18/9.] SHELLS FROM PERAK AND THE NICOBAR ISLANDS. 737 



Acmella moreletiana, Nevill (Handl. Moll. Ind. Mus. 1878, 

 p. 251, Batti Malve). (Plate LIX. fig. 4.) 



Testa minima, subaperte umbilicata, conico-turrita, hyalina, per- 

 lucida, polita atque nitida ; circa regionem umbilicalem confertim 

 plicata, plicis validis, regulariter incisis, prope suturam [sub 

 " lente "] minutissime striatula, striis sape haud videndis ; 

 anfract. 5|, convexiusculi, gradati, sutura excavata sejtmcti, 

 ultimo globuloso, inferne convexo ; apertura per/ecte rotundata, 

 marginibus approximatis , sed haud continuis ; peristomate paulu- 

 lum incrassato, margine columellari sensim rotundato, umbilicum 

 haud tegente. 

 Long. 2, diani. 1^ mil. (G.N.) 



The late Dr. Stoliczka found this species in abundance on the little 

 island of Batti Malve, twenty miles south of Car Nicobar. The regular 

 distinct plications of the central portion of the base, which crowd the 

 interior of the umbilicus, are a peculiar characteristic ; in some of 

 the scarcely mature specimens, under a strong lens, I can just detect 

 near the suture, here and there, traces of a most minute striation ; 

 otherwise the shell is of a perfectly smooth, polished, and translucent 

 texture ; the whorls are more convex than those of A. roepstorffiana, 

 the aperture higher in proportion to its breadth, with the columellar 

 margin not bent abruptly back over the umbilicus, but evenly and 

 gently rounded. Colonel Austen's figures of both these species are 

 excellent, scarcely to be surpassed. The only possible criticism is 

 that the margins of the aperture of this species, in especial, may to 

 some appear continuous, which is not the case (G. 2V.). 



Acmella roepstorffiana, Nevill (Handl. Moll. Ind. Mus. 1878, 

 p. 25, Katchall, Nicobar Islands). (Plate LIX. fig. 5.) 



Testa minima, peranguste umbilicata, conico-turrita, nitida, sub- 

 translucida, sericina, omnino distincte, subconfertim et regulariter 

 striata, striis acute filiformibus , obliquis, ad basin flexuosis, prope 

 regionem umbilicalem paululum magis conspicuis ; anfract. 5, 

 gradati, vix convexiusculi, sutura excavata sejuncti, ultimo sub- 

 cylindrico, ad peripheriam paululum compresso; apertura minima, 

 subcircularis, peristomate incrassato, haud continue, subobsolete 

 duplici, margine externa perconvexo, margine columellari valide 

 retrorsum arcuato plus minusve umbilicum tegente. 

 Long, li diam. 1 mill. (G. N.) 



This small species, a few specimens only of which were found by 

 the late Dr. Stoliczka at Katchall, one of the Nicobar Islands, is 

 distinguished from all the other described species of the genus by 

 its being throughout regularly, rather strongly striated, the striae 

 being acute and " thread-like ; " the shell is of a silky, translucent 

 and shining texture, with 5 almost cylindrically turreted whorls, 

 the last a trifle compressed at the periphery ; the umbilicus is ex- 

 ceedingly narrow and partially overlapped by the thickened peristome, 

 which here and there, under the lens, clearly shows a duplex cha- 

 racter ; the aperture is very small, unusually broad in proportion to 



