Occasional Papers of the Museum of Zoology 5 



spending to the gradual nature of the westward increase in 

 aridity. 



There is as yet too Uttle data available on the distribution 

 of the Orthoptera within the state to make generalizations pos- 

 sible, but this fauna will probably be found to resemble the 

 flora in being characterized by comparative uniformity from 

 north to south across the state, but by marked changes from 

 east to west. Most of the species, in common with the vascu- 

 lar plants."* could probably be placed in three broad categories 

 according to their distribution in North Dakota— (i) gener- 

 ally distributed, (2) eastern, and (3) western. Comparatively 

 few could be designated as forms of northern or southern dis- 

 tribution within the state. 



NOTES ON COLLECTING LOCALITIES 

 Red River Valley. — Only a small amount of collecting w^as 

 done in this part of the state. A few days' collecting in the 

 fields and groves bordering the Bois-de-Sioux River at Fargo, 

 and a few specimens from Grand Forks and Pembina give an 

 altogether inadequate idea of the fauna of the valley. 



Drift Prairie Plain. — A. Devils-Stump Lake Region (Devils 

 Lake, Ramsey and Benson counties ; Stump Lake, Nelson 

 County; Sheyenne River, Eddy and Nelson counties). — The 

 region about Devils Lake is typical rolling drift prairie, but 

 little dissected, with glacial lakes occupying many of the 

 depressions. Devils Lake is the largest of these, with Stump 

 Lake next in size ; within a few miles are a considerable num- 

 ber of small lakes and ponds. All of these lakes at a not far 

 distant time occupied a much larger area than they do at 

 present ; the rapid recession of the water in the lakes has left 



* Stevens, O. A., 1920, The Geographical Distribution of North 

 Dakota Plants. Amer. Journ. Bot., vii, pp. 231-242, i fig. 



