the Cyclostomacea of Eastern Asia. 45^ 



and its associated genera, Rhiostoma, Spiraculum, &c., must fall 

 into the same group. 



This little section, the species of which also agree in their 

 velvety epidermis, when in good condition, appears to coincide 

 in so many points with the subgenus Myxostoma of Troschel, 

 that it may probably be classed with that section. The charac- 

 ters of the Burmese species are 



Testa late umbilicata, depressa, subdiscoidea, epidermide fusca 

 hispidiila induta; anfractibus rotundatis. Apertura circularis, 

 peristomate incrassato. Operculum crassum, corueum, anfractuum 

 marginibus lamellatira elevatis. 



The species included are — 

 C. pinnulifer, Bens. Khasi Hills. 

 C. calyx, Bens. Molmain*. 

 C. hispidulus, W. Blanf. Ava. 



III. The discoidal species of India and Ceylon, with thin 

 opercula. These are — 



C. phanotopicus, Bens. Darjiliug. 



C. ravidus, Bens. Nilgiri Hills and Ceylon. 



C. stenostomus, Sow. Nilgiri Hills. 



C. deplanattts, Pfr. Nilgiri Hills. 



C. annulatus, Trosch. Ceylon. 



a Bairdii, Fh: Ceylon; 

 and one or two Ceylonese species with which I am unacquainted. 

 C. Bairdii, C. stenostomus, and C. deplanatus are so closely 

 allied as to be scarcely more than local varieties ; and the same 

 is the case with C. ravidus and C. annulatus. 



IV. A group of shells arranged by PfeiflFer under Leptopoma, 

 but differing from the species of that genus in the non-expanded 

 peristome, in the rounder whorls, more globose forms, slower 

 increase in the size of the whorls, and consequent comparative 

 smallness of the mouth, and in the tendency to a rapid and 

 irregular descent of the last whorl in aged specimens. The 

 species are peculiar to Ceylon and Southern India, and comprise 

 the following : — 



C. coeloconus, Bens. Southern India. 



C. malleatus, W. Blanf. Shevroy and Nilgiri Hills. 



C. halophilus, Bens. Ceylon. 



C. orophilus, Bens. Ceylon; 

 and three or four other Ceylonese species, the differences be- 

 tween which and the two last mentioned are very minute. 



* The locality is, I believe, erroneously given as Akoutoung, Pegu. I 

 have collected largely and repeatedly at that locality, but never met with 

 a specimen ; whereas the shell is abundant at Molmain. 



