Genus Thericium Monterosato, 1890

Type species. Cerithium vulgatum Bruguière, 1792, by original designation (Monterosato 1890: 163). Present-day, Mediterranean.

Note. Most authors have placed these Atlantic cerithiid species in the genus Cerithium Bruguière, 1789 . Landau et al. (2004a: 5) argued that true Cerithium (sensu stricto) was an Indo-Pacific genus, characterised by a flaring outer lip with a tooth-like extension abapically projecting over the anterior siphonal canal, and a relatively longer siphonal canal. We follow those authors in using Thericium Monterosato, 1890, at full genus level.