Passage 8.54.3
ἀνασχὼν δὲ ἔνθα Πηγὰς ὀνομάζουσιν οἱ Ἀρκάδες καὶ παρὰ γῆν τε τὴν Πισαίαν καὶ παρὰ Ὀλυμπίαν ἐξελθών, ἐκδίδωσιν ὑπὲρ Κυλλήνης ἐπινείου τοῦ Ἠλείων ἐς τὴν θάλασσαν. ἔμελλε δὲ ἄρα μηδὲ Ἀδρίας ἐπισχήσειν αὐτὸν τοῦ πρόσω· διανηξάμενος δὲ καὶ τοῦτον, μέγα οὕτω καὶ βίαιον πέλαγος, ἐν Ὀρτυγίᾳ τῇ πρὸ Συρακουσῶν ἐπιδείκνυσιν Ἀλφειός τε ὢν καὶ πρὸς Ἀρέθουσαν τὸ ὕδωρ ἀνακοινούμενος.
Rising again at the place the Arcadians call Pegae, and flowing onward past the territory of Pisa and Olympia, it discharges itself into the sea beyond Cyllene, the port of the Eleans. But even the Adriatic Sea could not hold back its further advance; having crossed this great and formidable expanse of ocean, it reappears on the island of Ortygia opposite Syracuse, revealing itself there as indeed the river Alpheios and mingling its waters with those of Arethusa.