Achelōüs
(
Ἀχελῷος). The largest river in Greece. It rises in Mt.
Pindus, and flows southward, forming the boundary between Acarnania and
Aetolia, and falls into the Ionian Sea opposite the islands called Echinades. It is about 130
miles in length. The god of this river is described as the son of Oceanus and Tethys, and as
the eldest of his 3000 brothers. He fought with Heracles for Deïanira, but was
conquered in the contest. He then took the form of a bull, but was again overcome by Heracles,
who deprived him of one of his horns, which, however, he recovered by giving up the horn of
Amalthea (q.v.). According to Ovid (
Met. x. 87), the Naiads changed the horn which Heracles took from
Acheloüs into the horn of plenty. Acheloüs was from the earliest times
considered to be a great divinity throughout Greece, and was invoked in prayers and
sacrifices. Acheloüs was regarded as the representative of all fresh water; hence we
find in Vergil
Acheloïa pocula, that is, water in general. The Sirens
are called Acheloiades, as the daughters of Acheloüs.