In their recent paper on theLimes Tripolitanus(JRSxxxix, 81–95), Mr. Goodchild and Mr. Ward Perkins have published an inscription from thecentenariumnow known as Gasr Duib, recording its erection in A.D. 244–246—when M. Iulius Philippus was emperor and his son of the same names still (nobilissimus)Caesar—and naming Cominius Cassianus as governor; and they note that the well-known governor of Numidia, M. Aurelius Cominius Cassianus, is customarily dated A.D. 208, so that ‘unless there has been an error in the reading of the consular names on the significant Lambaesis inscription, we can only conclude that the Cominius Cassianus of the Gasr Duib inscription was a son or relative of the earlier Legatus’ (op. cit. 92). It so happens that the customary dating can now be shown to be wrong, and the governorship in question can demonstrably be assigned to the decade A.D. 240–250 even without the assistance of the new discovery; and so many points of interest arise from a consideration of the evidence, that it seems worth while to set it forth at some length. At the same time, it seems desirable to put forward a revised list of the governors of Numidia from the accession of Severus in 193 to the time of Gallienus, under whom the last of the senatorial governors and commanders-in-chief of that province were appointed; for the list given by Pallu de Lessert is nowhere in need of such considerable revision as for that period, as a result of the fresh epigraphic evidence which has come to light in the past half-century. It will be convenient to take the case of identity first, and to deal with the succession of governors thereafter.