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



46. P. gracile, Lea. 



lo gracilis, Lea, Proc. Acail. Nat. Sci., p. 394, 18G1. Jour. Acad. Nat. Sci., v, pt. 3, 

 p. 349, t. 39, f. 217. Obs., ix, p. 171. 



Description. — Sliell smooth, conical, pale purple ; spire regularly 



conical ; sutures regularly impressed ; whorls about nine, flattened. 



angular in the middle; aperture rather small, rhomboidal; 

 197. ° 



outer lip acute and sinuous ; columella pale purple, very much 



twisted and bent out ; canal short and widely efTuse. 



Habitat. — Coosa Eiver, Alabama; Wm. Spillman, M. D. 



Diameter, '30; length, '90 inch. 



Observations. — I have two adults before me. They are 



precisely alike, except that one has an obscure band visible 



in the inside. It is a graceful, symmetrical species, with a 



slight purplish tint which is stronger at the base than at the apex. 



It is allied to lo Spillmanii on one side and to lo viridula on the other, 



both herein described. The epidermis is rather more shining than 



usual, and the channel is short and Avide. The upper part of the 



■whorls, below the line of the suture, is lighter. The aperture is about 



one-third the length of the shell. — Lea. 



The figure is from Mr. Lea's plate. 



47. P. Spillmanii, Lea. 



Trypanostoma Spillmanii, Lea, Proc. Acad. Nat. Sci., p. 173, 18G2. Jour. Acad. 

 Nat. Sci., V, pt. 3, p. 271, t. 3G, f. 82. Obs., ix, p. 86. 



Description. — Shell smooth, regularly conical, dark olive; spire 



much raised ; sutures regularly impressed ; whorls about 



» J i' ) Fig. 198. 



nine, flattened ; aperture rather small, rhomboidal, white 

 within, sometimes banded; outer lip acute, sinuous; colu- 

 mella white and very much twisted. 



Operculum ovate, reddish-brown, rather thin, with the 

 polar point near the base. 



Habitat. — Noxubee Eiver, Mississippi; Wm. Spillman, 

 M. D. : and Tennessee ; J. Clark. 



Diameter, -46; length, 1-20 inches. 



Observations. — Six specimens are before me, one of them 

 is slightly carinate. In some there is a disposition to put on a whit- 



