Countermark

https://rpc.ashmus.ox.ac.uk/countermark/960 
GIC 844 ii
ANTO C I V (or VI), laureate head of M. Aurelius, facing r. (on silver coins)
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC II, 1810 Show 1810 14 2
RPC II, 1801 Show 1801 43 2
RPC II, 1803 Show 1803 37 2