Istros, Thrace, AR Drachm, 6.82 g. 4th C. BC. 

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

AMNG 414; McClean 4354; Mionnet I, 25; Northwick 748; Canarache 52; Dima Razdel hoard, 4, inv. 49.2.159

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