GRASSHOPPERS — GURNEY AND BROOKS 71 



occurring in southern (aspen-willow association) localities, the larger, 

 darker form in the north (aspen-spruce association). Both forms 

 contain long-winged and short-winged individuals, often together in 

 one population; the short-winged type usually predominates but 

 occasionally (as in the Cypress Hills in 1952) the long- winged type 

 appears more numerous. 



Descriptive notes: A small to medium-sized, fully winged member 

 of the mexicanus group; closely related to borealis stupefactus, from 

 which it differs primarily in wing length, and to borealis palaceus, 

 from which it differs mainly in the less strongly upturned male sub- 

 genital plate. Males with tegmina usually varying from slightly 

 short of the apex of the abdomen to slightly beyond the abdomen, 

 occasionally a little short of reaching supra-anal plate or at the other 

 extreme with as much as one-fourth of the tegmen reaching beyond the 

 abdomen. Females with tegmina varying from a condition in which 

 about two-thirds of the abdomen is covered to one in which the 

 tegmina extend beyond the abdomen by nearly one-fourth of their 

 length. Posterior third of male abdomen occasionally strongly re- 

 ciu-ved dorsally, especially in specimens from northern Rocky Moun- 

 tains, but usually abdomen is horizontal or only moderately recurved. 



Variation: The size of 12 representative males measured (in 

 millimeters) varies in pronotal length from 3.7 to 4.7 (av. 4.2), in 

 length of hind femur from 9.7 to 12.2 (av. 10.8), and in length of teg- 

 men from 8.4 to 16.4 (av. 12.6). Eight females vary in pronotal 

 length from 4.1 to 5.5 (av. 4.8), in length of hind femur from 10.2 to 

 12.7 (av. 11.4), and in length of tegmen from 11.0 to 16.6 (av. 13.0). 

 The largest specimens are from the northwest, particularly the North- 

 west Territories and Alaska. 



Male genitalia: Cercus (fig. 7, j) variable, usually about as in 

 figure 7,j-l; supra-anal plate with lateral elevations strongly raised; 

 furculae usually strongly tapered, separation evident to base, and 

 scarcely reaching middle of supra-anal plate (fig. 9,c-l), sometimes 

 variable (fig. 9,c-2, c-3) ; subgenital plate in lateral view with dorsal 

 margin varying from essentially straight or slightly upturned apically 

 (fig. lQ,d-l) to moderately upturned, in posterior view with margin 

 usually entire, rarely with an indication of twin apices (fig. ll,c-l); 

 posterior surface of subgenital plate rather evenly rounded, without 

 development of the rectangular-shaped disk usually characteristic of 

 borealis palaceus, as in fig. 1 1 ,d-5. Aedeagus with main stem relatively 

 short; dorsal valve moderately sclerotized but not parchment-like as 

 in bruneri, in dorsal view lacking the triangular projection shown for 

 bruneri (fig, 3,k,l) ; accessory lobe relatively large and frequently 

 directed somewhat laterally; epiphallus as drawn (fig. 8,/). 



