564 PROCEEDINGS OF THE ACADEMY OF [DeC, 



a finely striate form with rounded periphery. At the following locali- 

 ties the striation is slightly coarser and the periphery weakly angular : 

 Petit Jean Mts., Logan Co.; Poteau Mts., Sebastian Co. 



Indian Territory: Wyandotte and Wister, slightly angular specimens ; 

 Sugar Loaf Mt., rounded periphery and coarse sculpture. 

 Pyramidula perspectiva (Say). 



Chadwick, Christian Co., southwestern Mo. ; Arkansas, Magazine Mt,, 

 Logan Co., somewhat abundant on the north side of the summit, a 

 few taken also on the dry southern side down to the railroad station. 



At Rogers, Benton Co., Ark., a small form of 'perspectiva was found, 

 normal in form and sculpture but only 7 mm. diam. The species is else- 

 where so constant in size that this local form is noteworthy. 

 Helioodiscus parallelus (Say). 



Arkansas: Rogers, Benton Co.; Magazine Mt., Logan Co. 



Indian Territory: Wyandotte, Vinita, South McAlester and Lime- 

 stone Gap. 



The specimens from Magazine Mt., where a large series was taken, 

 are scarcely over 3 mm. in diameter with 4^ whorls. Those from the 

 Territory are slightly larger, 3.8 mm., with 5 whorls. We saw nothing 

 of H. fimbriatus Weth., reported from this region by Simpson. 

 Suocinea avara Say. 



Magazine Mt., north side of summit, and Petit Jean Mts., Logan Co., 

 Ark.; Vinita, Wister and Limestone Gap, I. T. 



LYMNiEID^. 

 Lymaaea desidiosa Say. 



Rogers, Ark. 

 Lymnaea columella Say. 



Oklahoma City, Okla. (Ferriss). 

 PlanorbiB trivolvis Say. 



Rogers, northeastern Ark.; Limestone Gap, I. T. 

 Ancylus kirklandi Walker. 



Hardy, Sharp Co., Ark. (Ferriss). Erroneously reported as A. 

 haldemani in these Proceedings for 1900, p. 457, according to Walker, 

 Nautilus, XVII, July, 1903, p. 29. 



In Texas we took it at New Braunfels, on rushes in Comal Creek. It 

 was also sent fromGarcitas Creek and the Guadelupe River, Victoria Co., 

 by Hon. J. D. Mitchell (1899). 

 Ancylus walkeri n. sp. 



Shell pale corneous, thin, oval, the right and left sides equally curved ; 



