A number of Thraco-Macedonian cities issued silver with a facing lion and quadripartite incuse stamp. Yours looks like Akanthos maybe, but it could also be Bosporan.
JA is correct ... Ummm, here are a couple of my examples (sadly, not exactly what you're looking for, but kinda in the ball-park) Bruttium, Rhegion Caria, Mylasa *edit* Oh, it sounds like JA has already scored you an answer (the dude is clever)
Something like this but one denomination larger... Tauric Chersonesos, Pantikapaion AR Triobol. Late 6th-early 5th century BC. Facing lion's head / Quadripartite incuse square. Frolova, Frühe, Type II (unlisted dies); MacDonald 3/2; Anokhin -.
Those are actually pretty cool. The Bruttium like the one @stevex6 posted, but mainly the Chersonesos like @John Anthony posted are on my want list. Not on top but somewhere in the middle. I always thought they looked on the awsome side.