Constantius II, AE Centenionalis, November 6, 355-Spring 360, First Series, Lugdunum, Officina 1
D N CONSTAN_TIVS P F AVG
Composite-diademed, draped, cuirassed bust right
FEL TEMP-REPARATIO
Helmeted soldier standing left, shield on left arm, spearing falling horseman, shield on ground at right, horseman wears pointed cap, turns to face soldier and extends left arm
GPLG in exergue
17mm, 2.42g
RIC VIII, -- (cf. RIC 189, but unlisted with composite diadem type)
Ex Warren Gemmell, detectorist find in United Kingdom and registered with Portable Antiquities Scheme, February 2008

Note: RIC 189 is listed with pearl-diadem. This unusual example is a composite of pearl, rosette and plain diadem with forehead jewel. Nice style.