Hypius

Hypius or Hypios (Ancient Greek: Ὕπιος),^[1] also Hyppius or Hyppios (Ὕππιος),^[2] was a river of ancient Bithynia, not far westward from the Sangarius River. The river itself is very small; but at its mouth it is so broad that the greater part of the fleet of Mithridates was enabled to take up its winter quarters in it.^[3] According to the Periplus of Pseudo-Scylax, this river formed the boundary between the territories of the Bithyni and the Mariandyni.^[4]

It is identified with the modern Büyük Melen Su in Asiatic Turkey.^[5]