(Κηφισσός), the divinity of the river Cephissus, is described as a son of Pontus and Thalassa, and the father of Diogeneia and Narcissus, who is therefore called (Cephisius. (Hygin. Fab. Praef.; Apollod. 3.5.1; Ov. Met. 3.343, &c.) He had an altar in common with Pan, the Nymphs, and Achelous, in the temple of Amphiaraus near Oropus. (Paus. 1.34. 2.)
[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