MOLLUSCA. 473 



8. Planorbis Riippelli, Dunker. 



' Streams on lughlands of Tigr^. Common. The peculiar 



jkeel near the suture described by Dunker is wanting in 



' my specimens, and is probably accidental. The mouth is 



very oblique, less so, however, than in the Natal species, 



L. Pfeifferi, Krauss. 



9. P. sp. nov. 

 Lake Ashangi. Dead specimens found on the shore 

 with Physa contorta. This is very near the Indian 

 P. compressus, but the umbUicus is more open, and the 

 keel more basal and less median. It is very near 

 P. Natalensis also, but differs in the mouth being sinuate 

 near the periphery, and less arcuate above, in the lower 

 guiface being more convex, and the shell more com- 

 pressed. 



10. P. Natalensis (^) Eiauss. 



Stream on Wadela plateau. Only a single specimen 

 was obtained, which may be the above species ; the 

 whorls appear rather narrower and less angulate at the 

 periphery. 



IV. 



LAND MOLLUSCA. 



Of these also but a very meagre series was obtained, 

 the country being evidently excessively poor in land- 

 shells. No Cyclostorrwbcea have ever been found in this 

 part of Africa, and the large Jchatince and their aUies 

 were entirely wanting in the country traversed, although 



