composed of CARDIUM Groenlandicum, Auct. fig. 123*, and other similar
species of Cardium, the teeth of which are either wholly wanting, or
very indistinct. Northern Ocean.
APICIAL. Belonging to the apex. The apicial extremity of the aperture
of a univalve shell, is that which is nearest to the apex of the spire.
APICULUM. Humph. TROCHUS, Lam.
APLEUROTIS. Rafinesque. A genus unfigured and imperfectly described as
differing in some respects from Terebratula and other Brachiopodæ.
APLEXUS. Fleming. A genus composed of PHYSA Hypnorum, Drap. &c. and
described as having the inner lip simple, and not spread over the body
whorl.
APLODON. Rafinesque. A genus proposed to be established at the expense
of the genus HELIX, but upon what grounds does not appear from the
imperfect description which is unaccompanied by a figure.
APLUSTRE. Schum. A genus formed for the reception of those species of
BULLA which have the spire uncovered. _Ex._ Bulla Aplustre,
(_aplustre_, a flag.) Auct. fig. 289.
APLYSIA. Linn. (_a_, without; [Greek: Pluô], to wash.) _Fam._
Laplysiens, Lam. Aplysiana, Bl.--_Descr._ Horny, transparent,
clypeiform, or shield-shaped, placed horizontally on the back of the
animal, with its convex side uppermost; apex slightly incurved.--_Obs._
The animal producing this shell has derived its name from the purplish
liquor which it exudes, when disturbed. In contour, it has been fancied
to present a certain likeness to a hare crouching, and on this account
was called _Lepus marinus_, or sea hare, by the ancients. The shell
bears a strong resemblance to Dolabella, which, however, is much
thicker, and more testaceous. The species are found in the
Mediterranean, European, and West Indian Seas. A. Petersoni, fig. 254.
APLYSIACEA. Bl. The second family of the order Monopleurobranchiata,
Bl. The animals composing this family are either destitute of shells,
or are provided with internal ones, which are flat, open, oblique, with
the apex or nucleus slightly incurved, not distinctly spiral. This
family contains the genera, Aplysia and Dolabella. The first
sub-spiral, with the apex terminal; shell thin, horny. Fig. 254. The
second the same, but thick and shelly. Fig. 255.
APOLLON. Montf. RANELLA Ranina, Auct. Placed by De Blainville in that
division of Ranella, which is characterized as being umbilicated. Fig.
393.
APOROBRANCHIATA. Bl. The first order of the second section of
Paracephalophora Monoica, Bl. The Thecosmata is the only family of this
order containing any approach to shells, these are Hyalæa and Cymbulia.
APORRHAIS. Petiver. A genus formed of ROSTELLARIA Pes-pelicani, _Auct._
(fig. 404) and similar species. Although the shell presents no
characters to distinguish it generically from Rostellaria, those who
have examined the soft parts are convinced that it is distinct. Of the
three species now known and figured in part I. of Thesaurus
Conchyliorum, by the Author, one is common on our own coast, and in the
Mediterranean; also North America. See ROSTELLARIA.
AQUATIC. A term applied by some authors to those species of Molluscous
animals, which inhabit fresh water, either in rivers, or salt water
standing pools, as distinguished from the marine or Mollusca. See
Fresh-water.
AQUILLUS. Montf. TRITON Lampas, Cutaceus, &c. Auct. Placed by De
Blainville in the division of the genus Triton, which is described as
having a short spire, being covered with tubercles and umbilicated.
Triton Cutaceus, fig. 399.
ARCA. Auct. (Anglicè, a boat.) _Fam._ Arcacea, Lam.--_Descr._ Obliquely
transverse, subquadrate, equivalve, or nearly so, inequilateral, thick,
ventricose, longitudinally ribbed, dentated near the inner margins;
hinge rectilinear, forming a flat, external area, upon which the
ligament is spread in cross rows, and having a series of small, regular
teeth, extending on both sides of the umbones in each valve; muscular
impressions distant.--_Obs._ The shells composing this genus are easily
distinguished from those of all other bivalve shells, by the straight,
linear row of small, notched teeth, and by the area between the
umbones. The genus _Cucullæa_ makes the nearest approach to it in this
respect, but it may easily be known from it by the outermost teeth on
each side of the row being oblique, and lengthened out; and also by the
prominent edge of the muscular impression. These shells are found
recent, in various marine localities; fossil, in the tertiary deposits.
The Arca Noæ, formerly regarded as the type of this genus, has, with
several other species, been separated from it under the name of
Bysso-arca, by Swainson, on account of an hiatus in the ventral margin,
to admit the passage of a byssus; this is not found in the true Arcæ.
The true Arcæ are mostly tropical. Arca Antiquata, fig. 131. Bysso-arca
Noæ, 132.
ARCACEA. Lam. A family of the order Conchifera Dimyaria, characterized
by a series of teeth placed on the hinge in a line. The genera may be
distinguished as follows,
1. ARCA. Hinge straight; valves close. Fig. 131.
2. BYSSO-ARCA. Valves gaping. Fig. 132.
3. CUCULLÆA. Distant teeth oblique; posterior muscular impression
prominent. Fig. 133.
4. PECTUNCULUS. Hinge curved. Fig. 134.
5. NUCULA. The same, with a pit in the centre of the hinge,
including Myopara and Crenella. Figs. 135 to 137.
6. SOLENELLA. Fresh water, oval; a series of teeth on one side of
the hinge, only two or three on the other. Fig. 138.
ARCHAIAS. Montf. A genus of microscopic Foraminifera.
ARCHONTE. Montf. HYALÆA, Auct.
ARCINELLA. Schum. CHAMA Arcinella, Auct.
ARCTICA. Schum. CYPRINA Icelandica, Auct.
ARCUATED. (Arcus, an arch.) Bent in the form of an arch, as Dentalium,
fig. 2.
AREA. A flat space or disc, on any part of a shell. As for instance,
the triangular space on the hinge of Arca, fig. 132, and Spondylus.
ARENACEOUS. (Arena, sand.) Of a sandy texture, as the sand tubes
surrounding the bodies of some of the Annellides, named Arenaria on
this account. But the word is more commonly used to intimate the habits
of the animal, burrowing with its shell in the sand.
ARETHUSA. Montf. A genus of microscopic Foraminifera.
ARGONAUTA. Auct. Commonly called the "Paper Sailor." _Fam._ Pteropoda,
Bl. _Order_ Cephalopoda Monothalamia, Lam.--_Descr._ Light, thin,
transparent or nearly so, symmetrically convolute, carinated by a
double row of tubercles, terminating smooth or tuberculated ribs
radiating towards the centre; aperture large, elongated; peritrême
acute, interrupted by the body whorl.--_Obs._ The exquisitely
beautiful, light and delicate fabrics included under the above name are
inhabited by a molluscous animal named the _Ocythöe_, which is provided
with tuberculated arms. These, hanging over the sides of the aperture,
give to the whole the appearance of a vessel propelled by oars: a
poetical illusion further heightened by the broad, flat membranes of
the two arms, which, when vertically expanded, present an idea of
sails. Pliny has described the Nautilus (the name has been changed by
the moderns) as sailing gracefully on the Mediterranean waters; and
Pope has versified the idea in the well known lines
"Learn of the little Nautilus to sail, Spread the thin oar and
catch the driving gale."
Scientific men have long been engaged in the interesting discussion,
whether the animal really belongs to the shell in which it is found, or
whether, having destroyed the rightful owner, it has possessed itself
of the "frail bark." It is now, however, proved beyond the shadow of a
doubt that the Argonaut is the testaceous part of the Ocythöe, and that
the broad membranes which in some representations have been
artificially placed as sails, are naturally bent backwards over the
shell like the mantle of some other molluscs. The interesting
experiments of Madame Power, in the Mediterranean, have contributed
very materially to lead the investigations of Naturalists to a
satisfactory conclusion. This lady kept a cage under water, in which
Argonautæ were bred in great numbers, giving her an opportunity of
tracing the gradual development of the shell in all its stages, from
the elastic and transparent nucleus to the full grown "Paper Sailor."
Fig. 485.
ARIANTA. Leach. A sub-genus of land shells, containing HELIX
arbustorum, Auct. (Gray, Turton, p. 137.)
ARION. A genus of slugs which have no shells.
ARROW-HEADS. One of the names by which fossils of the genus Belemnites
were formerly known.
ARTEMIS. A genus of bivalve shells, distinguished from those of the
genus Venus, by having a rounded, denticular form, and a deep, angular
sinus in the palleal impression. This does not appear to me to be a
sufficient ground of generic distinction, the palleal impressions of
the Veneres being subject to great variations. British, also from West
Indies, South America, Australia, &c. A. lincta, fig. 118.
ARTICULATED. (Jointed.) Applied to distinct parts of shells, which are
fitted or jointed into each other, as the valves of Chitones and those
of Balani. The operculum of Nerita is said to be _articulated_ to the
columella, having a small process by which it is as it were locked
under the edge. See _Introduction_. The word is also applied to the
Cirri, which protrude from the oral openings of Cirripedes.
ARTICULINA. D'Orb. A genus of microscopic Foraminifera.
ASIPHONIBRANCHIATA. Bl. The second order of Paracephalophora Dioica,
Bl. Consisting of spiral univalves, which have no notch or canal at the
anterior part of the aperture. This order is divided into the families
Goniosomata, Cricosomata, Ellipsostomata, Hemicyclostomata, and
Oxystomata.
ASPERGILLUM. Lam. (From _Aspergo_, to sprinkle.) _Fam._ Tubicolæ, Lam.
Pyloridea, Bl.--_Descr._ The small, equal, equilateral valves are
cemented into, so as to form part of, a large tube; the umbones are
slightly prominent outside. The tube is elongated, rather irregular,
granulated with sandy particles, and terminated at the base by a convex
disc, which is perforated by small pores, elongated into tubes round
the edge, presenting a resemblance to the spout of a watering pot,
whence the name is derived. _Loc._ New Holland, Java, New Zealand, Red
Sea. Fig. 44. Aspergillum Vaginiferum.
ASSIMINEA. Leach. _Fam._ Turbinacea, Lam.--_Descr._ Inclining to oval,
light, thin, covered with a horny epidermis, spire produced into an
acute pyramid; whorls slightly angulated in the centre, rounded
beneath; aperture elliptical, slightly modified by the last whorl;
inner lip planed; outer lip thin; operculum horny, subspiral. Found in
brackish water; one species may be procured abundantly on the muddy
shores of the Thames, in Kent. There are also species from Calcutta,
China, Tahiti, and Australia. Without comparing the animals, it is
difficult to distinguish this genus from some species of Littorina.
Fig. 363. A. Grayana.
ASTACOLUS. Montf. A genus of microscopic Foraminifera. CRISTELLARIA
Crepidula, Lam.
ASTARTE J. Sowerby. (Name of a Sidonian Goddess, _Ashtaroth_ in
Scripture.) _Fam._ Nymphacea, Lam. Genus Crassina, Lam.--_Descr._
Suborbicular, equivalve, inequilateral, thick, compressed; hinge with
two solid diverging teeth in the right valve, one tooth and a slight
posterior elevation in the left; muscular impressions, two in each
valve, uniform, united by a simple palleal impression; ligament
external.--_Obs._ This genus differs from Venus, Cytheræa, &c. in not
having a posterior sinus in the impression of the mantle. The hinge
also differs in having but two cardinal teeth. Astarte differs from
Crassatella in having no internal cartilage in the hinge. Some of the
species are British, others are from America, and one from Sicily. The
fossils occur in Crag, Lower Oolite, &c. Fig. 110. A. Danmoniensis.
ASTROLEPAS. Klein. CORONULA Testudinaria, Auct. CHELONOBIA, Leach. Fig.
15.
ATLANTA. Lesueur. _Fam._ Pteropoda, Lam. and Bl.--_Descr._ Spiral,
convolute, transparent, fragile, compressed, with a broad, fimbriated,
dorsal keel, and a narrow aperture. This shell, which is called "_corne
d'ammon vivant_," is found in the Atlantic. The small Pteropod, figured
in Sowerby's Genera as Limacina, belongs to this genus. Atlanta
Helicialis, fig. 220.
ATRACTODON. Charlesworth. (Mag. Nat. Hist. 2nd series, Vol. 1. p. 218.
) A genus proposed for the admission of a singular fossil shell, found
on the beach at Felix-stone, of which the following are the
characters;--fusiform, aperture equalling the spire in length,
terminating anteriorly in a slightly recurved canal; columellar lip
smooth, curved, thickened posteriorly into a blunt tooth; spire
obtuse.--_Obs._ This shell would be a Fusus were it not for the tooth
on the posterior extremity of the columellar lip. The only species
known is regularly striated in a spiral direction, and named A.
Elegans.
ATRYPA, Dalman. A genus of brachiopodous bivalves, distinguished by the
valves being nearly equal, and the umbones not separated by an
intermediate area. A. reticulata, fig 302.
ATTACHED. Shells are attached to marine substances by various means; in
some cases by a _byssus_, or a bunch of tendinous fibres passing
through an opening between the valves, which gape at their margins to
admit a free passage, as in the genera Byssoarca and Mytilus. In other
cases the byssus is of a more compact substance, and passes through a
perforation in the shell itself. This is the case with many of the
brachiopodous shells, in some species of which the perforation is in
the point of the umbones, a specimen of which is represented in the
Introduction. This species of attachment does not keep the animal
motionless, although it is confined to a particular spot. Other shells
are attached by a portion of their own substance, as in Chama,
Spondylus, Serpula, &c. in which instances, the attached valve is
motionless, and is termed the under valve. The Pedunculated Cirripedes
are attached by a tubular tendinous process, called a peduncle.
ATTENUATED. Drawn out, long, thin, tapering, as the extremities of
Ovulum Volva, fig. 442.
ATYS. Montf. A generic name including those species of BULLA, which are
described as "convolute, with the last whorl covering the rest and
hiding the spire, the apex rounded at both ends." Bulla Naucum, Auct.
fig. 250.
AURICLE. (A little ear.) See AURICULATED.
AURICULA. Lam. (Dim. from _Auris_ an ear.) _Fam._ Auriculacea. Bl.
Colimacea, Lam.--_Descr._ Oval or oblong, cylindrical or conical;
aperture long, narrow, generally narrowest in the centre; rounded
anteriorly, with two or three strong folds on the inner lip, and the
outer lip thickened, reflected or denticulated; spire short, obtuse,
epidermis horny, brown.--_Obs._ The above description includes the A.
coniformis, f. 298. and several other conical species with narrow
apertures which formed the genus _Melampus_, Montf. and _Conovulus_,
Lam. The latter author suppressed his genus on ascertaining the
Conovuli to be land shells. We exclude, however, the A. Dombeyana, Lam.
f. 300. and several similar species, which being more rounded, having
thin outer lips and but one fold on the columella, are described under
the generic name _Chilina_, Gray. It appears rather doubtful whether
the Auriculæ are marine or fluviatile, but the animals appear to be
amphibious. The Auriculæ are principally found in Salt Marshes of
Tropical climates, some small species are found on the Southern
European Coasts, as far north as Britain and south as Tierra del Fuego.
The Auriculæ formed a part of the genus Voluta of Linnæus, f. 297. A.
Judæ, f. 298. A. Coniformis.
AURICULATED. Some bivalve shells, such as _Pecten_, fig. 171, 172, have
a flat, broad, somewhat triangular appendage on one or both sides of
the umbones, called an _auricle_, or little _ear_. If on one side only,
they are said to be _uni-auriculated_; if on both, they are said to be
_bi-auriculated_.
AURICULACEA. Bl. The second family of the order Pulmobranchiata, thus
described; "shell thick, solid; aperture more or less oval, always
large, rounded anteriorly, and contracted by teeth or folds on the
columella." This family is included in the genus Voluta of Linnæus, on
account of the plaited columellar lip, a character by which that
heterogeneous assemblage of shells is distinguished. It forms part of
the family of _Colimacea_, Lam. from which they differ not only in
general form, but also in the fact of the animals being partly
amphibious, always living (according to De Blainville) on the sea
shore, and being occasionally covered with water for a short time. It
contains the genera Pedipes, Auricula, Pyramidella.
AURIFERA. Bl. OTION, Auct.
AURIFORM. (From _Auris_, an ear; _forma_, shape.) Ex. _Haliotis_, fig.
338.
AURISCALPIUM. Megerle. ANATINA, Lam.
AVICULA. Lam. (From _Avis_, a bird). _Fam._ Malleacea, Lam.
Margaritacea, Bl.--_Descr._ Inequivalve, inequilateral, foliaceous,
subquadrate, oblique, pearly; hinge rectilinear, lengthened into
auricular appendages, with a small indistinct tooth in each valve, an
elongated, marginal, ligamentiferous area, and an hiatus in the left
valve, for the passage of a byssus; one circular muscular impression,
near the centre of each valve, with a series of smaller ones arranged
in a line towards the umbones.--_Obs._ The Meleagrinæ of Lamarck,
Margaritiferæ, Schum. included in this description, consist of the more
rounded species, and do not present the elegant obliquity of form, nor
the wing-like auricles from which the genus Avicula receives its name.
The Aviculæ are pearly within. From A. margaritifera, a young specimen
of which is figured in the plates, fig. 164, is obtained oriental
pearls. This is an example of Meleagrina. A. Hirundo, fig. 163, belongs
to the genus Avicula of Lamarck. It is, however, needless to continue
the separation. Aviculæ are from E. and W. Indies, Mexico, Coasts of
the Pacific, Mediterranean, British Islands, &c. Fossil species occur
in the London clay, &c.
AXINUS. J. Sowerby.--_Descr._ Equivalve, transverse; posterior side
very short, rounded, with a long ligament, placed in a furrow,
extending along the whole edge; anterior side produced, angulated,
truncated, with a flattish _lunule_ near the beaks. The late Mr. James
Sowerby, who described this shell in the Mineral Conchology, did not
consider his genus as established, not having seen the hinge.
AXIS. The imaginary line, round which the whorls of a spiral shell
revolve. The extremities of the axis are pointed out in fig. 379, by
the letters, _a. a._ See "COLUMELLA."
AZECA. Leach. _Fam._ Colimacea, Lam.--_Descr._ "Animal like Bulinus,
with subcylindrical, rather obtuse shell, covered with a polished
periostraca (epidermis); aperture pear-shaped, curved and pointed at
the top; the margin thick, obtuse, united all round and toothed; the
axis imperforated." Gray's edition of Turton's British Shells, page
189.--_Obs._ The Turbo Tridens of Montagu, upon which this genus is
founded, resembles Bulinus lubricus in general form and character. Both
these shells differ from the true Bulini in having the peritreme
entire, and in being pellucid and glossy. Azeca differs from Bulinus
lubricus in having three teeth in the aperture, two on the inner lip
and one on the outer. Not seeing the necessity for creating a genus on
grounds so slight, I have simply transcribed the description given
above, leaving others to form their own conclusions as to the propriety
of separating this shell from the genus Bulinus. Britain, Central and
Southern Europe. Azeca Tridens, fig. 290.
AZEMUS. Ranzani. CONIA, Leach.
BACULITES. Lam. _Fam._ Orthocerata, Bl. Ammonacea, Lam.--_Descr._
Straight, conical, tubular, laterally compressed; chambers divided by
very sinuous lobed septa, the last elongated; aperture elliptical;
siphon dorsal.--_Obs._ This genus differs from Orthoceras in the same
manner in which Ammonites differs from Nautilus, having its septa
sinuated and branched. A Baculite might be described as a straight
Ammonite. This genus is known only in a fossil state. It is found in
the Cretaceous Limestone of Maëstricht and Valognes. Fig. 484. B.
Faujasii.
BALANUS. Brug. (an Acorn; "gland de Mer." Fr.) _Order_ Sessile
Cirripedes, Lam. _Fam._ Balanidea, Bl.--_Descr._ Shell composed of six
valves articulated to each other side by side in a circle, by the
insertion of lamina; closed at the base by a flat, cylindrical or
cup-shaped valve, by which it is generally attached; and at the apex by
a conical operculum, consisting of four valves in anterior and
posterior pairs. Each valve of the shell is divided into a rough
triangular portion pointed towards the apex, and a flat area on each
side.--_Obs._ This description includes the _Acasta_ of Leach, which
growing in sponges, has the base cup-shaped; _Conoplæa_ of Say, which
being attached to the stems of Gorgonia and sea-weeds has the base
elongated and lanceolate, and _Chirona_, Gray. Balanus is the only
genus of Sessile Cirripedes the shells of which consist of six parietal
valves, except _coronula_, which has no shelly base, is flatter, and
has the valves of the operculum placed horizontally. The Balani are
common in all seas, adhering to rocks, corals, floating timber, and to
each other. The fossil species are found in the newest strata, at
Bordeaux, Paris, &c. Fig. 25. B. Tintinnabulum; 26. _Acasta_ Montagui;
27. Balanus galeatus, _Conoplæa_, Say.
BALANIDEA. Bl. The second family of the class Nematopoda, Bl.
corresponding with Sessile Cirripedes, Lam., and consisting of
Coronular Multivalves, which are fixed, and in a manner soldered to
submarine substances, by the base of the shell; as distinguished from
the Lepadicea, Bl., Pedunculated Cirripedes, Lam., which are attached
by a fleshy stalk. The Balanidea are composed of two sets of valves,
besides the shelly plate or base on which they rest. The first, called
the Parietal valves, are arranged so as to surround the body of the
animal; the second, called the Opercular valves, are placed
horizontally, so as to cover the aperture.
BALEA. Gray. _Fam._ Colimacea, Lam.--_Descr._ Spiral, turrited,
concentrically striated, sinistral, and covered with a thin brown
epidermis; spire composed of numerous whorls, gradually increasing in
size; aperture small, sub-quadrate; peritrême entire, slightly
thickened, with a very slight fold on the columella; axis
perforated.--_Obs._ A genus of small land shells, found in moss at the
roots of trees in Britain, not very nearly resembling any other land
shells, except Clausilia, from which they differ in not having the
clausium. They have been placed in Helix by De Ferrusac, and in Pupa by
Draparnaud. B. fragilis, fig. 296. _Helix perversa_, Fer. _Pupa
perversa_, Drap.
BARBATA. Humphrey. UNIO, Lam.
BARNACLES. PENTELASMIS, Auct. (fig. 34.) Called Anatifa, by Linnæus and
Lamarck, from the ancient notion that they were the eggs or embryo of
the Barnacle Duck. See ANATIFER.
BASE. In all shells which are attached to sub-marine substances, the
base is that part of the shell which forms the point of attachment,--as
for instance, the attached valve of Spondylus, the basal plate of
Balanus, the lower part of the peduncle of Pentelasmis; in Unattached
Bivalves, the margin opposite to the umbones, where the foot of the
animal, or the part analogous to it, protrudes; in spiral univalves,
the aperture, which rests on the back of the animal when walking.
Lamarck and some other authors have used the term _base_ as simply
opposed to apex, and apply it to the anterior of the aperture.
BATOLITES. Montf. HIPPURITES, Auct.
BEAK. The Apices, or points of the valves of a bivalve shell, generally
termed UMBONES, in descriptions. Also any part which is rostrated or
drawn out like a beak.
BEAKED. See BEAK and ROSTRATED.
BEAR'S-PAW-CLAM. The common name for Hippopus maculatus, a
representation of which is given in the plates, fig. 156.