4i6 



Records of the Indian Museum. 



[Vol. XVI, 



two genera together rather on the resemblance between the radulae 

 than on other anatomical grounds. 



The conclusion we derive from the above observations is that 

 the genera Fenouilia and Paraprososthenia are not Hydrobiidae 

 but resemble the Pleuroceratidae^ within the limits of which they 

 mav be included provisionally, rather than any other family. 



A. 



-Radulae of Hydrobiidae and ('.') Pieuroceratidae from China and 

 Europe. 



A. LithoglypliHs fitscns, Zieg. from K. Kurope. 



B. Lithoglyphus lilipiitamis, Gredler, from the 'rong-'ring Lake, 



China. 



C. Fenouilia ki'eitnei'i (H&\xn\aiyr) from Krh-Hai Lake, China. 



D. Paraprosostlienia coggini, sp. nov. from the same lake. 



Their possible relationship to the Rissoidae cannot be discussed 

 in a satisfactory manner owing to lack of anatomical information 

 about that family. Some relationship to forms like those included 

 in the genus Iravadia, Blanford, is not impossible, but the position 

 of that genus is also doubtful. It is found in brackish water, 

 chiefly in the estuaries of the Ganges and Irrawaddi and also in 

 the backwaters of the West Coast of India. 



