Thankfully there is enough information of the coin to solve this puzzle. The clue is the MA on the reverse side. It is specifically used along with the two Victories by Constantius II and Constans at the Arles mint.
This coin is from Constantius II, 337-361 A.D.
Arles mint
Billon reduced centenionalis (average weight of 1.65g and diameter of 15-16mm)
Struck 347-348 A.D.
Obv.: CONSTANTI-VS P F AVG
Rev.: VICTORIAE DD AVGG Q NN
ex: MA (monogram) over PARL (only P is visible)