North American Fauna No. 27, U S. Dept. Agr. Biological Survey. 



Plate V. 



Fig. 1.— Tangled Mass of Uprooted Trees, Result of Landslip, 

 Athabaska River. 



Fig. 2. -Muskeg, a Type of Swamp Characteristic of the Athabaska-Mackenzie 



Region. 



Fig. 3.— Bank of Athabaska Above House River, Showing Slide Terraces. 



