Contribution to the knowledge of Leucosiidae I. The identity of Leucosia craniolaris (Linnaeus, 1758), and redefinition of the genus Leucosia Weber, 1795 (Crustacea: Brachyura)

A study of the genus Leucosia Weber, 1795, led to the establishment of the identity of the type species, L. craniolaris (Linnaeus, 1758), designation of a neotype and redefinition of the genus. Leucosia is now restricted to 4 species: the type species L. craniolaris (Linnaeus, 1758), L. punctata Bell, 1855, L. moresbiensis Haswell, 1880, and a new species, L. rubripalma. They differ from all other species heretofore assigned to the genus in having first male pleopod with a screw-like tightly coiled shaft, terminating in a setose muff. The species are described or redescribed and illustrated, extended synonymies are given, and a key for their identification is provided.