Countermark

https://rpc.ashmus.ox.ac.uk/countermark/117 
GIC 1
Apollo, head r.
circular (or slightly oval) 
For the head cf. AMNG vol.3.2, pl.24, 15. 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 1588 Show 1588 5 1
RPC I, 1588 Show 1588 4 1
RPC I, 1588 Show 1588 6 1