Polydorus (Ancient Greek: Πολύδωρος) son of Hippomedon is an Argive of the Epigoni, the second generation that took Thebes in vengeance for the Seven. Pausanias and Hyginus name him among the avengers; Apollodorus' muster at 3.7.2 omits him — a roll-call disagreement the atlas leaves open. He is distinct from Cadmus' Theban son, from Priam's youngest son, and from Penelope's Zacynthian suitor.
Adapted from Wikipedia, "Polydorus" · CC BY-SA 4.0
I.Epigonos
Hyginus makes him son of Hippomedon and Euanippe daughter of Elatus. Pausanias lists him among the Epigoni who attacked Thebes after their fathers' deaths before the Cadmeia.
Apollodorus' catalogue of the Epigoni does not include this Polydorus, so ancient musters disagree on whether Hippomedon's son marched. The atlas keeps him as the Argive avenger named by Pausanias and Hyginus.
II.Homonyms
This atlas entry (polydorus-epigoni) is Hippomedon's son alone. Distinct from Cadmus' son Polydorus (father of Labdacus), from Priam's Trojan son, from the Ceteian warrior slain by Odysseus, and from polydorus-zacynthus among Penelope's wooers.