Constantius II, AE3, Nicomedia.

DN CONSTAN-TIVS PF AVG, pearl diademed, draped, cuirassed bust right.
FEL TEMP RE-PARATIO, soldier spearing fallen horseman who is 
wearing a Phrygian helmet, no beard, clutching horses's neck.

Mintmark: SMNB

RIC VIII Nicomedia 65 var (no fieldmark), Rare

Gordon Jensen's collection, Nov. 2010
Gordon also has a similar Nicomedia 65 var with SMNA.