Watch List notes:

Bithynia, Kios. Ca. 350-300 B.C. AR hemidrachm (14 mm, 2.15 g, 12 h). Contemporary imitation. Poseidonios, magistrate. Laureate head of Apollo right / Prow of galley left, star on side; above and below, magistrate's name: ΠΟΣΕΙ-ΔΩΝΙΟΣ. Le Rider 358-80; RG 3. VF, toned. 

The odd style of the head of Apollo and the star on the galley, as well as the fact that the obverse lacks the ethnic KIA below the head of Apollo, suggest this coin is imitative.