Istros, Thrace, AR drachm, 5.82 g. 4th C. BC. 

Two male heads facing, the left inverted.
ISTRIH, sea-eagle left on dolphin, Greek Z beneath eagle's tail, 
D beneath dolphin. 

Rauch 97, 87. Var of BMC 9 and AMNG 431 (both with H under tail). 

With permission of H. D. Rauch GmbH - Auction 97, Lot 87, April 2015.