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 
PTARM/GAN 
MT. WHYTE 
Fic 15.—North profile of ridge above and southeast of Ross Lake, 1 mile 
(1.6 km.) south of Stephen Station on the Canadian Pacific Railway. 
The position of the Albertella zone is shown at 4 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, 1916. 
exact horizon of a Cambrian subfauna (Albertella) that had in its 
entirety been found only in drift boulders in the Kicking Horse 
Valley east of Wapta Lake. 
