- 71 _ 



GemTS YOIDIA MSller. 

 YOLDIA 0VALI3 Gabb. 



Yoiaia ovalls O-abb, 1373, Trans. Am. Philos. Soc, new ser., 

 vol. 15, -op. 255-256. 



Description .- "Shell small, oorapressed, s\ib-elliptioal; 

 beaks slightly in advance of the middle; hinge line sloping rrent- 

 ly, base and ends rour.de-^; surface smooth or bearing a few faint 

 impressed concentric lines on the anterior part near the base. 

 Length .35 inch, width .15 inch." (Jabb, 1873) 



Ty-oe locality .- Santo Domingo. 



Shell of medium size, thin, polished, transversely sube:'lip- 

 tical, moderately conve?:, decidedly compressed posteriorly; ant- 

 erior dorsal margin shorter and more oblique than the posterior, 

 the distal ends of both abruptly Joining the lateral marp-ins; 

 anterior lateral margin roimded; upper portion of the posterior 

 lateral margin almost at right angles to the dorsal niargin, low- 

 er portion rounding evenly into the gently and symmetrically &ro\m.te 

 ventral margin; umbones very Idw, situated anterior to the median 

 hori.-:ontal ; behind the ambo lies a very narrov/, slightly ir.presc- 

 ed area, sc;,LLptured v,lth fine lines and containing in its proximal 



