Shell rather large for the genus, regularly fusiform, thin, translucent, bluish white, with a roughened surface of waxy lustre, and a shining tip of a delicate yellow tint. Spire about half the length of the shell, of seven decidedly shouldered whorls, besides the nucleus. Aperture long and narrow. Posterior sinus large and nearly round, commencing at the suture and reaching to the shoulder, cutting into the top of the varix formed by the thickening of the last transverse rib, thus showing a thickened border with the upper edge rounded but not raised above the surface of the shell, extending farther back than the inner edge and curving strongly with the lines of growth, nearly meeting in front; from this the thin outer lip reaches far forward over the aperture, leaving a very narrow opening. Near the anterior end it is pinched in slightly, then bends abruptly backward as though cut off obliquely, revealing the entire width of the canal, and, curving a little upward, forms a slight notch before joining the columella. The edge of the lip is rounded and crimped by the termination of the revolving threads. Columella with a slight sigmoid curvature and an inconspicuous layer of enamel. Suture distinct, undulating, slightly channelled. The concave subsutural band occupies about a third of the width of the upper whorls, and is crossed by fine indistinct lines of growth. Conspicuous, rather broad, angular, oblique ribs cross the whorls, scarcely evident on the subsutural band, but rise somewhat abruptly on its lower edge, forming a sharp shoulder at the periphery. There are eleven of these ribs on the body whorl, reaching to the base of the canal; these, with their equally broad, concave interspaces, are ornamented with about twenty-five conspicuously raised, uniform, rounded threads, pretty regularly separated, but a little crowded on the anterior end of the canal. On the penultimate whorl there are six of them, the first just above the shoulder and the last just above the suture. Lines of growth very indistinct. Nucleus small, shining, consisting of three and a half regularly coiled whorls, the lower one ornamented with a peripheral keel. The entire surface of the shell is covered with minute granules, closely crowded except on the nucleus, where they are somewhat scattered and discernible only under a high magnifying power. Length, 15 mm. ; breadth, about 6 mm.; length of aperture, about 7 mm.; breadth, about 2 mm.

USA. Off Cape Lookout, North Carolina