74 PROCEEDINGS OF THE ACADEMY OF [Feb., 



to V. himieraUs calif ornica Pils. IngersoU also (on the same page of 

 his report) records Fluminicola seminalis Hinds and F. hindsi Stm. 

 from "Salt Lake, Utah/' and F. nuttalliana Stm. from "Warm 

 Springs, near Salt Lake, Utah." The two last mentioned may well 

 be doubted. He also, on p. 399, records Succinea nuttalliana Lea 

 from the Warm Springs locality — a doubtful record. Binney^* 

 records Succinea haydeni W. G. B. from Salt Lake City. 



Utah Lake, Utah. 



This district is covered by the Salt Lake topographic sheet of the 

 United States Geological Survey. Utah Lake was included in Lake 

 Bonneville during the " Lake Period. " It now remains fresh because 

 it has an outlet, the Jordan River, through which it drains into 

 Great Salt Lake. However, the water is said to l)e not so free from 

 salts as formerly, owing to the extensive use of water for irrigation. 

 Cameron-^ reports that the mineral content, chiefly sodium chloride, 

 of the lake water increased from 300 parts of total solids per million 

 parts of solution in 1883, to 1,400 parts per million in 1903 — a period 

 of twenty years. It is not likely that the salinity will increase so 

 much as to be fatal to fresh-water mollusks or even to seriously 

 modify them. CalF" and Stearns have discussed the influence of 

 temperature and salinity in modifjdng the shells of this region, 

 and the arid region farther west. In his bulletin Call records the 

 following species from Utah Lake: 



Pisidium compressum Prime. Lymncea stagnalis Linn. 



Sph(eriu77i dentatum (Hald.). LymncBa utahensis Call. 



Ancylus sp. Physa ampullacea Gld. 



Carinifex newherryi (Lea), living. Physa gyrina elliptica Lea. 

 Fluminicola jusca (Hald.). 



His assertion that S. dentatum here attains great size strongly 

 suggests that he really found P. pilshryanum Sterki, which was not 

 then described, but has since been described from Bear Lake (fossil) 

 and reported from Utah Lake (recent) by Sterki.^^ Yarrow^- reports 

 finding Lymncea stagnalis [= appressa] and Planorbis trivolvis Say 



28 2d Suppl. to 5th vol. Terr. Moll., p. 40. 



^^ Cameron, "The Water of Utah Lake," Science, n. s., vol. XXI, p. 257, 1905. 



30 Call, U. S. Geol. Surv., Bull. No. 11, 1884. Stearns, Proc. U. S. Nat. Mus., 

 XXIV, 1901, 271-299; N. Amer. Fauna, No. 7, pp. 269-283. 



^' Sterki, "Sphserium pilshryanum n. sp.," The Nautilus, XXII, pp. 141-142, 

 1909; "A preliminary catalog of the North American Sphseriidse, " Annals of 

 Carnegie Museum, X, p. 437, 1916. 



'2 Yarrow, (Wheeler's) U. S. Geog. Surv. W. of 100th Meridian, V, pp. 941, 

 946-947, 1875. 



