Lynceus was the son of Aphareus and Arene, and the grandson of Perseus. He was one of the Argonauts and participated in the Calydonian boar hunt. He had preternaturally keen sight, and could even see things that were underground. He and his brother, Idas, fought with the Dioscuri (Castor and Pollux). Lynceus spied Castor in ambush, enabling Idas to kill him; Lynceus himself, however, was killed by Pollux.