453 Mr. W. T. Blanford on the Classification of 



13. Cyclophorus, Montfort. 

 Within the area to which these observations especially apply 

 there exist several distinct series of forms of this well-known 

 and important genus, some of them differing from the type at 

 least as widely as Leptopoma does. These should be separated 

 as subgenera. 



I. Of the several groups classed under Cyclophorus, one of the 

 most distinct is that for which the following appellation was, a 

 few years ago, suggested by Mr. Theobald. It may be thus 

 characterized: — 



Lagocheilus, Theobald, MS. 

 Testa anguste umbilicata, turbinate- conica, parva, spiraliter lirata, 



epidermide fusca (in exemplis junioribus ssepe hispidula) induta. 



Peristoma incrassatum, superne ad angulam rima transversa bre- 



viter incisum. Operculum planum, tenue, albidum. 



Type, C. scissimargo, Bens., from Tenasserim. 



The other species (all from Burma) are 



C. tomotrema, Bens. Khasi Hills. 



C. , n. sp. Pegu. 



The animal of the last species has a longitudinal groove above 

 the posterior end of the foot, somewhat as in the Auriculoid 

 genus Melampus. 



The shells are all about the same size as C. halophilus, Bens., 

 and its allies, but easily distinguished by their thickened lip, 

 greater solidity, and the peculiar slit at the angle of the upper 

 margin of the peristome. To this section the little species 

 found by Mr. Theobald in the Andamans, and previously re- 

 ferred to, appears to belong. 



II. The next group* comprises certain discoidal shells, also 

 Burmese, as a type of which C. calyx, Bens., may be selected. 

 The operculum is thicker than in other Cyclophori, and has free 

 and rough margins to its whorls, so as to be absolutely identical 

 with that of Pterocyclos pullatus and it allies. In C. calyx, also, 

 there is a slight expansion of the outer peristome at the suture 

 corresponding to the wing in Pterocyclos. A similar slight 

 expansion is seen in C. phanotopicus, Bens., from the Hima- 

 layas, which, however, has a thin operculum. I consider, there- 

 fore, that in these forms and in the Burmese species of Ptero- 

 cyclos we have that almost complete passage from one genus 

 into the other, to which I have already referred, and clear evi- 

 dence of their close natural affinity. There can be little doubt 

 that Pterocyclos belongs to the same subfamily as Cyclophorus ; 



* For this section I proposed, in a paper printed in the ' Journal of the 

 Asiatic Society of Bengal' for 1863 (p. 322), the name Scabrina. Further 

 study of the genus has led me to the conclusions expressed above. 



