16 Records of the Indian Museum. [Vol. XXIV, 



Naukuchia Tal. Unfortunately most of them were dead shells and 

 are not, therefore, available for anatomical study. 



Genus Segmentina Fleming. 



1921. Segmentina, Annandale and Prashad, op. cit., p. 585. 



In the Tal area we found specimens of S. calathus (Benson), 

 the only Indian species which Dr. Annandale and I were able to 

 assign definitely to this genus. 



Segmentina calathus (Benson). 



.1821. Segmentina calathus, Annandale and Prashad, op. cit., p. 585. 



We found only a few specimens of this widely distributed 

 species amongst the algae in Naiui Tal. The specimens were found 

 only near the shores. 



Family HYDROBIIDAE. 



In spite of careful search no representatives of this family 

 were discovered by us in the Tal Lakes and I am very doubtful 

 as to whether any of them are really endemic in the lakes. While 

 making this rather bold statement I am aware of the record of some 

 specimens of Tricula moniana and Bythinia pulckella from Naini Tal 

 byNevillin his Hand-ljst, 1 but that does not necessarily mean that 

 the specimens referred to were collected in the lake itself. Ben- 

 son's type-series of the former species was collected in a small 

 stream flowing into Bhim Tal and probably Stoliczka's specimens 

 referred to by Nevill were also obtained from some stream around 

 Naini Tal. The only specimen of B. pulchella (also from 

 Stoliczka's collection, but not now to be traced in the Indian 

 Museum) must also have been collected outside the lake, as the 

 species is not known to inhabit large areas of clear water. 



Genus Tricula Benson. 



1921. Tricula, Prashad, Rec. Ind. Mus. XXII, p. 67. 

 I have nothing further to add to my recent account of the 

 genus and of the species, T. moniana, of the Tal area. 



Genus Digoniostoma Annandale. 



1920. Digoniostoma, Annandale, Ind. Joum. Med. Res. VIII, p. 104. 



1921. Digoniostoma, Annandale, Rec. Ind. Mus. XXII, p. 4. 



The only species which we actually found in the Tal area 

 was Benson's . Paludina pulchella. It has, on shell-characters 

 alone, been recently assigned to the genus Digoniostoma , but the 

 radula and soft parts are certainly different from those of D. 

 cerameopoma , the type-species of the genus. I do not, however, 



1 Hand-List Moll. Ind. Mus. II, pp. 35 and 62 (1884). 



