The taxonomic position of the monotypic genusLydomorphusFairmaire 1882 is clarified. The examination of the type series of L.cinammomeusFairmaire 1882 indicated that the large genusCylindrothoraxEscherich 1896 is a junior synonym ofLydomorphus(n. syn.); consequently new combinations for 73 species are proposed. The male syntype is designated as lectotype ofL. cinammomeus.The female syntype belongs toL. angusticollis(Haag-Rutenberg 1880), the closest relative ofL. cinammomeus. L. cinammomeusis redescribed and figured, andCylindrothorax csikiiKaszab 1955 is synonymized with it (n. syn.). Two new subgenera,Pardolydus[including onlyL. dusaulti(Dufour 1821)], andSomalolydus(including species of thebifoveicepsgroup) are described.