Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
ταυρόδερμος: ἀσπίς, ἡ ἐκ δέρματος ταύρου, Ἰω. Τζέτζ. Ἀλληγ. Ἰλ. Π. 79. - Ἐτέθη ἐν τῷ Θησ. Στεφ. ἄνευ παραπομπῆς εἰς τὸ χωρίον, Συναγωγὴ Λέξ. Ἀθησ. Κουμανούδη.
