Istros, Thrace, AR Drachm, 6.76 g. 4th C. BC. 

Two male heads facing, the right inverted.
ISTRIH, sea-eagle left on dolphin, X beneath eagle's tail. 

AMNG 413; BM Black Sea 236; BMC 3; Berlin 12; Canarache 26; Dima Razdel hoard, 3, inv. 49.1.60

Image courtesy of Mihai Dima, "The Razdel Hoard".