Countermark

https://rpc.ashmus.ox.ac.uk/countermark/998 
GIC 780
denominational mark Γ<
circular 
7 mm 
= 3½ assaria. Applied on coins 32-36 mm in diameter 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VI, 5178 (temporary) Show 4409 1 6
RPC X, — (number not assigned), type ID 60883 Show 1706 10 10