New and recently described freshwater crabs (Crustacea: Decapoda: Brachyura: Potamidae, Gecarcinucidae and Parathelphusidae) from Thailand

The identity and taxonomy of 21 species of Thai freshwater crabs described between 1869 and 1992 of the families Potamidae (Potamon kanchanaburiense Naiyanetr, 1992; P. maesotense Naiyanetr, 1992; P. boonyaratae (Naiyanetr, 1987); Potamon phuphanense Naiyanetr, 1992; P. erawanense Naiyanetr, 1992; P. maehongsonense Naiyanetr, 1992; P. yotdomense (Naiyanetr, 1984); Dromothelphusa phrae (Naiyanetr, 1984); Larnaudia chaiyaphumi Naiyanetr, 1982; Thaipotamon siamense (A. Milne Edwards, 1869); T. smitinandi (Naiyanetr & Türkay, 1984); Thaiphusa sirikit (Naiyanetr, 1992); Demanietta tritrungense (Naiyanetr, 1986)), Gecarcinucidae (Phricotelphusa ranongi Naiyanetr, 1982; Thaksinthelphusa yongchindaratae (Naiyanetr, 1988)) and Parathelphusidae (Somanniathelphusa bangkokensis Naiyanetr, 1982; S. maehongsonensis Naiyanetr, 1987; S. fangensis Naiyanetr, 1987; S. denchaii Naiyanetr, 1984; S. nani Naiyanetr, 1984; Heterothelphusa beauvoisi (Rathbun, 1902)) are clarified. Four new genera are established (three belonging to the Potamidae: Thaipotamon, Kanpotamon and Thaiphusa; and one to the Gecarcinucidae: Thaksinthelphusa), and 13 new species (11 Potamidae: Potamon lipkei, P. nan, P. namlang, P. jarujini, P. maesariang, Ρ. ubon, P. somchaii, Thaipotamon lomkao, Τ. dansai, Τ. varoonphornae, Kanpotamon duangkhaei; and two Parathelphusidae: Somanniathelphusa phetchaburi, S. chiangmai) described. Detailed descriptions and figures are provided of all the taxa.