A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖
- Author: George Brettingham Sowerby
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the shells of each of those genera, several constant and well marked
distinctions, by which they maybe at once recognized. In the Ranellæ,
the varices run in two rows along the spire; in the Murices, they form
three or more rows; but in the Tritons, they do not follow each other,
_i.e._ they do not occur in the same part of each volution. The large
species of Triton, are sometimes used as trumpets. The Tritons are
brought from the Mediterranean, Ceylon, the East and West Indies, and
South Seas. Fig. 398 to 401.
TRITONIDEA. Sw. A genus of "Buccininæ," Sw. thus described: "Shell
bucciniform, but the basal half is narrowed, and the middle more or
less ventricose; spire and aperture equal. Pillar at the base with two
or three obtuse and very transverse plaits, not well defined; outer lip
internally crenated and with a superior siphon; inner lip wanting, or
rudimentary." This genus is the same as the one first distinguished by
Mr. Gray under the name of Pollia. We do not regret the discovery made
by Mr. Swainson of that name being previously occupied for a genus of
Lepidopterous Insects. Fig. 415, represents Tritonidea articularis.
(Pollia, Gray.)
TRIVIA. Gray. A genus composed of those small species of CYPRÆA, Auct.
which are characterized by small ridges on the dorsal surface, and have
the anterior of the columella internally concave and ribbed. C.
Pediculus. Auct. fig. 449, 450.
TROCHATELLA. Sw. A sub-genus of Helicinæ, consisting of those species
which are acute and trochiform.
TROCHIA. Sw. A genus of the family Buccininæ, thus described: "shape
intermediate between Purpura and Buccinum; whorls separated by a deep
groove; inner lip when young, depressed, when adult, thickened, convex
and striated; basal canal very small. T. sulcatus. E. M. 422. f. 4."
Sw. Malac. p. 300.
TROCHIDON. Sw. A sub-genus of "Trochinæ," Sw. Lardn. Cyclop. Malac. p.
351.
TROCHILÆA. Sw.? PILEOLUS, Auct.
TROCHURUS. Humph. MONODONTA. Lam.
TROCHUS. Auct. (_A top._) _Fam._ Turbinacea, Lam. Goniostomata,
Bl.--_Descr._ Turbinated, thick, striated, tuberculated or smooth;
spire elevated, conical, consisting of numerous whorls; under surface
discoid; aperture more or less depressed in an oblique direction,
generally angular; columella arcuated, more or less prominent at its
union with the outer lip, contiguous to the axis of the shell;
operculum horny, orbicular, with numerous whorls.--_Obs._ Lamarck
distinguished this genus from Turbo by the general form, which is more
conical, and the aperture, which is angulated, while that of Turbo is
rounded. Monodonta or Odontis is only separated on account of the notch
at the termination of the columella. But these characters glide so
imperceptibly from one genus to the other, that there is no line of
demarcation to be found but in the operculum. Accordingly, Sowerby (in
Gen. of Sh. 37.) has stated his reasons for considering as Trochi, all
the species which have horny opercula; and as Turbines, all those which
have testaceous opercula. Fig. 358 to 360. The Trochi are found in all
climates.
TROPÆUM. Sow. CRIOCERATITES.
TROPHON. Montf. MUREX Magellanicus, Auct. and several other species
which belong more properly to Fusus than to Murex.
TRUMPET SHELL. A large species of Triton (variegatus), used by natives
of South Sea Islands as a trumpet, to call warriors and herds of cattle
together. It answers the purpose tolerably well, producing a very
sonorous blast.
TRUNCATED. (_truncus_, cut short.) Terminating abruptly, as it were cut
short. _Ex._ Solenensis, fig. 60.
TRUNCATULANA. D'Orb. A genus of microscopic Foraminifera.
TRUNCATELLA. Risso. A genus composed of several species of land shells
which have been confounded by some authors with Cyclostoma. The genus
is thus described: "Shell turriculated, cylindrical, decollated or
truncated at the apex, no epidermis; aperture oval, short, with lips
continuous, simple." _Ex._ Truncatella truncatulina, Lowe, Zool. Journ.
5. p. 80. Our plates, fig. 520, 521. It is found on the shores ofBritain, the Mediterranean, and West Indies.
TUBA. Lea. A genus of small fossil shells, described as resembling
Turbo, but with the aperture more like that of Melania. Lea. Contrib.
Geol.
TUBERCLE. (_tuberculus._) A small swelling excrescence, or knob.
TUBERCULATED. Having a number of small lumps or pimples, as Turrilites,
fig. 483.
TUBICINELLA. Lam. (_Tubicen_, a trumpeter.) _Order_, Sessile
Cirripedes, Lam.--_Descr._ A cylindrical tube, composed of six
elongated valves jointed together side by side, striated
longitudinally, surrounded by concentric rings; aperture circular,
enclosed by an operculum of four valves, placed perpendicularly in an
epiphragm.--_Obs._ The Tubicinellæ are found with nearly the whole
shell buried in the thick skin of the whale. T. Balænarum.
TUBICOLARIA. Lam. (_Tuba_, a tube; _cola_, an inhabitant.) A family of
the order Conchifera Dimyaria, Lam. consisting of bivalves soldered as
it were within, or connected with, a testaceous tube. The genera
contained in this family may be thus distinguished.
ASPERGILLUM. Valves fixed, tube perforated and fringed. Fig. 44.
TEREDINA. Valves fixed, prominent, tube closed at one end.
Fossil. Fig. 46, 47.
CLAVAGELLA. One valve fixed, the other free. Fig. 45.
TEREDO. Both valves free, tube open at both ends. Fig. 48, 49.
FISTULANA. Valves free, tube closed at one end, straight, long.
Fig. 53, 54.
GASTROCHÆNA. Valves free, tube closed at one end, short,
bulbous. Fig. 52.
TUBIVALVES. Bl. Shells composed of two valves connected in a tube,
corresponding with the family Tubicolæ of Lamarck.
TULIPARIA. Sw. A sub-genus of "Coronaxis," Sw. Lardn. Cyclop. Malac. p.
311.
TURBINACEA. Bl. The sixth family of Polythalamacea, Bl. containing the
genera Cibicides and Rosallites, microscopic Foraminifera.
TURBINACEA. Lam. A family of the first section of the order
Trachelipoda, Lam. containing the following genera.
SOLARIUM. With umbilicus reaching to the apex; including
_Bifrontia_ and _Orbis_. Fig. 353 to 356.
ROTELLA. A callosity on the under side. Fig. 357.
PHASIANELLA. Oval; operculum shelly. Fig. 367.
PLANAXIS. Columellar lip flat; aperture notched. Fig. 365.
TURBO. Top-shaped; mouth generally round; operculum shelly. Fig.
368.
TROCHUS. Top-shaped; mouth generally angulated; operculum horny,
consisting of many whorls; including _Elenchus_. Fig. 358, 359,
361.
MARGARITA. Operculum horny, consisting of few whorls; pearly.
Fig. 362.
LITTORINA. Similar, not pearly; including _Assiminnea_. Fig.
363, 363*.
PHORUS. Attaching dead shells, stones, &c. Fig. 360.
MONODONTA or ODONTIS. A notch and prominent point at the lower
part of the aperture. Fig. 366.
LACUNA. With an umbilicus. Fig. 364.
TURRITELLA. Elongated, screw-shaped. Fig. 369 to 371.
TURBINATED. (_Turbo_, a top,) Top-shaped. The term is applied generally
to those shells which are large at one extremity, and narrow to a point
at the other. _Ex._ Trochus, fig. 358; Turbinellus, fig. 382.
TURBINELLUS. Auct. (_A little top._) _Fam._ Canalifera, Lam.
Siphonostomata, Bl.--_Descr._ Turbinated, thick, wide near the apex,
generally tuberculated; spire short, depressed, mammillated; aperture
rather narrow, terminating anteriorly in an open canal; outer lip
thickened within; columella having from three to five prominent,
compressed, transverse folds. The species of this genus are mostly
tropical.--_Obs._ The Turbinelli are a well marked genus of marine
shells, the species of which are numerous. No fossil species are known.
The genus Cancellaria makes the nearest approach to Turbinellus in some
characters, but may be distinguished by the roundness of its form, the
raised lines inside the outer lip, and the obliquity of the folds on
the columella. Fig. 382 to 384.
TURBO. Auct. (_A top._) _Fam._ Cricostomata, Bl. Turbinacea,
Lam.--_Descr._ Turbinated, solid, ventricose, generally grooved or
tuberculated; spire short, pointed; aperture generally rounded,
sub-effuse anteriorly, entire; operculum shelly, solid, incrassated on
the outer side, horny and sub-spiral on the inner side. The Turbines
are mostly tropical.--_Obs._ The only certain means of distinguishing
this extensive genus of marine shells from Trochus, is the operculum,
which in the latter genus is horny, spiral, and composed of a great
number of whorls. The Trochi, however, are in general more conical, and
flatter at the under side of the whorls, and this constitutes Lamarck's
distinction between the genera. T. setosus, fig. 368.
TURGID. (_Turgidus._) Puffed up, swollen, inflated. This term is
applied synonymously with Ventricose.
TURRICULA. Humph. MELANIA, Auct.
TURRICULACEA. Bl. The seventh family of the Order Polythalamacea, Bl.
containing the genus Turrilites, fig. 483.
TURRILITES. Lam. (_Turris_, a tower; [Greek: lithos], a stone.) _Fam._
Turriculacea, Lam. Ammonacea, Bl.--_Descr._ Chambered, turrited,
spiral; septa sinuous and lobate, perforated by a siphon; aperture
rounded, with the outer lip expanded. This genus, which is
distinguished from the other Ammonacea by having the spire produced,
_i. e._ not being convolute, consists of several species, occurring
only in chalk-marl. Fig. 483.
TURRIS. Montf. A genus composed of those species of MITRA, Auct. which
have the whorls angulated, with the aperture lengthened and undulated.
TURRITED. The spire of an univalve shell is said to be _turrited_ when
the whorls of which it is composed are regulated so as to have the
appearance of little turrets rising above each other, as in Mitra, fig.
431.
TURRITELLA. Lam. (_A little tower._) _Fam._ Turbinacea, Lam.
Cricostomata, Bl.--_Descr._ Turrited, elongated, generally grooved
spirally; spire pointed, consisting of numerous whorls; aperture
rounded or angulated; inner and outer lips thin, confluent anteriorly;
operculum horny.--_Obs._ The shells composing this well defined genus,
are commonly called screws, a name to which the spiral grooves of most
of the species seems to entitle them. Fig. 370, T. imbricata.
TYMPANOSTOMA. Schum. (_Timbrel mouth._) POTAMIS, Brongn.
TYPHIS. Montf. A genus composed of MUREX tubifer, Auct. and other
similar species, which have the canal closed and a perforated tube
between each varix on the angulated part of the whorls. Besides the
fossil species originally described, there are now five species known,
which are figured in part 200, of the Conchological Illustrations by
the Author. Typhis tubifer, fig. 397.
ULTIMUS. Montf. (_The last._) A genus composed of OVULUM gibbosum,
Auct. fig. 443, and other species in which the canals are not
distinctly defined, nor elongated. This fanciful name is given to the
genus on account of its being described in the last page of the book.
UMBILICATED. (_Umbilicatus._) Having an umbilicus, as Nautilus
umbilicatus.
UMBILICUS. (_A navel._) The hollow formed in spiral shells when the
inner side of the volutions do not join each other, so that the axis is
hollow. The umbilicus is marked with the letter u in Helix algira, fig.
The term is also used to express any small, neat, rounded hollow.
UMBO. (_The boss of a buckler or shield._) The point of a bivalve shell
above the hinge, which constitutes the apex or nucleus of each valve,
from which the longitudinal rays diverge, and the lines of growth,
commencing at the minutest circle, descend in gradually enlarging
concentric layers to the outer margin. The umbones will be marked with
the letter _u_, in Cytherea, fig. 117.
UMBRELLA. (_A little shade._) _Fam._ Semiphyllidiana, Lam. Patelloidea,
Bl.--_Descr._ Patelliform, sub-orbicular, compressed, rather irregular;
apex slightly raised, placed near the centre; margin acute; internal
surface with a central, callous, coloured disc, surrounded by a
continuous, irregular muscular impression.--_Obs._ This genus is known
from Patella, by its continuous muscular impression. It is commonly
called the Chinese Umbrella shell. There are but two species at present
known; the U. Mediterranea, and the U. Indica, fig. 233.
UNDATED. (_Unda_, a wave.) Waved.
UNDULATED. (_Undulatus._) Minutely waved.
UNGUICULATED. (_Unguis_, a nail or hoof.) An unguiculated operculum is
one in which the layers are disposed laterally, and the nucleus
constitutes part of the outer edge.
UNGULINA. Daud. (_Ungula_, a nail or claw.) _Fam._ Mactracea, Lam.
Conchacea, Bl.--_Descr._ Equivalve, sub-orbicular, sub-equilateral,
with margins entire, simple, closed all round; hinge with one short,
sub-divided cardinal tooth in each valve, and a very minute additional
tooth in one valve, an oblong ligamentary pit divided into two
portions, one of which receives the cartilage, the external ligament is
immediately below the umbones; muscular impressions, two in each valve,
oblong; impression of the mantle entire. U. transversa, fig. 88. Coast
of Africa.
UNI-AURICULATED. Having one AURICLE. See AURICULATED.
UNICORNUS. Montf. MONOCEROS, Auct.
UNIO. (_A pearl._) _Fam._ Nayades, Lam. Submytilacea, Bl.--_Descr._
Inequilateral, equivalve, regular, free, pearly within, covered by a
smooth epidermis without; umbones prominent, generally corroded;
muscular impressions two in each valve, lateral, distant; the anterior
composed of several small divisions; hinge varying in age, species, and
individuals.--_Obs._ The above description is framed so
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