NO. I FORMATIONS OF BEAVERFOOT-BRISCO-STANFORD RANGE I3 



The Idaho fauniile is characterized by Monograptiis cf. marri Perner (prob- 

 ably the identical form). 



M. cf. pandiis Lapworth (also so far not distinguishable). 



Cyrtograptus murchisoni Carruthers. 



M. marri and pandus are Gala-Tarannon forms, while Cyrtograptus murchi- 

 soni characterizes the base of the Wenlock in Britain. 



The Idaho fauna may therefore be a little younger than the Sinclair Canyon 

 fauna, but it is in general of the same age. 



Beaverfoot Formation : t- . ^^ . 



reet Meters 



I. Gray, compact, hard, cliff-forming limestone with con- 

 siderable gray chert in nodules, stringers and thin sheets 



or irregular layers. (Estimate) 400 12 1.9 



Fauna. — No fossils were collected on Sinclair Mountain 

 but at a locality a mile (1.6 km.) west and down the 

 canyon the following fauna was found in a few layers 

 of light colored, fine-grained limestone superjacent to 

 the Wonah Quartzite : * 



Cohimnaria alveolata Goldfuss 



Columnaria (Paleophyllufii) cf. stokesi (Edwards and Haime) 



Faz'osites sp. 



Strcptelasma rusticum Billings 



Rhynchotrema argenturbica (White) 



Zygospira cf. recurvirostris Hall 



Plectamhonites cf. sa.veiis (Sardeson) 



Hebertella cf. occidentalis (Hall) 



Dinorthis cf. subquadrata (Hall) 



As the result of his study of the formation. Dr. Kirk reports as follows : 



The Beaverfoot (Richmond) is composed in the main of heavy bedded 

 dolomitic limestones, weathering brownish to lead colored. It seems to vary 

 in thickness in different sections. In the Upper Columbia Lake and Winder- 

 mere Creek sections it apparently does not exceed 200 feet in thickness. In 

 the Sinclair Canyon sections higher beds are present, consisting of thinner- 

 bedded, purer limestones, and here it attains a thickness of about 400 feet. 

 The fauna is identical with that of the upper Bighorn of Wyoming, of the 

 upper portion of the Fremont of Canon City, Colorado, and of the Richmond 

 of Stony Mountain, Manitoba. 



Bcatricea sp. 



Recepfaculites sp. 



Paleofavosites sp. 



Streptelasnia trilobatiim Whiteaves 



Columnaria ah'eolata Goldfuss 



Columnaria (Paleophyllum) cf. stokesi (E. and H.) 



Halysites sp. 



Rhynchotrema cf. capax (Conrad) 



Rhynchotrema argenturbica (White) 



Zygospira cf. recurvirostris Hall 



Plectam,bonites cf. saxeus (Sardeson) 



Hebertella occidentalis (Hall) 



Dinorthis subquadrata (Hall) 



Maclurina sp. 



Endoceras sp. 



^ As identified by Mr. Edwin Kirk. 



