NEW MELANIDjE OF THE UNITED STATES. 317 



being so angular. The folds on the upper whorls are close and well defined, but 

 disappear below. They are slightly curved, and the aperture is about one-third the 

 length of the shell. 



*&"• 



GONIOBASIS OIFFICILTS. PI. 37, fig. 163. 



Testa plicata, subattenuata, tenebroso-oliva vel fuscescente, subteuui, evittata ; spira attenuata, niuero- 

 nata; suturis irregulariter impressis; anfractibus instar octonis, convexiusculis ; apertura parviuseula. 

 ovato-rhoniboidea, intus albido ; labro acuto, subsinuoso : columella incurva, incra.ssata et con- 



torta. 



Shell folded, somewhat attenuate, dark olive or brownish, rather thin, without 

 bands ; spire attenuate, sharp-pointed ; sutures regularly impressed ; whorls about 

 eight, slightly convex; aperture rather small, ovately rhomboidal, whitish within; 

 outer lip acute, subsinuous; columella bent in, thickened and twisted. 

 Proc. Acad. Nat. Sci. 1862, p. 267. 



Hah. — Tennessee, Dr. Edgar. 



My cabinet. 

 Diam. -31, Length -82 inch. 



Remarks. — This is one of the Melania [Goniobasis) Deshaysiana group, and is nearly 

 allied to sparus herein described, but may at once be distinguished from that species 

 by being flatter on the whorls, and in being of a darker color. There is but a single adult 

 specimen before me, the apicial whorls of which are eroded. Some of the youn<>- 

 specimens are perfect to the apex, and the upper whorls present close folds slightly 

 curved and decussate, with revolving striae. These are hardly perceptible on the 

 adult specimen. In outline it resembles Melania {Goniobasis) columella (nobis), but 

 differs in the color and in the form of the lower part of the columella. The aperture 

 is about one-third the length of the shell. 



**&* 



Goniobasis Bairdiana. PI. 37, fig. 164. 



Testa plicata, subattenuata, tenebroso-fusca, subcrassa, univittata ; spira subattenuata, mucronata ; sutu- 

 ris impressis; anfractibus octonis, convexiusculis; apertura parviuseula, ovato-rhomboidea, intus 

 albida et univittata ; labro acuto, vix sinuoso ; columella incurva, pa rum iuerassata et valde. con- 

 torta. 



Shell folded, somewhat drawn out, dark brown, rather thick, single-banded ; whorls 

 subattenuate, sharp-pointed ; sutures impressed ; whorls eight, slightly convex ; ap- 

 erture rather small, ovately rhomboidal, whitish within and single-banded ; outer lip 

 sharp, scarcely sinuous ; columella bent in, somewhat thickened and very much 

 twisted. 



Proc. Acad. Nat. Sci., 1862, p. 267. 



Hob. — Columbia River at Fort George, Oregon, J. Drayton. 



My cabinet and cabinet of Smithsonian Institution. 



Diam. -^'k Length "66 inch. 



si 



