Countermark

https://rpc.ashmus.ox.ac.uk/countermark/266 
GIC 139
laureate bust r.
square 
c. 5 mm 
differentiated from GIC 138 as on later coins 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC IV, 6950 (temporary) Show 2390 1 4.3