"34 ihiii'crsitx of Michigan 



Circotetiix azurcscens (Bruner). — Aledora, July 30, 1920, 

 2 females; Amidon, Aug. 24-25, 1920, 27 males, 8 females. 



Taken only in the valley of the Little Missouri River and 

 its bordering Bad Lands in the southwestern part of the state. 

 It was found on bare clay slopes among the Bad Lands, and 

 was taken on a dry butte covered with a scattered growth of 

 bunch-grasses and sage-brush in the river valley at Medora. 

 It is apparently a much more characteristically xerophilous 

 form 'than either A. carlinianiis or C. rabnla. 



The coloration of this species is light, corresponding in a 

 remarkable way with that of the whitish or grayish clay sur- 

 faces upon which it is normally found. When motionless 

 against such a background it is almost impossible to distin- 

 guish individuals from their surroundings, even when the spot 

 where they are resting has been marked down within a few 

 inches. The disinclination of this form to take flight is prob- 

 ably connected with this fact. It seems to be a remarkably 

 unwary species for a member of this genus ; while alert and 

 ready to take flight, it wall allow a close approach before 

 actually 'taking alarm, and then instead of flying a long dis- 

 tance it usually goes only a few yards, often circling around 

 so as to alight a short distance from where it started. It will 

 continue to do this even after several unsuccessful attempts 

 to capture it have been made. The flight is usually low and 

 direct. The stridulation of Circotetiix azurescens is not loud; 

 it consists of a rapid series of notes — zzzt-zzzt-zzzt-zzzt — 

 uttered at the rate of one and a half or two per second for 

 short periods while in flight. 



LOCUSTIN.^E 



Hypochlora alba (Dodge). — Amidon, Aug. 21-28, 1920, 11 

 males, 3 females. 



