Rhantus rugulosus Régimbart, 1899, R. rohani Peschet, 1924, R. colymbitoides Gschwendtner, 1932 and R. tigris sp. n. form a monophyletic group, here referred to as the R. rugulosus-clade. The ground pattern of this group is discussed, and the species are briefly described. R. rugulosus + R. tigris is the sister group of R. rohani + R. colymbitoides. The former is Oriental, the latter Afrotropical. The extant distribution range of the R. rugulosus-clade, i.e., a disjunct range with species occurring either in the Oriental or the Afrotropical region, is explained by Miocene dispersal and late Cenozoic vicariance events.