20 PROCEEDINGS OF THE NATIONAL MUSEUM vol. no 



response to ecological conditions. For these reasons, and perhaps 

 because of genetic factors as well, bilituratus bilituratus shows much 

 diversity in superficial appearance. This is especially evident in 

 regions where a number of comparatively distinct, large, and relatively 

 stable ecological associations occur; such large and diverse areas occur 

 across southern Canada and in the moim tains. The junior author 

 has attempted to segregate Canadian specimens on the basis of the 

 above and other external characters. In the southern coastal areas of 

 British Columbia and from Vancouver Island there are small to 

 medium-sized, moderately dark, often more hairy specimens, the 

 tegmina frequently barely covering the abdomen. In most of the 

 interior of southern British Columbia (range lands) specimens of 

 moderate size, more brownish, and with red hind tibiae occur. A 

 single series taken at Westbank, British Columbia, in 1923 includes 

 rather large, predominantly yellowish specimens with the tegmina 

 only about long enough to cover the abdomen. In northern British 

 Columbia, Northwest Territories, and in Alaska the type usually 

 developed is very large, blackish, with reddish hind tibiae, and very 

 long tegmina; obviously of the same type but somewhat smaller are 

 specimens from the foothills of Alberta and from the forested regions 

 of Alberta, Saskatchewan, and Manitoba. In the grasslands of 

 southern Alberta, Saskatchewan, and Manitoba the predominant 

 type is of moderate size and grayish, with the tegmina extending 

 scarcely beyond the abdomen, and usually with bluish or buff hind 

 tibiae; in the eastern, more humid part of this area (parklands) the 

 form is similar but more brownish and more often with reddish hind 

 tibiae, very like specimens from interior British Columbia. In 

 Ontario and Quebec specimens are nearly intermediate between those 

 from the forested area of the prairie provinces and from the eastern 

 grasslands, usually have red hind tibiae, and are comparatively 

 stable in appearance. In dry years, during periods of grasshopper 

 abundance, and when there is a trend toward swarming, the grassland 

 types of central Canada develop longer tegmina, are of increased size 

 and paler color, and usually have bluish hind tibiae. By and large, 

 in Canada, observations suggest that most if not all major ecological 

 areas have a smaller, grayer, shorter- winged type during "poor 

 grasshopper years" and a larger, more yeUow, and longer-winged 

 type during "good grasshopper years." These differences seem more 

 noticeable in areas which generally are dry than in those where 

 moisture is abundant. 



Genitalic characters of the populations in different parts of Canada 

 do not differ significantly or consistently enough to warrant, at this 

 stage of our knowledge, the recognition of separate subspecies. It 

 would appear that the superficial appearance of the populations in 



