Shell is rather tall and slender. Not glossy. Whorls are swollen and angulated at the periphery. Last whorl occupies about half shell height. Spire is very slightly cyrtoconoid (apical angle of large shells about 20°). The protoconch is a little swollen, smooth or nearly so. Ornament of numerous, hardly visible, fine spiral cords (about fifty on the last whorl and twenty on the penult) and opisthocline costae on basal half of each whorl of the spire and peripheral region only of last whorl. The costae tend to disappear on the last two whorls, especially towards the aperture, and are very variable in number, but 12 may occur on the penult, 15-19 on the previous whorl. Aperture occupies about 40 % of shell height. Outer lip with wide and deep anal sinus, peripheral bulge, and moderately long siphonal canal. There is neither varix nor internal thickening on the outer lip.
Up to 17 x 5 mm.
White-grey, sometimes slightly yellow near the apex and outer lip.
The head is a transverse fold with the mouth under it; it also bears a short tentacle on each side, but the animals are blind and without eyes. Males have a sickle-shaped penis on the right of the head. The foot is large, both long and broad. The body is white or cream. Operculum present on foot.
Soft bottoms, 40-400 m deep in the northern part of their range, 600-3000 m in the southern part.
Widespread throughout the north-east Atlantic and extends into the Mediterranean and along the arctic coast of Asia. Only in the northern North Sea (Distr. T. nivalis).