2i6 Bulletin 39 388 



But a single specimen of this ver}^ distinct species was col- 

 lected by Dr. A. C. Veatch from the Upper Gatun of Old Man 

 Sam Creek in eastern Costa Rica. It differs from the other 

 known American Carditameras by its convex shell and strongly 

 curved beaks. The ribs are large and strongly nodulated at 

 first, becoming irregularly wrinkled near the ventral margin. 

 The hinge is unfortunatel}^ broken on our specimen, a left valve, 

 but the sm.all anterior lateral still remains which shows this shell 

 to belong to the section Carditamera 



Gatiin Stage: Old Man Sam Creek, i mile south from 

 shore. 



Genus VEIMERICARDIA, Lamarck 



Venericardia scabricostata Guppy Plate 32, figures 14, 17 



Cardita scabricostata Guppy, 1866, Quart. Journ. Geol. Soc. Loudon, 

 vol. 22, p. 293, pi. 18, fig. 10. 



Cardita scabricostata Gabb, 1873, Trans. Amer. Phil. Soc, vol. 15, p. 



252. 

 Venericardia scabricostata Maury, 1917, Bull. Amer. Pal., vol. 5, p. 



362, pi. 33, fig. I. 



This species originally described by Guppj^ from the Bowden 

 beds of Jamaica is common in the Miocene of Costa Rica and 

 frequently forms small zones in the Gatun beds. It occurs also 

 in the Miocene of Santo Domingo. 



The ribs numbering about 18 are high, narrow and strongly 

 granulated. The interspaces are wide and generally smooth. 

 Gatun Stage: Zone E, G, Saury creek. 



Zo7ie I, J, East Grape Point creek. 

 Coll. 5, Red Cliff creek. 

 Headwaters of Middle creek. 

 Coll. C, Comadre creek. 



Venericardia Terryi, n. sp. Plate 32. figures 12, 13 



Shell of medium size, solid, moderately convex and sub-cir- 



