96 THE CHICAGO ACADEMY OF SCIENCES. 



& Caenoz. Geol., p. 72, 1881.— White, 3rd An. Rep. U. S. Geol. Surv., p. 445, pi. 

 29, figs. 22-23, 1882; Bull. U. S. Geol. Surv., no. 128, p. 80, 1895.— Schcchert, 

 Bull. U. S. Nat. Mus., 53, i, p. 357, 1905. 



Limnaa (Limnophysa) vctusta Meek, U. S. Geol. Surv. 40th Parallel, IV, 

 p. 191, pi. 17, fig. 4, 1877.— Marcou, Proc. Xat. Mus., VIII, p. 337, 1885. 



Lymnophysa vctusta White, An. Mag. Xat. Hist., ser. 5, VI, p. 249, 1880. 



"Shell small, elongate-subovate, or subf usiform ; spire moderately 

 prominent, conical, scarcely as long as the aperture ; volutions five and 

 a half to six, compressed-convex ; last one not very ventricose, some- 

 times almost subcylindrical ; suture well defined, with comparatively 

 little obliquity ; surface showing only obscure lines of growth ; aperture 

 very narrow, subovate ; columella with a moderately distinct fold. 



"Length, 0.56 inch; breadth, 0.26 inch" (Meek). 



Type : U. S. Xat. Mus., no. 693. 



Horizon : Bridger formation. Middle Eocene Period. 



Locality : Ham's Fork, north of Fort Bridger, Uinta County, 

 southwestern Wyoming. 



Remarks : "Among existing species this may be compared with 

 L. decidiosa of Say, some varieties of which it quite nearly resembles. 

 Its body volution, however, is less ventricose, and its aperture less 

 expanded, than we see in any of the several forms that have been 

 supposed to be varieties of that species. It is, perhaps, more nearly 

 allied to some of the real or supposed varieties of L. Jiumilis, Say; 

 though not exactly agreeing with any of them. It varies much in 

 form" (Meek). 



Vetusta belongs in the subgenus Stagnicola. It closely resembles 

 some of the recent species of the palustris-rcflexa groups. 



Galba similis (Meek). Plate XVI, figures 14, 15, 18. 19. 



Limnaa similis Meek, Proc. Phil. Acad., p. 314, 1860. — Bi.xney, L. & 

 F. W. Sh. X. A., II, p. 72, 1865. — Conrad, Smith. Check List, p. 9, 1866.— Meek, 

 Simpson's Rep. Great Basin Utah, pp. 367, 373, pi. 5, fig. 2, 1876. — White, Bull. 

 U. S. Geol. & Geog. Surv. Terr., Ill, p. 611, 1877.— Meek, U. S. Geol. Surv. 

 40th Parallel, IV, p. 191, pi. 17, fig. 3, 1877.— White, Amer. Journ. Sci. & Arts, 

 ser. 3, XX, p. 45, 1880.— Miller, Journ. Cin. Soc. X. H., Ill, p. 82, 1SS0. ; Mes. 

 & Csenoz. Geol., p. 72, 1881.— White, 3rd An. Rep. U. S. Geol. Surv., p. 445, pi. 

 29, figs. 20-21, 1882.— Marcou, Proc. Xat. Mus., VIII, p. 337, 1885.— White, 

 Bull. U. S. Geol. Surv., no. 128, p. 80, 1895— Schuchert, Bull. U. S. Xat. Mus., 

 53, i, p. 356, 1905. 



Limnophysa similis White, An. Mag. X. H., Ser. 5, VI. p. 249, 1880. 



"Shell small, narrow-subovate, approaching subfusiform ; spire 

 rather prominent, nearly as long as the aperture ; volutions five and 

 a half to six, convex ; suture rather deep and oblique ; surface showing 

 only fine, obscure lines of growth, scarcely visible without the aid of 



