NEW MELANIDiE OF THE UNITED STATES. 283 



species, having a more characteristic auger-shaped mouth, and this specimen has a 

 single band, while four specimens of twrjida have each five bands. It is also top- 

 shaped while the twrjida is globose. It is not easily confounded with any other species, 

 being wider for its length than any other Trypanostoma I am acquainted with. The 

 aperture is full one-half the length of the shell, and the body whorls is nearly two- 

 thirds the length of the whole shell. 



Trypanostoma Stcamoeense. PI. 36, fig. 104. 



Testa plicata, conica, luteo-cornea, subcrassa; spira attenuata, mucronata; suturis imprcssis ; anfractibus 

 uodeuis, convexiusculis, superne carinatis, in medio plicatis; apertura parviuscula, rhoniboidea, 

 intus albida ; labro acuto, sinuoso ; columella ineurva, inferne iucrassata et contorta. 



Shell plicate, conical, yellowish horn-color, rather thick ; spire attenuate, pointed ; 

 sutures impressed ; whorls eleven, somewhat convex, carinate above, plicate in the 

 middle ; aperture rather small, rhomboidal, whitish within ; outer lip acute, sinuous ; 

 columella incurved, thickened below and twisted. 

 Proc. Acad. Nat. Sei., 1862, p. 175. 



Hah. — Sycamore, Claiborne County, East Tennessee, J. Lewis, M. D. 



My cabinet and cabinet of Dr. Lewis. 

 Diam. -36, Length -92 inch. 



Bemarhs. — A single specimen only is before me. It is a rather small, very symmet- 

 rical species. The seven upper whorls are carinate, the three middle ones are fur- 

 nished with numerous rather obscure folds, the lower whorl is smooth. In outline it 

 resembles labiaium, herein described, but cannot be confounded with that species 

 which is not plicate, nor yellowish, and the form of the lower part of the aperture is 

 very different. The aperture is little more than the fourth of the length of the shell. 



Trypanostoma dux. PI. 36, fig. 105. 



Testa carinata, pyramidata, crassa, rufo-fusceseente ; spira valde elevata; suturis parum impressis ; an- 

 fractibus instar novenis, planulatis ; apertura subgrandi, rhombic;!, intus pallido salmonia ; labro 

 acuto, sinuoso ; columella incrassata et valde contorta. 



Shell carinate, pyramidal, thick, reddish brown ; spire much raised ; sutures 

 slightly impressed ; whorls about nine, flattened ; aperture rather large, rhombic, pale 

 salmon color within and very much twisted. 



Operculum subpyriform, dark brown, with polar point near to the basal line. 

 Proc. Acad. Nat. Sci.. 1S62, p. 170. 



Hah. — Tennessee River, "W. Spillman, M. D. Fox River, Illinois, J. Sampson ; 

 Oostenaula, Rev. G. White ; Tuscumbia, B. Pybas. 



My cabinet and cabinets of Dr. Spillman and Mr. Sampson. 

 Diam. -75. Length 1*80 inch. 



