OF CONCHOLOQY. 305 



13. P. moriforme, Lea. Fig. 40. Subcylindrical, solid ; 

 spire obtusely conical ; suture impressed ; wliorls 9, canalicu- 

 late ; aperture small, rhombic ; outer lip acute, very sinuous ; 

 columella thickened below, and very much twisted. Horn- 

 color, with a single narrow band near the base. N. Geo.; 

 Tusciunbia^ Ala. 



14. P. Pybasii, Lea. Fig. 41. Somewhat cylindrical, 

 pyramidal, obtuse at apex ; whorls 8, flattened, with a deep, 

 wide sulcus and raised carinate periphery. Greenish-brown, 

 doubly banded; the upper band filling the sulcus. Tuscumhia^ 

 Ala. 



15. P. Showalterii, Zea. Fig. 42. Subcylindrical, much 

 lengthened, thick; spire greatly elevated; suture much im- 

 pressed ; whorls 9, somewhat flattened, the last convex below, 

 striate or smooth. Horn-color or brown, with sometimes a 

 single band at base. N. Geo., N. Ala. 



c. Angulate species., striate below the periphery. 



16. P. Thortonii, Lea. Fig. 43. Pyramidal, thick; spire 

 regularly elevated ; whorls 10, flat, the last angled but not 

 carinate on the periphery ; aperture small, rhombic ; lip very 

 sinuous ; columella much twisted. Horn-color, with or with- 

 out deep, wide bands. N. Ala., Tenn. 



16a. P. trivittatum, i/ea. Fig. 44. Smooth, sub-fusiform, 

 rather thin ; spire conical, pointed, carinate at apex ; whorls 

 8, flattened, the last large, ventricose. Olivaceous, three- 

 banded. Tomhighee River, Miss. 



17. P. infrafasciatum, Anth. Fig. 45. Conical, smooth, 

 solid ; spire cylindrically elevated ; apex decollate ; whorls 

 8 — 9, slightly concave in the middle ; body whorl carinate on 

 the periphery, with below it two or three prominent striae. 

 Pale brown, with a single narrow band near the base. Tenn. 



17a. P. fastigiatum, Aiith. Fig. 46. Conical, smooth, 

 moderately thick ; spire elevated; apex carinate, acute; whorls 

 10, flattened; suture furrowed; growth-lines very strong; body 

 carinate at the middle, and again below it; canal produced. 

 Pale yellowish-green, with 2 reddish-brown bands. Tenn. 



18. P. Postellii, Lea. Fig. 47. Pyramidal, obtuse; apex 

 carinate, rather thick; whorls 8, flattened, the last rather 

 small; periphery angulate; aperture very small. Horn-color, 

 without bauds. Tennessee River ^ N. Ala. 



19. P. incurvum, Lea. Fig. 48. Pyramidal, carinate, 

 rather thin; spire elevated; suture regularly impressed; whorls 

 8, flattened, the last angulate at the periphery and obscurely 

 striate below; aperture small; outer lip extremely sinuous. 

 Horn-color, without bands. Florence, Ala. 



Differs from No. 18 ia the great curve of the outer lip. 



