286 Mr. W. H. Benson on some new Indian Cyclostomata. 



has produced some fine and rare shells, but it has not yet been 

 explored thoroughly by a practised conchologist. 



An additional character which I have distinctly ascertained in 

 Diplommatina folliculus and D. costulata, and which appears also 

 in D. Huttoni, may probably be found coextensive with the true 

 species, viz. the truncation of the columella far within the aper- 

 ture, so as to present the appearance of an oblique plait. In 

 some specimens this featui'e appears to be developed so far back 

 as to be immersed, or imperfectly distinguishable, from the aper- 

 ture ; but a sufficient series will reveal the character ; otherwise 

 the outer lip of a specimen may be broken for the purpose of 

 examining the interior. 



In the only two specimens which I possess of the Australian 

 species brought by Mr. Strange (vide Annals, vol. x. p. 352), I 

 cannot make out the fold distinctly from the aperture, and I am 

 unwilling to sacrifice either of the specimens by the destruction 

 of the outer lip ; a more extensive series is necessary to establish 

 the point, although one example affords an indication of the cha- 

 racter very remotely seated. I have some reason to think that 

 this species has been described by Dr. Pfeifi^er, for his Supjde- 

 ment to the Helicidce, as Pupa Strangei ; in which case it will 

 eventually be classed as D. Strangei ; I therefore still refrain from 

 describing it as a new species. It was, at first, the fate of D. fol- 

 liculus to be classed with BuUmus by the same author, thus 

 affording a tolerable proof of the difficulty of reconciling the 

 general characters of the shell, apart from the operculum, with 

 the Cyclostomida. 



In reply to an inquiry regarding another shell, the proper 

 station of which, in the absence of an operculum, is still noted 

 as doubtful, Dr. Gray informs me that Cyclostoma minus of 

 Sowerby [Diplom. minor of Gray, D. Sowerbyi of Pfeiffer) has no 

 plait apparent on the columella in the Museum specimens. In 

 addition to the want of a double peristome, which is characteristic 

 of the three Himalayan and the single Australian species, that 

 shell differs from adult specimens of the other species in the non- 

 continuity of the expanded peristome, and in the imperfect cos- 

 tulation of the whorls ; in fact, several characters applicable to 

 the other four species have been set aside from my original de- 

 scription in order to admit this doubtful species, viz. " anfractu 

 ultimo subascendente/' " peristomate duplicato," and " margi- 

 nibus callo parietali appresso junctis." 



An urgent exhortation to Capt. Hutton to repeat, on living 

 specimens of the Himalayan species, the examinations which 

 failed to discover the presence of an operculum (found by Dr. J. 

 E. Gray in two or three specimens of Diplommafina in the Bri- 



