SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE SHERZER. 



PLATE XI. 



FIG. I. Line of contact between two "dirt zones," Lefroy Glacier. These zones repre- 

 sent outcropping edges of depositional strata. 



Mitn 



FIG. 2. 'Dirt zones" upon Lefroy Glacier, frequently confused with "dirt bands" of Forbes. Compare figure 2, 



plate XVI. 



