334 



THE UNIVERSITY SCIENCE BULLETIN. 



Form: The following are the measurements in millimeters of the 

 specimens at hand : 



Length of body 32 to 37 . 5 



Width of head 14.5 to 16.5 



Expanse of fore wings 97 to 110 



Greatest width of fore wing 17 to 18 



Greatest width of operculum 6.5 to 7.5 



Greatest length of operculum 9.5 to 10 



The opercula are distinctly longer than broad if the extension beyond 

 the coxal cavity be included. They overlap slightly for a short distance 

 medially and the posterior margin is broadly rounded, the mesal portion 

 distinctly longer and straighter than the outer part. 



Genitalia: The supra-anal plate of the male is roundingly excavated 

 apically and without a median tooth or with the bare suggestion of a 

 very broad one. The uncus, viewed laterally, is regularly curved and 

 narrowed to the obtuse apex. Viewed caudally it is distinctly triangular, 

 the apex being quite pointed. The ventral piece has the arms deeply 

 and rather narrowly divided to receive the apex of the uncus. The 

 last ventral segment of the male is less than twice as wide as long 

 and the apex is distinctly rounded. The pygofers of the female have 

 a large but acute median spine which strongly exceeds the distinct 

 lateral angles. The last ventral segment of the female is comparatively 

 long, with the lateral margins distinctly sinuate and with the angular 

 excavation of the posterior margin reaching slightly over one-third of 

 the distance to the base. Each of the lateral pieces of the ovipositor 

 bears three faint ridges followed by about ten teeth, the third to sixth 

 of which are large and distinct. 



Distribution: This species seems to be well distributed over 

 the western two-thirds of the state as shown by the following 

 map. Davis reports it from Colorado also. 



