6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. "JJ 



The main objective was to find fossils in the great Lyell hme- 

 stone ^ in order to determine its position in the scheme of classifica- 

 tion. Many attempts have been made during the past six years, but 

 without success, as the thick-bedded, coarse magnesian limestones 

 were uniformly unfossiliferous except for the presence of a few 



I'lij. 8. — Tilted Mountain Falls, west foot of Tilted Mountain and north- 

 east of Lake Louise Station, on the Canadian Pacific Railway, Alberta. 

 Water flowing over thick-bedded magnesian L^pper Cambrian Lyell lime- 

 stones. (C. D. Walcott, 1924.) 



casts of worm trails and the cylindrical structures supposedly built 

 up by the secretions of algal growth, both of which may occur in 

 sedimentary formations from the pre-Cambrian to the present day. 

 In measuring a section from Fossil Mountain (fig. i) eastward 

 into Oyster Mountain, the Lyell limestones were found to form the 

 main north and south ridge, and in two large, glacial cirques cutting 



' Smithsonian Misc. Coll., Vol. 72, No. i, 1920, p. 15. 



