PLEUROCERA. 127 



Observations. — Quite a number of this species were among the shells 

 sent to me by Mr. "White, collected by him in the northern part of Ala- 

 bama some years since. It was supposed to be a varietj^ of Mclania 

 (Goniobasis) proxima, Say, but the form of the aperture is quite dif- 

 ferent, having an expanded outer lip. It is also larger, some speci- 

 mens being nearly an inch long, and it has not a carina, but usually 

 three stria3, the middle one of which rises almost to a carina. In 

 some specimens there is only a single stria, sometimes two, ordinarily 

 three, and rarely four. Usually the upper stria is continued on the 

 lower whorl, extending to the aperture, but rarely any of the others. 

 The aperture is about two-sevenths the length of the shell. It is 

 allied to Whitei, herein described, but is a smaller species and diflfers 

 in color, striae and in the aperture. — Lea, 



Figure 238 is a copy of that given by Mr. Lea. 



70. P. Knoxvillense, Lea. 



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

 Nat. Sci., V, pt. 3, p. 274, t. 36, f. 87. Obs. ix, p. 96. 



Description. — Shell smooth, subulate, rather thin, pale horn-color; 

 spire attenuately conical, sharp pointed; sutures regularly im- 

 pressed; whorls ten, slightly convex, carinate towards the 

 apex, the last somewhat constricted ; aperture small, sub- 

 rhomboidal, white within ; outer lip acute, sinuous ; columella 

 thickened below and a little twisted. 



Habitat. — Knoxville, Tennessee ; President Estabrook. 



Diameter, '50 ; length, -80 inch. 



Observations. — A single specimen only of this species was received 

 from President Estabrook. It is closely allied to Estabrookii, herein 

 described, but maybe distinguished by the form of the inferior part 

 of the columella and the channel being more drawn backwards. It is 

 a smaller species, of rather lighter horn-color and the whorls are 

 rather more bulging. The aperture is less than one-third the length 

 of the shell. — Lea. 



Figured from Mr. Lea's plate. I doubt whether this is dis- 

 tinct from Trypanostoma iSycamorense, Lea, which, like this, is 

 described from one specimen onl}'. 



