Maynooth. MAYENNE (anciently Meduana), a river of France, rises in the hills of the department of Orne, near Pré-en-Pail, and flows westward till its confluence with the Varenne. It then takes a southerly direction, and empties itself into the Loire. In the upper part of its course it is inclosed between rocky banks; but from Laval, where it becomes navigable, it flows southward with a broad and deep current through extensive and beautiful meadow-lands. The principal towns on its banks are Mayenne, Laval, Entrames, and Château-Gonthier. It receives, from the right, the Ernée and the Oudon, and from the left the Aron and the Jouanne. Its total length is 125 miles, and it is navigable for 55 miles.