28 



AMERICAN JOUENAL 



V. simplex, G-ld. 

 '* tridentata, Wolf. 



CARYCHIUM, Say. 



C. exiguum. 



LYMN^A, Lamarck. 



L. umbrosa, Say. 

 " reflexa, '• 

 " caperata, " 

 " desidiosa, " 

 " humilis, " 

 " exigua, Lea. 

 " curta, " 

 " parva, " 



PHYSA, Drapernaud. 



P. gyrina, Say. 

 " hypnorum, Drapernaud. 

 " Hildrethiana, Lea. 



HELISOMA, Swainson. 



H. trivolvis, Say. 

 " bicarinatus, Say. 



MENETUS, H. and A. Adams. 

 M. exacutus, Say. 



G-YRAULUS, Agassiz. 



G. deflectus, Say. 

 " parvus, '• 



PLANORBULA, Hald. 

 P. armigera, Say. 



ANCYLUS, Geoffrey. 

 A. tardus. Say. 



VALYATA, 0. F. Miiller. 

 V. tricarinata. Say. ' 

 MELANTHO, Bowditch. 



M. subsolida, Anth. 

 " rufa, Hald. 

 " exilis. Lea. 



VIYIPARA, Mont. 



V. intertexta, Say. 

 " subpurpurea, Say. 

 " contectoides, Binney. 



SOMATOGYRUS, Gill. 



S. isogona, Say. 



AMNICOLA, Gld. and Hald. 



A. decisa, Hald. 



" limosa, Say. 

 " porata, Say. 

 " CMcinnatiensis, Antli. 



BYTHINELLA, Leach. 



B. obtusa, Lea. 



POMATIOPSIS, Tryon. 



P. Cincinnatiensis, Lea. 

 " lapidaria, Say. 



PLEUROCERA, Rafinesque. 



P. subulare, Lea. 

 " Lewisii, " 



GONIOBASIS, Lea. 



Gr. gracilior, Anth. 



" livescens, Menke. 



SPH^RIUM, Scopoli. 



S. solidulum, Prime. 

 " triangular e. Say. 

 " transversum, " 

 " sphsericum, Anth. 

 " rosaceum. Prime. 

 " occidentale, " 



PISIDIUM, Pfeiffer. 



P. abditum, Hald. 

 " var labile. Prime. 



UNIONIDiE. 



UNIO, Brug. 



U. multiplicatus. Lea. 

 " pustulatus, " 

 " pustulosus, " 



