422 Records of the Indian Museum. [Vol. XVI, 



and the columella curved. The main axis of the aperture forms 

 an acute angle with that of the shell. 



Measurements of shells {in millimetres). 



Length of shell 

 Maximum diameter of shell 

 Length of spire (dorsal view) 

 Length of aperture 

 Breadth of aperture 



We have extracted the dried animal from a shell. It seems 

 to resemble that of Fenouilia but is much shrivelled. The 

 operculum is ovoid, thin, horn}^, of a dark brown colour and 

 resembles that of F. ftreitneri in sculpture. 



We have already pointed out certain characters in which the 

 radula differs from that of Fenouilia. The following is a more 

 precise account of the differences. The central tooth is low in 

 proportion to its breadth, its base is produced at either side and 

 sharply pointed but broadly and rather deeply concave. The cusp 

 is very large, extending downwards far beyond the base of the tooth. 

 The lateral tooth is bent in such a way that the narrow basal part 

 makes an obtuse angle with the broad upper part. The main 

 denticulation of this tooth is very large, occupying nearly half 

 the free margin. The inner marginal tooth is much broader than 

 the outer marginal and its denticulations are blunt. The triangu- 

 lar membrane on the outer margin of the outer marginal tooth 

 is short and confined to the upper third. 



Type specimen: M 11598/2 in the collection of the Zoological 

 Survey of India. 



Locality. Erh-Hai (Tali Fu Lake), Yunnan, W. China, alt. 

 6,700 ft. 



The shape and structure of the shell are so like those 

 of Paraprososthenia gredleri (Neumayr) from the same lake that 

 we do not consider a complete generic separation possible in the 

 present state of our knowledge. It must be remembered, however, 

 that we know as yet nothing but the shell of P. gredleri. The resem- 

 blance in the shell to that of Pyrgula, Cristofora & Jan (of which 

 the anatomy seems to be equally unknown) is probably quite 

 superficial. If we are right in thinking that the anatomy resembles 

 that of Fenouilia, as the radula undoubtedly does, there can be 

 no relationship to Oncomelania , Gredler (= Hypsobia, Heude), the 

 soft parts of which, according to Heude, ' are of the. Hydrobiid 

 type. In considering the value of the radula as a guide to 

 affinities, however, it must be remembered that the same author 

 (op. cit., pi, xxxiii, fig. 8) figures the teeth of Delavaya (which also 

 appears to be of the Hydrobiid type and is regarded by Bavay 

 and Dautzenberg on shell-characters as no more than a subgenus 



Heude, Mem. Hist. Nat. Emp. Chinois I, pi. xxxiii, figs, 1-7 (iSqo), 



