EXPLANATION OF PLATE XL 



Planorbis exustus, Deshayes. 

 Figs. 1, la. — Young shell from Inle Lake, highly magnified. 



Limnaea shanensis, sp. nov. 



Fig. 2. — Marginal teeth of radula, x 554. 



Fig. 3. — Central and lateral teeth of radula, x 554. 



Limnaea mimetica, sp. nov. 

 Fig. 4. — Lateral and marginal tooth of radula, x 554. 



Succinea indica, Pfeiffer. 



Fig. 5. — Lateral and marginal tooth of radula, x832. 

 Fig. 6. — Upper jaw, x 50. 



Planorbis velifer, sp. nov. 



Fig. 7. — Upper view of shell of typical form, x 13. 



Fig. 8. — Lower view of same shell, x 13. 



Fig. 9. — Upper view of shell of the var. ciliata, x 13. 



Fig. 10. — Front view of shell of typical form, xl3. 



Fig. 11. — Lower view of mouth of another shell of the typical form, x 13. 



? Planorbis saigonensis, Crosse and Fischer. 



iwer view of 

 stream, x 13. 



Fig. 12. — Lower view of mouth of subfossil shell fromfedge of He-Ho 



