GRASSHOPPERS — GURNET AND BROOKS 57 



Male genitalia: Cercus (fig. 7,6) broad for group, the apex 

 oblique at ventral side; subgenital plate (fig. 16,a) strongly upturned, 

 twin apices (posterior view) well developed; aedeagus (figs. 2,n; 3,a) 

 with dorsal valve extending laterally more than anteriorly, and re- 

 curved dorsally and posteriorly, conspicuously concave on posterior 

 surface, the apex of valve (dorsally) membranous; accessory lobe 

 comparatively elongate; apex of aedeagus dorsally produced beyond 

 dorsal valve. 



Female genitalia: Cercus slightly more robust and blunt than in 

 mexicanus; dorsal valve of ovipositor with "scoop" well developed, 

 the dorsal shoulder at base angular. 



Coloration: General coloration relatively dark for group. Hind 

 femur with four dark transverse dorsal bands (including knee), inner 

 paginal area rich yellowish, occasionally tinged with pinkish, outer 

 paginal area yellowish to light brown, paler along ventral margin, 

 ventral surface yellowish, the outerhalf tinged with pink; hind tibia 

 usually red; tegmen with conspicuous blackish flecks; wing trans- 

 parent, with faint tinges of yellowish near base. (Brett, 1947, p. 33, 

 reported that of 100 specimens of spretus he examined in the Bruner 

 Collection, University of Nebraska, 85 percent had red hind tibiae 

 and 15 percent glaucous or pale hind tibiae.) 



Variation: The size of 14 representative males, measured in milli- 

 meters, varies in pronotal length from 4.2 to 5.5 (av. 4.8), in hind 

 femur from 11.5 to 14.2 (av. 13.0), and in tegmen from 19.0 to 26.0 

 (av. 22.8). Seven measured females vary in pronotal length from 

 4.8 to 5.4 (av. 5.1), in hind femur from 13.2 to 15.2 (av. 14.2), and 

 in tegmen from 23.0 to 25.5 (av. 24.6). No correlation between size 

 differences and geographic distribution has been recognized. 



The extent to which the tegmen extends posteriorly beyond the 

 apex of hind femur varies from 4.5 to 10 mm., with an average of 

 about 7 mm. for males examined. For females, extremes of 5, and 

 10, and an average of about 8 mm. occur. 



Measurements by Riley, et al. (1878, pp. 47-49), are not compa- 

 rable to the present ones because the former concern the distances 

 that various body structures exceed others. Faure's (1933) measure- 

 ments are expressed in averages only. His averages for length of 

 tegmen are higher than ours, perhaps because more distance at the 

 very base of the tegmen was included through not using the method 

 later recommended by the International' Locust Conference (see ^p. 6 

 of the present paper) . 



Of the males seen, there is none with pale hind tibiae which may 

 not owe the lack of pigmentation to immersion in fluid. The hind 

 tibiae of two or three of the females seem to be pale from original 

 coloration, though fading is suggested by some of the oldest specimens. 



