192 1. 1 • Manipiir Molluscs. 5S9 



We have examined the radulae of A. verruca, A. viola and 

 A. ceylanicus. Although the teeth differ in certain particulars from 

 those figured by Walker in the second paper cited above, they 

 conform sufficiently well to his description. 



Ancylus (Ferrissia) verruca, Benson. 



1855. Ancylus veri'ttca, Benson, Ann. Mag. Nut. Hist. (2) XV', p. ii. 

 1876. Ancylus verruca, Hanlc)' and 'I'heobald, Conch. Ind., pi. Ixxxi. 



tigs- 2. 3- 



1914. Feyfissia verruca, Walker, Nauiilusl\.YJ^\\, p. Ii6. 



1915. Ancylus verruca, Pre.ston, Faun. Brit. Ind., Fresliiv.-Moli.. 



p. 105. 



Specimens from Imphal, Manipur, agree fairly well with 

 Hanley and Theobald's figures except in being rather higher, 

 narrower and taller. There is considerable variation in these 

 respects, however, and our specimens are smaller than the one 

 figured in the Conch. Indica. 



The animal closely resembles that of .4. viola, a new species 

 that we describe in greater detail, but has the left epipodial lobe 



B 



Fig. i8. — Radulnr tectli ol' Ancylus. 



.\. A. viola, Annandale and Prashad. 

 B. A. verruca, Benson. 



relatively larger. We figure the radular teeth as seen under an 

 oil-immersion lens. The mouth is a longitudinal slit provided 

 with thin lateral lips and with a minute tongue-sliaped process 

 on the floor. The upper jaw is lunate and, though thin and deli- ' 

 cate and somewhat broken up, has a concrete character as a whole. 

 The majority of the side-pieces take the form of saddle-shaped 

 denticles arranged in a long single row running parallel to and 

 just inside the lip on either side. The uppermost piece on each 

 side, however, is plate-like and the lowest is large and curved. 



A. verruca has a wide range in the Indian Empire and Ceylon 

 but is somewhat sporadic. In the neighbourhood of Imphal we 

 found it not uncommon on the underside of the floating stems 

 of water plants and leaves in ponds. 



Ancylus (Ferrissia) viola, sp. nov. 



The shell is small and thin but opaque and of a dark brown 

 or blackish colour. It is of suboval form, slightly narrower be- 

 hind than in front and from It times to twice as long as broad- 



