Pontos, Gorgonian head on shield 

Amisos, Pontus, AE22, (7.22g) Time of Mithradates VI, c. 80 BC,
     Gorgonian head on shield. / 
AMISOU, Nike advancing right, with palm over shoulder,
     monograms above and below. 

SNG BMC 1188-1189. 

Courtesy of Münzen & Medaillen GmbH (DE), Auction 13
Closed 9th October 2003, lot 237.
J.P. Righetti Sale, Part III