or MECHI'LIUS or MECIILIA'NUS. The Codex Theodosianus contains frequent notice of this magistrate, who appears to have been Corrector Lucaniae et Bruttiorum under Constantine the Great, A. D. 316 (12. tit. 1. s. 3), proconsul of Africa in the same reign, A. D. 324 (12. tit. 1. s. 9), consul with Pacatianus, A. D. 332, and praefectus praetorio, or, as Gothofredus thinks, praefectus urbi, sc. Romae, under the sons of Constantine, A. D. 339 (6. tit. 4. s. 3, 4, 7). An Hilarian appears, but without any note of his office, in a law of A. D. 341. This is probably Mecilius Hilarian; but the Hilarianus or Hilarius (if indeed he be one person) who appears in the laws of the time of Gratian and Valentinian II., and of Honorius, as praefectus urbi, A. D. 383, and as praefectus praetorio, A. D. 396, must have been a different person. Perhaps the last is the Hilarius mentioned by Symmachus. (Symmachus, Epist. lib. 2.80, 3.38, 42, ed. Paris, 1604; Gothofred. Prosop. Cod. Theodos.)