32 CD. Walcott — Position of the Olenellus Fauna. 



feet above tlie Olenellus zone, although a Lower Cambrian 

 species in the Atlantic Province. 



In the Pioche section * the fauna of the Olenellus zone is 

 larger. It includes Eocystites ?? longidactylus ? Lingulella 

 Ella, Kutorgina pannula, Acrothele subsidua, Acrotreta 

 gemma, Orthis Highlandensis, Hyolithes Billingsi, Olenellus 

 Gttlberti, Olenoides levis, Crepicephalus Augusta and C. Lilt- 

 ana. Of these Eocystites ff longidactylus is very doubtfully 

 identified by single plates ; Kutorgina pamda, Acrothele sub- 

 sidua, Acrotreta gemma and Hyolithes Billingsi pass to the 

 zone above or that carrying Olenellus. 



In the Wasatch section of Utah Olenellus Gilberti occurs in 

 a narrow band of arenaceous shale that is subjacent to silico- 

 argillaceous shales, containing a number of species that I form- 

 erly referred to the Olenellus fauna. Restricting the fauna to 

 only those species occurring in association with Olenellus or a 

 grouping of species characteristic of the Olenellus zone, where 

 Olenellus is present, all the species, with the exception of 

 Olenellus Gilberti and Cruziana sp. f, are referred to the 

 Middle Cambrian fauna. 



In the section of Mount Stephen and Castle Mountain, in 

 British Columbia, Mr. McConnellf found the Olenellus fauna 

 at the base of the Castle Mountain limestone ; beneath it there 

 are dark-colored argillites and sandstones, estimated at over 

 10,000 feet in thickness, which correspond in position and 

 character to the pre-Olenellus strata of the Wasatch section, 

 which are referred to the Algonkian Period. In the collection 

 made by Mr. McConnell from the Olenellus zone there are 

 Olenellus sp. ?, Ptychoparia Adamsi and Protypus senectus. 

 The fauna of the Middle Cambrian zone is 2,000 feet higher 

 in the section and includes in the collection made by Dr. 

 Rominger : 



Sponge f 



Lingulella Mc Connelli (sp.) 

 Crania? Columbiana Walcott. 

 Linnarssonia, like L. sagittalis. 

 Acrotreta gemma var. depressa 



Walcott. 

 Kutorgina pannula White. 

 Orthis sp.? 



Orthisina Alberta Walcott. 

 Scenella conula Walcott. 

 Platyceras JRomingera Walcott. 



Hyolithettus. 



Agnostus interstrictus White. 



Karlia Stephenensis White. 



Olenoides Nevadensis Meek. 



Zacanthoides spinosus Walcott. 



Bathyuriscus Howelli Walcott. 



JBathyuriscus (Kootenia) JDaw- 

 soni Walcott. 



Ogygopsis Klotzi Rominger. 



Ptychoparia Cordilleras, Romin- 

 ger. 



* Op. cit.. p. 35. 



f Geol. and Nat. Hist. Survey Canada, Ann. Rept. new ser., vol. h, 1887; 

 Kept. Geol. Structure of a portion of the Rocky Mountains, p. 29 D. 



