Ănĭo, ēnis, m., = Ἀνίων, Strab., Ἀνίης, Plut. (the orig. form was Ănĭen: non minus quam XV. milia Anien abest, Cato ap. Prisc. p. 684 P.; also in Stat.: praeceps Anien, S. 1, 5, 25; 1, 3, 20. Still Enn., acc. to Serv. ad Verg. A. 7, 683, used the form Anio, ōnis, analogous to the Gr. Ἀνίων; cf. also Anionis in Front. Aquaed. § 92; and, ANIONIS, Inscr. Orell. 3203; and thus, during the whole class. per., Anio remained the principal form of the nom., while the remaining cases of Anien were retained; only Aug. and post-Aug. poets, e. g. Prop. 5, 7, 86; Stat. S. 1, 3, 70, have as an access. form. Ănĭēnus, i; cf. Mart. Cap. 8, 72; Prisc. p. 684 P; Phoc. Ars, p. 1691 P.; Schneid. Gram. II. 148; Rudd. I. p. 60; Neue, Formenl. I. pp. 163, 187),
the classic tributary stream of the Tiber , which , taking its rise in the Apennines , passes along the southern Sabine country , separating it from Latium; and at Tibur , beside its cataract (hence, praeceps Anio, * Hor. C. 1, 7, 13), it presents the most charming natural beauties; now Teverone , Cic. Corn. Fragm. ap. Prisc. p. 684 P.: Anio spumifer, Prop. 5, 7, 81; Ov. M. 14, 329; Plin. 3, 12, 17, § 109 al. The waters of the upper Anio are very pure, and in ancient times aqueducts conveyed them to Rome. The first, called Anio Vetus, was constructed B. C. 271, by M'. Curius Dentatus and Fulvius Flaccus; it began twenty miles from Rome, but wound about for fortythree miles. The second, built by the emperor Claudius, and known as Anio Novus, took up the stream forty-two miles from Rome, and was about sixty miles in length, preserving the highest level of all the aqueducts of Rome, cf. Front. Aquaed. §§ 6, 13, 15; Nibby, Dintorni, I. pp. 156-160; cf. Mann. Ital. 1, 517; Müll. Roms Camp. 1, 157; 1, 229; 1, 241; 1, 306 al.