Marcus Aurelius Denarius. 169/170 AD. 

Obv: M ANTONINVS AVG TR P XXIIII, laureate head right 
Rev: SALVTI AVG COS III, Salus standing left, holding scepter & feeding snake 
  on altar from a patera. 

RIC 222, RSC 546.

With permission of cngcoins.com, the AK Collection.