Watch List notes:

Anonymous. Ca. 199-170 B.C. AR denarius (19 mm, 4.76 g, 3 h). Uncertain mint in Italy. Helmeted head of Roma right; behind, [X] / ROMA in exergue, the Dioscuri riding right; below, GR. Crawford 169/1; Sydenham 289; Sempronia 1. VF, obverse little off center. Very rare. 

Ex RBW collection (not in previous sales); Hirsch 158 (4 May 1988), 276.