562 VICTOR E. SHELFORD 
EXPLANATION OF FIGURES 
11 The habitat of C. purpurea limbalis near Glencoe, Illinois, showing several 
stages in the development of the forest on the bluff. The area to the right of the © 
imaginary line between a and 6 is stable enough to support some sweet clover. 
Here the tiger beetle larvae are most abundant. The area between lines joining 
a and b and a and ¢ is in the early shrub stage. To the left of ac the shrubs are 
denser, and larger and some trees are present. 
12 Habitat of C. tranquebarica in the pine zone of the ridges at the south end 
of Lake Michigan. The dark portion in the foreground is the shadow of a tree. 
At the left is the cattail zone of the depression; between a and b, the sedge zone; 
between b and c the zone of high depression plants. The white blossoms here are 
those of Parnassia caroliniana; their distribution, September, 1906, corresponds 
approximately to the distribution of the larvae of C. tranquebarica which arose 
from eggs laid in May and June, 1905. The portion above and to the right of 
c represents the higher portion of the ridge and the habitat of C. scutellaris. 
