84 



No. 22. BHYNCHONELLA FORBESEI, Dav. Plato IV., fig. 15, 

 Ida, b, c. 



RHYNCHONELLA FOEBESEI, Dav. Ool. Hon., Pal. Soc., p. 84, pi. 

 xvii., fig. 19. 



Shell small, globular, nearly circular ; beak small, incurved ; 

 foramen minute, margined by a narrow deltidium ; fold and 

 sinus very slightly denned ; surface ornamented by about 

 twenty small ribs on each valve ; length four, breadth three- 

 and-half, depth three lines. 



In 1852 I had only seen some specimens of this species lent to 

 me by Professor Edward Forbes. I was consequently very 

 pleased to find, among Mr. Darell Stephens' s specimens, several 

 examples which he had obtained at Bradford Abbas. It is 

 probable that the specimens communicated to me by Professor 

 Forbes, from "the Inferior Oolite of Somersetshire," had been 

 obtained in the Bradford Abbas district. 



No. 23. KHYNCHOKELLA SPINOSA, Schloth. Plate IV., fig. 19. 



TEREBEATULITES SPINOSUS, Schlothcim. Mm. Taachcnbach, vol. 

 vii., 1813. 



Shell transverse, sub -pentagonal, wider than long, more or 

 less spherical ; smaller or dorsal valve sometimes very convex ; 

 mesial fold not rising very much above the regular convexity of 

 the valve ; ventral valve slightly less deep than the dorsal one ; 

 sinus of moderate depth ; beak very much incurved, acute ; 

 foramen small, front-line forming a convex curve; surface of 

 valves ornamented by a variable number of angular ribs which 

 sometimes bifurcate. From distance to distance along the ridge 

 of each plait rise long, slender, tubular spines, which sometimes 

 attain six or nine lines in length. Their number is variable, as 

 well as the regularity of their disposition. Length ten-and-half, 

 breadth twelve, depth eight lines. 



This is well-known fossil which was figured (but not named) 

 by Knorr as far back as the year 1755. It varies very much in 

 the number, width, and depth of its ribs ; I have counted as 

 many as forty-six on each valve. It is a common fossil near 



