*2i. Deiitaliii))! biscxangnlaiuni Sowerby. PI. I, fig. 7. 



1S60. Dcntaliurn blscxangiilatiini Sowerby, Thes. Conch. III, p. 102, pi. 223, fig. 8. 



1872. Dentallum bisexangulatnin Sowerby, Conch. Icon. XVIII, pi. 3, fig. 14. 



1877. Dentalium bisexangulatiun Sowerby. Brazier, Proc. Linn. Soc. N. S. Wales II, p. 57. 

 1879. Dentalium bisexangulatiiui Sowerby. VON Martens, Monatsber. Preuss. Akad. Wiss. 



Berlin, p. 739. 

 1885. Dfii/a/iinji bisexatignlatiun Sowerby. CooKE, Ann. Mag. N. H. (5), XVI, p. 273. 

 1897. Dentalium bisexangulatum Sowerby. PiLSBRV & Shari', Man. of Conch., vol. XVII, 



p. 15, pi. 2, fig. 25. 



Diagnosis. Shell well curved, solid, moderately stout, the length about 11 or 1 2 times 

 the greatest diameter; white. Sculpture of about 12 (11 to 13) strong longitudinal narrow ribs, 

 about a third as wide as the concave intervals, which are ribless or show a weak median thread 

 on the convex side (or occasionally all the intervals except one or several on the concave side 

 have low median threads); growth-striae fine and superficial. Aperture a trifle compressed 

 laterally, strongly angulated by the projecting ribs on the concave margin. Anal orifice rounded, 

 with a wide, shallow notch on the convex side. 



Length 68, length of aperture 6,5, breadth 6 mill; height of arch from chord 10 mill. 

 Length 72, length of aperture 6,2, breadth 6 mill; height of arch from chord 1 1,5 mill. (P. & Sh.). 



D i str ibution. Java (Sowerby); Singapore (Archer); Yokohama, Japan (Loomis); Gulf 

 of Suez (Mac-Andrew); Torres Straits and Vicinity, 8 — 30 fms (Chevert Exp.); Ouerimba Isl. 

 and Mozambique (Peters coll.). 



Remarks. No specimens were obtained by the Siboga. Pilsbry states that there are 

 oftener 1 1 than 1 2 ribs, and that the development of an intermediate thread in each space 

 over the greater part of the shell is occasional though probably exceptional. 



*2 2. Detitalium intcj'calahiin Gould. Pl. L fig. 9. 



1859. Dentalium intercalatiim Gould, Proc. Bost. Soc. Nat. hist. VII, p. 166. 



? Dentalium intercalatiim Gould, Otio Conch. 

 1872. Dentalium intercalatiim Gould. SowERBY, Conch. Icon. XVIII, pl. 7, fig. 45. 

 1897. Dentalium intercalatiim Gould. PiLSBRY & Sharp, Man. of Conch., vol. XVII, p. 23, 



pl. II, figs 88, 89. 

 1904. Dentalium intercalatiim Gould. Jos. C. Verco. Notes on South-Austr. Moll. Trans. 



Proc. Rep. Roy. Soc. S. A., vol. XXVIII, p. 135—138, pl. XXVI (fig. of radula). 

 1897. Dentalium Bednalli Pilsbry & Sharp, Man. of Conch. vol. XVII, p. 248, pl. 39, figs i, 2, 3. 



1878. Dentalium octagonum Angas (non Lam.), P. Z. S. p. 868, Henley Beach S. A. 



? 1893. Dentalium octogonum Adcock's Hand List of the Aquatic MoUusca inhabiting South- 

 Austr. p. 10. 



It is practically impossible to give one clear diagnosis for this exceedingly variable 

 species. Here follows first the diagnosis of D. inlcrcalahivi Gould, being taken after a young 

 specimen, then of D. bednalli P. & Sh. being a description of an old specimen of ititcrcalatum 

 under a new name. 



Diagnosis of a young specimen. Shell strongly curved and conspicuously tapering 

 in ils earlier half, the later half nearly straight and less tapering; white, lusterless. At and near 



