A new freshwater crab of the family Hymenosomatidae MacLeay, 1838 from New Caledonia (Crustacea, Decapoda, Brachyura) and an updated review of the hymenosomatid fauna of New Caledonia Author D., Guinot ISYEB (CNRS, MNHN, EPHE, Sorbonne Université), Institut Systématique Évolution Biodiversité, Muséum national d’histoire naturelle, case postale 53, 57 rue Cuvier, 75231 Paris cedex 05, France guinot@mnhn.fr Author de, Mazancourt V. Unité Biologie des organismes et écosystèmes aquatiques (BOREA), Muséum national d’histoire naturelle, Sorbonne Université, Université de Caen Normandie, Université des Antilles, CNRS, IRD, CP 26, 57 rue Cuvier, 75231 Paris cedex 05, France & Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin. Germany. valentin.seizilles-de-mazancourt@edu.mnhn.fr text European Journal of Taxonomy 2020 2020-06-22 671 1 29 journal article 21610 10.5852/ejt.2020.671 6f6af3d0-601d-47dc-849d-8ad21170e570 2118-9773 3906756 9EF19154-D2FE-4009-985C-1EB62CC9ACB0 Neorhynchoplax euryrostris Davie & Richer de Forges, 1996 Fig. 9 Neorhynchoplax euryrostris Davie & Richer de Forges, 1996: 260 , figs 2b, d, 3. Belongs to the group of species of Neorhynchoplax in which the lateral carapace margin is armed with a distinct recurved spiniform tooth just above the first ambulatory leg (P2); a characteristic shared with Richerius marqueti gen. et sp. nov. is the long setae that cover the outer surface of the stout palm and the fingers of the chelipeds, especially in males ( Fig. 9 ). It is estuarine to tidal freshwater. The species was until now only known from the type material collected on the western coast of New Caledonia (Dumbea, Le Cap) where it inhabits crevices in rotting logs at the edge of the water at low tide; and under stones in freshwater ( Davie & Richer de Forges 1996: 261 ). Thanks to the Hydrobio Expedition, “Our Planet Reviewed”, it was found in the Iouanga River and in a stream tributary of the Negropo river, at 4 m a.s.l., where it cohabits with Odiomaris aff. pilosus . These newly collected specimens were all found in a similar habitat, among aquatic vegetation in the lower part of the river under the marine influence, with a variable salinity ranging from freshwater to brackish water depending on the tide.