A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖
- Author: George Brettingham Sowerby
Book online «A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖». Author George Brettingham Sowerby
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:--
MITRA. Elongated; aperture narrow; strong folds on the
columella; including _Mitrella_, _Mitreola_, _Tiara_, and
_Conohelix_. Fig. 431, 432.
MARGINELLA. Outer lip reflected; including _Volutella_,
_Persicula_, _Gibberula_, and _Glabella_. Fig. 437.
COLUMBELLA. Outer and inner lips denticulated or granulated.
Fig. 430.
VOLUTA. Outer lip thickened; folds on the columella; aperture
generally wide; apex papillary; including _Scaphella_, _Harpula_,
_Volutilithes_, _Cymbiola_. Fig. 433, 436.
MELO. Shell comparatively light; spire short, sometimes hidden;
apex round, spiral; folds on the columella laminar. Fig. 435.
CYMBA. Upper edge of the aperture separated from the body whorl
by a flat disc; apex mammillated, irregular; folds on the
columella. Fig. 434.
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._
CYRENELLA. Three cardinal teeth; ligament long; shell thin. Fig.
114.
CYCLAS. Thin, oval; cardinal and lateral teeth; anterior side
shortest, including _Pera_.
PISIDIUM. The same, with the posterior side shortest. Fig. 112.
CYRENA. Thick; cardinal and lateral teeth. Fig. 113.
POTAMOPHILA. Two thick cardinal teeth. Fig 115.
_Marine._
CYPRINA. Two cardinal teeth, and one remote lateral tooth. Fig.
116.
VENUS. Three cardinal, no lateral teeth; including _Artemis_.
Fig. 118, 119, 119a.
CYTHEREA. Several cardinal teeth; one very short lateral tooth.
Fig. 117, 117_a_, 117_b_, 117_c_, 117d.
PULLASTRA. Cardinal teeth notched, otherwise like Venus. Fig.
120.
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.
Comments (0)