Countermark

https://rpc.ashmus.ox.ac.uk/countermark/236 
GIC 111 iii
laureate (?) head r.
circular 
7 mm 
possibly applied at Antioch. Head might represent Caligula, under whom no bronze coins were struck at Antioch. 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 3868 Show 3868 28 1
RPC I, 3868 Show 3868 30 1