Roman Republic
Cn. Gellius (138 BC), Denarius 138 BC, Rome mint
Obverse: helmeted head of Roma to right, X to left, laurel-wreath as border
Reverse: Mars in quadriga, right, holding shield in left hand and grasping captive beside him with right hand, CN•GEL below, ROMA in exergue
Diameter 17 mm, weight 3.84 g