Gallienus, AD 265-266. Sole reign. billon antoninianus. 22.4 mm. 3.4 g. Rome. 

GALLIENVS AVG, radiate head right.
MERCVRIO CONS AVG, Criocamp springing right. 
Mintmark: sideways H. 

RIC V-1, Rome 242 (Sole reign); Goebl 0741b; Sear 10289.

With permission of Eidmar auction 3, lot 557 (on biddr.com), March 2024.