Passage 10.6.5
χρόνῳ δὲ ὕστερον καὶ Πυθὼ τὴν πόλιν, οὐ Δελφοὺς μόνον ἐκάλεσαν οἱ περιοικοῦντες, καθὰ καὶ Ὁμήρῳ πεποιημένα ἐν καταλόγῳ Φωκέων ἐστίν. οἱ μὲν δὴ γενεαλογεῖν τὰ πάντα ἐθέλοντες παῖδα εἶναι Δελφοῦ Πύθην καὶ ἀπὸ τούτου βασιλεύσαντος γενέσθαι τῇ πόλει τὸ ὄνομα ἥγηνται· λόγος δὲ ὃς ἥκει τῶν ἀνθρώπων ἐς τοὺς πολλούς, τὸν ὑπὸ τοῦ Ἀπόλλωνος τοξευθέντα σήπεσθαί φησιν ἐνταῦθα, καὶ διὰ τοῦτο ὄνομα τῇ πόλει γενέσθαι Πυθώ· πύθεσθαι γὰρ δὴ τὰ σηπόμενα οἱ τότε ἔλεγον, καὶ τοῦδε ἕνεκα Ὅμηρος πεποίηκεν ὡς ἡ τῶν Σειρήνων νῆσος ἀνάπλεως ὀστῶν εἴη, ὅτι οἱ τῆς ᾠδῆς αὐτῶν ἀκούοντες ἐπύθοντο ἄνθρωποι.
At a later time, however, the inhabitants around called the city itself Pytho as well, not only Delphi, as indeed Homer does in the Catalogue of the Phocians. Those who desire to derive everything from genealogies state that Pythes was a son of Delphus, and that from him, who was once king, the city acquired its name. But the common tradition among most men says that the serpent shot by Apollo rotted here, and therefore the city's name became Pytho; for the men of that age used the verb pythesthai to describe something rotting. For this reason also Homer wrote that the island of the Sirens was filled with bones, because the people who listened to their singing wasted away ("epython").