Watch List notes:

M. Opimius. Denarius, 131 BC. Obv. Helmeted head of Roma right; behind, tripod; below chin, barred X. Rev. Apollo in biga right; below, M·OPEIMI; in exergue, ROMA. Cr. 254/1; B. (Opeimia) 16. AR. 3.77 g. 18.00 mm. Partly toned. About VF. The moneyer is presumably the brother of L. Opimius.