Watch List notes:

The Collection of Roman Republican Coins of a Student and his Mentor Part III

C. Al. Denarius, Sicily circa 209-208, AR 4.33 g. Helmeted head of Roma r., with loop beneath visor; behind, X. Rev. The Dioscuri galloping r.; below, ROMA in linear frame. Sydenham 191a. RBW 321. Crawford 75/1c.
Very rare. Light iridescent tone and good extremely fine
Ex Sternberg sale XXI, 1988, 220.