Macrianus AR Antoninianus. 

Obv: IMP C FVL MACRIANVS P F AVG, radiate, cuirassed bust right 
Rev: MARTI PROPVGNITORI, Mars advancing left holding spear & shield. 

RIC 10, RSC 9.

[Imported from dirtyoldcoins.com, apparently from an ancientauctionhouse.com eBay auction]