GLOSSARY. 
Beak, in univalves, that portion of the 
base of the body which is drawn out 
into a rostrated form. See page 4. 
In bivalves, the points of the um- 
bones. See page 6. 
Beard, the process by which shells of 
the genera Mytilus, Pinna, &c. ad- 
here to rocks, composed of silky 
filaments. See Byssus. 
Bi, prefixed to any word signifies two 
or double. 
Biangulated, having two corners or 
angles. 
Biauriculated, having two ears or 
auricles. 
Bicuspid, having two points. 
Bidentate, with two teeth. 
Bifarious, parting in opposite direc- 
tions. 
Bifid, divided or cleft ; double. 
Bifurcate, double-pronged, or two 
pointed. 
Bilabiated, having a double lip or 
edge, or with an outer and inner lip, 
as in some bivalves. 
Bilobate, divided into two lobes, or 
prominences. 
Bimarginate, furnished with a double 
margin. 
Bipartite, composed of or divided into 
two parts; double. 
Biradiated, doubly rayed. 
Birostrated, double-beaked. 
Bivalve, a conventional term, applied 
to shells consisting of two parts, em- 
bracing the whole of the class Con- 
chifera. See page 6. 
Blotched, applied to shells which are 
spotted in an irregular manner. 
Blunt, obtuse, opposed to acute. 
Borer, a shell which pierces rocks, 
wood, &c. and forms a habitation 
therein, as Pholas, Saxicava, &c. 
Byssus, a beard, by which shells of 
the genera Mytilus, and Pinna, &c. 
are atiached to marine bodies. 
Cc 
Calcareous, relating to lime, of a limy 
nature. This term is applied to the 
opercule of univalves, when com- 
posed of carbonate of lime with 
animal matter, as opposed to those 
which are of a horny texture. 
Callosity, a protuberance, applied to 
the bumps on the outer surface ; the 
coating on the umbilicus of the 
Natice, &e. 
Campanulate, bell-shape. 
Canal, the groove, which is a prolon- 
gation of the aperture in univalves, 
and situate in the inside of the beak. 
See page 4. ‘ 
Cancellated, longitudinally and trans- 
versely ribbed. é 
127 
Carina, a keel. 
Carinated, haying a thin ledge passing 
spirally round the volutions in uni- 
valves, and also on the back or am- 
bit of the symmetrical univalves, 
such as Ammonites, &c. 
Cartilage, a flexible, fibrous substance, 
by which the valves in the Con- 
chifera are united, situate near the 
beak. See Ligament, page 6. 
Chambered, those shells which are 
divided into distinct compartments, 
are called chambered, viz. the genera 
Nautilus, Ammonites, &e. See page 
4. Some species of Calyptr@a are 
chambered. 
Cicatrix, the glossy impression in the 
inside of the valves, to which the 
muscles of the animal are affixed. 
Ciliated, edged with parallel hairs, 
bristles, or appendages, like the eye- 
lids. 
Cinereous, ash-coloured, of the colour 
of wood ashes. 
Clausium, a bony plate situate in a 
groove on the columella of the genus 
Clausilia. 
Clavate, when ashell is attenuated at 
one extremity, and the -other be- 
comes suddenly thickened, it is 
clavate, or club-shaped. 
Clavicle, a little key. Applied to the 
bony appendage of the hinge of some 
Anatine, &c. 
Claviform, club-shaped. 
Clypeiform, shield-shaped. 
Columella, the upright spiral pillar in 
the centre of most of the univalve 
shells. See page 4. 
Columellar lip, the inner lip, situate in 
front of the body on the right side of 
the aperture in univalves. See Inner 
lip, page 4. 
Commissure, a joint or seam formed 
by the junction of the valves in the 
Conchifera. 
Complicated, doubled together. 
Compressed, perpendicularly squeezed 
together, in opposition to depressed, 
which is horizontally flattened. 
Concamerated, arched over, vaulted. 
Concamerations, divided into com= 
partments, asin the Nautili. 
Concentric, running to a centre, as the 
transverse striz or ribs in the Con- 
chifera, in opposition to longitudinal. 
Conche, shells consisting of two or 
more pieces or valves, bivalves, or 
multivalves. 
Cone, the form of a sugar-loaf. 
Confiuent, running together. 
Conoid, a figure like a cone, sugar- 
loaf-shaped. 
Contorted, twisted, or incumbent on 
each other, in an oblique direction. 
Convoluted, rolled upon itself, twisted 
