Gallienus, AE antoninianus, Siscia mint. 

GALLIENVS AVG, radiate head right.
SALVS AVG, Salus standing left, holding sceptre and feeding 
serpent rising from altar, P in right field. 

RIC 581K Siscia; Goebl 1462b; Sear -. 

Contributed by Marcy, 2010.