Antoninus Pius  AR Denarius
Obv:

ANTONINVS AVG PIVS PP, laureate head right.
Rev. COS IIII Pax (or Felicitas), draped, standing left, 
holding branch and long caduceus.

BMCRE 527; Cohen 258; RIC 130.

With permission of cngcoins.com, the AK Collection.