Passage 8.5.1
Λυκούργου δὲ ἀποθανόντος Ἔχεμος ὁ Ἀερόπου τοῦ Κηφέως τοῦ Ἀλέου τὴν Ἀρκάδων ἔσχεν ἀρχήν. ἐπὶ τούτου Δωριεῖς κατιόντας ἐς Πελοπόννησον ὑπὸ ἡγεμόνι Ὕλλῳ τῷ Ἡρακλέους Ἀχαιοὶ περὶ ἰσθμὸν τὸν Κορινθίων κρατοῦσι μάχῃ, καὶ Ἔχεμος ἀποκτίννυσιν Ὕλλον μονομαχήσαντά οἱ κατὰ πρόκλησιν. τάδε γὰρ ἐφαίνετο εἰκότα εἶναί μοι μᾶλλον ἢ ὁ πρότερος λόγος, ἐν ᾧ βασιλεύειν τε Ἀχαιῶν τηνικαῦτα Ὀρέστην ἔγραψα καὶ Ὕλλον καὶ Ὀρέστου βασιλεύοντος ἀποπειρᾶσαι καθόδου τῆς ἐς Πελοπόννησον. φαίνοιτο δʼ ἂν τῷ ὑστέρῳ τῶν λόγων καὶ Τιμάνδρα συνοικήσασα ἡ Τυνδάρεω τῷ ἀποκτείναντι Ὕλλον Ἐχέμῳ.
After the death of Lycurgus, the Arcadians were ruled by Echemos son of Aeropos, son of Cepheus, who was the son of Aleus. In his reign, the Dorians under the leadership of Hyllus, the son of Heracles, attempted to invade the Peloponnese. The Achaeans engaged them in battle near the Isthmus of Corinth, and Echemos, accepting a challenge to single combat, killed Hyllus. This version of the event seems to me more plausible than an earlier account I wrote, in which I said Orestes was then king of the Achaeans and that Hyllus tried to invade the Peloponnese during Orestes' reign. The later account might also be confirmed by Timandra, daughter of Tyndareus, who is said to have married Echemos, the slayer of Hyllus.