Veiled head Roman coin mystery [解決]

I have recently purchased this coin as part of a lot. I have been trying to identify it. The bust reminds me of the Divo Constantine coins, but I can't find the type. To me the reverse looks like a man fighting a lion or something similar. Does anyone know what it might be?

2.5g; ~16.8mm.

Can are roman or greece.i think the head is tyche.

 When I saw the reverse it reminded me of the Nemean lion on a modern coin, as part of a series. 

Moesia, Markianopolis Pseudo-Autonomous Issue Circa 3rd century AD 

Obverse: MAPKIANO????C. Turreted, veiled and draped bust of Tyche right 

Reverse: MAPKIANO?O?IT? / N Herakles standing right, strangling Nemean lion; in field left, club 

References: AMNG I 536; Voegtli 1m; SNG Copenhagen - Size: 20mm, 3.93g 

 As in this coin from Gibraltar. 

N#14621 

 The previous reply has these pictures > 

 Not sure about the lettering. 

Thank you, both. ZacUK, you blow my mind with your numismatic knowledge. Thanks a lot!

It is indeed a civic issue from the 3rd century, a Tyche/Heracles with the Nemean lion type. The inscription says MAΡKIANOΠOΛIΣ on the obverse, and MAΡKIANOΠOΛITΩN on the reverse.