-ac- 



tion of the postero-lateral :r,argln. 



Dlmensicms. - length, 2 nm; alt. 2.2 mm.; seraidiam. , .8 mm. 



Rema. rks .- This species is represented b^ a single left valve. 

 The "blisters" at the points of intersection of the radial and con- 

 centric sculpture are unusual and give the shell a peculiar appear- 

 ance. The STiecinen is verj- srrall and is probably an immature in- 

 di vi dual . ^ c^^^-^^— ^ - 



Occurrence.- lower Miocene : Bov;den beds, Bowden, Jamaica. 



