393 Dominican Fossils — Maury 229 



wholly unlike the representation of that species. From the Plio- 

 cene to recent P. Cumirigianus Dunker {niultilineatus Dall) our 

 shell differs in its smaller size ; its beaks are more anterior ; and 

 the whole shell is proportionately shorter than that species. 



Locality. — (Exp'd '16) Bluff 3, Cercado de Mao. (Scarce). 



Genus Don ax Linne 



Donax ezqualis Gabb 

 Plate 39, Figures 10, n 

 Donax cequalis Gabb, Trans. Amer. Phil. Soc, vol. 15, p. 249, 1873. 

 Donax cequalis Dall, Trans. Wagner Inst. Sci. vol. 3, pt. 5, p. 966, 



1900 ; pt. 6, p. 1587, 1903. 

 Gabb had but a single small valve measuring 6 x4.75 mm. 

 We have seven, the smallest 6X4.50 and the largest 9X6.50, in- 

 dicating that as the shell increases in size the length becomes 

 proportionally slightly greater. This species has never heretofore 

 been figured. It also occurs at Bowden. 



Localities. — (Exp'd '16) Bluff 3, Cercado de Mao (6 valves); 

 Zone H, Rio Cana at Caimito (a single shell). 



Genus Sanguinolaria Lamarck 



Sa7iguinolaria {Psammotella) Smithwoodwardi, n. sp. 



Plate 38, Figures i, 2 



Our fossils very closely resemble recent specimens of P. oper- 

 culata Gmelin {rufescens Chemnitz) from the Pacific coast at 

 Acapulco, Mexico. This shell has been usually referred to the 

 genus Tellina, but Dr. Dall has pointed out that its true affinities 

 are with Sanguinolaria , section Psammotella. 



Our shells are rostate, inequivalve, the left valve greatly 

 compressed, very flat ; right valve gently convex especially an- 

 teriorly ; although we found ten left valves we collected only a 

 single right valve and its interior is concealed by the matrix, its 

 surface is very smooth, marked only with very fine, concentric 

 striae and faint, obsolete, microscopic radial lines ; umbonal ridge 

 with a shallow, narrow sulcus along its crest and a broad undula- 

 tory sulcus in front of the ridge ; left valve marked only by deli- 



