218 HEMIPTERA. 



tree seems to have its musician, and the rolhng of their 

 drmns may be heard in every direction. Tliis circumstance, 

 however, does not render it any the less remarkable that the 

 first of the band should keep their appointed time with such 

 extreme regularity. The dog-day harvest-fly measures about 

 one inch and six tenths from the front to tlie tips of the 

 wing-covers, which, when spread, expand about three inches. 



Its body is black on the upper side ; the under side of the 

 head, tlie breast, and the sides of the belly are covered with 

 a white substance resembling flour ; the top of the head and 

 the thorax are ornamented with olive-green lines and char- 

 acters, one of which, in the shape of the letter W, is very 

 conspicuous ; the legs, and the front edge and principal veins 

 of the wing-covers and of the wings are also green, and there 

 is a dusky zigzag spot on the little cross-veins near the tip 

 of the wing-covers ; and the valves beneath the body of the 

 males are wider than long. This species has heretofore 

 been mistaken for the Cicada pridnosa, or frosted harvest-fly, 

 described by Mr. Say, which is found in the Middle States, 

 measures two inches to the tips of the wing-covers, has a 

 white spot each side of the base of the abdomen, a second on 

 the middle of the sides, and a third near to the tip, and has 

 the valves of the males lono;er than wide.* I am not aware 



* The form and pi-oportlons of the abdomhial valves have decided me to sepa- 

 rate the canicularis from Mr. Say's pruinosa, although, with the exception of their 

 difference in size, tliej' present no other constant characters which will invariably 



