1903.] NATURAL SCIENCES OF PHILADELPHIA. 195 



POMATIOPSIN^. 

 Pomatiopsis lapidaiia (Say). 



Seligman, Barry county, Mo. 



HELICINID^. 

 Helicina orbiculata tropica (Jan.). 



Seligman,* Mo. ; Petit Jean,* 'Yell county, Ark. 



HELICID^. 

 Polygyra leporina (Gld.). 



Poteau* and Antlers,* I. T. 

 Polygyra dorfeuilliana (Lea). 



Springfield, Green county, southwestern Missouri. Typical P. 

 dorfeuilliana sampsoni Weth., 7.8 to 8.2 mm. diam. Seligman, Barry 

 county, southwestern Missouri. Typical P. d. sampsoni, diam. 8-9 

 mm. 



Chester, Crawford county, Ark. Varying from 6| to 8 mm. diam., 

 some specimens shomng transition toward var. sampsoni in width of 

 the umbiUcus. 



Rich Mountain, Polk county. Ark. Specimens typical, 7-7f mm. 

 diam. 



Hot Springs, Garland county. Ark. Like the preceding. 



Carrion Crow Mountain, in Gum-dog township, Pope county. Ark. 

 This is about ten miles north of Petit Jean Mountains. Rather heavy 

 specimens, 6.2 to 7.6 mm. diam., with the lower lip-tooth somewhat 

 prominent in a basal view. 



Tushkahoma, I. T. The specimens vary from 6.2 to 8 mm. diam., 

 are rather solid and somewhat more striate beneath than in typical 

 dorfeuilliana. The parietal tooth is rather small. The umbilicus 

 varies from that of typical dorfeuilliana to as wide as sampsoni, so that 

 there is here a perfect transition between the two. A large series 

 was collected. 



Antlers, Choctaw Nation, I. T. Three specimens measuring 6, 6.2 

 and 7.5 mm. diam. The lip is much thickened, immersing the teeth, 

 and the parietal tooth is unusually large and square. 



In the largest shell the umbilicus is that of sampsoni, and the aperture 

 less obstructed, diam. 8 mm. 



Standley, Choctaw Nation, I. T. Diam. 7 to 7.5 mm., the specimens 

 varying from dorfeuilliana to sampsoni in umbilicus. Aperture normal. 



Poteau, Choctaw Nation, I. T. Rather solid, distinctly striate 

 beneath, varving from 7.5 to 8.7 mm. diam.. and from the small 



