524 



RET. B. B00& WATSON" ON THE 



on the convex curve, but is visible on tbe concave curve too. 

 From the angulation, the curve is very equable in either direc- 

 tion. About two thirds along toward the apex it bends 

 more back. The shell is thin, brilliant, semiopaque, white. 

 Sc^ulpture. Very faint and fine scratches on the lines of 

 growth. Mouth large, oval, very slightly flattened on the front 

 side, from which the thin sharp edge is obliquely cut off towards 

 the convex curve. The posterior opening is much smaller, 

 nearly round, and the edge is thin and chipped. L. O SS. B. 

 at mouth 0-067, at swell O'l, at apex 0*033. 

 This is twice the size oi C. gadus, Montague; but it resembles 

 that in the angulation, which, however, is here more marked at 

 the summit of the swelling ; its expansion from the smaller end 

 is much more gradual, and its contraction from the angulation 

 on to the mouth is more rapid. 



2. CADrLTTS VULPIDENS, W. 



St. 24. Mar. 25, 1873. Culebra Island, St. Thomas, D.W. 

 Indies. 390 fms. Mud. 1 specimen. 



Shell. — Like the canine tooth of a small Carnivore ; long, sharp, 

 bent, swollen (a little obliquely) nearer the broader end. The 

 swelling is greatest on the convex curve, and lies there a 

 little nearer the mouth (about one fourth of the length) than it 

 does on the concave, where it is at about one third of the length. 

 This obliquity makes the form a little un symmetrical. From 

 the swelling the shell contracts more rapidly towards the 

 mouth. Toward the apex the bend increases, and the end of 

 the shell is a very little contracted. The shell is pretty strong, 

 brilliant, opaquish white. Sculpture. Very minute, but sharp, 

 microscopic scratches on the lines of growth. Mouth small, 

 round, obliquely truncated backward toward the convex curve. 

 Edge thin and sharp. Posterior opening round ; the edge thick, 

 flat, slightly gnawed and broken, projecting a little on the 

 convex curve side. L. 0'35. B. at mouth 039, at swelling 

 069, at apex 03. 



This is smaller and less symmetrical than C. colulridens^ and the 

 mouth is much smaller. Than Dentalium clavatum, Gould, which 

 it much resembles, this is more contracted in front and less so 

 behind, and has more of angulation in its tumidity. Than D. 

 (jadits, Mont., this is a much less stumpy shell, being less swollen 



