432 GEOLOGICAL SURVEY OF THE TEERITOEIES. 



great numbers at any point. I have met with no specimens of CeutJio- 

 pMlus in the middle district; yet I see no reason why they should not be 

 found there; and Dr. Haldeman speaks (Stansbury's Eeport) of the 

 larva of a Phalango])sis among the collections made in Salt Lake Valley. 



Udeopsylla rohusta is rarely met with, though it has a wide range. I 

 do not think I have seen more than fifteen or twenty in the three sum- 

 mers I have traveled over the Western Territories. It is found from 

 Western Kansas to Idaho, on each side of the dividing range. 



EpMppitytlia gracilipes appears to be a southern insect, as it has not 

 been found farther north than Southern Colorado and Northera Arizona. 



Opomola hrachyptera has been observed in the adult state at only one 

 point in the West, on the North Platte, east of the Black Hills; but I 

 have some specimens in the larva state taken in Cache Yalley, Utah, 

 which, I think, belong to this species. 0. bwittata does not appear to 

 extend farther west than the broad plains of Kansas and Nebraska. 

 When we approach the mountains in New Mexico and Colorado it is 

 replaced by 0. neo-Mexieana,. a very closely allied species. 



So far as I am aware, no species of Acridium has yet been traced to 

 the immediate base of the mountains, the western range of the few 

 species that extend upon the plains being confined to the extreme east- 

 ern part of Colorado and western part of Nebraska. 



CaloiJtenus is represented in all parts of the West, as well as through- 

 out the United States. (I cannot speak positively in regard to Cali- 

 fornia.) (7. hivittatus is found east of the range from New Mexico to 

 Montana, and west of it from Salt Lake north to the head-waters of 

 Snake River ; and although it is not mentioned among the collections 

 made in Washington Territory, yet I am of the opinion it will be found 

 there. G. spretus is generally distributed from the Mississippi Eiver to 

 the Sierra Nevada Eange, and north and south from Texas to British 

 possessions. I have traced it west of the range in the middle district 

 from Northern Arizona (I find it among Dr. Palmer's collections made 

 there) to Helena and Deer Lodge, in Montana ; but I have no satisfac- 

 tory evidence of its being found in the western district. G. Dodgei, which 

 is closely related to the Pezotettigi, has been collected only at a great 

 elevation on Pike's Peak. 



: I have not met with G. femur -rubrum west of the mountains, and have 

 some doubt in regard to most of the specimens found in Colorado and 

 Wyoming which are referred to this species, for nearly all I have seen 

 appear to have unspotted elytra, and to be uniformly more slender than 

 the specimens found in the States. At one point in Wyoming I found 

 these and G. hivittatus with the posterior tibia invariably of a bluish- 

 purple color, yet when immersed in strong alcohol they became of a 

 bright purplish-red before the color entirely faded. 



Pesotettix picta, which is a very x^retty insect when living, looking 

 very much like the larva of Bomalea centurio, appears to be confined to 

 Eastern Colorado. P. obesa has been found only on the mountains, be- 

 tween Southern Montana and Idaho, at an elevation of more than six 

 thousand feet. 



The range of the species of (Edipodini will be given in my synopsis, 

 as I have not yet completed the examination of all my specimens of this 

 group. 



The relative numbers of species in the various grou]3S correspond with 

 what might be anticipated from the character of the country. Where 

 broad and comparatively barren x)lains occupy a large portion of the 

 area of the country, it is natural that the Galopteni and (Edipodini 

 should predominate, and that the Locustidw should be less numerous 



