A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖
- Author: George Brettingham Sowerby
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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:--
CYPRÆA. Lips thickened, inflected, with teeth; spire hidden,
including _Cypræovulum_, _Luponia_, _Trivia_. Fig. 444 to 450.
OVULUM. Lips thickened, inflected, with slight crenulations;
spire hidden. Fig. 440 to 443.
ERATO. Lips thickened, inflected; spire visible; a groove down
the back. Fig. 454.
TEREBELLUM. Cylindrical, open at the anterior extremity;
columella smooth; suture of the spire canaliculated. Fig. 451, 452.
OLIVA. Columella plaited, swelled into a varix at the anterior.
Fig. 457, 458.
ANCILLARIA. The same, but the suture of the spire covered with
enamel. Fig. 455, 456.
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--
CORBULA, with a prominent curved tooth. The Fresh-water species
has been separated under the name _Potamomya_. Fig. 89.
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.
CORONULA. (_Corona_, a crown, dim.) _Order_, Sessile Cirripedes, Lam.
_Fam._ Balanidea, Bl.--_Descr._ Six radiated valves, joined side by
side in a circle, forming a depressed cone; internal structure of the
valves, porous or chambered; thickened at the base; operculum
consisting of four valves in pairs; imbedded horizontally in a
cartilaginous substance.--_Obs._ The shells composing this genus are
found partly imbedded in the skin of whales, and the shells of
tortoises, and are therefore destitute of the shelly foundation on
which the Balani and other Coronular Multivalves are supported. C.
Testudinaria, (CHELONOBIA, Leach,) fig. 15. C. Balænarum, (CETOPIRUS,
Ranz.) fig. 16. C. Diadema, (DIADEMA, Ranz.) fig. 17.
CORONULAR MULTIVALVES are those which have their parietal valves joined
together side by side in a circle, surrounding the body of the animal,
so as to form a sort of coronet. This is the characteristic of the
Sessile Cirripedes of Lamarck's system, the Balanidea of De Blainville.
CORRODED. (_Corrodo_, eat away, consume.) The umbones, apices, and
other thick parts of shells, are frequently worn away or consumed by
the action of the element in which they exist. As the thickest parts of
some shells are the most subject to this operation, it appears to the
author to arise from the outer surface of the shell, being less under
the influence of the animal juices than the other parts; and therefore,
more exposed to the influence of the surrounding element. This,
however, is not the case with respect to the Nayades and other
fresh-water shells; with these, corrosion does not take place until
after the thick epidermis which covers them, becomes wounded by some
means or other, and then the animal thickens its shell within as fast
as it is corroded without.
CORTALUS. Montf. (Conch. Syst. 1. 115.) A genus of microscopic
Foraminifera, placed by De Blainville in a division of the genus
Rotalites.
COSTATED. Ribbed, as Cardium Angulatum, fig. 123.
COSTELLARIA. A sub-genus of the genus Tiara, Sw. (Mitra.) C. rigida.
Swainson, Zool. Ill. 1st series, pl. 29.
COWRY. A common name for shells of the genus Cypræa.
CRANIA. (_Cranium_, a skull.) _Fam._ Rudistes, Lam. _Order_,
Pallio-branchiata, Bl.--_Descr._ Inequivalve, equilateral, irregular,
sub-quadrate; upper valve patelliform, conical, with the umbo near the
centre; lower valve attached by its outer surface; muscular
impressions, 4 in each valve; two large, posterior, distant; two small,
near to each other, central. No hinge teeth; no ligament.--_Obs._ This
genus properly belongs to the Brachiopoda, Lam. It differs from
Orbicula in the mode of attachment, which in the latter, is by a byssus
passing through the lower valve, and not by the valve itself. Hipponyx
has only two muscular impressions in each valve. The name of this genus
is derived from the inner surface of the attached valve, which presents
a remarkable resemblance to the facial portion of a human skull. This
appearance is caused by the situation and elevated edges of the
muscular impressions. Fig. 197. Coasts of Britain and Mediterranean.
CRASSATED. (_Crassus_, thick.) Used to express a thickness in the
substance of a shell. _Ex._ Glycimeris, fig. 67.
CRASSATELLA. Lam. (_Crassus_, thick.) _Fam._ Mactracea, Lam. Conchacea,
Bl.--_Descr._ Equivalve, inequilateral, close, thick, rounded
anteriorly, rostrated posteriorly, with denticulated margins, smooth,
or ribbed transversely; hinge with a triangular pit containing the
cartilage, two anterior cardinal teeth, and a posterior depression in
one valve; one anterior tooth and a slight anterior marginal elevation,
and a posterior elevation in the other valve. Muscular impressions
distant, strongly marked. Palleal impression not sinuated.--_Obs._ The
few recent species known are marine, several being brought from the
coasts of New Holland. Fossil species are found in Calcaire-grossier
and London clay. The Crassatella are known from the Veneres, &c., by
the ligamentary pit in the hinge, and from Lutraria and Mactra by the
thickness and closeness of the shell. Fig. 84, C. rostrata.
CRASSINA. Lam. ASTARTE, Sow.
CRASSIPEDES. Lam. (_Crassus_, thick; _pes_, foot.) The first section of
the order Conchifera Dimyaria, Lam. In this section the foot of the
animal is thick, and the shell gapes considerably. It is divided into
the families Tubicolæ, Pholadidæ, Solenidæ, and Myaria. Fig. 44 to 76.
CRASSISPIRA. Sw. A genus separated from COLUMBELLA, Auct. for which Mr.
Swainson quotes "Pleurotoma Bottæ, Auct." Crassispira fasciata, Sw.
Lardn. Cyclop. Malac. p. 313.
CRENATED. (_Crena_, a notch.) Applied to small notches, not
sufficiently raised or defined, to be compared to teeth. _Ex._ The
hinge of Iridina, fig. 150.
CRENATULA. Lam. _Fam._ Malleacea, Lam. Margaritacea, Bl.--_Descr._
Compressed, foliated, irregular, sub-equivalve, inequilateral, oblique;
umbones terminal; hinge linear, nearly straight, with a series of
excavations, containing the cartilage, while the intervening ridges are
covered with the ligament, properly so called. Muscular impression
oblong, indistinct.--_Obs._ This genus is known from Perna by the
hinge, which in the latter is composed of a series of regular,
straight, ligamentary grooves placed across it. In Crenatula also there
is no passage for the byssus, as in Perna. C. Mytiloides, fig. 168.
Coasts of the Red Sea.
CRENULATED. Finely crenated or notched.
CREPIDULA. Lam. (_Crepidula_, a little slipper.) _Fam._ Calyptracea,
Lam. and Bl.--_Descr._ Oval, irregular, patelliform; apex lateral,
incurved, or sub-spiral; external surface convex, smooth, ribbed,
waved, or covered with spines; interior concave, smooth, with a
flattish septum reaching nearly half across the cavity; epidermis light
brown.--_Obs._ The difference between this genus and Calyptræa is that
in the latter, the septum is more free from the sides of the shell, so
that, instead of forming a regular plate, covering half the aperture,
it assumes a variety of shapes, and in some is cup-shaped, in others
forked, and in some forms a little angular shelf. Indeed, the
variations are so numerous that I think it would be better to throw the
two genera into one, and then divide them into smaller groups. Some
species of Calyptræa are farther removed from each other with respect
to the characters of the septum and general form of the shell, than
they are from the Crepidulæ. Fig. 239. Mediterranean, North and South
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