Number 123 July io, 1922 



OCCASIONAL PAPERS OF THE MUSEUM OF 

 ZOOLOGY 



UNIVERSITY OF MICHIGAN 



Ann Arbor, Michigan Published by the University 



THE MAMMALS OF WASHTENAW COUNTY, 

 MICHIGAN 



By Norman A. Wood 



Three natural physiographic divisions cross Washtenaw 

 County from northwest to southeast. The northwestern part 

 of the county is occupied by the rough interlobate moraine of 

 loose-textured soil, the Interlobate Lake District ; a broad 

 Clay Morainic Belt occupies most of the central part of the 

 county; and in the southeastern corner of the county. is found 

 a low Lake Plain, once the bed of glacial Lake Maumee. 



The Interlobate Lake District has a conspicuous system of 

 moraines, making up a most irregular land surface. Steep 

 knolls 100 to 200 feet in height are closely associated with, 

 basins, which are often deep, and some of which are occupied 

 by lakes. Small, undrained depressions occur everywhere, 

 producing thousands of acres of swamp and marsh land. 



The Clay Morainic Belt occupies the region from just below 

 Portage Lake to Ypsilanti. It is composed of glacial till plains 



