Watch List notes:

THRACE. Byzantion. 2nd century BC. (Bronze, 19 mm, 3.17 g, 12 h), in alliance with Kalchedon. Head of Athena to right, wearing crested Corinthian helmet. Rev. BYZAN / KAΛXA Bull standing left on grain ear. HGC 3.2, 1431. Schönert-Geiss 1254 (V3/R3). Very rare - only two examples recorded by Schönert-Geiss, and only two additional examples on CoinArchives. Green patina. Rough, otherwise, very fine.
From the Byzas Collection, ex Naumann 80, 4 August 2019, 40.