ERIDANUS, in Ancient Geography, a river of Attica, falling into the Ilissus.—Another Eridannus, the more ancient name of the Padus, an appellation ascribed by Pliny to the Greeks; followed in this by Virgil. It rises in Mount Vesulus, in the Alpes Cottice, and dividing the Cisalpine Gaul into the Cispadana and Transpadana, and swelled on each hand with no inconsiderable rivers from the other Alps and the Apennines, falls by seven mouths into the Adriatic. Famous in mythology, from the story of Phaëton; whose sisters, the Heliades, were here changed into poplars, according to Ovid.