470 The Molluscan Family Planorhidae 



PLATE 117 



Shells of Planorbidae 



1-6. Parapholyx pusilla F. C. Baker. Six miles west of Pyramid Lake, Nevada. 



Figm-e 1, holotype; 2-5, paratypes; 6, costate specimen. U.S.N.M., 308925. 

 7-14. Parapholyx nevadeyisis J. Henderson. Pyramid Lake, Nevada. U.S.N.M., 75440. 



15. Parapholyx nevadensis J. Henderson. Pyramid Lake, Nevada. Scalariform speci- 



men. U.S.N.M., 126765. 



16. Parapholyx nevadensis J. Henderson. Pyramid Lake, Nevada. LlS.N.M., 75439. 

 17-26. Parapholyx nevadensis J. Henderson. Pyramid Lake, Nevada. \'ariation in 



form, neritoid to bulimoid. U.S.N.M., 63493. 

 27-30. Parapholyx mailliardi Hanna. Eagle Lake, California. From type lot. C.A.S., 

 23040. 



All figures are enlarged about 3y> diameters 



