96 
ARCA carinata. 
TAB. XLIV.—Lower figures. 
Spec. Cuar. Very convex, parallellipipedal, anterior 
side flattish, separated by an acute angle, trun- 
cated at nearly a right angle; posterior side 
rounded ; surface longitudinally ribbed. 
eee 
Axsove twice as wide as long; hinge straight; beaks 
slightly incurved. The ribs or stria are chiefly alternately 
one rather more prominent than the other ;\sometimes on the . 
sloping sides there are two faint rising strie intervening. 
The angles, of the usual form of those of Arca Noce Linn. 
are very sharp, and the shell not so wide. 
These are from the micaceous sand of the Devizes Canal. 
They are remarkably neat impressions, shewing the direc- 
tion of the hinge teeth, if I am not misled by the roughness 
ofthe sand. Mrs. Gent was so obliging as to favour me 
with these, and Thomas Meade, Esq. has assisted me with 
fine specimens, from his cabinet. 
