258 limnjEINjE. 



Sub-gen. physodon, Haldernan. 



Shell solid, smooth, elliptical; outer lip thick; columella 

 toothed. 



microstoma, Hold. 



Genus PIIYSOPSIS, Krauss. 



Shell sinistral, imperforate, ovate, thin ; aperture longi- 

 tudinal ; inner lip none ; columella involute, plicate, trun- 

 cate at the fore part ; outer lip simple, acute. 



Ex. P. Africana, Krauss, pi. 83, fig. 10. 



The animal of Physopsis has not been examined, but the 

 peculiar conformation of the shell would seem to indicate 

 some important difference in the mantle-margin. The only 

 species described is from South Africa, and the shell, in 

 having the base of the columella truncated, exhibits the 

 same relation to Physa that Achatina does to Bulimus 

 anions? the Helicidce. 



* 



Genus CAMPTOCERAS, Benson. 



Tentacles filiform, obtuse. Mantle scarcely going beyond 

 the lips of the shell. Foot short, scarcely exceeding the 

 length of the aperture. 



Shell sinistrorsal, elongated ; spire produced, whorls few, 

 disunited ; aperture oblong, entire, produced and reflexed 

 anteriorly. 



Ex. C. terebra, Benson, pi. 84, fig. 1. 



The animal adheres, beneath the surface, to the decaying 

 stems of a long reedy grass, in a deep piece of water in the 

 wide alluvial bed of the Puuugunga, near Moradabad in India. 



