CHIEFLY OF THE UNITED STATES. 145 



Trtpanostoma affine. pi. 23, fig. 57. 



Testa canaliculata, pyramidata, cornea; spira valde elevata ; suturis regulariter impressis ; anfractibus 

 instar novenis, oanaliculatis, supra planulatis ; apertura subrhomboidea, intus albida vel vittata ; 

 labro acuto, sigmoideo; columella incrassata et valde contorta. 



Shell channelled, pyramidal, horn-color; spire very much raised ; sutures regu- 

 larly impressed : whorls about nine, channeled, flattened above ; aperture subrhom- 

 boidal, whitish or banded within ; outer lip acute, sigmoid ; columella thickened and 

 very much twisted. 



Proc. Acad. Nat. Sci. 1S64, p. 4. 



Hob. — Smith's Shoals, Cumberland River, East Tennessee, Maj. S. S. Lyon, U. S. E. 



My cabinet. 



Diam. -60, Length 1-35 inches. 



Remarlcs. — This species is allied to Thorntonii, (nobis,) and belongs to the group 

 of which canaliculatum, Say, may be considered the type. It differs from that spe- 

 cies in having a longer fuse or basal channel, in which character it approaches the 

 genus lo. It is closely allied to moniliferum, (nobis,) but differs in having a shorter 

 spire; being channelled on the periphery and having no nodules. There is usually a 

 well defined channel above the periphery, the middle of the lower whorl being cari- 

 nate. Below the carina there is usually a single stria. Two specimens of the four 

 before me have a broad single band on the upper whorls and several bands in the 

 interior. The base of the columella is very much twisted backwards, and the edge 

 of the outer lip is disposed to be thickened. The aperture is rather more than one- 

 third the length of the shell. 



-'o^ 



Trypanostoma univittattjm. pi. 23, fig. 58. 



Testa obtuso-carinata, pyramidata, subcrassa, dilute olivacea, nitida, univittata; spira elevata; suturis 

 impressis ; anfractibus planulatis ; apertura parviuscula, rhomboidea, intus albida, obsolete univittata ; 

 labro acuto, sigmoideo ; columella inferne incrassata et valde contorta. 



Shell obtusely carinate, pyramidal, somewhat thick, pale olive, shining, with a 

 single band; spire elevated; sutures impressed; whorls flattened; aperture rather 

 small, rhomboidal, whitish within, obscurely single banded ; outer lip acute, much 

 curved ; columella thickened below and very much twisted. , 



Proc. Acad. Nat. Sci. 1864, p. 112. 



Hah. — Cahawba River, Alab., E. R. Showalter, M. D. 

 Cabinet of W. D. Hartman, M. D. 

 Diam. -45, Length 1-2 inches. 



RemarTcs. — A single specimen was received by Dr. Hartman from Dr. Showalter, 



37 



