I04 Bryant Walkkr 



Pi.ANORBis TRivoLVis Say. 



Includes subcrcnatns Cpr., with oregonensis Tryon, occidentalis Cooper, 

 and tumens Cooper, non Cpr., as synonyms and probably hornii Tryon ac- 

 cording to Dall (32, p. 89). Pilsbry also (95, p. 65) lists hornii as a variety. 



Planorbis TRivoiAUS BiNNiiYi Tryon. 



Planorbis corpulentus Gould, U. S. Expl. Exp., 1852, p. 114, fig. 130; Hal- 

 deman, Mon., 1844, P- ^9, pl- HI, figs. 7-9; W. G. Binney, L. & F. W. 

 Shells, pt. II, 18O5, p. 114, figs. 191-2; Sowerby, Con. Icon., 1877, Sp. 

 4, pl, I, fig. 4; pl. X, fig. 4b. 



Planorbis binncyi Tryon, Am. J. of Con., Ill, 1867, p. 197. 



Type locality : West Coast. 



Planorbis umbflicatellus Cockerell. 



Planorbis iniibilicatiis Taylor, J. of Con., IV, 1885, p. 351, text-fig. non 



Miiller (1774). 

 Planorbis uinbilicatclbis Cockerell, Con. Ex., 1885, II, p. 68. 

 Type locality : Brandon and Birtle, Manitoba. Ranges from New York 



to South Dakota. See also Vanatta (137, p. 117). 



Planorbis vermicularis Gould. 



Is referred to parvus by Vanatta (136, p. 55), but is considered dis- 

 tinct by Dall (32, p. 95). 



Genus SEGMENTINA Fleming, 1817. 



Subgenus PLANORBULA Haldeman, 1842. 



Segmentina armigEra (Say). 



Dr. Pilsbry informs me that he has seen the type of Planorbis lautiis 

 H. Ads. and that it is a young specimen of this species. 



SEGMENTINA ARMIGERA CAMPESTRIS DawSOn. 



Segnientina armigera campestris Dawson, Rep. Brit. N. A. Boundary Com., 



1875, p. 349. 

 Type locality : Red River Valley, Canada, 



SEGMENTINA CIIRISTYI Dall. 



Segmentina cJiristyi Dall, Rep. Harriman Exp. XIII, 1905, p. 99, pl. ii, 

 figs. lO-II. 



Type locality : High Bluff, Manitoba ; Fort Smith, Mackenzie River. Re- 

 ported from South Dakota by Walker (151, p. 11). 



SEGMENTINA CRASSIEAERIS Walker. 



Segmentina crassilabris Walker, Naut., XX, 1907, p. 122, pl. 7, figs. 4-6. 

 Type locality : Hamtramck, Wayne Co., Mich. 



