4 SMITHSONIANT MISCELLANEOUS COLLECTIONS VOL. 92 



Measurements of the Shells of Lymnaea palustris ka::akensis, n. siibsp., from near 

 Novo Troetskaya, Kacaksta)^ 



Type 



LYMNAEA (GALBA) PALUSTRIS DRAVERTI, n. subsp. 



Plate I, fig. 9 



Shell somewhat resembling that of L. palustris kasakensis but having 

 a more broadly conical spire ; whorls seven and a half, convex, gently 

 rounded, turning gradually into the suture, which is deep ; aperture 

 small and subovate, oval by comparison with that of kasakensis, 

 columella not twisted, umbilical chink of large size. 



Type. — U.S.N.M. no. 469681, from the River Om, near Omsk, 

 Siberia. 



This species is known only from the type locality. Collected by 

 Prof. Pierre Dravert, after whom it is named. 



Measurements of the Shells of Lymnaea palustris draverti, n. subsp., from the 

 River Om, near Omsk, Siberia 



Type 



