Fossil Mollusks From the John Day Basin in Oregon 



Polygyra expanse, Hanna. Op. cit. 

 Polygyra martini Hanna. Op. cit. 



Polygyrella polygyrella (Bland and Cooper.) Mentioned herein as being in 

 the University of Oregon Collection. 



Pyramidula mascallensis Hanna. Op. cit. Mentioned herein as being in the 

 University of Oregon Collection. 



Pyramidula simillima Stearns. 



Helix (Patula) perspectiva Say. Stearns, (in White.) U. S. Geol. 

 Surv. Bull. 18, p. 14, pi. Ill, fig. 7, 1885. 



Pyramidula perspectiva simillima Stearns, Proc. Wash. Aead. Sci. 

 Vol. 2, p. 657, pi. 35, fig. 7, 1900. (Figure reproduced from U. S. 

 Geol. Surv. Bull. 18 cited above. No description added.) Stearns, 

 Science, n. s. Vol. 15, p. 153, 1902. (No description.) Stearns. 

 Univ. of Calif. Publ. Geol. Vol. 5, p. 67, 1906. (This is a nude name 

 and cannot hold in nomenclature.) 



Ehiostoma americana n. sp. Described herein. 



Unio condoni White, U. S. Geol. Surv. Bull. 18, p. 13, pi. 2, figs. 1-3, 1885. 

 Migranaja condoni (White.) Hannibal, Proc. Mai. Soc. Lon. Vol. 

 10, p. 124 and 197, 1912. 



Transmitted May 27, 1920. 

 Issued August 26, 1920. 



EXPLANATION OF PLATE I 



Figures la, and 1&. Gastrodonta imperforata Hanna. Enlarged approx- 

 imately 1% times. 



Figures 3o, 3&, and 3c. Helicina oregona, n. sp. All enlarged approxi- 

 mately six times. 



Figures 4a, and 4b. Khoistoma americana, n. sp. Both enlarged approxi- 

 mately six times. 



[8] 



