Watch List notes:

Denarius after 211, AR 3.77 g. Helmeted head of Roma r.; behind, X. Rev. The Dioscuri galloping r.; below, ROMA in linear frame. Sydenham –. RBW 372. Crawford 88 ~.
Wonderful iridescent tone and good extremely fine

According to R. Russo this coin, despite being without symbol, is definitely an unrecorded variety of the second spearhead series for stylistic reasons.