Taxonomy of the freshwater crabs of Costa Rica, with a revision of the genus Ptychophallus Smalley, 1964 (Crustacea: Decapoda: Pseudothelphusidae) Author Magalhães, Célio Author Wehrtmann, Ingo S. Author Lara, Luis Rólier Author Mantelatto, Fernando L. text Zootaxa 2015 3905 3 301 344 journal article 42408 10.5281/zenodo.235127 16b434af-bed4-43fd-bdfc-0f29bcaec7bb 1175-5326 235127 4DA803F1-30C6-4FC3-8EEF-9690A89822A6 Ptychophallus Smalley, 1964 Pseudothelphusa ( Ptychophallus ) Smalley, 1964b : 9 . Ptychophallus ( Semiptychophallus ) Pretzmann, 1965 : 5 [ type species Pseudothelphusa xantusi Rathbun, 1893 , by original designation]. Ptychophallus ( Microptychophallus ) Pretzmann, 1965 : 5 [ type species Ptychophallus ( Microptychophallus ) goldmanni Pretzmann, 1985 , by original designation]. Type species . Pseudothelphusa tristani Rathbun, 1896 [by original designation]. Diagnosis . Third maxilliped with exopod about 0.5 to 0.7 length of ischium. G1 stout, with a prominent, oblong apex bent cephalically, joined to the main stem by narrow peduncle; marginal suture on mesial surface, usually straight, not twisted to other surfaces; lateral process large, usually bilobed (except P. goldmanni ); caudal ridge extending longitudinally on distal half of caudal surface; mesial process usually subtriangular. Distribution . The species of Ptychophallus are distributed from northern Costa Rica to southern Panama in hydrographic basins from both Caribbean and Pacific drainages. Remarks . The relationships with other pseudothephusid genera, infered by G1 morphology, were discussed by Rodriguez (1982) .