AERARII, a class of Roman citizens subject to a poll-tax arbitrarily fixed by the censor (from Lat. aes, in its subsidiary sense of "poll-tax"). They were (1 ) the inhabitants of conquered towns who possessed the ius conubii and ius commercii, but no political rights; Caere is said to have been the first example of this (353 B.c•) (2) full citizens subjected to civil degradation (infamia) owing to their employment or to conviction for crime ; (3) persons branded by the censor. Those who were thus ex cluded from the tribes and centuries had no vote, were incapable of filling Roman magistracies and could not serve in the army. According to Mommsen, the aerarii were originally the non assidui (non-holders of land). The expressions "tribu movere" and "aerarium facere" are explained by A. H. J. Greenidge—the first as relegation from a higher to a lower tribe or total exclu sion from the tribes, the second as exclusion from the centuries. Other views of the original aerarii are that they were : artisans and freedmen (Niebuhr) ; inhabitants of towns united with Rome by a hospitium publicum, who had become domiciled on Roman territory (Lange) ; only a class of degraded citizens, including neither the cives sine suffragio nor the artisans (Madvig) ; identi cal with the capite censi of the Serbian constitution (Belot. Greenidge).