Macedonia uncertain Mint. AR hemiobol,  8 mm. ca. 460-420 BC. 0.49g.

Bridled horse's head right.
Dolphin left within incuse square. 

Tzamalis, 87 var (Nomism. Khronika 18, 1999), (dolphin right). 

With permission of cngcoins.com, auction Triton XIV, lot 57, Jan. 2011.
Estimate: US$500.