1903.] XATUKAL SCIENCES OF PHILADELPHIA. 209 



teeth of tlie normal form. Such specimens are known from West 

 Granby, Hartford comity, Conn.; Garrettsville, 0. (PL X, fig. 7); 

 Greenwich, N. Y. (Acad. Coll.); Deering, N. H.; Litchfield, N. Y. 

 (Coll. G. H. Clapp) ; Ottawa, Can. (Coll. Bryant Walker),!" and Ithaca, 

 N. Y. (Coll. H. E. Sargent). In the adult specimens I have seen, like 

 thatfigured (diam. 3 mm.), the umbilicus is about as wide as in multi- 

 dentata. In those examined by Mr. Clapp it is narrower, as in lamelli- 

 dens; but his shells are not full grown, measuring only 2 to 2.5 mm. 

 in diameter. From the occurrence of this form as rare single speci- 

 mens, always with typical multidentata, I am still disposed to look 

 on the specimens as accelerated individuals, sporadically occurring — 

 the pioneers of a new race, further advanced in evolution than multi- 

 dentata. If my view is correct, this race of the future will be parallel 

 to lamellidens, which has in the past undergone a like transformation. 

 A view apparently much simpler is held by Mr. Clapp, who regards 

 the Northern specimens with continuous barriers as really V. lamelli- 

 dens, which in this view has an extensive range north to Canada. 



Vitrea walkeri (Pilsbry). PI. X, figs. 4, la, 5. 



Gastrodonta xvalheri Pils., Proc. Acad. Nat. Sci. Phila., 1900, p 146 Ferriss 

 Nautilis, XIV, pp. 52, 58. 



Range : Great Smoky Mountains, in Graham county, N. C, and Mon- 

 roe county, Tenn. 



This form is about the size of V. multidentata, ordinarily measurino- 

 about 2.9 mm., with 5^ to 5f whorls, and an umbilicus contained 

 about 5^ times in the diameter of the shell, much as in midtidentata. 

 It is either toothless or has radial barriers of the lamellidens type, 

 but the wider umbilicus and minutely decussate surface readily sep- 

 arate the species from lamellidens. 



No specimens have turned up since our expedition of 1899, and it 

 remains one of the rarest of land snails. Figs. 4, 4a represent a shell 

 from Tuskeegee Mountain; fig. 5 a specimen from Talassee Ford of 

 the Little Tennessee river. 



Vitrea andrewsae (W. G. Binney). PI. XI, figs. 9, 9a, 10, 11, lla, 116. 



Zonites andrewsi W. G. B., Ann. N. Y. Acad. Sci., I, p. 359, PI 15 fig D 

 (1S79); [First] Supplement to Terr. Moll., V, p. 144, PI. 2, fig. D (reprint 

 from Ann. N. Y. Acad.) ; Man. Amer. Land Sliells, p. 228, fig 251 Sterki 

 Nautilus, VII, p. 16 (1893). > B o . oierKi, 



Gastrodonta andrewsce W. G. B., Walker and Pilsbrj^ Moll, of Mt. Mitchell 

 Region, N. C, in Proc. Acad. Nat. Sci. Phila., 1902, p. 437. 



Range: Roan Mountain (type locality) to Paint Rock on the French 

 Broad river, and eastward to the Black Mountains, N. C. 



'-° Ottawa Xaturalist, XIV, p. 94, 1900. A single specimen of " lamellidens " 

 with multidentata, collected by Gilbert Heron, is recorded by Mr. Walker 

 14 



