or A'LPHEUS (Ἀλφειός or Ἀλφεός), the god of the river Alpheius in Peloponnesus, a son of Oceanus and Thetys. (Pind. Nem. i. l; Hes. Th. 338.) According to Pausanias (5.7.2) Alpheius was a passionate hunter and fell in love with the nymph Arethusa, but she fled from him to the island of Ortygia near Syracuse, and metamorphosed herself into a well, whereupon Alpheius became a river, which flowing from Peloponnesus under the sea to Ortygia, there united its waters with those of the well Arethusa. (Comp. Schol. ad Pind. Nem. 1.3.) This story is related somewhat differently by Ovid. (Met. 5.572, &c.) Arethusa, a fair nymph, once while bathing in the river Alpheius in Arcadia, was surprised and pursued by the god; but Artemis took pity upon her and changed her into a well, which flowed under the earth to the island of Ortygia. (Comp. Serv. ad Virg. Ecl. 10.4; Verg. A. 3.694; Stat. Silv. 1.2, 203; Theb. 1.271, 4.239; Lucian, Dial. Marin. 3.) Artemis, who is here only mentioned incidentally, was, according to other traditions, the object of the love of Alpheius. Once, it is said, when pursued by him she fled to Letrini in Elis, and here she covered her face and those of her companions (nymphs) with mud, so that Alpheius could not discover or distinguish her, and was obliged to return. (Paus. 6.22.5.) This occasioned the building of a temple of Artemis Alphaea at Letrini. According to another version, the goddess fled to Ortygia, where she had likewise a temple under the name of Alphaea. (Schol. ad Pind. Pyth. 2.12.) An allusion to Alpheius' love of Artemis is also contained in the fact, that at Olympia the two divinities had one altar in common. (Paus. 5.14.5 ; Schol. ad Pind. Ol. 5.10.) In these accounts two or more distinct stories seem to be mixed up together, but they probably originated in the popular belief, that there was a natural subterraneous communication between the river Alpheius and the well Arethusa. For, among several other things it was believed, that a cup thrown into the Alpheius would make its reappearance in the well Arethusa in Ortygia. (Strab. vi. p.270, viii. p. 343; Senec. Quaest. Nat. 3.26; Fulgent. Myth. 3.12.) Plutarch (de Fluv. 19) gives an account which is altogether unconnected with those mentioned above. According to him, Alpheius was a son of Helios, and killed his brother Cercaphus in a contest. Haunted by despair and the Erinnyes he leapt into the river Nyctimus which hence received the name Alpheius