Chapter IV: Part 4

CANTHORBIS. Sw. A sub-genus of the sub-family Trochinæ, Sw. Described
as being "nearly disc-shaped: spire but slightly raised; the margin of
the body-whorl flattened, and serrated with flat spines; inner lip
united to the outer; pillar and aperture as in the last. (Tubicanthus.)
C. imperialis. Mart. 173. f. 1714." This sub-genus appears to include
those species of which De Montfort's genera Imperator and Calcar are
formed.

CANTHROPES. Montf. Described as resembling a Nautilus, with the whorls
increasing so gradually, that the dorsal edge of the aperture advances
but little beyond the last whorl. This genus is not mentioned by
Blainville or Lamarck.

CAPITULUM. Klein. POLLICIPES Mitellus, Lam. fig. 37*.

CAPRELLA. ----? PLEKOCHEILUS, Guild. AURICULA Caprella, Lam.

CAPRINA. D'Orb. DICERAS. Auct.?

CAPRINUS. Montf. (Conch. Syst. t. 2. p. 143.) The figure appears to be
intended to represent Helix Nux-denticulata.

CAPSA. Brug. _Fam._ Nymphacea, Lam.--_Descr._ Equivalve transverse,
subequilateral, subtrigonal; cardinal teeth, two in one valve, one
notched in the other; lateral teeth remote, obsolete; an external
ligament; two muscular impressions in each valve; a large sinus in the
muscular impression of the mantle.--_Obs._ This genus is so nearly
related to Donax, that it is difficult to distinguish it at first
sight. The Capsæ, however, have not the short, plain, straight,
posterior side, the distinct lateral teeth, nor the crenulated margins
which characterize nearly all the Donaces. They are found in the
British Channel, Brazil, and coast of Pacific Ocean. They are known
from Erycina by not having the pit in the hinge for the ligament. Fig.
109. C. Braziliensis.

CAPULUS. Montf. _Fam._ Calyptracea, Lam.--_Descr._ Obliquely conical,
posteriorly recurved; apex pointed, sub-spiral; aperture large,
rounded, oval; with two muscular impressions, lateral, meeting behind;
epidermis horny, rather velvetty. Britain, Mediterranean, West Indies,
California, Australia.

CARDIACEA. (Cardiacées, Lam.) A family of the order Conchifera
Dimyaria, Lam. Most of the genera of shells contained in this family
are included in the very extensive family of Conchacea, in the system
of De Blainville. They are described as having irregularly formed
cardinal teeth, generally accompanied by one or two elongated lateral
teeth. Most of the species are ventricose, and have regular radiating
ribs. This family contains the genera Cardium, Cardita, Cypricardia,
Hiatella, Isocardia, and others enumerated in the explanation of
figures 122 to 130. Their characters may be thus explained.

1. CARDIUM. Two cardinal and two lateral teeth in each valve,
including _Hemicardium_, _Papyridea_ and _Aphrodita_, in the last
of which the teeth are nearly obsolete. Fig. 122, 123, 123*, 123**.

2. VENERICARDIA. Two oblique cardinal teeth, one elongated;
including _Cardita_, which has the umbones nearly terminal.
_Pachymya_ may probably be included, but the hinge is not known.
Fig. 121, 124, and 130.

3. HIPPOPODIUM. One elongated cardinal tooth. Fig. 129.

4. MEGALODON. Hinge broad, septiform, with a large tooth in the
centre of one valve. Fig. 127.

5. ISOCARDIA. Teeth laminar; umbones spiral. Fig. 126.

6. CARDILIA. The same, with a septiform posterior laminar tooth.

7. HIPPAGUS. Shaped like Isocardia, without teeth. Fig. 128.

CARDILIA. Desh. _Fam._ Cardiacea, Lam. A genus formed for the reception
of Isocardia semi-sulcata, Lam. and a small fossil shell, which
Deshayes had formerly named Hemi-cyclonosta Michelini; thus described,
(translation) "shell oval, oblong, longitudinal, white, heart-shaped,
ventricose, with large prominent umbones; hinge with a small cardinal
tooth and a pit at the side; a spoon-shaped projection for the
reception of the internal ligament; anterior muscular impression
rounded, not deep; the posterior being upon a thin, horizontal lamina,
projecting in the anterior." Deshayes further remarks that although the
animal is unknown, the relations of the genus may be established by
means of the shell alone. Two families contain all the shells which
have the internal ligament inserted in a spoon-shaped projection; in
the one, that of the Anatinæ, the ligament is supported upon a little
bone, which is not soldered to the hinge; in the other, that of the
Mactraceæ, this little bone has no existence. In the former, all the
shells are inequivalve; in the latter equivalve. And M. Deshayes,
considering that the valves are equal, and that there is no separate
bone to the hinge, is of opinion that the genus ought to be placed near
the Lutrariæ, and not far from the Anatinæ. C. semisulcata, fig. 501,
2.

CARDINAL MARGIN. The edge of a bivalve shell on which the teeth is
placed.

CARDINAL TEETH. The teeth upon the hinge directly beneath the umbones
of a bivalve shell, as distinguished from the lateral teeth, which are
placed at a distance on each side. In Venus, fig. 119, the cardinal
teeth, are marked by the letter c.

CARDIOCARDITES. Bl. A genus separated from CARDITA, Auct. Thus
described (translation) "oval species, with the inferior margin nearly
straight, or a very little inflated, crenulated and completely closed.
_Ex._ La C. Ajar, Adans Seneg. pl. 16. fig. 2."

CARDISSA. _Sw._ A genus composed of those species of CARDIUM _Auct._
which are heart-shaped. _Ex._ C. dionæum, fig. 122. And C. Cardissa.

CARDITA. Brug. _Fam._ Cardiacea, _Lam._ Submytilacea, Bl.--_Descr._
Equivalve, inequilateral, ovate, subquadrate or oblong, marked
externally by ribs radiating from the umbones and terminating in a
crenulated margin on the inner surface; cardinal teeth in one valve,
one long, thick, oblique; another short, more straight; in the other
valve one long, oblique, thick. Muscular impressions two in each valve,
rather oval; palleal impression not sinuated.--_Obs._ This description
includes Lamarck's genus Venericardia, which, although consisting of
the more oblong species, is not considered sufficiently distinct to
justify the separation. Cypricardia is distinguished from this genus by
a remote lateral tooth. Mediterranean, Africa, East Indies, &c. Cardita
calyculata, fig. 124.

CARDIUM. Auct. _Fam._ Cardiacea, Lam. Conchacea, Bl.--_Descr._
Equivalve, sub-equilateral, sometimes gaping posteriorly, ornamented on
the outside by ribs radiating from the umbones; cardinal teeth, two in
each valve, locked into each other crosswise, lateral teeth, two in
each valve, remote; muscular impressions, two in each valve; palleal
impression entire. Ligament external, inflated.--_Obs._ Although this
genus includes many remarkable forms, the characters are so easily
defined that there is no difficulty in distinguishing it from any other
genus. C. angulatum, fig. 123. C. Groenlandicum, fig. 123*. APHRODITA,
Lea. C. Hemicardium, fig. 123**. fig. 122. C. Dionæum. It is somewhat
surprising that this genus, which contains some of the most beautiful
forms of bivalve Testacea, should have been left till quite lately
without any attempt to revise the species and settle the synonyms. The
author of this Manual has endeavoured to remedy this defect by
publishing a catalogue of all the species hitherto known, which amount
to 97, including many new species described by him in the "Proceedings
of the Zoological Society," in 1840. Parts 46 to 51, 149 and 150, and
177 to 184 of his Conchological Illustrations contain figures of 60
species. Cardia are frequent in all climates.

CARINARIA. Auct. _Class_, Cephalopoda. _Division_, Monothalamia, Lam.
_Fam._ Nectopoda, Bl.--_Descr._ Symmetrical or nearly so, conical,
thin, glassy, fragile, patelliform; with a fimbriated dorsal keel; apex
convolute, bent forwards; aperture oval, pointed at the dorsal
extremity. _Hab._ Amboyna, Indian Ocean, and Mediterranean Sea.--_Obs._
A most singular and beautiful shell, remarkable for its transparency,
its fragile structure, and the dorsal keel, whence it derives its name.
It was once so rare that a single specimen was known to realize one
hundred guineas. Fig. 488. C. Mediterranea.

CARINATED. (From _Carina_, a keel.) Applied to any shell having a
raised, thin ledge, passing round a whorl or any other part of a shell,
as in Carinaria, fig. 488.

CARINEA. Sw. A genus formed for the reception of OVULUM gibbosum, Auct.
and similar species, fig. 443.

CARINELLA. Adanson. LUTRARIA papyracea, Lam. LIGULA, Leach. _Fam._
Mactracea, Lam. Fig. 77.

CARINIDEA. Sw. A sub-genus of the genus Canthorbis, Sw. (Turbo.) thus
described, "Imperforate; spire pyramidal, acute; basal whorl concave
beneath, and carinated round its circumference; aperture oval, entire,
slightly angulated at the base of the pillar, which turns inwards. C.
concavus, Martini, 168, fig. 1620, brevispinosus? Sow. Gen. (Turbo,)
fig. 1."

CAROCOLLA. Auct. _Fam._ Colimacea, Lam.--_Descr._ Orbicular, depressed,
with the outer sides of the whorls angulated or keeled, whorls few;
peritreme reflected; columella contiguous to the axis; epidermis
thin.--_Obs._ This genus differing from Helix only in the whorls being
angulated, is hardly distinct enough from the latter to justify the
separation. In De Ferrusac's system these species constitute the
division Helicigona, of the genus Helix. C. Lamarckii, fig. 277. East
and West Indies, Philippines, South America and Europe.

CARTILAGE. See LIGAMENT.

CARYCHIUM. Müll. _Fam._ Auriculacea, Bl. Colimacea, Lam.--_Descr._
Oblong or cylindrical, with gradually increasing whorls, few in number;
aperture straight, short, with a fold on the columella.--_Obs._ This
genus of minute land shells differs from Auricula chiefly in the soft
parts. De Furrusac enumerates three species, C. Lineatum, C.
Corticaria, (_Odostomia_, Flem.) and C. Minimum, fig. 301. De
Blainville places it in his genus Auricula, as "species with two folds
and a posterior tooth on the columella," giving a figure of A. Mysotis
as his example, and quoting the name Phitia, Gray. Europe.

CASSIDARIA. Lam. (From Cassis) _Fam._ Purpurifera, Lam. Entomostomata,
Bl.--_Descr._ Oval, ventricose, spirally grooved and tuberculated, with
a short turrited spire and a large aperture, terminating anteriorly in
a recurved canal; outer lip thickened, reflected, undulated or
denticulated; inner lip expanded over a part of the body whorl and the
columella, with part of its lower edge free.--_Obs._ The recent species
of this genus are not numerous; the few fossil species occur in the
tertiary strata. C. carinata is found in Calc-grossier and London Clay.
In general form this resembles CASSIS, but is at once distinguished by
the canal, which does not turn abruptly back, but is slightly curved
upwards. ONISCIA (C. Oniscus, &c. Lam.) is distinguished by the
shortness of the canal, and the granulated surface of the inner lip.
Fig. 407. C. Echinophora. Mediterranean.

CASSIDEA. Sw. (from Cassis.) A genus composed of those species of the
genus CASSIS, Auct. which have the "aperture wide; outer lip never
broad or flattened, but sometimes slightly inflected; inner lip
spreading, but never dilated or detached beyond the base into a
prominent rim." East Indies. Ex. C. Glauca, fig. 411.

CASSIDULA. Humph. PYRULA, Auct.

CASSIDULINA. D'Orbigny. A genus of microscopic Foraminifera.

CASSIS. (A helmet.) _Fam._ Purpurifera, Lam. Entomostomata,
Bl.--_Descr._ Oval or triangular, ventricose, thick, generally
tuberculated, with a short varicose spire; aperture long, sometimes
narrow, with the outer lip thickened and reflected, generally
denticulated; the inner lip spread over the surface of the body whorl,
indented and incrassated at its inner edge; canal turned suddenly over
the back of the shell. _Hab._ Seas of tropical climates. The fossil
species are rare, occurring in the tertiary strata.--_Obs._ The large,
common species of this well known genus are used for shell cameos and
as ornaments on chimney pieces, grottos, &c. and are remarkable for the
triangular disc, presented by the inner lip, which, in many species, is
thickened and spread over the front of the body whorl and the angulated
outer lip. The smaller, more rounded species, which have widened
apertures, have been separated by Swainson, under the generic name
CASSIDEA. The C. rufa, coarctata, &c. are formed by Mr. Stutchbury into
a new genus under the name CYPRÆCASSIS, for reasons which will be
stated under the word. Cassidaria is distinguished by the gradual curve
of the canal. Fig. 410 is Cassis tuberosa, diminished.

CASTALIA. Lam. _Fam._ Trigonées, Lam.--_Descr._ Fluviatile, equivalve,
inequilateral, trigonal, with corroded umbones; hinge with two laminar,
transversely striated teeth, one of which is posterior, remote from the
umbones, short, divided, the other anterior, elongated; epidermis
thick; internal surface pearly. Lamarck, in describing this shell,
states, that he regards it as intermediate between Trigonia and Unio.
It should, however, certainly have been placed in the family of
"Nayades," and perhaps should form a part of the genus UNIO itself. C.
ambigua, Lam. fig. 140. South America.

CATILLUS. Brong. (A little dish.) INOCERAMUS, Sow.

CATOPHRAGMUS. Sow. (From [Greek: Katô], _beneath_; [Greek: phragmos] _a
place_ _paled in_.) _Order_, Sessile Cirripedes, Lam.--_Descr._ Light
principal valves, cemented side by side in a circle; eight small
pointed valves beneath, covering the joints of the upper circle, and
numerous still smaller valves forming the base of the shell; operculum,
four valves.--_Obs._ This is the only genus of Sessile Cirripedes,
consisting of eight principal valves, excepting Octomeris, which is
destitute of the accessary pieces from which the genus derives its
name. Fig. 23. C. imbricatus. South Africa.

CAUDAL CANAL. The elongated hollow process which terminates the
aperture anteriorly of some univalve shells. For instance, Murex
Haustellum, fig. 396, has an elongated caudal canal.

CELLANTHUS. Montf. VORTICIALIS, Bl. A genus of microscopic
Foraminifera.

CELLULACEA. Bl. The second order of Cephalophora, Bl. consisting of
doubtful microscopic bodies, with a number of variously arranged
shells, as distinguished from the true Polythalamia, Bl. or chambered
shells. See FORAMINIFERA.

CEMORIA. Flemingii. Leach. A small patelliform shell, differing from
Fissurella, in having the fissure placed behind the apex, which is
produced, pointed and incurved. It is the Patella Fissurella, Müll.
Patella Noachina, Chemn. F. Noachina, Sow. Puncturella, Lowe. Fig. 244.
Cemoria Flemingii. Scotland and Tierra del Fuego.

CENTRAL. A term used to indicate the position of the muscular
impression of a bivalve shell when it is near the centre of the inner
surface. It is also applied to the siphon perforating the septum of a
chambered shell when it is placed near the centre of the plate.
_Sub_-central is also used as a comparative term, to indicate the
position of the siphon, or of the muscular impression, is _near_ the
centre. Thus in Placuna (fig. 184), the muscular impression is central:
in Exogyra (fig. 183), it is _sub_-central.

CEPA. Humph. ANOMIA, Linn.

CEPHALOPHORA. Bl. The first class of Malacozoæ, Bl. Divided into:
_Order_ 1. Cryptodibranchiata; 2. Cellulacea; 3. Polythalamacea. The
first consisting of Cuttle-fish, &c. which are destitute of shells; the
second composed of those microscopic cellular bodies, which are
regarded as shells by some authors; and the third containing the true
chambered shells.

CEPHALOPODA. Lam. (Cephalopodes.) ([Greek: Kephalê], _kephale_, head;
[Greek: pous], [Greek: podos], _podos_, foot.) The fourth order of the
_class_ Mollusca, Lam. containing molluscs, which are characterized by
having a series of arms surrounding the head, which is placed above a
sack-shaped body. This order is divided into Polythalamia, or
many-chambered shells; Monothalamia, or single-chambered cephalopods;
and Sepiaria, or cuttle-fish. Fig. 463 to 488.

CEPOLIS. Montf. Belonging to the genus HELIX, Auct.

CERATODES. Guild. ([Greek: Keratôdês], like a horn.) A genus composed
of the flat, orbicular species of AMPULLARIA, Auct. which present so
near a resemblance to the Planorbes, as to have been considered as
belonging to them. Planorbis has, however, a horny texture, and no
operculum, and it is always reversed, which may be observed by placing
the spire upwards. Fig. 320, represents Ampullaria (Ceratodes)
Cornu-arietis.

CERIPHASIA. Sw. A sub-genus of Melanianæ, thus described, "Cerithiform;
outer lip thin, dilated at the base; aperture small, slightly
emarginate, without any internal groove; inner lip thin. C. sulcata,
Sw. fig. 38. p. 204." (Sw. Lard. Cyclop. Malac. p. 342.)

CERITHIUM. Brug. _Fam._ Canalifera, Lam. Entomostomata, Bl.--_Desc._
Elongated, ribbed, tuberculated, or rarely smooth, with a lengthened,
turrited, pointed, pyramidal spire, consisting of numerous whorls;
aperture sub-quadrate, terminated anteriorly by a tortuous canal; outer
lip thickened, sometimes reflected, expanded; inner lip thickened
posteriorly; operculum horny, spiral, with numerous whorls.--_Obs._ The
fresh-water shells described as Cerithia by Lamarck, are separated
under the name Potamis, and may be known by the thick, horny epidermis.
Triphora, Desh. has the canal closed, except at the extremities.
Cerithium Telescopium, does not appear to present the same characters
as the other Cerithia, and has been separated by some writers under the
generic name Telescopium. Cerithium Aluco, fig. 372. Mediterranean,
East and West Indies, Coasts of the Pacific, Gallapagos, Australia, &c.
Some small species are British. Fossils are numerous in the tertiary
beds.

CERVICOBRANCHIATA. Bl. The second order of Paracephalophora
Hermaphrodita, Bl. containing symmetrical patelliform shells, divided
into the families Retifera and Branchifera.

CETOCIS. Montf. _Fam._ Orthocerata, Lam. and Bl. Placed by De
Blainville in his section of Belemnites, characterized as having small
folds at the apex. _Ex._ B. Penicillatus.

CETOPIRUS. Ranz. CORONULA BALÆNARIS, Auct. fig. 16.

CHAMA. Auct. _Fam._ Chamacea, Lam. and Bl.--_Descr._ Inequivalve,
irregular, thick, foliaceous, attached by the umbo of the lower and
larger valve. External ligament placed in a groove, following the curve
of the umbones. Umbones spiral, coiled round on the back of the valves;
hinge with a thick, crenated, lengthened tooth, in one valve, entering
a corresponding cavity in the hinge margin of the other; muscular
impressions, two in each valve, distinct, lateral.--_Obs._ The Linnæan
genus Chama, included the beautiful shells now called Tridacna. These
are exceedingly different from the true Chama, being regular and
unattached. The Chama (Tridacna) gigas, when at its full age and
development, is the largest shell known. Specimens have occurred
weighing upwards of 500 lbs., and measuring two feet across. Diceras
may be known from Chama by the spiral horns into which the umbones are
produced; Isocardia, by the regularity of the shells, and it is hardly
necessary to mention Spondylus, which may be known by the triangular
disc between the umbones; Cleidothærus, Stutch. which resembles Chama
in general form, has a separate bony appendage attached to the hinge,
and may, moreover, be distinguished by its elongated muscular
impression. Fig. 153, C. Lazarus. E. and W. Indies.

CHAMACEA. Bl. The seventh family of the order Lamellibranchiata, Bl.
containing the genera Chama, Diceras, Etheria, Tridacna, Isocardia and
Trigonia.

CHAMACEA. Lam. A family belonging to the order Conchifera Dimyaria,
Lam. described as inequivalve, attached, irregular; with or without a
single rough tooth on the hinge; with two lateral muscular impressions
in each valve. This family contains the genera--

1. CHAMA. Leafy; umbones spiral. Fig. 153.

2. ETHERIA. Very irregular, pearly, without teeth. Fig. 155.

3. DICERAS. Like Chama, but the umbones free, produced. Fig. 154.

CHAMBERED. When the cavity of a shell is not continuous, but is divided
by shelly diaphragms or septa, it is said to be chambered. This is the
case with the shells of the Polythalamous Cephalopoda, as in the
Nautilus (see Introduction). The character is not confined to these, as
it occurs in some species of Spondyli, and in several turrited
univalves.

CHAMOSTRÆA. De Roissy. CLEIDOTHÆRUS. Stutch.

CHARYBS. Montf. A genus of microscopic Foraminifera.

CHELIBS. Montf. A genus of microscopic Foraminifera.

CHELINOTUS. Sw. A genus of "HALIOTIDÆ," Sw. including Velutina, Lam. a
species of Sigaretus from Tonga, and Coriocella, Bl. Thus described,
"Animal cheloniform, broad; depressed; the mantle larger than the
shell, lobed in front; tentacula two, short, obtuse; eyes basal; mouth
circular; shell ear-shaped, thin, fragile, imperforate; pillar none."

CHELONOBIA. Leach. CORONULA Testudinaria, Auct. Fig. 15.

CHERSINA. Humph. ACHATINA, Lam.

CHICOREUS. Montf. A generic division of the genus MUREX, consisting of
such species as have three ramified varices. _Ex._ M. inflatus, fig.
395.

CHILINA. Gray. _Fam._ Auriculacea, Bl. Colimacea, Lam.--_Descr._ Oval,
thin, covered with an olive green epidermis; spire rather short,
consisting of few whorls; aperture large, oval, rounded anteriorly;
outer lip thin, joining the inner lip without a sinus; inner lip spread
over part of the body whorl, terminating in a thick columella with one
or two folds.--_Obs._ These shells differ from the true Auriculæ in the
thinness of the outer lip. C. Dombeyana (Auricula Dombeyana, Auct.)
Fig. 300. The illustrated catalogue published by the author (Sow.
Conch. illustr. parts 135, 136) contains 13 species. Rivers of South
America.

CHILOTREMA. Leach. A sub-genus of HELIX, containing Helix lapicida,
Auct. Gray, Turton, p. 140.

CHIMOTREMA. ----? Belongs to HELIX.

CHIONE. Megerle. CYTHERÆA maculosa, (fig. 117, c.) sulcata, circinata,
&c. Auct. and other similar species.

CHIRONA. Gray. A genus of Balanidæ, the shells consisting of six
parietal valves and two opercular valves; the upper edges of the
parietal valves are sloped and the structure is not tubular.

CHISMOBRANCHIATA. Bl. The second order of the first section of
Paracephalophora Monoica, Bl. Those Mollusca belonging to this order
which have shells, have them either internal or external, but always
scutiform, with depressed spires and wide, haliotoid, oblique
apertures, without a columellar lip properly so called. This order
partly answers to the family MACROSTOMATA, in the system of Lamarck. It
contains the genera Coriocella, Sigaretus, Cryptostoma, Oxinoe,
Stomatella and Velutina.

CHITON. Auct. ([Greek: chiton], an integument.) _Fam._ Phyllidiana,
Lam. _Class_, Polyplaniphora, Bl.--_Descr._ Oval, consisting of eight
arched valves arranged in a series across the body of the animal and
fixed in the skin which forms a rim around them, sometimes scaly,
spinose, or rugose, sometimes smooth.--_Obs._ The genus Chiton,
commonly called "Coat of Mail," from its resemblance to jointed armour,
remains to the present day in exactly the same state with regard to its
boundaries as that in which Linnæus found it, and in which he left it.
That illustrious Naturalist placed it among the multivalves in his
purely Conchological system, although the animal is totally different
from the Cirripedes. The shells are prettily marked, and are found
attached to the rocks in all seas of Tropical and Southern climates,
but fossil species are almost unknown. Fig. 227, C. Spinosus. The genus
is divided by Guilding into Chiton, Canthopleura, Phakellopleura,
Chitonellus and Cryptoconchus. Zool. Journ. XVII. p. 27. The author of
this manual has lately attempted a revision of this interesting but
neglected genus, and has given a catalogue of all the species hitherto
known, as far as they could be identified among the confused mass of
synonyms and descriptions to be found in the works of various
Conchological writers. This catalogue is to be found in his
Conchological Illustrations, and refers to figures of 102 species, 92
of which are contained in parts 38 to 45, and 159 to 176.

CHITONELLUS. Lam. (From _Chiton_) Separated by Lamarck from Chiton, on
account of the valves being placed at a greater distance from each
other, the soft integument of the animal intervening. Fig. 228, C.
striatus. Philippines.

CHLOROSTOMA. Sw. A sub-genus of "Trochinæ." Sw. (Trochus) of which C.
argyrostoma is given as an example. Sw. Lard. Cyclop. p. 350.

CHONDRUS. Hartmann. ABIDA, Leach. A genus formed for the reception of
PUPA secale, Drap. Pupa Juniperi, Montague, which have plaits in the
aperture.

CHRYSOAR. Montf. Probably a species of ORTHOCERAS.

CHRYSODOMUS. Swains. "Distinguished from Fusus, by the comparative
shortness of the basal channel, and the ventricose or enlarged shape of
the body whorl. The beautiful orange-mouthed Whelk of England is a
typical example; and the few others now known are all of a very large
size, and chiefly found in Northern Seas, where they represent the more
elegant Fusi of tropical latitudes; the outer lip is always thin and
smooth." Sw. page 90, paragraph 78, described at page 308.

CHRYSOLUS. Montf. POLYSTOMELLA, Bl. A genus of microscopic
Foraminifera.

CHRYSOSTOMA. Sw. A genus of the family "Rotellinæ," Sw. Thus described
"Shell turbinate; the whorls few and convex; aperture effuse, round;
inner lip thickened just over, and almost concealing the umbilicus.
Nicobaricus, Martini, 182 fig. 1822-5." Sw. Lard. Cyclop. Malac. p.
327.

CHTHALAMUS. Ranz. _Fam._ Balanidea, Bl. Order, Sessile Cirripedes,
Lam.--_Descr._ "Shell much depressed, valves thick, thickened at the
base, with prominent areas; operculum nearly horizontal, composed of
four valves."--_Obs._ This description would apply generically to the
shell called Platylepas in the British Museum, only nothing is said
about the prominent plates jutting from the internal surface of the
valves. The difference between this genus and BALANUS consists
principally in the horizontal position of the operculum, and general
flatness of the shell. C. stellatus, fig. 18.

CIBICIDES. Montf. A genus of microscopic Foraminifera.

CIDARIS. Swains. A genus composed of TURBO Smaragdus, petholatus, and
other similar species. The word Cidaris is, however, already in use for
a genus of Echinæ.

CIDAROLLUS. Montf. A genus of microscopic Foraminifera.

CILIATED. (ciliæ, hairs.) Having minute hairs as in Orbicula, Lingula,
&c. and the jointed feelers of the Cirripedes.

CIMBER. Montf. NAVICELLA, Auct.

CINERAS. Leach. (_Cinereus_, ash-coloured.) _Order_, Pedunculated
Cirripedes, Lam.--_Descr._ Animal with a quadrilateral body, supported
on a fleshy peduncle, with an opening in front of the upper part for
the passage of a bunch of ciliated tentacula. Immediately above this
aperture is a pair of small elongated valves, placed in a nearly
horizontal position; at the lower part is another tripartite pair
placed perpendicularly, one on each side, and a narrow, angulated,
keel-shaped piece placed at the back.--_Obs._ The nearest approach to
this genus is Otion. (C. Vittatus, fig. 42.) Found upon substances
floating in the sea.

CINEREOUS. (_Cinereus_) Ash-coloured.

CINGULA. Fleming. RISSOA, Leach.

CIONELLA. Jeffreys. _Fam._ Colimacea, Lam.--_Descr._ Oblong or
elongated; last whorl large; apex rather acute; columella,
sub-interrupted; aperture canaliculated, sub-effuse at the base;
margins very unequal; no umbilicus. BULINUS octonus, lubricus, acicula,
&c. Auct. C. lubrica, fig. 285.

CIRCE. Schum. VENUS castrensis, fig. 117 d. V. sulcatina, arabica,
pectinata, Auct. and other similar species.

CIRRIPEDES. Lam. The tenth class of invertebrated animals, so named
from the curled and ciliated branchia which protrude from the oval
aperture of the shells. The class Cirripedes of Lamarck constitutes the
entire genus _Lepas_ of Linnæus. They are divided into two sections;
first, Sessile Cirr. attached by the basal portion of the shell;
second, Pedunculated Cirr. supported upon a Peduncle. Figs. 14 to 45.

CIRROBRANCHIATA. Bl. The first order of Paracephalophora Hermaphrodita,
Bl. This order has been formed for the purpose of giving a place in the
system to the genus Dentalium. The animal of which has lungs,
consisting of numerous filaments, having their basal origin in two
radical lobes under the neck.

CIRRUS. J. Sowerby (cirrus, a tendril.) _Fam._ Turbinacea, Bl. and
Lam.--_Descr._ Spiral, conical, with a hollow axis; whorls contiguous,
numerous, rounded, or slightly angulated.--_Obs._ This fossil genus
resembles Trochus, from which it is known by the deep funnel-shaped
umbilicus. Fig. 349, C. nodosus.

CISTULA. Humph. CYCLOSTOMA, Lam.

CLANCULUS. Montf. TROCHUS _Pharaonis_, Lam.--_Obs._ This, with several
other species, belong more properly to MONODONTA, Lam. ODONTIS, Sow.
Fig. 361.

CLATHODON. Conrad. GNATHODON, Gray.

CLAUSILIA. Drap. (_Clausium_, a valve or folding door.) _Fam._
Colimacea, Lam. Limacinea, Bl.--_Descr._ Spire elongated, consisting of
many volutions; aperture small, sub quadrate, having several
tooth-shaped folds on the columella. A small, elastic, shelly plate,
attached to the columella within, called the Clausium, its office being
to enclose the aperture when the animal has retired within the
shell.--_Obs._ This last character distinguishes it from the Pupæ, to
some of which it bears a very near resemblance. _Hab._ Land, in the
central and southern parts of Europe, several British species. Fig.
295, C. Macascarensis.

CLAUSIUM. A name applied to the beautiful contrivance whence the genus
Clausilia derives its name, consisting of a little bony tortuous plate,
placed in a groove on the columella. Here it serves the purpose of a
door, which, when not prevented by counteracting pressure, springs
forward on its elastic ligament, and encloses the animal in his
retirement. The aperture is opened by pushing back the clausium into
the groove.

CLAUSULUS. Montf. Conch. Syst. 1, 179. A genus of microscopic
Foraminifera.

CLAVA. Humph. CERITHIUM, Lam.

CLAVAGELLA. Lam. (_Clava_, a club.) _Fam._ Tubicolæ, Lam. Pyloridea,
Bl.--_Descr._ Two irregular flattish valves, one fixed or soldered, so
as to form part of the side of an irregular shelly tube; the other free
within the tube near the base.--_Obs._ The shells composing this genus
are found in stones, madrepores, &c. and appear to form the connecting
link between Aspergillum, which has both valves cemented into the tube;
and Fistulana, in which both are free. Fig. 45, a fossil Clavagella.
Found recent on the Coast of Malta and New South Wales.

CLAVALITHES. Sw. A genus composed of some fossil shells, separated from
the genus Fusus, which, having the general form of Turbinella Rapa, &c.
are considered by Swainson, as holding an intermediate station between
Fusus and the Turbinellidæ.--_Descr._ "Unequally sub-fusiform; the body
whorl, and spire, being conic; and the canal suddenly contracted and
attenuated; terminal whorls papillary; inner lip thick; pillar smooth,
C. longævus, clavellatus, Noæ, ponderosus, Sw."--_Obs._ The papillary
spire may form a sufficient reason for separating this genus from
Fusus, while the absence of plates on the columella places them at a
still greater distance from Turbinella.

CLAVATE. When one extremity of the shell is attenuated, and the other
becomes suddenly ventricose or globular, it is said to be Clavate.
_Ex._ Murex Haustellum, fig. 396.

CLAVATULA. Lam. The generic name by which Lamarck originally
distinguished those species of Pleurotoma which were remarkable for the
shortness of their canals. In his system, however, they are re-united
to Pleurotoma. Fig. 381, P. Strombiformis.

CLAVICANTHA. Sw. A genus separated from Pleurotoma, Lam. consisting of
species, which are described as "thick, sub-fusiform; the surface
rugose, and the whorls sub-coronated; channel short; slit assuming the
form of a short, broad sinus. C. imperialis, E. M. 440, spirata, E. M.
440, fig. 5, conica, E. M. 439, fig. 9, echinata, E. M. 439, fig. 8,
Auriculifera, E. M. 439, fig. 10."

CLAVICLE. (_clavis_, a key.) A little key. This term is applied to the
bony appendage in the hinge of some species of Anatina, (those included
in the generic term Lyonsia) Cleidothærus, Myochama, &c.

CLAVULINA. D'Orb. A genus of microscopic Foraminifera.

CLAVUS. Montf. A genus of microscopic Foraminifera.

CLEIDOTHÆRUS. Hutch. ([Greek: Thairos], hinge, [Greek: Kleis],
clavicle.) _Fam._ Chamaceæ or Myariæ, Lam.--_Descr._ Inequivalve,
irregular, solid, attached; with one cardinal, conical tooth in the
free valve, entering a corresponding indenture in the other; and an
oblong shelly appendage, fixed by an internal cartilage in a groove
under the umbones; muscular impressions, two in each valve, one
elongated, the other uniform.--_Obs._ This shell is like Chama in
general form, but is distinguished by the clavicle or shelly appendage
from which its name is derived. Fig. 75. New South Wales.

CLEODORA. _Per. et Les. Fam._ Pteropoda, Lam. Thecosomata,
Bl.--_Descr._ Thin, transparent, pyramidal, with flat alate sides, and
oval aperture. Fig. 221, C. cuspidata.

CLISIPHONITES. Montf. Microscopic. LENTICULINA, Bl.

CLITHON. Montf. NERITINA Corona, spinosa, &c. Auct. fig. 325.

CLITIA. Leach. _Fam._ Balanidea, Bl. _Order_, Sessile Cirripedes,
Lam.--_Descr._ Sub-conical, compressed, consisting of four unequal
valves, two larger and two smaller, joined together side by side, by
the interlocking of their dentated edges, a process somewhat like that
which joiners call dove-tailing. Operculum, consisting of two unequal
pointed valves.--_Obs._ Clitia is known from Creusia, by the
articulations of the valves, and by the operculum, which in Creusia
consists of four valves. Fig. 20. C. Verruca, (Lepas Verruca, Gmelin.)
Britain and Peru.

CLOSE. The margins of a bivalve shell are described as being close,
when there is no hiatus between them in any part, otherwise they are
described as _gaping_.

CLOTHO. Faujas. _Fam._ Conchacea, Bl. More properly belonging to the
Pyloridea, Bl.; and the Lithophagidæ, Lam.--_Descr._ "Oval, nearly
regular, longitudinally striated, equivalve, sub-equilateral; hinge
consisting of a bifid tooth, curved like a crochet, larger in one valve
than in the other." This description is translated from Blainville, who
states that he has never seen the shell. Annales du Museum D'Histoire
Naturelle, tom. 9, pl. 17, fig. 4-6.

CLYPEIFORM. (_Clypeus_, a shield.) Open, flat, shaped like a shield or
buckler, as Umbrella, fig. 233, and Parmophorus, fig. 242.

CLYPIDELLA. Sw. A sub-genus of Fissurella, described as having one
extremity of the shell slightly raised. C. pustula. Sow. Gen. fig. 3.

COAT OF MAIL. A common name given to shells of the genus Chiton, on
account of their resemblance to jointed armour.

COBRESIA. Hübner. VITRINA, Auct.

COCHLIATE. (_Cochleare_, a spoon). Applied to any shell or part which
is hollow and oval, as Patellæ, &c. The cavity containing the cartilage
in Mya, fig. 71, is Cochleate.

COCHLICELLA. One of the sub-genera into which De Ferrusac has divided
the genus Helix, consisting of Bulinus decollatus, fig. 279, and
similar species. See Helix.

COCHLICOPA. Fer. A sub-genus of Helix, partly corresponding with
Polyphemus of De Montfort, and consisting of species of Achatina, which
have the outer lip undulated.

COCHLITOMA. Fer. A sub-genus of Helix, corresponding with the genus
Achatina, Auct. not including those with undulated outer lips.

COCHLODINA. Fer. A sub-genus of Helix, including the genus Clausilia,
Auct.

COCHLODONTA. Fer. A sub-genus of Helix, containing Pupa Uva, Auct. &c.

COCHLOGENA. Fer. A sub-genus of Helix, containing pupiform shells, such
as Azeca tridens, fig. 290.

COCHLOHYDRA. Fer. A sub-genus of Helix, composed of the genus Succinea,
Auct.

COCHLOSTYLA. Fer. A sub-genus of Helix, composed of the genus Bulinus,
Auct.

COLIMACEA. Lam. This Family, of the order Trachelipoda, Lam. includes
all land shells, which might with propriety be divided into three
sections, the first of which contain the following well-known genera:--

1. SUCCINEA. Oval, transparent, oblique; animal amphibious. Fig.
265, 266.

2. HELIX. The type of which is the common snail shell. The
separation of _Carocolla_, on account of the angulated whorls, or
that of _Geotrochus_, on account of the turbinated shape, cannot be
well maintained. Fig. 264, 267, 268, 273 to 276, 278 to 281, 294.

3. ANOSTOMA. The aperture turned up towards the spire. Fig. 271,
272.

4. STREPTAXIS. Whorls excentric. Fig. 269, 270.

5. BULINUS. Oval; aperture entire, including _Bulimulus_, _Balea_,
_Cionella_, _Azeca_. Fig. 282 to 285, 289, 290, 296.

6. ACHATINA. A notch terminating the columella. Fig. 286 to 288.

7. PUPA. Cylindrical; including _Vertigo_, _Alæa_, &c. Fig. 291 to
293.

8. CLAUSILIA. Cylindrical, with a clausium. Fig. 295.

_Obs._ The above are united in the system of De Ferrusac under the
generic name Helix, and divided into sub-genera as explained under
that word.

The next section, included in the family Auriculacea, Bl., contains
the genera Auricula, Chilina, Carychium, Marinula, Scarabæus, and
Partula. Fig. 297 to 302.

The third section contains the following genera of land shells with
opercula.

1. CYCLOSTOMA. Aperture round; operculum spiral. Fig. 303, 304.

2. NEMATURA. Last whorl contracted; operculum spiral. Fig. 305.

3. HELICINA. Aperture semi-lunar or angulated; operculum
concentric. Fig. 306, 307.

4. PUPINA. Shell polished; operculum concentric; aperture round.
Fig. 524.

5. STROPHOSTOMA. Aperture turned up towards the spire, like
Anostoma, but said to have an operculum. Only known fossil. Fig.
97.

COLUMBELLA. Auct. (Columba, a dove.) _Fam._ Columellata, Lam.--_Descr._
Thick, oval, or angular; with short spire, and long narrow aperture,
contracted in the centre, and terminating in a short canal; outer lip
thickened and dentated; inner lip irregularly crenated. Epidermis thin,
brown. Operculum very small, horny.--_Obs._ Those species of Mitra,
which resemble Columbella in shape, may easily be distinguished by the
plaits on the columella. The Columbellæ are marine, and few fossil
species are known. Fig. 430, C. Mercatoria. Swainson has divided this
genus into the following: _Columbella_, consisting of C. Mercatoria,
&c.; _Pusiostoma_, consisting of the Strombiform species;
_Crassispira_, which is most probably a Cerithium; _Nitidella_,
consisting of the smooth species; _Conidea_, consisting of the more
conical species; another set of the more conical species has been
removed from this family, and placed in that of the "Coninæ," but as
they are separated by no essential character, we suppose this has
merely been done for the purpose of completing the "circle" of the last
mentioned family, which otherwise would not have reached the required
number of five. Mediterranean, East and West Indies, South America,
Coast of California, Gallapagos, &c.

COLUMELLA. A solid column formed by the inner sides of the volutions of
a spiral univalve. It is sometimes described as the inner lip of the
aperture, of which it forms a part; but the term would be more properly
confined to that portion of the inner lip which is seen below the body
whorl, over which the remainder of the lip is frequently spread. All
the inner edge of the aperture, including that part of it which covers
the body whorl, is called the columellar lip. In fig. 431, the anterior
termination of the columella is indicated by the letter c. The axis, is
an imaginary line drawn strictly through the centre of the whorls,
whether their inner edges form a solid column or not.

COLUMELLAR LIP. The inner lip. See COLUMELLA.

COLUMELLATA. Lam. A family of the order Trachelipoda, Lam. containing
the following genera:--

1. MITRA. Elongated; aperture narrow; strong folds on the
columella; including _Mitrella_, _Mitreola_, _Tiara_, and
_Conohelix_. Fig. 431, 432.

2. MARGINELLA. Outer lip reflected; including _Volutella_,
_Persicula_, _Gibberula_, and _Glabella_. Fig. 437.

3. COLUMBELLA. Outer and inner lips denticulated or granulated.
Fig. 430.

4. VOLUTA. Outer lip thickened; folds on the columella; aperture
generally wide; apex papillary; including _Scaphella_, _Harpula_,
_Volutilithes_, _Cymbiola_. Fig. 433, 436.

5. MELO. Shell comparatively light; spire short, sometimes hidden;
apex round, spiral; folds on the columella laminar. Fig. 435.

6. CYMBA. Upper edge of the aperture separated from the body whorl
by a flat disc; apex mammillated, irregular; folds on the
columella. Fig. 434.

7. VOLVARIA. Cylindrical; aperture long, narrow; folds on the
columella; spire hidden. Fig. 439.

COLUS. Humphrey. FUSUS, Lam.

COMPLANARIA. Sw. A subgenus of ALASMODON (Unio), thus described, "shell
winged; the valves connate; the bosses very small and depressed;
cardinal teeth two or three; lateral teeth represented by irregular
grooves. C. gigas (Unio), Sow. Man. fig. 141. Alasmodon complanatus,
Say. C. rugosa, Sw."

COMPRESSED. Pressed together, or flattened. The application is the same
as in common use. A Patella may be described as a vertically compressed
cone. A Ranella, on account of the two rows of varices skirting the
whorls, appears, as it were, laterally compressed. A bivalve shell is
said to be compressed when it is flat, that is, when but a small cavity
is left in the deepest part when the valves are closed. Perhaps the
Placuna placenta, fig. 184, is the most remarkable instance of this.

CONCAMERATIONS. (_Con_, with, _camera_, a chamber.) A series of
Chambers joining each other, as in Nautilus, Spirula, &c.

CONCENTRIC. A term applied to the direction taken by the lines of
growth in spiral and other shells, (_longitudinal_ of some authors.)
Every fresh layer of shelly matter forms a new circle round an
imaginary line, drawn through the centre of the spiral cone, down from
the nucleus. When the edges of the successive layers are marked by any
external characters, the shell is said to be concentrically striated,
banded, grooved, costated, &c. A fine illustration of the latter is to
be seen in the Scalaria or Wentletrap, fig. 351, Lines, bands, ribs,
&c. in the opposite direction, (_transverse_ of some authors,) are
"radiating" in bivalves, as the ribs of Cardium, fig. 123, and "spiral"
in univalves, that is, following the direction of the whorls, as the
bands of colour in Pyramidella, fig. 342.

CONCHACEA. Bl. The eighth family of the order Lamellibranchiata, Bl.
The shells are described as follows: nearly always regular, valves
closed all round; apices curved towards the anterior; dorsal hinge
complete, with teeth and ligament; the latter external or internal,
short and thick; two distinct muscular impressions, united at the lower
part by a parallel impression, which is frequently sinuated at the
posterior. The genera described in this family are divided into three
sections. First, those which are regular, and have distant lateral
teeth, Cardium, Donax, Tellina, Lucina, Cyclas, Cyprina, Mactra, and
Erycina. Second, those which are regular, and have no distant lateral
teeth, Crassatella and Venus. Third, those which are irregular,
Venerupis, Coralliophaga, Clotho, Corbula, Sphænia, and Ungulina.

CONCHACEA. Lam. A family of Lamarck's order Conchifera Dimyaria.
Regular, unattached in general, closed at the sides. They are always
more or less inequilateral. The _Marine_ Conchacea are those which
inhabit the sea. The fluviatile Conchacea are those which are found in
rivers, ponds, &c. Each of these contain various genera, which may be
arranged as follows:--

_Fluviatile._

1. CYRENELLA. Three cardinal teeth; ligament long; shell thin. Fig.
114.

2. CYCLAS. Thin, oval; cardinal and lateral teeth; anterior side
shortest, including _Pera_.

3. PISIDIUM. The same, with the posterior side shortest. Fig. 112.

4. CYRENA. Thick; cardinal and lateral teeth. Fig. 113.

5. POTAMOPHILA. Two thick cardinal teeth. Fig 115.

_Marine._

1. CYPRINA. Two cardinal teeth, and one remote lateral tooth. Fig.
116.

2. VENUS. Three cardinal, no lateral teeth; including _Artemis_.
Fig. 118, 119, 119a.

3. CYTHEREA. Several cardinal teeth; one very short lateral tooth.
Fig. 117, 117_a_, 117_b_, 117_c_, 117d.

4. PULLASTRA. Cardinal teeth notched, otherwise like Venus. Fig.
120.

5. ASTARTE. Three cardinal teeth; ligament short. Fig. 110.

VENERICARDIA belongs to the Cardiacea.

CONCHIFERA. Lam. The 11th class of Invertebrata, consisting of all
those animals which have bivalve shells. Lamarck divides the class into
Dimyaria, which have two adductor muscles; and Monomyaria, which have
but one.

CONCHOLEPAS. Montf. (CONCHA, a shell; lepas, a stone or rock.) _Fam._
Purpurifera, Lam. Entomostomata, Bl.--_Descr._ Oval, imbricated, thick;
with a very short spire and large oval patelliform aperture,
terminating anteriorly in a slight emargination; outer lip crenated,
with two produced points or teeth towards the anterior, inner lip
smooth, nearly flat, reflected over the last whorl, so as nearly or
entirely to cover it; operculum horny. Marine, only one species known,
from Peru.--_Obs._ This shell is placed near Patella by Lamarck, on
account of its large open aperture; but having a horny operculum, and
resembling Purpurea in other respects. Fig. 418. Concholepas Peruviana.

CONCHOTRYA. Gray. (_Concha_, a shell; [Greek: Truo], (_tryo_) to bore.)
_Order_, Pedunculated Cirripedes, Lam.--_Descr._ Five pieces, two pairs
ventral, one single; shaped like Pentelasmis. Found in holes.

CONCHYLIOMORPHITE. A term used by De Blainville to designate the cast
or model of a fossil shell, formed by a siliceous substance which has
entered or surrounded it when in a liquid state, and subsequently
become hardened into flint. The shell has afterwards decomposed or
fallen off by accident, leaving its external or internal characters to
be conjectured from the monumental impressions that remain.

CONCHYTA. Hupsch Mus. CALCEOLA, Lam.

CONE. A common name for shells of the genus Conus.

CONE. This mathematical term is used by conchologists in its utmost
latitude of signification to express a body, which in its formation,
commences in a small point, called the apex, and increases in width
towards the conclusion or base. It is applied to all shells, whether
the increase in width be gradual or sudden; or whether in its growth,
it takes a straight, oblique, curved, or spirally-twisted course. In
this sense, a bivalve would be described as a pair of rapidly
enlarging, oblique cones, and the aperture of every spiral shell would
be its base. But this phraseology being in disuse, it is only mentioned
here that it may be understood when occasionally met with.

CONELLA. Sw. A genus composed of species of the genus Columbella, Lam.
which have a conical form, and which, on that account, are considered
by Swainson as belonging to his family of Coninæ. Swains. Lardner.
Cyclop. Malac. described at p. 312. C. picata, Sw. fig. 17, a. p. 151.

CONFLUENT. A term applied to two parts of a shell when they gradually
flow into each other, as, for instance, the inner and outer lips of
Univalves when they pass into each other at the anterior extremity,
without the intervention of a notch or angle.

CONIA. Leach. _Fam._ Balanidea. _Order_, Sessile Cirripedes,
Lam.--_Descr._ Four rather irregular valves, of porous structure,
placed side by side, so as to form a circular cone, supported at the
base on a shelly plate, and closed at the aperture by an operculum
consisting of four valves in pairs. Distinguished from Creusia by its
porous structure and by its flat support; that of Creusia being
cup-shaped. Fig. 21, Conia porosa.

CONICAL. A term applied in the ordinary sense, and not as explained
above, under the word CONE.

CONIDEA. Sw. A genus separated from Columbella, Lam. thus described,
"Mitra shaped, fusiform; spire equal or longer than the aperture; the
whorls tumid; outer lip slightly gibbous above, contracted below;
margin not inflected; striated within; inner lip terminating in an
elevated ridge, but with the teeth obsolete. C. semipunctata,
(_Columbella_, Lam.) Mart. 44. fig. 465, 466." Africa.

CONILITES. _Fam._ Orthocerata, Lam. & Bl.--_Descr._ "Conical, straight
or slightly curved; having a thin external covering, independent of the
nut or alveole, which it contains. Alveole transversely chambered,
sub-separable." (Translated from Lam.)--_Obs._ The difference between
Belemnites and Conilites is that the external sheath of the latter is
thin, and not filled up with solid matter, from the point of the
alveole to the apex, as in the former. De Blainville places in this
genus the genera Thalamulus, Achelois and Antimomus, Montf. two of
which are figured, Knor. Sup. Fab. iv. fig. 1. 1. 8. 9. Conilites
Pyramidatus, fig. 470.

CONILITHES. Sw. A sub-genus of Coronaxis, Sw. (Coni, with coronated
whorls) thus described, "Conic; spire considerably elevated; the
aperture linear, C. antediluvianus, Sow. Gen. f. 1."

CONOHELIX. Sw. (_Conus and Helix._) The generic name given to those
species of Mitra which are conical in form. Fig. 432, C. marmorata.

CONOPLÆA. Say. _Order_, Sessile Cirripedes, Lam. A genus composed of
Balani, attached to the stems of Gorgonia, having their bases
elongated. _Ex._ fig. 27, Balanus Galeatus.

CONORBIS. Sw. A genus composed of species of CONUS, such as C.
dormitor, (Sowerby, gen. fig. 8) which have elevated spires and the
upper part of the outer lip deeply sinuated. Mr. Swainson considers
these fossil species as analogous to the Pleurotomæ. _Sw._ Lard.
Cyclop. Malac. p. 312.

CONOVULUM. A genus proposed by Lamarck, to include the small, conical
species of Auricula, which have the outer lip simple. This genus was
afterwards abandoned by the author. _Ex._ fig. 298, Auricula
coniformis.

CONTIGUOUS. (_Contingo_, to touch.) A term applied to the whorls of
spiral shells when they rest upon, or touch each other. This is the
case in a great majority of instances. When, on the contrary, there is
a space between the whorls, they are said to be non-contiguous,
detached, or free. Examples of non-contiguous whorls are to be seen in
Scalaria, fig. 351 (in this case, the distance between the whorls is
small), and in Crioceratites, fig. 482. A "_Columella contiguous to the
axis_," is when in the centre of the shell and takes the place of the
imaginary line which forms its axis.

CONTINUOUS. Carried on without interruption, as the siphon in Spirula,
the varices in Ranella, fig. 394, which, occurring in a corresponding
part of each whorl, form a continuous ridge.

CONULARIA. Miller. A genus of Orthocerata, described as conical,
straight, or nearly so, divided into chambers by imperforate septa;
aperture half closed; apex solid, obtuse; external surface finely
striated. Resembling Orthoceras, but wanting the siphon. Fig. 449.

CONUS. Auct. ([Greek: Kônos], a cone.) _Fam._ Enroulées, Lam.
Angyostomata, Bl.--_Descr._ Conical, convolute, with a short spire,
consisting of numerous whorls; and narrow lengthened aperture,
terminating in a slight emargination at each extremity; outer lip thin;
epidermis thin; operculum small, pointed, horny.--_Obs._ This
well-known genus of shells is easily distinguished from any other, by
its conical form, its smooth columella, its narrow aperture, and thin
outer lip. The form of the spire varies from flat and even partially
concave, to a regular pyramidal cone; and the upper edges of the whorls
are rounded in some species, angulated in others, and in some are waved
or coronated. The variety of marking and the numerous delicate tints of
these shells have caused them to be highly appreciated by amateur
collectors; and many species, as the C. Ammiralis, or admiral; the C.
Gloria Maris, or Glory of the Sea; the C. Cedonulli ("I yield to
none"), and others, have always produced good prices in the markets. We
give figures of the principal forms, as expressed in the genera
proposed by De Montfort, of Rhombus, Hermes, Rollus and Cylinder, in
figures 459 to 462. Many new species were brought to this country by
Mr. Cuming, and are represented in parts 24, 25, 28, 29; 32, 33, 36,
37; 54, 55, 56, 57; 147, 148; 151 to 158 of the Conchological
Illustrations, by G. B. Sowerby, jun. See CORONAXIS, Swainson. The
cones are mostly tropical, some are found as far north as the
Mediterranean, and south as the Cape of Good Hope. The most beautiful
species are from the East and West Indies.

CONVOLUTÆ. (Enroulées, Lam.) A family of the 2nd section of the order
Trachelipoda, Lam. the genera of which may be distinguished as
follows:--

1. CYPRÆA. Lips thickened, inflected, with teeth; spire hidden,
including _Cypræovulum_, _Luponia_, _Trivia_. Fig. 444 to 450.

2. OVULUM. Lips thickened, inflected, with slight crenulations;
spire hidden. Fig. 440 to 443.

3. ERATO. Lips thickened, inflected; spire visible; a groove down
the back. Fig. 454.

4. TEREBELLUM. Cylindrical, open at the anterior extremity;
columella smooth; suture of the spire canaliculated. Fig. 451, 452.

5. OLIVA. Columella plaited, swelled into a varix at the anterior.
Fig. 457, 458.

6. ANCILLARIA. The same, but the suture of the spire covered with
enamel. Fig. 455, 456.

7. CONUS. Turbinated, numerous whorls; spire flat or short,
conical; columella smooth. Fig 459 to 462.

CONVOLUTE. (_Con_, together; _volvo_, to revolve). This term can be
strictly applied only to symmetrical shells, signifying that the
volutions are parallel to each other in a horizontal direction, as in
the Ammonites, &c.; but the term is also commonly used in describing
such shells as Conus, in which, the direction of the whorls being
scarcely oblique, the last whorl almost entirely covers those which
precede it. This is the case with Lamarck's family of Enroulées. Fig.
440 to 462.

CORALLIOPHAGA. Bl. CYPRICARDIA Coralliophaga, Lam.--_Descr._ Oval,
elongated, finely striated from the apex to the base, cylindrical,
equivalve, very inequilateral; umbones slightly raised and quite
anterior; hinge nearly the same in both valves; two small cardinal
teeth, one of which is bifid, placed before a kind of lammellated
tooth, beneath a very slender external ligament; two small, distant,
muscular impressions, united by a striated palleal impression, which is
strongly striated posteriorly.--_Obs._ This shell, which is found in
the empty holes of dead Lithodomi, in some instances conforming its
shape to its situation, differs from Cypricardia of Lamarck,
principally in its cylindrical form. C. Carditoidea, fig. 92.
Mediterranean and East Indies.

CORBICULA. Megerle. CYRENA, Lam.

CORBIS. Cuv. (_A basket._) _Fam._ Nymphacea, Lam.--_Descr._ Transverse,
oval, thick, ventricose, equivalve, sub-equilateral, free, cancellated,
with denticulated internal margins; hinge with two cardinal and two
lateral teeth in each valve; of the latter, one near and one remote
from the umbones; muscular impressions lunulate, two in each valve,
united by an entire palleal impression, without a sinus.--_Obs._ This
genus, of which only two or three recent species are known, resembles
many species of Venus and Cytherea in general form; but differs in
having lateral teeth, and in the palleal impressions which in all the
Veneres, &c. is sinuated. From Lucina it may be known, not only by its
oval form, but also by the muscular impressions, which, in Lucina are
produced into an elongated point; it will also be distinguished from
Tellina, by the want of a posterior fold in the valve, for which that
genus is remarkable. C. Fimbriata, fig. 101, is an inhabitant of the
Indian Ocean. Several fossil species are found in the recent
formations, above the chalk, at Grignon and Hauteville.

CORBULA. Brug. (_A little basket._) _Fam._ Corbulacea, Lam. Conchacea,
Bl.--_Descr._ Inequivalve, sub-equilateral, transverse, gibbose, not
gaping; cardinal tooth in each valve, conical, curved, prominent,
inserting its extremity into a pit in the opposite hinge; cartilage
attached to the tooth of the smaller valve, and the pit in the larger;
muscular impressions, two in each valve, distant, rather irregular;
palleal impression posteriorly angulated.--_Obs._ The shells composing
this genus were placed in Mya by Linnæus, but differ from the true Myæ
in having a sinus in the palleal impression, and a prominent
ligamentiferous tooth in each valve, whereas the Myæ have but one. The
Corbulæ are marine, some species inhabiting the British coasts. Fossil
species occur abundantly in green sand, London clay, crag, and
corresponding formations. Fig. 89. C. Nucleus.

CORBULACEA. (Corbulées, Lam.) A family of the order Conchifera
Dimyaria, Lam., containing the genera--

1. CORBULA, with a prominent curved tooth. The Fresh-water species
has been separated under the name _Potamomya_. Fig. 89.

2. PANDORA. Thin, pearly, no teeth. Fig. 90.

CORDIFORM. (_Cor_, a heart.) Heart-shaped, a term applied generally to
any shell which may be fancied to resemble a heart in shape, as
Isocardia, fig. 126, and Cardium Dionæum, fig. 122.

CORIACEOUS. (_Corium_, leather.) Of the substance of leather. _Ex._,
the integument into which the valves of Chitones are inserted.

CORIOCELLA. Bl. The animal designated by this name is described by De
Blainville as being without any traces of shell, either internal or
external. This must have arisen from the imperfection of the specimen
described, probably deprived by accident of its shell. The testaceous
appendage of the Coriocella is now well known to naturalists. It is a
milky white, transparent shell, shaped like Sigaretus.

CORNEA, and PISUM, Megerle. CYCLAS, Lam.

CORNEO-CALCAREOUS. A term used to express the mixture of horny and
shelly matter which enters into the composition of some shells,
Aplysia, for instance. It is also applied to those Opercula, which are
horny on one side, and testaceous on the other, as that of Turbo.

CORNEUS. Horny. A species of Patella has had the specific name corneus
given to it, because its texture more nearly resembles that of a horn
than that of a shell. The epidermis of fresh-water shells is of a
similar composition.

CORNUCOPIA. Humph. LEPAS, Linn.

CORONALES. See CORONULAR MULTIVALVES.

CORONATED. (_Corona_, a crown.) Applied to shells when ornamented with
a series of points, tubercles, &c., round the upper edges of the
volutions. _Ex._ Conus Nocturnus, fig. 459.

CORONAXIS. One of the two genera into which Swainson divides the genus
Conus, consisting of those species which have a row of tubercles on the
upper edge of the whorls, an arrangement by which he would in many
instances, not only separate between two individuals of the same
species, but also between two parts of the same shell; for instances
occur in which the earlier whorls are coronated, while the body whorl
and the penultimate are perfectly plain.