A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖
- Author: George Brettingham Sowerby
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for instance, the attached valve of Spondylus, the basal plate of
Balanus, the lower part of the peduncle of Pentelasmis; in Unattached
Bivalves, the margin opposite to the umbones, where the foot of the
animal, or the part analogous to it, protrudes; in spiral univalves,
the aperture, which rests on the back of the animal when walking.
Lamarck and some other authors have used the term _base_ as simply
opposed to apex, and apply it to the anterior of the aperture.
BATOLITES. Montf. HIPPURITES, Auct.
BEAK. The Apices, or points of the valves of a bivalve shell, generally
termed UMBONES, in descriptions. Also any part which is rostrated or
drawn out like a beak.
BEAKED. See BEAK and ROSTRATED.
BEAR'S-PAW-CLAM. The common name for Hippopus maculatus, a
representation of which is given in the plates, fig. 156.
BELEMNITES. Auct. ([Greek: Belemnon], _belemnon_, a dart, or arrow.)
_Fam._ Orthocerata, Bl. and Lam.--_Descr._ Straight, conical,
consisting of two parts; the _external_ portion forming a thick solid
sheath, with a cavity at the base to admit the internal portion or
nucleus, which is mathematically conical, and is divided into chambers
by smooth simple septa perforated by a lateral siphon.--_Obs._ These
singular fossils, which are found in most secondary beds, have long
attracted the attention of philosophers as well as of the ignorant,
from whom they have received the various appellations of
Thunder-Stones, Petrified Arrows, Petrified Fingers, Devil's Fingers,
Spectre Candles, &c. The above description is framed to include the
genera Hibolithes, Porodragus, Cetocis, Acamas, and Paclites of De
Montfort, and Actinocamax, Stokes. Fig. 466 to 468.
BELLEROPHON. Montf. (or Bellerophus).--_Descr._ Convolute, symmetrical,
umbilicated, with a double dorsal ridge; aperture wide,
semilunar.--_Obs._ The fossils composing this genus resemble Nautilus
in general appearance, but not being chambered shells they approach
very near to Argonauta, from which they differ only in the thickness of
their shell and in roundness of their external form. This genus is
erroneously placed by De Montfort among chambered shells, and by De
Blainville next to Bulla. It belongs to the Monothalamous Cephalopoda
of Lamarck. This fossil is found principally in the Carboniferous
Limestone. Fig. 486, 487, represent B. tenuifasciata.
BELOPTERA. The bony support of a species of Cuttlefish, partly
resembling Sepia.
BIAPHOLIUS. Leach. A genus believed to be identical with Hiatella.
BI-AURICULATED. Having two auricles placed at the sides of the umbones,
as in Pecten, fig. 171. See AURICULATED.
BICATILLUS. Sw. A sub-genus of "Calyptrædæ," including those species,
which have cup-shaped internal septa, as for example, Calyptræa
extinctorium, fig. 235.
BICONIA. Sw. A sub-genus of "Calyptrædæ," including those species in
which the septum is partly spiral.
BIFID. Divided, double.
BIFRONTIA. Deshayes. Also OMALAXIS, Desh. _Fam._ Turbinacea,
Lam.--_Descr._ Discoidal, planorbicular, with whorls sometimes not
contiguous; umbilicus deep, keeled at the margin; aperture
subtriangular, somewhat dilated; outer lip acute, separated by a deep
notch at both extremities.--_Obs._ We do not see any reason for
separating this genus from SOLARIUM, except the last mentioned
character. The few fossil species which this genus contains (Solarium
disjunctum, Bifrons, &c.) are found principally in the Paris basin.
Fig. 354. Solarium Bifrons.
BI-FURCATE. Double pronged, or having two points. _Ex._ the internal
appendage of Calyptræa Equestris, fig. 234.
BIGENERINA. D'Orb. A genus of microscopic Foraminifera.
BILABIATED. Having the edge of the outer lip as it were doubled, by one
part of the lip being more thickened and reflected than the other, so
as to form a ledge, or second lip.
BILOBATE. Having two prominent parts, as the outer lip of Rostellaria
Pes-Peleeani, fig. 404.
BIPARTITE. Composed of or divided into two parts; double; as the valves
of Platylepas, fig. 19, each of which has a septiform division in the
centre; also the area on the hinge of Spondylus. See Frontispiece.
BIROSTRA. Sw. A genus composed of species of OVULUM, which have
elongated extremities, as, for instance, Ovulum Volva, fig. 442.
BIROSTRITES. Lam. (Double Beak.) A fossil formerly considered as a
distinct bivalve shell, with conical umbones, and placed in the family
of Rudistes by Lamarck, but now known to be an internal cast of
Sphærulites, fig. 196.
BISIPHYTES. Described by De Montfort as resembling a Nautilus, but
having two distinct siphons. As no such fossil species is now known to
Naturalists, it appears probable that De Montfort having a specimen of
some Nautilus, with an accidental depression, took it for a second
siphon.
BITHINIA. Gray. A genus described as differing from PALUDINA, in having
the operculum shelly, and the mouth of the shell thickened internally.
PALUDINA impura, Auct. Fig. 537.
BITOMUS. Montf. A microscopic shell, deriving this general appellation,
from the appearance of a double aperture.
BIVALVE. A shell composed of two equal, or nearly equal principal
parts, each part having a separate nucleus, turning upon each other by
means of a hinge. The class Conchifera of Lamarck, Acephalophora of De
Blainville severally include the whole of the bivalve shells; the
latter name being derived from the fact that the animals have not
distinct heads, and neither eyes nor tentacula. All bivalve shells are
marine or fresh-water. They form the class Dithyra of Aristotle. It may
be observed that some of the Acephalophora, the Pholades, for example,
have small testaceous pieces fixed on the hinge, which are called
accessary valves. These are still fairly bivalve shells, although the
genus Pholas has been placed by some writers among the multivalves.
BOAR'S TUSK. A common name given to shells of the genus Dentalium. One
particular species has received a specific name in accordance with a
supposed resemblance, namely, Dentalium Aprinum, (of a Boar.)
BONELLIA. Desh. A genus formed, in the first instance, for the
reception of Bulinus terebellatus, Lam. which Mr. G. B. Sowerby, in his
Genera of Shells, united with the genus PYRAMIDELLA. M. Deshayes,
however, in his new edition of Lamarck, makes the genus Bonellia
include several species which I have arranged in the genus Eulima. From
the remarks of M. Deshayes, tom. 8, p. 286, 287, we are led to suppose
that the estimated difference between Eulima and Bonellia consists in
the latter having the axis perforated; or in other words, umbilicated.
After remarking "que Mr. Sowerby, junr. confond deux choses bien
distinctes, sous le nomme d'Eulima," M. Deshayes gives the following
description of his genus, (translated) "shell turriculated, smooth,
polished, with the apex acute and laterally inclined; axis perforated
throughout its length; aperture small, entire, angular at the
extremities; columella simple and without folds; outer lip thin,
simple, nearly parallel with the longitudinal axis." That author
further remarks, "Mr. Sowerby, junr. à signalé cinque espèces vivant,
que nous rapportons à notre genre." (Sowerby, junr. Conchological
Illustrations, parts 52 and 53; 50, Great Russell Street, Bloomsbury.)
The species thus selected are E. splendidula, E. marmorata, E.
interrupta, E. imbricata, E. brunnea; the two last of which have the
umbilicus so inconsiderable, as to be scarcely distinguishable from
other species, which M. Deshayes has left in the genus Eulima, and
which have a slight hollow, almost approaching to a perforation, behind
the columella. Eulima marmorata, (Bonellia, Desh.) is figured in the
plates, fig. 348.
BODY WHORL. The last whorl, constituting the bulk of the shell.
BORELIS. Montf. MELONIA, Bl. A genus of microscopic Foraminifera.
BORER or PIERCER. A term applied to those species of Acephalopodous
Mollusca, which bore holes as dwellings in the rocks, as the Pholades,
and some others.
BRACHIOPODA. Lam. A family of symmetrical bivalves belonging to the
third section of Lamarck's _order_ "Conchifera Monomyaria," described
as bivalve (generally symmetrical) adhering to marine bodies, by a
tendon passing through the shell, having no true ligament. What most
distinguishes this family and renders it remarkable is the structure of
the animal. It has two elongated, tendril-shaped arms. When the animal
is in a state of repose these arms are coiled up spirally and enclosed
in the shell, but when required for use, are unfolded and extended.
This family contains the genera Orbicula, Terebratula and Lingula, in
the system of Lamarck, to which may be added Thecidium, Productus,
Spirifer, Magas, Pentamerus, Crania, Strigocephalus, Strophomena, and
some others enumerated in the explanation of figures 201 to 219. The
above genera may be thus distinguished.
ORBICULA. Umbones central; byssus passing through a hole in the
flat valve. Fig. 201.
ATRYPA. Without foramen or space between the valves. Fig. 203.
PRODUCTA. The same, valves produced, overwrapping; including
Leptæna. Fig. 206, 206*.
TEREBRATULA. Hinge of the upper valve produced beyond that of
the other, with a pit or foramen; including _Delthyris_, _Orthis_,
_Trigonosemus_, _Magas_, _Strophomena_. Fig. 202, 205, 207, 208,
209.
SPIRIFER. The same, with deep triangular area; spiral folds in
the interior; including _Trigonotreta_ and _Cyrtia_. Fig. 204, 214,
215.
THECIDIUM. Large valve attached; curved ridges in the inner
surface; two jutting points or teeth on the hinge. Fig. 216.
CRANIA. Attached by the surface of the valve; muscular
impressions four, forming a face. Fig. 197, _a_, b.
PYCNODONTA. Irregular; hinge with raised pointed teeth. Fig.
217, 218.
PENTAMERUS. Valves divided by septa; including _Gypidia_. Fig.
210 to 213.
LINGULA. Valves equal, gaping, with a peduncle. Fig. 219.
BRACHITOMA. Swainson. A genus composed of PLEUROTOMA strombiformis and
similar species, described as "sub-fusiform; resembling a small
Strombus or Fusus; spire and aperture of equal length; canal short;
outer lip slightly ascending, and forming a short canal; sinus very
small and nearly semicircular; inner lip thickened above. B.
Strombiformis, Sow. Man. fig. 381." Europe, East and West Indies,
China, &c.
BRANCHIFERA. Bl. The second family of the order Cervicobranchiata,
containing the following genera of symmetrical univalves:--Fissurella,
Emarginula, and Parmophorus.
BRISMÆUS. Leach. _Order._ Pedunculated Cirripedes. Lam.--_Descr._ Seven
plates, three pairs lateral, one dorsal; form cylindrically conical;
pedicle not described. _Hab._ Holes in corals. B. Rhophodius, fig.
38.--_Obs._ This minute shell most nearly resembles Pollicipes
Mitellus, fig. 37*, but the difference may be seen at once by comparing
the figures.
BRONTES. Montf. This generic name is given to such species of MUREX as
have a very long, closed canal; with a short spire, circular aperture,
and are destitute of spires and ramifications. Brontes (Murex)
Haustellum, fig. 390.
BUCARDIA. Schum. ISOCARDIA, Auct.
BUCCINUM. Linn. _Fam._ Purpurifera, Lam. Entomostomata, Bl.--_Descr._
Subovate or oblong, covered with an epidermis; spire turrited,
consisting of few whorls; aperture wide, subovate, terminating
anteriorly in a very short canal, reflected over the back; outer lip
simple, slightly reflected; inner lip spread over a portion of the body
whorl, terminating in a thick, smooth columella; operculum horny.
_Hab._ British Seas, Northern Ocean, and Coast of Africa. Most of the
fossil species occur in Crag, some in upper marine formation and London
clay.--_Obs._ There are considerable difficulties in keeping this genus
distinct from others nearly related to it, into which many of the
species run by imperceptible gradations. The genus _Nassa_ has been
separated on account of the little notch, which terminates the
columella. Some species of Terebra come so close upon the Buccina, that
it is difficult to say where one genus ends and the other begins. T.
Buccinoides, fig. 427. Buccinum Undatum, the common Whelk, fig. 421.
BUFO. Montf. A generic division of the species composing Ranella,
characterized as having the shell not umbilicated. _Ex._ R. ranina,
fig. 394. The above character is scarcely sufficient in some cases,
even as a specific distinction.
BULBUS. Humph. RAPELLA, Swainson. A genus formed for the reception of
PYRULA papyracea, Auct. (fig. 389), and similar species. RAPANUS,
Montf.
BULIMIMA. Montf. A genus of microscopic Foraminifera.
BULIMULUS. Leach. _Fam._ Colimacea, Lam. The author is unacquainted
with the characters by which the two or three species included in this
genus are to be distinguished from Bulinus. We have represented, fig.
283, Bulimulus trifasciatus, Leach, (Bulinus Guadaloupensis, Auct.)
This occurs in the same limestone which encloses the half fossilized
human remains from the Grand Terre of Guadaloup. Several species are
described by the Rev. L. Guilding in the Zoological Journal, namely,
the B. Undulatus, Antiguensis, and Proteus; but neither from the shells
themselves, nor from the figures of the animal, can we draw any
information as to the generic character; the difference alleged by
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