284 New Species of Corbula from Jamaica. 



account of a diflferent orismology in Mr. Keeve's excellent 

 monograph. 



Corbula Krebsiana. C. t. trigona, perinequivalvi, inequi- 

 laterali ; valva dextra rostrata ; margine ventrali antice rotun- 

 data, postic^ recta : albida, supra et antic6 rubro tincta : valva 

 parva concentric^ striata; valva dextra concentric^ sulcata, 

 sulcis crebris, parvis : apicibus prominentibus, involutis : umbo- 

 nibus convexis : dentibus parvis. Long. 6.1 millim. ; alt. 5.1 

 millim. ; lat. 3.8 millim. 



Shell trigonal, very inequivalve, inequilateral, with the large 

 valve rostrated; with the ventral margin rounded anteriorly, 

 nearly straight posteriorly : white, often tinged with pink on 

 the beaks and umbones except posteriorly : small valve finely 

 concentrically striated ; large finely and closely furrowed : beaks 

 prominent, much involuted : umbones very convex ; with small 

 posterior angles, one on the small valve and Wo on the other : 

 teeth small. 



Length .24 inch ; height .2 inch ; breadth .15 inch. 



Probably it resembles C. operculata Phil. 



Station. — Muddy bottom, at a depth of 8 or 4 fathoms ; C. B. A. ! 



Habitat. — In the harbor of Kingston, between K. and Port 



yal ; C. B. A. ! About 60 specimens were obtained, most 

 of which are less than .2 inch long. 



Corbula Blandiana. C. t. crassa, subrhombica, vix ine- 

 quivalvi, perinequilaterali ; margine antic^ rotundata, aliunde 

 rectilinear!, postice infra acuminata: alba: costis magnis, suba- 

 cutis, concentricis, postice minoribus; lineis radiantibus tuber- 

 culatis, microscopicis ; tuberculis deciduis ; valvis ambobus simi- 

 liter insculptis ; apicibus prominulis, vix involutis : umbonibus 

 planulatis, postic^ valdd angulatis: dentibus parvis. Long. 

 11"'.2 ; alt 6"'.6 ; lat. 4"'.5. 



Shell thick, subrhombic, slightly inequivalve, very inequila- 

 teral ; anteriorly well rounded, with the other margins nearly 



