492 



UNI0NI1LE. 



Sub-gen. naidea, Swainson. 

 Shell not winged, ob-ovate ; surface of valves smooth. 



arnygdalum, Lea. 

 biangulatus, Lea. 

 Boydianus, Lea. 

 contradens, Lea. 

 cuprinus, Lea. 

 Floridensis, Lea. 

 foliaceus, Gould. 

 hyalinus, Lea. 

 lenior, Lea. 



modioliformis, Lea. 

 nigrinus, Lea. 

 obtusus, Lea. 

 papyraceus, Gould. 

 pellucidus, Lea. 

 rhombeus, Wag. 

 Tappauianus, Lea. 

 tenerus, Bav. 

 ventricosus, Soland. 



Sub-gen. obovaria, Rafinesque (Rhipidodonta, M'orch). 

 Shell not winged, sub-rotund ; surface of valves smooth. 



circulus, Lea. 

 coccineus, Lea. 

 dolabelloides, Lea. 

 ebenus, Lea. 

 Kirtlandianus, Lea. 

 lens, Lea. 

 Lesueurianus, Lea. 

 Masoni, Conr. 

 membranaceus, Maton. 

 nucleopsis, Conr. 



Paranensis, Lea. 

 personatus, Say. 

 pilaris, Lea. 

 rotundatus, Lam. 

 rubellus, Conr. 

 subrotundus, Lea. 

 torsus, Bqfin. 

 unicolor, Lea. 

 variabilis, Maton. 



Sub-gen. niaa, Swainson. 

 Shell not winged, oblong; surface of valves smooth. 



angustus, Lam. 

 atratus, Swains. 

 auratus, Swains. 

 Blandingianus, Lea. 



brevidens, Lea. 

 Buddianus, Lea. 

 callosus, Lea. 

 camptodon, Say. 



