OF OONCHOLOGY. 3l5 



80. P. turgidum, Lea. Obtusely conical, inflated, 

 smooth, thick ; spire short, pointed at apex, with slight su- 

 ture; whorls 7, flattened, obtusely angulate in the middle; 

 aperture small, trapezoidal. Greenish-yellow, with two to five 

 bands. Holston River, E. Tenn. 



81. P. minor, Lea. Fig. 143. Obtusely conoidal, smooth, 

 rather thick ; spire obtusely conical ; suture impressed ; whorls 

 7, somewhat convex, the last large ; aperture large, sub-rhom- 

 boidal, produced below. Yellowish, with one or two bands, 

 or not banded. Tenn. 



82. P. pumilum, Lea. Fig. 144. Conoidal, rather solid, 

 smooth, shining; spire obtusely conical; suture much im- 

 pressed ; whorls 7, somewhat convex, the last large, inflated ; 

 aperture large, rhomboidal, broadly effused below. Yellowish- 

 green, doubly banded. Tenn. 



Larger, more pyramidal, with a darker epidermis, and more rhombic 

 aperture than PL bivittatum, Lea. 



83. P. opaca, Ayith. Figs. 145 — 8. Ovate-conic, smooth, 

 rugose ; spire obtusely elevated ; whorls 6, sub-convex, with 

 very strong curved growth-lines ; body whorl obtusely angu- 

 lute in the middle ; aperture broad ovate. Greenish-olive or 

 very dark brown, purple within. Tenn. 



Fig. 145 is nigrostoma, Anth. ; Fig. 146 is opaca, Anth. ; Fig. 147 is 

 iostoina, Anth. ; and Fig. 148 is Tennesseense, Lea. 



83a. p. napoideum, Lea. Fig. 149. Obtusely conoidal, 

 rather thick; spire short, mucronate, suture impressed; 

 whorls 7, above slightly convex, the last inflated ; aperture 

 large, sub-rhomboidal. Horn-color, without bands, within 

 white. Tenn. 



84. P. trochulus, Lea. Fig. 150. Top-shaped, smooth, 

 very much swollen ; spire very obtuse ; suture impressed ; 

 whorls 6, flattened above, inflated below ; aperture large, rhom- 

 boidal. Yellow, with a narrow band below. Rolston River ^ 

 Tenn. 



