312 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



Feet 

 layers, from a few feet to 30 feet (9.1 m.) in thickness. 

 One of these, 480 feet (146.3 m.) from the base forms 

 a slight terrace 1,655 



Meters 



5044 



Total of Eldon formation 2,728 831.5 



Stephen Formation 

 I. Thin-bedded, dark gray and bluish-black limestone.... 315 96.0 



Fauna. — (57c) : 



Micromitra zenohia Walcott 



Obolus mcconnelli (Walcott) 



Nisusia alberta (Walcott) 



Hyolithes carinatus Matthew 



Agnostus sp. 



Elrathia ? sp. 



Dorypyge sp. 



Bathyuriscus sp. 



2a. Greenish siliceous shale 23 7.0 



Fauna. — (57y) : 



Obolus (Westonia) ella ? (Hall and Whitfield) 

 2b. Thick-bedded, bluish-gray limestone, breaking up on 

 weathering into thin layers ^-inch to. 3 inches (1.3 to 



7.6 cm.) thick 22 6.7 



Fauna. — (582) : 



Micro'mitra zenobia Walcott 



Nisusia alberta Walcott 



2c. Greenish siliceous shale 70 21.3 



2d. Alternating bluish-gray, bedded, compact limestone, sili- 

 ceous and arenaceous shale, mostly shale below 210 64.0 



Fauna. — (S7g) : 



Cruziana sp. 



Micromitra (Iphidella) pannuJa (White) 



Obolus {Westonia) ella (Hall and Whitfield) 



Hyolithes sp. 



" Ptychoparia " sp. 



Glossopleura boccar (Walcott) 

 Total 2 325 99.0 



Total Stephen formation 640 195.0 



The siliceous and arenaceous shale containing the 

 Ogygopsis fauna on Mount Stephen has not been 

 recognized in the Mount Bosworth section. I looked 

 for it in 2a-d (above), but did not find a similar shale 

 or fauna. It was probably a local deposit. 



Cathedral and Ptarmigan ^ Formations 



la. Thin-bedded, gray to lead-gray arenaceous limestones, 



weathering buff-gray to dull light gray 404 123. i 



^ Many fine fossils of the Albertella fauna as it is typically developed to 

 the south above Ross Lake, were collected in the drift on the south slope of 

 Mount Bosworth, indicating the presence of the Ptarmigan formation here 



