The noun Κύννης is the genitive singular of Κύννα, a proper name referring to the Egyptian city of Canopus (Greek: Κάνωβος). In this passage, Aristophanes uses the local toponym in the genitive to denote 'rays from the eyes of Canopus,' a metonymy where the city stands for its patron goddess Isis (often associated with the star Sirius or the moon in comic exaggeration). The choice of the rare form Κύννης rather than the more common Κάνωπος reflects the poet's preference for archaic or poetic variants to fit the meter and his specific allusion to the 'Canopic' light, which the scholiasts explain as a reference to the brightness of the eyes of the goddess Isis, whose cult was centered at Canopus. This usage is a deliberate comic hyperbole, equating the brightness of the eyes of the character Hermes (or the goddess in the context of the play) with the celestial radiance of the Canopic star.