REHN AND HEBARD 127 



Distribution. — The range of typical gracilipes extends from 

 southern Colorado south to northern Chihuahua, Mexico (Casas 

 Grandes), east to western Texas (Marathon) and west to central 

 (Pine) and central southern (Baboquivari Mountains) Arizona, 

 apparently passing into gracilipes constrida in west central Texas 

 and western Kansas. Of our material that from northern and 

 central New Mexico is most typical, while the specimens from 

 western Texas are not typical, although nearer the present form 

 than gracilipes constricta. The vertical distribution of the present 

 race is, from the evidence of the material before us, from about 2200 

 feet (Tucson) to about 7000 feet (Fort Wingate). 



Biological Notes. — The present form inhabits a variety of coun- 

 try, but usually is found in grama or other grasses varying 

 from six inches to several feet high, which frequently grow in park- 

 like country under mesquite and acacia, and again the insect has 

 been taken in rabbit weed (various species of composites). On 

 numerous occasions it has been taken attracted to light at night. 

 On one occasion it was taken drinking water at the edge of a rock 

 tinaja or basin. It is in general a rather scarce species, although so 

 widely distributed. 



The earliest date we have for the insect is July 22 (Pine, Ari- 

 zona) and the latest October 12 (Tucson). Immature specimens 

 were taken as late as October 11 (Tucson), which shows that the 

 latest date given above is doubtless considerably before the actual 

 latest date of seasonal occurrence. 



Morphological Notes. — The form of the fastigium varies some- 

 what in the male sex, this being as described in the greater portion 

 of the specimens from New Mexico, but narrower in the Arizona, 

 west Texas and Fort Wingate individuals of that sex. The bulla- 

 tion of the pronotum and width of the same across the expanded 

 lateral lobes is less in the individuals from western Texas than in 

 any others, in all the females, however, less pronounced than in the 

 males. The form of the caudal margin of the pronotal disk in the 

 male varies from regularly arcuate to roundly obtuse-angulate 

 regardless of locality, the same margin in the female always more 

 decidedly angulate though equally variable, the immediate angle oc- 

 casionally acute produced. The tegmina of male with three to five 

 rami to the discoidal vein. The abdomen of the male always bears 



TRANS. AM. ENT. SOC, XL. 



