560 



PROCEEDINGS OF THE ACADEMY OF 



[Dec. 



3. — G. demissa brittsi, Mena, Ark. The outline figures are natural size. 



adults are very similar to G. acerra, and doubtless it was this form 

 which Simpson records as acerra in his Indian Territory list. 



Numerous other localities for G. d. hrittsi may be found in the works 

 cited above, under the names demissa, brittsi, lamellata, acerra and 

 gularis. 

 Zonitoides arborea (Say). 



Chadwick, Christian Co., Mo.; Magazine Mt. and Blue Mt. Station, 

 Logan Co., Ark.; Vinita, Sugar Loaf Mt. and Limestone Gap, I. T. 



The specimens from the summit of Magazine Mountain are small with 

 a small umbilicus, and smoothish, glossy sm-face with the most delicate 

 sculpture in place of the usual wrinkles. The very minute dense spiral 

 striation is better developed than usual in Z. arborea. 

 Zonitoides minuscula alachuana (Dall). 



We took this in Logan Co., Ark., at Magazine Mountain, both on the 

 north and south sides of the summit; very scarce. This race differs 

 from Northern Z. minuscula by its much wider umbilicus. It was origi- 

 nally described from Alachua Co., Fla. 



Vitrea multidentata (Binn.). 



Proc. A. N. S. Phila., 1903, p. 208, PI. X, figs. 6, 6a. 



Magazine Mt., Logan Co., Ark., on rocks in the great talus of the 

 cliff along the northern side of the summit. The specimens are very 

 fine and typical, usually with two rows of five or six teeth each, but 

 some show three rows. 



This is very much farther west than the species has hitherto been 

 recorded, and is the only locality known west of the Mississippi River, 

 Vitrea simpsoni (Pils.). 



y. significans and V. simpsoni have no spiral sculpture, only a faint 



fine granulation, when examined with a high power. The radial 



grooves of the upper surface are weaker in V. simpsoni than in V. 



, ignificans, especially on the inner whorls. We took the typical form of 



y. simpsoni at Limestone Gap, I. T., and along a creek about ten miles 



