Οἰωνοῖς μαντευομένους ἀκούω τινὰς καὶ ἐπ’ ὄρνισι καθημένους ἐξετάζειν πτήσεις τε αὐτῶν καὶ ἕδρας. καὶ ᾄδονταί γε ἐπὶ ταύτῃ τῇ σοφίᾳ Τειρεσίαι τε καὶ Πολυδάμαντες καὶ Πολύειδοι καὶ Θεοκλύμενοι καὶ ἄλλοι πολλοί. σπλάγχνων δὲ ἄρα φύσεις καὶ θέσεις καταγνῶναι δεινοὶ ἦσαν καὶ Σιλανοὶ καὶ Μεγιστίαι καὶ Εὐκλεῖδαι καὶ ἐπὶ τούτοις πολὺς κατάλογος.
I hear that someone people practice divination by birds and devote themselves to their study and scrutinize their flight and the quarters of the sky where they appear. And seers like Teiresias and Polydamas and Polyeidus, Theoclymenus and many another are celebrated for their knowledge of this art, while men such as Silanus, Megistias, Euclides, and the long tail of their successors were skilled in deciding upon the dispositions of the entrails. (Loeb, adapted).
Update (25/09/2014) - Plutarch, Comparison of Nicias and Crassus 2.3:
ὁ δὲ Κράσσος ὑψηλὸς περί γε ταῦτα καὶ μεγαλόφρων, οὐ πρὸς Κλέωνας οὐδ’ Ὑπερβόλους μὰ Δία τοῦ ἀγῶνος ὄντος,
ἀλλὰ πρὸς τὴν Καίσαρος λαμπρότητα καὶ τρεῖς τοῦ Πομπηίου θριάμβους οὐχ ὑπείξας,Crassus, indeed, showed a certain loftiness and largeness of spirit in this regard, for he contended not with men like Cleon and Hyperbolus, far from it, but against the brilliant Caesar, and against Pompey with his three triumphs; (Loeb, adapted).