The subscriptions to Paul's epistles are no part of the original. In their present form they are ascribed to Euthalius, a bishop of the fifth century. Some of them are obviously incorrect.
M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition,
published by Thomas Nelson, 1897. Public Domain, copy freely.
Bibliography InformationEaston, Matthew George. "Entry for Subscriptions". "Easton's Bible Dictionary".