Constantius II AE18. 

Obv: DN CONSTAN-TIVS PF AVG, pearl diademed, draped & cuirassed bust right 
Rev: FEL TEMP R-EPARATIO, Soldier standing left, foot resting on shield, 
 spearing fallen horseman wearing a Phrygian helmet, reaching backwards; left 
 field: E; PCON in ex. 

RIC VIII Arles 224, rated R2. 

This issue is the only Fel Temp type with an E (as opposed to an Epsilon) as 
 a field mark.

Contributed by Dane, December, 2008.