SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 6 NUMBER 4 



CAMBRIAN 

 GEOLOGY AND PALEONTOLOGY 



No. 4-RELATIONS BETWEEN THE CAMBRIAN AND 



PRE-CAMBRIAN FORMATIONS IN THE VICINITY 



OF HELENA, MONTANA 



(With Plates 39 to 44) 



BY 



CHARLES D. WALCOTT 



(Publication 2416) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



JUNE 24, 1916 



