Lunatia is a genus of predatory sea snails, marine gastropod mollusks in the family Naticidae, the moon snails. The species in this genus have been brought in synonymy mostly with Euspira Torigoe & Inaba (2011) provided a rather arbitrary assignment of species to respectively Euspira and Lunatia and this has been at one time uploaded in the WoRMS classification. However this is not based on any in-depth phylogenetic analysis and has proved inconsistent when some closely related European species (e.g. Euspira guillemini, E. macilenta) were then not congeneric. Until a substantiated phylogenetic hypothesis is published for the group, Lunatia is here considered a junior subjective synonym of Euspira and all the species accepted under Euspira, following in this Marincowich (1977), Kabat (1991)