Passage 8.34.4
Πελοποννησίων δὲ οἱ τὰ ἀρχαῖα μνημονεύοντες πρότερα τῷ Ὀρέστῃ τὰ ἐν Ἀρκαδίᾳ γενέσθαι φασὶν ὑπὸ Ἐρινύων τῶν Κλυταιμνήστρας ἢ ἐν Ἀρείῳ πάγῳ τὴν κρίσιν, καὶ αὐτῷ κατήγορον οὐ τὸν Τυνδάρεων---περιεῖναι γὰρ οὐκέτι ἐκεῖνον---, Περίλαον δὲ ἐπιστῆναι δίκην καὶ ἐπὶ τῷ αἵματι τῆς μητρὸς αἰτοῦντα ἅτε ἀνεψιὸν τῆς Κλυταιμνήστρας· Ἰκαρίου γὰρ παῖδα εἶναι Περίλαον, γενέσθαι δὲ ὕστερον καὶ θυγατέρας τῷ Ἰκαρίῳ.
But among the Peloponnesians, those who recall ancient traditions claim that Orestes' experiences in Arcadia at the hands of Clytemnestra's Erinyes happened prior to his trial on the Areopagus; and that not Tyndareus—who no longer survived—but Perilaus accused Orestes, bringing a charge against him for his mother's blood, since Perilaus was the cousin of Clytemnestra; for Perilaus was the son of Icarius, and Icarius later also had daughters.