458 THE CHICAGO ACADEMY OF SCIENCES. 
the twisted type of Galba than of the gyrate type of Lymnea, and the 
whole shell suggests the emarginata group of the genus Galba. 
Subgenus POLYRHYTIS Meek, 1876. 
1876. Polyrhytis Mrex, Rep. U. S. Geol. Surv. Terr., IX, p. 532. (Limnea 
kingti Meek.) 
1877. Polyrhytis MEEK, Exp. 40th Parallel, Pal., pp. 192, 193. 
1844. Polyrhytis Tryon, S. and S. Conch., III, p. 101. 
1905. Polyrhytis DatL, Mollusks of Alaska, p. 64. 
1908. Polyrhytis BAKER, Science, N. S. XXVII, No. 703, p. 943. 
SHELL: With well-marked longitudinal folds or ribs; spire broad- 
ly acute, generally shorter than aperture; axis twisted; columella lip 
broadly expanded, obscuring the fold more or less; umbilical chink 
well marked. 
ANIMAL, JAW, RapuLA and GENITALIA: Unknown. 
DISTRIBUTION: Pliocene to recent fauna. 
Meek’s Polyrhytis would seem to be a well marked division of 
the Lymneids, characterized by a longitudinally ribbed, ventricose 
shell. Call’s Lymnea utahensis answers well to the diagnosis of Poly- 
rhytis and is accordingly placed here. As remarked by Meek (Exp. 
40th Parallel Pal., p. 193) Polyrhytis bears somewhat the same re- 
lation to Lymnea that Costella Dall bears to Physa. No other recent 
Lymnea at all resembles utahensis in the possession of this peculiar 
sculpture which is probably produced by the unfavorable character of 
their habitat, as remarked by Call. 
Polyrhytis is placed tentatively near Stagnicola. The genitalia 
and radula of wtahensis are unknown and until these are published the 
group cannot be definitely placed. 
Galba utahensis (Call). Plate XXII, figures 9-11; plate 
XXIV, figures 22-27. 
Radix ampla var. utahensis Catt, Bull. U. S. Geol. Surv., II, pp. 373, 379, 
381; p. 401, pl. 6, figs. 7-9, 1884——KerEep, West American Sh., pp. 149, 314, 1904. 
Radix utahensis Catt, Proc. Davenport Acad. Sci., V, p. 5, pl. 1, figs. 7-9, 
1886. 
Limnea ampla var. utahensis STEARNS, Proc. Nat. Mus., XXIV, p. 291, 1901. 
?Limne@a catascopium INGERSOLL, Proc. Daven. Acad. Sci., II, p. 132, 1877. 
Radix ampla GiLBert, Mon. U. S. Geol. Surv., I, p. 298, 1890. 
Lymnea utahensis SteERK1, Nautilus, XXII, p. 142, 1909. 
SHELL: “Globose, somewhat umbilicated, irregularly costate, light 
horn color, nearly pellucid; spire rather small, conical; whorls four to 
four and one-half, convex, rather flattened above, giving rather a 
