NEREUS, the old man of the sea, as his name (comp. νάω, modern Greek νερό, water) denotes, was described in Greek legend as full of wisdom and knowledge, friendly to men, but requiring compulsion before he reveals to them all that he knows. The struggle in which Heracles wrestles and overcomes him is a favourite subject of early Greek art; Heracles, the representative of toiling active man, bends to do his will even the power of the sea, αλιoς γepωv. The fifty daughters of Nereus, the Nereids, are personifications of the smiling, quiet sea with all the gifts which it offers to men. None of the Nereids have any individual character except Thetis, Amphitrite, and Galatea. Thetis and Amphitrite are the queen or mistress of the sea in the legend of different localities; Galatea is a Sicilian figure, who plays with and deludes her rustic lover of the shore, Polyphemus. It is impossible to treat in brief of the religious conceptions on which the mythology of Nereus is founded, or of the connexion between the early representations of Nereus and Heracles and similar subjects in pre-Hellenic art.