Plate XVII 



FIG. 1. The well-developed flat of the Mississippi, near Prairie du Chien, 

 Wis. Scale about 2 miles per inch. (Waukon, la.-Wis., Sheet, TLS.G.S.) 



FIG. 2. A meander of the Missouri River. FIG. 3. Later development of 

 Scale about 2 miles per inch. (Marshall, a meander. Scale as in fig. 2. 

 Mo., Sheet, U. S. G. S.) (Butler, Mo., Sheet, U. S. G. S.) 



