Shell extremely slender, thin, white, with nine or ten delicately rounded whorls; transverse sculpture consisting only of the delicate yet evident lines of growth ; nucleus very small, not differentiated from the rest of the shell by color or texture; three nuclear whorls marked by a distinct, apparently finely serrate equatorial carina, which soon becomes obsolete; fasciole slightly concave, smooth, except for lines of growth; remainder of whorl covered with fine slightly raised spiral threads separated by nearly equal interspaces and continued to the anterior end of the canal; last whorl more than half the length of the shell; aperture simple, the notch broad, not very deep, and lying upon the preceding whorl; outer lip moderately arched forward, simple ; columella hardly washed with callus; canal rather narrow and unusually long; Lon. of shell, 14.0 mm; of last whorl, 8.0 mm; max. lat. of shell, 3.2 mm.
DESCRIBED BY DALL as Mangelia scipio

This is a remarkably delicate and singular shell; the mouth being broken, the characters of the lip were made out from the lines of growth. It is not like any other species known to me. The nearest relative seems to be Daphnella monoceros Watson, which is much larger and less attenuated in proportion to its size. The long narrow canal of the present species forbids its reference to Daphnella, and it is not improbably related nearly to the Pleurotomella group, and to M. pelagia Dall.

Caribbic. Off St. Vincent. Near Dominica.