\ 



pwst conspicuous f eati-ires of dominicense are the hif^h, full uni- 

 bones, the lar.~e numTDer -^f rihs (fifty- five to sixty). 



The single Ohipola specir-en referred to this species is a 

 somevrhat TJorn, imperfect valve ^ith the ant ero- dorsal margin 



longer than on the tj^ical ^owdeii f om, the " ' of the ajitero- 



lateral margin more convex, the median ribs i;7ith flat tops and 

 sloping- sides so that Hie interspaces are wider; the difference 

 in ornamentation is prohably due to wear. 



Occ-urrence .- U'rnex Olipocen: Ghi-pola, Florida (Dall, 1900); 

 lower Miocene: Bowren oea, Soiydon, Jamaica fGupp^", 



18 66, IB 74; Dall, 1900). 



