162 



Eastern Wyoming, from Laramie River to Red Buttes, Minnesota 

 (Thomas). 



Remark. — In the Minnesota portion of Red River Valley, at Glyndon, on 

 the Northern Pacific road, and near Morris, on the Saint Paul and Pacific 

 road, I found a small variety of this genus quite abundant, which, though 

 differing slightly from occidentalis, appears to belong to that species. 



Foveola of the vertex elongate, rounded in front; frontal costa solid 

 above the ocellus and slightly sulcata below it, with a row of punctures each 

 side. The pronotura has the lateral carinse tolerably well-defined and 

 almost right-angled, especially in the male. Elytra and wings about as long 

 as the abdomen in the female. Posterior femora reach the tip of the abdo- 

 men. Antennae extend to the posterior extremity of the pronotum. Pros- 

 ternal spine broadly transverse at the base. The cerci of the male are short 

 and tapering, turning up very shghtly ; the tip of the sub-anal plate is entire, 

 not notched. 



Coloi- of the living insect. — The face is sometimes almost milk-white, 

 with a few luteous or purplish dots sprinkled over it; the cheeks are pale, 

 but a black stripe, quite narrow, runs down the sulcus below the eye ; the 

 usual black stripe behind the eye, extending upon the pronotum, is present, 

 but is very variable. The lateral and posterior margins of the pronotum are 

 bordered by a broad, pale, purplish band; a very narrow white stripe extends 

 down the side of the thorax from the base of the elytra to the insertion of 

 the posterior legs. The elyti-a are almost uniform in color; sometimes a few 

 dim dots can be seen along the middle field, yet many specimens appear to 

 have them unspotted ; the general color is a dark ash-brown, wings trans- 

 parent, tinged with blue ; this bluish cast is very evanescent, almost wholly 

 disappearing from a specimen kept for ten hours, though not immersed in any 

 liquid. The external face of the posterior femora is crossed by three oblique 

 dark and two intermediate white bands; the dark bands cross over to the 

 upper margin of the inner face ; inner face and under side yellow. The pos- 

 terior tibiae pale greenish-blue, generally with a dark ring near the base ; 

 spines black. Tarsi dark above, white beneath. Abdomen dark, mottled 

 above; the posterior margins of the segments bluish-white ; venter yellowish- 

 white. 



Length about 0.8 or 0.9 of an inch. July 5-11. 



