Watch List notes:

Thrace, Byzantion in alliance with Kalchedon Æ 27mm. 3rd century BC. Veiled head of Demeter to right / Poseidon seated to right, holding aphlaston and trident; ΒΥΞΑN to right, ΚΑΛΧΑ to left. Schönert-Geiss 1271-5; HGC 3.2, 1428. 8.14g, 27mm, 12h.

Extremely Fine.

From the inventory of a UK dealer.