Shell small, turriform, mechanically truncated in adult individuals. Only one extant marine genus.
 

« Shells small, rarely exceeding 10mm in length in the adult truncated form. The shell has many whorls but most of these are lost when the animal becomes adult. Sculpture, when present, consists of rather strong axial costae which may extend from suture to suture or disappear on the whorl periphery. In a few species or members of a single species this sculpture may be entirely absent. Operculum paucispiral with or without a thin accessory plate of calcium on its outer surface. » – Clench & Turner: “A catalogue of the family Truncatellidae with notes and descriptions of new species”, Occasional Papers on Mollusks vol.I num.13, Cambridge 1948, p.162.