Between Chalcedon and Heracleia flow several rivers, among which are the Psillis and the Calpas and the Sangarius, which last is mentioned by the poet.1
The Sangarius has its sources near the village Sangia, about one hundred and fifty stadia from Pessinus. It flows through the greater part of Phrygia Epictetus, and also through a part of Bithynia, so that it is distant from Nicomedeia a little more than three hundred stadia, reckoning from the place where it is joined by the Gallus River, which has its beginnings at Modra in Phrygia on the Hellespont. This is the same country as Phrygia Epictetus, and it was formerly occupied by the Bithynians. Thus increased, and now having become navigable, though of old not navigable, the river forms a boundary of Bithynia at its outlets. Off this coast lies also the island Thynia. The plant called aconite grows in the territory of Heracleia. This city is about one thousand five hundred stadia from the Chalcedonian temple and five hundred from the Sangarius River.