29 



Diagnosis. Shell small, solid and strong, straight or with a sudden little curve at the 

 apex. .Sculpture of 8 — 14 narrow rounded rather strong riblets at the top, increasing their 

 number by intercalation of secondary riblets which appear at irregular distances from the top, 

 but not in each interval, the number of riblets near aperture varying between 15 — 20. Riblets 

 sometimes persistent, sometiriies subobsolete toward aperture and often slightly twisted round 

 the shell's longitudinal axe, especially near the apex. Growth striae inconspicuous. Apex with 

 a short wide incision, a little asymmetrical on the convex side. It is generally worn by erosion, 

 the apex giving then the impression of being obliquely truncated. There is in one individual a 

 short supplemental tube around the anal orifice. Aperture rounded, not oblique, with moderately 

 thin, but strong edges. Colour white or grayish white, sometimes totally covered by a dark 

 brown deposit. 



a. Length 17 mill., greatest diameter 2 mill. 



b. Length 15 mill., greatest diameter 2 mill. 



c. Length 11 mill., greatest diameter 1,5 mill. 



28. Dciitaluiiii rodustuj/i Brazier. PI. \T, fig. 29. 



1877. DcntaliiDii robustnin Brazier, Proc. Linn. Soc. N. S. Wales, II, p. 56. 



1897. Dentaliuiii robustuiii Brazier. PiLSBRY & SHARP, Man. of Conch., vol. XVII, p. 12. 



Stat. ? I Spec. 



Diagnosis. Shell nearly straight, thick, dull white, longitudinally 9-ribbed, ribs rounded, 

 wide apart, narrow toward the apex, interstices flattened, smooth; apex with small perforation, 

 entire; aperture thickened, regular. 

 Length 20, diameter of apex 0,75, base 2,5 mill. (Br.\zier). 



Distribution. Katow, New Guinea 8 fathoms, sandy mud and coral (Chevert E.xp.). 



Remarks. Probably a young shell was obtained by the Siboga Exp. The label got 

 somehow lost, and the exact locality being now unknown it might be substituted by the more 

 general indication of Eastern part of the Malay Archipelago. I have not seen specimens of 

 ro67istu>ii but its diagnosis covers our .Siboga specimen rather well. Ours is more attenuated and 

 the anterior aperture is not thickened, but these differences may be owing to youth. It greatly 

 resembles D. enneagonuin K. Martin of the Java tertiary (Sammlungen des geol. Reichsmus. in 

 Leiden, i'' Serie, Band III, 1883 — 1887, Palaeontol. Erg. v. Tiefbohrungen auf Java, K. Martin, 

 p. 187, Tab. X, fig. 186). There are in some of the intervals one or two very faint riblets, 

 arising past the middle of the shell's length. 



29. Dcntalhuii Cookei Pilsbry & Sharp. PI. \T, figs 20, 21. 



1885. Dentalium acus Cooke, Ann. Mag. N. H. {5), XVI, p. 274. 



1897. Dentalium Cookei Pilsbry & Sharp, Man. of Conch., vol. XVII, p. 29. 



Not Dcntaliniii acus Eichwald 1856. 



Stat. 204. 4° 20' S., 122° 58' E. Northern entrance of Buton strait. From 75 — 94 Metres. Sand 



with dead shells, i Spec. 

 Stat. 207. 5° 7.5 S., 1 22° 39' E. Buton strait. 148 Metres. Grey mud. 2 Spec. 



