ii8 Bryant Walker 



Lanx pr.I'Ci.arus (Stimpson). (Mss.?) 



Ancylus pr<vclarus ''Stimpson" Lea, Obs. XI, 1866, p. 141. 



This apparently iindescribed species is "referred to and distinguished 

 from neivherryi by Lea. 



Lanx subrotundus (Tryon). 



Ancylus siihrotundus Tryon, Am. J. of Con., I, 1863, p. 230, pi. 22, fig. 14. 

 Type locality : Umpqvia River, Oregon. 



Subgenus WALKEROLA Hannibal, 1912. 



Lanx (Walkerola) klamathensis Hannibal. 



Lanx (JValkcrola) klamathensis Hannibal, Pr. Mai. Soc. Lond., X, 1912, 



p. 149, pi. VHL fig. 25. 

 Type locality : Upper Klamath Lake, Ore. 



Genus FISHEROLA Hannibal, 1912. 

 FiSHEROLA EANCTDEs Hannibal. 



Fisherola lancidcs Hannibal, Pr. Mai. Soc. Lond., X, 1912, p. 152, pi. VHI, 



fig- 35- 

 Type locality : Snake River, Washington. 



Genus ACROLOXUS Beck. 



Does not occur in our fauna. Of the two species referred to it by 

 Binney, one, A. nitttaUii, is a Lanx and the other, A. filosns, is a RJiodacmea. 



Subfamily FERRISSHN^ Walker, 1917. 



Genus FERRIS SI A Walker, 1903. 

 Ferrissia boreaeis (Morse). 



Ancylus horcalis Walker, Naut., XVIII, 1904. p. 80, pi. 6, figs. T4-16. 

 Ferrissia caurina ("W. Cooper," W. G. Binney). 



Ancylus canrinus, J. G. Cooper, Pr. Cal. Acad. Sci., IV, 1870, p. 100. 



Tryon (132, p. 229) refers this species to fragilis, but it is an error. 



Is doubtfully referred to Ferrissia fragilis Try. as a variety by Cooper 

 (25, p. too), but later (26, p. 83) he considers it distinct. Dall (32, p. no) 

 also doubtfully refers it to fragilis. 



Ferrissia caurina subalpina (J. G. Cooper). 



Ancylus caurinus suhalpinus J. G. Cooper, Pr. Cal. Acad. Sci., (2), III, 1890, 



p. 82, pi. I, figs. 27-28. 

 Type locality: Yosemite Valley and Bloody Canyon, Cal. Also Oregon. 



