Before the conquest of Mithridates, they are named by Appian, 
(de
Bell. Mithridatico, c. 15, tom. i. p. 661, of the last and best edition, by John Schweighaeuser. Lipsiae, 1785 8 vols. largo octavo.)
Xenophon, who had encountered the Colchians in
his retreat, (Anabasis, l. iv. p. 320, 343, 348, edit.
Hutchinson; and Foster's Dissertation, p. liii. - lviii., in Spelman's English version, vol. ii.,) styles them Before the conquest of Mithridates, they are named by Appian, (de
Bell. Mithridatico, c. 15, tom. i. p. 661, of the last and best edition, by John Schweighaeuser. Lipsiae, 1785 8 vols. largo octavo.)