PHYSAD^. 83 



Family PHYSADJE, Haldeman. 

 Monog. Physa, p. 5, 1842. 



Genera. 



1. Shell oblong, spiral, aperture oval, entire 

 below. 



Subfamily Limn^in^. 



Dextral, spire more or less elongated, 



LiMN^A, Lamarck. 

 Sinistral, oblong. Margin of the mantle 



fringed, . . Physa, Draparnaud. 

 Sinistral, oval-elongated. Mantle-margin 



simple, . . . BuLiNUS, Adanson. 



2. Shell turbinate, spiral, not umbilicated, 

 whorls gibbosely rounded. 



Subfamily Pompholigin^, Dall. 



PoMPHOLYX, Lea. 



3. Shell turbinate, spiral, umbilicate, whorls 

 angulated and carinated. 



(57) 7 



