1. The Mare Magnum is that which flows from the west out of the Ocean and extends toward the South, and then stretches to the North. And it is called Magnum because the rest of the seas are smaller in comparison with it. It is also called Mediterranean because it flows through the midst of the land (per mediam terram) as far as the Orient, separating Europe and Africa and Asia.
Chapter 20. On the abyss.
1. The abyss is the deep water which cannot be penetrated; whether caverns of unknown waters from which springs and rivers flow; or the waters that pass secretly beneath, whence it is called abyss. For all waters or torrents return by secret channels to the abyss which is their source.
Chapter 21. On rivers.
6. Certain of the rivers have received their names from causes peculiar to them, and of these some which are told of as famous in history should be mentioned.
7. Geon is a river issuing from Paradise and surrounding the whole of Ethiopia, being called by this name because it waters the land of Egypt by its flood, for γῆ in the Greek means terra in the Latin. This river is called Nile by the Egyptians, on account of the mud which it brings, which gives fertility.
8. The river Ganges, which the holy Scriptures call Phison, issuing from Paradise, takes its course toward the regions of India.... It is said to rise in the manner of the Nile and overflow the lands of the East.
9. The Tigris, a river of Mesopotamia, rises in Paradise, and flows opposite the Assyrians (contra Assyrios), and after many windings flows into the Dead Sea. And it is called by this name because of its velocity, like a wild beast that runs with great speed.
10. The Euphrates, a river of Mesopotamia, greatly abounding in gems, rises in Paradise and flows through the midst of Babylonia.... It irrigates Mesopotamia in certain places just as the Nile does Alexandria. Sallust, however, a most reliable author, asserts that the Tigris and the Euphrates arise from one source in Armenia, and going by different ways are far separated, an intervening space of many miles being left, and the land which is enclosed by them is called Mesopotamia. Therefore as Hieronymus noted, there must be a different explanation of the rivers of Paradise.
24. Tanus was the first king of the Scythians, from whom the river Tanais is said to have been named. It rises in the Riphaean forest, and separates Europe from Asia, flowing in the midst between two divisions of the world, and emptying into the Pontus.