THE
CONCHOLOGIST’S FIRST BOOK:
A
SYSTEM
OF
TESTACEOUS MALACOLOGY,
Arranged expressly for the use of Schools,
IN WHICH
THE ANIMALS, ACCORDING TO CUVIER, ARE GIVEN WITH THE SHELLS,
A GREAT NUMBER OF NEW SPECIES ADDED,
AND THE WHOLE BROUGHT UP, AS ACCURATELY AS POSSIBLE, TO THE PRESENT
CONDITION OF THE SCIENCE.
BY EDGAR A. POE.
SECOND EDITION.
WITH ILLUSTRATIONS OF TWO HUNDRED AND FIFTEEN SHELLS, PRESENTING A
CORRECT TYPE OF EACH GENUS.
PHILADELPHIA:
PUBLISHED FOR THE AUTHOR, BY
HASWELL, BARRINGTON, AND HASWELL,
AND FOR SALE BY THE PRINCIPAL BOOKSELLERS IN THE UNITED STATES.
1840.
Entered according to act of Congress, in the year 1839, by EDGAR A. POE,
in the clerk’s office for the eastern district of Pennsylvania.
Printed by
Haswell, Barrington, and Haswell.
PREFACE
TO THE FIRST EDITION.
The term “_Malacology_,” an abbreviation of “_Malacozoology_,” from the
Greek μαλακος, _soft_, ζωον, _an animal_, and λογος, _a discourse_, was
first employed by the French naturalist De Blainville to designate an
important division of Natural History, in which the leading feature of
the animals discussed was the _softness_ of the flesh, or, to speak with
greater accuracy, of the general envelop. This division comprehends not
only the _Mollusca_, but also the _Testacea_ of Aristotle and of Pliny,
and, of course, had reference to molluscous animals in general—of which
the greater portion have shells.
A treatise concerning the shells, exclusively, of this greater portion,
is termed, in accordance with general usage, a Treatise upon Conchology
or Conchyliology; although the word is somewhat improperly applied, as
the Greek _conchylion_, from which it is derived, embraces in its
signification both the animal and shell. Ostracology would have been
more definite.
The common works upon this subject, however, will appear to every person
of science very essentially defective, inasmuch as the _relation_ of the
animal and shell, with their dependence upon each other, is a radically
important consideration in the examination of either. Neither, in the
attempt to obviate this difficulty, is a work upon Malacology at large
necessarily included. Shells, it is true, form, and, for many obvious
reasons, will continue to form, the subject of chief interest, whether
with regard to the school or the cabinet; still there is no good reason
why a book upon _Conchology_ (using the common term) may not be
malacological as far as it proceeds.
In this view of the subject the present little work is offered to the
public. Beyond the ruling feature—that of giving an anatomical account
of each animal, together with a description of the shell which it
inhabits,—I have aimed at little more than accuracy and simplicity, as
far as the latter quality can be thought consistent with the rigid
exactions of science.
No attention has been given to the mere _History_ of the subject; it is
conceived that any disquisition on this head would more properly
appertain to works of ultimate research, than to one whose sole
intention is to make the pupil acquainted, in as tangible a form as
possible, with _results_. To afford, at a cheap rate, a concise, yet
sufficiently comprehensive, and especially a well illustrated
school-book, has been the principal design.
In conclusion, I have only to acknowledge my great indebtedness to the
valuable public labors, as well as private assistance, of Mr. Isaac Lea,
of Philadelphia. To Mr. Thomas Wyatt, and his late excellent _Manual of
Conchology_, I am also under many obligations. No better work, perhaps,
could be put into the hands of the student as a secondary text book. Its
beautiful and perfectly well-coloured illustrations afford an aid in the
collection of a cabinet scarcely to be met with elsewhere.
E. A. P.
PREFACE
TO THE SECOND EDITION.
In issuing a second edition of this “Conchology,” in so very brief a
period since the publication of the first large impression, the author
has little more to do than to express the high pleasure with which he
has seen his labors well received. The success of the work has been
decided; and the entire design has been accomplished in its general
introduction into schools.
Many important alterations and additions are now made; errors of the
press carefully corrected; many more recently discovered American
species added; and the work, upon the whole, is rendered more worthy the
public approbation.
E. A. P.
INTRODUCTION.
The term “_Conchology_,” in its legitimate usage, is applied to that
department of Natural History which has reference to animals with
testaceous covering or shells. It is not unfrequently confounded with
_Crustaceology_, but the distinction is obvious and radical, lying not
more in the composition of the animal’s habitation, than in the
organization of the animal itself. This latter, in the _Crustacea_, is
of a fibrous nature, and has articulated limbs; the shell, strictly
adapted to the members, covers the creature like a coat of mail, is
produced at one elaboration, is cast or thrown aside periodically, and,
again at one elaboration, renewed; it is moreover composed of the animal
matter with phosphate of lime. In the _Testacea_, on the contrary, the
inhabitant is of a simple and soft texture, without bones, and is
attached to its domicil by a certain adhesive muscular force; this
domicil, too, is a permanent one, and is increased, from time to time,
by gradual additions on the part of the tenant; while the entire shell,
which is distributed in layers, or strata, is a combination of carbonate
of lime, with a very small portion of gelatinous matter. Such animals,
then, with such shells, form, alone, the subject of a proper
“Conchology.”
Writers have not been wanting to decry this study as frivolous or
inessential; most unjustly assailing the science itself, on account of
the gross abuses which have now and then arisen from its exclusive and
extravagant pursuit. They have reasoned much after this fashion:—that
Conchology is a folly, because Rumphius was a fool. The _Conus Cedo
Nulli_ has been sold for three hundred guineas; and the naturalist just
mentioned gave a thousand pounds sterling for one of the first
discovered specimens of the _Venus Dione_ (of Linnæus). But there have
been men in all ages who have carried to an absurd, and even pernicious
extreme, pursuits the most ennobling and praiseworthy.
To an upright and well regulated mind, there is no portion of the works
of the Creator, coming within its cognizance, which will not afford
material for attentive and pleasurable investigation; and, so far from
admitting the venerable error even now partially existing to the
discredit of Conchology, we should not hesitate to acknowledge, that
while few branches of Natural History are of more direct, _very few_ are
of more adventitious importance.
Testaceous animals form the principal subsistence of an immense number
of savage nations, inhabitants of the sea-board. On the coast of Western
Africa, of Chili, of New Holland, and in the clustered and populous
islands of the Southern seas, how vast an item is the apparently
unimportant shell-fish in the wealth and happiness of man! In more
civilized countries it often supplies the table with a delicate luxury.
Nor must we forget the services of the _pinna_ with its web, nor of the
_purpura_ with its brilliant and once valuable dye, nor omit to speak of
the pearl-oyster, with the radiant nacre, and the gem which it produces,
and the world of industry which it sets in action as minister to the
luxury which it stimulates.
Shells, too, being composed of particles already in natural combination,
have not within them, like flowers and animals, the seed of dissolution.
While the preparation of a specimen for the cabinet is a simple
operation, a conchological collection will yet remain perfect for ages.
These important circumstances being duly considered, in connexion with
the universally acknowledged beauty and variety, both of form and
colour, so strikingly observable in shells, it is a matter for neither
wonder nor regret that these magnificent _exuviæ_, even regarded merely
as such, should have attracted, in a very exclusive degree, the
attention and the admiration of the naturalist. The study of Conchology,
however, when legitimately directed, and when regarding these _exuviæ_
in their natural point of view, as the habitations, wonderfully
constructed, of an immensely numerous and vastly important branch of the
animal creation, will lead the mind of the investigator through paths
hitherto but imperfectly trodden, to many novel contemplations of
Almighty Beneficence and Design.
But it is, beyond all doubt, in a geological point of view that
Conchology offers the most of interest to the student; and here, by
reference to the fair pages of a profound and mighty knowledge to which
it has pointed out the searcher after truth, are triumphantly refuted
all charges brought against it of insignificance or frivolity.
“In fine, the relations of the mollusca,” says De Blainville, “with the
mineral kingdom, and consequently with the mass of the earth which they
contribute to form, are not devoid of interest, for without seeking here
to resolve the physiological question—whether the conchyliferous
mollusca borrow of the inorganic kingdom the calcareous matter which
composes their shells, or whether they form it of themselves, it is
still certain that they produce, at least, changes upon the surface of
the earth by accumulating this material in some places more than in
others, and in consequence that they alter the physiognomy of the
superficial structure of the globe, the study of which constitutes
geognosy.”
“By this,” says Parkinson, “we are taught that innumerable beings have
lived, of which not one of the same kind does any longer exist—that
immense beds composed of the spoils of these animals, extending for many
miles under ground, are met with in many parts of the globe—that
enormous chains of mountains, which seem to load the surface of the
earth, are vast monuments, in which these remains of former ages are
entombed—that, though lying thus crushed together, in a rude and
confused mass, they are hourly suffering those changes, by which, after
thousands of years, they become the chief constituent parts of gems, the
limestone which forms the humble cottage of the peasant, or the marble
which adorns the splendid palace of the prince.” Fossil, wood, coral,
and shells, are, indeed, as Bergman very forcibly observes, the only
true remaining “medals of Creation.”
EXPLANATION OF THE PARTS OF SHELLS.
MULTIVALVE.
A MULTIVALVE shell is composed of more parts than two. Every part of a
shell which is connected by a cartilage, ligament, hinge, or tooth, is
called a valve of such shell; thus, the Chitons have eight transverse,
broad, but very short valves, placed on the back of the animal, and
inserted at their sides into a marginal tough ligament. Plate I. fig.
11, _a a a_.
_Operculum_ consists of four small valves on the summit of the Lepas,
which shut up the superior orifice; it is in a certain degree
stationary, and different from the operculum of univalve shells, which
will hereafter be described. Plate I. fig. 1, A. Fig. 9 represents a
profile view of the operculum removed from its place, _a_ the front
valves, _b_ the back valves. Fig. 10 a front view of the operculum.
_Base_ is that part of the shell by which it is fixed to rocks and other
bodies. Plate I. fig. 1 and 2, B B B.—H is a piece of stone to which the
base is fixed, and G a piece of wood to which the shells of this section
are generally attached.
_Ligament_ is the membranous or tendinous substance by which the valves
or parts of the shell are attached. Some multivalve shells are connected
by the parts of one valve locking into another. Plate I. fig. 2, D D D.
The ligaments vary considerably in their texture, being scaly, prickly,
smooth, or punctated.
_Ridges_ are certain convexities in many of the Lepas tribe, sometimes
longitudinal and sometimes transverse. Plate I. fig. 1, F F.
_Peduncle._ A sort of stem by which the shells of the Anatifera are
attached to wood, &c. It is a membranaceous substance, similar to a
bladder but materially thinner, and filled with a liquid which evidently
affords nourishment to the animal. Plate I. fig. 2, C C; the peduncle is
usually affixed to a piece of wood as represented at G.
_Feelers_ are those crenated arms, evolved from the side of the
Anatifera. While the animal is in the water it continually moves its
feelers, evidently for the purpose of entangling minute marine insects,
as food. Plate I. fig. 2, E E.
_Accessory valves_ are small plates which cover the apex at the hinge of
the Pholades, or are situated below the hinge. Plate I. fig. 3, _a_.
_Margin._ A fleshy border in which the valves are attached in the genus
Chiton. Plate I. fig. 11, _b b_.
BIVALVE.
Bivalve shells consist of two parts or valves, connected by a cartilage,
and a hinge which is generally composed of teeth; those of the one valve
locking into a cavity in the other.
The valves of some bivalve shells are formed exactly alike, and others
are very different; the one being smooth, the other rugose; one flat and
another convex; and often one is shorter than the other.
The shells of the Mya, Solen, Tellina, Venus, and others, have in
general both valves alike, while those of the Spondylus, Ostrea, and
Anomia, have in general dissimilar valves. The first of these kinds are
called equivalve, and the latter inequivalve.
_Equilateral_ shells, are those whose sides are alike, as in the shells
of the genus Pecten. Plate II. fig. 2, and Plate VII. fig. 14. This is
also exemplified in the Pectunclus.
_Inequilateral valves_ are shells whose sides are unequal; and of
different shapes, as in the Mactra, Donax, &c.
_Summit_ is the most elevated point of that part of the shell in which
the hinge is placed. Plate I. fig. 4, _i k_.
In naming this the summit we do not follow the axiom of Linnæus, but
because we consider it more properly the summit of the shell than the
opposite extremity.
_Base_ is the reverse of the above, or that part of the shell
immediately opposite the summit. Plate I. fig. 6 and 7, _d d_.
_Sides_, the right and left parts of the valves. Plate I. fig. 6, _c_.
_Posterior slope_ is that part of the shell in which the ligament is
situated. In viewing the posterior slope in front, the beaks of the
shell retire from view. Plate I. fig. 4, _i_.
_Anterior slope_, that part of the shell opposite the posterior slope;
in viewing it in front, the beaks point to the observer. Plate I. fig.
4, _k_.
_Disk_, the convex centre of a valve, or most prominent part of the
valve, suppose it with its inside lying undermost. Plate I. fig. 4, _o_.
_Inside_, the concave part of a valve. Plate IV. fig. 6, _m_.
_Muscular impression_ is the impression left on the inside of the
valves, by the adhering muscles of the animal. It differs in most
shells, according to the shape of the animal, as semi-ovate, round,
lunate, elongated, &c. As a specific distinction, it is often of great
use; being, with a very few exceptions, alike in shells of the same
species. Some shells have only one cicatrix, as the Edible Oyster and
Mytilus; others have two, and some few more; the Tellina for example.
Plate I. fig. 6 and 8, _e e e e_.
_Lunule._ The lunated depressions, situated in the anterior and
posterior slopes. In different species of Venus they are prominent
characteristic marks, often of much service in ascertaining a species.
Plate I. fig. 4, _b b_.
_Ligament perforation._ The circular aperture, or perforation through
which the ligament passes; by which the animal of the Anomia attaches
itself to stones and other marine extraneous bodies, it is in general
situated in the flat valve, though there are a few exceptions to the
contrary. Plate I. fig. 7, _m_.
_Hinge_ is the point at which bivalve shells are united; it is formed by
the teeth of one valve inserting themselves between those of the other,
or by the teeth of one valve fitting into the cavities or sockets of the
opposite one.
It is on the peculiar construction of the _hinge_ that the generic
character of bivalve shells is principally founded, together with the
general contour of the shell. Plate II. fig. 1 and 3, _q q q_.
_Teeth of the hinge._ Upon the number and relative situation of the
teeth principally depend the specific distinctions; they are of various
forms, and very differently placed; some are single and large, others
numerous and small, orbicular, spatuliform, laminated, &c. Some hinges
have no visible teeth, and are termed _inarticulate_.—When a primary
tooth has a groove or hollow in its centre, it is called complicated.
Plate IV. Fig. 6, _e_; those with few teeth are termed _articulate_.
Plate IV. fig. 1 and 12; and those with many teeth _multiarticulate_.
Plate IV. fig. 2, 3, 4, &c. Plate I. fig. 6, and 8, _g g g g_.
_Primary teeth_ are those teeth in general situated in the centre of the
hinge, and are for the most part broad, large, and distinct, often
elevated; and in general are inserted in a cavity in the opposite valve.
They however differ very much in some shells, but may easily be
distinguished. Plate IV. fig. 1, 3, and 7, _a a a a a_. These are also
termed the Cardinal Teeth.
_Lateral Teeth_, Plate IV. fig. 10, are teeth which diverge from the
Umbo, and are in general long and flat, often double and divided by a
groove or hollow. Plate IV. fig. 2, 4, 6, and 7. _b b b b_.
_Double Teeth_, Plate IV. fig. 1, _c c_.
_Incurved Teeth_ are those which are bent round, as in the single tooth
of the Solen. Plate IV. fig. 8, _f f_.
_Recurved Teeth_, are those which are bent backwards, as in the hinge of
the Panopea and Spondylus.
_Middle Teeth_, Plate IV. fig. 4, _d d_. These are also termed Cardinal
Teeth.
_Numerous Teeth_, are those small upright teeth, set in rows, of which
the hinges of all the species of the genus Arca are formed. Plate IV.
fig. 10, _k k_.
_Cavity of the Hinge._ The hollow depression in which the ligament of
the Ostrea is situated, generally of a triangular form. Plate IV. fig.
11, _g_.
_Ligament_ of the Hinge, or cartilage, is that flexible fibrous
substance by which the valves are united, and the hinges kept in their
proper places; generally situated under the beaks of the shell. Plate
II. fig. 1, 3, and 4, _l l l_; Plate IV. fig. 3, _n_.
_Beak_ is the extreme point of the summit of bivalves, which in many
species turns spirally downwards or to the one side, as in some species
of Venus, &c. From this circumstance it is seldom the highest part of
the shell. Plate II. fig. 5, _r r_.
_Seam._ When the valves are closed, the line of separation between them
is so called. Plate II. fig. 6, _t t_.
_Umbo._ That part situated immediately under the _beak_. Plate I. fig.
6, _w_; and Plate II. fig. 4, _w_.
_Ears._ The processes on each side of the beak, in most species of that
division of Ostrea, called Pecten; some have one ear very large, and the
other small; and some are scarcely observable on one side. Pl. II. fig.
2, _h h_.
_Superior Ear._ Plate IV. fig. 11, _h_.
_Inferior Ear._ Do. do. _i_.
_Margin._ The extreme edge of the whole shell, or the circumference of
either valve, all round. Plate I. fig. 4, _p_; and Plate II. fig. 1,
_p_.
_Crenulated margin._ That fine notched edge of shells, which unite into
notches in the opposite valve, as genus Donax. Plate IV. fig. 6, _m m_.
_Striæ_ are fine thread-like lines, generally on the exterior surface of
shells, and are sometimes both longitudinal and transverse. When the
striæ of shells appear indistinct, as if worn out, it is termed
_obsolete striæ_. In some instances the insides of shells are striated;
for example, the Fasciolaria Tulipa. The character of the striæ is often
of much use in distinguishing species. Plate II. fig 2, _f_.
_Right Valve_ is that valve which, when viewed with the inside
uppermost, has the anterior slope pointing to the right hand. Plate I.
fig. 8; and Plate IV. figs. 5 and 6, _B_.
_Left Valve._ The opposite of the above; the anterior slope points to
the left hand, when viewed from the inside. Plate IV. figs. 3, 6, 7, 9,
&c.
_Length of the Shell_ is taken from the ligament, or the beak, to the
opposite margin. For example, Mytilus: it is longer than it is broad,
and the Solens are broader than long. Plate I. fig. 5, _u u_; and Plate
II. fig. 4, _v v_.
_Breadth_ is measured from the most extreme edge of the anterior and
posterior slopes, being in a contrary direction from its length. Many
shells are _broader than long_, such as most of the Myæ, Solenæ,
Tellinæ, &c.; and the Mytilus, Ostrea, Pinna, &c., are in general longer
than broad. Plate I. fig. 5, _v v_. Plate II. fig. 4, _v v_.
_Byssus_, or _beard_, is an appendage composed of filaments of a silky
texture, by which some of the Bivalves fasten themselves to their beds,
such as the Mytilus, Pinnæ, &c. Plate II. fig. 6, _s_.
UNIVALVE.
The shells called univalve, or those composed of one part only, are far
more numerous than the two preceding, both in genera and species; and it
requires a considerable degree of attention to discriminate many of the
_species_, as they run into each other so much; and they are divested of
the strong and distinct character afforded by the teeth of bivalves;
besides many of the species there are several varieties.
In the examination of shells of this order, the general contour or
outline of the whole shell is the first particular to be attended to, as
this leads to those distinctions necessary in the definition of simple,
spiral, or turbinated shells, Univalves with a regular spire, and those
without a regular spire. The genera of this order are formed principally
from the shape of the aperture, taken in conjunction with the general
shape of the shell; from the spire being lengthened or depressed, being
with or without a canal, the length of the beak and its direction,
together with the particular form of the outer lip: the colour of shells
only serves as a specific distinction, and cannot in this respect, in
all cases, be depended upon, although in others it is an unvarying test.
The particular manner in which the spots are disposed frequently
characterises species.
_Apex._ The summit, tip, or highest part of the spire. Plate II. figs.
7, 8, 9, _A A A_.
_Base_ is the opposite extremity from the apex, or tip of the spire. In
shells with a beak it implies the tip of such beak; Plate II. fig. 11,
_B_. In shells without a beak it is understood to be the lower part, as
before-mentioned, opposite the apex; Plate II. figs. 8 and 9, _B B_. In
the Patella and some others, the base of the shell is that part on which
it rests when it is laid on its mouth. In the Dentalium and Teredo it is
the wider end.
_Body_ of the shell is the first or lower whorl of the spire, in which
the aperture is situated, and is in general longer than the remaining
whorls. Plate II. figs. 10 and 12, _F F_; and Plate III. figs. 7 and 9,
_F F_.
_Front_ of the shell is that side where the aperture is situated. Plate
II. fig. 7, _I_; and Plate III. fig. 8, _I_.
_Back_ is the opposite side to that in which the aperture is placed or
turned directly from the observer. Plate III. figs. 5 and 10, _G G_.
The _venter_, or belly, is the most prominent part of the lower whorl or
body, generally situated in the vicinity of the lip over the aperture;
and formed by the convexity of the aperture. It is in general only made
use of in describing shells whose body is large in proportion to the
size of the spire. Plate III. figs. 5 and 10, _H H_.
_Sides._ The extreme edges of the shell, when viewed either in front or
from the back. Plate II. fig. 11, _K K K K K K K K_. Right side is, when
the shell is viewed in front that side next the observer’s left hand.
Left side, the side with the aperture in it.
_Aperture_, or mouth, is that part of the lower whorl or body by which
the animal protrudes itself. This is one of the principal generic
distinctions of Univalve shells, and differs very much in shape; some
apertures being rounded, others semilunar, angular, &c. Plate II. figs.
9 and 11, _C C_; and Plate III. figs. 1, 3, and 14, _C C C_. Some
apertures have a canal at their base, and others are devoid of it. In
various genera it extends the whole length of the shell, as in the
Cypræa, and some of the Cones with depressed spires. This in several
individuals is either entirely open, or is closed by an operculum or
lid, which is usually affixed to the foot of the animal.
_Canal_, or gutter, is the inside of the elongations of the aperture, or
both lips of the shell of those species with a beak, in which it forms a
concave channel or gutter, running from its commencement in the aperture
to the extremity or base. Plate II. figs. 10 and 11, _Q Q_. Plate III.
fig. 8, _Q_. Some species are furnished with two canals, one situated at
the junction of the outer lip and body, as in the Murex.
_Beak_ is that lengthened process in which the canal is situate; it
commences a little higher up, on the outside, than the insertion of the
canal in the inside, which is always distinctly marked by the line of
the aperture. Plate II. fig. 11, _p_. This process is not so conspicuous
in some of the species of Voluta, but is more marked in the genera
Murex, Fusus, Pyrula, &c.
_Pillar_, or _columella_, is that process which runs through the centre
of the shell in the inside from the base to the apex in most univalve
shells, and appears to be the support of the spire: and, indeed, seems
to form that part of the shell: it is in general grooved or folded; but,
as it is situated in the interior of the shell, a minute description is
unnecessary. Plate II. figs. 10 and 12, _M M M M M_; and Plate III. fig.
9, _M M M_. The internal edge of its base is frequently described as
having plaits, &c.
_Plaited Columella_ are those folds, or plaits, which are the
distinguishing characteristic of the Volutæ and other genera. Plate II.
fig. 7, _z_.
_Pillar Lip_ is a continuation of the glossy process with which the
aperture is lined, and expanded on the columella. Plate III. figures 7
and 8, _O O_. This is termed the inner lip by some authors.
_Outer Lip._ The expansion, or continuation of the body of the shell on
the left margin of the aperture, and is also lined with the glossy
process of the aperture. Plate II. fig. 7, _N_; and Plate III. fig. 8,
_N N N_. The latter is an example of the alated or winged shells.
_Operculum_, or lid. This is only an appendage to the turbinated or
spiral shells affixed to the foot of the animal, sometimes of a
testaceous, in others of a horny or cartilaginous substance. It acts as
a door or lid, and is calculated for the protection of the animal, when
it retires within its dwelling, from the intrusion of its enemies, and
adapted to the shape of the aperture, which it closes nicely up: as
exemplified in the operculum of the Turbo, and is of a hard, stony
appearance. Plate III. fig. 4.
_Spire_ consists of all the whorls of the shell, except the lower one,
which, as before observed, is termed the body of the shell. Plate II.
fig. 12, _D_; and Plate III. figures 7 and 8, _D D_.
The spire is a prominent feature of the Univalve; and upon its being
elevated, depressed, &c., depends much of the generic and specific
definition. Adanson, in his ‘Natural History of Senegal,’ says that the
external character of the spire varies according to the plane they turn
upon, which, he observes, is either horizontal, cylindrical, conic, or
ovoid. At the same time, he admits that there are a great many
intermediate forms which cannot properly be defined.
It must be remembered that many of the young shells have not the same
number of wreaths as the adults; from which it would appear, that the
part of the animal nearest the apex never increases in size. The number
of wreaths cannot, at all times, be depended upon. A full grown shell
may, however, be known from the outer lip, which has generally an
unfinished appearance in young shells. Indeed, in all the land and fresh
water shells it is a distinct criterion, as they are never complete in
the form of the outer lip till full grown.
_Whorl_ is one of the wreaths or volutions of the shell. Plate II. fig.
8, _L_; and Plate III. fig. 10, _L_.
_Depressed Spire_ is when the spire is very flat, as in the shells of
the genus Planorbis, &c. Pl. II. fig. 12, _D_; and Pl. III. fig. 5, _S_.
A flat shell is figured in Plate III. fig. 14.
_Involuted Spire_, those shells which have their whorls, or wreaths,
concealed in the inside of the first whorl or body, as in some of the
Nautili and Cypræa.
_Suture of the Spire_, or whorls, is a fine spiral line, which separates
the wreaths or whorls from each other; it is sometimes crenulated,
undulated, or sulcated, and not unfrequently elevated or projecting.
Plate II. fig. 9, _E E_.
_Reversed_, or _Heterostrophe Spire_, is when the volutions of the spire
revolve in the same manner as a common corkscrew, or when the aperture
is placed downwards, the nature of the spire runs upwards from the right
hand to the left, Plate III. fig. 13.
In some of the more depressed species of Helix, or Nautilus, great
attention is requisite in order to ascertain which is really the upper
side of the shell, for it is on that side the spiral turns are to be
taken from the centre or apex; and, in most instances, this is to be
determined by the oblique direction of the aperture to the under part,
where the lip rarely extends so far as on the upper part. In fixed
shells, such as Serpulæ, there is no difficulty, as the side which is
sessile must be considered as the base or under part. Thus, in the
Serpula Lucida the fixed part is sometimes very small, and the mouth
turns spirally upwards, in a contrary direction to the sun; and
therefore must be considered a reversed or heterostrophe shell, the same
as if the volutions nearest the mouth had turned laterally upon the
centre or fixed ones. This shell, indeed, is most frequently found with
regular lateral volutions; and though subject to great variety, with
respect to contortions, it invariably turns the aperture one way.
In some species of Nautilus, however, there can be no rule to ascertain
whether the shells are dextral or sinistral; for when the aperture is
exactly central, the lip embraces the body equally, and the sides of the
shell are similar.
_Chambers_ are the cavities divided by partitions, at regular or
irregular intervals; as in the Spirula. Plate III. fig. 11, _W W W W W_.
In some of the Serpulæ there are also divisions, but they are not
regular as in the Nautili and Spirulæ; and besides, they differ from
them in being devoid of a siphunculus or communication between the
chambers, the animal forms a complete partition, and adds to its shell,
which it would appear to be necessitated to do from its body growing too
large for its abode.
Several of the Patellæ have chambers formed of laminous partitions,
subspiral cells, or processes; these in general lie horizontally, and
are quite open at one end, as in the Patella Testudinaria, the
Crepidula, and Calyptræa.
_Umbilicus_ is in general a circular perforation in the base of the
lower whorl, or body, of many univalve shells. This is common to most of
the Trochi, in some species of which it penetrates from the base to the
apex; widest at the base, and gradually tapering to the top. Plate III.
fig. 1, _u_.
_Sub-umbilicated_ shells are those which have the umbilicus covered in a
greater or less degree by a thin process; which, in some, almost
entirely closes the opening or mouth. This character is most commonly to
be met with among species of Buccinum and Murex.
Shells which have no umbilicus are termed imperforate.
_Siphunculus_ is that small round perforation which forms a
communication between the chambers of the Spirulæ, and penetrates
through the whole spire of the shell. Plate III. fig. 11, _v_.
_Varices_ are transverse ribs which cross the whorls of shells in some
species of Buccinum, Murex, and Tritonia, and exemplified in the
Cassidaria. Varices are formed by the periodical growth of the shells,
these being the margin of the outer lip, to which the animal has
attached its periodical enlargements. In some species they have more the
form of sutures than ribs; this is owing to the margin of the outer lip
being but slightly developed.
_Ribs_ are those longitudinal and transverse protuberances which are in
many of the univalve shells. Plate III. fig. 12, _R R R R_.
_Teeth_ of univalves, or tooth-shaped protuberances, are fine, white
laminæ, or ridges, running spirally backwards, in a parallel direction
to each other; those on the exterior lip may, in most instances, be
traced through the outside of the shell, and are nearly alike in length.
Plate III. fig. 13, _a_.
_Epidermis_ is a skin, or cuticle, covering the exterior surface of
shells, destined by nature to protect their surface from being injured.
It is membranaceous, somewhat similar to the periosteum which covers the
bones of animals. This substance is the production of the animal
inhabiting the shell; it is uniformly observed in some species, and not
at all in others. Shells with a rugged or uneven surface have almost
always this epidermis. In some it is strong, laminated, velvety,
fibrous, or rough, often beset with long hairs, and in others very thin,
smooth, and pellucid, and admits the colours of the shell to shine
through it. In some species it is so dusky that it entirely obscures the
beautiful colouring of the shell beneath. Although many shells are very
beautiful, even with this cuticle on them, they are much more so when it
is removed; but I would by no means advise the collector of shells to
remove it, unless he may have several duplicates of the same species;
and then he may do it by way of variety. It is always preferable,
however, to keep them in a state of nature.
A shell with epidermis is represented in Plate III. fig. _X_; and the
effect of the epidermis removed.
All other protuberances, furrows, &c., will be described at the end of
this work in a Glossary of Terms used in the Science.
DESCRIPTION OF PLATE IV.
HINGES OF BIVALVE SHELLS.
Fig. 1. Hinge of the Unio pictorum, _a_ Primary tooth, _c c_ double
teeth.
Fig. 2. Hinge of the _Solen_. _b_ Lateral teeth.
Fig. 3. Hinge of the Lucina radula, _a a_ Primary teeth, _n_ cartilage.
Fig. 4. Hinge of the _Cardium_. _b_ Lateral tooth, _d d_ middle teeth,
_l l_ spines.
Fig. 5. Hinge of the Lutraria.
Fig. 6. Inside of both valves of the _Donax trunculus_. _A_ is the left
valve, and _B_ is the right valve, _b_ lateral teeth, _e_ primary
complicated tooth, or cleft in the middle, _m m_ crenulated margin.
Fig. 7. Hinge of the _Venus_, _a a_ Primary teeth.
Fig. 8. Hinge of _Spondylus gæderopus_, _f f_ incurved teeth.
Fig. 9. Hinge of Isocardia Cor.
Fig. 10. Hinge of the Pectunculus, _k k_ numerous small teeth; the
distinguishing characteristic of the Family _Arcacea_.
Fig. 11. Hinge of the Pecten, _g_ cavity of the hinge, _h_ superior ear,
_i_ inferior ear.
Fig. 12. Hinge of _Anomia Ephippium_.
CLASSIFICATION.
CLASS I.
ANNULATA.
FOUR FAMILIES.
Fam.
1. _Dorsalia._ Two genera.
1. Arenicola. Species 1
2. Siliquaria. „ 8
2. _Maldania._ Two genera.
1. Clymene. Species 1
2. Dentalium. „ 21
3. _Amphitritæa._ Four genera.
1. Pectinaria. Species 2
2. Sabellaria. „ 2
3. Terebella. „ 4
4. Amphitrite „ 7
4. _Surpulacea._ Five genera.
1. Spirorbis. Species 6
2. Serpula. „ 26
3. Vermilia. „ 9
4. Galeolaria. „ 2
5. Magilus. „ 2
CLASS II.
CIRRHIPEDA.
ONE FAMILY.
1. _Cirrhipeda._ Ten genera.
1. Tubicinella. Species 1
2. Coronula. „ 5
3. Balanus. „ 30
4. Acasta. „ 4
5. Creusia. „ 3
6. Pyrgoma. „ 1
7. Anatifera. „ 6
8. Pollicipes. „ 6
9. Cineras. „ 1
10. Otion. „ 2
CLASS III.
CONCHIFERA.
TWENTY FAMILIES.
1. _Tubicola._ Six genera.
1. Aspergillum. Species 4
2. Clavagella. „ 4
3. Fistulana. „ 4
4. Septaria. „ 2
5. Teredina. „ 2
6. Teredo. „ 3
2. _Pholadaria._ Two genera.
1. Pholas. Species 18
2. Gastrochæna. „ 3
3. _Solenea._ Four genera.
1. Solen. Species 21
2. Panopea. „ 1
3. Solecurtus. „ 10
4. Glycimeris. „ 2
4. _Myaria._ Two genera.
1. Mya. Species 8
2. Anatina. „ 12
5. _Mactracea._ Seven genera.
1. Lutraria. Species 14
2. Mactra. „ 44
3. Crassatella. „ 11
4. Erycina. „ 2
5. Ungulina. „ 2
6. Solemya. „ 4
7. Amphidesma. „ 45
6. _Corbulacea._ Two genera.
1. Corbula. Species 10
2. Pandora. „ 4
7. _Lithophaga._ Three genera.
1. Saxicava. Species 9
2. Petricola. „ 13
3. Venerirupis. „ 8
8. _Nymphacea._ Ten genera.
1. Sanguinolaria. Species 9
2. Psammobia. „ 21
3. Psammotea. „ 7
4. Tellina. „ 68
5. Tellinides. „ 2
6. Corbis. „ 2
7. Lucina. „ 26
8. Donax. „ 31
9. Capsa. „ 3
10. Crassina. „ 1
9. _Conchacea._ Seven genera.
1. Cyprina. Species 2
2. Cytherea. „ 83
3. Venus. „ 100
4. Veniricardia. „ 5
5. Cyclas. „ 15
6. Cyrena. „ 10
7. Galathea. „ 1
10. _Cardiacea._ Five genera.
1. Cardium. Species 57
2. Cardita. „ 23
3. Cypricardia. „ 5
4. Hiatelia. „ 2
5. Isocardia. „ 4
11. _Arcacea._ Four genera.
1. Arca. Species 41
2. Cucullæa. „ 1
3. Pectunculus. „ 22
4. Nucula. „ 45
12. _Trigonacea._ Two genera.
1. Trigonia. Species 1
2. Castalia. „ 1
13. _Naiadea._ Four genera.
1. Unio. Species 167
2. Hyria. „ 2
3. Anodonta. „ 49
4. Iridina. „ 6
14. _Chamacea._ Three genera.
1. Diceras. Species 1
2. Chama. „ 18
3. Etheria. „ 5
15. _Tridacnea._ Two genera.
1. Tridacna. Species 7
2. Hippopus. „ 1
16. _Mytilacea._ Three genera.
1. Mytilus. Species 42
2. Modiola. „ 32
3. Pinna. „ 15
17. _Mallacea._ Five genera.
1. Crenatula. Species 7
2. Perna. „ 10
3. Malleus. „ 6
4. Avicula. „ 19
5. Meleagrina. „ 2
18. _Pectinea._ Seven genera.
1. Pedum. Species 1
2. Lima. „ 6
3. Pecten. „ 62
4. Plagiostoma. „ 10
5. Plicatula. „ 5
6. Spondylus. „ 21
7. Podopsis. „ 2
19. _Ostracea._ Six genera.
1. Ostrea. Species 49
2. Gryphea. „ 1
3. Vulsella. „ 6
4. Placuna. „ 3
5. Anomia. „ 9
6. Crania. „ 1
20. _Brachiopoda._ Three gen.
1. Orbicula. Species 1
2. Terebratula. „ 13
3. Lingula. „ 1
CLASS IV.
MOLLUSCA.
TWENTY-THREE FAMILIES.
1. _Pteropoda._ Six genera.
1. Hyalea. Species 2
2. Clio. „ 2
3. Cleodora. „ 2
4. Limnacina. „ 1
5. Cymbulia. „ 1
6. Pneumodermon „ 1
2. _Phyllidiacea._ Six genera.
1. Phyllidia. Species 3
2. Chitonellus. „ 2
3. Chiton. „ 63
4. Patella. „ 49
5. Umbrella. „ 2
6. Pleurobranchus. „ 2
3. _Calyptracea._ Seven gen.
1. Parmophorus. Species 4
2. Emarginula. „ 5
3. Fissurella. „ 22
4. Pileopsis. „ 9
5. Calyptrea. „ 9
6. Crepidula. „ 13
7. Ancylus. „ 5
4. _Bullacea._ Three genera.
1. Acera. Species 1
2. Bullæa. „ 2
3. Bulla. „ 19
5. _Aplysiacea._ Two genera.
1. Dolabella. Species 2
2. Aplysia. „ 37
6. _Limacina._ Five genera.
1. Limax. Species 5
2. Vitrina. „ 3
3. Testacella. „ 2
4. Parmacella. „ 2
5. Onchidium. „ 2
7. _Colimacea._ Eleven genera.
1. Helix. Species 203
2. Carocolla. „ 22
3. Achatina. „ 24
4. Anostoma. „ 3
5. Helicina. „ 19
6. Pupa. „ 40
7. Clausilia. „ 15
8. Bulimus. „ 63
9. Succinea. „ 7
10. Auricula. „ 16
11. Cyclostoma. „ 38
8. _Lymnacea._ Three genera.
1. Lymnea. Species 33
2. Physa. „ 10
3. Planorbis. „ 22
9. _Melaniana._ Three genera.
1. Melania. Species 54
2. Pirena. „ 6
3. Melanopsis. „ 3
10. _Peristomiana._ Three gen.
1. Valvata. Species 3
2. Paludina. „ 31
3. Ampularia. „ 13
11. _Neritacea._ Four genera.
1. Neritina. Species 27
2. Nerita. „ 20
3. Navicella. „ 4
4. Natica. „ 36
12. _Ianthinea._ One genus.
1. Ianthina. Species 3
13. _Macrostomiana._ Four gen.
1. Sigaretus. Species 6
2. Stomatella. „ 5
3. Stomatia. „ 2
4. Haliotis. „ 19
14. _Plicacea._ Two genera.
1. Tornatella. Species 6
2. Pyramidella. „ 6
15. _Scalarina._ Three genera.
1. Scalaria. Species 14
2. Vermetus. „ 2
3. Delphinula. „ 5
16. _Turbinacea._ Eight gen.
1. Solarium. Species 7
2. Trochus. „ 99
3. Monodonta. „ 34
4. Turbo. „ 51
5. Planaxis. „ 4
6. Phasianella. „ 12
7. Turritella. „ 21
8. Rotella. „ 7
17. _Canalifera._ Eleven gen.
1. Cerithium. Species 45
2. Pleurotoma. „ 29
3. Turbinella. „ 23
4. Cancellaria. „ 49
5. Fasciolaria. „ 8
6. Fusus. „ 46
7. Pyrula. „ 29
8. Struthiolaria. Species 2
9. Ranella. „ 15
10. Murex. „ 73
11. Triton. „ 31
18. _Alata._ Three genera.
1. Rostellaria. Species 4
2. Pterecera. „ 7
3. Strombus. „ 32
19. _Purpurifera._ Eleven gen.
1. Cassidaria. Species 5
2. Cassis. „ 25
3. Ricinula. „ 9
4. Purpura. „ 62
5. Monoceros. „ 5
6. Concholepas. „ 1
7. Harpa. „ 9
8. Dolium. „ 7
9. Buccinum. „ 66
10. Eburna. „ 5
11. Terebra. „ 24
20. _Columellaria._ Five genera.
1. Columbella. Species 20
2. Mitra. „ 80
3. Voluta. „ 44
4. Marginellæ. „ 24
5. Volvaria. „ 7
21. _Convoluta._ Six genera.
1. Cypræa. Species 118
2. Ovula. „ 12
3. Terebellum. „ 3
4. Ancillaria. „ 4
5. Oliva. „ 63
6. Conus. „ 181
22. _Nautilacea._ Two genera.
1. Spirula. Species 1
2. Nautilus. „ 2
23. _Heteropoda._ Two genera.
1. Argonauta. Species 3
2. Carinaria. „ 3
The American species are designated by a *.
[Illustration:
_Pl. 1._
_Parts of Shells_
_P.S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 2._
_Parts of Shells._
_P.S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 3._
_Parts of Shells._
_P.S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 4._
_Hinges of Shells._
_P.S. Duval. Lith. Phil^a._
]
[Illustration:
_Pl. 5._
_1. Siliquaria, 2 Dentalium, 3 Pectinaria, 4 Sabellaria, 5 Terebella,
6. Amphitrite, 7 Spirorbis, 8 Serpula, 9 Vermilia, 10 Galeolaria,
11. Magilus, 12. Tubicinella, 13. Coronula, 14. Balanus, 15 Acasta,
16 Creusia, 17 Pyrgoma, 18 Anatifera, 19 Pollicipes, 20 Cineras, 21.
Otion, 22 Aspergillum._
_P.S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 6._
_1 Clavagella, 2 Fistulana, 3 Septaria, 4 Teredina, 5 Teredo, 6
Pholas, 7 Gastrochæna, 8 Solen 9 Panopea, 10. Solecurtus, 11.
Glycimeris 12 Mya, 13. Anatina, 14 Lutraria, 15 Mactra, 16.
Crassatella, 17 Erycina, 18 Ungulina, 19 Solenimya, 20 Amphidesma,
21 Corbula, 22 Pandora, 23 Saxicava._
_P.S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 7._
_1. Petricola 2 Venerirupis 3. Sanguinolaria, 4. Psammobia, 5.
Psammotea, 6. Tellina, 7. Tellinides, 8. Corbis, 9. Lucina, 10.
Donax, 11. Capsa, 12. Crassina, 13. Cyclas, 14. Cyrena, 15.
Galathea, 16. Cyprina, 17. Cytherea, 18. Venus, 19. Venericardia,
20. Cardium, 21. Cardita, 22. Cypricardia, 23. Hiatella._
_P.S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 8._
_1. Isocardia, 2. Cucullea, 3 Arca, 4. Pectuncules 5 Nucula, 6.
Trigonia, 7 Castalia, 8. Unio, 9. Hyria, 10. Anodonta, 11. Iridina,
12 Diceras, 13. Chama, 14. Etheria, 15 Tridacna, 16 Hippopus 17.
Mytilus, 18. Modiola, 19 Pinna, 20. Crenatula, 21. Perna, 22.
Malleus._
_P. S. Duval. Lith. Phil^a._
]
[Illustration:
_Pl. 9._
_1. Avicula, 2 Meleagrina, 3 Pedum, 4 Lima, 5 Pecten, 6 Plagiostoma 7.
Plicatula, 8 Spondylus, 9 Gryphea, 10 Ostrea, 11. Vulsella, 12
Placuna, 13 Anomia, 14 Crania, 15 Orbicula, 16 Terebratula, 17
Lingula, 18 Hyalea, 19 Cleodora, 20 Limacina, 21 Cymbulia, 22
Chitonellus, 23 Chiton, 24 Patella, 25 Pleurobranchus, 26 Umbrella,
27 Parmophorus, 28 Emurginula, 29 Fissurella._
_P. S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 10._
_1 Pileopsis, 2 Calyptera, 3 Crepidula, 4 Ancylus, 5 Bullæa, 6 Bulla,
7 Aplysia, 8 Dolabella, 9 Parmacella, 10 Limax, 11 Testacella, 12
Vitrina, 13 Helix, 14 Carocolla, 15 Anostoma, 16 Helicina, 17 Pupa,
18 Clausilia, 19 Bulimus, 20 Achalina, 21 Succinea, 22 Auricula, 23
Cyclostoma 24 Planorbis, 25 Physa, 26 Lymnea, 27 Melania, 28
Melanospsis, 29 Pirena, 30 Valvata, 31 Paludina, 32 Ampularia, 33
Neritina, 34 Navicella, 35 Nerita._
_P. S. Duval, Lith. Phil^a._
]
[Illustration:
_Pl. 11._
_1 Natica, 2 Janthina, 3 Sigaretus, 4 Stomalella, 5 Stomatia, 6
Haliotis, 7 Tornatella, 8 Pyramidella, 9 Vermetus, 10 Scalaria, 11
Delphinula 12 Solarium, 13 Rotella, 14 Trochus, 15 Monodonata, 16
Turbo, 17 Planaxis, 18 Phasianella, 19 Turritella, 20 Cerithium 21
Pleurotoma, 22 Turbinella, 23 Cancillaria, 24 Fasciolaria, 25 Fusus,
26 Pyrula, 27 Struthiolaria, 28 Ranella, 29 Murex, 30 Triton, 31
Rostellaria._
_P. S. Duval Lith. Phil^a._
]
[Illustration:
_Pl. 12._
_1 Pteroceras, 2 Strombas, 3 Cassidaria, 4 Cassis, 5 Ricinula, 6
Purpura, 7. Monoceros, 8 Concholepas, 9 Harpa 10 Dolium, 11 Buccinum
12 Eburna, 13 Terebra, 14 Columbella, 15 Mitra, 16 Voluta 17
Marginella 18 Volvaria, 19 Ovula, 20 Cyprea, 21 Terebellum, 22
Ancillaria, 23 Olivia, 24 Conus, 25 Spirula, 26 Nautilus 27
Argonauta, 28 Carinaria._
_P. S. Duval, Lith. Phil^a._
]
CONCHOLOGY.
CLASS I.
ANNULATA.
Animal soft, elongated, vermiform, naked or inhabiting a tube, which it
never entirely quits; the body furnished either with segments or
transverse wrinkles; often without a head, eyes or antennæ; without
articulated feet, but most of them having in their place bristly,
retractile knobs, disposed in lateral rows: mouth subterminal, either
simple, orbicular, with lips, or in the form of a proboscis; often with
jaws, a knotted longitudinal medulla, and nerves for sensation and
motion; the blood red, circulating by means of arteries and veins:
respiration by external or internal branchiæ, which are sometimes
imperceptible. _Four Families._
FAMILY I.
DORSALIA. Two Genera.
1. Genus _Arenicola_.
_Animal._ The gills, or respiratory organs dorsal, or disposed
lengthways on the body.
_Shell._ Supposed to be tubular. One species.
Arenicola piscatorium.
2. Genus _Siliquaria_. Pl. V.
_Animal._ See Arenicola.
Shell very thin, conical, tubular, involuted in a spiral manner, loosely
and irregularly; aperture circular, sharp edges, interrupted in the
middle by a notch, extending like a slit through the greater portion of
its length, and stopping abruptly at some distance from the summit.
Inhabits the Indian seas. Eight species.
Siliquaria anguina.
S. muricata.
S. lævigata.
S. lactæa.
S. rugosa.
S. terebella.
S. lima.
S. spinosa.
FAMILY II.
MALDANIA. Two Genera.
1. Genus _Clymene_.
_Animal._ Respiratory organs not determined, supposed to be at the
posterior part of the body.
_Shell._ Tube thin and slender, open at both ends, encrusted externally
with sand and fragments of shells. One species.
Clymene amphistoma.
2. Genus _Dentalium_. Pl. V.
_Animal._ Body elongated, conical, sub-vermiform, enveloped in a fistula
mantle as far as the anterior third, and ending in a bourrelet pierced
in its middle by an orifice with fringed edges; foot altogether
anterior, proboscidiform, terminated by a conical appendage, contained
in a kind of cup with festooned edges; head distinct, oval, with a
terminal mouth in the middle of a digitated lip; a pair of lateral jaws,
formed each of two little oval shells garnished with points.
_Shell._ Tubular, regular, symmetrical, slightly curved longitudinally,
tapering gradually to the rear, and opening in a round orifice at each
end. Inhabits the British seas. Twenty-one species.
Dentalium elephantinum.
D. aprinum.
D. sulcatum.
D. fasciatum.
D. pseudo-antalis.
D. radicula.
D. antalis.
D. arictinum.
D. octogonum.
D. deforme.
D. novemcostatum.
D. sexangulaire.
D. striatum.
D. dentalis.
D. corneum.
D. nigrum.
D. politum.
D. eburneum.
D. clava.
D. fissura.
D. coarctatum.
FAMILY III.
AMPHITRITÆA. Four Genera.
1. Genus _Pectinaria_. Pl. V.
_Animal._ Respiratory organs in general known, and disposed at or near
the anterior part of the body; not separated or covered by an operculum.
_Shell._ A membranous papyraceous tube in the form of a reversed cone;
unfixed; exterior covered with sandy adhesions. Two species.
Pectinaria capensis.
P. belgica.*
2. Genus _Sabellaria_. Pl. V.
_Animal._ But slightly differing from the Pectinaria.
_Shell._ Tubes numerous, united in a common mass, composed of
agglutinated particles of marine substances, cellular at the base;
orifice expanded. Found in the Indian Ocean. Two species.
Sabellaria alveolata.
S. crassissima.
3. Genus _Terebella_. Pl. V.
_Animal._ Body tubicular, elongated, cylindrically depressed, attenuated
posteriorly; a row of nodulous and setiferous papillæ on each side;
numerous filiform, twisted tentacula surrounding the mouth.
_Shell._ An elongated cylindrical and membranous tube with lash-like
appendages at the end; covered with adhesions of sand and shells.
Inhabits the coast of New Holland. Four species.
Terebella conchilega.
T. ventricosa.
T. cristata.
T. vermicuta.
4. Genus _Amphitrite_. Pl. V.
_Animal._ Body tubicular, elongated, cylindrical, attenuated behind with
many annulated segments.
_Shell._ An elongated cylindrical tube growing thinner towards the base,
of a tough membranous texture, and generally without adhesions.
Mediterranean sea. Seven species.