18 PROCEEDINGS OF THE NATIONAL MUSEUM vol. no 



a maximum of 8.5; for the males the average is 8.3, the maximmn 11.0 

 mm. The aedeagus of the shorter-winged of the two males is normal 

 for bilituratus bilituratus, and the cercus is comparatively narrow. 

 The other male, with a wider cercus (fig. 7,g), has the dorsal valve of 

 the aedeagus rather irregular along the lateroanterior margin, but 

 without any indication of spretus. A male with a similarly abnormal 

 dorsal valve was taken in Flathead Co., Mont., July 8, 1917, and its 

 tegmina exceed the hind femora by 5.5 mm. Rehn (1952) noted the 

 considerable variation shown by Alaskan specimens. The folded 

 tegmina of some individuals examined by him scarcely surpassed the 

 apices of hind femora, while those of other individuals exceeded the 

 femora by a distance about equal to pronotal length. 



Rehn and Hebard (1906), under the names intermedius, atlanis, and 

 bilituratus, discussed the variation observed in the cerci and other 

 organs of specimens from various Western States. When recording 

 this grasshopper from Oregon, Fulton (1930) used the name M. 

 mexicanus bilituratus, and he observed that cerci of males vary from a 

 little less than twice as long as middle width to nearly three times as 

 long as broad. He noted that a series from Malin had consistently 

 narrower cerci than those from other Oregon localities. 



It is evident from rearing experiments under different conditions 

 of temperature, relative hmnidity, and food (Parker, 1930) for 

 bilituratus bilituratus (called mexicanus mexicanus), that size, color, 

 spotting of tegmen, length of tegmen, and color of hind tibia vary in 



Explanation of Figure 3 

 Except as noted, lateral views of aedeagus drawn from preparations in glycerine. 



a: Melanoplus spretus: 1, Arapahoe Peak, Colo.; 2, 3, neotype, posterior and lateral views 



of aedeagus, dry preparation. 

 b: M. mexicanus: 1, 18 miles north of Alpine, Tex.; 2, Durango, Mex., lateroventral view 



of aedeagus (p, lateral projection). 

 c: M. bilituratus vulturnus: 1, holotype, dry; 2, Priest Bridge, Md. (m, membranous fold; 



X, carina; y, hooklike apex; z, concave area). 

 d: M. bilituratus defectus, Tempe, Ariz., reared (x, anterior margin; y, flaplike area of 



dorsal valve; z, sinuate margin of flap). 

 e: M. bilituratus bilituratus, Wasaga Beach, Ontario, Canada. 

 /; Intermediate between M. bilituratus bilituratus and M. bilituratus defectus. Baker, Nev., 



dorsal valve only. 

 g: M. bilituratus, uncertain subspecific position, Kokernot Mt., Alpine, Tex., dorsal valve 



only. 

 h: M. bilituratus defectus. Chandler, Ariz. 

 i: M. devastator, Roseville, Calif. 



j: M. borealis borealis, Nachvak Bay, Labrador, Canada. 



k: M. bruneri, Mt. Moriah, Nev. (x, triangular projection of dorsal rim of dorsal valve). 

 /: Same specimen as k, right half of aedeagus in dorsal view. 

 m: M. bilituratus bilituratus, Vancouver Island, British Columbia, Canada, same view as /. 



