Passage 8.25.12
ἔστι δὲ Τουθόα ποταμός· ἐμβάλλει δὲ ἐς τὸν Λάδωνα καὶ ἡ Τουθόα κατὰ τὸν Θελπουσίων ὅρον πρὸς Ἡραιεῖς, καλούμενον δὲ ὑπὸ Ἀρκάδων Πεδίον. καθότι δὲ αὐτὸς ὁ Λάδων ἐκδίδωσιν ἐς τὸν Ἀλφειόν, Κοράκων ὠνόμασται νᾶσος. οἱ δὲ ἥγηνται τὴν Ἐνίσπην καὶ Στρατίην τε καὶ Ῥίπην τὰς ὑπὸ Ὁμήρου κατειλεγμένας γενέσθαι νήσους ποτὲ ἐν τῷ Λάδωνι ὑπὸ ἀνθρώπων οἰκουμένας, ἃ οἱ πεπιστευκότες μάταια ἴστωσαν·
There is a river called Tuthoa, which also flows into the Ladon. Tuthoa lies along the boundary between Thelpusa and Heraea, an area Arcadians call "Pedion" (Plain). At the point where the Ladon itself empties into the Alpheios, there is an island known as Korakon ("of the crows"). Some believe that Enispe, Stratie, and Rhipe—mentioned by Homer in his verses—were once islands located within the Ladon river and inhabited by men; but those who trust in such accounts should know that their beliefs are in vain.