In Virgil, Scylla, the daughter of Nisus, is confused with the sea-monster, the daughter of Phorcys.
According to Roscher (in his Lexikon der Mythologie), who identifies the ciris with the heron, the story of Nisus and Scylla (like these of Acdon, Procne, Philomela and Tereus) was invented to give an aetiological explanation of the characteristics of certain birds.
It was no time for brilliant initiative or adventurous politics; the need was to avoid Scylla and Charybdis, and a via media had to be found in church and state, at home and abroad.
The metamorphoses of Scylla and of Picus, king of the Ausonians, by Circe, are narrated in Ovid (Metamorphoses, xiv.).
After encountering many adventures in all parts of the unknown seas, among the lotuseaters and the Cyclopes, in the isles of Aeolus and Circe and the perils of Scylla and Charybdis, among the Laestrygones, and even in the world of the dead, having lost all his ships and companions, he barely escaped with his life to the island of Calypso, where he was detained eight years, an unwilling lover of the beautiful nymph.