In modern editions of Photius’ Bibliotheca the partition of chapters dedicated to Aelius Aristides’ Platonic orations (247-248) is based only on manuscript Marcianus graecus 451. In this paper, I’m aiming at a different division of these chapters based on manuscript Marcianus Graecus 450, with the support of several kind of data drawn from the Aristidean textual tradition. Furthermore, I intend to determine some other features of the manuscript after which Photius’ chapters are patterned.