This coin is not listed in RIC or Bastien's Le Monnayage de L'Atelier de Lyon. It should come after RIC VII Lyons 54. This coin was probably struck during the 1st civil war between Constantine and Licinius, or at least during the lead up to it, as this series is not known for Licinius. The special martial bust might also indicate it was struck during the war.
CONSTANTINVS P AVG; laureate and cuirassed bust right with spear over right shoulder and shield on left.
SOLI INVICTO COMITI; Sol rad., raising r. hand, globe in l.; stg. l., chlamys across l. shoulder; across fields A- S.
in ex. PLG
RIC VII Lyons -; Bastien -