Watch List notes:

C. Servilius M.f. AR Denarius, 136 BC. Obv. Helmeted head of Roma right; on the left, wreath and XVI monogram; below, ROMA. Rev. The Dioscuri rearing in opposite directions, with spear reversed; in exergue, C·SERVEIL(dot, instead of I)·M·(two dots, instead of F). Cf. Cr. 239/1 var; Cf. B. 1 var. AR. 3.85 g. 20.50 mm. RRR. Very rare and interesting engraver's mistake. A choice example, well centred on a broad flan, brilliant and lightly toned, with a hint of iridescence. About EF.

Struck by an unfinished obverse die. The engraver omitted to join some ending dots, which are the first step of the engraving.