EXPLANATION OF PLATE VI. 

 All the figures are from direct photographs of natural size. 



Lecythoconcha lecythis (Benson). 



Figs, i, 2. — Large shells of pond-phase from Imphal, Mani- 

 pur. 



Acrostoma variabilis (Benson). 



Fig. 3. — Type-specimen of var. laevis, nov., from Sylhet. 



,, 4. — Another specimen of the same variety, from the 

 Manipur Valley. 



,, 5. — Cotype of var. semilaevigata. Nevill, from Sylhet. 



,, 6. — Cotype of var. subspinaia, nov., from the Manipur 

 Valley. 



