4.QuintiusGallius, so at least his name appears in the best MS., for others read Q. Gallius or Q. Gallus, seems to have been legate of Q. Marcius Philippus, the proconsul of Asia. Two of Cicero's letters (ad Fam. 13.43 and 44) are addressed to him.
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