6 University of Michigan 



to ten feet. The water had drained away in August, leaving the 

 ground bare, though still wet and soft. Under the cover of the 

 buttonbush there is no herbage whatever, and upon the ground 

 there are only a few decaying logs and a few small sticks, which 

 often carry a light growth of moss. 



Around the edges of this swamp there is a narrow belt of 

 thick herbage, closely encroached upon by the typical forest of 

 the flood-plain. 



Fifty mouse traps set in this habitat took eight northern 

 white-footed mice and two house mice the first night, August 5. 



Shore habitat: 



Procyon lotor lolor. Raccoon. Tracks. 



Peromyscus leucopus noveboracensis. Northern white-footed mouse, i. 



Along the shores of the Galien River a narrow strip of bare 

 ground was exposed in July and August. The ground of this strip 

 is mostly mud, but in a few places it is sand or gravel. Usually 

 the habitat is narrow, but in some places it is five to ten feet wide. 



Tracks of raccoon were frequent on the shore along the river. 

 From a few mouse traps set on the bare mud shore one northern 

 white-footed mouse was taken August 4 beside a drift log. 



Mud-bar herbage habitat: 



Peromyscus leucopus noveboracensis. Northern white-footed mouse. 4. 



A few small recently formed mud bars occur along the Galien 

 River in its outer bends. These bars have not yet had time to 

 become forested, and on their outer edges nearest the river there 

 is usually no vegetation, this part being included in the shore 

 habitat. On their older portions next the forest of the flood- 

 plains occurs a thick growth of herbs, several armual grasses, and 

 rarely a willow, Salix sp., or a seedling tree of white elm, Ulmus 

 americana, Cottonwood, Popuhis deltaides, maple, Acer riibrum or 

 saccharinum, and others of the t}-pical flood-plain species. The 

 vegetation during August is very thick, and reaches a height of 



