EXPI.ANATION OF PLATE VII. 



The line between the two views of each shell shows the actual 

 height of the specimen. 



Limnaea acuminata, Lamarck. 



Fig. I. — Shell from the edge of the Loktak Lake, Manipur. 



,, 2.— Normal shell from a patch of Potamogeton near the 

 outflow of the same lake. 



,, 3. — Abnormal shell from the same habitat. 



Limnaea ovalior, sp. nov. 



Fig. 4. — Shell from a pool of foul water in the jungle near 

 Dimapur, E. Assam. 



Figs 5, 6. — Shells of the type-series, from a buffalo-wallow 

 at the edge of the Loktak Lake, Manipur. 



