Occasional Papers of the Museum of Zoology 9 



side, and between Medora and Amidon average 15 to 20 miles 

 across. 



Medora is situated in the valley of the Little Missouri where 

 the Northern Pacific Railroad crosses the river. The eleva- 

 tion of the town is approximately 2,250 feet. Miss Thompson 

 and Miss Olson spent a few days here during July and August, 

 1920. Orthoptera were found in abundance on the dry, sandy 

 flood-plain and the arid clay and sand slopes of the buttes and 

 terraces, among the rather scanty growth of sage-brush, clumps 

 of grasses, low cacti, and other xerophytic vegetation found 

 in these situations ; they were also abundant in cultivated fields 

 on the terraces. 



Conditions at Amidon are more typical of the region as a 

 whole. The town is situated on the uplands, near the edge 

 of the Bad Lands bordering the big bend of the Little Mis- 

 souri River, to the southeast of Medora. The uplands in 

 general are covered with thick, tough sod, but the vegetation 

 of short grasses and low herbaceous plants is scanty and during 

 the greater part of the season appears parched and brown. 

 Rank growths of tall grasses and herbage are scarce, and are 

 confined to small areas in the bottoms of the watercourses. 

 The steep, sandy clay slopes in the Bad Lands are usually 

 nearly bare, but the Bad Lands as a whole are covered with 

 vegetation. The summits of the ridges and the broader level 

 areas are covered with scanty growths of grasses, cacti, etc., 

 and along the "breaks" (where the upland drops away into 

 Bad Lands) there are often quite dense patches of low shrub- 

 bery and small groves or clumps of aspens. Some of the buttes 

 rising above the plain support a growth of shrubs and small 

 trees on their steep, rough slopes ; the vegetation of their flat- 

 topped summits is similar to that of the plain below. Near the 

 "breaks" along the watercourses there are occasional scattered 



