208 PROCEEDINGS OF THE ACADEMY OF [Feb.. 



spire is lower, either flat or but slightly convex; and with one excep- 

 tion, all have the same minute umbilicus. In one specimen, from 

 Clingman Dome, No. 2,490 of the collection of Mr. George H. Clapp 

 (PI. X, figs. 8, 8a), the umbilicvis is decidedly larger, .6 mm. wide, the 

 shell having a diameter of 6.2 mm., with 6^ whorls. Whether this is 

 an individual variation or the representative of a race of more widely 

 imibilicate shells, remains to be determined. 



In 1900 Mr. Ferriss traced this beautiful and excessively rare species 

 far to the northeast of the original locality, taking specimens at Mt. 

 LeConte, and at Indian Gap and Newfound Gap on the Big Pigeon 

 river. 

 Vitrea lamellidens ( Pils- 1. PL X, figs. 2, ;% 3a, -.ib. 



Gastrodonta lamellidens Pils., Nautilus, XI. p. 1.34 (April. 1S98); Proc. 

 Acad. Nat. Sci. Pliila., 1900, p. 145. Ferriss, Nautilus, XII, p. 99; XIV, 

 pp. 52, 58. Walker and Pilsbry, Proc. Acad. Nat. Sci. Phila., 1902, p. 437. 



Range : Great Smoky Mountains, along the Tennessee-North Carolina 

 boundary, from the Little Tennessee river to Thunderhead Mountain 

 (the type locality), and eastward in Graham county, N. C. ; also in the 

 Black Mountain range at Bluff Mountain and Pinnacle of the Blue 

 Ridge. 



Similar to V . multidentata, but armed within with curved, obliquely 

 radial barriers instead of rows of teeth, and having a narrower imibili- 

 cus, its width contained about 10 times in that of the shell, while in 

 multidentata it is contained only about 6 times. 



In about 150 individuals collected in 1899 and previoasly, which I ex- 

 amined, all had from one to three lamellae; but a very large shell, diam.. 

 3.8 mm., found by Mr. Ferriss on Thunderhead in 1900, has no lamellae 

 whatever — a feature of senility. Even in the youngest individuals I 

 have seen, such as PI. X, fig, 2, diam. 1.4 mm., there are two or three 

 barriers, though one would expect rows of teeth in so early a stage. 

 Not one T'. multidentata has yet been found with lamellidens, which 

 lives mainly in the moist heights, where the mountains lift their heads 

 into the clouds. We did hot find it in the "coves" below. 



Vitrea multidentata (Binney). PI. X, figs. 6, 6a. 



W. G. Binney, Man. Amer. Land Shells, p. 183 (1885). 



The southernmost locality is Talassee Ford of the Little Tennessee 

 river, whence Mr. Ferriss reports it.^ 



Figured for comparison with the preceding and following species. 

 With ordinary specimens of midlidentata there sometimes occur shells 

 in which radial barriers similar to those of V. lamellidens replace the 



9 Nautilus, XIV, 58. ~~~ 



