PLELROCERA. 125 



Operculum ovate, very dark brown, with the polar point ou the 

 basal margin at the left. 



iZa?;«7a<.— Cumberland River near the Ford, north side of the moun- 

 tain, and Big Creek, south of mountain, at Cumberland Gap, Teun. 



Diameter, -32 ; length, -85 inch. 



Observations.— Qyntii a number of specimens were sent to me by 



Major Lyon, from both the above habitats. They are all very much 



the same in color and size, and none are banded. None were perfect 



at the apex, but the upper whorls, I think, from indica- 



rig.235. 

 tions in a few specimens will be found to be carinate. 



It is between Christyi and modestum (nobis). From the 



former it differs in having the base of the columella less 



twisted, in having a smaller aperture, and having the 



whorls more convex. From the latter it differs in being a 



smaller species, being darker and having a less expanded 



outer lip. The aperture is about one-third the length of 



the shell. I name this after Major S. S. Lj'on, of the Engineer Corps 



of the U.S. Army, being collected by him during the campaign, last 



year, to Cumberland Gap, East Tennessee, where he obtained several 



new Melanidoe. — Lea. 



68. P. viridulum, Anthony. 



STelania rirklnla, Anthony, Ann. Lye. N. Y., vi, p. 84, t. 2, f. 2, March, 1854. BiN- 

 NKY, Check List, No. 293. Brot, List, p. 31. Ree\'E, Monog. Mel., sp. 243. 



Description. — Shell conical, smooth, rather thick; olive-green; 

 spire much elevated ; whorls eight or nine, slightly convex ; sutures 

 impressed; aperture elliptical, small, within whitish; outer lip much 

 Fig. 23G. waved or auger-shaped, extending forward at base, and form- 

 ing a broad sinus in that region. 



Diameter, -35 inch (9 millim.) ; length, 1 inch (26 millim.). 

 Length of aperture, -32 inch (8 millim.); breadth of aperture, 

 •IG inch (4 millim.). 

 Habitat. — Tennessee. 

 Observations. — Somewhat like 31. Saffurdi, Lea, but is clearly distin- 

 guishable by its more elongated form, its greater number of wliorls 

 and size and color of aperture. Differs from M. reaularis, Lea, by its 

 less number of whorls, and their convexity, as well as by its peculiar 

 green color. — Anthony. 



