A revision of the family Deckeniidae Ortmann, 1897 (Crustacea: Decapoda: Brachyura: Potamoidea), with description of a new genus (Gecarcinucidae: Gecarcinucoidea) from the Seychelles,Indian Ocean

The family Deckeniidae Ortmann, 1897, is revised and only 2 East African species are recognised, D. imitatrix Hilgendorf, 1869, and D. mitis Hilgendorf, 1898. The identity of the poorly known species from Seychelles, Indian Ocean, Deckenia alluaudi A. Milne Edwards and Bouvier, 1893, is clarified. This species is redescribed, assigned to a new genus (Seychellum gen. nov.), removed from the Deckeniidae sensu stricto and transferred to the family Gecarcinucidae Rathbun, 1904.