Countermark

https://rpc.ashmus.ox.ac.uk/countermark/346 
GIC 222
female (?) head r. (Tranquillina?)
If the head is not female cmk is probably the same as GIC 98 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VI, 5763 (temporary) Show 5252 8 6