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MANUAL OF THE MOLLUSCA;*
/ .
OR, A
RUDIMENTARY TREATISE
RECENT AND FOSSIL SHELLS.
BY
S. P. WOODWARD,
*
ASSOCIATE OF THE LINNEAN SOCIETY;
ASSISTANT IN THE DEPARTMENT OF MINERALOGY AND GEOLOGY
IN THE BRITISH MUSEUM; AND
MEMBER OF THE COTTESWOLDE NATURALISTS' CLUB.
ILLUSTRATED BY
A. N. WATERHOUSE AND JOSEPH WILSON LOWRY.
LONDON:
JOHN WEALE, 59, HIGH HOLBOEN.
MDCCCLI.
in Lih,
LONDON
PRINTED BY WILLIAM OSTELL,
HART STREET, BLOOMSBURY.
CONTENTS.
PAGE
Table of the Sub-kingdoms and Classes of Animals 2
INTRODUCTION.
CHAPTER I.
ON THE POSITION of THE MOLLTJSCA IN THE ANIMAL KINGDOM.
Characters of the four primary groups ; Vertebrata
Mollusca Articulata Radiata. Their equal antiquity ... 3
CHAPTER II.
CLASSES or THE MOLLTJSCA. 1. Cephalopoda. 2. Gasteropoda.
3. Pteropoda. 4. Brachiopoda. 5. Conchifera. 6.
Tunicata 6
CHAPTER III.
HABITS AND ECONOMY or THE MOLLUSCA. Sedentary tribes,
their mode of attachment ; locomotive tribes, their means
of progression ; situations frequented by shell -fish. Food :
vegetable- infusorial- and animal-feeders. Use of shell-fish
to other animals for food ; use of shells for ornamental and
other purposes ; prices of shells. Duration of molluscous
animals ; tenacity of life ; fecundity ; oviposition 10
252012
VI CONTENTS.
CHAPTER IV. PAGE
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. Nervous
system; organs of sense. Muscular system. Digestive
system ; lingual teeth ; secretions. Circulating system ;
aquiferous canals. Respiratory system. The shell, its
composition and structure; nacreous, fibrous, and porcel-
laneous shells ; epidermis ; erosion of fresh-water shells.
Formation and growth of the shell ; adult characters ; de-
collated shells ; monstrosities ; colours ; the operculum ;
homologies. Temperature and hybernation. Reproduc-
tion : of lost parts ; by gemmation ; viviparous ; alternate ;
oviparous. Development 21
CHAPTER V.
CLASSIFICATION. Affinities; analogies; species; genera; fami-
lies ; the quinary system 55
CHAPTER VI.
NOMENCLATURE. Synonyms; authorities; types 59
ABBREVIATIONS 61
SYNOPSIS OF THE GENERA.
CLASS I. CEPHALOPODA. ORDER I. DIBRANCHIATA 62
SECTION A. OCTOPODA 64
Fam. I. Argonautid#d#.---Spirula .., 77
ORDER II. TETRABRANCHIATA 83
Fam. I. Nautilidce. Nautilus, Lituites, Trochoceras, Cly-
menia , 83
Fam. II. Orthoceratidte. Orthoceras, Gomphoceras, On-
coceras, Phragmoceras, Cyrtoceras, Gyroceras, Ascoceras 87
Fam. III. Ammonitida. Goniatites, Bactrites, Ceratites,
Ammonites, Crioceras, Turrilites, Hamites, Ptychoceras,
Baculites 91
CLASS II. GASTEROPODA , 97
ORDER I. PROSOBRANCHIATA 103
SECTION A. SIPHONOSTOMATA lOi
Fam. I. Strombidce. Strombus, Pteroceras, Rostellaria,
Seraphs 104
Fam. II. MuricidcB. Murex, Pisania, Eanella, Triton, Tas-
ciolaria, TurbinelJa, Cancellaria, Trichotropis, Pyrda,
Fusus 106
Fam. III. Buccinida. Buccinum, Pseudoliva, Anolax,
Halia, Terebra, Eburna, Nassa, Phos, Ringicula ?, Pur-
pura, Purpurina, Monoceros, Pedicularia, Bicinula, Pla-
naxis, Magilus, Cassis, Oniscia, Cithara, Cassidaria, Do-
lium, Harpa, Columbella, Oliva, Aneillaria 110
Fam. IV. Conida. Conus, Pleurotoma 117
Fam. V. Volutida. Voluta, Cymba, Mitra, Yolvaria, Mar-
gineUa 118
Fam. VI. Cypraida. Cypra3a, Erato, vulum 120
Vlll CONTENTS.
PAGE
SECTION B. HOLOSTOMATA 122
Fam. I. Naticida. Natica, Sigaretus, Lamellaria, Narica,
Yelutina 122
Fam. II. Pyramidellida. Pyramidella, Odostomia, Chem-
nitzia, Stylina, Loxonema, Macrocheilus . . / .' . . . 125
Fam. Ill, Cerithiadce. Cerithium, Potamides, Nerinaea,
Fastigiella, Aporrhais, Struthiolaria 127
Fam. IV. Melamadae. Melania, Paludomus, Melanopsis... 130
Fam. V. TurritelliddB. Turritella, Aclis, Csecum, Verme-
tus, Siliquaria, Scalaria 132
Fam. VI. Litorinidae. Litorina, Solarium, Phorus, Lacuna,
Litiopa, Eissoa, Skenea, Truncatella, ? Lithoglyplius .,, 134
Fam. VII. Paludinidte. Paludina,Ampullaria, Amphibola,
Yalvata 138
Fam. VIII. Neritidae. Nerita, Pileolus, Neritina., Navicella 140
Fam. IX. Turbinidce. Turbo, Phasianella, Imperator, Tro-
chus, Eotella, Monodonta, Delphinula, Adeorbis, Euom-
phalus, Stomatella, Broderipia 142
Fam. X. Haliotis. Haliotis, Stomatia, Scissurella, Pleuro-
tomaria, Murchisonia, Trochotoma, Cirrus, lanthina 146
Fam. XI. Fissurellid(B. rissurella, Puncturella, Simula,
Emarginula, Parmophorus 149
Fam. XII. Calyptraidce. Calyptrsea, Crepidula, Pileopsis,
Hipponyx 151
Fam. XIII. PatellidcB. Patella, Acmsea, Gadinia, Sipho-
uaria 153
Fam. XIV. Dentaliada. Dentalium 156
n. XV. CUtonida. Chiton . . 156
NOTICE.
THE second part of this Manual is now in preparation, and
will be published early in the summer. It will contain an ac-
count of the remaining orders of shell-fish: a chapter on the
Geographical Distribution of the MoUusca, with a Map of the
Marine and Terrestrial Provinces ; a chapter on the distribution
Fossil Shells ; another on the methods of collecting and pre-
serving Land, Fresh-water, and Sea-shells ; the Preface ; and an
Index of the genera and technical terms .
The writer desires to acknowledge his obligations to Mr.
Hugh Gumming. Professor Edward Forbes, and other gentlemen
vho have assisted him by advice, and the loan of specimens :
dso to Mr. Tan Voorst, for permission to copy some interesting
igures from the " British MoUusca : ?J and his thanks are most
especially due to Mr. John Edward Gray, Keeper of the Zoolo-
gical Department of the British Museum, for access to his library
cabinet, and the use of some of the best engravings which
llustrate these pages.
KINGDOM ANIMALIA.
SUB-KINGDOM I. VEBTEBRATA.
CLASS I. MAMMALIA.
II. AVES.
III. REPTILIA.
IV. PISCES.
SUB-KINGDOM II.
MOLLUSCA.
CLASS I. CEPHALOPODA.
II. GASTEROPODA.
III. PTEROPODA.
IV. BRACHIOPODA.
V. CONCHIFERA.
YI. TUNICATA.
SUB-KINGDOM III,
AKTICULATA.
CLASS I. INSECTA.
II. ARACHNIDA.
III. CRUSTACEA.
IV. CIRRIPEDA.
Y. ANELLATA.
YI. ENTOZOA.
SUB-KINGDOM IY. EADIATA.
CLASS I. ACALEPHA.
II. ECHINODERMATA.
III. ZOOPHYTA.
IY. FORAMINIFERA.
Y. INFUSORIA.
YI. AMORPHOZOA.
MANUAL OF THE MOLLUSCA.
INTRODUCTION.
CHAPTER I.
ON THE POSITION OF THE MOLLUSCA IN THE
ANIMAL KINGDOM.
ALL known animals are constructed upon four different types,
and constitute as many natural divisions or sub-kingdoms.
1. The first of these primary groups is characterized by an
internal skeleton, of which the essential, or ever-present part, is
a backbone, composed of numerous joints, or vertebra. These
are the animals most familiar to us ; beasts, birds, reptiles, and
fishes, are four classes which agree in this one respect, and are
hence collectively termed vertebrate animals, or the vertebrata.
2. Another type is exemplified in the common garden-snail,
the nautilus, and the oyster ; animals whose soft bodies are pro-
tected by an external shell, which is harder than bone, and equally
unlike the skeleton of fishes, and the hard covering of the crab
and lobster. These creatures form the subject of the present
history, and are called mollmca.*
* Mollusca soft (animals), from mollis. The Greeks termed them Ma-
lakia, whence the modern word Malacology, or the study of shell-fish.
B 2
M^TCAL OF TKE
3. The various tribes of insects, spiders, crabs, and worms>
Lave no internal skeleton ; but to compensate for it, their outer
integument is sufficiently hard to serve at once the purposes of
bones, and of a covering and defence. This external armature,
like the bodies and limbs which it covers, is divided into seg-
ments or joints, which well distinguishes the members of this
group from the others. The propriety of arranging worms with
insects will be seen, if it be remembered, that even the butterfly
and bee commence existence in a very worm-like form. This
division of jointed animals bears the name of the articulate.
4. The fourth part of the animal kingdom consists of the
coral-animals, star-fishes, sea-jellies, and those countless micro-
scopic beings which swarm in all waters. Whilst other animals
are bi-lateral, or have a right and left side, and organs arranged
in pairs, these have their organs placed in a circle around the
mouth or axis of the body, and have hence obtained the appella-
tion of radiata.
These groups illustrate successively the grand problems of
animal economy. The lower divisions exhibit the perfection-
izing of the functions of nutrition and reproduction ; the higher
groups present the most varied and complete development of
the senses, locomotive powers, and instincts. We may also trace
in them an ideal progression from the simplest to the most
complicated structure and conditions. Commencing with the
Infusorial monad, we may ascend in imagination by a succession
of closely allied forms, to the sea-urchin arid holothuria* ; and
thence by the lowest organized worms, upwards to the flying
insect. Or, starting at the same point, we may pass from the
polypes to the tunicaries ; and from the higher kinds of shell-
fish to the true fishes, and so on to those classes whose physical
organization is most nearly identical with our own.
The mollusca are thus related to two of the other primary
groups ; by the affinity of their simpler forms to the zoophytes,
See the History of British Star-fishes, by Professor E. Forbes.
MOLLUSCA IN THE ANIMAL KINGDOM. 5
and of their highest class to the fishes ; to the cirripedes and
other articulate animals, they present only superficial and illusive
resemblance.
And further, we shall find that although it is customary to
speak of shell-fish as " less perfect" animals, yet they really
attain the perfection of their own type of structure ; indeed it
would seem to have been impossible to make any further advance,
physical, or psychical, except by adopting a widely different
plan from that on which the molluscous animals have been
constructed.
The evidence afforded by geological researches at present
tends to shew that the four leading types of animal structure
have existed simultaneously from the very beginning of life
upon the globe ;* and though perpetually varying in the form
under which they were manifested, they have never since entirely
ceased to exist.
By adding to the living population of the world, those forms
which peopled it in times long past, we may arrive at some dim
conception of the great scheme of the animal kingdom. And if
at present we see not the limits of the temple of nature, nor
fully comprehend its design, at least we can feel sure that there
is a boundary to this present order of things ; and that there has
been a plan, such as we, from our mental constitution, are able
to appreciate, and to study with ever-increasing admiration.
* Mr E. Logan, Geological Surveyor of the Canadas, has discovered foot
prints of a tortoise, near Montreal, in the "Lingula Shale," or oldest fossi-
biferous rock at present known.
MANUAL OF THE MOLLUSCA.
CHAPTER II.
CLASSES OP THE MOLLUSCA.
THE mollusca are animals with soft bodies, enveloped in a mus-
cular skin, and usually protected by a univalve or bivalve shell.
That part of their integument which contains the viscera and
secretes the shell, is termed the mantle ; in the univalves it
takes the form of a sac, with an opening in front, from which
the head and locomotive organs project : in the bivalves it is
divided into two lobes.
The univalve mollusca are encephalous, or furnished with E
distinct head ; they have eyes and tentacula, and the mouth is
armed with jaws. Cuvier has divided them into three classes,
founded on the modifications of their feet, or principal locomo-
tive organs.
1. The cuttle-fishes constitute the first-class, and are termed
cephalopoda* because their feet, or more properly arms, are at-
tached to the head, forming a circle round the mouth.
Fig. l.f Oral aspect of a Cephalopod.
* From Cepkale, the head and poda feet. See the frontispiece and pi. I.
f Fig. 1. Loligo mdgaris, Lam. \. From a specimen taken off Tenby, by J.
S. Bowerbank, Esq. The mandibles are seen in the centre, surrounded by the
circular lip, the buccal membrane (with two rows of small cups on its lobes),
the eight sessile arras, and the long pedunculated tentacles (t), with their en-
larged extremities or clubs (c). The dorsal arms are lettered (d), the funnel (f).
CLASSES OF THE MOLLUSCA.
2. Iii the gasteropoda* or snails, the under side of the body
forms a single muscular foot, on which the animals creep or
glide.
Fig. 2. A Gastero^od.\
3. The pterpoda% only inhabit the sea, and swim with a pair
of fins, extending outwards from the sides of the head.
Fig. 3. A Pteropod.
The other mollusca are acephalous, or destitute of any dis-
tinct head ; they are all aquatic, and most of them are attached,
or have no means of moving from place to place. They are di-
vided into three classes, characterized by modifications in their
breathing-organ and shell.
4. The brackiapoda^ are bivalves, having one shell placed
on the back of the animal, and the other in front ; they have nc
* Gaster, the under side of the body.
f Fig. 2. Helix desertorum. Forskal. From a living specimen in the
British Museum, March, 1850.
\ Pteron, a wing.
Fig. 3. Hyaloea tridentata, Lam., from Quoy and Gaimard.
^[ Brachion, an arm ; these organs were supposed to take the place ol
the feet in the preceding classes.
MANUAL OF THE MOLLUSCA.
special breathing organ, but the mantle performs that office ; they
take their name from two long ciliated arms, developed from the
sides of the mouth, with which they create currents that bring
them food.
Fig. 4, 5, 6. Brachiopoda*
5. The conchifera,} or ordinary bivalves, (like the oyster),
breathe by two pairs of gills, in the form of flat membraneous
plates, attached to the mantle ; one valve is applied to the right,
the other to the left side of the body.
6. The tunicata have no shell, but are protected by an elas-
tic, gelatinous tunic, with two orifices ; the breathing-organ
takes the form of an inner tunic, or of a riband stretched across
the internal cavity.
Five of these modifications of the molluscan type of organiza-
tion, were known to Linnaeus, who referred the animals of all
his genera of shell-fish to one or other of them ; % but unfortu-
nately he did not himself adopt the truth which he was the first
* Fig. 4. (3). Rhynchonella psittacea, Chem, sp., dorsal valve, with the
animal (after Owen). 5, 6, Terebratula australis, Q,uoy. From specimens
collected by Mr. Jukes. (2). Ideal side view of both valves, (f, the retractor
muscles, by which the valves are opened). (1). Dorsal valve. These wood-
cuts have been kindly lent by Mr. J. E. Gray.
f Conckifera, Shell-bearers.
J The Linnsean types were Sepia, Limax, Clio, Anemia, Ascidia. Tere-
Iratula was included with Anomia, its organization being unknown.
CLASSES OF THE MOLLUSCA.
to see ; and here, as in his botany, employed an artificial, in pre-
ference to a natural method.
The systematic arrangement of natural objects ought not,
however, to be guided by convenience, nor " framed merely for
the purposes of easy remembrance and communication." The
true method must be suggested by the objects themselves, by
their qualities and relations ; it may not be easy to learn, it
may require perpetual modification and adjustment, but inas-
much as it represents the existing state of knowledge it will aid
in the UNDERSTANDING of the subject, whereas a " dead and
arbitrary arrangement" is a perpetual bar to advancement, " con-
taining in itself no principle of progression." (Coleridge.)
Fig. 7. A Bivalve.*
Fig. 8. A Tunicavy.^
Mya truncata, L. . From Forbes and Hanley.
t Ascidia merttula, Mull. Ideal representation; from a specimen dredsred
by Mr. Bowerbank, off Tenby.
B 3
10 MANUAL OF THE MOLLUSCA.
CHAPTER III.
HABITS AND ECONOMY OF THE MOLLUSCA.
EVERY living creature has a history of its own ; each has charac-
teristics by which it may be known from its relatives ; each has
its own territory, its appropriate food, and its duties to perform
in the economy of nature. Our present purpose, however, is to
point out those circumstances and trace the progress of those
changes which are not peculiar to individuals or to species,
but have a wider application, and form the history of a great
class.
In their infancy the molluscous animals are more alike, both
in appearance and habits, than in after life ; and the fry of the
acquatic races are almost as different from their parents as the
caterpillar from the butterfly. The analogy, however, is reversed
in one respect ; for whereas the adult shell-fish are often seden-
tary, or walk with becoming gravity, the young are all swimmers,
and by means of their fins and the ocean-currents, they travel
to long distances, and thus diffuse their race as far as a suitable
climate and conditions are found. Myriads of these little
voyagers drift from the shores into the open sea and there perish ;
their tiny and fragile shells become part of a deposit that is for
ever increasing over the bed of the deep sea, at depths too
great for any living thing to inhabit. (Forbes.)
Some of these little creatures shelter themselves beneath the
shell of their parent for a time, and many can spin silken threads
with which they moor themselves, and avoid being drifted away.
They all have a protecting shell, and even the young bivalves
have eyes at this period of their lives, to aid them in choosing an
appropriate locality.
After a few days, or even less, of this sportive existence, the
HABITS AND ECONOMY OF THE MOLLUSCA. 11
sedentary tribes settle in the place they intend to occupy during
the remainder of their lives. The tunicary cements itself to rock
or sea-weed ; the shipworm adheres to timber, and the pholas
and UtJiodomus to limestone rocks, in which they soon excavate
a chamber which renders their first means of anchorage unneces-
sary. The mya and razor-fish burrow in sand or mud; the
mussel and pinna spin a byssus ; the oyster and spondylus
attach themselves by spines or leafy expansions of their shell ;
the brachiopoda are all fixed by similar means, and even some
of the gasteropods become voluntary prisoners, as the Upponyx
and vermetus.
Other tribes retain the power of travelling at will, and shift
their quarters periodically, or in search of food ; the river-mussel
drags itself slowly along by protruding and contracting its flexible
foot ; the cockle and trigonia have the foot bent, enabling them
to make short leaps ; the scallop (pector opercularis) swims
rapidly by opening and shutting its tinted valves. Nearly all
the gasteropods creep like the snail, though some are much
more active than others; the pond-snails can glide along the
surface of the water, shell- down wards ; the nucleobranches and
pteropods swim in the open sea. The cuttle-fishes have a
strange mode of walking, head-downwards, on their outspread
arms ; they can also swim with their fins, or with their webbed
.arms, or by expelling the water forcibly from their branchial
chamber ; the calamary can even strike the surface of the sea
with its tail, and dart into the air like the flying-fish. (Owen.)
By these means the mollusca have spread themselves over
every part of the habitable globe ; every region has its tribe ;
every situation its appropriate species ; the land-snails frequent
moist places, or woods, or sunny banks and rocks, climb trees,
or burrow in the ground. The air-breathing limneids live ir
fresh- water, only coming occasionally to the surface; and the
auriculas live on the sea-shore, or in salt-marshes. In the sea,
each zone of depth has its molluscous fauna. The limpet and
periwinkle live between tide-marks, where they are left dry twice
12 MANUAL OF THE MOLLUSCA.
a-day ; the trochi and purpura are found at low water, amongst
the sea-weed ; the mussel affects muddy shores, the cockle re-
joices in extensive sandy flats. Most of the finely-coloured shells
of the tropics are found in shallow water, or amongst the breakers.
Oyster-banks are usually in four or five fathom water ; scallop-
banks at twenty fathoms. Deepest of all, the terebratula are
found, commonly at fifty fathoms, and sometimes at one hundred
fathoms, even in Polar seas. The fairy-like pteropoda, the
oceanic- snail, and multitudes of other floating molluscs, pass
their lives on the open sea, for ever out of sight of land ; whilst
the litiopa and scylltea follow the gulf-weed in its voyages, and
feed upon the green delusive banks.
The food of the mollusca is either vegetable, infusorial, or
animal. All the land-snails are vegetable-feeders, and their de-
predations are but too well known to the gardener and farmer ;
many a crop of winter corn and spring tares has been wasted by
the ravages of the " small grey slug." They have their likings,
too, for particular plants, most of the pea-tribe and cabbage-
tribe are favourites, but they hold white mustard in abhorence,
and fast or shift their quarters while that crop is on the ground.*
Some, like the " cellar-snail," feed on cryptogamic vegetation, or
on decaying leaves ; and the slugs are attracted \^ fungi, or any
odorous substances. The round-mouthed sea-snails are nearly
all vegetarians, and consequently limited to the shore and the.
shallow waters in which sea- weeds grow. Beyond fifteen fathoms,
almost the only vegetable production is the nullipore ; but here
corals and horny zoophytes take the place of algce and afford a
more nutritious diet.
The whole of the bivalves, and other head-less shell-fish, live
on infusoria, or on microscropic vegetables, brought to them by
the current which their ciliary apparatus perpetually excites ;
such, too, must be the sustenance of the magilus, sunk in its
* Dilute lime-water and very weak alkaline solutions are more fatal to
snails than even salt.
HABITS AND ECONOMY OF THE MOLLUSCA. 13
coral bed, and of the calyptrcea 9 fettered to its birth-place by its
calcarious foot.
The carnivorous tribes prey chiefly on other shell-fish, or on
zoophytes ; since, with the exception of the cuttle-fishes, their
organization scarcely adapts them for pursuing and destroying
other classes of animals. One remarkable exception is formed by
the stylina, which lives parasitically on the star-fish and sea-
urchin ; and another by the testacelle, which preys on the com-
mon earth-worm, following it in its burrow, and wearing a
buckler, which protects it in the rear.
Most of the siphonated univalves are animal-feeders ; the
carrion-eating stromb and whelk consume the fishes and other
creatures whose remains are always plentiful on rough and
rocky coasts. Many wage war on their own relatives, and take
them by assault ; the bivalve may close, and the operculated
nerite retire into his home, but the enemy, with rasp-like tongue,
armed with silicious teeth, files a hole through the shell, vain
shield where instinct guides the attack ! Of the myriads of small
shells which the sea heaps up in every sheltered " ness," a large
proportion will be found thus bored by the whelks and purples ;
and in fossil shell-beds, such as that in the Touraine, nearly half
the bivalves and sea-snails are perforated, the relics of antedi-
luvian banquets.
This is on the shore, or on the bed of the sea; far away
from land the carinaria and firola pursue the floating acalephe ;
and the argonaut, with his relative the spirula, both carnivorous,
are found in the " high seas," in almost every quarter of the
globe. The most active and rapacious of all are the calamaries
and cuttles, who vindicate their high position in the naturalists'
" system," by preying even on fishes.
As the shell-fish are great eaters, so in their turn they afford
food to many other creatures ; fulfilling the universal law of eat-
ing, and being eaten. Civilized man still swallows the oyster,
although snails are no longer reckoned " a dainty dish ;" mussels,
cockles, and periwinkles are in great esteem with children and
MANUAL OF THE MOLLUSCA.
the other unsophisticated classes of society ; and so are scallops
and the kaliotis, where they can be obtained. Two kinds of
whelk are brought to the London market in great quantities ; and
the arms of the cuttle-fish are eaten by the Neapolitans, and also
by the East Indians and Malays. In seasons of scarcity, vast
quantities of shell -fish are consumed by the poor inhabitants of
the Scotch arid Irish coasts.* Still more are regularly collected
for bait ; the calarnary is much used in the cod-fishery, off New-
foundland, and the limpet and whelk on our own coasts.
Many wild animals feed on shell-fish ; the rat and the racoon
seek for them on the sea-shore when pressed by hunger; the
South-American otter, and the crab-eating opossum constantly
resort to " salt-marshes, and the sea, and prey on the mollusca ;
the great whale lives habitually on the small floating pteropods ;
sea-fowl search for the literal species at every ebbing tide;
whilst, in their own element, the marine kinds are perpetually
devoured by fishes. The haddock is a " great conchologist ;"
and some good northern sea-shells have been rescued, unbroken,
from the stomach of the cod ; whilst even the strong valves of
the cyprina are not proof against the teeth of the cat-fish
(anarJiicas) .
They even fall a prey to animals much their inferiors in saga-
city ; the star-fish swallows the small bivalve entire, and dissolves
the animal out of its shell; and the bubble-shell (phyline),
itself predacious, is eaten both by star-fish and sea-anemone
(actinia).
The land-snails afford food to many birds, especially to the
thrush tribe ; and to some insects, for the luminous larva of the
glow-worm lives on them, and some of the large predacious
beetles (e. g. carabus violaceus and goerius olens}, occasionally
kill slugs.
The greatest enemies of the mollusca, however, are those of
their own nation ; scarcely one-half the shelly tribes graze peace-
See Hugh Miller's Forbes, from Alder and Haneock.
MANUAL OP THE MOLLTJSCA.
which M. Valenciennes regards as the organ of smell*. Messrs
Hancock and Erableton attribute the same function to the la-
mellatecl tentacles of the nudibranchs, and compare them withi
the olfactory organs of fishes.
The labial tentacles of the bivalves are considered to be or-
gans for discriminating food, but in what way is unknown (fig.
18. I. .) % The sense of taste, is also indicated rather by the
habits of the animals, and their choice of food, than by the
structure of a special organ. The acephala appear to exercise
little discrimination in selecting food, and swallow anything that
is small enough to enter their mouths, including living animal-
cules, and even the sharp spicula of sponges. In some instances,
however, the oral orifice is well guarded, as in pecten (fig. 10.)
In the Enceplmla, the tongue is armed with spines, employed
in the comminution of the food, and cannot possess a very de-
licate sense. The more ordinary
and diffused sense of touch is pos-
sessed by all the mollusca ; it is
exercised by the skin, which is
everywhere soft and lubricous,
and in a higher degree by the
/.. P-T i i AC -i \ Fig- 12. Lenton Squamosum.-\
fringes of the bivalves (fig. 12),
and by the filaments and tentacles (vibraculd) of the gasteropods ;
the eye-pedicels of the snail are evidently endowed with great
sensitiveness in this respect. That shell-fish are not very sensi-
ble of pain, we may well believe, on account of their tenacity of
life, and the extent to which they have the power of reproducing
lost parts.
Muscular System. The muscles of the moUusca are prin-
cipally connected with the skin, which is exceedingly contractile
in every part. The snail affords a remarkable, though familiar
* Mr. Owen regards the membraneous lamella between the oral tentacles
and in front of the mouth, as the seat of the olfactory sense. See Fig. 44.
f Fig. 12. Lepton sqaumosum Mont., from a drawing by Mr. Alder, ia
the British Mollusca ; copied by permission of Mr. Van Voorst.
STRUCTURE AND PHYSIOLOGY OF THE MOLLTJSCA. 25
instance, when it draws in its eye-stalks, by a process like the
inversion of a glove-finger ; the branching gills of some of the
sea-slugs, and the tentacles of the cuttle-fishes, are also emi-
nently contractile.*
The inner tunic of the ascidians (fig. 8, t.) presents a beau-
tiful example of muscular tissue, the crossing fibres having much
the appearance of basket-work ; in the transparent salpians,
these fibres are grouped in flat bands, and arranged in charac-
teristic patterns. In this class (tunicatd) they act only as
sphincters (or circular muscles), and by their sudden contraction
expel the water from the branchial cavity. The muscular foot of
the bivalves is extremely flexible, having layers of circular fibres
for its protrusion, (fig. 18./) and longitudinal bands for its re-
traction (fig. 30 k) ; its structure and mobility has been com-
pared to that of the human tongue. In the burrowing shell-fish
(such as solen\ it is very large and powerful, and in the boring
species, its surface is studded with silicious particles (spicula),
which render it a very efficient instrument for the enlargement
of their cells. (Hancock.} In the attached bivalves it is not
developed, or exists only in a rudimen-
tary state, and is subsidiary to a gland
which secretes the material of those threads
with which the mussel and pinna attach
themselves. (Fig. 13.) These threads
are termed the byssus ; the plug of the
anomia, and the pedicel of terebratula
T P .. Fig. 13. Dreissena.\
are modifications 01 the byssus.
In the cuttle-fishes alone, we find muscles attached to in-
ternal cartilages which represent the bones of vertebrate animals ;
the muscles of the arms are inserted in a cranial cartilage, and
those of the fins in the lateral cartilages, the equivalents of the
pectoral fins of fishes.
* The muscular fibres of shell-fish do not exhibit the transverse stripes
which characterize voluntary muscles in the higher animals.
f Fig. 13. Dreissena potymorpha (Pallas sp.) from the Surrey timber-
docks. /, foot, b, byssus.
C
*o MANUAL OF THE MOLLUSCA.
Muscles of a third kind are attached to the shell. The valves
of the oyster (and other mono-myaries) are connected by a single
muscle ; those of the cytherea (and other di-myaries\ by two ;
the contraction of which brings the valves together. They are
hence named adductors ; and the part of the shell to which they
are attached is always indicated by scars. (Tig. 14, a. a').
A
i place of
Pig. 14. Left valve of Cytherea chione*
The border of the mantle is also muscular, and the pL
its attachment is marked in the shell by a line called the pallial
impression (p ) ; the presence of a bay, or sinus ( s ), in this line,
shews that the animal had retractile siphons ; the foot of the
animal is withdrawn by retractor muscles also attached to the
shell, and leaving small scars near those of the adductors
(Fig. 30*).
The gasteropods withdraw into their shells when alarmed,
by a shell-muscle, which passes into the foot, or is attached to
the operculum ; its impression is horse- shoe-shaped in the lim-
pet, as also in navicella, concholepas, and the nautilus ; it be-
* Fig. 14. Cytherea chione, L., coast of Devon, (original) ; h, the hinge
ligament ; u, the umbo ; I, the lunule ; c, cardinal tooth ; 1 1', lateral teeth ;
a, anterior adductor ; ', posterior adductor ; p, pallial impression ; s, sinus,
occupied by retractor of the siphons.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 27
comes deeper with age. In the spiral univalves, the scar is
less conspicuous, being situated on the columella, and sometimes
divided, forming two spots. It corresponds to the posterior
retractors in the bivalves.
Digestive system. This part of the animal economy is all-
important in the radiate classes, and scarcely of less consequence
in the mollusca. In the ascidians (fig. 8, i\ the alimentary
canal is a convoluted tube, in part answering to the oesophagus,
and in part to the intestine ; the stomach is distinguished by
longitudinal folds, which increase its extent of surface ; it receives
the secretion of the liver by one or more apertures. In those
bivalves, which have a large foot, the digestive organs are con-
cealed in the upper part of that organ ; the mouth is unarmed,
except by two pairs of soft membranous palpi, which look like
accessory gills (fig. 18. I. t.) The ciliated arms of the brachi-
pods, occupy a similar position (figs. 4, 5, 6), and are regarded
as their equivalents*. The encephalous mollusca are frequently
armed with horny jaws, working vertically like the mandibles of
a bird ; in the land-snails, the upper jaw is opposed only by the
denticulated tongue, whilst the limneids have two additional
horny jaws, acting laterally. The tongue is muscular, and armed
with recurved spines (or lingual teeth), arranged in a great va-
riety of patterns, which are eminently characteristic of the
genera.* Their teeth are amber-coloured, glossy, and trans-
lucent ; and being silicious (they are insoluble in acid), they can
be used like a file, for the abrasion of very hard substances.
With them the limpet rasps the stony nullipore, the whelk bores
holes in other shells, and the cuttle-fish doubtless uses its tongue
in the same manner as the cat. The tongue, or lingual ribbon,
usually forms a triple band, of which the central part is called
the rachis, and the lateral tracts pleura, the rachidiari teeth
* The preparation of tlie lingual ribbon as a permanent microscopic object,
requires some nicety of manipulation, but the arrangement of the teeth may
be seen by merely compressing part of the animal between two pieces of
glass.
C 2
MANUAL OP THE MOLLUSCA.
sometimes form a single series, overlapping each other, or there
are lateral teeth on each side of a median series. The teeth on
the pleurse are termed uncini ; they are extremely numerous in
the plant-eating gasteropods. (Fig. 15. A.)*
Fig. 15. Lingual Teeth of Mollusca.
Sometimes the tongue forms a short semi-circular ridge/
contained between the jaws ; at others, it is extremely elongated,
and when withdrawn, its folds extend backwards to the stomach.
The lingual ribbon of the limpet is longer than the whole ani-
mal; the tongue of the whelk has 300 rows of teeth ; and
the great slug has 160 rows, with 180 teeth in each row.
Fig. 16. Tongue of the
The front of the tongue is frequently curved, or bent quite
over ; it is the part of the instrument in use, and its teeth are
* Fig. 15. A. Lingual teeth of trochus cinerarius (after Loven). Only
the median tooth, and the (5) lateral teeth, and (90) uncini of one side of a
single row are represented. B. One row of the lingual teeth of cyprcea
europaa; consisting of a median tooth, and three uncini on each side of it.
t Fig. 16. Lingual ribbon of buccinum undatum (original), from a pre-
paration communicated by \Vm. Thomson, Esq., of King's College.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 29
often broken or blunted. The posterior part of the lingual rib-
bon usually has its margins rolled together, and united, forming
a tube, which is presumed to open gradually. The new teeth
are developed from behind forwards, and are brought successively
into use, as in the sharks and rays amongst fishes. In the
bullada the rachis of the tongue is unarmed, and the business of
communicating the food is transferred to an organ which re-
sembles the gizzard of a fowl, and is often paved with calcarious
plates, so large and strong as to crush the small shell-fish
which are swallowed entire. In the
aplysia, which is a vegetable-feeder,
the gizzard is armed with numerous
small plates and spines. The stomach
of some bivalves contains an instru-
ment called the crystalline stylet," Kg 1? Gizsar ^ f Bulla ,
which is conjectured to have a si-
milar use. In the cephalopods there is a crop in which the
food may accumulate, as well as a gizzard for its trituration.
The liver is always large in the mollusca (fig. 10) ; its se-
cretion is derived from arterial blood, and is poured either into
the stomach, or the commencement of the intestine. In the
nudibranehs, whose stomachs are often remarkably branched,
the liver accompanies all the gastric ramifications, and even
enters the respiratory papillas on the backs of the eolids. The
existence of a renal organ has been ascertained in most classes ;
in the bivalves it was detected by the presence of uric acid. The
intestine is more convoluted in the herbivorous than in the car-
nivorous tribes : in the bivalves and in Jialiotis it passes through
the ventricle of the heart ; its termination is always near the
respiratory aperture (or excurrent orifice, when there are
* Fig. 17. Gizzard of bulla lignaria (original). Front and side view of a
half-grown specimen, with the part nearest the head of the animal down,
wards ; in the front view the plates are in contact. The cardiac orifice is in
the centre, in front ; the pyloric orifice is on the posterior dorsal side, near
the small transverse plate.
30 MANUAL OP THE MOLLUSC A.
two*), and the excrements are carried away by the water which
has already passed over the gills.
Besides the organs already mentioned, the eiicephalous mol-
lusks are always furnished with well- developed salivary glands,
and some have a rudimentary pancreas ; many have also special
glands for the secretion of coloured fluids, such as the purple of
the murex, the violet liquid of ianthina and aplysia t the yellow
of the bulladce, the milky fluid of eolis, and the inky secretion of
the cuttle-fishes. A few exhale peculiar odours, like the garlic-
snail (helix alliaria) and eledone moschata. Many are phos-
phorescent, especially the floating tunicaries (salpa and pyrosoma),
and bivalves which inhabit holes ( plwladidce). Some of the cuttle-
fishes are slightly luminous ; and one land-slug, the phosphorax,
takes its name from the same property.
Circulating system. The mollusca have no distinct absorbent
system, but the product of digestion (chyle) passes into the ge-
neral abdominal cavity, and thence into the larger veins, which
are perforated with numerous round apertures. The circulating
organs are the heart, arteries, and veins ; the blood is colourless,
or pale bluish white. The heart consists of an auricle (sometimes
divided into two), which receives the blood from the gills ; and
a muscular ventricle which propels it into the arteries of the
body. Prom the capillary extremities of the arteries it collects
again into the veins, circulates a second time through the respi-
ratory organ, and returns to the heart as arterial blood. Besides
this systemic heart, the circulation is aided by two additional
branchial hearts in the cuttle-fishes ; and by four in the brachio-
poda. Mr. Alder has counted from 60 to 80 pulsations per
minute in the nudibranchs, and 120 per minute in a vitrina.
Both the arteries and veins form occasionally wide spaces, or
* In most of the gasteropods the intestine returns upon itself, and ter-
minates on the right side, near the head. Occasionally it ends in a perfo-
ration more or less removed from the margin of the aperture, as in trocho-
toma, fissurella, macrochisma, and dentalium. In chiton the intestine is
straight, and terminates posteriorly.
STRUCTURE AND PHYSIOLOGY OP THE MOLLUSCA. 31
sinuses ; in the cuttle-fishes the oesophagus is partly or entirely
surrounded by a venous sinus ; and in the acephala the viceral
cavity itself forms part of the circulating system.
The circulation in the tunicaries presents a most remarkable
exception to the general rule, for their blood ebbs and flows in
the same vessels, as it was supposed to do in the human veins
before the time of Harvey. In the transparent salpce it may be
seen passing from the heart into vessels connected with the
viscera and tunics, and thence into the branchial vessels ; but
when this has continued for a time, the movement ceases, and
recommences in the opposite direction, passing from the heart
to the gill and thence to the system. (Lister.} In the compound
tunicaries, there is a common circulation through the connecting
medium, in addition to the individual currents.
Aquiferous canals. Sea-water is admitted to the visceral
cavity of many of the mollusks (as it is also in radiate animals),
by minute canals, opening externally in the form of pores.
These aquiferous pores are situated either in the centre of the
creeping disc, as in cyprtea, conus, and ancillaria ; or at its mar-
gin, as in haliotis, doris, and aplysia. In the cuttle-fishes, they
are variously placed, on the sides of the head, or at the bases of
the arms; some of them conduct to the large sub-orbital
pouches, into which the tentacles are retracted.
Respiratory system. The respiratory process consists in the
exposure of the blood to the influence of air, or water con-
taining air ; during which oxygen is absorbed and carbonic acid
liberated. It is a process essential to animal life, and is never
entirely suspended, even during hybernation. Those air-
breathers that inhabit water are obliged to visit the surface fre-
quently ; and stale water is so inimical to the water-breathers,
that they soon attempt to escape from the confinement of a glass
or basin, unless the water is frequently renewed.* In general,
* When aquatic plants are kept in the same glass with water-breathing
snails, a balance is produced ; which enables both to live without change of
water.
32 MANUAL OF THE MOLLUSCA.
fresh-water is immediately fatal to marine species, and salt-water
to those which properly inhabit fresh ; but there are some which
affect brackish water, and many which endure it to a limited ex-
tent. The depth at which shell-fish live, is influenced by the
quantity of oxygen which they require ; the most active and
energetic races live only in shallow water, or near the surface ;
those found in very deep water are the lowest in their instincts,
and are specially organized for their situation. Some water-
breathers require only moist sea-air, and a bi-diurnal visit from
the tide, like the periwinkle, limpet, and Jcellia ; whilst many
air-breathers live entirely in the water or in damp places by the
water-side. In fact, the nature of the respiratory process is the
same, whether it be aquatic or aerial, and it is essential in each
case that the surface of the breathing-organ should be preserved
moist. The process is more complete in proportion to the ex-
tent and minute sub -division of the vessels, in which the circu-
lating fluid is exposed to the revivifying influence.
The land-snails (pulmonifera), have a lung, or air-chamber,
formed by the folding of the mantle, over the interior of which
the pulmonary vessels are distributed ; this chamber has a round
orifice, on the right side of the animal, which opens and closes
at irregular intervals. The air in this cavity seems to renew
itself with sufficient rapidity (by the law of diffusion), without
any special mechanism.
In the aquatic shell-fish, respiration is performed by the
mantle, or by a portion of it specialized, and forming a gill
(brancJiia). It is effected by the mantle alone in one family of
tunicaries (pelonaiadce), in all the brachiopoda> and in one family
of gasteropods (actceonidte).
In most of the tunicata, the breathing organ forms a distinct
sac lining the muscular tunic, or mantle (fig. 8. #.) ; this sac has
only one external aperture, and conducts to the mouth, which is
situated at its base. It is a sieve-like structure, and its inner
surface is clothed with vibratile cilia* which create a perpetual
* From cilium, an eyelash ; they are only visible under favourable circum-
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 33
current, setting in through the (branchial) orifice, escaping through
the meshes of the net, and passing out by the anal orifice of the
outer tunics. The regularity of this current is interrupted only
by spasmodic contractions of the mantle, occurring at irregular
intervals, by which the creature spirts out water from both orifices,
and thus clears its cavity of such accumulated particles as are
rejected by the mouth ; and too large to escape through the
branchial pores. In the salpians, these contractions are ryth-
mical, and have the effect of propelling them backwards. In the
ordinary bivalves, the gills form two membranous plates on each
side of the body ; the muscu-
lar mantle is still sometimes
united, forming a chamber
with two orifices, into one
of which the water flows,
whilst it escapes from the
other ; there is a third open-
ing in front, for the foot, but
this in no wise influences the
branchial circulation. Some- ^ 18 - Trigonia pectinata*
times the orifices are drawn out into long tubes, or siphons, es-
pecially in those shell-fish which burrow in sand. (Figs. 19
and 7.)
Fig. 19. Bivalve wth long siphons.^
stances, with the aid of a microscope ; but the currents they cause are easily
made perceptible by dropping fine sand into the water over them.
* Trigonia pectinata, Lam. (original). Brought from Australia by the
late Captain Owen Stanley. The gills are seen in the centre through the
transparent mantle, o, mouth j / 1, labial tentacles ; f t foot ; v, vent.
f Fig. 19. Psammobia vespertina, Chemn. after Poli, reduced one half.
The arrows indicate the direction of the current, r $, respiratory siphon.
t *, excurrent siphon.
C 3
34 MANUAL OF THE MOLLUSCA.
Those bivalves which have no siphons, and even those in
which the mantle is divided into two lobes, are provided with
valves or folds which render the respiratory channels just as
complete in effect. These currents are not in any way connected
with the opening and closing of the valves, which is only done
in moving ; or in efforts to expel irritating particles.*
In some of the gasteropoda the respiratory organs form tufts,
exposed on the back and sides (as in the nudibranches), or pro-
tected by a fold of the mantle (as in the infer obranclies and
tectibranches of Cuvier). But in most the mantle is inflected,
and forms a vaulted chamber over the back of the neck, in which
are contained the pectinated or plume-like gills (fig. 61). In the
carnivorous gasteropods (siphon ostomata) the water passes into
this chamber through a siphon, formed by a prolongation of the
upper margin of the mantle, and protected by the canal of the
shell ; after traversing the length of the gill, it returns and es-
capes through a posterior siphon, generally less developed, but
very long in ovulum volva, and forming a tubular spine in typhis.
In the plant-eating sea-snails (liolostomata), there is no true
siphon, but one of the " neck-lappets" is sometimes curled up
and performs the same office, as in paludina and ampullaria (fig.
84). The in-coming and out-going currents in the branchial
chamber, are kept apart by a valve-like fringe, continued from
the neck -lappet. The out-current is still more effectually isolated
mfasurella, kaliotis, and dentalium, where it escapes by a hole in
the shell, far removed from the point at which it entered. Near
this outlet are the anal, renal, arid generative orifices.
The cephalopods have two or four plume-like gills, symme-
trically placed in a branchial chamber, situated on the under-side
* If a river-mussel be placed in a glass of water, and fine sand let fall
gently over its respiratory orifices, the particles will be seen to rebound from
the vicinity of the upper aperture, whilst they enter the lower one rapidly.
But as this kind of food is not palatable, the creature will soon give a plunge
with its foot, and closing its valves, spirt the water (and with it the sand)
from both orifices ; the motion of the foot is, of course, intended to change
its position.
STRUCTURE AND PHYSIOLOGY OF THE MOLLI3SCA. 35
of the body ; the opening is in front, and occupied by a funnel,
which, in the nautilus, closely resembles the siphon of the palti-
dina, but has its edges united in the cuttle-fishes. The free
edge of the mantle is so adapted that it allows the water to enter
the branchial chamber on each side of the funnel ; its muscular
walls then contract and force the water through the funnel, an
arrangement chiefly subservient to locomotion.* Mr. Bower-
bank has observed, that the eledone makes twenty respirations
per minute, when resting quietly in a basin of water.
In most instances, the water on the surface of the gills is
changed by ciliary action alone ; in the cephalopods and salpians,
it is renewed by the alternate expansion arid contraction of the
respiratory chamber, as in the vertebrate animals.
The respiratory system is of the highest importance in the
economy of the mollusca, and its modifications afford most va-
luable characters in classification. It will be observed that the
Cuvierian classes are based on a variety of particulars, and are
very unequal in importance ; but the orders are characterized by
their respiratory conditions, and are of much more nearly equal
value.
Orders. Classes.
Dibranchiata. Owen.
Tetrabranchiata. Owen.
Nucleobranchiata. Bl.
ENCEPHALA Prosobranchiata. M. Edw.
Pulmonifera. Cuv.
Opisthobranchiata. M. Edw. -
Aporobranchiata. Bl.
( Palliobranchiata. Bl.
ACEPHALA j Lamellibranchiata. BL
( Heterobranchiata. Bl.
The Shell. The relation of the shell to the breathing-organ
is very intimate ; indeed, it may be regarded as a pneumo-skeleton,
* A very efficient means of locomotion in the slender pointed calamaries,
which dart backwards with the recoil, like rockets.
v CEPHALOPODA.
GASTEROPODA.
i
PTEROPODA.
BRACHIOPODA.
CONCHIFERA.
TUNICATA.
36 MANUAL OF THE MOLLUSC A.
being essentially a calcified portion of the mantle, of which the
brea thing- organ is at most a specialised part.*
The shell is so characteristic of the mollusca that they have
been commonly called "testacea" (from testa "a shell"), in
scientific books ; and the popular name of "shell-fish," though
not quite accurate, cannot be replaced by any other epithet in
common use. In one whole class, however, and in several
families, there is nothing that would be popularly recognised as
a shell.
Shells are said to be external when the animal is contained in
them, and internal when they are concealed in the mantle ; the
latter, as well as the shell-less species, being called naked mollusks.
Three-fourths of the mollusca are univalve., or have but one
shell; the others are mostly bivalve, or have two shells; the
pJiolads have accessory plates, and the shell of chiton consists of
eight pieces. Most of the multivalves of old authors were arti-
culate animals (cirripedes), erroneously included with the mollusca,
which they resemble only in outward appearance.
All, except the argonaut* acquire a rudimental shell before
they are hatched, which becomes the nucleus of the adult shell ;
it is often differently shaped and coloured from the rest of the
shell, and hence the fry are apt to be mistaken for distinct species
from their parents.
In cymba (fig. 20) the nucleus is large and irregular; mfusus
antiquus it is cylindrical ; in the pyramidellidce it is oblique ; and
it is spiral in carinaria, atlanta, and many limpets, which are
symmetrical when adult.
The rudimentary shell of the nudibranchs is shed at an early
* In its most reduced form the shell is only a hollow cone, or plate, pro-
tecting the breathing organ and heart, as in Umax, testacella, carinaria. Its
peculiar features always relate to the condition of the breathing-organ ; and in
terebratula and pelonaia it becomes identified with the gill. In the nudi-
branchs the vascular mantle performs wholly or in part the respiratory office.
In the cephalopods the shell becomes complicated by the addition of a distinct,
internal, chambered portion (phragmocone), which is properly a visceral
skeleton ; in spirula the shell is reduced to this part.
STRUCTURE AND PHYSIOLOGY OF THE MOLLTJSCA. 37
age, and never replaced. In this respect the
molluscan shell differs entirely from the shell
of the crab and other articulate animals,
which is periodically cast oif and renewed.
In the bivalves the embryonic shell forms
the umbo of each valve ; it is often very unlike
the after-growth, as in unio pictorum, cyclas
henslowiana and pecten pusio. In attached
shells like the oyster and anomia the umbo fre-
quently presents an exact imitation of the sur-
face to which the young shell originally adhered.
Shells are composed of carbonate of lime,
with a small proportion of animal matter.
The source of this lime is to be looked Fig. -20. Cymba*
for in their food. Modern inquiries into organic chemistry have
shown that vegetables derive their elements from the mineral
kingdom (air, water, and the soil), and animals theirs from the
vegetable. The sea-weed filters the salt-water, and separates
lime as well as organic elements ; and lime is one of the most
abundant mineral matters in land plants. From this source the
mollusca obtain lime in abundance, and, indeed, we find frequent
instances of shells becoming unnaturally thickened through the
superabundance of this earth in their systems. On the other
hand, instances occur of thin and delicate-shelled varieties, in
still, deep water, or on clay bottoms ; whilst in those districts
which are wholly destitute of lime, like the lizard in Cornwall,
and similar tracts of magnesian- silicate in Asia Minor, there are
no mollusca. (Forbes?)
The texture of shells is various and characteristic. Some,
when broken, present a dull lustre like marble or china, and are
termed porcellanous ; others are pearly or nacreous ; some have
& fibrous structure; some are horny, and others glassy and trans-
lucent.
* Fig. 20. Cymba .proboscidalis, Lam., from a very young specimen in
the cabinet of Hugh Cmning, Esq., from Western Africa.
38
MANUAL OF THE MOLLTJSCA.
Fig. 21. Pinna. Fig. 22. Terebratula. Fig. 23. Pearl*
The nacreous shells are formed by alternate layers of very
thin membrane and carbonate of lime, but this alone does not give
the pearly lustre which appears to depend on minute undulations
of the layers, represented in fig. 23. This lustre has been suc-
cessfully imitated on engraved steel buttons. Nacreous shells,
when polished, form "mother of pearl ;" when digested in weak
acid, they leave a membraneous residue which retains the original
form of the shell. This is the most easily destructible of shell-
textures, and in some geological formations we find only casts of
the nacreous shells, whilst those of fibrous texture are completely
preserved.
Pearls are produced by many bivalves, especially by the
Oriental pearl-mussel (avicula margaritifera), and one of the
British river-mussels (wiio margaritiferus). They are caused by
particles of sand, or other foreign substances, getting between
the animal and its shell ; the irritation causes a deposit of nacre,
forming a projection on the interior, and generally more brilliant
than the rest of the shell. Completely spherical pearls can only
be formed loose in the muscles, or other soft parts of the animal.
The Chinese obtain them artificially, by introducing into the
living mussel foreign substances, such as pieces of mother-of-pearl
fixed to wires, which thus become coated with a more brilliant
material.
* Tigs. 21, 22, 23. Magnified sections of shells, from Dr. Carpenter.
Fragments of shell ground very thin, and cemented to glass slides with Canada
balsam, are easily prepared, and form curious microscopic objects. A great
variety of them may be procured of Mr. C. M. Topping, of Pentonville.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSC A. 39
Similar prominences and concretions pearls which are not
pearly are formed inside porcellanous shells ; these are as
variable in colour as the surfaces on which they are formed.*
The fibrous shells consist of successive layers of prismatic cells
containing translucent carbonate of lime ; and the cells of each
successive layer correspond, so that the shell, especially when
very thick (as in the fossil inoceramus and trichites), will break
up vertically, into fragments, exhibiting on their edges a structure
like arragonite, or satin- spar. Horizontal sections exhibit a
cellular net- work, with here and there a dark cell, which is empty.
(fig. 21.)
The oyster has a laminated structure, owing to the irregular
accumulation of the cells in its successive layers, and breaks up
into horizontal plates.
In the boring-shells (pJioladidte) the carbonate of lime has an
atomic arrangement like arragonite, which is considerably harder
than calcarious spar; in other cases the difference in hardness
depends on the proportion of animal matter, and the manner in
which the layers are aggregated.!
In many bivalve shells there occurs a minute tubular structure,
which is very conspicuous in some sections of pinna and oyster-
shell.
The brachiopoda exhibit a characteristic structure by which
the smallest fragment of their shells may be determined; it
consists of elongated and curved cells, matted together, and
often perforated by circular holes, arranged in quincunx order
(fig. 22).
But the most complex shell-structure is presented by the
porcellanous gasteropoda. These consist of three strata which
readily separate in fossil shells, on account of the removal of their
* They are pink in turbinellus and strombus ; white in ostrea ; white or
glassy, purple or black in mytilus ; rose-coloured and translucent in pinna.
(Gray.}
f The specific gravity of floating shells (such as argonanta and ianthind)
is lower than that of any others. (De la Beche.)
40
MANUAL OF THE MOLLUSC A.
B
animal cement. In fis;. 24. a represents the outer, b the middle,
and c the inner stratum ; they
may be seen, also, in fig. 25.
Each of these three strata
is composed of very nume-
rous vertical plates, like cards
placed on edge ; and the di-
rection of the plates is some-
times transverse in the central
stratum, and lengthwise in ri &- 24 Sections of a cone.*
the outer and inner (as in cyprcea, cassis, ampullaria, and bull-
mm\ or longitudinal in the middle layer, and transverse in the
others (e. g. conus, pyrula, oliva, and valuta).
Each plate, too, is composed of a series of prismatic cells,
arranged obliquely (45), and their direction being changed in
the successive plates, they cross each other at right angles.
Tertiary fossils best exhibit this structure, either at their broken
edge, or in polished sections. f (Bowerbank) .
The argonaut-shell, and the bone of the cuttle-fish, have a
peculiar structure ; and the Hippurite is distinguished by a can-
cellated texture, unlike any other shell, except, perhaps, some of
the cardiacece and chamacete.
Epidermis. All shells have an outer coat of animal matter
called the " epidermis" (or periostracum), sometimes thin and
transparent, at others thick and opaque. It is thick and olive-
coloured in all fresh-water shells, and in many arctic sea-shells
(e. g. cyprina and astarte) ; the colours of the land-shells often
* Sections of conus pondwosus, Brug., from the Miocene of the Tonraine.
A, longitudinal section of a fragment, B, complete horizontal section; a, outer
layer; b, middle; c, inner layer; d, e,f, lines of growth.
f It is necessary to bear in mind that fossil shells are often pseudomor-
pJums, or mere casts, in. spar or chalcedony, of cavities once occupied by shells ;
such are the fossils found at Blackdown, and many of the London clay fossils
at Barton. The Palseozoic fossils are often metamorphic, or have undergo]
a re-arrangement of their particles, like the rocks in which they occur.
one
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 41
depend on it ; sometimes it is silky as in helix sericea, or fringed
with hairs, as in trichotropis ; in the whelk and some species of
triton and conus it is thick and rough like coarse cloth, arid in
some modiolas it is drawn out into long beard-like filaments.
In the cowry and other shell-fish with large mantle lobes, the
epidermis is more or less covered up by an additional layer of
shell deposited externally.
The epidermis has life, but not sensation, like the human
scarf-skin ; and it protects the shell against the influence of the
weather, and chemical agents ; it soon fades, or is destroyed,
after the death of the animal, in situations where, whilst living,
it would have undergone no change. In the bivalves it is organ-
ically connected with the margin of the mantle.
It is most developed in shells which frequent damp situations,
amongst decaying leaves, and in fresh -water shells. All fresh-
waters are more or less saturated with carbonic-acid gas, and in
limestone countries hold so much lime in solution as to deposit it
in the form of tufa on the mussels and other shells.* But in the
absence of lime to neutralise the acid, the water acts on the shells,
and would dissolve them entirely if it were not for their protecting
epidermis. As it is we can often recognise fresh-water shells by
the erosion of those parts where the epidermis was thinnest,
namely, the points of the spiral shells and the umbones of the
bivalves, those being also the parts longest exposed. Specimens
of melanopsis and bithinia become truncated again and again in
the course of their growth, until the adults are sometimes only
half the length they should be, and the discoidal planorbis some-
times becomes perforated by the removal of its inner whirls ; in
these cases the animal closes the break in its shell with new
layers. Some of the unios thicken their umbones enormously,
and form a layer of animal matter with each new layer of shell,
so that the river-action is arrested at a succession of steps.
* As at Tisbury, in Wiltshire, where remarkable specimens of anodons
were obtained by the late Miss Benett.
MANUAL OF THE MOLLUSCA.
FORMATION AND GROWTH OF THE SHELL.
The shell, as before stated, is formed by the mantle of the
shell-fish, indeed, each layer of it was once a portion of the man-
tle, either in the form of a simple membrane, or as a layer of
cells ; and each layer was successively calcified (or hardened with
carbonate of lime) and thrown off by the mantle to unite with
those previously formed. Being extra- vascular it has no inherent
power of repair. (Carpenter.)
The epidermis and cellular structures are formed by the mar-
gin (or collar) of the mantle; the membranous and nacreous
layers, by the thin and transparent portion which contains the
viscera; hence we find the pearly texture only as a lining
inside the shell, as in the nautilus, and all the aviculida and
If the margin of a shell is fractured during the life-time of the
animal, the injury will be completely repaired by the reproduction
both of the epidermis and of the outer layer of shell with its pro-
per colour. But if the apex is destroyed, or a hole made at a
distance from the aperture, it will merely be closed with the
material secreted by the visceral mantle. Such inroads are often
made by boring worms and shells, and even by a sponge (cliond)
which completely mines the most solid shells. In Mr. Gray's
cabinet is the section of a cone, in whose apex a colony of UtJwdomi
Fig. 25. Section of a cone perforated by lithodomi.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 43
had settled, compelling the animal to contract itself, faster even
than it could form shell to fill up the void.
Lines of growth. So long as the animal continues growing,
each new layer of shell extends beyond the one formed before it ;
and, in consequence, the external surface becomes marked with
lines of growth. During winter, or the season of rest which cor-
responds to it, shells cease to grow ; and these periodic resting-
places are often indicated by interruptions of the otherwise regu-
lar lines of growth and colour, or by still more obvious signs. It
is probable that this pause, or cessation from growth, extends
into the breeding season ; otherwise there would be two periods
of growth, and two of rest in each year. In many shells the
growth is uniform ; but in others each stage is finished by the
development of a fringe, or ridge (varix\ or of a row of spines,
as in tridacna and murex. (Owen, Grant.)
Adult characters. The attain-
mpnt of the full-growth proper to
each species is usually marked by
ihanges in the shell.
Some bivalves, like the oyster,
and gryphcea (fig. 26), continue to
.ncrease in thickness long after
;heyhave ceased to grow outwards; K S- 26 ' Section of gryphcea*
the greatest addition is made to the lower valve, especially near
,he umbo ; and in the spondylus some parts of the mantle secrete
more than others, so that cavities, filled with fluid, are left in the
substance of the shell.
The adult teredo smdfatulana close the end of their burrows ;
the pholadidea fills up the great pedal opening of its valves ; and
the aspergillum forms the porous disk from which it takes its
name. Sculptured shells, particularly ammonites, and species of
rostellaria mdfusus, often become plain in the last part of their
* Fig. 26. Section of gryphoea incurva, Sby. Lias, Dorset, (original ; dimi-
nished one half), the upper valve is not much thickened ; the interior is filled
with lias.
44 MANUAL OF THE MOLLTJSCA.
growth. But the most characteristic change is
the thickening and contraction of the aperture
in the univalves. The young cowry (fig. 27)
has a thin, sharp lip, which becomes curled in-
wards, and enormously thickened and toothed in
the adult ; the pteroceras (pi. 4, fig. 3) deve-
lopes its scorpion-like claws, only when full-
grown ; and the land-snails form a thickened lip,
or narrow their aperture with projecting pro-
cesses, so that it is a marvel how they pass in
and out, and how they can exclude their eggs, -^
(e. g. pi. 12, fig. 4, anastoma; and fig. 5, helix
hirsuta).
Yet at this time they would seem to require more space and
accommodation in their houses than before, and there are several
curious ways in which this is obtained. The neritida and auri-
culiddB dissolve all the internal spiral columnf of their sheljs ;
the cone (fig. 24, B,) removes all but a paper-like portion of its
inner whirls ; the cowry goes still further, and continues removing
the internal layers of its shell-wall, and depositing new layers
externally with its overlapping mantle (fig. 76), until, in some
cases, all resemblance to the young shell is lost in the adult.
The power which mollusks possess of dissolving portions of
their own shells, is also exhibited by the murices, in removing
those spines from their whirls which interfere with their growth ;
and by the purpurce and others in wearing away the wall of their
aperture. The agency in these cases is supposed to be chemical.
Decollated shells. It frequently happens that as spiral shells
become adult they cease to occupy the upper part of their cavity ;
the space thus vacated is sometimes filled with solid shell, as in
magilus ; or it is partitioned off, as in vermetus, euomphalus,
turritella and triton (fig. 62). The deserted apex is sometimes
very thin, and becoming dead and brittle, it breaks away, leaving
* Cypraa testudinaria, L., young.
f This is sometimes done by the hermit-crab to the shells it occupies.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 45
the shell truncated, or decollated. This happens constantly with
the truncatellce, cylindrella, and bulimus decollates ; amongst the
fresh-water shells it depends upon local circumstances, but is very
common vrithpirena and cerithidea.
Forms of shells. These will be described particularly under
each class ; enough has been said to show that in the molluscan
shell (as in the vertebrate skeleton) indications are afforded o
many of the leading affinities and structural peculiarities of the
animal. It may sometimes be difficult to determine the genus of
a shell, especially when its form is very simple ; but this results
more from the imperfection of our technicalities and systems,
than from any want of co-ordination in the animal and its shell.
Monstrosities. The whirls of spiral shells are sometimes
separated by the interference of foreign substances, which adhere
to them when young ; the garden-snail has been found in this
condition, and less complete instances are common amongst sea-
shells. Discoidal shells occasionally become spiral (as in speci-
mens of planorbis found at Rochdale), or irregular in their
growth, owing to an unhealthy condition. The discoidal ammo-
nites sometimes show a slight tendency to become spiral, and
more rarely become un symmetrical, and have the keel on one
side, instead of in the middle.
All attached shells are liable to interference in their growth,
and malformations consequent on their situation in cavities, or
Tom coming in contact with rocks. The dreissena polymorpha
distorts the other fresh-water mussels by fastening their valves
h its byssus ; and balani sometimes produce strange protube-
rances on the back of the cowry, to which they have attached
themselves when young.*
In the miocene tertiaries of Asia Minor, Professor Forbes
* In the British Museum there is a helix terrestris (cheinn.) with a small
stick passing through it, and projecting from the apex and umbilicus. Mr.
Pickering has, in his collection, a helix hortensis which got entangled in a nut-
shell when young, and growing too large to escape, had to endure the incubus
to the end of its days.
46 MANUAL OF THE MOLLUSCA.
discovered whole races of netitina, paludina, and melanopsis, wit;
whirls ribbed or keeled, as if through the unhealthy influence o
brackish water. The fossil periwinkles of the Norwich Crag ar
similarly distorted, probably by the access of fresh-water ; paralle
cases occur at the present day in the Baltic.
Reversed shells. Left-handed, or reversed varieties of spira
shells have been met with in some of the very common species
like the whelk and garden-snail. Bulimus citrinus is as often
sinistral as dextral ; and a reversed variety of/usus antiqum wa
more common than the normal form in the pliocene sea. Othe
shells are constantly reversed, as pyrula perversa, many species o
pupa, and the entire genera, clausilia, cylindrella, physa, and tn
pJioris. Bivalves less distinctly exhibit variations of this kind
but the attached valve of chama has its umbo turned to the righ
or left indifferently ; and of two specimens of lucina childreni in
the British Museum, one has the right, the other the left valv
flat.
The colours of shells are usually confined to the surface beneat
the epidermis, and are secreted by the border of the mantle
which often exhibits similar tints and patterns (e. g. voluta undu
lata, fig. 73). Occasionally the inner strata of porcellanous shell
are differently coloured from the exterior, and the makers of shell
cameos avail themselves of this difference to produce white o
rose-coloured figures on a dark ground.*
The secretion of colour by the mantle depends greatly on th
action of light ; shallow- water shells are, as a class, warmer am
brighter coloured than those from deep water ; and bivalve
which are habitually fixed or stationary (like spondylus and pecten
pleuronectes) have the upper valve richly tinted, whilst the lowe
one is colourless. The backs of most spiral shells are darke
* Cameos in the British Museum, carved on the shell of cassis cornuta
are white on an orange ground ; on c. tuberosa, and madagascariensis, whit
upon dark claret-colour ; on c. rufa, pale salmon-colour on orange ; and on
strombus gig as, yellow on pink. By filing some of the olives (e. g. oliva utri
culus] they may be made into very different coloured shells.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 47
than the under sides ; but in ianthina the base of the shell is
habitually turned upwards, and is deeply dyed with violet. Some
colours are more permanent than others ; the red spots on the
naticas and nerites are commonly preserved in tertiary and oolitic
fossils, and even in one example (of n. subcostata schl.) from
Devonian limestone. Terebratula hast at a, and some pectens of
the carboniferous period, retain their markings ; the orthoceras
anguliferm of the Devonian beds has, zig-zag bands of colour ;
and a terebratula of the same age, from arctic North America,*
is ornamented with several rows of dark red spots.
The operculum. Most spiral
shells have an operculum, or lid,
with which to close the aperture
when they withdraw for shelter
(see gasteropoda). It is deve-
loped on a particular lobe at the
posterior part of the foot, and
, PI i Fig, 28. Trochus ziziphinus.^
consists of horny layers, some
times hardened with shelly matter (fig. 28).
It has been considered by Adanson, and more recently by
Mr. Gray, as the equivalent of the dextral valve of the conchifera ;
but however similar in appearance, its anatomical relations are
altogether different. In position it represents the byssus of the
bivalves (Loven) ; and in function it is like the plug with which
unattached specimens of bysso-arca close their aperture. (Forbes.)
Homologies of the shell. J The shell is so simple a structure
that its modifications present few points for comparison; but
even these are not wholly understood, or free from doubt. The
* Presented to tlie British Museum by Sir John Richardson.
f Trochus ziziphinus, from the original, taken in Pegwell Bay abundantly.
Phis species exhibits small tentacular processes, neck-lappets, side-lappets,
;entacular filaments, and an operculigerous lobe.
Parts which correspond in their real nature (their origin and develop-
ment) are termed homologous ; those which agree merely in appearance, or
)ffice, are said to be analogous.
48 MANUAL OF THE MOLLUSCA.
bivalve shell may be compared to the outer tunic of the ascidian,
cut open and converted into separable valves. In the concJiifera
this division of the mantle is vertical, and the valves are right
and left. In the brachiopoda the separation is horizontal, and
the valves are dorsal and ventral. The monomyarian bivalves lie
habitually on one side (like the pleuronectidce among fishes) ; and
their shells, though really right and left, are termed " upper"
and " lower" valves. The univalve shell is the equivalent of
loth valves of the bivalve. In the pteropoda it consists of dorsal
and ventral plates, comparable with the valves of terebratula. In
the gasteropoda it is equivalent to both valves of the concJiifera
united above.* The nautilus shell corresponds to that of the
gasteropod ; biit whilst its chambers are shadowed forth in many
spiral shells, the siphuncle is something additional ; r and the entire
shell of the cuttle-fish and argonautf have no known equivalent
or parallel in the other molluscous classes. The student might
imagine a resemblance in the shell of the ortkoceras to a lack-bone ;
but the true homologue of the vertebrate skeleton is found in the
neural and muscular cartilages of the cephalopod; whilst its
phragmocone is but the representative of the calcarious axis (or
splanchno-skeleton) of a coral, such as amplexus or siphonophyllia.
Temperature and hybernation. Observations on the tempera-
ture of the mollmca are still wanted ; it is known, however, to
vary with the medium in which they live, and to be sometimes a
degree or two higher or lower than the external temperature; with
snails (in cool weather), it is generally a degree or two higher.
The mollusca of temperate and cold climates are subject to
hybernation ; during which state the heart ceases to beat, respira-
* Compare fssurella or trochus (fig. 28) with lepton squamosum (fig. 12).
The disk of hipponyx is analogous to the ventral plate of hyalsea and tere-
bratula.
f The argonaut shell is compared by Mr. Adams to the nidamental cap-
sules of the whelk ; a better analogue would have been found in the raft of
the ianthina, which is secreted by the foot of the animal, and serves iv float
the egg -capsules.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 49
tion is nearly suspended, and injuries are not healed. They also
(Bstivate, or fall into a summer sleep when the heat is great ; but
in this the animal functions are much less interrupted. (Midler.)
Reproduction of lost parts. It appears from the experiments
of Spallanzani, that snails, whose ocular tentacles have been de-
stroyed, reproduce them completely in a few weeks ; others have
repeated the trial with a like result. But there is some doubt
whether the renewal takes place if the brain of the animal be
removed as well as its horns. Madame Power has made similar
observations upon various marine snails, and has found that por-
tions of the foot, mantle, and tentacles, were renewed. Mr.
Hancock states that the species of eolis are apt to make a meal
off each other's bronchia, and that, if confined in stale water,
they become sickly and lose those organs ; in both cases they are
quickly renewed under favourable circumstances.
Reproduction by gemmation. The social and compound tu-
nicaries resemble zoophytes, in the power they possess of bud-
ding out new individuals, and thus of multiplying their commu-
nities indefinitely, as the leaves on a tree. This gemmation takes
place only at particular points, so that the whole assemblages
are aggregated in characteristic patterns. The buds of the social
tunicaries are supported at first by their parents, those of the
compound families by the general circulation, until they are in a
state to contribute to the common weal.
Viviparous reproduction. This happens in a few species of
gastropods, through the retention of the eggs in the oviduct,
until the young have attained a considerable growth. It also
appears to take place in the acephalans, because their eggs gene-
rally remain within some part of the shell of the parent until
hatched.
Alternate generation. Amongst the tunicaries an example
is found of regulated diversity in the mode of reproduction. The
salpians produce long chains of embryos, which, unless broken
by accident, remain connected during life ; each individual of
these compound specimens produces solitary young } often so im-
D
50
MANUAL OP THE MOLLUSCA.
like the parent as to have been described and named by natural-
ists as distinct species; these solitary salpians again produce
chains of embryos, like their grand-parents. (C/iamisso.)
Oviparous reproduction. The sexes are distinct in the most
highly organised (or dioecious) mollusca ; they are united in the
(iiionwcious) land-snails, pteropods, brachiopods, tuiiicaries, and
in part of the conchifers. The prosobranchs pair; but in the
dioecious acephalans and cuttle-fishes, the spermatozoa are merely
discharged into the water, and are inhaled with the respiratory
currents by the other sex. The monoecious land-snails require
reciprocal union ; the limneids unite in succession, forming float-
ing chains.
The eggs of the land-snails are separate, and protected by a
shell, which is sometimes albuminous and flexible, at others cal-
carious and brittle; those of the fresh-water species are soft,
mucous, and transparent. The spawn of the sea-snails consists
of large numbers of eggs, adhering together in masses, or spread
out in the shape of a strap or ribbon, in which the eggs are ar-
ranged in rows ; this nidamentat ribbon is sometimes coiled up
spirally, like a watch-spring, and attached by one of its edges.
The eggs of the carnivo-
rous gasteropods are in-
closed in tough albuminous
capsules, each containing
numerous germs ; these
are deposited singly, or in
rows, or agglutinated in
groups, equalling thepareiji
animal in bulk (fig. 70).
The nidamental capsulu
of the cuttle-fish are clus-
tered like grapes, each
containing but one embryo ; those of the calamary are gron
Fig. 29. Spaivn of Doris*
Nidamental ribbon of Doris Johnstoni. (Alder and Hancock.}
nipec
I
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 51
in radiating masses, each elongated capsule containing 30 or
40 ova. The material with which the eggs are thus cemented
together, or enveloped, is secreted by the nidamental gland, an
organ largely developed in the female gasteropods and cepha-
lopods (fig. 43, n).
Development. The molluscan ovum consists of a coloured
yolk (vitellus), surrounded by albumen. On one side of the yolk
is a pellucid spot, termed the germinal vesicle, having a spot or
nucleus on its surface. This germinal vesicle is a nucleated cell,
capable of producing other cells like itself; it is the essential part
of the egg, from which the embryo is formed ; but it undergoes
no change without the influence of the spermatozoa.* After im-
pregnation, the germinal vesicle, which then subsides into the
centre of the yolk, divides spontaneously into two ; and these
again divide and subdivide into smaller and still smaller globules,
each with its pellucid centre or nucleus, until the whole presents
a uniform granular appearance. The next step is the formation
of a ciliated epithelium on the surface of the embryonic mass ;
movements in the albumen become perceptible in the vicinity of
the cilia, and they increase in strength, until the embryo begins
to revolve in the surrounding fluid. f
* No instance of " partheno-genesis" is known among the moUusca ; the
most " equivocal " case on record is that related by Mr. Gaskoin. A speci-
men of helix lactea, Mull., from the South of Europe, after being two years
in his cabinet, was discovered to be still living ; and on being removed to a
plant-case it revived, and six weeks afterwards had produced twenty young
ones!
f According to the observations of Professor Loven (on certain bivalve
mollusca), the ova are excluded immediately after the inhalation of the sper-
matozoa, and apparently from their influence; but impregnation does not
take place within the ovary itself. The spermatozoa of cardium pygmaum
were distinctly seen to penetrate, in succession, the outer envelopes of the ova,
and arrive at the vitellus, when they disappeared. With respect to the " ger-
minal vesicle ;" according to Barry, it first approaches the inner surface of
the vitelline membrane, in order to receive the influence of the spermatozoa ;
it then retires to the centre of the yolk, and undergoes a series of sponta-
neous subdivisions. In M. Loven's account, it is said to "burst" and par-
D 2
f
52 MANUAL OF THE MOLLUSCA.
Up to this point nearly the same appearances are presented
by the eggs of all classes of animals, they manifest, so far, a
complete " unity of organization." In the next stage, the de-
velopment of an organ, fringed with stronger cilia, and serving
both for locomotion and respiration, shews that the embryo is
a molluscous animal; and the changes which follow soon point
out the particular class to which it belongs. The rudimentary
head is early distinguishable, by the black eye-specks ; and the
heart, by its pulsations. The digestive and other organs are first
" sketched out," then become more distinct, and are seen to be
covered with a transparent shell. By this time the embryo is
able to move by its own muscular contractions, and to swallow
food; is is therefore " hatched," or escapes from the egg.
The embryo tunicary quits the egg in the cloacal cavity of its
parent, and is at this time provided with a swimming instrument,
like the tail of the tadpole, and with processes by which it attaches
itself as soon as it finds a suitable situation.
The young bivalves also are hatched before they leave their
parent, either in the gill cavity or in a special sac
attached to the gills (as in cyclas), or in the in-
terspaces of the external branchial laminae (as in
unio). At first they have a swimming disk, fringed
with long cilia, and armed with a slender ten-
tacular filament (Jlagellum). At a later period this
disk disappears progressively, as the labial palpi
are developed ; and they acquire a foot, and with
it the power of spinning a byssus. They now
tially dissolve, whilst the egg remains in the ovary, and before impregnation ;
it then passes to the centre of the yolk, and undergoes the changes described
by Barry, along with the yolk, whilst the nucleus of the germinal vesicle, or
some body exactly resembling it, is seen occupying a small prominence on
the surface of the vitelline membrane, until the metamorphosis of the yolk
is completed, when it disappears, in some unobserved manner, without ful-
filling any recognized purpose.
* Fig. 30. Very young fry of crenella marmorata, Forbes, highly magni-
fied ; el, disk, bordered with cilia if, fiagellum ; v v 3 valves ; m, ciliated mantle.
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 53
have a pair of eyes, situated near the labial tentacles (fig. 30*, e) }
which are lost at a further stage, or replaced by numerous ru-
dimentary organs placed more favourably for vision, on the bor-
der of the mantle.
Most of the aquatic gasteropoda are very minute when
hatched, and they enter life under the same form, that which
Fig. 30 *. Try of the Mussel*
has been already referred to as permanently characteristic of the
pteropoda. (Tig. 60.)
The Pulmonifera and Cephalopoda produce large eggs, con-
* Fig. 30*. Fry of mytilus edulis, after Loven. from their relation to final
causes.* A second class of analogical resemblances are purely
external and illusive ; they have been termed mimetic (Strick-
land}, and, by their frequency, almost justify the notion that a
certain set of forms and colours are repeated, or represented in
every class and family. In all artificial arrangements, these mi-
metic resemblances have led to the association of widely dif-
ferent animals in the same groups. f Particular forms are also
represented geographically J and geologically, as well as sys-
tematically.
In all attempts to characterise groups of animals, we find,
that in advancing from the smaller to the larger combinations,
many of the most obvious external features become of less avail,
and we are compelled to seek for more constant and comprehen-
sive signs in the phases of embryonic development, and the con-
dition of the circulating, respiratory, and nervous systems.
Species. All the specimens, or individuals, which are so much
alike that we may reasonably believe them to have descended
from a common stock, constitute a species. It is a particular
provision for preventing the blending of species, that hybrids are
always barren; and it is certain, in the case of shells, that a
great many kinds have not changed in form, from the tertiary
* For example, the paper nautilus, from its resemblance to carinaria, was
long supposed to be the shell of a nucleobranche, parasitically occupied by the
" ocythoe."
f E. g. Aporrhais with strombus, and ancylus with patella.
J Monoceros imbricatum and buccinum antarcticum take the place, in
South America, of our common whelk and purple, and solen gladiolus and
solen americanus of our solen siliqua and ensis.
The frequent recurrence of similar species in successive strata may lead
beginners to attribute too much to the influence of time and external circum-
stances ; but such impressions disappear with further experience.
CLASSIFICATION. 57
period to the present day, a lapse of many thousand years,
and through countless generations. When individuals of the
same brood differ in any respect, they are termed varieties ; for
example, one may be more exposed to the light, and become
brighter coloured ; or it may find more abundant food, and grow
larger than the rest. Should these peculiarities become perma-
nent at any place, or period, should all the specimens on a
particular island or mountain, or in one sea, or geological forma-
tion, differ from those found elsewhere, such permanent variety
is termed a race ; just as, in the human species, there are white
and coloured races. The species of some genera are less subject
to variation than others ; the nuculcE, for example, although very
numerous, are always distinguishable by good characters. Other
genera, like ammonites, terebratula, and tellina, present a most
perplexing amount of variation, resulting from age, sex, supply
of food, variety of depth, and of saltness in the water. And
further, whilst in some genera every possible variety of form
seems to have been called into existence, in others only a few,
strikingly distinct forms, are known.
Genera are groups of species, related by community of struc-
ture in all essential respects. The genera of bivalves have been
characterised by the number and position of their hinge-teeth ;
those of the spiral univalves, by the form of their apertures;
but these technical characters are only valuable so far as they
indicate differences in the animals themselves.
Families are groups of genera, which agree in some more
general characters than those which unite species into genera.
Those which we have employed are mostly modifications of the
artificial families framed ^by Lamarck, a plan which seemed more
desirable, in the present state of our knowledge, than a subdi-
vision into very numerous families, without assignable characters.
The orders and classes of mollusca have already been referred
to ; those now in use are all extremely natural.
It has been sometimes asserted that these groups are only
scientific contrivances, and do not really exist in nature ; but
D 3
MANUAL OF THE MOLLUSCA.
this is a false as well as a degrading view of the matter. The
labours of the most eminent systematists have been directed to
the discovery of the subordinate value of the characters deriv-
able from every part of the animal organization ; and, as far as
their information enabled them, they have made their systems
expressive " of all the highest facts, or generalisations, in natural
history. 55 (Owen.)
M. Milne Edwards has remarked, that the actual appearance
of the animal kingdom is not like a well-regulated army, but
like the starry heavens, over which constellations of various mag-
nitude are scattered, with here and there a solitary star which
cannot be included in any neighbouring group.
This is exceedingly true ; we cannot expect our systematic
groups to have equal numerical values,* but they ought to be of
equal structural importance ; and they will thus possess a sym-
metry of order, which is superior to mere numerical regularity.
All the most philosophic naturalists have entertained a belief
that the development of animal forms has proceeded upon some
regular plan, and have directed their researches to the discovery
of that " reflection of the divine mind. 55 Some have fancied
that they have discovered it in a mystic number, and have ac-
cordingly converted all the groups mi fives. -\ We do not under-
value these speculations, yet we think it better to describe things
so far only as we know them.
Greafr difficulty has always been found in placing groups
according to their affinities. This cannot be effected in the
way in which we are compelled to describe them a single series ;
for each group is related to all the rest ; and if we extend the
representation of the affinities to very small groups, any arrange-
* The numerical development of groups is inversely proportional to the
bulk of the individuals composing them. ( Waterhouse.}
f The quinarians make out five molluscous classes, by excluding the tnni-
cata ; the same end would be attained in a more satisfactory manner by re-
ducing the pteropods to the rank of an order, which might be placed next to
the opistho branches.
NOMENCLATURE. 59
merit ou a plane surface would fail, for the affinities radiate in
all directions, and the " net-work" to which Fabricius likened
them, is as insufficient a comparison as the " chain" of older
writers.*
CHAPTER VI.
NOMENCLATIVE.
THE practice of using two names generic and specific for
each animal, or plant, originated with Linnaeus ; therefore no
scientific names date further back than his works. In the con-
struction of these names, the Greek and Latin languages are
preferred, by the common consent of all countries.
Synonyms. It often happens that a species is named, or a
genus established, by more than one person, at different times,
and in ignorance of each other's labours. Such duplicate names
are called synonyms ; they have multiplied amazingly of late,
and are a stumbling-block and an opprobium in all branches of
natural history. f
* The quinary arrangement of the molluscous classes reminds us of the
eastern emblem of eternity the serpent holding its tail in its mouth.
The following diagram is offered as an improved circular system :
[FISHES.]
Di-brauchiata.
Nucleo- Tetra-
Opistho- Proso-
Aporo- ^~\1 Pulmo-
Pallio- Lamelli-
Hetero-branchiata.
[ZOOPHYTES.]
f In Pfeiffer's Monograph of the Helicidte, a family containing seventeen
genera, no less than 330 generic synonyms are enumerated; to this list, Dr.
Albers, of Berlin, has lately added another hundred of his own invention !
MANUAL OF THE MOLLUSCA.
One very common estuary shell rejoices in the following
variety of titles:
Scrobicularia piperata (Gmelin sp).
Trigonella plana (Da Costa).
Mactra Listeri (Aucf).
My a Hispanica (Chemnitz).
Venus borealis (Pennant).
Lutraria compressa (Lamarck).
Arenaria plana (Megerle).
As regards specific names, the earliest ought certainly to be
adopted, with, however, the following exceptions :
1. MS. names; which are only admitted by courtesy.
2. Names given by writers antecedent to Linnaeus.
3. Names unaccompanied by a description or figure.
4. Barbarisms; or names involving error or absurdity, *
It is also very desirable that names having a general (Eu-
ropean) acceptation, should not be changed, on the discovery of
earlier names in obscure publications.
With respect to genera, those who believe in their real ex-
istence, as " ideas of the creating mind," will be disposed to set
aside many random appellations, given to particular shells with-
out any clear enunciation of their characters ; and to adopt later
names, if bestowed with an accurate perception of the grounds
which entitle them to generic distinction.f
Authority for specific names. The multiplication of syno-
nyms having made it desirable to place the authority after each
* This subject was investigated, and reported upon, by a committee of the
British Association, in 1842 ; but the report was not sufficiently circulated.
f Several bad practices against which there is, unhappily, no law
should be strongly discountenanced. First, the employment of names already
in familiar use for other objects ; such as cidaris (the title of a well-known
genus of sea-urchins), for a group of spiral shells ; and arenaria (a property of
the botanists), for a bivalve. Secondly, the conversion of specific into generic
titles, a process which has caused endless confusion ; it has arisen out of the
vain desire of giving new designations to old and familiar objects, and thus
obtaining a questionable sort of fame.
NOMENCLATURE. 61
name, another source of evil has arisen; for several naturalists
(fancying that the genus-maker, and not the species-maker ', should
enjoy this privilege) have altered or divided almost every genus,
and placed their signatures as the authorities for names given
half a century or a century before, by LINNAEUS or BRUGUIERE.*
British naturalists have disowned this practice, and agreed to
distinguish, by the addition of " sp.," the authorities for those
specific names whose generic appellations have been changed.
Types. The type of each genus should be that species in
which the characters of its group are best exhibited, and most
evenly balanced. (Waterliouse^ It has, however, been cus-
tomary to take as the type, that species which the genus-maker
placed first on his list ; although by so doing there is risk of
adopting an aberrant form, or one which very feebly represents
the group, of which it is an obscure member.
* The authorities appended to specific names, are supposed to indicate an
amount of work done in the determination and description of the species ;
when, therefore, the real author's name is suppressed, and a spurious one
substituted, the case looks very like an attempt to obtain credit under false
pretences.
ABBREVIATIONS.
Etym., etymology. Syn., synonym. Distr., distribution.
M.S., manuscript, i. e., unpublished.
Sp., species. Brit. M., (in the) British Museum.
Distr., Norway New Zealand ; including all intermediate seas.
Fossil, lias chalk ; implies that the genus existed in these, and all inter-
vening strata. Chalk means that the genus commenced in the
chalk, and has existed ever since.
Depth ; 50 fms. ; genus found at all depths between low-water and 50
fathoms. A fathom is six feet.
^ one-fourth the real size ; ^ magnified four times.
Lat., breadth. Long., length. Alt., height or thickness.
line., (uncia) an inch. Lin., (linea) a line, the -^ of an inch.
Mill., millimetre, the twenty-fifth part of an inch.
MANUAL OP THE MOLLUSCA.
CLASS I. CEPHALOPODA.
THE cuttle-fishes, though excluded by dealers from the list of shell-fish, are
the most remarkable, and, rightly considered, the most interesting of any ;
whilst their relatives, the nautili and ammonites, are unmatched for the sym-
metry and wondrous architecture of their pearly shells.
The principal locomotive organs of the cephalopoda, are attached to the
head, in the form of muscular arms or tentacles ;* in addition to which, many
have fins ; and all can propel themselves by the forcible expulsion of water
from their respiratory chamber.
Unlike most of the mollusca, they are symmetrical animals, having their
right and left sides equally developed ; and their shell is usually straight, or
coiled in a vertical plane. The nautilus and argonaut alone (of the living
tribes) have external shells ; the rest are termed " naked cephalopods," be-
cause the shell is internal. They have powerful jaws, acting vertically, like
the mandibles of birds ; the tongue is large and fleshy, and part of its surface
is sentient, whilst the rest is armed with recurved spines ; their eyes are large,
and placed on the sides of the head ; their senses appear to be very acute.
All are marine ; and predatory, living on shell-fish, crabs, and fishes.
The nervous system is more concentrated than in the other mollusca ;
and the brain is protected by a cartilage. The respiratory organs consist of
two or four plume-like gills, placed symmetrically on the sides of the body,
in a large branchial cavity, opening forwards on the underf side of the head ;
in the middle of this opening is placed the siphon or funnel. The sexes are
always distinct ; but the males are much less numerous than the females, and
in many species, at present unknown. They are divided into two orders, the
names of which are derived from the number of the branchitz.
ORDER I. DlBRANCHIATA, Owen.
Animal swimming ; naked. Head distinct. Eyes sessile, prominent.
Mandibles horny (PI. I., fig. 2). Arms 8 or 10, provided with suckers.
Body round or elongated, usually with a pair of fins ; branchia two, fur-
* M. Schultze compares the arms of the cephalopods" to the oral filaments of
myxine.
\ According to the established usage, we designate that the under or ventral side
of the body, on which the funnel is placed. But if the cuttle fishes are compared
with the nucleobranch.es, or the nautilus with the holostomatous gasteropods, their
external analogies seem to favour an opposite condusion.
CEPHALOPODA. 63
nished with muscular ventricles ; ink-gland always present ; parietes of the
funnel entire.
Shell internal (except in argonauta), horny or shelly, with or without
air-chambers.
The typical forms of the cuttle-fishes were well described by Aristotle, and
have been repeatedly examined by modern naturalists ; yet, until Professor
Owen demonstrated the existence of a second order of cephalopods, departing
from all the abovementioned characters, it was not clearly understood how
inseparably the organisation of the cuttle-fishes was connected with their con-
dition as swimming mollusca, breathing by two gills.
The characters which co-exist with the two gills, are the internal ru-
dimentary shell, and the substitution of other means of escape and defence,
than those which an external shell would have afforded ; viz. : powerful arms,
furnished with suckers ; the secretion of an inky fluid, with which to cloud
the water and conceal retreat ; more perfect organs of vision ; and super-
added branchial hearts, which render the circulation more vigorous.*
The suckers (antlia or acetabula), form a single or double series, on the
inner surface of the arms. Prom the margin of each cup, the muscular fibres
converge to the centre, where they leave a circular cavity, occupied by a soft
caruncle, rising from it like the piston of a syringe, and capable of retraction
when the sucker is applied to any surface. So perfect is this mechanism for
effecting adhesion, that while the muscular fibres continue retracted, it is
easier to tear away the limb than to detach it from its hold.f In the decapods,
the base of the piston is surrounded by a horny dentated hoop ; which in the
uncinated calamaries, is folded, and produced into a long sharp claw.
The ink-bag (fig. 33), is tough and fibrous, with a thin silvery outer
coat ; it discharges its contents through a duct which opens near the base of
the funnel. The ink was formerly used for writing (Cicero), and in the pre-
paration of sepia ;% and from its indestructible nature, is often found in a
fossil state.
* In a few species, which have no fins, the arms are webbed. In the only kind
which has an external shell, it is confined to the female sex, and is secreted by the
membranes of the arms. It is now quite certain that such shells as those of the fossil
ammonites and orthocerata. would be incompatible with dibranchiate organization.
t " The complex, irritable mechanism, of all these suckers, is under the complete
control of the animal. Mr. Eroderip informs me that he has attempted, with a hand-
net, to catch an octopus that was floating by, with its long and flexible arms entwined
round a fish, which it was tearing with its sharp hawk's bill ; it allowed the net to ap-
proach within a short distance before it relinquished its prey, when, in an instant, it
relaxed its thousand suckers, exploded its inky ammunition, and rapidly retreated
under cover of the cloud which it had occasioned, by rapid and vigorous strokes of its
circular web." (Owen.)
J Indian ink and sepia are now made of lam :-smoke, or of prepared charcoal.
64 MANUAL OF THE MOLLUSCA.
The skin of the naked cephalopods is remarkable for its variously coloured
vesicles, or pigment-cells. In sepia they are black and brown ; in the calamary,
yellow, red, and brown ; and in the argonaut, and some octopods, there are
blue cells besides. These cells alternately contract and expand, by which the
colouring matter is condensed or dispersed, or perhaps driven into the deeper
part of the skin. The colour accumulates, like a blush, when the skin is irri-
tated, even several hours after separation from the body. During life, these
changes are under the control of the animal, and give it the power of chang-
ing its hue, like the chameleon. In fresh specimens, the sclerotic plates of
the eyes have a pearly lustre ; they are sometimes preserved in a fossil state.
The aquiferous pores are situated on the back and sides of the head, on
the arms (drackial), or at their bases (buccal pores).
The mantle is usually connected with the back of the head by a broad
("nuchal") muscular band; but its margin is sometimes free all round, and
it is supported only by cartilaginous ridges, fitting into corresponding grooves,*
and allowing considerable freedom of motion.
The cuttle-fishes are nocturnal, or crepuscular animals, concealing them-
selves during the day, or retiring to a lower region of the water. They in-
habit every zone, and are met with equally near the shore, and in the open
sea, hundreds of miles from land. They attain occasionally a much greater
size than any other mollusca. MM. Q,uoy and Gaimard found a dead cuttle-
fish in the Atlantic, under the equator, which must have weighed 2 cwt. when
perfect ; it was floating on the surface, and was partly devoured by birds.
Banks and Solander, also met with one under similar circumstances, in the
Pacific, which was estimated to have measured six feet in length. (Owen.)
The arms of the octopods are sometimes two feet long.f From their habits,
it is difficult to capture some species alive, but they are frequently obtained,
uninjured, from the stomachs of dolphins, and other fishes which prey upon
them.
SECTION A. OCTOPODA.
Arms 8 ; suckers sessile. Eyes fixed, incapable of rotation. Body
united to the head by a broad cervical band. Branchial chamber divided
longitudinally by a muscular] partition. Oviduct double ; no distinct nida-
mental gland. Shell external and one-celled (mono-thalamous) > or internal
and rudimentary.
The Octopods differ from the typical cuttle-fishes in having only eight
arms, without the addition of tentacles ; their bodies are round, and they sel-
* Termed the "apparatus of resistance," by D'Orbigny.
t Denys Montfort, having represented a " kraken octopod," in the act of scuttling
a three-master, told M. Defrance, that if this were " swallowed," he would in his next
edition represent the monster embracing the Straits of Gibraltar, or capsizing a whole
squadron of ships. (D'Orbigny.)
CEPHALOPODA. 65
clora have fins. They are the most eccentric or " aberrant" mollusks, supe-
rior in organization to all the rest, but manifesting some remarkable and
unexpected analogies with the lowest classes of animals.
The males of some species of octopus and eledone, are similar to the fe-
males, but are comparatively scarce. Only the females of many others are
known, and every specimen of the argonaut hitherto examined (amounting to
many hundreds), has been of that sex. Dr. Albert Kolliker has suggested
that the real males of the argonaut, and also of octopus granulatus and
tremoctopus viol-acmes are the hectocotyles, previously mistaken for parasitic
worms.
The hectocotyle of octopus granulatus was described by Cuvier,* who ob-
tained several specimens from octopods captured in the Mediterranean. It is
five inches in length, and resembles a detached arm of the octopus, its under
surface being bordered with 40 or 50 pairs of alternate suckers.
The hectocotyle of tremoctopus was discovered by Dr. Kolliker, at Messina,
in 1842, adhering to the interior of the gill-chamber and funnel of the
poulpe ; it is represented in PL I., fig. 3. The body is worm-like, with two
rows of suckers on the ventral surface, and an oval appendage at the posterior
end. The anterior part of the back is fringed with a double series of bran-
chial filaments (250 on each side). Between the branchiae are two rows of
brown or violet spots, like the pigment cells of the tremoctopus. The suckers
(40 on each side) closely resemble those of the tremoctopus, in miniature.
Between the suckers are four or five series of pores, the openings of minute
canals, passing into the abdominal cavity. The mouth is at the anterior
extremity, and is minute and simple; the alimentary canal runs straight
through the body, nearly filling it. The heart is in the middle of the back,
between the branchiae ; it consists of an auricle and a ventricle, arid gives
origin to two large vessels. There is also an artery and vein on each side,
giving branches to the branchial filaments. A nerve extends along the in-
testine, and one ganglion has been observed. The oval sac incloses a small
but very long convoluted tube, ending in a muscular vas deferens ; it contains
innumerable spermatozoa.
The hectocotyle of the argonaut was discovered by Chiaje, who considered
it a parasitic worm, and described it under the name of trichocephalus aceta-
bularis ; it was again described by Costa,^ who regarded it as " a spermato-
phore of singular shape ;" and lastly by Dr. Kolliker 4
Tt is similar in form to the others, but is only seven lines in length, and
has a filiform appendage in front, six lines long. It has two rows of alternate
* An. Sc. Nat. 1 Series, t. 18. p. 147. 1829.
t An. Sc. Nat. 2 Series, 7. p. 173.
t Lin. Trans. Vol. 20, pt. 1, p. 9; and in his own zootoraical berichte, where it is
figured.
66 MANUAL OF THE MOLLUSCA.
slickers, 45 on each side ; but no branchia ; the skin contains numerous
changeable spots of red or violet, like that of the argonaut.*
According to the observations of Madame Power, " the newly hatched
argonaut has no shell, and is quite unlike what it afterwards becomes ; it is a
sort of little worm, having two rows of suckers along its length, with a fili-
form appendage at one extremity, and a small swelling at the other. It might
be supposed to represent an extremely small bmchial appendage, from which
the other parts were afterwards to be developed."! (Kolliker.)
FAMILY I. AllGONAUTID^E.
Dorsal arms (of the fern ale> webbed at the extremity, secreting a symme-
trical involuted shell. Mantle supported in front by a single ridge on the
funnel.
Genus AKGONAUTA, Lin. Argonaut or paper sailor.
Etymology., argonautai, sailors of the ship Argo.
Synonyms, ocythoe (Rafinesque). Nautilus (Aristotle and Pliny).
Example, A. hians, Soland, pi. II., fig. 1. China.
Fig. 32. Arg^naufa argo L. swimming .t
The shell of the argonaut is thin and translucent ; it is not moulded on
the body of the animal, nor is it attached by shell-muscles ; and the unoccu-
pied hollow of the spire serves as a receptacle for the minute clustered eggs.
The argonaut sits in its boat with its siphon turned towards the keel, and its
sail-shaped (dorsal) arms closely applied to the sides of the shell, as in fig. 32,
where, however, they are represented as partially withdrawn, in order to show
the margin of the aperture. It swims only by ejecting water from its fun-
* Similar instances of a permanently rudimentary condition of the male sex, oc-
cur amongst the lowest organized parasitic crustaceans; the males of achtheres, ler-
nceopoda, tracheliaster, fyc., are frequently a thousand times smaller than the female,
upon whom they live, and from whom they differ both in form and structure.
Gosse has described a similar disparity of the sexes in asplanchna.
t An. Sc. Nat. 2 Series, vol. 16, p. 185.
t From a copy of Rang's figure, in Charlesworth's Magazine; one-fourth the na-
tural size ; the small arrow indicates the current from the funnel, the large arrow th ;
direction in which the " sailor" is driven by the recoil.
Poli has represented it sitting the opposite way ; the writer had once an argonaut
shell with the nucleus reversed, implying that the animal had turned quite round in it>
shell, and remained in that position. The specimen is now in the York Museum.
.V
CEPHALOPODA. 67
nel, and crawls in a reversed position, carrying its shell over its back like a
snail. (Madame Power and M. Jiang.)
It was the nautilus (primus) of Aristotle, who described it as floating on
the surface of the sea, in fine weather, and holding out its sail- shaped arms to
the breeze ; a pretty fable, which poets have repeated ever since.
Distribution : 4 species of argonaut are known ; they inhabit the open sea
throughout the warmer parts of the world. Captain King took several from
the stomach of a dolphin, caught upwards of 600 leagues from any land.
Fossil : A. hians is found in the sub-apennine tertiaries of Piedmont. This
species is still living in the Chinese seas, but not in the Mediterranean.
FAMILY II. OCTOPODHXE.
Arms similar, elongated, united at the base by a web. Shell represented
by two short styles, encysted in the substance of the mantle. (Owen.)
OCTOPUS, Cuvier. Poulpe.
Etym., octo, eight, pous (poda) feet.
Syn., cistofjus. (Gray.)
Ex., 0. tuberculatus Bl., pi. I., figs. 1 and 2 (mandibles).
Body oval, warty or cirrose, without fins ; arms long, unequal ; suckers
in two rows ; mantle supported in front by the branchial septum.
The octopods are the "polypi" of Homer and Aristotle; they are solitary
animals, frequenting rocky shores, and are very active and voracious ; the
females oviposit on sea-weeds, or in the cavities of empty shells. In the
markets of Smyrna and Naples, and the bazaars of India, they are regularly
exposed for sale. "Although common (at St. Jago) in the pools of water left
by the retiring tide, they are not very easily caught. By means of their long
arms and suckers they can drag their bodies into very narrow crevices, and
when thus fixed it requires great force to remove them. At other times they
dart tail first, with the rapidity of an arrow, from one side of the pool to the
other, at the same instant discolouring the water with a dark chesnut-brown
ink. They also escape detection by varying their tints, according to the nature
of the ground over which they pass. In the dark they are slightly phospho-
rescent." (Darwin)*
Professor E. Forbes has observed that the octopus, when resting, coils its
dorsal arms over its back, and seems to shadow forth the argonaut's shell.
Distr., universally found on the coasts of the temperate and tropical zones ;
46 species are known ; when adult they vary in length from 1 inch to 2 feet,
according to the species.
PINNOCTOPUS, D'Orb. Finned octopus.
Body with lateral fins, united behind.
* Journal of a Voyage round the "World. The most fascinating volume of travels
published since Defoe's fiction.
MANUAL OF THE MOLLUSCA.
The only known species, P. cordiformis, was discovered by MM. Quoy
and Gaimard, on the coast of New Zealand; it exceeds 3 feet in length.
ELEDONE. (Aristotle.) Leach.
Type, E. octopodia, L.
Suckers forming a single series on each arm ; length 6 to 18 inches. E.
moschata emits a musky smell.
Distr., 2 sp. Coasts of Norway, Britain, and the Mediterranean.
CIRROTEUTHIS, Eschricht. 1836.
Etym., cirrus, a filament, and teuthis a cuttle-fish.
Body with two transverse fins ; arms united by a web, nearly to their
tips; suckers in a single row, alternating with cirri. Length 10 inches.
Colour violet. The only species (C. Mullen Esch.} inhabits the coast of
Greenland.
PHILONEXIS, D'Orb.
Etym., philos, an adept in nexis, swimming.
Type, P. atlanticus, D'Orb.
Arms free ; suckers in two rows ; mantle supported by two ridges on the
funnel. Total length, 1 to 3 inches.
Distr., 6 sp. Atlantic and Medit. Gregarious in the open sea ; feeding
on floating mollusca.
Sub-genus. Tremoctopus (Chiaje), pi. I., fig. 3.
Name from two large aquiferous pores (tremata) on the back of the head.
Arms partly, or all webbed half-way up.
Distr., 2 sp. T. quoyanus and violaceus. Atlantic and Medit.
SECTION B. DECAPODA.
Arms 8. Tentacles 2, elongated, cylindrical, with expanded ends. Suckers
pedun culated, armed with a horny ring. Mouth surrounded by a buccal
membrane, sometimes lobed and funished with suckers. Eyes moveable in
their orbits. Body oblong or elongated, always provided with a pair of fins.
Funnel usually furnished with an internal valve. Oviduct single. Nidamental
gland largely developed. Shell internal ; lodged loosely in the middle of the
dorsal aspect of the mantle.
The arms of the decapods are comparatively shorter than those of the
octopods ; the dorsal pair is usually shortest, the ventral longest. The tenta-
cles originate within the circle of the arms, between the third and fourth pairs;
they are usually much longer than the arms, and in cheiroteuthis are six times
as long as the animal itself. They are completely retractile into large sub-
ocular pouches in sepia, sepiola, and rossia ; partly retractile in loligo and
sepioteuth'is ; non -retractile in cheiroteuthis. They serve to seize prey which
may be beyond the reach of the ordinary arms, or to moor the animal in
safety during the agitation of a stormy sea.
CEPHALOPODA. 69
The shell of the living decapods is either a horny "pen" (gladius) or a
calcarious "bone" (sepion)-, not attached to the animal by muscles, but so
loose as to fall out when the cyst which contains it is opened. In the genus
spirula, it is a delicate spiral tube, divided into air-chambers by a series of
partitions (septa}. In the fossil genus spirulirostra, a similar shell forms the
apex of a cuttle-bone ; in the fossil conoleuthis a chambered shell is combined
with a pen ; and the belemnite unites all these modifications.
The decapods chiefly frequent the open sea, appearing periodically like
fishes, in great shoals, on the coasts and banks. (Owen, D'Orb.)
FAMILY III. TEUTHID2E. CALAMAKIES, OR SQUIDS.
Body, elongated ; fins short, broad, and mostly terminal.
Shell, (gladius or pen) horny, consisting of three parts, a shaft, and two
lateral expansions or wings.
Sub-family A. Myopsida, D'Orb. Eyes covered by the skin.
LOLIGO. (Pliny) Lamarck. Calamary.
Syn., teuthis (Aristotle) Gray.
Type, L. vulgaris (sepia loligo L.) Fig. 1. PI. I., fig. 6 (pen).
fen, lanceolate, with the shaft produced in front ; it is multiplied by age,
several being found packed closely, one behind another, in old specimens.
(Owen. )
Body tapering behind, much elongated in the males. Tins terminal,
united, rhombic. Mantle supported by a cervical ridge, and by two grooves
in the base of the funnel. Suckers in two rows, with horny, dentated hoops.
Tentacular club with four rows of suckers. Length (excluding tentacles)
from 3 inches to 2| feet.
The calamaries are good swimmers ; they also crawl, head-downwards, on
their oral disk. The common species is used for bait, by fishermen, on the
Cornish coast (Couch). Shells have been found in its stomach, and more
rarely sea-weed (Dr. Johnston). Their egg-clusters have been estimated to
contain nearly 40,000 eggs (Bohadsch).
Distr., 21 sp. in all seas. Norway New Zealand.
Sub-genus. Teudopsis, Deslongchamps, ]835.
Etym., teuthis, a calamary and opsis like.
Type, T. Bunellii, Desl.
Pen, like loligo, but dilated and spatulate behind.
Fossil, 5 sp. Upper Lias, France, and Wurtemberg.
GONATUS, Gray.
Animal an&pen like loligo in most respects. Arms with 4 series of cups,,
tentacular club with numerous small cups, and a single large sessile cup
armed with a hook ; funnel valveless.
70 MANUAL OF THE MOLLUSCA.
Distr., a single species (G. amana, Holier sp.) is found on the coast o
Greenland.
SEPIOTEUTHIS, Blainville.
Type, S. sepio'idea, Bl. Animal like loligo ; fins lateral, as long as th(
body. Length from 4 inches to 3 feet.
Distr. > 13 sp., West Indies, Cape, Ked Sea, Java, Australia.
BELOTEUTHIS, Minister.
Efym.., belos, a dart and teuthis.
Type, B. subcostata, Miinst. PL IT., fig. 8., L T . Lias, Wurtemberg.
Pen, horny, lanceolate ; with a very broad shaft, pointed at each end
and small lateral wings.
Distr., 6 sp. described by Miinster, considered varieties (differing in ag(
and sex), by M. D'Orbigny.
GEOTEUTHIS, Miinster.
Etym., ge, the earth (i. e. fossil) and teuthis.
Syn., belemnosepia (Agassiz.) belopeltis (Yoltz) loligosepia (Quenstedt.)*
Pen broad, pointed behind ; shaft broad, truncated in front ; lateral wing.'
shorter than the shaft.
Fossil, 9 sp. U. Lias, Wurtemberg ; Calvados ; Lyme Regis. Severa
undescribed sp. in the Oxf. clay, Chippenharn.
Besides the pens of this calamary the ink-bag, the muscular mantle, anc
the bases of the arms, are preserved in the Oxford clay. Some of the ink-
bags found in the Lias are nearly a foot in length, and are invested with f.
brilliant nacreous layer ; the ink forms excellent sepia. It is difficult to un-
derstand how these were preserved, as the recent calamaries " spill their ink"
on the slightest alarm. (Buckland}.
LEPTOTEIJTHIS, Meyer.
Etym., Leptos thin, and teuthis.
Type, L. gigas Meyer, Oxford clay, Solenhofen.
Pen very broad and rounded in front, pointed behind; with obscure diverg-
ing ribs.
CRANCHIA, Leach, 1817.
Named in honour of Mr. J. Cranch, naturalist to the Congo expedition.
Type, C. scabra, Leach.
Body large, ventricose ; fins small, terminal ; mantle supported in fronl
by a branchial septum. Length 2 inches. Head very small. Eyes fixed
Buccal membrane large, 8-lobed. Arms short, suckers in two rows. Tenta-
cular clubs finned behind, cups in 4 rows. Funnel valved.
Pen long and narrow.
* These names must be set aside, being incorrect in themselves, and founded or
a total misapprehension of the nature of the fossils.
CEPHALOPODA. 7 1
Distr., 2 sp. W. Africa. In the open sea.
This genus makes the nearest approach to the octopods.
SEPIOLA. (Rondelet) Leach, 181?.
Ex., S. atlantica (D'Orb.) PL I., fig. 4.
Body short, purse-like ; mantle supported by a broad cervical band, and a
ridge fitting a groove in the funnel. Fins dorsal, rounded, contracted at the
base. Suckers in 2 rows, or crowded, on the arms, in 4 rows on the tentacles.
Length 2 to 4 inches.
Pen, half as long as the back. S. stenodactyla (sepioloidea, D'Orb.) has
no pen.
Distr., 6 sp. Coasts of Norway, Britain, Medit., Mauritius, Japan,
Australia.
Sub-genus. Rossia, Owen (Fidenas? Gray). Mantle supported by a
cervical ridge and groove. Suckers in 2 rows on the tentacles. Length 3
to 5 inches.
Distr., 6 sp. Regent Inlet, Britain, Medit., Manilla.
Sub-family B. Oigopsida, D'Orb.
Eyes naked. Fins always terminal, and united, forming a rhomb.
LOLIGOPSIS, Lam. 1811.
Etym., loligo, and opsis, like.
Type, L. pavo (Lesueur).
Body elongated, mantle supported in front by a branchial septum. Arms
short. Cups in 2 rows. Tentacles slender, often mutilated. Funnel valveless.
Pen slender, with a minute conical appendix. Length from 6 to 12 inches.
Distr., pelagic. 8 sp. N. Sea, Atlantic, Medit., India, Japan, S. Sea.
CHEIROTEUTHIS, D'Orb.
Etym., cheir, the hand, and teuthis.
Type, C. veranii, Per.
Mantle supported in front by ridges. Funnel valveless. Ventral arms
very long. Tentacles extremely elongated, slender, with distant sessile cups
on the peduncles, and 4 rows of pedunculated claws on their expanded ends.
Pen slender, slightly winged at each end. Length of the body 2 inches ;
to the tips of the arms 8 inches ; to the ends ot the tentacles 3 feet.
Distr., 2 sp. Atlantic, Medit. On gulf-weed, in the open sea.
HISTIOTEUTHIS, D'Orb.
Etym., histion, a veil ; and teuthis.
Type, H. bonelliana, Fer. Length 16 inches.
Body short. Fins terminal, rounded. Mantle supported in front by
ridges and grooves. Buccal membrane 6-lobed. Arms (except the ventral
pair), webbed high up. Tentacles long, outside the web, with 6 rows of den-
tated cups on their ends.
72 MANUAL OF THE MOLLUSCA.
Pen short and broad.
Distr., 2 sp. Mediterranean ; in the open sea.
ONYCHOTEUTHIS, Lichtenstein. Uncinated calamary.
Etym., onyx, a claw, and teuthis.
Type, 0. banksii, Leach. ( = bartlingii?) PI. I., fig. 7 and fig. 8 i
Syn., ancistroteuthis (Gray). Onychia (Lesueur).
Pen narrow, with hollow, conical apex.
Arms with 2 rows of suckers. Tentacles long and powerful, armed with
a double series of hooks ; and usually having a small group of suckers at the
base of each club, which they are supposed to unite, and thus use their tenta-
cles in conjunction.* Length 4 inches to 2 feet.
The unciuated calamaries are solitary animals, frequenting the open sea,
and especially the banks of gulf- weed (sargasso). O. banksii ranges from
Norway to the Cape and Indian ocean ; the rest are confined to warm seas.
0. dussumieri has been taken swimming in the open sea, 200 leagues north
of the Mauritius.
Distr., 6 sp. Atlantic, Indian ocean, Pacific.
ENOPLOTEUTHIS, D'Orb. Armed calamary.
Etym., enoplos, armed, and teuthis.
Type, E. smithii, Leach.
Syn., ancistrochirus and abralia (Gray), octopodoteuthis (Ruppell), verani;
(Krohn).
Pen lanceolate. Arms provided with a double series of horny hooks, con
cealed by retractile webs. Tentacles long and feeble, with small hooks at th<
end. Length (excluding the tentacles) from 2 inches to 1 foot ; but somi
species attain a larger size. In the museum of the College of Surgeons then
is an arm of the specimen of E. unguiculata, found by Banks and Solander ii
Cook's first voyage (mentioned at p. 64) supposed to have been 6 feet lon<
when perfect. The natives of the Polynesian Islands, who dive for shell-fish
have a well-founded dread of these formidable creatures. {Owen.)
Distr., 10 sp. Medit., Pacific.
OMMASTREPHES, D'Orb. Sagittated calamary.
Etym., omma, the eyes, and strepho, to turn.
Type, 0. sagittatus, Lam.
Body cylindrical ; terminal fins large and rhombic. Arms with 2 rows o
suckers, and sometimes an internal membranous fringe. Tentacles short am
strong, with 4 rows of cups.
Pen, consisting of a shaft with three diverging ribs, and a hollow conies
appendix. Length from 1 inch to nearly 4 feet.
* The obstetric forceps of Professor Simpson were suggested by the suckers of th
calamary.
CEPHALOPODA. 73
The sagittated calamaries are gregarious, and frequent the open sea in all
climates. They are extensively used in the cod-fishery off Newfoundland, and
are the principal food of the dolphins and cachalots, as well as of the albatross
and larger petrels. The sailors call them " sea-arrows" or "flying squids,"
from their habit of leaping out of the water, often to such a height as to fall
on the decks of vessels. They leave their eggs in long clusters floating at the
surface.
Distr., 14 recent sp. ; similar pens (4 sp.) have been found fossil in the
Oxford clay, Solenhofen ; it may, however, be doubted whether they are ge-
nerically identical.
FAMILY IV. BELEMNITID^.
Shell consisting of a pen, terminating posteriorly in a chambered cone,
sometimes invested with a fibrous guard. The air-cells of the phragmo-cone
are connected by a tiphuncle, close to the ventral side.
BELEMNITES, Lamarck. 1801.
Etym., belemnon> a dart.*
Ex., B. puzosianus, pi. II., fig. 5.
Phragmocone horny, slightly nacreous, with a minute globular nucleus at
its apex ; divided internally by numerous concave septa. Pen represented by
two nacreous bands on the dorsal side of the phragmocone, and produced be-
yond its rim, in the form of sword-shaped processes (pi. II., fig. 5).f Guard,
fibrous, often elongated and cylindrical ; becoming very thin in front, where
it invests the phragmocone. J
Nearly 100 species of belemnites have been found in a fossil state, ranging
from the lias to the gault, and distributed over all Europe. The phragmocone
of the belemnite, which represents the terminal appendix of the calamaries, is
* The termination lies (from lithos, a stone) was formerly given to all fossil genera.
t The most perfect specimens known are in the cabinet of Dr. Mantell, and the
British Museum ; they were obtained by William Buy in the Oxford clay of Christian
Malford, Wilts. The last chamber of a lias belemnite in the British Museum is 6
ncheslong, and 2 inches across at the smaller end; a fracture near the siphuncle
shows the ink-bag. The phragmocone of a specimen corresponding to this in size,
measures 7^ inches in length.
t The specific gravity of the guard is identical with that of the shell of the recent
sinna, and its structure is the same. Parkinson and others have supposed that it was
jriginally a light and porous structure, like the cuttle bone; but the inucro of the
iepiostaire, with which alone it is homologous, is quite as dense as the belemnite. We
ire indebted to Mr. Alex. Williams, M.R.C.S., for the following specific gravities of
recent and fossil shells, compared with water as 1,000 :
Belernnites puzosianus, Oxford clay 2,674
Belemnitella mucronata, chalk 2,677
Pinna, recent, from the Mediterranean 2,607
Trichites plottii, from the inferior oolite 2,670
Conus monile, recent 2,910
Conus ponderosus, Miocene, Touraine 2,713
E
74 MANUAL OP THE MOLLUSCA.
divided into air-chambers, connected by a small tube (siphuncle), like the shel
of the pearly nautilus. It is exceedingly delicate, and usually owes its preser
tioii to the infiltration of calc. spar ; specimens frequently occur in the lias
with the meniscus-shaped casts of the air-chambers loose, like a pile of watch,
arlasses. It is usually eccentric, its apex being nearest to the ventral side o:
the guard. The guard is very variable in its proportions, being sometimes
only half an inch longer than the phragmocone, at others one or two feet ii
length. These variations probably depend to some extent on age and sex
M. D'Orbigny believes that the shells of the males are always (comparatively)
long and slender ; those of the females are at first short, but afterwards grow-
ing only at the points, they become as long in proportion as the others. Thjt
guard always exhibits (internally) concentric lines of growth; in B. irregularu.
its apex is hollow. The belemnites have been divided into groups by the pre-
sence aud position of furrows in the surface of the guard.
SECTION I. ACCELI (Bronn.) without dorsal or ventral grooves.
Sub-section 1. Acuarii, without lateral furrows, but often channelled at
the extreme point.
Type., b. acuarius. 20 sp. Lias Neocomian.
Sub-section 2. Clavati, with lateral furrows.
Type, b. clavatus. 3 sp. Lias.
SECTION II. GASTJIOCCELI (D'Orb.) Ventral groove distinct.
Sub-section 1. Canaliculati, no lateral furrows.
Type, b. canaliculatus. 5 sp. Inf. oolite Gt. oolite.
Sub-section 2. Hastati, lateral furrows distinct.
Type, b. hastatus. 19 sp. U. lias Gault.
SECTION III. NOTOCCELI (D'Orb.) with a dorsal groove, and fir
each side.
Type, b. dilatatus. 9 sp. Neocomian.
The belemnites appear to have been gregarious, from the exceeding abuiul-
ance of their remains in many localities, as in some of the marlstone quarrie-
of the central counties, and the lias cliffs of Dorsetshire. It is also probabL
that they lived in a moderate depth of water, and preferred a muddy bottom
to rocks or coral-reefs, with which they would be apt to come in perilous col-
lision. Belemnites injured in the life-time of the animal have been frequently
noticed.
BELEMNITELLA, D'Orb.
Syn., actinocamax, Miller (founded on a mistake.)
Type, B. mucronata, Sby. PL II., fig. 6.
Distr., Europe; N. America. 5 sp. U. greensand and chalk.
The guard of the belemnitella has a straight fissure on the ventral side < I
its alveolar border ; its surface exhibits distinct vascular impressions. The
CEPHALOPODA.
75
phragmocone is never preserved, but casts of the alveolus show that it was
chambered, that it had a single dorsal ridge, a ventral process passing into the
fissure of the guard, and an apical nucleus.
ACANTHOTEUTHIS (Wagner), Munster.
Etym., acantha, a spine, and teuthis.
Syn., Keleeno (Munster.) Belemnoteuthis?
Type, A. prisca, Ruppell.
Founded on the fossil hooks of a calamary, preserved in the Oxford clay
of Solenhofen. These show that the animal had 10, nearly equal arms, all
furnished with a double series of horny claws, throughout their length. A
pen like that of the ommastrephes has been hypothetical^ ascribed to these
arms, which may, however, have belonged to the belemnite or the belemno-
teathis.
BELEMNOTEUTHIS (Miller), Pearce, 1842.
Type, B. antiquus (Ounuington), fig. 33.
Shell consisting of a phragmocone, like
that of the belemnite ; a horny dorsal pen
with obscure lateral bands ; and a thin
fibrous guard, with two diverging ridges on
the dorsal side.
Animal provided with arms and tenta-
cles of nearly equal length, furnished with
a double alternating series of horny hooks,
from. 20 to 40 pairs on each arm ; mantle
free all round ; fins large, medio- dorsal
(much larger than in fig. 33).
Fossil in the Oxford clay of Chippen-
ham. Similar horny claws have been found
in the lias of Watchett; and a guard equally
thin is figured in Buckland's Bridgewater
Treatise, t. 44, fig. 14.
In the fossil calamary of Chippenham,
the shell is preserved along with the mus-
cular mantle, fins, ink-bag, 'funnel, eyes,
and tentacles with their horny hooks ; all
the specimens were discovered, and deve-
loped with, unexampled skill, by William
Buy, of Sutton, near Chippenham.
Fig. 33. BelKmnoteuthis*
* Fig. 33. Belemnoteuthis antiquus, , ventral side, from a specimen in the cabinet
of William Cunnington, Esq., of Devizes. .The last chamber of 'the phragmocone is
preserved in this specimen, a, represents the dorsal side of an uncompressed phrag-
mocone from the Kelloway rock, in the cabinet of J. G. Lowe, Esq. ; c, is an ideal sec-
tion of the same. Since this woodcut was executed, a more complete specimen has
fO MANUAL OF THE MOLLUSCA.
CONOTEIJTHIS, D'Orb.
Type, C. Dupinianus, D'Orb. PI. II., fig. 9. Neocomian, France.
Phragmocone slightly curved. Pen elongated, very slender.
This shell, which is like the pen of an ommastrephe, with a chambered
cone, connects the ordinary calamaries with the belenmites.
FAMILY V. SEPIADJS.
Shell (cuttle-bone or seplostaire) calcarious ; consisting of a broad lami-
nated plate, terminating behind in a hollow, imperfectly chambered apex
{mucro). Animal with elongated tentacles, expanded at their ends.
SEPIA (Pliny), Linnseus.
Type, S. officinalis, L. PL I., fig. 5.
Syn., belosepia, Voltz. (B. sepio'idea, pi. II., fig. 3, mucro only.)
Body oblong, with lateral fins as long as itself. Arms with 4 rows oi
suckers. Mantle supported by tubercles fitting into sockets on the neck and
funnel. Length 3 to 28 inches.
Shell as wide and long as the body; very thick in front, concave internally
behind ; terminating in a prominent mucro. The thickened part is composed
of numerous plates, separated by vertical fibres, which render it very light and
porous. T. Orbignyana, pi. II., fig. 2.
The cuttle-bone was formerly employed as an antacid by apothecaries ; it
is now only used as "pounce," or in casting counterfeits. The bone of *
Chinese species attains the length of 1| feet. (Adams.)
The cuttle-fishes live near shore, and the mucro of their shell seems in-
tended to protect them in the frequent collisions they are exposed to in swim-
ming backwards. (D'Orb.}
Distr., 30 sp. World-wide.
Fossil, 5 sp. Oxf. clay, Solenhofen. Several species have been foun
on mucrones from the Eocene of London and Paris. PI. II., fig. 3.
SFIRULIROSTRA, D'Orb.
Type, S. BeUardii (D'Orb.) PL II., fig. 4. Miocene, Turin.
Shell, mucro only known ; chambered internally ; chambers connected
by a ventral siphuncle ; external spathose layer produced beyond the phrag
mocone into a long pointed beak.
BELOPTERA (Blainville) Deshayes.
Etym., belos, a dart, and pteron, a wing.
Type, B. belemnitoides, Bl. PL II., fig. 7.
been obtained for the British Museum ; the tentacles are not longer than the ordinar /
arms, owing, perhaps, to their partial retraction ; this specimen will be figured in D)
Mantell's "Petrifactions and their Teachings." d, is a single hook, natural size; tha
specimens belonging to Mr. Cunnington and the late Mr. C. Pearce, show the largs
acetabular bases of the hooks.
CEPHALOPODA. 77
Shell, mucro (only known) chambered and siplmncled; winged externally.
Fossil, 2 sp. Eocene. Paris ; Bracklesham
BELEMNOSIS, Edwards.
Type, B. anomalus, Sby. sp. Eocene. Highgate (unique.)
Shell, mucro, chambered and siphuncled ; without lateral wings or elon-
gated beak.
FAMILY VI. SPIRULHLE.
Shell entirely nacreous ; discoidal ; whirls separate, chambered (potytkala-
mous^) with a ventral siphuncle.
SPIRULA, Lam., 1801.
Syn., h'tuus, Gray.
Ex., S. leevis (Gray.) PI. I., fig. 9.
Body oblong, with minute terminal fins. Mantle supported by a cervical
and 2 ventral ridges and grooves. Arms with 6 rows of very minute cups
Tentacles elongated. Funnel valved.
Shell placed vertically in the posterior part of the body, with the involute
spire towards the ventral side. The last chamber is not larger in proportion
than the rest ; its margin is organically connected ; it contains the ink-bag.
The delicate shell of the spirula is scattered by thousands on the shores of
New Zealand ; it abounds on the Atlantic coasts, and a few specimens are
yearly brought by the Gulf- stream, and strewed upon the shores of Devon and
Cornwall. But the animal is only known by a few fragments, and one perfect
specimen, obtained by Mr. Percy Earl on the coast of New Zealand.
Distr., 3 sp. All the warmer seas.
ORDER II. TETRABRANCHIATA.
Animal creeping ; protected by an external shell.
Head retractile within the mantle. Eyes pedunculated. Mandibles cal-
carious. Arms very numerous. Body attached to the shell by adductor mus-
cles, and by a continuous horny girdle. Branchiae four. Funnel formed by
the folding of a muscular lobe.
Shell external, camerated (poly-thalamous) and siphuncled; the inner
layers and septa nacreous ; outer layers porcellanous.*
It was long ago remarked by Dillwynn, that shells of the carnivorous gas-
teropods were almost, or altogether, wanting in the palseozoic and secondary
strata ; and that the office of these animals appeared to have been performed,
in the ancient seas, by an order of cephalopods, now nearly extinct. Above
1,400 fossil species belonging to this order are now known by their
shells ; whilst their only living representative is the nautilus pompilius,
* The Chinese carve a variety of patterns in the outer opaque layer of the nautilus
shell, relieved by the pearly ground beneath.
78
MANUAL OP THE MOLLT7SCA.
of which several specimens have been brought to Europe within the last few
years.*
The shell of the tetrabranchiate cephalopods is an extremely elongated
cone, and is either straight, or variously folded, or coiled.
It is straight in orthoceras . baculites.
bent on itself in ascoceras . ptychoceras.
curved in cyrtoceras . toxoceras.
spiral in trochoceras . turrilites.
discoidal in gyroceras . crioceras.
discoidal and produced in . lituites . . ancyloceras.
involute in nautilus . 9 ammonites.
Internally, the shell is divided into cells or chambers, by a series of parti-
tions (septa], connected by a tube or siphuncle. The last chamber is occupied
by the animal, the rest are empty during life, but in fossil specimens they are
often filled with spar. When the outer shell is removed (as often happens to
fossils,) the edges of the septa are seen (as in PL III., figs. 1, 2.) Sometimes
they form curved lines, as in nautilus and orthoceras, or they are zig-zag, as
in goniatites (fig. 53,) or foliaceous, as in the ammonite, fig. 34.
Fig. 34. Suture of an ammonite.^
The outlines of the septa are termed sutures ;J when they are folded the
elevations are called saddles, and the intervening depressions lobes. In
ceratites (fig. 54) the saddles are round, the lobes dentated; in ammonites
both lobes and saddles are extremely complicated. Broken fossils show that
the septa are nearly flat in the middle, and folded round the edge (like a shirt -
frill), where they abut against the outer shell- wall (fig. 37).
The siphuncle of the recent nautilus is a membranous tube, with a very
thin nacreous investment ; in most of the fossils it consists of a succession oi
funnel shaped, or bead-like tubes. In some of the oldest fossil genera, act I"
noceras, gyroceras, and phragmoceras, the siphuncle is large, and contains in
* The frontispiece, copied from Professor Osven's Memoir, represents the animal oi
the first nautilus, captured off the New Hebrides, and brought to England by Mr. Ben-
nett; it is drawn as if lying in the section of a shell, without concealing any % part of it.
The woodcut, fig. 43, is taken from a more perfect specimen, lately acquired by the
British Museum, in which the relation of the animal to its shell is accurately shown.
t A. heterophyllus, Sby., from the lias, Lyme Regis. British Museum. Only
side is represented ; the arrow indicates the dorsal saddle.
J From their resemblance to the sutures of the skull,
,.
CEPHALOPODA.
79
its centre a smaller tube, tlie space between the two being filled up with radiat-
ing plates, like the lamellaj of a coral. The position of the siphuncle is very
variable ; in the ammonitida it is external, or close to the outer margin of
the shell (fig. 37). In the nautilidae it is usually central (fig. 35), or internal
(% 36).
Fig. 35. Nautilus. Fig. 36. ' Clymenia. Fig. 37. Hamites*
The air-chambers of the recent nautilus are lined by a very thin, living
membrane ; those of the fossil orthocerata retain indications of a thick vascu-
lar lining, connected with the animal by spaces between the beads of the
siphuncle. f
The body-chamber is always very capacious ; in the recent nautilus its
cavity is twice as large as the whole series of air-cells ; in the goniatite (fig.
39), it occupies a whole whirl, and has a considerable lateral extension ; and
in ammonites communis it occupies more than a whirl.
Fig. 38. Ammonites. Fig. 39. Goniatites.%
* Fig. 35. Nautilus pompilius, L. Fig. 36. Clymenia striata, Miinst., see pi. II.,
fig. 16. Fig. 37. Hamites cylindraceus Defr., see fig. 58.
t The apocryphal genus spongarium, was founded on detached septa of an ortho-
ceras, from the Upper Ludlow rock, in which the vascular markings distinctly radiate
from the siphuncle. Mr. Jones, warden of Chin Hospital, has several of these in
apposition.
I Fig. 38. Section of ammonites obtusus, Sby. lias, Lyme Regis ; from a very young
specimen. Fig. 39. Section of goniatites sphtericus, Shy. carb. limestone, Bolland (in
the cabinet of Mr. Tennant.) The dotted lines indicate the lateral extent of the body-
chamber.
80
MANUAL OF THE MOLLUSCA.
The margin nf the aperture is quite simple in the recent nautilus, and
affords no clue to the many curious modifications observable in the fossil
forms. In the ammonites we frequently find a dorsal process, or lateral pro-
jections, developed periodically, or only in the adult (fig. 55, and pi. III., fig. 5),
In phragmoceras and gomphoceras (figs. 40, 41) the aperture is so
much contracted that it is obvious the animal could not have withdrawn its
head into the shell like the nautilus.
Fig. 40. Gomphoceras. Fig. 41. Phragmoceras.*
M. Barrande, from whose great work on the Silurian Formations of
Bohemia these figures are taken, suggests that the lower part of the aperture
(s s) which is almost isolated, may have served for the passage of the funnel,
whilst the upper and larger space (c c) was occupied by the neck ; the lobes
probably indicate the position of the external arms.
The aperture of the pearly nautilus is closed by a disk or hood (fig. 43, k),
formed by the union of the two dorsal arms, which correspond to the shell-
secreting sails of the argonaut.
In the extinct ammonites we have evidence that
the aperture was guarded still more effectively by a
horny, or shelly operculum, secreted, in all probabi-
lity, by these dorsal arms. In one group (arietes,)
the operculum consists of a single piece, and is horny
and flexible.f In the round-backed ammonites the
operculum is shelly, and divided into two plates by a
straight median suture (fig. 42). They were de-
scribed in 1811, by Parkinson, who called them tri-
gonellites, and pointed out the resemblance of their Fig. 42.1
* Fig. 40. Gomphoceras Bohemicum (Barrande), reduced view of the aperture ; *,
the siphonal opening. Fig. 41. phragmoceras callistoma (Barr.) both from the U.
Silurian, Bohemia.
t This form was discovered by the late Miss Mary Anning, the indefatigable col-
rector of the lias fossils of Lyme Regis, and described by Mr. Strickland, Geol. Journal,
vol. I., p. 232. Also by M. Voltz, Mem. de 1'Institute, 1837, p. 48.
% Trigonellites lamellosus, Park. Oxford clay, Solenhofen (and Chippenham ; ) as-
sociated with ammonites lingulatus, Quenstedt. (= A. Brightii, Pratt). From a speci-
men in the cabinet of Charles Stokes, Esq.
CEPHALOPODA. 81
internal structure to the cancellated tissue of bones. Their external surface is
smooth or sculptured ; the inner side is marked by lines of growth. Forty-
five kinds are enumerated by Bronn ; they occur in all the strata in which
ammonites are found, and a single specimen has been figured by M. D'Archiac,
from the Devonian rocks of the Eifel, where it was associated with goniatites*
Calcarious mandibles or rhyncholites (F. Biguet) have been obtained from
all the strata in which nautili occur ; and from their rarity, their large size
and close resemblance to the mandibles of the recent nautilus, it is probable
that they belonged only to that genus.f In the Muschelkalk of Bavaria one
nautilus (N. arietis, JReinecke, = N. bidorsatus, Schlotheim,) is found, and two
kinds of rhyncholite ; one sort, corresponding with the upper mandible of the
recent nautilus, has been called " rhyncholites hirundo" (pi. II., fig. 11), the
other, which appears to be only the lower mandible of the same species, has
been described under the name of " conchorhynchus avirostris."^:
In studying the fossil tetrabranchiata, it is necessary to take into consi-
deration the varying circumstances under which they have been preserved.
In some strata (as the lias of Watchett) the outer layer of the shell has dis-
appeared, whilst the inner nacreous layer is preserved. More frequently only
the outer layer remains ; and in the chalk formation the whole shell has
perished. ' In the calcarious grit of Berkshire and Wiltshire the ammonites
have lost their shells ; but perfect casts of the chambers, formed of calcarious
spar, remain.
Fossil orthocerata and ammonites are evidently in many instances dead
shells, being overgrown with corals, serpulse, or oysters ; every cabinet affords
such examples. In others the animal has apparently occupied its shell, and
prevented the ingress of mud, which has hardened all around il ; after this it has
decomposed, and -contributed to form those phosphates and sulphurets commonly
present in the body-chamber of fossil shells, and by which the sediment around
them is so often formed into a hard concretion. || In this state they are
* The trlgonellites have been described by Meyer as bivalve shells, under the
generic name of aptychus; by Deslongchamps under the name of Munsteria. M.
D'Orbigny regards them as cirripedes ! M. Deshayes believes them to be gizzards of
the ammonites. M. Coquand compares them with teudopsis; an analogy evidently
suggested by some of the membranous and elongated forms, such as T. sanguinolarius,
found with am. deprcssus, in the lias of Boll. Ruppell, Voltz, Quenstedt, and Zieten,
regard the trigonellites as the opercula of ammonites, an opinion also entertained by
many of the most experienced fossil collectors in England.
t M. D'Orbigny has manufactured two genera of calamari.es out of these nautilus
beaks! (rhynchoteufhis and. paltzoteuthis). In the innumerable sections of ammonite&
which have been made, no traces of the mandibles have ever been discovered.
1 Lepas avirostris (Schlotheim), described by Blainville as the beak of a
brachiopod !
Called spnndylolites by old writers.
|| In the alum-shale of Whitby, innumerable concretions are found, which, when
struck with the hammer, split open, and disclose an ammonite. See Dr. Mantell's.
''Thoughts on a Pebble," p. 21.
^ E a
M MANUAL OF THE MOLLUSCA.
permeated by mineral water, which slowly deposits calcarious spar, in crys-
tals, on their walls ; or by acidulous water, which removes every trace of the
shell, leaving a cavity, which at some future time may again become filled
ar, having the form of the shell, but not its structure. In some sec-
tions of orthocerata, it is evidenf that the mud has gained access to the air-
cells, along the course of the blood-vessels ; but the chambers are not entirely
filled, because their lining membrane has contracted, leaving a space between
itself and certain portions of the walls, which correspond in each chamber.
With respect to the purpose of the air-chambers, much ingenuity has
been exercised in devising an explanation of their assumed hydrostatic func-
tion, whereby the nautilus can rise at will to the surface, or sink, on the
approach of storms to the quiet recesses of the deep. Unfortunately for such
poetical speculations, the nautilus appears on the surface, only when driven
up by storms, and its sphere of action is on the bed of the sea, where it
creeps like a snail, or perhaps lies in wait for unwary crabs and shell-fish,
like some gigantic " sea-anemone." with outspread tentacles.
The tetrabranchs could undoubtedly swim, by their respiratory jets
the discoidal nautili and ammonites are not well calculated, by their forms,
for swimming ; and the straight -shelled orthocerata and baculites must have
held a nearly vertical position, head-downwards, on account of the bu-
of their shells. The use of the air-chambers, is to render the whole animal
(and shell) of nearly the same specific gravity with the water.* The object
of the numerous partitions is not so much to sustain the pressure of the water,
as to guard against the collisions to which the shell is exposed. They are most
complicated in the ammonites, whose general form possesses least strength.f
The purpose of the siphuncle (as suggested by Mr. Searles \Vood) is to main-
tain the vitality of the shell, during the long life which these animals cer-
tainly enjoyed. Mr. Forbes has suggested that the inner courses of the
hamites, broke off, as the outer ones were formed. But this was not the case
with the orthocerata, whose long straight shells were particularly exposed to
danger ; in these the preservation of the shell was provided for by the in-
creased size and strength of the siphuncle, and its increased vascularity.
endoceras we find the siphuncle thickened by internal deposits, until (in s
of the very cylindrical species) it forms an almost solid axis.
The nucleus of the shell is rather large in the nautili, and causes
* A nautilus pompiUus (in the cabinet of Mr. Morris) weighs lib., and when t
siphuncle is secured, it floats with a |lb weight in its aperture. The animal \
have displaced^ pints (= 2|lbs ) of water, and therefore, if it weighed 31bs., the spe<
gravity of the animal and shell would scarcely exceed that of salt water.
t The siphuncle and lobed septa did not hold the animal in its shell, as Von B-
imagined: that was secured by the shell-mu&cles. The complicated sutures perh
indicate lobed ovaries ; they occur in genera, which must have produced very sir
eggs.
CEPHALOPODA.
opening to remain through the shell, until the umbilicus is filled up with a
callous deposit : several fossil species have always a hole through the centre.
In the ammonites, the nucleus is exceedingly small, and the whirls com-
pact from the first.
It has been stated that the septa are formed periodically ; but it must not
be supposed that the shell-muscles ever become detached, or that the animal
moves the distance of a chamber all at once. It is most likely that the
adductors grow only in front, and that a constant waste takes place behind, so
that they are always moving onward, except when a new septum is to be
fanned ; the septa indicate periodic rests.
The consideration of this fact, that the nautilus must so frequently have
an air-cavity between it and its shell, is alone sufficient to convince us, that the
chambered cephalopoda could not exist in very deep water. They were pro-
bably limited to a depth of 20 or 30 fathoms at the utmost.*
It is certain that the sexes were distinct in the tetrabrancJuata, but since
only the female of the living nautilus is known, we are left to conjecture how
ar the differences observable in the shells, are dependant on sex. At. D'Orbigny,
having noticed that there are two varieties of almost every kind of ammonite.
one compressed, the other inflated naturally assumed that the first were
the shells of male individuals ( $ ), the second of females ( $ ). Dr. Melville
has made a similar suggestion with respect to the nautili ; namely, that the
umbilicated specimens are the males, the iniperforated shells, females. This
is rendered probable by the circumstance, that all the known specimens of
uiii's were female, and that the supposed male (2V. macromph<
very rare, as we have noticed amongst the male dibranchiata. Of the other
recent species, both the presumed sexes (N. umbilical us lbs. to the square inch. Empty bottles, securely corked, and
sunk with we-.iihts be, end 100 fathoms, are always crushed, If filled with liquid, the
cork is driven in. and the liquid replaced by salt water; and in drawing the bottle
np nsrain. the cork is returned to the neck of the bottle, generally in a reversed posi-
tion. v j> F. Beaufort.)
84
Fig. 43. Namtilu* pompiliiu in its shell.*
The umbilicus is small or obsolete in the typical nautili, and the whirls
enlarge rapidly. In the palaeozoic species, the whirls increase slowly, and
are sometimes scarcely in contact. The last air-cell is frequently shallower
in proportion than the rest.
Animal. In the recent nautilus, the mandibles are horny, but calcified to
a considerable extent ; they are surrounded by a circular fleshy lip, external
to which are four groups of labial tentacles, 12 or 13 in each group, they
appear to answer to the buccal membrane of the calamary (fig. 1). Beyond
these, on each side of the head, is a double series of arms, or brachial ten-
tacles, 36 in number ; the dorsal pair are expanded and united to form the
hood, which closes the aperture of the shell, except for a small space on each
side, which is filled by the second pair of arms. The tentacles are lamellated
* This woodcut and 18 others illustrating the tetrabranchiata, are the property of
Mr. Gray, to whom we are indebted for their use. Fig. 43 represents the recent
nautilus, as it appears on the removal of part of the outer shell-wall (from the specimen
in the British Museum). The eye is seen in the centre, covered by the hood (h) ; t,
tentacles, nearly concealed in their sheaths ; /, funnel ; m, margin of the mantle, very
much contracted ; n, nidamental gland ; a, c, air-cells and siphuncle; s, portion of the
shell ; a, shell-muscle. The internal organs are indicated by dotted lines ; b, bran-
chiae; h, heart and renal glands ; c. crop; g, gizzard; /, liver; o, ovary.
CEPHALOPODA. 85
on their inner surface, and are retractile within sheaths, or " digitations,"
which correspond to the eight ordinary arms of the cuttle-fishes ; their supe-
riority in number being indicative of a lower grade of organization. Besides
these there are four ocular tentacles, one behind and one in front of each eye ;
they seem to be instruments of sensation, and resemble the tentacles of doris
and aplysia (Owen}. On the side of each eye is a hollow plicated process,
which is not tentaculiferous. The respiratory funnel is formed by the folding
of a very thick muscular lobe, which is prolonged laterally on each side of the
head, with its free edge directed backwards, into the branchial cavity ; behind
the hood it is directed forwards, forming a lobe which lies against the black-
stained spire of the shell (fig. 43 *.)* Inside the funnel is a valve-like fold
(fig. 44 s). The margin of the mantle is entire, and extends as far as the
edge of the shell ; its substance is firm and muscular, as far back as the line
of the shell-muscles and horny girdle, beyond which it is thin and transparent.
The shell-muscles are united by a narrow tract, across the hollow occupied by
the involute spire of the shell ; and are thus rendered horse-shoe shaped.
The siphuncle is vascular ; it opens into the cavity containing the heart ( pe-
ricardium}, and is most probably filled with fluid from that cavity. (Owen.)
Respecting the habits of the nautilus, very little is known, the specimen
dissected by Professor Owen had it crop filled with fragments of a small crab,
and its mandibles seem well adapted for breaking shells. The statement that
it visits the surface of the sea of its own accord, is at present unconfirmed
by ob servation, although the air cells would doubtless enable the animal to
rise by a very small amount of muscular exertion.
Professor Owen gives the following passage, from the old Dutch naturalist,
Rumphius, who wrote in 1705, an account of the rarities of Amboina.
" When the nautilus floats on the water, he puts out his head and all his tenta-
cles, and spreads them upon the water, with the poop of the shell above water ;
but at the bottom he creeps in the reverse position, with his boat above him,
and with his head and tentacles upon the ground, making a tolerably quick
progress. He keeps himself chiefly upon the ground, creeping also sometimes
into the nets of the fishermen ; but after a storm, as the weather becomes
calm, they are seen in troops, floating on the water, being driven up ly the
agitation of the waves. This sailing, however, is not of long continuance ;
* The funnel is considered the homologue of the foot of the gasteropods, by Loven,
a conclusion to which we cannot agree. The cephalopoda ought to be compared with
the larval gasteropods, in which the foot only serves to support an operculum; or
with the floating tribes in which the foot is obsolete, or serves only to secrete a nida-
mental raft (ianthina). However, on examining the nautilus preserved in the British
Museum, and finding that the funnel was only part of a muscular collar, which ex-
tends all round the neck of the animal, we could not avoid noticing its resemblance
to the siphonal lappets of paludina, and to that series of lappets (including the oper-
culigerous lobe) which surrounds the trochus (fig. 87).
86
MANUAL OF THE MOLLUSCA.
for having taking in all their tentacles, they upset their boat, and so return to
the bottom."
Fig. 44. Nautilus expanded.*
Distr., 2 or 4 sp. Chinese seas, Indian ocean, Persian gulf.
Fossil, about 100 sp. In all strata, S. and N. America (Chile). Europe,
India (Pondicherry).
Sub-genus. Aturia (Bronn), = Megasiphonia D'Orb.
Type, N. zic-zac Sby. PL II., fig. 12, London clay, Highgate.
Shell, sutures, with a deep lateral lobe ; siphuncle nearly internal, large,
continuous, resembling a succession of funnels.
Fossil, 4 sp. Eocene, N. America, Europe, India.
Sul-genus ? Discites, McCoy. Whirls all exposed ; the last chamber
sometimes produced. L. silurian. Garb : limestone.
Temnocheilus, McCoy. Founded on the carinated sp. of the Carb. lime-
stone.
Cryptoceras, D'Orb. Founded on N. dorsaMs Phil, and one other spe
in which the siphuncle is nearly external.
* Ideal representation of the nautilus, when expanded, by Professor Loven,
appears to have taken the details from M. Valenciennes memoir in the Archives dn
Museum, vol. 2, p. 257. //,, hood, s, s : phon. It is just possible, that when the
nautilus issues from its shell, the gas contained in the last, incomplete, air-chamber,
may expand ; but this could not happen under any great pressure of water.
CEPHALOPODA.
87
LITUITES, Breynius.
Etym., lituus, a trumpet.
Syn., Hortolus, Moutf. (whirls separate.) Trocholites, Conrad.
Ex., L. convolvans, Schl. L. lituus, Hisinger.
Shell, discoidal ; whirls close, or separate ; last chamber produced in a
straight line ; siphuncle central.
Fossil, 15 sp. Silurian, N. America, Europe.
TROCHOCERAS, Barrande, 1848.
Ex., T. trochoides, Bar,
Shett t nautiloid, spiral, depressed.
Fossil, 16 sp. U. Silurian, Bohemia.
Some of the species are nearly flat, and having the last chamber pro-
duced would formerly have been considered Lituites.
Fig. 45. Clymenia striata, Munst.* Fig. 46. C. linearis, Munst.
OLYMENIA, Munster, 1832.
Etym., clymene, a sea-nymph.
Syn. Endosiphonites, Ansted. Sub-clymenia, D'Orb.
Ex., C. striata, pi. II., fig. 16 (Mus. Tennant).
Shell, discoidal ; septa simple or slightly lobed ; siphuncle internal.
Fossil, 43 sp. Devonian, N. America, Europe.
FAMILY II. ORTHOCERATIDJE.
Shell, straight, curved, or discoidal ; body chamber small ; aperture con-
tracted, sometimes extremely narrow (figs. 40, 41) ; siphuncle complicated.
It seems probable that the cephalopods of this family were not able to
withdraw themselves completely into their shells, like the pearly nautilus ;
this was certainly the case with some of them, as M. Barrande has stated,
for the siphonal aperture is almost isolated from the cephalic opening. The
shell appears to have been often less calcified, but connected with more vas-
cular parts than in the nautilus ; and the siphuncle often attains an enor-
mous development. In all this, there is nothing to suggest a doubt of their
being tetrabranchiate ; and the chevron-shaped coloured bands preserved on
the orthoceras anguliferus,\ sufficiently prove that the shell was essentially
external.
* Fig. 45. Sutures of two species of Clymenia from Phillips' Pal. Fos., Devon-
shire.
\ Figured by D'Archiac and Verneuil, Geol. Trans.
MANUAL OF THE MOLLUSCA.
OKTHOCERAS, Breyn.
Etym., orthos, straight, and ceras, a horn.
Syn., cycloceras, McCoy. Gonioceras, Hall.*
Ex. 0. giganteiun (diagram of a longitudinal section), pi. II, fig. 14.
Shell, straight ; siphuncle central ; aperture sometimes contracted.
Fossil, 125 typical sp. (D'Orb).f L. Silurian Trias; N.America, Aus-
tralia, and Europe.
The orthocerata are the most abundant and wide spread shells of the
old rocks, and attained a larger size than any other fossil shell. A fragment
of 0, giganteum, in the collection of Mr. Tate of Alnwick, is a yard long, and
1 foot in diameter, its original length must have been 6 feet. Other species,
2 feet in length, are only 1 inch in diameter, at the aperture.
Sub-genus I. Cameroceras, Conrad (= melia and thoracoceras, Fischer?).
Siphuncle lateral, sometimes very large (simple ?} .
Casts of these large siphuncles were called hyalites by Eichwald.
27 sp. L. Silurian Trias ? N. America and Europe.
xl
Fig. 47. Actinoceras.l Fig. 48. Ormoceras.
2. Actinoceras (Bromij, Stokes. Siphuncle very large, inflated between
the chambers, and connected with a slender central tube by radiating plates.
6 sp. L. Silurian Garb, N. America, Baltic, and Brit.
3. Ormoceras, Stokes. Siphuncular beads constricted in the middle (making
the septa appear as if united to the centre of each). 3 sp. L. Silurian, N.
America.
.4. Huronia, Stokes. Shell extremely thin, membraneous or horny ?
Siphuncle very large, central, the upper part of each joint inflated, connected
* Theca and Tentaculites are provisionally placed with the Pteropoda, they proba-
bly belong here.
t M Barrande has discovered 100 new species in the Upper Silurian rocks of
Bohemia.
I Fig. 47. Actinoceras Richardsoni, Stokes. Lake Winipeg (diagram, reduced |).
Fig. 48. Ormoceras, Bayfieldi, Stokes. Drummond Island, (from Mr. Stokes' paper,
Geol. Trans.)
CEPHALOPODA.
with a small central tube by radiating plates. 3 sp. L. Silurian. Drummond
Island, Lake Huron,
l\
Fig. 49. Huronia verfebralis.*
Numerous examples of this curious fossil were collected by Dr. Bigsby
(in 1822), and by the officers of the regiments formerly stationed on Drum-
mond Island. Specimens have also been brought home by the officers of
many of the Artie expeditions. But with the exception of one formerly in
the possession of Lieut. Gibson, 68., and another in the cabinet of Mr.
Stokes, the siphuncle only is preserved, and not a trace remains of septa or
shell wall. Some of those seen by Dr. Bigsby in the limestone cliff's, were 6
feet in length.
5. Endoceras, Hall (Cono-tubularia Troost}. Shell extremely elongated,
drical. Siphuncle very large, cylindrical, lateral ; thickened internally by re-
peated layers of shell, or partitioned off by funnel-shaped diaphragms. 12 sp.
Lower Silurian, New York.
6. Shell perforated by two distinct siphuncles? 0. bisiphonatum Sby,
Caradoc saridstone, Brit.
" Orthocerata with two siphuncles have been observed, but there has
always appeared something doubtful about them. In the present instance,
however, this structure cannot be questioned." (J. Sowerby.)
Small orthocerata of various species, are frequenlly found in the body
chamber and open siphuncle of large specimens.! The endoceras gemelli-
parum and proleiforme of Hall, appear to be examples of this kind.
GOMPHOCERAS, J. Sby, 1839.
Etym., gomphos, a club, and ceras, a horn.
* Fig. 49. Huronia vertebralis, Stokes, a, from a specimen in the Brit. M., presented
by Dr. Bigsby. The septa are added from Dr. Bigsby's drawing ; they were only in-
dicated in the specimen by "colourless lines on the brown limestone," b. represents
a weathered section, presented to the Brit. Mus. by Captain Kellett and Lieutenant
Wood of H.M.S. Pandora. The figures are reduced .
t Shells of Seller ophon and Ai urchisonia are found under the same circumstances.
90
MANL'AL OF THE 310LLUSCA.
ty>?.. Apioceras (Fisclier). Poterioceras (McCoy).
Type, G. pyriforme, Sby., fig. 51, and G. Bohemicum, Bar. fig. 40.
!> eoc
Fig. 50. Endoceras.*
Fig. 51. Gomphoceras.i
Shell, fusiform or globular, with a tapering apex ; aperture contracted
the middle ; siphuncle moniliforni, sub-central.
Di$tr. t 10 sp. Silurian Garb ; N. America, Europe.
ONCOCERAS, Hall.
Eti/m. y oncos, a protuberance.
Type, O. constrictum, Hall. Trenton limestone.
Shell, like a curved goinphoceras ; siphuncle external.
Distr., 3 sp. Silurian, New York.
PHKAGMOCEEAS, Broderip.
Etym., phragmos?* partition, and ceras, a horn.
Type, P. ventricosum (Steininger sp.), pi. II., fig. 15.
Shell curved, laterally compressed : aperture contracted in the mid
sipJi uncle, ventral, radiated. Ex., P. callistoma, Bar., fig. 41.
Distr., 8 sp. U. Silurian Devonian, Brit., Germany.
* Fig. 50. Diagram of an endoceras (after Hall), a, shell-wall 6. Wall of s
huncle. c c c. Diaphragms (" embryo-tubes " of Hall).
t Fig. 51. Gomphoceras pyriforme. L. Ludlow rock, Mochtre hill, Herefords]
(from Murch, Silur, syst., reduced ^). *. Beaded siphuncle.
CEPHALOPODA.
91
CYRTOCERAS, Goldf. 1533.
Etym., cv.rtos, curved, ceras, horn.
Syn., Campulites, Desh. 1832 (including gyroceras). Aploceras, I>'Orb.
Cainpyloceras and trigonoceras, McCoy.
Ex., C. hybridum, volborthi and beaumonti (Barrande).
Shell, curved ; siphuncle small, internal, or sub-central.
Distr., 36 sp. L. Silurian, Carb X. America, and Europe.
Fig. 52.*
GTROCERAS, Meyer, 1829.
Etym., gyros, a circle, and ceras.
Sy/i., Nautiloceras, D'Orb.
Ex., G. eifeliense, D'Arch., pi. II., fig. 13. Devonian, Eifel.
Shell, natitiloid ; whirls separate ; siphnncle excentrie, radiated.
Fossil, 17 sp. U. Silurian Trias? X. America, and Europe,
ASCOCERAS, Barrande, 1848.f
Etym., ascos, a leather bottle,
Shell, bent upon itself, like ptychoceras.
Di&tr. t 7 sp. U. Silurian, Bohemia.
FAMILY III. AinioxiTiDJC.
Shell. Body-chamber elongated; aperture guarded by processes, and
closed by an operculum ; sutures angulated, or lobed and foliated ; siphuncle
external (dorsal, as regards the shell).
The shell of the ammonitida has essentially the same structure with the
nautilus. It consists of an external porcellanous^ layer, formed by the collar
* Fig. 52. Gyroceras goldfussii (= ornatum Goldf). 6. Siphuncle of G. depress**,
Goldf. sp. Devonian. Eifel. From M.M. D'Archiac and Verneuil.
t In Haidinger's Berichte. *
J Its microscopic structure has not been satisfactorily examined : Prof. Forbes
detected a punctate structure in one species.
92 MANUAL OF THE MOLLUSCA.
of the mantle only ; and of an internal nacreous lining, deposited by the whole
extent of its visceral surface. There is an ammonite in the British Museum,
evidently broken and repaired during the life of the animal,* which shews
that the shell was depositedy>0#i within. In some species of ammonites the
collar of the mantle forms prominent spines on the shell, which are too deep
for the visceral mantle to enter ; they are therefore partitioned off (as in A.
armatus, Lias) from the body whirl and air cells, and not exhibited in casts.
The baculites, and ammonites of the section cristati, acquire when adult
a process projecting from the outer margin of their shell. Certain other
ammonites (the ornati, coronati, &c.) form two lateral processes before they
cease to grow (pi. III., fig. 5). As these processes are often developed in
very small specimens, it has been supposed that they are formed repeatedly
in the life of the animal (at each periodic rest), and are again removed when
growth recommences. These small specimens, however, may be only dwarfs.
In one ammonite, from the inferior oolite of Normandy, the ends of these
lateral processes meet, "forming an arch over the aperture, and dividing
it into two outlets, one corresponding with that above the hood of the nautilus,
which gives passage to the dorsal fold of the mantle ; the other with that
below the hood, whence issue the tentacles, mouth, and funnel ; such a modi-
fication, we may presume, could not take place before the termination of the
growth of the individual."t (Owen.)
M. D'Orbigny has figured several examples of deformed ammonites., in
which one side of the shell is scarcely developed, and the keel is consequently
lateral. Such specimens probably indicate the partial atrophy of the branchiae
on one side. In the British Museum there are deformed specimens of Am.
obtusus, amaltheus, find tuberculatus.
Fig. 53.J
* A serpentinus Schloth, U. Lias, Wellingboro. Rev. A. W. Griesbach.
t This unique and abnormal specimen is in the cabinet of S. P. Pratt, Esq.
J Fig. 53. Goniatiies sphericus, Sby. Front and side views of a specimen from the
carb limestone of Derbyshire, in the cabinet of Mr. J. Tennant; the body-chamber
and shell-wall have been removed artificially.
CEPHALOPODA.
93
GONIATITES, De Haan.
Etym., gonia, angles (should be written gonialites ?).
Syn., aganides, Montf.
Examples, G. Henslowi, pi. III., fig. 1., G. sphericus, fig. 53, and 39.
Shell, discoidal ; sutures lobed ; siphuncle dorsal,
Distr. 150 sp. Devonian Trias, Europe.
BACTRITES, Sandberger (= stenoceras, D'Orb ?).
Shell, straight ; sutures lobed. Type, B. subconicus, Sbger.
Distr., 2 sp. Devonian Germany.
ifOhA Ay^ y 1 ^ hnS **&
Fig. 54.*
CEEATITES, De Haan.
Type, C. nodosus, pi. III., fig. 2.
Shell, discoidal ; sutures lobed, the lobes crenulated. Fig. 54.
Distr., muschelkalk, 8 sp. Germany, France, Russia, Siberia.
Salt-marls (Keuper). 17 sp. S. Cassian, Tyrol.
M. D'Orbigny describes 5 shells from the gault and U. greensand as
ceratites; but many ammonites have equally simple sutures, when young.
Fig. 55. t
AMMONITES, Bruguiere.
Etym,, ammon, a name of Jupiter, worshipped in Libya under the form
of a ram. The ammonite is the cornu ammonis of old authors.
* Fig. 54. Suture of ceratites nodosus (Brug). The arrow in the dorsal lobe
points towards the aperture.
t Fig. 55. Ammonites rostratus, SLy. From the U. green-sand of Devizes, in the
cabinet of W. Cunnington, Esq. b, front view of one of its partitions.
94
MANUAL OF THE MOLLUSCA.
SyH. f orbulites Lam. planulites, Montf.
Shell, discoidal ; inner whirls more or less concealed ; septa undulated ;
sutures lobed and foliated ; siphuncle dorsal.
Distr., 530 sp. Trias chalk. Coast of Chili (D'Orb.) Santa Fe de
Bogota (Hopkins), New Jersey, Europe, and S. India.
Capt. Alexander Gerard discovered ammonites similar to our L. oolitic-
species, in the high passes of the Himalaya, 16,200 feet above the sea.
Section A. Bac/c, with an entire Jceel.
1. Arietes, L. oolites, A. bifrons (pi. III., fig. 6), bisulcatus (pi.
Ill, fig. 7).
2. Falciferi, L. oolites, A. serpentinus, radians, hecticus.
3. Cristati, cretaceous, A. cristatus, rostratus (fig. 55), varians.
B. Back crenated.
4. Amalthel, ool. A. amaltheus, cordatus, excavatus.
A. rhothornagensis (pi. Ill, fig. 4).
5. Rhothomagenses, cret.
C.
6. Disci.,
oolitic,
D. .
7. Dentati,
/ cret.
tool.
E.
8. Armati,
L. ool.
9. Capricorni,
10. Ornati,
L. ool.
ool.
A. discus, clypeiformis.
Back channelled.
A. dentatus, lautus.
A. Parkinsoni, anguliferus.
Back squared.
A. armatus, athletus, perarmatus.
A. capricornus, planicostatus.
A. Duncaiii, Jason (pi. III., fig. 5).
Fig. 56. Ammonites coronatus.*
F. Back round., convex.
11. Heterophylli, L. ool. A. heterophyUus (fig. 34).
12. Ligaii, cret. A. planulatus (pi. Ill, fig. 3).
13. Annulati, ool. A. annulatus, biplex, giganteus.
14. Coronati, ool. A. coronatus (fig. 56), sublsevis.
15. Fimbriati, ool. A. fimbriatus, lineatus, hircinus.
* Fig. 56. Profile of ammonites coronatus, Brug. (reduced ^ from D'Orbigny)
Kelloway rock, France, d 1. dorsal lobe ; ss, dorsal saddles ; V V . lateral lobes ; s's'.
lateral saddles; accessory and ventral lobes. The number of accessory lobes increases
with age.
CEPHALOPODA. 05
16. Cassiani, 36 sp. of very variable form, and remarkable for the number
and complexity of their lobes. Trias, Austrian Alps.
T^ nl
A 3
Fig. 57.*
Ex., A. Maximiliani (fig. 57), A, Metternichii.
CRIOCERAS, Leveille.
Etym., krios, a ram, and ceras, a horn.
Syn., tropseum, Sby.
Ex., C. cristatum, D'Orb. (pi. III., fig. 8).
Shell, discoidal ; whirls separate,
Distr., 9 sp. Neocomian Gault ; Brit., France.
TOXOCERAS, D'Orb.
Etym., toxon, a bow, ceras, a horn.
Ex., T. annulare, D'Orb. (pi. III., fig. 12.)
Shell, bow-shaped ; like an ammonite uncoiled.
Distr., 19 sp. Neocomian. Between this and crioceras and ancylo ceras
there are numerous intermediate forms.
ANCYLOCERAS, D'Orb.
Etym., anculos, incurved.
Ex.* A. spinigerum (pi. III., fig. 10).
Shell, at first discoidal, with separate whirls ; afterwards produced at a
tangent and bent back again, like a hook or crosier.
Distr., 38 sp. Inf. oolite chalk. S. America (Chile and Bogota), Europe.
SCAPHITES, Parkinson.
Etym., scaphe, a boat.
Ex., S. equalis (pi. III., fig. 9).
Shell, at first discoidal, with close whirls ; last chamber detached and
recurved.
Distr., 17 sp. Neocomian chalk. Europe.
HELICOCERAS, D'Oub.
Etym., helix (helicos), a spiral, and ceras, horn.
Ex., H. rotundum, Sby, sp. pi. III., fig. 11 (diagram).
Fig. 57. Am. Maximiliani Klipstein. (= A. bicarinatus Miinst). Trias, Hall-
stadt (copied from Quenstedt). A, Profile shewing the numerous lobes and saddles.
B, suture of one side; v, dorsal saddle.
96 MANUAL OF THE MOLLUSCA.
Shell, spiral, sinistral ; whirls separate .
Distr. > 11 sp. Inf. oolite? chalk. Europe.
TURRILITES, Lam.
Etym., turns, a tower, and lithos, a stone.
Shell, spiral, sinistral ; aperture often irregular.
Distr., 27 sp. (Bronn). Gault chalk. Europe.
The turrilite was perhaps di-branchiate, by the atrophy of the respiratory
organs of one side. M. ;D'Orbigny includes in this genus particular specimens
of certain Lias ammonites which are very slightly unsymmetrical ; the same
species occur with both sides alike. He also makes a genus (heteroceras) of
two turrilites, in which the last chamber is somewhat produced and recurved.
T. reflexus (Quenstedt, T. 20, fig. 16) has its apex inflected and concealed.
Fig. 58. Sutures of hamites cylindraceus, Defr.*
HAMITES, Parkinson.
Etym., hamus, a hook.
Ex., H. attenuates, pi. III., fig. 15.
Shell, hook-shaped, or bent upon itself more than once, the courses sepa-
rate.
Distr. , 58 sp. Neocomian chalk. S. America (Tierra del Fuego)
Europe.
The inner courses of this shell probably break away or are '* decollated"
in the progress of its growth (Forbes). M. D'Orbigny has proposed a new
genus, hamulina, for the 20 neocomian species.
PTYCHOCEHAS, D'Orb.
Etym., ptyche, a fold.
Ex., P. emericianum, D'Orb., pi. III., fig. 14.
* Fig. 58. Space between two consecutive sutures of the right side, from a speci-
men in the Brit. Mus. a. dorsal line. b. ventral. Baculite limestone, Fresville.
GASTEROPODA.
97
Shell, bent once upon itself; the two straight portions in contact.
Distr., 7 sp. Neocomian chalk. Brit. France.
BACULITES, Lamarck.
Etym., baculus, a staff.
Ex., B. anceps. PI. III., fig. 13.
Shell, straight, elongated ; aperture guarded by a dorsal process.
Dlstr., 11 sp. Neocomian chalk. Europe, S. America (Chile).
Baculina, D'Orb. B. Rouyana. Neoc., France. Sutures not foliated.
The chalk of Normandy has received the name of baculite limestone, from
lie abundance of this fossil.
CLASS II. GASTEROPODA.
The gasteropods, including land-snails, sea-snails, whelks, limpets, and the
ke, are the types of the mollusca ; that is to say, they present all the leading
;atures of molluscous organization in the most prominent degree, and make
ss approach to the appearance and condition of fishes than the cephalopods,
id less to the crustaceans and zoophytes than the bivalves.
Their ordinary and characteristic mode of locomotion is exemplified by the
)mmon garden-snail, which creeps by the successive expansion and contraction
its broad muscular foot. These muscular movements may be seen following
ich other in rapid waves when a snail is climbing a pane of glass.
The nucleobranches are "aberrant" gasteropods, having the foot thin and
irtical ; they swim near the surface of the sea, in a reversed position, or
ihere to floating sea-weed.
Fig. 59. A nucleobranche.*
The gasteropods are nearly all unsymmetrical, the body being coiled up
irally, and the respiratory organs of the left side being usually atrophied,
i chiton and dentalium the branchite and reproductive organs are repeated
i each side.
* Fig. 59. Carinarla cymbium, L. sp. (after Blainville), Mediterranean ; p, pro
scis; t, tentacles; b, branchiae; s, shell; /, foot; d, disk.
93
MANUAL OF THE MOLLUSCA.
A few species of cymba, litorina, paludina, and helix, are viviparous ; the
rest are oviparous.
"When first hatched the young are always provided with a shell, though in
many families it becomes concealed by a fold of the mantle, or it is speedily
and wholly lost.*
The gasteropods form two natural groups; one breathing air (pulmonifera) t
the other water (brancMfera). The air-breathers undergo no apparent meta-
morphosis ; when born, they differ from their parents in size only. The
water-breathers have at first a small nautiloid shell, capable of concealing
them entirely, and closed by an operculum. Instead of creeping, they swim
with a pair of ciliated fins springing from the sides of the
head ; and by this means are often more widely dispersed
than we should be led to expect from their adult habits ;
thus some sedentary species of calyptraa and chiton have
a greater range than the " paper-sailor," or the ever-drifting (
oceanic-snail.
At this stage, which may fairly be compared with the
larval condition of insects, there is scarcely any difference
between the young of eolis and aplysia, or buccinum and
vermetus. (M. Edw.)
The development of the branchiferous gasteropods may be observed with
much facility in the common river-snails (paludina] ; which are viviparous,
and whose oviducts in early summer contain young in all stages of growth
some being a quarter of an inch in diameter.
Fig. GO.t
Fig. 61. Paludina vivipara.%
Embryos scarcely visible to the naked eye have a well-formed shell, orna-
mented with epidermal fringes ; a foot and operculum ; and the head has long
delicate tentacula, and very distinct black eyes.
* M. Loven believes that the embryo shell of the nudibranches falls off at the time
they acquire a locomotive foot.
t Fig. 60. Fry of Eolis (from Alder and Hancock) ; o, the opeiculum ; the origins"
s not larger than the letter o.
I Fig. 61. Paludina vivipara L. (original); the internal organs are represented at
if seen through the shell. The ovary, distended with eggs and embryos, occupies the
right side of the body whirl ; the gill is seen on the left ; and between them the termi
nation of the alimentary canal. Surrey Docks, June, 1850.
GASTEROPODA. 99
The development of the pulmoniferous embryo is best seen in the trans-
parent eggs of the fresh-water limneids ; these are not hatched until the young
have passed the larval condition, and their ciliated head-lobes (or veil), are
superseded by the creeping disk, or foot.
The shell of the gasteropods is usually spiral, and univalve ; more rarely
tubular, or conical,, and in one genus it is multivalve. The following are its
principal modifications :
A. Regularly spiral,
a. elongated or turreted ; terebra, turritella.
b. cylindrical; meyaspira, pupa.
c. short ; buccinum.
d. globular; natica, helix.
e. depressed ; solarium.
f. discoidal; planorbis.
y. convolute; aperture as long as the shell ; cyprtea, bulla.
h. fusiform; tapering to each end, likefusus.
i. trochi-form ; conical, with a flat base, like trochus.
k. turbinated ; conical, with a round base, like turlto.
1. few- whirled; helix hcemastoma. PI. XII., fig. 1.
m. many-whirled; helix polygyrata. PI. XII., fig. 2.
n. ear-shaped ; haliot'is.
B. Irregularly spiral ; siliquaria, vermetus.
C. Tubular; dentalium.
D. Shield-shaped; umbrella, parmophorus.
E. Boat-shaped; navicella.
F. Conical or limpet-shaped patella.
G. Multivalve and imbricated ; chiton.
The only symmetrical shells are those of carinaria, atlanta, dentalium,
and the limpets. *
Nearly all the spiral shells are dextral, or right-handed ; a few are con-
stantly sinistral, like clausilia ; reversed varieties of many shells, both dex-
tral and sinistral, have been met with.
The cavity of the shell is a single conical or spiral chamber ; no gastero-
pod has a multilocular shell like the nautilus, but spurious chambers are
formed by particular species, such as triton corrugatus (fig. 62), and euomphalus
pentangulatus ; or under special circumstances, as* when the upper part of the
spire is destroyed.
Some spiral shells are complete tubes, with the whirls separate, or scarcely
* The curve of the spiral shells and their opercula, and also of the Nautilus, is a
logarithmic spiral; so that to each particular species may be annexed a number, indi-
cating the ratio of the geometrical progression of the dimensions of its whirls. Rev.
H. Moseley, " On geometrical forms of turbinated and discoid shells." Phil. Trans.
towd. 1838. Pt.2,p.351.
TOO
MANUAL OF THE MOLLUSCA.
in contact, as scalaria, cyclostoma, and valvata ; but more commonly the
inner side of the spiral tube is formed by the pre-existing whirls (fig. 62).
The axis of the shell, around which the whirls are coiled, is sometimes
open or hollow ; in which case the shell is said to be perforated, or umbili-
cated (e, g. solarium). The perforation may be a mere chink, or fissure (riant),
as in lacuna ; or it may be filled up by a shelly deposit, as in many nalicas.
In other shells, like the triton, the whirls are closely coiled, leaving only a pillar
of shell, or columella, in the centre ; such shells are said to be imperf orate.
apex.
anterior canal.
Fig. 62. Section of a spiral univalve*
The apex of the shell presents important characters, as it was the nucleus
or part formed in the egg ; it is sinistral in the pyramidellidte, oblique and
spiral in the nucleobranches and emarginula, and mammillated in turbinella
pi/rum andfusus antiquus.
The apex is directed backwards in all except some of the patellida, in which
it is turned forwards, over the animal's head. In the adult condition of some
shells the apex is always truncated (or decollated), as in cylindrella and bull-
mus decollatus ; in others it is only truncated when the animals have lived
* Fig. 62. Longitudinal section of triton corrugatus, Lam., from a specimen in the
cabinet of Mr. Gray. The upper part of the spire has been partitioned off many times
successively.
GASTEROPODA. 101
fn acidulous waters (e. g. cerithidea wcA.pirena}, and specimens may be ob-
tained from more favorable situations with the points perfect.
The line or channel formed by the junction of the whirls is termed the
suture.
The last turn of the shell, or body -whirl, is usually very capacious ; in
the females of some species the whirls enlarge more rapidly than in the males
(e. g. buccinum undatum). The "base" of the shell is the opposite end to
the apex, and is usually the front of the aperture.
The aperture is entire in most of the vegetable feeders (holostomata], but
notched or produced into a canal, in the carnivorous families (siphonostomata};
this canal, or siphon, is respiratory in its office, and does not necessarily indicate
the nature of the food. Sometimes there is a posterior channel or canal,
which is excurrent, or anal, in its function (e. g. strombida and ovulum volva] ;
it is represented by the slit in scissurella, the tube of typhis, the perforation
infissurella, and the series of holes in haliotis.
The margin of the aperture is termed the peristome ; sometimes it is con-
tinuous (cyclostoma), or becomes continuous in the adult (carocolla) ; very
frequently it is " interrupted," the left side of the aperture being formed only
by the body-whirl. The right side of the aperture is formed by the outer
lip (labrum), the left side by the inner or columellar lip (labium), or partly
by the body- whirl (termed the "wall of the aperture" by Pfeiffer).
The outer lip is usually thin and sharp in immature shells, and in some
adults (e. g. helicella and bulimulus] ; but more frequently it is thickened ;
or reflected ; or curled inwards (inflected*), as in cypraa; or expanded as in
pteroceras ; or fringed with spines as in murex. When these fringes or ex-
pansions of the outer lip are formed periodically they are termed varices.
Lines of colour, or sculpture, running from the apex to the aperture are
spiral or longitudinal, and others which coincide with the lines of growth are
" transverse," as regards the whirls ; but stripes of colour extending from
the apex across the whirls are often described as "longitudinal" or "radia-
ting," with respect to the entire shell.
Shells which are always concealed by the mantle are colourless, like Umax
and parmophorus ; and those which are covered by the mantle-lobes when
the animal expands, acquire a glazed or enamelled surface, like the cowries ;
when the shell is deeply immersed in the foot of the animal it becomes partly
glazed, as in cymba. In all other shells there is an epidermis, although it is
sometimes very thin and transparent.
In the interior of the shell the muscular impression is horse-shoe shaped,
or divided into two scars ; the horns of the crescent are turned towards the
head of the animal.
The operculum with which many of the gasteropods close the aperture of
their shell, presents modifications of structure which are so characteristic of
the sub-genera, as to be worthy of particular notice. It consists of a horny
layer, sometimes strengthened by the addition of calcarious matter on its ex-
102 MANUAL 'OF 'THE ' ftOLLTTSCA.
terior, and in its mode of growth it presents some resemblance to the sheH
itself. Its inner surface is marked by a muscular scar, whose lines bear no
relation to the external lines of growth, and its form is unlike the muscular
scar in the shell. It is developed in the embyro, within the egg, and the
point from which it commences is termed the nucleus ; many of the spiral
and concentric forms fit the aperture of the shell with accuracy, the others
only close the entrance partially, and in many genera, especially those with
large apertures (e. g. dolium, cassidaria, harpa, navicella), it is quite rudi-
mentary or obsolete.
Fig. 63. Fig. 64. Fig. 65. Fig. 06. Fig. 67.
The operculum is described as
Concentric, when it increases equally all round, and the nucleus is central
or sub-central, as in paludina and atnpullaria (pi. IX., fig. 26) .
Imbricated or lamellar (fig. 64), when it grows only on one side, and the
nucleus is marginal, as in purpura, phorus, and paludomus.
Claw-shaped, or unguiculate, (fig. 63, with the nucleus apical or in front),
as in turbinellus and fusus ; it is claw-shaped and serrated in strombus
(fig. 69).
Spiral, when it grows only on one edge, and revolves as it grows ; it is
always sinistral in dextral shells.
Paucispiral, or few- whirled (fig. 66), as in litorina.
Sub-spiral, or scarcely spiral, in melania. PI. VIII., fig. 25*.
Multispiral or many-whirled (fig. 65) as in trochus, where they some-
times amount to 20 ; the number of turns which the opereulum makes is not
determined by the number of whirls in the shell, but by the curvature of the
opening, and the necessity that the operculum should revolve fast enough to
fit it constantly (Moseley).
It is said to be articulated when it has a projection, as in nerita
(fig. 67).
Too much importance, however, must not be attached to this very va-
riable plate, as an aid to classification ; it is present in some species of vvluta,
olwa, conus, mitra, and cancellaria, but absent in others ; it is (indifferently)
horny or shelly in the species of ampullaria and natica ; in paludina it is
concentric, in paludomus lamellar, in valvata spiral ; in solarium and ceri-
thium, it is multispiral or paucispiral.
Some of the gasteropoda can suspend themselves by glutinous thready
GASTEROPODA.
103
like litiopa and rissoa parva, which anchor themselves
to sea-weeds (Gray), and cerithidea (fig. 68), which
frequently leaves its proper element, and is found
hanging in the air (Adams). A West India land-
snail (cyclostoma suspensum) also suspends itself (Guild-
ing). The origin of these threads has not been ex-
plained ; but some of the limaces lower themselves to
the ground by a thread which is not secreted by any
particular gland, but derived from the exudation over
the general surface of the body (Lister; D'Orbigny).
The division of this extensive class into orders and
families, has engaged the attention of many naturalists,
and a variety of methods have been proposed. Cu-
vier's classification was the first that possessed much
merit, and several of his orders have since been united
with advantage.
Fig. 68.
System of Cuvier.
Class. GASTEROPODA.
Order 1. Pectinibranchiata
2. Scutibranchiata
3. Cyclobranchiata
4. Tubulibranchiata
5. Pulmonata
6. Tectibranchiata
7. Inferobranchiata
8. Nudibranchiata
Class. HETEROPODA.
System now adopted.
Ord. Prosobranchiata, M. Edw.
Ord. Pulmonifera.
Ord. Opisthobranchiata, M. Edw.
Ord. Nucleobranchiata. Bl.
ORDER I. PROSOBRANCHTATA.
Abdomen well developed, and protected by a shell, into which the whole
animal can usually retire. Mantle forming a vaulted chamber^ over the back
of the head, in which are placed the excretory orifices, and in which the
branchiae are almost always lodged. Branchiae pectinated, or plume-like,
situated (proson) in advance of the heart. Sexes distinct. (M. Edwards.)
SECTION A. SIPHONOSTOMATA. Carnivorous Gasteropoda.
Shell spiral, usually imperforate ; aperture notched or produced into a
canal in front. Operculum horny, lamellar.
Animal provided with a retractile proboscis ; eye-pedicels connate with the
tentacles ; margin of the mantle prolonged into a siphon, by which water is
conveyed into the branchial chamber ; gills 1 or 2, comb -like, placed obliquely
o\er the back. Species all marine.
104 MANUAL OF THE MOLLTJSCA.
FAMILY I. STROMBID^. Wing-shells.
Shell with an expanded lip, deeply notched near the canal. Operculum
claw-shaped, serrated on the outer edge.
Animal furnished with Jarge eyes, placed on thick pedicels ; tentacles
slender, rising from the middle of the eye-pedicels. Foot narrow, ill adapted
for creeping. Lingual teeth single ; uncini, three on each side.
The strombs are carrion feeders, and, for molluscous animals, very active ;
they progress hy a sort of leaping movement, turning their heavy shell from
side to side. Their eyes are more perfect than those of the other gasteropods,
or of many fishes.
Fig. 69.*
STROMBUS, L. Stromb.
JStym., stromlos, a top.
Type, S. pugilis. PL IV., fig. 1.
Shell rather ventricose, tubercular or spiny ; spire short ; aperture long,
with a short canal above, and truncated below ; outer lip expanded, lobed
above, and sinuated near the notch of the anterior canal. Lingual teeth
(S. fioridus) 1 cusped ; uncini, 1 tri-dentate, 2, 3 claw-shaped, simple.f
Distr., 60 species. West Indies, Mediterranean, Red Sea, India, Mau-
* Fig. 69. Strombus aims -Dianas, L. (after QuoyandGaimard), Amboina. p, pro-
boscis, between the eye-pedicels ; /, foot, folded up ; o, operculum ; m, border of
the mantle ; s, respiratory siphon.
t The lingual dentition of strombus resembles that of aporrhais, and is unlike that
of the whelks; but it is more probable that aporrhais is the representative of strom-
bus, than that it is very closely allied.
GASTEROPODA. 105
ritius, China, New Zealand, Pacific, West America. On reefs, at low water,
and ranging to 1 fathoms.
Fossil, 5 cretaceous species ; 3 sp. Miocene . South Europe. There is a
group of small shells in the eocene tertiary strata of England and France,
nearly related to the living S. fissurellus L., some of which have been placed
with rostettaria, because the notch in the outer lip is small, or obsolete. They
probably constitute a sub -genus, to which Swainson's name strombidia, might
be applied. Example, S. Bartonensis. PL IV., fig. 2.
The fountain-shell of the West Indies, S. gigas, L., is one of the largest
living shells, weighing sometimes four or five pounds ; its apex and spines are
filled up with solid shell as it becomes old. Immense quantities are annually
imported from the Bahamas for the manufacture of cameos, and for the
porcelain works ; 300,000 were brought to Liverpool alone in the last year,
1850 (Mr. Archer).
PTEROCERAS, Lam. Scorpion-shell.
Etym., pteron, a wing, and ceras, a horn.
Type, P. lambis. PL IV., fig. 3.
Shell like strombus when young ; outer lip, of the adult, produced into
several long claws, one. of them close to the spire, and forming a posterior
canal.
Distr., 10 sp. India, China.
Fossil, nearly 100 sp. are enumerated by D'Orbigny, ranging from the
lias to the upper chalk ; many of them are more nearly related to aporrhais
(certthiadue).
ROSTELLARIA, Lam.
Etym., rostellum, a little beak.
Syn., fusus, Humphreys.
Example, R. curta. PL IV., fig. 4.
Shell with an elongated spire ; whirls numerous, flat ; canals long, the
posterior one running up the spire ; outer lip more or less expanded, with
only one sinus, and that close to the beak.
Distr., 5 sp. Red Sea, India, Borneo, China. Range, 30 fathoms.
Fossil, 70 sp. Neocomian chalk (=aporrhais ?). 6 sp. Eocene .
Britain, France, &c.
The older tertiary species have the outer lip enormously expanded, and
smooth-edged ; they constitute the section hippochrenes of Montfort (e. g.
Rost. ampla, Solander. London clay).
Sub-genus;" Spinigera, D'Orb. 184?. Shell like rostellaria ; whirls
keeled ; keel developed into a slender spine on the outer lip, and two on each
whirl, forming lateral fringes, as in ranella. Fossil, 5 sp. Inf. oolite-
chalk. Britain, France.
F 3
106 MANUAL OP THE MOLLUSCA.
SERAPHS, Montfort. (Terebellum, Lam.)
Etym., diminutive of terebra, an auger.
Type, S. terebellum (Linnaeus sp.)=T. snbulatum, Lam. PL IV., fig. 5.
Shell smooth, sub-cylindrical; spire short or none; aperture long and
narrow, truncated below ; outer lip thin.
Distr.y 1 sp. China. Philippines, 8 fms. (Cuming.)
Fossil, 5 sp. Eocene . London, Paris.
The animal of terebeUum has an operculum like strombus ; its eye-pedicel's
are simple, without tentacles (Adams). In one fossil species, T. fusiforme,
there is a short posterior canal, as in rostellaria.
FAMILY II.
Shell with a straight anterior canal ; aperture entire behind.
Animal with a broad foot ; eyes sessile on the tentacles, or at their base ;
branchial plumes 2. Lingual ribbon long, linear ; rachis armed with a sin-
gle series of dentated teeth ; uncini, single. Predatory, on other mollusca.
MUREX (Pliny) L.
Types, M. palma-rosa?, PL IV., fig. 10. M. tenuispina, PL IV., fig. 9. M,
haustellum, PL IV., fig. 8. M. radix, pinnatus. ^
Shell ornamented with three or more continuous longitudinal varices ;
aperture rounded ; beak often very long ; canal partly closed ; operculum
concentric, nucleus sub-apical (PL IV., fig. 10) ; lingual dentition (M. erinaceus),
teeth single, 3 crested ; uncini single, curved.
Distr., 180 sp. "World- wide; most abundant on the W. coast of tropical
America, in the Chinese Sea, West coast of Africa, West Indies ; ranging
from low water to 25 fathoms, rarely at 60 fathoms.
Fossil, 160 sp. Eocene . Britain, France, &c.
A few of the species usually referred to this genus, belong to pisania
and trophon.
The murices appear to form only one-third of a whirl annually, ending in
a varix ; some species form intermediate varices of less extent. M. erinaceus
a very abundant species on the coasts of the channel, is called "sting-winkle"
by fishermen, who say it makes round holes in the other shell-fish with its
beak. See p. 27. The ancients obtained their purple dye from species of
murex ; the small shells were bruised in mortars, the animals of the larger
ones taken out. (F. Col.) Heaps of broken shells of the M. trunculus and
caldron- shaped holes in the rocks may still be seen on the Tyrian shore.
(Wilde.) On the coast of the Morea, there is similar evidence of the
employment of M. brandaris for the same purpose. (M. Boblaye.)
TYPHIS, Montfort.
Etym., typhos, smoke.
GASTEROPODA. 107
Type, T. pungens. PL IV.. fig. 11.
Shell like murex ; but having tubular spines between the varfces, of which
the last is open, and occupied by the excurrent canal.
D-istr., 8 sp. Medit., W. Africa, Cape, India, W. America. 50 fms.
Fossil, 8 sp. Eocene . London, Paris.
PISANIA, Bivon, 1832.
Etym., a native of (the coast near) Pisa, in Tuscany.
Syn., Pollia, Enzina, and Euthria (Gray).
Types, P. maculosa. PL IV., fig. 14 (Enzina) zonata. PL IV., fig. 15.
Shell with numerous indistinct varices, or smooth and spirally striated ;
canal short ; inner lip wrinkled ; outer lip crenulated.
Operculum ovate, acute ; nucleus apical.
The pisanice have been usually confounded with buccinum, murex, and
ricinula,
Distr., about 120 sp. W. Indies, Africa, India, Philippines, S. Seas, W
America.
Fossil, ? sp. Eocene . Brii,, France, &c.
RANELLA, LAM. Frog-shell.
Syn., Apollon, Montfort and Gray.
Types, R. grauifera. PL IV., fig. 12. R. spinosa.
Shell with two rows of continuous varices, one on each side.
Operculum ovate, nucleus lateral.
Distr., 50 sp. Medit., Cape, India, China, Australia, Pacific, W. America.
Range, low-water to 20 fms.
Fossil, 23 sp. Eocene .
TRITON. Lam.
Etym. Triton, a sea-deity. Syn., persona (Montf. Gray).
Type, T. tritonis, L. sp. PL IV., fig. 13.
Shell with disconnected varices ; canal prominent ; lips denticulated.
Operculum ovate, sub-concentric.
Distr., 100 sp. W. Indies, Medit,, Africa, India, China, Pacific, W.
America. Ranging from low-water to 10 or 20 fathoms ; one minute species
has been dredged at 50 fathoms.
Fossil, 45 sp. Eocene. Brit., 'France, &c. Chile.
The great triton (T. tritonis) is the conch blown by the Australian and
Polynesian Islanders. A very similar sp. (T. nodiferus) is found in the
Medit., and a third in the W. Indies.
FASCIOLARIA, Lam.
Elym., fasciola, a band.
Type, F. tulipa. PL V., fig. 1.
108 MANUAL OF THE MOLLTJSCA.
Shell fusiform, elongated ; whirls round or angular ; canal open ; co-
lumellar lip tortuous, with several oblique folds. Operc. claw-shaped. F.
gigantea of the S. Seas, attains a length of nearly two feet.
Distr., 16 sp. W. Indies, Medit., W. Africa, India, Australia, S. Pacific,
W. America.
Fossil, 28 sp., U. chalk. Prance.
TUEBINELLA, Lam.
Etym., diminutive of turbo, a top.
Type, T. pyrum. PL V., fig. 2.
Shell thick ; spire short ; columella with several transverse folds. Oper-
culum claw-shaped. Fig. 63. The shank-shell (T. pyrum} is carved by the
Cingalese, and reversed varieties of it, from which the priests administer
medicine, are held sacred.
Distr., 70 sp. W. Indies, S. America, Africa, Ceylon, Philippines,
Pacific, W. America.
Fossi^ 20 sp. Miocene .
Sub-genera. Cynodonla (Schum.) T. cornigera. PI. V., fig. 3.
Latirus (Montf.) T. gilbula. PL V., fig. 4.
Cuma (Humphr.) T. angulifera, inner lip with a single prominent fold
operculum like purpura.
Lagena (Schum.) T. Smaragdula, L. sp. N. Australia.
CANCELLARIA, Lam.
Etym., cancellatus, cross-barred.
Type, C. reticulata. PL V., fig. 5.
Shell cancellated ; aperture channelled in front : columella with several
strong oblique folds ; no operculum. The animals are vegetable feeders.
(Desh.)*
Distr., 70 sp. W. Indies, Medit., W. Africa, India, China, California.
Fossil, 60 sp. Eocene . Britain, France, &c.
TRICHOTROPIS, Broderip, 1829.
Etym., Thrix, (trichos) hair, and tropis, keel.
Type, T. borealis, PL VI., fig. 8. (= ? Admete, Phil., no operculum.)
Shell thin, umbilicated; spirally furrowed; the ridges with epidermal
fringes ; columella obliquely truncated ; operc. lamellar, nucleus external.
Animal with a short broad head ; tentacles distant, with eyes on the
middle ; proboscis long, retractile.
Lingual dentition similar to strombus ; teeth single, hamate, denticulated ;
uncini 3 : 1 denticulate 2 and 3 simple.
* Cancellaria and trichotropis form a small natural family connected with ceri*
thiadae and strombidce.
GASTEROPODA . 109
Listr., 8 sp. Northern seas. U. States, Greenland, Melville Island, Beh-
ring's Straits, N. Brit. 15 80 fms.
Fossil, 1 sp. Miocene . Brit.
PYRULA, Lam. Tig-shell.
Etym., diminutive of pyrus, a pear.
Syn., Ficula, Sw. Sycotypus, Br.,Cassidula, Humph. Cochlidium, Gray.
Type, P. ficus. (PI. V., fig. 6.)
Shell pear-shaped ; spire short ; outer lip thin ; columella smooth : canal
long, open. No operculum in the typical species.
Distr., 39 sp. W. Indies, Ceylon, Australia, China, W. America.
Fossil, 30 sp. Neocomian . Europe, India. Chile.
Pyrula ficus has a broad foot, truncated and horned in front ; the mantle
forms lohes on the sides, which nearly meet over the hack of the shell.
Chinese seas, in 17 35 fms. water. (Adams.)
Sub-genera. Fulgur, Montf. P. perversa. (= Pyrella, Sw. P. spirillus.)
Rapana, Schum. P. bezoar, shell perforated. Operc. lamellar, nu-
cleus external.
Myristica. Sw. P. melongena. PI. V., fig. 7. Operc. pointed, curved.
Fusus, Lam. Spindle-shell.
Syn., Colus, Humph. Leiotomus, Sw. Strepsidura, Sw.
Type, F. colus. PI. V., fig. 8.
Shell fusiform ; spire many-whirled ; canal straight, long ; operculum
ovate, curved, nucleus apical. PI. V., fig. 9*.
Distr., 100 sp. World-wide. The typical sp. are sub-tropical. Aus-
tralia, New Zealand, China, Senegal, U. States, W. America, Pacific.
Fossil, 320 sp. Bath oolite ? Gault Eocene . Brit. &c.
Sub-genera, Trophon, Montf. F. magellanicus, PI. IV., fig. 16. 14 sp.
Antarctic and Northern seas. Brit, coast. 5 70 fathoms. Fossil, Chile,
Brit.
Clavella, Sw. (cyrtulus, Hinds) body- whirl ventricose, suddenly con-
tracted in front ; canal long and straight. Resembling a turbinella, without
plaits. 2 sp. Marquesas, Panama. Fossil, Eocene. F. longsevus (Solander),
Barton, &c.
Chrysodomus, Sw. F. antiquus (var.) PI. V., fig. 9. Canal short ; apex
papillary; lingual dentition like buccinum, 12 sp. Spitzbergen, Davis's
Straits, Brit., Medit., Kamschatka, Oregon. Low water to 100 fms. Fossil,
pliocene. Brit., Sicily.
Pusionella, Gray. F. pusio, L. sp. (=F. nifat, Lam.), columella keeled.
Operc., nucleus internal, 7 sp. Africa, India. Fossil, tertiary. France,
Fusus colosseus and proboscidalis, Lam., are two of the largest living
gasteropoda. Fusus (chrysodomus] antiquus, called the red-whelk on the
coasts of the channel, and " Buckie" in Scotland, is extensively dredged for
110
MANUAL OP THE MOLLUSCA.
the markets, being more esteemed than the buccinum. It is the " roaring
buckle," in which the sound of the sea may always be heard. In the Zetland
cottages it is suspended horizontally, and used for a lamp ; the cavity con-
taining the oil, and the canal the wick. (Fleming.) The reversed variety
(F. contrarius, Sby) is found in the Medit., and on the coast of Spain ; it
abounds in the pliocene tertiary (crag) of Essex. The fusus deformis, a
similar sp., found oif Spitzbergen, is always reversed.
FAMILY III. BUCCINID^.
Shell notched in front ; or with the canal abruptly reflected, producing a
kind of varix on the front of the shell.
Animal similar to murex ; lingual ribbon long and linear, (fig. 16) ra-
chidian teeth single, transverse, dentated in front ; uncini single. Carnivorous.
BUCCINUM, L. "Whelk.
Etym., buccina, a trumpet, or triton's-shell.
Type, B. undatum. PI. V., fig. 10.
Shell few whirled ; whirls ventricose ; aperture large ; canal very short,
reflected; operculum lamellar, nucleus external. (See pisania.)
Distr., 20 typical species. Northern and Antarctic seas. Low water to
100 fins. (Forbes). (B ? clathratum, 136 fins., off Cape.)
Fossil, 130 sp., including pisania, &c. Gault ? Miocene . Brit., France.
Fig. 70. Nidamental capsu'es of the Whelk.*
The whelk is dredged for the market, or used as x bait by fishermen ; it
may be taken in baskets, baited with dead fish. Its nidamental capsules are
aggregated in roundish masses, which, when thrown ashore, and drifted by
the wind resemble corallines. Each capsule contains five or six young, which,
when hatched, are like fig. 70, b : a, represents the inner side of a single
capsule, shewing the round hole, from which the fry have escaped.
* Fig. 70. From a small specimen, on an oyster-sjiell, in the cabinet of Albany
Hancock, Esq. The line at b, represents the length of the young shell.
GASTEROPODA. HI
Submenus. Cominella, Gray. Ex. B. limbosum, purpura maculosa, &c.
Operculutti as mfusus. About 12 sp.
PSEUDOLIVA, Swainson.
Etym., named from its resemblance to oliva, in form.
Syn., sulco-buccinum, D'Orb. Gastridium (Gray), G. Sowerby.
Type, P. plumbea. PL V., fig. 12.
Shell globular, thick ; with a deep spiral furrow near the front of the
body-whirl, forming, as in monoceros, a small tooth on the outer lip ; spire
short, acute ; suture channelled ; inner lip callous aperture notched in front ;
operculum ? Animal unknown.
Distr., 6 sp. ? W. America.
Fossil, 5 sp. Eocene. Brit., France, Chile.
? ANOLAX (Roissy), Conrad. Lea.
Etym., an aulax, without furrow.
Syn., buccinanops, D'Orb. Leiodomus, Sw. Bullia, Gray.
Types, A. gigantea, Lea- Buc. Isevigatum. B. semiplicata, PI. V., fig. 14.
Shell variable ; like buccinum, pseudoliva, or terebra ; sutures enamelled ;
inner lip callous.
Animal without eyes ; foot very broad ; tentacles long and slender ;
operculum pointed, nucleus apical.
Distr., 26 sp. Brazil, W. Africa, Ceylon, Pacific, W. America.
Fossil, 3 sp. Eocene . N. America, France.
I? HALIA, Eisso.
Etym., halios, marine. Syn., priamus, Beck.
Types, bulla helicoides (Brocchi). Miocene, Italy. Helix priamus (Meus-
chen). Coast of Guinea ?
Shell like achatina ; ventricose, smooth ; apex regular, obtuse ; operc. ?
The fossil species occurs with marine shells, and sometimes coated by a coral
(lepralia).
TEREBRA, Lamarck. Auger-shell.
Syn., acus, Humph. Subula, Bl. Dorsanum, Gray.
Type, T. maculata. PI. V., fig. 13.
Shell long, pointed, many-whirled ; aperture small ; canal short ; operc.
pointed, nucleus apical.
Animal blind, or with eyes near the summit of minute tentacles.
Distr., 109 sp., mostly tropical. Medit. (1 sp.) India, China, W. America.
Fossil, 24 sp. Eocene . Brit., France, Chile.
EBURNA, Lamarck. Ivory-shell.
Etym., elur, ivory. Syn., latrunculus, Gray.
12 MANUAL OF THE MOLLUSCA.
Type, E. spirata. PL V., fig. 11.
Shell umbilicated when young ; inner lip callous, spreading and covering
the umbilicus of the adult ; operculum pointed, nucleus apical.
Distr., 9 sp. Red Sea, India, Cape, Japan, China, Australia. Solid,
smooth shells, which have usually lost their epidermis, and are pure white,
spotted with dark red ; the animal is spotted like the shell. 14 fois. (Adams.)
NASSA, Lam. Dog-whelk.
Etym., nassa, a basket used for catching fish.
Syn., desmoulinsia and northia, Gray.
Type, N. arcularia. PL V., fig. 15.
Shell like buccinum ; columellar lip callous, expanded, forming a tooth-
like projection near the anterior canal. Operc. ovate, nucleus apical. Lingual
teeth arched, pectinated ; uncini, with a basal tooth.
The animal has a broad foot, with diverging horns in front, and two little
tails behind. N. obsoleta (Say) lives within the influence of fresh water and
becomes eroded. N. reticulata, L., is common on the English shores, at
low-water, and is called the dog-whelk by fishermen.
Distr., 68 sp. Low-water 50 fms. World-wide. Arctic, Tropical and
Antarctic Seas.
Fossil, 19 sp. Eocene . Brit., &c., N. America.
Sub-genus, cyllene, Gray. C. Oweni, PL V., fig. 17. Outer lip with a
slight sinus near the canal ; sutures channelled. W. Africa, Sooloo Islands,
Borneo. Fossil, Miocene, Touraine.
Cyclonassa, Swainson. C. neritea, PL V., fig. 16.
PHOS, Montfort.
Etym., pkos, light, Syn., rhinodomus, Sw.
Type, P. senticosus, PL V., fig. 18.
Shell like nassa ; cancellated ; outer lip striated internally, with a slight
sinus near the canal ; columella obliquely grooved.
The animal has slender tentacles, with the eyes near their tips.
Distr., 30 sp. (Cuming.) Red Sea, Ceylon, Philippines, Australia,
W. America.
? RINGICULA, Deshayes.
Etym., diminutive of ringens, from ringo, to grin.
Type, R. riugens, PL V,, fig. 21.
Shell minute, ventricose, with a small spire ; aperture notched, columella
callous, deeply plaited ; outer lip thickened and reflected.
Distr., 4 sp. ? Medit., India, Philippines, Gallapagos.
Fossil, 9 sp., Miocene . Brit., Trance. Rinyicula is placed with nassa
GASTEROPODA. 113
by Mr. Gray, and Mr. S. Wood ; it appears to us very nearly allied to cinulia
(=avettana, D'Orb.) in tornatellidce.
PURPURA (Adans), Lam. Purple.
Type, P. persica, PL VI., fig. 1.
Shell striated, imbricated or tuberculated ; spire short ; aperture large,
slightly notched in front ; inner lip much worn and flattened. Operc.
lamellar, nucleus external. PL VI., fig. 2. Lingual dentition like murex
erinaceus ; teeth transverse, 3 crested ; uncini small, simple.
Many of the purpurce produce a fluid which gives a dull crimson dye ; it
may be obtained by pressing on the operculum. P. lapillus abounds on the
British coast at low-water, amongst sea-weed ; it is very destructive to
.mussel-beds (Fleming).
Distr., 140 sp. W. Indies, Brit., Africa, India, New Zealand, Pacific,
Chile, California, Kamschatka. From low-water 25 fathoms.
Fossil, 30 sp. Miocene . Brit., France, &c.
Sub-genus. Concholepas, Favan. C: lepas (Gmelin sp.) PL VI., fig. 3.
Peru. The only sp. diifers from purpura in the size of its aperture, and
smallness of the spire.
?PURPURINA (Lycett, 1847). D'Orb.
Shell, ventricose, coronated ; spire, short ; aperture, large, scarcely notched
in front.
Fossil, 9 sp., Bath-oolite. Brit. France. The type, P. rugosa, some-
what resembles purpura chocolatum (Duclos), but the genus probably belongs
to an extinct group.
MONOCEROS, Lam.
Etym., monos, one ; ceras, horn.
Syn., acanthina, Fischer. Chorus, Gray.
Type, M. imbricatum. PL VI., fig. 4 (Buc. monoceros, Chemn).
Shell, like purpura ; with a spiral groove on the whirls, ending in a pro-
minent spine on the outer lip. This genus is retained on account of its geo-
graphical curiosity ; it consists of sp. of purpura, lagena, turbinella, pseudo-
liva, &c.
Distr., 18 sp. W. coast of America.
Fossil, tertiary. Chile.
M. gigantens (chorus) has the canal produced like fusus. M. cingulatum
is a turbinella, and several sp. belong more properly to lagena.
PEDICULARIA, Swainson.
Type, P. sicula. PL VI., fig. 5 (thyreus, Phil.}.
Shell very small, limpet-like ; with a large aperture, channelled in front,
and a minute, lateral spire. Lingual dentition peculiar ; teeth single, hooked,
denticulated ; uncini., 3 ; 1, four-cusped, 2, 3, elongated, three-spined.
114 MANUAL OF THE MOLLUSCA.
Distr., 1 sp. Sicily, adhering to corals. Closely allied to purpura
madreporarum, Sby. Chinese Sea.
RICINULA, Lam.
Etym., dimunitive of ricinus, the (fruit of the) castor-oil plant.
Ex., R. arachnoides. PL VI., fig. 9 (=murex ricinus L.).
Shell t thick, tubereulated. or spiny ; aperture contracted by callous pro-
jections on the lips. Operc. as in purpura.
Distr. 25 sp. India, China, Philippines, Australia, Pacific.
Fossil, 3 sp. Miocene . France.
PLANAXIS, Lam.
Type, P. sulcata. PI. VI., fig. 6. Syn., quoyia and leucostoma.
Shell, turbinated ; aperture notched in front ; inner lip callous, channel-
led behind ; operculum subspiral (quoyia) or semi-ovate. PI. VI., fig. 7.
Distr., 11 sp. W. Indies, Red Sea, Bourbon, India, Pacific, and Peru.
Fossil, miocene ?
Small coast shells, resembling periwinkles, with which Lamarck placed
them.
MAGILUS, Montf., 1810.
Syn., campulote, Guettard, 1759. Leptoconchus, Riippell.
Type, M. antiquus. PI. V., figs. 19, 20.
Shell, when young, spiral, thin ; aperture channelled in front ; adult,
prolonged into an irregular tube, solid behind ; operculum lamellar.
Distr., 1 sp. ? Red Sea. Mauritius. H
The magilus lives fixed amongst corals, and grows upwards with the
growth of the zoophytes in which it becomes immersed ; it fills the cavity of
its tube with solid shell, as it advances.
CASSIS, Lam. Helmet-shell.
Syn., bezoardica, Schum. Levenia, Gray. Cyprsecassis, Stutch.
Type, C. flammea. PL VI., fig. 14.
Shell, ventricose, with irregular varices ; spire, short ; aperture lo
outer lip reflected, denticulated ; inner lip spread over the body-whirl ; ca
sharply recurved. Operculum small, elongated ; nucleus in the middle of the
straight inner edge.
Distr., 34 sp. Tropical seas; in shallow water. W. Indies, Medit.,
Africa, China, Japan, Australia, New Zealand, Pacific, Mexico.
Fossil, 36 sp. Eocene . Chile, France.
The queen. conch (C. madagascariensis) and other large species, are used
in the manufacture of shell cameos, p. 46. The periodic mouths (varices]
which are very prominent, are not absorbed internally as the animal grows.
ONISCIA, Sowerby.
Etym., oniscus, a wood louse. Syn,, morum, Bolten.
GASTEROPODA.
115
Type, 0. oniscus ; 0. cancellata, pi. VI., fig. 15.
Shell, with a short spire, and a long narrow aperture, slightly truncated
in front ; outer lip thickened, denticulated ; inner lip granulated.
Distr., 6 sp. W. Indies, China, Gallapagos. (20 fras.)
Fossil, 3 sp. Miocene.
CITHARA, Schumacher.
Etym., cithara, a guitar. Syn., mangelia, Reeve (not Leach).
Type, cancellaria citharella, Lam. (cithara striata, Schum.)
Shell, fusiform, polished, ornamented with regular longitudinal rihs;
aperture linear, truncated in front, slightly notched behind ; outer lip mar-
gined, denticulated within ; inner lip finely striated. Operc.
Distr., above 50 sp. of this pretty little genus were discovered by Mr.
Cuming, in the Philippine Islands.
CASSIDAEIA, Lam.
Etym., cassida, a helmet.
Syn., morio, Montf. Sconsia, Gray.
Type, C. echinophora. PI. VI., fig. 13.
Shell, ventricose ; canal produced, rather bent. No operculum.
Distr., 5 sp. Medit.
Fossil, 10 sp. Eocene . Brit., France, &c.
Fig. 71.*
DOLIUM, Lam. Tne tun.
Type, D. galea. PI. VI., fig. 12.
Shell, ventricose, spirally furrowed ; spire small ; aperture very large ;
outer lip crenated. No operc.
Distr., 14 sp. Medit., Ceylon, China, Australia, Pacific.
* D. perdix, L. sp. nat. size (after Quoy). Vanicoro, Pacific. The proboscis
is exserted, and the siphon recurved over the front of the shell.
116 MANUAL OF THE MOLLUSCA.
Fossil, 1 sp. (? Chalk. Brit.) Miocene. S. Em-ope.
Sub-genus, malea, Valenc. (D. personation) outer lip thickened and denti-
culated ; inner lip with callous prominences.
HARPA, Lani. Harp-shell.
Type, H. ventricosa. PL VI., fig. 11. (=Buc. harpa, L.)
Shell, ventricose ; with numerous ribs, at regular intervals; spire small ;
aperture large, notched in front. No operc.
The animal has a very large foot, with the front crescent- shaped, and
divided by deep lateral fissures from the posterior part, which is said to sepa-
rate spontaneously when the animal is irritated. Mostly obtained from deep-
water, and soft bottoms.
Distr., 9 sp. Mauritius, Ceylon, Philippines, Pacific.
Fossil, 4 sp. Eocene . France.
COLUMBELLA, Lam.
Eti/m., diminutive of columba, a dove.
Type, C. mercatoria. PL VI., fig. 1 0.
Shell, small ; with a long narrow aperture ; outer lip thickened (especi-
ally in the middle), dentated ; inner lip crenulated. Operculum very small
lamellar.
Distr., 200 sp. Sub-tropical. W. Indies, Medit., India, Gallapagos,
California. Small, prettily-marked shells ; living in shallow water, on sandy
flats, or congregating about stones. (Adams.)
Fossil, 8 sp. Miocene . (The Brit. sp.
Sub-genus. Columbellina, D'Orb. 4 sp. Cretaceous. France, India.
aper-
GASTEROPODA. 117
Sub-genera. Olivella, Sw. 0. jaspidea, pi. VI., fig. 19.
Animal with small, acute frontal lobes. Operc. nucleus sub-apical.
Scaphula, Sw. O utriculus, pi. VL, fig. 18.
Frontal lobes large, rounded, operculate.
Agaronia, Gray. 0. hiatula, pi. VI., fig. 17.
No eyes or tentacles. Frontal lobes moderate, acute.
ANCILLARIA, Lam.
Etyrn., ancilla, a maiden.
Types, A. subulata, pi. VI., fig. 20. A. glabrata, pi. VI. fig. 21.
Shell like oliva ; spire produced, and entirely covered with shining
enamel. Operc. minute, thin, pointed. Lingual teeth pectinated. Uncini
simple, hooked.
Animal like oli va ; said to use its mantle-lobes for swimming. (D'Orb.)
In A. glabrata, a space resembling an umbilicus, is left between the callous
inner lip and the body whirl.
Distr., 23 sp. Red Sea, India, Madagascar, Australia, Pacific.
Fossil, 21 sp. Eocene . Brit., France, &c.
FAMILY TV. CcfNiDja, Cones.
Shell inversely conical ; aperture long and narrow ; outer
lip notched at or near the suture; operculum minute,
lamellar.
Animal, foot oblong, truncated in front ; with a conspi-
cuous (aquiferous?) pore in the middle. Head produced.
Tentacles far apart. Eyes on the tentacles. Gills 2. Lin-
gual teeth (uncini ?) in pairs, elongate, subulate, or hastate.
CONUS, L. Cone-shell.
Types, C. marmoreus, pi. VII., fig. 1. C. geographicus, antediluvianus, &c.
Shell conical, tapering regularly ; spire short, many-whirled ; columella
smooth, truncated in front ; outer lip notched at the suture ; operculum
pointed, nucleus apical.
Distr., 269 sp. AU tropical seas. Medit., 2 ; Africa, 23 ; Red Sea, 5 ;
Asia, 124 ; Australia, 16 ; Pacific, 25 ; Gallapagos, 3 ; W. America, 20 ;
W. Indies and Brazil, 21.
Fossil, 80 sp. Chalk . Brit., France, India, &c.
The cones range northward as far as the Mediterranean, and southward to
the Cape ; but are most abundant and varied in equatorial seas. They inhabit
fissures and holes of rocks, and the warm and shallow pools inside coral-reefs,
ranging from low water to 30 and 40 fathoms ; they move slowly, and some-
times (C. aulicus) bite when handled ; they are all predatory. (Adams.)
Sub-genus. Conorbis, Sw. C. dormitor, PL VII., fig. 2. Eocene .
Brit., France.
* Fig.- 72. Lingual teeth of bela turricula (after Lov6n).
118
MANUAL OF THE MOLLUSCA.
PLEUROTOMA, Lam.
Etym., pleura, the side, and toma, a notch. Syn., turns, Humph.
Types, P. Babylonica, PL VII., fig. 3. P. miteformis, &c.
Shell fusiform, spire elevated ; canal long and straight ; outer lip with a
deep slit near the suture. Operculum pointed, nucleus apical.
Distr., 430 sp. World-wide. Greenland, Brit., 17 ; Medit., 19 ; Africa,
15; Red Sea and India, 6 ; China, 90; Australia, 15; Pacific, 0? W.
America, 52 ; W. Indies and Brazil, 20. The typical sp. about 20 (China,
16 ; W. America, 4.) Low water to 100 fathoms.
Fossil, 300 sp. Chalk. Brit., France, &c. Chile.
Sub-genera. Drillia, Gray. D. umbilicata, canal short.
Clavatula, Lam., canal short, operc. pointed, nucleus in the middle of the
inner edge. C. mitra, PL VII., fig. 4.
Tomella, Sw., canal long ; inner lip callous near suture. T. lineata.
? Clionella, Gray. C. sinuata, Born sp. (= P. buccinoides) freshwaters,
Africa.
Mangelia, Leach, (not Reeve). Apertural slit at the suture ; no operc.,
M. tamiata, PL VII., fig. 5. Greenland, Brit., Medit.
Bela, Leach. Operc. nucleus apical. B. turricula, PL VII., fig. 6.
Defrancia, Millet,* no operc. D. linearis, PI. VII., fig. 7.
? Lachesis, Risso, L. minima, PL VII., fig. 8, apex mammillated ; operc.
claw-shaped. Medit., S. Brit. In shallow water.
Daphnella, Hinds. D. marmorata. New Guinea. (Buc. junceum. L. clay).
FAMILY V. VOLUTION.
Shell turreted, or convolute ; aperture notched in front ; columella
liquely plaited. No operculum.
Fig. 73. t
Animal with a recurved siphon ; foot very large partly hiding the \
* According to Mr. S. Hanley, Defrancia is synonymous with Mangelia.
t Fig. 73. V. undulata, Lam. Australia (from Quoy and Gaiinard),
GASTEROPODA.
119
mantle often lobed and reflected over the shell ; eyes on the tentacles, or near
their base. Lingual ribbon linear ; rachis toothed ; pleura unarmed.
VOLUTA, L. Volute.
Type, V. musica, PL VII., fig. 9.
Syn., cymbiola, harpula, Sw. Volutella, D'Orb. Scapha, &c., Gray.
Shell ventricose, tliick ; spire short, apex mammillated ; aperture large,
deeply notched in front ; columella with several plaits. V. musica and a few
others have a small operculum.
Animal, eyes on lobes at the base of the tentacles ; siphon with a lobe on
each side, at its base ; lingual teeth 3 cusped.
V. vespertilio and hebrcea fill the nuclei of their spires with solid shelL
V. tbrasiliana forms nidamental capsules 3 inches long. (D'Orb.) In V.
angulata the mantle is produced into a lobe on the left side, and overlaps the
shell.
W. Indies, Cape Horn, W. Africa, Australia, Java, Chili.
Chalk . India, Brit., Trance, &c.
Volutilithes, Sw. Spire pointed, many-whirled, columella
V. spinosus, PI. VII., fig. 10.
(V. abyssicola], dredged at 132 fathoms; off the Cape.
Distr., 70 sp.
Fossil, 80 sp.
Sub -genera.
plaits indistinct.
Living, 1 sp. (
(Adams).
Fossil, Eocene.
Brit., Paris.
Scaphella, Sw. Fusiform, smooth.
Ex., V. magellanica. Fossil, V. Lamberti, Crag, Suffolk.
Melo, Brod. Large, oval ; spire short.
Type, M. diadema, PL VII., fig. 11. New Guinea, 8 sp.
CYMBA, Broderip. Boat-shell.
Syn., Yetus (Adans.) Gray.
Type, C. proboscidalis, PL VII., fig. -12, and fig.
74 (= V. cymbium, L.)
Shell like voluta ; nucleus large and globular ;
whirls few, angular, forming a flat ledge round the
nucleus.
The foot of the animal is very large, and deposits
a thin enamel over the under side of the shell. It is
ovo-viviparous, and the young animal is very large
when born ; the nucleus becomes partly concealed by
the growth of the shell.
Distr., 10 sp. W. Africa, Lisbon.
MITRA, Lam. Mitre -shell.
Syn., turris, Montf. Zierliana, Gray. Tiara,
Sw.
Cymba.
120 MANUAL OF THE MOLLUSCA.
Types, M. episcopalis, PI. VII., fig. 13. M. vulpecula, fig. 14.
Shell fusiform, thick ; spire elevated, acute ; aperture small, notched in
front ; columella obliquely plaited ; operculum very small.
The animal has a very long proboscis ; it emits a purple liquid, having a
nauseous odour, when imitated. The eyes are placed on the tentacles, or at
their base. Range, from low water to 15 fathoms, more rarely in 15 80
fathoms.
Distr., 350 sp. Philippines, India, Red Sea, Medit., W. Africa, Green-
land (1 sp.), Pacific, W. America. The extra-tropical species are minute.
M. Greenlandica and M. cornea (Medit. sp.) are found together in the latest
British Tertiaries (Forbes.)
Fossil, 90 sp. Chalk . India, Brit., France, &c.
Sub-genera. Imbricaria, Schum. (conoelix, Sw.)
Shell, cone-shaped. I. conica, PL VII., fig. 15.
CyUndra, Schum. (Mitrella, Sw.)
Shell, olive-shaped. C. crenulata, PL VII., fig. 16.
VOLVARIA, Lam.
"Etym., volva, a wrapper.
Type, V. buUoides, PL VII., fig. 1?.
Shell cylindrical, convolute ; spire minute ; aperture long and narrow ;
columella with 3 oblique plaits in front.
Fossil, 5 ? sp. Eocene. Brit., France.
MARGINELLA, Lam.
Etym., diminutive of margo, a rim.
Syn., porcellana (Adans.) Gray. Persicula, Schum.
Types, M. nubeculata, PL VII., fig. 18. M. persicula, fig. 19.
Shell, smooth, bright ; spire short or concealed ; aperture trunca
front; columella plaited; outer lip (of adult) with a thickened margin.
Animal similar to cyprsea.
Distr., 90 sp. Tropical, W. Indies, Brazil, Medit. (1 small sp.) W.
Africa, China, Australia.
Fossil, 30 sp. Eocene . France, &c.
Sub-genus. Hyalina, Schum. Outer lip scarcely thickened.
Type, voluta pallida, Mont., W. Indies.
FAMILY VI. CYPR^IDJE. Cowries.
Shell convolute, enamelled ; spire concealed ; aperture narrow, (
at each end ; outer lip (of adult) thickened, inflected. No operculum.
Animal with a broad foot, truncated in front ; mantle expanded on each
side, forming lobes, which meet over the back of the shell ; these lobes are
usually ornamented with tentacular filaments; eyes on the middle of the ten-
tacles or near their base ; branchial plume single. Lingual ribbon long,
GASTEROPODA.
121
partly contained in the visceral cavity ; rachis I toothed ; uncini 3. The
cowries inhabit shallow water, near shore, feeding on zoophytes.
CYPILEA, L. Cowry.
Etym., Cypris, a name of Venus.
Types, C. tigris, C. mauritiana, PI. VII., fig. 20.
Shell ventricose, convolute, covered with
shining enamel ; spire concealed ; aperture
long and narrow, with a short canal at each
end ; inner lip crenulated ; outer lip inflected
and crenulated. (Lingual uncini similar).
The young shell has a thin and sharp
outer lip, a prominent spire, and is covered
with a thin epidermis, fig. 75. When full-
grown the mantle lobes expand on each side,
and deposit a shining enamel over the whole
shell, by which the spire is entirely concealed.
There is usually a line of paler colour which
indicates where the mantle lobes met. Cu-
Fig. 75. Cyprcea, . . J
young* prtea annulus is used by the Asiatic Islanders
;o adorn their dress, to weight their fishing-nets, and for barter.
Specimens of it were found by Dr. Layard in the ruins of Nimroud.
Dhe money-cowrey (C. moneta] is also a native of the Pacific and Eastern
eas : many tons weight of this little shell are annually imported into this
country, and again exported for barter with the native tribes of Western
Africa ; in the year 1848 sixty tons of the money-cowry were imported into
Jiverpool ; and in 1849 nearly three hundred tons were brought to the same
)lace, according to the statement of Mr. Archer in the Industrial Exhibition.
Mr. Adams observed the pteropodous fry of C. annulus, at Singapore, adhering
in masses to the mantle of the parent, or swimming in rapid gyrations, or
with abrupt jerking movements by means of their cephalic fins.
Distr., 150 sp. In all warm seas (except E. coast S. America?) but
most abundant in those of the old world. On reefs and under rocks at low
water.
Fossil, 78 sp. Chalk . India, Brit., France, &c.
Sub -genera. Cyprovula, Gray. C. capensis, PI. VII., fig. 21. Aper-
tural plaits continued regularly over the margin of the canal.
Luponia, Gray. C, algoensis, PI. VII., fig. 22. Inner lip irregularly
plaited in front.
Fig. 76.
Trivial
* Fig. 75. Cyprsea testudinaria, L., young, China.
t Fig. 76. Trivia europaea, Mont. From the "British Mollusca," by Messrs.
Forbes and Hanley.
122 MANUAL OF THE MOLLUSCA.
Trivia, Gray. C. europsea, PL VII., fig. 23 ; fig. 76, and 15, B
Small shells with strise extending over the back. (Uncini ; 1st denticulat
2, 3, simple.)
Distr., 30 sp. Greenland, Brit., W. Indies, Cape, Australia, Pacific, W
America.
ERATO, Risso.
Etym., Erato, the muse of love-songs and mimicry. Type, E. Isevis
PL VII., fig. 24.
Shell minute ; like marginella ; lips minutely crenulated. Animal, liki
trivia.
Distr., 8 sp. Brit., Medit., W. Indies, China.
Fossil, 2 sp. Miocene . Trance, Brit. (Crag.)
OVULUM, Lam.
Etym., dimunitive of ovum, an egg. Syn., amphiceras, Gronov.
Types, 0. ovum, pi. VII., fig. 25. O. gibbosa and verrucosa.
Shell) like cyprcea; inner lip smooth.
Distr., 36 sp. Warm seas. W. Indies, Brit., Medit. China, W. America
Fossil, 11 sp. Eocene . France, &c.
Sub-genus, calpurna, Leach. O. volva (" The weaver's shuttle"). Aper.
ture produced into a long canal at each end. Toot narrow, adapted fo]
walking on the round stems of the gorgonice, &c., on which it feeds. C
patula inhabits the S. coast of Britain, it is very thin, and has a sharp oute]
lip.
SECTION B. HOLOSTOMATA. Sea-Snails.
Shell, spiral or limpet shaped ; rarely tubular or multivalve : margin ol
the aperture entire. Operculum, horny or shelly, usually spiral.
Animal with a short non-retractile muzzle ; respiratory siphon wanting,
or formed by a lobe developed from the neck (fig. 61), gills pectinated o:t
plume- like, placed obliquely across the back, or attached to the right side ol
the neck ; neck and sides frequently ornamented with lappets and tentaculai
filaments, Marine or fresh-water. Mostly phytophagous.*
FAMILY I. NATICIDJD.
Shell, globular, few-whirled ; spire small, obtuse ; aperture, semi-lunar :
lip, acute ; pillar often callous.
Animal, with a long retractile proboscis ; lingual ribbon linear ; rachw, I
toothed; uncini, 3 (similar to trivia, fig. 15, B.) ; foot very large ; mantle-lobe s
largely developed, hiding more or less of the shell. Species all marine.
* These " sections" are not very satisfactory, but they are better than any othei:
yet proposed, and they are convenient, on account of the great extent of the ordn
proso-branchiata. Natica and scalaria have a retractile proboscis. Pirena has
notched aperture, and aporrhais, a canal.
GASTEROPODA.
NATICA (Adans.), Lamarck.
Syn. t mammilla, Schm. Cepatia, Gray. Nacca, Risso.
>~
6. Pyrula reticulata, Lam. i. China .................................... 109
(Jlyristica] melongena, L. . ^bfU.V.lV^.V^a.... 109
.sus colus, L. ^. Ceylon .................. ............... 109
(Chrysodomus) antiquos, Mull. (var. contrarius, Sby.) Red
- (operculum). [Crag, TValton, Essex 109
10. Buccinum undatum, L. ^. Britain .................................... 110
11. Eburna spirata, L sp. . Ceylon .................................... Ill
12. Fseudoliya plumbea, Chemn. sp. . W.America ..... Ill
13. Terebra maculata, L. sp. . Moluccas .............................. Ill
14. --- (BuUia) semiplicata, Gray. S.Africa ........................ Ill
15. Xassa arcularia, L. sp. . Moluccas ................................. 112
16. -- (Cyclonassa] neritea, L. sp. Mediterranean .................. 112
(Cyllene) Oweni, Gray. E.Africa .............................. 112
nticosus, L. sp. . X.Australia .............................. 112
19. Magilus antiquus, Montf. i. Red Sea .............................. 114
- do. young. (Leptoconchus) .................................... 1 14
21. f Ringicula ringens, Lam. f. Eocene, Paris ..... . .................. 112
MANUAL OF THE MOLLUSCA.
PLATE VI.
Bvccinufae.
PAGE
1. Purpura persica, L. sp. . India 113
2.- lapilliis, L. sp. (operculum.) Britain 113
3 _ ( Concliolepas) peruviana, Lam. . Peru 113
4. Monoceros imbricatum, Lam. . Cape Horn 1 A 3
5. Pedicularia sicula, Sw. Sicily 113
6. Planaxis sulcata, Brag. sp. India 114
7. _ } (operculum) 114
8. Trichotropis borealis, Brod. N. Britain 108
9. Ricinula arachaoides, Lam. China 114
10. Coluinbella mercatoria, Gmel. sp. W.Indies 116
11. Harpa ventricosa, Lam. ^. Mauritius 116
12. Dolium galea, L. sp. \. Mediten-anean 115
13. Cassidaria echinophora, L. \. Medit 115
14. Cassis flammea, L. China , 114
15. Oniscia cancellata, Sby. China 11-1
16. Oliva porphyria, L. |. Panama 116
17. (Agaronia) hiatula, Gm. sp. f . W. Africa 11?
18. (Scaphula} utriculus, Gm. sp. . Africa
19. (OHvella) jaspidea, Gm. sp. W. Indies 117
20. Aucillaria buccinoi'des, Lam. . Eocene, Isle of Wight 11?
21. glabrata, L. sp. i. W.Indies 117
J.W.l.owrv fc.
MANUAL OP THE MOLLUSGA.
PLATE VII.
Conidte.
PAGE
1. Conus marmoreus Gm. . Cliiria .................................... 117
2. - (Conorbis) dormitor, Solander. Eocene, Barton ........... .- 117
3. Pleurotoma Babylonica, L. sp. | . China ........................... 118
4. Clavatula mitra, Gray. W.Africa .................................... 118
5 . Mangelia taeniata, Desh. -f-. Mediterranean ........................ 118
6. Bela turricula, Mont. sp. Britain .................................... 118
7. Defrancia linearis, Bl. sp. f. Medit .................................. 118
8. Lachesis minima, Mont. sp. -f. Britain .............................. 118
VolutldcB.
9. Voluta musica, L. \. W.Indies ....................................... 119
1 . Volutilithes spinosus, L. sp. |. Eocene, Barton .................. 119
11. Melo diadema, Lam. sp. ^. New Guinea ........................... 119
12. Cymba proboscidalis, Lam. sp. i. W. Africa ........................ 119
13. Mitra episcopalis, D'Arg. i. Ceylon ...... ........................ 119
14. - vulpecula, L. . Singapore ............... ^^- .............. 120
15. -- (Imbricaria) conica, Schuin. ^ttjlljjpinBs /^rtv-Cu ....... 120
16. -- ( Cylindra) crenulata, Chernn. China ........................ 120
17. Volvaria bullo'ides, Lam'. Eocene, Grignon ........................ 120
18. Marginella nubeculata, Lam. . W. Africa ........................... 120
1 9. - - (Persicula) lineata, Lam. W. Africa ..................... 120
Cyprasicke.
20. Cyprsea Mauritiana, L. i. India Pacific ........................... 121
21. -- (Ci/provula) capeusis. Gray. . S. A'frica ............... 121
22. - (L?tponia) algoeiisis, Gray. S, Africa ..................... 121
23,23*- (Trivia] europeea, Mont. Britain ..................... 122
24. Erato Isevis, Donovan. Britain . ...................................... 122
25. Ovulum ovum, L. sp. i. New Guinea .............................. 122
MANUAL OF THE MOLLUSCA.
PLATE VIII.
Naticidce.
PAGE
1. Natica canrena, L. sp. . China 123
2. (Globulus) sigaretina, Lam. . Eocene, Paris 123
3. (Cermna) fluctuata. Sby. |-. Pliilippines 123
4. Sigaretus haliotoides, L. sp. . W. Indies 1 24
5. (Naticina) papilla, Chemu. sp. Africa 124
6. Lamellaria perspicua, Mont. Mediterranean 124
7. Velutina Isevigata, L. sp. Britain 124
8. Narica cancellata, Chemn. sp. Pacific 124
9. Neritopsis radula, L. sp. Sandwich Islands 141
Pyramidellidtz.
10. Pyramidella auris-cati, Chemn. sp. Mauritius 125
11. (Obeliscus) dolabrata, Gmel. sp. W.Indies 125
12. Odostomia plicata, Mont. sp. f. Britain 125
13. Chemnitzia elegantissima, Mont. sp. f. Weymouth 126
14. Eulima polita, L. Britain ,, 126
15. Stylifer astericola, Brod. Philippines 12
Cerithidae.
16,16*. Cerithium nodulosum, Brug. -|. Moluccas 127
17. - (Bittium) reticulatum, Da Costa. Britain 127
18. Triphoris perversus, L. sp. Mediterranean 128
19. Potamides mixtus, Defr. Eocene, Paris 12
20. (Pyrazus) palustris, Brug. -|. India
21 . (Terebralia) telescopium, Brug. J. India 12
22. ~ (Pirenelld) mammillatus, Risso sp. Mediterranean 12
23. (Lampania) zonalis, Gray. Chusan 128
24. (Cerithidea) decollatus, L. sp. Cape 12
Melaniadce.
25. 25* Melania amarula, L. sp. f . Madagascar 131
26. (Melanatria) fluminea, Gm. sp. . Madagascar 131
27. (Melafusus) fluviatilis, Say. |. TJ. States 131
28. (Anculotus) prsemorsa, Say. U. States 131
29. - (Vibex) fuscata, Gm. sp. Africa 131
30. Melanopsis costata, Eer. Syria 132
81.- (Pirena) atra. L. sp. |. Ceylon 132
tote Weate>.185l.
MANUAL OF THE MOLLUSCA.
PLATE IX.
Turritellida.
PAGE
1. Turritella, imbricata, L, W.Indies 132
2. (Mesalia) sulcata, var. Lam, Eocene, Paris 132
3. _ (Proto) cathedralis, Brongn. f. Miocene, Bordeaux... 132
4. Aclis perforatus, Mont. sp. f . Guernsey 132
5. Caecum trachea, Mont. 4. Britain 133
6. - (fry, magnified f) 133
7. Vermetus lumbricalis, Gm. sp. (young.) W. Africa 133
8. Siliquaria anguina, L. sp. . New Guinea 133
9. Scalaria pretiosa, Lam. China 133
Litorinidte.
10. Litorina litorea, L. Britain 134
11. - - (Tectaria) pagodas, L. . Zanzibar 133
12. - (Fossarus) sulcatus, S. Wood. Mediterranean 135
1 3. - ( Modulus) tectum, Gm. sp. N. Australia 135
14. (Risella) nana, Lam. sp. . Tasmania 135
1 5. Solarium perspectivum, L. sp. f . China 135
16. Lacuna pallidula, Da Costa. Britain 136
17. Rissoa labiosa, Mont. Britain 136
18.-- - (Hydrobia) ulvse, Penn. Britain 137
19, - (Jeffrey sia) diaphana, Alder. (Operculum) Britain 137
20.- - (Skenea) planorbis, O. Fabr. (^ inch). Britain 137
21. Nematura deltee, Bens. f. India 137
22. Lithoglyphus fuscus, Pfr. sp. Danube 138
23. Amnicola isogona, Say. IT. States 131
24. Litiopa bombix, Kiener. Mediterranean 136
25. Truncatella subtruncata, Mont. sp. f . Mediterranean 137
Paludinidce.
26. Faludina Listeri, Hanley. |. Norwich 138
27.- (Bithinia) teutaciilata, Mont. Norwich 138
28. Valvata piscinalis, Miill. Norwich 140
29. cristata, Mull. Norwich 140
30. Ampullaria globosa, Sw. \. India 138
31 . - ( Marisa) cornu-arietis, L. sp. Brazil 139
32. - (Lanistes) Bolteniana, Chernn. sp. i. Nile 139
33. Amphibola avellana, Chemn. sp. New Zealand 139
54. Paludomus aculeatus, Gm. sp. Ceylon .' 133
Neritidce.
35. Nerita ustulata, L. Scinde 141
36. ( Velates] perversus, Gm. sp. Eocene, Soissons 141
37. 38. Pileolus plicatus, J. Sby. Bath oolite, Ancliff 141
39. Neritina zebra, Brug. Pacific 141
40. crepidularia. Less. India 142
41 . Navicella porcellana, Chemn. sp. Mauritius Pacific 142
10 MANUAL OE THE MOLLTJSCA.
PLATE X.
1 . Phorus corrugatus, Reeve. |. Kurachee, India ..................... 135
Turbinid