Watch List notes:

SELEUCIS and PIERIA, Antioch. Gaius (Caligula), with Agrippina Senior. AD 37-41. AR Tetradrachm (26mm, 14.25 g, 12h). Dated RY 2 (AD 37/8). Laureate head of Gaius right / Draped bust of Agrippina Senior right; B (date) above ET to right. McAlee 223; RPC I 4165; Prieur 64. Toned, light roughness, hints of iridescent tone. Fine. Very rare, five known to Prieur, and four in CoinArchives.

From the D.K. Collection.