Passage 8.14.12
ἔστι δὲ ὁ Πέλοψ δῆλος οὐ πολλήν τινα παραπλεύσας θάλασσαν, ἀλλὰ ὅσον ἀπὸ τοῦ Ἀλφειοῦ τῶν ἐκβολῶν ἐς τὸ ἐπίνειον τὸ Ἠλείων. οὐκ ἂν οὖν τό γε πέλαγος τὸ Μυρτῷον ἀπὸ Μυρτίλου τοῦ Ἑρμοῦ φαίνοιτο κεκλημένον, ἀρχόμενόν τε ἀπὸ Εὐβοίας καὶ παρʼ Ἑλένην ἔρημον νῆσον καθῆκον ἐς τὸ Αἰγαῖον· ἀλλά μοι δοκοῦσιν Εὐβοέων οἱ τὰ ἀρχαῖα μνημονεύοντες εἰκότα εἰρηκέναι, λέγοντες ἀπὸ γυναικὸς Μυρτοῦς τῷ πελάγει γεγονέναι τὸ ὄνομα τῷ Μυρτῴῳ.
Pelops is plainly known to have crossed not a very great stretch of sea, but only such distance as lies from the mouth of the Alpheius to the harbor serving the Eleans. Thus, the Myrtoan Sea could not reasonably be said to take its name from Myrtilus, son of Hermes, since it begins from Euboea and extends past the desert isle of Helene into the Aegean. Instead, it seems to me that those Euboeans who have preserved ancient traditions speak plausibly in asserting that the name "Myrtoan" was given to the sea from a woman named Myrto.