Countermark

https://rpc.ashmus.ox.ac.uk/countermark/511 
GIC 391
caduceus, winged
circular 
4 mm 
The countermark was probably applied at some time before the next issue of coins under Vespasian and was contemporary with GIC 437 (on coins of Agrippina) 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 2153 Show 2153 1 1
RPC I, 2153 Show 2153 2 1
RPC I, 2153 Show 2153 3 1
RPC I, 2153 Show 2153 4 1
RPC I, 2153 Show 2153 5 1
RPC I, 2153 Show 2153 6 1
RPC I, 2153 Show 2153 7 1
RPC I, 2153 Show 2153 8 1
RPC I, 2153 Show 2153 9 1
RPC I, 2153 Show 2153 10 1
RPC I, 2153 Show 2153 11 1
RPC I, 2153 Show 2153 13 1
RPC I, 2153 Show 2153 12 1
RPC I, 2153 Show 2153 14 1
RPC I, 2153 Show 2153 15 1