NO. 6 



SMITHSONIAN EXPLORATIONS, I914 



ing from the higher points to the valley surrounding the range. 

 Nearly five miles in thickness of rock were measured, and in the 

 limestone belts reefs of fossil algal remains were studied and large 

 collections made with the assistance of Mrs. Walcott and Charles E. 

 Resser and sent on to Washington. 



It was found that the algal remains were deposited very much 

 in the same manner as those that are now being deposited in many 

 fresh-water lakes, and that many of the forms had a surprising 



Fig. 10. — Upper surface of a lens-shaped concretionary-like form which 

 resembles some of the siliceous deposits of the Yellowstone Park hot springs. 

 This form has been named Gallatinia pertexa. Numerous cells such as occur 

 in the Blue-green algje have been found in thin sections of this type of sup- 

 posed algal deposit. 



similarity to those being deposited in the thermal springs and pools 

 of the Yellowstone National Park. 



In the lower portion of Deep Creek Canyon southeast of the city 

 of Helena, a deposit of siliceous shale was examined, where some 

 years ago Dr. Walcott discovered the remains of crab-like animals 



