Watch List notes:

BITHYNIA, Kalchedon. Circa 245-240 BC. AR Tetradrachm (30mm, 16.16 g, 12h). In the name and types of Lysimachos. Diademed head of the deified Alexander right, with horn of Ammon / Athena Nikephoros seated left, left arm resting on shield, spear behind; monograms to inner left, outer right, and in exergue. Marinescu Issue 27, 65 (O26/R60); HGC 7, 524. Some roughness. VF. Extremely rare, one of three examples known for this issue, the other two in public collections (Athens and the ANS).