Watch List notes:

Thrace, Byzantion in alliance with Kalchedon Æ27. 3rd century BC. Veiled head of Demeter to right; c/m: owl / Poseidon seated to right, holding aphlaston and trident; ΒΥ[ΞΑNT] before, ΚΑΛΧΑ[Δ] behind. Cf. Schönert-Geiss 1257-82; HGC 3.2, 1428. 9.46g, 27mm, 1h.

Very Fine.

From the William Stancomb Collection;
Ex Helios Numismatik, Auction 4, 14 October 2009, lot 18.