58 PROCEEDINGS OF THE ACADEMY OF [Feb., 



type, in the University of Colorado Museum, measures 3.1 mm. in 

 altitude, 1.3 mm. in width. Whorls 6. Common at Sta. 77, west 

 of St. Charles, Idaho, June 27, 1916. 



Sta. 78, natural turnpike forming the northern barrier of Bear 

 Lake and separating it from Mud Lake and Dingle Swamp. The 

 sandy soil of this broad barrier is in places composed largely of fossil 

 shells of the same species that abound along the beach, leading to the 

 belief that the beach shells have mostly been washed from the sand 

 by the waves and are fossil. Though we found no live mollusks in 

 the lake, many of the shells, especially Lymncea and Planorhis, were 

 rather fresh, and all were of species that might be expected to now 

 live in the region, though only two or three of the species were actually 

 taken alive in the valley. As the lake is now used to regulate the 

 flow of water in the streams and ditches, the water level fluctuates 

 considerably, and at the time of our visit the water in the lake, as 

 well as in the streams, was high. The beach material yielded the 

 following: 



Sphwrium pilsbryanum Sterki. Valvata utahensis (Call) . 



Pisidium compressum Prime. Planorhis trivolvis near binneyi 

 Pisidimn n. sp. T^yon. 



Pyramidula cronkhitei anihonyi Planorhis parvus Say. 



Pils. Planorhis exacuous Say. 



Vertigo ovata (Say). Physa ampullacea Gld. 



Fluminicola fusca (Hald.). Aiicylus sip. 



Paludestrina longinqua (Gld.). Lymncea proxima Lea. 



Carinifex newherryi (Lea). Lymncea stagnalis appressa Say. 



Valvata humeralis calif ornica Pils. Lymncea utahensis Call. 



Baker, in his Lymnseidse of North America, records L. proxima 

 also from the Utah end of the lake. L. utahensis at this station is 

 on the average more elongate than those from the type locality at 

 Utah Lake, but on the whole they cannot be separated. Valvata 

 h. californica is here more highly polished and closely coiled than at 

 Sta. 127, Utah Lake. 



Sta. 79, roadside pools west of Sta. 78, near St. Charles. Lymncea 

 proxima Lea and Aplexa hypnoruni (L.). 



Sta. 80, bank of St. Charles Creek, at the north edge of the town: 



Agriolimax campestris montana Pyramidula cronkhitei anthonyi 



(Ing.). Pils. 



Succinea avara Say. Euconulus fulvus alaskensis Pils. 

 Zonitoides arhorea (Say). 



