Countermark

https://rpc.ashmus.ox.ac.uk/countermark/150 
GIC 30
ΚΟΤΙ before laureate bust r. (Antonine emperor?)
circular 
Applied twice on one example 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC IV, 9978 (temporary) Show 4021 2 4.2
RPC IV, 9978 (temporary) Show 4021 4 4.2
RPC IV, 9978 (temporary) Show 4021 3 4.2
RPC IV, 9978 (temporary) Show 4021 1 4.2