CHOEROBOSCUS, GEORGIUS, also called CHARTO PHYLAX (c. A.D. 6o ) , deacon and professor at the oecumenical school at Constantinople. A course of his lectures on grammar has come down to us in the shape of notes taken by his pupils. He drew from the best authorities—Apollonius Dyscolus, Herodian, Orion, Theodosius of Alexandria. These lectures were much used by Constantine Lascaris in his Greek grammar and by Urban of Belluno (end of I 5th century) . Other works : commentary on the canons of Theodosius on declension and conjugation, which is extant; a treatise on orthography, of which a fragment (on quantity) has been preserved; a tract on prosody; commentaries on Hephaestion and Dionysius Thrax; and grammatical notes on the Psalms.