738 LIETJT.-COL. GODWIN-AUSTEN AND MR. NEVILL ON [Dec. 2, 



its height, and almost circular, with the margins almost but not 

 quite continuous, the columellar one being abruptly bent back over 

 the umbilicus, and then beautifully and boldly rounded. I named 

 this interesting little species after my friend Mr. F. A. de Roepstorff, 

 Dep. Sup. Andaman-I. Commission, to whom both the Museum at 

 Copenhagen and myself are indebted for many interesting Mollusca 

 and Coleoptera from the Andaman and Nicobar Islands (G. N.). 



Opisthostoma perakensis, n. sp. (Plate LX, figs. 1, la, 16.) 



Shell dextral, much depressed, ovate, the last whorl reflected half 

 a turn back and rising to a level with the penultimate suture ; colour 

 ruddy brown ; sculpture fine ribbing, wide apart and regular to the 

 apex. Spire depressed, sides parallel, apex flat, suture deep. 

 Whorls 4, sides convex ; penultimate and antepenultimate equal, the 

 last reversed. Aperture circular, vertical ; peristome double, inner 

 lip circular, continuous ; the outer lip angular below. 



Size, alt. - 30, major diam. 0*33 in. 



Perak. (Indian Museum, Calcutta.) 



Two examples of this very curious extremely minute shell were 

 discovered by Mr. G. Nevill when washing out some of the larger 

 specimens of the shells from the limestone caves, showing how 

 often such delicate small species must be overlooked and lost by 

 collectors (H. H. G.-A.). 



Opisthostoma paulucci^:, Crosse and Nevill, Journ. de 

 Conchyliologie, t. xix. pp. 197 & 205 (1879), pi. viii. fig. 1. 

 (Plate'LX. figs. 2, 2a, 2b.) 



Shell dextral, very depressed, ovate, the last whorl reflected more 

 than a half turn backwards and rising to the top of the antepenulti- 

 mate whorl ; colour ruddy brown ; the ribbing strong and wide on 

 the last two whorls, very close and fine on those above. Spire 

 depressed, sides parallel to axis, apex flat, suture moderately im- 

 pressed. Whorls 4, penultimate and antepenultimate equal, their 

 sides flat, the last whorl rounded and reversed. Aperture triangular, 

 subvertical. Peristome double, both inner and outer lips. 



Size, alt. - 30, major diam. 033 in. 



Perak. (Indian Museum, Calcutta.) 



This shell, a close ally in size and form of 0. perakensis, presents 

 a few characters by which it can be easily distinguished. I have, 

 however, only seen one specimen, which was found in a similar way 

 to that above described. Mr. Nevill informed me, before leaving for 

 India, that this shell had been described by M. H. Crosse from a 

 specimen he had sent him {G.-A.). 



Diplommatina crosseana, n. sp. (Plate LX. figs. 3, 3a.) 



Shell dextral, elongately fusiform, sculpture widely and regularly 

 costulate, colour pale sienna-brown ; spire gradually decreasing, 

 suture moderately impressed. Whorls 7 ; antepenultimate the largest 

 and most swollen ; penultimate short, from the last rising rapidly on 

 it ; constriction behind the aperture. Aperture rectangular, sub- 



