A Conchological Manual, George Brettingham Sowerby [little readers .TXT] 📗

pot,

   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, having

   thin 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