Passage 8.24.2
ὁ δὲ ἀληθέστατος τῶν λόγων ἐστὶν Ἔρυκος τοῦ ἐν Σικανίᾳ δυναστεύσαντος παῖδα εἶναι τὴν Ψωφῖδα, ᾗ συγγενόμενος Ἡρακλῆς ἀγαγέσθαι μὲν αὐτὴν ἐς τὸν οἶκον οὐκ ἠξίου, καταλείπει δὲ ἔχουσαν ἐν τῇ γαστρὶ παρὰ Λυκόρτᾳ, ξένῳ μὲν ὄντι αὐτοῦ, παροικοῦντι δὲ ἐν πόλει Φηγίᾳ, πρὸ δὲ τοῦ Φηγέως τῆς βασιλείας Ἐρυμάνθῳ καλουμένῃ· ἐπιτραφέντες δὲ αὐτόθι Ἐχέφρων καὶ Πρόμαχος Ἡρακλέους τε ὄντες καὶ τῆς γυναικὸς τῆς Σικανῆς μετέθεντο τῇ Φηγίᾳ τὸ ὄνομα Ψωφῖδα ἀπὸ τῆς μητρός.
But the most accurate of the accounts is that Psophis was the daughter of Eryx, who reigned in Sicily. When Heracles had relations with her, he did not think it proper to bring her into his own household; instead he left her pregnant with Lycortas, who was his friend, residing in the city called Phegia at that time, but earlier named Erymanthus before the reign of Phegeus. Echephron and Promachus, who were born and raised there and were the children of Heracles and the Sicilian woman, changed the name of the city from Phegia to Psophis after their mother.