﻿6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 78 



a gradually increasing depth up to 30 inches on the passes just above 

 timber line. 



Snow scjualls followed nearly every afternoon until August 30, 

 when camp was moved from between Fossil and Skoki Mountains 

 to below the pass at the head of Johnston Creek Canyon. Snow came 

 again on September 5, 9, and 18. Secretary and Mrs. Walcott re- 

 turned to Lake Louise Station, packed their collections and left for 

 Washington on September 21, which was the most beautiful day of 



Fig. 10. — Looking south down Johnston Canj-on from divide at its head, 

 which is formed of limestones of the Ordovician Sarbach formation, in 

 which the canyon has been largely eroded. See figure 2. (Mary Vaux 

 Walcott, 1925.) 



the season. Only eight camps were made while on the trail. It was 

 more through good fortune than favorable conditions that a fine 

 series of fossils from critical horizons in the great lower Paleozoic 

 section north of Bow Valley was discovered and collected. These 

 fossils increase our knowledge of the history and life of the Cor- 

 dilleran Sea of this time and afiford the data for comparison with Ufe 

 and conditions in the Appalachian Trough and the great upper 

 IVIississippi embayment of Upper Cambrian time. 



In the interval between the snow storms of September 5 and Q 

 several new fossil zones were found in the Lower Ordovician rocks 



