15 
GERVILLIA ? acuta. 
TAB. DX.—fig. 5. 
Spec. Cuar. Ovate-lanceolate, oblique, narrow, de- 
pressed, slightly curved ; anterior extremity 
acute ; teeth in the hinge variously disposed. 
Externatty this shell exhibits a few lines of growth; 
it is comparatively thin : its width (the longest measure 
from the two extremities) is four times its length; the 
anterior portion is rather remarkably attenuated, the 
other extremity is rounded. Found in a calcareous 
sand-stone at Collyweston, by the late Lady Wilson. 
We have not been able to ascertain whether this have 
any hollows in the area of the hinge destined for the 
ligament, as that part is not visible in the specimen, al- 
though there are four or five casts of the inside, and one 
or two of the outside upon it. The thinness of the shell 
would lead us to think it an Avicula, were not the teeth 
so large, and differently placed. 
