432 PROCEEDINGS OP THE ACADEMY OF PVCay, 



shape, and in the regularly increasing whorls, but differs in color, 

 in the less crowded sculpture of radial grooves, the presence of 

 microscopic revolving sculpture, which is absent in hammonis, and 

 in having nearly a whor] additional. In the examination of these 

 forms for the revolving sculpture a compound lens of at least 100 

 diameters is necessary for satisfactory results. V. xoheatleyi and F. 

 petropliila pentadelphia, which have similar sculpture, differ in 

 having a more open umbilicus and in the rapid enlargement of the 

 last whorl. It differs from V. rhoadsi by the smooth base ( V. 

 rhoadsi being radially grooved beneath), the closer radial grooves, 

 M^ider umbilicus, and in color. 

 Vitrea vanattai P. and W., n. sp. PI. XXIII, figs. 4, 5, 6. 



Shell rather narrowly umbilicate (the umbilicus about one-sixth 

 the diameter of the shell), depressed, thin, honey-yellow and trans- 

 lucent. Sculpture of many deeply impressed, irregularly spaced 

 radial grooves, much less conspicuous beneath, and very fine, 

 rather faint, close spiral lines. Whorls 5, slowly increasing, the 

 last much wider. Aperture oblique, broadly lunate, the peristome 

 simple and thin as usual. Alt. hardly 2, diam. 4.5 mm. 

 Mt. Mitchell, two adult specimens and one young. 

 This species belongs to the same group as the preceding, from 

 which it differs in color, the more depressed body-whorl, less 

 crowded and deeper radial grooves, which are more distinct 

 beneath, in having a half»-whorl more and a wider umbilicus. In 

 V. hammo7iis the sculpture is much closer, the grooves of V. 

 vanattai resembling those of the species of the section Glyphyalinia. 

 It resembles V. cllnginani, but with the same number of whorls 

 the shell is much smaller, and the shape of the aperture differs 

 somewhat. 



It is named for Mr. Edward G. Vanatta, in recognition of his 

 long and careful work upon the smaller Zouitidse of the collection 

 of the Academy. 



The group of V. hammonis, clingmani, approxima and vanattai 

 ■consists of species similar in general form and in the coarser sculp- 

 tui-e. V. hammonis differs from all the others by the smaller 

 number of whorls and less depressed contour ; V. clingmani, with 

 the same number of whorls as the following species, is conspicuously 

 larger. V. approxima and V. vanattai have about the same num 

 ber of whorls, but the former is greenish, less deeply sculptured, 



