Watch List notes:

MYSIA, Kyzikos. Circa 550-450 BC. EL Stater (20mm, 15.97 g). Head of Acheloös left; to right, tunny upward / Quadripartite incuse square. Hurter & Liewald I 11a = Gulbenkian 607; otherwise, unpublished. Double struck. Near VF. Extremely rare, only four in CoinArchives (Triton XXIV, lot 563; Roma XX, lot 209; Roma XVII, lot 469; and Berk BBS 191, lot 1).

From the Siren Collection.