BITHYNIA, Kalchedon. Circa 260-220 BC. AR Tetradrachm (28.5mm, 17.05 g, 12h). In the name and types of Alexander III. Head of Herakles right, wearing lion skin / Zeus Aëtophoros seated left; HP monogram in left field, Θ below throne; grain ear in exergue. Price 936 (Callatis); Türkoğlu –; HGC 7, 521. Toned. Good VF. Well centered and struck. Rare.