(Πολύγονος), a son of Proteus, a grandson of Poseidon and brother of Telegonus. The two brothers were killed by Heracles at Torone, when they challenged him to a contest in wrestling. (Apollod. 2.5.9.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890