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
of microscopic fossils, now termed Foraminifera; the genus Nummulites,
although large, may probably belong to the same class, and perhaps it
would have been better to have included the remaining genus, Nautilus,
in the next family, from which it differs in having the septa which
divides the chambers simple at their edges.
_Ammonacea_ (plates, fig. 477 to 484). The edges of the septa of
these are all more or less sinuous and complicated. This family
contains the following genera, Ammonites, Ammonoceras, Baculites, and
Turrilites, the latter of which presents a singular anomaly in having
an oblique spire, like that of the order Trachelipoda, while it is
divided into chambers by sinuous septa.
Order _Monothalamous Cephalopoda_.
The only shells included in this order belong to the genera Argonauta
(plates, fig. 485), placed here by Lamarck, and Bellerophon (plates, fig.
486 and 487), a fossil genus subsequently added.
Order _Heteropoda_.
The singular and beautiful transparent shell contained in this order, under
the generic name Carinaria, forms a covering to a small portion of an
animal, equally remarkable and equally distinct from those of all other
orders.
The above arrangement, although far from perfect, and requiring numerous
modifications, is perhaps liable to as few objections as any other yet
proposed, and will certainly be more easily understood by those who have
not the opportunity of studying the soft parts of the animal.
* * * * *
CONCHOLOGICAL MANUAL.
ABIDA. Leach. A genus founded on a species of PUPA, which has the
peristome slightly reflected, and numerous plaits in the aperture. Pupa
Juniperi, Pupa secale, Draparnaud. Great Britain; also Central and
Southern Europe.
ABRA. Leach. A genus composed of AMPHIDESMA tenue, prismaticum, and
other small thin species. British Channel and Mediterranean. _Fam._
Mactracea.
ABSIA. Leach. LITHOTRYA, Sowerby. _Fam._ Pedunculated Cirripedes.
ACAMAS. Montfort. BELEMNITES multiforatus, Blainville. A species
described as being perforated at the apex, by a stellated perforation.
No species of Belemnite at present known agreeing with the description;
it is supposed to have been taken from a broken specimen.
ACANTHOCHETES. A name given to a species of Chiton having bunches of
bristles at the sides of the valves.
ACARDO. Commerçon. Described from a pair of bony plates, taken from the
vertebræ of the Whale, and mistaken for a bivalve shell, destitute of a
hinge.
ACARDO. Swainson. A generic term applied by Swainson to the nearly
toothless species of Cardium, named C. edentulum by some authors; C.
Greenlandicum by others: fig. 123*.
ACASTA. Leach. _Order_, Sessile Cirripedes, _Lamarck_. BALANUS
_Montagui_, Sowerby. A small genus separated from Balanus, on account
of the cup-shaped base, but re-united by Sowerby, who shews, in his
Genera of Shells, that this is a merely accidental circumstance,
resulting from the situations in which the shells acquire their growth.
If, for instance, the Balanus be attached to a flat surface, in an open
situation, the base will be short and flat; if it be placed in a hollow
among other growing substances, it will be lengthened out in order that
the aperture of the shell may be even with the outer surface of the
surrounding mass; and if, as in the Acastæ, it be imbedded in a soft
and loose substance, the base, being left to itself, will take a
regular form. The Acastæ are found imbedded in sponges. _Ex._ Balanus
Montagui, of Great Britain, fig. 26. Also found in the Pacific ocean
and Philippines.
ACAVUS. Montfort. _Fam._ Limacinea, Blainville; Colimacea, Lamarck. A
division of the genus Helix, which may be considered synonymous with De
Ferrusac's sub-genus Helicogena. De Montfort has given H. Hæmastoma, as
an example. Fig. 267.
ACCESSARY VALVES, are the smaller or less important testaceous plates,
found on the hinge or dorsal margins of the true valves of some shells.
Example, the small plates on the hinge of Pholas, fig. 55, a. The
Pholades were placed by Linnæus and Bruguière among multivalve shells.
ACEPHALOPHORA. Blainville. (_a_, without; [Greek: kephale], head.) The
third class of the type Malacozoaria, Bl. including all bivalve shells,
the animals of which have no distinct head. This class corresponds with
the Conchifera of Lamarck, and is divided into the orders
Palliobranchiata, Rudistes, Lamellibranchiata, and Heterobranchiata,
the last of which contains no genera of testaceous Mollusca.
ACHATINA, Auctorum. _Fam._ Colimacea, Lam. (from Achates, an agate.)
_Fam._ Limacineæ, Bl. _Gen._ POLYPHEMUS, Montf.--_Descr._ Shell oval or
oblong, sub-turrited, light, thin; aperture oval, or pyriform; outer
lip sharp; columella smooth, tortuous, truncated, so as to form a notch
at its union with the outer lip.--_Obs._ It is from this notch that we
are enabled to distinguish Achatinæ from Bulini, which, moreover,
generally have a reflected outer lip. The Polyphemi of Montfort have an
undulation in the centre of the outer lip. Achatina Virginea, fig. 286.
Polyphemus Glans, fig. 288. These land shells are found in various
parts of the globe, but attain the greatest size and richness of
colouring in tropical climates; particularly in the West India Islands.
ACHATINELLA. SOW. A small group of shells, differing from Achatina in
having the inner edge of the outer lip thickened, and a slight groove
near the suture of the spire. Fig. 287. Sandwich Islands.
ACHELOIS. Montf. CONILITES Achelois. Knorr. Supp. T. 4, fig. 1.
ACICULA. Nilson. ACHATINA Acicula, Auct. CIONELLA, Jeffreys.
ACIONA. Leach. A genus described by De Blainville as consisting of
those species of Scalaria, the whorls of which do not touch each other.
If this account be correct, the genus proposed by Leach will include
the typical species of Scalaria, such as S. pretiosa.
ACME. Hartmann. A genus formed of TURBO fuscus, Walker. AURICULA
lineata, Drap. thus described--"Shell sub-cylindrical, with a blunt
tip; mouth ovate, simple, thin, slightly reflected over the pillar,
forming a slight perforation." The animal is said to resemble a
Cyclostoma, but has no operculum. Auricula lineata, Drap. Hist. 57, t.
3, fig. 20, 21. Southern Europe.
ACTEON. Montf. TORNATELLA, Lam.
ACTINOCAMAX. Stokes. A genus of Belemnitiform Fossils.
ACULEATED. Beset with sharp spines, as the margin of Chiton aculeatus,
fig. 227.
ACUMINATED. Terminating in a point, as the apex of Melania subulata,
fig. 313.
ACUS. Humphrey. TEREBRA of Lamarck.
ACUTE. Sharp, pointed, or sharp-edged.
ADDUCTOR MUSCLE. That which draws the two valves of a shell together,
and leaves a mark on the inner surface of each, called the MUSCULAR
IMPRESSION.
ADELOSINA. D'Orb. A genus of microscopic Foraminifera.
ADESMACEA. Bl. (_a_, without; [Greek: Desma], _desma_, ligament.) The
10th family of the order _Lamellibranchiata_, Bl. composed of Mollusca
which either bore tubular dwellings in rocks, wood, &c. or live in
testaceous tubes, their shells being consequently destitute of the
hinge ligament. The action of opening and shutting the valves being
limited to the narrow space to which they are confined, or else the
valves themselves being soldered into the tube, renders it unnecessary
for them to have a ligament to keep them in their places. The genera
Pholas, Teredina, Fistulana, and Septaria, belong to this family, which
corresponds in part with the families Tubicolaria and Pholadaria, of
Lamarck.
ADNA. Leach. One of the genera separated by Leach from _Pyrgoma_, and
characterized as consisting of an upper valve, supported on a
funnel-shaped base, which is not buried in the coral to which it is
attached, like Pyrgoma, but is seen externally. The operculum consists
of four valves. Adna, fig. 32. British Channel and Mediterranean.
ADNATE. A term applied by some authors to those shells belonging to the
family of Unionidæ, which have the valves joined together at the dorsal
margin, not like other bivalves, by a distinct ligament, but by the
substance of the shell itself, the valves appearing to grow together in
such a manner that they cannot be separated without one of them being
broken as will be seen in our figure of Dipsas plicatus, fig. 142. This
circumstance has been made the foundation of specific and even generic
distinctions, for which however it is insufficient, because many
species which when young are "_adnate_," when fully grown have their
valves joined together only by a ligament.
ÆGLIA. Say. A division of "Unionidæ," described as having the "shell
cuneate; bosses prominent; cardinal teeth much compressed, placed on
one side of the bosses. Æglia ovata, _Say_. Occidens _Lea_. Am. Tr.
iii. pl. 10." Lardner's Encyclopedia of Malacology.
AGANIDES. Montf. ORBULITES, Lam.
AGATHIRSES. Montf. SILIQUARIA, Auct.
AGINA ----? Belongs to SAXICAVA, Auct.
AKERA. Bl. The fourth family of the order Monopleurobranchiata, Bl.
containing the genera Bulla, Bullæa and Bellerophon, which, excepting
the last, constitutes the family Bullæana, Lam.
AKERA. A genus of extremely light, horny shells, resembling BULLA, from
which it differs, in the outer lip being separated from the body whorl,
which is elastic. _Ex._ Bulla fragilis, fig. 247.
ALÆA. Jeffrey's. A genus of minute land shells, resembling _Vertigo_,
but separated because they are dextral, while Vertigo is sinistral.
_Ex._ fig. 292. A. marginata, Pupa marginata, Drap. found in marshy
ground, roots of trees, moss, &c. Britain and Southern and Central
Europe.
ALASMODON. Say. A division of the genus UNIO, Auct. consisting of those
species which have cardinal, but no lateral teeth. _Ex._ A.
complanatus, fig. 141. North America and Europe.
ALATÆ. Lam. A family of the order Trachelipoda, Lam. containing the
following genera which may be thus distinguished.
ROSTELLARIA. Sinus close to the canal; including _Hippochrenes_,
and _Aporrhais_, Fig. 402 to 404.
STROMBUS. Sinus not close to the canal. Fig. 406.
PTEROCERAS. Same, digitated. Fig. 405.
ALATED. (From Ala, a wing.) Winged, a term applied to shells, when any
portion of them is spread out in any direction, as in fig. 403.
Hippochrenes, Montf. and fig. 147, Unio Alatus.
ALCADIA. Gray? (B. M. Syn. p. 134) Helicinæ which have a notch in the
aperture. A distinction which it is impossible to maintain. See
HELICINA.
ALATUS. Humphrey. STROMBUS, Auct.
ALECTRION. Montf. BUCCINUM Papillosum, Auct. fig. 422.
ALEPAS. Rang. A genus of Pedunculated Cirripedes without a shell.
ALVEOLINA. D'Orbigny. A genus of microscopic Foraminifera.
AMALTHUS. Montf. A. margaritaceus, Montf. is a species of AMMONITES
described as very flat, keeled, with an angular aperture. It belongs to
the family Ammonacea, Lam.
AMARULA ----? A genus composed of MELANIA Amarula, Auct. and similar
species.
AMBIGUÆ. Lam. The fourth section of the order Conchifera Dimyaria,
containing the family Chamacea, fig. 153 to 155.
AMICULA. A genus formed for the reception of CHITON amiculatus, Auct.
the valves of which are covered by an integument; so as to be
completely hidden externally.
AMIMONUS. Montf. CONILITES ungulatus, Knorr. A species distinguished
only by being slightly curved; _Fam._ Orthocerata, Lam.
AMMONACEA. Bl. The fourth family of the order Polythalamia, Bl. or
chambered shells, described as thin, chambered, discoidal, convolute,
symmetrical, generally compressed, with visible whorls. This last
character is used in De Blainville's System to distinguish the
Ammonacea from the Nautilacea. This family contains the genera
Discorbites, Scaphites, Ammonites, and Simplegas.
AMMONACEA. Lam. The seventh family of Polythalamous Cephalopoda, Lam.
containing the genera Ammonites, Orbulites, Ammonoceras, Turrilites and
Baculites, to which may be added Amalthus, Simplegas, Ellipsolites,
Nautellipsites, Hamites, Icthyosarcolites, and other genera mentioned
in the list of figures 477 to 484.
AMMONITES. Auct. (from Jupiter Ammon.) _Fam._ Ammonacea, Lam. and
Bl.--_Descr._ Symmetrical, convolute, discoidal, orbicular; chambers
numerous, divided by lobated, branched or sinuous septa, perforated by
a Siphon; aperture generally more or less modified by the last whorl.
The fossils of the secondary strata which compose this genus are
numerous and well known; they are vulgarly termed "snake-stones," and
some of them are extremely beautiful, particularly when the internal
structure is exhibited by a section. There is some difficulty in
distinguishing them from the Fossil Nautili, for although the whorls,
being visible and the Septa _sinuous_, may be taken as the
characteristics of the Ammonites, yet there are several species which
partake the characters of both. The Orbulites of Lamarck (fig. 479) for
instance, have sinuous septa like Ammonites, but the last whorl covers
those which precede it as in Nautilus. Simplegas Montf. and Bl. (fig.
475) has the whorls visible externally and the septa simple. Ammonites
is figured in the plates (478).
AMMONOCERAS, or AMMONOCERATITES. Lam. (from _Ammon_ & [Greek: Keras],
ceras, horn.) The shells
Comments (0)