596 MR. K. A. SMITH ON SHELLS [Juiie 2, 



Pfeififer, have the spire a trifle shorter, and the body-whorl the 

 least more ventrieose. la all the apex is reddish, and the linos of 

 growth rather coarse. 



25. Cyclostoma (Adelostoma) triste, Tapparone Canefri, 

 var. ? 



Hab. Faro and Shortland Islands and Choiseul Bay in Bougain- 

 ville Straits and Santa Anna Island {Guppy) ; Guadalcanar (Mac- 

 gillivray, in Brit. Mus.). 



Dr. Tap])arone Canefri has kindly compared specimens from these 

 islands with his C. triste, and is of opinion that they may be con- 

 sidered a variety of it; and observes that the New-Guineanforni is a 

 little smaller, its spire a little more slender, its surface more glossy, 

 the colour redder, and the apex of the spire darker. 



The shells under examination are clothed with a very thin epi- 

 dermis when in a fresh condition, exhibiting numerous very fine 

 spiral thread-like lines, which entirely disappear in worn shells and 

 can easily be rubbed off with a brush. For several species having 

 a similar epidermis and an incomplete peristome, Dr. Tapparone 

 Canefri has proposed the subgenus Adelostoma. The little shell 

 Cyclostoma infans from Wild lisland, Admiralty group, described 

 from the 'Challenger' Collection (Proc. Zool. Soc. 1884, p. 226, 

 pi. xxiii. fig. 8) belongs to the same section. 



26. Leptopoma jAcauiNOTi, Pfelffer. 



Hah. Rua Sura Island, off the north coast of Guadalcanar. 



This species does not appear to have been frequently met with by 

 collectors, and is chiefly known (as Cyclostoma pcllucida) by Rous- 

 seau's description in the 'Voyage an Pole Sud,' and the diagnosis 

 by Pfeiffer taken from the figure in the Atlas to that work. The 

 three specimens collected by Mr. Guppy are uniformly seuiipellucid 

 white, with the exception of the apex, which is pale reddish. The 

 whorls are five in number, considerably convex, rapidly enlarge, and 

 are sculptured throughout with very fine concentric striae besides 

 the more prominent spiral lirse, which are most distinct upon the 

 body-whorl above the prominent carina at the periphery. The peri- 

 stome is moderately and equally expanded all round except at the 

 short interruption at the body-whorl and just under the umbilicus, 

 where it is conspicuously emarginate. The operculum is thin, pale 

 dirty yellowish, consists of about eight volutions which are separated 

 by a raised revolving sutural line and sculptured with rather coarse 

 cross-lines of growth. 



The largest of the three specimens from Rua Sura is 15 millims. 

 high, 17 at its greatest diameter and Vlh at its smallest. 



L. immaculatum, Chemnitz, is very like this species in some 

 respects, but differs a little in form, having a taller and more conical 

 spire, less rounded whorls, a more shallow suture, &c. 



27. Leptopoma vitueum. Lesson. 



Hab. Santa Anna, Sin^bo, and Shortland Islands. 



