71 



the middle slightly swollen. Aperture circular, posterior aperture small, circular, the margin thui 



and sharp. 



Length lo, diam. of mouth 1,25 milL, diam. of apex of a larges specimen 0,5 mill. 



Distr ibu t i o n. Gulf of Oman. lat. 24°49'N., 58° 56' E. 345 fm.s. mud. Karachi (one 

 example). 



Remarks. Larger than C. gadiis Mont., which we have not seen north of Bomba}'. 

 It is a very smooth white shell, in some examples ringed obscurely with cinereous grey, in 

 others pure white, incurved, shining posteriorly attenuated, from the centre to the mouth tumid, 

 aperture round, margin acute. It was dredged very abundantly in the locahty above given. 



*i8. Cadiihis clavatus Gould. PI. III, fig. 42. 



1859. Dcntaliiun clavatnni Gould, Proc. Bost. Soc. Nat. Hist. VII, p. 166. 

 1865. Heionyx clavatiis Stimpson, Amer. Journ. Coiich. I, p. Q^, pi. 9, fig. 14. 

 1897. Cadulus clavatus (Gould). PiLSBRY & Sharp, Man. of Conch., vol. XVII, p. 185, pi. 26, 

 figs 80, 81, 79. 



Diagnosis. Shell rather slender, moderately solid, considerably curved; maximum 

 diameter situated near the larger end, gradually tapering posteriorly, anteriorly rather rapidly 

 contracting at the sides and especially on the convex face, and very slightly on the concave 

 face. Tube slightly flattened between the convex and concave sides throughout, least so at the 

 apex. Bluish-white, becoming opaque white near the ends from the greater thickness of the 

 shell there. Surface smooth, glossy, showing no striation; aperture slightly oblique, rounded-oval, 

 a little more flattened on the convex than on the concave side. Apex small, rounded-oval, 

 with perfectly simple, sharp edge. Length 11, diameter at aperture 1,2 X i,4, at greatest girth 

 1,76 X 1,85, at apex 0,55 X 0,6 mill. (P. & Sh.). 



D ist r ib u tio n. Hongkong Harbor, China 6 — 20 fms (Stimpson); Gulf of Suez(?) 

 (Mac-Andrew). 



Mr A. H. CooKE (Ann. and Mag. Nat. hist. (5) XVI, p. 275 (1885) reports Cadtdus 

 clavatus from the Gulf of Suez, but it is questionable wheter that really refers to the same 

 specific form. 



19. Cadulus colubridens Watson. PI. III, fig. 41. PI. VI, fig. 66. 



1879. Cadulus colubridens Watson, Journ. Linn. Soc. Lond. XIV, p. 523. 



1886. Cadulus colubridens Watson, Challenger Rep. Scaph. p. 18, pi. III, fig. i. 



1897. Cadulus colubridens Watson, PiLSBRY & Sharp, Man. of Conch., vol. XVII, p. 184, 

 pi. 26, fig. 71. 



Stat. 208. 5° 39' S., 122° 12' E. Banda Sea. 1886 Metres. Solid green mud. 2 Spec. 

 Stat. 211. 5°40'.7S., 120° 45'. 5 E. Banda Sea. 1158 Metres. Coarse grey mud, superficial layer 



more liquid and brown. 2 Spec. 



Diagnosis. Shell like an adder's fang, long, sharp, bent, very slightly flattened, swollen 

 near the broader end. The swell, which is faintly angulated and is at one-fourth of the length, 



