140 A. Alcock — A New BracUopod. [JTo. 2, 1894.] 



The shell is remarkable in being inequilateral, having a well-mark -= 

 ed bulge to the left side (the shell being held ventral valve downwards 

 and beak pointing backwards) : and this asymmetry is shown by the 

 lines of growth to have existed from an early period of life. 



The dorsal valve is slightly more convex than the ventral ; and 

 both valves have the margin simple, entire, and broadly turned OA'-er 

 and bevelled all round. 



Internally, the dorsal valve has very prominent cardinal processes, 

 and a small slender loop, the greatest convexity of which does not 

 reach forward beyond the first fifth of the length of the shell. 



The ventral valve has a re-curved beak which conceals the small 

 deltidium, the latter consisting of a single piece transversely striated, 

 and the beak being truncated by a thick-edged foramen. 



Greatest length of the shell 73 millim., greatest breadth 68 

 millim. 



I have named this species after the great Ellizabethan navigator 

 John Davis, who appears to have been the first I^nglish explorer to 

 take an interest in the Maldive Islands. 



The plate explains itself. 



