16 IOWA STUDIES IN NATURAL HISTORY 
sedges perhaps out-do the composites. Following upon these in 
ever decreasing numbers of species and individuals are the 
Leguminoseae, Liliaceae, ete. 
GENERAL FAUNAL CHARACTERISTICS 
With reference to its fauna, Johnson County is located in the 
Upper Austral Zone,* as is most of the state of lowa, the excep- 
tion being a narrow strip in the north part just below the Minne- 
sota line, which is in the Transitional Zone. The Upper Austral 
is divided into the Carolinian Faunal Area and the Upper So- 
noran Area, lowa falling into the Carolinian Area except for 
the small strip mentioned above. This is the area of the greater 
part of the middle states, and in it are found both the grey and 
the fox squirrel. 
Johnson County, in particular, representing as it does an inter- 
digitation of the forest and prairie, naturally affords a mingling 
of habitats suitable for the animals of both types of environment. 
Thus we may expect to find within a few rods of each other such 
typically forest forms as the grey and fox squirrels, and such 
typically prairie forms as the 13-lined spermophile and the com- 
mon bull snake. 
*Merriam, ‘Life zones and erop zones of the United States, Bulletin No. 10, U. S. 
Department of Agriculture, Division of Biological Survey, 1898, pp. 1-79. 
