Shelf. A broad conical shell with a blunt apex, the base not much extended and the last whorl very large; it appears smooth, glossy and slightly translucent. The shell is often covered by a thin periostracum or its remains. There are 5-6 whorls which are tumid and meet at sutures placed below the periphery of the upper whorl and made to look rather deep by a small subsutural flattening of the lower whorl. The bluntness of the apex is due to the somewhat sunken position of the protoconch; the apical angle is 45-50°. Though apparently smooth fine growth lines and spiral lines are present, the latter most marked basally, the former prosocline in direction.
The protoconch has 0.8 whorls, measures about 1 mm across, bears very fine spiral lines and is clearly but not markedly distinct from the rest of the shell.
Aperture. Oval, narrow above and below, bounded by a peristome lying in a prosocline plane; not clearly separated from a short siphonal canal. The outer lip arises just below the periphery of the last whorl at an angle about 20° to the shell axis, It follows a smooth, more or less semicircular curve to the distal end of the siphonal canal, showing hardly any inflexion at its base. Its edge is thickened. The columella is vertical and rather broad and over the last whorl the inner lip forms an extensive glaze, which, with the columella, is marked with minute pustules. The siphonal canal is very short, widely open and bent a little to the left of the long axis of the aperture. Its distal edge is slightly thickened.
Colour. While — ivory.
Size. Up to 38 x 25 mm. Last whorl = 80-85% of total height; aperture = c. 60% of total height.
Animal. There is no snout, the head ending in a transverse ridge with the mouth ( = opening of a proboscis pouch) on its underside. Two rather short tentacles arise from the fold each with an eye on a bulge on the outer side, basally. The mantle edge is plain, and it bears a long siphon on the left side. Males have a narrow, sickle-shaped penis arising from the floor of the mantle cavity behind the right tentacle, the male pore near its lip.
The foot is broad and double-edged anteriorly, tapering to a rounded point posteriorly. The operculum is oval, broad at one side and narrow at the other where a terminal nucleus lies.
Colour. Yellowish.
Geographical distribution. A northern, perhaps nearly circumboreal species found from sea area Sole northwards to north Norway the Faeroes, Greenland. Not recorded from the English Channel, the North Sea south of Dogger, the Skagerrak or Kattegat. It seems to be rather rare in lower latitudes, but is common in higher.
Habitat. On soft bottoms, sand and mud, form 70-400 m, deeper in the more southern parts of its range.
Food. Unknown.

From Lofoten (NW Norway) and W and NW of Iceland (Oskarsson, 1966) along the European shelf south to the extreme north of the Bay of Biscay (THALASSA st Z422, 48°21 N, 09°39 W, 1175 m, 1 fresh shell). Normally it is a shelf species, occurring in 100-300 m but sometimes it is found on the upper part of the continental slope (several records from the Porcupine Expedition 1869 from off Ireland and the Thalassa station above).