Watch List notes:

Cn. Calpurnius Piso. Ca. 189-180 B.C. AR denarius (18.7 mm, 3.89 g, 10 h). Rome mint. Helmeted head of Roma right; X behind / CN·CALP monogram / ROMA, the Dioscuri on horseback riding right, each holding spear; star above each. Crawford 153/1; Sydenham 348; RSC Calpurnia 1. aVF. 

Ex RBW collection (not in previous sales).