68 AMERICAN MARINE CONCHOLOGY. 
twelve very minute lines at the base of the body-whorl. Spire 
gradually tapering to an acute apex. Aperture elongated, about 
one-third the length of the shell, acutely angular above, produced 
and rounded below. Onter lip sharp and thin, entire; pillar lip 
with a single sharp, oblique fold; opercule horny ; ivory or soiled 
white. 
Length 5, diam. 2 mill. 
Mr. Gwyn Jeffreys believes this to be a variety of O. impressa, ' 
Say. 
New England ; New York. 
7. O. semInuDA, Adams. Fig. 120. 
(Jaminea.) Bost. Journ. Nat. Hist., ii. 280, t. 4, f. 18. 1839. 
Shell small, acute, conic. Whorls seven, convex; upper whorls 
and half of the body-whorl longitudinally rugose, crossed by three 
equidistant revolving lines, presenting a granulated appearance. 
At the base of the lower whorl are four revolving lines, beginning 
on the middle, where the folds abruptly terminate. Suture dis- 
tinct, divided by an indistinct spiral ridge. Aperture oval; the 
outer lip very thin, and scalloped by the revolving lines; the pil- 
lar lip with an inconspicuous fold. Glossy white, translucent. 
Length 3.75, diam. 1.75 mill. 
New England, southwards. 
8. O. impressa, Say. Fig. 121. 
(Turritella.) Journ. Philad. Acad., ii. 244. 1822. 
Odostomia insculpta, De Kay, Moll. N. Y. 115, t. 31, £297. 1843. 
Shell elevated, thick, opaque, regularly tapering to the apex. 
Whorls seven, flat, with a deeply impressed suture; body-whorl 
with ten deeply sculptured closely approximated revolving striz 
on the lower half, and five distant revolving lines on the upper 
half; about four on the next whorl, and gradually diminishing in 
number above. Aperture ovate, acute above, effuse beneath. Lip 
simple; fold on the pillar-lip near the middle, distinet under the 
Jens, and deepening within. Soiled white, the sculptured lines 
rufous. 
Length 5, diam. 2 mill. ” 
New England, southwards. 
Genus ACLIS, Lovén. 
Ind. Moll. Scand. 16. 1846. 
The animal has a linguiform foot, much produced anteriorly, 
