Watch List notes:

Sex. Pompeius. 137 B.C. AR denarius (17 mm, 3.73 g, 12 h). Rome mint. Helmeted head of Roma right; jug behind, X below chin / [SEX · P]O · FOSTLV[S] around, [ROMA] in exergue, she-wolf standing right, head left, suckling the twins Romulus and Remus; behind, birds on fig tree; to left, the shepherd Faustulus standing right. Crawford 235/1a; Sydenham 461; RSC Pompeia 1. Toned VF, typical tight flan, marks in obverse field, tip of nose flattened. 

Faustulus was the shepherd who discovered Romulus and Remus being suckled by the she-wolf and adopted them. The allusion here is that the moneyer's family claimed descent from this legendary shepherd.