Taxonomic revision of the endemic Cameroonian freshwater crab genus Cumberlidge, 1994 (Crustacea, Decapoda, Brachyura, Potamonautidae), with descriptions of two new species from Nkongsamba and Yabassi.

The taxonomy of the freshwater crab genus Cumberlidge, 1994, is reviewed based on type material and newly obtained specimens from three different localities in southwestern Cameroon. The genus is endemic to Cameroon and previously included two species: (Bott, 1969) (type species) from Lake Ossa wetland complex (altitudes below 400 m asl) and (Bott, 1959) from Kumba and Mt. Manengouba (altitudes above 1300 m asl). Here two new species of are described based on morphological and/or genetic data: from the Nlonako Ecological Reserve (1000-1400 m asl) in the sub-montane zone and . from Yabassi in the lowlands. A redescription and amended diagnostic features of and are provided, and the genus diagnosis is updated to accommodate all four species. An identification key is also provided for the species of . A tree of phylogenetic relationships based on three mtDNA loci (COI, 12S rRNA, and 16S rRNA) supports the taxonomic revision, and indicates speciation of species along an altitudinal gradient, but further phylogenetic analyses are needed to understand whether this can lend support to the hypothesis that there is a montane centre of speciation along the Cameroon Volcanic Line. The phylogenetic tree also shows that Cumberlidge, Mvogo Ndongo, Clark & Daniels, 2019 and Cumberlidge & Clark, 1992 are sister genera that may be derived from the lineage.