168 Mr. E. A. Smith on Mollusca from the 



postice fissurata ; apertura fere circularis, intus alba, ad marglncm 

 obliquum tenuis, acuta. 

 Longit. 90 millim., diam. max. 10. 



Hah. Off Colombo, lat. 6° 32' N., long. 79° 37' E., in 675 

 fathoms. 



This species rather closely resembles the fossil D. grande^ 

 Deshajes, but the style of 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 perfect 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 

 millim. 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 

 Atlantic, but somewhat more slender in form and not quite 

 similar in sculpture. 



20. Dentalium usitatum. (PI. IV. figs. 16, 16 a.) 



Testa parva, mediocriter gracilis, alba, parum arcuata, liris longitu- 

 dinahbus teuuissimis circiter 20-25 sequalibus instructa, lineis 

 incremeuti obliquis sculpta, ad apicem baud fissa. 



Longit. 31 millim., diam. max. 2*7. 



Hah. Off Colombo, lat. 6° 32' N., long. 79° 37' E., in 675 

 fathoms, and Bay of Bengal in 597 fathoms. 



The two specimens examined do not look as if they are 

 young shells. The white colour is varied here and there with 

 narrow oblique somewhat pellucid zones. 



21. Dentalium insoUtum. (PI. IV. figs. 17, 17 a.) 



Testa gracilis, conspicue arcuata, lasvis, polita, subpeUucida, alba, 

 hand circulariter tubulata, utrinque leviter plana, hneis iucrementi 

 tenuissimis striata, ad apicem baud fissa. 



Longit. 3G millim., diam. max. 2-b. 



Hah. Bay of Bengal, in 597 fathoms. 

 The peculiarity of this species consists in its being a little 

 compressed, so that the tube is not circular. It is broadest 



