Lycus in Harpers Dictionary of Classical Antiquities (1898)

1. Son of Poseidon and the Pleiad Celaeno, married to Dircé. He assumed the government of Thebes after his brother Nycteus, for Labdacus, who was a minor; and, after the death of Labdacus, for his son Laïus. He was either killed by Amphion (q.v.) and Zethus, or (according to another account) handed the government of Thebes over to them at the behest of Hermes. 2. Son of Poseidon, tyrant of Thebes, killed by Heracles for murdering his father-in-law Creon during his absence and for plotting against his wife Megara and his children.