OF CONCHOLOGY. 309 



S9. P. gradatum, Anthon>j. Figs, 82 — 84. Smooth, coni- 

 cal, solid; whorls 7 — 8, slightly concave, with a distant ele- 

 vated ridge closely overlying the suture and the projecting 

 shoulder of the succeeding whorl, so as to form a series of 

 steps to the sub-acute apex; body whorl large, sub-cylindrical, 

 angulate on the periphery, and striate below; aperture sub- 

 rhomboidal ; columella straight, channel deep, narrow, slightly 

 recurved. Greenish horn-color, sometimes banded. S. W. Va., 

 E. Tenn. 



Fig. 82 is typical, Fig. 83 eartattim, Lea, and Fig. 84 eximia, Antli, 



39a. P. cinctum, Lea. Fig. 85. Heavy, carinate ; spire 

 sub-elevated; suture impressed; whorls 7, planulate, carinate 

 in the middle; aperture small, rhomboidal, broadly produced 

 below. Dark corneous, whitish within. N. Ala. 



Perliaps tlie same as No. 40, 



39b. P. carinatum, Ler. Fig. 86. Acutely conical, cari- 

 nate, tbin, diaphanous; spire acute; whorls 9, carinate, above 

 striate; aperture small, rhomboidal; lip acute, sinuous. Red- 

 dish horn-color. Bull Run, tributary to Clinch River ^ E. 

 Tenn. 



A very youag sLtell, undoubtedly; it is not unlikely the young of No. 

 40. 



40. P. aratum, Lea. Figs. 87, 88, Conical, rather thick; 

 suture deeply grooved ; whorls 6, flattened, carinate just above 

 the suture; aperture small, sub-rhomboidal. Dark horn-color. 

 E. Tenn. 



41. P. lativittatum, Lea. Fig. 89. Sub-attenuate, cari- 

 nate, rather thin, shining; spire ccmical; suture linear; whorls 

 7, flattened, angulate in the middle, with a hair-like line below 

 it. Dark horn-color, with a broad central band of intense 

 brown, below which the shell is yellowish. ChikasaJva River, 

 Ala. 



41a. P. strictnm, Lea. Fig. 90. Sub-attenuate, carinate, 

 thin, semi-transparent; spire regularly conical; suture linear; 

 whorls 6, flattened, body whorl angulate. Pale horn-color, 

 with a single hair-like, pale brown band. S. Carolina. 



42. P. modestum, Tjea. Fig. 91. Smooth, conical ; suture 

 impressed; whorls 9, flattened, angular in the middle; aper- 

 ture rhomboidal, with a rather long, straight canal. Horn- 

 color, white within. Tennessee River, Ala. 



Evidently the young of a large species. 



43. p. Leaii, 'y'rT/o?!. Fig. 92. Smooth, conical; spire ele- 

 vated, striate towards the apex, with a slight suture; whorls 

 9, flattened, obtusely angular in the middle; aperture small, 

 sub-rhomboidal, with a short, twisted canal. Dark olive-green, 

 lighter below the suture, white within, purple on the base of 

 the columella. Coosa River, Ala. 



