1906.] NATURAL SCIENCES OF PHILADELPHIA. 543 



We took this subspecies at the following localities: Monett, Barry- 

 Co., Mo.; Petit Jean Mts., Sebastian Co., Ark.; W3^andotte, Vinita, 

 Wister, South McAlester and Limestone Gap, Indian Territory. 



It is before us from three localities near the northeastern angle of 

 Texas: Gainesville, Cass Co. (Ragsdale); Wood Co. (R. Walton Coll.); 

 and DeKalb, Bowie Co. (Ferriss). 

 Polygyra obstricta occidentalis n. subsp. PI. XXII, figs. 30, 31, 32. 



Shell imperforate, slightly convex or nearly flat above, very convex 

 beneath ; similar to the more strongly carinate form of P. o. carolinensis, 

 but differing by the reduced teeth, those of the lip being very small 

 or vestigeal. Surface rib-striate, very minutely and densely papillose 

 between the riblets, not coarsely roughened as in obstricta. Whorls 4^ 

 to nearly 5, the last slightly descending in front. 



Alt. 7.7, diam. 18.7 mm. 



Alt. 8.2, diam. 17.8 mm. 



Alt. 7, diam. 17 mm. 



Alt. 7.5, diam. 16.5 mm. 



Northern Arkansas, probably from near Benton, Saline Co. Col- 

 lected by Prof. Stuart Weller. Collections of Ferriss and A. N. S. Phila. 



This form is readily distinguishable by its dwarf stature and much 

 reduced lip-teeth. It is less acutely keeled than typical P. obstricta. 

 It is evidently what Mr. Sampson^** reports from Independence Co., 

 Ark. He found one specimen 20.5 mm. in diameter. 



P. obstricta carolinensis (Lea) extends westward in the South to 

 Grand Cane, De Soto Co., La., where it was collected by Mr. George 

 Williamson. Typical P. obstricta has not, I believe, been found west 

 of the Mississippi River. 

 Polygyra inflecta (Say). PI. XXII, fig. 1. 



Missouri: Chadwick, Christian Co. 



Arkansas: Rogers, Benton Co.; Blue Mountain Station and Maga- 

 zine Mountain, both on the north and south sides of the summit, and 

 Petit Jean Mts., Logan Co.; Poteau Mountain, south of Gwynn P.O. 

 (Hartford Station), Sebastian Co. 



Indian Territory: Wyandotte, along the Grand River, Wyandotte 

 Nation; Sugar Loaf Mt., Wister and Limestone Gap, Choctaw Nation. 



This common snail was everywhere found in abundance; and since 

 in various places it has diverged to form local races or species, some 

 account of its variation may be timely. The type locality given by 

 Thomas Say is "lower Missouri" — that is, along the Missouri River 



« MoUusca of Arkansas, 1893, p. 186 



