Angyostomata, Bl.--_Descr._ Smooth, slender, oblong, sub-cylindrical;
spire obtuse, short, sometimes hidden; (Seraphs, Montf.) aperture long,
narrow posteriorly, wider anteriorly; outer lip slightly thickened,
truncated, unconnected at the base with the columella; inner lip thin,
smooth, nearly straight, spread over a portion of the body-whorl,
continued in a ridge above the sutures of the spire.--_Obs._ Montfort
has separated the fossil species with hidden spires, under the name
Seraphs. (T. convolutum, Lam.) Only one recent species is known, of
which there are several varieties, one spotted, one marked in
sub-spiral lines, another in patches. It is brought from the East
Indies. Fig. 451, T. convolutum; 452, T. subulatum.
TEREBRA. (_An augur, a piercer._) _Fam._ Purpurifera, Lam.
Entomostomata, Bl.--_Descr._ Subulate, elongated, pointed, turrited;
spire long, consisting of numerous whorls; aperture small terminating
in a short, reflected canal; outer lip thin; columella tortuous;
operculum horny. The recent species are mostly tropical.--_Obs._ Nearly
all the species enumerated by Lamarck and other authors are included by
De Blainville in his genus Subula; those few species which that
conchologist left in the present genus, being shorter and more
ventricose than the others, approximate in shape to some of the
Buccina, and are distinguished by Mr. Gray under the generic name
Bullia. It seems strange, that De Blainville, being convinced of the
necessity of separating the two groups, and consequently applying a new
generic term to one of them, should have given that term to the larger
number and the more typical species of the Lamarckian genus. Fig. 427,
Bullia vittata. (Terebra.) Fig. 428, Terebra maculata. (Subula.)
TEREBRALIA. Sw. A genus of "Cerithinæ," Sw. thus described: "Outer lip
much dilated, generally uniting at its base to the inner lip; leaving a
round perforation at the base of the pillar; channel truncate;
operculum round: palustre. Mart. f. 1472." Sw. p. 315.
TEREBRATING SHELLS. (_Terebro_, to pierce.) Shells which reside in
holes pierced in rocks, wood, &c. by means of some corrosive secretion
of the animal. _Ex._ Pholas, Teredo, &c.
TEREBRATULA. Brug. (_Terebrans_, bored.) _Fam._ Brachiopoda,
Lam.--_Order._ Palliobranchiata, Bl.--_Descr._ Inequivalve,
equilateral, oval or sub-trigonal, ventricose or compressed, attached
by a tendon passing through an opening in the dorsal, or upper and
larger valve, the umbo of which advances beyond that of the other
valve; hinge destitute of a ligament, with two teeth in the dorsal
valve, locked into corresponding cavities in the ventral, or lower
valve, and with two curious processes originating at the umbo of the
lower valve, presenting, in some species, the appearance of fine
winding tape, advancing towards the front of the valve, and again
receding to the centre, where the ends unite; muscular impressions two,
placed near the centre of each valve.--_Obs._ The Terebratulæ are
included in the genus Anomia in the system of Linnæus. The recent
species are not very numerous--they are found in all climates. The
fossil species are more numerous than the recent ones, occurring in the
secondary and tertiary formations. T. Psittacea, fig. 202.
TEREDINA. (From Teredo.) _Fam._ Tubicolæ, Lam. Adesmacea, Bl.--_Descr._
Valves equal, inequilateral, with prominent umbones, as it were
soldered to the outside of the rounded end of a shelly tube, of which
they form a part; aperture of the tube partly divided; a flat accessary
valve placed on the umbones.--_Obs._ This genus, which is only known in
a fossil state, is distinguished from Teredo, by the valves being fixed
on the tube, and the tube being closed at one extremity. Fig. 46, 47,
T. personata.
TEREDO. Auct. (_A piercer._) _Fam._ Tubicolæ, Lam. Adesmacea,
Bl.--_Descr._ Valves equal, inequilateral; presenting when closed, an
orbicular figure, with a large angular opening in front, and a rounded
opening at the back; placed at the anterior extremity of an irregular,
flexuous, elongated tube, open at both ends; the anterior termination
divided in a double aperture opened and closed at the will of the
animal by two opercula.--_Obs._ This genus of Molluscous Animals, is
remarkable for boring holes in wood, which are filled by their
elongated tubes, and give it a honey-comb appearance. Fig. 48. T.
Navalis. Fig. 49, a piece of bored wood.
TERMINAL. When the umbones of a bivalve shell are placed at or near the
extremity, as in Mytilus, fig. 158, Pinna, fig. 162, they are said to
be _terminal_. The same term is also applied to the nucleus of an
operculum, when it forms an extreme point, or is close to one of the
edges.
TESSELLATED. (Wrought in chequer-work). A term applied to the colouring
of shells, when arranged in regular defined patches like a tessellated
pavement.
TESTACELLA. (_Testa_, a shell.) _Fam._ Limacinea, Lam. and
Bl.--_Descr._ Haliotoid, compressed; aperture wide, oblique; columella
flat, oblique; spire short, flat, consisting of less than two
whorls.--_Obs._ This shell which is extremely small compared with the
animal, is placed upon its back, near the posterior extremity. The
animal is found in some of our gardens, and very much resembles the
common garden slug. Fig. 261, T. Haliotoidea.
TESTACEOUS. (_Testa_, a shell.) Shelly. Testaceous Mollusca, are soft
animals having shells. A testaceous operculum is one composed of shelly
matter.
TETRACERA. Bl. The first family of the order Polybranchiata, Bl.
containing no genera of testaceous mollusca.
TEXTILIA. Sw. A sub-genus of Conus, consisting of Conus bullatus, &c.
Sw. Malac. p. 312.
TEXTULARIA. Defr. A genus of microscopic Foraminifera.
THALAMUS. Montf. A genus described as resembling Conilites, but curved
and granulated.
THALLEPUS. Sw. A genus of "Aplysianiæ," Sw. thus described: "Body more
slender and fusiform;" (than Aplysia,) "the lobes of the mantle short,
and incapable of being used for swimming; tentacula two, large, ear
shaped; eyes not visible. T. ornatus, _Sw._ Sp. Nov." Sw. p. 359.
THALLICERA. Sw. A generic name under which Swainson distinguishes
AMPULLARIA Avellana, Auct.
THECIDIUM. (_Thecas_, a box.) _Fam._ Brachiopoda, Lam. _Order_,
Palliobranchiata, Bl.--_Descr._ Lower valve concave, sub-trigonal, with
the umbo produced into a triangular, slightly incurved beak, and with
two short, pointed processes advancing from beneath the umbones; upper
valve flat, rounded square, with a short, blunt appendage, formed to
fit between the tooth-like process of the other valve; its inner
surface ornamented with symmetrically curved ridges.
THECOSOMATA. Bl. The first family of the order Aporobranchiata, Bl.
containing the genera Hyalæa, Cleodora, Cymbulia, Pyrgo.
THELICONUS. Sw. A sub-genus of Conus. Lardn. Cyclop. Malac. p. 312.
THELIDOMUS. Sw. A generic name under which Swainson has described a
division of the genus Helix, and which he has also used to designate a
genus in the family of "Rotellinæ," founded upon an aggregate of loose
particles collected and agglutinated in a spiral form by the larva of
an insect. Sw. Malac. p. 330 and 353.
THEMEON. Montf. A genus of microscopic Foraminifera.
THEODOXUS. Montf. A division of the genus Nerita. Fig. 324, N.
virginea.
THETIS. Sow. (_A sea nymph._) A genus of fossil shells, described as
resembling Mactra, but not having the internal ligament, and having
several small, acuminated, cardinal teeth, but no lateral teeth. It
resembles Tellina in some degree, but has not the posterior fold.
THIARELLA. Sw. A sub-genus of Mitra, Lardn. Cyclop. Malac. p. 319.
THRACIA. Leach. _Fam._ Lithophagidæ, Lam. Pyloridea, Bl. A genus
described as intermediate between Anatina, and Mya, and in some degree
resembling Corbula. T. corbuloides, fig. 93.
THUNDER-STONES. One of the vulgar appellations which have been applied
to shells of the genus Belemnites.
THIATYRA. Leach. A genus composed of AMPHIDESMA _flexuosa_, Lam. and
similar species, belonging more properly to the genus LUCINA.
TIARA. Sw. A genus of "Mitranæ," Sw. thus described: "Aperture narrow,
linear, or of equal breadth throughout; outer lip and base of the body
whorl contracted, the former generally striated; an internal canal at
the upper part of the aperture; shell (typically) turrited, and equally
fusiform; representing the _Muricidæ_ and Cymbiola." Sw. Malac. p. 319.
The principal difference between Tiara and Mitra appears to be that in
the latter, the aperture is more linear and contracted in the centre.
Mitra Episcopalis is an example.
TINOPORUS. Montf. A genus of microscopic Foraminifera.
TIRANITES. Montf. A division of the genus Baculites.
TOMELLA. Sw. A genus of "Pleurotominæ," Sw. thus described: "Fusiform,
smooth; the spire of very few whorls, and not longer than the channel;
inner lip with a thick callosity at the top; the slit short and wide;
lineata, En. Méth. 440, f. 2, clavicularis, Ib. f. 4. filosa. En. Méth.
440, f. 6. lineolata. Ib. f. 11." Sw. p. 314.
TOMOGERUS. Montf. ANASTOMA, Auct. Fig. 471.
TONICHIA. Gray. Syn. B. M. p. 126. A genus composed of those species of
Chiton which have the margin smooth.
TORNATELLA. Auct. _Fam._ Plicacea, Lam.--_Descr._ Oval, spirally
grooved; spire short, rather obtuse, consisting of few whorls; aperture
long, narrow, rounded anteriorly; outer lip simple; inner lip thin,
slightly spread, columella spiral, incrassated, confluent with the
outer lip. The recent species are few. Several fossil species occur in
London Clay, Inferior Oolite and Calcaire-grossièr. Monoptygma, Lea,
resembles this genus, but has a fold on the inner lip. Fig. 343, T.
solidula.
TORTUOUS. (_Tortuosus_) Twisted. This adjective is sometimes applied as
a specific name; as Arca tortuosa.
TRACHELIPODA. Lam. ([Greek: trachêlos], _trachelos_, a neck; [Greek:
poda], _poda_, foot.) The third order of the class Mollusca, in the
system of Lamarck. The trachelipodous mollusca are described as having
the posterior part of the body spirally twisted and separated from the
foot; always enveloped in a shell. The foot is free, flat, attached to
the base of the neck. Shell spiral, and enclosing the animal when at
rest. This order contains the families, Colimacea, Lymnacea, Melaniana,
Peristomiana, Neritacea, Janthinea, Macrostomata, Scalariana, Plicacea,
Canalifera, Alata, Purpurifera, Columellaria, Convolutæ. The genera
belonging to these families, are represented in the plates, fig. 264,
to 462.
TRANSVERSE. (Crosswise.) A shell is said to be transverse, when its
width is greater than its length, that is, when it is longer from one
side to the other than from the umbones to the ventral margins. The
term is applied by some authors to express the direction of the lines
of growth in bivalve shells, and the spiral lines in spiral shells. See
CONCENTRIC.
TRAPEZIUM. Meg. CYPRICARDIA, Lam.
TRAPEZIFORM, or
TRAPEZOID. ([Greek: trapezion], _trapezion_, _trapezium_; [Greek:
eidos], _eidos_, form.) Having four unequal and unparallel sides. _Ex._
Cucullæa, fig. 133.
TRIBULUS. Klein. RICINULA, Lam.
TRICHOTROPIS. Brod. and Sow. ([Greek: Trichos], _trichos_, hair;
[Greek: tropis] _tropis_, keel.) _Fam._ Purpurifera, Lam.--_Descr._
Turbinated, keeled, thin, umbilicated; aperture longer than the spire,
entire; columella obliquely truncated; outer lip thin, sharp; epidermis
horny, produced into long hairs at the angles of the shell; operculum
horny, with the nucleus lateral.--_Obs._ Although the shells of this
genus have something of the shape of Turbo, they are distinguished from
that genus at once by the thinness of the shell. They are also known
from Buccinum, by the absence of a canal. Only two or three species are
known, which belong to the Northern and Arctic Oceans. T. bicarinata,
fig. 429.
TRIDACNA. Auct. _Fam._ Tridacnacea, Lam. Chamacea, Bl.--_Descr._
Equivalve, regular, inequilateral, radiately ribbed, adorned on the
ribs with vaulted foliations, waved at the margins, with a large,
anterior hiatus close to the umbones, for the passage of a large
byssus, by which the animal fixes itself to marine substances; hinge
with a partly external ligament; two laminar teeth in one valve, one in
the other.--_Obs._ The beautiful shells composing this genus are of a
delicate white colour, tinged with buff. One species, the T. gigas,
attains a remarkable size, measuring from two to three feet across, and
weighing five hundred pounds. Tridacna is distinguished from Hippopus
by the large opening in the hinge. T. elongata, fig. 157.
TRIDACNACEA. Lam. A family belonging to the first section of the order
Conchifera Dimyaria, Lam. described as regular, equivalve, solid, and
which are remarkable for the deeply sinuated or undulated ventral
margin. This family contains the genera:
1. HIPPOPUS. Valves closed at or near the hinge. Fig. 156.
2. TRIDACNA. An hiatus near the hinge. Fig. 157.
TRIDENTATE. (_Tridentatus_.) Having three teeth, or salient points.
_Ex._ Hyalæa tridentata, fig. 226.
TRIGONA. Schum.? Triangular species of CYTHEREA, such as C. lævigata,
Triplas corbicula, ventricosa, bicolor, &c. Fig. 117 _b._
TRIGONACEA. Lam. A family belonging to the order Conchifera Dimyaria,
containing the genera Trigonia and Castalia, the latter of which ought
to be removed to the Nayades. Fig. 139, 140.
TRIGONAL. Triangular, having three sides.
TRIGONELLA. Humph. MACTRA, Auct.
TRIGONIA. Brug. ([Greek: trigônon], _trigonon_, triangular.) _Fam._
Trigonata, Lam. Camacea, Bl.--_Descr._ Equivalve, inequilateral,
transverse, sub-trigonal, costated and granulated without, pearly and
iridescent within, denticulated on the inner margin, rounded
anteriorly, truncated posteriorly; hinge with four oblong, compressed,
diverging teeth in one valve, receiving between their grooved sides,
two similar teeth in the other; ligament external, thick; muscular
impressions two in each valve.--_Obs._ Only one recent species of this
marine genus is known, the T. pectinata, which comes from New Holland;
and was formerly so rare, that a much worn odd valve has been sold for
a considerable sum. It is of a brilliant pearly texture within, tinged
with purple or golden brown. Fossil species occur in Lias, upper and
lower Oolite, and Green-sand. T. Pectinata, fig. 139.
TRIGONOSEMUS. König. A genus composed of species of TEREBRATULA, Auct.
which have one valve produced into a beak, perforated, or as it were
truncated at the apex. T. lyra, fig. 208, differing from Terebratula
lyra, Lam.
TRIGONOSTOMA. A sub-genus of Helix, with a trigonal aperture. Gray's
Turton, p. 139.
TRIGONOTRETA. König. A genus composed of species of Terebratula, Auct.
which have the hinge of the larger valve produced into a triangular
disc, divided by a triangular foramen in the centre. Spirifer, Sowerby,
belongs to this genus. Fig. 214, 215.
TRILOBATE. ([Greek: Treis] three; [Greek: lobos], division, lobe.)
Divided into three lobes or principal parts. Ex. Malleus, Fig. 165.
TRILOCULINA. D'Orbigny. A genus of microscopic Foraminifera.
TRIPARTITE. (_Tripartitus_) composed of or divided into three separate
parts.
TRIPHORA, or TRISTOMA. Deshayes. A genus composed of small reversed
species of CERITHIUM, Auct. which have the anterior canal closed at the
anterior of the aperture, but opened at the extremity, and a small
tubular opening on the upper part of the whorls, making three openings
on the body whorl. This genus stands in the same relation to Cerithium
as the Typhis to Murex. Fig. 375 in the old plates, and fig. in the new
plates.
TRIPLEX. Humph. MUREX, Linn.
TRIPLODON. Spix. HYRIA, Auct.
TRIPTERA. Quoy et Gaimard, CUVIERA, Fer. Described in the Voyage de la
Coquille, and represented as a molluscous animal destitute of a shell.
TRIQUETRA. Bl. Triangular species of VENUS Auct.
TRISIS. Oken. ARCA tortuosa, Auct.
TRISTOMA. Described as TRIPHORA.
TRITON. Auct. _Fam._ Siphonostomata, Bl. Canalifera, Lam.--_Descr._
Oblong or oval, thick, ribbed or tuberculated, with discontinuous
varices placed at irregular distances; spire prominent, mammillated;
aperture round or oval, terminating anteriorly in a generally long,
slightly raised canal; columellar lip granulated or denticulated; outer
lip thickened, reflected, generally denticulated within; epidermis
rough; operculum horny.--_Obs._ However nearly allied the Tritons may
appear to be to the Murices and Ranellæ there are still to be traced in
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.
t. 5. p. 80. Our plates, fig. 520, 521. It is found on the shores of
Britain, 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.
1. ASPERGILLUM. Valves fixed, tube perforated and fringed. Fig. 44.
2. TEREDINA. Valves fixed, prominent, tube closed at one end.
Fossil. Fig. 46, 47.
3. CLAVAGELLA. One valve fixed, the other free. Fig. 45.
4. TEREDO. Both valves free, tube open at both ends. Fig. 48, 49.
5. FISTULANA. Valves free, tube closed at one end, straight, long.
Fig. 53, 54.
6. 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.
1. SOLARIUM. With umbilicus reaching to the apex; including
_Bifrontia_ and _Orbis_. Fig. 353 to 356.
2. ROTELLA. A callosity on the under side. Fig. 357.
3. PHASIANELLA. Oval; operculum shelly. Fig. 367.
4. PLANAXIS. Columellar lip flat; aperture notched. Fig. 365.
5. TURBO. Top-shaped; mouth generally round; operculum shelly. Fig.
368.
6. TROCHUS. Top-shaped; mouth generally angulated; operculum horny,
consisting of many whorls; including _Elenchus_. Fig. 358, 359,
361.
7. MARGARITA. Operculum horny, consisting of few whorls; pearly.
Fig. 362.
8. LITTORINA. Similar, not pearly; including _Assiminnea_. Fig.
363, 363*.
9. PHORUS. Attaching dead shells, stones, &c. Fig. 360.
10. MONODONTA or ODONTIS. A notch and prominent point at the lower
part of the aperture. Fig. 366.
11. LACUNA. With an umbilicus. Fig. 364.
12. 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.