108 LAND AND FRESH- WATER SHELLS OF N. A. [PART IV. 



52 a. P. cylindracetun, Lea, 



Trypanostoma cylindracenm, Lea, Proc. Acad. Xat. Sci., p. 4, 1864. Jour. Acad, 

 Nat. Sci., vi, p. 142, t. 73, f. 57, 1867. 



Description. — Shell smooth, cylindrical, rather thick, banded or 

 without bands ; spire rather raised ; sutures irregularly impressed ; 

 whorls flattened, slightly impressed, swollen below the sutures ; 

 aperture rather small, rhomboidal; outer lip acute, somewhat sinu- 

 ous ; columella thickened, incurved and twisted. 

 Fig. 205. 



Habitat. — Hoaue County, East Tennessee. 



Diameter, -41; length, l-i inches. 



Observations. — I have three specimens of this pupasform 

 species before me. Two of them are of a light horn-color ; 

 the third has a daik-brown band over more than two-thirds 

 of the whorls, above which along the sutures it is yellow. 

 In this specimen, the base of the columella is purple and 

 the interior is purplish. In all the three specimens the body-whoii is 

 impressed; above the periphery, amounting almost to a channel. It 

 is allied to parvum and moriforme (nobis) but is larger and more cylin- 

 drical than the first, and smaller and less pyramidal than the latter. 

 The aperture is about one-third the length of the shell. The apices 

 were too much eroded to ascertain the number of whorls, but there 

 are probably about eight, — Lea. 



52 b. P. Roanense, Lea. 



Tri/panostoma Roanense. Lea, Proc. Acad. Nat. Sci., p. 4, 1864. Jour. Acad. Nat, 

 Sci., vi, p. 142, t. 23, f. 52, 1867. 



Description. — Shell smooth, obtusely conical, thick, banded or with- 

 out bands; spire obtuse; sutures impressed ; whorls flattened, swollen 



below the sutures ; aperture rather small, rhomboidal ; outer 



' ^ Fig. 206. 



lip acute, sinuous; columella whitish, thickened and very 

 much twisted. 



Habitat.— Uoane County, East Tennessee. 



Diameter, "41; length, "80? inch. 



Observations. — This species is allied to cylindraceiwi, but 

 differs in being shorter and wider in proportion. It diflers also in the 

 form of the bands where they exist. Two of the six specimens before 

 me have a single narrow band below the middle, and one has a second 



