Genus Lampsilis Rafinesque. 

 Section Lampsilis Rafinesque. 

 Group of Lampsilis ovatus. 

 Section Eurynia. Rafinesque. 



Genus Medionidus Simpson. 



GrouD of Mcdionidi/s conradicus. 

 •' ' " " u'dkcri. 



" " " subtcnhis. 



Genus Nephronaias Crosse and Fischer. 



Group of Nephronaias medellinits. 



avcryi. 

 " " " macncillii. 



reticidatns. 

 " " " scamnattis. 



Genus GlEbula Conrad. 



-4- 



