Passage 5.6.3
τὰ δὲ ἐρείπια ταῦτα πλησιαίτατά ἐστι τοῦ Ἀνίγρου. καὶ Ἀρήνην μὲν ἀμφισβητοίης ἂν μὴ ὀνομασθῆναι τὸ Σαμικόν, τῷ δὲ ποταμῷ Ἀνίγρῳ Μινυήιον τὸ ὄνομα εἶναι τὸ ἀρχαῖον ὡμολογήκασιν οἱ Ἀρκάδες. ὅρον δὲ Ἠλείοις πρὸς τὴν Μεσσηνίαν τῆς Νέδας τὰ ἐπὶ θαλάσσῃ γενέσθαι τις πείθοιτο ἂν ὁμοῦ τῇ ἐς Πελοπόννησον Ἡρακλειδῶν καθόδῳ.
These ruins lie very close to the Anigrus River. Now, though one might dispute that Samicum was once called Arene, the Arcadians themselves do agree that the river Anigrus was originally named Minyeius. One might also reasonably be convinced that, from the time of the Heracleidae's invasion into the Peloponnese, the boundary between the Eleans and Messenia on the coast has been at the river Neda.