Watch List notes:

BITHYNIA. Kalchedon. Circa 387/6-340 BC. Tetradrachm (Silver, 21 mm, 15.06 g), Rhodian standard. KAΛX Bull standing left above grain ear; to left, monogram of YT. Rev. Quadripartite incuse square with stippled surfaces. HGC 7, 509. Cf. SNG BM Black Sea 93-8 (different control). Good very fine.