Commentary Purg XII 49-51

In the Thebaid (IV.187-213), Alcmaeon, son of Amphiaraus, the seer (who is, in a certain sense, a stand-in for Statius himself [see C.Inf.XX.31-39]), is left with the task of avenging his father's death.  This came about after his wife, the mother of Alcmaeon, Eriphyle, betrayed his whereabouts to Polynices for the price of a necklace, with the result that Amphiaraus (see [Inf XX 31-36]), who had foreseen the dreadful end of the civil war in Thebes and had hidden himself in order to escape his own death in it, ended up fighting and dying in the war.  He pledged his son to avenge him, which indeed he did do by slaying his own mother.  That the necklace, made by no less an artisan than Vulcan, had belonged to the goddess Harmonia marked Eriphyle's pride in thinking herself worthy of wearing it.  As was the case for Lucifer, the first exemplary figure in this listing, Eriphyle is not named.