Countermark

https://rpc.ashmus.ox.ac.uk/countermark/146 
GIC 26 ii
Eastern potentate, bust l., wearing diademed tiara (without letter)
oval 
10 x 6.5 mm 
attribution to Edessa likely, but not certain 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 4246 Show 4246 10 1
RPC I, 4264 Show 4264 18 1
Show 12
RPC I, 3868 Show 3868 32 1