on aiooarentl;!; adult shells. One of the left valves shows t'^ree 

 small, but distirist, projections, viiile ciost of the others have 

 suggestions of two or three similar processes. Sifrht valves h^-'ve 

 Gorres"oo- i:1i ri?, but obscure, -le or ess ions. 



K, gu J ^y i maj." be recognize! by its nunerous v?eak radials and 

 by the presence of de:^inite crenulations on only the dorsal por- 

 tion of the inner mar?-in. The ciifferences betv/een this species 

 and the Tampa silex grapiTnatus Dall are stated in the above quotat- 

 ion. In the case of M. grariimatus v ar. curtulus Da3.1 (.1) , of the 



(1). idem. 



Ohipola marl, these differer.ces are even more r; renounce'^ . '^'■r.e 

 recent Antillean M. citrinus 3olten (2) is larger, wider, more 



(E). i:us. Bolt., let ed., p. 137, 1798 {= lu. suleatus Lamarck). 



rounded anteriorly and the entire inner marc^in is orenulatei?. 



Occurrence .- io~er I'iocene: Bowden beds, Bowden, Jamaica. 

 (Dall, 18 08). 



