Genus Aclis Lóven, 1846

Type species. Alvania supranitida Wood, 1842 [= Aclis minor (Brown, 1827)], by monotypy. Eastern Atlantic and Mediterranean. Syntypes of A. minor were figured by Oliver et al. (2020: Fig. 13).

Description. Shell vitreous, usually elongated; protoconch smooth, globose, dome shaped, paucispiral or multispiral; teleoconch with convex whorls, commonly with one or more spiral keels, presence of microscopic spiral striae close to the sutures; aperture wide, outer lip usually opisthocline, inner lip distinctly reflected, umbilical fissure commonly present, most anterior region of aperture commonly drawn out towards the center of the shell and flattened (adapted from Bouchet & Warén 1986).

Remarks. A complete list of synonyms was presented by Bouchet & Warén (1986). Only Cyclonidea Laseron, 1956 (Type species: Cyclonidea carina Laseron, 1956, by original designation), which was previously synonymized with Aclis is currently considered as valid (Poppe & Tagaro 2016).