CERTO´NIUM or CERTO´NUS(Κερτώνιον, Κερτωνός), a place in Mysia, only mentioned by Xenophon (Xen. Anab. 7.8.8), on the road between Adramyttium and Atarneus. It has been conjectured that it may be the Cytonium (Κυτώνιον) of Theopompus (Steph. s. v. Κυτώνιον). But Cytonium was between Mysia and Lydia; and Xenophon's Certonus is in Mysia.
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