MOLLTJSCA OF THE ' CHALLENGER ' EXPEDITION. 389 



greyish-yellow epidermis, which adheres closely, but is apt to rub 

 through. Spire is high, narrow, conical, and slopingly scalar in 

 consequence of the drooping shoulder between the suture and the 

 keel. Apex is more or less eroded in all the four specimens : it 

 consists of not more than 1| embryonic whorls, which are globose, 

 smooth, and with the point a little obliquely pressed down. 

 Whorls 8\, rather short except the last, of regular increase, angu- 

 lated above the middle ; the shoulder between the suture and the 

 keel is straight-lined. From the keel the whorls are slightly con- 

 tracted to the inferior suture, and the profile-line here is scarcely 

 convex. The last whorl is feebly tumid below the keel, and is 

 drawn out from a produced conical base into a long, narrow, 

 cylindrical, very slightly upturned snout, which projects on the 

 right side of the base. Suture a fine, sharp, slightly irregular 

 line, well defined by the contraction of the whorl above and 

 the straight line of the shoulder on the whorl below. Month 

 club-shaped, being oval above, and prolonged below into a long, 

 but not very narrow, canal, which is a little sinuous, and widens 

 towards its end in consequence of the oblique cutting-away of the 

 pillar-lip. Outer Up, which is thin, sharp, and patulous, leaves 

 the body at a right angle and advances quite straight to the keel, 

 above which lies the deep, thin-lipped, U-shaped sinus, whose lower 

 margin runs parallel to, but a little above, the carinal thread ; 

 from the keel the lip-edge advances with a long, free, forward 

 curve and a sinuous double sweep, first convex and then concave, 

 to the point of the snout, where the edge is prominent, rounded, 

 and patulous. Inner lip almost hyaline, being cut into the sub- 

 stance of the body-whorl, but not extending beyond the mouth- 

 edge ; it is slightly concave above, straight in the middle, and 

 very early and obliquely cut away in front, from which point, for 

 the sixth of an inch, it advances to the extreme point of the shell 

 as a delicate, thin, sharp lamina bordering the canal. The oper- 

 culum seems to have been broken, probably in the attempt to 

 extract it; but it is obviously small, thin, and pale yellow. 

 H. 1-6. B. 0-51. Penult, whorl, height 0"24. Mouth, total 

 height 0-83, breadth 0'28. 



The animal of this species is preserved in one specimen, that 

 from St. 146 ; it is deeply retracted, and is of a pale buif 

 colour. 



The name I have selected is descriptive of the sculpture of the 

 shell. 



