On a new genus and new species of pilumnid crab from Taiwan, and the generic placements of Heteropanope changensis (Rathbun, 1909) and Pilumnopeus pereiodontus Davie and Ghani, 1993 (Crustacea: Decapoda: Brachyura)

Specimens of a small pilumnid crab found inside intertidal sediment rocks in Taiwan are here described as a new genus and new species, Cryptopilumnus taiwanensis. While superficially similar to species of Aniptumnus Ng, 2002, Heteropanope Stimpson, 1858 and Pilumnopeus A. Milne-Edwards, 1867, it nevertheless differs markedly in several key characters (the low or indistinct anterolateral teeth, the absence of a transverse suture between male thoracic sternites 1 and 2, and the presence of teeth on the ischium and merus of the third and fourth ambulatory legs). In addition, the taxonomy of two problematic species, Heteropanope changensis (Rathbun, 1909) and Pilumnopeus pereiodontus Davie and Ghani, 1993, are discussed and both are transferred to the new genus.