183 
DIANCHORA. 
Gen. Cuar. An attached inequivalved bivalve, the 
attached ‘valve having an opening in place of a 
beak, the other beaked and eared; hinge with- 
out teeth. ; 
SEIT 
” Atrnoven I expect there are but few shells with these 
characters, I think the attached valve of importance enough 
to separate them as a distinct Genus from Plagiostoma, 
which in other respects they closely resemble. This charac- 
ter is the more remarkable, as it is united with an angular 
aperture at the back of the shell, seemingly formed for the 
passage of a ligament, by which the animal could fix itself 
to rocks, &c. as in Plagiostoma. The beak and parts around 
it are mostly very thin, the ears small, and the general 
contour of the shell oblique. 
DIANCHORA striata. 
TAB. LXXX.—Fig. 1, 
Spec. Cuar. Oblique, ovate-triangular, beak pro- 
minent, free valve obscurely ribbed. 
a — 
Lenern and breadth nearly equal, and the form would be 
ovate, were it not for the projecting beak, from which the 
free valve is gradually flattened to a sharp edge, and: which 
