HERMUS, (anc. geog.), a river of Ionia; which rising near Doryleum, a town of Phrygia, in a mountain sacred to Dindymene or Cybele, touched Mysia, and ran through the Regio Combausta, then through the plains of Smyrna down to the sea, carrying along with it the Paëtolus, Hyllus, and other less noble rivers. Its waters were said to roll down gold, by Virgil and other poets.