310 AMERICAN JOURNAL 



45. P. Tuomeyi, Lea. Fig. 93. High, conical, carinate, 

 somewhat thick; spire conical, elevated, attenuate; suture 

 scarcely impressed; whorls 10, flattened, with a raised line in 

 the middle, and sometimes a second obsolete one above it; 

 aperture small, very much twisted below. Dark brown, very 

 dark within. N. Ala. 



Differs from No. 43 in the form of the aperture, in color, and the smootk 

 apicial whorls. 



46. P. gracile, Lea. Fig. 94. Conical, smooth, shining; 

 spire elevated ; suture regularly impressed ; whorls 9, flat- 

 tened, angular in the middle; aperture sub-rhomboklal, with 

 a much twisted wide fuse below. Pale purple outside and 

 inside. Coosa River, Ala. 



47. P. Spilmanii, Ijea. Fig. 95. Regularly conical, smooth ; 

 much raised; suture regularly impressed; whorls 9, flattened, 

 angulate just above the suture, the body whorl with an ob- 

 scure line on the angle ; aperture rather small, rhomboidal ; 

 lip sinuous, with a short, wide, very much twisted canal. 

 Dark olive, white within, sometimes banded. Noxubee River, 

 Miss.; Tenn. 



48. P. planogyrum, Anth. Fig. 96. Elevated, conical, 

 smooth, thick; spire much elevated, nearly rectilinear; suture 

 cliannelled; whorls 10 — 11, flat or concave, the periphery with 

 a raised, rounded, sub-crenulated ridge, generally visible on 

 the whorls of the spire. Dark hoi'n-color, with a narrow brown 

 band on the lower half of the whorl. Ala. 



49. P. pyrenellum, Conr. Fig. 97. Elevated, conical, 

 smooth; whorls 7 — 8, flat, the body whorl angulated in the 

 centre; aperture large, short rhomboidal. Light greenish or 

 brownish. N. Ala. 



Wider, and without the raised revolving ridge of No. 48. 



50. P. Conradi, Tryon. Figs. 98, 99. Narrowly elevated, 

 acute; upper whorls carinate; whorls 8 — 10, flat, angulate on 

 the periphery; aperture small, rhomboidal. Reddish-brown, 

 inclined to yellowish under the suture, brownish within. Ala. 



Much more narrowly lengthened than pyrenellum, with which it has 

 been confounded. 



51. P. regulare, Lea. Smooth, conical, rather thick; 

 spire elevated; suture somewhat impressed; whorls 10, flat- 

 tened, a little angulated on the peripliery; aperture small, 

 rhomboidal. Dark horn-color, white within. Oconee District, 

 Ten7i. 



52. P. validum, Anth. Fig. 100. Ovate-conic, smooth, 

 thick; spire obtusely elevated; whorls slightly rounded, 6 re- 

 maining, with strong growth-lines amounting to varices on the 

 body; body whorl slightly convex, not distinctly angulate; 

 aperture small, ovate, with a well-marked, short channel below. 

 Olivaceous, bluish-white within, without bands. Tenn. 



