88 



valve to the front, with one central rib ; two or three also occupy 

 the lateral portions of this valve. Beak small, incurved ; fora- 

 men minute ; length four, width five, depth two-and-half lines. 



Obs. Mr. Darell Stephens has found only one example, at 

 Crewkerne Station, of this small but well-marked species. It 

 bears some resemblance to one or two species of Rhynchonellas 

 described by Messrs. Chapuis and Duwalque, from the Lias of 

 Luxembourg, but differs from them in size and some other 

 respects, as well as in stratigraphical position. As I could find 

 no named species from the Inferior Oolite with which to identify 

 it, I have thought it preferable to give it a separate designation. 



Since the above was written and the plates completed I found f 

 among another lot of specimens sent for my examination by 

 Mr. Darell Stephens, 



TEREBRATULA BTJCKMANI, Dar. Ool. Hon. Pal. Soc., p. 44, pi. vii., 

 fig. 15-16. 



Shell oval, longer than wide; valves convex, smooth; dorsal 

 valve with a central longitudinal elevation extending from the 

 umbone to the front, and sometimes very slightly biplicated 

 near the front ; 110 regular sinus in ventral valve ; beak small, 

 incurved, and truncated by a circular foramen almost touching 

 the umbone of the opposite valve ; length eighteen, breadth 

 eleven, depth eight lines. 



Three examples of this species were found by Mr. Stephens in 

 the Inferior Oolite of Bradford Abbas. 



