1869.] Contributions to Indian Malacology : 133 



is slightly expanded, the edge cut into minute teeth like those of 

 a saw except on the inner or columellar margin. Operculum externally 

 slightly concave, white, calcareous ; the spiral sculpture obsolete near 

 the centre in old specimens ; internally membranaceous. Major diameter 

 0.34, minor 0.28, axis 0.22, diameter of the aperture 0.14 inch. 



This is a very curious and interesting species which, while differing 

 in many respects from any known form, has marked affinities with 

 shells belonging to distinct groups. Had the shell been discovered 

 without the operculum, there could have been very little hesitation 

 in considering it a large form of Cyathopoma ; the sculpture and 

 general shape are precisely those of the types of that genus, and in some 

 species, as Cyathopoma jilocinctiom, there is a thick epidermis, and 

 also the very singular internal crenulation of the mouth, which is 

 more marked in the present shell than in any allied species. The 

 operculum, however, is totally different : instead of the whorls having 

 the curious raised and incurved edges so characteristic of Cyatlwpoma 

 they are flat and almost obsolete near the centre, on the outer surface, 

 being far less distinct than in typical species of Cyclotus. 



The hairy fringe around both the periphery and the umbilicus so 

 closely resembles that in Cyclophorus (Craspedotropis) cuspidatus, 

 Bens., that there can be no question of a certain affinity between the 

 two species, and there is considerable resemblance in their general 

 form. The apertures, however, differ greatly, and there are marked 

 distinctions in the operculum. 



On the whole, I think it highly probable, that the present generic 

 type, and perhaps Craspedotropis also, will finally have to be consider- 

 ed as sub-genera of Cyatlwpoma. 



5.— Mychopoma limbiferum, n. sp. Pi. XVI, fig. 4. 



Testa anguste umbilicata, turbinata } tenuis, epidermide decidu,d,fulvd, 

 striyisfuscis, obliqids spiralibusque notatd, vel unicolori fused, fimbriam 

 pilorum brevium circa umbilieumferente, induta ; sub epidermide albida 

 liris confertis spiralibus ornata. Spira conica ; sutura valde impressa. 

 Anfr. 5 \ convexi, ultimus teres, antice sub-descendens. Apertura obliqua, 

 fere circularis : peristoma duplex ; externum limbo sub-late expanso 

 circumdatum, ad anyulum aperturce antice porrectum ; internum vix dis- 

 cretion intus sub-distanter corruyatum ; margine columellari amhorum 

 valde repando, glabro, vix expansiusculo. Operculum minus crassum 



