This is a report of the systematics of the orthopterous families Acrididae and Tetrigidae of Alberta, Saskatchewan, and Manitoba between the forty-ninth and fifty-fifth parallels of north latitude. Comments are made on a nurnber of allied American species of special interest to workers in the area.
Four species of Tetrigidae, representing two subfamilies, and 87 species or subspecies of Acrididae, representing three subfamilies, have been collected in the area. This is less than one-sixth of the total described from North America.