Genus Aliculastrum Pilsbry, 1896

Type species: Bulla cylindrica Helbling, 1779

The genus Aliculastrum was introduced by Pilsbry (1896) as a replacement name for Alicula Ehrenberg, 1831 . The latter name was preoccupied by Alicula Eichwald, 1830 in reference to another group of marine gastropods with a projecting spire and based on a fossil placed in the family Scaphandridae (Bouchet 2010) . The type species, Aliculastrum cylindricum was originally ascribed to the genus Bulla (Helbling 1779) and has been arbitrarily attributed to the genera Atys (Sowerby 1870; Gosliner et al. 2008) and Aliculastrum (Habe 1952; Lin 1997; Qi 2004). There is very limited literature documenting the characters that define the genus Aliculastrum . According to Lin (1997), this genus includes species that possess a cylindrical elongated shell, with spiral grooves at both ends and no umbilicus. Aliculastrum cylindricum was described as umbilicated (Helbling 1779; Adams 1850). However, Chemnitz (1788) mentioned that this is simply a depression that looks very much like an umbilicus. Species ascribed to this genus in the tropical West Pacific include A. cylindricum (Helbling, 1779), A. debilis (Pease, 1860) and A. parallelum (Gould, 1846) (Pilsbry 1896; Habe 1952; Lin 1997; Carlson & Hoff 2003; Qi 2004) (Tab. 1).