SUBFAMILY I. TRYXALINJE. 221 



from Montana, Kansas and Nebraska, and Walker (1906, 55) from 

 as far northwest as Yernon, B. C. It is also known from Aweme, 

 Manitoba, and lias been recorded by Brunei' (ISSoa) from Yaki- 

 ma River, Wash., and by R. & H. from Salt Lake City, Utah. 

 Gillette (1904, 24) mentions it as "a very common species on dry 

 grassy slopes over all the eastern portion of Colorado, particularly 

 northward, near and for some distance within the first foothills. 

 Specimens have been taken at an altitude of 8,000 feet. This 

 insect doubtless causes heavy losses on the native pasture lands 

 of the State." 



The name of this species was changed by Thomas (1873, 82) 

 from bicolor to coloradus, the former name being preoccupied in 

 Xlcno'botJirus.. It is therefore mentioned by many of the older 

 authors as Stenobothnts colonuliis Thos. McXeill (1897, 224), 

 when he founded the genus AutpJiitornus, restored the original 

 name bicolor. In many specimens the median dorsal stripe ex- 

 tends only to base of thorax. A variety having the dorsal surface 

 wholly brown was given the name unicolor by Thomas (1873, 81). 



YI. AMBLYTROPIDIA Stal, 1873, 93, 107. (dr., '-blunt" + "keel.") 

 Species of medium size having the head short, obtuse, feebly 

 ascending; vertex with disk convex, sides not raised, median 

 carina low; apex declivent and rounded into the frontal costa, the 

 latter wide, not sulcate, its margins parallel ; antenna? filiform, 

 rather stout, not flattened, slightly shorter than head and thorax 

 in both sexes; pronotum with disk flat, hind margin sharply but 

 obtusely angulate, median carina distinct, cut near the middle, 

 lateral carina? parallel, low but evident; lateral lobes slightly 

 higher than long, front and hind margins nearly vertical, lower 

 one with front portion strongly ascending ; tegmina and wings sur- 

 passing the tip of abdomen ; hind femora stout, their outer face 

 convex; hind tibia? with 13 to 15 spines on outer margin; sub- 

 genital plate of male conical, subacute, feebly ascending, not 

 longer than the preceding segment; valves of ovipositor exserted. 

 Kirby (1910, 114) recognizes 13 species, two of them, one of 

 which is a synonym, from the United States, the others from 

 Mexico, Central and South America. 



94. AMBLYTROPIDIA OCCIDEXTALIS (Saussure), 1861, 317. Blunt-headed 

 Locust. 



Rather robust, moderately compressed. Color variable, ranging from 

 blackish-brown to ashy-gray, the females usually a seal-brown, often with 

 the dorsal surface dull clay-yellow; median carina and upper fourth of 



