CALLIRRHOE, in Greek legend, second daughter of the river-god Achelous and wife of Alcmaeon (q.v.). At her earnest request her husband induced Phegeus, king of Psophis in Arcadia, and the father of his first wife Arsinoë (or Alphesiboea), to hand over to him the necklace and peplus (robe) of Harmonia (q.v.), that he might dedicate them at Delphi to complete the cure of his madness. When Phegeus discovered that they were really meant for Callirrhoe, he gave orders for Alcmaeon to be waylaid and killed (Apollodorus iii. 7, 2. 5-7; Thucydides ii. 102). Callirrhoe now implored the gods that her two young sons might grow to manhood at once and avenge their father’s death. This was granted, and her sons Amphoterus and Acarnan slew Phegeus with his two sons, and returning with the necklace and peplus dedicated them at Delphi (Ovid, Metam. ix. 413).