Passage 1.41.3
οὐ πόρρω δὲ τοῦ Ὕλλου μνήματος Ἴσιδος ναὸς καὶ παρʼ αὐτὸν Ἀπόλλωνός ἐστι καὶ Ἀρτέμιδος· Ἀλκάθουν δέ φασι ποιῆσαι ἀποκτείναντα λέοντα τὸν καλούμενον Κιθαιρώνιον. ὑπὸ τούτου τοῦ λέοντος διαφθαρῆναι καὶ ἄλλους καὶ Μεγαρέως φασὶ τοῦ σφετέρου βασιλέως παῖδα Εὔιππον, τὸν δὲ πρεσβύτερον τῶν παίδων αὐτῷ Τίμαλκον ἔτι πρότερον ἀποθανεῖν ὑπὸ Θησέως, στρατεύοντα ἐς Ἄφιδναν σὺν τοῖς Διοσκούροις· Μεγαρέα δὲ γάμον τε ὑποσχέσθαι θυγατρὸς καὶ ὡς διάδοχον ἕξει τῆς ἀρχῆς, ὅστις τὸν Κιθαιρώνιον λέοντα ἀποκτείναι· διὰ ταῦτα Ἀλκάθουν τὸν Πέλοπος ἐπιχειρήσαντα τῷ θηρίῳ κρατῆσαί τε καὶ ὡς ἐβασίλευσε τὸ ἱερὸν ποιῆσαι τοῦτο, Ἀγροτέραν Ἄρτεμιν καὶ Ἀπόλλωνα Ἀγραῖον ἐπονομάσαντα.
Not far from the tomb of Hyllus is a temple dedicated to Isis, and beside it stands another temple sacred to Apollo and Artemis. Alcathous, they say, built it after killing the lion known as the "Cithaeronian lion." By this lion many had been destroyed, among them Euippus, the son of their king Megareus. An elder son named Timalcus had previously been slain by Theseus, when campaigning together with the Dioscuri against Aphidna. Thus Megareus promised his daughter in marriage and succession to his kingdom to the man who should kill the Cithaeronian lion. It was for these reasons that Alcathous, son of Pelops, undertook the fight against the beast, prevailed against it, and later, when he became king, erected this sacred place, naming Artemis "Agrotera" (the Huntress) and Apollo "Agraeus" (the Hunter).