12 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 66 



The season's work was undertaken with two principal objects 

 in view : first, to determine if possible the base line of demarcation 

 between the Lower and Middle Cambrian; and second, to locate the 



CATHEDRAL 



Fig 15. — North profile of ridge above and southeast of Ross Lake, i mile 

 (1.6 km.) south of Stephen Station on the Canadian Pacific Railway. 



The position of the Albcrtclla zone is shown at A where the thin band of 

 shale forming the Ross Lake shale member of the Ptarmigan formation may 

 be seen from the Kicking Horse Pass as a dark narrow band. 



The relative positions of the Cathedral, Ptarmigan, Mount Whyte, and St. 

 Piran formations are indicated on the plate. Photograph by Walcott, igi6. 



exact horizon of a Cambrian subfauna (Albcrtclla) that had in its 

 entirety been found only in drift boulders in the Kicking" Horse 

 Valley east of Wapta Lake. 



