90 LAXD AND FRESH-WATER SHELLS OF N. A. [PART IV. 



31. P. Henryanum, Lea. 



Tnjpanostoma Jlenryanum, Lea. Proc. Acad. Kat. Sci., p. 272, 18G2. Jour. Acad. 

 :Nat. Sci., V, pt. 3, p. 351, t. 39, f. 222. Obs., ix, p. 173. 



Description.— ^h.Q\\ carinate, attenuate, sharp-pointed, thin, semi- 

 transparent, pale horn-color, without bands; spire regularly 

 Fig. 109. 1- ' i- => 



attenuately conical ; sutures regularly impressed ; whorls ten, 



flattened, the last one regularly carinate and striate in the 

 middle ; aperture, small, subrhomboidal, whitish within ; outer 

 lip very sharp and sinuous ; columella bent in and very much 

 twisted. 

 Habitat. — Tennessee? Smithsonian Institution. 

 Diameter, -29 ; length, 80 inch. 



Observations. — Among the Melanidoc sent to me by Prof. Henry, 

 Secretary of the Smithsonian Institution, were a few of this species, 

 which I at first regarded as a variety of Melania {TnjpanosComa) 

 uncialis, Hald., but it is certainly a distinct species. In the spire it Is 

 very much the same, but the color is paler, and in the form of the 

 aperture it is quite different, — ?(?ici!rt7is having a retrorse chaunel at the 

 base while our species curves towards the front and has a more deli- 

 cate columella, and is altogether more fragile. All the specimens 

 before me have six revolving strife on the lower whorl, below the 

 periphery. The aperture is not quite one-third the length of the 

 shell. 



I have sincere pleasure in dedicating this species to my friend Prof. 

 Joseph Henry, Secretary of the Smithsonian Institution, who liber- 

 ally has placed the fresh-water mollusca of that admirable Institution 

 under my examination. — Lea. 



32. P. Lewisii, Lea. 



Trypanostomn Letclsii, Lea, Proc. Acad. Nat. Sci., p. 172, 1862, Jour. Acad. Nat. 

 Sci., V, pt. 3, p. 292, t. 36, f. 120. Obs., ix, p. 114. 



Description. — Shell sulcate, somewhat thin, high, conical, dark 

 brown or horn-color, banded; spire very much drawn out; sutures 

 slightly impressed, wiiorls about eleven, flattened; aperture small, 

 subrhomboidal, banded within; outer lip acute, slightly sinuous; 

 columella slightly thickened below and very much twisted. 



Habitat.— VQOv'ia., Illinois ; J. Lewis, M. D. 



Diameter, -47; length, 1-12 inches. 



