136 PROCEEDINGS OF THE ACADEMY OF [March' 



The shells figured by Binney as B. schiedeanus {Manual of American 

 Land Shells, p. 399, fig. 437) are apparently B. d. liquobilis. They are 

 certainly not the true schiedeanus, of which figures may be found in 

 the Manual of Conchology. 

 Bulimulus dealbatus (Say). Pl.VI, fig. 13. 



Helix dealbata Say, Journ. Acad. Nat. Sci. Phila., II, p. 159, 1821. 



Say gave the localities "Missouri and Alabama." His specimens 

 in the Academy Museiun are labelled Alabama. One of these three, 

 agreeing with the dimensions given by him, is figured (pi. VI, fig. 13), 

 as the type of the species. The Alabama form has a globose last whorl 

 and rather large umbUicus. The aperture is a little more than half 

 the total length of the shell, but much less than the diameter of the 

 shell. The shell is profusely striped with ragged white stripes on a pale 

 brownish ground. The type measures, alt. 19.4, diam. 12.2, length of 

 aperture 10.6 mm. 



The same form occm-s in Tennessee, Kentucky (Warren county), 

 and west to Kansas (Shawnee county). Some specimens from the 

 humid portion of Texas also seem to belong here. 

 B. d. ozarkensis n. subsp. PI. VI, fig. 14, 15. 



B. dealbatus Say, Pilsbry, Proc. A. N. S. Phila., 1903, p. 204 (Seligman, Mo.). 



On the northern and western borders of the Ozark uplift this form 

 has been differentiated. The whole shell, and especially the last 

 whorl, is narrower, the aperture is smaDer, ordinarily half the total 

 length or less, and the umbilicus is narrower. The shape is about that 

 of B. d. ragsdalei, but the last whorl is not rib-striate, though the 

 spire is weakly so. Coloration as in dealbatus. Specimens measure: 



Distribution, northern and western outliers of the Ozark system: 

 Mammoth Spring, Fulton county, Arkansas ; Sehgman, Barry county, 

 southwestern Missouri (fig. 14); Rogers, Benton county, Arkansas 

 (fig. 15) ; Lmaestone Gap, Choctaw Nation, Indian Territory. 



