DESCRIPTIONS OF CARIBBEAN MIOCENE FOSSILS. " 343 



CORBIJLA, Brug. 



C. Lavaleana, d'Orb., La Sagra's Cuba, PI. 21, figs. 9-12. 

 C. disparilis, d'Orb., loc. cit., PI. 21, figs. 1-4. 



Both species found at Sapote, on the Reventazon. 



TELLINA, Linn. 



T. Dariena, Conrad, PI. 44, fig. 13. 



id., Conrad, Pacific R. R. Report, vol. 5, p. 328, PL 6, f. 53. 

 T. semilaevis, Gabb, Proc. Phila. Acad., 56Y, 1860. 



First described by Conrad, from the Isthmus. I renamed it in the Evans col- 

 lection from Chiriqui, where it is abundant in the black shale near the coalj and 

 I have subsequently found it in the Oronli canon associated with Turritella Gatu- 

 nensis and the Area described below. 



No specimens have ever been found showing the hinge, so the subgenus must 

 remain uncertain, though the form certainly allies it to Peronceoderma. 



Figure. Natural size. 



T. SP. INDET., PI. 44, fig. 14, 14a. 



A single internal cast from Sapote which retains the cast of the hinge, and but 

 few other details except the general outline. It seems to be an Arcopagia, from 

 the strong lateral teeth and the slightly twisted posterior end. 



Figure. Natural size. 



MERETRIX, Lam. 

 M. SAPOTENSis, Gabb, n. s., PL 44, fig. 15. 



Shell moderately large, convex, thin; inequilateral, the small strongly incurved 

 beaks being about a third of the total length from the anterior end, which is nar- 

 row and produced, most prominent a little above the middle and sloping up nearly 

 straight to the beaks with a very faint convexity in the lunular region. Posterior 

 cardinal margin broadly curved and sloping to the end of the shell, which is broad 

 and round ; base forming almost a third of a circle, not perfect in outline however, 

 being a little more prominent near the front edge of the pallial sinus, and also 

 being markedly straightened as it slopes upwards in front. Surface marked by 

 small concentric ribs, evidently polished when alive. The lunule, rather large, is 

 bordered by an impressed line, so faint as only to be visible with a glass in certain 

 directions of reflected light. • Internal margin smooth ; pallial sinus small and 

 angular. 



Figure. Natural size. 



Locality. Sapote, Costa Hica, where I found only the specimen figured. 



