Kyzikos, Mysia. AE18 semi-autonomous issue. AD 138-161. 4.33 g. 

Draped bust of Kore Soteira right, wearing diadem and necklace, within laurel wreath.
KYZIKHNWN, Triton right, holding rudder and dolphin. 

Paris 196 (but without necklace); SNG France 602 (ditto). 
Rare.

With permission of cngcoins.com, auction 94, Lot 881, Sept 2013.