34 
EMARGINULA tricarinata. 
TAB DXIX.—fig. 2. 
Spec. Cuar. Conical, with the apex bent down ; 
surface marked with three principal and se- 
veral lesser ribs, the spaces between them 
nearly smooth ; base oblong. 
Tus three ribs upon the posterior portion of this Emar- 
ginula are very prominent ; the middle one is divided by 
the marginal fissure, which gradually filling up as the 
shell grows, leaves a striated surface in the centre of it. 
EMARGINULA scalaris. 
TAB. DXIX.—fig. 3. 
Spec. Cuar. Conical, ribbed ; apex excentric ; ribs 
many, connected by numerous. cross ‘lines ; 
base obovate. 
Aumost upright, the apex being very litttle bent for- 
prig at, P Siig 
ward; the ribs are equal, and the central one divided 
into two by the fissure in the margin. 
These are all from the Ancliffe Oolite. They all so 
much resemble each other, and are so small, that al- 
though there might be some doubts respecting the genus 
of the first, it did not seem desirable to place them upon 
separate plates. 
