1906.] NATURAL SCIENCES OF PHILADELPHIA. 539 



the Petit Jean Mts., Logan Co., Ark. A few were taken at Blue 

 Mountain Station, Logan Co., Ark. ; and in Indian Territory, Wyandotte 

 Nation, at Wyandotte, on the top of the bluff, in dry woods under 

 stones. Some of them are very small, barely over 6 mm. diam. Speci- 

 mens from Springfield, Mo., are also small, 6.6 to 7 mm. diam. 



The localities now known for P. jacksoni follow : 



Southwestern Missouri: Camden Co. ; " Dade Co. ; " Ash Grove and 

 Springfield, Green Co. ; Jasper Co. ; Barry Co. ; " Macdonald Co." 



Arkansas: Eureka Springs, Carroll Co.; Washington Co.;" Rogers, 

 Benton Co.;^^ Porter and Chester, Crawford Co.; Van Buren Co.; 

 Frankhn Co.;" Sebastian Co.;" Blue Mt. Station and Petit Jean Mts., 

 Logan Co. ; Rich Mt. and Mena, Polk Co.^^ 



Indian Territory: Wyandotte, Wyandotte Nation; Fort Gibson, 

 Cherokee Nation; Poteau, Choctaw Nation.^^ 



The range of the species eastward in northern Arkansas remains to 

 be mapped. On the south its limit is apparently indicated with ap- 

 proximate accuracy, since the explorations of Mr. Ferriss in Arkansas 

 south of Polk county, and of both of us in the adjacent portions of 

 Indian Territory, failed to bring P. jacksoni to light. 



Polygyra jacksoni deltoidea (Simpson). PI. XX, figs. 6, 7. 



Helix {Polygyra) jacksoni var. deltoidea Simps., Proc. U. S. Nat. Mus. 1888, 

 p. 450. 



Similar to P. jacksoni, except that the front edge of the parietal 

 callous is very thick and raised in an erect triangle. Alt. 3.5, diam. 8 

 mm., or smaller, diam. 7.5 mm. This form has been found only near 

 Fort Gibson, I. T. It has not before been illustrated. The figures are 

 from cotypes. 

 Polygyra jacksoni simpsoni n. subsp. PI. XX, figs. 8, 9, 10, 11. 



Larger than P. jacksoni and wholhj imperforate, though the axis is 

 hollow except in the last whorl, and the young shells therefore are 

 perforate. The aperture does not differ from that of P. jacksoni, but 

 there is a small tubercle within on the columella, seen upon breaking 

 into the base. Whorls 5^. Alt. 4.7, diam. 9.3 mm. The largest 

 specimen taken measures 9.5 mm. diam., the smallest 8.3 mm. 



The types were taken by us near Wyandotte, Wyandotte Nation, 

 in the northeast angle of Indian Territory, on the south bank of Grand 

 River, on a steep rocky bluff facing north. Mr. Simpson found this 

 form near Fort Gibson, I. T., and it may be what Sampson refers to as 



" Recorded on the authority of Mr. F. A. Sampson. 

 " Recorded on the authority of J. H. Ferriss. 



