This shell has nearly the same form as Astyris holbollii or rosacea as figured by Sars (Moll. Reg. Arct. Norv., t. 16, fig 1), but is proportionally a little wider anteriorly, and when immature has a peripheral angulation, not sharp but distinct enough to be readily observed. It differs from that species in (1) being more solid and strong; (2) having no transverse riblets anywhere, but a very fine close spiral striation on the early whorls; (3) having a firm smooth polished epidermis showing no lines of growth; (4) having a more regular, acute, and smaller apex, and less swollen apical whorls; (5) having the outer lip thickened, strengthened by a varicoid swelling, internally strongly lirate with six or eight raised lirae, the inner lip with a raised callus and nine or ten deeply incised grooves on the canal. The color of the deep-sea species is a little more pink and its appearance more elegant owing to the polished epidermis. It averages about the same size as the A. rosacea. The specimen figured is 8.0 mm. long and 3.5 mm. in maximum width.

Astyris profundi was described from the western Atlantic. Bouchet & Waren (1985:168) display the holotype, decapitated but with remains of a multi-spiral protoconch. Our seven adult specimens are also decapitated and frequently damaged on the lip, most likely due to predation by crabs. None of the adult specimens show remains of a protoconch. One juvenile specimen shows a multispiral eroded protoconch with 3,5 whorls that is quite conical ; this general outline is in agreement with the description from Dall (1889). The nucleus shows oblique lines followed by whorls which are granulated with short oblique lines above the suture.
A similar species from NW Africa is Mitrella nitidulina (Locard, 1897). It has been figured by Bouchet & Waren (1985: 168, figs 388, 399-400). It is known in the NE Atlantic from the Bay of Biscay to Morocco. This species has a multispiral protoconch that is more raised and convex in its ultimate whorl. Furthermore it shows finer striations on the lower body whorl and columella.

From A. diaphana Verrill, it differs in most of the above characters as well, but especially in being still broader in proportion. From a dwarf specimen of Cotonopsis lafresnayi the present form would differ by its less constricted canal, more regularly ovate whorls, less conspicuous varix, and especially by its less acute spire without traces of ribs anywhere. The very oblique edge of the columella is extended into a sharp plait, which appears to project like a tooth behind the columellar callus, and, being so far up, would at first sight be taken as unconnected with the pillar margin, which is masked by a false edge, in front, of labial callus.

Cuba, off Morro Light, Havana in 805 fms.. Also thirty-six miles S.W. from Cape Hatteras, North Carolina, in 107 fms., sandy bottom.