Animal with an elongated foot, truncated in front, where it forms a duplicature, the upper margin less developed than the lower ; tentacles long, cylindrical, united by a sinuated veil, eyes at their exterior base ; snout very short; opereuligerous lobe simple. The radula has the formula 4+1+1+1+4; the central tooth very short, transverse, multicuspidate ; lateral tooth also transverse and multicuspid ; marginals small, transverse, simple. P. Fischer remarks that the dentition is paradoxical, there being 4 instead of 2 marginal teeth ; but this multiplication of the marginals has also been observed in other genera of the Taenioglossa, especially in Struthiolaria.
Shell small, always sinistial, conic, sometimes veutricose ; spire high, subulate ; protoconch mostly smooth, elongate, with an obtuse nucleus. Whorls about 15, with 2 or 3 spiral keels, usually closely granulated, the axial ornamentation mostly not continuous from whorl to whorl. Suture usually not deep. Aperture small, with a tubular, short, basal canal. Outer lip sinuate near the suture, sometimes produced into a canal at the fully gerontic stage. Columella smooth. Operculum paucispiral, with subcentral nucleus.
Nearly two hundred species are now known, inhabiting the West Indies, Europe, Indian Ocean, Polynesia, and Australasia.
Fossil.—Tertiarv.
These molluscs often attain a considerable size before losing their larval characters, particularly when distant from the shore.