548 



THE AMERICAN NATURALIST 



[Vol. LIV 



tation is completed after transformation. Immediately after 

 emerging from the pupal shells, the adults are pale yellowish 

 white, with two large conspicuous jet-black areas on the yellow- 

 ish white prothorax. In a few hours the entire prothorax de- 

 velops this same black pigment am! becomes almost uniformly 

 black. 



In some localities the pupa', in response to special conditions, 

 construct neat little chimneys of earth several inches in height 

 into which their burrows lead. I did not. however, find a single 

 specimen of these unique structures in my locality, although the 

 soil conditions varied greatly. 



At Vinson Station. 1 was afforded an excellent opportunity to 

 observe the occurrence, habits and notes of the dwarf or casinii 

 form as well as the typical, much larger form, since both oc- 

 curred here. Although the earliesl musical expressions of the 

 larger form were heard at my home on May '1A. the distinctive 

 notes of the dwarf form were not heard until nearly a w r eek later. 

 A rather well-defined colony of these smaller cicades appeared in 

 some low, shrubby oaks only a few rods from my home, and re- 

 mained locally abundant here throughout the period of their 

 visitation. It was here that I spent much time in observing their 

 habits. Although the pup» of the larger and the dwarf form 

 emerged from the ground within the same area in some places, 

 and both forms were singing in the same trees and shrubs, both 

 species appeared to mate among themselves. At no time did I 

 observe a single instance of cross-mating. Although now and 

 then I heard an occasional casinii form singing in the nearby 

 woods, this form confined itself almost entirely to the narrow 

 limits of the shrubby oak growths where it first appeared. 



the larger and the smaller forms, for they are entirely different 

 in character. The song of the larger form is a low, and to my 

 ear usually pleasing, droning, — ah-oo — ah-oo — ah-oo — ah-oo — 



