CALLISTO, in ancient fable, the daughter of Lycæon, king of Arcadia, and one of Diana's attendants. She bore a son, Arcas, to Jupiter, who endeavoured to conceal his amour from Juno by metamorphosing the nymph into a she-bear. In this disguise, through the artifice of Juno, Callisto was slain by Diana; and under the name of Arctos she was placed among the stars. The story of Callisto is variously related by different authors. (See Ovid. Met. ii.; Hygin. Fab. 176, 177; Apollod. iii.)