Pyramidellids with, usually, small (<5.5 mm long), broadly conical or ovate shells, of not more than seven whorls. Sculpture, if any, confined to microscopic spiral striae or fine lines of growth. Shell white, sometimes with a grayish, yellowish or bluish tinge. Aperture rhomboid to oval, usually acute-angled above. Columella usually gently curved, merging almost imperceptibly with the base of the penultimate whorl. A columellar fold always present. Protoconch partly submerged in the teleoconch, its angle of inclination varying, though usually around 90° (type A, and B). Operculum with an opaque, opercular 'anchor' of varying thickness and with or without a distinct indentation and groove created by the columellar tooth.