The cylindropsyllid type genus Cylindropsyllus Brady, 1880 is revised and a new species C. kunzi sp.n. from the North Sea is added. Of the other species a detailed redescription and figures are given, distribution records are compiled and some phylogenetic data are presented. It is suggested that Cylindropsyllus and the monotypic Cylinula Coull, 1971 are sister groups, the latter being the apomorphous lineage because of the unisegmented mandibular palp and the prehensile endopodite P1. Cylindropsyllus sp. Monard, 1935 cannot be assigned to any known species. An amended diagnosis of the genus Cylindropsyllus and a comparison with Cylinula are presented.