A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖
- Author: George Brettingham Sowerby
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whence the name is derived. _Loc._ New Holland, Java, New Zealand, Red
Sea. Fig. 44. Aspergillum Vaginiferum.
ASSIMINEA. Leach. _Fam._ Turbinacea, Lam.--_Descr._ Inclining to oval,
light, thin, covered with a horny epidermis, spire produced into an
acute pyramid; whorls slightly angulated in the centre, rounded
beneath; aperture elliptical, slightly modified by the last whorl;
inner lip planed; outer lip thin; operculum horny, subspiral. Found in
brackish water; one species may be procured abundantly on the muddy
shores of the Thames, in Kent. There are also species from Calcutta,
China, Tahiti, and Australia. Without comparing the animals, it is
difficult to distinguish this genus from some species of Littorina.
Fig. 363. A. Grayana.
ASTACOLUS. Montf. A genus of microscopic Foraminifera. CRISTELLARIA
Crepidula, Lam.
ASTARTE J. Sowerby. (Name of a Sidonian Goddess, _Ashtaroth_ in
Scripture.) _Fam._ Nymphacea, Lam. Genus Crassina, Lam.--_Descr._
Suborbicular, equivalve, inequilateral, thick, compressed; hinge with
two solid diverging teeth in the right valve, one tooth and a slight
posterior elevation in the left; muscular impressions, two in each
valve, uniform, united by a simple palleal impression; ligament
external.--_Obs._ This genus differs from Venus, Cytheræa, &c. in not
having a posterior sinus in the impression of the mantle. The hinge
also differs in having but two cardinal teeth. Astarte differs from
Crassatella in having no internal cartilage in the hinge. Some of the
species are British, others are from America, and one from Sicily. The
fossils occur in Crag, Lower Oolite, &c. Fig. 110. A. Danmoniensis.
ASTROLEPAS. Klein. CORONULA Testudinaria, Auct. CHELONOBIA, Leach. Fig.
15.
ATLANTA. Lesueur. _Fam._ Pteropoda, Lam. and Bl.--_Descr._ Spiral,
convolute, transparent, fragile, compressed, with a broad, fimbriated,
dorsal keel, and a narrow aperture. This shell, which is called "_corne
d'ammon vivant_," is found in the Atlantic. The small Pteropod, figured
in Sowerby's Genera as Limacina, belongs to this genus. Atlanta
Helicialis, fig. 220.
ATRACTODON. Charlesworth. (Mag. Nat. Hist. 2nd series, Vol. 1. p. 218.
) A genus proposed for the admission of a singular fossil shell, found
on the beach at Felix-stone, of which the following are the
characters;--fusiform, aperture equalling the spire in length,
terminating anteriorly in a slightly recurved canal; columellar lip
smooth, curved, thickened posteriorly into a blunt tooth; spire
obtuse.--_Obs._ This shell would be a Fusus were it not for the tooth
on the posterior extremity of the columellar lip. The only species
known is regularly striated in a spiral direction, and named A.
Elegans.
ATRYPA, Dalman. A genus of brachiopodous bivalves, distinguished by the
valves being nearly equal, and the umbones not separated by an
intermediate area. A. reticulata, fig 302.
ATTACHED. Shells are attached to marine substances by various means; in
some cases by a _byssus_, or a bunch of tendinous fibres passing
through an opening between the valves, which gape at their margins to
admit a free passage, as in the genera Byssoarca and Mytilus. In other
cases the byssus is of a more compact substance, and passes through a
perforation in the shell itself. This is the case with many of the
brachiopodous shells, in some species of which the perforation is in
the point of the umbones, a specimen of which is represented in the
Introduction. This species of attachment does not keep the animal
motionless, although it is confined to a particular spot. Other shells
are attached by a portion of their own substance, as in Chama,
Spondylus, Serpula, &c. in which instances, the attached valve is
motionless, and is termed the under valve. The Pedunculated Cirripedes
are attached by a tubular tendinous process, called a peduncle.
ATTENUATED. Drawn out, long, thin, tapering, as the extremities of
Ovulum Volva, fig. 442.
ATYS. Montf. A generic name including those species of BULLA, which are
described as "convolute, with the last whorl covering the rest and
hiding the spire, the apex rounded at both ends." Bulla Naucum, Auct.
fig. 250.
AURICLE. (A little ear.) See AURICULATED.
AURICULA. Lam. (Dim. from _Auris_ an ear.) _Fam._ Auriculacea. Bl.
Colimacea, Lam.--_Descr._ Oval or oblong, cylindrical or conical;
aperture long, narrow, generally narrowest in the centre; rounded
anteriorly, with two or three strong folds on the inner lip, and the
outer lip thickened, reflected or denticulated; spire short, obtuse,
epidermis horny, brown.--_Obs._ The above description includes the A.
coniformis, f. 298. and several other conical species with narrow
apertures which formed the genus _Melampus_, Montf. and _Conovulus_,
Lam. The latter author suppressed his genus on ascertaining the
Conovuli to be land shells. We exclude, however, the A. Dombeyana, Lam.
300. and several similar species, which being more rounded, havingthin outer lips and but one fold on the columella, are described under
the generic name _Chilina_, Gray. It appears rather doubtful whether
the Auriculæ are marine or fluviatile, but the animals appear to be
amphibious. The Auriculæ are principally found in Salt Marshes of
Tropical climates, some small species are found on the Southern
European Coasts, as far north as Britain and south as Tierra del Fuego.
The Auriculæ formed a part of the genus Voluta of Linnæus, f. 297. A.
Judæ, f. 298. A. Coniformis.
AURICULATED. Some bivalve shells, such as _Pecten_, fig. 171, 172, have
a flat, broad, somewhat triangular appendage on one or both sides of
the umbones, called an _auricle_, or little _ear_. If on one side only,
they are said to be _uni-auriculated_; if on both, they are said to be
_bi-auriculated_.
AURICULACEA. Bl. The second family of the order Pulmobranchiata, thus
described; "shell thick, solid; aperture more or less oval, always
large, rounded anteriorly, and contracted by teeth or folds on the
columella." This family is included in the genus Voluta of Linnæus, on
account of the plaited columellar lip, a character by which that
heterogeneous assemblage of shells is distinguished. It forms part of
the family of _Colimacea_, Lam. from which they differ not only in
general form, but also in the fact of the animals being partly
amphibious, always living (according to De Blainville) on the sea
shore, and being occasionally covered with water for a short time. It
contains the genera Pedipes, Auricula, Pyramidella.
AURIFERA. Bl. OTION, Auct.
AURIFORM. (From _Auris_, an ear; _forma_, shape.) Ex. _Haliotis_, fig.
338.
AURISCALPIUM. Megerle. ANATINA, Lam.
AVICULA. Lam. (From _Avis_, a bird). _Fam._ Malleacea, Lam.
Margaritacea, Bl.--_Descr._ Inequivalve, inequilateral, foliaceous,
subquadrate, oblique, pearly; hinge rectilinear, lengthened into
auricular appendages, with a small indistinct tooth in each valve, an
elongated, marginal, ligamentiferous area, and an hiatus in the left
valve, for the passage of a byssus; one circular muscular impression,
near the centre of each valve, with a series of smaller ones arranged
in a line towards the umbones.--_Obs._ The Meleagrinæ of Lamarck,
Margaritiferæ, Schum. included in this description, consist of the more
rounded species, and do not present the elegant obliquity of form, nor
the wing-like auricles from which the genus Avicula receives its name.
The Aviculæ are pearly within. From A. margaritifera, a young specimen
of which is figured in the plates, fig. 164, is obtained oriental
pearls. This is an example of Meleagrina. A. Hirundo, fig. 163, belongs
to the genus Avicula of Lamarck. It is, however, needless to continue
the separation. Aviculæ are from E. and W. Indies, Mexico, Coasts of
the Pacific, Mediterranean, British Islands, &c. Fossil species occur
in the London clay, &c.
AXINUS. J. Sowerby.--_Descr._ Equivalve, transverse; posterior side
very short, rounded, with a long ligament, placed in a furrow,
extending along the whole edge; anterior side produced, angulated,
truncated, with a flattish _lunule_ near the beaks. The late Mr. James
Sowerby, who described this shell in the Mineral Conchology, did not
consider his genus as established, not having seen the hinge.
AXIS. The imaginary line, round which the whorls of a spiral shell
revolve. The extremities of the axis are pointed out in fig. 379, by
the letters, _a. a._ See "COLUMELLA."
AZECA. Leach. _Fam._ Colimacea, Lam.--_Descr._ "Animal like Bulinus,
with subcylindrical, rather obtuse shell, covered with a polished
periostraca (epidermis); aperture pear-shaped, curved and pointed at
the top; the margin thick, obtuse, united all round and toothed; the
axis imperforated." Gray's edition of Turton's British Shells, page
189.--_Obs._ The Turbo Tridens of Montagu, upon which this genus is
founded, resembles Bulinus lubricus in general form and character. Both
these shells differ from the true Bulini in having the peritreme
entire, and in being pellucid and glossy. Azeca differs from Bulinus
lubricus in having three teeth in the aperture, two on the inner lip
and one on the outer. Not seeing the necessity for creating a genus on
grounds so slight, I have simply transcribed the description given
above, leaving others to form their own conclusions as to the propriety
of separating this shell from the genus Bulinus. Britain, Central and
Southern Europe. Azeca Tridens, fig. 290.
AZEMUS. Ranzani. CONIA, Leach.
BACULITES. Lam. _Fam._ Orthocerata, Bl. Ammonacea, Lam.--_Descr._
Straight, conical, tubular, laterally compressed; chambers divided by
very sinuous lobed septa, the last elongated; aperture elliptical;
siphon dorsal.--_Obs._ This genus differs from Orthoceras in the same
manner in which Ammonites differs from Nautilus, having its septa
sinuated and branched. A Baculite might be described as a straight
Ammonite. This genus is known only in a fossil state. It is found in
the Cretaceous Limestone of Maëstricht and Valognes. Fig. 484. B.
Faujasii.
BALANUS. Brug. (an Acorn; "gland de Mer." Fr.) _Order_ Sessile
Cirripedes, Lam. _Fam._ Balanidea, Bl.--_Descr._ Shell composed of six
valves articulated to each other side by side in a circle, by the
insertion of lamina; closed at the base by a flat, cylindrical or
cup-shaped valve, by which it is generally attached; and at the apex by
a conical operculum, consisting of four valves in anterior and
posterior pairs. Each valve of the shell is divided into a rough
triangular portion pointed towards the apex, and a flat area on each
side.--_Obs._ This description includes the _Acasta_ of Leach, which
growing in sponges, has the base cup-shaped; _Conoplæa_ of Say, which
being attached to the stems of Gorgonia and sea-weeds has the base
elongated and lanceolate, and _Chirona_, Gray. Balanus is the only
genus of Sessile Cirripedes the shells of which consist of six parietal
valves, except _coronula_, which has no shelly base, is flatter, and
has the valves of the operculum placed horizontally. The Balani are
common in all seas, adhering to rocks, corals, floating timber, and to
each other. The fossil species are found in the newest strata, at
Bordeaux, Paris, &c. Fig. 25. B. Tintinnabulum; 26. _Acasta_ Montagui;
Balanus galeatus, _Conoplæa_, Say.
BALANIDEA. Bl. The second family of the class Nematopoda, Bl.
corresponding with Sessile Cirripedes, Lam., and consisting of
Coronular Multivalves, which are fixed, and in a manner soldered to
submarine substances, by the base of the shell; as distinguished from
the Lepadicea, Bl., Pedunculated Cirripedes, Lam., which are attached
by a fleshy stalk. The Balanidea are composed of two sets of valves,
besides the shelly plate or base on which they rest. The first, called
the Parietal valves, are arranged so as to surround the body of the
animal; the second, called the Opercular valves, are placed
horizontally, so as to cover the aperture.
BALEA. Gray. _Fam._ Colimacea, Lam.--_Descr._ Spiral, turrited,
concentrically striated, sinistral, and covered with a thin brown
epidermis; spire composed of numerous whorls, gradually increasing in
size; aperture small, sub-quadrate; peritrême entire, slightly
thickened, with a very slight fold on the columella; axis
perforated.--_Obs._ A genus of small land shells, found in moss at the
roots of trees in Britain, not very nearly resembling any other land
shells, except Clausilia, from which they differ in not having the
clausium. They have been placed in Helix by De Ferrusac, and in Pupa by
Draparnaud. B. fragilis, fig. 296. _Helix perversa_, Fer. _Pupa
perversa_, Drap.
BARBATA. Humphrey. UNIO, Lam.
BARNACLES. PENTELASMIS, Auct. (fig. 34.) Called Anatifa, by Linnæus and
Lamarck, from the ancient notion that they were the eggs or embryo of
the Barnacle Duck. See ANATIFER.
BASE. In all shells which are attached to sub-marine substances, the
base is that part of the shell
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