CADULUS-GADILA. 173 



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 curved side. Length 0"35 inch, breadth at mouth 0039 : at 

 swelling 0*069 ; at apex 003 inch ( Watsoii). 



Culehra Island, West Indies, 390 fras. (Chall.). 



Cadul'us vulpidens Wats., Journ. Linn, Soc. Lond., xiv, p. 524 

 (1879) ; Chall. Rep., p. 18, pi. 3, f. 2. 



This is smaller and less symmetrical than Cadulus colubridens, 

 and the mouth is much smaller. Than Dentalimn 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 Cadu- 

 lus gadus Mont., this is a much less stumpy shell, being less swollen 

 in the middle and more drawn out before and behind ; it is also 

 straigbter. Cadulus ventricosus Bronn has the swelling nearer the 

 mouth ( Wats.). 



C. sAURiDENs Watson. PI. 25, fig. 56. 



Shell long, narrow, scarcely bent, swollen very slightly near the 

 middle of the convex curve, just perceptibly and a little more ante- 

 riorly on the concave ; both the bend and the contraction are greater 

 towards the apex than towards the mouth. There is a very slight 

 compression between the back and the belly of the shell ; it is thin, 

 brilliant, scarcely opaque, white. Sculpture: There is none, except 

 perhaps some very faint microscopic traces of longitudinal texture. 

 Mouth rather small, very oblique ; edge thin, but not chipped. 

 Apical opening small, straight across the shell, thin, chipped. Length 

 0-12 inch, breadth at mouth 001, at swelling 002, at apex 0.009 

 inch. (Watso72). 



Culebra Island, West Indies, 390 fms. (Challenger). 



Cadulus sauridens Wats., Journ. Linn. Soc. Lond., xiv, p. 525 

 (1879) ; Chall. Rep., p. 19, pi. 3, f. 4 (1885). 



This differs from Cadulus rastridens Wats., in being less bent, less 

 swollen, the swelling more central, more apparent on the convex 

 curve ; the shell is less attenuated posteriorly and more so ante- 

 riorly ; there is no transverse sculpture ; the mouth here is oblique, 



