193 
PECTEN orbicularis. 
TAB. CLXXXVL 
Spec. Char. Orbicular, much depressed, concen- 
trically striated ; striae elevated, sharp ; one 
valve smooth ; ears nearly equal, broadest at 
the base. 
A thin tender shell ; the stride are many, a line distant 
from each other ; the length and breadth are equal ; the 
ears rather large. 
One of the tender products of the green sand of the 
Devizes canal, preserved by Mrs. Gent, ft appears to 
he unfrequent, as I have seen but one individuaL 
