REPORT ON THE GASTEROPODA. 641 



Shell. — Oval, subgibbous, a little abruptly contracted and slightly constricted and 

 truncated above, striated, thin, hyaline, umbilicated, with a longish curved mouth. 

 Sculpture: Longitudinals — there are very many slight equal hair-like lines of growth 

 Spirals — with the exception of a narrow nearly medial band, which is smooth, the whole 

 surface is scratched with fine smooth regular square-cut widely parted furrows. These are 

 rather more regularly arranged above than below, where the interstices are more wide and 

 less regular ; but toward the end of the shell in both directions the furrows tend to become 

 crowded ; they extend to the very edge of the funnel-shaped depression of the apex ; but 

 the depression itself is smooth except for the twisted edge of the outer lip, which at 

 the generic sinus is reverted as usual but somewhat narrowly : in front they score the 

 umbilicus on one side, but do not quite extend to the edge of the pillar. Colour hyaline 

 to translucent. Mouth long, curved, rather narrow, and not much enlarged in front. 

 Outer lip convex, posteriorly produced ; the generic twisted sinus is rather small ; above 

 it the lip rises and advances, and forms a sharp curve : from this point the lip runs out to 

 the right, at first straight or faintly concave, and here a little contracted, but afterwards 

 with a very regular curve, and increasingly patulous to the point of the shell. Top very 

 obliquely truncate, with a bluntish edge and a small funnel-shaped depression, which, 

 through the generic sinus, leads into the interior of the shell. Inner lip: there is no 

 glaze on the body, the curve of which is a little gibbous above ; the pillar-edge is narrow, 

 reverted, bluntly toothed, twisted, and truncated in front ; at the top of the pillar this 

 edge is very much twisted, and is there separated from the body, leaving a very narrow 

 but deep fissure communicating with the deep umbilicus which lies behind, and is partly 

 covered by the expanded and projecting pillar-edge. H. 0*44 in. B. 0"24. Breadth of 

 mouth at same place, 0"07. 



I do not know any Atys with which to compare this very beautiful and delicate species. It has 

 something of the gibbosity of Atys cylindrica (Helb.), var. solida, in its stumpiest forms ; but the 

 texture of the shell, the sculpture, and the umbilicus are very different. The specimens from 

 Stations 186 and 187 are quite young shells, but are, I have no doubt, this species. From Honolulu, 

 40 fathoms, there is a specimen of Atys probably belonging to this species, but in too bad condition 

 for identification with any certainty. 



5. Atys (Dinia) denti/era, A. Adams. 



Bulla (Atys) denti/era, A. Adams in Sowerby's Thes. Conch., vol. iii. pt. 11, p. 588, sp. 93, pi. cxxv. 



fig. 124. 

 Atys (Dinia) denti/era, Adams, Genera, vol. ii. p. 21. 



„ dentifera, Reeve, Conch. Icon., vol. xvii. pi. iii. fig. 13. 



„ (Dinia) denti/era, v. Martens, Moll. Mauritius, &c, p. 303. 



July 29, 1874. Levuka, Fiji. 12 fathoms. 



(ZOOL. CHALL. EXP. — PART XLII. — 1886.) Tt 81 



