80 DENTALIUM-FISSIDENTALIUM. 



Off Colombo, Ceylon, lat. 6 3V N., long. 79 87' E., in 675 

 fms. (Investigator Exped.). 



D. profundorum SMITH, Annals and Mag. N. H. (6), xiv, p. 167, 

 pi. 4, f. 18 (Sept., 1894). 



This species rather closely resembles the fossil D. grande Deshayes, 

 but the style of the striation is not quite the same, and the form is 

 not quite so slender. The fine thread-like slightly rounded riblets 

 are about eighty in number, and usually rather broader than the 

 intervening striae. None of the three specimens examined are per- 

 fect posteriorly, so it is impossible to describe the fissure properly. 

 In the largest example a mere notch indicates the existence of a slit 

 in the normal position. 



In a second specimen there is a distinct lateral fissure 3 mill, in 

 length, but whether this is an accidental fracture is not quite certain. 

 The surface of this species appears to be subject to erosion, for 

 patches are broken away here and there throughout the entire length 

 of the shell. 



D. capillosum Jeffreys, is a closely allied species from the Atlan- 

 tic, but somewhat more slender in form and not quite similar in 

 sculpture. (Smith). 



D. VERNEDEI " Hanley" Sowerby. PL 3, figs. 35, 43. 



Shell gently curved, solid, whitish, with or without some pale yel- 

 lowish zones, lusterless. Sculpture, about 40 rounded, longitudinal 

 riblets on the larger portion of the shell, most of equal size, and 

 parted by interstices narrower than the riblets ; but toward the apex 

 the riblets become alternately small and large ; growth-strise close, 

 fine and prominent. Aperture circular, at nearly a right angle with 

 tube. Anal orifice circular, with a deep and rather wide slit on the 

 convex side. 



Length 90, diam. of aperture 11, height of arch above chord 12- 

 13 mill, (specimens). 



Length 133, diam. 15 mill. (Dkr.). 



Japan (McAndrew coll. ; Dunker) ; China (Garrett). 



D. vernedei Hanley, SOWERBY, Thes. Conch.,iii,p. 101, pi. 223, f. 

 3 (1860) ; Conch. Icon., xviii, pi. 1, f. 3 (1872). DUNKER, Index, 

 Moll. Mar. Jap., p. 153 (l&&'2')."Antali8 verendi A. Ad.," CLESSIN, 

 Conch. Cab., p. 26. 



This species is more curved and more slowly increasing than D. 

 rectum, and has the riblets subequal except toward the apex. 



