D i st r i bu ti o n. Torres Strait, Cape York, N. E. Australia, 3 — 11 fms. (Challenger). 



Remarks. Than SiphodeiitaliiDii prionotuin Wats., this is smaller, straighter, but toward 

 the apex more bent, not narrovved at the mouth ; smaller at the apex, and the whole texture 

 of the shell is different. Than Siphodentaliuin vitretun Sars, this is less cylindrical, is not 

 contracted toward the mouth, and is much smaller toward the apex. (Watson). 



Genus Cadulus Philippi 1844. 



1844. Cadulus Philippi, Enum. Moll. Sicil II, p. 208. 



1897. Cadulus Philippi. PiLSBRY & Sharp, Man. of Conch., vol. XVII, p. 142. 



Shell more or less swollen near the middle or anteriorly, contracting toward the aperture 

 as well as tapering posteriorly. Type Dentalium ovh/udi I'hil. 



Key to sections of Cadulus. 



a. Apex with slits or notches. 



ó. xA^pex with two lateral slits Section Dischides. 



ó' . Apex with four or more slits Section Polyschides. 



a' . Apex entire, unslit. 



b. Obese ; both ventral and dorsal outlines convex and projecting 



beyond a chord connecting the adjacent lip edges; .... Section Cadulus s.s. 



(of this section no species are as yet reported from the Indo- 



pacific province). 

 ó'. More slender or attenuated-, ventral outline convex; dorsal outline 



as a whole concave, not projecting beyond a chord connecting 



the ends of shell Section Gadila. 



Section Dischides Jeffreys 1867. 



1867. Dischides Jeffreys, Ann. Alag. of Nat. Hist. (3), XX, p. 251. 



Shell rather slender, not much bulging-, apex cut into an anterior and a posterior lobe 

 b)- two deep lateral slits, one on each side. Type C. (Dischides) poliüis S. V. Wood. 



8. Cadulus dic/iclus (Watson). PI. lII, fig. 48. PI. VI, fig. 51. 



1879. Sipliodentalium dicheluin Watson, Journ. L. -S. Lond. XIV, p. 521. 



Siphodentalium dichehiin Watson, Challenger Report p. 15, pi. 2, fig. 7. 

 1897. Cadulus {Disc/iidi-s-group) dichelus (Watson). PlLSBRY & SlIARP, Man. of Conch., vol. 

 XVII, p. 145, pi. 26, fig. 73. 



Stat. 59. 10° 22.75., 123° 16.5 E. W'estern entrance Samau-strait. 390 Aletres. Coarse coral- 



sand with small stones. i Spec. 



Diagnosis. Shell long, slightly swollen at about three-fifth of its length; the swelling 

 bulges on the concave curve, but the convex curve is uninterrupted; between these two curves 



SIBOGA-EXPEDITIE T.IV. 9 



