New Species of Corbula from Jamaica. 237 



bose, with tlie dorsal margins nearly straight and the ventral 

 margin well excurved: whitish: with moderately developed 

 concentric irregular ridges and striae; with the larger valve 

 sculptured more regularly and deeply than the other ; with very 

 minute radiating striaa in the young : beaks small, not involute : 

 umbones very convex, indistinctly angulated anteriorly, with 

 a sharp but not very prominent angle posteriorly : teeth robust. 

 It is the analogue of C. 7iasula, which inhabits the Pacific 

 coast of tropical America. 



Length .41 inch ; height .235 inch ; breadth .235 inch. 



Station. — Sand, in 3 or 4 fathoms water ; C. B. A. ! 



Habitat. — St. Thomas; T. Bland! in sched. in Mus. Amh. 

 In the east part of the harbor of Kingston, Jamaica ; C. B. A. ! 

 About 250 specimens were collected. 



CoEBULA Kjoeriana. C. t. C. SwiftiancB simili ; sed poste- 

 rius vix rostrata, paullulum productiore: rugis concentricis 

 robustioribiLS, in lunulam productis; valvis ambobus similiter 

 insculptis: angulo umbonali acutiore, a margine dorsali plus 

 remota. Speciminis magni long. 12"'.2 ; alt. 7'".6 ; lat. 6"'.2. 



This species so closely resembles C. Swiftiana^ that a specifi- 

 cation of the differences will sufiice for description. C. Kjceri- 

 ana is not so distinctly rostrated, although usually a little more 

 elongated posteriorly : the concentric ridges are stouter, and are 

 continued into the lunule ; both valves are sculptured alike : 

 the umbonial angle is more acute and distinct, and is a little 

 more distant from the posterior dorsal margin. 



Length of a large specimen .48 inch ; height .3 inch ; breadth 

 .26 inch. 



Station. — In mud, in 4 or 5 fathoms water ; C. B. A. ! 



Habitat. — St. Thomas; T. Bland! in sched, in Mus. Amh. 

 Kingston harbor, Jamaica ; C. B. A. ! We obtained 70 speci- 

 mens, most of which are immature. 



Corbula Babrattiana. C. t. ovato-triangulari, subtenui, 



