Passage 9.18.1
ἐκ Θηβῶν δὲ ὁδὸς ἐς Χαλκίδα κατὰ πύλας ταύτας ἐστὶ τὰς Προιτίδας. τάφος δὲ ἐπὶ τῇ λεωφόρῳ δείκνυται Μελανίππου, Θηβαίων ἐν τοῖς μάλιστα ἀγαθοῦ τὰ πολεμικά· καὶ ἡνίκα ἐπεστράτευσαν οἱ Ἀργεῖοι, Τυδέα ὁ Μελάνιππος οὗτος καὶ ἀδελφῶν τῶν Ἀδράστου Μηκιστέα ἀπέκτεινε, καί οἱ καὶ αὐτῷ τὴν τελευτὴν ὑπὸ Ἀμφιαράου γενέσθαι λέγουσι.
The road from Thebes to Chalkis passes through these gates, the Proitides. Near the main road is shown the tomb of Melanippus, who was among the bravest of the Thebans in warfare. When the Argives attacked, this Melanippus killed Tydeus and Mecisteus, brother of Adrastus; and they say his own death came at the hands of Amphiaraus.