EDITORIAL 651 
with the drainage, as for example inthe case of Mosquito Creek. 
This stream, whose valley is followed by the Chicago, Rock 
Island and Pacific, and the Chicago, Milwaukee, and St. Paul 
railways, has a quite well developed flood plain and a broad, 
open valley in its upper portion. As it comes within the influence 
of the river loess, the valley is choked and becomes a mere 
narrow defile. This and the other features mentioned are not 
exceptional, but are found at quite distinct points along the 
Missouri, and are of considerable significance in the matter of 
genesis of the loess. There are numerous other items of interest 
relative to the map, but sufficient has perhaps been said to call 
attention to its value. lala Ie. 18): 
™Geology Plymouth county, Iowa Geol. Surv., Vol. VIII, 1898, pp. 324-332. 
