2S 



L. cyclostomatiformis, Lea. Coosa and Cahawba rivers 

 Black Warrior river. 



Genus SOMATOGYRUS. Gill. 



S. subglobosus, Say. Coosa river ? Alabama river. 



S. Currierianus, Lea. " Huntsville/' Decatur. 



S. parvulus, Tryon. Tennessee river at Bridgeport 5 

 Coosa river. 



S. aureusi Tryon* Tennessee river ; Cahawba river 5 

 Alabama river ; Coosa river* 



Genus POMATIOPSIS. Tryon. 

 P. lapidaria, Say. 



Family NERITID/E. 



Genus KERITELLA. Humphrey. 



- N. reclivata, Say. Mobile Bay? (var. floridana, 

 Shuttleworth. 

 N. Showalteriij Lea. Coosa river.* 



Family HELCINIDJE. 



Genus HELICINA, Lamarck. 

 Sub-genus OLIGYRA, Say* 



O. orbiculata, Say. Motevallo. 



*i --- - 



*No specimens with opercles are known. It is therefore yet uncertain if 

 this species be a Neritetta. 



