Watch List notes:

CYCLADES, Delos. Circa 308-87 BC. Chalkous (Bronze, 11 mm, 0.99 g, 1 h). Laureate head of Apollo to right; counter marked with a bee in an oval indent. Rev. Δ - Η Kithara; to right, swan standing left. BMC 10. HGC 6, 501. Cf. Joy 511; for the countermark, cf. the Mykonos dichalkon that appeared in CNG MBS 60, 2002, 598. Green and brown patina. Fine.
From the Perioikos Collection, Switzerland.