(Ἀφθόνιος) of Alexandria is mentioned by Philostorgius (3.15) as a learned and eloquent bishop of the Manichacans. He is mentioned as a disciple and commentator of Mani by Photius and Peter of Sicily, and in the form of abjuring Manichaeism. Philostorgius adds, that Aetius had a public disputation with Aphthonius, in which the latter was defeated, and died of grief seven days afterwards.
[P.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890