278 NEW MELANIDiE OF THE UNITED STATES. 



aperture small, constricted, rhomboid al, whitish within; outer lip acute, sinuous; 

 columella thickened below and twisted. 



Proc. Acad. Nat. Sci. 1862, p. 174. 



Hob— Cincinnati, Ohio, T. G. Lea. 



My cabinet and cabinet of Dr. Hartman. 

 Diain. '33, Length "76 inch. 



Remarlcs. — Among a large number of young Melania { Trypanostoma) canaliculate 

 and conica, Say, sent by my brother, long since, I found eight specimens of this small 

 species. All seem to be full grown and are very nearly of the same size. They may 

 be at once distinguished from canaliculata by their being much smaller, being much 

 more narrow and having no channel or furrow on the middle of the whorl. The 

 aperture is also much smaller. It differs entirely from conica in the whorls, which 

 regularly decrease to the apex, while in that species they decrease rapidly to the 

 apex, which is sharp-pointed. The aperture is about one-third the length of the shell. 

 None of these specimens have bands; one is slightly brownish inside towards the 

 base. This is very different from Mr. Say's Melania simplex. 



Trypanostoma minor. PI. 36, fig. 95. 



Testa laevi, obtuse conoidea, subcrassa, luteolii, vittata ; spira obtuso-conoidea ; suturis valde imprcssis ; an- 

 fractibus septenis, convexiusculis. ultimo grandi ; apertura grandi, subrbomboidea, intus alba, intcr- 

 dum vittata ; labro acuto, sinuoso ; columella ineurvft, inferno" inerassata et parum contorta. 



Shell smooth, obtusely conoidal, rather thick, yellowish, banded ; spire obtusely 

 conical ; sutures much impressed ; whorls seven, somewhat convex, the last large ; 

 aperture large, subrhomboidal, white and usually banded within ; outer lip acute, 

 sinuous ; columella incurved, thickened below and slightly twisted. 

 Proc. Acad. Nat. Sci.. 1862, p. 174. 



Hab.~ Tennessee, Prof. Troost. 



My cabinet and cabinet of Dr. Troost. 

 Diam. -32, Length -54 inch. 



Remarks. — Pour specimens were found among a number of young shells from Prof. 

 Troost. It is a modest little species which might easily be taken for a young Melania 

 conica, Say. It is most nearly allied to bivittata, herein described, but may be distin- 

 guished by being wider in proportion, having a shorter spire, being less polished, 

 and not so bright a yellow. It differs also in the brown bands being much less dis- 

 tinctly marked, the upper whorls showing none, while the other is beautifully banded 

 to the apex. The two species differ in columella, minor having nearly half of it 

 perpendicular, while bivittata has that portion twisted backwards. The bands seem 

 to be uncertain in this species, one having two bands, two having one baud and the 

 other having no band. The aperture is nearly half the length of the shell. 



