2 University of Michigan 



on this island, on the north side, which is surrounded by a 

 small clearing. 



Habitats and Habitat Distribution. — Except for the rocky 

 shores the island is built up of old dunes of varying size, and 

 is nearly entirely covered with the original forest of oak, 

 maple, birch, ironwood, with a few Norway and white pines. 

 This forest becomes thinner at the south end, where the ridges 

 support a very scattered stand of oak with a ground-cover of 

 grasses. The north beach consists largely of an outcrop of 

 limestone and is the narrowest of beaches. In some places 

 back from the water's edge it has a thin covering of sand. The 

 east beach is wide and sandy with thickets of willow and dog- 

 wood between the bare beach and forest. The south beach is 

 similar to the east one except that it is separated from the true 

 forest by grass-covered ridges, and is very dry. The west beach 

 is the widest and has a large area covered with a sparse growth 

 of coarse dune grass. Other localities noted are Rattlesnake 

 Point, Lighthouse Point and South Point. There is a single 

 pond on the island, surrounded by a grassy marsh which gives 

 place on the north side to a cranberry bog and elsewhere meets 

 the forest. 



The following habitats for ants were distinguished : 



1. Low hardwood forest. On the low ground the woods 

 are damp, dark and cool with little ground-cover except for a 

 few ferns and herbaceous flowering plants. The surface of the 

 ground is covered with dead leaves overlying a rather loose, 

 black leaf-mold. 



2. High hardwood forest. On the ridges the forest is 

 drier and more open than in the swales, with a more complete 

 ground-cover of grasses and other plants. The top mold is 

 looser and drier and the accumulation of dead leaves less than 

 in the preceding habitat. 



