Bay of Biscay to Canarias, Mediterranean; the species occurs in the deep circalittoral, the continental shelf and the slope (1450m, ‘Porcupine’ 1870; 1205m, ‘Travailleur’ 1881-1882 – Nobre, 1900). A depth of 2664m is mentioned off Algeria, without further explanations. Original taxon: Cioniscus gracilis.
 
The embryonal whorl shows two characteristic spiral keels. The teleoconch, of 4-5 whorls only, bears the usual undulating radials crossed by weak spirals. Above: a specimen dredged at 200m deep, off Dubrovnik, S. Croatia. 1,7mm. Original pictures provided by R. Stanić (HR) – (CC BY-NC-SA).

« Shell of nearly equal breadth throughout, thick, semitransparent, and glossy. Sculpture: numerous sharp and flexuous longitudinal ribs, which extend to the base; there are about 25 on the last whorl; each whorl is angulated or shouldered at the top; the first whorl and a half, which form the apex, are marked by two slight spiral striae, but are otherwise smooth and polished. Colour: whitish, with a faint tinge of yellowish-brown. Spire very gradually tapering to a blunt and apparently truncated point; apex somewhat inflected. Whorls 5½, convex, but rather compressed. Suture deep. Mouth somewhat more round than oval; peristome continuous or complete. Outer lip flexuous, usually strengthened by a rib, contracted above. Inner lip attached to the pillar, which is oblique; there is no umbilicus. » – Op. cit. p.341.