130 GEOLOGY AND PALEONTOLOGY OF THE WEST INDIES. 



plicate, with a long, narrow, usually curved hinge. The valve margins 

 from the tip of the hinge to about the middle of the shell are dentate in 

 the upper valve and correspondingly punctate in the attached valve. 



Localities. East of La Cruz and northeast of Santiago, Cuba, sta- 

 tions 3441, 3443, and 5255. A large specimen, probably of this species, 

 comes from the gorge of Yumurl River, Cuba, station 3454, Vaughan. 

 Guajay, Cuba, Barnum Brown. 



Type. British Museum? 



Figured specimens. U. S. Nat. Mus. Nos. 167059, 167061, 167062. 



Unio bitumen, new species. 

 (Plate 9, Figures 3 a-c.) 



The following is a description of this species : 



Shell elongate, moderately inflated, inequilateral; beaks high, apparently 

 smooth; posterior ridge high near the umbones, becoming broad and low 

 distally. A broad depression extends from the umbones to the middle of the 

 ventral margin, producing a concavity in the ventral margin. Anterior mar- 

 gin acutely rounded; posterior margin broadly rounded; dorsal margin 

 arcuate. Hinge unknown. Ligament external, preserved in the type. 



Length, 68 mm.; diameter, 29.5 mm. 



The name Unio is here used in the broad sense, the material at hand 

 being insufficient to determine the precise generic position of this 

 species. 



Locality. Angela Elmira asphalt mine, near Bejucal, Cuba, station 

 3652, Wiebusch, collector. 



Geologic horizon. Oligocene? 



Type.U. S. Nat. Mus. No. 167063. 



Pecten (Pecten) ventonensis, new species. 

 (Plate 12, Figures 1 a, 6.) 



The following is a description of this species : 



Shell large, equilateral, inequivalve; right valve convex, with 23 to 25 

 rather high ribs, flattened on top, usually medially furrowed and closely 

 transversely grooved or granulate, and separated by equal concave inter- 

 spaces; left valve concave, with 23 or 24 narrow, even, rounded ribs, becoming 

 obsolete towards the lateral margins, separated by wider, nearly flat inter- 

 spaces; right submargins small, plane to convex, nearly smooth; left sub- 

 margins strongly convex, narrow, nearly smooth; ears subequal, nearly- 

 straight, with a few narrow, obsolescent riblets, strongest on the right anterior 

 ear; byssal notch shallow; both valves grooved internally in accordance with 

 the external ribbing; secondary sculpture of fine, close, raised, concentric 

 lamellae, extending over disk and ears alike, but very faint on the submargins 

 and usually eroded from the ribs of the convex valve. 



Alt., 39 mm.; lat., 42 mm.; diam., 11 mm. 



This species is closely related to Pecten medius Lam., living off the 

 southern Atlantic and Gulf coasts of the United States, from which it 

 differs as follows: On the right valve the ribs of the fossil extend nearer 



