SIDERIS a river of Hyrcania, mentioned by Pliny (6.16. s. 18), which flowed into the Caspian sea.
It cannot be now determined to which river he refers, but he states from it the Caspian sea was called the Hyrcanian. [V]
Dictionary of Greek and Roman Geography, illustrated by numerous engravings on wood. William Smith, LLD. London. Walton and Maberly, Upper Gower Street and Ivy Lane, Paternoster Row; John Murray, Albemarle Street. 1854.