhabitants of any of
the other zones, judging from the scanty opportunities
which occur for investigating the contents of this exten-
sive sea-bed. The point of zero in the scale of sub-
marine life has not yet been, and perhaps never will be,
found.

CVlll

INTRODUCTION. [cH.

Abundance of Molluscan life. — The whole surface of
our globe teems Avith a mass of animal and vegetable
life, to which the MoUusca contribute by no means an
inconsiderable quota. Owing to the solid and perma-
nent nature of their shells, many fossiliferous strata
are almost entirely composed of such exuviae ; and this
process of accumulation is still going on in the exist-
ing sea-bed to an enormous extent. No one can have
had any experience in exploring the bottom of our
own seas, and examining our tertiary strata, ^vith-
out noticing how closely the contents of a well-filled
dredge, taken from a submarine shell-bank, resemble
the same quantity of material dug out of a crag-pit ;
and perhaps nothing can give a more striking idea of
the incalculable lapse of time which must have taken
place in the history of the world, than the formation of
these strata which, after all, are only a few pages of
the great book. We here see layer upon layer of organic
remains heaped up and compressed, to a depth of thii^ty
feet, each layer being only a few inches deep, but repre-
senting numerous and successive generations that have
long passed away.

It has not yet been ascertained to what depths mol-
luscan life extends. The late Sir James Clark Ross,
in the interesting account of his Antarctic Voyage (vol. i.
p. 202), says, " I have no doubt that, from however
great a depth we may be enabled to bring up the mud
and stones of the bed of the ocean, we shall find them
teeming with animal life ; the extreme pressure at the
greatest depth does not appear to affect these creatures.
Hitherto we have not been able to determine this point
beyond a thousand fathoms ; but from that depth shell-
fish have been brought up with the mud.^^ Still greater
depths have been lately reached in recovering the Me-

VI,] INTRODUCTION. cix

diterranean telegraph-cable^ and with the same results ;
and the forthcoming work of Dr. Wallich on " The
North- Atlantic Sea-bed" will doubtless contain some
important observations on the existence and forms of
animal life at extreme depths in the Arctic Sea.

Although it does not come strictly within the scope
of the present treatise^ I cannot help contrasting the
fecundity of the sea with the comparative steriHty of the
land^ as regards animal life — if we consider the countless
shoals which swarm in every part of the ocean and
thickly cover its bed, and that the air_, even in its lower
zones, is almost lifeless. The lines in the 12th Canto of
the ' Faerie Queene ^ seem to corroborate this idea, al--
though not so intended by the poet : —

" O what an endlesse worke have I in hand,

To count the seas abundant progeny,
Whose fruitfull seede farre passeth those in land,

And also those which wonne in th' azure sky !

For much more eath to tell the starres on hy,
Albe they endless seeme in estimation,

Then to recount the seas posterity :
So fertile be the flouds in generation.
So huge their numbers, and so numberlesse their nation.

Witnesse th' exceeding fry which there are fed.
And wondrous sholes which may of none be red."

Geological relations. — In local lists of MoUusca, and
even in more elaborate works on this subject, it has been
the custom to state that the habitat of certain species is
restricted to " calcareous soils," ^' oolitic formations,"
"limestone," "chalk," "trap," and other strata. I believe^
however, that mineralogical conditions have very little
to do with the habitat of any of the Mollusca, nor with
their comparative abundance or scarcity in any locality,
except so far as food, moisture, or shelter, as well as the
secretion of their shells, is concerned. Such conditions

ex

INTRODUCTION. [cH.

are merely what logicians call '' accidents/^ All the earth
(even granite and felspar) is said to contain calcareous
matter, although the proportion is of course greater in
some formations than in others. The case of two com-
mon and conspicuous land-shells occurs to me with
reference to this question. Helix lapicida is directed
by Forbes and Hanley^ " to be sought for in limestone
and chalky districts." It is common, however, in the
trap formation of the Lower Harz, as well as in the
molasse of Switzerland. According to Moquin-Tan-
don the Cyclostomata " aiment surtout les terrains cal-
cairesf;" but our only species (C elegans) is tolerably
abundant in Jersey, where there are no calcareous strata.
It would be easy to adduce many similar instances to
prove that the habitat of Mollusca is not so restricted,
as has been stated, in their geological relations. But
there is no doubt that, with regard to land- shells,
both granite and peat (which are at the opposite ends
of the geological scale) are equally unfavourable to mol-
luscan Hfe; because the former is not easily disinte-
grated and converted into mould, so as to support vege-
tation, and the latter, being chiefly composed of the bog-
moss (or Sphagnum), is either innutritions or distasteful
to snails. The same observation applies to fir- woods,
which do not appear to be inhabited by the Mollusca.
With respect to the marine Mollusca, it may be ob-
served that the phytophagous kinds will be found in
abundance wherever sea-weeds flourish, and that in the
deeper zones of the sea, in which such vegetation is
absent, an ample supply of animal food is not wanting.
But the substance of molluscous shells undoubtedly de-
pends on the nature of the soil ; and carbonate of lime
seems to be as necessary to most snails for the secretion
* Brit. Moll. iv. p. 66. t Hist. Moll. Fr. t. ii. p. 492.

VI.] INTRODUCTION. Cxi

and formation of their dwellings^ as egg-shells, or lime,
are to laying-hens. The shells of our common garden-
snail (H. aspersa) in Guernsey are remarkably thin, owing
to the deficiency of calcareous material; and specimens
oiH.pomatia, from granite formations in alpine districts,
are far inferior in weight to those from our challv downs,
although they do not differ in size.

Channel Isles. — Some conchologists entertain a doubt
whether the Mollusca of Guernsey and the other Chan-
nel Isles ought to be included in the British fauna,
because of their greater proximity to the French than to
the English coast. The Sarnie fauna and flora (although
undoubtedly peculiar) have, however, been hitherto con-
sidered by our best naturahsts as belonging to Great
Britain; and our Continental neighbours have never
claimed them as their own, although they have appro-
priated Corsica, or " annexed" it to France, in a Natural-
history point of view. Some of the Mollusca, taken in
that part of the English Channel which is adjacent to
Guernsey, are peculiarly Southern forms and have not
occurred in any other part of our seas. Nearly all of
them are very conspicuous and handsome. They are
Cardium papillosum, Argiope decollata, Haliotis tuber-
culattty Murex corallinus, Triton cutaceus, and T. nodi-
ferus. Of these six species only three (viz. Haliotis tuber -
culata, Triton cutaceus, and T. nodiferus) are noticed by
either De Gerville, or CoUard des Cherres, as having been
found on the opposite coast of Brittany ; and Bouchard-
Chantereaux has not included anv of them in his list of
marine shells found on the coast of Normandy. Dr.
Bowerbank has identified some of the sponges from
Sark as northern species. In respect of geographical
position, some of the Channel Isles are not so very much
nearer France than England. Guernsey is distant about

Cxii INTRODUCTION. [CH.

sixty miles from the Bill of Portland^ and about thirty-
five miles from Cape Carteret on the coast of Brittany.
All the six species which I have above mentioned are
found on our side of the Guernsey coast.

Exotic and spurious species. — The fauna of any par-
ticular country (although isolated^ like Great Britain)
cannot be satisfactorily studied by itself and without
reference to the fauna of other parts of the same district.
The habit of observing and comparing the Mollusca of
different countries is of undeniable advantage; and it
may be favourably contrasted with the tendency of local
naturalists and collectors to exaggerate trifling differ-
ences^ which would have disappeared on a more extended
survey. The enlargement and increase of such expe-
rience have the same beneficial effect on a mind inclined
to the cultivation of science, as travelling in a foreign
land, with one's eyes open, has in expanding the intellect
and impro\4ng our social nature. By such means our
notions become in each case less contracted ; and (which
is perhaps of more importance) our ideas with regard to
the labours of other naturalists are imbued with a spirit
of greater liberality and charity than if we had pursued
the selfish course of working in our own sphere without
any intercourse or sympathy with them.

The " index expurgatorius," containing the species of
Mollusca which are termed "spurious" (being those
which have been admitted into catalogues of British
shells, but have not been proved to be indigenous to
this country), is now very small, owing to the labours of
Dr. Gray in revising the list of our land and freshwater
shells, and of the authors of the ^ British Mollusca ' in a
similar revision of our marine shells. The casual intro-
duction of tropical or foreign shells by means of ship-
wrecks or ballast is not so frequent as has been supposed.

VI.] INTRODUCTION. CXiii

— although it sometimes occurs^, and I have several times
picked up on the sea-strand, near a port resorted to by
foreign vessels, shells which had evidently come from
ballast. Strangers of this kind may, however, be de-
tected without much difficulty by the application of in-
trinsic evidence. A much more fertile and perplexing
source of error, as regards the introduction of spurious
species, consists in collectors of Mediterranean, as well
as British, shells not taking sufficient care to keep these
collections separate; and too much praise cannot be
given to Mr. M ^Andrew, whose labours and experience
in the investigation of the European MoUusca are so
well known, for his extreme accuracy in the above re-
spect.

' 'Sea-side sketch, — Having offered this imperfect view of
the British Mollusca, with regard to their structure and
habits, and their relation to other animals and ourselves,
as well as to their distribution, I cannnot refrain from add-
ing another page to this unusually long introduction, to
exhibit a charming and truthfal picture by my lamented
and highly gifted friend. Professor Edward Forbes : —
" To sit down by the sea-side at the commencement of
ebb, and watch the shore gradually uncovered by the
retiring water, is as if a great sheet of hieroglyphics —
strange picture-writing — were being unfolded before us.
Each line of the rock and strand has its peculiar cha-
racters inscribed upon it in living figures, and each figure
is a mystery, which, though we may describe the appear-
ance in precise and formal terms, has a meaning in its
life and being beyond the wisdom of man to unravel.
How many and how curious problems concern the com-
monest of the sea-snails creeping over the wet sea- weed !
In how many points of view may its history be considered !
There are its origin and development — the mvsterv of

cxiv INTRODUCTION. [CH. VI.

its generation — the phenomena of its growth — all con-
cerning each apparently insignificant individual; there
is the history of the species — the value of its distinctive
marks — the features which link it with higher and lower
creatures — the reason why it takes its stand where we
place it in the scale of creation — the course of its distri-
bution— the causes of its difiusion — its antiquity or no-
velty— the mystery (deepest of mysteries) of its first
appearance — the changes of the outline of continents and
of oceans which have taken place since its advent, and
their influence on its own wanderings. Some of these
questions may be clearly and fairly solved ; some of them
may be theoretically or hypothetically accounted for;
some are beyond all the subtlety of human intellect to
unriddle. I cannot revolve in my mind the many que-
ries which the consideration of the most insignificant of
organized creatures, whether animal or vegetable, sug-
gests, without feeling that the rejection of a mystery,
because it is a mystery, is the most besotted form of
human pride *.'^

* Nat. Hist. Eur. Seas, p. 12.

In his tarn parvis, atque tarn nullis, qujc ratio ! quanta vis ! quam
inextricabilis perfectio ! — Pliny.

AQUATIC.
Class I. CONCHIFERA, or BIVALVES.

Body of an oval form, and usually compressed at its sides :
mantle divided into two lobes which correspond with the valves
of the shell. It has no distinct head : but inside the mantle,
and within its folds, is contained a mouth ; and the edges of
the mantle in those bivalves which have it open, or of the
tubes which are formed by it in those which have it closed, are
often fringed with short filaments, which serve the purpose of
tentacles or feelers. Some kinds have also imperfect or rudi-
mentary eyes, which are set in the interstices of those fila-
ments where the mantle is open. The foot is tong*ue-shaped,
and sometimes capable of considerable extension. It is used
by the animal for creeping or attaching itself to other bodies
by a byssus or bundle of muscular threads. Reproductive
system similar to that of the monoecia among plants — both
sexes being united in the same individual, which is capable of
fertilizing itself. The whole, or most important part, of the
body is covered by a shell, formed of two valves which are
connected behind by a hinge or ligament. Respiratorij organs
consisting of gills.

Order LAMELLIBRANCHIATA

*

Gills 4, semicircular or leaf-shaped, arranged in pairs on
each side of the body.

This Order comprises all the freshwater bivalves of
Great Britain ; and they are divided into three families.

Family I. SPH^MID^.

Body subglobular : mantle open in front, and forming at the
posterior side a cylinder, which is often divided near its open-
ing into two tubes. The cylinder or tubes are contractile and

* So called from the leaf -like form of the gills.

B

2 SPH.ERIID^.

extensile, — the longer tube (when there are two) being used
for respiration and nutrition, and the shorter tube for excre-
tion. The outer edges of the mantle, as well as of the cylinder
or tubes, are simple, and not furnished with papillae or fila-
ments. The mouth consists of a slit which is placed between
the anterior adductor muscle and the base of the foot, and it has
two small triangular lips. Foot wedge-shaped, thin, and ca-
pable of great extension.

Shell composed of two thin, oval or subtriangular valves,
which are more or less inequilateral. The valves are of equal
size. The outer surface of the shell is protected by a dehcate
epidermis, and the inside is slightly lined with nacre. The
hinge is furnished with cardinal and lateral teeth, to enable the
valves to lock more closely into each other when the shell is
shut. The ligament is external, although it is sometimes seated
so far within the hinge as to be scarcely visible on the outside :
it is placed at the longer, or posterior, side of the hinge.

The animals of this family are ovoviviparous^ retaining
the fry for some time between the mantle and gills.
They are tolerably active in their habits, using their foot
for crawling like a leech ; and some of them float with
the beaks of their shell downwards, or suspend them-
selves in that position to the under surface of the water
by means of a very fine byssus which they secrete and
spin with their foot. In the winter they appear to be
torpid, and bury themselves in the mud, lil^e other fresh-
water bivalves. During this period they probably cannot
procure their food, which consists of animalcula. Speci-
mens which I had in confinement soon after Christmas
never put out their tubes, and only used their foot to
creep under some moss which was in the vessel. This
they did as often as I removed them from their place of
shelter.

The Spk(S7mdce closely resemble their marine repre-
sentatives, the Kelliadxe, which are also ovoviviparous :
])ut the mantle is more open and the ligament external in
the present family; while the ligament is internal in the

SPH^RIID^. 3

Kelliadce, and the beaks of their shell are much more
acute. This curious and distinct group of freshwater
bivalves has been carefully investigated by our country-
man, the Rev. Leonard Jenyns ; and his monograph on
the British species of Cyclas and Pisidium, which was
published in the Transactions of the Cambridge Philo-
sophical Society for 1832, is full of valuable and inter-
esting information. Since that time the labours of natu-
ralists have been divided even in this humble and com-
paratively obscure study. Several French conchologists,
especially MM. Normand and Gassies, have separately
devoted themselves to a critical examination of their
native species of the above genera; and lately M. Bour-
guignat has favoured the scientific world with an elabo-
rate essay on the recent and fossil species of Sphcerium
(or Cyclas) which have been found in France. This
essay was published in the ' Memoires de la Societe des
Sciences physiques et naturelles de Bordeaux/ tome i.
1854. The only recent species described or noticed by
him, which is not also found in this country, is the
Cyclas solida of Normand. It appears to form an inter-
mediate link between Sphcerium and Cyrena; and M.
Bourguignat has separated it from the former under the
generic name of Cyrenastrum. I mention this in con-
sequence of the Cyrena (or Corbicula) fluminalis oc-
curring so frequently as a fossil in our upper tertiary
beds, and in the hope that the Cyrenastrum solidum may
also turn up in the same deposits, and lead to an eluci-
dation of the question how the limits of the true Cijrena,
in its living state, have become so restricted since the
glacial epoch. The only other genus of this family [Fisi-
dium) has lately had an equal amount of laborious atten-
tion bestowed on it by an eminent member of the French
corps of conchologists. The ^ Essai monographique sur

B 2

4 SPH^RIID.E.

ies Pisidies Francaises/ by Dr. A. Baudon of Mouy;, may
be profitably consulted by those who take a particular
interest in this subject. It was published at Paris in
1857, and contains fifty-five pages, and five plates of ad-
mirably executed figures. All the species of Pisidium
described by Dr. Baudon, with the exception of P. co-
nicum, appear to be also common to this country ; but
one of them (the P. Recluzianum of Bourguignat), which
was at that time imperfectly known to the author of this
essay, and its generic relation to Pisidium properly ques-
tioned by him, happens to be a marine shell, viz. the
Turto7iia minuta, M. Gassies having procured specimens
from Belfast, where it is abundant.

Genus I. SPH^'EIUM>^ Scopoli. PI. I. f. 1, 2.

Body nearly equilateral : mantle having a double tube.

Shell slightly inequilateral ; beaks placed near the centre
of the dorsal margin.

This genus was founded in 1777 by Scopoli (Introd.
ad Hist. Nat. p. 397, no. 88) in sufiiciently explicit
terms, taking the Tellina cornea of Linne as the type ;
but Bruguiere (who was followed by Draparnaud and
other authors) afterwards proposed for the same genus
the name of Cyclas, by which it has been more generally
known. Owing, however, to the bibliographical re-
searches of Dr. Gray, the older and equally appropriate
name of Sphcerium was restored by him in 1847 ; and
this latter name has been since adopted by Morch, Bour-
guignat, and other continental conchologists. The Jaw
of priority seems to require the recognition and use of
this name. I am aware that in thus advocating the
substitution of another (although an older) name for that

* From its spherical shape.

SPH^RIUM. 5

of Cyclas, whicli has so long received the sanction of
naturalists^ the principle of usage may be to some extent
violated^ and that it may be urged, with great reason,
that LimrKEa and Succinea ought to give place to Nerito-
stoma and Auricula, which Klein had previously pro-
posed, as well as Physa to that of Adanson's genus
Bulin ; but I am only in the present case following the
lead of experienced naturalists, and the conflict of au-
thorities ought to be determined by the strict rules of
justice. The word being derived from cr^acptov, it ought
not to be spelt Sphmrium, as has been done by some
authors.

1. Sph^kium corneum^, Linne.

Tellina cornea, Linn. Syst. Nat. ed. xii. p. 1120. Cyclas coi-nea, Forbes &
Hanley, Brit. Moll. ii. p. 113, pi. xxvii. f.3, 4, 5, 6.

Body white, gre^dsh, brown, or yellowish : tuhes rather
long, slightly tinged with flesh-colour : foot somewhat longer
than the shell, of a faint rosy hue towards its extremity.

Shell subglobular, nearly equilateral, compressed iu front,
rather thin, glossy, yellowish horn-colour, with often paler
bands or zones which denote the periods of growth, and occa-
sionally having faint streaks of brown which radiate from the
beaks towards the front margin, shghtly but closely striate
transversely, and marked by obscure hnes in a longitudinal
direction, so as to give the surface a reticulated appearance
under a high magnifying power : ejndennis rather thin : beaks
almost central : ligament short and narrow, scarcely visible on
the outside : inside bluish-white : Tiiyige strong, having a double
cardinal tooth in each valve, besides two lateral teeth in the
right, and four in the left valve ; the cardinal teeth are very
small, but distinct ; the lateral teeth form elevated ridges or
plates, and are subtriangidar at their extremities, those on the
anterior side being the largest : ^nuscidar scars or impressions
faint, owing to the thinness of the interior hning : pallial scar
scarcely discernible. Length 0-35. Breadth 0*45.

Yar. 1. flavescens. Smaller and rounder; body and shell

* Horn-colour.

6 sphj]:rud^.

straw-colour. C. flavescens, Macgillivray, Moll. Aberd. p. 246.
S. citrinum, l^ormand, Coup d'oeil CycL p. 1.

Var. 2. nucleus. Smaller and much more globular. C. nu-
cleus, Studer, Kurz. Verzeichn. p. 93.

Var. 3. Scaldiana. Shell more oval and of a paler colour.
C. Scaldiana, Norm. Cycl. p. 5, f. 1, 2.

Yar. 4. Pisidioides. Shell subtriangular, and rather more
produced at its posterior slope ; ti^ansverse (or concentric) striae
coarser : ligament slightly perceptible on the outside. S. Pisi-
dioides, Gray in Ann. & Mag. Nat. Hist. July 1856, p. 25.

Habitat : Slow rivers, lakes,, ponds and ditches, as
well as open drains in woods, everywhere in this country ;
and it occiu's in a fossil state in the upper tertiary de-
posits at Copford in Essex and other places. Var. 1. is
from Cumberland (Gilbertson) ; Westmoreland (Glover);
Grand Canal, Dublin (Warren) ; Aberdeenshire (Mac-
gillivray & Taylor) ; in a lake near Lerwick (Norman) .
Var. 2. Crymlyn bog, near Swansea (J. G. J.) ; Barton
run, Norfolk (Gunn) ; Richmond (Choules). Var. 3.
Oxwich marsh, near Swansea, and Thames at Clifden
Hampden (J. G. J.) . The colour of the body in this variety
is yellowish- white; tubes close together, irregularly jagged
at their edges, but not fringed, the branchial tube bein":
double the breadth of the other, which is funnel-shaped ;
foot white and broad. Var. 4. Grand Junction Canal at
Paddington. The shells of this remarkable variety are
much eroded, probably on account of the water being
charged with the refuse from manufactories or sewers.
The result of a careful comparison of these shells ^Yith.
other varieties and the typical form, and the circum-
stance that no other form of this variable species has
been found associated with it, incline me to believe that
it has not sufficient claims to rank as a distinct species.
It closely resembles the Cyclas rivalis of Dupuy (Hist,
nat. Moll. terr. et fluv. France, p. 668, tab. 29. f. 5),

SPH^RIUM. 7

which is another variety of the present species. Dr.
Baudon and M. Bourguignat both agree with me in the
above opinion. This species is widely distributed in
Europe; its northern limit being (according to Von
Wallenberg) Lapland^ and its southern limit being (ac-
cording to Philippi) Sicily. Young shells are extremely
flat, and might be easily mistaken for a different species.
This common species was first made known by our
countryman, the celebrated Dr. Lister, in his Treatises
on the history of English animals, in 1678. It is the
. Tellina rivalis of O. F. Miiller, and the Cyclas rivalis of
Draparnaud, who evidently described and figured the
next species {S. rivicola) as the Tellina cornea of Linne.

2. S. Rivi'coLA*, Leach.

Cyclas rivicola, (Leach) Lamarck, An. sans Yert. vi. p. 267 ; F. & H. ii.
p. Ill, pi. xxvii. f. 1, 2, and (animal) pi. Q. f. 1.

Body yellowish-grey, or hght brown : tubes short, white,
and nearly of equal length : foot thick, and capable of great
extension, greyish-white : gills sometimes slightly tinged with
red.

Shell oval, ventricose, nearly equilateral, much compressed
in front, rather solid, glossy, yellowish horn-colour, or ohve-
green, with often darker bands or zones, deeply ridged con-
centrically, especially towards the lower or front margin, the
ridges being crossed by obscure lines which radiate from the
beaks : epidermis rather thick : anterior side rounded : pos-
terior side more produced and subtruncate : heciks central,
small, and flattened : ligament short, prominent, and distinctly
visible on the outside : inside white and nacreous, with some-
times a yellowish tinge : hinge and teeth stronger than in /S.
Gorneum, but nearly of the same form : muscular and pallial
scars distinct. L. 0*7. B. 0*9.

Habitat : Slow rivers and canals in the metropolitan,
midland, and northern counties of England, as well as

* Inhabiting brooks.

8 SPH^RIID^.

near Dublin ; and it is one of our upper tertiary fossils.
It is a local species. On the continent it ranges from
Holland to Italy.

This fine species may be distinguished from S. corneum
by its much greater size, its form being oval instead of
globular, the strong transverse ridges, and the con-
spicuous ligament. The young of this are also much
flatter in proportion to their size. Both species occur
together. >S^. rivicola was first indicated by Lister as
having been found at Doncaster.

3. S. ova'le^, Ferussac.

Cijclas ovalis, Fer. in Ess. Meth. 1807, pp. 128, 136. 8. pallidum, Gray
in Ann. N. H. ser. 2. xvii. p. 465, woodcut.

BoBY milk-white : tuhes long, united nearly all the way :
foot tongue-shaped, very extensile and flexible : gills of a
faint blush-colour.

Shell oblong, somewhat compressed, not so equilateral as
the two preceding species, owing to the greater development of
the posterior side, thin, semi transparent, not very glossy,
yellowish, with sometimes a brown tint and darker zones of
growth, with occasionally some faint rays in the direction of
the lower margin, finely striate concentrically : epidermis thin :
anterior side rounded : posterior side truncate, and sloping
towards the lower margin, which is curved and sharp : heaks
small, nearly central, and slightly prominent : ligameiit long
and narrow, distinctly visible on the outside: inside ashy-
white : hinge straight on the posterior side, and incurved on
the other side ; cardinal and lateral teeth arranged as in S.
corneum, but the former are exceedingly small and difficult to
distinguish : muscular and pallial scars very faint. L. 0-4.
13. 0-6.

Habitat: Exmouth (Clark) ; PaddingtonCanal(J.G.J.);
canals and ponds in Lancashire (Darbishire) . A speci-
men also exists in the late Dr. Turton's collection of
British shells, but without any note of the locality.

* Egg-shaped.

SPH^RIUM. 9

Mr. Daniel says that he found this species in the Grand
Surrey Canal some years before it was noticed by Dr.
Gray, but that he then considered it to be a variety of
C rivicola. It is found in company with all the other
species of Sphcerium. A living specimen, which had been
taken early in February, and kept in a vessel by itself,
gave birth about three weeks afterwards to some young
ones at intervals of two or three days. Immediately on
being excluded, they were very active, and used their long
foot as an organ of progression, by extending it to its full
length ; and, after attaching its point to the bottom of
the vessel, like a leech, they drew up their shell to it; and
by repeating this several times they contrived to travel
along for some little distance. They seemed to be fond
of nestling under their mother for the sake of shelter or
shade.

There cannot be much doubt that this elegant and
very distinct species is the same as that which Drapar-
naud, in his ^ Histoire naturelle des Mollusques ter-
restres et fluviatiles de la France ' (p. 130, pi. x. f. 6, 7),
described and figured under the name of Cyclas lacustris.
He distinguished it from S. corneum and S. rivicola by
its being " plus mince, plus transparente, plus pale et
beaucoup plus aplatie." His description of the beaks
and hinge also exactly agrees with that of our species ;
and the very difierent terms in which he cha^racterized
his C. caliculata preclude our supposing that this accu-
rate naturalist could have taken for it a variety of the
last-named species. Ferussac, being aware of the error
which Draparnaud had committed in referring the spe-
cies in question to the Tellina lacustris of Miiller, gave
it the appropriate name which I have now adopted. The
species appears, however, to have been lost in France ;
and all the continental conchologists have applied the

B 5

10 SPH^RIID^.

name given by Draparnaud to some one of tlie nume-
rous varieties of either Miiller^s species or S. corneum.
The Cyclas rhomboidea of Say_, to which Dr. Gray sup-
posed our shell to be allied, is only a fourth of an inch
long, and, according to Gould, is an obscure or doubtful
species. Its nearest congener in this country appears
to be S. rivicola ; but it may be readily distinguished
from that species by its oblong and subangular shape,
thinner texture, much paler colour and fainter striae,
and especially by its straight hinge-line. The Devon-
shire and Lancashire sj^ecimens are of a darker colour
than those from the Paddington Canal. The young
exhibit the same form as the adult ; and, like the other
species, their shells are slightly iridescent.

4. S. lacus'tre^, Miiller.

Tellina lacustris, Miill. Verm. Hist. pt. ii. p. 204. Cyclas caliculata,
F. & H. ii. p. 115, pi. xxxvii. f. 7 (as C. lacustris), and (animal) pi. O.
f.7.

Body whitish, slightly tinged with grey or rose-colour :
tuhes long ; the branchial one cylindrical and truncate at its
orifice, which is large ; the other rather conical, and having
a smaller opening : foot nearly twice the length of the shell,
obtuse at its extremity : mantle fringed with grey.

Shell nearly round, or subrhombic, equilateral, compressed,
especially towards the lower and side margins, extremely thin,
glossy and semitransparent, light horn-colour, or greyish,
with sometimes a few darker zones and an iridescent hue,
very faintly striated concentrically : epidermis very thin : an-
terior and posterior sides cut ofi' and sloping from shoulders on
the upper or dorsal side towards the front margin, which is
slightly curved and has sharp edges: heahs central, very pro-
minent, and capped with the fry or nucleus of the shell, Avhich
Ls more globular than in the subsequent stages of growth :
ligament narrow, thin, and just discernible on the outside :
inside bluish-white, with very little nacre, owing to the thin
texture of the shell : hinge rather strong ; teeth arranged as

* Inliabiting lakes.

SPHiERIUM. 11

in the other species, but the cardinal teeth are smaller and the
lateral ones shorter in proportion : muscular and pallial scars
scarcely perceptible. L. 0*3. B. 0*4.

Yar. 1. Brochoniana. SheU much larger and flatter ; leaks
smaller and less prominent. S. Broclionianum, Bourguignat,
Monogr. p. 20, pi. 3. f. 1, 2, 3.

Var. 2. rotunda. Shell rounder and flatter ; epidermis yel-
lowish-green.

Var. 3. Rycklioltii, Shell small, triangular, and globular ;
healcs very prominent. C. Bychlioltii, Norm. Cycl. p. 7, f. 5, G.

Habitat : Lakes^ ponds^ and canals, and. stagnant
water everywhere in England, Wales, and Ireland; but
I have not observed it in Scotland, nor seen any notice
of its having been found there. Yar. 1. Clumber lake,
Notts (J. G. J.). This considerably exceeds the usual
form in size, being in length 0*45, and in breadth 0 6,
although its depth or thickness is only 0*25. Var. 2.
Singleton, near Swansea (J. G. J.). Var. 3. Marsh be-
tween Exmouth and Budleigh Salterton (J. G. J.). In
another piece of stagnant water near Exmouth a small
globular variety occurs, in which the beaks are not pro-
minent. A monstrosity is also sometimes met with, in
which the lower or front margin is constricted or divided
by a groove. Mr. Kenyon foimd it in the North of Eng-
land ; and I have also taken it in Crymlyn bog, near
Swansea. Some shells, which Mr. Choules has found
near Richmond, partake of the characters both of this
species and S. ovale, and apparently form an interme-
diate link between them. According to Middendorft' this
species inhabits Siberia ; and Philippi and Terver have
recorded it from Sicily and North Africa. It has also a
wide range in the intermediate parts of Europe. It
often occurs in company with S. corneum; and I have
found it alive in the hardened mud of a pond which
had been drained and its bed so completely dried up

12 SPH^RIID^.

by tlie sun as scarcely to show the marks of any foot-
steps on it.

This differs from all the other species of Spharium in
the shell being rounder and of a suhquadrate form^ its
great tenuity, and especially in the singular caps or ca-
lyces which surmount the beaks.

I cannot agree with the learned authors of the ' Bri-
tish Mollusca'' in preferring Draparnaud's name of
caliculata to that which had been long before assigned
to this species by Miiller. The description given by the
illustrious Danish naturalist does not appear to me at all
deficient in that accuracy and precision which characterize
all his writings ; and if some continental authors have
erroneously confounded this species with the Cyclas la-
custris of Draparnaud, this cannot be a sufficient reason
for continuing the mistake. At any rate_, the best French
authorities (including rerussac_, Blainville, and Moquin-
Tandon), as well as nearly all the conch ologists of our
own country, have adopted Miiller^s name in preference
to that of Draparnaud.

Although Mr. Jenyns has, in his excellent Mono-
graph, given an interesting notice of the habits of this
moUusk in a state of confinement, some further details,
which have been communicated to me by my friend
Dr. Lukis, of Guernsey, of its natatory, spinning, and
other performances, may not be unacceptable. In one
of his letters to me he says, " I placed a number
in a small fish-globe in clear water taken from the
sluggish stream in which they were captured. In a
short time they commenced crawling about and actually
ascending the slippery concave glass. In a few days a
considerable number of the fry had been cast, vidiich
proved far more active than their parents, readily climb-
ing the sides of the glolie, and rarely missing their foot-

SPH^RIUM. 13

ing, while the adults made many ineffectual attempts ;
but both fry and adults^ when they reach the edge of the
water, take to the surface easily_, and creep along slowly,
and apparently with caution, as if in search of some
floating substance, near which they will rest for hours.
The exserted foot moves, during this under-surface pro-
gression, by a gentle vermicular action, the siphons being
at the same time protruded. The foot during repose
is usually retracted, and does not seem necessary for
mere floating-purposes/^ And he adds, " An inter-
esting little scene occurred in the globe the other even-
ing. Several individuals had reached a few leaves and
hanging roots of minute water-plants which floated in
the centre of the globe, down the stems of which three
or four had crept to a depth of about an inch and a half.
There they reposed : but they were not absolutely mo-
tionless ; for, to my surprise, the whole group, plants and
all, were dreamingly enjoying the delights of a slow but
long- continued rotation. At first I thought some mi-
nute water-insect had found its way unbidden into the
globe, and was thus illustrating, like some learned lec-
turer to his sleepy audience, the laws of planetary mo-
tions. But no such lecturer was there : yet, as the
revolution brought two of the little moUusks closer under
inspection, I observed their siphons to be curved exactly
in the opposite direction to the line of motion. Here
was a solution at once of the nymph-like aTp6^i\o<i,
which was evidently due to the recoil consequent upon
the circulation and expulsion of the water through the
siphons. The fortuitous position of the two individuals
and the combined action of their expulsive tubes may
not occur again ; but the whole incident was so inter-
esting and remarkable that I could not help recording
it. The fry are growing rapidly ; and I opine the

14 SPH^RIIDiE.

amount of exercise they indulge in is conducive to their
health. I have observed the Eulima distorta, Rissoa
parva and cingillus, as well as the Odostomice and Jef-
freysice, ascend to the edge of a basin and creep along
the under- surface of the water^ in the same manner as
the Jjymnceadce. But it is singular that bivalves should
imitate their less unwieldy moUuscan brethren in this
seemingly unsuitable mode of progression/^ In another
letter he says^ " Sometimes a single individual will sus-
pend itself to a little bit of the stem of a Lemna, and whirl
quite alone for hours^ even rapidly — say fifteen to twenty
revolutions in a minute/^ And in a subsequent letter
he goes on to say, " The young are far more active than
the parents. I do not perceive their siphons to be ever
exserted, while this is almost constantly the habit of the
older ones. They all continue to climb the glass globe,
and rather more so in the evening, probably preferring
to roam in the dark. I have had a fresh supply of about
half a dozen, which, soon after being immersed, began
an inspection of their new domain, and continued for a
day or two more restless than the others. On climbing
the glass, the front margin of the valves is applied to it,
and at the same time both the foot and the siphons are
exserted. The foot being extended to its full length, its
extremity is cautiously pressed against the glass, and
after a short pause the upward movement of the body
commences, which is the work of a second of time;
then another short pause, after which the front margin
of the valves and the point of the foot are again applied
cautiously to the glass, and the foot is again protruded
to repeat the same process. When the edge of the water
is reached the pauses are longer, and it is necessary for
the creature to be doubly cautious, for here is the point
of greatest difficulty. However, the foot is conveyed

SPH^RIUM. 15

horizontally along the surface of the water, which ap-
pears to recede partially from it. On examining it with
a lens, the foot is distinctly seen to have an undulating
action on the surface, as well as an irregular and im-
perfect contraction and elongation along its whole ex-
tent ; but it is never quite retracted, excepting when its
base and the front margin of the valves are in contact
with some floating weed which is capable of supporting
the whole. Thus this elegant shell traverses the still
surface. But it is most curious to see it descending the
thread-like stems of the Lemna, or some assemblage of
these delicate fibres : even a single stem is quite suffi-
cient ; and if the shell is free from any other contact, it
immediately begins its rotatory movement. A single
shell, thus suspended, revolves upon its axis in a direc-
tion which is most frequently from right to left of the
observer, or in the opposite direction from that of a
teetotum when made to spin by the fingers of the right
hand. I have suspended single threads to circular pieces
of cork in the water ; but the stems of the Lemna are
preferred. Cyclas cornea is much less active or inclined
to ascend the glass ; in fact, I have not yet seen it ac-
complish the feat of its congener. Several of the C caly-
culata (Sphcerium lacustre) will remain among the stems
of the duckweed for hours perfectly inactive, with closed
valves, as if sleeping or resting after their previous
fatigue. When the valves are pressed against the glass
while ascending, there seems to be a fulness about the
base of the foot, as if the mantle served for adhesion to
the glass.^^ Dr. Lukis afterwards informed me that he
had detected the byssal filament in S. lacustre. He
says, '^ I have this morning watched one, which had
reached the surface, spm its filament j and descend to

16 SPH^RIID^.

half an inch below the surface, where it remained sus-
pended for some time. It occupied three hours in
spinning this short thread. I think it consists of more
than a single filament ; for some minute particles, which
were floating in the water, became entangled in it. The
surface of the water was again depressed or cupped.^'
And he concluded by saying that he found the number
of filaments to vary from one to at least four, which in
one instance were far apart, the siphons or tubes and
foot being at the same time exposed ; and that the
animal had the power of raising itself by means of this
byssus again to the surface, after having been suspended
for some time below it. The filaments appeared not to
exceed half an inch in length ; and rarely could more
than a single thread be seen. M. Bouchard-Chante-
reaux has likewise, in his extremely interesting Cata-
logue of the Land and Freshwater Mollusks which in-
habit the Department of the Pas-de- Calais, noticed that
the young of S. corneum possess the same faculty of
spinning a transparent thread and attaching themselves
by means of it to water-plants.

Genus II. PISI'DIUM ^ C. Pfeifi"er. PL I. f. 3, 4.

Body inequilateral : mantle having only a single tube.

Shell inequilateral : beaks placed near the shorter or an-
terior end.

This genus was established by Carl Pfeiflfer in 1821, to
separate from Sphcerium the smaller species which have
only one tube or siphon, and whose shells are not so
equilateral. This generic distinction seems to be well
founded, in respect both of the soft parts of these mol-

* Pea -shaped.

PISIDIUM. 17

lusks and of their shells; and it has received almost
the universal assent of conchologists. The habits of the
little Pea shells are the same as those of the larger
members of the same family ; and they inhabit nearly
the same situations. One species (P. pusillum) does not
seem to require a constant, or even a frequent supply of
water, being often found living at the roots of bog-moss
which is dried up in the summer, and of grass in mea-
dows which are only irrigated in the spring ; and Nils-
son noticed, in his history of the land and river mol-
lusks of Sweden, that he had frequently found the same
species (which he erroneously referred to the P. fontinale
of C. Pfeiffer) living between the bark and wood of fallen
trees in moist places. They possess the same faculty as
the Sph(Eriaj of floating, or creeping in an inverted posi-
tion under the surface of the water. These tiny Pea
shells, or cockles, swarm in every slow river, streamlet,
lake, pool, horse-pond, ditch, and open drain ; and they
are greedily devoured by fish and ducks. In their turn,
they are fond of animal food ; and Dr. Baudon, in his
admirable Monograph, says that he has often observed
Pisidia attached to the drowned carcases of small ani-
mals, as well as to bones which had been thrown into
ditches and streams, and from which the muscular fibres
had not been removed. Perhaps, however, animalcula
fed upon the meat, and were the real objects of attrac-
tion to the Pisidia. Their shells are sometimes so
thickly encrusted with a ferruginous or mineral deposit
from the muddy sediment of the water which they in-
habit as to resemble small lumps of dirt. This deposit
appears to be partly owing to a secretion of the animal,
aided by its generally inactive habits. Water -beetles do
not allow themselves to be clogged in the same manner.
Whether this is one of the artifices by which animals

18 spHtERiid^.

escape the observation of their natural enemies is a
question which requires a molluscan mind to solve.

The critical investigation of the different species which
compose this genus is quite as difficult as it is with regard
to the large freshwater mussels. Little reliance can be
placed on the characters afforded by an examination of
the body^ or soft parts, of the animal. The form and
comparative length of the tube are especially liable to
vary even in the same individual ; and under the influ-
ence of heat and light the most Protean changes with
respect to this organ may be observed. The size of the
foot is equally a deceptive character ; and colour is al-
ways a most uncertain test. The general shape and
appearance of the shells, as w ell as the position of their
beaks, appear to offer almost the only reliable grounds
of distinction. Size, substance, sculpture, and lustre are
not of much account, as they mainly depend on the
chemical ingredients of the water inhabited by these
moUusks, as well as on their supply of food. In making
an investigation like the present, there appear to be four
courses open to the naturalist. The first, which is,
perhaps, the easiest, is to reduce all hitherto described
species to one or two, and thus to cut the Gordian knot
without further ceremony. The second, which has been
pursued to such an extent on the Continent and in the
United States of America, is to multiply the number of
species ad infinitum. The only check which can be im-
posed on this method of wholesale and indiscriminate
fabrication is the bar of scientific opinion ; and in coun-
tries where nearly all the naturalists are culprits, there
is not much likelihood of justice being so severely admi-
nistered as to prevent the repetition of such venial
offences. The third course is, to adopt the labours of
preceding writers without any inquiry. And the fourth

PISIDIUM. 19

is, honestly and to the best of one^s ability carefully to
work out the subject and to submit the result to the
free criticism of other naturalists. This last course I
have endeavoured to pursue ; and I shall not feel in the
least degree mortified or discouraged if the conclusions I
have arrived at, with much pains and great hesitation,
are not accepted by all my scientific brethren.

To give some idea of the labour involved in this in-
vestigation, I may mention that my own cabinet con-
tains no less than 274 parcels of Pisidia, which have
been, in the course of the last thirty or forty years, col-
lected from different localities and sources, and comprise
many thousands of specimens ; that I have personally
examined the types of those species which have been de-
scribed by Dr. Turton, Mr. Jenyns, Mr. Alder, Dr. Bau-
don, and other conchologists who have published on the
subject; that I have collected these tiny shells in many
parts of Holland, Germany, France, Switzerland, and
Italy, for the sake of comparison with British forms jj
and that I have had to refer to numerous works in many
languages in order to collate the descriptions of forty-
one different species which have been proposed by Euro-
pean writers within the last century. Of these, I cannot
conscientiously recognize more than six as distinct.

It will be convenient to divide the British species,
which are five in number, according to their shape, as
follows : —

A. Triangular. 1. P. anmicum. 2. P. fontinale.

B. Oval. 3. P. pusillum.

C. Bound. 4. P. nitidum.

D. Ohlong. 5. P. roseum.

20 SPH^RIIDiE.

A. Triangular.

1. PisiDiuM am'ntcum*^ Miiller.

Tellina amnica, Miill. Yerm. Hist. p. 205. P. amnieum, F. & H. ii. p. 133,
pi. xxxvii. f. 8, 9, and (animal) pi. O. f. 8.

Body greyish -white, rather transparent; tube short, sub-
conical, obliquely truncate at its orifice : foot broad at its
base, abruptly pointed, and very extensible : mantle bordered
with grey.

Shell subtriangular, rather ventricose and solid, glossy,
strongly grooved concentrically, horn-colour or yellowish-
grey : epidermis rather thick : anterior side abruptly truncate :
posterior side much produced, and sloping towards the lower
margin, which is obliquely curved : healcs rather prominent,
but obtuse : ligament short, conspicuous : inside bluish-white
and nacreous : hinge strong and curved ; teeth arranged as in
Splioerium, but the lateral teeth in this and other species of
Pisidium are exceedingly strong and developed in proportion
to the size of their shells : rnuscular and pallial scars well
marked. L. 0*3. B. 0*375.

Yarieties occur in which the striae are more numerous,
fewer, stronger or fainter than usual.

Habitat : Slow rivers, lakes_, canals, and streams in
all parts of the kingdom. It is also one of our com-
monest upper tertiary fossils. Its continental range ex-
tends from Siberia to Naples, and it is also found in
Algeria. This is the largest kind of Pisidium.

2. P. fontina'le tj, Draparnaud.

Cyclas fontinalis, Drap. Hist. Moll. p. 130, pi. x. f. 8-12. P. Henslowi-
anum (var. without appendages), Jenyns in Ann. Nat. Hist. Aug. 1858,
p. 104.

Body whitish or grey, rather transparent : tube generally
short, but capable of considerable extension and dilatation,
conical, obliquely trimcate at its orifice, where it is so flexible
that the edges are sometimes entire and at other times jagged :
foot long and curved : mantle bordered with grey.

* Inhabiting rivers. f Inhabiting fountains.

PISIDIUM. 21

Shell subtriangular, somewhat ventricose, thin, rather
glossy, finely but irregularly striate concentrically, greyish-
white : epidermis very thin : anterior side abruptly truncate :
posterior side rounded, and sloping gently towards the lower
margin ; the anterior and posterior margins are compressed,
especially towards the beaks, on each side of which they form
a kind of shoulder : heaks prominent and rather acute : liga-
ment very short and scarcely perceptible : inside white and
nacreous : hinge short, but very strong ; dentition as in P.
amnicwn, except that the cardinal teeth do not assume the
shape of an inverted Y : muscidar and pallial scars the same
as in that species. L. 0*15. B. 0'175.

Yar. 1. Henslowana. Each valve fui^nished with a plate-
Hke appendage near the beaks. Tellina Hensloiuana, Shep-
pard in Linn. Trans, xiv. p. 150. P. Henshiuianmn, F. & H.
ii. p. 131, pi. xxxvii. f. 11.

Yar. 2. pulchella. Shell more glossy, strongly and regu-
larly grooved ; heahs less acute. P. pidchellum, Jen. p. 18,
tab. xxi. f. 1-5 ; F. & H. ii. p. 128, pi. xxxvii. f. 12, 13.

Yar. 3 pallida. Shell more ventricose, irregularly striate,
and of a paler colour, with occasionally a few darker rays
which diverge from the direction of the beaks to the lower
margin.

Yar. 4. cinerea. Shell larger and flatter, with fainter striae.
P. cinereum, Alder, Suppl. Cat. Moll. Northumb. p. 4 ; F. & H.
ii. p. 125, pi. xxxvi. f. 2.

Habitat : Slow streams and standing water every-
where in these isles ; and it is one of our upper tertiary
fossils. It also ranges from Siberia to Sicily. Var. 1.
occurs in many of the northern^ eastern, home, and
south-western counties of England, as well as in South
Wales and Cork. This is also one of our tertiary fossils,
and extends from Sweden to the South of France.
Specimens from the Swansea Canal, near some tinworks,
have the beaks more or less eroded, in consequence pro-
bably of the water containing an extremely diluted por-
tion of sulphuric acid, which is used in that manufac-
tm'e. The fact, which has been noticed and considered

22 SPH^RIID^.

remarkable by some authors^ of the eave-like projection
appearing in the middle of young shells_, agrees with its
position in adult shells^ because this curious appendage
is never placed close to the beak. Var. 2. More com-
mon than the last variety^ and also inhabiting Sweden
and France. It deserves its name^ being a very pretty
object. Mr. Jenyns now considers it to be the same
species as his P. Henslowianum. Var. 3. Marshes and
pools near Swansea. It is probably the P. pallidum of
Gassies. Var. 4. Widely diffused in this country, and
also inhabiting France and Italy. The outline of some
specimens of this last variety is that of an equilateral
triangle. It is the P. australe of Philippi, and the Cyclas
lenticularis of Normand.

This species is extremely variable, and has conse-
quently received a great number of names. Out of the
41 so-called species of Pisidium which have been de-
scribed by European conchologists, no less than 21 belong
to the present form. On the Continent the type is
generally known by Polios name of Casertanum.

If the diagnosis, characters, and figures given by
Draparnaud for his Cyclas fontinalis had been more
carefully studied, it would, I think, have been obvious
that they do not apply to the Tellina pusilla of Gmelin,
with which this species has been generally (but with
doubt) allocated by so many authors. The principal
difference between these two species consists in the
former (P. fontinale) being triangular and somewhat
depressed, and having prominent beaks ; while the other
(P. pusillum) is oval and ventricose, and has obtuse
beaks. Draparnaud^s diagnosis is as follows : " C. testa
globosa, subdepressa, subina3quilaterali ; umbone sub-
acuto." Gmelin says his shell is " ovata, ventricosa ;^'
and his description of its colour as " sordide alba ^' is

PISIDIUM. 23

peculiarly appropriate to tlie P. pusillum of modern
authors. C. Pfeiffer^ in 1821;, appears to have recog-
nized Draparnaud^s shell by the same specific name of
" fontinale '" and the only distinction which he makes
between this species and his own P. obtusale (which I
regard as a variety of P. pusillum) is that the former is
described " umbone subacuto", and the latter '' umbone
obtusissimo."

It chiefly differs from P. amnicum in being very much
smaller (although the variety cinerea is nearly as large) ^
in the shell being thinner^ the posterior margin much
less produced, the i)eaks being more prominent, and the
ligament scarcely conspicuous. The cardinal teeth are
also more separate, and do not diverge from a common
base or root as in that species and Sphcerium.

B. Oval.

3. P. pusii/lum*, Gmelin.

Tellina pusilla, G-inelin, Syst. Nat. p. 3231 . P. 'pusillum, F. & H. ii.
p. 123, pi. xxxvii. f. 10, and (animal) pi. O. f. 9.

Body whitish, with occasionally a faint tinge of yellow or
red: tube short, subcorneal or cylindrical, truncate, orifice
small and its edges plain : foot longer than the shell, narrow
and slender : mantle bordered with reddish-grey.

Shell oval, compressed but swollen, thin, not so glossy as
in the other species, finely but irregularly striate concentri-
cally, a few of the striae being larger than the others and de-
noting the successive stages of growth, yellowish-white or
cinereous : epidermis very thin : anterior side rounded : poste-
rior side also rounded, and sloping very gradually below ; this
side is very httle more produced than the other, which makes
the contour of the shell more equilateral than in the foregoing
species ; both these sides are compressed, and especially above :
lower margin rounded : beaks not prominent, but blunt : liga-
ment short and inconspicuous: inside greyish-white, vrith

* Little.

24 SPH.«RIID^.

scarcely any nacreous lustre ; other internal characters the
same as in P. fontinale. L. 0-175. B. 0-2.

Var. ohtusalis. Shell smaller and much more ventricose ;
healcs prominent, very obtuse. P. ohtusale, C.Pfeiffer, Deutsch.
Land- und Sussw.-MoU. i. p. 125, t. 5. f. 21, 22 ; F. & H. ii.
p. 120, pi. xxxvi. f. ] .

Habitat : Mossy swamps, shallow ditches, drains,
grassy pools, and similar situations throughout aU the
country ; and it is one of our upper tertiary fossils. It
ranges from Lapland to Corsica, and is generally diffused
in Europe. Dr. Baudon says that it is the same species
as the P. vejitricosum of Prime ; so that it appears to be
also a native of the United States bf America. The
variety obtusalis occurs in similar situations with the
typical form ; but it is more local and not so abundant.
The intermediate gradation between the two forms is
almost infinite ; but the essential and common character
of both is the same, viz. the beaks being nearly central
and obtuse.

Having carefully studied the description and figure
given by Poli of his Cardium Casertamim, I have not
been able to arrive at the same conclusion which Moquin-
Tandon and other French conchologists have formed,
that this species is the type of the one which I have de-
scribed as P. fontinale ; and I consider that it ought
more properly to be referred to the present species. Poli
says his shell is " subrotunda f' and his figure shows
that it is much more equilateral than P. fontinale. He
also remarked the irregularity of the strise arising from
the marks of groAvth, which appears to be more cha-
racteristic of this than of the other species. As, how-
ever, he did not notice any other species, it is of course
very difficult to say precisely which species he meant ;
and under these circumstances I think it is preferable
not to revive an obscure and doubtful species, indicated

PISIDIUM* 25

by a local name, when we have at least equally good
reasons and authority for adopting a name bestowed by
an earlier writer, and which, besides, is not liable to the
same objection. This species differs from P. fontinah
in its shape being oval instead of triangular, and in its
beaks being more central, and blunt or compressed. Its
colour is also yellowish- white instead of grey ; and it has
much less lustre. It is the Cyclas fontinalis of Nilsson.

C Round.

4. P. ni'tidum*, Jenyns.

P. nitidum, Jen. p. 16, tab. xx. f. 7, 8 ; F. &H. ii. p. 126, pi. xxxvii. f. 14.

Body whitish, -^dth sometimes a faint tinge of yellow, caused
by the colour of the liver : tube short, funnel-shaped ; orifice
wdde, and its edges notched or puckered : foot rather long,
thin, slender, and finely pointed : mantle bordered with grey.

Shell suborbicular, compressed except in the upper part
where it is rather ventricose, thin, extremely glossy, iridescent
(especially in the young state and near the beaks) , finely and
regularly striated or ribbed concentrically, with from 3 to 5
separate and deeper grooves which encircle the umbonal region,
the strise or ribs being rather broad ; yellowish- white or light
horn-colour : epidermis a mere film : anterior side somewhat
truncate, but rounded: posterior side slightly produced and
sloping abruptly below : lower margin rounded : healcs nearly
central, rather prominent, but obtuse : ligament very short,
and scarcely discernible : inside w^hitish, and plainly showing
the scars of the adductor muscles and mantle : hinge and teeth
as in the two last species. L. 0*15. B. 0*15.

Var. splendens. Shell of a lemon-colour, nearly half as
large again as that of the ordinary form, stronger, less glossy,
rather more obhque, and less deeply striated, with the beaks
more swollen and the hgament stronger and perceptible.

Habitat : Lakes, ponds, and standing water in all
parts of the kingdom from Zetland to the Channel
Isles. Malm has described and figured it as a Swedish

* Glossy.

C

26 SPH^RIID^.

species ; and Moquin-Tandon has noticed it as Corsican.
I have found it also on all parts of the Continent. The
variety splendens of Baudon occurs in lakes near Lerwick,
and at Balmacarra in West Ross. A monstrosity or
distortion of this species, as well as of P. fontinale (var.
Henslowand), is sometimes met with, which has the
valves constricted or divided by a longitudinal groove.
This accidental phenomenon in the typical form of P.
fontinale induced M. Bourguignat to consider it a distinct
species, and to give it the name of P. sinuatum. It is
caused by a laceration or injury of the front margin of
the mantle.

This may be distinguished from all the preceding spe-
cies by its rounded outline, much more glossy and iri-
descent appearance, and by a few separate and deeper
grooves or lines which encircle the beak and are espe-
cially perceptible in young shells. This is also the only
kind of Pisidium which has the tube funnel-shaped and
its outer margin crenulated or plaited. For the dis-
covery of this species science is indebted to Mr. Jenyns.

D. OhJong.
5. P. Ro'sEUM^, Scholtz.

p. roseum, Scholtz, Schlesien's L.- und W.-Moll. p. 140; Jeffr. in Ann.
Nat. Hist. s. 3. vol. iii. p. 38, pi. ii. f. 3.

Body opaline white, orange -yellow, red, or rose-eoloiu- in
the upper part : tube long, slender, subconical, and truncate at
its orifice : foot long, semitransparent.

Shell subrhombic, ventricose, thin, very glossy, deeply and
regularly striated concentrically ; yellowish-white or light
horn-colour : epidermis extremely thin : anterior side truncate
and sloping abruptly below : posterior side much produced and
rounded : lovjer margin nearly straight : healcs placed con-
siderably on one side, rather prominent, but obtuse : ligament

* Eosc -colour.

PISIDIUM. 27

inconspicuous : inside nacreons-white : Tiinge-Une nearly
straight ; cardinal teeth very minute and almost impercep-
tible ; lateral teeth not well developed, except towards their
outer edges, which are strong and sharp : muscular QXid.'paUial
scars scarcely visible. L. 0*1. B. 0-15.

Habitat : Marshes, ponds, ditches, and stagnant water
from Zetland to Guernsey. It also occurs in Silesia,
Sweden, and France ; and I have found it in Prussia.
It has probably escaped notice in other parts of the Con-
tinent.

This species differs from all its congeners in its oblong
or rhomboid shape, which is principally owing to the
greater extension of the posterior side, and to the beaks
being consequently placed so much out of the centre, as
well as to the compression and nearly straight outline of
the lower or front margin. It is considerably more
ventricose than P. nitidum, which it resembles in its
gloss and sculptm^e. The umbonal strise are, besides,
not perceptible in the species under consideration ; and
the tube does not appear to have the margin of its
orifice plaited. The body has usually a rosy or reddish
hue in the upper part, which is discernible in the dried
animal.

It was not without much hesitation that I adopted the
name given by Scholtz for this species, because in a
Supplement to the second edition of his work he con-
sidered it to be a variety of P. fontinale ; but the colour
of the animal, which at first induced him to propose
this as a distinct species, appears to form a good and
constant mark of distinction, and one of the epithets
which he applied to the shell ("langlichrundlich^^) is
very appropriate. The only other species of Pisidium
besides this, which Scholtz has noticed, are fontinale,
amnicum, and obtusale. Whether it may ultimately be
united with nitidum is, however, a question which I, for

c2

28 UNIONID/E.

one^ shall not consider unreasonable, although my pre-
sent impression is that they are distinct species. The
variation of form and sculpture is undeniably very great
in all freshwater shells ; and this is probably caused not
only by the greater or less supply of food procurable
by these mollusks, but also by the chemical ingredients
of the water from which their materials are secreted or
extracted. Development of size, and of particular por-
tions of the shell (by which its shape is determined),
seems to depend on the former condition, while its
solidity and sculpture are affected by the nature of the
fluid which these moUusks inhabit. The present species
is the P. tetragonum of Normand and the P. arcceforme
of Malm.

As some test of specific distinction, I would remark
that the following species of Pisidiiim are often found
living together : viz., amnicum Sind fontinale (var. Hens-
lowana) ; fontinale and pusillum ; and fontinale (var.
pallida), nitiduyn, and roseum. Each of the above is also
sometimes found solitary, or in company with various
species of SphcBriurn,

Family II. UNIONIDtE.

Body oblong, compressed : mantle open on all sides except
at the back, but forming at the posterior side two orifices,
which correspond with the cylinder or tubes of the SpJiceriidce.
The smaller and upper, or excretal, orifice is separated from
the larger and lower, or branchial, orifice by an intermediate
fold of the mantle. The margin of the first-mentioned orifice
is plain ; but the other is fringed with several rows of cim
or tentacles. Mouth placed as in the last family. Foot large,
broad, and tongue-shaped.

Shell equivalve, oblong, inequilateral, compressed : epi-
dermis thick : becdcs (which form the nucleus or young shell)
plaited or wrinkled: ligament external, strong, and always
conspicuous : inside pearly : himje furnished with lateral teeth

UNIONID^. 29

only ; those on the anterior side being sometimes so much
developed as to resemble cardinal teeth.

Some of these mollusks^ which are often called " fresh-
water Mussels/^ are ovoviviparous^ like those of the last
family, and retain their young within the folds of the
mantle for some time before they are finally excluded ;
while others are oviparous, like the majority of mollusks.
It was for a long time supposed that they were of sepa-
rate sexes, and Von Siebold distinguished Atiodonfa
cygiiea as the male, and A. Cellensis as the female, of the
same species ; but Moquin-Tandon seems to have now
proved satisfactorily that both sexes are common to each
individual or that they are all monoecious. They in-
habit rivers and other large pieces of water. Their
habits are tolerably active in the spring, or when in
search of a suitable feeding-place ; and by means of their
large fleshy foot they are able to traverse considerable
distances, leaving a track or furrow in the soft mud.
When the water is slowly drained off", or dried up by the
heat of summer, as well as in the winter, they bury them-
selves in the mud. Their food consists of Entomostraca
and other minute animals. According to Mr. Anthony,
an American conchologist, who has especially studied
the members of this family, some species spin a byssus.
It is difficult to separate this family from their marine
analogues, the true Mussels, on merely malacological
grounds ; but I believe a good conchological distinction
(considering the shell to form an integral and important
part of the animal) is maintainable in the position of the
ligament and beaks. The former is external in the
UnionidcB, while it is internal in the MytiUdcs ; and the
beaks are nearly terminal in the latter, but in the former
they are seldom placed at a less distance than one-fourth
from the anterior end. Besides these marks of distinc-

30 UNIONIDiE.

tion^ there are no lateral teeth in Mytilida, and in My-
tilus the cardinal teeth are conspicuous. In the Unio-
nid(2, on the other hand, the lateral teeth are always,
and the cardinal teeth never, present. I am quite aware
that this last statement will be objected to by all those
conchologists who believe that, at all events, the shells of
Vnio are furnished with cardinal teeth. But I venture
to submit that these teeth are lateral, and not cardinal ;
that they are not, like the cardinal teeth in the S^jIkb-
riidcB, placed at a right angle to the hinge-line, but that
they are, on the contrary, parallel to it; and that they
are always lamellar and form more or less elevated ridges,
like the true lateral teeth in other bivalves. In the
genus Anodo7ita, indeed, the lateral teeth are not so
strongly developed as in Unio, and they may in some
cases be considered as rudimentary ; but in nearly all
the species of Anodonta these teeth form a well-defined
and often sharp crest, especially on the posterior or liga-
mental side. The unusually great length and strength
of the ligament in Anodonta seems to render the use of
lateral teeth in supporting the hinge almost unnecessary ;
and in this, as well as in many other cases of a similar
kind, the original form of such organs is retained in an
imperfect state, although their use has ceased to exist.

The study of the European members of this family
has for a long time attracted the attention of continental
naturalists ; and Carl Pfeiffer, Rossmassler, and Henri
Drouet have especially applied themselves to this diffi-
cult task. A valuable monograph has been published
by the last-named naturalist, entitled " Etudes sur les
Naiades de la France ;^^ the work being dedicated to the
late King of Portugal, whose devotion to conchology
was the more remarkable because this branch of natural
history has not been cultivated by many crowned heads.

«

UNIO. 31

In this country very little has been done to advance our
knowledge of the Unionidce ; and it would be extremely
desirable if naturalists who reside in the country would
carefully notice and record any instances of different
kinds occurring in the same waters, and whether any
intermediate forms are found in such localities.

Genus I. U'NIO^ Philippsson. PI. I. f. 5, 6.

Body elongated, rather ventricose : gills nearly straight :
labial paljps ovate.

Shell elongated, soUd : lateral teeth strong : lunide or heart-
shaped depression on the anterior side distinct.

This genus was founded by Philippsson in 1788 in an
inaugural Lecture entitled " Dissertatio historico-natu-
ralis sistens nova Testaceorum genera ;" but, owing to
the circumstance of its having been delivered at a meet-
ing of which Hetz was the president, the latter has
usually had the credit of founding the genus. From
this genus it has been since proposed to separate the
Pearl-Mussel, under the name of Margaritana, or Alas-
modon, on account of the teeth being less developed ; but
there does not appear to be sufficient reason, on con-
chological grounds, for this separation. The animals, or
bodies, of these so-called genera cannot be distinguished
from each other. All the species are, according to
Moquin-Tandon, oviparous.

Many species of Unio have been described by Conti-
nental writers ; and even Moquin-Tandon, who is by no
means addicted to this kind of manufacture, has ad-
mitted no less than eleven. Two of these (viz. U. Batavus
and U. rhomboideus [or littoralis]) , which are widely dif.
fused throughout France, have not yet been detected in

* A pearl.

32 UNIONID^.

this country, although the latter is not uncommon, in a
fossil state, in our upper freshwater tertiary beds.

That part of the shell which surrounds the beaks
(called the " umbonal region ") is sometimes eroded or
excoriated in these, as well as in other members of the
family. I believe it is caused by the chemical action of
gases which are evolved from the mud in which this por-
tion of the shell is usually imbedded. No reliance can
therefore be placed on such a feature as a mark of specific
distinction.

The word " Unio ^' is, according to Pliny, masculine.

1. Unio tu'midus^, Philippsson.

U. tumidus, Philipps. Nov. Test. Gen. p. 17 ; F. & H. ii. p. 140, pi. xl. f. 1.

Body greyish : mantle bordered with white ; the excretal
orifice being produced into a short tube, and of a brownish
colour with sometimes a few purplish streaks ; the branchial
orifice mottled with orange-brown : foot milk-white, with a
pale orange tint, thick and broad : gills pale grey : labial
palps rather broad.

Shell oval, very convex above, solid, rather glossy, yel-
lowish-brown, transversely wrinkled : epidermis rather thick :
heahs slightly incurved, and placed at a distance of about one-
fourth from the anterior side : umbonal region prominent and
strongly plaited in a wave-like manner, the folds sometimes
rising into sharp knobs or tubercles : lunule lance-shaped and
narrow : ligament short, strong, and prominent : anterior side
rounded and regularly sloping towards the front: posterior
side gradually sloping to a wedge-hke point : lower inargin
reffularlv curved: inside white and nacreous, with a faint
tinge of blue : hinge strong ; the right valve having on its
anterior side a broad, thick, and bifid tooth, Avhich is slightly
bent forwards, and irregularly grooved so as to make its crest
notched, and having on its posterior side a long and deep
channel or groove, formed by a double plate, to receive the
corresponding tooth of tlie other valve ; left valve furnished
at its anterior side yni\\ a single wedge-shaped and strong

* Swollen.

UNio. 33

tooth, which is also grooved and notched like the double tooth
of the right valve into which it locks ; this valve has also a
long, sharp and crest-like plate on the posterior side which is
morticed into the channel or groove above mentioned : muscular
2iDA pallial scars very deep and distinct. L. 1*5. B. 3.

Var. 1. radiata. Shell thinner : epidermis green, marked
with divergent yellow rays, which are interrupted by trans-
verse narrow zones of the latter colour ; posterior side more
compressed above: hinge-line nearly straight, especially in
half-grown specimens.

Var. 2. ovalis. Shell triangular-oval, or wedge-shaped,
compressed and somewhat incurved in the middle, rather
inequivalve in consequence of the right valve slightly over-
lapping the other, dark olive-brown : anterior side much
broader and abruptly truncate : lunule very broad, deep, and
oblique. Mya ovalis, Montagu, Test. Brit. pp. 34 & 563.

Habitat : Rivers, canals, and ponds in England as
far north as the Went in Yorkshire, and also in South
Wales ; and it is one of our upper tertiary fossils. Its
range extends northwards as far as Finland ; but it does
not appear to have been met with south of the Rhone.
Var. 1. R. Avon, near Bath (Clark) ; Railway lake near
Oxford (Whiteaves). Var. 2. R. Avon, Wilts (Montagu);
R. Brent (Metcalfe) ; and from Mrs. Loscombe's col-
lection of British shells. The late Mr. Clark also found
this variety near Bath, having a green epidermis which
is marked longitudinally with yellow rays, and trans-
versely with alternate zones of green and yellow. My
cabinet contains a specimen of the last variety, wliich
was sent by Col. Montagu to my late friend Mr. Dillwyn,
and by the latter presented to me with a few other
typical specimens from that excellent British zoologist.
The inside of each valve bears, in his well-known hand-
writing, the words "Mya ovalis, Wiltshire." This, there-
fore, shows what Montagues species really was ; and it
is the more interesting because the authors of the ' British

c 5

34 UNIONID^.

Mollusca ' referred it both to U. tumidus and U. picto-
rum, while Moquin-Tandon considered it to be a variety
of U. Batavus, It is more strictly a monstrosity^ or
abnormal form^ than a variety.

This species sometimes occurs in company with the
next. The Rev. A. M. Norman has recorded in the
' Zoologist' for 1857 having taken specimens at Fleck-
ney and Wistow in Leicestershire of the extraordinary
dimensions of nearly 4i inches in breadth and more
than 2 inches in lengthy the weight being over 3 ounces.
Beneath the epidermis the colour of the shell in this and
the next species is cream-white. A single individual of
U, tumidus has been known to lay 1500 eggs in two or
three days. They are deposited in small clusters, each
of which contains about 100 eggs.

2. IT. picto'rum*, Linne.

Mya pictorum, Linn. Syst. Nat. ed. xii. p. 1112. U. pictorum, F. &H.
ii. p. 142, pi. xxxix. f. 1, and (animal) pi. Q. f. 2,

Body clear red, with a more or less grej^sh tint : mantle
bordered with brown ; orifices of the same form and colour as
in the last species : foot reddish or yellowish -white, large and
tongue-shaped : gills grey : labial palps oval.

Shell oblong, compressed, not so solid as the last species,
glossy, yellow, with narrow zones of brown which denote
the marks of growth, transversely wrinkled, with stronger
furrows on the posterior side : epidermis rather thin : beaks
very httle incurved, and placed at a distance of between one-
fourth and one-fifth from the anterior side : umbonal region
not so prominent nor so strongly wrinkled as in the preceding
species : lumde long and narrow : ligament longer than in U.
tumidus : upper margin or hinge-line nearly straight : anterior
side rounded : posterior side very gradually sloping and rounded
at its extremity, compressed or pinched-up above : lower margin
nearly straight : inside cream-white or salmon-colour, highly
nacreous : Jiinge not so strong as in the last species ; the teeth

* Painters'.

uNio. 39

similarly arranged, but they are finer, sharper, and more erect :
muscular scars distinct : pallial scar faint, owing to the greater
thickness of the nacreous lining. L. 1-33. B. 3.

Var. 1. racliata. Shell having faint and narrow rays of
green which diverge from the beak.

Var. 2. curvirostris. Shell smaller, shorter, and flatter:
epidermis yellowish-green, with brown zones : posterior side
curved and wedge-shaped. U. curvirostris, Normand.

Var. 3. latior. Shell broader and shorter, yellowish-brown.

Var. 4. compressa. Shell very broad and flat ; upper margin
raised and curved : posterior side greatly compressed and at-
tenuated, assuming a beak-like form, and having a double
ridge and furrow which runs from the beak in the younger
state of growth : lower margin straight : lunule broad, and ex-
tending between the beaks, so as to separate them from each
other.

Habitat : Rivers, ponds, and canals throughout En-
gland ; but it does not appear to have been found north
of Yorkshire. It is also one of our upper tertiary fossils.
It ranges from Finland to Algeria and Sicily. Var. 1.
R. Avon, Bath (Clark). Var. 2. From Clark's and
Mrs. Loscombe's collections of British shells,, but with-
out any indication of locality. Var. 3. Canal near
Oxford (Whiteaves). Var. 4. Norwich (Bridgman).
This remarkable form might easily be raised to the
rank of a distinct species ; but I can only regard it as
abnormal, and analogous to the variety ovalis of U. tu-
midus.

This species was confounded by Lister, Linne, Miiller,
Draparnaud, and all the older writers with U. tumidus.
It differs from that species in the form of the shell, which
is oblong instead of oval ; in its much greater propor-
tionate breadth ; its thinner texture ; in the upper and
lower margins being nearly straight and parallel, instead
of being curved and wedge-shaped ; in the umbonal
region being much less prominent and swollen; and in

86 UNIONIDiE.

the hinge not being so strong, nor the teeth so thick,,
as in U. tumidus. It has been noticed by Mr. Norman
to attain, in ponds at Fleckney and Wistow in Leices-
tershire, the great size of 4^^ inches in breadth and 2\
in length, and to weigh 2 oz. 6 dr.

It is, however, by no means easy to draw a satis-
factory line of separation between this and the last
species, which are connected by several intermediate
forms, and especially by the U. Philippi of Dupuy. The
fact of their inhabiting the same spot shows, at all
events, that one of them is not a local variety of the
other ; and this ought, I think, to weigh in the scale of
specific distinction. Whether one, or both, of these now
reputed species have become in course of time permanent
varieties or " races '' of the same or some other species,
may be regarded as an antiquarian (although interesting)
question, which does not properly belong to the province
of the zoologist.

Both of these species produce pearls, though of very
small size and inferior lustre. A consolidated mass of
pearly secretion is sometimes formed inside the right
valve near the margin of the posterior side. The shells
were used by Dutch painters (from which the specific
name of pictormn originated) for holding their colours ;
and they are still to be had of any artists' -colourman in
this country, containing a preparation of ground gold
and silver leaf, for illuminating work, the other purpose
having been superseded by palettes. Bouchard-Chan-
tereaux calculated that each individual of U. piciorum
produced, in the breeding-season of May, June, and
July, no less than 220,000 eggs.

The variety curvirostris bears a strong resemblance to
some of the varieties of U. Batavus ; but there is no
satisfactory proof of that species having been found in

uNio. 37

Great Britain. A specimen named Unio Batavus in
Dr. Turton^s collection of British shells is clearly a dwarf
variety of that species^, and is the Unio nana of Lamarck,
U. amnicus of Ziegler, U. Batavus var. e. pusillus of Ross-
massler, and U. nanus of Dupuy. This specimen does
not at all agree with the description or figure given
by Turton of his My sea Batava in his ' Manual ^ ; and it
was not accompanied by any note of the locality. I do
not, however, despair of this species, as well as of U.
rhomboidezis (or littoralis), being discovered in this
country. Both of them inhabit the North of France ;
and the latter once lived in our eastern counties.

3. U. margari'tifer*, Linne.

j\fya margaritifera, Linn. Syst. Nat. ed. xii. p. 1112. JJ. margaritiferus,
F. & H. ii. p. 146, pi. xxxviii (as Alasmodonta margaritifera).

Body dirty grey, with sometimes a tint of flesh-colour :
mantle bordered below with brown, and above with white;
cirri oblong and dark brown : foot large, tongue-shaped, grey-
ish-yellow, or dirty red : gilJs greyish-brown, with whitish
streaks : labial palps broader than long, and united for two-
thirds of their length.

Shell oblong, much compressed, sohd, having a dull surface,
dark bro^vn, or nearly black, transversely and irregularly
wrinkled, especially on the posterior side, with very fine but
obscure longitudinal striae, which are interrupted by the fines
of growth : epidermis thick : heahs incurved, and placed at a
distance of about one-fourth from the anterior side : umhondl
region not prominent, always decorticated or eroded, and to
such an extent as to expose several of the inner layers : lunide
narrow and indistinct : ligament very long, and extending to the
anterior side : hinge-line curved : anterior side rounded : pos-
terior side very gradually sloping and rounded at its extremity,
pinched-up above into a blunt keel or ridge : lovjer margin
straight : inside pearly-white, with a tint of flesh-colour and
blotches of olive-green in the region of the adductor muscles,
pitted in the middle by tubercular folds of the mantle : hinge

* Pearl-bearer.

38 UNIONID.E.

strong ; the right valve having on its anterior side a very broad,
thick, and blunt double tooth, the crest of which is irregularly
tubercled, and on its posterior side a blunt and obscure ridge -
like plate, which in yoiing specimens is grooved or double ;
left valve furnished at its anterior side with a single, conical,
strong and blunt tooth which locks into the double tooth, the
posterior tooth in this valve being similar to the corresponding
one in the right valve : muscular and pallial scars very deep
and distinct. L. 2-4. B. 5.

Var. 1. sinuata. Shell rather broader in proportion to its
length than in the type, yellowish-brown : lower margin in-
curved towards the middle. U. sinuata, Lam. Hist. An. s.
V. vi. pt. i. p. 70.

Var. 2. Boissyi. Shell proportionably longer : lower mar (jin
convex, or rounded. U. Roissyi, Michaud, Compl. p. 112.
pi. xvi. f. 27, 28.

Habitat : Mountain rivers and streams throughout
the British Isles. It is found in several parts of the
Swansea Canal where the bottom is gravelly, having
been carried in by the water-courses which supply it.
It also ranges through the mountainous and hilly parts
of the Continent from Lapland to the Pyrenees. Var. 1.
West of Scotland (Bedford and J. G. J.) ; West of
Ireland (Humphreys and Barlee). A specimen of this
form from Co. Kerry measures nearly 6 inches in
breadth or width. Var. 2. Yorkshire (Sowerby). A
monstrosity also occurs having a longitudinal ridge in
the middle of the sheU.

This species differs from all the others in its shell
being much longer (measured from the beak to the lower
or front margin) as well as more depressed, in its dull
aspect and much darker colour, the extensive erosion of
its umbonal region, and especially in the posterior teeth
being scarcely developed.

The lining of mother-of-pearl is equal to half the
entire thickness of the shell, as may be seen by grinding

ANODONTA. 39.

and polishing one of the valves. The surface of the shell
is of a dull white beneath the epidermis. Pearls ob-
tained from this kind of Mussel are mostly white ; but
they are sometimes green or brown, and occasionally
(but very seldom) they are met with of a lovely pink
colour and worth being set in a brooch or ring.

In Forbes and Hanley^s work will be found a full and
interesting account of the freshwater pearl fisheries,
which have been for so many centuries, though with
little success, prosecuted in these Islands. But to amuse
my readers, and to give some idea of the state of Natural
History in Camden^s time, I will add the following
extract from his ' Britannia,^ under the head of " Cum-
berland."

" Higher up, the little river Irt runs into the sea,
in which the shell-fish having by a kind of irregular
motion {oscitatione) taken in the dew, which they are
extremely fond of, are impregnated, and produce pearls,
or to use the Poet's phrase, baccce conchea, shell-berries,
which the inhabitants, when the tide is out, search for,
and our Jewellers buy of the poor for a trifle, and seU
again at a very great price. Of these and the like Mar-
modeus seems to speak in that line,

" Gignis et insignes, antiqua Britannia, baccas."

It seems that Marmodeus wrote a Latin poem on
jewels and precious stones, which was published at
Cologne in 1539.

Genus II. ANODON'TA^, Lamarck. PI. 11. f. 1, 2.

Body oblong-oval, compressed : gills flexuous : labial palps
lanceolate.

Shell oblong-oval, thin : hinge having only rudimentary
teeth : lunule slight and indistinct.

* Toothless.

40 UNIONID^.

The habits of the Anodontce are the same as those of
the Uniones ; but they differ, according to Moquin-Tan-
don, in being ovoviviparous.

It is by no means an easy task to distinguish some of
the species of Unio ; but the difficulty is much greater
in attempting to separate the various forms of Anodonta.
Even the great Danish naturalist, Miiller, entertained
grave doubts, nearly a century ago, whether there ex-
isted more than one Scandinavian species ; although his
hesitation was not participated in by Nilsson and subse-
quent writers on the Mollusca of that country. In other
parts of the Continent, the long array of specific names,
which have been recorded by H. Drouet, shows that the
tendency of modern conchologists has been vastly to
increase the number of European species. In this
country, Montagu, with all his powers of discrimination,
evidently entertained considerable doubt as to the spe-
cific difference between A. cygnea and A. anatina ; and
Turton, more than thirty years ago, expressed his opinion
"that all our supposed species of this genus maybe
justly resolved into one, varying in their outline, con-
sistence, and colour, from age and local circumstances."
This view has been adopted by Dr. Gray and the authors
of the ' British Mollusca.^ However, as long as any di-
stinction of species is recognized, we must endeavour to
deduce from the observation of natural phenomena any
facts which may facilitate such investigation. One of
these facts seems to consist in ascertaining whether any
different forms inhabit together the same spot and under
exactly similar conditions, without any appearance of an
intermediate link or gradation. Montagu has recorded
such a fact with respect to his Mytilus avonensis and
M. anatinus ; Drouet has given other instances of the
collocation of several species of Anodonta in French

ANODONTA. 41

waters ; and Baudon has also noticed the same circum-
stance in the Departement de FOise. All these cases
would lead us to infer that there exist at least two
distinct species of Anodonta in the North of Europe ;
and I am only at present prepared to go to this extent.
At the same time, I do not dispute the claims of other
forms to specific rank. It would be unseemly, as well
as unjust, thus to depreciate the labours of those
naturalists who have so ably and carefully endeavoured
to solve this perplexing problem j and there is quite as
good reason for believing that their views as to the ex-
tension, are as correct as Ours as to the reduction, of the
specific line. Although, therefore, I only propose to
admit two old Linnean species {A. cygnea and A. ana-
Una) J some at least of the varieties hereafter indicated
may be considered distinct species by those of my readers
who from experience or choice may be inclined to take
another view of the case.

1. Anodonta cyg'nea*, Linne.

Mytilus cygneus, Linn. Syst. Nat. ed. xii. p. 1158. A. cygnea (partly),
F. & H. ii. p. 155, pi. xl. f. 2, 3, & xli, and (animal) pi. Q. f. 3.

Body grey, with a yellowish or reddish tint : mantle bor-
dered with tawny-brown : foot large, broad, dirty-yellow, with
a tinge of orange or red : gills grey, with occasionally a reddish
hue, of a gauze-like textm-e : labial palps broadly triangular.

Shell oblong, rather ventricose, thin, moderately glossy,
yellowish-green or brown, transversely and irregidarly grooved
b)'- the hues of growth, and wrinkled in the same direction on
the posterior and lower sides : epidermis thin ; heahs straight,
placed at a distance of about one-fourth from the anterior ex-
tremity : umhonal regioyi compressed, strongly plaited : liga-
ment rather long, strong, partly concealed within the over-
lapping edges of the upper margin or hinge-hne, which is
straight : anterior side not gaping, rounded, and abruptly

* Belonging to (e. g. food for) swans.

42 UNIONID^.

sloping below : posterior side gradually sloping and com-
pressed above, produced into a rounded wedge-like point, and
gaping : lower margin nearly straight : inside pearl-white and
highly iridescent : hinge slight, having a rather sharp ridge -
like plate on the posterior side in each valve : muscular and
pallial scars very slight and indistinct. L. 2*75. B. 5-35.

Var. 1. radiata. Shell larger, yellowish-green, beautifully
marked with longitudinal rays or streaks of the same colour,
which are sometimes alternate : heaJcs placed at a distance of
only one-third from the anterior side. Mytilus radiatus, Miill.
Verm. Hist, pt. ii. p. 209.

Var. 2. incrassata. Shell more swollen and solid, ohve-
brown : upper margin, or hinge-line, rather curved on the
posterior side. Mytilus incrassatus, Shepp. in Linn. Trans.
xiii. p. 85, pi. 5. f. 4.

Var. 3. Zellensis. Shell broader, yellowish-brown, having
the upper and lower sides nearly parallel ; 'posterior side much
produced. Mytilus Zellensis, Gmel. Syst. Nat. p. 3262.

Var. 4. pallida. Shell light yellow or fawn-colour : hinge-
line rather cui'ved, and raised on the posterior side, which is
produced to a long wedge-like point : lower margin rounded.

Var. 5. rostrata. Shell oblong-oval, somewhat resembhng
in shape Modiola vulgaris : upper margiyi forming a dorsal
crest, which is slightly raised and curved: anterior side
rounded : posterior side attenuated, and ending in a long
curved wedge-Hke point : lower margin nearly straight. A.
rostrata, (Kokeil) Eossmiissler, Iconogr. iv. p. 25, f. 284.

Habitat : Slow rivers, lakes, canals, and ponds
throughout the kingdom as far north as Banffshire ; and
it is one of our upper tertiary fossils. It ranges from
Siberia to the Pyrenees. Var. 1. Bog of Allen, Ireland
(Turton) ; Clumber lake, Notts (J. G. J.). This variety
is the Mytilus stagnalis of Gmelin, the M. dentatus of
Turton's Conchological Dictionary, and the M.jMludosus
of his work on the British Bivalves. Specimens of this
variety measure upwards of 6 inches in breadth. Dr.
Turton^s type (of which only one valve remains) has a
small pearly tubercle on the ridge of the laminar tooth ;

ANODONTA. 43

and I suspect that the Doctor mistook this excrescence
for a cardinal tooth, and therefore applied the specific
epithet " dentatus/^ He omitted any mention of this
character in his Dithyra, when he changed the name to
" paludosus/^ Var. 2. Scarborough (Bean) ; Otters
pool, Lancaster (Tyler) ; Oxwich marsh, near Swansea
(J. G. J.). This is the A. ponderosa of C. PfeiflPer.
Var. 3. Bog of Allen, Ireland (Humphreys) ; Clumber
lake, Notts (J. G. J.). It is the A. Cellensis of C.Pfeiffer.
Var. 4. West of Ireland (Humphreys). Var. 5. R.
Corfe, Dorset (J. G. J.) ; ponds at Wistow in Leicester-
shire, Wynyard Park, Co. Durham, and Oxford (Nor-
man). This appears to be the Mytilus Avonensis of
Montagu (Test. Brit. p. 172), judging from his descrip-
tion and the figure of that species which is given by
Maton and Rackett in the ' Linnean Transactions,^ vol.
viii. pi. 3. A. f. 4. The shell of this species is also liable
to be distorted ; and I have a specimen in which the
lower part of the left valve is deeply notched opposite
the beak, owing to an injury of the mantle on that side^
the other valve being entire.

The fry have triangular and pearly shells, which might
easily be mistaken for the valves of a Cypris or smaller
Entomostracan. The epidermis only is coloured in this,
as well as in the other species : the surface of the shell
itself, under the epidermis, is white or colourless.

2. A. anati'na*, Linne.

Mytilus anatinus, Linn. Syst. Nat. ed. xii. p. 1158. A. cygnea (partly),
F. & H. ii. p. 155, pi. xxxix. f. 3.

Body grey, of different shades of intensity : mantle bordered
with dark brown : foot yellowish-grey, or red : cjiUs, greyish-
brown.

* Belonging to {e. g. food for) ducks.

44 UNIONID^.

Shell oval, rather compressed, not so thin as in the usual
or typical form of the last species, olive-green or brown, ^vith
darker transverse bands denoting the lines of growth, and
irregularly wrinkled in the same direction : epidermis rather
thicker than in A. cygnea : heaJcs straight, placed at a distance
of about one-third from the anterior end : umhonal region
compressed, closely plaited : ligament short and prominent :
upper margin or hinge-line raised into a kind of crest, and
curved: anterior side rounded and gaping below, with an
oblique slope towards the lower edge : posterior side curved
and abruptly sloping to a wedge-like point: lower margin
gently curved : inside and hinge as in A. cygnea ; but the
lining is much thicker in the present species, and the muscular
impressions are consequently much more deep and distinct.
L.2-1. B.3o.

Yar. 1. radiata. Shell (or rather the epidermis) marked
with green and yellow rays.

Yar. 2. ventricosa. Shell larger, more solid, exceedingly
tumid, especially in the middle and towards the umbonal
region, also marked with green and yellow rays. A. ventri-
cosa, C. Pfeiffer, ii. p. 30, pi. iii.

Yar. 3. complanata. Shell oval, greatly compressed, brown:
healcs placed close to the anterior margin : upper margin raised
and curved : anterior side abruptly truncate. A. complanata,
(Ziegler) Rossmiissler, iv. p. 24, f. 283.

Habitat : Same as that of A. cygnea; but it ranges
further to the south, being a Sicilian species. It has
not been noticed in this country as a tertiary fossil.
Var. 1. The rayed markings form scarcely a varietal
character, being common to half-grown individuals of the
last, as well as of this, species. Var. 2. R. Exe (Clark).
This variety has been referred by Moquin-Tandon
to A. cygnea ; but it evidently belongs to the short
form, or what is generally called A. anatina. None of
my specimens (of which I possess a series) are as broad
as the one represented by Pfeiffer in his figure 4. This
variety attains a larger size than the typical form, being
more than 3 inches long, 5 wide, and 2 in depth. Var. 3.

DREISSENID.E. 45

Gumfrieston, near Tenby (Smith). A monstrosity, or
distortion, of this last variety is also in my cabinet,
which is flatter and has a rounded outline above in
consequence of the umbonal region not projecting. A
young specimen of the same variety is nearly round.
This appears to be analogous to the variety rostrata of
A, cygnea, and tends to confirm the idea of the two
species being distinct.

The chief points of difiference between A. cygnea and
A. anatina are, that the shells of the latter species are
smaller and comparatively longer ; the hinge-line or
crest is raised in that species, instead of being straight
or parallel to the lower margin ; and the posterior side
slopes abruptly instead of (as in A. cygnea) gradually.

Family III. DEEISSENID^.

Body nearly rhomboidal, compressed : mantle closed, except
at the posterior side, where it is folded into two orifices, one
for respiratory and nutritive, and the other for excretal purposes,
besides an opening at the lower or front margin for the passage
of the foot. The upper, or excretal, fold is the smallest, and is
not much produced : the other fold is extended into a pyra-
midal tube, which has a thickened or reflected margin and is
fringed with numerous short spine-shaped cirri or tentacles :
foot long and tongue-shaped, furnished with a byssal groove.

Shell equivalve, oblong, triangular, very inequilateral,
ventricose, covered with a thick and horny epidermis : heahs
placed at the anterior end : ligameyit internal : inside porcelain -
white : hinge furnished with minute cardinal teeth, but some-
times toothless ; below the beak in each valve is a triangular
shelf or hollow plate (as in the marine genus Crepidula) for the
reception of the anterior muscle.

These characters are also generic, as the family con-
tains but one genus. In their general aspect the Dreis-
senidce bear a closer resemblance than the last to the

46 DREISSENID>«.

Myiilidce ; but the mantle of tlie animal in the present
family is nearly closed, and the hinge of the shell is
furnished inside with a transverse plate or septum, which
is a peculiar and unmistakeable feature. Mytilus has
also several cardinal teeth; but I have failed to detect
any in the British species of Dreissena, although the
authors of the ^ British Mollusca ' and Moquin-Tandon
mention an " obscure apical elevation," or "dent cardinale
a peine saillante/' in the right valve of this species.
However, cardinal teeth certainly do exist in three species
of Dreissena from the Indian and Pacific Oceans, which
have been described by Erichson in Wiegmann^s ' Archiv
fiir Naturgeschichte ' for 1836. The same author also
incidentally remarks that the European species (which
he called Tichogonia fluviatilis) has a rudimentary tooth.
The mantle is for the most part closed and produced
into tubes on the posterior side, instead of being open
throughout as is the case in Mytilus.

Genus DBEISSE'NA *, Van Beneden. PI. II. f. 3, 4, 5.

Although the establishment of this genus is due to
Van Beneden, the probability of its separation from
Mytilus was first suggested by an equally distinguished
zoologist of our own country. Dr. Gray. The Dreissence
may be called " freshwater Mussels " with greater pro-
priety than the Uniones, or Anodontce ; and the habit and
faculty which the Dreissenca possess, in common with the
true JNIussels, of mooring or attaching themselves by a
strong byssus to extraneous substances, put us \qvj
much in mind of their marine analogues. They are also
equally gregarious and capable of living for a long time
out of water.

* N^med ftfter M. Dreissens, a druggist at Mazeylh.

DREISSENA. 47

Only one species is known in Europe ; and it was first
noticed (in 1754) by the Russian traveller and natura-
list^ Pallas, in the River Wolga, as well as in the Black
Sea. The epithets of " fluviatilis ^^ and "marinus"
which he applied to these two forms, coupled with the
circumstance that this was antecedent to the era and
usage of binomial appellations, have given rise to con-
siderable controversy as to whether these forms belong
to different species or to varieties of the same species,
one of which has a freshwater, and the other a marine,
habitat. The last supposition would be quite consistent
with the fact observed by Nilsson, that several shells,
which are usually inhabitants only of fresh water, live
in the Baltic Sea together with other shells which are
peculiarly marine.

Dreissena polymor'pha *, Pallas.

Mytilus polymor'phus, &c., Pallas, It. Euss. i. p, 478. Dreissena 'poly-
mor;pha, F. & H. ii. p. 165, pi. xlii. f. 4, 5, and (animal) pi. Q. f. 4.

Body dark- coloured : 7nantle bordered in front with greyish -
white, at the posterior side being yellowish or fawn -colour,
and striped hke the shell with zigzag marks of reddish -brown ;
cirri of the branchial orifice arranged in concentric rows, red-
dish-grey, with a tint of brown at their base : foot oblong and
cylindrical, grey, with a slight rosy hue : gills greyish : labial
palps rather large, triangular, and lanceolate : hyssus composed
of several stout and flexible threads.

Shell oblong, rising into a sharp keel in the middle of each
valve and flattened below, pointed at the end or beak, and
gradually, but obliquely, widening towards the fi'ont, rather
solid, but not glossy, yellowish-brown, and often marked trans-
versely on the upper part with undulating or zigzag streaks of
purple or dark brown, strongly but irregidarly wrinkled in the
same direction, and longitudinally but shghtly puckered at
irregular intervals : epidermis silky ; beneath the epidermis
the surface is purplish-brown ; healt's small, quite terminal, and

* Many-shaped.

48 DRETSSENID/E.

much incurved : ligament long and narrow, fitting into a groove
of the hinge in each valve : upper margin angular : anterior
side nearly straight : posterior side curved : lower margin in-
curved, and forming in the middle a large slit for the passage
of the foot and byssus : inside slightly nacreous : hinge strong,
toothless, but furnished inside each valve with a triangular
and concave plate which is placed under the beak : muscular
and j9aZZmZ scars indistinct. L. 1*4. B. 0-6.

Habitat : Slow rivers, canals, and lakes in the eastern,
home, midland, and northern counties of England, as
well as in a canal near Worcester (Reece), Bath (Hutton),
and at Edinburgh. In the North of France, Belgium,
and Germany it is also common and widely diffused.
In one respect this species may be said to be truly metro-
politan; for it has been found in the most frequented
streets of London, after they have been flushed with
water from the New Biver, where it abounds. Mr.
Norman informs me that he saw immense numbers of
the Dreissena in a living state, lining some of the iron
water-pipes which had been taken up in Oxford Street,
and that the colouring of the shells was as vivid as if the
animal had lived in the light of day.

It is difficult to believe, in the absence of some proof
to the contrary, that this species is not indigenous to
the whole of the North of Europe, as well as to Bussia.
The circumstance of its not having been noticed in this
country before 1824, and then only in a metropolitan
locality, does not preclude the possibility of its having
previously existed in some other part of Great Britain ;
and its not having been previously recorded as British
rather proves a want of observation or opportunity than
its non-existence. Helix Cartusiana, H. obvoluta, and
Clausilia Rolphii, all of which are conspicuous land shells,
were not known to the observant Montagu, although
they are not uncommon in some parts of this country

DREISSENA. 49

and are clearly indigenous species; and many other
similar instances_, both at home and abroad, might be
cited on this point, as well as with respect to the sudden
and unaccountable appearance and disappearance of cer-
tain species in particular spots. With regard to the
period at which the Dreissena first made its appearance
or was noticed on the Continent, M. Moerch has lately
investigated its geographical history and has ascertained
that it was common in the interior of Germany before
1780, and that it then inhabited streams which flowed
into the Rhine. In a work by H. Sander of Carlsruhe,
published in that year, and entitled " Vaterlandische
Bemerkungen fiir alle Theile der Naturgeschichte,^^ he
described in unscientific, but intelligible, terms a fresh-
water Mussel which was not uncommon in that district,
and to which he gave the name of Pinna fluviatilis. This
description clearly applies to our Dreissena. In draining
the Haarlem See, the Dreissena was found in abundance ;
and it appears that no communication ever existed be-
tween that great lake and any port or harbour. It has
also been found in an inland lake near Copenhagen. It
was at one period thought (and even by the unimagi-
native Linne) that the Teredo^ or ship-worm, had been
imported into Europe from India; but that idea has
been quite dispelled, as much for the reason that some
species of Teredo which are found in Europe also occur
there in tertiary formations, as because they are different
from oriental or tropical kinds. The first of these reasons
may again, and with the like success, be urged in favour
of the Dreissena being a native of the North of France ;
for, in a recent article by M. Charles D^Orbigny, pub-
lished in the ^ Bulletin de la Societe Geologique de
France ^ (2^ ser. t. xvii. p. 66), and entitled " Sur le
diluvium a coquilles lacustres de Joinville," Dreissena

50 DREISSENID^.

polymorpha is enumerated as one of the fossils. Mr.
Prestwicli informs me that this deposit was in all pro-
bability contemporaneous with those of St. Acheul and
Amiens^ and that at all events it belongs to what is
termed by modern geologists the upper tertiary forma-
tion. I am therefore not without hope that this remark-
able shell may be discovered in the corresponding strata
in this country. It is frequently founds in a recent or
li\dng state_, with the Anacharis alsinastrurrij an aquatic
plant which chokes up our canals and is said to have been
imported from North America. Respecting \\\.q Anacharis,
Messrs. Hooker and Arnott. in their excellent work on
the British Flora, remark that '^\i seems inexplicable how
this plant should have occurred in so many different
places at the same time.^^ Perhaps if the Eriocaulon
septangularey or Naias flexilis, both of which are also
North-American water-plants, and are at present con-
fined to a very few stations in the Hebrides and West of
Ireland, had been placed in conditions which were more
favourable to their growth and propagation, each of them
might have spread with as great rapidity as the Ana-
charis. If, as I believe, the indigenousness of the
Dreissena as regards this country should hereafter be
established, the ingenious theories which have been pro-
posed to account for the mode of its transport across the
seas will not require further discussion.

PECTINIBRANCHIATA. 51

Class II.
GASTEROPODA*, or UNIVALVES.

Body of a conical shape : mantle tormmg a single lobe, which
only covers the front: head usually distinct, and furnished
with tentacles, of which the upper pair (in those kinds which
have four), or the single pair, have in most cases two eyes,
placed either at their tips or base, or on separate stalks : foot
a muscular disk, by means of which the animal generally
crawls, or sometimes floats in an inverted position on the
under surface of the water : reproductive system various ; some
kinds being hermaphrodite, and ha\ing both sexes united in
the same individual, but requiring impregnation by another
individual ; while in other kinds the sexes are separate, each
individual being either male or female : resphxitory system con-
sisting of gills, or lung-like organs ; the former, and some of
the latter, being possessed by aquatic kinds ; while the terres-
trial kinds are only furnished with the lung-like organ : those
kinds which are aquatic, and have this last organ, eliminate
oxygen from the water and also respire atmospheric air ; but
the terrestrial kinds, or Snails, breathe only the pure air, like
vertebrated land animals.

Shell usually present, conical or spiral, and covering the
whole, or most important parts, of the body.

The only two Orders which we have to deal with in
this division of the subject are as follows : —

I. Pectinibranchiata.

II. Pulmonobranchiata.

Order I. PECTINIBRANCHIATA

J,

Body spiral : respiratory apparatus consisting of a single
comb-like gill, which is placed within the mantle, on the upper
side of the head.

Shell external and spu^al.

* Foot forming the belly. f Having comb-like gills.

D 2

52 NERITID^.

Only three families of this Order inhabit the fresh
waters of this country. They are, —

I. Neritid^.

II. PaLUDINIDyE.

III. Valvatid^.

All these freshwater Snails have two tentacles, and the
same number of eyes, which are placed at the base of the
tentacles. Their shells are furnished with an epidermis
and operculum.

Family I. NEEITID^.

Body oval, having a short spiral turn at the end : eyes
placed outside the tentacles at their base : gill inside the
mantle : sexes separate.

Shell semiglobose, with an excentric spire and a semicircu-
lar mouth : operculum having an excentric and short spire,
and furnished imderneath with an apophysis or projecting pro-
cess which locks into the columellar or piUar lip.

Although the members of this family are very
numerous and widely dispersed beyond the limits of our
seas, we have only a solitary representative, forming the
single species of one genus.

NERITI'NA*, Lamarck. PI. III. f. 1, 2, 3, 4.

Body furnished with a strong and prominent snout or
muzzle : tentacles long : eyes placed on footstalks : foot broad.

Shell triangular-oblong : ojperculum calcareous and sohd.

The mollusks of this genus inhabit waters which have
a stony or gravelly bottom. Their habits are sluggish ;
raising their shell but little dming their march, and then
only showing their tentacles, eyes, and the front of their

* Diminutive of Nerita, a genus of marine shells.

NERITINA. 53

mantle. They have not been observed to float_, or creep
on the under surface of the water^ which may account
for the shells being so often found encrusted with cal-
careous matter. Their tentacles_, however^ appear to be
extremely sensitive and always in motion. They are
vegetable feeders. Their eggs are generally deposited
and carried on the shell until they are hatched or de-
veloped. These are rounded, of a yellow colour, and
provided with a thick and leathery covering, which splits
in two when the fry are excluded, the upper half being
detached and the other part left adhering to the parent
shell. Moquin-Tandon says the eggs are deposited in
a cluster of from 50 to 60.

Valuable notices of the genera Nerita and Neritina
by M. Recluz will be found in the 1st volume of the
'Journal de Conchyliologie;' and M. Pouchet has pub-
lished an elaborate monograph on the Nerita fluviatilis,
considered in an anatomical and physiological point of
view. Neritina is very closely allied to Nerita, and pro-
bably only forms a section of the latter genus. There are
marine, as well as freshwater, species of Neritina.

Neritina fluvia'tilis*, Linne.

Nerita fluviatilis, Linn. Syst. Nat. ed, xii. p. 1253. N. fluviatilis, F. &
H. iii. p. 3, pi. Ixxi. f. 1,2, and (animal) pi. H. H. f. 1.

Body of a clear jellowish-grey, speckled with black above,
white below : head and snout black : mouth very large, fur-
nished with cartilaginous jaws and a Ungual plate or riband,
which is very complicated : tentacles clear greyish-white, darker
at the sides, and more or less streaked with black transversely ;
they diverge widely from their base, and are very slender,
ending in a fine point : eyes very large and black : foot obtusely
rounded in front, and having its extremity or tail covered by
the operculum when the animal is crawling.

Shell convex above, slightly compressed towards the spire,

* Inhabiting rivers.

54 NERITID^.

and almost concave below, solid, moderately glossy, j'ellowish
or brown, with often bro^vn or white zigzag streaks, spots, or
bands, which run lengthwise or in a spiral direction, and
marked with fine but distinct transverse strise or plaits, which
are more conspicuous towards the suture : epidermis thin :
wliorls 3, rather convex, the last or lowermost exceeding two-
thirds of the whole shell, increasing veiy rapidly and dispro-
portionately in size : spire very short and oblique : suture
rather deep : mouth, or aperture, semilunar : outer lip sharp :
j)illar-lip exceedingly broad, polished and flat, with a sharp
and plain edge : operculum semilunar, glossy, of an orange or
yellowish colour, marked spirally with two or three slight
grooves, and ti'ansversely with numerous and flexuous striae ;
its external edge is thin and has a border (sometimes two) of
black or yellowish-red, both above and below ; its internal
edge is thick ; the spire of the operculum is placed at the
lower side, and formed of 1| or 2 whorls ; attached to the
under side of the opercular spire is a singular process, re-
sembling a second but much smaller operculum, which has
also a thickened edge on the inside, and projects obliquely so
as to act as a bolt in fastening the operculum to the pillar-lip.
L. 0-35. E. 0-25.

Habitat : Slow rivers^ streams, and lakes through or
into which Avater flows, or having a stony or gravelly
bed, in all parts of the kingdom, from the Orkneys to
Cornwall. It has been found in the peat-bed at New-
bury ; but this is not, I believe, recognized as belonging
to the upper tertiary formation. This species ranges
from rinmark to Algeria and Sicily, where the form or
variety called by Lamarck N. Batica prevails. A dwarf
variety has been described by Nilsson, which inhabits the
shores of the Baltic Sea, adhering to seaweeds and
stones, sometimes at a distance from the mouth of any
river, and living in company with the common Mussel
and a few other decidedly marine shells. He also noticed
that these last are similarly dwarf forms. A variety in
which the shell is quite black has been found l^y Mr.
North in the Ouse. Many other varieties have been

PALUDINA. 55

described by European authors as distinct species; but
they appear only to differ from the typical kind in size
and colour^ as well as in the spire being more or less
excentric. In adult specimens, the septa or internal
walls of the spire are wanting, and appear to have been
absorbed, as stated by Dr. Gray. This is also the case
in Melampus or Conovulus,

Family 11. PALUDINIDiE.

Body elongated, spiral, and having a prominent snout : eyes
placed outside the tentacles at their base : gill inside the
mantle : sexes separate.

Skell having a long symmetrical sjnre and an oval mouth :
operculum also oval, irregularly concentric or paucispiral.

These mollusks are, as well as those of the last family,
herbivorous ; but they differ in being ovoviviparous, in-
stead of oviparous. Their habits are much more active
than those of the Neritidce. They sometimes, but rarely,
float. The fry are furnished with opercula before they
are excluded by the mother. According to Bouchard-
Chantereaux, the young remain in the ovary, to the num-
ber of 20 or 30, for two months, at the end of which time
only 2, 3, or 4 are born, the period of accouchement ex-
tending over several days.

Genus I. PALUDI'NA*, Lamarck. PI. III. f. 5, 6.

Eyes placed on short pedicles or footstalks : operculum horny,
irregularly concentric, and having its nucleus on the inner
side.

Lister and Cuvier have investigated, although at very
distant intervals, the anatomy of these mollusks, which

* Inliabitina: marshes.

56 PALUDINID.E.

are the largest of our freshwater Pectinibranchs. Lister
says he was indebted to Dr. Plot^ the historian^ for the
discovery that they were viviparous ; and he says that the
males are smaller than the females and their shells have
less-swollen whorls. They inhabit slow rivers^ ponds and
canals ; and one species lives within the influx of the tide
in the Thames. The epidermis of the last-formed whorl
in the young shell, when it leaves its mother, has three
transverse rows of recurved bristles, which in after- growth
are replaced by the coloured bands that encircle adult
shells, the formation of these bands, as well as of the
bristles, being caused by difierent organs which are suc-
cessively developed in the same part of the mantle. It
has been stated in that useful periodical 'The Zoologist'
(p. 7402) that our native Pahidince are not always vivi-
parous, and that a specimen of P. vivipara deposited in
an aquarium some eggs from which the fry were subse-
quently excluded. This was in the winter, and after the
Paludina had been kept for many months in a state of
confinement. It is hoped that further observations will
be made on this point, as the ovoviviparous character of
this genus constitutes one of the grounds of distinction
from the next genus, Bythinia.

1. Paludina contec'ta*. Millet.

Cyclosfoma contectum, Millet, Moll. Maine et Loire (1813), p. 5. P. Lis-
ten, F. & H. iii. p. 8, pi. Ixxi. f. 16.

Body dark grey or brown, with yellow specks : head small,
but globular : snout prominent and bilobed : tentacles long and
widely spread out, blacldsh, with grey tips ; the right tentacle
of the male shorter and thicker at its point than the left : eyes
round and black : foot cloven or bilobed in front, and rounded
behind ; its tail or extremity nearly covered by the operculum
when the animal is crawling.

* Covered (?". e. by the operculum).

PALtDINA. 57

Shell conical, moderately solid and glossy, yellowish, with
sometimes a green or brown tinge ; the last whorl having 3,
and each of the two preceding whorls 2, spiral brown bands,
the uppermost of which is usually the broadest ; there are also
numerous and very fine spiral striae, besides faint and irregular
lines of growth : epidermis rather thick : whorls 7, extremely
convex ; the last being equal to about one-half of the shell ;
they increase gradually in size, except the two first, which
are disproportionately small and twisted, resembling those of
Succinea : suture remarkably deep : mouth oval, or approaching
to a circular shape : outer Up sharp and slightly reflected : inner
lip separate from the columella ; both lips forming a complete
peristome : umbilicus small, oblique, but very distinct and deep,
exposLug part of the internal spire : operculum rather thin,
compressed towards the nucleus, which causes the under side
to project, like the boss of a shield ; it is marked with nume-
rous concentric striae and more distant lines of growth. L. 1-5.
B. 1-25.

Habitat : Slow rivers^ canals, and large pieces oi
standing water^ throughout the greater part of England,
as far north as Yorksliire. It is, however, rather local.
This is a Finland species, and ranges south to the
Pyrenees.

This mollusk, when at rest, adheres firmly to stones
and wood ; but on being touched, it immediatelly falls oft'.
It sometimes attains to a large size, one of my specimens
being more than 2 inches long and If broad.

The Linnean description of Helix vivipara accords
more properly with that of the next species, w^hich has
only an umbilical chink (^^imperforata'^), and is pecu-
liarly "subovata^^ and ^^obtusa.^^ The name given by
Millet to the present species, which does not appear to
have been known to the authors of the ' British Moliusca,^
must of course be adopted in preference to the very
modern one of '' Listeri" which was proposed by them.
Miiller considered this species to be that of Linne ; and
he described the other as Neritafasciata.

D 5

58 PALUDINID^.

2. P. viYi'pARA^, Linne.

Helix mvipara, Linn. Svst. Nat. ed. xii. p. 1247. P vivipara, F. & H.
iii. p. 11, pi. Ixxi. f. 14, 15, and (animal) pi. H. H. f. 2.

Body of a darker colour than that of P. contecta : snout
broad: tentacles bluish-black, with bright yello^y spots; the
difference of their size in the male being very perceptible : eyes
rather large : foot very broad, and slightly truncate in front.

Shell oval, rather solid, but not so glossy as that of P. con-
tecta, yellowish -green, with bands and striae as in that spe-
cies ; the surface of the two last whorls is often iiTCgularly
indented or pitted: epidermis rather thin: whorls G|, rather
convex, the last exceeding one-half of the shell, gradually in-
creasing in size, except the first, which is extremely small and
twisted, but much less prominent than in the last species,
making the point of the spire to appear blunt : suture rather
deep : mouth oval, and less inclined to a circular shape than in
P. contecta : outer li/p rather thick and slightly reflected : inner
lip united above to the columella, but both lips form a com-
plete peristome : there is no umbilicus, but instead of it there
is a small and narrow chink behind the inner lip : operculum
rather thick, comj)ressed transversely, and marked with strong
lines of increase and finer intermediate striae. L. 1*5. B. 1*2.

Var. iinicolor. Without bands.

Habitat : The same as that of the last species (with
which it is often found living)^ except that the Rev. Dr.
Gordon has found it at Findhorn in the Moray Firth
district. Sir Charles Lyell has recorded its occurrence
in the lacustrine deposit at Mundesley in Norfolk. Its
northern range abroad is also the same ; but it extends
southwards to Naples, and (according to Philippi) pro-
bably also to Sicily. The variety has been found by
Mr. Pickering in Hertfordshire_, and by myself in the
Thames at Richmond. I have also a monstrosity in
which the last whorl has a keel occupying the place of
the upper band.

This species differs from P. contecta in its shell being

* Bringing forth its young alive and perfect.

BYTHINIA. 59

thicker and longer, the whorls being much less swollen,
the suture not so deep, the apex or point of the spire
more blunt, and the mouth being less circular. Its size
is not quite equal to that of the other species, the largest
British specimen which I have of this being 1 1 inch
long and 1^ broad.

The animal is rather active. M. Millet counted in a
female 82 young ones of different sizes. Mr. Clark has
remarked that, in all the specimens which he procured
from the River Exe, the point of the spire is eroded.
This is probably owing to the influx and admixture of
sea-water in that part of the river, because there are few,
if any, manufactories on the banks of the Exe. In the
Paddington Canal and parts of the Thames near London,
the erosion is evidently owing to the last-mentioned cause.
Draparnaud named this species Cyclostoma achatinum.

Genus II. BYTHI'NIA *, [Bithinia] Gray.
PI. III. f. 7, 8, 9.

Eyes sessile: opercuhim testaceous and solid, irregularly
concentric, and having its nucleus nearly in the middle.

This was first indicated by Dr. Gray as a subgenus of
Paludina; and the name which he proposed has been
adopted by almost all conchologists. The chief differ-
ence between this and Paludina consists in the animal
of Bythinia being oviparous, instead of ovoviviparous, —
its eyes being sessile, instead of placed on stalks or tu-
bercles as in the other genera of this family, — and in the
operculum being testaceous and concentric, with its
nucleus placed almost in the middle. The tentacles of
the male are of equal size in the present genus. Although
the derivation of the word Bythinia would imply that

* Inhabiting deep water.

60 PALUDINID^

these mollusks inhabit deeper water than others of the
same family, such is not the case. They generally fre-
quent small streams, canals, shallow ponds and ditches.
They lay their eggs in three long rows on stones, as well
as on the stalks and leaves of water-plants.

1. Bythinia tentacula'ta *, Linne.

Helix tentaculata, Linn. Syst. Nat. ed. xii. p. 1249. Bithinia tcntaculafa,
F. & H. iii. p. 14, pi. 1^. f. 5, 6, and (animal) pi. H. H. f. 3.

Body dark bro^Ti or almost black above, dirty grey beneath,
covered with small and irregular specks of yellow : head small
and semioval : snout long and deeply cleft in front : tentacles
very long and slender, greatly diverging : eyes large, oval, and
black : foot much broader than the snout, rounded in front,
with a blunt and rounded tail which is half concealed by the
operculum when the animal is crawling.

Shell subconical or oval, rather sohd and glossy, nearly
opaque, of an amber colour, with often more or less of a brown-
ish tint, very finely and closely striate in a spiral direction and
crossed transversely by the marks of growth ; the spii'al striae
are sometimes confluent and form white lines : epidermis very
thin : whorls 6, convex ; the last exceeding one-half of the
shell, and the rest diminishing in proportion and ending in
rather a sharp point : suture rather oblique and deep. : mouth
oval, angular above : outer lip thick, and sometimes strength-
ened by a white, rather strong, internal rib, which when re-
peated gives the shell a slightly varicose appearance ; this hp
is very little reflected : inner Up united to the columella, but
forming with the other hp a complete peristome : umhilical
chink small and narrow : operculum obhquely oval, very thick,
angular at the top, compressed or indented in the middle of
the upper half; it is marked with exquisitely fine concentric
stria} and a few coarser ridges, denoting the marks of periodical
increase, which form raised platforms or layers, the smallest
or first-formed being uppermost. L. 0-5. B. 0-25.

Var. 1. ventricosa. Shell white: whorls more swollen.
Paludina ventricosa, Menke.

Var. 2. decoUata. Upper whorls wanting in half-grown and

* Having tentaclea.

BYTHINIA. 61

adult specimens ; their place being supplied by a nearly flat
and semispiral plate, as in Bulimus decoUatus.

Var. 3. eoccavata. Whorls more rounded, and suture much
deeper.

Habitat : Slow rivers^ ponds^ and still waters every-
where in England_, Wales^ and Ireland^ as well as at
Frazerbiirg in Aberdeenshire ; and it is perhaps the
most abundant fossil in the lacnstrine beds of our upper
tertiaries. Var. 1. Devonshire (Mus. Turton) ; Bristol
and Wandsworth (J. Gr. J.) ; Richmond^ Surrey (Choules) .
Var. 2. Woolwich and Cardifi* (J. G. J.) ; Co. Armagh
(Waller). Var. 3. Cardiff (J. G. J.). This last variety
seems to connect the present species with B. Leachii ; but
it differs from the last-mentioned species in its greater
size, as well as the oval shape of the mouth. B. tenta-
culata ranges from Siberia to Sicily. The animal is
sluggish, but irritable. It sometimes floats, or creeps
on the under surface of the water. Draparnaud says
that it feeds on animal as well as vegetable substances.
The shell is often encrusted with a ferruginous or mineral
deposit. From this circumstance Draparnaud derived
the name of impura which he gave this species, having
needlessly changed the prior one assigned to it by Linne.
The epidermis in young specimens is slightly hispid and
resembles a fine velvety pile.

This species was first made known and admirably
described by our countryman. Lister.

2. B. Leach'ii"^, Sheppard.

Turbo Leachii, Sliepp. in Linn. Trans, xiv. p. 152. Bithinia Leachii, F.
& H. iii. p. 16, pi. Ixxi. f. 7, 8, and (animal) pi. H. H. f. 4.

Body greyish-white, with black and yellow specks : tentacles
very flexible : foot slender.

* Named afteii Dr. Leach, a celebrated English zoologist.

62 PALUDINIDJi:.

Shell conical, rather thin, glossy, and semitransparent,
greyish horn- colour or amber, microscopically striate in a
spii'al direction, and irregularly marked by the lines of growth :
epidermis extremely thin : whorls 5, very convex and rounded,
but narrow, the last occupying about one-half of the shell :
spire rather abruptly pointed : suture nearly straight, ex-
tremely deep : mouth nearly round, very slightly angular above,
where the outer lip meets the columella : outer lip rather thick,
and strengthened by a slight internal rib, scarcely reflected,
except below : inner lip forming with the other lip a com-
plete peristome : umbilicus small and narrow, but distinct :
operculum almost circular and flat, otherwise like that of the
last species. L. 0*25. B. 0-2.

Var. elongata. Shell smaller ; spire more produced.

Habitat : Nearly the same as that of B. tentaculata ;
but the present species does not extend so far norths
and it is more local and much less abundant. It is
also equally rare as a tertiary fossil. The variety is
from Woolwich marshes and Northampton. Malm has
recorded this species as Swedish; and Morelet has
noticed it as inhabiting Algeria.

This species is distinguishable from the last, in com-
pany with which it is sometimes found living, by its
much smaller size, the whorls being more swollen and
narrower (giving the shell a scalariform appearance), the
very deep suture and distinct umbilicus, as well as by
the shape of the mouth and operculum. It is sometimes
known by the specific name of ventricosa, which was origi-
nally given to it by Dr. Gray, but without any description.
The Cyclostoma simile of Draparnaud, to which the pre-
sent species has been referred by some authors, is very
different, as will be seen presently. Specimens in Dr.
Turton^s collection, named respectively "Paludina simi-
lis/' " P. viridis/' and " P. anafmaj" all belong to B.
Leachii, being merely difterent stages of growth. The
late M. D^Orbigny gave me, at llochdle, in 1830 some

HYDROBIA. 63

shells which he had received from Draparnaud under the
name of " Cyclostoma anafinum.'^ These appear to be
a small variety of the present species, and are probably
the B. humilis of M. Boubee.

Genus III. HYDRO'BIA *, Hartmann.
PL III. f. 10, 11, 12.

Ei/es placed on tubercles : operculum horny and thin, pauci-
spiral.

The little mollusks which are comprised in this genus,

although very closely related to the true and marine

RissocBy appear to have as much right to be generically

separated from the latter as Neritina has to form a

distinct genus from Nerita. Nearly all the Hydrobice

are inhabitants of fresh and pure water; but one of

them [H. ventrosa) frequents estuaries, as well as pools

and ditches close to the sea-shore which are liable to be

occasionally overflowed by the tide, and the water of

which is more or less brackish. Those species which

inhabit fresh water have been arranged by Moquin-

Tandon in a subgenus of Bythinia, named by him Bythi-

nella. With Bythinia, as well as with Rissoa, this genus

has undoubted relations. It differs, however, from the

former in the eyes not being sessile, but placed on short

tubercles, and from the latter in wanting the caudal

filament which is appended to the foot. The shell of

Hydrobia has besides an umbilical cleft which does not

exist in Rissoa ; while its operculum is decidedly not

Bythinian, but Rissoan, or rather Littorinan. It may

therefore be considered as in many respects forming an

intermediate link between those two genera, but having

a greater affinity to Rissoa. The ' genus Hydrobia was

* Living in water.

64 PALIJDINID^.

founded by Hartmann in 1821. An objection has been
made to the name on the ground that it had been pre-
viously used for a genus of small water-beetles ; but it
does not seem that any confusion or inconvenience is
likely to result from the use of the same name in such
different departments of zoology, and precedents are not
wanting for such a double application. We have only
two species of Hydrobia-, but on the Continent there
are four or five times that number, including Hydrobia
marginata which existed duiing the Glacial epoch in our
eastern counties and Bedfordshire, but appears not to
have survived that period.

The estuarine or brackish -water species of Hydrobia
were formed by Professor D^Orbigny into another genus,
which he called Paludestrina ; and these also constitute
the genus Paludinella of Pfeiffer and Loven.

1. Hydrobia si'milis *, Draparnaud.

Cyclostoma simile, Drap. Moll. Terr, et Fluv.Fr. p. 34, pi. i. f. 15. Bissoa
anatina, F. & H. iii. p. 134, pi. Ixxxvii. f. 3, 4.

Body dark grey, with a yellow or brown tint and white
flaky specks : head rather large and prominent : snout broad,
long, and ridged transversely: tentacles long, slender, and
diverging : eyes large and rather protuberant : foot short, very
broad, and expanded on each side in front, rounded behind,
and extending considerably beyond the operculum when the
animal is crawling.

Shell subconical or oval, rather thin, glossy, semitrans-
parent, yellowish horn-colour, or sometimes clear white, ob-
scurely and slightly marked by the lines of growth : ejnderiiiis
a mere film : whorls 5-6, rounded, but compressed ; the last
exceeding one-half of the shell : spire rather pointed : suture
somewhat oblique and deep, forming a narrow canal : mouth
oval : outer Z//> thin, shghtly reflected : inner lip united to the
columella, but continuous with the outer hp : umhilical chinh
obhque, small, but distinct : opercidum oval, obtusely angular

* KesembHng another species.

HYDROBIA. 65

above, thin and flat, having a lateral and indistinct spire of
only 2 whorls, and resembling that of the marine genus Lit-
torina ; it is marked with strong, but remote, irregular and
flexuous lines of increase. L. 0'15. B. 0*1.

Habitat : Muddy ditches which are occasionally, but
seldom, overflowed by the tide, by the side of the Thames
from Greenwich to below Woolwich. These ditches are
separated from the river by a high and broad embank-
ment, which is provided at distant intervals with sluices
to drain off the surface water. It lives there in company
with Bythinia tentaculata and other freshwater shells,
as well as with the more marine and peculiar moUusk,
Assiminia Gray ana; and it is gregarious. Its food
appears to consist of decaying vegetable matter ; and its
habits are rather active, creeping and floating with tole-
rable rapidity. Mr. Prestwich and Mr. Pickering found
specimens of it in peat, in the main-drainage-cutting
between Woolwich Arsenal and the exit to the Thames,
through Plumstead Marshes ; but it can scarcely be con-
sidered one of our upper tertiary fossils. This species is
widely diffused in France, and extends south to Corsica.
The Paludina meridionalis of Risso appears to be only a
rather longer and stouter form of this species, judging
from typical specimens in the Museum at the Jardin des
Plantes.

No one can, I think, take the trouble of carefully
comparing specimens of this shell with the description
and figure given by Draparnaud of his Cyclostoma simile,
without being satisfied of their specific identity ; and the
general consent of continental conchologists is in favour
of this view. In France H. similis inhabits fr^esh water.
Morelet states that in the South of Portugal it is found
both in running water and marshes, and that the shells
of the males have a longer spire than those of the other

66 PALUDINID^.

sex. British authors have referred this species to the
Cyclostoma anatinum of Draparnaud, but_, as I believe,
erroneously. The Bulimus anatinus of Poiret, from which
Draparnaud seems to have taken the specific name of
his species, is in all probability the Turbo ulvce of Pennant.
That species is universally known in France by the name
which Poiret gave. Michaud, in his Supplement to
Draparnaud's last work, mentions Cyclostoma anatinum
as inhabiting " les eaux saumatres ; ^^ although Drapar-
naud gives a difPerent habitat (" les eaux donees") for the
same species. It is not impossible that the latter meant
Bythinia Leachii. The contour of the shell of H. similis
is not unlike that of a dwarf Bythinia Leachii ; but the
channeled suture, as well as the very different operculum,
will readily serve to distinguish them, irrespectively of
size.

2. H. VENTRo'sA *, Montagu.

Turbo ventrosus, Mont. Test. Brit. ii. p. 317, pi. 12. f. 13. Rissoa vetiirosa,
F. & H. iii. p. 138, pi. Ixxsvii. 11,5, 6, 7.

Body dark grey, almost black in front: head rather pro-
tuberant: snout long and ridged transversely: tentacles fili-
form, with black and grey rings : eyes on very short stalks,
placed a httle behind the outer base of the tentacles : foot
cleft in front and rounded behind.

Shell forming a lengthened cone, rather thin, glossy, semi-
transparent, yellowish horn-colour, obscurely but closely
striate by the lines of growth : epidermis very delicate : luhorls
6-7, rounded and swollen ; the last not being equal to half
the length of the shell : spire pointed : suture rather obhque
and deep : mouth oval : outer lip thin, shghtly reflected : inner
lip in adult specimens separate from the columella and forming
with the other lip a complete peristome : umhilical chink very
small : operculum like that of II. similis, but having a smaller
spire and closer lines of increase. L. 0*2. B. 0-125.

* Swollen.

HYDROBIA. 67

Yar. 1. minor. Shell much smaller : spire shorter.

Var. 2. decollata. Shell slightly eroded : sjnre truncate.

Yar. 3. ovata. Shell having a much shorter spire, consist-
ing* of only 4 whorls, which are more swollen than usual, and
the last considerably exceeds one-half of the shell.

Yar. 4. elongata. Shell having its spire proportionally
longer, with sometimes as many as 8 wliorls.

Yar. 5. pellucida. Shell clear white, and nearly transpa-
rent.

Habitat : Abundantly in many estuaries and in track-
ish water in which the admixture of fresh predominates
over salt, throughout England and Y^^ales; and I have
also taken it in Larne Lough, Ireland. It occurs in
the upper tertiary bed at Clacton, and elsewhere in the
estuary of the Thames. Var. 1. Burry River, South
YYales (J. G. J.). Var. 2. Burry River, but not in the
same part of the estuary where the first variety is found,
and Guernsey (J. G. J.). Var. 3. Oxwich marsh, near
Swansea (J. G. J.). Var. 4. ArnokVs pond, Guernsey
(J. G. J.). Var. 5. Manorbeer, Pembrokeshire (J. G. J.) ;
Scarborough (Bean) : very rare. This species inhabits
similar situations along the sea-coasts of Sweden, France,
and Portugal, as well as of Algeria.

H. ventrosa is gregarious, and sometimes lives in com-
pany with H. ulvcBy which however is more of a marine
than a freshwater species. The latter is never found
out of the reach of the tide, and inhabits the mud flats
and ooze ; while the present species usually lives in ponds
and ditches into which the sea only flows at high water
or in spring tides. The habits of this species are more
active than those of H. ulvce ; and I have observed that
when they are found together the latter may be seen
crawling slowly over the mud and Ulva at the bottom of
shallow pools, while the other seems to disport itself by

68 PALUDINID^.

floating with tolerable rapidity along the under surface
of the water. The shell is often encrusted with a mineral
deposit or covered with an algoid or confervoid growth.
The variety 5 resembles the Cyclostoma viti^eum of Dra-
parnaud and the Paludina diaphana of Michaud. Some-
times the shell is distorted by having the upper part of
the spire twisted to one side, or by the last whorl having
a few obscure spiral ridges.

This small, but abundant, species has received a great
number of names from modern conchologists, in conse-
quence of their referring it to ill-defined species of ancient
authors. I do not believe that it is the Turbo stagnorum
of Baster, because he describes the habitat to be "in
aquis dulcibus," and the aperture or mouth to be mar-
gined. Nor can I identify it with the Helix octona of
Linne, which is said to have eight whorls and a round
aperture. Nor is it, in my opinion, the Turbo theriyialis
of Gmelin, because he gives an inland habitat (Pisa) and
says that the shell is white and has only four whorls.
There can, however, be no doubt of its being the Cy-
clostoma acutum of Draparnaud ; and this specific name
has been adopted by almost every continental naturalist.
The Paludina muriatica of Lamarck is evidently H. ulv(S.

This species differs from H. similis in its long spire,
the suture not being channeled, and in the umbilical
chink being very much smaller. From H. ulvca it may
be known by its being less than half the size of that
species, its much deeper suture, the body or last whorl
not being keeled (as is the case in H. ulvce), as well as in
the inner lip being disconnected from the columella.

The shells which Mr. Pickering found some years ago,
about two miles below Gravesend, together with a spe-
cimen of Litiopa bombyx, and which Forbes and Hanley
considered (but with some doubt) to be a variety of

HYDROBIA. 69

H. ventrosa, bear siicli a close and suspicious resem-
blance to a Cape of Good Hope species of Hydrobia,
that I cannot venture to include it among the British
MoUusca. It does not appear to have been described by
any author ; but Mr. G. B. Sowerby has named it Rissoa
castanea, on my authority, in his ^ Illustrations of British
Conchology.' Both Mr. Pickering and myself have
failed to rediscover this species in the spot where he
originally found it, although we have at different times
carefully searched for it. The fact of Litiopa bombyoo,
which is peculiar to the Gulf- weed, having been taken
with it, leads to the supposition that both of these shells
might have been accidentally brought into the Thames,
attached to the keel, rudder, or anchor of an inward-
bound vessel, and carried by the tide into the ditch where
they were discovered by Mr. Pickering. Many other
modes of introduction will doubtless occur to my readers.

I received some years ago from the late Mr. G.B. Sow-
erby two specimens of Hydrobia Ferussina, which he said
had been found in Hampshire. I do not propose to add
this species to the British list on such slight and insuffi-
cient grounds ; but as Helix obvoluta has only been found
in the same county, as a British shell, and both these
species inhabit the greater part of Prance, I merely call
the attention of conchologists to the circumstance, it
being not improbable that the H. Ferussina may also
turn up in the South of England.

The Hydrobia marginata [Paludina marginata of Mi-
chaud) inhabited this country a Iqng time ago, but ap-
pears to have become extinct as a British species. Sir
Charles Lyell first, I believe, recorded it as occurring in
the Mundesley bed, where I have since found it ; it also
occurs in the weU-known upper tertiary strata at Grays,
Stutton, Clacton, and Cropthorn ; and I lately detected it

70 VALVATID.E.

among some shells collected by Mr. Wyatt from a similar
deposit at Biddenham near Bedford. This species now
inhabits the South and South-west of France, as well as
the Jura and Switzerland ; and it has been found in a
fossil state in the lacustrine beds at Amiens.

The Natica Kingii of Forbes and Hanley (iii. p. 343,
pi. ci. f. 1, 2) belongs to this family, and not to the
Naticidce. It is the LWioglyphus Naticoicles of Ferussac,
and inhabits the Danube. Professor King is said to
have found the specimen (which is now in my collection)
in the bottom of a fishing-boat at Cullercoats. How this
Austrian and freshwater species could have got to the
Northumberland coast, is very difficult to say. Professor
King informs me that he never received any shells from
the Danube, and that his statement as to the Northum-
brian locality is perfectly correct. The question of the
indigenousness and unaccountable habitat of this speci-
men must therefore remain a mystery.

Family III. VALVATID^.

Body elongated, spiral : eyes placed within the tentacles at
their base : gill protruding beyond the edge of the mantle, the
respiration being aided by a tentacular filament : sexes united,
or common to each individual.

Shell having a short but symmetrical spire and a circular
mouth : operculum regularly multispiral.

This family comprises only one genus {Valvata), which
was founded by the Danish naturalist, Miiller. It is
remarkable for its branchial apparatus, which is external
or protruded when the animal is moving. In this posi-
tion it resembles a feather, and caused Geoftroy to give
to these elegant little creatures the expressive name of
" porte-plumet." Besides this branchial plume, the ani-

VALVATIDiE. 71

mal has another peculiar organ to facilitate its respira-
tion^ consisting of a filament or appendage to the mantle^
which might be mistaken for a third tentacle or a para-
sitic worm, and is placed on the right side of the body.
The form of the shell and operculum is very graceful^
and is somewhat like that of Trochus or Margarita.

The members of this family and genus are vegetable
feeders. They are very shy. Miiller relates that he
was tantalized by watching them for several hours, in
the hope that they would show themselves and enable
his draughtsman to make a sketch of the animal and
its curious plume, but that he was disappointed. He
appears to have consoled himself by the idea that the
little snails acted on the proverbial principle that you
were not to put any trust in man ! The reproductive
system of these mollusks is peculiar, and resembles
that of Ancylus, or the freshwater Limpet. Although
each individual is of both sexes, it is at first only male
or female, and afterwards changes its sex. They are
gregarious, and inhabit slow rivers, streams, canals, and
nearly stagnant water. The shells may often be seen
attached to the cases of the Phryganea, or May-fly, and
thus collected form a very pretty object.

The shells of some of the Valvatidce closely resemble
in shape the cases made by the larvse of certain insects ;
and their similarity is so great that Mr. Swainson pro-
posed a new genus of Mollusca for these insect-cases,
under the name of Thelidoinus. Such instances of mi-
metic analogy occur in other branches of the animal king-
dom. The valves of some Entomostraca, belonging to
the genus Estheria, are not unlike those of a young Ano-
donta in appearance, although their structure and compo-
sition are very diflPerent.

72

VALVATID^.

VALVA'TA^, Miiller. PI. III. f. 13, 14, 15.

Eyes nearly sessile : operculum horny and thin.

1. Valvata piscina^'lis t, Miiller.

Nerita 2>isci7ialis, Miill. Verm. Hist. pt. ii. p. 172. V. piscinalis, F. & H.
iii. p. 19, pl.lxxi. f.9, 10.

Body of a clear yellomsh'gTey, with small and indistinct
milk-white specks : snout long, narrow, and transversely
wrinkled : tentacles long, cylindiical, rather close together, and
slightly recurved at the point : eyes large and round, but not
prominent: foot separate from the snout and six times as
broad, deeply cleft in front and rounded behind; its tail
nearly covered by the operculum : hrancliial plume transparent,
bearing on each side fourteen slender offsets, which are placed
at right angles to the stalk : branchial appendage of the same
size and length as the tentacles.

Shell forming a depressed cone, subglobular, rather solid
and opaque, brownish-yellow, closely and regularly striate
transversely, and more or less distinctly ridged in a spiral
direction, which often gives the surface an elegantly reticu-
lated appearance : whorls 6, rounded and convex, the last being
rather less than one-half of the shell : spire compressed and
blunt : suture nearly straight and very deejD : mouth circular :
outer lip rather thick and reflected : inner lip quite separate
from the columella and continuous with the outer lip, so as to
form a complete peristome : umbilicus round, not large, but
very deep, exposing nearly all the interior of the spire : oper-
culum circular, slightly compressed in the middle, forming a
concentric spire of from 10 to 12 whorls, the outer edges of
which are thickened and raised so as to project over and
partly overlap the succeeding whorl of the operculum. L.0-25.
B. 0-275.

Yar. 1. clepressa. Shell having the spire more depressed and
the umbilicus consequently larger. V. depressa, C. Pfeiffer,
Deutsch. Moll. i. p. 100, pi. ii. f. 33.

Yar. 2. subcylindrica. Shell having the spire more produced,
and flattened at the top : imibilicus small.

* Closed by a valve, or operculum.

f Inhabiting fish-ponds.

VALVATA. 73

Var. 3. acuminata. Shell having the sjjire still more pro-
duced, and ending in rather a sharp point.

Habitat : Slow and still waters throughout the Bri-
tish Isles ; common in our upper tertiary beds. Var. 1
occurs also in various parts of the kingdom ; but it is
more local, and not found with the typical form. The
young of both these forms have invariably the spire pro-
portionably more depressed than in the adult. Var. 2.
Grassmere (J. G. J.). This somewhat resembles the well-
known form called " antiqua '^ by Professor Morris, from
the upper tertiary deposit at Grays. Var. 3. Avon E/.,
Bristol (J. G. J.) j Northof Ireland (Mrs. Puxley). Spe-
cimens of the typical form, which Mr. Bridgman pro-
cured and kindly sent me, from brackish water at Lynn,
are much thicker and of a darker colour than usual, and
have stronger striae ; and the opercula have fewer whorls
and slighter ridges. In another variety which I have
received from my valued friend and correspondent, Mr.
Waller, and which he found at Finnoe, Co. Tipperary,
the shell is more conic and. the spiral ridges form irre-
gular white lines. A monstrosity has also occurred to
me, in which the spire is twisted to one side. This spe-
cies ranges from Siberia to Naples.

In May, June, July and August the eggs of this mol-
lusk are deposited on various substances, and sometimes
on the shell of a Planorbis. They are united in a gela-
tinous mass, and enclosed in a globular capsule having a
short stalk, by which it is attached. The eggs contained
in each capsule number, according to Bouchard-Chante-
reaux, from 60 to 80 ; but Moquin-Tandon, who appears
to have observed many cases of such egg-laying and
-hatching in an aquarium, states that out of 19 capsules
the number of eggs in each varied from 4 to 24 only.
When the eggs have come to maturity, which is about the

E

74i VALVATID^E.

twelfth day after they have been laid^ the capsule^ being
distended^ bursts^ and abont two -thirds of the fry emerge
and enter on their career of life. The capsule then re-
sumes its former shape, and retains the rest of the fry
for four days longer, w hen they are, in their turn, hatched
or emancipated.

Both Draparnaud and Montagu were aware that this
species was furnished with the branchial plume ; but the
former included it in the heterogeneous assemblage of
species which he called Cyclostoma, assigning the next
species to Valvata; and our countryman referred one
species to Helix and the other to Turbo. The present
species is the Nerita obtusa of Studer ; and Draparnaud
adopted his specific name.

2. V. crista'ta"^, Miiller.

V. cristata, Miill. Verm. Hist. pt. ii. p. 198 ; F. & H. iii. p. 21, pi. Ixxi.
f. 11, 12, 13.

Body dark grey or brown, with a few small black specks on
the upper part, slate- colour underneath : snout prominent,
rather narrow and curved, faintly wrinkled : tentacles long,
slender, close together but recurved at their points : eyes small
and round : foot quite separate from the snout, and resembling,
in proportion to its size, that of the last species : hranchial
jilume transparent, bearing about 15 offsets on each side of the
stalk : hranchial ap^endaye rather shorter than the tentacles.

Shell forming a flat coil, concave beneath, rather solid,
semitransparent, yellowish or greyish-horncolour, closely and
regularly striate transversely : epidermis very thin : whorls 5,
the last exceeding in breadth all the rest put together : spire
flat, or slightly concave omng to the convexity of the whorls :
mouth circular ; outer lip thin and slightly reflected : inner lip
separate from the columella and continuous with the outer lip :
umhilicus very large and open, fully exjiosing the interior of
the spire : operculum circular, concave like an inverted pot-
lid, forming a concentric spire of about a dozen whorls, the

* Crested ; so called from its brancldal plume.

VALVATA. 75

outer edges of which are membranous and project in front so
as to make slight ridges. L. 0*025. B. 0*125.

Habitat : Lakes, canals, ponds and ditches, with the
last species. It has an equally extensive range both
here and abroad, except that the present species does
not appear to have been found south of Corsica. It is
also one of our upper tertiary fossils. A monstrosity is
in my collection, which has the last whorl detached and
coiled upwards, as is not unfrequently the case with
several species of Planorbis.

The branchial plume is not always protruded, even
when the animal is crawling.

Although the spire in some specimens is a trifle more
depressed or sunk than usual, I am not aware that the
Valvata spirorbis of Draparnaud (which Moquin-Tandon
regards as a variety of the present species) has ever been
found in this country. The V. minuta of that author is
a totally different species, having a globular shell, with a
produced spire, and resembling a miniature V.piscinalis.
The present species is the V. planorbis of Draparnaud.

There is no difficulty in distinguishing V. cristata
from the fry of V. piscinalis, much less from the adult,
where the great difference of size affords a sufficient
criterion. The shell of the present species in all stages
of growth is quite flat, and resembles that of a Planorbis,
constituting apparently a passage into that genus ; while
the other is trochoid or subglobose, and has a prominent
spire. Their bodies, or the soft parts of the animal, do not
present such a decided difference. The tentacles of V.
piscinalis are, however, rather more slender, and the
snout is proportionably larger than in this species.

E 2

76 * PULMONOBRANCHIATA.

Order II. PULMONOBEANCHIATA*.

Body spiral : respiratory apparatus principally consisting of
an internal cavity or sac, formed by a fold of the mantle, and
lined with a network of vessels, which serves the purpose of
lungs.

Shell usually external and spiral, but sometimes internal
and rudimentary or wanting. In the two latter cases the
mantle is external and forms a shield on the back.

With respect to the reproductive system of the Mol-
lusca comprised in this Order, it may be observed that
each individual of those kinds which do not possess an
operculum has both sexes united in itself, but requires
to be fertilized b}^ another individual, while those which
have an operculum are of different sexes. The former
are androgynous, answering in some respects to the
botanical term " monoecious ;^^ and the latter are strictly
" dioecious.^'

The Pulmonobranchs, Pulmobranchs, Pulmonifers, Pul-
monates, or Pneumonobranchs, by all of which various
names these mollusks have been called, on account of the
analogy which their organ of breathing bears to the
lungs of vertebrate animals, respire for the most part
atmospheric air. The aquatic kinds obtain also some air
from the water by means of auxiliary branchial organs.
All the land mollusks, or Snails, belong to this Order.
The other members of it are aquatic ; but none of them
inhabit the open sea, although a few, belonging to the
genera Melampus or Conovulus and Otina, are amphi-
bious. These last I propose to include in the marine
Mollusca, as they live in the sea for many hours out of
the twenty-four, and are only met with on dry land

* Having a lung-like gill.

LIMN^lDiE. 77

when the tide has retired. One species of Melampus is
found in brackish, but never in fresh, water.

In this country, about three-fourths of the Pulmono-
branchs are terrestrial; the remaining fourth live in
fresh and shallow water, occasionally rising to the sur-
face or crawling out of their native element to renew
the supply of air. They are nearly all herbivorous ; but
the Testacella, or Shell- Slug, feeds exclusively on the
earthworm, and the Slugs and many kinds of Snail (both
terrestrial and aquatic) eat animal as well as vegetable
substances, and are occasionally cannibals. It has been
proposed to call the tentacles of the aquatic kinds by
another name (viz. vibracles), in consequence of their
being contractile, instead of retractile like the tentacles
or horns of land-snails, and also because they do not
bear the eyes on their tips or extremities, as in the last-
mentioned kinds. This distinction seems, however, to be
unnecessary ; and much confusion might result from such
an innovation, as the word ' tentacles ^ has been so long
and universally applied to the feelers of all the Gastero-
poda or univalve MoUusca.

They may be conveniently divided according to their
different habitats ; and the freshwater kinds will be de-
scribed first, so as to complete this branch of the subject.
These are aU covered or protected by a shell, and are
comprised in the undermentioned family.

Family LIMN^ID^.

Body generally long and spirally coiled, but in one genus
short and hood-shaped : mantle covering the upper part in front:
head short : tentacles 2, contractile : eyes placed on the inner
base of the tentacles, a little towards the front : foot oval, used
for crawling or floating.

Shell spiral, or hood-shaped.

78 LlMNiEIDiE.

Genus I. PLANOR'BIS^ Guettard. PL IV. f. 1, 2, 3.

Body long, twisted in a flat coil : tentacles very long and
slender : foot short and narrow, attached to the upper part of
the body by a stalk, which is shaped like the lower half of an
honi'glass.

Shell quoit-shaped, or flat : whorls cylindrical : spire dex-
tral, or turning from left to right, and visible on each side.

This genus has some remarkable peculiarities. One
of them consists in the habit of the animal emitting its
purple-coloured blood, or a fluid like that which is se-
creted by the Aplysia, on being irritated, apparently as a
means of defence against its enemies. Another is, having
several of its vital organs placed on the left side of its
body, instead of on the right (as is the case with nearly all
the other Gasteropoda), while the spire of its body and
shell is coiled the other way, viz. from left to right. And
a third peculiar feature consists in the form of its shell,
wliicb is flat or concave on one or both of its sides, re-
sembling that of an Ammonite, The body of these mol-
lusks is too small for its shell ; and when crawling, the
animal leaves part of the shell empty, putting one in
mind of loose and ill-fitting clothes. O. F. Miiller, nearly
a century ago, seems to have satisfactorily settled the
question that was then raised as to whether the shells
were right- or left-handed ; but the discussion has lately
been renewed. The shell being viewed in its natural
position, there can be no doubt of its being dextral.
Some of the smaller species of Planorbis, inhabiting
marshes and very shallow water which are dried up in
summer, close the mouth of their shell with an epi-
phragm, or filmy covering, like that of some land-snails.
The animal then retires into the interior of its coil and

* Flat-coil.

PLANORBIS. 79

awaits the return of moist and more congenial weather.
All of them frequent stagnant or slowly-running water,
and are herbivorous. Their eggs are enclosed in a
globular bag, which is fixed to stones and the stalks or
leaves of submerged water-plants. Owing to the sluggish
habits of most of the species, as well as to the nature
of their habitat, the surface of their shells is apt to
become encrusted with a mineral or vegetable deposit.
The genus seems to have been originally indicated by
Petiver in his ' Gazophylacion.''

There being several species, it may be more con-
venient to divide them, as before, into sections.

A. Shell glossy ; last whorl very large in proportion to the
rest, and partly covering the preceding one.

1. Planorbis linea'tus*, Walker.

Helix lineata, Walker, Test. Min. Ear, p. 8, pi. 1 . f. 28. P. laacstris, F. & H.
iv. p. 162, pi. cxxviii. f. 1-3.

JioDY reddish-brown, tinged with violet, dark purple in
front with a few black specks : head strongly bilobed : ten-
tacles filiform, diverging at their base : eyes small, but distinct,
scarcely prominent : foot broad and rounded in front, gradu-
ally narrowing and pointed behind.

Shell quoit-shaped, the upper being rather more convex
than the lower side, both sides depressed or almost concave in
the middle, rather thin, very glossy, semitransparcnt, reddish
or yellowish-horncolour, or grey, closely striate in a trans-
verso direction, the striae becoming curved towards the mouth :
epidermis very slight : periphery (or circumference of the
outer whorl) bluntly keeled: luhorls 4, compressed on all
sides ; the last exceeding in size the rest of the shell, and con-
cealing nearly two-thirds of the preceding whorl in its clasp :
suture distinct, but not deep : mouth obliquely heart-shaped :
outer lip thin and flexuous, obtusely angulated above : um-
hilicus small and rather deep : inside the last whorl are from

* Streaked.

80 LIMN^ID.^.

2 to 5 rows of curved plates, which are arranged on each side
across the spire, opposite to each other and at nearly equi-
distant intervals. L. 0-065. B. 0-2.

Habita-T : Slow streams and ditches in the home and
eastern counties, as well as in Guernsey (Lukis), Notts
(Lowe), and Co. Tipperary (Humphreys) ; but it is a
local species. It is found in our upper tertiary strata.
According to Malm it occurs in Sweden ; and it appears
to have a wide range over the more temperate parts of
Europe, as far south as Toulouse.

This pretty and curious little mollusk is rather active,
and is usually found on duck-weed and other aquatic
plants. It lays only from 3 to 8 eggs, which come to
maturity in ten or twelve days. The internal plates,
which are observable outside the last whorl of the shell,
form half-closed chambers ; and the animal retreats into
the front one for safety. These plates appear to answer
the same purpose as the teeth or folds which barricade
the apertures of many of the small land-snails. They are
also only formed in adult individuals. The peculiarity
of this structure induced one of its earliest discoverers,
Lightfoot, to call the present sheU a Nautilus ; and the
late Professor Fleming proposed for it on the same grounds
a new genus {Segmentind) , which has been adopted by
Capt. Brown and Dr. Gray ; but, even as a test of concho-
logical distinction, this character does not seem to be of
any value. Miiller noticed, in his description of the next
species, that a few of the specimens which he had exa-
mined had two streaks, like ligaments, in the upper part
of the last whorl, apparently indicating the marks of
fracture and mending of the shell, by which he may
possibly have meant this species ; but he only described
one species of this form, which still bears the name he
gave it, Planorbis nitidus. The present species was first

PLANORBIS. 81

made known by Mr. Walker, an intelligent bookseller at
Faversliam in Kent, tbe description of it having been
supplied to bim by Mr. Jacob. The only share which
Mr. Boys appears to have had in the discovery is his
having sent parcels of shell-sand to Walker; but the credit
of the publication entirely belongs to the latter. Two
years afterwards Lightfoot described and published this
species in the ^Philosophical Transactions/ under the
name of Nautilus lacustris.

2. P. n/tidus*, Miiller.

P. nitidus, Miill. Verm. Hist. pt. ii. p. 163 ; F. & H. iv. p. 161, pi. cxxvii.
f.11,12.

Body reddish-grey, with sometimes a yellowish tinge, and
marked with extremely fine dark-grey specks : tentacles very
long and slender : eyes rather large : foot short, very broad in
front, and sHghtly narrowing behind to an abrupt but not a
fine point.

Shell shaped like the last, but flatter and with much more
of the spire visible above, in consequence of the last whorl
not clasping such a large part of the preceding one, very thin,
glossy and prismatic, hght-j^ellowish-horncolour or grey, with
sometimes a reddish tinge, faintly striate by the lines of growth,
with occasionally a few spiral microscopical hues, which are
more distinct on the under side, giving an appearance of the
sculptui'e pecuhar to the shells of Limncea : epidermis ex-
tremely dehcate : periphery rather sharply keeled : whorls 4-5,
the last covering about one -half of the preceding whorl : su-
ture rather deep : mouth and outer lip formed as in P. lineatus,
but larger : umbilicus small, not deep. L. 0-06. B. 0*225.

Habitat: Ponds, marshes, and stagnant water through-
out Great Britain, from the Moray Firth district south-
wards. It is also one of our upper tertiary fossils.
MiddendorflP has included it in his list of Siberian shells ;
and it is extensively distributed over the European con-
tinent, having apparently its most southern limit in

* Shining.

E 5

82 LIMNvEID^.

Corsica. Although it is much less local than the last spe-
cies^ I am not aware of their having been found together.

Its habits are slower and more timid than those of P.
lineahis ; and it is not so fertile, never laying more than 6
eggs. The shell is often infested by the minute egg-cases
of a water-insect, or coated with the spores of Confervce.

The shell differs chiefly from that of the last species in
being of a lighter colour, flatter, and thinner, in the
whorls being more visible above, the keel being much
sharper, and especially in the absence of the internal
septa or partitions.

B. Whoi'ls few.

3. P. Nauti'leus"^, Linne.

Tm^bo Nautileus, Linn. Syst. Nat. ed. xii. p. 1241. P. Nautileus, F. & H.
iv. p. 152, pi. cxxyi. f. G, 7.

Body greyish- brown, with sometimes a faint reddish tinge,
minutely speclded with black : head very large and thick :
tentacles long and cylindrical, greatly diverging : eyes distinct,
scarcely prominent : foot broad, rounded in front, and ending
in a blunt point behind.

Shell quoit-shaped, having the upper side flat and the
lower side rather convex, thin, not glossy, light-brown or grey,
sometimes white, closely striate by the lines of growth, which
at distant but regular intervals form strong curved ridges and
frequently rise into projections like the rowels of a spiu* on the
outside : epidermis rather thick : periphery bluntly and in-
distinctly keeled : whorls 3, depressed above, the last exceed-
ing in size the rest of the shell : suture rather deep : mouth
oblique, and either oval or nearly circular, according to the
greater or less depression of the whorls : outer Up thin, form-
ing with the inner lip in the adult a complete peristome : iim-
hilicus very large and exposing all the spire. L. 0*035. B. 0-1.

Var. cristata. Shell having the transverse ridges stronger,
and the periphery deeply notched or crested by them. P. cris-
tatusy Drap. Hist. Moll. p. 44, pi. ii. f. 1-3.

* Shaped like a Nautilus.

PLANORBIS. . 83

Habitat : On aquatic plants in marshes, lakes, ponds,
and ditches, from the northernmost extremity of Zetland
to the Channel Isles. It is also one of our upper tertiary-
fossils. The variety is not uncommon, and merges in-
sensibly into the ordinary form. The degree of sculpture
appears to depend much on age, as it is usually stronger
in half-grown individuals and disappears in the adult.
A monstrosity also occurs in which the whorls are more
or less twisted and separate from each other, sometimes
being raised like a snake lying on its coil. The range of
this species abroad extends from Finland to the Pyre-
nees and even to Algeria.

This pretty little mollusk is slow in its movements,
and may be noticed feeding on the decaying leaves of the
Iris pseudacorus and water-plants. According to Bou-
chard-Chantereaux, it lays only from 3 to 6 eggs, which
leave the capsule in ten or twelve days. The sculpture
of the shell is extremely elegant ; and it is by far the
smallest of its kind. The minuteness of its size, dull
appearance, and comparatively large umbilicus will at
once serve to distinguish it from either of the foregoing
species. If the rings which encircle each whorl are
marks of annual growth, it must attain a very respectable
old age for a mollusk, as I have counted as many as 20
rings in one specimen. In all probability, however, these
marks do not indicate the annual, but only the periodical
growth, several of them being formed in the first year.

4. P. al'bus^ Miiller.

P. alhus, Miill. Yerm. Hist. pt. ii. p. 164; F. & H. iv. p. 149, pi. cxxvi.
f.1,2.

Body grey or dirty-brown, sometimes inclined to a reddish
hue, with fine but indistinct black specks : head thick, rounded

* White.

in front : tentacles widely spread at their base, long, slender,
and pointed : eyes small and rather of an oval shape : foot
narrow, rounded in front and narrowing gradually behind to
a blunt point.

Shell flat above, with a depression in the centre, slightly
concave below, rather thin, not glossy, greyish-white, closely
striate in the line of growth, and more strongly striate or
ridged spirally : epidermis thick, sometimes hispid or bristly :
'periphery slightly compressed on each side, but not keeled :
whorls 5, the last exceeding the rest in size : suture rather
deep : mouth obliquely oval : outer lip slightly reflected ; the
upper part projecting considerably: inner lip spread on the
columella, but continuous with the outer lip : umhilicus very
large, but not deep. L. 0-08. B. 0-275.

Var. Draparnaldi. Shell more closely and sharply striate
in the line of growth : periphey^y distinctly keeled : umbilicus
deeper. P. sjnrorbis, Drap. Hist. Moll. p. 45, pi. ii. f. 8-10.
Helix Draparnaudi, Sheppard, in Linn. Tr. xiv. p. 158. P.
Draparncddi, Jeffr. in Linn. Tr. xvi. p. 386.

Habitat : Same as that of the last species^ but more
generally diffused. The most northern limit in these
islands appears to be Aberdeenshire. It is also an upper
tertiary fossil. The variety has been found at Holbrook
in Suffolk (Sheppard) ; Cardiff, Bristol^ and Church
Stretton in Shropshire (J. G. J.). It has been referred
by the authors of the ' British MoUusca ' to the P. margi-
natus of Draparnaud. This common species ranges from
Siberia to Portugal and Algeria.

The spire is often twisted or distorted in this, as well
as in the other species of Planorbis. The spiral strise
are always visible, even in dead and water- worn speci-
mens which have lost their epidermis. The finest spe-
cimens I have seen were kindly sent to me by my friend
Mr. Norman, who found them at Kibworth, Co. Durham,
their diameter being rather more than a third of an
inch.

In all probability this was the Helix spirorbis of Linne.

PLANORBIS. 85

The description of its colour {" alba^^), as well as all the
other characters given of this species in the ^ Fauna
Suecica/ are peculiarly appropriate to P. albus. The
present species being common in Sweden, and not likely
to be confounded with any other, could scarcely have
escaped the keen observation of the great naturalist;
and it was not otherwise noticed by him. However, as
the confusion has already been too great in the specific
names of this genus, I will not venture to increase it by
restoring Linnets name.

5. P. gla'ber*, Jeffreys.

P. (/later, Jeffr. in Linn. Tr. xvi. p. 387 ; F. & H. iv. p, 150, pi. cxxvi. f.8,9,

Body yellowish-grej : tentacles rather short, cylindi-ical, and
ending in a blunt point : foot rather broad, especially in front,
with a yellowish edge.

Shell rather convex above and depressed in the centre,
concave below, rather thin, glossy and sometimes iridescent,
greyish -horncolour and occasionally marked with white curved
streaks in the line of growth, finely but irregularly striate
transversely, and very faintly and obscurely striate in the op-
posite or spiral direction ; the spiral stride are only visible in
some lights and by the aid of a strong magnifying power :
epidermis thin and smooth : j;eripAer?/ rounded : whorls 5, con-
vex, but somewhat angular, the last scarcely exceeding one-
half of the shell : suture very deep : mouth rather more circular
than oval : outer lip shghtly reflected, the upper edge project-
ing a httle beyond the lower one : inner lip united to the colu-
mella, but continuous with the outer Hp : umbilicus large and
rather deep. L. 0'05. B. 0-15.

Habitat : On aquatic plants in marshes, lakes, and
ponds, from Burra fiord in Unst to Penzance ; but it is
not generally diffused. It is an upper tertiary fossil. I
only know of about twenty localities. The largest speci-
mens I have seen were found by Mr. Bridgman near

* Polished.

86 LIMN^ID^.

Norwich, and measure nearly a quarter of an inch in
diameter. It is distributed throughout the greater part
of the Continent, and ranges from Sweden to Corsica
and Algeria. According to the Rev. R. T. Lowe, it also
inhabits Madeira.

This species differs from P. albus in its smaller size
and glossy aspect ; in the upper side being rather convex,
instead of flat (owing to the rotundity of the whorls) ;
in its deeper suture and umbilicus ; in the upper part of
the outer lip not projecting so much, in consequence of
which the mouth appears to be more circular; and,
especially, in not having the strong and regular spiral
striae which characterize the last species. The mouth is
also not nearly so large; and the periphery is never keeled
or compressed. The present species is equally abundant
where it occurs ; but I am not aware that both species
have been found living together.

It is the P. Icevis of Alder, and probably also the
P. cornit of Ehrenberg from the Nile. The P. Ross-
mcBSsleri of Auerswald appears to be only a large variety
of the same species, having the peristome thickened by
an inner rib (as in the next species), judging from Ross-
massler's description and figure, as well as from an ex-
amination of typical specimens in the Museum at the
Jardin des Plantes. Yon Martens has published, in the
^ Malakozoologische Blatter' for 1859, some excellent
dissertations on the synonymy of a few of the European
land and freshwater shells, and is of opinion that this
species is also the P. gyrorbis of v. Seckendorf and has
five other aliases.

PLANORBIS. 87

C. Whorls many, keeled.
6. P. spiror'bis^_, Miiller.

P. spirorhis, Miill. Verm. Hist, pt.ii. p. 161 ; F. & H. iv. p. 159, pi. crxvii.
f.9, 10.

Body purplish-grey or redclish-brown, with minute black
specks on the foot : tentacles rather long, slender and pointed :
foot short and narrow, obtusely rounded in front and angular
behind.

Shell slightly concave above and flat below, or vice versa,
slightly wider at the base, rather solid, glossy, brownish horn-
colour, closely striate in the line of growth, and marked spirally
with very faint and minute striog : epidermis thin : periphery
angular, and sometimes bluntly keeled on the lower side :
whorls b~Q, gradually increasing in size, the last not exceeding
in diameter one-sixth of the whole spire ; they are rounded,
but angular : suture deep : mouth nearly circular, often thick-
ened or strengthened inside by a rib : outer lip very slightly
reflected : inner lip continuous with the other lip, but spread
over the columella : umbilicus very large and shallow. L. 0*04.
B. 0-25.

Yar. ecarinata. Shell smaller, light grey, having one whorl
less than usual and no trace of a keel. P. spirorhis, Moq.-
Tand. Hist. MoU. Fr. p. 437, pi. xxxi. f. 1-5.

Habitat : On plants and grass in shallow and stag-
nant water everywhere from the Moray Firth district to
the Channel Isles. It is also a fossil of our upper ter-
tiary beds. The variety appears to be very rare in this
country. I have only found it once ; and that was in
Oxwich marsh, near Swansea. A monstrosity not un-
frequently occurs, in which the whorls are more or less
twisted and separated. Some specimens which my late
friend Mr. Barlee found at Penzance resemble a minute
corkscrew; and in another form of the same kind of
distortion which I found in Bishopston Valley, near

* Round-spired.

88 LIMNiEIDiE.

Swansea, the last whorl only is separated from the rest
and curled upwards. In the last-mentioned locality
there was a great deal of mud which had been brought
down by a stream and deposited in the grassy pool where
I found the shells. This mud must have inconvenienced
the mollusk and prevented its completing the spire of
its shell on the usual plane ; so that it gave the last whorl
an outward twist, apparently in order to get clear of the
incumbrance. When the drains and splashy pools in
which this kind of Planorbis lives are dried up by the
heat of summer, it retires far within its shell and closes
the mouth or opening with a yellowish- white and rather
solid lid, patiently waiting for the next shower of rain
and fasting in the mean time. This species inhabits
Siberia, and ranges as far south as Algeria and Sicily.

It differs from P. glaber in the whorls being much
narrower and consequently more compact, and in usually
having a blunt keel on the periphery.

The typical or ordinary form is the P. rotundatus of
Poiret, P. vortex var. ^. of Draparnaud, and P. leuco-
stoma of Michaud, besides having other specific names
for several of the varieties.

7. P. vor'tex"^, Linne.

Helix vortex, Linn. Sjst. Nat. ed. xii. p. 1243. P. vortex, F. & H. iv. p. 157,
pi. cxxvii. f. 6-8.

Body reddish-brown, with a slight tint of violet, rather
distinctly marked with minute black specks : tentacles very
long, slender and finely pointed : foot evenly rounded in front
and keeled behind.

Shell much compressed, concave above and flat below, thin,
glossy, yellowish or greyish-horncolour, finely and closely
striate in the line of growth, and occasionally having a few
obscure and extremely minute spiral stria3 : epidermis thin :

* Whirlpool.

PLANORBIS. 89

periphery slightly keeled towards the lower side, and always
angular in consequence of the outward compression of the
shell : wliorls 6-8, gradually enlarging, the last not exceeding
in diameter one-fifth of the whole spire, angular on both sides
and sloping gently towards the outer edge : suture well de-
fined, but not deep : mouth obliquely oval, ending above in
rather an acute angle, and having the inside sometimes thick-
ened by a slight rib : outer lip not reflected : inner lip much
spread on the columella, but continuous with the outer lip :
umbilicus very large and shallow. L. 0-05. B. 0-3.

Yar. compressa. Shell thinner and much flatter, with the
keel more distinct and sharp and placed nearly in the middle
of the periphery. P. compressus, Mich. Compl. p. 81, pi. xvi.
f. 6-8.

Habitat : The same as that of P. spirorbis, and having
a similar range at hoAie and abroad as far southward as
Algeria. It is, however, not so generally diffused as
that species. They are sometimes found together. The
present species is also one of our upper tertiary fossils.
The variety is not uncommon. I have a distortion from
Clumber lake, Notts, in which the spire is displaced on
the lower side, and the first whorls are set at an acute
angle to those which succeed.

This mollusk is sluggish, but fond of floating. It lays
from 10 to 12 eggs. The epiphragm is thin and mem-
branous.

The shell diff'ers from that of P. spirorbis in being
thinner, flatter, and rather longer, and in having a distinct
and prominent keel. This species was first described
and figured by Lister.

8. P. CARINA Tus *, Miiller.

P. carinatus, Mlill. Yerm. Hist, pt, ii. p. 175 ; F. & H. iv. p. 153, pi. cxxvii.
f. 4, 5.

Body deep -reddish brown with a yellowish tint, and of a

* Keeled.

90 LIMNiEIDiE.

lighter colour underneath, finely and rather distinctly marked
with black specks : tentacles long, slender, bluntly pointed :
foot acutely rounded in front and obtusely so behind.

Shell compressed, concave above and flat or very slightly
convex below, rather thin and glossy, yellowish-horncolour,
finely and closely striate in the line of growth, with a few
slight spiral strife : ej)idermis thin : pgr^p7iery strongly keeled
towards the middle : whorls 5-6, the diameter of the last being
rather less than a third of the whole spire, moderately con-
vex above, but much less so beneath, sloping gradually on
both sides to the periphery : suture deep : mouth obliquely
oval, sharply angulated above, the inside sometimes thickened:
outer lip slightly reflected : inner lijp continuous with it, much
spread on the columella : umbilicus very indistinct, owing to
the lower side being nearly flat. L. 0-1. B. 0-5.

Yar. disciformis. Shell flatter and thinner, of a yellowish
colour, having the last whorl larger in proportion to the others,
and the keel more prominent and sharp and placed exactly in
the middle. P. lutescens (afterwards altered to disciformis),
Jeffr. in Linn. Tr. xvi. pp. 385 & 521.

Habitat : Marshes and stagnant water in our home
and eastern counties, as well as in those of Dorset, Somer-
set, Northampton, York, Glamorgan, and many parts of
Ireland. Dr. Leach says that it also occurs near Edin-
burgh. It is, however, local, and never plentiful. It is
an upper tertiary fossil. The variety is found in Bucks,
Oxford, Cambridge, Glamorgan, Cork, and Tipperary, and
is somewhat rare. This variety bears the same relation
to the typical form as the P. compressus of Michaud does
to P. vortex. The monstrosity, so common in this genus,
in which the last whorl is disjoined from the rest, also
occurs, but very seldom. It is a Swedish species, and
ranges southward to Portugal and Corsica.

This mollusk is very slow in its movements, but ap-
pears to be fond of floating. It lays from 10 to 20 eggs,
which quit the capsule in from ten to fifteen days. It is
occasionally met with in company with the next species.

PLANORBIS. 91

This is in all probability the Helix i:tlanorhis of the
^ Fauna Suecica/ which is described as " plana" and
" margine prominulo;" but as the description and figure
given by Lister^ to which Linne there refers, sipply to the
Helix complanata of the latter, more confusion will be
avoided by the adoption of Miiller^s name.

9. P. complana'tus "^^ Linne.

Helix complanata, Linn. Syst. Nat. ed. x. p. 769. P. marginatus, F. & H.
iv. p. 165, pi. cxxvii. f. 1-3.

Body of a deep violet-red, with very fine black specks, espe-
cially on the edges of the foot : tentacles very long and slender,
bluntly pointed : foot rounded in front, convex behind, and
ending in an obtuse tail.

Shell concave above and slightly convex below, rather
soHd and opaque, not glossy, yellowish-horncolour with some-
times a tinge of brown, closely but irregularly striate in the
line of growth and more or less distinctly striate in a spiral
direction : epidermis rather thick : 'periphery strongly keeled
on the under side : ivhorls 6, the diameter of the last being
about one-fourth of the whole spire, convex above and slightly
so beneath, sloping abruptly on the upper, and gradually on
the lower side to the peripher}^ : suture moderately deep :
mouth roundish-oval, slightly angulated above by the keel, the
inside being sometimes strengthened by a rib : outer lip a little
reflected : inner lip continuous with it and affixed throughout
to the columella : umbilicus broad and very shallow. L. 0-125.
B. 0-6.

Yar. 1. rhomhea. Shell smaller, more soHd, rather more
convex above and deeply umbihcated below ; keel blunt and
almost obsolete. Helix rhomhea, Turton, Conch. Diet. p. 47.

Var. 2. alhida. Shell whitish or colourless.

Habitat : Marshes, ponds, canals, ditches and stand-
ing water everywhere in England, Wales, and Ireland ;
but I am not aware of any Scotch locality. It is one of
our upper tertiary fossils. The variety 1. is from Dublin

* Flattened. '

93 LIM^MIBM.

and the South of Ireland ; and the other variety has
been found by Mr. Choules at Eltham in Surrey. A
monstrosity, having the whorls dislocated and more or
less separate from each other, sometimes corkscrew-
shape, has been found by Mr. Bean near Scarborough,
and by myself on Crymlyn Burrows, near Swansea. It
is the Heliw Cochlea of Brown (Mem. Wern. Soc. pi. xxiv.
f. 10) and H. terebra of Turton's ' Conchological Dictio-
nary.' This common species is widely distributed in Eu-
rope from Finland (according to Nordenskiold and Ny-
lander) to Algeria and Sicily.

It is a sluggish and slimy as well as a very irritable
mollusk, and often indulges itself in floating lazily along
the under surface of the water. It lays from 8 to 10
capsules, each of which contains from 6 to 21 eggs ; so
that it appears to be more prolific than many of its con-
geners.

Its shell may be distinguished from that of P. cari-
natus by its narrower and more rounded whorls, as well
as by the keel being placed below, instead of in or to-
wards the middle of, the periphery. It is usually larger
and thicker than that species and is much more gene-
rally diffused and plentiful.

There can be no doubt that this is the Helix compla-
nata of Linne, whose epithet "deorsum carinata^' is
peculiarly appropriate; but both MUller and Drapar-
naud have substituted other names (viz. umbilicatus and
marginatus) on w^hat I cannot help considering as very
insufficient grounds. If Linne's name was prior to what
is termed " the binomial epoch," and therefore inadmis-
sible (which is a very questionable objection), still Gme-
lin's adoption of that name, as well as Miiller's, take
precedence of the one proposed by Draparnaud. It must
also be borne in mind that this species and P. carinatus

PLANORBIS. 93

are connected together through the P. submarginatus of
Cristofori and Jan, alias the P. intermedins of Char-
pentier. Some of the aberrant forms are as difficult to
separate as those of P. spirorbis and P. vortex. The
present species was first made known by Lister.

The P. turgidus described by me in the ' Linnean
Transactions ' is not a British species ; and I was mis-
informed as to the locality. Its nearest ally is, as I
stated, P. corneus ; but it has been erroneously referred
by subsequent writers to the present species.

D. Wliorh roimded and not keeled.

10. P. cor'neus^, Linne.

Helix cornea, Linn. Syst. Nat. ed. xii. p. 1243. P. corneus, F. & H. iv.
p. 147, pi. cxxvii. f. 1-3.

Body dark red or nearly black, of a greyish hue beneath,
with black and grey specks on the upper part : tentacles long
and curved, with rather blunt tips : eyes of a moderate size
and not prominent : foot slightly tubercled, narrow and angu-
lated in front, rounded and convex behind.

Shell rather deeply concave above and nearly flat below,
somewhat solid and opaque, glossy, whitish-horncolour with
a reddish-brown tinge, closely but irregularly striate by the
curved hnes of growth and marked with fine and close -set
spiral striae, which are more perceptible in the first whorls ;
the upper surface is also sometimes pitted or impressed in an
irregularly quadrangular form like cut-glass : epidermis rather
thin: periphery rounded and quite destitute of any keel or
angularity : wliorls b-Q, more perceptible on the umbilical or
lower side, in consequence of that part of the spire being
intorted ; diameter of the last whorl rather less than a third
of the whole shell ; they are very convex above and rather
compressed beneath : suture deep : mouth forming a segment of
two-thirds of a circle : outer lip a little reflected, the upper
side not projecting much beyond the lower one : inner lip con-

*■ Horn-coloured.

94 LIMN^ID^.

tinuoiis, but closely attached to the columella and widely
spread on it: umhilicus broad and shallow. L. 0-35. B. 1.

Yar. albina. Shell perfectly white.

Habitat : Marshes^ ponds^ and ditches in many parts
of England and Ireland ; but, although gregarious, it is
very local. It occurs in a fossil state in the mammalian
crag of Suffolk, as well as in the upper tertiary beds of
Suffolk, Essex, and Worcestershire. The variety is found
in Surrey. It is a Siberian species, and diffused over the
Continent as far south as Corsica. M. Terver has found
a thin variety of it in Algeria.

This far exceeds in size any other European species of
Planorbis. Its anatomy, embryology, and habits were
accurately described by Lister nearly two centuries ago ;
and he seems to have made several experiments, but in
vain, with the hope of being able to fix and render useful
the purple dye which this moUusk so plentifully yields.
It is a sluggish and extremely sensitive animal ; and
when irritated it emits the fluid or secretion in con-
siderable quantity from a gland at the sides of its neck.
It may often be seen floating on a warm and still summer
day. It lays only two or three capsules, each containing
from 20 to 40 eggs, which are excluded at the end of
fifteen or sixteen days. The epidermis of the young shell
is covered with fine down, its surface resembling velvet
pile. In this state it is the P. similis of Miiller.

11. P. contor'tus*, Linne.

Helix contorta, Linn. Syst. Nat. ed. xii. p. 1244. P. contortus, F. & H. iv.
p. 160, pi. cxxvi. f.3.

Body black, with a slight tinge of red : tentacles remarkably
slender : eyes very small : foot broad and rounded in front,
narrowing behind to a blunt tail.

* Twisted.

PHYSA. 95

Shell flat above, with a deep depression or concavity in the
middle, very concave below, rather solid for its size, and opaque,
yellowish-brown or horn-colour, closely and deeply striate in
the line of growth, but not otherwise sculptured : ejpidei^mis
rather thick : periphery rounded : ivJiorls 8, extremely compact
and much compressed, angular above and slightly so beneath:
suture deep : mouth semilunar, occasionally strengthened in-
side by a rib : outer lip not reflected, the upper side scarcely
projecting beyond the lower one : inner lip thin, not con-
tinuous but attached to the columella : umbilicus large and
deep. L. 0-075. B. 0-175.

Yar. alhida. Shell nearly white.

Habitat : On water-plants in lakes, ponds, and ditches
throughout the greater part of Britain, and reaching as
far north as the Shetland Isles ; but it is local. It is also
an upper tertiary fossil. The variety was found by me
in a lake near Lerwick, with specimens of the ordinary
colour. The usual monstrosity occurs in which the spire
is dislocated. Abroad it ranges from Siberia to Portugal
and Corsica.

This curious little moUusk is slow, irritable, and fond
of floating. It is not very prolific ; for each capsule (of
which it lays from 5 to 9 during the breeding-season)
contains only from 6 to 8 eggs, giving an annual average
of about 50 for an individual.

The shell of this, as well as of the last species, is so
diflPerent from any other which I have described, that it
is unnecessary to make any comparison. Their forms
are, however, represented by many analogous species in
North America. "*

Genus II. PHY'SA*, Lamarck. PL IV. f. 4, 5, 6, 7.

Body rather long, and twisted in a spiral coil : tentacles long
and slender -.foot rather long, rounded in front and pointed

* A bladder.

96 limn.^idtE.

behind, attached to the upper part of the body by a very short
and broad stalk or pedicle.

Shell conic -oval or oblong : spzVe produced, sinistral or
turning from right to left.

This peculiar and characteristic genus has intermediate
relations with Plano7^bis and Litmicea. It resembles the
first in its long tentacles, as well as in some of the organs
being placed on the left, instead of on the right side of
the body ; and it agrees with the latter in the form of
its shell : but it differs from 1)oth in the spire being
sinistral, although that is not a very important cha-
racter. The shells of Physa have a remarkably polished
appearance, caused in some cases by their being more
or less enveloped by an expansion or lobe of the mantle,
the lubricating friction of which always keeps the surface
smooth and bright. These little mollusks frequent shal-
low, and generally clear water, and are gregarious. Their
eggs are deposited in strips of a gelatinous consistency,
which are fixed to submerged stones as well as to the
stalks and leaves of aquatic plants.

A. Mantle having plain edges and not expanded over the shell,
which is covered with an epidermis and has a long spire.

1. Physa hypno'rum*, Linne.

Bulla hypnorum, Linn. Syst, Nat. ed. xii, p. 1182. P. hi/pnorum, F. & H.
iv. p. 143, pi. cxxii. f. 6, 7.

Boj^Y lustrous, dark grey, dusky bro^Ti, or almost black, with
sometimes a faint tint of blue, covered ^vith very minute black
or dark-grey specks : tentacles long, slender, and pointed, di-
verging considerably at their base : eyes very small and not
very distinct : foot lance-shaped, narrow, blunt and truncate in
front, compressed and rather pointed behind.

Shell oblong, spindle-shaped, thin, highly pohshed, semi-
* Frequenting the Hypnurn, a kind of moss.

PHYSA. 97

transparent, yellowish or reddisli-horncolour, faintly striate by
the lines of growth, and marked spirally with a few very in-
distinct striae, which are only perceptible by means of a high
magnifying power : epidermis very thin : ivhorls 6-7, convex,
but slightly compressed at the sides, the last exceeding in size
all the rest put together : spire tapering, but blunt at its ex-
tremity : suture distinct, though not deep : movjJi oval, con-
tracted on the inner side by the periphery of the penultimate
wborl, acutely angulated above and rounded below: outer Up
thin and fiexuous : inner lip spread on the columella, which
has a strong and broad fold on its lower side. L. 0'5. B. 0-2.

Habitat : Ponds, ditches, and among grass in pools
which are quite dried up in summer, throughout these
isles from the Moray Firth district to Guernsey; but
it is rather local. It is also an upper tertiary fossil.
A variety occurs in which the shell is smaller and of a
dark copper-colour; and I also possess a specimen in
which the spire is eroded and truncate, the opening
having been filled up by a shelly plate. Miiller recorded
a specimen which had only the right eye, the other being
wanting. It is a native of Siberia, and ranges southward
to Nice and the Eastern Pyrenees. According to Gould
and Philippi, it is the same species as the P. elongata of
Say, which inhabits the northern and western parts of
the United States.

This mollusk is rather active in its habits, and may be
seen in fine weather floating with tolerable rapidity. It
is rather prolific ; and the young attain their full size at
the end of the second year. The largest specimens I
have ever seen of this species were found by me more
than a quarter of a century ago, in fish-ponds at Fre-
mington, in the north of Devon, some of which are
three-quarters of an inch in length.

Gmelin supposed that the Bulla hypnorum of Linne
might be a variety of the next species ; and Miiller, for
nearly the same reasons, called the present species Plaii-

F

98 LIMN^ID^.

orbis turritus. But the Linnean epithets ^'^spira pro-
minente ^' and '' spira obsoleta " appear unmistakeably
to distinguish the two species; and, at all events, it
would now be very inconvenient to make any change of
name by adopting that given by Miiller, instead of the
one by which this species is so universally known. The
late Dr. Fleming proposed to separate it generically from
the next under the name of Aplexa -, but this separation
has only been adopted by a very few conchologists. A
well-known European species, P. acuta, seems to con-
nect the two British forms, both as regards the soft parts
of the animal and the shell.

B. MantU having lobes or digitated processes which expand
over the shell ; the latter being destitute of an epidermis
and having a short spire.

2. P. fontina'lis"^, Linne.

Bulla fontinalis, Linn. Syst. Nat. ed. xii. p. 1185. P. fontinalis, F. & H.
iv. p. 140, pi. cxxii. f. 8, 9.

Body lustrous, dark grey with sometimes a sHght tint of
yellow or violet : mantle fringed with about a dozen lobes or
digitations of imequal size : tentacles rather slender, hght grey :
eyes conspicuous: foot obtusely rounded in front, and con-
tracted behind to a somewhat fine point.

Shell oval, extremely thin, glossy, semitransparentjgrej-ish-
horncolour with a slight tinge of yellow or brown, faintly
striate by the Hues of growth and microscopically striate in a
spiral direction : vjhorJs 4-5, swollen, the last occupying con-
siderably more than three-fourths of the shell : spire not much
produced, blunt at its point : suture moderately deep : 7nouth
nearly of the same form as that of the preceding species, but
much larger and wider in proportion : o^lfer lip very thin and
flexuous : i7i7ier lip much spread on the columella, which has a
slight and narrow fold on its lower side. L. 0-35. B. 0-25.

Yar. 1. injiata. Shell half as large again as the usual size :

* Frequenting fountains.

PHYSA. 99

ivhorls angular towards the suture, the middle one rather
more prominent than the penultimate whorl, causing the
summit of the spire to appear abruptly terminated.

Yar. 2. curta. Spire extremely short. Bulla Jluviatilis,
Turt. Conch. Diet. p. 27.

Yar. 3. ohlonga. Spire considerably produced.

Yar. 4. albina. Shell of a milk-white colour.

Habitat : On water-cresses and other aquatic plants
in running brooks, as well as in slow rivers, canals^ and
ditches everywhere in Great Britain, as far north as
Aberdeenshire. Var. 1. Dublin (Humphreys and War-
ren). Var. 2. Clonoony Barracks, Ireland (Brown) ;
Bramerton, Norfolk (J. G. J.). Var. 3. Anglesea, on
Chara aspera (J. de C. Sowerby) ; Naas, Ireland (Hum-
phreys). Var. 4. Birkenhead. (Webster). This species
is widely diflPused on the Continent, and ranges from
Finland to Sicily.

This common and pretty little moUusk is rather lively,
creeping and floating by jerks. A considerable por-
tion of the shell (especially the back of the spire) in its
living state is often covered with the spores of Con-
fervae or some of the freshwater Algae, which shows
that the mantle does not envelope all the surface. When
the fry are excluded from their gelatinous case, they are
about the size of a pin's head, and are very active. The
jerking motion which this animal has, is said to be owing
to its being infested by a small kind of parasitic worm
which causes it some uneasiness. I should rather be in-
clined to attribute this motion to the length and narrow-
ness of the foot, which has to support a comparatively
bulky shell. According to Montagu, the P. fontinalis
spins a filament by which it lets itself down to the bottom
after floating, if there is no leaf or stalk near it. Leach
says that when it is annoyed by the approach of wander-

f2

100 LIMN.^ID^.

ing animals, it repulses them with repeated blows, in-
flicted by a rapid movement of the shell ; the foot being
the point of fixture. This species was first described
and figured by Lister.

The shell is more ventricose than that of the last spe-
cies ; and it has a much shorter spire and a larger
mouth.

The Bulla rivalis of Maton and E-ackett, which was
supposed to have been found in Hampshire, is a common
West- Indian species, which now bears that name. It is
the P. Sowerbyana of D^Orbigny.

Mr. Choules has described in the 'Zoologist' a species
of Physa which he found in a water-tank in Kew Gar-
dens, and which Mr. Norman (being misinformed as to
the precise locality) has proposed to admit into our
native Fauna. It appears to be a variety of the P. acuta
of Draparnaud, but it is undistinguishable from speci-
mens in the British Museum which were collected in
Cuba, St. Thomas, and St. Croix ; and it has probably
])een introduced with some aquatic tropical plant. Dr.
Hooker informs me that many West-Indian plants have
])een imported and cultivated in the Gardens. P. acuta
has never (so far as I am aware) been found in this
country ; and although it is abundant in the middle
and South of France, it has not been recorded as inha-
biting any of the northern Departments. The P. sub-
opaca of Lamarck is a variety of that species.

The P. alba of Turton, who stated that he had received
it from Capt. Blomer as a native of Towyn in North
Wales, is the P. contorta of Michaud, and is only known
to inhabit the Eastern Pjrrenees, Corsica, Sicily, and
Algeria.

LIMN.EA. ^ 101

Genus III. LIMNiE'A *, {Lymnea) Bmguiere.
PL IV. f. 8, 9, 10.

Body rather long and twisted in a spiral coil: 7?^a(i pro-
minent : tentacles short, triangular and flattened : foot oblong,
bilobed or notched in front and obtusely rounded behind, at-
tached to the upper part of the body as in Physa.

Shell conic-oval or elongated : spii^e usually produced,
dextral or turning from the left to right.

As in Physa, some of the species of Limncea, which
appear to form a transitional link between the two
genera, have their shells enveloped by an outer fold or
lobe of the mantle. These species have been generically
separated by some authors under the several names of
A^nphipeplea, Lutea, and Myxas. The difference be-
tween such and the typical species is, however, not greater
than between the two forms of Physa which I have above
noticed. All the species of Limnaa frequent shallow
and still waters ; and they are very prolific and grega-
rious. Their mode of propagation is very singular — three
or more individuals being united in a chain for that
purpose. Leach has remarked that, in consequence of
the sexual parts being distant fi'om each other, one in-
dividual is able, at the same time, to perform the function
of each sex with two others, as was first observed by
Geoffroy about the middle of the last century. The
spawn resembles that of the last genus.

The generic name has been spelt by authors in no less
than nine different ways ; but the correct orthography is
undoubtedly LimrKsa (from Xifivalos:), as proposed by
Rang.

* Inhabiting marshes.

102' LIMN^ID^.

A. Shell extremely thin and fragile, and almost enveloped by

an outer lobe or membranous expansion of the mantle :
sjpire very short.

1. LiMNiEA GLUTiNo'sA*, Mliller.

Biiccinum glutinosum, Miill. Verm. Hist. pt. ii. p. 129. Lhnn<2U8 gluti-
nosus, F. & H. iv. p. 182, pi. cxxiv. f. 6, 7.

Body dark grey, with a greenish-yellow tinge and bright-
yellow or whitish specks : tentacles very short, rather triangular,
with blunt tips : eyes placed on tubercles on ttie inner side of
the tentacles, very black and distinct : foot exceedingly large,
broad in front and obtusely rounded before and behind.

Shell globosely-oval, so excessively thin as to be almost
membranous, highly polished, transparent, yellowish or greyish-
horncolour, with a few indistinct darker spiral zones, remotely
and irregularly striate by the lines of growth, which are stronger
towards the suture, and closely but microscopically striate in
a spiral direction : epidermis extremely thin : whorls 3-4,
globular, the last forming nearly the whole of the shell : spire
slightly produced : suture rather deep : mouth oval, a little con-
tracted above by the projection of the penultimate whorl :
outer lip very thin : inner Up much spread on the columella
and thickened at its edges : columellar /o^tZ (forming the lower
part of the pillar of the spire) curved and sharp. L. 0-55.

B. 0-45.

Yar. mucronata. Shell not quite so globular : sp>ire more
produced.

Habitat : Lakes and ponds in the home and eastern
counties, as well as in a ditch near Dunster Castle in
Somersetshire (Leach) ; Bala Lake (Gibbs) and a pond
near Windermere (Bulwer) ; but it is a local species^
although abundant where it occurs. Its periodical re-
appearance in the same spots has been remarked both
by Mr. Bridgman and Mr. Whiteaves to be very uncer-
tain and unaccountable. Specimens have been kindly
sent to me by Mr. Bridgman, in which the spire is more

* SKmy.

LIMN^A. 103

or less intorted^ resembliug in this respect tlie form of
L. involuta. Tiie present species ranges from Finland,
througli Sweden, Germany, and France, as far south as
the Pyrenees.

It is rather an active mollusk, and nearly always in
motion. Bouchard-Chantereaux.says that each of its
capsules contains from 30 to 40 eggs. In the young the
shell is entirely covered by the pallial fold.

2. L. involu'ta*, Thompson.

Limnetis invohctus, (Harvey) Thomps. in Ann. Nat. Hist. v. p. 22. Lim-.
TUBUS involutus, F. & H. iv. p. 184, pi. cxxii. f. 11.

Body unknown as to its external parts, except that the
greater part of the shell is covered by the mantle.

Shell oval, rather glossy, semitransparent, yellowish -horn-
colour with a tinge of brown, closely but irregularly striate by
the lines of growth, which are stronger towards the suture,
often impressed and sometimes constricted by a few spiral
grooves in different parts of the shell : ejndermis thin : luhorls
3-4, convex, the last covering all the rest except the point of
the spire or nucleus : spire flat or slightly concave, with the
point upraised and twisted : suture distinct, but not deep :
nioutJi pear-shaped : oiiter li}:) thin, slightly reflected : inner Vp
much spread on the columella : fold narrow and sharp. L. 0*4.
B. 0-275.

Habitat : A small mountain-lake, and a stream which
flows into it, at Cromaglaun near Killarney ; not rare.
In one of my specimens, which has the mouth some-
what contracted below, a tendency to an umbilical cleft
is observable.

It is strange that no other locality but the one above
mentioned has ever been discovered, here or abroad, for
this remarkable species. It has some affinity to L. glu-
tinosa, and may ultimately prove to be an aberrant form
of that species, corresponding with the variety Burnetti

* Having the spire intorted or sunk.

104 LIMNiEID^.

of L. peregra. Very little is known with respect to the
external parts of the body; but Professor Goodsir has
given some valuable details of its internal organization,
which are published in an appendix to Mr. Thompson's
paper in the ^Annals of Natural History/ He says,
'' In structure the Limnaus involutus resembles the other
species of the genus ;^' from wliich remark it might be
inferred that the mantle has not the expanded lobe
which is peculiar to the subgenus Amphipeplea. Dr.
Perceval Wright, however, informs me that the greater
part of the shell in this species is covered by the mantle,
as in L. glutinosa. The form and substance of the shell
are also similar in both of these species.

B. Exterior of the shell never covered by the mantle : spire

produced.

3. L. PER EGRA*, Miiller.

Buccinum 'peregrum, Miill. Verm. Hist. pt. ii. p. 130. Limnmcs fcreger,
F. & H. iv. p. 168, pi. cxxiii. f. 3-7.

Body yellowish-grey, with a brown or olive-green tinge,
mottled with black and covered with small yellow or milk-
white, and black .specks : tentacles diverging from each other
at nearly a right angle : eyes distinct : foot oblong, very broad,
nearly truncate in front, and obtusely rounded behind.

Shell obliquely ovate, thin, moderately glossy, semitrans-
parent, yellowish-horncolour, irregularly striate by the lines
of growth, and closely and microscopically striate in a spiral
direction, with occasionally a few indistinct spiral ridges and
pitmarks : epidermis rather thin : ivhorls 5, convex, the last
occupying three-fourths of the shell : spire produced and
pointed : suture rather deep : mouth large, oval, very Httle
contracted above by the projection of the penultimate whorl :
outer lip thin, slightly reflected : inner lip folded on the colu-
mella and thickened, forming behind it a slight umbihcal cleft :
fold rather prominent and curved. L. 0-75. B. 0*425.

* Traveller.

LIMN^A.

105

Var. 1. Burnetti. Body a little broader than that of the
typical form, dark olive, spotted with opaque yellow : mantU
nearly black, with a few paler spots. Shell rather globular
and solid, of a dull aspect, yellowish-brown, closely and
strongly striate in the line of growth : epidermis rather thick :
the last whorl nearly covering all the others : spire exceed-
ingly short, nearly truncate and almost intorted. L. 0*725.
B. 0-65. Limncea Burnetti, Alder in Ann. Nat. Hist. n. s. ii.
p. 396, pi. ii., top figures. Limnceus Burnetti, T. & H. iv.
p. 172, pi. cxxiii. f. 8, 9.

Var. 2. lacustris. Body of a darker colour than usual.
SheU resembling that of the last variety ; but it is much
smaller and more glossy, and has strong and regular transverse
grooves, and the spire is not quite so short nor inclined to be
intorted. The shell is often eroded. Oulnaria lacustris, Leach,
MoU. Brit. Syn. p. 107.

Yar. 3. liitea. Shell remarkably solid, having a very short
spire of from 3 to 4 whorls. Helix lutea, Mont. Test. Brit,
p. 380, tab. 16. f. 6.

Var. 4. ovata. Body of a paler colour. Shell ampuUaceous
and rather thinner than usual : whorls exceedingly convex,
the last being larger in proportion to the rest : sp)ire very
short : suture deep : mouth very large. Limneus ovatus, Drap.
Hist. Moll. p. 50, pi. ii. f. 30, 31.

Var. 5. acuminata. Shell resembling the last variety in all
respects, except in having a more produced spii'e and a smaller
mouth.

Var. 6. intermedia. Shell rather compressed towards the
front margin and thinner than usual : sj)ire more produced :
mouth expanded. Limnea intermedia, Per. in Lam. An. s. V.
vi. pt. ii. p. 162.

Var. 7. ohlonga. Shell oblong and compressed in front.

Var. 8. lahiosa. Shell smaller, having the outer lip remark-
ably expanded and reflected. L. 0*5. B. 0-35.

Var. 9. picta. Shell rather smaller than the last, and beau-
tifully marked by alternate bands of brown and white, which
are sometimes confluent.

Var. 10. maritima. Shell dwarfed, rather solid : spire pro-
duced : suture deep. L. 0*4. B. 0*225.

f5

106 LIMN^ID^.

Yar. 11. Succineceformis, Shell shaped like a Succinea, and
very thin : whorls 4 : spire small and oblique.

Yar. 12. decollata. Shell more or less eroded : spire trun-
cate.

Yar. 13. sinistrorsa. Shell resembling that of a Pliysa in
having the spire sinistral or reversed, rather solid ; the spiral
ridges distinct and prominent. Limnceus lineatus, Bean, MS. ;
E. & H. iv. p. 168, pi. cxxiii. f. 7.

Yar. 14. scalar if or mis. Shell oblong, with deep and regular
transverse striae: ivhorls more or less disjoined: suture con-
sequently very deep.

Habitat : Still and slowly running waters every-
where. Var. 1. Loch Shene^ Dumfriesshire (Burnett) ;
Breconshire (Moggridge) . Var. 2. Mountain-lakes in
Zetland^ Scotland, Ireland, and the North of England.
Var. 3. South Devon (Montagu) ; South Wales (J.G.J.):
thrown up by the tide at the mouths of rivers. Var. 4.
Lakes, canals, and large ponds ; attaining sometimes a
considerable size. Var. 5. With the last. Var. 6. Ponds.
Var. 7. Lewes, Suffolk ; Church Stretton, Salop ; Bear-
haven, Co. Cork (J. G. J.). Var. 8. Appin, Argyleshire
(Bedford). Var. 9. Ulva L, Hebrides (same). Var. 10.
Marshes on the sea- coasts of Glamorganshire and North
Devon (J. G. J.). Var. 11. Kensal Green (J. G. J.).
Var. 12. Church Stretton ; Oxwich, near Swansea
(J. G. J.). Var. 13. Scarborough (Bean). Var. 14.
Warminster (J. G. J.). This and the two last forms are
rather monstrous than varietal. This species is fre-
quently met with in our upper tertiary beds. The typical
form and several of its varieties extend from Siberia to
Sicily. It is a very ubiquitous species ; and Capt. Hut-
ton found a variety of it in Afghanistan.

The variability of this common and abundant species
is equal to the extent of its geographical distribution. I
was at first inclined to consider that the Limneus ovatus

LIMN^A. 107

of Draparnaud, and its allied forms^ would legitimately
constitute a distinct species ; but, after a very careful
and protracted comparison of many hundred specimens,
I could not satisfactorily separate them from interme-
diate varieties. The difference in the colour of the body,
as well as in the consistency and even the shape of the
shell, appears to depend on the nature and quantity of
the food, the chemical ingredients of the water, and the
degree of stagnation or rapidity of its current. M. Mo-
relet, in his description of the Portuguese land and fresh-
water Mollusca, says, with much naivete, of the L. inter-
media, "aussi reconnaissable que puisse Tetre une espece
dont le caractere principal est de n^en point avoir.^^ The
difficulty of admitting or rejecting such forms as specific
is quite as great as in the case of Anodonta. I have
merely noticed some of the more peculiar varieties of the
present species.

L. peregra is not very slow in its movements. It is
nearly amphibious ; and, as its name imports, it is fond
of wandering and seeing a little of the world, being
occasionally met with at some distance from its native
element in a damp meadow or climbing up the trunk of
a willow-tree. This habit reminds one of the inland
travels of the Perca scandens. An interesting account
of the floating voyages made by our moUuscan traveller
on an old canal near Inchbroom will be found in the
Rev. Dr. Gordon^s Contributions to the ^ Zoologist.' He
says that when the shoal of L. peregra had fairly started,
they resembled a fleet of herring-boats in miniature.
This moUusk is very proliflc and lays about 1300 e^g^
in a season, contained in clusters of from 12 to 180. It
is zoophagous, as well as phytophagous ; and a writer in
the ^ Zoologist^ lately stated (p. 7400) that it ate min-
nows when they were confined together in an aquarium.

108 LIMNiEIDiE.

I have seen these pond-snails attack and devour their
own brothers and sisters under the same circumstances,
when they had no other supply of food ; and this was
done by piercing the spire of the shell near its point,
which was thinner and somewhat eroded bv the action
of the water. Their shells are often coated with mud.

It is probable that Linne considered this species to be
a variety of his Helix auricularia. What his H. limosa
was, it is now impossible to say with any certainty. His
epithet ^^ oblongiuscula " for that species appears to be
more appropriate to L. palustris ; while the term "ovata "
which he uses for " auricularia ^' is applicable both to
this last species and L. jjeregra. In the first edition of
the ' Fauna Suecica/ H. limosa is described as having an
operculum like Paludina or Bythinia ; but in the second
edition this character is omitted. Nearly a centmy be-
fore Linnets time the present species had been distin-
guished by Lister, although not by any specific name.
At least 30 species have been made by Continental au-
thors out of some of its countless varieties.

4. L. auricula'ria *, Linne.

Helix miricularia, Linn. Syst. Nat, ed. xii. p. 1249. Limnaus uuricula-
rius, F. & H. iv. p. 169, pi. cxxxiii. f. 1.

Body dull greenish-brown or yellow, mottled with black,
and covered with veiy small bright-yellow or mill{:-white, and
black specks : tentacles broad, flat and conic, diverging as in
the last species : eyes small and indistinct : foot bordered with
yellow, prominent and obtusely rounded in front, keeled and
rounded behind.

Shell obliquely globose-oval, thin, glossy, semitransparent,
yellowish-horncolour, deeply but irregularly striate by the
lines of growth, with very much finer and closer intermediate
striae, which are arranged in rows, and regularly but indi-
stinctly ridged in a sphal direction : epidermis thin : ivhorls

* Ear-shaped.

LIMN^A. 109

4-5, veiy much -swollen and expanded in front, the last occu-
pying at least five-sixths of the shell : spire oblique, exceed-
ingly small, but produced and ending in a sharp point : suture
very deep : mouth extremely large, roundish oval, a little con-
tracted and nearly tnmcate on the inner side both by the
penultimate whorl and the columellar fold : outer lip thin, con-
siderably reflected : inner lip slightly thickened on the colu-
mella and forming behind it a slight umbilical cleft : fold
prominent, strongly curved and sharp. L. V12d. B. 0-825.

Yar. 1. acuta. Body of a greyish colour and closely covered
with black spots. Shell smaller than the typical form, more
oblong, and having the last whorl and mouth proportionably
narrower. Limneus acutus, Jeffi'. in Linn. Tr. xvi. p. 373. Lim-
noius auricularius, var., F. & H. iv. p. 171, pi. cxxiii. f. 2.

Yar. 2. albida. SheU smaller and thinner, white, with a
shorter spire and less distinct striae. L. 0'675. B. 0*55.

Habitat : Lakes^ marshes, slow rivers, canals,, deep
ditches and large ponds in most parts of Great Britain ;
but it is locals and does not satisfactorily appear to have
been found in Scotland. Y'ar. 1. Marshes on the sea-
coast of Glamorganshire ; Church Stretton, Salop ; Kent;
Co. Tyrone (J. G. J.) : Yoxford, Suffolk (Barlee). This
variety is intermediate between L. peregra and the pre-
sent species ; but being found only with the former spe-
cies, I am inclined to think it belongs to L. auricularia,
A monstrosity of this form in my collection has a second
or inner mouth formed by a plate on the columellar
side. Var. 2. Bath (Clark) ; Blenheim lake (Mrs. Richard
Smith). The variety acuta is one of our upper tertiary
fossils. This species ranges from Siberia to Portugal.

Its habits are inactive ; and when it crawls, only the
front edge of its mantle and the tentacles are perceptible.
It occasionally may be seen floating on the surface of
the water. It is apt to be infested, as well as its con-
geners, by an annelid allied to the Nai's vermicularis of
Miiller, which usually takes up its abode between the

110 LIMN^ID^.

neck and mantle and over the tentacles of the moUusk,
incessantly vibrating, and apparently not parasitic but
feeding on animalcules. Possibly, however, these worms
may have the same truly parasitic propensities which are
attributed to the Nereid, that often takes up its abode
with the Hermit-crab in the same empty shell, and of
which my friend Mr. S pence Bate has given in the ' Zoo-
logist' (1859, p. 6687) an amusing account, as follows :
— " The soft and serpent-like Annelide smells the repast
that the master of the house is enjoying, and, like a wily
guest, takes care to be present at the meal, even though
unbidden. See ! beneath the Crab the beautiful head
glides out. While the self-confident owner is devouring
one piece, and in his full enjoyment looking round and,
perhaps, admiring the submarine scenery, the worm at-
tacks that which is in the other hand, and by little and
little the Crab feels it going, and makes an effort to stop
it on the way ; but it evidently can be seen, by his man-
ner, that he cannot believe that any one would be so
rude as to steal his dinner out of his very mouth, and
does not think much about the undevoured food, but
which, nevertheless, is slowly, gradually and surely taken
away."

Draparnaud noticed, besides the parasitic worms, four
long and very minute filaments or tubes, which he
thought were auxiliary organs of respiration; but sub-
sequent naturalists have not confirmed this discovery.
Muller states that he kept a specimen of L. auricularia
alive from June to October in the clearest water, which
was never renewed, and that it appeared to have no
other nourishment than Cryptogamia or Confervoid
spores.

This species chiefly difi'ers from some of the varieties
of the last, with which it is connected by the form acuta,

LIMNiEA. Ill

in the shell being much more swollen, and having the
last whorl and mouth excessively large in proportion
and the spire consequently smaller. The rows of very
minute longitudinal striae may also be regarded as an-
other test of distinction. Young shells are more slender
than those of L. peregra. The present species was first
described by Lister.

5. L. stagna'lis*, Linne.

Helix stagnalis, Linn. Syst. Nat. ed. xii. p. 1249. LimncBUS stagnalis,
F. & H. iv. p. 174, pi. cxxiv. f. 4, 5.

Body fawn-colour or yellowish- grey with a reddish tint,
covered with very small brown and milk-white specks : ten-
tacles rather long and pointed : foot having a narrow edge of
yellow, very broad at its sides, swollen and keeled behind.

Shell elongated, of a moderate thickness, semitransparent,
yellowish-horncolour or greyish-white with sometimes a
sHght tinge of red, irregularly striate by the lines of growth,
with extremely fine and close-set interstitial striae, which are
curved and arranged in rows, and regularly but indistinctly
ridged in a spiral direction, so as to form, by intersecting the
longitudinal striae, quadrangular facets, resembling those of
cut glass : epidermis thin : luhorls 7-8, rather convex and
bulging out in the middle, the last occupying nearly three-
fourths of the shell : spire oblique, much produced and taper-
ing to a fine point : suture moderately deep, margined above
by a narrow white line, which is formed by the upper edge of
the preceding whorl : mouth oval, interrupted on its inner side
by the periphery of the penultimate whorl and the columellar
fold : outer lip rather thin and slightly reflected : imier lip
spread on the columella and thickened in adult specimens :
fold prominent and very strongly curved. L. 2. B. 1.

Var. 1. fragilis. Shell smaller, more slender and tapering.
Helix fragilis, Linn. Fn. Suec. 2187 ; Mont. Test. Brit. p. 369,
tab. 16. f. 7.

Yar. 2. cdhida. Shell of the last-mentioned form, but of a
white colour.

* Inhabiting ponds.

112 LIMNiEID^.

Var. 3. lahiata. Shell dwarfed and more solid, with the
outer lip much reflected and thickened. L. 0*9. B. 0*55.

Var. 4. sinistrorsa. Spire reversed.

Habitat : Slow rivers, marshes, and standing water
throughout the kingdom; but it is more local than L.
peregra. Var. 1. Kennet and Avon Junction Canal,
Wilts (Montagu) ; Surrey and Croydon Canal (Leach) ;
R. Cam at Cambridge (Granger) ; Grand Canal, Dublin
(Warren). This variety is the Stagnicola elegans of
Leach. Var. 2. From the last-mentioned locality. Var. 3.
Lough Neagh, Ireland (Moggridge). Var. 4. Kenn Moor,
Somerset (Norman). This species is one of our upper
tertiary fossils. It ranges from Siberia to Naples.

This mollusk is sluggish, but fond of floating. Before
descending to the bottom it withdraws its body into the
shell, and in so doing disengages the air from its pouch,
which escapes with a perceptible noise. The shell is
remarkably handsome ; but it is often disfigured by a
coating of vegetable or calcareous matter. The outer
lip sometimes becomes thickened in consequence of a
temporary cessation of growth ; and in such cases vari-
cose marks are observable on the spire at intervals.
Young shells are extremely slender, and the mouth is
not expanded as in adult specimens. In this state they
somewhat resemble L. glabra in form, and might be
mistaken for a new species. Miiller tried the experi-
ment of cutting oflP the heads of some of this kind of
mollusk to see if they would be reproduced ; but he tells
us that the poor animals did not long sur^dve the opera-
tion. Menke supposed that the shell of this species was
the helmet of the Frogs in Homer^s ^ Batrachomyo-
machia^; but, in opposition to this ingenious idea, it may
be remarked that the L, stagnalis does not appear to

LIMN^A. 113

have ever existed in Greece. From the description of
the armour of the Frogs, it does not appear that any
species in particular was intended : —

" Form'd of the varied shells the waters yield,
Their glossy helmets glisten'd o'er the field."

It is not likely that Homer was a conchologist, or distin-
guished one shell from another for poetical purposes.
The kind of shell in question must have made cumber-
some helmets for the valiant Frogs.

L. stagnalis is a large and favourite object for the
aquarium ; and Mr. Lloyd has recorded in the ^ Zoologist^
some interesting observations as to the mode of its
respiration.

The shell is so much larger and longer than that of
any other LimncBa, that it is unnecessary to make any
further comparison between them.

C. Spire of the shell much produced, and whorls gradually

enlarging.

6. L. palus'tris*, Miiller.

Buccinu7n palustre, Mllll. Yerm. Hist. pt. ii. p. 131. Limnceus palustris,
F. & H iv. p. 180, pi. exxiv. f. 2.

Body dark grey, with a tinge of violet-brown, covered with
fine black and yellowish-white specks : tentacles conic, curved
and pointed : eyes placed on small tubercles : foot oblong,
truncate and slightly notched in front, narrowing behind and
ending in a blunt tail.

Shell oblong, rather solid, of a somewhat duU hue, yellowish-
brown with sometimes a violet tint, sculptured as in L. stag-
nalis, but the spiral ridges are generally more prominent and
numerous : e/pidermis rather thin : wliorJs 6-7, rounded and
moderately convex, the last occupying about two-thirds of the
shell : spire produced and tapering to a somewhat fine point :
siitwre rather deep, often margined above by a narrow white

* Inhabiting bogs.

114 LIMN.EID^.

line, which is caused by the appearance through the shell of
the upper edge of the preceding whorl : mouth obliquely oval,
but contracted on the inner or columellar side : outer lip rather
thick, scarcely reflected, but expanded below : inner lip spread
on the columella : fold extremely prominent and sharp. L. 1.
B. 0-4.

Yar. 1. Corvus. Shell much larger and more swollen, of a
purplish -brown colour. L. 1-35. B. 0-65. HeliM Corvus,
Gmel. Syst. Nat. p. 3665.

Var. 2. elongata. Spire elongated.

Var. 3. tincta. Shell shorter and broader, Hght brown
with a purplish mouth. Limneus tinctus, JefFr. in Linn. Tr.
xvi. p. 378.

Yar. 4. conica. Shell conic, greyish -white, with a deep
suture and an umbihcal cleft. L. Q-o. B. 0*25.

Yar. 5. rosea -lahia'ta. Mouth of the shell furnished inside
with a rose-coloured or white rib.

Yar. 6. decoUata. Spire truncate.

Habitat : Marshes, ditches, and shallow pools every-
where from Aberdeenshire to the Channel Isles. Var. 1.
Suffolk (Barlee). Var. 3. Falmouth (J. G. J.). Var. 3.
Swansea and Dorsetshire (J. G. J.) ; Anglesea (Gibbs).
This last variety resembles a Bulimus in form. Var. 4.
Banks of the Thames from Hammersmith to Woolwich
(J. G. J.) ; Cork (Humphreys) . This is a peculiar variety;
but as it is connected with the typical form by the variety
tincta, and it is not found in company with any other
form, I do not consider it to be specifically distinct. Some
specimens have a longer spire and resemble L. truncatula.
Var. 5. Belfast (Thompson); Cork (Humphreys). Var.6.
Preston (Gilbertson) ; Guernsey (Lukis) ; Ballinahinch,
Co. Gal way (J. G. J.). This species is also one of our
upper tertiary fossils. Abroad it ranges from Siberia to
Algeria and Sicily.

It has the character of being a slow, irritable, and very

LIMN^A. 115

greedy animal — none of which are amiable qualities in
our own species ! Owing to the nature of its habitat^
the shell is apt to have a coat of hardened mud. The
whorls are sometimes more or less distorted or scalari-
form. Draparnaud says that the animal has only two
aeriferous tubes, instead of four as in L. auricularia ; but
this remarkable and anomalous organization does not
appear to have been observed by other naturalists.

This species differs from all the preceding in the shell
being thicker and the whorls much more narrow. It
was first (and well) described by Lister.

Mr. Bean was kind enough to give me specimens of
L. cornea (a native of the North- American lakes) which
his son was said to have collected in the West of Ireland.
It is allied to the present species, through the variety
tincta ; but I suspect there must have been some mistake
as to the alleged Irish locality.

7. L. trunca'tula*, Miiller.

Buccinum truncatulum, Miill. Verm. Hist. pt. ii. p. 130. Limnmis trun-
catulus, F. & H. iv. p. 177, pi. cxxiv. £ 3.

Body dark brown or grey, of a lighter colour on the lower
side, covered with fine black specks : tentacles short, but slender,
rounded at their tips : eyes nearly sessile : foot rather short,
marked with milk-white spots, which are scattered and larger
than the black specks, nearly truncate in front, gradually
narrowing and abruptly rounded behind.

Shell oblong-conic, turreted, rather solid for its si^e,
glossy, yellowish-brown or horncolour ; sculpture the same as
in the two last species : epidermis thin : whorls 5-6, rounded
and convex, but compressed in the middle, so as to make the
top of each appear somewhat truncate ; the last whorl occu-
pying about three-fifths of the shell : spire abruptly tapering
to a rather fine point : suture extremely deep : mouth oval,
scarcely contracted on the inner side : outer lip sharp : inner
lip continuous with it and reflected on the columella, behind

* Slightly truncate.

116 LIMN^IDyE.

which is a distinct umbilical chink : fold rather slight but
thick. L. 0-4. B. 0-2.

Var. 1. major. Shell larger : whorls more swollen and the
last considerably exceeding the usual proportion of size.

Yar. 2. elegans. Shell much larger, more solid and slender,
greyish-white, marked with coarse spiral ridges : S2)lre much
produced : suture oblique : outer lip thickened. L. 0-6. B.
0-225.

Var. 3. minor. Shell much smaller, thinner and semi-
transparent, dark horncolour, marked with stronger and closer
longitudinal striae. L. 0-285. B. 0-165.

Var. 4. alhida. Shell smaller, milk-white.

Var. 5. scalariformis. Shell smaller : whorls nearly dis-
united.

Var. 6. microstoma^ Shell smaller and narrower : ivhork
more swollen : mouth contracted.

Habitat : Banks of slow and muddy rivers and
streams, marshes, ditches, grassy pools, waterfalls, and
moist places everywhere from the northernmost point of
Zetland to Jersey. Var. 1 . Penzance (Millet and Barlee) ;
Newton Nottage, Glamorganshire (J. G. J.). Var. 2.
Hants (Mus. Loscombe). Var. 3. Momitainous tracts
and sea-side marshes. Var. 4. Battersea (J. G. J.) :
Crymlin Burrows, Swansea, (Moggridge). Var. 5. War-
minster (J. G. J.). Var. 6. Southampton (J. G. J..
Besides these varieties, my cabinet contains specimens
in which the spire is more produced, or shorter with
the whorls partly intorted, and some have interrupted
spiral bands of white lines. This species occurs in our
upper tertiary beds. Its foreign distribution extends
from Siberia to Algeria and Sicily; and, according to
Captain Hutton, it is a native of Afghanistan.

This abundant but pretty little mollusk is nearly
amphibious, being more frequently met with out of the
water than in it. It is also found in very elevated spots.

LIMNJLA. 117

Moquin-Tandon states that lie had observed it in the
Pyrenees at a height of 1200 metres (nearly 4000 feet) ;
and instances of its occurring at a tolerable elevation in
this country might doubtless be also given, as I have
found it living at the sides of all our mountain tarns,
but no other animal in company with it. It deposits its
spawn on the mud, which is its usual habitat, and not,
like its congeners, on the stalks and underneath the leaves
of water-plants.

The form of its shell somewhat resembles that of L.
peregra, var. maritima ; but its minute size and turricu-
lated spire will serve to distinguish the present from
any other species. This is the Limneus minutus of Dra-
parnaud and Helix fossaria of Montagu. The name it
now bears seems to have been derived, not from the
truncature or decollation of the spire, but from the
truncate or turreted form of the whorls.

8. L. gla'bra^, Miiller.

Buccinum glahrum, Miill. Yerm. Hist. pt. ii. p. 135. Limnaus glaher,
F. & H. iv. p. 178, pi. cxxiv. f. 1.

Body dusky-grey with a tinge of slate-colour, covered with
minute, but distinct, black specks : tentacles rather long : eyes
placed on prominent tubercles : foot truncate in front, from
which it spreads a little towards the rear, ending in a thick
and narrow tail.

Shell cyHndrical, rather thin and glossy, greyish-horn-
colour or brownish, sculptured as in the three preceding species :
epidermis very thin : whorls 7-8, rounded but not very convex,
the last occupying not much more than half the shell : spire
produced and ending in a somewhat blunt point : suture slight,
but distinct, margined as in the two foregoing species : mouth
pear-shaped, contracted above at an acute angle, and furnished
inside with a thick broad white rib, which is placed at a httle
distance from the opening : outer lij) thin, scarcely reflected :

* Smooth.

118 LIMN^ID^.

inner Up rather thick : fold somewhat prominent and sharp.
L. 0-6. B. 0-2.

Yar. elongata. Spire more produced, so as to alter the
relative proportions of length and breadth.

Habitat : Ditches and shallow pools, but sparingly-
distributed in this country. It appears, however, to have
been found in the following counties and places, — viz.
Northumberland, Durham, York, Salop, Norfolk, Suffolk,
Essex, Oxon, Wilts, Dorset, Cornwall, Guernsey, Jersey,
Cork and Belfast. Although local, it is plentiful where
it occurs. It ranges from Scandinavia to France as far
south as the lower Pyrenees,

It is an exceedingly sluggish and timid mollusk, but
ventures occasionally on a very short floating excursion.
It often retires considerably within its shell, when it
forms the inside lip or rib. The repetition at intervals of
this lip, which is seen through the semitransparent shell,
gives the latter a varicose appearance. The shell is also
liable to lose its first or apical whorls, and consequently
to become decollated.

This species is the Bulimus leucostoma of Poiret, Helix
octanfracta of Montagu, and lAmneus elongatus of Dra-
parnaud.

Genus IV. AN'CYLUS*, Geoffroy.
PL IV. f. 11, 12, 13, 14.

Body oval, conic, slightly twisted behind ; head very large :

tentacles short, nearly cylindrical but thicker at their base :

foot oval, or oblong, obtusely rounded in front and behind,

closely attached to the upper part of the body : respiratory

pouch or sac forming a short tube.

Shell hood-shaped, with an incomplete or rudimentary spire,
which is in some species dextral and in others sinistral.

* Hooked.

ANCYLUS. 119

This is in some respects an anomalous genus^ although
undoubtedly related to Limncea, Menke and other con-
chologists have proposed to separate it from the LimnceidiB
and to make it a distinct family by itself. The resem-
blance of its shell to the marine Limpet, or Patella^ has
caused this to receive the not inappropriate name of the
" freshwater Limpet," — showing that the sea and land
have their respective representatives or analogues in the
system of Nature. It was for a long time supposed,
even by the great Cuvier, that the Ancyli were branchi-
ferous ; but it has now been satisfactorily ascertained,
by the careful investigations of Mr. Berkeley and other
able physiologists, that they are truly pulmoniferous,
although they are also capable (like other aquatic Pul-
monobranchs) of extracting air from the water for the
purpose of respiration. They inhabit both rapid and still
waters, attached to stones and the leaves of plants. They
are not inactive in their habits, but have never been
observed in a floating position. One of our native species
(A. fluviatilis) is nearly as amphibious as the Limncea
peregra and L. truncatula ; and it may often be seen on
rocks at the side of waterfalls, having no other moisture
than the spray which occasionally falls on it. When it
crawls, only the tips of its tentacles, and sometimes the
front edge of its mantle, are visible. The only two
British species of Ancylus are apt to be infested with a
number of quasi-parasitic worms, as is also the case with
many kinds of Limncea. The food of the Ancyli consists
of freshwater Alga3 or Confervse, as well as of decayed
vegetable matter. They are said also to eat or swallow
a certain quantity of very fine gravel or sand, apparently
to assist their digestion, which is very slow. They can
live a long time without any nourishment.

120 LIMNiEID.^.

A. Body sinistral. Shell dextral.

1. Ancylus fluvia'tilis*, Miiller.

Ancylus fluviatilis, Miill. Verm. Hist. pt. ii. p. 201 ; F. & H. iv. p. 18G,
pi. cxxii. f. 4.

Body slate-colour or dark grey, with fine black specks :
tentacles somewhat triangular at the base, becoming slender
towards their tips, which are blunt : eijes not very prominent,
but distinct : foot oval, nearly equal in circumference to the
mouth of the shell.

Shell semi-oval, incurved towards the front like a helmet
of the ancients, rather thin, not glossy, yellowish -grey or horn-
colour, strongly and regularly striate longitudinally in a radi-
ating direction from the crown to the margin or outer edge of
the mouth (some of the striae often forming remote ridges) and
very finely striate transversely or in the line of growth : anterior
margin somewhat narrower than the other : epidermis rather
thin : spire forming the beak and being equal to about half a
whorl, with a compressed and blunt top, which turns a little
to the right, bending down towards and nearly reaching the
posterior margin : mouth oval : outer lip membranous, slightly
reflected. L. 0-3. B. 0-233.

Yar. 1. Capuloides. Shell larger and higher, with the beak
not placed so near the posterior margin. L. 0*415. B. 0*3.
A. Capuloides, (Jan) Porro, Mai. Com. p. 87, pi. 1. f. 7.

Yar. 2. gihhosa. Shell smaller, more swoUen, with the
beak reaching or overhanging the posterior margin. A. gih-
bosus, Bourguignat in Journ. de Conch, iii. (1853) p. 186.

Yar. 3. alhida. Shell milk-white and more finely striated.

Habitat : Abundantly on stones and rocks in shallow
rivers and streams everywhere from Aberdeenshire to
the Channel Isles. I once found it of a dwarf size on
the leaves of the white water-lily in a stagnant pond
near Swansea, into which no stream had flowed within
the memory of man, living in company with A. lacustris,
and coated with a confervoid growth. Yar. 1. R. Corfe,

^ Inhabiting rivers.

ANCYLUS. 121

Dorset : very rare (J. G. J.). Var. 2. Sark ; Osmington
mills^ near Ringstead^ Dorset ; Dunboy, near Bearhaven,
Co. Cork (J. G. J.). This last variety is the A. deper-
ditus of Ziegler and Dupuy ; but (according to Bour-
guignat) not of Desmarest, who first used that name
for another species. Intermediate forms in respect of
the position of the beak incline me to consider this only
a variety. Var. 3. Wokey hole^ near Wells (Beevor) ;
Scarborough (Bean) ; near Torquay (Norman) ; Arish
mill^ near Lul worthy Dorset (J. G. J.). Specimens
from different places vary in colour from white to dark-
horncolour or reddish-brown. This species is also one
of our upper tertiary fossils. Abroad it ranges from
Finland to Algeria and Sicily ; and the Rev. R. T. Lowe
has incladed it in his list of Madeiran land-shells.

M. Bouchard- Chantereaux published, nearly thirty
years ago, an extremely interesting account of the em-
bryogeny of A. fluviatilis, illustrated by a plate showing
the successive development of the spawn into the fry.
He says, each individual lays, in the course of the breed-
ing-season, about 80 eggs, which are enclosed in from
7 to 10 capsules and arrive at maturity in from twenty-
four to twenty-seven days, according to the temperature.
The animal seems to be more fond of Fontinalis antipy-
retica than of any other plant.

Many species have been carved out of this variable
kind by Continental authors. In very young shells may
be detected faint traces of a more complete spire, which
is intorted so as to cause a concavity in the beak, called
by M. Bourguignat the " depression apicale.^^ This
species was first made known by Lister, and described
by him under the name of Patella fluviatilis, but ac-
companied by other epithets. It has by some authors
been considered to be the Patella lacustris of Linne ;

G

122 LIMN^ID/E.

but I will defer my remarks as to this name until I have
to treat of the next species.

E. Body dextral. Shell sinistral.
2. A. lacus'tris *_, Linne.

Patella lacustris, Linn. Syst. Nat. ed. x. i. p. 783. A. ohlovgus, F. & H. iv.
p. 188, pi. cxxii. f, 5.

Body yellowish-grey with a greenish tinge, covered with
minute and indistinct dark specks : tentacles thick, pointed at
the tips : eyes as in the last species : foot truncate in front and
very round behind, having a few yellow specks interspersed
among the black ones.

Shell oblong, obUquely twisted to the left, thin, glossy
greyish -horncolour, very finely but indistinctly striate as in
A. fiuviatilis, but without the intermediate ridges : anterior
margin very little narrower than the other : e/pidermis thick :
heak sharp and ridge-like, turning obliquely to the left, but
placed close to the margin : month oblong : outer lip membra-
nous, reflected. L. 0-25. B. 0-1.

Yar. ].. compressa. Shell rather larger, and considerably
broader and flatter, than usual.

Yar. 2. alhida. Shell milk-white, with a light-grey epi-
dermis.

Habitat : On the under side of the leaves of water-lilies
and other aquatic plants^ as well as on fallen leaves of
trees_, in slow rivers^ lakes, canals, marshes, and ponds
throughout the greater part of the kingdom as far north
as Aberdeenshire. It is, however, a local species.
Y^ar. 1. Dunstall, StaflTordshire (J. G. J.). Y^ar. 2.
Grand Canal, Dublin (Y^arren). It is also one of our
upper tertiary fossils. Its foreign distribution is the
same as that of the last species.

Miiller states that this is not only a freshwater but a
marine shell, having taken it alive and adhering to marine

* Inhabiting lakes.

ANCYLUS. 123

species of Conferva, in the Baltic Sea. According to
Mr. WhiteaveSj it hibernates between the sheathing
leaves of Sparganium ramosum.

This species is easily recognizable from A. fluviatilu-
by its different habitat and the oblong shape of its shell,
as well as by the form of the beak, which is twisted
decidedly to the left, instead of being (as in the other
species) nearly central or inclined to the right.

It has been called by some authors A. oblongus, being
the specific name given to it by Lightfoot under the im-
pression that this was not the Patella lacustris of Linne.
There can, however, be scarcely any doubt that Linne
meant this species, and not A. fluviatilis, because in his
^ Fauna Suecica ' he mentions its being rather common
in lakes and attached to the submerged leaves of aquatic
plants, especially of Stratiotes. His description of the
shell is applicable to either species.

Nearly half a century ago, a curious instance of false
analogy occurred with respect to an organism which
Draparnaud described and figured (in his admirable
History of the Land and Freshwater MoUusca of France)
as " Ancylus spina-rosce'^ from specimens sent him by
Ferussac. These specimens were afterwards discovered
not to be testaceous; and many conjectures were from
time to time made as to their nature. It was supposed
by some that they were parts of a small pod or capsule,
by others that they were the bracts of a flower-stalk, and
by not a few naturalists that they were scales of a fish.
The puzzle, however, was at last solved by the discovery
that these nondescripts were the valves of a Cyjjris, and
therefore belonged to the Crustacea.

TERRESTRIAL.

The Slugs and Land-Snails^ which (as I before observed)
constitute about three-fourths of the British Pulmono-
branch Mollusca^ may be conveniently divided into two
sections. The first section agrees in all essential particu-
lars^ except that of having retractile (instead of contrac-
tile) tentacles^ with the aquatic family of Limnmd^E, which
have been above described. The second corresponds with
the Pectinibranch Mollusca in having separate sexes,
their eyes at the base of the tentacles, and univalve spiral
shells which are furnished with opercula ; and the main
point in which it differs from that great Order consists
in the organs of respiration, resulting from the nature
of their respective habitats. All the land Pulmono-
branchs are more slimy than their aquatic representa-
tives ; and they appear to be less inactive in their habits.

The first section comprises four families, viz., —

* Tentacles, almost in every case, 4 : eyes placed on the tips of
the upper, or single, pair : shell rudimentary, shield-like,
or complete and spiral.

I. LlMACID^.

II, Testacellid^.
III. Helicid^.

** Tentacles 2, besides rudiments of a second or lower pair : eyes
placed at the internal base of the developed pair : shell
spiral, elongated.

lY. Carychud.'e.

LIMACID.^. 125

Family I. LIMACID.E.

Body long, straight, and flexible : mantle covering only the
upper part of the back, and forming a shield : head prominent :
tentacles 4, cylindrical, arranged in pairs, the upper pair being
the longest : eyes 2, placed on bulbs at the tojD of the upper
tentacles : foot united to the body and coextensive with it.

Shell either rudimentary and of an indefinite form, or
shield- shaped, placed underneath the mantle.

I do not propose to treat of this family aud its com-
ponent members to the same extent as my opportmiities
have enabled me to do with respect to the testaceous
members of the same Order ; and I must admit that I
have not paid equal attention to this part of the subject.
The aspect^ and much less the handling, of these slimy
creatures cannot be considered as especially inviting ;
and as I believe the majority of my readers share in this
opinion, I may with greater confidence ask their indul-
gence for any shortcomings on this point. At the same
time I would observe that the subject offers, to those
who are inclined to pursue it, a wide field of research
and a greater prospect of novelty than can be expected
from the study of the testaceous Mollusca. The ana-
tomy, physiology, and habits of the Slugs were described
nearly two centuries ago by our countryman, Dr. Lister,
in his admirable treatises on British animals ; and Mr.
Nunneley and the Rev. B. J. Clarke have lately done
much to increase our knowledge of these mollusks. Some
of their remains have been detected in our upper ter-
tiary beds at Copford, as well as in similar deposits in
the South-west of France.

126 LIMACID^.

Genus I. ARI'ON *, Ferussac. PI. V. f. 1, 2.

Body nearly cylindrical, with a strongly wrinkled skin :
sJmld oblong, shagreened: respiratory orijice placed near the
front edge of the shield : foot furnished at its posterior extre-
mity or tail with a mucus- or sKme-gland.

Shell amorphous, consisting of loose calcareous grains
which are covered by the hinder part of the shield.

The Arions, or black slugs, frequent damp and shady
woods, as well as hedge-banks and gardens. During
the daytime they lurk under stones and logs of wood,
or bury themselves in the earth, where they excavate a
sort of tunnel ; but at night, and after rain, they sally
forth to feed. They are great pests in gardens, gene-
rally selecting the best cabbages and most succulent
vegetables. They are, however, not very particular
about their food, and act the part of land-scavengers,
devouring animal matter of all kinds in every state of
decomposition, and even each other^s slime. They may
be frequently met with in garden-walks, after a shower,
in search of food. During the season of reproduction
they deposit their eggs, which are very numerous, sepa-
rately underground. When at rest, they contract their
bodies into a lump. In this state they offer a dainty
prize to ducks. They differ from the Limaces, or com-
mon slugs, in their respiratory orifice being placed in
front, instead of near the hinder part, of the shield, in
having a slime-gland at the tail, and in the arrangement
of the teeth.

* The name of an ancient musician and poet : scarcely appropriate to
this genus.

ARION. 127

1. Arion a'ter*_, Linne.

Limax afer, Linn. Syst. Nat. ed. x. p. 652. A. Em])iricorum, F. & H. iv.
p. 7, pi. D. D. D. f. 4.

Body rather contracted and rounded in front, pointed behind,
varying greatly in colour, from black to brown, red, yellow,
greenish, and even white, with all the intermediate shades,
covered with prominent and large tubercles : shield, or mantle,
finely shagreened, of a lighter colour than the rest of the
body: tentacles coarsely shagreened, much swollen at their
tips, especially the lower pair : foot generally having a yellow
border, which is crossed at the sides by close and curved dark
lines: slime of a yellowish colour. L. 4. B. 0-5.

Shell consisting of small separate calcareous grains of
unequal size.

Habitat : Woods, hedges, fields, and all sorts of damp
places in the country tliroughout these Isles. Abroad
it ranges from Siberia to Portugal and Corsica, as well
as to Madeira ; and a variety of it was found as far north
as Jan Mayens Isle by the naturalist who accompanied
Prince Louis Napoleon^ s expedition.

This species has had an infinity of names given to it,
on account of its extreme variability of colour. It is
the A. Empiricorum of Ferussac, so called from the cal-
careous substance which is found under the shield having
been formerly used in the preparation of medicine.

The A.flavus of Ferussac {Limax flavus, Miiller), which
has been found in the North of England by Mr. Alder
and Mr. Blacklock, as well as by Mr. Norman and Mr.
Whiteaves in Somersetshire and Oxfordshire, appears,
according to Moquin-Tandon, to be a doubtful species.
MM. Bouchard-Chantereaux and Normand state that
this last-mentioned species or variety inhabits woods and
moist places in the North of France.

* Black.

128 LIMACID/E.

2. A. horten'sis"^^ Ferussac.

A. hortensis, Fer. Hist. Moll. p. 65, pi. ii. f. 4-6 ; F. & H. iv. p. 10,
pi. E.F.F. f. 1.

Body longer than that of the last species in proportion to
its size, and of nearly an equal breadth throughout, brown,
red, yellow, grey, greenish, or black, usually more or less di-
stinctly marked on the back and sides with stripes or longitu-
dinal bands, and covered with coarse oblong tubercles : shield
having usually a dark stripe down the middle and another on
each side : tentacles not much swollen at their tips • foot nar-
I'owly bordered with grey, yellow, reddish, or orange : slkne
yellowish or whitish. L. 1-5. B. 0-35.

Shell of an ii-regular shape, composed of grains like those
in the last species, but cemented together by a calcareous
matrix, so as to resemble tiny lumps of the conglomerate
which is called by geologists " breccia."

Habitat : Under stones and dead leaves in gardens,
fields, and damp spots everywhere. Its foreign distri-
bution is also perhaps equally extensive with that of
A. ater.

According to Bouchard-Chantereaux, the eggs of A.
hortensis are phosphorescent during the first fifteen days
after they have been laid. They take from twenty to
forty days to arrive at maturity, and the young become
adult towards the end of the first year.

This species differs from A. ater in being much smaller
and more slender, as well as in usually having longitu-
dinal lines or stripes. The substitute for a shell is also
more compact, and making some approach to a definite
form, in the present species. Dr. Gray describes the
shell to be '^ distinct, oval, concave ;" but tliis description
does not agree with the generic character of this part of
the animal.

It is the A. fasciatus of Nilsson. Miiller described

* Frequenting gardens.

GEOMALACtJS. 129

two slugs [Limaoo cinctus and L.fuscus) as having longi-
tudinal stripes; and although it is most probable that
one or both of them may be identical with the present
species^ the name given by Ferussac has been adopted
to prevent confusion.

Genus II. GEOMA'LACUS f- PL V. f. 3.

Body resembhng that of Arion, but more extensile and
keeled on the back, besides having the reproductive oriliee
placed near the base of the right lower tentacle, in which
respect it differs both from that genus and Lhnax.

Shell unguiform, imbedded in the shield.

This genus, of which only one species is known, appears
to be intermediate between Arion and Lhnax. I suspect
that the Lhnax anguiformis of Morelet (Moll. Port. p. 3G,
pi. iii. f. 1) also belongs to the present genus, if indeed
it is not the same species as ours.

Geomalacus maculo'sus J, AUman.

G. nmculosus, Allm. in Ann. N. H., new series, xvii. p. 297, pi. 9 ; F. & H.
iv. p. 12, pi. F. F. F*. f. 5.

No detailed account of this curious slug has been
published ; but it is described to be an exceedingly beau-
tiful animal, measuring, when creeping about, two inches
in length ; the colour of the shield and upper part of the
body is black, elegantly spotted with yellow ; the under
surface of the foot light yellow, and divided into three
nearly equal bands; the edge of the foot brown, with
transverse sulci. A white-spotted variety also occurred.
It can elongate itself, so as to assume the appearance of
a worm and thus enter exceedingly small apertures. It
was discovered by an active and indefatigable Irish
naturalist, Mr. William iVndrews of Dublin, during the

t Earth-mollusk. | Spotted.

G 5

130 LIMACIDvE.

autumn of 1842^ ^^on rocks around Lough Carrough,
to the south of Castlemain Bay, Co. Kerry, in the West
of Ireland." Mr. Andrews informs me that it is im-
possible to appreciate the extreme beauty of this slug
without observing it in the living state. The surmise
offered by the authors of the ' British Mollusca/ that
this may be an Asturian, as well as an Irish, slug, is pro-
bably well founded. Morelet^s description, in 1845, of
his Limax anguiformis appears to have escaped their
notice. He especially mentions the peculiar form of
the slug and the position of the respiratory organ.

Genus III. LI'MAX^ Linne. PL V. f. 4, 5.

Body nearly cyhndrical, with a wrinkled skin, and more or
less keeled on the back : sliield sometimes shagreened, but in
most cases concentrically striate : respiratory orifice near the
hinder edge of the shield : reproductive orifice close to and
behind the right upper tentacle : foot not furnished with a
mucus -gland.

Shell oval or shaped hke a finger-nail, formed of concentric
layers, and covered by the hinder part of the shield (Limacella,
Brard).

The habits of this kind of slug are nearly the same as
those of Avion; but some of them appear to like the
company of man more than he desii'cs, being often
found in kitchens and domestic offices. They are, how-
ever, sometimes useful in eating that kind of fungus
which causes dry rot, and another kind which infests
cellars and makes choice Port wine what is termed
^'^ corked." Among themselves they are also sociable,
and are often found clustered together in the same spot.
Gardeners have great cause to complain of their voracity^
and especially when they see the finest strawberries have
been selected for their supper or early repast.

* Slug.

LIMAX. 131

A. Shield shagreened

I

1. LiMAX GAGATES*, Drapamaud.

L. gagates, Drap. Hist. Moll. p. 122, tab. ix. f . 1 ; F. & H. iv. p. 24,
pi. D. D. D. f. 3.

Body very slightly contracted and nearly cylindrical in front,
gradually tapering to a point behind, varying from slate-colour
to dark-red or even black, covered "with small oblong inter-
laced tubercles : shield oblong, somewhat truncate in front
and rounded behind, apparently divided into two lobes, finely
shagreened or grained: tentacles very short and thick, not
much swollen at their tips : hack sharply keeled its whole
length, bordered with white or a lighter colour than the rest
of the body : sUme nearly colourless. L. 2-5. B. 0-85.

Shell oval, rather thick (especially in the middle), and
slightly wrinkled.

Habitat : Hedges and at the roots of grass and the
foot of old walls in many parts of Great Britain from
the Clyde district to Guernsey; but it appears to be a
local species. It also occurs in the north, east, west, and
south of France, ranging to Corsica and Algeria, and
probably also to Naples. Mr. Norman has given an
excellent description of this species in the ^ Zoologist^
for 1853, and remarked that when at rest this slug as-
sumes a more rounded form than any other British
kind, contracting and squeezing itself into so small
a compass that its height is but little exceeded by its
length. Its slime is thick and glutinous, resembling
varnish. The apparent division of the shield into two
lobes, as noticed by Draparnaud, is owing to its being
indented behind by the keel.

* Jet.

132 LIMACID/E.

2. L. MARGiNA Tus *^ Miiller.

L. marginatus, Miill. Verm. Hist. pt. ii. p. 10. L. Sowerbii, P. & H. iv.
p. 22, pi. E. E. E. f. 3.

Body nearly cylindiical, truncate and slightly tumid in front,
gradually tapering to a point behind, yellowish or reddish-
browTi speckled with black, irregularly wrinkled : shield oblong,
obtusely rounded at both ends, wider and slightly truncate
behind, partly bordered with a dark band on each side and
occasionally streaked down the middle, veiy irregularly granu-
lated : tentacles thick, not much swollen at their tips : hack
having a prominent keel or ridge, which extends the whole
length from the hinder edge of the shield to the tail, and is of
a lighter colour than the rest of the body : foot pale-margined :
slime colourless. Dimensions same as in the last species,

SuELL oval, thickened, with conspicuous lines of growth :
boss or nucleus near one end, rather prominent. L. 0-2.
B. 0-125.

Habitat : Under stones, among dead leaves, and at
the foot of old walls everywhere. The shell or Limacella
has been fonnd in our upper tertiary beds. Although
this must be a widely diflused species, it does not appear
to have been noticed by any Continental writers except
Miiller, Moquin-Tandon, and the Abbe Stabile, accord-
ing to whom it inhabits Denmark and the mountainous
districts of France and Lugano.

This slug is inactive in its habits and secretes a thick
and tenacious slime. Stabile says that it is much preyed
upon by the Silphce, Carabi, and other large carnivorous
beetles. L. marginatus is said in its turn to attack and
eat other animals, and especially live worms and smaller
slugs.

Miiller' s description seems to be sufficient for the
identification of this species with that of Draparnaud
and subsequent authors, who have adopted the name first
given to it. He particularly mentions its having a white

* Bordered.

LIMAX. 133

keel, as well as marginal streaks on the shield, — although
he says it inhabits the beech, which character is more
applicable to L. arborum. Draparnaud doubted whether
his species was that of Midler because of this difference
in the habitat. It is the L. Sowerbii of Ferussac and
L. carinatus of Risso and Leach. The shell is the
Limacella unguiculus of Brard.

The shield in this species is much smaller in proportion
to its body than in L. g agates ; and the respiratory orifice
is in the last-named species placed more towards the
middle of the shield-area. The colouring is also dif-
ferent.

B. Shield concentrically wrinkled.

3. L. fla'vus *, Linne.

L.flavus, Linn. Syst. Nat. ed. x. i. p. 652; F. & H. iv. p. 19, pi. E. E. E.
f. 1.

Body slightly contracted in front, rather broad in the middle,
and tapering gradually to a point behind, yellowish, speckled
with white and black so as to form a kind of network, covered
with coarse oval tubercles : head of a bluish colour : shield
oblong, larger and more rounded behind, elegantly grooved by
concentric and rather undulating Hues : tentacles bluish ; the
upper pair rather short, the lower ones remarkably so : foot
keeled towards the tail, margined with yellowish- white ; sole
milk-white : sli7ne yellow. L. 4. B. 0*75.

Shell obliquely oval or quadrangular, rather concave on the
under side, thin, crystalhne and nacreous, with distinct lines
of growth : boss shghtly projecting behind : margin membra-
nous. L. 0-3. B. 0-125.

Habitat : Cellars, wells, sculleries, and other damp
places, as well as in moist woods, everywhere. It is
also common in the northern and central parts of
Europe.

* Yellow.

134 IIMACIDJE.

This kind of slug is nocturnal, but very active. Its
slime is abundant and stains linen of a yellow colour.
It appears to be fond of bread, cooked vegetables, and all
sorts of kitchen refuse.

It is probable that the L. flavus of Miiller may be a
variety of Avion ater, because he describes the shield as
not having any concentric wrinkles, although in the
same description he also notices a yellow slug which
seems to belong to the present species. This is the
L. variegatus of Draparnaud ; and its shell is probably
the Limacella concava of Brard.

4. L. agres'tis *, Linne.

L. agrestis, Linn. Syst. Nat. ed. x. i. p. 652 ; F. & H. iv. p. 13, pi. D. D. D.
f. 3.

Body spindle-shaped, slender, ash-grey with a reddish or
yellowish tinge and sometimes mottled, nearlj^ smooth : shield
rather large, more tumid behind, the concentric striae more
remote and indistinct than in any of the other species : tentacles
dark grey : hack obhquely, but not strongly, keeled towards
the tail: foot having very pale sides: slhne milky. L. 1*5.
B. 0-4.

Shell obliquely oval or inclined to oblong, concave on the
under side, rather thin, with indistinct hues of growth, and
marked obliquely by exceedingly minute striae which cross
each other: boss very small, slightly projecting behind on one
side : margin membranous, rather broad, and obliquely striate.
L. 0-2. B. 0-1.

Habitat : Fields, gardens, and woods throughout the
British Isles. The shell is also one of our upper tertiary
fossils. Its foreign distribution extends from Siberia to
Corsica and Algeria, and (according to Lowe) Madeira.

This slug is a great pest in the kitchen garden, and
does not even spare succulent leaves and roots of flower-
plants. Mr. Whiteaves says that it also feeds on earth-

* Inhabiting fields.

LIMAX.

135

worms. Its slime is abundant and viscous, feeling like
a lump of sticky fat. Miiller states that when it is
touched it draws in its horns and remains all day as if it
were dead, but in the evening it recovers itself. It is
extremely prolific, producing several families, averaging
fifty each, in the course of the breeding-season, viz. from
April to November. According to Leuch, a German
naturalist, a pair of these slugs have been known to lay
776 eggs. These eggs have retained their vitality and
the young have been developed from them after having
been dried eight times successively in a furnace. It has
the same faculty as L. arborwn of letting itself down
from one branch of a tree to another or to the ground,
by means of a slimy thread. Mr. Norman informs me
that in the earlier part of the year this slug is usually
creamy- white or light-drab ; that as the summer passes
away it assumes a darker hue, and brown flakes are
more or less thickly scattered over the surface; and
that during the autumn it is frequently of a rich brown
colour. A monstrosity of L. agrestis was found by Mr.
Gibbs, having the upper tentacles united into one.

Lister first distinguished the field-slug from other
kinds bv its smaller size and the nature of its slime :
and he also described its shell by appropriate characters.
This shell is the Limacella obliqua of Brard.

5. L. ARBORUM *, Bouchard-Chantereaux.

L. arborum, Bouch.-Chant. Moll. Pas-de-Cal. p. 28 ; F. & H. iv. p. 17,
pi. E. E. E. f. 2 (as L. arboreus).

Body rather slender, gelatinous, sea-green or bluish-grey
with irregular yellowish -white spots, indistinctly streaked with
a darker colour down the sides, leaving a lighter stripe in the
middle from the shield to the tail, finely wrinkled : shield

* Inhabiting trees.

136 LIMACID,?:.

rounded in front and obtusely angulated behind, the concentric
or transverse striae rather fine, streaked lengthwise, the middle
stripe being usually darker : tentacles short, yellowish-grey :
hacTc distinctly keeled towards the tail : foot having its edges
nearly white : slime colourless. L. 3. B. 0-4.

Shell squarish-oval, nearly flat, very thin, glossy, and iri-
descent, with minute nacreous tubercles ; lines of growth in-
distinct, obliquely striate as in the last species : boss nearly
inconspicuous and subterminal : margin broad, thin and mem-
branous. L. 0-2. B. 0-125.

Habitat: Trees (especially the beech) ^ as well as among
rocks and under stones^ both inland and on the sea-coast,
in most parts of Great Britain, from the north of Zetland
to the Channel Isles. According to Von Martens, it is
the L. Livonicus of Schrenck, and inhabits Russia ; it
occurs in several parts of Norway; Bouchard-Chan-
tereaux and Norm and have instanced localities in the
North of Erance, and 1 have found it in the Lower Harz :
but it has not been noticed further south. It has been
probably mistaken for the young of the next species.

M. Bouchard- Chantereaux^ who first described the
tree- slug, says that it prefers old trees, feeding on de-
cayed wood and not touching the leaves ; and he adds
that it is not prolific. He has often seen the young
(which he believes to be the L. filans or spinning-slug of
Hoy and some other English authors of the last century)
spin its slimy thread and descend from one branch to
another, but not plunging into air (or taking what bathers
would call " a header '') without apparent fear and
hesitation, the sole of its foot exhibiting during the
descent a similar movement to that which is observable,
while it is crawling on the sides of a glass vessel. In a
remote cluster of the Shetland Isles, called the Out-
Skerries, where I have taken this slug, with my friend
Mr. Norman, no trees exist ; but perhaps it found de-

LIMAX. 137

caying seaweed to be equally palatable. Its slime is
abundant ; and the animal, on being touched, yields a
fluid like clear water. Professor E. Forbes found it
plentifully, creeping on bare stones and rocks, at an
elevation of above 1500 feet, near Connor Cliffs, above
Dingle, in Kerry. Mr. Lowe observes that it prefers
walnut-trees. Mr. Daniel informs me that he has seen
this slug in couples during the pairing- season suspended
by slimy threads from the branch of a tree.

6. L. MAx'iMUS^, Linne.

L. yymximus, Linn. Syst. Nat. ed. xii. p. 108. L. cinereus, F. & H. iv.
p. 15, pi. D. D. D. f. 1.

Body rather slender, yeUo wish-grey, but varying in intensity
of colour and being sometimes quite black, with occasionally
streaks or spots of black or white, covered with numerous and
elongated tubercles, so as to appear strongly wrinkled : shield
oblong, very tumid, somewhat contracted or even pointed
behind, distinctly and regularly striate : tentacles (especially
the upper pair) long in comparison with those of other species,
yeUowish-brown : bacJc rounded, except close to the tail, where
there is a shght keel : foot edged with white : slime whitish.
L. 4-5. B. 0-75.

Shell squarish-oblong, rather convex above and nearly flat
beneath, solid, irregularly crystalline, rather glossy and na-
creous, with distinct lines of growth, obhquely striate as in
the two last species : boss very small, placed near one end : mar-
gin thin and membranous. L. 0*5. B. 0*325.

Habitat : Woods, gardens, hedges, under old logs of
wood, and nearly everywhere in town and country. Its
foreign range extends from Finland to Corsica and
Algeria, and (according to Mr. Lowe) Madeira.

This is the largest species of LimaXy and sometimes
exceeds six inches in length. It is inactive in its habits,
not very prolific, and exudes a thick and glutinous slime,

* Largest.

138 LIMACID^.

which is iridescent when dried. Its eggs are deposited
in a cluster and slightly attached to each other. When
alarmed, or at rest_, this slug merely draws its head within
the shield, but does not otherwise contract its body.
When irritated, it is said to expand its shield. It is
liable to be infested, as well as some of the other slugs,
by a white parasitic mite, called Philodromus (or Acarus)
limacum, which swarms about its body and, according
to Mr. Jenyns, dwells in its respiratory cavity, but which
does not seem to cause the slug any harm or incon-
venience, except perhaps in feeding on its slime and
slightly lessening the secretion. Mr. Daniel informs me
that these slugs suspend themselves in pairs during the
breeding- season by threads of slime, and that they always
feed by night, but that the variety cinereo-niger of
Nilsson prefers terra firma to mid-air and keeps much
more respectable hours. Like all other slugs and snails,
it will soon eat its way out of a large pill-box, or even a
stouter one made of cardboard, if confined in it. The
shell or ossicle which is contained under the shield was
known to Pliny ; and it was used by the ancient phy-
sicians for the sake of its carbonate of lime. The sub-
stratum of this shell is membranous ; and a layer of the
same filmy material covers the upper surface, having the
appearance and character rather of a periosteum than of
a Molluscan epidermis.

The young of this species- may be distinguished from
L. arhorum, among other respects, by its upper tentacles
being proportionally much longer, as well as by the pos-
terior margin of its shell being more pointed. The shell
of L. maximus is also longer, more convex, and thicker.

Miiller gave this species the name of cinereus, on the
supposition that the L. maxi7nus of Linne might be a
variety of Avion ater ; but the diagnosis of the great

LIMAX. 139

Swedish naturalist is couched in the same terms as that
of his predecessor, Lister, who accurately distinguished
the present species from the black slug. It is the L.
antiquorum of Ferussac ; and the shell is the Limacella
parma of Brard.

The L. brunneus of Bouchard-Chantereaux (F. & H.
iv. p. 20, pi. F. F. F. f. 4) is, according to Moquin-Tan-
don, a doubtful species ; and it is probably only one of
the numerous varieties of L, agrestis. It is rather local,
but appears to be widely distributed in this country, from
Zetland to Cornwall. In France its range extends
from Boulogne to the Pyrenees. In Dr. Gordon^s ex-
cellent contributions to the ^ Zoologist ^ it is stated that
this little slug, which is not uncommon in the Moray
Firth district, is the most lively and fearless of its tribe,
and that when disturbed, instead of contracting itself
into a lump, like most of its congeners, it makes bold
and repeated efforts to escape from the annoyance and
crawl away. The only essential diff"erence that I can
detect between it and L. agrestis is, that this slug is
smaller (scarcely an inch in length when crawling), and
of a uniform brown colour; and M. Bouchard-Chan-
tereaux admits that it is closely allied to the latter species.
The original L. brunneus of Draparnaud differs somewhat
in colour. The British species so called appears to be
the L. parvulus of Normand (Descr. Lim. Valencienues,
p. 8j, judging from his description.

The L. tenellus of Forbes and Hanley (iv. p. 21, pi.
F. F. F. f. 3), which they refer to Miiller^s species of that
name, can scarcely be considered as more than provi-
sionally introduced into the list of British slugs. Moquin-
Tandon reckons this also to be a doubtful species.
Miiller describes his L. tenellus as being ten inches long
(although this is evidently a typographical error) ; and

140 TESTACELLIDiE.

Nilsson describes his species of the same name as being
equal in size to L, flavus ; while the authors of the
^British Mollusca' state that the dimensions of their
slug do not exceed an inch and a quarter in length.
Miiller, Draparnaud, and Nilsson also mention its
having a greenish hue, which the British slug does
not appear to have possessed, M. Drouet says this
species belongs to Avion. A single specimen was found
by Mr. Blacklock in a wood at Allansford, near Shortly
Bridge, in Northumberland, and by him communicated
to Mr. Alder, who published the discovery in the ' Trans-
actions of the Northumberland and Newcastle-upon-
Tyne Natural History Society.^ It may possibly have
been the young or a variety of L. flavus. As, however,
this tribe is gregarious or at any rate individually
numerous, it is to be hoped that further researches will
be made, so as to settle the question as regards not only
the specific distinction of this slug, but also the pro-
priety of its admission into the British fauna.

Family II. TESTACELLID.^.

Body cyhndrical, exceedingly long and flexible : mantle ru-
dimentary, but capable of being occasionally expanded, gene-
rally covered by the shell : other characters similar to those of
Limacidoe, except in a few anatomical particulars.

Shell ear-shaped, with a very small terminal spire, ex-
ternal, and occupying the same place as the mantle in the last
family.

This family comprises only one genus, viz., —

TESTACEL'LA*, Cuvier. PL V. f. 6-9.

Body of a firm texture, with a nearly smooth skin : tentacles
cylindrical: labial j^alps extensible: foot margined.

* Diminutive shell.

TESTACELLA. 141

Shell solid : spire consisting of half a whorl : columellar fold
internal, very broad.

This peculiar genus appears to form a natural family
of itself, when viewed with respect to the British Mol-
lusca only ; but it is connected with the Slugs on the
one hand through the genus Parmacella, which has no
representative in this country, and on the other hand
with the Snails through the Vitrina semilunar of Fe-
russac (also a Continental mollusk), which Oken called a
Testacella. The Testacella partake in some degree of
the nature both of a Slug and a Snail, having a long
naked body and a small shell placed near its tail. The
shell serves to protect the heart, liver, and other vital
organs. The Snail-slug was first made known by the
celebrated Reaumur in 1740 through the Academy of
Sciences at Paris, in consequence of a communication
made to him by M. Dugue from Dieppe, and which con-
tains an excellent account of the shape, habits, and mode
of reproduction of this curious mollusk. From that
period down to 1800, many observations were made and
recorded in France on the same subject ; but it was only
in the last-mentioned year that Cuvier, being struck by
the remarkable aspect of the shell, constituted for it, in
his ' Lessons on Comparative Anatomy,' the genus Tes-
tacella. This name was adopted both by Lamarck and
Draparnaud in 1801 ; but in the following year it was
erroneously altered by Faure-Biguet to Testacellus. This
slight history of the name is given to prevent a con-
tinuance of this mistake, which was adopted by Fe-
russac, Sowerby, Gray, and other naturalists. By far
the most complete and valuable account, considered in a
conchological as well as a palseontological point of view,
which has been given of this genus, is contained in a

142 TESTACELLID.E.

monograpli by MM. Gassies and Fisclier, publislied at
Paris in 1856.

The Testacella appears to be the only land-mollusk
which has truly predaceous habits ; its marine representa-
tives in this respect being the Cuttle and the Whelk. It
is scarcely inferior to the tiger_, snake, or shark in its
cunning and ferocity. Its prey chiefly consists of earth-
worms, which it hunts underground and pursues through
their galleries, crouching occasionally and making a
spring on its \ictim. It is said that when the poor worm
has had the start of its pursuer, the Snail-slug intercepts
it by tunnelling across the line of its retreat. It will
devour a lob-worm much longer than itself, seizing it in
the middle; and when the writhings have been succeeded
bv exhaustion, it detaches and swallows one half of the
worm; and after that has been digested, it finishes its
long meal with the other portion. For this purpose its
mouth is furnished with an apparatus of sharp recurved
teeth, which enables the Testacella to retain a firm hold
of its victim and swallow it more easily. The worm is
provided with some means of defence, in the rows of stiff
bristles which encircle its rings ; and by contracting its
body a short respite is occasionally gained. But the
chance of ultimate escape or safety is very slight. When
the Testacella sees or scents its prey, it glides softly and
cautiously towards it ; and, apparently without taking any
notice of the worm, it seems to feel its way, and usually
succeeds in fastening itself on an unprotected part of
the body between the rings. The attack, if unsuccessful
at first, is renewed ; but if the worm resists too long, the
Testacella gets impatient, and by pressing or doubling
its victim into the earth, by which means the rings are
forced open, its purpose is effected and the meal secured.

TESTACELLA. 143

Although it also feeds on slugs and snails^ and even on its
own species (the shells of which have been found in its
stomach) J it will not eat dead animals, and even refuses
pieces of a fresh worm which has been chopped up to
feed it. It only sallies out at night in search of its prey,
burying itself deep in the ground during the daytime.
After having gorged itself with a worm, it rests many
hours in a half-torpid state until the meal has been di-
gested ; and it can remain fasting a long time (as much as
fourteen or fifteen nights) until hunger impels it to make
a fresh hunt. It does not fear the cold, or appear to
suffer any inconvenience from it except when the ground
is hardened by frost ; and in this respect it resembles the
Slugs, the Vitrince, and some of the Zonites, all of which
are nearly as carnivorous and hardy as the Testacella.

Gassies and Fischer are of opinion that the holes which
may be sometimes remarked in the shields of the Limax
gagates and other Slugs have been made by the Testa-
cella, for the sake of extracting the calcareous matter
from the internal shells or Limacella of the Slugs to
form its own more complete shell ; and they have noticed
that the Slugs which have been thus attacked soon die.
If the Testacella is taken fresh from the ground and kept
a short time in the hand, the warmth seems to revive it
and induce it to crawl away ; but if its retreat is op-
posed, it will violently bite the skin and oblige the ex-
perimentalist to let it go, from an instinctive feeling' of
disgust. During cold northerly and easterly winds these
creatures enclose their bodies in a kind of cocoon, like
that of the silkworm, which is secreted from their skin
and often mixed with earthy and extraneous particles.
Mr. Norman has informed me that in this state their
mantle is expanded to such an extent as to cover all the
upper part of the body. Ferussac appears to have been

144 TESTACELLID.E.

mistaken in supposing that the whole gf the body was
enveloped by the mantle. If this slimy pellicle be sud-
denly removed, the Snail-slug is liable to be attacked by
a disease which usually ends in its death. Heavy rains
destroy a number of them. The average length of life in
the Testacellce appears to be five or six years. Their
smell is like that of worms, but even more nauseous.
They chiefly frequent gardens, where they are sure of
finding their proper food; but they may occasionally be
met with in woods near inhabited places, as well as at the
foot of old walls. In winter they bury themselves very
deep in the ground ; and my gardener once brought me
living specimens of T. Maugei which he had dug up in
trenching some celery-roots at a depth of about two feet.
The eggs are laid separately, and are very large in pro-
portion to the size of the body. These somewhat re-
semble hen^s eggs both in shape and consistency, and
are covered with a rather thick and tough skin. If they
are taken out of the earth and exposed to a cold air, they
frequently crack and burst in pieces which fly ofi" to some
little distance. Faure-Biguet appears to have succeeded
in preserving the eggs under such circumstances by
plunging them as soon as taken into boiling water. It
is believed that the Testacella never come to the surface,
except occasionally during the breeding-season, but that
at all other times they live underground. Their eyes,
however, are perfect ; and their horns, or tentacles, are
rather long and extremely sensitive. '

TE STAGE LLA. 145

Testacella Halioti'dea*^, Draparnaud.

T. haliotidea, Drap. Hist. Moll. p. 121, tab. ix. f. 12-14. T. haliotoidea,
F. & H. iv. p. 2d, pi. G. G. a. f. 1.

Body contracted towards the front and somewhat pointed at
the head, rather smaller in the middle, a little broader behind,
capable of extending itself like a worm, with a thick and
tough skin, which is smooth when the animal is crawling at its
full length, but transversely wrinkled when it is at rest, yel-
lowish-brown, sometimes mottled or speckled with black, red,
or white : lips or labial lobes flexible and extensible, resembling
a third (but much shorter and thicker) pair of tentacles : mantle
very small and thin, not much larger than the shell : tentacles
rather short, smooth, brown, very little swollen at their ex-
tremities : eyes placed on the upper side of the tentacular ex-
tremities, but not quite at the end : hack convex, divided into
three nearly equal parts by two longitudinal grooves which
extend on each side of it from the front edge of the shell to
within a very short distance of the tentacles ; these grooves
have parallel offsets above and below, which are finely rami-
fied: foot bordered with distinct and prominent edges. L. 3.
B. 0-4.

Shell oblong, compressed, especially in the middle and to-
wards the front margin, solid, not glossy, closely striate by
the lines of growth, and sometimes also marked by a few in-
distinct lines which radiate from the spiral point : epidermis
rather thick : spire terminal, sharp, and very small : anterior
margin rounded : posterior margin obliquely truncate : lateral
margins obtusely curved : mouth exceedingly large : pillar lip
thickened and slightly reflected : fold flat and sharp-edged.
L. 0-25. B. 0-15.

Yar. scutulnm. Body yellowish, speckled with brown. Shell
narrower : spire more produced and pointed. Testacella scu-
tidum, Sowerby, Gen. Sh. f. 3-6.

Habitat : Gardens at Norwich, Plymouth, Bideford,
Youghal, andBandoii. The variety, which was first dis-
covered by the late Mr. Sowerby in his garden at Lam-
beth, is not uncommon in many parts of the metropolitan

* EesembUng a Hcdiotis or ear shell.

H

116 TESTACELLID/E.

district^ as well as in Guernsey. This species has been
noticed by Continental writers as occurring throughout
a great part of France (principally in the South and
South-west^ but also, according to Collard des Cherres
and De PHopital, in the Department of Finisterre and at
Caen), Spain, Algeria, Corsica, Sicily, Madeira, and the
Canary Isles. It has also been found in a fossil state
near Clermont and in the South of France.

Whether this singular and somewhat anomalous mol-
lusk is really indigenous to this country, or has been in-
troduced and acclimatized, it is almost impossible to say.
The means by which MoUusca become spread are various ;
and Man is one of the unconscious agents of such diffu-
sion. A usual habitat of this kind of Testacella is at the
roots of flower-plants, or under heaps of dead leaves in
gardens ; and if a plant were imported into this country
from the botanic garden at Montpellier with the native
soil or a compost made of leaf-mould, either the Snail-
slug or its eggs would perhaps accompany it.

The European Snail-slug is by no means prolific, lay-
ing only 6 or 7 eggs from April to July. During this
operation its head and tentacles are drawn in. The eggs,
when new-laid, are pointed at each end. The young are
excluded at the end of from twenty-five to thirty days.
The slime is abundant and colourless.

Mr. Tapping described in the * Zoologist' for 1856
(p. 5105) what he considered a new species of British
Testacella, under the name of Medii'Templi. It was
found in only one part of the Middle-Temple Gardens,
under the shelter of a south-west waU. But his descrip-
tion scarcely differs from that of the variety scutulum ;
and Mr. Norman, who has examined typical specimens of
the supposed species, informs me that they belong to
that variety. The colour of the body, as well as the form

TESTACSLLA. 147

of the s}iell_, are exceedingly variable characters in this

genus.

It is the Testacella Europcea of De Roissy, who pro-
posed a change of name in consequence of Lamarck
havings a few months previous to the publication of the
* Histoire ^ of Draparnaud, described what was then sup-
posed to be the same species under the somewhat similar
name of Haliotoides ; but it now appears that Lamarck^s
species is the one which I am next about to notice.

The T. Maugei of Ferussac was observed by the late
Mr. J. S. Miller, the Curator of the Philosophical Insti-
tution of Bristol, between forty and fifty years ago, in
the nursery-gardens of Messrs. Miller and Sweety near
that city, where it is still to be found in considerable
numbers. It has been since, to a certain extent, natu-
ralized or acclimatized in this country, having been ob-
served in other parts of Somersetshire, as well as at Ply-
mouth and Cork. I may add to this list of localities my
own garden at Norton near Swansea, which was occa-
sionally supplied with plants from Miller and Sweet^s
nurseries. It was originally (in 1801) noticed as a native
of Teneriffe; and it appears to be also indigenous to
Madeira, the Canary Isles, Portugal, and the South-west
of France. A variety of it (called T, Deshayesii or
Alta-ripce) occurs in a fossil state at Haute-Rive in
France. This species has a smaller head, as weU as a
much larger and more convex (almost semicylindrical)
shell, than T. Haliotidea. The present spedles is more
prolific and gregarious than its congeners. Mr. Norman
has kept specimens of T. Maugei y as well as of T. Halio-
tidea and its variety scutulum, alive for some time, and
has carefully watched their habits in a state of confine-
ment. He says that the nest of earth which T, Maugei
makes for itself in times of drought reminded him not a

H 2

118 TESTACELLIDtE.

little of the cocoon of the Puss-moth. "VYithin this co-
coon the Testacella lies encysted until nioisture_, working
its way through the walls of its dwelling, rouses it again
into activity and sends it forth in quest of food. While
in the encysted state, a thin white membrane (a deve-
lopment of the mantle) is extended from beneath the
shell and stretched over the back and sides of the ani-
mal. An admirably-designed protective shield is thus
formed, which checks evaporation from the surface of
the body, and enables the flow of mucus, which is so
essential to the life of the animal, still to course along
the lateral canals and thence be distributed through the
branching channels over the entire surface of the body.
When T. Maugei is removed from its cyst and the body
moistened with water, the extended membrane is gradu-
ally retracted until it is entirely withdrawn beneath the
shell. Mr. Norman also remarks that the habits of this
species resemble in many respects those of the earth-
worm, which (like the Testacella) may in times of drought
be found coiled up in as compact a mass as possible
within a chamber of the baked soil. The T. Maugei
has also the power of greatly elongating and extending
the body, which very much facilitates its passage through
the earth. The Testacella and its prey are both noc-
turnal animals; and those who wish to procure speci-
mens should look for them at daybreak, especially after
a warm dewy night in the months of July and August.
Mr. Normal has had as many as five dozen living
T. Maugei sent to him from Clifton, which were taken
in this way. The eggs of this species are large, oval,
opaque, and covered with a cream-coloured tough skin.
The shell is developed upon the young, while still in the
embryo state.

HELICID.E. 149

Family III. HELICIDJE.

Body long and spirally coiled : mantle covering the front or
anterior part : tentacles nearly always 4 (rarely 2 only), re-
tractile : eyes placed on the tips of the upper or single pair :
foot oblong, distinct from the rest of the body.

Shell spiral, and in almost every case capable of containing
the whole body.

This family comprises the true Snails, and abounds in
species as well as individuals. L. Pfeiffer described no
less than 1149 species of the typical genus, Helix, in
1848, when his very serviceable Monograph on this
family was published ; and if we add to this list the re-
sult of subsequent discoveries or reputed novelties, as
well as all the species of Bulimus and other allied genera
(which scarcely differ fi'om Helix, and are only considered
distinct for the sake of more easy classification), we can
form some idea how exceedingly numerous this family
is. Strictly speaking, it only consists of one genus, like
TestacellidcB ; and there is rather a generic than a family
resemblance among its members. The chief points of
difference between the genera of the present family are,
that in Succinea the body is ordinarily a trifle larger
than the shell ; in Vertigo the two lower or smaller ten-
tacles are wanting ; in Clausilia the shell has a reversed
spire, and is furnished inside with a small moveable pro-
cess ; in Bulimus, Pupa, and Balia the spire is longer,
and in the last-mentioned genus reversed; while in
Cochlicopa and Achatina the spire is more produced and
the mouth of the shell is channeled or notched at its base.
But without some artificial classification of this kind the
genus Helix would be too unwieldy; and the division
into subgenera is generally considered inconvenient, be-
cause it occasions additional and unnecessary nomen-

150 HELICID^.

clature. The genera into whicli this family may be
divided_, as regards the British species, are as foUows : —

* Shell oval, usually not quite covered by the body. 1. Src-

CIKEA.

** Shell globular or round, glassy, sometimes covered in
part by a lobe or expansion of the mantle. 2. YixRCifA.

3. ZONITES.

*** Shell shaped like the last, but not glassy, nor any part of
it covered by the mantle. 4. Helix.

**** Shell cylindrical: mouth often furnished inside with
teeth, and in one genus also with a moveable plate. 5. Bu-
LiMus. 6. Pupa. 7. Vertigo. 8. Balia. 9. Clausilia.

***** Shell shaped Hke the last : mouth more or less notched
at the base, and sometimes also toothed. 10. Cochlicopa.

11. ACHATLNA.

Genus I. SUCCrNEA *, Drapamaud.
PI. VI. f. 1-3.

Body gelatinous, usually incapable of being quite contained
within the shell : tentacles 4 ; upper pair conic, lower pair very
short : foot large, oblong-.

Shell oval or oblong, thin, amber-colour : S2nre short :
raoutJi large.

The Amber Snails are allied to the Limncea in form
and habits, as well as in some respects to the Slugs and
the true Snails, or Helices — showing that the order of
Nature is not like the steps of a ladder, but bears a
greater resemblance to chain- or net-work, every link or
mesh of which is connected with the other. These snails
are in a great measure amphibious. Mr. Benson men-
tions his having found our common species (>S^. putins)
creeping on stones under water in an Irish lough, in
company with species of Planorbis, Bythinia, and Physa,

* Amber-colour.

SUCCINEA. 151

althougli he had also observed that an Indian species of
Succinea frequented dry places where no water ever
lodged. Miiller says, however, that they are no more
amphibious than Helix nemoralis, a variety of which he
had seen living many days in a brook. Although the
Succinece inhabit the banks of lakes and marshy places,
and may even, after a flood of heavy or continued rain,
be seen under water, I have noticed that they do not
like remaining in it, but crawl out on comparatively
dry land, or climb up the stalks of aquatic plants and
willows. When they are under water they draw in their
tentacles. They can float on the water in a reversed
position ; and in dry weather they withdraw themselves
far into the shell, covering up the mouth with a mem-
branous epiphragm like the Planorbis spirorbiSj var. lea-
costoma. They are vegetable feeders. Their eggs are
agglutinated together and deposited on the stalks and
leaves of aquatic plants, as well as upon stones at the
water's edge. Succinea are found in all parts of the
world ; and the extent of their variation is equally great.
Their shells may be distinguished from those of Limnceu
by the absence of any fold on the columella or pillar.

1. Succinea pu'tris ^, Linne.

Helix ptctn's, Linn. Syst. Nat. ed. xii. p. 1249. S. putris, F, & H. It.
p. 132, pi. cxxxi. f. 4, 5.

Body rather thick, reddish-yeUow, closely covered with
small, flat and irregularly- shaped tubercles : tentacles short ;
upper pair not much swollen at their tips, and marked with
minute and indistinct black specks : snout, or front of the head,
large and very tumid : foot broad, nearly triuicate in front,
triangular and slightly pointed behind.

Shell oval, very thin, semitransparent, glossy, of an amber-

* Frequenting putridity.

152 HELICID.E.

colour with often a greenish or reddish hue, finely but irregu-
larly striate by the lines of growth, otherwise quite smooth :
epidermis rather thick : whorls 3-4, convex, the last occupy-
ing at least four-fifths of the shell : spire short, abrupt and
blunt at the point : suture rather oblique and deep : mouth
oval : outer lip slightly thickened, contracted above, where it
joins the columella: pillar lip sharp. L. 0*6. B. 0-3.

Var. 1. suhglohosa. Shell shorter and broader in proportion
to its length, usually much smaller and more soUd.

Yar. 2. vitrea. Shell extremely thin : spire smaller.

Var. 3. soUdula, Shell much thicker, reddish-yeUow.

Habitat : On water-plants and other herbage, as well
as on mud, in all sorts of moist places, from the extreme
north of Zetland to the Channel Isles. Var. 1 . Marshes
and by the side of lakes, on the sea-coast and in moun-
tainous districts. Var. 2. Carmarthenshire (J. G. J.) ;
Cork (Humphreys). Var. 3. Deptford, Wilts (J. G. J.).
This species is one of our upper tertiary fossils. Abroad
it ranges from Siberia to Naples ; and Captain Hutton
has found it in Afghanistan. Probably some exotic
species are mere varieties of this widely-diffused shell.

It is a sluggish mollusk, and secretes a quantity of
slime. The clusters of eggs are oblong. It hibernates
early, and passes the winter attached to stones by means
of its epipliragm, which resembles silver-paper. The
shell sometimes attains the length of an inch.

xVccording to the strict rules of priority, Klein^s spe-
cific name of vetula ought to be adopted ; but it is now
obsolete. This name may possibly have been derived
from an account which was given by Tulpius, an ancient
and very learned physician, in his medical observations,
of a wonderful cure performed on an old woman of
eighty-nine by a dose of two of these snails pounded up
alive !

SUCCINEA. 153

2. S. e'legans^, Kisso.

S. elegans, Eisso, Moll. Alp. Marit. p. 59, no. 128. S.putris, var., F. & H,
iv. p. 135, pi. cxxxi. f. 1-3.

Body thick, yellowish-brown, sometimes nearly black, co-
vered with minute round tubercles and clusters of black
specks : tentacles very short, yellowish- white and transparent,
streaked down the middle with lines of black specks ; upper
pair rounded at their tips : snout round and somewhat tumid :
foot broad, rounded in front and behind, narrower at the tail.

Shell oblong, not very thin, glossy, scarcely semitrans-
parent, amber-colour with a brownish or reddish hue, sculp-
tured like the last species : epidermis rather thin : whorls 3-4,
moderately convex but compressed towards the suture, the
last occupying about three-fourths of the shell : spire rather
short and pointed : suture remarkably oblique, not very deep :
mouth oval: outer lip slightly tliickened and considerably in-
flected above : pillar lip sharp. L. 0*6. B. 0-25.

Yar. 1. minor. Shell smaller and thinner, of a reddish-
brown colour, with a shorter spire and more expanded mouth,

Yar. 2. ochracea. Shell smaller and thicker, also reddish-
brown, with a larger spire and smaller mouth.

Habitat : Similar situations and as extensively distri-
buted as >S^. /?w^m. Var, 1. Falmouth; Hammersmith
(J. G. J.). Var. 2. Scarborough (Bean); Newcastle
(Alder) ; Tenby ; Tingwall lake, Zetland (J. G. J.). The
last variety is often mistaken for S. oblong a. This spe-
cies is also one of our upper tertiary fossils. Abroad it
is found everywhere between Finland and Sicily. Ac-
cording to Deshayes, it inhabits the Morea ; and Captain
Hutton notices it as an Afghanistan shell.

The present species sometimes occurs living with ;S^.
putris, of which, on account of the great variability of
form which prevails in all the species of this genus,
S. elegans has been considered by some authors as a
variety. Each of these species has, however, its own

* Graceful.

H 5

154 HELICID^.

corresponding variety ; and I am inclined to consider
them distinct. The species now under consideration
differs from S. putris in the darker colour of its body
and the more slender shape of the shell, as well as in
its longer and more pointed spire. It forms a passage
through its second variety from the last to the next
species.

It is the S. Pfeijferi of Rossmassler, as well as the
>S^. gracilis of Alder, but not of Lea. M. Bourguignat
has ascertained, by a recent examination of Risso^s col-
lection, that it is the present species which the celebrated
naturalist of Nice described as S. elegans ; and his de-
scription sufficiently corresponds with that of Ross-
massler.

3. S. oblon'ga*, Draparnaud.

S. oblonga, Drap. Hist. Moll. p. 59, pi. iii. f. 24, 2.5 ; F. & H. iv. p. 137,
pi. cxxxi f. 6, 7.

Body short, brown or grey of different shades, with some-
times minute black spots, finely shagreened : tentacles rather
short ; upper pair scarcely inflated at their tips : foot short and
rather broad, bluntly pointed behind.

Shell oblong- oval, rather solid, moderately glossy, brownish
or reddish-yellow, with sometimes a greenish hue, rather
strongly but irregularly striate by the hnes of growth, but
devoid of any other scidpture : epidermis thick : ivhorls 3-4,
convex, the last occupying about two-thirds of the shell : sjnre
prominent, but abrupt and blunt at the point : suture oblique
and very deep : mouth roundish-oval: outer Zi^j rather thick,
considerably inciu'ved on the columella : Inner lip sUghtly re-
flected. L. 0-25. B. 0-175.

Habitat : Dry ditches, chiefly near the sea-coast. It
is a very local species in this country. I have found it
among the sand-hills on Crymlyn Burrows near Swan-
sea, and in a similar situation on Braunton Burrows

* Oblong.

VITRINA. 155

near Bideford in North Devon. Mr. Kenyon is said to
have found it near Glasgow^ Mr. M'^ Andrew at Balti-
more^ Mr. Wright and Mr. Carroll near Cork, and
Mr. Waller discovered it among turf-bogs at Finnoe,
Co. Tipperary. The last appears to be the only inland
locality. It is not uncommon in our upper tertiaries.
This species is widely diffused on the Continent from
Sweden to Lugano ; and the S. ahbreviata of Morelet,
from Braganza in Portugal, appears to be only a variety
of it.

S. oblonga is unmistakeably different from either of
the foregoing species, being invariably so very much
smaller and having such a large spire in proportion to
the size of the shell, with a deeper suture and a rounder
mouth. I can scarcely regard the S. arenaria of Bou-
chard-Chantereaux as even a well-marked variety of this
species. Most, if not all, of the British specimens belong
to this form. The greater solidity of its shell and the
comparatively shorter spire are probably owing to the
nature of its habitat. According to Bouchard-Chan-
tereaux this variety buries itself in the sand and makes
a rather solid epiphragm. The shell is usually covered
with a viscous slime or exudation from the animal, by
which a slight coating of dirt is sometimes formed.

Genus II. VITRlNA*, Draparnaud. PL VI. f. 4-6.

Body short, usually incapable of being quite contained within
the shell : mantle furnished with a supplementary lobe, which
is extended over the front of the shell when the animal crawls ?
tentacles 4, cylindrical, the lower pair very short : foot rather
narrow.

Shell somewhat globular, extremely thin and transparent :
spire short : mouth obUquely semilunar : outer lip thin : no
umbilicus.

* From vitrum, glass.

156

HELICIDiE.

These little Glass-Snails are allied to the Slugs in
some of their habits^ and to the true Snails in the form of
their shells, leading to the former tlirough Succinea and
to the latter through Zonites. Their food is partly vege-
table, consisting of Jungermannice. and decayed leaves,
and partly animal. They are said to attack earth-worms,
although not in the same way as Testacella. I once saw
no less than seven individuals of V. pellucida busily en-
gaged in feeding on a scarcely dead worm, which was
faintly writhing about and endeavouring in vain to get
rid of its tiny assailants. They have also been noticed
eating horsedung. They live in moist and shady places,
but are seldom met with until late in the autumn. Their
eggs are deposited in small heaps and have a membranous
covering. The whole of the body can be withdrawn into
the shell. They are very hardy, and capable of enduring
an extreme degree of cold. I have found a variety of
the V. diaphana on the Rifelberg near Monte Rosa, at a
height of between 7000 and 8000 feet above the level of
the sea, living among perpetual snows and on ground
that never thaws. Only one species now inhabits this
country, although another {V. diaphana) formerly did
so, as is proved by its occurrence in our upper tertiary
strata. This last species has a wide range over the Con-
tinent, and, according to Potiez and Michaud, inhabits
the North of France. It has been observed on the
Vosges Mountains at a height of upwards of 4000 feet.
Several other species are found on the Continent.

VlTRINA PELLU'CIDA*, Miillcr.

V. pellucida, Miill. Verm. Hist. pt. ii. p. 15 ; F. & H. iv. p. 30, pi. cxxxi.
f. 8-10, and (animal) pi. I. I. I. f. 2.

Body rather slender, grey with more or less of a reddish

* Transparent.

VITRINA. 157

tinge, and having some minute black specks on the anterior
part : foot yellowish underneath, pointed behind.

Shell convex above, rather depressed below, exceedingly
thin and brittle, remarkably glossy and almost iridescent,
nearly transparent, marked indistinctly by the lines of growth,
as well as by close-set and very minute striae in a spiral di-
rection : eindermis thin : whorls 3-4, convex, the last occu-
pying more than two-thirds of the shell : sj^ire extremely short,
rising gradually to a blunt point : suture very slight, forming
a narrow groove, which is striate across : mouth nearly round,
except where it is interrupted by the periphery of the penul-
timate whorl : outer Up not very thin, nor inflected above :
pillar lip sharp. L. 0'125. B. 0*25.

Yar. 1. depressiuscida. Shell rather oval and flatter on
both sides : spire scarcely raised above the level of the last
whorl. V. Draparnaldi and V. depressa, Jeffr. in Linn. Trans,
xvi. pp. 326, 327.

Var. 2. Dillwynii. Shell nearly globular, with the last
whorl very convex : spire more prominent. V. Dillwynii,
Jeffr. I. G. p. 506.

Habitat : Under stones and logs of wood, as well as
among moss and dead leaves, in woods and shady places
throughout Great Britain. Var. 1. Neighbourhood of
Swansea and Plymouth (J. G. J.). It approaches very
near to V. major of the elder Ferussac and V. Drapar-
naldi of Cuvier, with which I at one time considered it
to be identical. Var. 2. Sand-hills near Swansea, at
the roots of Rosa spinosissima. The foreign range of
this common species extends from Siberia to Sicily.

This is an active and hardy creature, and, whether
crawling or at rest, it seems always to keep the outer
lobe of its mantle in motion, so as to polish the shell.
Bouchard-Chantereaux says that it does not begin laying
its eggs until September, October, or November, and that
the young attain their full growth in from eight to ten
months. He believes it does not live longer than from
twelve to fifteen months, having always found a number

158 HELICID.^.

«

of dead individuals in January, after tlie close of the
breeding-season. Miiller lias noticed that it is most
lively during rain, and that it does not soon die if put in
water. He added that while it was under water it ex-
tended all its body except the tentacles, which were
drawn in, and feigned death; that after the lapse of
some hours it crept out of the water cautiously and by
degrees, and if it was not alarmed by the observer it
stretched out its horns, and after crawling into some
place of shelter withdrew its body into the shell. Mr.
Daniel, having collected both of these species in Ger-
many, informs me that V. pellucida is much more gre-
garious than V. diaphana.

Genus III. ZONI'TES*, De Montfort. PI. VI. f. 7-9.

Body long, rather bulky, but always capable of being con-
tained within the shell : mantle thick and slightly reflected :
tentacles 4, cylindrical, swollen or bulbous at the tips : foot
narrow.

Shell conical, usually depressed, thin and semitransparent,
extremely glossy : sjyire composed of several whorls : mouth
obliquely semilunar : outer lip thin : umbilicus more or less
distinct.

These pretty little snails resemble the Vitrince in the
bulkiness of their bodies and the glassy appearance of
their shells, as well as in the structure and arrangement
of their dental apparatus or lingual riband. The edge
teeth are hooked in the present genus and Vitrina, but
serrated or notched in Helios. Their habits also are
nearly the same as those of the VitrincBj being rather
zoophagous than phytophagous. They greedily devour
all kinds of animal food, whether fresh or putrid ; and

* From zona, a girdle.

ZONITES.

159

they are said even to attack the larger snails and to enter
their shells for that purpose. They frequent dark and
damp places, heing generally met with under stones, old
bricks, and logs of wood which are partly buried in the
earth, as well as under and among dead leaves and moss
in woods ; and one kind inhabits cellars, vaults, and wells.
Some of them give out when touched or disturbed a fetid
smell like that of garlic, which may be perceived at a
considerable distance. Their eggs are laid in the earth
and joined together in small clusters.

A. Spire depressed : umbilicus open.
1. ZoNiTEs cella'rius^, Miillcr.

Helix cellaria, Miill. Verm. Hist. pt. ii. p. 38. Z. cellarhcs, F. & H. ir.
p. 33, pi. cxx. f. 1-3, and (animal) pi. H. H. H. f. 3.

Body obtusely rounded in front and narrowing gradually
behind, nearly covered with small and rounded but very flat
tubercles, rather transparent, slate-colour or bluish-grey, with
a faint tinge of yellow : tentacles long and slender, with very
large bulbs surmounting the upper pair, bluish or yellowish-
grey, finely speckled with black: foot very narrow, pointed
and somewhat keeled behind.

Shell compressed, nearly as convex above as below, thin
and brittle, very glossy, semitransparent, yellowish or brown -
ish-horncolour above, and whitish with often a greenish tinge
underneath, irregularly striate by the curved lines of growth,
which are stronger near the suture, and microscopically stri-
ate, like Vitrhia, in a spiral direction : epidermis rather thick :
whorls 5-6, dilated, regularly increasing in size, the last occu-
pying about one-half of the shell : spire extremely short and
nearly flat, almost central : suture slight, forming a narrow
groove or chanuel : mouth obliquely and deeply semilunar :
outer lip shghtly reflected : wnhilicus broad and deep, ex-
posing nearly all the interior of the spire. L. 0*2. E. 0*5.

Yar. 1. Gomplanata. Shell rather smaller : spire very flat.

* Frequenting cellars.

160 HELICID^.

Var. 2. albida. Shell white or colourless.

Yar. 3. compacta. Shell not so white underneath : whorls
more convex and compact, the last not being so much dilated :
spire more prominent.

Habitat : Cellars, vaults, drains and sculleries, under
stones, loose bricks, tiles and logs of wood about houses,
as well as under stones and fallen trees which have lain
long on the ground in woods, everywhere from Zet-
land to Guernsey, The varieties are occasionally found.
Var. 3 approaches the next species in form. Z. cellarius
occurs in a semifossil state at Copford, Clacton, and
Maidstone. Its foreign distribution extends from Fin-
land to Algeria and Sicily ; and Mr. Lowe has recorded
it from Madeira and the Canaries. Gould has described
it as a North- American species, and says it is the Helix
glapjhyra of Say ; but he adds that it was probably im-
ported from Europe about water-casks or greenhouse
plants.

Miiller has noticed the shy habits of this snail, and
says that, when crawling, it alternately withdraws one
of its horns half-way, although there is no obstacle in
front of it, and immediately puts it out again. Mr.
Sheppard remarked that it had a very fetid smell, much
resembling that of the urine voided by the common
snake se defendendo, and by which one might frequently
be guided to the spot where it lies concealed. He also
noticed that in some instances this odour was not per-
ceptible until the snail had been immersed in boiling
water. The organ of smell must be very acute in this,
as well as all the other species of Zonites, judging from
the size of their tentacular bulbs, in which this sense is
supposed to be placed. Its slime is watery and abun-
dant. The dark band which often encircles the suture
in dead shells is owing to the dried remains of part of

ZONITES. 161

the body appearing through the shell. A specimen in
my collection has the outer or last whorl marked by a
rufous band between the suture and the periphery.

Linne does not appear to have known this common
species. Much confusion has been caused by the post-
humous editor of his ' Systema Naturae ' (Gmelin) care-
lessly changing the name which Miiller gave to a differ-
ent species of Helix from nitida to nitens, and applying
the latter name to the present species. This is the
Helix lucida of Pulteney^ but not of Draparnaud^ and
the H. nitida of the last-named author.

2. Z. allia'rius "^^ Miller.

Helix alliaria, Mill, in Ann. Phil, new ser. iii. p. 379. Z. alUarius, F.& H.
iv. p. 34, pi. cxx. f. 5, 6.

Body resembling that of Z. cellarius ; but it is of a much
darker colour, and the tentacles are shorter in proportion.

Shell more convex above and less so below than in the
last species, rather more solid and glossy, of a darker colour
on the upper side and not so white underneath, sometimes
marked with a few indistinct spiral lines : whorls 5, rather
convex, often irregularly coiled, the last not so large in pro-
portion to the others as in Z. cellarius : spire somewhat pro-
duced : suture moderately deep, but not channeled : mouth
narrow : outer Up sharp, slightly reflected near the pillar :
umbilicus open and deep. L. 0"1. B. 0'275.

Yar. viridula. Shell greenish- wbite.

Habitat : Under stones on hills and open spots, as
well as among sand-hills ; having an equally wide distri-
bution with the last species, but more local. The variety
is from Northumberland (Alder) ; Kent (Smith) ; So-
merset (Norman) ; Cork (Humphreys) ; Belfast (Thomp-
son) ; Lincolnshire, Salop, Zetland, and Co. Tyrone
(J. G. J.). This species is one of our upper tertiary

* Garlicky.

162 HELICIDiE.

fossils. It has been recorded by M. Grateloup as occur-
ring at Dax in the Department of the Landes, and
by M. Terver at Lyons ; but it has probably been passed
over in other parts of Europe as a variety of Z. glaber,
which is not uncommon in France, Germany, and Swit-
zerland.

This snail has a very strong and pungent smell of gar-
lic, especially when it is irritated ; and I have perceived
it at a distance of several feet from the spot. Having
found living specimens under stones in a bed of wild
garlic, I thought at first that they might have fed upon
this herb and thus acquired the peculiar odour ; but I
afterwards observed that this scent was quite as power-
ful in specimens collected on an open down where there
was no garlic. Mr. Norman informs me that the scent
varies in intensity, and is sometimes scarcely percep-
tible, even after considerable irritation of the animal.

It difiers from Z. cellm^ius, the young of which it re-
sembles, in the darker colour of its body and shorter
tentacles, as well as in the spire of its shell being more
produced, the mouth narrower, and the umbilicus more
open. If the two shells are held sideways, with the
mouth towards the observer, the last whorl of Z. cella-
rius will appear deeper than in the other shell.

There has been much controversy among Continental
writers as to whether this species is distinct from the
HelLv glahi^a of Studer. I incline to the opinion of
Schmidt, that thev are different. One test mentioned
by this author in support of his view is rather curious,
viz. that Z. allim'ius wants the bitter flavour of the other
species ! I much doubt if all conchologists would relish
making such experiments.

ZONITES. 163

3. Z. NiTi DULUs *, Draparnaud.

Helix nitidula, Drap, Hist. Moll. p. 117. Z. nitidulus, F. & H. iv. p. 36,
pi. cxx. f. 8-10.

Body dark-grey or slate-colour, with a brownish tinge,
covered with flat and irregularly-shaped tubercles of a darker
hue, which give a speckled appearance : tentacles rather short
and conical ; bulbs small : foot rather narrow in front, swollen
and keeled behind.

Shell compressed, more convex above than below, thin,
moderately glossy, scarcely semitransparent, brown or yel-
lowish-horncolour above, whitish underneath, especially about
the umbilicus ; sculptured as in Z. cellarius, but having the
spiral striae more regular and distinct : epidermis rather thick :
whorls 4^b, convex and rounded, the last occupying rather
more than one-half of the shell : spire slightly raised, nearly
central : suture rather deep : mouth round, except where it is
interrupted by the periphery of the penultimate whorl : outer
lip not so obliquely set as in the last species, nor reflected :
umbilicus very broad and deep, fully exposing the interior of
the spire. L. 0-15. B. 0-33.

Var. 1. nitens. Shell rather smaller and of a lighter colour,
with a dull and waxy appearance ; last whorl somewhat larger
in proportion to the others and laterally expanded. Helix
nitens, Michaud, Compl. Drap. p. 44, pi. xv. f. 1-5.

Var. 2. Helmii. Shell resembling that of the above-men-
tioned variety, but of a pearl-white colour. Helix Helmii,
GUbertson's MS.

Habitat : Under stones and among dead leaves, moss,
and herbage in woods, hedge-banks, and elsewhere in
this country, from the Moray Firth district to Guernsey.
Var. 1. South Wales, West coast of Scotland, and many
other places. This variety is more widely diffused than
the typical form, which is not uncommon on the banks
of the Thames near London and seems to prefer watery
places, like Z. nitidus. Var. 2. Preston (Gilbertson) ;
Sevenoaks, Kent (Smith). This species is one of our

* Rather glossy.

164 HELICID^.

upper tertiary fossils. On the Continent it ranges from
Russia to the Pyrenees, and the variety nitens extends
also to Sicily.

It is a shy animal and delights in dark places, being
sometimes found underground at a depth of some inches
where the earth is loose. Its flesh is of a rather firm
consistency, and its slime is watery and abundant. It
does not emit any offensive smell.

The shell differs from that of Z. cellar ius in being
smaller, and in having one whorl less, the spire more
raised, and a much larger and deeper umbilicus. Its
surface is also much less glossy.

I cannot recognize anything more than a varietal
distinction between the Helix nitidula of Draparnaud and
the H, nitens of Michaud, which are regarded by Conti-
nental authors as different species. This last is not the
H. nitens of Gmelin or of Maton and Rackett. The
variety Helmii is H. nitens, var. albina, of Moquin-Tan-
don, which I have found near Lausanne.

4. Z. pu'rus *, Alder.

Helix pura, Aid. Cat. Northumb. Moll. p. 12. Z. purns, F. & H. iv.
p. 37, pi. cxxi. f. 5, 6.

Body yellowish-grey or whitish, with fine black specks and
close-set tubercles, slightly transparent : tentacles very long
and nearly cylindrical ; bulbs small : foot very narrow, slightly
pointed in front and rounded behind.

Shell compressed, rather more convex above than below,
very thin, not very glossy but somitransparent, light horn-
colour, with a yellow or reddish tinge on the upper side, ex-
quisitely sculptured transversely by numerous curved striae,
and spirally by still finer and almost microscopic lines, the
intersection of which gives the surface a reticulated appear-
ance : epidermis thin : vjhorls 4, convex, but dilated laterally,

* Clear.

ZONITES. 165

the last occupying scarcely one-half of the shell : spire slightly
raised : suture moderatel}' deep, puckered by the lines of
growth : mouth nearly round and not much interrupted by
the penultimate whorl : outer lip not very oblique : umbilicus
rather narrow, but deep, disclosing all the internal spire.
L. 0-075. B. 0-15.

Var. margaritacea. Shell pearl-white and nearly trans-
parent.

Habitat : Among dead leaves and moss in woods
throughout the greater part, if not the whole, of Great
Britain from the Moray Firth district to Cornwall, as
well as in Ireland, but more local and less common than
the last species. The variety is equally diffused. This
species is one of our upper tertiary fossils. Gerstfeldt,
as well as Middendorff, has recorded its occurrence in
East and West Siberia; and other writers have given
Scandinavian, German, French, and Swiss localities for
it. I found it in tolerable plenty at Alexisbad and else-
where in the Lower Harz and also near Lausanne.

Its habits are almost subterranean, and in other re-
spects resemble those of Z. nitiduJus, with which it is
often found, and from which it differs in its much smaller
size, the delicate form and sculpture of its shell, and the
umbilicus not being so large in proportion. According
to L. PfeifFer, it is the Helix Hammonis of Strom, which
was found at Trondjhem and published in 1765; but
Miiller has referred it to Z. nitidus. Judging from the
description and figure given by Gould (in the ' Inverte-
brata of Massachusetts,^ p. 183, f. Ill) of his Helioc
electrina, I cannot agree with L. Pfeiffer in considering
that species identical with the present, either as regards
form or sculpture; and the habits of each species are
quite different.

166 HELICID^.

5. Z. radia'tulus*, Alder.

Helix radiatula, Aid. Cat. Northumb. Moll. p. 13. Z. radiatulus, F. & H.
iv. p. 38, pi. cxxi, f. 1 .

Body dark horncoloiir : tentacles nearly black, the upper
ones very slender and the lower pair short : foot exceedingly
narrow, pointed behind, its sides marked \^dth minute black
specks.

Shell compressed, equally convex on both sides, very thin,
remarkably glossy, semitransparent, dark horncolour, distinctly
and beautifully marked across the whorls on the upper side by
strong curved and close-set striae which reach the suture, the
under side being also marked, but less distinctly, by similar
striae : epidermis thin : vjhorJs 41, convex, and very little di-
lated laterally, the last occupying rather less than one-half of
the shell : sjnre slightly raised : suture moderately deep : mouth
nearly round, sometimes thickened inside by a broad but slight
white rib : outer lip scarcely oblique : umbilicus narrow, but
rather deep, disclosing all the internal spire. L. 0*075. B. 0*15.

Var. viridescenti-alha. Shell greenish-white.

Habitat : Under stones, logs of wood, dead leaves,
and moss in woods, from the Moray Firth district to
Dorset. The variety is from Shropshire, Co. Cork, and
Co. Tyrone (J.G.J.) ; Belfast (Thompson). This species
is one of our upper tertiary fossils. Malm has recorded
it as a Swedish shell, Scholtz as Silesian, Moquin-Tan-
don and others from different parts of France, Stabile
from Lugano, and myself from the Lower Harz and
Switzerland.

This little moUusk is less shy and inactive than Z.
purus, and usually frequents moister places. It re-
sembles that species in the size and form of the shell ;
but the peculiar sculpture, more glossy appearance, and
narrower umbilicus of the present species will easily
serve to distinguish it from Z. purus.

* Slightly rayed.

ZONITES. 167

It is the Helix nitidula, var. P, of Draparnaud, as well
as the H. nitidosa of Ferussac and H. str'iatula of Gray ;
but both these latter names were nnaccompanied by de-
scriptions. The H. striatula of Linne, Miiller^ and Olivi
are different from that of Dr. Gray and from each other.

6. Z. ni'tidus*^ Miiller.

Helix nitida, Miill. Yerm. Hist. pt. ii. p. 32. Z. nitidus, F. & H. iv. p. 39,
pi. cxx. f. 4, 7.

Body strongly truncate in front, bluish-black or dark-
brown, covered with large round flat tubercles which are in-
terspersed with a few minute milk-white specks : snout small,
short, broad, and tumid ; tentacles rather thick and short ;
bulbs globular: foot obtusely rounded in front, narrow and
somewhat keeled behind.

Shell semiglobular, much more convex above than below,
not very thin, but glossy and semitransparent, chocolate-
brown, marked transversely by numerous curved striae which
are stronger and puckered towards the suture, and very finely
granulated under the microscope : epidermis rather thin :
whorls 5, convex, the last occupying about one-half of the
shell : spire somewhat prominent, with a blunt point : suture
deep : mouth round, except where the penultimate whorl con-
tracts it : outer lip rather obliquely set, thin, and reflected near
the pillar : lonbilicus narrow, but deep, exposing all the interior
of the sphe. L. 0*1. B. 0-275.

Var. alhida. Shell white or colourless.

Habitat : Under loose stones and decayed wood, as
well as at the roots of grass and on mud in bogs and
moist places, from the North of Scotland to Guernsey.
Specimens of the variety were found by Mr. Choules
among the rejectamenta of the Thames at Richmond.
Although dead shells, they have not become bleached
by exposure to the sun. A monstrosity also sometimes
occurs, in which the whorls are slightly disunited, as in

* Glossy.

168 HELICID.E.

Z, alliarius. This species is one of our upper tertiary
fossils. Its foreign range extends from the North of
Russia to Corsica and Algeria, through all the inter-
mediate countries.

Nothing appears to be known as to the habits of this
snail, except that it is, like its congeners, of an inactive
or sluggish nature and that it forms a slight epiphragm
during the heat of summer.

The shell differs from that of Z. radiatulus (which it
somewhat resembles) in its much larger size, more pro-
minent spire, the last whorl not being so large in propor-
tion, and the striae being very much slighter.

Gmelin made one of his usual blunders in changing
the name which Miiller gave this species to nitens ; and
Draparnaud, apparently without any reason, substituted
in his ' Histoire ^ a new name [lucida) for the correct
one which he had pre\iously given in his ' Tableau.^

7. Z. ExcAVATus*, Bean.

Helix excavata, Bean, in Alder's Cat. North. Moll. p. 13. Z. excavatus,
F. & H. iv. p. 40, pi. cxxi. f. 2-4.

Body lead-coloured (Alder).

Shell compressed, more convex on the upper than the
lower side, glossy, semitransparent, light-brown or tawny,
strongly and deeply striate in the line of growth : epidermis
rather thin : ivhorls 5^, convex and nearly cylindrical, the last
occupying not much more than one-thu'd of the shell : sjoire
slightly prominent : suture very deep : 7noutJi round, except
where it is interrupted by the penultimate whorl, somewhat
compressed below : outer lip as in the last species : umbilicus
broad and deep, exposing all the internal spire. L. 0*085.
B. 0-225.

Var. vitrina. Shell greenish-white, transparent. Helix vi-
trina, Fer. Tabl. Syst. p. 45. If. viriduJa, Menke, Syn. Moll.
p. 20.

* Hollowed -out.

ZONITES. 169

Habitat : Under fallen trees and among dead leaves
and moss in sliady woods. The tract of country over
which it is diffused comprises the South and South-west
of Scotland, North of England, West and South of
Ireland, North and South Wales, Isle of Wight, and
Cornwall ; but it is a local species. The variety is from
South Wales, Cork, and Connemara.

This species has been considered peculiar to Great
Britain, and to be the only land-shell which does not
inhabit any other part of the world ; but I have reason to
believe that the greenish- white variety is the Helix vi-
trina of Ferussac, as well as the H. viridula of Menke, H.
petronella of Charpentier, and probably also the H. clara
of Held. In the ^ Malakozoologische Blatter ^ for 1858
will be found a critical dissertation by Von Wallenberg on
the Helix viridula of Menke compared with Z. purus, in
which the author showed that these were quite different
species ; and I can answer for the identity of Z. exca-
vatus var. vitrina (or viridula) with the H. petronella of
Charpentier, having found specimens of the latter on the
Corner glacier in Switzerland at a height of about 7000
feet above the sea-level, and afterwards compared them
with the types in Charpentier^s collection at Devens
while I was on a visit to that eminent naturalist. In a
letter which is now before me from the late M. Char-
pentier, dated 28th August, 1854, he says the H. vi-
trina of Ferussac (but not that of Wagner, which is a
Brazilian species) is identical with his own H. petronella^
and that it is very different from H. radiatula, with which
it has only a slight relation in respect of the striae. Fe-
russac did not give any description of his species. Instead
therefore of the present species being exclusively British,
it likewise appears to inhabit Lapland, Finland, Ger-
many, and Switzerland. The publications of Alder and

I

170 HELICID^.

Menke having been made in the same year, I trust T may
be pardoned in indulging a patriotic feeling and giving
the precedence to my own countryman, especially as the
name proposed by Menke designates a variety and not
the species.

It differs from its nearest ally, Z. nitiduSy in its less
prominent spire, more compact whorls, much stronger
striae, deeper suture, and more open umbilicus.

8. Z. crystal'linus*, Miiller.

Helix crystallina, Miill. Verm. Hist. pt. ii. p. 23. Z. crystalUnus, F. & H.
iv. p. 41, pi. cxxii. f. 1, 2.

Body clear greyish- white, nearly transparent: tentacles rather
short ; upper pair ebony-black, coloured by the retractor nerve ;
lower pair grey : foot narrow, pointed behind, whitish.

Shell depressed, more convex below than above, thin, very
glossy and iridescent, transparent, greenish-white or hyahne
like glass, very finely and closely striate transversely, espe-
cially towards the suture : epidermis very thin : whorls 4^5,
rather convex, but compressed outwards, increasing gradually
in size : spire not much raised : suture slight, but distinct :
7nouth semilunar, sometimes strengthened inside by a slight
<rib, which is seen through the shell : outer lip obhquely set,
very thin : umbilicus narrow and only exposing a small part
of the penultimate whorl. L. 0*065. B. 0*125.

Var. complanata. Shell nearly flat on both sides ; the last
whorl proportionally larger than the others.

Habitat : Under stones and decayed pieces of wood,
as well as among dead leaves and moss, in woods and
shady places, from the Moray Firth district to Guernsey.
The variety w^as found by me in Leigh Woods nearBristol.
This species is one of our upper tertiary fossils. Its
foreign distribution is very extensive, and ranges from
Finland to Algeria and Sicily, as well as to Madeira and
the Azores.

* Like crystal.

ZONITES. 171

This exquisite little shell was first noticed as British
by Dr. Gray in the ^ Medical Repository ^ for 1821.

B. Shell conical, having a sHght depression and perforation

instead of an nmbilicus.

9. Z. FULvus* Miiller.

Helix fulva, Miill. Yerm. Hist. pt. ii. p. 56 ; F. & H. iv. p. 75, pi. cxviii.
f. 8, 9.

Body dark-grey or slate- colonr, with very fine black specks :
tentacles very long; bulbs globnlar: foot rounded in front,
pointed and keeled behind, having some scattered milk-white
specks on the sole or under part.

Shell pyramidal, thin, glossy and semitransparent, horn-
colour or tawny, finely but irregularly striate in the line of
growth, and marked spirally with close microscopical hues,
which are more distinct and regular at the base : epidermis
very thin : wliorls 5 \, cylindrical, increasing gradually in size :
periphery obtusely keeled : spire very prominent, but blunt :
suture deep : mouth semilunar, compressed and narrow : outer
lip curved, but not oblique, refiected on the pillar : umhilicus
consisting of a slight indentation, with sometimes a small hole.
L. 0-1. B. 0-1.

Var. Mortoni. Shell of a paler colour, with the spire more
depressed and peripheral keel sharper. Helix Moi'toni, Jeffr.
in Linn. Trans, xvi. p. 332.

Habitat : Under decayed wood, leaves, and stones in
shady woods and marshy places, from the Moray Firth
district to the South of England, as well as all over Ire-
land. Specimens collected in dry situations are much
larger than those which are found in wet moss. The
variety is from Somerset and North Hants. This species
is one of our upper tertiary fossils. Its foreign range
extends from Siberia to Sicily, as weU as to the Azores.
According to Philippi, it is the same species as the Helix

* Tawiiy.

I 2

172 HELlCIDi*:.

Chersina of Say, which inhabits Georgia and a consider-
able tract of North America.

It is the Helix Trochiformis of Montagu. In all
probability the adult specimen from which Miiller de-
scribed his Helix fulva was the H. edentula of Draparnaud
or the H. bidens of Chemnitz, both of which have a white
keel and lip, as noticed by Miiller in his description.
The last-mentioned species is Scandinavian as well as
French, and is closely allied to H. edentula. In the
present species neither the keel nor lip is white.

This species forms a passage to the next genus. Helix,

Genus IV. HE'LIX^S Linne. PI. VI. f. 10, 11.

Body rather long, always capable of being contained within
the shell : mantle thick, shghtly cloven on the under side :
tentacles 4, cylindrical, more or less swollen or bulbous at the
tips : foot in most species broad.

Shell conical, not very glossy : spire usually produced, rarely
depressed or flat : mouth forming an obUque segment of a circle,
which differs in size according to the degree in which it is in-
tersected by the penultimate whorl : outer lip sometimes thin,
but more frequently strengthened by an internal rib or re-
flected, in some cases furnished with tooth-like tubercles
which contract the mouth : umhilicus usually distinct and more
or less open, but in a few species quite closed or wanting, ex-
cept in the young state.

This genus comprises all the true Snails. They are
for the most part vegetarians ; but they occasionally show
a preference to animal food, both raw and cooked — being,
like Man, omnivorous. Every wood, hedge-bank, old
wall, field, and garden yields some kinds; while others
frequent mountains, water-sides, open plains, and sand-
downs near the sea. Most of them prefer shade and

* A coil.

HELIX. 173

moisture ; but some delight to bask in the sun^s rays^
and protect their soft and tender bodies from the heat
by forming an epiphragm or film that covers the mouth
of the shell. They would soon perish if the secretion
of slime were checked. Their habits are nocturnal or
crepuscular; and they are seldom met with crawling
about m the daytime, unless in wet weather or after a
lieavy shower of rain. Before the sun has fully risen
they retire to their lurking-places and hasten to conceal
themselves under stones or logs of wood, among dead
leaves, at the roots of grass, in the bark of trees, or in
the chinks and crevices of rocks and walls. Some of
them, which have no such place of shelter to resort to,
attach themselves to the stalks of grass or leaves of trees
and other herbage, by means of a secretion like that of
which the epiphragm is formed. During the pairing-
season they are furnished with crystalline darts which
they shoot at each other, after preliminary coquettings,
increasing this mutual excitement by long-continued
caresses with their horns. These curious love- weapons
have been observed sticking in the bodies of snails after
such conflicts. They are contained in a special pouch
or receptacle ready for use, and are peculiar to the pre-
sent genus. Their shape varies according to the species.
In some species each individual has only one of these
missiles, in others two; and a few species have none
at all. The eggs of the Helices, which are usually round
and united in a cluster, are laid underground, in short
and slanting galleries which the mother snail excavates
in the moist or loose earth with her foot. The tentacles
of these, as well as of all other land- snails, are with-
drawn in the same manner as the fingers of a glove
turned inside out.

The present genus, as restricted by some conchologists,

174 HELICID^.

only comprises those species which are more or less
globular and have usually a semilunar mouth. But the
line of demarcation seems to have been drawn close
enough when it excluded those species having turreted
shells, such as the Bulimi, which only differ from some
of the Helices in the spire being a little more produced.
The number of British Helices is not sufficiently large
to justify the artificial separation_, by some conchologists,
of a few species which have a depressed spire and a
more or less complete peristome, under the generic
titles of Carocolla or Chilotrema, and Zurama or Am-
plexus otherwise Vallonia.

Three species of Helix appear to have lived in this
country during the glacial era; but they have since
become extinct, or at any rate have not been noticed by
any writer on British Conchology, although they are all
of a tolerably large size. Their shells are found in the
upper tertiary beds of our Eastern counties. They have
survived and still exist in the northern and temperate
parts of Europe. One of these species is the H. i^uderata
of Studer, which ranges from Siberia and Lapland to the
alpine districts of France and Switzerland. Another is
the H. incarnata of Miiller, which does not seem to
extend quite so far north, but inhabits Sweden, Germany,
France, Switzerland, and Lugano. Mr. Daniel informs
me that he has found it in the Loess at Baden. The
third species is the H.fruticum of Miiller, which is found
living in every part of the European continent between
Finland and Switzerland, and (according to Gerstfeldt)
also inhabits Siberia and the Amoor territory. Mr.
S carles Wood has recorded this last species as a pliocene
fossil in consequence of his havdng found an imperfect
specimen at Stutton; and I lately detected it in the
lacustrine bed at Mundesley.

HELIX. 175

A. Shell globosely conic : outer lip sometimes thickened :
uinhilicus small or indistinct.

1. Helix lamella' TA *^ Jeffreys.

H. laniellata, Jeffr. in Linn. Trans, xvi. p. 333 ; F. & H. iv. p.73, pi. cxvii.
f. 8, 9.

Body whitish ; back and head bluish-grey (A. Miiller).

Shell pyramidal, thin, of a silky appearance and lustre,
yellowish -homcolour or tawny, closely and regularly striate
or plaited in the line of growth, with similar but much finer
striae in the interstices : epidermis rather thick : luhorls 6,
cylindrical and compact, increasing gradually in size: spire
rather compressed and blunt : suture deep : mouth semilunar :
outer lip thin, slightly reflected on the pillar : umbilicus narrow,
but very deep. L. 0-08. B. 0-09.

Habitat : Among dead leaves (especially those of the
holly) in woods in the northern counties of England,
Anglesea, the North and West of Scotland, and throughout
the greater part of Ireland. It also occurs as a fossil in
our upper tertiary beds at Copford. Dr. A. Miiller has
found it near Kiel and on the Isle of Rugen in Holsteiii,
and Lilljeborg afterwards discovered it in Sweden ; but
it does not appear to have been noticed elsewhere on the
Continent.

The plaits on the surface of the shell are membranous
and form part of the epidermis. Further particulars of
the animal are desirable. I unfortunately neglected the
opportunity of making a note of it.

This species is the H. Scarburgensis of Alder (from
Beanos MS.) and the H. seininulum of Rossmassler.

* Covered with small plates.

176 HELICIDJi:.

2. H. aculea'ta"^, Miiller.

H. aculeata, Miill. Verm. Hist. pt. ii. p. 81 ; F. & H. iv. p. 74, pi. cxvii.
f. 5, 6.

Body rounded in front and gradually narrowing behind,
greylsh-slateeolour or light-brown : tentacles long, thick, and
nearly cylindi'ical ; upper ones covered with minute black
specks : foot slender.

Shell globosely-pyramidal, rather thin, not glossy, horn-
colour or light-brown, marked transversely by about 30 plaits
of the epidermis, which rise in the middle of each whorl to a
sharp thorn-like point, as well as by smaller intermediate
folds, and striate spirally by close-set microscopic lines :
epidennis thick : ivhorls 4-4|, convex, gradually increasing in
size : periphery slightly and obtusely keeled : sjnre somewhat
compressed and blunt : suture deep : mouth rather large and
forming a deep arch : outer lip thickened with a white rib
and reflected in adult specimens : umbilicus narrow and small.
L. 0-1. B. 0-1.

Yar. allida. Shell of a whitish colour.

Habitat : Among dead leaves and moss in woods,
from Aberdeenshire to the Channel Isles. Variety from
Bath (Clark) . This species is one of our upper tertiary
fossils. Its foreign distribution extends from Finland
to Italy^ and even to the Azores.

The animal walks with its shell erect, carrying it in
the most graceful manner. I have observed it feeding
on the Jungermannia platyphylla. Mr. Daniel informs
me that in Germany it travels high up into trees, par-
ticularly the alder, and that in the autumn it uses the
falling leaves as a locomotive to reach the ground. The
shell is an exquisitely beautiful object, especially when
it is fresh and encircled with its coronet of spines. This
character alone will serve to distinguish it from any
other British species of Helix.

It is the H. spinulosa of Montagu.

* Prickly.

HELIX. 177

3. H. poma'tia*^ Linne.

H. pomatia, Liim. Syst. Nat ed. xii. p. 1244 ; F. &H. iv. p. 4G, pi. cxvi. f. 2.

Body obtusely rounded in front and narrowing behind to a
rather fine point, yellowish-grey, with sometimes a brownish
tinge, covered aU over with large oval tubercles or granulations,
which are of a yellow colour with greyish interstices : manth
furnished on its upper part with three fleshy and prominent
lobes : tentacles very long and nearly cylindrical ; terminal
bulbs on the upper pair small and globular: foot large and
broad, rounded in front and obtusely pointed behind.

Shell globular, thick and strong, opaque, of rather a duU
aspect, yellowish- white, with spiral bands of brown, which lat-
ter colour is more or less difiused over the surface ; these bands
are four or five in number on the last or body whorl, and are
sometimes confluent, and there are generally two or three (but
occasionally only one) on the penultimate whorl ; the surface is
also marked by numerous but irregular lines of growth and very
fine spiral or longitudinal striae : epidermis rather thick : whorls
4| or 5, extremely convex, the last occuppng about two-thirds
of the shell : spire short and ending in a rather blunt point :
suture not very deep, but distinct : mouth nearly round, slightly
contracted and angulated above by the projection of the pen-
ultimate whorl : outer lip thick, reflected over the umbilicus,
margined inside with reddish-brown : inner Up spread over
the columella and scarcely distinguishable : umhiliciis narrow
and small. L. 1-75. B. 1-75.

Var. albicla. Shell whitish or colourless.

Habitat : Woods^ hedgebanks_, and uncultivated places
in Surrey, Hertford, Kent, Oxon, Wilts, and Gloucester-
shire. The variety has been found by Mr. Brewer near
Reigate. There was at one time a popular notion that
it had been introduced into this country by the Romans,
because it is found near several ancient encampments ;
but there does not appear to be any other foundation
for this idea. The H. pomatia has not been found at
Wroxeter or York, or in many other parts of England

* Operculated.

1 5

178 HELICIDiE.

and Wales where the Romans built cities or had im-
portant military stations ; and in all probability this
kind of snail was not known to them, as another species
(H. lucorum) takes its place in Central Italy. There is
no better reason for the rumour which is mentioned by
Montagu, that it was imported from Italy about the
middle of the 16th century, either as an article of food
or for medicinal purposes, and turned out in SmTey by
a Mr. Howard at Albury. It was well known to Lister,
who wrote in 1678, as the largest of our native snails ;
and in all probability it is equally indigenous with H.
aspersa or the common garden-snail. Neither of these
species has been found in any recognized stratum of the
upper tertiary formation in this country. The foreign
distribution of H. pomatia extends from Finland (Nor-
denskiold and Nylander) to Lombardy (Villa) j but it does
not appear to have been found in the South of France.

This large snail makes a common and rather a
favourite dish in the North of France and some parts of
Switzerland ; and Lister gave a recipe for dressing and
cooking it in this country. It is furnished with a
peculiar mouth-piece, by means of which it effectually
keeps out the cold and wet while it is hibernating.
This covering is not like an operculum, forming part of
the animal, but consists of a solid, calcareous and slightly
convex plate, which exactly fits the aperture of the shell.
It is secreted and formed by the mantle ; and after it
has served the purpose for which it was made it is thrust
aside, and may be found lying on the ground on the
return of spring and genial weather. The snail repairs
its shell, when broken, in a more substantial manner than
other kinds, on account of the superabundance of its
calcareous secretion ; and it can for that purpose with-
draw its mantle far into the interior of the spire, so as to

HELIX. 179

reach almost the summit. Owing to its large size and
the consistency of its body^ it has been from an early
period a favourite study of comparative anatomists.
Lister, Cuvier, and others have published full details of its
internal organization. But the most interesting account
of its physiology and habits is contained in a memoir by
M. Gaspard_, which will be found in the ^Annales des
Sciences Naturelles ;^ and an excellent abstract of it,
with notes by Professor Bell, appeared in the 1st volume
of the ' Zoological Journal.^ Space will not admit of its
being reproduced here ; but I wiU briefly mention the
more salient points of this excellent memoir. M. Gas-
pard says that when the period of hibernating has arrived
these snails become indolent, lose their appetite, and
associate together. Each snail then excavates with its
large and muscular foot a hole in the ground, just large
enough to contain the shell ; this it roofs in and lines
with earth and dead leaves, making with its slime a kind
of mortar, and smoothing over the inner surface of its
winter domicile. Having accomplished this, it closes
the mouth of the shell with a thick calcareous lid, the
substance of which, when first poured out from the edges
of the mantle, resembles liquid plaster of Paris. It
then withdraws its body far into the interior of the shell,
covering, as it retires, the empty space with several layers
in succession of a fine membrane or film, in order the
more completely to exclude the cold air. In this snug
receptacle it remains in a torpid state until the return of
spring, all animal functions being in the mean time sus-
pended. It then loosens and casts aside its winter bands
and resumes its former life. In the genial month of
May, these snails unite for propagation, and in June they
commence laying their eggs, usually producing only a

180 HELICID^.

single brood in the year. The eggs are about the size
of a small pea, and much resemble in colour and con-
sistency the berries of the mistletoe. They are laid in a
kind of nest, which the mother snail makes in the loose
earth, in order to protect them from wet and the heat of
the sun. No incubation is necessary, and they are left
to the care of nature. The young are developed at the
end of from twenty-one to forty-five days, according to
the season and state of the temperature. The little snail,
when it is first excluded, lives only on the pellicle of the
egg, the whole of which is eaten by it. This provision
is similar or analogous to that which is appropriated to
the young of land vertebrate animals. The experiments
made by M. Gaspard with respect to the function of
those organs in snails which are called " eyes,'^ led him
to conclude that these mollusks are totally devoid of
sight and are quite insensible to light, that they do
not perceive an obstacle placed in their way until they
touch it, and that, after being deprived of their horns
which support the so-called eyes, they guide themselves
as surely as before. It may be observed that this
absence of sight and apparent insensibility to light are
quite consistent with the nocturnal habits of snails.
Perhaps the deficiency of this sense is supplied by the ex-
cessive susceptibility of the skin to outward impressions.
M. Gaspard remarks that he found in these pretended
optical bodies, or " eyes,^^ nothing more than the organs
of an exquisite sense of touch, arising from a large nerve
Avhich runs through the tentacles and is expanded over
their extremities. He also denies the existence of any
sense of hearing or smell in these mollusks ; but this
latter statement does not appear to agree with the ob-
servation of subsequent writers.

HELIX. 181

This is sometimes called tlie " Apple-snail/^ whicli is
an appropriate name as regards its shape ; but the word
"pomatia " is derived from irdiia an operculum, and not
from pomum an apple. Pliny and Dioscorides applied
the same name to it, and for a similar reason.

B. Shell globose : outer Up reflected : umbilicus wanting, ex-
cept in the young.

4. H. ASPERSA^, Miiller.

H. aspersa, Miill. Verm. Hist, pt.ii, p. 59 ; F. & H. iv. p. 44, pi. cxvi. f. 1.

Body oblong, narrow and rounded in front, pointed behind,
dark-brown or dirty-grey, mottled with milk-white specks,
coarsely and strongly granulated : tentacles long and slender,
considerably diverging from each other, brown ; bulbs small :
foot broad, rounded in front and finely pointed behind, having
a narrowish border of yellow, and transversely wrinkled.

Shell globular, rather solid, opaque, not glossy, yellowish,
with spiral dark-reddish-brown bands ; these bands are often
five in number on the last whorl and three on the preceding one,
but some of them are frequently confluent, and they are always
more or less interrupted by transverse and zigzag streaks of
white ; the sculpture consists of numerous pit-marks, which
probably correspond with the tubercles of the mantle, as well
as of very fine, but indistinct, spiral striae, giving the surface
a shagreened appearance : epidermis rather thick : luliorls 4|,
convex, the last occupying about two-thirds of the sheU : spire
short and ending in a blunt point : suture rather oblique, well
defined but not deep : mouth obhquely roundish-oval, obtusely
angulated above : outer lip rather thin, white and considerably
reflected, much incurved towards the columella : inner lip ex-
tremely thin and spread on the columella : umbilicus slightly
perceptible in the young, but afterwards covered by a fold and
thickening of the pillar lip. L. 1*4. B. 1-4.

Var. 1. albo-fasciata. Shell reddish-brown, with a single,
white band.

Var. 2, eocalbida, Menke. Shell yellowish or whitish.

Var. 3. conoidea, Picard. Shell smaller, more conical, and
thinner : mouth smaller.

* Besprinkled.

182 HELICID.E.

Var. 4. tenuis. Shell dwarfed, extremely thin, and nearly
transparent ; bands reddish-brown.

Habitat : Woods and gardens (especially the latter),
from the Moray Eirth district to the Channel Isles. I
have not found it so far north as Zetland. Vars. 1 and 2
are rather local, but not uncommon. Mr. Bridgman
has found the latter under hornbeam hedges near Nor-
wich. Var. 3. Sand-hills and cliffs on the sea-side.
Var. 4. Downs on the south coast of Guernsey. The
dwarf size and extremely thin texture of this last variety
are probably owing to the absence of calcareous material
in the soil where it is found. Monstrosities sometimes,
but rarely, occur in which the spire is reversed, or the
whorls are more or less disjoined, in some cases so
much so that the shell resembles a ram^s-horn. The
late M. D'Orbigny showed me a colony of the reversed
monstrosity in his garden at Rochelle. Mr. Bridgman
succeeded in rearing a young specimen of the same
monstrosity and bringing it to maturity by feeding it on
cabbage and lettuce leaves. This species has been found
in the peat-bed at Newbury, but has not been noticed
as an upper tertiary fossil. It does not appear to inhabit
the North of Europe nor Germany (although C. Pfeiffer
has noticed it as found in gardens there) ; but its range
extends southward from Erance to Sicily, as well as to
Spain, Algeria, and the Azores. It seems to take the
place of H. pomatia in some parts of Europe.

Lister says that, having put one of these snails and a
Limax ater together in the same vessel, he found the
next day that the slug had been killed and half-eaten by
its companion; and he also remarked that the fluid,
which exudes so copiously from the body of H. aspersa
when it is pricked, was used in his time in bleaching
wax for artistic purposes, as well as in making a firm

HELIX. 183

cement mixed with the white of eg^. The latter eco-
nomical use might now be repeated with success, but by
a less cruel operation, viz. killing and pounding, instead
of pricking the snail, and straining the fluid. The
garden-snail is much more prolific than many of its con-
geners. Bouchard-Chantereaux mentions that he has
often counted from 100 to 110 eggs which had been
laid by a single individual. Brard noticed that they are
very sensible of cold, and hibernate early, clustering to-
gether in the crevices of old w^alls and trunks of trees,
and attached to each other by their membranous epi-
phragms or winter coverings. They make great havoc
in kitchen- gardens and spoil the 'best wall-fruit. There
is, however, some compensation for this mischief: a
kind of broth is made from them and used as a remedy
for pulmonary complaints. This kind of snail is occa-
sionally eaten by the French ; but it is not held by them
in the same estimation as the Apple-snail. Dr. Gray
says that the glassmen at Newcastle once a year have
a snail-feast, and that they generally collect the snails
themselves in the fields and hedges the Sunday before
the feast-day. They are supposed to have the power of
excavating holes in limestone rocks to form their winter
quarters. The late Dr. Buckland first called the atten-
tion of geologists to this circumstance ; and M. Bou-
chard-Chantereaux has lately published, in the ^Annales
des Sciences N-atureUes^ (4^ serie, p. 197-218), an article
entitled '^Observations sur les Helices saxicaves du Bou-
loiniais,'' which will well repay the trouble of a perusal.
By way of further illustrating the habits of our com-
mon garden-snail, I trust I may be excused in transfer-
ring to these pages a short poem by Cowper, which ought
to be known to all conchologists. It is called ^^The
Snail," and is as follows : —

184 HELICID^.

" To grass, or leaf, or fruit, or wall,
The Snail sticks close, nor fears to fall,
As if he grew there, house and all

Together :

' ' Within that house secure he hides,
Wlien danger imminent betides
Of storm, or other harm besides

Of weather,

" Give but his horns the slightest touch.
His self-collecting power is such
He shrinks into his house with much

Displeasure,

" Wliere'er he -dwells, he dwells alone ;
Except himself has chattels none.
Well satisfied to be his own

Whole treasure,

" Thus, hermit-like, his life he leads,
Nor partner of his banquet needs,
And, if he meets one, only feeds

The faster,

" Who seeks him must be worse than blind,
(He and his house are so combined,)
If, finding it, he fails to find

Its master."

This common species received from Pennant in 1766
the appropriate name of Helix hortensis ; bnt in con-
sequence of that name having been applied by Miiller,
although nearly eight years afterwards, to a different
species or a supposed species, the present name has been
adopted by nearly all conch olo gists. The H. grisea of
Linne, to which this species has been referred by some
authors, is stated to inhabit Sweden, which is not the
case with H. aspersa.

The H, aperta of Born can hardly be considered a
British shell, — the sole ground for supposing it to be a
native of this country being the discovery by the late
Professor E. Forbes in 1839 of a dead specimen in a

HELTX. 185

cart-track in Guernsey. Dr. Lukis, who was at that
time and is still a resident there,, informs me that he has
frequently searched in vain for this remarkable shell;
and I have accompanied him in one of these excursions.
Its shape is not much unlike that of the variety tenuis of
H. aspersa, which is common in Guernsey and is fre-
quently bandless and without coloured markings. H,
aperta is not found anywhere in France, except in the
extreme South ; it is also a native of Italy. It is the
H. Naticoides of Draparnaud. This snail is said to
feed on vine-leaves; and it ranks with the ortolan in
gastronomic celebrity. Forbes^ s specimen might possibly
have been imported and dropped by some French sailor,
who had feasted on its contents. This specimen, how-
ever, is not to be found in the British Museum, where it
was said to have been deposited by the discoverer ; and
Dr. Baird (who has the charge of this department) in-
forms me that he has never seen it, although he has
made inquiries and searched more than once for it.

5. H. nemora'lis*, Linne.

H. nemoralis, Linn. Syst. Nat. ed. xii. p. 1247 ; F. & H. iv. p. 53, pi. cxv.
f. 1-4.

Body dark brown, tinged with yellow, and covered with very
small and close-set round tubercles : mantle of a greenish hue,
marked with yellowish specks : tentacles of a darker coloiu*,
very long and rather slender ; bulbs globular : foot angular in
front, gradually narrowing and pointed behind.

Shell globular, depressed below, rather solid and nearly
opaque, moderately glossy, yellow, brown, pink, white, and of
various other colours and shades, with from 1 to 5 spiral
bands, which are usually brown, rarely white, and occasionally
confluent or interrupted ; the sculjiture consists of close, but
irregular, hnes of growth and minute sj)iral undulating striae :

* Inhabiting gi'oves.

186 IIELICID.^.

epidermis rather thin : wliorls 5^, convex, the last occupying
about three -fifths of the shell : spire short and ending in a
blunt point : suture slight : mouth obliquely and deeply cres-
cent-shaped : outer Up thick, reflected and strengthened by a
strong internal rib, much inflected above, slightly angular
beneath, where it makes an abrupt bend towards the colu-
mella ; colour of the lip, rib, and columella reddish-brown :
inner Up consisting of a slight reddish-brown layer : umhiUcus
open and narrow in the young, but afterwards covered and
quite closed. L. 0*65. B. 0'9.

Var. 1. Jiortensis. Shell smaller and more globular: mouth
white-lipped, and rib of the same colour : inner Up excessively
thin and coloured or banded like the rest of the shell. H. hor-
tensis, Miill. Yerm. Hist. pt. ii. p. 52.

Yar. 2. hyhrida. Shell of the same size as the &st variety,
but not quite so globular : mouth and rib of a pink or liver-
colour. H. hyhrida, Poiret, Coq. Aisne, p. 71.

Yar. 3. major, Ferussac. Shell much larger and rather more
depressed than usual.

Yar. 4. minor. Shell dwarfed, of the same shape and colour
as the first variety.

Habitat : Woods, hedges, gardens, and similar situ-
ations everywhere ; and it is one of our upper tertiary
fossils. Var. 1. Nearly equally diffused and common.
Var. 2. More local, but not rare. Var. 3. Sand-hills and
downs ; remarkably large on the rocky Isle of Arran,
Co. Gal way (Barlee). Var. 4. Zetland (Barlee) ; Loch
Carron, Ross-shire (J. G. J.). This last is analogous to
the dwarf variety alpestris of H. arhustorum. A re-
versed, as well as a scalariform, monstrosity sometimes
occurs J but they are very rare. This abundant, but
pretty, shell ranges from Norway to Sicily; and the
variety hortensis is described by Gould as North Ameri-
can, although he was strongly of opinion that it had been
imported and become to a certain extent acclimatized.

This kind of snail is said to be eaten in France ; but I
believe such an experiment has not been tried in this

HELIX. 187

country. Lister says that thrushes are very fond of
them, and, in order to eat them, pierce the upper part of
the shells with their beaks. He also remarks that they are
more hardy than other snails and are the first to make
their appearance when spring returns. Mr. Whiteaves
has observed that they are often destroyed by ants.
Miiller relates that he had detected a young lizard,
which he had confined together with a live H. nemoralis
in a box, entering the shell and eating the snail. They
appear to be fond, in their turn, of animal food. Mr.
James Sowerby mentioned, in the ^ Zoological Journal,^
the case of a pet specimen of this kind of snail which
preferred roast mutton to lettuce-leaves. All the snails
are omnivorous ; but they seldom have the opportunity
of feasting upon cooked meat.

The variety of colour, as well as the number and
arrangement of the bands and markings in this common
shell are almost infinite. Albin Gras has enumerated
no less than 198 varieties of the typical form alone, and
Moquin-Tandon has distinguished 46 more of the form
called hortensis. The colour of the animal also varies
nearly as much as that of the shell.

A great controversy has long raged between con-
chologists, as to whether the two forms called iiemoralis
and hortensis are distinct species. Linne united them ;
Miiller separated them. In modern times, Forbes and
Hanley agree with the former, and Dr. Gray with the
latter. Mr. Norman contends stoutly that they are not
the same species; and his principal reason is that H.
nemoralis invariably, but H. hortensis never, has a cal-
careous, and frequently coloured, deposit on the colu-
mella. He has referred, in the ' Zoologist,' to " a school-
boy's amusement in Southey's days," in backing his
" black-mouths " [nemoralis) against any number of

188 HELICID.E.

"white-moutlis^^ (horiensis) -, and he offered to give odds
of ten to one in favour of the former. The variety hybrida
seems^ however, to connect the two above-mentioned
forms, so far as concerns their conchological distinc-
tion ; and the only malacological character of importance,
upon which a difference between them can be founded,
consists in a slight variation of shape in their love-darts.
With great deference therefore to the opinion of those
who rank these forms as separate species, I cannot help
regarding H. nemoralis as the type, and H. hortensis and
H. hybrida as local or casual varieties of one and the
same species. I have never found any two of these forms
living together; and M. Bouchard- Chantereaux and
others have made the same remark.

6. H. arbusto'rum^, Linne.

H. arhustorum, Linn. Sjst. Nat. ed. xii. p. 1245 ; F. & H. iv. p. 48, pi. cxv.
f. 5, 6.

Body lustrous, dark grey or almost black above, and of a
light slate-colour below, covered with round tubercles : mantle
marked with a few indistinct milk-white specks : tentacles
slender, much diverging, glossy and black; bulbs very globular :
foot narrow and shghtly keeled at the tail, with the sides trans-
versely grooved.

Shell globular, somewhat compressed below, usually rather
solid and nearly opaque, glossy, yellowish mottled with brown,
mostly ha^TLUg a single brown spiral band round the middle of
each whorl or a little above it, closely but coarsely and irre-
gularly ridged in the line of growth, and very finely striate in
a spiral direction : epidermis rather thin : wJiorls 5-6, convex,
the last occupying about three-fifths of the shell : spire vary-
ing in length, but usually depressed and always ending in
a blunt point : suture rather deep : mouth forming a segment
of two-thirds of a circle : outer lip thick, white and reflected,
sometimes strengthened by an internal, but not well-defined
rib, much inflected above and rounded beneath : inner Up con-

* Inhabiting copses.

HELIX. 189

sisting of a mere film which is spread on the cohimella : umbi-
licus very small and oblique, nearly concealed by a fold of the
outer lip. L. 0*5. B. 0*8.

Yar. l.Jfavescens. Shell yellowish-white, generally without
any band.

Yar. 2. major. Shell larger : sj)ire more depressed. L. 0*7.
B. 1.

Yar. 3. dlpestris, Ziegler. Shell smaller : s'pire more raised.
L. 0-5. B. 0-65.

Yar. 4. fusca, Ferussac. Shell dark-brown, with or with-
out the band, very thin and semitransparent.

Habitat : Among alders and in moist and shady
woods and hedges, as well as occasionally in meadows
by the side of rivers, from Zetland to Cornwall. It is
rather a local species, and does not appear to have been
found in the Channel Isles^ probably because the con-
ditions there are not suitable to it. Vars. 1 & 2 are not
very uncommon. Y'ar. 3. Hoddesden, Herts^ on the
marshes by the side of the River Lea, the specimens
being numerous and all of the same form and size
(Pickering). Such a locality is very remarkable for this
dwarf variety, which I have taken on the Swiss Alps, in
the region of perpetual snow. The same variety occurs
in the upper tertiary beds at Copford. Yar. 4. Lunna,
East Zetland, where there is no limestone or other cal-
careous rock. This probably accounts for the extreme
thinness of the shell. It appears to be the H. pice a of
Ziegler. My cabinet contains a distortion, from Oxford-
shire, in which the spire is exceedingly raised. This
species is distributed over the greater part of Europe.
Von Wallenberg has recorded it from Lapland; and
Aradas and Maggiore found it in Sicily. Mr. Lowe has
included it in his list of Madeiran land-shells.

Bouchard- Chantereaux says that this snail lays its
eggs from July to September, and that the young attain

190 HELICID^.

their full growth in fifteen or sixteen months after they
are excluded. Moquin-Tandon enumerates this as one
of the eatable kinds, but he adds that it is not much
esteemed. The shell varies considerably in size. The
epiphragm is exceedingly thin and like silver-paper.

It was known to Lister, who appropriately called it
" Cochlea maculata.^' Whether it is the species which
Linne described as H. arbustorum is questionable, as his
diagnosis ("Testa umbilicata, convexa, acuminata, aper-
tura suborbiculari bimarginata, antice elongata ^') is
scarcely applicable to this species. It is, however, a
Swedish shell; and the present name has been adopted
by every author.

C. SheU conical : mouth furnished with an internal rib :

umhiUcus distinct.

7. H. Cantia'na *, Montagu.

H. Cantiana, Mont. Test. Brit. p. 422, and Suppl. p. 145, pi. 23. f. 1 ;
F.& H. iv. p. 50, pi. cxvi. f. 8, 9.

Body yellowish, with a rosy or blush- colour tint in front,
covered with small and numerous greyish tubercles : mantU
marked with close-set milk-white specks : tentacles greyish-
brown, widely diverging ; upper pair rather thick at the base,
but becoming slender towards the point; bulbs nearly spherical:
foot somewhat truncate in front, ending in a triangular, swollen
and keeled tail, with close transverse grooves at its sides.

Shell subglobular, somewhat compressed both above and
below, rather thin and semitransparent, slightly glossy, yellow-
ish-white, with often a tint of reddish-brown or fawn-colour,
especially on the last whorl towards the mouth and on the
under side, and often marked with a white, but indistinct,
spiral band, which is placed a httle above the periphery and
does not extend much beyond the last half of the body whorl ;
sculpture consisting of rather close, but irregular, curved trans-
verse striae : epidermis thin, covered in young and half-grown

* Kentish.

HELIX. 191

specimens with short hairs, which are easily rubbed off and
disappear in the adult : ivJioi^ls G-7, convex, the last occupying
rather more than one -half of the shell : spire short and ending
in a blunt point : suture rather deep : mouth oblique, forming
a segment of about three-fifths of a circle, furnished inside
with a rather thick white rib, which is placed at a little
distance from the edge : outer lip thin and slightly reflected,
not much inflected above, rounded beneath, and folding over at
its junction with the columella : umbilicus small and narrow,
but rather deep, exposing the whole of the spire. L. 0*4.
B. 0-7.

Habitat : Hedges, wooded banks, and walls, in the
home and many of the southern counties of England, as
well as in Northumberland, Yorkshire, Gloucestershire,
Somersetshire, Monmouthshire, and Glamorganshire.
In the appendix to Welsh and Whitelaw^s ' History of
Dublin,^ it is stated to inhabit that neighbourhood ; but
this locality seems to be doubtful, as subsequent writers
on Irish Conchology have not confirmed the correctness
of such statement. It does not appear to range north
of England; but it is found in France, Illyria, Italy,
and Sicily.

Bouchard-Chantereaux mentions its breeding at so
early an age that the mouth of its then tender sheU is
often broken at the edge in the course of propagation.
The eggs are laid in a damp spot. It hibernates from
November to February, and forms an epiphragm like
a film of the finest blown glass.

Lister appears to have indicated H. Cantiana as a large
variety of H. rnfescens, or a distinct species, which he says
is found in Kent. It is the H. Carthusiana of Drapar-
naud, but not the H. Cartusiana of Miiller ; and Donovan
described it under the name of H. pallida, which is
much more appropriate than the one it now bears. The
present species is very unlike any of those which I have
above described.

192 HELICID.?:.

The H. limbata of Draparnaud has been introduced
into the list of our Mollusca on the authority of the late
Mr. G. B. Sowerby, in consequence of several specimens
having been once found on hedges near Hampstead. It
is about half the size of the last species, of a reddish-
brown colour, more conical and strongly striate, and it
has a very conspicuous white band encircling the peri-
phery. It inhabits the centre and South of France ; and
Terver has found it as far north as Rouen. Possibly it
may be rediscovered in this country and have its claim
to admission as a British species recognized.

8. H. Cartusia'na *, Miiller.

H. Cartusiana, Miill. Verm. Hist. pt. ii. p. 15. H. Carthusiana, F. & H.
iv. p. 51, pi. cxvi. f. 5, 6.

Body rather narrow and much rounded in front, yellow or
saffron -colour, with a faint tinge of red ; tubercles close-set
and finely, but indistinctly, speckled with brown ; neck marked
with a short longitudinal black line which commences at the
base of the upper tentacles : mantle covered with minute milk-
white specks : tentacles long ; upper pair very slender ; bidbs
very small and nearly globular : foot somewhat rounded in
front and narrowing behind.

Shell subconic, depressed above, rather more globular below,
somewhat solid and nearly opaque, not very glossy, yeUowish-
white, with a tint of fawn-colour or light-brown, and generally
marked with a white spiral band, which is placed a little
above the periphery and does not extend much beyond the
last half of the body whorl ; sculptui^e consisting of irregular
striaD in the line of growth, which are stronger towards the
suture and on the upper whorls, as well as of faint and in-
fhstinct spiral striae, which are only perceptible on the um-
bilical region and by the aid of a strong magnifying power ;
besides this striation, the surface of the lower or body whorl
is indented by crowded and indistinct pit-marks, giving it a
shagreened a^^pearance : epidermis rather thin: wliorls G-7,
compressed above and convex beneath, so as to make the

* From its having been fii'st discovered near a Carthusian Monastery.

HELIX. 193

periphery appear slightly keeled ; the last occupying about
half the shell : spire short, but somewhat pointed : suture rather
deep : mouth of the same shaj)e as in the last species, and simi-
larly strengthened inside by a broad white rib, which is visible
on the outside and placed near the opening : outer Up thin and
very little reflected, except towards the umbilicus, not much
inflected above : umbilicus very small and narrow, having more
the character of a perforation, and partly covered by the re-
flexion of the outer lip. L. 0-275. B. 0*5.

Yar. rujilabris. Shell smaller, with the inside rib of a
reddish-brown colour. H. 7'ujilahris, Jeflr. in Linn. Trans, xvi.
p. 509.

Habitat : On grass and herbage in the hollows of
downs on the Kentish and Sussex coasts ; common.
The variety is found at Lewes and Littlehampton.
Gerstfeldt, as well as Middendorff, has recorded this as
a Siberian species ; but it does not appear to have been
noticed in the North of Europe. It inhabits the whole
of France, the Rhine district, South Germany, Switzer-
land, Dalmatia, Italy and Greece. Miiller, who first
described this species, says that he received French
specimens from Geofiroy.

This mollusk is hardy, and during the heat of the
day remains attached to stalks of grass and leaves of
plants by means of a film, of the same nature as the
epiphragm, which it secretes for that purpose. The
edges of the mouth or outer lip are thus agglutinated.
The animal has a singular habit of protruding the whole
of its foot before any other part of the body when it
issues from the shell to commence its w^alk. Its eggs
are nearly as large as those of H. Cantianaj which has
nearly three times the bulk of the present species. I
have never observed any appearance of hairs on the
shell ; but perhaps none of my specimens are sufficiently
young to show this character.

K

194 . HELICIDiE.

Dr. Leach says that Mr. Gibbs first discovered this
species to be an inhabitant of Britain, in 1814, and com-
municated it to Col. Montagu, who named it in his
MS. "Helix Gibbsii.^' It is the H. Carthusianella of
Draparnaud, who mistook Miiller^s species for H. Can-
tiana. It differs from the last-mentioned species in the
shell being of a much less size, more solid and nearly
opaque, and in the spire being more depressed and the
umbilicus much smaller and more contracted.

All authors subsequent to Miiller (with the exception
of Gmelin and Poiret) have written the specific name
with an " h,'' i. e. Carthusiana. The name of the religious
Order is said to have been derived from Cartuse or Char-
treuse, a hamlet near the famous Monastery; and in
Ducange's Glossary the monks are called '' Cartusienses,
a Cartusiensibus montibus.^' I therefore think the ori-
ginal spelling of Cartusiana ought to be retained.

9. H. RUFEs'cENS *, Pcnuaut.

H. rufescens, Penn. Brit. Zool. iv. p. 134, pi. Ixxxv. f. 127; F. &H. iv.
p. 66, pi. cxviii. f. 4, 7.

Body yellowish, grey, or brown, of various degrees of in-
tensity, with dark-brown stripes running along the neck and
on to the tentacles, rather strongly tubercled : tentacles of the
same colour as the rest of the body; upper pair long and
slender, lower ones very short ; foot of a hghter colour, some-
what narrow and slender, but short.

Shell subconic, compressed above and angularly rounded
below, rather solid and nearly opaque, scarcely glossy, light ash-
grey with generally a reddish- brown hue, sometimes trans-
versely streaked with the last colour, and often marked with
a white spiral band which encircles the last whorl, finely and
closely but irregularly striate transversely : peri'phery obtusely
keeled: epidermis not very thin: wJiorJs 6-7, depressed above
and convex beneath, the last occupying rather more than half

* Of a reddisli colour.

HELIX. 195

the shell : spire short and blunt : suture rather deep : mouth
obliquely semilunar, higher than broad, furnished inside with
a broad white rib, which is distinctly visible outside and placed
at a little distance from the opening : outer lip not very thin,
slightly reflected, especially towards the umbilicus, sharply but
not much inflected above : umbilicus narrow, but distinct, ex-
posing all the interior of the spire. L. 0-3. B. 0*5.

Yar, 1. albicla. Shell white or colourless.

Yar. 2. minor. Shell smaller : spire more raised.

Habitat : Hedges^ gardens, shrubberies and suburban
woods, among nettles, under stones and logs of wood,
and in strawberry- and violet-beds, in most parts of
England from Westmoreland southwards, as well as in
South Wales and Ireland. The two varieties are not
uncommon ; and I have a scalariform distortion. It is
one of our upper tertiary fossils. This species does not
appear to be known in the North of Europe ; but it is
common in the North of France and at Heidelberg, and
(according to Morelet) it inhabits Algeria. Mr. Lowe
has enumerated it as a Madeiran species. If Ferussac
is right in referring to it the H. Altenana of Kickx, the
present species is a native of other parts of Germany.

H. rufescens was accurately described by Lister, who
said it was a favourite food of thrushes. Little heaps of
empty shells, with the spire broken, may often be seen
in our gardens ; so that the safety of a strawberry crop
may be partly ensured by encouraging these favourite
songsters. This little snail never goes out in the daytime,
unless after a shower of rain. According to Bouchard-
Chantereaux, it lays from 40 to 50 eggs, between the
months of August and October, and the young are
excluded at the end of from twenty to twenty-five days.
The shells of these young ones, and even of such as have
as many as four whorls, are really hispid. This was first

k2

196 " HELICID^.

noticed by Montagu; but as he evidently confounded
H. hispida "v^dth the present species in tbis stage of
growth^ bis statement tbat the young of H. rufescens was
covered witb bairs was discredited. Capt. Bruce Hutton
bas quite satisfied me on tbis point ; and tbe bairs are
very easily discerned witb a lens of moderate power.
Tbey are very sbort and caducous ; but tbe sockets of
tbe bairs, or tbe impressions wbicb are caused by tbeir
insertion into tbe epidermis, remain on tbe surface of
full-grown specimens, and may be seen under a micro-
scope. M. Drouet bas lately confirmed tbis fact of tbe
young sbells being bispid. In some specimens from
Clifden, Co. Galway, tbe sbell is finely striate in a
spiral direction.

Having bad an opportunity of observing in tbeir native
babitats tbe H. circinnata, montana, and ccelata of Studer,
wbicb appear to belong to one and tbe same species, I
am not inclined to consider tbem as varieties of H. ru-
fescens. Tbeir spire is mucb more depressed and tbe
suture deeper tban in tbe present species. I bave, boAv-
ever, no doubt tbat tbe H. glabella of Draparnaud, and
probably also tbe H. clandestina of Hartmann, are tbe
same as our sbell. Tbe H. rufescens of Gmelin and
Grateloup are very different from tbis, tbe former being
a river sbell and tbe latter an exotic species.

10. H. coNciN^NA^, Jeffreys.

H. concinoia, Jeffr. in Linn. Trans, xvi. p. 336. H. hispida, var, concinna,
F. & H. iv. p. 70, pi. cxviii. f. 2, 3.

Body histrous, reddish-brown, minutely tubercled or gra-
nulated : tentacles of a lighter colour ; upper pair larger and
more slender than in the next species {H. hispida) ; lower
ones very short : foot narrow, of a greyish colour on its sides

and sole.

* Neat.

HELIX. 197

Shell siibconic, compressed on both sides, rather soKd for
its size, but semitransparent, somewhat glossy, light ash-grey,
with occasionally faint streaks of reddish-brown, giving the
shell a prettily mottled appearance ; there is also frequently
on the last whorl a white spiral band like that in H. rufescens ;
the surface also is transversely striate as in that species : jperl-
jpliery obtusely and indistinctly keeled : epidermis rather thick,
sparsely covered with short white hairs, which are easily
rubbed off: ivliorls 6-7, compact, rather depressed above and
slightly convex beneath, the last scarcely occupying one-third
of the shell : spire short and blunt : suture deep : mouth ob-
Kquely semilunar, considerably higher than broad, furnished
inside with a sharp white rib, which becomes thicker towards
the umbilicus and is placed near the opening : outer lip not
very thin in adult specimens and somewhat reflected ; umbi-
licus rather broad, open and deep. L. 0-2. B. 0-4.

Var. 1. alhida. Shell white.

Yar. 2. minor. Shell smaller and also white : spire more
depressed than usual.

Habitat : Under stones among nettles and the Arum
maculatum, as well as at the roots of grass in moist
places; generally distributed. Var. 1. With specimens
of the usual colour. Var. 2. South of Ireland (Dill-
wyn) j Bath (Clark); Dover (J. G. J.). The typical
form occurs not unfrequently in our upper tertiary beds.
It is not uncommon in many parts of the Continent,
but it has been probably overlooked and considered a
variety of H. hispida. The second variety I found at
Calais, as well as at Dover.

Between two and three years after I had described
this species in the ' Transactions ' of the Linnean So-
ciety, I had some misgivings as to its being distinct from
some of the numerous varieties of H. hispida, and I
expressed this doubt in a Supplement to my Monograph ;
but as the species I had proposed is adopted by Conti-
nental naturalists, and there is a fair probability that this
has quite as good a claim to specific distinction as many

198 HELlClDiE.

others, I have now ventured to restore it. The shell is
never globose, like that of H. hispida, and it is more
glossy ; the umbilicus is considerably more open ; and
the hairs are more scattered and easily shed. Besides
these differences in the shell, Mr. Smith has pointed out
in the ^Zoologist' (1854, p. 4333) that the animal is
darker- coloured, and the foot narrower and far less
fleshy than in H. hispida, which has a thick yellowish-
white foot. From H. rnfescens, with which the present
species seems to connect H. hispida, it differs in the
shell being much smaller, and in the whorls being more
rounded and compact, though equally numerous. All
these three species are found together. Sometimes the
shell of H. concinna exhibits several formations in suc-
cession of the labial rib.

Beck has referred the H. umbrosa of Partsch to the
variety minor of the present species ; but, judging from
Rossmassler's figure, the Austrian shell is much more
globular. Neither can this be the H. depilata of C.
Pfeiffer, which he describes as subglobose and having a
narrow umbilicus. He compares it with H. sericea, and
not with H. hispida.

11. H. His'piDA"^, Linne.

H. hisjndrr, Linn. Syst. Nat. ed. xii. p. 1244 ; F. & H. iv, p. 68, pi. cxviii.
f. 1, and (animal) pi. G. G. G-. f. 1.

Body greyish-brown or slate-colour, mottled with black ;
tubercles speckled -udth milk-white : tentacles rather thick, of
a somewhat darker colour than the rest of the body : foot
rounded in front, marked with fine black specks, gradually
narrowing behind to a rather blunt, convex and keeled tail.

Shell subconic, more convex above than below, rather thin
and semitransparent, very little glossy ; colour, markings, and
sculpture the same as in H. concinna, but the colour of the

* Bristly.

HELIX. 199

present species is usually much darker and of a uniform yel-
lowish-brown : perifphery rounded, and seldom keeled or an-
gulated : epidermis thick, closely covered with short recurved
white hairs, which are persistent and not easily rubbed off :
wJiorls 6-7, rounded and moderately convex on both sides,
the last occupying about one-third of the shell: Sjpire some-
what raised, but blunt : suture deep : mouth obliquely semi-
lunar, rather broader than high, sometimes (especially in the
adult) furnished with an interior rib, as in the last species :
outer lip thin, not reflected, and very little inflected above :
umbilicus small and narrow, but deep. L. 0*185. B. 0-3.

Var. 1. suhrufa. Shell reddish -brown and more solid, with
a strong labial rib.

Yar. 2. albida. Shell thinner, white or colourless.

Yar. 3. conica. Shell smaller : spire more raised.

Yar. 4. nana. Shell much smaller, but with a strong labia^
rib : spire depressed. L. 0-1. B. 0-2.

Yar. 5. suhglobosa. Shell more globular and much thinner,
homcolour or white : umbilicus very small. H. sericea, Alder,
Suppl. Cat. Northumb. Moll. p. 4.

Habitat : Everywhere under stones and logs of wood,
as well as among moss and herbage in woods^ gardens,
hedges and all sorts of rural spots. Var. 1. Not un-
common in dry situations. Var. 2. In osier-beds, as
well as on the limestone at Kendal. Var. 3. At the
roots of Rosa spinosissima on the sand-hills near Swan-
sea. Var. 4^ Freshwater, Isle of Wight (Metcalfe).
Var. 5. Northumberland and Durham (Alder) : Ham-
mersmith; Plymouth; Brocklesby, Lincolnshire (J.G. J.).
I have noticed this variety in Continental collections
as H. sericea ; but it is certainly not Miiller^s species of
that name, although forming a passage to it. Distor-
tions of the spire are sometimes met with. This species
is common in our upper tertiary strata. It has a wide
range, extending from Siberia to Sicily, from which
latter place Philippi has recorded it under the name of

200 HELICID^.

H. sericea. Mr. Lowe has noticed it as inhabiting
Madeira. In all probability it derives its origin from
a preglacial epoch.

This little snail does some mischief in our gardens by
nibbling before the dawn of day the leaves of some of
the more succulent plants. The Rev. Revett Sheppard
remarked that it w^as an amphibious species, being " fre-
quently found some feet below the surface of water on
stakes and piles, upon which it ascends and descends at
pleasure /^ and he added that the eggs resemble those
of birds and retain their form without shrinking. Ac-
cording to M. B ouch ard- Chanter eaux, the H. hispida lays,
between the months of April and September, 40 eggs,
which are globular, white and opaque ; the fry are born
at the end of the twentieth to the twenty-fifth day, and
emerge from the egg with nearly one whorl of their shell
formed ; and more than half of this embryonic shell is
then covered with minute red and straight hairs of a
tolerably strong consistence. The summit of the spire
is quite smooth and polished. The black spots on the
mantle are sometimes visible through the semitrans-
parent shell, even in dried specimens. The first-formed
whorls are often whitish, in consequence of their not
being occupied by the animal.

The H. plebeia of Draparnaud seems to*be one of the
numerous varieties of this species, judging from his
description and a comparison of specimens thus named
which I received from his friend M. D^Orbigny at
Rochelle. According to Moquin-Tandon, the umbilicus
of this variety is very narrow. Several other species
have been carved out of this variable and ubiquitous
form by Continental conchologists.

HELIX. 201

12. H. sERi'cEA*, Miiller.

H. sericea, Miill. Verm. Hist. pt. ii. p. 62; F. & H. iv. p. 71, pi. cxviii.
f. 5, 6.

Body yellowish-grey, closely tubercled : mantle reddish-
brown, with milk-white specks : tentacles rather long, of an
iron-grey colour : foot rather broad and slightly raised at its
sides.

Shell conical, subglobular, thin, but (by reason of its colour)
not usually semitransparent, scarcely glossy, grejish-white,
with sometimes a few slight transverse streaks of reddish-
brown, very finely but indistinctly striate in the line of grow' th :
periphery rounded, and never keeled or angidated : epidermis
rather thick, closely covered with rather long and very fine,
white, downy hairs, which are persistent and, when rubbed
off, leave their sockets very perceptible, giving the siuface in
that case a finely granulated appearance : whorls 6, extremely
convex, the last occupying nearly one-half of the shell : spire
considerably raised, but blunt: suture not very deep: mouth
semilunar, much broader than high, sometimes (in adult
specimens) furnished with a slight internal white rib, which
is much stronger towards the umbilicus : outer lip thin, a
little reflected, scarcely at all inflected above : umhilicus ex-
ceedingly small, but deep, having more the character of a
]3erforation. L. 0*2. B. 0"3.

Var. cornea. Shell horncolour, very thin, glossy and semi-
transparent ; the labial rib perceptible on the outside.

Habitat : Mossy banks and hedges in various parts
of the country, from the Moray Firth district to Corn-
wall, as well as at Tenby and Manorbeer in Pembroke-
shire. I am not aware of any Irish locality. The
variety was found by me at Lulworth. This species
occurs in our upper tertiary beds. It inhabits the more
temperate parts of Europe ; but according to Krynicki it
is found in the Caucasus, and Gerstfeldt has recorded
it as occurring in the province of Irkutsk in Siberia. It,
however, seems to be local both here and abroad. It is

* Silky.

K D

202 HELICIDyE.

difficult to ascertain its exact distribution, because of a
variety of H. hispicla being often mistaken for it.

It seems to aflPect elevated as well as moist situations.
Puton found it on the Vosges mountains at a height of
about 3772 English feet.

This shell is easily distinguishable from H. hispida by
tlie globoseness of its form and greater height of the
spire, by being much more thin and of a lighter colour,
by the want of any keel or angularity, and by the thicker
and downy covering of hair.

It is the H. hispida of Montagu, whose description of
the shell is, as usual, most accurate. He says " it is so
remarkably light and so covered with hairs, that when
let fall upon a hard body it is scarce heard." Beck is
of opinion that the H. sericea of Miiller is the young of
H. incarnata-, but the surface of immature shells of
that species is not hairy, but scaly or like seal-skin.
The present species appears to be the H. revelata of
Ferussac ; and it is also the H. granulata of Alder, and
my H. globular is.

13. H. revela'ta*, Michaud.

H. revelata, Mich. CompL p. 27, pi. xv. f. 6-8; F.& H. iv. p. 70, pi. cxix.
f. 1-3.

Body pale yeUowish-grey, sometimes having a reddish or
dusky hue, closely tubercled : mantle yellowish-brown, minutely
speckled mth brown and milk-white : tentacles rather thick
and long, of a dirty-grey colour faintly tinged with violet or
brown ; the upper ones finely granulated, with globidar bulbs :
foot rounded in front, triangular and keeled behind; sides
marked with transverse furrows.

Shell subglobular, somewhat compressed above and rounded
below, very thin and semitrunsparent, rather glossy, yellowish-
green, marked with irregidar wrinkles in the line of growth,

* Discovered.

HELIX. 203

which are stronger towards the suture and base of the shell,
making the former appear slightly puckered ; the surface is
also very finely granulated : periphery rounded and prominent :
epidermis rather thick, covered with short white hairs, which
are easily rubbed off: luhorls 4|-, very convex and swollen,
the last occupying two- thirds of the shell : spire very little
raised and blunt : suture remarkably deep : mouth forming a
segment of about three -fifths of a circle, contracted inside by
the prominence of the periphery, not furnished with a rib :
outer lip thin, a little reflected and considerably so near the
umbilicus, sharply inflected above: imihiliciis small, narrow,
and not deep. L. 0-185. B. 0-285.

Habitat : Downs on the sea-coast of our Southern
counties and the Channel Isles, as well as (according to
Mr. E. J. Lowe) in Nottinghamshire. The British
localities are so few that I will particularize them, in
the hope that the known range of this comparatively
rare species may be extended by further observation.
They are — Torquay (Hanley) ; Plymouth (Norman) ;
Devon (Bellamy) ; Megavissey (Couch) ; Pendennis
(Cocks, Benson) ; Land^s End (Millet) and Scilly Isles
(Barlee), — all the last four being Cornish localities;
Guernsey (Forbes and others) ; Sark (Lukis and J.G.J.) ;
Stanton-on-the- Wolds, Notts, in woods during October
(Lowe). It is found in the South-west of France and
in Portugal, as well as (according to Michaud) in the
alpine valleys of the former country.

In winter and dry weather it buries itself rather deep
in the earth, and must be looked for by pulling up tufts
of grass and large stones which are sunk in the ground,
as well as by searching among the roots of shrubs and
furze-bushes. It has a different kind of epiphragm for
summer and winter. The former kind is filmy, trans-
parent and iridescent, and it has a small round hole
corresponding with the position of the respiratory orifice,
thus enabling the animal to procure a continual supply

204 HELICID^.

of air from the atmosphere. The winter covering is
thicker^ opaque, and nearly white.

This is another instance of rather conspicuous land-
shells having been overlooked in places where observant
naturalists had long searched and obtained much smaller
species. Col. Montagu especially investigated the Tes-
tacea of our Southern counties ; and these have always
been a favourite haunt of our field or outdoor concho-
logists. The H. revelata was for the first time noticed
as a British species by Dr. Gray in 1840, in consequence
of the late Professor Edward Forbes having found it
in Guernsey and presented specimens to our National
Museum.

The H. revelata of Ferussac, who first used this name,
is (as I have before observed) the H. sericea of Miiller ;
but Michaud afterwards described and figured the pre-
sent species under the same name, supposing it to be
Ferussac's species. It therefore appears unnecessary
to adopt the name either of Ponentina or occidentalism
which were subsequently (in 1845) applied to this species
by Morelet and Recluz. The H. revelata of Bouchard-
Chantereaux is our H. fusca, of which I had an oppor-
tunity of satisfying him soon after the publication of
his excellent Memoir on the Land and Freshwater Mol-
lusca of the Pas-de-Calais. Some shells which I noticed
in the collection of M. D^Orbigny at Rochelle, in
1830, as having been received by him from Draparnaud,
under the name of H. sericea (two of which he kindly
presented to me and are now in my possession), belong
to the present species, and occasioned the remark which
I made in the Supplement to my paper in the ' Linnean
Transactions^ (vol. xvi. p. 507) as to the H. sericea of
the last-named author. Michaud's work was not pub-
lished until 1831.

HELIX. 205

14. H. Fus'cA*, Montagu.

H. fusca, Mont. Test. Brit. p. 424, pi. xiii. f . 1 ; F. & H. iy. p. 77, pi. cxix
f. 4, 5, and (animal) pi. G. G. G. f. 4.

Body long, yellowish-white or grey, with two longitudinal
streaks of brown leading to the tentacles, irregularly but rather
finely tubercled : mantle covered "with faint and minute specks
of brown and milk-white : tentacles long, bluish-grey with a
slight tinge of violet ; bulbs short : foot very long and narrow,
pointed behind, with a bluish tint on the sides near the sole.

Shell subcorneal, slightly compressed above and below, ex-
tremely thin and transparent, glossy, yellowish-brown, marked
transversely with strong but irregular wrinkles ; the surface of
young shells is also very finely striate in the same direction
like hair-cloth: periphery rounded, but encircled by a slight
keel : epidermis tolerably thick : whorls 5-^, convex, the last
occupying rather more than one-half of the shell : spire some-
what raised, but not pointed : suture distinct, though not deep :
mouth oblique, semilunar, considerably broader than high, not
furnished wdth a rib : outer lip very thin, reflected over the
umbilicus and sharply inflected above : umbilicus extremely
small and narrow, reduced to little more than a perforation.
L. 0-225. B. 0-35.

Habitat : Woods^ on young trees, and among nettles
and dog-mercury, in many parts of these isles from
Aberdeenshire to Devon, but not everywhere. It is one
of our upper tertiary fossils. Montagu mentions, in his
Supplement (p. 148), having received through Mr. Boys
from Scotland a shell which would seem from the de-
scription to be a white variety of this species ; but the
source is rather suspicious, as Mr. Boys was the means
of introducing many exotic shells into our Fauna. The
finest specimens in my collection were kindly sent to
me by the late Mr. Thompson of Belfast, from that
neighbourhood. H. fusca occurs in the North and South-

* Dark -brown.

206 HELICID^.

west of France ; but it does not appear to have been
noticed elsewhere on the Continent.

M. Bouchard-Chantereaux, who was the first to dis-
cover this species in France^ but who mistook it for H.
revelata, says that it inhabits young alders (the foliage
of which constitutes its food) in the woods near Bou-
logne, and protects itself from the heat of the day by
clinging to the underside of the leaves, falling with
them in September and October; and that it then occu-
pies itself in the work of reproduction, for which the
dead leaves offer a convenient place of retreat. Its eggs
number from 40 to 50, and are globular and of an opaline
lustre. The young are excluded about the twentieth
day after the eggs are laid, and become adult at the end
of from ten to twelve months. These pretty little snails
are tolerably active, and appear to be nearly always
moving their horns about. They secrete a good deal of
slime. According to Moquin-Tandon they are grega-
rious and sociable, and have been observed each mutually
polishing its neighbour's shell with its foot.

The shell differs from that of any other kind of British
Helix in its peculiar sculpture, which resembles that of
a Continental species, H. mcarnata. In shape and the
narrowness of its umbilicus it somewhat resembles H.
sericea ; but in the present species the spire is more de-
pressed, the last or body whorl is proportionally larger
than the others, and the epidermis is never hairy like
that of the last-named species, or H, revelata. The tex-
ture of this shell is also far more fragile than in either of
those species, and its colour is uniformly of a light yellow-
ish-brown, instead of whitish or dark greenish-brown.

This is not the H. fusca of Poiret (whose work pre-
ceded that of Montagu by two years) ; but as that shell

HELIX. 207

is only a variety of H. nemoralis and allied to the one
called hybrida, there does not appear to be any greater
reason for changing Montagues name than there was in
the similar case of H. revelata.

D. Shell siibconical or depressed, and banded : outer Up streng-
thened by an internal rib : umbilicus large or distinct.

15. H. Pisa'na^, Miiller.

H. Pisana, Miill. Verm. Hist. pt. ii. p. 60 ; F. & H. iv. p. 56, pi. cxv. f. 7, 8.

Body yellowish-grey with a tinge of red in front, rather
strongly tubercled : mantle often dark -brown, tinged with
yellow and marked with very small and numerous milk-white
specks : tentacles rather broad at their base, but slender, finely
shagreened; the so-called optic nerves continue along the
neck, so as to form two dark lines ; bulbs very globular and of
a reddish colour, indistinctly speckled mth brown : foot long,
somewhat truncate in front, gradually narrowing and pointed
behind, but not keeled.

Shell subglobular, slightly compressed above, convex below,
rather solid and opaque, moderately glossy, yellowish-white,
beautifully marked with brown spiral bands, which vary greatly
in number (there being sometimes as many as fifteen or sixteen
on the last whorl, but usually only one underneath), and more
or less marked transversely with short oblique streaks of the
same colour, causing the upper part of the shell to appear
speckled ; sculpture consisting of irregular striae in the hne of
growth and of fine, close, spiral striae, which intersect the
transverse striae on the upper whorls and give to the surface a
delicately reticulated appearance : perij^hery rounded : ejn-
dermis extremely thm and only perceptible under a micro-
scope : whorls 5J, very convex but compressed towards the
suture, the last occupying considerably more than one-half of
the shell: spire somewhat raised, but having a blunt point,
which is of a purplish-brown colour : suture rather slight :
mouth forming a segment of two-thirds of a circle ; interior
sometimes pink or blush- colour and furnished with a slight
rib, which is either pale yellowish, white, or pink : outer lip
sharp, but thickened, reflected in the direction of the umbihcus

* First found at Pisa.

208 HELICID^.

and especially over it, rather abruptly inflected above : mn-
bilicus extremely small, narrow and oblique. L. 0-5. B. 0-75.

Var. alba. Shell pale yellowish -white or snow-white, with
or without translucent markings. H. Pisana, var. alba, Shuttle-
worth, Moll. Cors. p. 15.

Habitat : On a hill and sand-banks, as well as in
gardens facing the sea, at Tenby in Pembrokeshire, to
the sonth and south-west of that charming watering-
place (Montagu and others) ; Manorbeer in the same
county (J. G. J.) ; St. Ives and Whitsand Bay, Cornwall
(Montagu) ; Jersey (Lukis) ; and also (according to Dr.
Turton) Balbriggan strand in Dublin Bay. Although
local, it is most abundant at Tenby, and is said to be
equally so in Jersey and near Dublin. Its foreign dis-
tribution seems also to be limited. The centre and
South of France, Spain, Portugal, Italy, Judaea, Dal-
matia, Illyria, Algeria, Madeira, the Canary Isles, and
Azores are the only extra- British localities that I have
seen recorded.

The limited range of this species in Great Britain is
unaccountable. I have endeavoured twice, with an in-
terval of nearly three years between each attempt, to
colonize this beautifully marked and peculiar shell on
the sand-hills near Swansea, by bringing a basketful of
live specimens from Tenby, a distance of only about
thirty miles ; and they were spread over diflferent parts of
the Burrows, in order to ensure a better chance of success.
But, although they seemed at first to thrive tolerably
well in the new locality, they did not multiply, and the
birds soon ate up the immigrants. These experiments
were made at different times of the year ; and the soil
and herbage on the Swansea sand-hills were the same as
at Tenby, the only difference being the aspect, which at
Swansea was more easterly. The colourin"r of the man-

HELIX. 209

tie corresponds with the markings of the shell. The
pink hue of the mouth appears to be deeper and brighter
in specimens which are exposed to the sun. Drapar-
naud says that this colour is more perceptible in the
shells of those individuals which have been kept a long
time without food, or after their death. These snails
adhere in the daytime to the stalks and leaves of grass,
as well as to shrubs, by means of a rather thick calca-
reous secretion, which lines the outer lip of the mouth.
My late friend Mr. Barlee informed me that at St. Ives
he procured live specimens by digging some inches in
the sand-hills, at the roots of the Carex arenaria, where
the snails had buried themselves, the weather being
then very hot and the herbage not affording much shelter
from the sun^s rays. Both in summer and winter they
close the mouths of their shells with an epiphragm,
which in the former case is filmy, very transparent and
iridescent, and in the latter opaque and like thin paper.
Mr. Millet says that they feed on the Eryngium mayn-
timum. According to St. Simon they are omnivorous.
One of them greedily devoured a globule of slime which
he had taken from a slug. In Jersey the thistles are
covered with them. It seems onlv to be found on the
coast-line, and never inland, in this country.

This and the three following species constitute a sub-
section, of which Risso made the genus Theba, from
Leaches MS. ; but H. Cantiana and other different forms
were associated with it both by Risso and Leach.

The present species was first described by Petiver, and
received from him the name of Pisana, but accompanied
by other characters which preclude his authority being
recognized for the name under the rules of the binomial
system. It is the H. zonaria of Pennant, H. rhodostoma
of Draparnaud, and H. cingenda of Montagu.

210 HELICID^.

16. H. virga'ta*, Da Costa.

H. virgata, Da Costa, Brit. Conch, p. 79, pi. iv. f. 7 ; F. & H. iv. p. 57,
pi. cxvii. f. 10.

Body yellowish-white or ash-grey, coarsely tubercled :
mantle often dark- violet, indistinctly speckled with milk-white
and brown: tentacles rather thick, cylindrico-conic, greyish
with a dusky tinge ; bulbs globular and reddish, speckled with
brown at their base : foot broad and rounded in front, gradually
narrowing behind and ending in a blunt but not keeled tail.

Shell conical, with a broad and convex base, rather solid
and opaque, moderately glossy, white or cream-colour, with a
single broad purplish-brown or chestnut band immediately
above the periphery and two or three other bands (sometimes
as many as six or seven) below it ; the colour, however, is
very variable, being occasionally plain yellowish, white, or dark
brown with white bands, or the dark bands are streaked or
interrupted so as to make the surface appear spotted ; sculp-
ture consisting only of stria3 in the line of growth, which are
closer on the upper whorls : 'periphery rounded, except in
young shells, which have a short but rather sharp keel : epi-
dermis scarcely perceptible : whorls 6, convex but slightly
compressed towards the suture, the last occupying more than
one-half of the shell : spire raised, purplish-brown at the
point : suture moderately deep : mouth forming a segment of
three-fourths of a circle, inside purplish-brown with a strong
rib of the same colour, or white in the albino variety : outer
lip sharp, reflected towards and over the umbilicus, rather
abruptly inflected above : umbilicus narrow, but deep, and ex-
posing nearly all the interior of the spire. L. 0*4. B. 0-55.

Yar. 1. suhaperta. Shell of a whiter hue : spire more de-
pressed : umbilicus wider.

Var. 2. subglobosa. Shell smaller, Avith a double band above
the periphery, last whorl larger in proportion to the others :
umbilicus wider.

Var. 3. submaritima, Des Moulins. Shell much smaller and
more deeply coloured, often with a violet tinge : spire raised.
L. 0-25. B. 0-325.

Yar. 4. carinata. Shell yellowish-white, compressed above :
periphery strongly keeled.

Habitat : Sandy downs and heaths in most parts of

* Banded.

HELIX. 211

England^ Wales, and Ireland, from Yorkshire to the
Channel Isles. It is generally found on the sea-coast,
where the conditions are probably more favourable to its
existence ; but it also inhabits inland districts, such as
Oxfordshire, Wilts, and Bath, and it is by no means
confined to calcareous soils. Var. 1. Bath (Clark).
This variety is allied to the H. neglecta of Draparnaud.
Var. 2. Bantry Bay and St. Mawes near Falmouth
(J. G. J.). Var. 3. Braunton burrows in North Devon, and
Swansea burrows (J. G. J.) ; Isle of Wight (Pickering).
This resembles the H. lineata [H. maritima, Draparnaud) .
Var. 4. Wingfrith near Wareham, about five miles from
the sea (Daniel). This is a remarkable variety, and re-
sembles the H. submaritima of Bossmassler from Oran.
Mr. Norman found at Clevedon a specimen of the ordi-
nary form which has the spire reversed. The foreign
distribution of this species appears to be confined to
France, Portugal, Italy, Greece, and the sea-board of
North Africa. In the North of Europe, Germany, and
Switzerland its place is taken by the H, unifasciata of
Poiret {H. candidula, Studer) ; but both that and the
present species are found together in the North of France.
This is one of the species which has given rise to the
popular notion that it sometimes rains snails. H. vir-
gata is extremely abundant and gregarious ; and in suit-
able weather myriads of them may be seen clinging to
the stalks of grass and leaves of shrubs. When the
season is very dry, however, they ensconce themselves
among the herbage ; but immediately on a shower of
rain falling they emerge suddenly from their lurking-
places and appear before the astonished rustic like Bo-
derick Dhu^s warriors at the sound of their chieftain^s
horn. The idea of their descending in showers may also
have originated in a whirlwind having caught up a num-

212 HELICID^.

ber of them by sweeping along a grassy plain and drop-
ping its contents in a limited area. Draparnand men-
tions this snail as eatable ; but it must be small game
for those who like that kind of food. It is, however,
supposed to impart a nice flavour to our South-country
mutton. Borlase, in his ' Natural History of Cornwall '
(1758), says —

" The sweetest mutton is reckoned to be that of the
smallest sheep, which usually feed on the commons where
the sands are scarce covered with the green-sod, and the
grass exceedingly short ; such are the towens or sand-
hillocks in Piran-sand, Gwythian, Philne, and Senan-
Green near the Lands-End, and elsewhere in like situa-
tions. From these sands come forth snails of the tur-
binated kind, but of different species, and all sizes from
the adult to the smallest just from the egg ; these spread
themselves over the plains early in the morning, and
whilst they are in quest of their own food among the
dews, yield a most fatning nourishment to the sheep.^'

In INIontagu^s time also it appears to have been the
prevailing opinion in the South of Devon that the H.
virgata contributed not a little to fattening sheep ; and
in a recent number of the ^ Field ^ newspaper a corre-
spondent says that this kind of food is supposed to
give Dartmoor mutton its admitted superiority. Bou-
chard-Chantereaux remarks that H. virgata does not
seem to mind the cold, and never hibernates ; that
during frost, or when the grass is covered with snow, it
covers the mouth of its shell with the same kind of epi-
phragm that it makes in summer as a protection against
the rays of the sun ; and that when a thaw takes place
it is again active and in search of food. It usually lays
its eggs from September to November, but sometimes as
late as January. He also observed that when the shell

HELIX. 213

was of a light colour the animal was black, and that
the clear transparent band which often accompanies the
white variety appeared to be black when the animal
occupied the shell. The largest specimens of H. virgata
that I have ever seen were collected by Mr. William
Thompson near Weymouth ; they were four-fifths of an
inch in breadth. Sometimes the mouth has two ribs,
which are placed at a little distance from each other.
Lady Elizabeth Finch presented me mth a very prettily-
marked variety from Sandgate.

This species differs from H. Pisana in its much smaller
size, more prominent spire, having only one band on the
body whorl, and in the larger and deep umbilicus. It
is very variable in the shape and markings of the shell.
Moquin-Tandon has particularized seventeen varieties,
besides eleven more of H. lineata, which very closely
approaches the present species. Several of these varie-
ties have been described by Continental authors as di-
stinct species. The typical form is the H. variabilis of
Draparnaud ; but the name given by Da Costa was long-
anterior.

17. H. capera'ta*, Montagu.

H. caper ata, Mont. Test. Brit. p. 430, pi. 11. f. 11 ; F. & H.'iv. p. 59,
pi. cxvii. f. 7. ^,

Body pale or yellomsh-grej, streaked with brown ; tuber-
cles rather large and close-set, with fine black points : mantle
greyish-brown, minutely speckled with black and milk-white :
tentacles long and rather slender, having a dusky hue ; bulbs
somewhat globidar : foot nearly truncate in front, ending in a
short and blunt tail, which is, as weU as the sides of the foot,
of a lighter colour.

Shell subcorneal, compressed both above and below, soHd
and opaque, not glossy, greyish-white, with usually a rather

* Wrinkled.

214 HELICIDiE.

narrow yellowish-brown or chestnut band immediately above
the periphery, and from two to seven smaller bands of the
same colour below it; the colour is equally variable in this
species as in II. virgata, being also occasionally plain yellowish-
white, or dark brown with a single white band, or the dark
bands are streaked or interrupted, so as to make the surface
appear mottled or spotted ; sculpture consisting only of striae
in the line of growth, which are exceedingly strong and close
together, resembling ribs : periphery obtusely keeled : epidermis
very slight : whorls 6, compressed towards the peripherj^, but
rather convex below ; the last occupying about two-fifths of
the shell ; top whorls minutely granulated : spire slightly
raised, often chestnut-brown at the summit : suture rather
deep : mouth shaped as in H. virgatii but more oblique, inside
furnished with a strong white rib which is sometimes double :
outer lip sharp, slightly reflected towards (and considerably
so over) the umbiHcus, somewhat inflected above : umbilicus
moderately open and exposing aU the inner spii'e. L. 0-225.
B. 0-375.

Var. 1. major. Shell larger. L. 0-25. B. 0-5.

Var. 2. ornata, Picard. Shell smaller, with broader and
darker bands. L. 0-15. B. 0-3.

Var. 3. subscala7^is. Shell conical : whorls more convex.

Var. 4. Gigaxii. Shell rather smaller : spire more de-
pressed : umhilicus consequently larger. H. Gigaxii, Char-
pentier, MS. in sched. and mus. Cuming !

Habitat : Under stones and on the stalks of grass
and shrubs in dry and sandy soils in most parts of
Great Britain^ both inland and maritime, from the
Moray Firth district to the Channel Isles. Var. 1.
Norwich (Bridgman) ; Surrey (Choules). Var. 2. Sandy
coasts of North and South V\^ales, South Devon, and
Cork (J. G. J.)- Var. 3. Cork (Humphreys) ; Swansea
(J. G. J.). Var. 4. Sandwich and Falmouth. This
species has not been noticed as an upper tertiary fossil,
or as inhabiting the North of Europe ; but it is widely
diffused over a great part of the Continent and ranges

HELIX. 215

through Germany^ France^ Portugal^ Spain, and Italy
to Algeria, Greece, and Palestine.

This is a sluggish moUusk and never leaves its retreat
or place of attachment, except after rain. It is often
found in gardens and corn-fields near the sea. Bouchard-
Chantereaux says that between the months of August
and October it lays from 35 to 40 eggs, which are quite
white and opaque, and that the young are excluded at
the end of from fifteen to twenty days, becoming adult
at the end of the next year. Brard hazarded a singular
conjecture, that the tinge of violet-brown" which is ob-
servable in the shells of this and a few other allied spe-
cies, and which fades away soon after death, may be
owing to an exudation or secretion by the animal of
oxide of manganese.

H. caperata differs from H. virgata in its much smaller
size, its depressed spire and larger umbilicus, and espe-
cially in the numerous rib-like strise which hoop round
each whorl. This appears to be the H. striatula of
Miiller, but not that of Linne. It is also in all proba-
bility the H. fasciolata and H. intersecta of Poiret, and
certainly the last-named species of Michaud ; but Poiret's
descriptions are much too brief and obscure for the pur-
pose of identification. Draparnaud also described and
figured the present species under the name of H. striata ;
but although the work which contains this description
and figure (the 'Tableau^) bears date and was published
before that of Montagu, Draparnaud^ s name cannot be
adopted, because Muller had previously described another
species di Helix under the same name. The present
species is allied to H. conspurcata of Draparnaud, which,
however, has a hispid shell and belongs to the last section
of Helix.

A specimen of the H. terrestris of Pennant [H. elegans,

216 HELICID.^.

Drap.) is in Dr. Turton^s collection of British shells,
marked ^' Cornwall '^ (the birthplace of many spurious or
exotic shells) ; but although it has not at present any
well-founded claim to British parentage, it is remarkable
that this characteristic species, which had been so long
considered as peculiar to the shores of the Mediterranean,
has been lately found by M. PAbbe Maillard at Beauvais
in the North of France ; and I have seen the specimens
and been satisfied as to the correctness of this discovery.

18. H. ericeto'rum*, Miiller.

H. ericetorum, Miill. Verm. Hist. pt. ii. p. 33 ; F. & H. iv. p. 61 , pi. cxvii. f. 4.

Body greyish-white or yellowish, with sometimes a tinge of
reddish-brown ; tubercles very close-set ; 7nantle marked with
rather small and irregular, but distinct, milk-white specks :
tentades rather long and thick, distinctly granulated, of a yel-
lowish-grey colour ; bulbs globular : foot shghtly angidated in
front, its sides having a narrow whitish border, and the tail
tapering to a blunt point.

Shell nearly circular, much compressed above, but not quite
so much below, rather thin, but nearly opaque, glossy, whitish
or cream- colour, with usually a rather broad chestnut band a
little above the periphery, and from two to six narrow bands of
the same colour below it, but all these bands (or some of them)
are often interrupted or altogether wanting ; sculpture con-
sisting of faint striae in the line of growth, and often of irre-
gular pit-marks or indentations, which are thickly scattered
over the siuface : periphery round, and not in the least keeled
or angular : ejndermis very thin : whorls 6, cyhndrical, the
last occupying about three-fifths of the shell : spire very slightly
raised, chestnut-brown at the summit : suture deep : mouth
nearly round, forming a segment of about four-fifths of a
circle, somewhat oblique, in consequence of the greater pro-
minence of the upper lip, and occasionally strengthened by a
slight internal rib: outer lip rather thick, shghtly reflected
and especially towards the columella, very abruptly inflected

* Frequenting heaths.

HELIX. 217

above : umbilicus extremely large and open, exposing a con-
siderable part of the penultimate and preceding whorls and all
the interior of the spire. L. 0-25. B. 0-675.

Yar. 1. alba, Charpentier. Shell milk-white.

Var. 2. minor. Shell smaller. L. 0-2. B. 0*5.

Yar. 3. instahilis. Shell smaller, of a darker colour, and
sometimes streaked or spotted : S2nre more raised : umbilicus
narrower. I£. instabilis, (Ziegler) var. (j, L. Pfeiifer, Mon. Hel.
i. p. 165.

Yar. 4. sinistrorsa. Shell having the sjnre reversed.

Habitat: Dry heaths, do wns_, and sand-hiUs, on thistles
and other plants, in various parts of Great Britain, but
apparently not ranging further north than the Hebrides.
Var. 1 is also not uncommon, and is (according to
Gray) the H. obliterata of Hartmann, besides having five
other names. Var. 2. Kendal (J. G. J.). Var. 3. Zona
(Lowe) ; Mull (Bedford) ; Connemara (J. G. J.). Var. 4.
Bridlington (Strickland). The shell is also inclined to
be occasionally scalariform. This species and several of
its varieties are widely diflPused over the Continent from
Cassel to Sicily; but it does not seem to inhabit the
extreme North of Europe, unless it is the same species
as that which Nilsson has described under the name of
H, ericetorum. The Swedish species has been considered
by many conchologists to be distinct, and it has been
named H. Nilssoniana by Beck, Malm, and other writers.
YV'ith the above exception, all the species comprised in
the present section appear to belong to what may be
termed a South -European type.

This is a shy and inactive mollusk, withdrawing itself
into the shell on the slightest touch. The specific name
now borne by this very elegant shell was first given to it
by Lister, who observed that continued rains kill a great
number of them — a fact which I can corroborate. It

218 HELICID.E.

commences egg-laying in August^ and retires into winter-
quarters in November^ when it shuts itself up by means
of its epiphragm and remains concealed at the roots of
grass or under the shelter of a stone until spring.

The flat shape of this shell, its exceedingly large um-
bilicus, and nearly circular mouth will easily serve to
distinguish it from any other of our banded Helices.

Linne was supposed by some to have given the name
of Itala to this species ; but L. Pfeifier considers it a
synonym of H. cespitum. The Linnean description, how-
ever, is " convexa^^ and the size that of a hazel-nut —
both of which characters are more appropriate to H.
virgata than to the present species. The original types
in the collection of the illustrious Swede appear to have
been so disarranged and confused by the late possessor
(Sir James Smith) and others, that I fear they are now^ of
little value as a means of identifying any of the species
described either in the ^ Fauna Suecica ' or the ' Systema
Naturae,^ except in a very few instances where the hand-
writing of Linne has been preserved on or with the
specimens ; and this unfortunately is very seldom the
case.

E. Shell depressed : outer lip usually thin and destitute of a

rib : umbilicus very large.

19. H. ROTUNDA TA"^, Miiller,

H. rotundafa, Miill. Verm. Hist. pt. ii. p. 29; F. & H. iv. p. 80, pi. cxix.
f. 6, 7, and (animal) pi. G. G. G. f. 2.

Body small in comparison with the shell and very slender,
rounded in front and ending in a blunt point, slate-colour or
light-grey with a faint tinge of blue, very finely speckled with
black on the front and sides ; tubercles rather large, flat,
round and thick, but not very distinct : mantle reddish-yellow,
marked with very close and distinct milk-white dots : tentm-les

* Eounded.

HELIX. 219

dark-grey with black specks ; upper pair rather close together
and nearly cylindrical; bulbs short, thick, and subglobular:
foot rather narrow, rounded in front, thickened at its sides, and
ending in a very slender but blunt tail.

Shell nearly circular, more compressed below than above,
rather thin but nearly opaque, moderately glossy and slightly
iridescent, yellowish- brown or horncolour, and marked trans-
versely with equidistant reddish-brown streaks or blotches ;
sculpture consisting of numerous curved transverse ribs, which
are equally strong on both sides and sometimes anastomose, as
well as of minute intermediate striae, and of a slight granula-
tion on the first whorl, which is destitute of ribs : periphery
bluntly keeled : epidermis not very thin : whorls 6-7, subcy-
lindrical, convex below, the last occupying about one-third of
the shell and the rest gradually diminishing in size : spire
slightly raised ; summit glossy and semitransparent : suture
very deep : mouth obliquely quadrangular, strengthened in
adult specimens by a narrow, but strong, white internal rib :
outer lip thickened in the adult, but usually sharp and thin,
very slightly reflected, and not much inflected above : umbi-
licus extremely large, open, and deep, exposing a considerable
part of all the whorls, as well as the whole of the internal
spire. L. 0-1. B. 0-275.

Var. 1. minor. Shell smaller.

Yar. 2. pyramidal'is. Shell subconical : spire more raised.

Yar. 3. Turtoni. Shell greatly depressed above and below :
5p^Ve nearly flat. H. Turtoni, Fleming, Brit. Anim. p. 269.

Yar. 4. alha, Moquin-Tandon. Shell pale yellowish-white
or with a greenish tinge.

Habitat : Under stones^ logs of wood_, and bark of
old trees, as well as in decayed wood and moss, and
among dead leaves, everywhere from the most northern
extremity of Great Britain to the Channel Isles. Var. 1
appears to be an alpine form. I have found it not only
in Zetland, and on the Jura and Swiss Alps, but also in
Guernsey. This form occurs also in our upper tertiary
beds, probably indicating their northern origin. Var. 2.
Swansea and other places (J. G. J.). Var. 3. Dublin
(Turton); Bath (Clark); Bristol, and Dunboy in Bantry

L 2

220 HELICIDyE.

Bay (J. G. J.) . This variety is the H. rotunclata of Tiir-
ton's ' Conchological Dictionary/ Var. 4. Bucks^ Surrey,
Kent, Essex, Oxon, Gloucester, Somerset, Salop, York,
Northumberland, Aberdeen, Glamorgan, and most pro-
])ably other counties ; but it is rare. This common
species ranges from Russia and Finland to Sicily and the
Azores.

This pretty little shell reminds one of a Solarium or
of the Trochus perspectivus. The animal is exceedingly
shy; and Miiller relates that he spent two hours in
watching one of them, before it made its appearance,
although he took every precaution not to alarm the little
creature. It appears not to be prolific. According to
Bouchard- Chantereaux, it only lays from 20 to 30 eggs
in the course of the breeding-season, viz. from May to
September. It secretes a very thin and transparent
epiphragm.

It is the H. radiata of Da Costa and Montagu. Some
authors have erroneously placed this and the two follow-
ing species in the genus Zonites ; but the textui-e and
aspect of the shells, as well as the arrangement of the
teeth, show that they belong to the present genus, and
not to Zonites.

20. H. rupes'tris^, Studer.

H. rwpeat.Tis,, Draparnaud, Tabl. Moll. p. 71. H~ imihilicata, F, & H. iv.
p. 81, pi. cxxi. f. 7. 8.

Body dark slate-colour, with sometimes a reddish tinge,
covered with minute depressed tubercles : mantle dusky
brown, indistinctly speckled with black : tentacles diverging,
dark-grey ; upper pair thick and almost cylindrical, with
nearly oval bulbs, which are about a fourth of the size of those
tentacles ; lower pair almost rudimentary and nearly black,
not more than a twelfth of the size of the other pair : foot

* Inhabiting rocks.

HELIX. 221

rounded in front, obtusely pointed behind ; sides marked with
minute and numerous black specks, which are arranged in
squares and form rather large spots.

Shell subcorneal, more compressed below than above, rather
solid but semitransparent, slightly glossy, dark-brown or horn-
colour, marked transversely with close-set curved strioe, which
are equally strong on both sides : periphery roimded, but ob-
tusely keeled in young specimens : epidermis rather thin :
whorls 5, cylindrical, compressed on the upper part and towards
the periphery, rather convex underneath, first whorl slightly
granulated : spire somewhat raised ; summit rather glossy
and transparent : suture remarkably deep : mouth horseshoe-
shaped, but compressed above, destitute of an internal rib :
outer Up thin, very slightly reflected in adult specimens, con-
siderably inflected above and below : umhilicus large, open, and
deep, exposing part of the whorls, as well as all the interior of
the spire. L. 0-075. B. 0-115.

Yar. viridescenti-alba. Shell greenish- white.

Habitat : On rocks, walls^ and ruins of castles, as well
as under stones on liill- sides, throughout the greater
part of this country. Fleming noticed it in his ' British
Animals* as a Scotch species, and Leach states that he
had observed it near the summit of mountains in Arran,
N. B.; its EngUsh range extends fi'om Westmoreland
to South Devon. It is also not uncommon in South
Wales and Ireland. The variety has been found by
Mr. Norman at Clevedon in Somersetsliire_, and by Mr.
Webster at Clifton, near Bristol. The spire is often
more or less raised, and not unfrequently distorted. This
species does not appear to be a pliocene fossil or to in-
habit the North of Europe ; but Dr. Zittel has taken it
near Baden. It is diflFased throughout Central and
Southern Europe, as far as Algeria, Sicily, and Greece,
and even (according to Lowe) ranges to Madeira.

Montagu observed, with respect to this species, that
it always affects lofty and exposed situations, braving
equally the scorching beams of the sun in summer and

222 HELiciDAi:.

tlie frigid winds of mnter^ without attempting to de-
scend. It forms^ however^ a thin membranous epi-
phragm for its protection against such extremes of heat
and cold, and shelters itself in clefts of rocks and crevices
of walls. This little snail, in crawling, usually carries
its shell quite upright, and not inclined to one side like
most of its congeners. The upper whorls of the shell
are generally bleached by exposure of that part to the
sun. The animal is ovo^dviparous, as well as that of
Pupa umbilicata ; and in specimens which I collected at
Kendal in the month of August, the fry in the interior
of the shell had a whorl and a half completely formed.
Moquin-Tandon counted in the matrix of several speci-
mens which he had received from Marseilles, from tliree
to seven young ones in each. It mostly frequents cal-
careous strata ; but in Germany it has been found on
felspathic rocks. It sometimes occurs in unusual places.
A specimen in my collection was taken by the trawl at
a depth of between twenty and thirty fathoms several
miles seaward of Plymouth, having been probably washed
down by a river or freshwater stream and transported
a long way before it sunk to the bottom.

This is the H. umbilicata of Montagu ; but as his
excellent work was published two years after Drapar-
naud's ' Tableau des Mollusques terrestres et fluviatiles
de la France,^ my patriotic inclinations, however strong,
will not justify me in preferring the name given by my
countryman to the more ancient one of the French con-
chologist. The above-mentioned work of Draparnaud
does not appear to have been known to Dr. Gray when
he published an improved edition of Dr. Turton^s ' Ma-
nual of British Land and Freshwater Shells.' The work
in question was published in 1801, Montagu's 'Testacea
Rritannica' in 1803, and Draparnaud's ^ Histoire natu-

HELIX. 223

relle des Mollusques terrestres et fluviatiles de la France'
was edited by his widow and appeared in 1805. Studer
first gave this species the name of '' rifpestris'^ in Coxe^s
^Travels through Switzerland^ (1789), but did not de-
scribe it.

21. H. pygm^'a"^, Drapamaud.

H. 2m^i(sa, Drap. Tabl. p. 93, aud Hist. p. 114, pi. viii. f. 8-10 ; F. & H.
iv. p. 83, pi. csxi. f. 9, 10.

Body greyish-brown or slate-colour, minutely speckled with
black ; tubercles round and much depressed : mantle brown,
with a slight tinge of red: tentacles rather close together,
nearly cylindrical, abruptly thickened at their base ; bulbs
indistinct : foot narrow and ending in a thick and keeled tail.

Shell nearly circular, depressed above and below, thin,
semitransparent, rather glossy and having a silky lustre, light-
brown or tawny, marked transversely with extremely fine
and close-set curved strias and spirally (especially round the
umbihcus) with a few delicate lines, which are only perceptible
with a high magnifier : periphery rounded and not keeled :
ejndermis rather thin : ivhorls 4, convex and cylindrical,
gradually increasing in size : spire not much raised ; summit
glossy and transparent : suture deep : mouth shaped as in
H. rupestris and not margined : outer lip thin, somewhat in-
flected on both sides : umbilicus moderately large, but deep
and fuUy exposing the interior of the spire, as well as part of
the penultimate whorl. L. 0-03. B. 0-06.

Habitat : Woods and moist places under stones and
among dead leaves, as well as at the roots of grass and
rushes^ from Oban to Guernsey. It is widely diffused^
although difficult to find on account of its minute size.
Saint- Simon seems to have been successful in taking it
several times and in considerable numbers by sweeping
the wet grass and herbage after rain with an entomolo-
gists' gauze net ; and Dr. Turton told me that he pro-

* Tiny,

224 HELICID/E.

cured many specimens by collecting a bagful of dead
and rather moist leaves and afterwards spreading them
on paper to dry, when the refuse yielded a good harvest.
This species has a wide range on the European continent
and has been met with in every country between Siberia
and Sicily, and is said also to inhabit the Azores.

Moquin-Tandon says that this tiny snail is extremely
timid and irritable, avoiding the garish light of day and
shutting itself up in its shell at the slightest touch, and
that when it is about to move it protrudes from the
shell the tail of its foot before any other part of the
body. Like the last species, it carries its shell erect
when crawling. It forms an excessively thin and deli-
cate epiphragm.

This beautiful little testaceous gem differs from H.
rupestris in its much smaller size, finer textm-e and
sculpture, lighter colour, fewer whorls, more depressed
spire, slighter suture, and more open umbilicus. Leach
and Fleming, however, regarded it as the young of the
last species, and M. D'Orbigny of Rochelle made the
same mistake. It w^as first noticed as a British shell by
Dr. Gray in the ^Medical Repository^ for 182L

It is the H. minuta of Studer in Coxe^s ^ Travels,^ and
H. Kirbii of Sheppard.

F. Shell depressed : outer lip thickened and reflected, some-
times forming a complete peristome.

22. H. PULCHELLA*, Miillcr.

H. 2iulchcUa, Miill. Verm. Hist. pt. ii. p. 30; F. & H. iv. p. 78, pi. cxix.
f. 9, 10,

Body gelatinous, milk-white ^\^th a faint tinge of grey or
yellow, nearly transparent, very sHghtly tubercled: mantle

* Pretty.

HELIX, 225

thick, yellowish, minutely speckled with white : tentacles
(upper pair) hyaline, thick, nearly cylindrical, with very thick
bulbs, which are half the length of those tentacles and nearly
round ; lower pair extremely small : foot short, broad, strongly
truncate and slightly bilobed in front, having a faint yellowish
border on the sides, and ending in a rather short and somewhat
rounded tail.

Shell depressed but sHghtly convex above and below, rather
solid although transparent and glossy, light-grey or white,
striate transversely by numerous and very fine, but somewhat
irregular and faint, curved lines, which are stronger in the
umbilical region, and occasionally marked with a few indistinct
spiral lines on the lower part : periphery rounded in the adult,
but slightly and obtusely keeled in the young : epidermis rather
thick : luhorls 3|, compressed towards the periphery, the last
exceeding in size the rest of the shell and considerably dilated
towards the mouth : sjnre very little raised ; suture rather
deep : mouth almost circular and trumpet-shaped, but very
slightly oblique : outer lip very thick and strongly reflected,
forming in the adult a complete peristome, much inflected on
both sides: umbilicus rather large, exposing a considerable
portion of the whorls and all the internal spire. L. 0*04.
B. 0-09.

Var. costata. Shell much less glossy, and marked trans-
versely with curved membranaceous ridges (of which there are
about forty on the last whorl), besides numerous intermediate
striae. H. costata, Midi. Yerm. Hist, pt, ii. p. 31 ; P. & H. iv.
pi. cxix. f. 8.

Habitat : Under stones and logs of wood, as well as
in moss and at the roots of grass, in moist situations,
from the Moray Firth district to the Channel Isles.
The variety is equally diffused, but not so common;
and it frequents dry and sandy places, often under loose
stones or bricks on old walls. Montagu says that he
had often found this variety with the typical form, and
he described the former, but with considerable doubt,
as a different species, mider the name of H. crenella ;
Maton and Rackett have made the same remark; the
authors of the ^British Mollusca^ state that ^^botli

L O

226 HELICID^.

varieties inhabit wet and dry localities indifferently ;" and
Malm has confirmed these observations and added that,
out of 100 specimens which he had collected in one
spot, twenty of them belonged to the variety. I have
not been so fortunate as to find them living together.
Miiller describes the present species as common in wet
moss, and the variety as very rare in an elevated spot at
some distance from any w^ater. Some specimens, how-
ever, of the variety are more strongly ridged than others ;
and there is an evident transition from the smooth to the
ridged form. I cannot detect any difference between
the shells except in respect of the membranaceous
ridges, wdiich form part of the epidermis and are easily
rubbed off, leaving the surface of the shell quite smooth.
This species is common jn our upper tertiary deposits.
Abroad it ranges from Siberia (according to Gerstfeidt)
to Lugano (according to Stabile), as well as to Corsica
and even to Madeira and the Azores. Gould says that
the typical form is rather common near Boston, and
that it has been noticed on the Ohio, and on the banks
of the Missouri, as high up as Council Bluffs. With
reference to the opinion of some that it had been intro-
duced into America from Europe, Dr. Binney remarks
that "it does not seem possible that so small an animal,
if naturalized since the arrival of Europeans, could have
been able to penetrate to the remote points in the
interior of the Continent w^here it is now found." With-
out quite concurring with the American conchologist in
this remark, I do not see how this little snail is likelv to
have been transported across the Atlantic from the one
hemisphere to the other. It only inhabits waste and un-
cultivated spots ; and a flower- or kitchen-garden woidd
be the last place to look for it. But the modes of trans-
port are various ; and it would be rash to assert positively

HELIX. 227

that H. pulchella has never crossed the Atlantic. If I
may be permitted to offer a suggestion on this knotty-
pointy I would remark that, being a comparatively north-
ern species, it is much more probable that it has spread
from the Arctic regions through Canada. This is one
of the European species which Dr. Thompson found in
Cashmir and Thibet, according to the identification of
Mr. Woodward.

This little creature is very shy and difficult to observe.
Its eyes appear remarkably black, in consequence of the
two upper tentacles being so transparent. The liver is
saffron-coloured ; and the upper part of the spire in dead '
shells often shows it. The epiphragm is like tissue-
paper and iridescent. Bouchard- Chantereaux says that
H. pulchella lays, in August and September, from 12 to
20 globular and opaline eggs, which are united in a
cluster two or three times the size of the shell. It seems
to be hardy, and has been found at rather considerable
heights. Von Martens noticed its occurrence on the
Dovre fjelds at an elevation of more than 2000 feet.

This species is the H. paludosa of Da Costa and
Montagu, and the Turbo Helicinus of Lightfoot; but
the name given by MUller is anterior to both of these.

23. H. lapici'da*, Linne.

H. lapicida, Linn. Syst. Nat. ed. xii. p. 1241 ; F. & H. iv. p. 65, pi. cxvi.
f. 3, 4.

Body yellowish-brown above, with a slight tinge of red in
front, and of grey behind and underneath, covered with mi-
nute close-set, unequal-sized tubercles, which are of a darker
colour and arranged in indistinct lines corresponding with
those of the tubercles or granulations on the surface of the
shell : mantle extended round and lining the mouth of the
shell, concentrically wrinkled and tumid, reddish-brown or

* Lapidary.

228 HELICID.E.

dusky, speckled with milk-white: tentacles yqyj long, dark-
grey with a slight tinge of yellow ; bulbs very short and glo-
bular : foot narrow and rounded in front, broader and keeled
behind, its sides having a whitish border.

Shell depressed above and below, rather solid, nearly opaque,
not glossy, yellowish tinted with reddish-brown, and irregu-
larly streaked across the whorls with the latter colour, marked
with indistinct hues of growth, and finely shagreened, like
seal-skin : peripliery strongly and sharply keeled : epidermis
rather thick : whorls 5, greatly compressed towards the peri-
phery, the last exceeding in size the rest of the shell and some-
what dilated towards the mouth : spire Yerj little raised, point
blunt : suture rather slight, but distinct : mouth obliquely oval,
angnlated above and below, with rather a deep notch in the
line of the keeled periphery : outer lip white, thickened and re-
flected, forming a complete peristome, abruptly and consider-
ably inflected on both sides : umbilicus rather large, exposing
a great part of the whorls and all the internal spire. L. 0*25.
B. 0-65.

Var. minor. Shell smaller and more deeply coloured.

Habitat: Moist rocks, woods, aud other places in
many parts of England, from Went Vale, Yorkshire, to
Portland Island. This species does not appear to be
fomid in Wales, Scotland, or Ireland. It has been sup-
posed to be restricted to calcareous districts; but Mr.
Reece has found it close to Worcester, and Capt. Bruce
Hutton at Linton in North Devon, in neither of which
places is there any limestone, chalk, or oolite. In a spe-
cimen now before me the whorls are twisted, like the sca-
lariform distortion of some kinds of Planorbis. This is
one of our upper tertiary fossils. Its foreign range extends
from Finland to Portugal; and Aradas and Maggiore
are said to have found a single specimen in Catania.

This is a rather hardy, but inactive snail. During
the daytime it lies concealed in the crevices of rocks or
old walls and under the bark of trees ; but in the dusk
of the evening, or after a shower of rain, it sallies fortli

HELIX.

229

in search of food, and may iu the latter case be met with
in considerable numbers. The coloured streaks on the
shell somewhat resemble those on H. rotundata. Lister
first made the present species known, and says he had
often found it in woods in Lincolnshire. Linne gave it
the inappropriate name it now bears, from an erroneous
idea that it ate or excavated calcareous rocks, as the
Teredo does wood. This notion probably originated in
the surface of the shell being rough and like a file. His
H. albella appears to be the immature or younger state
of- the variety called by Menke albina. This white
variety has not been noticed as British ; but it is found
in Sweden and many other parts of the Continent. I
have taken it in Switzerland and the Lower Harz, with
specimens of the usual colour. The H. albella of Fleming
(Brit. Anim. p. 260) may also be the same state of this
variety. He found a single dead specimen on the shore
at St. Andrews in 1810. It is not at all likely that
Draparnaud^s species of that name (the H. explanata
of Miiller) would have found its way so far north ; and
Dr. Fleraing says that his shell diflPers from Drapar-
naud^s description. The H. Somershamiensis of Sheppard
(Linn. Trans, xiv. p. 159) is probably the young of the
present species.

G. Shell flat or slightly concave above : outer lip thick and
furnished with a tooth-like tubercle : mnbilicus rather
large.

24. H. obvolVta*, Miiller.

H. obvoluta, Miill. Verm, Hist. pt. ii. p. 27 ; F. & H. iv. p. 63, pi. cxvii.
f. 1-3.

Body narrow and somewhat truncate in front, brown with a
slight reddish tinge,, and speckled with milli-white in several

* Wrapped-up.

230 HELICID^.

parts ; tubercles oblong and arranged in close lines, smaller in
front : mantle tumid, forming a narrow collar and leaving a
slight space empty round the neck : tentacles very long and
slender, dark-brown, shagreened; bulbs very globular: foot
deKcately edged with milk-white, ending in a long, narrow, tri-
angular and keeled tail.

Shell nearly circular, shaped somewhat like one of the men
in a backgammon board, except that this is spiral, flat above,
with a slight depression in the middle, and compressed below,
rather solid, opaque and of a lurid aspect, reddish-brown, finely
and closely striate in the line of growth : periphery rounded, but
compressed: epidermis very thick, closely covered with stiff
reddish-brown hairs : ivliorls 6-i-, cylindrical, but compressed at
the sides, gradually increasing in size, the first (being the
nucleus of the shell) nearly smooth and polished, and the last
slightly dilated towards the mouth : spire sunk below the level
of the last Avhorl: suture rather deep: mouth obhquely tri-
angular, in consequence of a tooth-like protuberance at the
peripheral edge : outer lip reddish-white, very thick and re-
flected, its upper margin abruptly and considerably inflected :
umhilicus rather large, exposing part of the whorls (especially
the last but one) and all the internal spire. L. 0-2. B. 0-5.

Habitat : On stumps and at the roots of trees in woods
at Ditcham and Stoner Hill near Buriton, in Hampshire,
where it is rather common. It is a native of France,
Germany, Switzerland, and Lombardy ; but it does not
seem to inhabit the extreme North or South of Europe.

This curiously-shaped snail is rather active, and
secretes a good deal of clear slime. Its epiphragm is
chalky- white and remarkably thick.

Considerable doubt has been raised by many British
conchologists (myself included) as to H. obvoluta being
really indigenous to this country. It was first noticed
by Dr. Lindsay (in 1831) as occurring in Ditcham
Wood. He found with it Zonites cellarius and HelicV
rufescens. Mr. Hawker says, in the ^ Zoologist ' for 1853
(p. 3764), "The two ridges (Stoner Hill and Ditcham
Wood) are quite distinct, and the intervening country

BULIMUS. 231

is low and flat : therefore I do not think it possible that
H. obvoluta could have spread or wandered from the
Ashford Woods to Ditcham/^ Stoner Hill appears to
be six miles distant from Ditcham Wood. This species
inhabits the North of France^ having been found by Dr.
Baudon at Morainval Wood near Mouy ; and if H. Car-
tusiana is British^ the present species has quite as good
a claim to the same privilege.

Genus V. BU'LIMUS*, Scopoli. PL VII. f. 1, 2.

Body long, always containable within the shell : tentacles 4 :
foot rather long and narrow.

Shell cylindrieally- conic or oblong, not thin or very glossy :
tuhorJs drawn-out : s^^ire long : month oval : outer lip usually
reflected, and sometimes (but not in British species) fiunished
with tooth-like tubercles : umh'dicus exceedingly small and
narrow.

I will not inflict upon my readers a repetition of the
stale and uninteresting controversy which formerly
vexed the conchological world as to the origin and mean-
ing of the name of this genus. A few words will suffice
to give its history. The celebrated French naturalist,
Adanson, proposed, in 1757, for a small freshwater mol-
lusk of Senegal, a new genus, which he called Bulin, being
a local word. This name was capriciously or inadvertently
changed by Scopoli into Bulimus ; and it was used by
him, and subsequently adopted by Bruguiere, to receive
a heterogeneous assemblage of land and freshwater
shells, having no affinity with Adanson^s species, or with
any of those to which the genus is now restricted. Dra-
parnaud in 1801 was the first to apply the generic word
to its present and generally recognized signification.

* A corruption of Bulin, an African word.

233 HELICID.E.

The difference between this genus and Helix is very
trifling. The tentacles in the present genus are rather
shorter, and there are also some minor points of ana-
tomical distinction. The shell of Bulimus has a longer
spire; but this is a comparative character, and the
degree of difference between the length of the spire in
Helix conica and the young of Bulimus ventricosus [Helix
Bulimoides of Moquin-Tandon) is scarcely appreciable.
It is not from the limited means of observation which
are afforded by a collection of the MoUusca in this or
any other particular country that a safe conclusion can
be anived at with respect to the line of generic distinc-
tion ; and this is especially the case with the genus now
under consideration. There are only three British species
of Bulimus ; and one of them, which is by far the most
common of all [B. acutus), has been restored by Moquin-
Tandon to the genus Helix. This species is included in
a section from which Leach constructed his genus
Elisma ; and it will be here described firsts as forming a
passage from Helix to the present genus.

The habits of the Bulimi are nearly the same as those
of the Helices. Our native species of Bulimus appear
to be exclusively herbivorous. They frequent open do^vns
and woods, and are rarely met with in the haunts of
men, though B. acutus infests gardens near the sea-coast,
being probably tempted by the more succulent pasture.
Their manner of o\dposition, as well as the shape and
arrangement of the eggs, are similar to what has been
observed with respect to the typical genus. Helix. A
peculiarity of this genus is the tendency which some
exotic species have to a reversal of the spire, attended
with a change of position in some of the principal organs
of the body. In other land-shells this phenomenon is
more usual in genera or species than in varieties.

BULIMUS. 233

A. Shell cylindrically conic : spire long and pointed : outer lip

thin and plain.

1. BuLiMUs acu'tus*^ Miiller.

Helix acuta, Miill. Verm. Hist. pt. ii. p. 100. B, acutus, F. & H. iv. p. 86,
pi. cxxviii. f. 5, and (animal) pi. Gr. G. G. f. 6.

Body rather thick, slightly narrowed and nearly truncate in
front, slender and pointed behind, semitransparent, yellowish-
grey of different shades of intensity, covered with very close
and flattened tubercles : mantle touching the outer lip of the
shell, tumid, marked with milk-white and brown specks : ten-
tacles greyish, of a darker hue on the upper part, nearly smooth ;
upper pair very sHghtly conic, with their bulbs dilated but
rather globidar ; lower pair very short : foot nearly truncate
in front, the sides transversely and very closely grooved, tail
blunt and keeled.

Shell turreted, opaque, white with a faint tinge of yellow,
transversely streaked with light-brown, sometimes having one
or two dark-reddish-brown or almost black bands encircling
the lower whorl, one of which (where there are two) is con-
tinued on the upper whorls ; the shell is occasionally white or
coloiu'less ; sculpture consisting of rather close but irregular
striae in the line of growth, which are stronger in some parts
than in others, and there are occasionally a few indistinct spiral
lines which intersect the striae and give the latter an appear-
ance of being disposed in curved rows ; the surface is also
sometimes wrinkled or faintly pitted: periphery rounded:
epidermis rather thin : whorls 8-9, convex, gradually increasing
in size, the upper one smooth, polished, and horncolour : spire
tapering, but blunt at its extremity : suture deep : mouth oval,
not much encroached upon by the penultimate whorl : outer
lip reflected on the pillar and slightly inflected at its upper
angle : umbilicus almost covered by the reflexion of the lip in
that part, but rather deep. L. 0*6. B. 0*2.

Var. 1. hizona. Shell smaller and having two dark bands on
the body whorl.

Yar. 2. inflata. Shell rather more ventricose, streaked with
brown or marked with a single dark band : spire shorter :
whorls proportionally broader.

* Pointed.

234 HELICID^.

Habitat : Downs and sand-hills on the sea-coast,
from Durness in Sutherlandshire (where it has been
found by the Rev. Walter Grigor) to the Channel Isles,
as well as throughout Wales and Ireland. The variety
bizona is remarkably pretty, and has been found in lona
by Messrs. Lowe and Berkeley; at Abergelly, near
Conway, by Mr. Gibbs ; near Cork by Mr. J. D. Hum-
phreys ; and at Tenby, and Portmarnock in Dublin Bay,
by myself. The variety inflata occurs with the typical
form, but merges insensibly into it through intermediate
gradations. It somewhat resembles the B. ventricosus
of Draparnaud. The present species is common in the
granitic, as well as calcareous districts ; but the only
authority for its being found anywhere except on the
sea-coast is that of the late Mr. Thompson of Belfast,
who says it " occasionally occurs inland.^^ It is a very
doubtful member of our upper tertiary list, Mr. Picker-
ing having only found a fragment of a shell, which he
believed was this species, in the deposit at Copford. The
circumstance of this not being a northern form makes the
identification more questionable. Abroad it seems also
to ])e confined to the coast-line, and ranges from France
to Algeria and Sicily. Hartmann is said, however, to
have found it near Romanshorn in Switzerland.

It is rather an active, but irritable creature, and with-
draws itself into its shell on the slightest touch. These
snails may be seen in the daytime clinging to the stalks
of grass and other herbage in countless numbers ; and
this attachment is effected by means of a pellicle secreted
in the same way as the epiphragm. The popular idea
that sheep feed on and are fattened by snails relates to
this kind as well as to Helix virgata ; and, as Montagu
very justly observes, " it is, indeed, impossible that those
animals should browse on such short grass as clothes

BULIMUS. 235

the hills above Whitsand Bay in Cornwall, without de-
vouring a prodigious quantity of snails^ especially in the
nighty or after rain, when they ascend the stunted blades/^
The summer epiphragm is very thin, transparent, and
iridescent; and it has a small hole in it, which corre-
sponds with the position of the respiratory orifice, thus
enabling the snail to procure fresh air without exposing
its body to the heat of the sun. The winter epi-
phragm is thicker, opaque, and yellowish, like paper.
Geologists can have some idea of the way in which land-
shells are accumulated and fonn tolerably thick strata,
from the fact recorded by Montagu, that the drifted sand
at Bigberry Bay in the South of Devon is full of dead
shells of the present species, to the depth of four feet.

This is the Turbo fas ciatus of Pennant and Montagu.

The B. articulatus of Turton (the typical specimen of
which is in my collection) is an exotic shell, and not
Lamarck^s species of that name, which is only a variety
of B. acutus.

B. Shell oblong : spire blunt : outer Up thickened and reflected.
2. B. monta'nus *, Draparnaud.

B. montaniis, Drap. Tabl. Moll. p. 65. B. LacJchamensis, F. & H. iv. p. 89,
pi. cxxviii. f. 6.

Body rather thick, rounded in front, narrowing gradually
and pointed behind, dark-red or greyish-brown ; tubercles
flattened, with yqyj fine black points : mantle indistinctly and
minutely speckled with milk-white and brown : tentacles some-
what thick and conical ; upper pair coarsely shagreened, with
thick and rather globular bulbs ; lower pair nearly smooth, of
a somcAvhat darker colour than the others : foot truncate in
front and ending in a long but blunt tail.

Shell conic-oblong, nearly semitransparent, rather glossy,

* Tnliabiting mountains.

236 HELIClDiE.

light-brown with a yellowish tint, but varying in intensity of
colour, faintly and irregularly striate in the line of growth,
and marked spirally ^ith fine and close-set but undulating
lines, which, being intersected by the transverse striae, give the
surface a slightly shagreened appearance : periphery rounded,
but compressed : epidermis rather thick : whorls 7^? somewhat
compressed, the last forming nearly one-half of the shell:
spire tapering, but somewhat abruptly, blunt at its extremity :
suture rather slight and obhque : mouth oval, a little con-
tracted on the inner side by the penultimate whorl : outer lip
white, reflected and considerably thickened within, where it is
of a reddish-brown colour : umhiUcus nearly covered by the
reflexion of the pillar lip, rather obhque, and deep. L. 0-65.
B. 0-225.

Habitat : On trunks of trees, chiefly of beech, ash, and
hornbeam, in the woods of our southern and western
counties. It is local, although tolerably plentiful where
it occurs. At Buriton in Hampshire it is found with
Helios obvoluta and Clausilia Roljjhii. The locality given
in the Appendix to Welch and Whitelaw^s ' History of
Dublin ' (viz. " neighbourhood of Dublin ") is very ques-
tionable, as the occurrence of this shell in Ireland has
not been noticed by Mr. Thompson or Mr. Waller. As a
tertiary shell it has only been discovered in the CI acton
deposit. Its foreign distribution appears to be limited
to the North and East of France, as well as the Pyrenees,
Germany, Switzerland, and Silesia, in all of which coun-
tries it is only known to inhabit elevated situations.

The colour both of the body and shell varies in in-
tensity. In immature specimens the periphery is keeled.
The young are sometimes encrusted with earth in the
same manner as B. obscurus.

It is the Helix Lackhamensis of Montagu ; but his
name is subsequent to that of Draparnaud and is, be-
sides, objectionable on account of its being derived from
a very obscure locality, which was not the first recorded
for the discovery of this species.

BULIMUS. 237

3. B. obscu'rus"^^ Miiller.

Helix obscura, Miill. Verm. Hist. pt. ii. p. 103. B. obscurus, F. & H. iv.
p. 90, pi. cxxviii. f, 7.

Body of a lighter colour than that of B. montanvs, -with the
tubercles comparatiTely more prominent : mantle larger and
more tumid in proportion to its size : tentacles less thick and
conical; upper pair finely, but distinctly, granulated, with
globular bulbs, which are dilated at the top ; lower pair mi-
nutely speckled with black : foot very deUcately and shghtly
fringed, narrow and angular in front, very broad behind, and
ending in a rather slender and pointed tail.

Shell much resembhng that of the last species, except in
size ; but differing also in the following particulars : — this is
shorter in proportion and more glossy ; it has no spiral lines,
but instead of them the transverse striae are divided by very
minute intermediate lines, and the surface consequently has
not the slightest appearance of being shagreened : luliorls only
6^ and more convex : sjoire more abrupt : suture deeper :
mouth proportionally larger : outer lip more reflected and not
so thick, plain white, and much more inflected above ; umhi-
licus a little more contracted. L. 0-35. B. 0'15.

Var. alha. Shell white or colourless.

Habitat : On the trunks of trees and among dead
leaves in woods, on hedge-banks and old walls, under
stones in rocky places, and sometimes in gardens, from
the Moray Firth district to South Devon, as well as in
South Wales and Ireland. It is much more generally
diffused than the last species. The variety has been
found by Mr. Smith at Sevenoaks in Kent ; and I have
observed it at Lulw^orth in Dorsetshire. My collection
contains a monstrosity, in which the mouth had been
broken and renewed in such a manner as to be much
stronger than it was before the fracture. This species
is in Mr. Brown's list of upper tertiary shells from Cop-
ford. It ranges from Siberia, through Finland, Sweden,

* Concealed.

238 HELICID.^.

France, Germany, Sv/itzerland, Portugal, and Lugano, to
Sicily.

Bouchard-Chantereaux says that tlie eggs of this
species, which are laid from May to September, are not
numerous, but very large in proportion to the size of
the animal. It hibernates early and makes a glassy or
papery epiphragm. It loves shade and moisture. It
has a remarkable habit, which it shares with the young
of Pujja secahj of covering its shell, or rather of causing
it to be covered, with a crust of fine earthy particles or
other extraneous matter, by means of its slime, or an
exudation from the epidermis. Adult as well as young
specimens are sometimes thus coated, but more frequently
the latter. It is perhaps an involuntary measure of
natural defence, with which many animals are provided,
in order to escape or delude their enemies; and even
the sharp eyes of a bird might be deceived by the dis-
guise which these little creatures put on. The Rev.
Revett Sheppard, in his interesting account of the Land
and Freshwater Shells of Suffolk, observes with respect
to the present species, "These shells, particularly in
their young state, show great sagacity and ingenuity by
covering themselves with an epidermis adapted to the
different situations in which they are found; and when
so covered, it is almost impossible for any other than a
conchological eye to detect them. If its abode be upon
the trunk of a tree covered with Lichens, then is the
epidermis so constructed as to cause the shell to resemble
a little knot on the bark covered with such substances.
If on a smooth tree, from whose bark issue small sessile
buds, as is frequently the case, it will pass off very well
for one of them ; and on a dry bank, or the lower part
of the body of a tree splashed with mud, its appearance
will be that of a little misshapen pointed piece of dirt.^^

BULIMUS. 239

The first of these curious resemblances may be caused
by the adhesion of Lichen spores^ which would grow as
well upon a shell as upon the bark of a tree ; and the
other cases I have endeavoured to explain. B. ohsciwus
is sometimes found at considerable heights, probably
indicating its Arctic origin. M. Puton observed it on
the Vosges mountains^ at an elevation of 2624 feet above
the level of the sea. It occasionally occurs on granite
and gneiss, but more commonly on calcareous strata.

The difference, which is slight, between this species
and B. montcmus will appear from the description. The
simplest character is that the latter is at least four times
the size of the other in cubical contents. Lister seems
to have been acquainted with the present species ; but
his notice of it is not satisfactory. In its young state
it is in all probability the Helix trochulus of Miiller.

The Helix detrita of Montagu (judging from a speci-
men received from him by Mr. Dillwyn and now in my
collection) is exotic, and apparently a variety of the
Bulimus Guadaloupensis of Biiiguiere.

The B. tuberculatus of Turton (the typical specimen
of which I also have) is the Helix pupa of Linne. It is
a native of the extreme South of Europe, and is not at
all likely to have been found in Worcestershire, whence
Dr. Tui'ton is said to have received it. Capt. Blomer,
who gave this specimen to Turton, told me that he had
been in Sicily; and he admitted that he might have
made a mistake as to the locality.

The Helix Goodallii of Miller is a West-Indian species,
and appears to have been introduced into this country
with pine-plants. It is still very common on the tan in
the pineries at Garraway and Co^s. nursery-gardens
near Bristol, where the late Mr. Miller first observed
this little shell about forty years ago. It has not been

240 HELICID^.

noticed elsewhere in this country. It is the Bulimus
clavulus of Turton.

The B. decollatus was recorded by Dr. Turton as
having been once found living in a greenhouse at Wat-
ton in the South of Devon, where it was observed to
breed for many years in succession ; but^ in consequence
of some alterations being made in the greenhouse, the
colonv was destroyed and became extinct. It is common
in the South of Europe, as well as on the opposite shores
of the Mediterranean; but its most northern locality
appears to be Agen, in the Department of Lot-et-
Garonne.

Genus VI. PUTA *, Lamarck. PL VII. f. 3, 4, 5.

Body slender, but generally short, always containable within
the shell : tentacles 4, short, especially the lower ones : foot
narrow.

Shell cylindrical, not very thin or glossy : whorls compact,
the last not broader, or very little more so, than the penulti-
mate or preceding one : spire long : mouth horseshoe-shaped
or semilunar, mostly furnished with one or more teeth ; some-
times there are also spiral plates and incomplete septa in the
interior : umbilicus oblique, very small, and contracted by an
upward twist of the last whorl at its base.

The Pup(S are all of a small size and gregarious. They
live in moss or in the crevices of rocks and walls, as well
as on exposed hill- sides under stones or at the roots of
grass. They are vegetable feeders, and appear to live
on small plants, Cryptogamia, and decaying leaves.
Some species are ovo viviparous. The mouth is paraUel
to the columella or axis of the shell ; and this, combined
with the last whorl being of nearly the same breadth
as the preceding one, causes the shell to assume some-

* Like the chrysalis of an iiiseet.

PUPA. 24]

what of an ellipsoid form. The whorls are also more
compact than in Bulimus ; and the mouth is usually
furnished in the present genus with transverse plates or
teeth, instead of the outer lip being merely thickened
by tooth-like tubercles, or of there being a similar protu-
berance on the columella, as is sometimes the case in
the former genus. The main characters of both these
genera, how^ever, are nearly the same, as regards their
habits as well as the body and shell.

The curious processes, called '^ teeth,^' which fence
in and contract the mouth of the shell in Pupa, are of
different kinds. In P. secede they form plate-like ridges,
which extend some way into the interior. In P. um-
bilicata and P. ringens the adult have either a simple
tooth on the columella and a spiral plate on the pillar lip,
or else several plate-like ridges as in P. secale, although
shorter and more curved ; but, in P. umbilicata and
P. ringens, the young have a much more complicated
apparatus. This consists of two long spiral ridges like
the worm of a corkscrew, one on the pillar lip and the
other on the pillar itself, besides a short transverse
plate or septum on the outer lip, which is reproduced at
intervals. In P. margmata the mouth is often famished
with a denticle or small tubercular tooth on the pillar,
and sometimes also with a similar process inside the
outer lip ; but it never has the plate-like ridges which
are found in the other species. All these various pro-
cesses appear to be formed in the same way, \dz. by folds
of the mantle secreting the testaceous matter in excess
and applying it to particular parts of the shell.

Two species of Pupa (viz. tridens and doliolum) have
lately been found in the North of France ; and it is
therefore not unlikely that they may be found in this
country.

242 HELICID^.

A. Spire long and pointed : mouth horseshoe- shaped, narrow,
and furnished with several teeth and folds : outer lip
slightly expanded and reflected.

1. Pupa seca'le"^^ Draparnaud.

P. secale, Drap. Tabl. Moll. p. 59 ; F. & H. iv. p. 101, pi. cxxk. f. 5.

Body brownish-grey or slate-colour, with a reddish tint,
slightly and irregularly tuberclcd : mantle minutely speckled
^vith black : tentacles short and thick ; bulbs oblong : foot
usually fringed, broader behind than in front, and ending in
a triangular and somewhat pointed tail.

Shell conic-oblong, rather sohd, opaque, somewhat glossy,
light-brown or yellowish-horncolour, marked transversely
or in the line of growth with numerous obhquely curved
striae : periphery rounded, but compressed : epidermis rather
thin : whorls 8-9, slightly convex and gradually increasing in
size, the four or five first whorls smaller in proportion to the
others, the last somewhat dilated and tr^isted at its base up-
wards to form the mouth : spire, although long, rather abrupt
and blunt at the jjoint : suture moderately deep : mouth longer
than broad, somewhat angular, and contracted by the teeth or
inside folds, which are as follows — two or three on the i^illar
(the middle one when there are three being in front of the
others), two on the pillar lip, and four inside the outer lip ;
the front tooth on the pillar lip is often accompanied by
a smaller tubercle or denticle, and it is placed so near the
point of insertion of the outer lip as often to appear a con-
tinuation or inflection of that lip ; the tooth-like plates or
folds inside the outer lip extend a considerable way into the
interior and are visible outside, resembling white hues : outer
lip thickened and slightly reflected : umbilicus extremely small
and oblique, fonning a narrow chink. L. 0-3. B. 0"125.

Var. alba. Shell white or colourless.

Habitat : Rocks, woods, and hill-sides in many parts
of England, from Westmoreland to the South of Devon,
as well as (according to Dr. Gibl:)on) near Crickhoweil in
Breconshire, South Wales. Dr. Lukis informs me that
he has not found it in the Channel Isles, although his

* A grain of rye.

PUPA. 243

brother believed that he had once taken P. avenacea (or
avena) in Guernsey. It is a local species^ but plentiful
wherever it occurs. It is not confined to calcareous di-
stricts. Mr. Eyton found it in abundance on the triassic
sandstone near Shrewsbury^ where there was no lime-
stone (nor, of course, chalk or oolite) within some miles
of the place ; and I obsei'ved it in equal plenty on the
Molasse in Switzerland. I am also credibly informed
that it has been found at Sudbury, near Harrow, on the
lower tertiary strata. The variety was found by me at
Lulworth in Dorsetshire ; but it is rare. This species is
widely diffused throughout Central Europe, ranging
south to Corsica ; but it does not appear to inhabit th^
North or extreme South of Europe.

The young have their shells encrusted with earth or
the spores of lichens and mosses, in the same way as
Bulimus obscurus; and even adult specimens have occa-
sionally a similar covering. From this latter circum-
stance I am confirmed in the opinion I ventured to
suggest with respect to that species, that the coat is not
purposely made by the animal, but is involuntarily caused
by the accidental adhesion of extraneous matter to the
outer surface of the shell, by means of the slime or
a glutinous film which exudes from or invests the epi-
dermis. Full-grown specimens have not the same need
of disguise for their protection as those which are
young and unprovided with teeth. In the daytime the
shells are attached by a thin pellicle to the under side of
stones and crevices of rocks.

This is the Turbo juniperi of Montagu ; and the im-
mature state is probably the Helix ventricosa of Miiller.
There is a great similarity of form between the young
of Ptipa and Helix.

M

9.

244 HELICIDyE.

B, Spire short and blunt : mouth horseshoe-shaped, rather
oblique, furnished with one or more teeth or folds, and
in the young with transverse plates and spiral serewlikc
ridges : outer lip thickened and reflected.

2. P. rin'gens *, Jeffreys.

P. ringens, Jeffr. in Linn. Trans, xvi. p. 356. P. Anglica, F. & H. iv. p. 99.
pi. cxxix. f. 6.

Body yellowish-grey or slate- colour, with several dark
lines or streaks along the sides, leaving a clear space in the
middle, underneath milk-white : mantle thick, projecting a
little beyond the mouth of the shell: tentacles short, of a
lighter shade than the upper part of the body; larger pair
cylindrical and stumpy, rather close together, the bulbs scarcely
(distinguishable ; lower pair more like tubercles : foot rounded
in front and obtusely pointed behind.

Shell subcylindrical, inclined to oval, rather solid, nearly
opaque, glossy and slightly iridescent, light-brown or yeliow-
ish-horncolour, closely but shghtly striate transversely : peri-
phery rounded, but compressed : epidermis thin : whorls 6 or
65, convex, the last being equal to more than one-third of the
shell and having its base sharply twisted upwards to form the
mouth, the two or three top whorls much smaller in propor-
tion to the rest : spire short, abruptly and bluntly pointed :
suture well defined, but not deep : mouth triangular, rounded
below, much contracted by the teeth or folds, which are as
follows — two on the pillar (the outside one being larger than
the other and extending far into the interior of the mouth in
the form of a spiral screw), two on the pillar lip (the outer-
most being much the larger and more prominent), and one
fold, with from one to three smaller denticles, inside the outer
lip and rather deeply seated, the larger one being visible out-
side ; besides these, there is a short curved side process or
fold, which connects the lip at its outer base with the larger
and more prominent tooth on the pillar, so as to resemble one
of the lower fronds of a trefoil leaf; the mouth in unformed or
immature specimens is furnished not only with two main spiral
ridges (viz. one on the pillar and the other on the pillar lip),
but also with a transverse plate, like those in Planorhis lineatus,
which lies at a right angle to the position of the folds within

* Grinning.

PUPA. 245

the outer lip of adult specimens and is repeated at short
intervals ; these transverse plates or septa are distinctly visible
outside the base of young shells : outer lijp dJidi pillar lip light
reddish-brown, much thickened and slightly reflected: um-
bilicus small, narrow and oblique, but distinct. L. 0-133.
B. 0-65.

Var. pallida. Shell of a lighter colour, sometimes whitish.

Habitat : Among dead leaves and moss, and at the
roots of grass, in moist places throughout the northern
counties of England, the West of Scotland, and all
Ireland, as well as in Guernsey. It occurs in a sub-
fossil state at Copford. Its foreign range appears to
be limited, so far as is at present known, — it having
only been fomid once in the rejectamenta of a river near
Toulouse (Moquin-Tandon), Cintra and the neighbour-
hood of Oporto (Morelet and Pring), and Algeria (More-
let and Dupuy). This southern distribution would seem
to bear out the conjecture made by the authors of the
' British MoUusca ' that the present species '' is probably
a member of our Atlantic fauna and of Southern or
South-western origin ; '^ but at the same time its occur-
rence as an upper tertiary fossil, with Helix lamdlata
and many other decidedly Northern forms, is a fact that
must not be overlooked in considering the geographical
distribution of the MoUusca.

This is a shy little creature, although tolerably active
when inclined to make its appearance. It has a singular
habit of withdrawing slowly one of its eyes, which rolls
backwards Kke a little ball until it reaches the neck,
while the tentacle which supports it remains extended
to its full length. This I have observed being done
when there was no obstacle in the way. It also retracts
occasionally, and apparently without any reason^ one of
its horns and not the other. It does not appear to be
ovoviviparous, lilve the next species (P. umbilicata) : at

246 HELICID^.

least I have not succeeded in finding any perfect embryo
inside a full-grown specimen, although the shells thus
examined were collected at the same period of the year
and in the same spot with specimens of P. umbilicata
which contained young ones completely formed. In a
living specimen of P. ringens which I have just received
with others from Dr. Lukis, the top whorls have been
accidentally broken off and replaced by an imperfect
septum, showing that these whorls are not occupied by
the animal after it has attained its maturity. The shell
varies considerably in the length of the spire; and in
the young it resembles that of a small conical Helix,
The internal structure of the shell was first noticed and
described by Mr. Alder in his excellent Memoir on the
Land and Freshwater Shells of Northumberland.

This species was first discovered by Mr. Bean, the
venerable, but still active, conchologist of Scarborough.
It is the Vertigo Anglica of Ferussac ; but although that
specific name is prior to the one which I have ventured
to adopt, it was unaccompanied by any description ; and
the Supplement to Wood^s ^ Index Testaceologicus ^ only
contains a figure of the shell, although referring to the
same name. The Pupa ringens of Michaud^s Supple-
ment to Draparnaud^s ' Histou^e,^ which bears a subse-
quent date to that of my Monograph in the ' Linnean
Transactions,^ is a different species from this, and is allied
to P. secale.

3. P. umbilica'ta *, Draparnaud.

P. umbilicata, Drap. Tabl. Moll. p. 58, and Hist. Moll. p. 62, pi. iii. f 39
40 ; F. & H. iv. p. 95, pi. cxxix. f. 7.

Body decidedly truncate in front and blunt behind, greyish-
* Having an umbilicus or navel.

PUPA. 247

brown with a dusky shade above, and of a paler hue on the
sides and rear, as well as underneath ; head and neck marked
with black specks, which are arranged in confused rows:
mantle annular or circular, minutely speckled with black and
milk-white: tentacles slightly transparent; upper pair close
together and nearly cylindrical, with large pear-shaped bulbs,
forming one-fourth of these tentacles; lower pair widely
separate from each other, very thick and sHghtly conical : foot
not fringed, rather broad, rounded in front and behind.

Shell subcylindrical or inclined to oval, rather thin "and
semitransparent, glossy and shghtly iridescent, yellowish -
brown or horncolour, closely but slightly and irregularty
striate in the line of growth : periphery rounded, or sometimes
very slightly and obtusely keeled: epidermis thin: whorls
6-7, convex, the last equal to about tv,^o-fifths of the shell
and sharply twisted upwards towards the mouth, the two iirst-
formed whorls much smaller in proportion to the rest : spire
short, abruptly and bluntly pointed: suture rather oblique,
well defined, but not deep : mouth sub triangular, contracted or
channeled below in the adult, furnished with a small and
short tooth-like ridge on the pillar near the insertion of the
outer lip (where it bends to form a junction with the lip), as
well as with a short and oblique ridge-like tooth on the pillar
lip ; young shells have a spiral screw on the pillar and another
on the pillar lip, the position of wliich nearly corresponds with
that of the ridge and tooth in the adult, and they have also
transverse plates hke those in the last species : outer lip white,
with sometimes a slight tinge of reddish-brown, much thick-
ened and considerably reflected: pillar lip also white and
thickened, almost straight : inner lip spread on the piUar :
umhilicus very small and oblique, contracted by a ridge or
crest at the base of the shell, which arises from the abrupt
and upward twist of the lower part of the body whorl.
L. 0-15. B. 0-075.

Yar. 1. edentida. Columellar tooth wanting.

Yar. 2. alha. Shell white or colourless.

Habitat : On old walls and rocks, under stones,
among dead leaves and beneath the bark of trees every-
where, from Zetland to the Channel Isles. It inhabits
hiffh as well as low situations. The first variety is not
uncommon. The second has been found by Mr. Norman

248 HELICID^.

at Plymouth and in Somersetshire, and by myself at
Grassmere, Church Stretton, Cardiff, and Tenby. This
species belongs to our upper tertiaries. It ranges from
Finland to Algeria, as well as to the Archipelago. Von
Martens considers it as a southern form, because it retires
early into winter quarters; and he remarked that he
could not find it in September in a place near Bergen,
where he had in the previous summer noticed it in abun-
dance and living in company with P. marginata.

Mr. Alder first indicated that this species is ovovivi-
parous, and recorded the fact in the Supplement to his
Catalogue of Land and Freshwater Shells found in the
vicinity of Newcastle. Adolf Schmidt published the same
discovery in the ^Zeitschrift fiir Malakozoologie ^ for
February 1853; and I can confirm the fact from my
own observation. Moquin-Tandon has more than once
seen two or three young ones attached to the shell of
their mother near the umbilicus and carried about by
her — a kind of marsupial arrangement. P. umbilicata
reproduces in July and August ; but it does not appear
to be prolific, as no more than 5 eggs have been found
in the womb at the same time. The epiphragm is very
thin and iridescent. Young shells are Trochiform and
obtusely keeled, and have a central and rather deep
umbilicus. The spire varies greatly in length. A
dwarfed, toothless and thin variety is the P. Sempronii
of Charpentier.

This species dificrs from P. ringens in being more
cylindrical and less barrel-shaped, as well as in the form
of the mouth and number of the teeth.

The observant Lister first made known this little
land-shell, and the young is probably his Trochus syl-
vaticus. The present species is the Helix muscorum of
Montagu; and it may also be that of Linne, as his

PUPA. 249

description in the ^ Fauna Suecica ^ of the form of the
mouth C^^ ovato-acuminata^, mucrone obtuso^^) agrees
better with this species than with P. marginata, to which
so many conchologists have attached the specific name
of muscorum. According to the strict rules of scientific
nomenclature, the present species (if it is not the Helta;
muscorum of Linne) ought to bear the name of cylin-
dracea, which was given to it by Da Costa in 1778, long
before either of Draparnaud^s publications; but I fear
justice must in the present instance cede to convenience,
as the name of umbilicata is so universally used. Da
Costa^s name appears to have shared the same fate as
the early leaf, —

" Ut silvce foliis pronos mutantur in annos,
Prima cadunt ; ita verborum vetus interit setas,
Et juvenum ritu florent modo nata vigentque."

C. Shell short, cyhndrical : spire blunt : mouth semioval, some-
times furnished with one or two tubercular teeth : outer
lip strengthened by a thick exterior rib.

4. P. margina'ta"^, Draparnaud.

P. marginata, Drap. Tabl. Moll. p. 58, and Hist. Moll. p. 62, pi. iii. f. 36-38.
P. muscorum, F. & H. iv. p. 97, pi. cxxix. f. 8, 9.

Body narrow and somewhat rounded in front, more slender
behind, lustrous, dark-grey with a brownish tint, finely speckled
with black, and of a much lighter shade on the under part ;
shghtly but closely tuberclcd : laantle as in the last species,
but the milk-white specks are larger : tentacles thick, opaque,
dusky, rounded at their points ; upper pair similar to those in
P. umbilicata, with subglobiilar bulbs ; lower pair somewhat
diverging from each other, conical, smooth, rather opaque, and
nearly black : foot not fringed, narrow but somewhat rounded
in front, broader behind, and ending in a triangular tail.

Shell subcylindrical, rather solid for its size, nearly opaque,
not very glossy, pale yellowish-brown or horncolour, faintly

* Margined.

M O

250 HELICID.E.

and irregularly, but closely, striate in the line of growth :
-peripliery rounded : epidermis thin : whorls 6-7, convex, but a
little compressed, the last equal to about one-third of the shell,
the two first whorls much smaller in proportion to the rest :
f?j)ire short, abruptly and bluntly pointed : suture rather deep :
mouth forming an oblique segment of about two-thirds of a
circle, furnished sometimes with a small tubercular tooth on
the columella, which is placed nearly in the middle ; inside
slightly tinged with reddish-brown : outer lip sharp, strength-
ened by a thick, white, exterior rib, which is placed at a little
distance from the margin ; outer edge slightly reflected : inner
lip spread on the pillar : umbilicus small and shallow, contracted
by a slight ridge or crest at the base of the shell. L. 0-133.
B. 0-6.

Var. 1. higranata. Shell rather smaller and thicker, and
having a tubercular tooth or denticle considerably within the
outer Kp, as well as that on the columella. P. higranata,
Kossmassler, Iconogr. ix, x. p. 27, f. 645.

Yar. 2. albina, Menke. Shell white.

Habitat : Under stones, at the roots of grass, and
among dead leaves, everywhere from the Moray Firth
district to Guernsey, especially on the sea-coast. Var. 1.
Bath (Clark) ; Lulworth, Dorsetshire (J. G. J.) ; Ox-
fordshire (Whiteaves) ; Weston-super-Mare (Norman).
Var. 2. Somersetshire (Clark, Norman, and J. G. J.) ;
Oxfordshire (Whiteaves). I have also found a monstro-
sity in which the lower whorl is furrowed, and another
which has the periphery keeled, — the former having been
apparently caused by a grain of sand adhering to the
mantle while the shell was in course of formation, and
the latter bv an accidental fracture of the last whorl, which
obliged the animal to make a new mouth and to shorten
the base. As an upper tertiary fossil it is very common,
and often indicates the former presence of littoral con-
ditions, as this species not only peculiarly affects sandy
shores and maritime places, but is also Avashed down in
great numbers by estuarine rivers and thrown up on

PUPA. 251

the beacli by the reflux of the tide. I have often found
it under such circumstances mixed with recent sea-shells
on a flat sandy coast. The Rev. Revett Sheppard says
that i, occurs "in profusion in Essex^ near Wrabness
Point, on the upper part of the marsh — a situation which
at high tides is covered with water.-*^ The foreign range
of this species is very extensive. MiddendorfiP, as well
as Gerstfeldt, has recorded it as Siberian ; Von Martens
has noticed it as inhabiting Iceland and Lapland ; it is
common in Scandinavia ; and southwards it has found its
way to Central Europe, Spain, Corsica, and Sicily,

This is a hardy and fearless little animal, and crawls
rapidly for its size, compared with the movements of
P. ringens. According to Moquin-Tandon this species
is ovoviviparous, as well as P. wmbilicata, and the young
are sometimes attached to the shell of the mother and
carried about by her. The work of reproduction takes
place in the months of July and August. The number
of eggs varies from 3 to 7. In some specimens the spire
is much longer or shorter, and the shell is consequently
narrower or broader than usual. The epiphragm is like
that of the last species, but is seldom complete.

This differs from P. umbilicata in the shell being more
cylindrical and mostly of a smaller size, as well as in the
mouth being semioval instead of triangular, but more
especially in having a strong back rib instead of a re-
flected lip. The present species seems to connect Pupa
with Vertigo.

In consequence of the hopelessly inextricable confusion
which has so long existed as to the identity of Linnets
Helix muscomwi with this or the last species, or the
Pupa minutissima of Hartmann (and which confusion
seems to be increased by every new writer on the sub-
ject), there scarcely seems to be any alternative but to

252 HELICID.E.

adopt Draparnaud's specific and significant name of mar-
ginata. It is more than probable that Linne knew both
this species and P. umbilicata, but did not distinguish
one from the other. The present species appears, how-
ever, to be the Helix muscorum of Miiller, who pointed
out the difiference between his and Linne' s species of the
same name. This is the Turbo chrysalis of Turton.

Genus VII. VERTrOO^ MiiUer. PI. VII. f. 6, 7, 8.

Body rather short, always containable within the shell :
tentacles 2 only, scarcely at all inflated at their extremities :
foot short.

Shell subcylindrical or fusiform, thin, and glossy : whorls
compact, the last considerably exceeding the others in size :
S2:)ire short, sometimes reversed : mouth semioval or semicircular,
usually furnished with several teeth, in which case the outer
lip is contracted : umhilieus scarcely perceptible, or consisting
of an obhque and naiTow chink.

The members of this genus are miniature forms of
Pupa ; and their habits are the same, except that these
are more retired and avoid the sun's rays more than
some species of Pupa. But the difierence between them
does not consist in size alone. The animal of Vertigo,
instead of having, like that of Pupa, four tentacles, has
only two, and is quite destitute of the lower pair. I have
satisfied myself, by a careful examination of many living
specimens, that not the slightest rudiment or vestige exists
of a second pair of tentacles in several species of Vertigo,
although in V. pyg7n(sa smd V. 2Msilla lines or dark spots
are discernible in the places which would be occupied by
these tentacles if they were present. Miiller was the
first to discover the fact of these moUusks being biten-
taculate, and founded on it the present genus. Several

* A turning round.

VERTIGO. 253

Continental naturalists of repute have also made inde-
pendent observations and arrived at the same conclu-
sion. An exotic species (F. rupestris) is half as large
again as Pupa mai^gmata ; and yet, according to Moquin-
Tandon, not a trace can be detected in this species of
Vertigo of the lower tentacles which are possessed by all
the species of Pupa. The shell of Vertigo differs also in
a corresponding degree from that of Pupa. The spire is
shorter ; and when the mouth is furnished with teeth (as is
commonly the case) the outer lip is contracted. It would
therefore seem to be quite as reasonable that Vertigo
should be separated from Pupa, as Bulimus from Helios.
The line of demarcation in either case is confessedly
slight. The value of such generic distinctions will pro-
bably not be admitted by all naturalists ; and unfortu-
nately there is no Court of Science to which an appeal
can be made for an adjudication of the point.

The typical and original species ( V. pusilla) has the
spire reversed or sinistral, from which character the name
now borne by the genus was derived.

A. SheU dextral, barrel-shaped : wom^A furnished with teeth.

1. Vertigo antiverti'go*, Draparnaud.

Pupa antivertigo, Drap. Tabl. Moll. p. 57, and Hist. Moll. p. 60, pi. iii.
f. 32, 33 ; F. & H. iv. p. 109, pi. cxxx. f. 7.

Body thick, lustrous and dusky, greyish-black with a tinge
of slate-colour or brown, covered with exceedingly minute
black or dark tubercles : snout short, but somewhat produced :
tentacles rather close together, subcyhndric ; bulbs forming one-
third of them, oval and obtusely pointed: foot oblong and
narrow ; edges very light grey and finely speckled with black ;
tail rather blunt.

Shell oval, thin, semitransparent, very glossy and of an

* Not reversed.

254 HELICID^.

opaline lustre, dark yellowish-brown with a reddish tinge,
very faintly and closely striate in the line of growth, and micro-
scopically striate in a spiral direction : perij^liey-y rounded :
epidermis very thin : ivliorls 4^, tumid and more prominent in
the middle, the last being equal to about half the shell, and
the first whorl and a half very small in proportion to the
others : sjnre short, very abrupt and blunt at the point : suture
deep : mouth small, semioval, contracted in the middle of the
outer edge, and furnished with teeth as follows — three on
the f>illar (the inner one of which is only a small tubercle, or
denticle), one on the pillar lip, and three or four (besides one
or two denticles) inside the outer lijj and placed at some
distance from the opening ; the teeth are of a reddish-brown
colour ; the principal ones are strong and arched, and the
labial or palatal teeth extend a little way in the form of ridges
and are visible outside ; all of them are of an irregular shape
and unequal in size and length : outer lip sharj), whitish,
flexuous or constricted in the middle of the front margin,
slightly reflected, and strengthened by an exterior rib of nearly
the same colour as the rest of the shell, which is placed at
some little distance from the margin ; outer edge much inflected:
inner lip sj)read on the pillar and tolerably thick in adult spe-
cimens, so as almost to form a complete peristome : umbilicus
moderately open, but somewhat contracted by a blunt and
wrinkled crest at the base of the shell. L. 0-065. B. 0-04.

Habitat : Under stones and logs of wood^ as well as
at the roots of grass, and on moss, flags, and water-
plants, in marshy places and at the sides of streams and
canals, generally throughout these isles, from the Moray
Firth district to Guernsey. It is also one of our upper
tertiary fossils. Abroad it is distributed from Sweden,
through the whole of Central Europe, to Portugal on the
west and Lugano on the east ; and Aradas and Mag-
giore have recorded a small variety (the Fupa pmsilla of
Bivona) as Sicilian.

This little mollusk carries its shell nearly straight on
its back, and balances it fi'om right to left (as if it Avere
topheavy) when crawling. It inhabits elevated as well
as moist places. The late Dr. Johnston of Berwick in-

VERTIGO. 255

formed me that he found it with V. pygmcea and V.
substriata at Fastcastle on Sparkleton Mountain, in
East Lothian, at a height of 1200 feet. Such localities
appear to have an obvious relation to the preglacial
origin of many of our MoUusca. The epiphragm of the
present species is filmy and iridescent, like that of the
smaller Pupce. Half- grown specimens have only two
teeth, viz, one on the pillar and the other on the pillar
lip. The number of teeth in adult specimens varies
from six to ten. The shell does not differ much in size.
It is the Turbo sexdentatus of Montagu, the V. sep-
temdentata of Ferussac, Charpentier, and others, the V.
octodentata of Studer, and the V. palustris of Leach.
The Pupa ovata of Say (a North- American shell) is
closely allied to this species.

2. V. Moulinsia'na*, Dupuy.

Pujpa Moulinsiana, Dup. Cat. G-all. Test. no. 284, and Moll. Fr. p. 415,
pi. 20. f. 11.

Body rather slender, dark-grey above and of a paler colour
below : tentacles rather thick, short, clavate and obtuse at their
extremities : foot narrow.

Shell oval, very thin and nearly transparent, exceedingly
glossy, light yellowish-horncolour, very faintly striate in the
line of growth and microscopically striate in a spiral direction :
periphery rounded : epidermis very shght : whorls 4,^, extremely
tumid, the last being larger than the rest of the shell, and the
first whorl and a half very small in proportion : spire short,
remarkably abrupt and blunt at the point : suture very deep :
mouth semioval or forming an arch equal to nearly two-thirds
of a circle ; teeth four, as follows — one on the middle of the
pillar, one on the pillar-lip, and two inside the outer hp ;
these teeth are of the same size, and placed at about equal
distances from each other and a httle within the mouth : outer
lip rather thin, whitish and reflected, strengthened by a slight

* Named after M. des Moulins, the author of several excellent papers
on the French Mollusca.

256 HELICID^.

exterior rib, which is of the same colour as the rest of the
shell and situate near the opening of the mouth ; outer edge
considerably inflected : inner lip scarcely perceptible and con-
sisting of a mere film : umbilicus rather open. L. 0*08. B. O-OO,

Var. hidentata. Labial or palatal teeth wanting.

Habitat : Under stones by the side of a small lake
at Ballinahinch near Koundstone, Co. Galway, where I
made this acquisition to the British Mollusca in 1845.
V. antivertigo and a variety of V. pygrrKEa were also
found by me at the same place and time ; but I had not
examined my specimens until I commenced describing
the species of Vertigo for this work. The month and
lip in the variety are completely formed. On the Con-
tinent the present species occurs in the North, South,
and West of France, the Cantons of Vaud and Valais in
Switzerland, and near Heidelberg. It is a local and rare
shell.

The description of the animal is taken from my '^'^ Notes
on Swiss Mollusca," which appeared in the ^ Annals and
Magazine of Natural History ' for January 1855 ; and I
there stated that the body is more slender and of a Kghter
colour than that of V. antivertigo, and that the ten-
tacles are more decidedly clavate. There is no trace of
a second or lower pair of tentacles. I observed it in
Switzerland feeding on Confervce. The situations in
which I found it in Switzerland were like that of the
Irish habitat; and I have no doubt that it will be re-
discovered in this country by attention being thus drawn
to it. The fen districts of our Eastern counties, as well
as the wilds of Connemara, require to be more thoroughly
searched. I did not keep one of my Swiss specimens,
from a desire to confine my collection exclusively to our
own MoUusca; but I have fortunately had, through the
kindness of Mr. Daniel, an opportunity of comparing

VERTIGO. 257

the Connemara specimens with some from Germany.
The latter are the largest.

This species differs from V. antivertigo in being larger,
more ventricose, and of a much lighter colour, in the
mouth and outer lip not being contracted, and especially
in the number and position of the teeth, which never
exceed four, instead of being from six to ten as in that
species. From V.pygmcea it may be distinguished by
being twice the size and very much more ventricose, and
also of a lighter colour. The difference is equally great
between all the three species. V. Moulinsiana resembles
V. antivertigo in form and V. pygmcea in the number of
teeth. It is among the largest of our native species of
Vertigo.

It is the Pupa Anglica of Moquin-Tandon^s ^ Cata-
logue of the Mollusca of Toulouse,^ but not that of
Alder or of Potiez and Michaud ; and it is the P. Char-
pentieri of Mr. Shuttleworth in Kiister^s edition of
Martini and Chemnitz, and my P. Desmoulinsiana. The
P. arctica of Von Wallenberg (Mai. Bl. 1858, p. 99, pi. i.
f. 3, and a, b, 4) from Lapland is perhaps a variety of the
present species, differing in not having the second and
smaller tooth on the outer lip.

3. V. pygm^'a"^, Drapamaud.

Pupa pygmcea, Drap. Hist. Moll. p. 60, pi. iii. f, 30, 31 ; F. & H. iv.
p. 106, pi. cxxx. f. 4-6.

Body slender, expanded and rounded in front, very gradually-
narrowing and pointed behind, of a dark greyish-slatecolour,
closely but indistinctly tubercled : mantle of a reddish hue,
finely speckled with black : tentacles very close together at the
base, but considerably diverging, with oblong bulbs ; in the place
of the lower tentacles two black spots are perceptible with a
high magnifying power : foot truncate in front, speckled with

* Dwarf.

258 HELICID.E.

black like the mantle, as well as with milk-white dots on the
sole ; tail very narrow, slightly rounded at the extremity.

Shell oval or inclined to cylindrical, rather solid for its size,
semitransparent, glossy, reddish-brown or yello"wish-horncolour,
very faintly striate in the line of growth, and also marked with a
few obscure spiral strias : jperiphery rounded : epidermis slight :
whorls 4:\, convex, but not very tumid, the last being nearly
as large as the rest of the shell, and the first whorl and a half
very small in proportion : spire short, abrupt and bluntly
pointed : suture moderately deep : mouth semioval, rather
higher than broad ; teeth four or five, arranged as follows —
one sharp and prominent tooth on the middle of the pillar, one
strong and thick tooth on the pillar lip, and two or three plate-
like teeth (more frequently the latter number) inside the
outer lip ; these last or labial teeth are seated considerably
within the mouth and appear to spring from a kind of rib,
which is formed inside this part of the lip and corresponds in
position with an outer rib of greater breadth and thickness ;
the third labial tooth is the smallest : outer lip rather thin, very
little reflected, strengthened by the outer rib above noticed,
which is sometimes reddish-brown like the rest of the shell,
but occasionally of a lighter colour ; outer edge abruptly
inflected : inner lip thickened in adult specimens : umhilicus
small and narrow, but rather deep. L. 0-065. B. 0*04.

Var. pallida. Shell thinner and of a lighter colour.

Habitat : Under stones and logs of wood, and at the
roots of grass, on hills and almost everywhere in this
country, from the Moray Firth district to Guernsey.
The variety inhabits marshy places, and has been found
by Mr. Daniel at Wool in Dorsetshire, and by myself
in the North of Devon as well as in Connemara with
V. Moulinsiana. This variety has probably been mis-
taken by collectors for V. alpestris. The present species
is not uncommon in our upper tertiary strata. It is
widely distributed abroad from Siberia and Finland to
Algeria and Sicily ; and it even reaches the Azores.

This is a tolerably active and lively little creature,
crawling by jerks and carrying its shell nearly upright.

VERTIGO. 259

It makes_, like its congeners, a filmy epiphragm, but
which is not iridescent. It may be in some degree
considered a subalpine form, as it occurs at considerable
heights. Dr. Johnston found it at the top of a moun-
tain in East Lothian at an elevation of 1200 feet, and
M. Puton on the Vosges at a height of 1640 feet. The
teeth do not appear to be formed in any of the whorls
except the last. They project into the mouth at right
angles, so as to present a chevaux de frise against all
intruders.

This species may at once be known from V. antivertigo,
as well as from F. Moulinsianaj by its more cylindrical
or narrower shape, and from the former by its having
only a single tooth on the pillar, instead of two or three
as in that species. The outer lip is also not contracted
and angulated as in V. antivertigo. The other points
of difference between the present species and V. Mou-
linsiana have already been noticed in the account of
that species.

Montagu was evidently acquainted with the present
species, but confounded it with V. antivertigo (his Turbo
sex dent atus) , in describing which he says, ^^ younger
shells have only four teeth.^^ I may observe that the
fifth or smaller tooth, which is placed within the outer
lip and close to the pillar lip, is seldom wanting, although
not so conspicuous as the others, and that five is the
usual, and four the exceptional number of teeth.

4. V. alpes'tris ■^, Alder.

V. alpestris, Alder, Trans. Nat. Hist. Soc. Newc. ii. p. 340. Pupa jpyg-
mcea, var. alpestris, P. & H. iv. p. 107, pi. cxxx. f. 6.

Body Hght-strawcolour : tentacles and foot longer than in
V. pygmcea.

* Inhabiting liigh land.

260 HELICID.E.

Shell subcjlindrical, thin and semitransparent, very glossy,
pale yellowish-horncolour, closely and rather strongly striate
in the line of growth : periphertj rounded : ejndermis thin :
vjhorls 4|, convex, but slightly compressed : spire short, abrupt
and bluntly pointed : suture excessively deep : mouth semi-
oval and subangular, owing to the outward compression of the
jjeriphery ; teeth four, viz. one sharp and prominent tooth on
the middle of the pillar, one strong and also prominent and
thick tooth on the pillar lip, and two lamellas or plate-Hke
teeth which are placed at some little distance within the outer
lip, but not on any rib or callous fold as in V. pygmcpji ; the
labial teeth are visible on the outside, owing to the thinness
and transparency of the shell: outer lip rather thick, very
slightly reflected, not strengthened by any rib either outside
or inside ; outer edge abniptly inflected : inner lip somewhat
thickened in adult specimens : umbilicus small and narrow,
but rather deep. L. 0-07. B. 0-04.

Habitat : Under stones and among dead leaves near
Clithero in Lancashire (Gilbertson) ; Lipwood, near
Hay don Bridge, Northumberland (J. Thompson) ; near
Ambleside, on slate (Miss Sarah Bolton); Grassmere
(J. G. J.). It is one of our most local species ; and it
does not appear to be extensively distributed abroad.
Maack has recorded it as Russian ; Von Wallenberg
found it in Lulea-Lapland ; Charpentier and myself in
several parts of Switzerland ; and I have also taken it in
the Lower Harz. It is in Mr. Brown's list of Copford
shells ; but as a variety of V. pygmcea has been often
mistaken for this species, I cannot satisfactorily recognize
it as one of our upper tertiary fossils.

In mv notice of the Harz Mollusca in the ^Annals
and Magazine of Natural History ' for November 1860
(p. 349) I stated that ^' this is a true Vertigo^ and has
not the slightest vestige of the lower pair of tenta-
cles.'^ The epiphragm is iridescent. The ' Malakozoo-
logische Blatter^ for 1858 (Taf. 1. f. 5. a-d) contains an
admirable representation of the shell.

VERTIGO. 261

This species differs from V. pygmaa in being more
cylindrical_, of a paler colour and nearly transparent,
and especially in tiie numerous and sharp transverse
strise, as well as in not having any rib either outside or
inside the mouth.

It is questionable whether the V. alpestris of Ferussac
is the same as our shell, because he gave no description ;
and his original specimens appeared to me, from tw^o
careful examinations which I made in 1860 and 1861,
to be the marsh variety (pallida) of V. pygmcea, and
not Alder^s species. I have, however, no doubt of the
present species being the Pupa ShuUlewoythiana of
Charpentier (Zeitschr. f. Malak. 1847, p. 148), having
compared with that naturalist the specimens I collected
in Switzerland. The Pupa borealis of Morelet from
Kamtschatka appears also to belong to this species.

5. V. substria'ta *, Jeffreys.

Alaa auhstriata, Jeifr. in Linn. Trans, xvi. p. 515. Fupa szihsfriata.
F. & H. iv. p. 108, pi. cxxx. f. 3.

Body grey of different shades : snont short, bilobed : te7ita-
cles slender, cylindrical or club-shaped, and divergent ; bulbs
equal to about one-fourth of their length : foot of a hghter
colour, thick, short, narrow and keeled at the tail.

Shell oval or subfusiform, rather thin and semitransparent,
glossy, pale yellowish-horncolour, very strongly and obliquely
striate and almost ribbed in the line of growth, but less so on
the body whorl, which is faintly striate spirally : periphery
rounded : epidermis rather thick : whorls 4^, very convex or
cyhndrical, and suddenly increasing in bulk, the penultimate
Avhorl slightly exceeding in breadth the last, which occupies
about one -half of the shell : spire short, very abrupt and
bluntly pointed : suture remarkably deep : mouth semioval,
contracted or sinuous in the middle of the outer edge ; teeth
from four to six, viz. from one to three (usually two) on the

* Slightly striate.

262 RELICIDM.

pillar, one on the pillar lip, and two or three on the inside of
the outer lip, the last springing from a white rib ; in half-
grown specimens the pillar lip has a spiral or longitudinal
fold : oiiter Up thin and slightly reflected, strengthened by a
strong rib, which is placed very near the opening of the mouth ;
outer edge abruptly inflected : inner lip thickened in the adult :
umhilicus small and narrow, contracted by a keel or ridge at
the base of the sheU. L. 0-065. B. 0-04.

Habitat : Under stones^ among dead and decaying
leaves, and at the roots of grass in woods and moist
places, in many parts of Great Britain from Skye to
Devon, as well as throughout Ireland. Mr. Brown has
enumerated it in his list of upper tertiary shells from
Copford. Abroad it has been noticed by Nordenskiold and
Nylander as inhabiting Finland, by Malm as Swedish,
and by Held as Bavarian. It does not appear to have
been found in France.

This exquisite little snail is tolerably active, though
timid, and carries its shell nearly upright. The epi-
phragm is like that of its congeners. There is no rudi-
ment or trace of lower tentacles ; and my first descrip-
tion of the animal (in 1830) is incorrect in that respect.
I have since very carefully examined a great many living
specimens, and could not detect with a Coddington lens
even a speck in the place usually occupied by these ten-
tacles. Dr. Johnston found this species in East Lothian
at a height of 1200 feet.

The form of the shell, and the strong transverse striae,
as well as the number and arrangement of the teeth,
will at once serve to distinguish this from any of the
foregoing species.

It is the V. curt a of Held ; and it closely resembles,
and may be specifically identical with, the Pupa milium
of Gould, which is a native of the United States.

VERTIGO. 263

B. Shell sinistral, fusiform : mouth furnished with teeth and

contracted.

6. V. pusil'la*_, Miiller.

V. imsiUa, Milll. Yerm. Hist. pt. ii. p. 124. Pupa pusilla, F. & H. iv.
p. Ill, pi. cxxx. f. 8.

Body oblong, slightly contracted and rounded in front and
insensibly narrowing behind, brown or greyish-slatecolonr
above, and whitish with a faint tinge of blue on the sides and
underneath, minutely tubercled : mantle yellowish-brown :
tentacles very close together at their base, but widely diverging,
thick, nearly cylindrical, dusky-grey with a slight tinge of
brown ; bulbs long, but not very prominent : foot broad and
rounded in front, very tumid, keeled and a httle pointed
behind.

Shell subfusiform, with somewhat of a quadrangular out-
line, thin and semitrans23arent, very glossy, horncolour with a
faint tinge of yellow, very slightly and remotely striate in the
line of growth : periphery rounded, with a tendency to angu-
larity : epidermis thin : luhorh 4^ or 5, very convex and
cylindi'ical, gradually increasing in size ; the penultimate
whorl as broad as the last, which occupies about two -fifths of
the shell : spire shortish, but rather tapering, and blunt at the
point : suture very deep : mouth semioval, contracted or sinuous
in the middle of the outer edge ; teeth six or seven, viz. two
on the pillar, two on the pillar lip (the inner one of which is
always larger, and the outside one tubercular and placed
in the angle where the outer lip joins), and two or three within
the outer lip (the third, when it is present, placed near the
pillar lip and being a mere tubercle) : outer lip rather thick
and slightly reflected, strengthened by a strong rib both out-
side and inside, which is situate near the opening of the mouth
and is yellowish- white ; outer edge rather abruptly inflected :
inner lip slightly thickened in full-grown specimens : umbilicus
small and narrow, contracted by a rather sharp and gibbous
crest or ridge at the base of the shell. L. 0-07. B. 0-045.

Habitat : Under stones and among dead leaves and
moss in woods, in various parts of Great Britain from
Westmoreland to Devon, as well as in the North and

* Little.

264 HELICID^.

West of Ireland ; but it does not appear to have been
detected in Scotland. Although diffused, it is local and
rare. It occurs in our upper tertiary strata. On the
Continent it ranges from Finland to the North of Italy, —
viz. Lugano (Stabile); Como (Porro) ; Lombardy (Villa) ;
and Aradas and Maggiore are said to have found a
specimen on the sea-shore at Catania.

This is a very shy little snail and slow in its move-
ments. When it is about to crawl and emerges from
the shell, it puts its foot foremost. Its slime is rather
abundant. The shell is carried perpendicularly. The
epiphragm is membranous and plaited. Miiller says
that under the microscope a small black line can with
great difficulty be detected in the place which is occupied
in the animal of Pupa by each of the lower tentacles.

The reversed direction of the spire is an easy mark of
distinction between this and all the foregoing species of
Vertigo, The present species is not a sinistral form or
variety of any other kind, as I have satisfied myself by
comparing this in a mirror (which of course makes the
spire appear dextral) with V. antivertigo and V. sub-
striata, in which the teeth are somewhat similarlv
arranged. The shape of the present species, if it were
dextral, would be intermediate between that of the last-
named species and V. eclentula.

Leach is the only conchologist who has proposed to
change the original name ; and he has rechristened this
species V. heterostropha. It must be recollected that
Miiller was the founder of the genus, as well as the dis-
coverer of the present species, which was at that time
the only one known ; so that, if any alteration were
necessary on account of the contrary direction of the
spire, this species ought at all events to retain the name
first given to it by its discoverer. I had long previously

VERTIGO. 265

proposed the institution of another genus {Alcea) for the
reception of those species which have a dextrorsal spire ;
but I now consider this generic addition to be quite
useless and untenable.

7. V. angus'tior *, Jeffi-eys.

V, angusfior, Jeffr. in Linn. Trans, xvi. p. 361. Pupa Venetzii, F. k H. iv.
p. 1 12, j)l. cxxx. f. 9.

Body short and stumpy, blackish in front and greyish on
the sides and underneath ; tubercles indistinct : mantle yellow-
ish-grey : tentacles thick, somewhat cylindrical, dusky-grey,
considerably diverging from each other ; bulbs scarcely distinct:
foot thick and narrow, pale-grey.

Shell subfusiform or barrel- shaped, narrower in proportion
than V.pusilla, rather sohd, but semitransparont, glossy, light
horncolour, strongly, obhquely and rather closely striate in
the line of growth : perijphery compressed and somewhat an-
gular: epidermis thin: whorls 4|, rather convex, but com-
pressed, gradually increasing in size, the penultimate one a
trifle broader than the last, which occupies about two-fifths
of the shell, the first or upper whorl smooth and shining :
spire rather short, abrupt and blunt at the point : suture rather
deep: mouth subtriangidar, and very narrow in consequence of
the great contraction or sinuosity of the outer edge in the
middle as well as towards the base ; teeth four or five, viz.
two on the pillar (the outer one of which is a little in advance
of the other), one on the pillar lip, which is sunk deep mthin
the mouth and resembles a strong curved plate more than a
tooth, and one thick and prominent tooth inside the outer lip,
with rarely a small tubercle by the side of it : outer lip ex-
ceedingly thick and scarcely inflected, strengthened outside
and uiside by a strong rib, which is situate near the rim and is
yellowish-white ; the inside rib remarkably thick and increasing
the contraction of the mouth : inner lip consisting of a shght
deposit on the columella : umhilicus very small, narrow and
indistinct, being much contracted by a sharp and gibbous keel
or crest at the base of the shell. L. 0-06. B. 0-035.

Habitat : At the roots of grass in marshy ground,

*■ Narrower.

N

266 HELICID^.

but only hitherto noticed in a few localities. These
are as follows : — Singleton near Swansea, and the rejec-
tamenta of the Avon River at Bristol (J. G. J.) ; Tenby
(Webster) ; Battersea fields (Stephens) ; Co. Clare
(Humphreys); and Connemara, Co. Galway (Warren).
Mr. Brown has noticed it among the shells in the upper
tertiary deposit at Copford. Abroad it has been found
in the North_, East, and South of France, as well as in
Germany, Switzerland, and Lugano. Near Villeneuve,
in the upper Valley of the Rhone, I observed it to be
tolerably plentiful in a wet meadow or piece of land by the
side of the road leading from Vevay to St. Maurice, as
well as in similar situations near Lausanne and at Chable
in the Valley of Bagne. The first-mentioned piece of
land had lately been mown ; and consequently these tiny
shells were more easily detected. I have thus specially
noticed these foreign localities, to indicate the kind of
station in which this rare shell may be sought for in
this country.

The animal is rather slow in its movements and carries
the shell upright on its back.

The shell difi'ers from V. pusilla in its much smaller
size and being proportionally narrower, in the distinct
and strong transverse striae, and especially in the shape
of the mouth, which is triangular and very narrow,
instead of being subquadrate and open (which is the case
in V. jmsilla), as well as in the number, shape, and
position of the teeth. The single labial tooth in the
present species is situate opposite to the space between
the two teeth on the columella, and would lock into
them if the two sides were in contact, like the hinge teeth
of many bivalve shells. An excellent and enlarged
figure of the shell is given in ' Wiegmann^s Archiv ' for
1838, pi. iv. f. 6.

VERTIGO. 267

I hope I may be excused saying a few words here
about the correct name of this species, as regards myself.
It is an invidious and unpleasant task to vindicate one^s
own supposed discoveries ; but it is at the same time
useful to the cause of Science, and in some respects re-
sembles the duty of a parent in defending his children.
As our Continental neighbours and friends would say,
" il faut faire une reclamation.^^

In the ^ Linnean Transactions^ for 1830 I proposed
the present species and gave it the name of "angustioVy'^
accompanied by a full description, in Latin, of its specific
characters. I also noticed particularly the contour of
the shell, the shape of the aperture or mouth, and the
position of the teeth, in comparison with those characters
in V, pusilla. In the following year Michaud described
and figured the same species in his Supplement to Dra-
parnaud^s posthumous work, under the name of V. nana.
In the ^Isis^ for 1837, Held also described the shell
and gave it the name of V. hamata. In 1838 Professor
A. Miiller again described and figured it in ' Wiegmann^s
Archiv ' as V. plicata. And, in order that this mite of
a shell should have as many names as any Spanish
Hidalgo, Rossmassler in 1839 redescribed and figured
it in his ' Iconographie,'' and adopted Charpentier's MS.
name of V. Venetzii. This last name has been used by
the authors of the ' British MoUusca ' ; and Held^s
name of plicata has been adopted by Moquin-Tandon,
imder an erroneous impression (originating apparently
in a typographical error in Rossmassler^ s work) that
the number of the ' Isis ^ which contained the latter
name was published in 1828, and not in 1838. I have
ascertained, by an examination of Michaud^s and Char-
pentier's types, that their species are the same as mine.
I have also no doubt of the Turbo vertigo of Montagu,

N 2

268 HELICID^.

as first described by him, being specifically identical with
it, and his name is conseqnently prior to all those which
I haA^e enumerated ; but the reduplication of the same
name, both in a specific and generic sense, would be
objectionable. V. pusilla, as well as the present species,
were confounded by Montagu in the subsequent part of
his description. I fear that this little episode will
interest none but bibliographical naturalists.

C. Shell dextral, cylindrical : mouth seldom furnished with

teeth.

8. V. eden'tula*, Draparnaud.

Piqrn fdentula, Drap. Hist. Moll. p. 52, pi. iii. f. 28, 29 ; F. & H. ir. p. 103,
pi. cxxx. f. 1.

Body rather slender, ash-grej', of a darker hue above, and
much paler behind as well as on the sides and underneath ;
tubercles extremely small, reduced to blackish or greyish dots :
mantle veiy pale reddish-grey ; tentacles thick, nearly smooth,
blackish-grey ; bulbs forming about one-third of their length,
oval, and verj- blunt ; there is no sign of any lower tentacles
and not even a spot to indicate their place : foot oblong and
narrow, slightly pointed behind.

Shell oblong, nearly cylindrical, thin, semitransparent and
glossy, light yellowish-brown or horacoloiu*, marked with slight,
but numerous, obhque and somewhat curved striae in the line of
gi^owth : periphery rounded, although having a slight tendency
to angularity : epidermis thin: whorls ^h-^^, moderately con-
vex, gradually increasing in size, the penultimate whorl rather
broader than the last, which occupies about two-fifths of the
shell : spire long, abrupt and blunt at the point : suture deep :
mouth forming an arch or segment of two-thirds of a circle,
dcvstitute of teeth : outer lip thin, very slightly reflected, except
towards the umbilicus, over which it folds on the side next to
the mouth : pillar lip nearly straight in adidt specimens ;
umbilinLs -narrow and contracted by the pillar, but rather deep.
L. 0-1. B. 0-05.

* Toothless.

VERTIGO. . 269

Yar. columella. Shell somewhat longer, and having the last
whorl a little broader than the next. Pupa columella, (Y.
Martens) Benz, Ueber WtirtenbiLrg. Eaun. p. 49.

Habitat : Y^oods, among dead leaves^ at the roots of
grass and in herbage, as well as on the trunks of trees,
in most parts of the kingdom, from the Moray Firth
district to Guernsey. This species, however, is local.
The variety has been found by Mr. YV^aller at Finnoe, Co.
Tipper ary. It inhabits moist er places than the typical
form and is the Pupa inornata of Michaud. The present
species is one of our upper tertiary fossils. Its foreign
range extends from the Amoor territory and Lapland to
Lombardy.

This elegant little mollusk is timid, and retires within
its shell at the slightest touch. When crawling, it
usually carries the shell in a slanting position. Its slime
is watery. Mr. Sheppard noticed that his Essex specimens
were uniformly darker than those which he found in
Suffolk. It inhabits considerable heights. Puton found
it on the Vosges Mountains at an elevation of 1150
metres, or 3773 feet. Young shells resemble those of a
conical Helix, and have a sharply keeled periphery and a
small umbilical perforation. Mr. E. J. Lowe says that
Professor Babington once observed this species in great
abundance on the under surface of the fronds ofAspidia
in autumn. They may be found in winter, together with
Carychium minimum and other minute shells, concealed
in the decayed stalks of the larger umbelliferous plants.

iUthough this species is peculiar and by no means un-
common, it seems to have escaped the notice of Mon-
tagu and the older writers on British Conchology. It is
the V. nitida of Ferussac, Turbo Offtonensis of Sheppard,
and mv AJcsa revoluta.

270 • HELICID^.

9. V. MiNUTis'siMA'^j Hartmann.

Pupa minutissima, Hartm. in Neue Alp. i. p, 220, pi. ii. f . 5 ; F. & H. iv.
p. 104, pi. cxxx. f. 2.

Body slightly narrow and rounded in front, very gradually
attenuated and somewhat blunt behind, finely shagreened,
greyish-slatecolour, streaked or dotted with black : mantle
greyish-brown and of a lighter hue than the upper part of the
body : tentacles greatly diverging, separated by a narrow groove,
very tumid at their base, broadly edged with black ; bidbs
slightly globular : foot of a paler colour (sometimes milk-white)
at the sides and underneath, with a faint tinge of yeUow
towards the middle of the sole, ending in a triangular and
blunt tail.

Shell oblong, nearly cylindrical, rather solid, semitrans-
parent and glossy, yellowish-brown or horncolour of different
shades, marked with strong, close-set, obliquely transverse and
rib-like stritB : jperijjhery rounded, but slightly compressed,
with a tendency to angularity : epidermis thin : tuhorls 5|,
moderately convex, gradually increasing in size, the last but
two being somewhat the broadest of all, the body whorl occupy-
ing about two-fifths of the shell : spire long, very abrupt and
blunt at the point : suture deep : mouth shaped as in V. eden-
tula, and (in British specimens) equally destitute of teeth :
outer lip thin, white, and reflected : umbilicus small, narrow
and obhque. L. 0-07. B. 0-035.

Habitat : Under stones on hills in a few scattered
places in Great Britain^ and which are as follows : —
Skye (MacaskiU) ; Balmerino, Fifeshire (Chalmers) ;
Arthur^s Seat^ Edinburgh (E. Forbes) ; Sunderland,
South Hylton on the Wear, and Pontefract on mag-
nesian limestone (Howse) ; Went Vale, Yorkshire (Ash-
ford) ; Durdham Downs near Bristol, and Lulworth in
Dorsetshire (J. G. J.) ; Undercliff, Isle of Wight (More).
As an upper tertiary fossil it has been found at Clacton
and Copford in our eastern counties. It is widely dif-
fused on the Continent fi'om Finland to Lombardy and

* Exceedingly minute.

BALTA. 271

Corsica ; and (assuming the Pupa Callicratis of Scacchi
to be the same species) it ranges to Sicily. According
to E/Oth it has been found at Athens.

This exquisitely beautiful but tiny creature is slow in
its movements, and carries its shell nearly upright when
it crawls. Puton is said to have found it at a height of
1352 feet on granite in the Vosges Mountains. The
epiphragm is very thin and glistening. The length of
the spire varies considerably in this, as well as the last
species. Our native examples are toothless ; but foreign
specimens have frequently a tooth on the pillar and an-
other within the outer lip ; and I found a specimen in
Switzerland which had three teeth, arranged triangularly
as in the Pupa triplicata of Studer.

This species is the Pupa minuta of Studer, P. mus-
corum of Draparnaud, Vertigo cylindrica of Ferussac,
Pupa obtusa of Fleming (but not of Draparnaud), and
it is probably also the P. costulata of Nilsson.

Genus VIII. BA'LIA*, [Balea) Prideaux.
PI. VII. f. 9, 10, 11.

Body long and slender, always containable mthin the shell :
tentacles 4, proportionally short : foot rather broad.

Shell sinistral, turriculate, thin, deUeately striate and
streaked "svith white in the line of growth : spire reversed, long
and pointed : mouth squarish, sometimes furnished with a small
tubercular tooth on the columella : umbilicus narrow and
oblique.

This generic group has only a single species which is
indigenous to this country. A few others are exotic.
In the reversed turn of the spire and general aspect, as
well as in the shape of the mouth and the straight pillar

* Bay-coloured.

272 HELICIDiE.

lip^ it closely resembles a young or incomplete Clausilia,
and might lead to the supposition that its growth or deve -
lopment had been suddenly arrested. It wants^ however,
the clausilium or twisted internal plate which is charac-
teristic of the adult Clausilia, as well as the oblique
teeth or folds which contract the aperture of that shell.
In the small tubercular tooth which is occasionally
formed on the pillar, Balia has some affinity to the
genus Vei'tigo ; but the mouth of the shell in the present
genus is of a different shape, and the spire is more elon-
gated or draw^n out. The shell of Balia, when viewed
in a mirror (so as to make the spire appear dextral), is
not unlike that of a wide-mouthed Pupa. The soft parts
of the animal do not present any peculiarity, or appear
to be different from those of the other genera above men-
tioned. The members of this genus are inactive in their
habits, and are fond of shade and moisture, but not of
excessive wet. They are usually found in the crevices
of rocks and walls and under the bark of old trees ; and
they probably feed on the spores of mosses and other
Cryptogamous plants, as I have observed them after a
shower of rain apparently thus occupied, while slowly
crawling over the trunk of a sycamore. They may be
called the " Tree-snail."

The present genus was first made known by Dr. Gray
in the '^ Zoological Journal' (vol. i. p. 61) under the
name of Balea, from MS. information furnished by Mr.
Prideaux, an assiduous conchologist and friend of Dr.
Leach. In a posthumous work of the latter author,
entitled ^ A Synopsis of the MoUusca of Great Britain,'
which was edited by Dr. Gray and published in 1852, the
same genus appears as Balcea. The word is probably
taken from halius (pro baclius), and not, as M. Bour-
guignat supposed, from ^a\to<; [maculosus] , as the shell is

BALIA. 273

not spotted. Balea and Balcsa may therefore be typo-
grapliical errors. M. Ch. D'Orbigny, in the ' Dictionnaire
d^Histoire Naturelle/ thought the name might be an
obsolete Latin word [baled) signifying a bark or vessel ;
but this meaning is not applicable to either the shape or
habits of our little snail, which rather dreads than courts
the water. Swainson substituted Balia for the original
name ; and his emendation has been adopted by Stabile
as well as Bourguignat, the latter of whom has published,
in his ^ Amenites Malacologiques/ an elaborate and valu-
able article on the species comprised in this genus.

1. Balia perversa"^, Linne.

Turbo ^erversus, Linn. Syst. Nat. ed. xii. p. 1240. Balea fragilis, F, & H.
iv. p. 114, pi. cxxviii. f. 8, 9.

Body rounded in front, slender and tapering behind, dark-
brown with a shade of grey, covered with minute black tuber-
cles and specks : snout prominent and rather tumid : tentacles
short, rather thick ; upper pair close together, cyhndro-conical
and broad at the base, with bulbs about one-sixth of their
length ; lower pair very small in proportion, and conical : foot
somewhat rounded in front and gradually narrowing to a
tumid and slightly keeled tail.

Shell club-shaped, thin, semitransparent, glossy, yellowish-
brown, with transverse and obhque streaks of white, closely
but irregularly striate in the line of growth, and also marked
with a few remote and indistinct spiral lines : peripheyy
rounded, with a tendency to angularity : epidermis rather
thin : whorls 7-8, convex, but shghtly com23ressed, regularly
increasing in size, the last being equal to about one- third of
the shell and much broader than the others, the first or top
whorl quite smooth, semiglobular, and shining : S2nre tapering
to a somewhat blunt point : suture deep : mouth squarish-oval,
higher than broad, sometimes furnished with a tubercular
tooth, which is placed nearly on the middle of the columella :
outer lip rather thin, white and reflected, especially over the
umbilicus, sinuous outside and sharply inflected above : pillar

* Awry, or twisted the wrong way.

N 5

274 HELICID^.

Up nearly straight : umhilicus forming a narrow and oblique
slit. L. 0-275. B. 0-1.

Var. viridula. Shell greenish-white and transparent.

Habitat : On the trunks of trees (chiefly of beech,
ash, sycamore, and apple), as well as on mossy rocks
and walls, in various parts of Great Britain and Ireland
from the Moray Firth district to Guernsey. The variety
was found near Cork by Mr. Humphreys. Professor
Morris has noticed this species as fossil in the upper
tertiary deposit at Grays. It ranges from Finland to
Sicily, and even to Madeira and the Azores. It is widely
diffused in Europe.

The Tree-snails are gregarious, and are found of differ-
ent ages in the same spot, as if forming a sociable family
party. It is difficult to discover them in dry weather,
as they lie concealed in crevices of rocks or under the
bark of trees ; but after rain they come out from their
hiding-places and feed on the moistened vegetation.
They are not particularly sensitive, and do not withdraw
into their shells on being touched or disturbed ; nor
are they afraid of cold, having been observed crawling
about when the temperature was very little above zero.
Puton found specimens on the Vosges Mountains at a
height of nearly 2300 feet. Bouchard-Chantereaux says
that B. perversa lays, in the beginning of autumn, from
12 to 15 whitish and globular eggs, which are of a large
size compared with those of most other snails, and that
the young are excluded or hatched on the fifteenth or six-
teenth day afterwards and become adult at the end of
their first year. Lister stated that the sexes were distinct
in this species, and that there was a difference of size
between the male and female, the latter being more
bulky; but Dr. Gray very properly remarks that this

CLAUSILIA. 275

cannot be the case, because in these moUusks each indi-
vidual is both male and female.

The shell of this species differs from the young of
Clausilia rugosa (which it somewhat resembles in form)
in being thinner and of a much lighter colour, in the
whorls being much more convex, and especially in the
periphery or basal edge being rounded, instead of sharply
angular as in the young shell of that species.

It is the Pupa fragilis of Draparnaud ; and Moquin-
Tandon has retained it in that genus. The Balia Sarsii
of Philippi appears to be only a variety of the present
species, judging from his description in the ^ Zeitschrift
fiir Malakozoologie ^ for June 1847, p. 84.

Genus IX. CLAUSI'LIA^, Draparnaud.
PI. VII. f. 12, 13, 14.

Body long and slender, always containable within the shell :
tentacles 4 ; upper pair rather long and prominent ; lower pair
very short and resembling conical nipples : foot long and
narrow.

Shell sinistral, spindle-shaped, rather solid, usually ribbed
transversely, and always more strongly, or wrinkled, towards the
mouth : spire reversed, long and pointed : mouth small, j)ear-
shaped, and twisted on the body whorl, having a deep sinus or
groove at its upper angle, furnished with two spiral plates and
sometimes also with intermediate ridges or teeth on the colu-
mella, as well as with a flexuous plate or fold behind the pillar
lip and curved plates or folds within the outer lip ; besides
these various processes there is a pecuhar and complicated ap-
paratus lying deep within the throat or cavity of the mouth
and consisting of a moveable and elastic nacreous -white plate
or ossicle, which is twisted and somewhat resembles a flat-
tened ram's-horn, serving the purpose of an operculum : outer
Up continuous and forming a complete peristome : hasal crest
(which is formed by an upward and abrupt twist and contrac-
tion of the last whorl) more or less prominent : umhilicus verj

* Furnished with a clausilium or operculum-like process.

276 HELICIDiE.

slight, and consisting of a narrow and oblique slit behind the
pillar lip.

The Clausilice are herbivorous. Some species inhabit
rocks, stony places, and old walls, while others seem to
prefer woods and shady spots, and are to be met with on
trunks of trees and under stones among herbage. They
bury their bodies and three-fourths of their shells in the
earth, and excavate a small oblique tunnel, for the pur-
pose of depositing their eggs.

The malacological relations of this genus are with
Bulimus and Pupa. In the form of the shell it is allied
to both of those genera, setting aside the circumstance
of the spire in the present genus being reversed ; but
the spire in Bulimus and Pupa is shorter than in Clau-
silia. As in most of the species of Pupa, the laminar
teeth in Clausilia are never formed until the last whorl
has been commenced.

A peculiar and characteristic feature of the present
genus is that the animal is provided with an internal
process called the " clausilium." It is analogous to the
testaceous appendages of Teredo, called " pallets ;^^ al-
though they are not homologous organs, nor is the clau-
silium attached to the body of the snail, like the pallets
to that of the Ship-worm. This remarkable process acts
as a valve or spring-door in closing the shell against all
intruders, and has been well described by Mr. J. S.
Miller, in the ^Annals of Philosophy' for 1822 (vol. iii.
p. 378), in the following words : —

" Independently of the various contrivances which
Nature has resorted to for the protection of the otherwise
vulnerable MoUusca, it has taken peculiar care to guard
the apertures of many univalves from the intrusion of
enemies ; hence the apertures are sometimes peculiarly
contracted and provided with numerous folds and teeth.

CLAUSILIA. 277

Other MoUusca have a calcareous operculum perma-
nently formed, which increases in thickness, and enlarges
on a depressed spiral plane, as the opening of the shell
extends with the growth of the animal, thus continually
assimilating to its size, and when the animal retreats,
excluding it completely from all external intrusion. In
the Cto^i/ia, Nature has continued the protection afforded
by means of contractions and folds, and also added an
opercular appendage. The inhabitant of the Clausilia,
when nearly full-grown, secretes a thread-like elastic
calcareous filament, one of whose ends is affixed to the
columella. This filament makes half a spiral turn round
the columella, insinuating between its folds. When the
animal finishes its shell and completes the aperture, it
secretes, at the unattached end of the filament, a spoon-
shaped calcareous lamina conforming at its margin to
the contour of the aperture. The lamina is somewhat
smaller than this, and its margin is rounded. Its ad-
hesion to an elastic filament enables the animal to push
it, when it comes out of its shell, against the columella ;
and the same elasticity closes it on the inhabitant re-
treating, thus securing it from intruding enemies. Thus,
then, this valve may be compared to a door provided with
an elastic spring. The elasticity of the filament may be
restored to its full power (in the empty shell) by some-
times immersing it in water, as I have ascertained in a
section made with a view to this inquiry.'^

Miiller had, nearly half a century before, accm'ately
described this singular piece of mechanism and called it
an ossiculum. He quaintly remarks that when the snail
has opened the door of its house, " Veneri et Cereri
otiosus vivit." The ^Journal de Conchyliologie^ for 1853
contains an excellent article by M. Cailliaud on the sub-
ject, which is illustrated by admirably executed figures.

278 HELICID^.

showing the position and shape of the clausilium or
ossicle in several species.

The Clausilia would seem to be more at home in the
South of Europe and Asia Minor than in any other part
of the world^ judging from the statistics given by Char-
pentier in his Monograph on the genus, which was in-
serted in the ' Journal de Conchyliologie' for 1852. He
enumerated 235 species ; and this number has since been
added to by M. Schmidt, who has lately published an
exhaustive essay on the same subject. None of them
have been discovered in North America. Three species
are dextral and inhabit Transylvania. Some of our na-
tive Clausilice occur in the upper tertiary strata of Essex,
Suffolk, and Norfolk ; and their origin, as inhabitants of
Northern Europe, must therefore be very remote.

A. Shell ribbed or striate transversely : clausilium having its

margin entire.

1. Clausilta rugo'sa*, Draparnaud.

C. rugosa, Drap. Tabl. Moll. p. 63. C. nigricans, F. & H. iv. p. 121,
pi. cxxix. f. 1, 2.

Body dark-grey or slatecolour, with a tinge of reddish-
brown, paler at the sides and underneath, indistinctly tuber-
cled in such a way as to appear wrinkled: tentacles thick,
minutely speckled with black ; upper pair rather close together,
with bluntly rounded bulbs which are darker than the ten-
tacles ; lower pair decidedly conical, and darker than the upper
ones: foot of a rather clear greyish colour, narrowing gra-
dually towards the tail, which is tumid and pointed.

Shell shaped like a long club, but somewhat attenuated at
the broader end, not thin and scarcely semitransparent, rather
glossy, light-brown or horncolour, with a few transverse
streaks and lines of white, marked with numerous and close-
set but somewhat irregular stricc in the line of growth, which
are curved on the upper and flexuous on the lower wliorls, as

* Wrinkled.

CLAUSILIA. 279

well as with a few indistinct spiral striae, the intersection of
which gives the surface a slightly granular appearance : jaeri-
pliery angular or ridged : ej)idermis rather thin : ivliorls 12-13,
compressed, regularly increasing in size, the last being equal
in bulk to about one -third of the shell, but somewhat nar-
rower than the two or three preceding whorls ; the first whorl
nipple-shaped and quite smooth : s^ire tapering to an obtuse
point : suture rather oblique, slight but distinct : mouth almost
funnel-shaped, compressed on the outer side, and having an
effuse base, like the lip of a water-jug; teeth or folds as
follows : — two on the pillar, the upper one of which is promi-
nent and oblique and forms one of the sides of a channel at
the outer angle, and the lower one is smaller and more sunk
or deeply seated, being also oblique and sometimes bifurcate,
and between these are occasionally from one to three smaller
folds or ribs ; one strong but deep-seated and not very distinct
crescent-shaped fold (or lunella) on the pillar lip ; one still more
sunken and very sHght spiral fold near the last ; and occasion-
ally one or two teeth (like those in Pupa) within the outer lip :
the outer lip is thick, white, and reflected : basal crest sharp and
angular, transversely ridged: umbilicus much contracted by
the intortion of the mouth : clausilium oval- oblong, regularly
curved, shghtly dilated above. L. 0-5. B. 0-1.

Var. 1. albida, SheU greenish-white, with a few white
transverse lines.

Var. 2. Eueretti, Miller. SheU smaller.

Var. 3. gracilior. Shell longer and more slender.

Var. 4. tumidula. SheU smaUer, shorter, and more ven-
tricose.

Var. 5. duhia. SheU larger and more ventricose. G. dubia,
Drap. Hist. MoU. p. 70, pi. iv. f. 10.

Var. 6. dextrorsa. SheU resembUng a Pujm in shape : sjoirc
dextral.

Habitat : On old walls and rocks, as well as under
stones and on the trunks of trees, throughout these isles,
from Zetland to Guernsey. Yar. 1. Dinton Hall, Bucks
(GoodaU). Var. 2. Bristol (MiUer) ; Whalsey Skerries,
Zetland; Giant's Causeway and Co. Tyrone (J. G. J.).
Var. 3. Battersea marshes (J. G. J.). This last variety
appears to be the Crugulosa of Ziegler. Var. 4. Brockley

280 HELICID.E.

Combe near Bristol^ and Connemara (J. G. J.). Var. 5.
Northumberland and Durham (Alder) ; Oxfordshire
(Whiteaves). Var. 6. Sevenoaks, Kent (Smith). This
species occurs in our upper tertiaries. Its Continental
range extends from Finland to Portugal and Lombardy.

The shells of different individuals of this species vary
considerably in the length of the spire and their com-
parative solidity, as well as in the degree of sculpture.
Sometimes a great part of the surface is quite smooth,
as if filed and polished ; and this is the case with living
specimens. How this effect is produced it is not easy
to say. Perhaps they lived in a sandy soil, and the
continual friction of the shells, when trailed along by
the animal, might account for the abrasion. Such spe-
cimens were in the collection of Dr. Turton and were
considered by him (as well as at one time by myself) to
be the C. parvula of Studer ; but the smooth and sleek
appearance of the last-mentioned shell is very diflPerent
from that of the above specimens. Some curious mon-
strosities occur, in some of which the spire is distorted,
or a faint keel or impressed lines encircle the whorls,
or the mouth is renewed in such a way as to show the
columellar folds in their incipient state. Lister was the
first to notice this shell ; and his communication to the
Royal Society ^^On the odd turn of some Shell-snails^^
is one of the earliest on their records.

It is (partly) the Helix perversa of Miiller, Turbo
bidens of Montagu (but not of Linne), T. nigricans of
Maton and Rackett, and Clausilia obtusa of C. Pfeiffer.
Many other names have been given by Continental au-
thors to difi'erent forms of this extremely variable species.

C parvula differs from the present species in being
smaller and quite smooth, with the exception of some
very faint transverse lines, which are only observable

CLAUSILIA. 281

with a lens^ or of a few striae near the mouth. It in-
habits the North of France^ as well as every other part
of the Continent^ and may be expected also to be found
in Great Britain.

2. C. Rolph'ii*, Gray.

C. Bolphii, Gray in Turt. Man. L. & F.W. Sh. p. 71, f. 51. C. plicafula,
F. & H. iv. p. 120, pi. cxxk. f. 3.

Body dark-hrowu or dusky, with a reddish hue above, grey-
ish-brown on the sides and underneath ; tubercles blackish,
arranged in very close Hues : mantle thick, yellowish-white,
with small specks of pure white : tentacles greyish-brown ;
upper pair rather short and stout, nearly cyhndrical as far as
the bulbs, slightly shagreened and covered with black dots,
which are so minute as scarcely to be visible with a lens of
ordinary power, the bulbs thick and nearly spherical ; lower
pair exceedingly short and of a paler hue than the others :
foot very long, narrower in front, ending in a slightly rounded
tail ; sole greyish-w^hite.

Shell fusiform, rather thinner than the last species but
scarcely semitransparent, shghtly glossy, reddish- or yellow-
ish-brown, with occasionally a few white lines dispersed here
and there over the surface, marked with strong, sharp and
somewhat regular transverse striae, of which there are from
sixty to seventy on the body of the last whorl; these striae
are curved on the upper and somewhat flexuous on the lower
part of the sheU, becoming fewer and consequently more re-
mote but stronger towards the outer Hp; spiral striae very
indistinct and scarcely perceptible : per'qjJiery angular : epi-
dermis rather thick : whorls 9-10, tumid, but somewhat com-
pressed, the last being rather less than one-third of the shell
and a little narrower than the two preceding whorls ; the two
or three first whorls are nearly of the same breadth and form
a short cylinder: spire abruptly tapering and obtuse at the
point : suture rather obhque, not very deep : mouth subqua-
drangular, sinuous on the outer side and effuse below ; teeth as
in C. rugosa, but in the present species there are often two or
three small teeth or ridges between the columellar folds, and
the lower of these folds is less prominent but often cruciate :

* Named after Mr. Rolph, an English conchologist.

282 HELICID^.

outer lip thick and rather broad, white or cream-coloured and
inflected : hasal crest short and curved : umbilicus indistinct :
clausilium oblong, regularly cui'ved, slightly contracted above.
L. 0-5. B. 0-15.

Habitat : Under stones, in the bark of trees, and
among dead leaves, in Kent, Sussex, and Hants, as well
as in Gloucestershire, but hitherto found only in a few
places. This species is one of our upper tertiary fossils.
It is not uncommon in the North and South of France,
Belgium, and parts of Germany. Probably it is also a
member of the Scandinavian fauna, assuming Nilsson^s
variety (B of C.plicatula to belong to the present species.
His diagnosis, although too short and indefinite for
satisfactory identification, appears to agree with the
main characters of our shell.

This species difters from C. plicatula (for which it
has been mistaken) in being more than twice the size,
much more ventricose and of a paler colour, in the spire
being more abrupt, and especially in the striae being
closer and more numerous in proportion to the size of
the sheU. From C. rugosa and its variety duhia this
differs in being also more ventricose and of a lighter
colour, as well as in having much coarser striae and in
being destitute of the distinct spiral striae, which impart
to the last- mentioned shell a decussated or slightly gra-
nular appearance. The mouth of the shell in C Rolphii
is, besides, larger and broader. The shell in this as well
as the other species varies considerably in respect of the
length of its spire and the development of its teeth and
basal crest. C. Mortilleti of Dumont is, according to
Schmidt, only a synonym of the present species ; although
Mr. Benson at one time considered that they were
distinct, and pointed out the difference between them in
the 'Annals of Natural History^ for July 1856.

CLAUSILIA. 283

3. C. biplica'ta"^j Montagu.

Turbo bijplicahis, Mont. Test. Brit. p. 361, tab. ii. f. 5. C. hi/jpUcata, F. & H.
iv. p. 118, pi. cxxix. f. 4.

Body reddish-grey, dusky or almost black above and paler
on the sides and underneath ; tubercles rather large, but irre-
gular : mantle minutely speckled with white : tentacles dirty
reddish-grey ; upj)er pair subcylindrical and finely shagreened,
with slightly tumid bulbs ; lower pair conical : foot long and
rather narrow ; tail depressed and bluntly rounded.

Shell subfusiform and slender, rather thin, but scarcely
semitransparent, having somewhat of a silky lustre, reddish-
or yellowish-brown, irregularly streaked with white lines,
which colour some of the striae and are often more conspi-
cuous near the suture, imparting a greyish hue to the shell,
strongly and closely striate in the line of growth, as in G.
Rolpliii ; but the striae in the present species are straighter,
although slightly flexuous on the last whorl : periphery obtusely
angular : epidermis rather thick : whorls 12-13, compressed,
the last being very little more than one-fourth of the shell and
slightly narrower than the preceding whorl ; the first whorl
and a haK are quite smooth and glossy, and the second whorl
is broader than the first : spire slender and gradually tapering,
obtuse at the point : suture rather oblique, not very deep :
mouth oval, angular, contracted below, where a narrow but
deep channel is formed ; outer margin compressed and nearly
straight ; teeth as in aU the foregoing species, but the inter-
lamellar denticles on the pillar seldom occur or are very slight :
outer lip white, expanded, prominent and detached, not so
thick as in the last species : hasal crest strong, nearly straight :
umhilicus broader than usual in this genus : clausilium nearly
oval, sHghtly curved, attenuated below. L. 0-65. B. 0*166.

Habitat : At the roots and in the bark of old willow-
trees ; Easton Grey, Wilts (Montagu) ; Clarendon, near
Salisbury (Bridgman) ; and banks of the Thames near
London, where this species is not uncommon. These
appear to be the only localities hitherto recorded or
known in this country. It has been found in a semi-
fossil state at Clacton and Grays in Essex. Its foreign

* Having two folds.

284 HELICIDE.

distribution is not very extensive; bat it occurs in many
parts of France, Germany, and Switzerland. If (as I
suspect) this is the same species as that which Malm
has referred to the C. lineolata of Held, it ranges north-
ward to Sweden.

This is an inactive mollusk, and seems to drag its shell
along with difficulty, as if it were an incumbrance. In
its natural state the shell has often a slight covering of
mud or dirt.

It differs from C. Rolphii in its shell being twice as
large and much more slender, in the constant presence
of white lines or streaks, and in seldom having any
interlamellar teeth, but chiefly in the form of the aper-
ture and the distinct channel at its base. In the latter
respect it also differs from the C. ventricosa of Dra-
parnaud.

It is the C. similis of Charpentier. Another of its
synonyms is the C. vivipara of Held ; but I am not
aware that the organization of the animal warrants this
last specific name.

B. Shell nearly smooth, glossy : clausillum having its margin

on the lower side notched.

4. C. lamina' TA*, Montag*u.

Ttirho laminatus, Mont. Test. Brit. p. 359, tab. ii. f. 4. C. Uminata,
F. & H. iv. p. 116, pi. cxxviii. f. 10.

Body slightly narrowed and nearly truncate in front, gradu-
ally attenuated and rather pointed behind, reddish-black or
greyish-brown, with a yellow tinge on the upper part, light-
grey on the sides and underneath ; tubercles somewhat large
and prominent, more or less .deeply coloured : mantle not
reaching the mouth of the sheU, annular and narrow, covered
with minute and indistinct black dots : tentacles rather short,
thick and diverging, reddish-brown ; upper pair very finely

* Having plates.

CLAUSILIA. 285

granular, with rather tumid bulbs ; lower pair more conical
and deeply coloured than the upper ones, and nearly smooth :
foot broad and rounded in front, transversely grooved at its
sides, and ending in a slender but blunt tail.

Shell of the same shape as C. hiplicata, but semitranspa-
rent and glossy, yellowish-brown with a faint tinge of red,
smooth to the naked eye, but under a magnifier delicately
striate in the line of growth, these strioe being more percep-
tible near the suture ; there are also a few coarse wrinkles
near the mouth and umbilicus, besides irregular pit-marks
dispersed over the surface : periphery much more rounded than
in any of the foregoing species : epidermis thin : whorls 12,
compressed, the last scarcely exceeding one-fourth of the
shell and a little narrower than the preceding whorl ; the first
two or three whorls are nearly of the same size and form a
short cyHnder : spire slender and gradually tapering, obtuse at
the point : suture rather oblique and slight : mouth oval or in-
clined to quadrangular, broad, rounded and eifuse at the base,
and not acutely angled above ; columellar teeth more strong
and prominent than in any of the other species which have
been above described ; there are three or four labial or palatal
folds, which are conspicuous outside, owing to the shell being
nearly transparent ; but there are no intermediate denticles
between the columeUar folds, nor any lunella : outer lip white,
expanded and thick : basal crest slight : umhilicus very small :
dausilium squarish- oblong, flexuous, with a deep notch on its
side near the base. L. 0-7. B. 0-15.

Var. 1. pellucid a. Shell thinner, more transparent, and very
glossy

Var. 2. alhida. Shell greenish-white.

Habitat : On the trunks and at the roots of trees
(especially the beech and ash), as well as among dead
leaves, and occasionally on mossy rocks, in woods
throughout a considerable part of these islands, from
Northumberland to Devon, and also in South Wales and
Ireland, but not everywhere. Var. 1. Penrice, Glamor-
ganshire (J. G. J.). It is rather difficult to account for
the thinness of these shells, as they were found in a
limestone district, and calcareous material was therefore

286 HELICID.E.

not wanting. Var. 2. Box Wood, near Bath (Clark) ;
Darn wood, Kent (Stephens) ; Clevedon, Somersetshire,
and Watlington, Oxfordshire (Norman) ; Surrey
(Choules) j Newmarket (Wright). This last variety has
also been noticed bv Malm as occurrincr in Sweden. C.
laminata has been found in the upper tertiary strata at
Copford. Its extra-British range extends from Einland
to Italy, and (according to Roth) it inhabits Smyrna.

This pretty land-shell is by no means common, al-
though it seems to be gregarious in some places. Bou-
chard-Chantereaux says that its eggs are enormous in
comparison with the size of the animal, being wider than
the mouth of the shell, and that their number seldom
exceeds from 10 to 12. They are laid in August and
September ; and the young are excluded on the twen-
tieth day, but do not become adult until the end of their
second yearns growth. According to DesMoulins, these
snails regularly leave their lurking-places at nightfall
and climb the trees in search of food, descending at sun-
rise. In wet weather, however, they may be found
crawling freely on the trunks of trees in the daytime.

This is the Helix bidens of Miiller (but not of Linne)
and the Clausilia bidens of Draparnaud, Nilsson, and
other writers, as well as the C. derugata of Ferussac.

C. labiata was introduced by Da Costa and Montagu
into the British fauna on the authority of Mr. Swain-
son ; but both of the localities mentioned by the latter
(viz. "an osier-ground in Battersea fields ^^ and "Hyde
Park near the banks of the Serpentine'^) are more ap-
plicable to C. biplicata than to the species in question,
which inhabits dry situations. It is a native of the
extreme South of Europe.

The C. solida of Draparnaud, which has been referred
by Ferussac and aU subsequent writers to C. labiata^ is

COCHLICOPA. 287

very different, and is more like C. papillaris or the Helix
bidens of Linne. C. solida has been found by Bonchard-
Chantereaux near Boulogne, and may therefore be dis-
covered in this country. Possibly this may have been
Pulteney's species, which was said to be found in Dorset-
shire and has been referred to C. papillaris. The last-
named species has been recorded by Nilsson as Swedish.
It is very common in the South of France and in Italy.

Genus X. COCHLrCOPA*, Ferussac.
PL VII. f. 15, 16, 17.

Body rather long, gelatinous and lustrous, always contain-
able within the sheU : tentacles 4 ; upper pair long and nearly
cylindrical ; lower pair short and conical : foot rather long and
narrow.

Shell oblong, rather sohd, smooth, glossy and transparent :
epider7nis resembling a coat of thin varnish : whorls rapidly
increasing in size, the last being much larger in proportion to
the others : sjjire long : mouth small, obliquely pear-shaped,
sometimes furnished with teeth and folds as in Clansilia, and
having the base more or less distinctly notched (especially in
the young) : outer lip thickened by an internal rib, but not re-
flected, sometimes channeled at its upper angle : umbilicus
wanting in the adult.

The position of the few European species which are
comprised in this genus has for a long time been de-
bateable ground. In 1817 Schumacher instituted the
genus Glandina for some species of Lamarck^s much
older genus Achatina, as weU as for other species which
will be presently referred to, the type of Schumacher^s
genus being the Bulimus glans of Bruguiere. Montfort's
genus Polyphemus, which had been previously founded
on the same type or species, was considered inadmissible,
because that name had been appropriated to a genus of

* Having a notch in the shell.

288 HELICID.E.

Crustacea. In 1819 the eldei: Baron Ferussac, in his
great work (or rather Prodromus to a work) on the Land
and Freshwater Mollusca, which was continued^ edited,
and published after his death by his son^ adopted the
genus Polyphemus of Montfort, in the synoptical table
which preceded this part of his work, for the species
comprised in the present genus, but added other species
which have no relation to those now under consideration.
Ferussac, however, in a subsequent part of the same
work, modified this view, and proposed to include this
miscellaneous assortment of species in a tenth subgenus
of Helix, which he called Cochlicopa. Tliis subgenus
he divided into two groups, one to contain the species
of Polyphemus, and the other [Stylo'ides) to contain
certain species of Achatina, as well as the Helix lubrica
of Miiller. In 1826 Risso republished Cochlicopa as a
separate genus, and restricted it to the above-named
species of Miiller; but the generic characters given by
him are very insufficient and in many respects incorrect.
In 1830 I proposed the genus Cionella, not being at that
time aware of Risso's publication ; and in my " Synopsis
of the Pulmonobranchous Mollusca of Great Britain,''
which appeared in the ' Transactions of the Linnean
Society' (vol. xvi. p. 347), I gave the following descrip-
tion of this genus : —

" Animal glutinosum. Tentacida inferiora brevissima.

*' Testa oblonga, seu elongata ; anfractu ultimo majore.
Apex acutinsculus. Columella subinterrupta. Apertura cana-
liculata, ad basin subefFusa, marginibus ina^quahssimis. U771-
hilicus nullus."

I also remarked that in this genus the columella forms
a sinus or channel in the aperture, though it does not
appear to be accompanied by any corresponding pecu-
liarity in the animal. The species which I referred to it

COCHLICOPA. 289

were tlie Helix lubrica of Miiller^ the Buccinum acicula
of the same author, the Bulimus octonus of Bruguiere,
and (subsequently) the Turbo tridens of Pulteney. I
see no reason for altering the opinion which I then
formed, so far as regards the first and last of these species :
but as the name of Cochlicopa is prior to mine, I have no
hesitation in substituting it for Cionella ; and I propose
to restore the Buccinum acicula of Miiller to the genus
Achatina. The Bulimus octonus of Bruguiere belongs
also to the last-mentioned genus. The Helix lubrica of
Miiller and Turbo tridens of Pulteney agree in all essen-
tial particulars, except in the latter being furnished with
teeth ; but it has been shown that in the genus Vertigo
some species are toothed and others toothless, and that
even an undoubted species of Helix (H obvoluta) is pro-
vided with similar processes. Bulimus tridens, quadri-
dens, and other allied species may also be cited in illus-
tration of this view, although they do not occur in this
country. Cochlicopa tridens forms a passage from Clau-
silia to Achatina ; and it is connected with C. lubrica
through the Achatina dentiens of Rossmassler. Leach
proposed the genus Azeca for C. tridens, and the genus
Zua for C. lubrica ; but these generic names are of
recent manufacture.

The tongue or lingual plate of Cochlicopa resembles
that of Bulimus ; and the members of the present genus
would therefore seem to be also herbivorous. They in-
habit wet and shady situations.

The British species of this genus form two artificial
sections, which I propose to define, as in other genera,
from characters furnished by the shell. These corre-
spond with the genera Azeca and Zua of Leach.

o

290 HELICID^.

A. Mouth furnished with teeth and folds : onter lip sinuous
or notched : inner lip thickened.

1. CocHLicoPA tri'dens*, Pultenej.

Turbo tridens, Pvilt. Cat. Dors. Sh. p. 46, pi. xix. f. 12. Azeca tridens,
F. & H. iy. p. 128, pi. cxxv. f. 9.

Body greyish-slatecolour with a faint tinge of yellow, closely
covered with small black specks, which impart a dusky or
sooty hue, strongly wrinkled : mantle rather thick, milk-white
or greyish : tentacles somewhat transparent ; upper pair verj-
slender, with bulbs occupying about one-fifth ; lower pair
rounded at their extremities : foot long, rounded in front and
slightly projecting beyond the mouth of the shell ; sides edged
with white, and minutely speckled with milk-white ; tail very
pointed.

Shell subcylindrical or shaped like a chrysalis, nearly trans-
parent, very shining and of almost an opaline lustre, light
yellowish-brown with a tinge of red, faintly and indistinctly
wrinkled in the line of growth and marked with extremely
minute spiral lines, which are only perceptible by the aid of a
powerful lens : periphery rounded in the adult, but sharply
and strongly keeled in young specimens : epidermis very thin :
ivhorls 7, rather tumid, the last and preceding whorl being
nearly of equal breadth, and much larger in proportion than
the others, which form a blunt cone : spire produced, rounded
at the point : suture slight, with a transversely wrinkled border :
mouth narrow, angularly curved or channeled at the base and
subtruncate in the young, and also channeled at the upper
angle ; it is still further contracted by the teeth or plate-like
folds, which are as foUows : — one principal fold on the pillar,
which is twisted round the inner lip, its crest sometimes notched,
and extends like a screw far into the interior, and there is
usually also a second smaU tooth or denticle close to the prin-
cipal fold and nearer the outer lip ; a strong fold winding
round the pillar lip, the end of which appears like a sharp and
prominent tooth ; and a sharp tooth -like tubercle on the
middle of the outer lip and placed on the inside edge of this
lip ; besides this last, there are occasionally two small and
scarcely" perceptible denticles placed below it : outer Up) sinuous
and (as well as the inner lip) encircled by a narrow rib, which

* Having tliree teeth.

COCHLICOPA. 291

is often reddish-brown or flesh-colour, — a nearly complete
peristome being thus formed, the interruption being caused by
the narrow channel at the upper angle of the mouth. L. 0*25.
B. 0-1.

Var. crystcdlma, Dupuy. Shell greenish-white and trans-
parent, like glass.

Habitat : Among herbage and on damp moss in woods,
but sparingly distributed, in many of the English counties
from Northumberland to Devon. I am not aware of its
having been found in the eastern counties, Wales, or
Ireland. According to Dr. Fleming it inhabits Scotland,
but only on the authority of Capt. Laskey, who is said
to have found it in Carline Park near Leith. The variety
is from Wheeley Castle, Worcestershire (Clark) ; on
Mercurialis perennis near Stansted, Kent (Smith); Taw-
stock Woods, near Barnstaple; and Brockley Combe,
Somersetshire (J. Gr. J.). This species is one of our
upper tertiary fossils. It does not appear to have an
extensive range abroad — Germany and France being the
only countries in which I can find any notice of its
occurrence. A variety of it (the Azeca Nouktiana of
Dupuy) has been found by Boissy in the Pyrenees ; and
the variety crystallina is also recorded as inhabiting the
South of France.

Scarcely anything is known as to the habits of this
curious snail. It appears to be gregarious and to love
shade and moisture. Mr. Alder justly observes that it
"seems to form a link between Bulimus and Clausilia,
resembling the former in shape and general appearance,
but approaching more nearly to the latter in having the
margin completely surrounding the aperture, and also
more particularly in having a longitudinal plate on the
columella considerably within the aperture, similar in
situation and making a slight approach in form to the

o2

292 HELICID^.

clausium of the genus Clausilia, though attached through
its whole length and inflexible/^

This species has been placed by different writers in no
less than eight genera^ and has received six specific
names. On the Continent it is more generally known as
Bulimus Menkeanus, in consequence of there being an-
other B. tridens ; but if the present species is not to be
placed in that genus, there can be no objection to retain
the original name given to it by Dr. Pulteney.

B. Mouth destitute of teeth or folds : outer hp entire :

mner lip thin.

2. C. LU BRiCA*, Mliller.

Helix lubrica, Miill. Verm. Hist. pt. ii. p. 104. Zua luhrica, F. & H. iv.
p. 125, pi. cxxT. f. 8, and (animal) pi. Gr. G. G. f. 5.

Body broad and rounded in front, gradually narrowing and
very pointed behind, black or dark greyish-slatecolour above,
of a paler grey on the sides and underneath, shghtly tubercled :
mantle greyish-browai, closely speckled with milk-white : ten-
tacles broad at their base and slightly transparent ; upper pair
slender, finely and distinctly granulated, with very globular
bulbs ; lower pair of the same length as these bulbs and rather
thick : foot somewhat angular in front, not extending beyond
the neck ; sides very delicately edged with a dusky line and di-
stinctly speckled wdth milk-white ; tad f)omted and rather flat.

Shell subcylindrical, wdth an approach to a turreted shape
in consequence of the base being wider than the top, nearly
transparent, very shining and lustrous, light yellowdsh-brown,
quite smooth and polished to the naked eye, but under a lens
marked with slight and curved transverse striae, especially near
the suture, and under a microscope very closely and faintly
striate in a spiral direction : periphery rounded in the adult,
very slightly angular in young specimens : epidermis exceed-
ingly thin: ivhorls 5 or 5|, tiunid, gradually increasing in
size, the last occupying about one-half of the shell : spire
produced, but rounded at the point : suture moderately deep,

* Slippery.

COCHLICOPA. 293

with a transversely wrinkled border : mouth placed obliquely,
proportionally much larger than in the other species : outer Up
very thick and strengthened by a broad inside rib, which is
usually reddish-brown or flesh-colour: pillar-lip apparently
furnished with a blunt tooth which forms the notch : inner lip
consisting of a slight deposit of shelly matter, which is spread
on the pillar. L. 0-25. B. 0-085.

Var. 1. hyalina. Shell greenish- white.

Var. 2. lubricoides, Fer. Shell smaller and more slender.

Var. 3. viridula. Shell shaped like the last variety, but
greenish-white.

Var. 4. fusca. Shell smaller and thinner, reddish-brown.

Var. 5. ovata. Shell much smaller and oval : spire shorter.

Habitat : Woods^ hedges^ fields^ gardens, and every-
where in the country, under stones and logs of wood
(especially when sunk deep in the ground or decayed),
as well as among moss and dead leaves, and at the
roots of grass in meadows (frequently after being iiTi-
gated), from Unst to Guernsey. Var. 1. Tawstock^ near
Barnstaple (J. G. J.). Var. 2. Bath (Clark) ; Church
Stretton, Salop ; Clifton- Hampden, near Oxford ; Baw-
leigh, near Barnstaple ; Minlough Castle, Co. Galway ;
Dunboy, Co. Cork (J. G. J.). Var. 3. Dunboy (J. G. J.).
This and the last variety appear to be the variety /3 of
Nilsson. It has much the aspect of a distinct species, if
placed by the side of the typical form ; but they are con-
nected by intermediate gradations. Var. 4. Guernsey
(Lukis). Var. 5. Cardiff (J. G. J.). Tliis species is very
common in our upper tertiary deposits. It has almost a
world-wide range (or is what has been erroneously termed
"cosmopolitan^^), being found in Kamtschatka and on
the steppes of Siberia, in the South of Italy, Algeria,
Madeira and the Azores, North America, Cashmere and
Thibet, and probably in every other part of Europe, Asia,
Africa, and America.

294 HELICID^.

This is a hardy but sluggish and impassive little mol-
lusk^ and lives on the highest mountains as well as in
the lowest plains. These habits and the capability of
enduring different conditions of climate and temperature
may account for the great extent of time and space
which it has enjoyed as a species. It is also in some
degree amphibious. In consequence of Geoffroy having
stated that it was killed by being put in water, and that
by this means the animal could be removed from the
shell, IMiiller tried some experiments, which convinced
him that the French natm^alist was more imaginative
than accurate. One of these snails, which Miiller had
forced to withdraw into its shell, was plunged into a cold
bath, and it immediately thrust out its body ; but, per-
haps catching sight of the philosophical experimentalist,
and apparently as if resigned to its fate, it staid three
hours in the water, when it crawled out and (seemingly
pleased at reaching dry land) put out its horns and
walked off. However, although they do not mind an
occasional soaking, they are often washed down by heavy
floods of rain or the overflow of rivers, and their shells
occur in great numbers in alluvial deposits. This cir-
cumstance will perhaps explain how certain kinds of
land-shells so frequently occur in fluviatile, estuarine,
or even lacustrine strata. Young shells of C. lubrica
are oval or almost globular, and have a slight umbilical
perforation. Full-grown specimens vary considerably in
size and the length of the spire. The epiphragm is very
thin, glistening and iridescent. That made in summer
lias a small respiratory hole. In France this sheU bears
the appropriate name of " la brillante.^^

This species differs from C. tridents in being turreted,
instead of spindle-shaped, in the whorls being more con-
vex and the suture consequently deeper, but especially

ACHATINA. 295

in the mouth being much larger and never famished with
teeth or folds.

It seems not to have escaped the keen notice of Lister.
Whether Linne was also acquainted with the present
species is another question. Some writers consider it to
be the Helix subcylindrica of his ' Systema Naturae ;' but
that shell is described as inhabiting fresh water and
having the inside lip or margin of the aperture reflected^
neither of which characters is applicable to C. lubrica.
It is^ however, the Turbo glaber of Da Costa.

Genus XI. ACHA'TINA*, Lamarck.
PI. VII. f. 18, 19, 20, 21.

Body long and slender, always containable within the shell :
tentacles 4 ; upper pair having small bulbs ; lower pair exceed-
ingly short : foot narrow.

Shell long and cylindrical, thin, glossy and smooth : ivJiorls
rapidly increasing in size : spire long : mouth oval or oblong,
without teeth or folds, but notched and nearly truncate at the
base : outer Up thin and plain : umhilicus wanting.

L. Pfeiffer described, fourteen years ago, no less than
157 species of Achatina; and in these days of species-
making and foreign enterprise, we may fairly assume
that this number has since been considerably increased.
In our own country we have only a solitary representa-
tive of this numerous genus, and that scarcely exceeding
in length one-sixth of an inch. Risso constituted out
of this minute species a new genus, which he named
Acicula. Beck proposed another genus (Ciceci/io2c/e5) for
its reception ; and Bourguignat has, in his ^ Amenites
Malacologiques,^ given another generic name [Ccecilia-
nella), as well as divided our species into several. One
of these species he has called '^ Anglica" and distin-

* Agate.

296 ' HELICID^.

gmslied the French, shell from it under the name of
Liesvillei. Whatever difference of opinion may, however,
exist as to the scientific value of the species which this
last-named author has so prodigally described, his biblio-
graphical learning and laborious research cannot fail to
command our admiration. The two generic names of
Ccpcilio'ides and Ccecilianella are founded on a peculiarity
which does not appear to be shared by any other British
land or freshwater snail ; although in the famous caves
of Adelsberg many of such instances occur. It is, that
this snail is eyeless. This remarkable fact, with respect
to the Achatina acicula (which will be presently de-
scribed), was first noticed by Nilsson, and it has been
fully confirmed by subsequent observation. The A. aci-
cula always lives underground ; and the conditions of its
habitat are therefore similar to those of the several spe-
cies of Zosjjeum, living in the inmost recesses of the
Illyrian caverns, into which the light of day never pene-
trates. It is true that Testacella, which is also a sub-
terranean mollusk, is not deficient in those organs which
are called eyes ; but this animal passes some of its
time (especially in the pairing-season) above ground,
while our little Achatina has never been observed on
the surface in a living state. Similar exceptions of eye-
less species, belonging to genera the animals of which
are usually ocellated, occur (although very rarely) among
our marine Cephalic Mollusca — as, for instance, Eulima
stenostoma and Mangelia nivalis; but these are deep-
water species, and very little is kno\\Ti as to the extent
to which light penetrates into the abysses of the ocean,
or as to its action on the sensorial organs of inverte-
brate animals. In all probability the A. acicula lives
upon animal matter ; for, in the spots where it has been
found living, no underground fungus or other vegetation

ACHATINA. 297

appears to exists and the form of the shell would induce
a belief that this snail is not only zoophagous but pre-
daceous. The shells of all the true species of Glandina,
which are carnivorous, have the same kind of notch or
truncature at the base as the present species of Acha-
Una. The structure of the lingual plate or tongue of
Glandina is similar to that of Buccinum and other ma-
rine Proboscidiferous Mollusca, which also have a notch
or canal in the mouth of their shells and are exclusively
predaceous. The present genus is closely allied to Co-
chlicopa through C. lubrica, the habits of which are partly
subterranean; but the notch in that shell is not so
strong or well marked as in this.

AcHATiNA Aci'cuLA *_, MiiUcr.

Bitccinum acicula, Miill. Yerm. Hist. pt. ii. p. 150. A. acicula, F. & H.
iv. p. 130, pi. cxxviii. f. 4.

Body quite white and nearly transparent, tubercled or gra-
nulated in hues : mantle rather thick, marked mtli a raised
longitudinal line in the middle : tentacles cylindrical ; upper
pair destitute of eyes or black specks ; lower pair forming
almost imperceptible bulbs : foot compressed, pointed behind,
and ending at the penultimate whorl of the shell when the
animal is crawling.

Shell turreted and slender, transparent, very thin, highly
polished and iridescent, ivory-white, with a yellowish tmge on
the upper part in fresh specimens (owing to the colour of the
liver), perfectly smooth and polished when examined with a
lens of ordmary power, except a few faint and irregular wrin-
kles in the line of growth, but under a microscope exhibiting
delicate and close-set spiral striae : periphery rounded : epi-
dermis exceedingly thin and forming a mere iilm : whorls oi,
not convex, but compressed and drawn out, rapidly increasing
in size ; the last occupying about one-half of the shell : spire
. very obtuse and rounded at the point : suture moderately deep
and obhque, apparently margined on the under side by reason
of the upper part of the succeeding whorl being seen through

* A hair-pin, used by Roman women.

o 5

298 HELICID^.

the pellucid sliell : mouth oblong, contracted by the penultimate
whorl, narrowing above into an acute angle, slightly widened
and rounded below, but interrupted by a deej) notch at the
base of the pillar lip : outer lip thin and flexuous : pillar lip
thick and curved : inner lip consisting of a slight deposit of
shelly matter, which is spread on the pillar. L. 0"175.
B. 0-04.

Habitat : Under stones and at the roots of bushes
and gi^ass, but usually some inches beneath the surface,
in various parts of the country from Yorkshire to Guern-
sey, as well as in Wales and Ireland. It occurs in our
upper tertiary strata. On the Continent it ranges from
Sweden to the South of Italy; and it has been also
noticed in Greece, Algeria, and Madeira. It is widely
diffused, but rather local, and difficult to find in a living
state.

Nilsson has given a good description of this curious
little mollusk, and has noticed that, in consequence of
the transparency of the shell, the irregular motion of its
breathing could be easily observed under a microscope,
and that, when the respiratory cavity was shut, the
motion ceased, but was resumed on the chamber being
again opened ; and he likened this alternate expansion
and contraction of the breathing- organ in this snail to the
pulmonary action of vertebrate animals. He supposed
that the A. acicula fed on the tender and juicy fibrils of
the roots of grass. Mr. Pickering informed me that a
considerable number of live specimens were once pro-
cured by a gentleman in Hertfordshire, while digging up
potatoes. His friend, not being a conchologist, thought
at first that they were little white maggots. It has been
stated that this species is only fomid in calcareous soils •
but, besides the last instance, its occurrence has been
noticed by Mr. Bridgman at Norwich, "on a sunny
bank near the Thorpe toll-bar, adhering to the roots of

carychiidtE. 299

grasSj in the loose earth between the stones/^ The epi-
phragm is very thin and glistening. The eggs are said
to be large in comparison with the size of the shell.

This is the Buccinum terrestre of Montagu; but it
can scarcely be the Helix octona of Linne (as some au-
thors have supposed), because that shell is described as
having eight whorls and a roundish mouth. The last
species is common in the West Indies, but in former
times found its way into collections of British shells,
owing to Dr. Pulteney having mistaken it for the Limncea
glabra, or Helix octona of Pennant.

Family IV. CAEYCHIID^.

Body long and spirally coiled : mantle covering the front or
anterior part : snout prominent : tentacles 2 (besides rudiments
of a second or lower pair), contractile : eyes at the base of the
developed tentacles and somewhat in their rear : foot oblong,
distinct from the rest of the body.

Shell spiral, oval-oblong, enveloping the whole body:
mouth somewhat ear-shaped, furnished with columellar folds
and a tooth-hke tubercle on the outer hp : umbilicus narrow
and indistinct.

This family forms part of an incongruous assemblage
of MoUusca, which Lamarck called Auricula or Auricii-
lacea, the type of which is the Bulimus fibratus or Auris-
Mid(B, As, however, Miiller had long previously indi-
cated the characters of the present family by his de-
scription of the genus Carychium, it would seem to be
an act of common justice to the memory of that great
naturalist that the patronymic or family name should
be taken from that of his original genus, and not from
Auricula, which was subsequently founded. A few am-
phibious Mollusca which belong to this family, and to
the genera Melampus (or Conovulus) and Otina, bein

cr

300 CARYCHIID^.

excluded from the category of land-shells and placed
with those having a marine habitat ^, there only remains
a single genus_, containing a solitary species^ for present
consideration. This is one of our smallest terrestrial
Mollusca.

There are several points of resemblance between this
family and the Limnceidae. The contractility of their
tentacles and the position of the eyes and reproductive
organs are nearly the same in each of these families;
and the only British member of the Carychiidce is semi-
aquatic in its habits and can live a long time under
water. Every individual of both families is male as well
as female.

Genus CARY'CHIUM f, Muller. PL VIII. f. 1, 2, 3, 4.

The characters of the body and shell are given in the
above definition of the family.

Carychium mi'nimum X) Miiller.

C. minimum, Miill. Verm. Hist. pt. ii. p. 125 ; F.& H. iv. p. 198, pi. cxxv. f. 6.

Body bilobed in front and rounded behind, transparent,
yellowish-white : snout as long as the tentacles and triangular :
tentacles Yerj close together, thick and conical, with somewhat
rounded extremities : eyes rather prominent, exceedingly black
and distinct : foot rounded in front, very finely speckled with
black and milk-white, terminating in a blunt and thick tail.

Shell subfusiform, transparent, but not very thin, glossy,
whitish, finely and closely striate in the line of growth, with
a few obsolete or indistinct spiral hues ; the transverse striae
are flexuous and stronger towards the suture, and they are
sometimes partly decussated by the spiral Hues in such a

* I accidentally omitted to notice, in my account of the Slugs, that one
of them also ( Onchidium Celticum) is marine.

t From its resemblance to a Murex or kind of whelk. + Smallest.

CARYCHITJM. 301

manner as to give the surface an appearance similar to that
which is observable on the shells of several species of Limncea
(showing the conchological relation between that and the
present genus) : periphery rounded : epidermis not very thin :
whorls 5-^, convex ; the last occupying nearly one-half of the
shell, and the penultimate whorl fully equalling (if not ex-
ceeding) it in breadth : spire moderately pointed : suture deep :
mouth obliquely oval, contracted below into a narrow channel,
furnished with a strong spiral fold or plait on the middle of
the pillar, and with another on the pillar lip : outer lip ex-
ceedingly thick and reflected, having on the middle of its
inside edge a strong tooth or tubercle which projects into the
mouth ; upper edge considerably inflected : inner lip thickened
in adult specimens and forming with the outer lip a complete
peristome : umbilicus consisting of an oblique slit. L. 0-07.
B. 0-035.

Habitat : Under stones and logs of wood, at the roots
of grass, and among moss and dead leaves, in woods
and damp places, everywhere from the Moray Firth
district to the Channel Isles, as well as throughout
Wales and Ireland. It is a member of our upper ter-
tiaries. Gerstfeldt has recorded it as a Siberian species,
Philippi as Sicilian, Morelet as inhabiting Algeria j and
it seems to be universally distributed over every part of
the Continent.

This is an exquisitely beautiful creature, both alive
and dead; and Miiller did scant justice to it in calling
it a " bestiola/' when he was apparently provoked by its
shyness. Its eyes are so exceedingly black and piercing
that they are visible through the shell, when the animal
is not disposed to venture out of doors. It inhabits
mountainous tracts as well as plains, but seems to prefer
the vicinity of water. Dr. Lukis informs me that it
makes its winter domicile in the hollow stems of the
larger marsh umbelliferous plants. The plaits or folds
are in course of formation at a very early period of
growth; and young shells have the columella notched

302 CYCLOSTOMATID^.

at tlie base, as in Cochlicopa and Achatina. The epi-
phragm is extremely thin and glistening. The spire is
complete ; and in this respect it differs from that of the
shells belonging to species which British conchologists
place in the genus Conovulus. The Rev. M. G. Berkeley
supposed that C. minimum might have the sexes distinct ;
but the anatomical details of its structure given by Mo-
quin-Tandon prove that such is not the case, and that this
animal agrees in its mode of reproduction with all the
other members of the inoperculated Pulmonobranchs.

The second section of the British Pulmonobranch
Mollusca comprises only the following —

Family V. CYCLOSTOMATID^.

Body long and spirally coiled : mantle covering the front or
anterior part, and encircling the neck with an extremely thin
fold : snout strong and elongated : tentacles 2 only, contractile :
eyes at the external base of the tentacles : foot long, distinct
from the rest of the body.

Shell spiral, oval or cylindrical, and enveloping the whole
body ; mouth round or oval : umbilicus small and narrow :
operculum paucispiral, testaceous or homy.

This extremely numerous family has its home in the
tropics. Only two members of it inhabit this country ;
and each of these is included in a separate genus. As I
have before observed, many characters of organization
are common to the present family and the Pectinibranch
Mollusca. They are dioecious : their tentacles are two
in number and contractile : their eyes are placed at the
base of these tentacles : and their shells are furnished
with opercula. But their respiratory system is very
different, and corresponds with that of other families of
Pulmonobranch Mollusca.

CYCLOSTOMA. 303

Our Continental neighbours are riclier than ourselves
in genera as well as species belonging to this family^
Of the typical genus^ Cyclostoma, two well-marked spe-
cies are common in France^ although one of them (C.
sulcatum) is confined to the South. As to Acme they
boast of having four species to our one ; but none of the
three which we want are found in the North of France.
Of a third genus, Pomatias, no less than six species are
French, while we have no representative of the genus.
Two of these last species (viz. P. septemspiralis or macu-
latus and P. obscurus) have been lately detected in the
extreme North of France ; and it is therefore not impos-
sible that they may be also met with in the South of
England. Their operculum is horny, instead of shelly as
in Cyclostoma; and the genus to which they belong
appears to bear nearly the same analogy to Cyclostoma
as Hydrobia does to Bythinia among the Pectinibranch
Mollusca.

The British genera comprised in this family may be
thus di\dded.

* Shell oval : operculum testaceous. Cyclostoma.
** Shell cyhndrical : operculum homy. Acme.

The position of the male organ of reproduction is also
different in these genera.

Genus I. CYCLO'STOMA *, Draparnaud.
PL VIII. f. 5, 6, 7, 8.

Body oblong, always containable within the shell : tentacles
cylindrical, with slightly swollen tips : foot small and broadish.

Shell oval, rather soHd : ivJiorls rapidly increasing in size :
spire short : mouth round : umhilicus obhque : operculum
roimdish, testaceous and solid, with a nearly central spire.

* Eound-mouth.

304 CYCLOSTOMATIDiE.

More than a centmy ago^ Guettard made known,
through the Academy of Sciences at Paris, the appa-
rently anomalous fact that a land-snail was fiu-nished
with an operculum. The genus Cyclostome was founded
by Lamarck in 1789 and reproduced in 1801, for the
reception of certain marine Gasteropoda which are now
referred to the genera Scalaria and Delphinula, But it
is to Draparnaud that science is indebted for the esta-
blishment of the genus Cyclostoma on a more correct
basis, although he comprised in it, besides the true
members of this genus, many freshwater species belong-
ing to the genera Paludina, Bythinia, and Hydrobia, and
even a species of Truncatella which is exclusively marine.
The present genus is restricted to those land-shells which
have a round mouth and a solid operculum; and the
structure of the animal is in strict accordance with that
of the shell.

Cyclostoma e'legans*, Miiller.

Nerita ekgans, Mull. Verm. Hist. pt. ii. p. 177. C. elegans, F. & H. iv.
p. 201, pi. cxxii. f. 3.

Body very thick, blunt and strongly bilobed in front, rounded
behind, dusky greyish-brown or almost black above, of a paler
hue underneath, coarsely wrinkled in fi'ont and finely tubercled
behind: mantle semiannular, rather tumid and smooth, speckled
with milk-white except at the sides : snout projecting beyond
the rest of the body, strongly bdobed in front, divided trans-
versely by distinct wrinkles, which are finely streaked with
grey : tentacles dark-coloured, strongly wrinkled across, with
nearly hemispherical bulbs, which are more transparent and
clear than the tentacles : eyes placed on reddish or whitish
tubercles, a Httle behind the tentacles : foot rounded in front
and divided into two equal parts by a longitudinal groove,
very dusky, especially on the sides ; tail rounded, and to a
great extent covered by the operculum.

* Elegant

CYCLOSTOMA. 305

Shell globose-oval, rather solid and opaque, scarcely gloss}-
(owing to the strong sculpture), yellowish-brown with more or
less of a reddish tinge and often marked with ii-regular streaks
or spots of reddish-brown or purple, sometimes plain yellow or
fawn-colour; the spots sometimes form three or more in-
distinct and interrupted rows on the body whorl ; sculpture
consisting of strong spiral ribs, of which there are about forty
on the last whorl, and of much finer but more numerous trans-
verse ribs, which do not cross the main ribs but intersect the
interstices, giving that part of the surface a somewhat reti-
culated appearance : jyeripliery rounded : e]piderm\s thin : whorls
4|-, exceedingly tumid, the last occupying considerably more
than two-thirds of the shell ; upper whorls purple or yellow-
ish-brown and quite smooth: spire bluntly pointed: suture
very deep : mouth circular, with the exception of a slight angle
at the upper part : outer lip and inner Up rather thick, very
slightly reflected, and forming a complete peristome : umbili-
cus twisted, but rather deep : operculum flat, composed of about
five whorls, strongly and closely marked with oblique and flex-
uous striae ; nucleus depressed, smooth, and of a darker colour,
like the nucleus or apex of the shell, L. 0*6. B. 0*4.

Habitat : Under stones and at the roots of fern and
farze in many parts of England^ Wales, and Ireland,
from Yorkshire to Alderney. It appears to frequent
chiefly the sea-coast and calcareous soils ; but it occurs
in Northamptonshire and Oxfordshire (inland counties),
as well as in parts of Norfolk where there is no chalk.
It has not been recognized with any degree of certainty
as a fossil of our upper tertiaries. Its foreign range is
southern, and includes Central Germany, France, Italy,
and Portugal ; and it extends to the Canaries. Donegal
Bay appears to be its most northern limit.

Lister gave, nearly two centuries ago, some excellent
details of the physiology of this mollusk; and in 1828
another of our countrymen (the Rev. M. G. Berkeley)
published, in the 'ZoologicalJournaF (vol.iv.p. 278-284),
further particulars of its anatomy. According to Moquin-
Tandon it is a vegetable feeder ; and the structure of its

306 CYCLOSTOMATID^.

tongue is the same as that of other phytophagous Mol-
lusca. The bulbs or points of the tentacles are sup-
posed to be olfactory organs. This species does not
make its appearance until the first warm days of spring ;
and in dry weather it buries itself in the earth. It is an
exceedingly timid animal. Montagu says that its strong
and muscular proboscis is of considerable service in
removing obstacles, and especially the earth when the
animal retires to its hibernaculum ; and he adds that it
is also used in crawling, to hold by, in order to bring
forward the body. Dr. Gray has described a remarkable
peculiarity in its mode of walking, as follows : — " The
foot is formed of two longitudinal portions : as the
animal walks, the portion on one side is first advanced,
while the animal holds on by the other ; and then holds
on with the advanced portion as the other side is gradu-
ally advanced before it.'^ This alternate action of the
two sides of the foot is nearly similar to that which
was observed by Adanson as to his genus Pedipes, of
which we have a representative in Melampus ; but in
that case the foot is divided into two transverse instead
of longitudinal sections, and the action is more like that
of a caterpillar, or what is called " looping.^^ Villa has
noticed that great numbers of C. elegans are devoured
by predaceous beetles, especially by those belonging to
species of Cychrus, which contrive to get into the shell
in spite of the solid and close-fitting operculum. This
curious lid or mouth-piece is as hard as a stone, and
covered on both sides with a thick and tenacious epi-
dermis, a double fringe of which completely encircles it
and causes the operculum to appear laminated. This is
one of our handsomest land-shells, and, if it were rare,
would be highly prized — like many other too familiar
objects of equal beauty.

ACME. 307

s

The " Cyclostoma marmorea " of Capt. Brown appears,
from tlie description and figure in the 'Edinburgh Journal
of Natural and Geographical Science' for October 1829,
to be a specimen of C. elegans which had been worn
smooth by attrition.

The C.ferrugineum of Lamarck was erroneously in-
troduced by Dr. Turton into the British fauna. It is a
native of the extreme South of Europe, and has not even
been found in France.

Genus II. ACME *, Hartmann.
Pl.VIII. f. 9, 10, 11, 12, 13.

Body elongated, always containable within the shell: ten-
tacles awl-shaped, without bulbs or swollen extremities : foot
narrow.

Shell cylindrical, rather thin : wliorls gradually increasing
in size : spire long, but ending in a blunt point : mouth oval :
umbilicus straight: operculum oblong, homy and thin, vdth
an excentric spire.

This singular genus of minute operculated land- shells
was first distinguished by Hartmann, and described by
him in the ' Neue Alpina ' of Steinmiiller for 1821 under
the name of Acicula. However, for some reason or other
which does not appear, Hartmann changed this name
for Acme, and redescribed the genus at considerable
length in the sixth volume of Sturm's ' Deutschlands
Fauna,' which was published also in 1821. Risso having,
as before stated, in 1826 used the name Acicula for
another genus with Achatina acicula as its type, and the
original founder having discarded it, there seems to be
no alternative but to adopt the second name given by
Hartmann to the present genus. It takes precedence of
a somewhat similar generic name(^cm««) which has been

* Point.

308 CYCLOSTOMATID^.

ascribed to Esclischoltz and used for the reception of some
marine shells which are allied to Patella. The present "
genus was (according to Charpentier) named Pupula by
Agassiz.

Acme lineata*, Draparnaud.

Bulimus lineatus, Drap. Tabl. Moll. p. 67. A. Uneata, F. & H. iv. p. 204,
pi. cxxv. f. 7.

Body milk-white speckled with brown, nearly transparent :
mantle dark-brown : snout very narrow, tumid, and curved,
marked transversely with flat, parallel and indistinct wrinkles :
tentacles nearly cylindrical, diverging, whitish, very finely
wrinkled across, each of them encircled at its base by a ring
of dark spots ; their extremities nearly pointed : foot rounded
in front, with a narrow tail.

Shell oblong- cylindrical, semitransparent and glossy, yel-
lorwish-brown, marked in the line of growth with remote curved
grooves or deep stria?, of which there are from twenty to thirty
on the body whorl, as well as with a few slight and obscure
spiral hnes : jperiphery rounded : epidermis of moderate thick-
ness ; whorls 6-7, compressed, the last occupying about two-
fifths of the shell : S2yire rounded at the point : suture distinct,
but not deep : mouth pear-shaped, effuse at the base, and con-
tracted above into a rather acute angle : outer lip thin and
flexuous : pillar Up reflected : inner lip sj^read on the colu-
mella : umbilicus small and nearly concealed by the reflexion
of the pillar lip : operculu7}i flat, sunk deep within the mouth,
marked with faint and irregular radiating strias ; spire formed
of only two whorls and a half. L. 0-085. B. 0-035.

Var. 1. alba. SheU white or colourless and transparent.

Var. 2. sinistrorsa. Spire reversed.

Habitat : Among decayed leaves in open drains, and
under stones which lie close to the ground, in woods
throughout a great part of these isles, from Lanark-
shire to the extremity of Cornwall, and also in Wales
and Ireland (East, West, North, and South), but not
everywhere or abundantly. Var. 1. Rejectamenta of

* Marked with lines.

ACME. 309

the River Avon at Bristol; Ballinahinch, Co. Galway
(J. G. J.) ; Killarney (Barlee). Var. 2. A single speci-
men among the refuse of the Avon at Bristol (J. G. J.) .
This species, as well as the reversed variety, has been
found in our upper tertiary beds at Copford. Gerstfeldt
has recorded it from Western Siberia, and Villa from
Normandy; but, although it occurs in intermediate
countries, I do not find any notice of it as Scandinavian.
It inhabits France, Germany, and Switzerland.

A living specimen, which I observed in the North of
Ireland, did not seem to be shy or inactive while kept
in the shade ; but when it was exposed to the glare of
the sun^s rays, it immediately shut up and disappeared.
Dr. Gray says that "the animal walks with its shell
nearly perpendicular, twisting it round in a very odd
manner, and then letting it suddenly fall again." The
strise on the shell are very irregular in respect of num-
ber ; and in a specimen now before me they are entirely
wanting in some parts ; so that I should not be much
surprised if the A. fusca of Beck (which he separated
from our species on account of its wanting the striae)
should prove to be merely a smooth variety of the
present species. Brown has apparently described and
figured this variety, in his 'Illustrations of the Land
and Freshwater Conchology of Great Britain and Ire-
land' (p. 29, pi. iv. f. 16), under the name of A. minuta.

The present species was first made known by Walker
{Test. min. rar. litt. Sandv. p. 12, f.42), and was described
by Montagu as Turbo fuscus, but subsequently to the
date and publication of Draparnaud's ' Tableau des Mol-
lusques.' Moquin-Tandon considered Walker's shell to
be distinct from that of Draparnaud, and has described
the former as quite smooth; but Jacob's diagnosis in
Walker's work distinctly mentions its being striated.

310

SPECIES OF DRAPARNaUD ; AND ERRATA.

After the foregoing part of this volume had been
printed, I received a communication of considerable im-
portance as regards the determination of some of the
species described by Draparnaud. It consisted of the
original types or specimens of that author, from the
public museum at Montpellier, and which, through the
great kindness of the Director, M. Michaud, I have now
had an opportunity of examining and comparing with
my own specimens. The following is the result of this
examination.

Species
described by Draparnaud.

Cyclostoma simile.
C. anatiiinm.
Clausilia pHoatula.,

Helix glabella.
H. sericea.

H. plebeium.
H. pygmsea.
H. nitidula /3.

Species
described in this ivorTc.

Hydrobia Bimihs.

H. ulvae.

One specimen is C. Rolphii.

(The rest are C. plicatula.)
H. rufescens.
One specimen is H. hispida,

var. subglobosa; and the

other is H. revelata.
H. hispida, var.
H. pygmaea.
Two specimens are Zonites

radiatnlus, and another is

Z. punis.

EREATA.

Page 49, at tlie end. The specimen of Dreissena polymorpha referred to
by M. Ch. D'Orbigny appears to be recent, and not fossil.
,, 55, line 15 from top, for " they" read " some of them."
,, 155, line 25. Vitrina. The accentuating mark ought to be over the

first syllable, and not over the second one which is short.
,, 200, line 25 from top, for '' plebeia'^ read ^^ plebemm."
,, 278, line 19, for " C. rugosa" read " Pupa riigosa."

ESTHETIC CONSIDERATIONS. 311

Thus far I have treated this branch of my subject in
a scientific point of view, and I have at the same time
endeavoured to illustrate some of the curious ways and
instincts of the Mollusca which inhabit the surface of
this country. I am not without hope that many others,
who possess better opportunities than I have at present,
may be induced to institute similar researches, and thus
to improve what I have done, as well as correct those
errors which have unavoidably occurred in a rather ex-
tensive investigation.

There is, however, another aspect in which the matter
may be considered ; and that is, with reference to our
own aesthetic ideas of these humble works of our Com-
mon Creator. Other divisions of animated nature have
received a large share of attention from philosophers
and poets ; and their best works in ancient and modern
times abound in references to the larger animals, as well
as to birds and insects, but more especially to flowers,
the simple yet ornate beauty of which appears to affect
the mind in a peculiar manner. But the less conspicuous
and attractive assemblage of snails, which have been
exhibited in the foregoing pages, (although equally in-
teresting to the naturalist) have not been honoured with
much notice by the philosopher or poet; and I woidd
venture to make this appeal to such on behalf of my
little favourites, trusting that their claims, as our fellow-
creatures, to a share of that sympathy which animates
the great and stirring intellects of this age may not be
entirely overlooked. A gifted and well-read friend has
kindly sent me the following result of his examination of
the subject in a poetical sense, which will, I hope, be
acceptable to some of my fair readers.

312 ESTHETIC CONSIDERATIONS.

The Snail in Poetry.

The snail has been but rarely the subject of poetical
treatment. Minor poets would be afraid of touching it ;
and even in the hands of those great masters to whom
it has been given to interpret the deeper harmonies of
the universe^ it is only upon rare occasions that this
little animal could fittingly present itself as a link in
the chain of their conceptions. One would naturally
first look for it in those descriptive poems which deal
with agriculture and gardening. But neither Cowper
in his ^ Garden ^ nor Virgil in his ' Georgics ' appear to
have honoured it with their notice. Nor does it enter,
I believe, into the pious yet discursive meditations of
George Herbert. Nor does Milton make it the subject
of any special reference in his magnificent description
of the six days' work, and varied wonders of creation.
It is not the snail, but the worm, which is there taken
as the type of that lower region of animal life. Indeed
there appears no great congeniality between the tribes
of the " Helicidae ^' and the atmosphere which has been
deemed suitable for epic or for serious poetry; they
do not readily live and flourish on Parnassus. Never-
theless their cause, as judged at the tribunal of the
Muses, is not to be pronounced hopeless; it must be
stated, on the contrary, that their humble pleadings
have been listened to, and that they have been admitted
into the realms of song. They have certainly been
neglected by the smaller fry ' of poets ; but they have
not been overlooked by the very greatest masters of the
art. It is instructive to observe the manner in which
the snail has been treated by Homer, Shakspere, and
Goethe ; from Avhom, in default of other instances, our
examples must needs be drawn. We shall there find

ESTHETIC CONSIDERATIONS. 313

the snail, not as the uninviting little creature it would
appear to the common eye, but under the light of imagi-
nation's ray. We may enter the realms of fantasy, and
we shall find it among those intruders which had to be
chased from the cradle of the fairy-queen. We shall
find it, centuries earlier, in Homer's mock-heroic poem,
where the belligerent frogs are represented as using the
shells of water-snails for their helmets. But the snail
has been raised to a much higher eminence in the poetic
sphere. Indeed, could a lonely snail be discovered on
the loftiest peak of Tenerific or Chimborazo, would not
the little animal, elated at that extreme height, become
a fit object for surprise and wonder, and partake of the
sublimity of the situation ? Well — supposing only that
we pass from the material to the moral world — in a simi-
lar situation Goethe has placed it, in that wild vision of
the Walpurgis-night. There, upon the top of the Harz
mountains, amidst that enchanted throng and tumul-
tuous rabblement of witches, sorcerers, daemons, owls,
bats, and all creatures of the night celebrating high
festival under the melancholy moon, in the "region of
misery and tribulation," did an adventurous and preter-
naturally sensitive snail detect the presence and mimask
the incognito of no less a person than Mephistopheles
himself, who in these words describes the occurrence : —

" Siehst du die Schnecke da ? Sie kommt herau gekrocben ;
Mit ihrem tastenden Gesicht
Hat sie mir schon was abgerochen.

Wenn ich aueh will, verlaugn' ich hier mich nicht."

This is beyond a doubt the most imposing appearance
which the little animal has made in literature.

The cases above cited, in which the snail appears as
actually taking part in the movement of the poem, in
which she is, so to speak, one of the characters of the

p

314 ESTHETIC CONSIDERATIONS.

drama, must of course be distinguished from those in
which she appears only by way of simile, or comparison ;
the movement of the poem being meanwhile interrupted.
The most interesting of the latter class is to be found in
Shakspere^s ^ Venus and Adonis/ a piece in which the
rich romantic or quasi-mythological colouring is so high
as to permit the introduction of such imagery without
any perceptible loss of poetic dignity. The following is
the simile alluded to : —

" Or as the snail, whose tender horns being hit,
Shrinks backward in his shelly cave with pain,

And there, all smother' d up, in shade doth sit,
Long after fearing to creep forth again ;

So, at his bloody view, her eyes are fled

Into the deep dark cabins of her head."

It would be difficult to find another equally beautiful
reference to the sensitive characteristic of the animal.
We cannot fail to observe that Homer, in accordance
with the sculpturesque tendency of Greek art, fixes
his attention more on the outward shelly covering ; but
the modern poets, in obedience to their more ^ subjective^
tendencies, give theirs rather to the inner sentient nature
of the inhabitant of the shell.

But after taking this hurried glance from the summit
of Mount Parnassus, we must descend into the plains
of prose ; and having thus refreshed ourselves with a
draught from the Castalian spring, we will present the
Geologists with a distant retrospect, which may be more
interesting to most of them than the view we have been
enjoying, although some of that learned body are not
ungifted with a vivid imagination.

The difficult and vexed problem of geographical dis-
tribution is so intimatelv connected with the science of

TABLE OF DISTRIBUTION. 315

Geology, that any reliable information with respect to
the present range of the European MoUusca cannot fail
to assist in the elucidation of this question ; but I would
again venture to express an earnest hope that, until suffi-
cient data have been collected, no more theories, crude
although plausible, may be put forth. It may be said that
they are easily made, and that by their discussion some
useful results are obtained ; but it must not be forgotten
that the eyes of our scientific compeers in Europe are
upon us, and that our reputation for accuracy, as well
as our position as naturalists, may be compromised if
we erect a fine superstructure on a foundation of sand,
instead of digging patiently, but steadily, until we reach
the solid rock.

I propose to show, in the following Table,

1st, All the species of land and freshwater Mollusca
now living in the British Isles, arranged in the natural
order of their classification.

2ndly, The extra- British distribution of any of these
species, north of a line drawn in the meridian of Bordeaux,
which may be assumed as an arbitrary point of demarca-
tion between the two extremes of climate in Europe ^.
These species may be termed " northern " forms.

3rdly, The like distribution, of any of the species com-
prised in the first category, south of the same line — being
therefore "southern ^' forms.

And 4thly, The occurrence of any of the above-men-
tioned species in a subfossil state, in the upper tertiary
strata of this country. With respect to the term " Upper
Tertiaries,^^ Mr. Prestwich has kindly supplied me with
the following definition : —

"By our upper Tertiaries I should be disposed to

* Draparnaud, in his "Tableau des Mollusques," proposed nearly the
same line of division between the North and South of France, the latter
being the olive-district.

p2

816

TABLE OF DISTRIBUTION.

mean all the Pliocene and Pleistocene strata^ i. e. all the
beds from the Coralline Crag inclusive up to the Alluvial
and Peat deposits. This division is convenient^ as the
tertiary strata of the Isle of Wight end with upper Eocene,
or possibly lowermost Miocene^ whilst in the London
district there are no traces of Miocene, and even the
upper Eocene is wanting; the gap, therefore, between
what may be called the Lower Tertiaries and the Upper
Tertiaries in this country is very considerable and well
marked.^'

Table showing the species of Land and Freshwater Mol-
lusca which have been described in the foregoing part
of this volume — their foreign range — and the occur-
rence of any of them as Upper Tertiary fossils. This
mark ( — ) signifies their occurrence in the district
indicated bv the column.

Species.

Aquatic.

Bivalves.

Sphasrium corneum

rivicola

ovale

lacustre

Pisidium amnicum

fontinale

pusilliun

nitidum

roseuni

Unio tumidus

pictorum

margaritifer

Anodonta cygnea

anatina

Dreissena polymorpha

15

o

14

c
o

CO

Distribution in other parts of
the worl(L

14 I 9

Siberia (Gerstfeldt).

Siberia. Only one specimen
found, and that was in the
nasal cavity of a fossil skull
of a Rhinoceros.

Siberia and Kamtschatka.

Siberia.

Siberia and Lake Baikal.

Siberia and Lake Baikal.

Siberia.

' )

TABLE OF DISTRIBUTION.

317

Species.

a

o

Aqua,tic {continued).

Univalves.

Neritina fluviatilis

Paludina contecta

vivipara

B jtliinia tentaculata ....

Leacbii

Hydrobia similis

ventrosa

Valvata piscinalis

cristata

Planorbis lineatus

nitidus

Nautileus

albus

glaber

spirorbis

vortex

carinatus ,

complanatus

corneus

contortus

Physa hypnorum

fontinalis

Limna^a glutinosa

involuta

peregra

auricularia

stagnalis

palustris

truncatula

glabra

Ancylus fluviatilis

lacustris

Number of aquatic spe-
cies 47

Terrestrial.

Arion ater

hortensis

Geomalacus maculosus . .
Limax gagates

marginatus

flavus

a

u

o

45

a- 2

45

34

Distribution in other parts of
the world.

Siberia.

Siberia. Var. depressa, R.Lena.
Siberia and Kamtschatka.

Siberia.
Siberia.
Siberia and Kamtscliatka.

Siberia.
Siberia.
Siberia and mouth of the

Eiver Ussuri.
Siberia.

Siberia and Steppes of Kirgis.
Siberia.

Siberia ; North America.
Siberia.

Siberia; Afghanistan.

Siberia.

Siberia.

Siberia and Kamtschatka.

Siberia ; Afghanistan.

Irkoutsk.

Siberia.

318

TABLE OF DISTRIBUTIOX.

Species.

Terrestrial (continued)
Univalves.

Limax agrestis '.

arborum

maximas

Testacella Haliotidea

Succinea putris

elegans

oblonga

Vitrina pellucida ,

Zonites cellarius

alliarius ,

nitidulus ,

purus

radiatiilus

nitidus

excavatus

crystallinus

fulvus

Helix lamellata

aculeata

pomatia

aspersa

nemoralis

arbustoriun ,

Cantiana

Cartusiana

nifescens

concinna

hispida

sericea

revelata ,

f usca

Pisana

rirgata

caperata

ericetoi'um

rotundata

rupestris

pygmaea

pulchella

lapicida

obvoluta

Bulimus acutus

montanus

obscurus

Pupa secale

e
u

o

02 &H

Distribution in other parts of
the world.

Siberia.

Siberia; Afghanistan.
Afghanistan.

Siberia.

N. America.

Siberia.

Siberia; N. America.

N. America.

Siberia.

Siberia.

Irkoutsk; Caucasus.

Siberia.
Siberia.

— Siberia.

TABLE OF DISTRIBUTION.

319

Species.

Terrestrial (continued).

Univalves.

Pupa ringens ,

umbilicata

marginata

Vertigo antivertigo

Moulinsiana

pygmaea

alpestris

substriata

pusilla

angustior

edentula

ininutissima

Balia perversa

Clausilia rugosa

E-olphii

biplicata

laminata

Cochlicopa tridens

lubrica

Achatina acicula

Carychium minimum

Cyclostoma elegans

Acme lineata

Number of terrestrial

species 74

Total number of

species 121

N.B. Doubtful cases are
not reckoned.

u
o

113

e

X!

O

115

80

Distribution in other parts of
the world.

Siberia.

Siberia.

N. America?

Siberia.

Smyrna.

Asia, Africa, and America.

Siberia.

Siberia.

Besides the species enumerated in the above list, four
more occur in our upper tertiary strata, but are not now
found living in this country. One of them [Hydrobia
marginata] is aquatic and inhabits the South of Europe.
The other three (viz. Helix fruticum, H. incarnata, and
H. ruderata) are terrestrial and inhabit both the North
and South of Europe. H. fruticu7n and H. ruderata are
also Siberian species.

It will be seen that, with only two exceptions (viz.

320 TABLE OF DISTRIBUTION.

Zonites alliarius and Pupa rinyens) , all the species which
occur in our upper tertiaries are northern forms, and
that very few are exclusively northern or southern.

In the body of this work the term " North of Europe"
has been used in the ordinary sense, and not with refer-
ence to the somewhat arbitrary line of demarcation
proposed in the foregoing Table. The authority can be
given for every locality ; but to have done this would
have taken a great deal of extra space and unnecessarily
encumbered the work.

321

ALPHABETICAL LIST OF AUTHOES AND WORKS

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328 LIST OF AUTHORS AND WORKS QUOTED.

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Taylor, Bridgman, Templer, E. J. Lowe, Hawker, Choules, Captain
Hutton, and others.

V

<*.

V"^/

<'

.«»«l

INDEX TO VOL. I.

Jt: .>

V „*

n

^S

The synonyms, as well as the names of spurious species, and of species,
genera, and other groups wliich are not described in this volume, are in
italics. — The figures in smaller type refer to the page in wliich the descrip-
tion of species, genera, and higher groups will be found.

AcHATiNA, Lam., 149, 150, 287, 288,
289, 295, 296, 297, 302.

acicula, MlilL, 296, 297, 298, 307.

dentiens, Rossm., 289.
Acicula, Risso, 295, 307.
Acicula, Hartm., 307.
Acmaa, Esch., 307.
Acme, Hartm., 307.

fiisca, Beck, 309.

iineata, Drap., 308.

minuta, Brown, 309.
Alasmodon, 31.
Alaa, Jeffr., 265.

remhita, Jeffr., 269.

stibstriata, Jeffr., 261.
AlasTuodonta

margaritifera, F. & H., 37.
Ammonite, 78.
Am2)hipcplea, 101, 104.
Amplexus, 174.
Ancylus, G-eoffr., 71, 118.

Capuloides, Jan, 120.

deperditus, Ziegl. (& Dup.), 121.

fluviatilis, Miill., 119, 120, 121,
122, 123.

gihhosus, Bourg., 120.

lacustris, Linn., 120, 122.

ohlongus, F. & H., 122, 123.

spina-rosce, Drap., 123.
Anodonta, Lam., 39.

anatina, Linn., 43.

Cellemis, C. Pfeiff., 43.

complanata, Ziegl., 44.

cygnea, Linn., 41.

cygnea (part.), F. & H., 43.

ponderosa, C. Pfeiff., 43.

rostrata, Kok., 42.

ventricosa, C. Pfeiff., 44.
Aplcxa, Flem., 98.
Ajjlysia, 78.

Aquatic, i.

Arion, Fer., 126, 130.

ater, Linn., 127, 128, 139.

Empiriconi.m, Fer., 127.

fasciatus, Nilss., 128.

flaims, Fer., 127.

hortensis, Fer., 128.
Assimi7iia

Grayana, 65.
Aurictda, Klein, 5.
Auricula, Lam., 299.
Auriculacea, Lam., 299.
Azeca, Leach, 289.

Notdetia7ia, Drap.. 291.

tridens, F. & H., 290.

Balcea, Leach, 272. 273.
Balm, Prideaux, 271. 273.

fragilis. F. & H., 273.

Sarsii, Phil, 275.
Balia, Prid., 149, 150, 271, 272.

perversa, Linn., 273.
Bithinia, Gray, 59.

humilis, Boub., 63.

Leachii, 61.

tentaculafa, 60.

ventricosa. Gray, 62.
BIVALVES, I.
Buccinum, 297.

acicula, Miill., 289, 297.

glahrum, Miill., 117.

glutinosum, Miill., 102.

palustre, Miill. , 113.

peregrum, Miill., 104.

terrestre, Mont., 299.

truncatulum, Miill., 115.
Bulimi, 174, 232.

BuLiMus, Scopoli, 114, 149, 150,231,
232,241,253,276,289,291.

acutus, Miill., 232, 233.

332

IXDEX.

BuLiMUS (contimted).

anatinus, Poir., 66.

articulatus, Lam., 235.

articulatus, Turt., 225.

auris-MidcB, 299.

clavulus, Turt., 240.

decollatus, 61, 240.

fihrafus, 299.

glans, Brug., 287.

Guadalo2(]p€nsis, Brug., 239.

Lackhamensis, F &H., 235.

leiccostoma, Poir., 118.

lineatus, Drap., 308.

Menkeanus, 292.

montanus, Drap., 235, 239.

obscurus, MiilL, 236, 237,239, 243.

octonus, Brug., 289.

quadridens, 289.

tridens, 289, 292.

tuberculafus, Turt., 239.

ventricosus, Drap., 232, 234.
Bidin, Adans., 5,231.
Bulla

fluviatilis, Turt., 99.

fontinalis, Linn., 98.

hypnorum, Linn., 96, 97.

Hvalis, Mat. & Rack., 100.
Bi/tkmella, Moq.-Tand., 63.
Bythinia, 59, 304.

Leachii, Shepp., 61.

tentaculata, Linn., 60.

CcBcilianella, Bourg., 295, 296.

Anglica, Bourg., 295.

Liesvillei, Bourg., 296.
C(Bcilio'ides, Beck, 295, 296.
Cardium

Casertanum, Poli, 24.
Carocolla, 174.
Carychiid.e, 124, 299, 300.
Carychium, MiilL, 299, 300.

minimum, MiilL, 269, 300, 302.
Chilotrema, 174.
Cionella, Jeffr., 288, 289.
Clausilia, Drap., 149, 150, 272, 275,
276,277,287,289,291,292.

hidens, Drap., 286.

biplicata, Mont., 283, 285, 286.

derugata, Fer., 286.

duhia, Drap., 279, 282.

Everetti, Mill., 279.

labiata, 286.

laminata, Mont., 284, 286.

lineolata, Held, 284.

Clausilia {continued).

Mortilleti, Dum., 282.

nigricans, Mat. & Rack., 278.

obtusa, C. Pfeiif., 280.

papillaris, Drap., 287.

parvula, Stud.. 280.

plicatula, Drap., 281, 282, 310.

Rolphii, Gray, 236, 281, 282, 283,
284, 310.

rugosa, Drap., 275, 278, 281, 282.

rugulosa. ZiegL, 279.

siniilis, Charp., 284.

solida, Drap., 286, 287.

ventricosa, Drap., 284.

vivipara, Held, 284.
ClausilicB, 276, 278.
CocHLicoPA, Risso, 149, 150, 287,
288, 289, 297, 302.

lubrica, MiiU., 289, 292, 294, 295,
297.

tridens, Pult., 289, 290, 294.
CONCHIFERA, i.
Conovulus, Lam., 55, 76, 299, 302.
Corbicula, 3.
Crepidula, 45.
Cyclas, Drap.

caliculata, Drap., 10.

cornea, F. & H., 5.

flavescens, Macg., 6.

fontinalis, Drap., 20.

fontinalis, Nilss., 25.

lenticularis, Norm., 22.

nucleus, Stud., 6.

ovalis, Fer., 8.

rhomboidea. Say, 10.

rivalis, Dup., 6.

rivalis, Drap., 7.

rivicola. Leach, 7.

Eyckholtii, Norm., 11.

Scaldiana, Norm., 6.

solida. Norm., 3.
Cyclostoma, 303, 304.

acutum, Drap., 68.

anatinum, Drap., 59, 63, 310.

contectuni, Millet, 56.

elegans, Mull., 304, 306, 307.

ferrugineum. Lam., 307.

impurum, Drap., 61.

marmorea. Brown, 307.

simile, Drap., 62, 64, 310.

sulcatum, 303.

vitreum, Drap., 68.
Cyclostomatid.e, 302.
Cyclostoine, Lam., 304.

INDEX.

333

Cyrena, 3.

fluminalis, 3.
Cyrenastrum, Bourg,, 3.

Delphimila, Lam., 304.
Dreissena, Van Bened., 46.

polyniorpha, Pall., 47.
Dreissenid.e, 45.

Elisma, Leach, 232.
Eulima
steoiostoma, 296.

GASTEEOPODA, 51, 304.

Geomalacus, Allm., 129.

maculosus, Allm., 129.
Glandina, Schum., 287, 297.
Gulnaria

lacustris, Leach, 105.

Helices, 173, 174, 218, 232.

Helicid.e, 124, 149.

Helix, Linn., 149, 150, 158, 172,

174, 232, 243, 246, 253, 269,

288, 289.
aculeata, Miill., 176.
ancfa, MiilL, 233.
alhella, Linn., 229.
albella, Flem., 229.
aUiaria, Mill., 161.
Altenana, Kicks, 195.
ajjerta, Born, 184, 185.
arbustonmi, Linn., 186, 188, 190.
aspersa, MiilL, 178, 181, 182, 184,

185.
auricularia, Linn., 108.
bidens, Chemn., 172.
bidens, Mull., 286.
bidens, Linn., 287.
Bulimoides, Moq.-Tand., 232,
ccplata, Stud., 196.
candidula. Stud., 211.
Cantiana, Mont., 190, 193, 194,

209.
caperata, Mont., 213, 215.
Carthusiana, Drap., 191.
Carthusiana, F. & H., 192.
CarthusianeJJa, Drap., 194.
Cartusiana. Miill., 191, 192, 231.
cellaria, Midi., 159.
cespitum, Drap., 218.
chersina, Say, 171.
cingenda, Mont. 209.

Helix {continued),
circinnata. Stud., 196.
clandestina, Hartm., 196.
clarci. Held, 169.
cochlea, Brown, 92.
complanata, Linn., 91, 92.
concinna, JefTr., 196, 198.
conica, Drap.. 232.
conspurcata, Drap., 215.
contorta, Linn., 94.
cornea, Linn., 93.
Corvus, Gmel., 114.
costata, Miill., 225.
crenella, Mont., 225.
depilata, C. Pfeiff., 198.
Draparnaudi, Shepp., 84.
edentula, Drap., 172.
electrina, Gould, 165.
elegans, Drap., 216.
ericetorum, Miill., 216.
ericetorum, Nilss.. 217.
excavata, Bean, 168.
explanata, Miill., 229.
fasciolata, Poir., 215.
fossaria, Mont., 117.
fragilis, Mont., 111.
fruticum, Miill., 174.
fulva, Midi, 171, 172.
fusca, Mont., 204, 205.
fusca, Poir., 206.
Gibbsii, Leach, 194.
Gigaxii, Charp., 214.
glabella, Drap., 196, 310.
glabra, Stud., 162.
glapliyra. Say, 160.
globularis, Jelfr., 202.
Goodallii, Mill., 239.
granulata, Aid., 202.
grisea, Linn., 184.
Hammonis, Strom, 165.
Helmii, Gilb., 163, 164.
hispida, Linn., 196, 197, 198, 200,

202, 310.
hortensis, Penn., 184.
hortensis, Miill., 186, 187.
hybrida, Poir. 186.
incarnata, Miill., 174, 202, 206.
instabilis, Ziegl., 217.
intersecta, Poir., 215.
Itala, Linn., 218.
Kirbii, Shepp., 224.
Lackhamensis, Mont., 236.
lamellata, JefFr., 175, 245.

334

INDEX.

Helix (continued').
lapicida, Linn., 227.
Umhata, Drap., 102.
limosa, Linn., 108.
Imeata, Walk., 79.
lineata, Olivi, 211, 213.
luhrica, Mull., 288, 289, 292.
lucida, Pult., 161.
lucida, Drap., 161.
lucorum, 178.
lutea, Mont., 105.
maritima, Drap., 211.
minuta, Stud., 224.
Tnontana, Stud., 196.
Mortoni, Jeffr., 171.
muscorum, Linn., 248, 249, 251.
muscorum, Mont., 248.
muscorum, Miill., 252.
Naticoides, Drap., 185.
neglecta, Drap., 211.
nemoralis, Linn., 151, 185, 187,

207.
Nilssoniana, Beck, 217.
nitens, G-mel., 164.
nitens, Mat. & Eack,, 164.
nitens, Mich., 163, 164.
nitida, Drap., 161.
nitida, Miill., 167.
nitidosa, Fer., 167.
nitidula, Drap., 163, 164, 167,

310.
ohliterata, Hartm., 217.
obscura, Miill., 237.
obvoluta, Miill., 229, 230, 231, 236,

289.
occidentalis, Reel., 204.
octanfracta, Mont., 118.
octona, Linn., 68, 299.
octona, Penn., 299.
pallida, Don., 191.
'paludosa, Da Costa, 227.
perversa, Miill., 280.
fetronella, Charp., 169.
ficea, Ziegl., 189.
Pisana, Miill, 207, 213.
planorbis, Linn., 91.
plebeium, Drap., 200, 310.
pomatia, Linn., 177, 178, 182.
Ponentina, Mor., 204.
'pulchella, Miill., 224, 227.
pupa, Linn., 239.
pur a, Aid., 164.
putris, Linn., 151.

Helix {continued).

pygmn?a, Drap., 223, 310.
radiata, Da Costa, 220.
radiatula. Aid., 166, 169.
revelata, Mich., 202, 204, 206, 207,

310.
revelata, Fer., 202, 204.
revelata, Bouch.-Ch., 204, 206.
rhodostoma, Drap., 209.
rhomhea, Turt., 91.
rotundata, Miill., 218, 229.
rotundata, Turt., 220.
ruderata, Stud., 174.
rufescens, Penn., 191, 194. 195,196,

197, 198, 230, 310.
rufescens, G-mel., 196.
rufescens, G-rateloup, 196.
rufilabris, Jeifr., 193.
rupestris. Stud., 220, 223, 224.
Scarburgensis, Aid., 175.
seminulum, Rossm., 175.
sericea, Miill., 198, 201, 202,

204.
sericea, Aid., 199.
sericea, Drap., 204, 310.
sericea, Phil., 200.
Somershamiensis, Shepp., 229.
spinulosa, Mont., 176.
spirorbis, Linn., 84.
stagnalis, Linn., 111.
striata, Miill., 215.
striata, Drap., 215.
striatula, Linn., 167, 215.
striatula, Miill., 167, 215.
striatula, Olivi, 16T.
striatula, Grray, 167.
subcylindrica, Linn., 295.
submaritima, Rossm., 211.
tentaculata, Linn., 60.
terebra, Turt., 92.
terrestris, Penn., 215.
Trochiformis, Mont., 172.
TrocMlus, MiUl., 239.
Turtoni, Flem., 219.
umbilicata, Mont., 220, 222.
umbrosa, Partsch, 198.
unifasciata, Poir., 211.
variabilis, Drap., 213.
ventricosa, Miill., 243.
virgata. Da Costa, 210, 211, 212,

213, 214, 215, 218, 234.
viridula, Menke, 168, 169.
vitriyia, Fer., 168, 169.

INDEX.

335

Helix {continued').

vitrina, Wagn., 169.

vivipara, Linn., 57, 58.

vortex, Linn., 88.

zonaria, Penn., 209.
Hydrobia, Hartm., 63, 304.

Ferussina, 69.

raarginata, Mich., 64, 69.

similis, Drap., 64, 310.

ulvce, 67, 310.

ventrosa, Mont., 66.

Kelliadcs, 2.

LAMELLIBRANCHIATA, i.
LimaceUa, Brarcl, 132.

concava, Brard, 134.

ohliqua, Brard, 135.

farma, Brard, 139.

unguiculus^ Brard, 133.
LiMAciD^, 124, 125.
LiMAx, Linn., 130.

agrestis, Linn., 134, 135, 139.

cmguiformis, Mor., 129, 130.

antiquorum, Fer., 139.

arbor eus, F. & H., 135.

arborum, Bouch.-Ch., 133, 135,
138

ater, Linn., 127, 182.

hrunneus, Drap., 139.

brunneus, Bouch.-Ch., 139.

carinatus, Risso (& Leach), 133.

cinctus, Miill., 129.

ci7iereo-niger, Nilss., 138.

cinereus, Miill., 137, 138.

filans, Hoy, 136.

flavus, Linn., 133, 140.

flavus, Miill., 127, 134.

fuscus, Miill., 129.

gagates, Drap., 131, 133, 143.

Limnicus, Scln-enck, 136.

marginatus, Miiil., 132.

maximus, Linn., 137, 138.

parvulus, Norm., 139.

Sowerbii, Fer., 132, 133.

tenellus, F. & H., 139.

tmellus, Miill., 140.

variegatus, Drap., 134.
LiMN^A, Brug., 1 01.

auricularia, Linn., 108, 109, 110,
115.

Burnetti, Aid., 103, 104.

cornea, 115. .

LiMN.EA {continued^.

glabra, Miill., 112, 117, 299.
ghitinosa, Miill., 102, 103.
invokita, Thomps., 103.
palustris, Miill., 108, 113.
peregra, Miill., 104, 107, 111. 112,

117, 119.
stagnalis, Linn., iii, 112, 113.
truncatula, Miill., 114, 115,

119.

LlMN.EID^, 77, 300.

LimncBus

auricvMrms, F. & H., 108.

Bitrnetti, F. & H., 104.

glaber, F. & H., 117.

glutinosus, F. & H., 102.

involutus, F. & H., 103.

lineatus, Bean, 106.

palustris, F. & H., 113.

pereger, F. & H., 104.

stagnalis, F. & H., 111.

truncatulus, F. & H., 115.
Limnea

intermedia, Fer., 105, 107-
Limneus

acutus, Jeffr., 109.

elongatus, Drap., 118.

minutus, Drap., 117.

ovatus, Drap., 105, 106.

tinctus, JefEr., 114.
Lithoglyphus

Naticoides, Fer., 70.
Lifiopa

bombyx, 68.
Lutea, 101.
Lymnea, Brug., 101.

Mangelia

nivalis, 296.
Margarita, 71.
Margaritana, 31.
Melampus, Montf., 55, 76, 299,

306.
Murex, 300.
Mya

margaritifera, Linn., 37.

ovalis, Mont., 33.

pictorum, Linn., 34.
Mysca

Batava, Turt., 37.
Mytilidce, 29, 46.
Mytihcs, 29, 46.

anatinus, Linn., 43.

336

INDEX.

Mytilus (continued).

avonensis, Mont., 40, 43.

cygneus, Linn., 4] .

dentattis, Tiu't., 42.

mcrassatus, Shepp., 42.

paludosus, Turt., 42.

polymo)'phus, Pall., 47.

radiatus, Miill., 42.

stagnalis, Gmel., 42.

Zellensis, Gmel., 42.
Myxas, 101.

Hatica

Kwgii, F. & H., 70.
Nautilus, 80.

lacustris, Lightf., 81.
Nerita, 53, 63.

elegans, Miill., 304.

fasciafa, Miill., 57.

fiuvicdilis, Linn., 53.

obtusa, Stud., 74.

piscinalis, Miill., 72.
Neritid.e, 52.
Neritina, Lam., 52, 63.

B(stica, Lam., 54.

fluTiatilis, Linn., 53.
Neritostoma, Klein, 5.

Onchidhim

Celticurn, 300.
Otina, 76, 299.

Paludestrina, D'Orb., 64.
Paludina, Lam., 55, 304.

anatina, 62.

contecta, Millet, 56.

diaphana, Mich., 68.

L«sz'm,F.&H., 56.

marginata, Mich., 69.

meridio7ialis, Eisso, 65.

muriatica, Lam., 68.

similis, 62.

ventricosa, Menke, 60.

viridis, 62.

vivipara, Linn., 5!?.
Paludinella, Pfeiff. & Lov., 64.
Paludinid>e, 55.
Parmacella, 141.
Patella, 119, 308.

fluviatilis, List., 121.

lacustris, Linn., 121, 122, 123.
PECTINIBRANCHIATA, 51.
Pedipes, Adans., 306.

Physa, Lam., 95.

acuta, Drap., 98, 100.

alba, Turt., 100.

contorta, Mich., 100.

elongata, Say, 97.

fontinalis, Linn., 98, 99.

hypnorum, Linn., 96.

Sowerbyana, D'Orb., 100.

subopaca, Lam., 100.
Pinna

fluviatilis, Sander, 49.
PisiDiUM, C. Pfeiff., 16.

amnicum, Miill., 20.

arccsforme, Malm, 28.

australe, Phil., 22.

cinereum, Aid., 21.

coniciim, 4.

fontinale, Drap., 20.

Henslowianum, Jen., 20, 21.

nitidum, Jen., 25.

obtusak, C. Pfeiff., 24.

pallidum, Gass., 22.

piclchellum, Jen., 21.

pusillum, Gmel., 23.

Eecluzianum, Bourg., 4.

roseum, Scholtz, 26.

sinuatum, Bourg., 26.

tetragonum, Norm., 28.

ventricosum. Prime, 24.
Planorbis, Guett., 78, 228.

albus, Miill., 83, 85, 86.

carinatus, Miill., 89, 92.

complanatus, Linn., 91.

compressus, Mich., 89, 90.

contortus, Linn., 94.

corneus, Linn., 93.

cristatus, Drap., 82.

disciformis, Jeffr., 90.

Draparnaldi, Jeffr., 84.

glaber, Jeffr., 85, 88.

gyrorbis, v. Seek., 86.

intermedins, Charp.. 93.

lacustris, F. & H., 79.

IcBins, Aid., 86.

leucostoma, Mich., 88, 151.

lineatus. Walk., 79, 82.

lutescens, Jeffr., 90.

marginafus, Drap., 84, 91, 92.

Nautileus, Linn., 82.

nitidus, Miill., 80, 81.

Rossmdssleri, Auersw., 86.

rotundatus, Poir., 88.

similis, Miill., 94.

INDEX.

337

Planorbis {continued).

spirorbis, MiilL, 87, 89, 93,

spirorbis, Moq.-Tand., 87.

spirorbis, Drap., 84.

submarginatus, Crist. & Jan, 93.

turgidus, JefFr., 93.

turritus, Miill., 98.

umbilicatus, Miill., 92.

vortex, Linn., 88, 90. 93.
PNEUMONOBRANCHS, 76.
Polyphemus, Montf., 287, 288.
PULMOBRANCHS, 76.
PULMONATES, 76.
PULMONIFERS, 76.
PULMONOBRATfCHIATA, 76.
PULMONOBRANCHS, 76.
Pupa, Lam., 149, 150, 240, 241,
243, 251, 252, 253, 264, 272,
276, 279.

Anglica, F. & H., 244.

Anglica, Moq.-Tand., 257.

antivertigo, Drap., 253.

arctica, v. Wall., 257.

avena, 243.

avenacea, 243.

bigranata, Rossm., 250.

borealis, Mor., 261.

Callicratis, Scacchi, 271.

Charpentieri, Shuttl., 257.

columella, v. Mart., 269.

costulata, Nilss., 271.

cylindracea. Da Costa, 249.

Desmoulinsiana, Jeffr., 257.

doliolum, 241.

edentula, Drap., 268.

fragilis, Drap., 275.

mornata, Mich., 269.

marginata, Drap., 241, 248, 249,
252, 253.

milium, Grould, 262.

minuta, Stud., 271.

minutissima, Hartm., 251, 270.

Moulinsiana, Dup., 255.

muscorum, F. & H., 249.

muscorum, Drap., 271.

obtusa, Flem., 271.

ovata, Say, 255.

pusilla, Biv., 254.

pusilla, F. & H., 263.

pygmaa, Drap., 257.

ringens, Jeflfr., 241, 244, 246, 248,
251.

ringens, Mich., 246.

Pupa {continued).

rugosa, Drap., 310.

secale, Drap., 238, 241, 242,246.

Sempronii, Charp., 248.

ShuttleworthimiOA, Charp,, 261.

substriata, F. & H., 261.

tridens, 241.

triplicata, Stud., 271.

umbilicata, Drap., 222, 241, 245,
246, 248, 251, 252.

Venetzil F. & H., 265.
PupxB, 240, 255.
Fupula, Agass., 308.

Eissoa

anatina, F. & H., 64.

castanea, JefFr., 69.

ventrosa, F. & H., 66.
RissocB, 63.

Scalaria, Lam., 304.
Segmentina, Flem., 80.
Solarium, 220.

SPHiERIID.E, I.

Sph^rium, Scop., 4.

Brochonianum,'Bo\XTg., 11.

citrinum. Norm., 6.

corneum, Linn., 5.

lacustre, Miill., 10.

ovale, Fer., 8.

pallidum, Gray, 8.

Pisidioides, Gray, 6.

rivicola, Leach, 7.
Btagnicola

elegans, Leach, 112.
Sfyloides, Fer., 288.
SucciNEA, Drap., 149, 150, 156. .

abbreviata, Mor., 155.

arenaria, Bouch.-Ch., 155.

elegans, Risso, 153, 154.

gracilis. Aid., 154.

oblonga, Drap., 153, 154, 155.

Pffeiferi, Rossm., 154.

putris, Linn., 150, 151, 153, 154.

Tellina

amnica, Miill., 20.

cornea, Linn., 5.

Henslowana, Shepp., 21 .

lacustris, Miill., 10.

pusilla, Gmel., 22, 23.

rivalis, Miill., 7.
Teredo, 49, 229, 276.

Q

338

INDEX.

Terrestrial, 124.
Testacella, Cut., 140 et scq.

AltcB-ripcB, 147.

Beshayesii, 147.

Europcea, De Roissy, 147.

Haliotidea, Drap., 145, 147.

Maugei. Fer., 144, 147, 148.

Medii-TempU, Tapp., 146.

scutulum, Sow., 145, 147.
Testacellcs, 144, 156.

TESTACELLIDiE, 124, I40, 149.

Testacelhis, Faiu'e-Big., 141.
Theha, Eisso, 209.
Tichogonia

flv.viatilis, Erichs., 46.
Trochus, 71.

perspectivus, 220.

sylvaticus. List., 248.
Truncatella, 304.
Turbo

bidens, Mont., 280.

bipUcatus, Mont., 283.

chrysalis, Turt., 252.

fasciatus, Penn., 23.5.

glaber, Da Costa, 295.

Helicinus, Lightf., 227.

juniper i, Mont., 243.

laminatus, Mont., 284.

Leachii, Shepp., 61.

JSautUeus, Linn., 82.

nigricans, Mat. & Rack., 280.

Offtonensis, Shepp., 269.

perversus, Linn., 273.

sexdentatus, Mont., 255, 259.

stagnorum, Easter, 68.

thermalis, Grmel., 68.

tridens, Pult., 289, 290.

ulvcB, Penn., 66.

ventrosus, Mont., 66.

vertigo, Mont., 267.
Turtonia

minuta, 4.

Unio, Philipps., 31.
amnicus, Ziegl., 37.
Batamis, 31.
curvirostris, Norm., 35.
litt oralis, 31.
margaritifer, Linn., 37.
margaritiferus, F. & H., 37.
nana, Lam., 37.
nanus, Dup., 37.
Phili'ppi, Dup., 36.

Unio {continued').

pictorum, Linn., 34.

rhomboideus, 31.

Roissyi, Mich.. 38.

sinuata. Lam., 38,

tumidus, Pliilipps., 32
Unionid.e, 28.
UNIVALVES, 51.

Vallonia, 174.
Valvata, Miill., 72.

antiqua, Morr., 73.

cristata, Miill., 74.

depressa, C. Pfeiff., 72.

minuta, Drap., 75.

piscinalis, Miill., 72.

planorbis, Drap., 75.

spirorbis, Drap., 75.

VALVATIDiE, 70.

Vertigo, Miill., 149, 150, 251, 252,

253, 256, 260, 264, 272, 289.
alpestris, Aid., 258, 259.
alfestris, Fer., 261.
Anglica, Fer., 246.
angustioi', JefFr., 265.
antivertigo, Drap., 253, 256, 257,

259, 264.
curta. Held, 262.
cylindrica, Fer., 271.
edentula, Drap., 264, 268, 270.
hamata, Held, 267.
heterostro'pha, Leach, 264.
minutissima, Hartm., 270.
Moulinsiana, Dup., 255, 257. 2.58,

259.
nana, Mich., 267.
nitida, Fer., 269.
octodentata, ^txxd., 255.
palustris. Leach, 255.
plicata, A. Miill., 267.
pusilla, Miill., 252, 253, 263, 266.

267, 268.
pygmsea, Drap., 252, 255, 256, 257,

259, 260, 261.
rupestris, 253.
septemdentata, Fer,, 255.
substriata, Jeifr., 255, 261, 264.
Venetzii, Eossm , 567.
ViTRiNA, Drap., 150, 155, 159.
d<pressa, Jeffr., 157.
diaphana, Drap., 156, 158.
Dillwynii, JefPr., 157.
Draparnaldi, Cuv., 157.

INDEX.

339

ViTRiNA {continued).

Draparnaldi, Jeffr., 157.

major, Fer., 157.

pellucida, Miill., 156, 158.

semilimax, Fer., 141.
VitrimB, 143, 158.

ZoNiTES, De Montf., 143, 150, 156,
158, 160, 220.
aUiarius, Mill., 161, 162, 168.
cellarius, Miill., 159, 160, 161, 162,

164, 230.
crystallinus, Miill., 170.

ZoNiTES {continued).

excavatus, Bean, 168, 169.

fulvus, MiUl, 171.

glaher, 162.

nitidulus, Drap., 163, 165.

nitidus, Miill., 163, 165, 167, 170.

purus, Aid., 164, 166, 169, 310.

radiatulus. Aid., i66, 168, 310.
Zospeum, Bourg., 296.
Zua, Leach, 289,

^M6r?e«, F.&H., 292.
Zurama, 174.

EXPLANATION OF PLATES.

Frontispiece.
Unio margaritifer, and pearl.

Plate I.

Figure 1. Sphcsrium rivicola, sliowing the double tube and foot.

2. Hinge of the shell.
3. Pisidium amtiicum, showing the single tube and foot.

4. Hinge of the shell.
5. Uiiio pictoi'um, showing both orifices and the foot.

6. Hinge of the shell.

Plate U.

Figure 1, Anodonta anatina, showing both orifices and the foot.
2. Hinge of the shell.

3. Dreissena ])olymorpha, showing the two orifices and tubes

in an inyerted position and the byssus attached to the
fragment of a yalve of an Anatina. 4. Shell. 5. Inside
of hinge.

Plate HI.

Figure 1. Neritinajluviatilis, showing the snout, tentacles, position
of the eyes, and the foot. 2. Shell. 3, 4. Operculum.
5. Paludina vwijmra. 6. Shell, showing the operculum in
situ.

7. Bythinia tentaculata. 8. Shell, showing the operculum

in situ. 9. Back view of shell.

10. Hydrohia similis. 11. Shell, showing the operculum ««
situ. 12. Natural size.

13. Valvata cristata, showing the branchial plume and fila-
ment. 14. Shell of V. piscinalis. 15. Operculum of
same.

Plate IV.

Figure 1. Planorhis corneus, showing the body and attachment ot
the foot. 2, 3. Shell.

4, 5. Physa fontinalis, showing the digitated lobes of the

mantle. 6, 7. Shell.

8. Lirnncea pereyra, showing the respiratory opening to the

right. 9, 10. Shell of L. stayncuis.

11, 12. AncyJus Jiuviatilis, showing the front and imder

side. 13, 14. Shell.

EXPLANATION OF PLATES. 341

Plate V.

Figure 1. Avion ater, showing the tentacles, eyes, shield, position
of the respiratory opening, and slime-gland at the tail.
2. Same at rest.

3. Geomalacus inaculosus (from Brit. Moll. pi. F.F. F*. f. 5).

4. Limax maximus, showing the position of the respiratory

opening. 5. Shell or Limacella.

6. Testacella Haliotidea, showing the labial palps (below the

tentacles) and the position of the shell. 7. Shell.
8. Egg.

Plate VI.

Figure 1. Succinea jmtns. 2. Shell.
3. Vitrina pellucida. 4. Shell.

5. Zonites cellarius. 6. Shell.

7. Helix aspersa. 8. Shell.

Plate VII.

Figure 1, Bulimus acidits. 2. Shell of var. injlata.

3. Pi^a umbilicata. 4. Shell. 6. Natural size.

6. Vertigo pygmcea, showing the two tentacles. 7. Shell.

8. Natural size.
9. Balia perversa. 10. Shell. 11. Natural size.
12. Clausilia laminata. 13. Shell. 14. Clausilium.
15. Cochlicopa luhrica. 16. Shell. 17. Natural size.
18. Achatina aciciila. 19. Head and tentacles. 20. Shell.

21. Natural size.

Plate VIII.

Figure 1. Carychiufn minimum, showing the position of the eyes.
2. Shell. 3. Natural size.

4. Cyclostoma elegans, showing the snout and position of the

eyes. 5. Shell. 6. Operculum.

7. Ac?7ie lineata, showing the position of the tentacles and

eyes. 8, 9. Shell. 10. Natural size. 11. Operculum
magnified.

THE END.

PRINTED BY TAYLOR AND FRANCIS;
RED LION COURT, FLEET STREET.

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