UNIO. 



497 



Sub-gen. quadrula, Rafinesque (Theliderma, Swains.). 



Shell not winged, quadrate or triangular ; surface of valves 

 tuberculated. 



apiculatus, Say. 

 asper, Lea. 

 asperrimus, Lea. 

 Cincinnatensis, Lea. 

 cornutus, Barnes. 

 Dorfeuillianus, Lea. 

 fragosus, Conr. 

 intermedius, Conr. 

 lachryniosus, Lea. 



metanevrus, Rajin. 

 Phillipsii, Conr. 

 pustulatus, Lea. 

 Rurnphianus, Lea. 

 Schoolcraftensis, Lea. 

 sparsus, Lea. 

 stapes, Lea. 

 tuberosus, Lea. 



Sub-gen. diplodon, Spix(Cucumaria, Conr. Naia, Stcains.). 

 Shell not winged, oval or oblong ; surface of valves plicate. 



acutissimus, Lea. 

 Chilensis, Gray. 

 Conradicus, Lea. 

 corrugatus, Retz. 

 cucumoides, Lea. 

 dorsuosus, Gould. 

 ellipticus, Spice. 

 Grayanus, Lea. 

 Hembeli, Conr. 

 hippopseus, Lea. 



hylseus, D'Orb. 

 laticostatus, Lea. 

 Murchisonianus, Lea. 

 Osbeckii, Phil. 

 pliciferus, Lea. 

 ponderosus, Sol and. 

 sernigranosus, V. d. Busch. 

 Sloatianus, Lea. 

 subtentus, Say. 

 trapezoides, Lea. 



Sub-gen. dysnomia, Agassiz. 



Shell not winged, quadrate or triaugular ; surface of valves 

 plicate. 



atrocostatus, Lea. 

 caelatus, Conr. 



infucatus, Conr. 

 foliatus, Hild. 



