Rha

RHA(Ῥᾶ ποταμός, Ptol. 5.9. §§ 12, 17, 19, 21, 6.14. §§ 1, 4; Ammian. 22.8.28; Ῥῶς, Agathem. 2.10: Volga) a river of Asiatic Sarmatia, which according to Ptolemy (l. c.), the earliest geographer who had any accurate knowledge of this longest of European streams, had its twin sources in the E. and W. extremities of the Hyperborean mountains, and discharged itself into the Hyrcanian sea. The affluents which Ptolemy (Ptol. 6.14.4) describes as falling into it from the Rhymmici Montes, and which must not be confounded with the river Rhymmus [RHYMMUS], are the great accession made to the waters of the Volgaby the Kamain the government of Kasan. Ammianus Marcellinus (l. c.) says that its banks were covered with the plant which bore the same name as the river—the rhaor rheonof Dioscorides (ῥᾶ, ῥῆον, 3.11) and rhacomaof Pliny (Plin. Nat. 27.105), or officinal rhubarb. (Comp. Pereira, Mat. Med. vol. ii. pt. 1. p. 1343.) The old reading Rha in the text of Pomponius Mela (3.5.4) has been shown by Tzschucke (ad loc.) to be a mistake of the earlier editors, for which he substitutes Casius, a river of Albania. The OARUS(Ὄαρος, Hdt. 4.123, 124), where, according to the story of the Scythian expedition, the erection of eight fortresses was supposed to mark the extreme point of the march of Dareius, has been identified by Klaproth, and Schafarik (Slav. Alt. vol. 1. p. 499)—who mentions that in the language of some tribes the Volgais still called Rhau —with that river.
[E.B.J]