354 E., Billings—New Species of Paleozoic Fossils, 
grown individuals. Surface finely striated, the strie curving 
forward on the ventral sides, and passing upward on the side 
at nearly a right angle, curve slightly backward on the dorsum. 
n a specimen eighteen lines in length, the width of the aper ; 
ture is about six lines and the depth about four, the propor — 
tions being slightly variable. 
e operculum has a very well-defined conical ventral limb, 
the apex of which is situated above the center, or nearer the 
dorsal than the ventral side. The dorsal limb forms a flat mar — 
gin, and is so situated that when the operculum is in place, the — 
plane of this flat border must be nearly at right angles tothe — 
longitudinal axis of the shell. In an operculum six Tines wide, 
the height of the lower limb to the apex of the cone is two and . 
a half lines, and the width of the flat border, which constitutes 
the dorsal limb, about one line. 
H. micans.—This is a long, slender, cylindrical species, with 
convex, and finely striated concentrically. On des | 
elongate ovate scars, arranged in the form of a star, | 
toward the ventral side being the longest. None of these se 
quite reach the margin. 
The shell and operculum are thin and of a finely Jamel 
structure, smooth and shining. 
curs at Bic and St. Simon; also at Troy, N. Y. 
Collectors, T. C. Weston and S. W. Ford. three 
the mays 
Sometimes numerous small specimens, from half a line ui lab 
lines in ee are found with the operculum on the poe : 
This shell appears to me at present to constitute a new 
