196 PROCEEDINGS OF THE ACADEMY OF [Feb., 



umbilicus of dorfeuilliana to the widely open condition of sanipsoni, 

 most of the specimens intermediate in size and umbilicus. A large 

 series. 



In some portions of southern Missouri and adjacent counties of 

 Arkansas, the specimens are larger than typical dorfeuilliana, and 

 widely open beneath, showing over one whorl. They are usualh* 

 qviite glossy, and rather weakly striate on the base. This form, var. 

 sampsoni Weth., seems to be quite distinct in this area. In the eastern 

 part of Indian Territory, the shells are rather hea^aer, more distinctly 

 striate on the base, and wherever a large series was collected they vary 

 from the dorfeuilliana form, in which but one whorl or a little less is 

 exposed beneath, to the sampsoni form of base; most specimens being 

 intermediate in these characters. This area therefore is one in which 

 differentiation has not taken place — a transition region. Cf. these 

 Proceedings for 1900, p. 449. 



Polygyra jacksoni (Bland). 



Springfield, Green county, and Chester,* Crawford county. Mo.; 

 Poteau* and Rich Mountain,* Ark. 

 Polygyra cragini (Call). 



DeKalb,* Cleburne county. Ark. ; Antlers,* I. T. 



Polygyra neglecta Pils. 



T. fallax Say var. minor, Wetherby, Some Notes on American Land Shells. 

 No. II, p. 11, in Joum. Cincinnati Soc. N. H., IV, December, 1881, p. 383. 

 Polygyra neglecta Pils., Nautilus, XIII, p. 40 (August, 1899). 



The above reference to Mr. Wetherby's work was overlooked by 

 me, or not recognized as pertaining to this species, when I defined 

 P. neglecta in 1899. He says: "Years ago I received from Springfield. 

 Mo., a small variety of this species [Triodopsis fallax], much lighter 

 colored, with a thicker and heavier shell than the type, with the 

 peristome reflected backward and rounded, and having a very distinct 

 facies. I have recently received the same variety from Mr. Sampson, 

 who collected it at Eureka Springs." 



The form would hardly be recognized from this note without speci- 

 mens from the localities mentioned ; and as several forms of the genus 

 have already been called "var. minor," it will probably not be advis- 

 able to revert to that name. Mr. Ferriss procured specimens at 

 Seligman, Barry county, and Springfield, Green county, both in south- 

 western Missouri. 

 Polygyra infleota (Say). 



Petit Jean, Yell county, Ark.; diam. 9-11 mm. Seligman, Mo.. 

 normal specimens with strong teeth, diam. 10 mm., and a very distinct 



