Chapter X: Part 10

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.

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.
279. 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 as to include
all the genera of the Lamarckian Nayades, together with Castalia, which
are placed in the family Trigonacea, they are all fresh-water shells,
commonly called fresh-water muscles. The distinctions of the various
genera into which they have been divided, will be found in their
respective places, and under the name Nayades. They are all represented
in figures 140 to 152. Of these fig. 145 to 148, are more generally
considered as forming the genus Unio.

UNIOPSIS. Sw. A sub-genus of Alasmodon. Sw. p. 382.

UNIVALVE. (_Unus_, one; _valva_, valve.) A shell consisting of a single
piece, as distinguished from Bivalves and Multivalves, which are
composed of two or more principal pieces. Spiral shells having an
operculum, are called sub-bivalves by some authors.

UPPER-VALVE. The free valve in attached bivalves.

UVIGERINA. D'Orb. A genus of microscopic Foraminifera.

VAGINA. Megerle. SOLEN _vagina_, Auct.

VAGINULA. (_A little sheath, the husk of corn._) _Class_, Pteropoda,
Lam.--_Descr._ Pyramidal, slightly inflated in the centre, thin,
fragile; aperture oblong, with the edges turned slightly
outwards.--_Obs._ The little shells of this genus, which are only known
in a fossil state, differ from Cuvieria in being pointed at the
extremity. Found in the tertiary beds of Bordeaux. V. Daudinii, fig.
225.

VAGINULINA. D'Orb. A genus of microscopic Foraminifera.

VALVATA. Müll. _Fam._ Peristomata, Lam. Cricostomata, Bl.--_Descr._
Thin, turbinated; spire short, composed of from three to six rounded
whorls; aperture circular; peritreme acute, entire; operculum horny,
spiral.--_Obs._ This genus of small shells resembles Cyclostoma, from
which the recent species may be known by the horny texture of the
external surface, being fresh-water shells. The fossils of course
belong to the fresh-water formations. V. piscinalis, fig. 322. Europe
and North America.

VALVES. (_Valva_, a door, a folding piece.) The two pieces composing a
bivalve shell, which close upon each other, turning upon a hinge
consisting of a ligament, cartilage, and teeth. See BIVALVE,
MULTIVALVE, and UNIVALVE.

VALVULINA. D'Orb. A genus of microscopic Foraminifera.

VARIX. (_A swelling vein._) A varix is formed on the outer surface of a
spiral shell, by the thickened, reflected edge of a former aperture,
after fresh deposits of testaceous matter have increased the size by
adding to the growth of the shell beyond it. In this manner there are
frequently many varices, or edges of former apertures, in various parts
of the spire and the body whorl. They are sometimes placed at regular
distances from each other, as in Harpa, fig. 419; sometimes
_continuous_, as in Ranella, fig. 394; sometimes _discontinuous_, as in
Triton, fig. 398; sometimes _ramose_, as in Murex, fig. 395; sometimes
_simple_, as in Scalaria, fig. 351; sometimes _spinose_, as in Murex
spinosus. The term _varix_ has also been applied to any swelling ridge,
such as that on the lower part of the columella of Ancillaria, fig.
456.

VELATES. Montf. NERITINA perversa, Auct. Fig. 326.

VELLETIA. Gray? A genus described as differing from ANCYLUS in being
dextral. VELLETIA lacustris, ANCYLUS lacustris, Auct. fig. Sowerby Gen.
fig. 2.

VELUTINA. Auct. _Fam._ Macrostomata, Lam.--_Descr._ Sub-globose,
covered with a velvety epidermis; spire short, composed of two rapidly
enlarged ventricose whorls; aperture large, sub-ovate; peritreme thin,
entire, separated from the last whorl; columella tortuous,
thin.--_Obs._ This shell does not resemble any other genus in the
family. Fig. 337. Northern Seas.

VENERICARDIA. Lam. A genus composed of the shorter species of Cardita.

VENERIRUPIS. Lam. (From _Venus_ and _rupis_, a rock.) The oblong
species of Venus Auct. which live in cavities of rocks and stones. This
genus is united by Sowerby with some other species of Venus under the
name Pullastra. V. Vulgaris, fig. 97.

VENTRAL. (_Venter_, the belly.) The margin of a bivalve shell opposite
the hinge. The under valve in Brachiopodous bivalves is the ventral
valve. The ventral surface of an univalve spiral shell is that which
faces the observer when the aperture is placed towards him. The ventral
part of the whorls of symmetrical convolute shells, is the inner part,
that which is nearest to the spire.

VENTRAL SIPHON. In symmetrical convolute univalves, is one placed near
the inner edge of the whorls.

VENTRICOSE. (_Ventricosus._) Swelled, rounded out, (_bombé Fr._) as
Harpa ventricosa, fig. 419.

VENUS. Auct. (_Goddess of Beauty._) _Fam._ Marine Conchacea, Lam.
Conchacea, Bl.--_Descr._ Equivalve, inequilateral, sub-globose,
sub-ovate, transverse, externally rugose, striated, ribbed, cancellated
or smooth; margins entire, simple, close; hinge with three more or less
distinct cardinal teeth, diverging from the umbones in each valve;
muscular impressions two, lateral, distant; palleal impressions
sinuated posteriorly; ligament external.--_Obs._ This extensive genus,
including some bivalves of splendour and beauty, justifying the name
given to it, may be known from Cytherea by the absence of a lateral
tooth, which is found near the cardinal teeth in the latter. Artemis is
distinguished not only by its beautiful form, but by the deep angular
sinus in the palleal impression. Fig. 119, 119 a. Found mostly in
temperate and tropical climates.

VERMETUS. Adanson. _Fam._ Scalariana, Lam. Cricostomata, Bl.--_Descr._
Spiral at the apex, irregularly twisted towards the aperture; aperture
round, small.--_Obs._ This shell resembles the Serpulæ in general
appearance, although it is regularly spiral near the apex. The animal
is known to be a true mollusc, rather nearly allied to that of the
genus Dentalium, which is also placed wrongly in the Lamarckian system.
Vermetus Lumbricalis, fig. 345. Coast of Africa.

VERMICULAR. (_Vermicularis._) Worm-shaped, tubular, serpentine. _Ex._
Vermilia triquetra, fig. 7.

VERMICULARIA. Lam. VERMETUS, Adanson; afterwards VERMETUS, Lam.

VERMILIA. Lam. A genus composed of species of Serpula, which are
attached by the whole length of the shell, no part being free. Vermilia
triquetra, fig. 7.

VERTEBRALINA. D'Orb. A genus of microscopic Foraminifera.

VERTEX. Apex.

VERTIGO. Müll. _Fam._ Colimacea, Lam.--_Descr._ Cylindrically fusiform,
sinistral, hyaline; aperture marginated, sinuated, denticulated on the
inner edge; peristome sub-reflected.--_Obs._ This genus of minute land
shells, resembles Pupa, but is a reversed, hyaline shell. Vertigo
pusilla, fig. 293. Europe.

VERRUCA. Schum. CLITIA, Leach.

VESICA. Sw. A sub-genus of Bulinus, Sw. p. 360.

VEXILLA. Sw. A genus of "Nassinæ," Sw. thus described: "General shape
of _Purpura_, the inner lip flattened and depressed; the outer, when
adult, thickened, inflected and toothed; aperture wide; picta _Sw._
Chem. pl. 157, f. 1504-5." Sw. Malac. p. 300.

VIRGULINA. D'Orb. A genus of microscopic Foraminifera.

VITRELLA. Sw. A sub-genus of "Bullinæ," Sw. Lardn. Cyclop. Malac. p.
360.

VITRINA. Drap. (_Vitreus_, glassy.) _Fam._ Limacinea, Lam. and
Bl.--_Descr._ Ovate, thin, glassy, fragile; spire short; last whorl
large; aperture wide, transverse; peritreme simple; columella spiral,
linear.--_Obs._ This genus of land-shells is not known in a fossil
state. The recent species are found among moss and grass, in shady
situations. De Ferussac has divided this genus into Helicolimax, fig.
263, and Helixarion, fig. 262.

VITULARIA. Sw. A genus of "Muricinæ," Sw. thus described: "General
habit of _Muricidea_, but the inner lip is depressed and flattened as
in the _Purpurinæ_; varices simple, nearly obsolete. Tuberculata, Sw.
En. M. 419. fig. 1. (_Murex vitulinus_, Auct.)" Sw. p. 297.

VIVIPARA. A generic name given by Montfort, and retained by some
authors for PALUDINA, Lam. on account of the animals being
_viviparous_, i. e. the young being perfectly formed before they leave
the ovaries.

VIVIPAROUS. See VIVIPARA.

VOLUTA. Auct. (_Volvo_, to revolve.) _Fam._ Columellaria, Lam.
Angyostomata, Bl.--_Descr._ Sub-ovate, rather angulated, thick,
generally tuberculated, smooth; spire short, conical, with a
mammillated apex; aperture generally angulated, large, terminating
anteriorly in a deep notch; columella smooth, with several plaits, of
which the lowest is the largest; outer lip thickened within.--_Obs._
The genus Voluta, as left by Linnæus, is only characterized by the
folds on the columella, and includes many shells which, although they
agree in this respect with the genus, are yet quite opposite to each
other in all other characters. Thus the Auriculæ, which are land
shells, and have the aperture entire, are mixed up with others which
are marine, and have a canal, as Turbinellæ, and the Fasciolariæ, and
others which have merely a notch, as the true Volutes. This genus, as
it is circumscribed at present, includes a great number of beautiful
shells, most of which are rich in colouring. CYMBA and MELO have been
separated by Mr. Broderip from the genus VOLUTA of Lamarck, for reasons
stated in their respective descriptions. Fig. 443.

VOLVARIA. Lam. (_Volva_, a shuttle.) _Fam._ Columellaria,
Lam.--_Descr._ Cylindrical, convolute, spirally striated; spire very
short, nearly hidden; aperture narrow, as long as the whole shell;
columella with three oblique plaits; outer lip dentated.--_Obs._ The
Volvaria are only known in a fossil state, and resemble some species of
Bulla in general form, but are distinguished by the plaits on the
columella. Fig. 439, V. concinna.

VOLUTELLA. Sw. (_A little volute._) A genus composed of those species
of MARGINELLA, Auct. which have the spire concealed, and the aperture
smooth within. Fig. 438, PERSICULA of Schumacher.

VOLUTILITHES. Sw. (_Voluta_, and [Greek: lithos], _lithos_, a stone.) A
genus composed of some fossil species of Voluta, which have the plaits
on the pillar generally numerous, indistinct, and sometimes wanting
altogether, with a pointed spire. Fig. 436, V. spinosa.

VOLUTION. See WHORL.

VORTICIALIS. Lam. A genus of microscopic Foraminifera.

VULSELLA. Lam. (_A little tongue._) _Fam._ Ostracea, Lau. Margaritacea,
Bl.--_Descr._ Equivalve, irregular, longitudinal, compressed, oblong;
umbones separated by a slight area in both valves; hinge with a large
pit in the centre, containing the cartilage, the ligament being spread
over the areas; muscular impressions, one on each valve, sub-central,
oblong.--_Obs._ This genus differs from Ostræa in the equality of the
valves, and in having a hollow pit in the hinge for the cartilage.
Vulsella lingulata, fig. 185.

WATERING-POT. Aspergillum, fig. 44, commonly so called on account of
the resemblance of its perforated termination to that of the spout of a
watering-pot.

WENTLE TRAP. Scalaria pretiosa, commonly so called.

WHORL. A complete turn or revolution round the imaginary axis of a
spiral shell. The last whorl is called the _body-whorl_. The whorls are
described as _non-contiguous_, when they do not touch each other;
_continuous_, in the opposite case. _Depressed_ when they are flat.
They are _angulated_, _heeled_, or coronated; _distinct_, or
indistinct. They are sometimes, as in Cypræa, hidden by the last whorl.

XYLOPHAGA. Sow. ([Greek: xulon], _zylon_, wood; [Greek: phagô],
_phago_, to eat.) _Fam._ Tubiscolæ, Lam.--_Descr._ Equivalve, globose,
closed at the back; with a large, angular hiatus in front; hinge with a
small curved tooth advancing from beneath the umbones in each
valve.--_Obs._ This shell, which is found in a cylindrical cavity,
eaten in wood by the animal, resembles Teredo, but has not the shelly
tube, nor the posterior hiatus. X. dorsalis, fig. 50, 51.

XYLOTRYA. Leach. XYLOPHAGA, Sow.

ZONITES. Montf. A genus formed of Helix Algira, and other similar
species with depressed spires and large umbilici; included in the
sub-genus Helicella. Fig. 279.

ZUA. Leach. A genus described as differing from Bulinus in having a
polished epidermis, and a thickened, not reflected lip. Zua lubrica, B.
lubricus, Auct.

ZURAMA. Leach. A sub-genus of Helix. H. pulchella, Auct. Gray's Turton,
p. 41.

* * * * *

EXPLANATION OF PLATES,

AND SYSTEMATIC VIEW OF THE

LAMARCKIAN ARRANGEMENT.

_Class_, ANNELIDES.
_Order_, SEDENTARIA.
_Fam._ Dorsalia.

FIG.

1. Siliquaria anguina. Agathirses, Montf.

_Fam._ Maldania.

2. Dentalium octogonum.

3. Pharetrium fragile, with the outer tube broken.

_Fam._ Serpulacea.

4. Serpula bicarinata.

5. Spirorbis Nautiloides, on sea-weed.

6. Galeolaria decumbens, on a Conia.

7. Vermilia triquetra.

8. Spiroglyphus, on a portion of Patella.

9. Magilus antiquus, old shell. Campulotus, Guild. (from Guerin.)

10. The same, in a young state.

11. Leptoconchus striatus.

12. Stylifer astericola.

13. The same, in a portion of Star-fish.

_Class_, CIRRIPEDES.
_Order_, SESSILE CIRRIPEDES

14. Tubicinella Balænarum.

15. Coronula Testudinaria. Chelonobia, Leach, Astrolepas, Klein.

16. ---- Balænaris. Cetopirus, Ranz.

17. ---- diadema. Diadema, Ranz.

18. Chthalamus, Ranz. (from Blainville.)

19. Platylepas pulchra, Leach. One valve separate, showing the inside.

20. Clitia Verruca, Leach. Octhosia, Ranz. Verruca, Schum.

21. Conia porosa. Teraclita, Schum.

22. Elminius Leachii.

23. Catophragmus imbricatus, (from Sowerby's Genera.)

24. Octomeris angulosus, (from Sow. Gen.)

25. Balanus tintinnabulum.

26. ---- Montagui. Acasta, Leach.

27. ---- galeatus, Conoplæa, Say.

28. Creusia gregaria. _b._ showing the internal structure.

29. Nobia grandis.

30. Savignium crenatum. }
}
31. Pyrgoma cancellata. } Pyrgoma, Auct.
}
32. Adna Anglicum. }
}
33. Megatrema semicostata.}

_Order_, PEDUNCULATED CIRRIPEDES.

34. Pentelasmis lævis. Antifa, Lam. a. anterior.

35. Scalpellum vulgare.

36. Smilium Peronii.

37. Pollicipes polymeus. Ramphidoma, Schum.

37*. Pollicipes mitellus. Capitulum, Klein.

38. Brismæus Rhophodius.

39. Lithotrya dorsalis. Absia, Leach, Litholepas, Bl.

40. Ibla Cuvieriana.

41. Heptalasmis Warwickii. Octolasmis, Gray.

42. Cineras vittatus.

43. Otion Cuvieri.

_Class_, CONCHIFERA.
_Order_, C. DIMYARIA.
_Fam._ Tubicolaria.

44. Aspergillum vaginiferum. Penicillus, Brug.

45. Clavagella, a fossil species.

46. Teredina personata.

47. Lignite, pierced by Teredinæ.

48. Teredo navalis; _a_, tube (from Sowerby's Genera.)

49. Wood bored by Teredo.

50. Xylophaga dorsalis. Xylotrya, Leach.

51. The same, in wood.
(This would be more properly placed in Pholadaria.)

52. Gastrochæna Modiolina, in the tube (from Sowerby's Genera.)

53. Fistulana Clava. }
} (From Sowerby's Genera.)
54. Tube of the same. }

_Fam._ Pholadaria.

55. Pholas Dactylus; _a_, plates of the hinge.

56. ---- papyracea. Pholadidæa.

57. Pholadomya Candida.

58. Galeomma Turtoni.

59. Front view of the same.

(Here Xylophaga should be placed, see Tubicolaria.)

_Fam._ Solenacea.

60. Solen ensis. Ensis, Schum. Ensatella, Sw.

61. Solen radiatus. Solenocurtus, Bl. Leguminaria, Schum. Siliqua,
Megerle.

62. Lepton squamosum. (from Turton.)

63. Novaculina gangetica.

64. Glanconome Chinensis.

65. Panopæa Australis. }
} (From Sowerby's Genera.)
66. Hinge of Panopæa Faujasii.}

67. Glycimeris Siliqua.

68. Solenimya Mediterranea.

_Fam._ Myaria.

69. Anatina rostrata. Auriscalpium, Megerle.

70. Anatinella Sibbaldii.

71. Mya truncata.

72. Periploma inæquivalvis. Osteodesma, Desh. _a_, bone of the
hinge, (from Blainville.)

73. Myochama anomioides; lower valve with clavicle, and hinge of
upper valve.

74. External view of the same, attached to a Trigonia.

75. Cleidothærus Chamoides, attached valve.

76. Upper valve of the same, with the clavicle.

_Fam._ Mactracea.

77. Lutraria papyracea. Ligula, Leach. Carinella, Adans.

78. ---- Solenoides. Cutellus ----?

79. Mactra Stultorum.

80. ---- plicataria. Spisula? Gray.

81. ---- Spengleri. Schizodesma, Gray.

82. ---- bicolor. Mulinia, Gray.

83. Gnathodon cuneatus. Clathodon, Conrad.

84. Crassatella rostrata.

85. Amphidesma reticulatum.

86. Erycina plebeja. Mesodesma, Desh.

87. Cuming mutica.

88. Ungulina transversa, (from Sowerby's genera.)

_Fam._ Corbulacea.

89. Corbula nucleus.

90. Pandora rostrata.

_Fam._ Lithophagidæ.

91. Petricola Roccellaria.

92. ---- Carditoidea. Coralliophaga, Bl.

93. Thracia corbuloides.

94. Saxicava rugosa.

95. Hiatella biaperta.

96. Sphænia Binghamii.

97. Venerirupis vulgaris.

_Fam._ Nymphacea.

98. Sanguinolaria rosea. Lobaria, Schum.

99. ---- Diphos. Soletellina, Bl.

100. Psammobia Ferroensis. Gari, Schum.

101. Corbis fimbriata. Fimbria, Megerle.

102. Grateloupia Moulinsii. (from Lea.)

103. Egeria triangulata, (from Lea.)

104. Lucina tigerina.

105. Tellina radiata.

106. ---- lingua-felis; _a_, showing the fold in the ventral
margin.

107. Tellinides rosea.

108. Donax cuneatus.

109. Capsa Braziliensis, young.

110. Astarte Danmoniensis. Crassina, Lam.

Fluviatile Conchacea.

111. Cyclas rivicola. Cornea, Megerle.

112. Pisidium amnicum. Pisum, Megerle.

113. Cyrena fuscata. Corbicula, Megerle.

114. Cyrenoides Dupontia.

115. Potamophila radiata. Galathæa, Lam. _v._ ventral margin.

Marine Conchacea.

116. Cyprina vulgaris. Arctica, Schum.

117. Cythera Meretrix; _e._ escutcheon.

117 _a._ C. Meroe; _Gen._ Meroe.

117 _b._ C. Tripla; _Gen._ Trigona.

117 _c._ C. maculata; _Gen._ Chione.

117 _d._ C. Castrensis; _Gen._ Circe.

118. Artemis lincta; _s_, sinus in the Palleal impression.

119. Venus cancellata. Antigona, Schum. _a._ anterior; _p._
posterior; _c._ cardinal teeth.

119 _a._ V. Verrucosa. Dosina, Schum.

120. Pullastra Textile.

_Fam._ Cardiacea.

121. Venericardia, recent species, resembling V. planicostata, Lam.

122. Cardium Dionæum. Cardissa, Sw. Hemicardium, Nonnull.

123. ---- angulatum.

123*. ---- Greenlandicum. Aphrodita, Lea, Acardo, Sw.

123**. --- hemicardium. _Gen._ Hemicardum.

124. Cardita calyculata.

125. Cypricardia angulata.

126. Isocardia Moltkiana.

127. Megalodon cucullatus, (from Sow. Min. Con.)

128. Hippagus Isocardioides, (from Lea.)

129. Hippopodium ponderosum, (from Sow. Min. Con.)

130. Pachymya gigas, (from Sow. Min. Con.)

_Fam._ Arcacea.

131. Arca antiquata.

132. Bysso-arca Noæ.

133. Cucullæa auriculifera, (from Sowerby's Genera.)

134. Pectunculus pilosus.

135. Myopara costata, (from Lea.)

136. Crenella.

137. Nucula margaritacea, three views.

138. Solenella Norrissii.

_Fam._ Trigonacea.

139. Trigonia pectinata.

140. Castalia ambigua. Tetraplodon pectinatus, Spix.

_Fam._ Nayades.

141. Alasmodon complanatus, Say. Margaritana, Schum.

142. Dipsas plicatus, Leach. Cristaria, Schum.

143. Hyria corrugata, Lam. Paxyodon, Schum. Triplodon.

144. Syrmatophora, Sow. Prisodon, Schum. Diplodon, Spix.

145. Unio littoralis, Lam. Mysca ovata, Turton.

147. ---- Alatus. Symphynota, Lea.

148. ---- Atratus, Lam. Naia, Sw.

149. Monocondylæa Paraguayana.

150. Iridina elongata. Pleiodon, Conrad. } Platiris, Lea.
}
151. Mycetopus solenoides, D'Orb. Spatha, Lea. }

152. Anodon Cataractus.

_Fam._ Chamacea.

153. Chama Lazarus. Jataronus, Adanson.

154. Diceras perversum, (from Sowerby's Genera.)

155. Etheria semilunata.

_Order_, MONOMYARIA.
_Fam._ Tridacnacea.

156. Hippopus maculatus.

157. Tridacna elongata.

_Fam._ Mytilacea.

158. Mytilus achatinus.

159. ---- polymorphus. Dreissina.

160. Modiola Tulipa.

161. Lithodomus Dactylus.

162. Pinna saccata.

_Fam._ Malleacea.

163. Avicula Hirundo.

164. ---- margaritifera. Meleagrina, Lam.

165. Malleus Vulgaris. Himantopoda, Schum.

166. Perna Ephippium.

167. Catillus Lamarckii. Inoceramus, Sow. (from Blainville.)

168. Crenatula mytoloides. }
}
169. Gervillia aviculoides. } (from Sowerby's Genera.)
}
170. Pulvinites Adansonii. }

_Fam._ Pectinides.

171. Pecten varius. Janera, Schum.

172. ---- Plica. Decadopecten, Rüppell.

173. Hinnites Pusio. Pecten Pusio, Lam.

174. Lima squamosa.

175. Dianchora striata, (from Sow. Min. Con.)

176. Plagiostoma spinosum, (from Sow. Min. Con.)

177. Spondylus Americanus, hinge. (See Frontispiece.)

178. Plicatula gibbosa. Harpax, Parkinson.

179. Pedum Spondyloideum, (from Sow. Gen.)

_Fam._ Ostracea.

180. Ostrea edulis.

181. ---- Folium. Dendostrea, Sw.

182. Gryphæa incurva.

183. Exogyra conica, (from Sow. Min. Con.)

184. Placuna placenta. _Gen._ Placenta, Schum.

185. Vulsella lingulata.

186. Anomia Ephippium.

187. Hinge of the same, with bony process.

188. Hinge, showing the fissure.

189. Placunanomia Cumingii.

190. Hinge of the same, showing the fissure.

191. Hinge of the unattached valve.

192. Mulleria. (from Sow. Gen.)

_Fam._ Rudistis.

193. Sphærulites foliacea. (Radiolites is more conical.)

194. Calceola Sandalina.

196. Birostrites inæquiloba, internal cast of Sphærulites.

197. _a._ Crania personata, dorsal valve; _b._
C. antiquata, interior.
(This would be more properly placed in Brachiopoda.)

198. Hippurites Cornucopia, (from Blainville.)

199. Hipponyx Cornucopia, attached valve.

200. Upper valve of the same.

_Fam._ Brachiopoda.

201. Orbicula lævis.

202. Terebratula Psittacea; _a._ anterior margin.

203. Atrypa reticularis. Trigonotreta, König.

204. Cyrtia exporrecta.

205. Delthyris plycotes, (from Dalman.)

206. Leptæna depressa, Dalman. Producta, Sow. (from Sow. Gen.)

206*. Producta antiquata.

207. Orthis basalis, Dalman. Strophomena, Rafinesque.

208. Trigonosemus Lyra, König.

209. Magas pumilus, Sow.

210. Gypidia conchidium, (from Dalman.)

211. Interior of the large valve of the same. (from Dalman.)

212. Pentamerus Aylesfordii, (from Sow. Min. Con.)

213. ---- lævis.

214. Spirifer trigonalis. }
} Trigonotreta, König, (from Sow. Gen.)
215. ---- dorsatus. }

216. Thecidium recurvirostrum.
(Here should come Crania, see Rudistes.)

217. Pycnodonta radiata, (from Fischer.)

218. Hinge of the same.

219. Lingula Anatina.

_Class_, MOLLUSCA.
_Order_, PTEROPODA.

220. Atlanta helicialis.

221. Cleodora cuspidata.

222. Creseis spinifera.

223. Cuvieria columella.

224. Spiratella limacinea, with animal; Limacella, Lam. Limacina
Cuvier. (from Blainville.)

225. Vaginula Daudinii.

226. Hyalæa tridentata. Archonte, Montf.

_Order_, GASTEROPODA.
_Fam._ Phyllidiana.

227. Chiton spinosus.

228. Chitonellus striatus. (from Sow. Gen.)

229. Patella oculus; _a._ anterior.

230. Patella pellucida. Helcion, Montf. Ansates, Klein.

231. Patelloida Antillarum. Lottia, Gray.

231*. Siphonaria Sipho.

_Fam._ Semiphyllidiana.

232. Pleurobranchus membranaceus.

233. Umbrella indica. Gastroplax, Bl.

_Fam._ Calyptracea.

234. Calyptræe Equestris.

235. ---- extinctorium.

236. ---- auriculata.

237. ---- Pileus. Infundibulum, Montf.

238. Side view of the same.

239. Crepidula Porcellana.

240. Capulus ungaricus, two views. Pileopsis, Lam.

241. Emarginula fissura.

242. Parmophorus elongatus. Scutus, Montf.

243. Rimula Blainvillii.

244. Cemoria Flemingii.

245. Fissurella oriens.

246. Ancylus fluviatilis.

_Fam._ Bullæana.

247. Bulla fragilis. Akera, Nonnul.

248. ---- aperta. Bullæa, Lam.

249. ---- aplustre. Aplustre, Schum.

250. ---- Naucum. Atys, Montf.

251. ---- lignaria. Scaphander, Montf.

252. ---- Ampulla.

253. ---- lineata.

_Fam._ Aplysiacea.

254. Aplysia Petersoni.

255. Dolabella Rumphii.

_Fam._ Limacinea.

256. Parmacella calyculata, Cryptella. Webb.

257. Parmacella Olivieri. (from De Ferussac.)

258. ---- palliolum. (from De Ferussac.)

259. Limax antiquorum.

260. Plectophorus corninus.

261. Testacella Haliotoidea.

262. Helixarion, Cuv. }
} Vitrina, Drap. Cobresia, Haubner.
263. Helicolimax pellucida. }

_Order_, TRACHELIPODA.
_Fam._ Colimacea.

_Sub-genera_ of De Fer.

264. Helix brevipes, Drap. Helicophanta.

265. Succinea amphibia. }
} Cochlohydra.
266. ---- patula. Amphibulima, Lam. }

267. Helix hæmastoma. Acarus, }
Montf. }
268. ---- Pomatia. } Helicogena.
}
269. Streptaxis contusa, Gray.}
}
270. Another view of the same.}

271. Anastoma depressum. }
}
272. Another view of the same. }
}
273. Helix nux-denticulata. } Helicodonta.
}
274. Proserpina nitida. }
}
275. Polygyra septemvolva. }
}
276. Another view of the same. }

277. Carocolla Lamarckii. }
} Helicigona.
278. Helix pileus. Geotrochus, Sw. }

279. ---- algira. Zonites, Montf. }
} Helicella.
280. ---- citrina. Naninia, Gray. }

281. ---- epistilum Helicostyla.

282. Bulinus rosaceus; _a._ apex. }
}
283. ---- Guadaloupensis; Bulinulus, }
Leach. } Cochlostyla.
284. ---- Lyonetianus. Gibbus, Montf. }
}
285. ---- lubricus. Cionella, Jeffreys.}

286. Achatina virginea Liguus, Montf. }
} Cochlitoma.
287. Achatinella, Sw. }

288. Polyphemus Glans, Montf. Cochlicopa.

289. Bulinus decollatus, in a young state. Cochlicella.

290. Azeca tridens, Jeffreys. Turbo tridens, } Cochlogena.
Gmelin. }

291. Pupa Uva. }
}
292. Alæa marginata; Jeffreys. }
} Cochlodonta.
293. Vertigo pusilla. }
}
294. Megaspira Ruschenbergiana. }

295. Clausilia Macascarensis; _a_, a break, }
to show the clausium. } Cochlodina.
}
296. Balea fragilis. }

297. Auricula Judæ.

298. ---- coniformis. Conovulum, Lam. Melampus, Montf.

299. Pedipes Adansonii.

299*. Scarabæus imbrium.

300. Chilina Dombeyana.

301. Carychium minimum.

302. Partula Australis.

303. Cyclostoma ferrugineum.

304. ---- Involvulus. Cyclophorus, Montf.

305. Nematura Deltæ.

306. Helicina major.

307. Operculum of the same.

_Fam._ Lymneana.

308. Limnæa stagnalis.

309. ---- auricularia. Radix, Montf.

310. ---- castanea. Physa, Drap.

311. Planorbis corneus.

312. Planaria niteus, (from Lea.)

_Fam._ Melaniana.

313. Melania subulata. Melas, Montf.

314. Melania prærosa and monodontoides. Anculosa, Say.

315. Melanopsis costata. Faunus, Montf.

316. Pirena terebralis.

317. Pasithæa striata, (from Lea.)

_Fam._ Peristomata.

318. Ampullaria fasciata. Amphibola; _a_, aperture.

319. ---- Guinaica. Lanistes, Montf.

320. ---- Cornu-arietis. Ceradotes, Guild.

321. Paludina Bengalensis.

322. Valvata piscinalis.

_Fam._ Neritacea.

323. Navicella elliptica.

324. Neritina virginea. Theodoxus, Montf.

325. ---- spinosa. Clithon, Montf.

326. ---- perversa. Velates, Montf. (from Sow. Gen.)

327. Natica mamilla. Polinices, Montf.

328. ---- lineata.

330. Nerita peloronta. Peloronta, Oken.

331. Neritopsis granosa.

332. Pileolus plicatus.

333. Janthina fragilis.

_Fam._ Macrostomata.

334. Sigaretus concavus.

335. Stomatia Phymotis.

336. Stomatella imbricata.

337. Velutina lævigata. Galericulus, Nonnul.

338. Haliotis rubra, young.

339. ---- tricostalis, Lam. Padollus, Montf.

340. Scissurella elatior, magnified. }
} (from Sow. Gen.)
341. Pleurotomaria reticulata. }

_Fam._ Plicacea.

342. Pyramidella terebellum.

343. Tornatella solidula. Acteon, Montf.

344. Monoptygma elegans. (from Lea.)

_Fam._ Scalariana.

345. Vermetus lumbricalis.

346. Rissoa reticulata.

347. Eulima labiosa.

348. ---- marmorata. Bonellia, Desh.

349. Cirrus nodosus, Sow.

350. Euomphalus pentangulus. (from Sow. Min. Con.)

351. Scalaria Pallassii. Aciona, Leach.

352. Delphinula laciniata.

_Fam._ Turbinacea.

353. Solarium perspectivum.

354. ---- Bifrons. Bifrontia and Omalaxis, Desh.

355. Orbis Rotella. (from Lea.)

356. Another view of the same.

357. Rotella vestiaria, Pitonellus, Montf.

358. Trochus stellaris, Lam. Calcar, Montf. Turbo, Sow.

359. ---- maculatus. Tectus, Montf.

360. ---- agglutinans. Phorus.

361. ---- Pharaonis. Clauculus, Montf.

362. Margarita tæniata.

363. Littorina vulgaris.

363*. Assiminea Grayana.

364. Lacuna pallidula.

365. Planaxis sulcata.

366. Monodonta labeo; Odontis, Sow.

367. Phasianella variegata.

368. Turbo setosus. Marmarostoma, Sw.

369. Tuba striata. (from Lea.)

370. Turritella imbricata.

371. Monotygma, Gray.

_Fam._ Canalifera.

372. Cerithium Aluco, front.

374. Nerinea Goodhallii. (from Geol. Trans.)

375. Triphora plicata. (from Deshayes.)

376. End view of the same.

377. Potamis muricata. Pyrazus, Montf. Tympanostomata, Schum.

378. Cerithium Telescopium. _Gen._ Telescopium.

379. Pleurotoma Babylonia; _a, a_, extremities of the axis.

381. ---- strombiformis, Clavatula, Lam.

382. Turbinella corniger. Scolymis, Sw.

383. ---- polygona. Polygonum, Schum.

384. Spirillus. _Gen._ Pyrella, Sw. Turbinella spirillus, Auct.

385. Cancellaria reticulata.

386. Fasciolaria Trapezium.

387. Fusus Colus; _a_, anterior of the aperture; p, posterior.

388. Pyrula perversa. Fulgur, Montf.

389. ---- papyracea. Rapanus, Schum. Bulbus, Humph. Rapella, Sw.

390. ---- Ficus. Ficula, Sw.

391. Struthiolaria straminea.

393. Ranella ranina. Apollon, Montf.

394. ---- neglecta. Bufo, Montf.

395. Murex inflatus. Chicoreus, Montf.

396. ---- haustellum. Brontes, Montf.

397. Typhis tubifer. (from Deshayes.)

398. Triton pilearis.

399. ---- cutaceus. Aquillus, Montf.

400. ---- Lotorium. Lotorium, Montf.

401. ---- anus. Persona, Montf.

_Fam._ Alatæ.

402. Rostellaria curvirostrum.

403. ---- columbaria. Hippochrenes, Montf. (from Sow. Gen.)

404. ---- Pes-pelicani. Aporrhais, Petiver.

405. Pteroceras aurantiacum.

406. Strombus pugilis.

_Fam._ Purpurifera.

407. Cassidaria echinophora. Morio, Montf.

408. Side view of the outer lip, to shew the canal.

409. Oniscia Oniscus. Cassidara.

410. Cassis tuberosa, reduced.

411. ---- erinaceus. Cassidea, Sw.

412. ---- testiculus. Cypræcassis, Stutchbury.

413. Ricinula horrida. Sistrum, Montf.

414. Purpura persica.

415. Tritonidea (_Pollia_, Gray.) articularis.

416. Phos senticosa.

417. Monoceros crassilabrum.

418. Concholepas Peruviana.

419. Harpa ventricosa.

420. Dolium maculatum.

421. Buccinum undatum; _a_, anterior of the aperture; _p_, posterior.

422. ---- papillosum. Alectrion, Montf.

423. Nassa arcularia.

424. ---- neritoidea. Cyclops, Montf.

425. Cyllene, Gray.

426. Eburna Zeylanica.

427. Bullia vittata.

428. Terebra maculata. Subula, Bl.

429. Trichotropis bicarinata.

_Fam._ Columellata.

430. Columbella mercatoria.

431. Mitra plicaria; _c_, termination of the columella.

432. Conohelix marmorata.

433. Voluta Vespertilio. Cymbiola, Sw.

434. Cymba porcina.

435. Melo Æthiopicus.

436. Volutilithes spinosus.

437. Marginella Glabella. Glabella, Sw. Cucumis, Klein.

438. ---- persicula. Volutella, Sw. Persicula, Schum.

439. Volvaria concinna.

_Fam._ Convolutæ.

440. Ovulum Ovum.

441. ---- verrucosum. Calpurnus, Montf.

442. ---- Volva. Radius, Montf.

443. ---- gibbosum. Ultimus, Montf.

444. Cypræovulum capense.

445. Cypræa arabica, back.

446. The same, front.

447. Cypræa Algoensis. Luponia, Gray, front.

449. ---- Pediculus. Trivia, Gray, back.

450. The same, front.

451. Terebellum convolutum. Seraphs, Montf.

452. ---- subulatum, front.

454. Erato Mangeriæ.

455. Ancillaria glabrata. Anolax, Brongn.

456. ---- cinnamonea.

457. Oliva Maura.

458. ---- subulata. Hiatula, Sw.

459. Conus nocturnus. Rhombus, Montf.

460. ---- Nussatella. Hermes, Montf.

461. ---- Textile. Cylinder, Montf.

462. ---- geographus. Rollus, Montf.

_Order._ CEPHALOPODA.
_First Division._ Polythalamous Cephalopoda.
_Fam._ Orthocerata.

463. Amplexus coralloides. (from Sow. Min. Con.)

464. Orthoceratites annulatus.

465. Nodosaria æqualis.

466. Belemnites, with the outer coat broken to shew the alveole.

467. ---- portion of the alveole separated.

468. ---- hastatus. Hibolithes, Montf. (from Blainville.)

469. Conularia quadrisulcata.

470. Conilites pyramidatus, (from Blainville.)

_Fam._ Lituacea.

471. Spirula Peronii.

_Fam._ Nautilacea.

472. Nummulites buticularis, outside. Helicites, Bl. Camerina, Brookes.

473. The same inside, to shew the chambers.

474. Nautilus pompilius, young. See Frontispiece.

475. Simplegas sulcata.

476. Endosiphonites. (from Camb. Philos. Trans.)

_Fam._ Ammonacea.

477. Ammonoceras. (from Blainville.)

478. Ammonites; _a_, break in the shell, showing the sinuous septa.

479. Orbulites crassus. Globulites, Nonnul. Angulites, Montf. reduced.

479*. ---- discus. Aganides, Montf.

480. Goniatites striatus.

481. Scaphites æqualis.

482. Crioceratites Duvallii.

483. Turrilites tuberculatus.

484. Baculites Faujasii. Portion near the centre.

484*. Hamites cylindricus; _a_, internal cast of part of the shell;
_b_, hollow external cast of the remainder.

_Second Division._ Monothalamous Cephalopoda.

485. Argonauta Argo.

486. Bellerophon tenuifasciata. (from Sow. Gen.)

487. The same, shewing the dorsal keel.

_Order._ HETEROPODA.

488. Carinaria Mediterranea.

* * * * *

EXPLANATION OF THE NEW PLATES.

_Order._ SESSILE CIRRIPEDES.

489. Pyrgoma monticularia. _Sub-genus_, Daracia, Gray, back and
front.

490. The same, in situ.

_Fam._ Myaria.

491. Lyonsia Norvegica. Anatina, Nonnul. Inside view of both valves.

492. Outside, with the valves closed.

493. Næra longirostrum. Anatina longirostris, Lam. Inside of both
valves.

494. Outside, with both valves closed.

495. A smaller species of Næra, shewing the inequality of the valves.

_Fam._ Mactracea.

496. Amphidesma tennis. Abra, Leach.

497. Ervillia nitens.

_Fam._ Corbulacea.

498. Potamomya, of some authors. A fresh-water shell resembling
Corbula. Outside, valves closed.

499. Inside of both valves.

Fluviatile Conchacea.

500. Cyclas amnica. Pera, Leach.

_Fam._ Cardiacea.

501. Cardilia semisulcata. Isocardia semisulcata, Lam. Internal view.

502. External view of the same valve.

503. Cardium apertum. Papyridea, Sw.

504. The same, shewing the umbones.

505. Pleurorynchus, fossil, (from Mineral Conchology.)

_Fam._ Phyllidiana.

506. Chiton fascicularis. Phakellopleura, Guild.

507. ---- amiculatus. Amicula, Gray.

_Fam._ Calyptracea.

508. Scutella, Brod. Internal view.

509. External view of the same.

510. Ancylus, a reversed species, illustrating the genus Velletia,
Gray. Enlarged view.

511. The same, natural size.

512. Pedicularia. Enlarged figure, (copied from Swainson.)

513. The same, natural size, growing on coral.

_Fam._ Colimacea.

514. Achatina? octona. Macrospira, Guild.

515. Stenopus cruentatus, Guild. Under side.

516. ---- lividus.

517. Helix, the aperture covered by the epiphragm.

518. Pupa secale, Drap. Abida, Leach.

519. ---- pagoda. Gonidomus, Sw.

520. Truncatella, enlarged figure.

521. The same, natural size.

522. Auricula caprella. _Gen._ Caprella, Nonnul. Front view.

523. The same, dorsal view.

524. Pupina vitrea.

526. ---- antiquata.

527. ---- Namezii.

528. ---- lubrica. Callia? Gray.

529. Cyclostoma, a pupiform species. Megalomastoma, Guild.

530. ---- Planorbulum. Cyclotus, Guild.

531. ---- a similar species, with the complicated notch at the
posterior part of the aperture. Pterocyclos, Gray.