UN 10. 



491 



the lakes and rivers of North America ; about five are 

 from Africa; at least ten undisputed species are European; 

 two only are from New Holland ; upwards of forty are from 

 the fresh waters of Asia ; and nearly thirty are South 

 American in their geographical distribution. 



Species of Unio. 



aheneus, Lea. 

 angustatus, Lea. 

 arctatus, Conr. 

 arctior, Lea. 

 arcus, Conr. 

 Barrattii, Lea. 

 bilineatus, Lea. 

 Gailliaudii, Ferus. 

 Corrianus, Lea. 

 dactylus, Lea. 

 Duttoniauus, Lea. 

 elongatus, Pfeiff. 

 fatuus, Lea. 

 Fisherianus, Lea. 

 folliculatus, Lea. 

 gibbosus, Barnes. 

 Ingallsianus, Lea. 

 iris, Lea. 

 Jayensis, Lea. 

 lanceolatus, Lea. 



lugubris, Lea. 

 marginalis, Lea. 

 nasutus, Say. 

 orieutalis, Lea. 

 parallelopipedon, D'Orb. 

 Patagonicus, D'Orb. 

 perstriatus, Lea. 

 phaseolus, Hild. 

 pictorurn, Linn. 

 platyrhynchus, Rossm. 

 productus, Conr. 

 rectus, Lam. 

 sagittiformis, Lea. 

 Sbepardianus, Lea. 

 strigosus, Lea. 

 teuuissimus, Lea. 

 teres, Rqfin. 

 tumidus, Retz. 

 Vaugbanianus, Lea. 



Sub-gen. bariosta, Rafinesque (Potamida, Swains). 

 Shell not winged, arcuated ; surface of valves smooth. 



crassus, Retz. 

 emarginatus, Lea. 

 Fellmanni, Desh. 



Lazarus, Lea. 

 monodontus, Say. 



