322 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



Feet Inches Meters 

 Eldonia ludwigi layer. 



6. Compact layer of bluish-gray, hard rock that splits more 



or less evenly 8 .2 



7. Alternating dirty- and bluish-gray shale 9 .2 



Hymenocaris perfecta bed. 



8. The same character as 6 : Compact layer of bluish-gray, 



hard rock that splits more or less evenly 8 .2 



9. Dirty-gray, earthy shale 2 .05 



10. The same character as 6 : Compact layer of bluish-gray, 



hard rock that splits more or less evenly i 4 .4 



This is one of the most important fossil-bearing 

 layers — sponges, annelids, holothurians, and crus- 

 taceans. 



11. Dark, dirty-gray, earthy shale 1.5 .05 



12. Bluish-gray, tough, brittle shale 1.5 .05 



7 7 2.3 



This is the prolific Marrella splendens layer. 



A few feet below the base of the quarry a calca- 

 reous shale in layers 2 to 4 feet (.6 to 1.2 m.) thick, 

 with thin layers of limestone, is almost made up of 

 comminuted fragments of trilobites. These beds ex- 

 tend down for 200 feet (60.9 m.) or more, and appear 

 to represent the Ogygopsis shale of the Mount 

 Stephen section. The strata above the shale in the 

 quarry up to the Eldon limestone do not appear to 

 have been deposited at Mount Stephen. A mile 

 (1.6 km.) west of the quarry at Burgess Pass the 

 section beneath the Eldon limestone is composed of 

 compressed and partly altered calcareous shales with- 

 out traces of either the Ogygopsis shale fauna or that 

 of the section at and above the fossil quarry on the 

 west slope of the ridge between Mount Field and 

 Mount Wapta. 



The student will find a description and discussion of 

 the origin of the Burgess shale in Smithsonian Mis- 

 cellaneous Collections, Volume 57, Number 6, 1912, 

 page 148, and papers on the fauna in Volume 57, Num- 

 bers 2, 3, and 5, 191 1 ; Volume 67, Number 5, 1919, 

 and Number 6, 1920. 



OTTERTAIL RANGE 



This range lies west of the Bow Range and south of the Kicking 

 Horse River. It is strange that it does not contain any rocks or 

 faunas related to those in the surrounding ranges. The three forma- 

 tions deposited there are enormously thick, and must have been laid 

 in a seaway which had no connection with those in which the strata of 

 either the Bow Range to the east, or the Stanford-Brisco Range to 

 the west, were laid. 



