BITHYNIA. Kalchedon. Circa 340-320 BC. Siglos (Silver, 19 mm, 5.29 g), Persic standard. KAΛX Bull standing left on grain ear. Rev. Quadripartite incuse square of mill sail pattern. HGC 7, 517. SNG BM Black Sea 112-117. Nicely toned and well centered. Very fine.