﻿AbstractThe New Caledonian Archipelago is a hot spot for biodiversity and endemism. Whereas popular groups such as birds and plants are well-studied, invertebrate groups such as ostracods remain ill-known. Here,Caledromusrobinsmithigen. et sp. nov.is described from a single locality on ‘Grande Terre’, the main island of the archipelago. The new genus belongs to thePsychrodromini, one of the four tribes in the subfamilyHerpetocypridinae(familyCyprididae).Caledromusgen. nov.can be distinguished from all other herpetocypridinids by a combination of the following factors: the absence of marginal septa in both valves, the mildly developed marginal valve structures, the small Rome organ on theA1, the total reduction of the five natatory setae on theA2, the rectangular second palp segment of theMx1, the broad and asymmetrical palp on the femaleT1, the absence of additional postlabyrinthal coils in theHpand the seta Sp of theCRwhich is a fixed spine. Because of the close similarity to the genusPsychrodromus, the new genus is thought to have Palaearctic affinities, contrary to other ostracod species in New Caledonia, which are either circumtropical or with Australian zoogeographical connections.