Kos,Caria, AR tetradrachm, ca 370-345 BC. 23 mm, 15 g. Magistrate Alkimachos. 

Bearded head of Herakles left, wearing lionskin headdress.
KWION ALKIMAXOS, crab, club below; all within dotted square.

BMC 12; Hoover 1302; Traite II-2, 1750a; Karl 348; Pixodarus 27a (this coin). 

With permission of Leu Numismatik AG - Web Auction 19, Lot 1375, Feb 2022