ii8 Bryant Walker 



Lanx PR^ci,ARUS (Stimpson). (Mss.?) 



Ancylus prceclarus "Stimpson" Lea, Obs. XI, 1866, p. 141. 



This apparently imdescribed species is referred to and distinguished 

 from newherryi by Lea. 



Lanx subrgtundus (Tryon). 



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

 Type locality : Umpqua River, Oregon. 



Subgenus WALKEROLA Hannibal, 1912. 



Lanx (WalkDrola) Ki^AMATHiiNSis Hannibal. 



Lanx (Walkerola) klamathensis Hannibal, Pr. A-Ial. Soc. Lond., X, 1912, 



p. 149, pi. Vni, fig. 25. 

 Type locality : Upper Klamath Lake, Ore. 



Genus FISHEROLA Hannibal, 1912. 

 Eisherola lanctdKs Hannibal. 



Pisherola lancides Hannibal, Pr. Mai. Soc. Lond., X, 1912, p. 152, pi. VHL 



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. nuttalln, is a Lanx and the other, A. filosus, is a Rhodaanea. 



Subfamily EERRISSHN^ Walker, 1917. . 



Genus FERRISSIA Walker, 1903. 

 Fe;rrissia boreaus (Morse). 



Ancylus borealis Walker, Naut., XVHL 1904, p. 80, pi. 6, figs. 14-16. 

 Fi;rrissia caurina ("W. Cooper," W. G. Binney). 



Ancylus caurinus, 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 Perrissia 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 subalpinus ]. 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. 



