228 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



nary report on the Sabine Mountain section in 1924, to include the 

 shales and intefbedded limestones of the section in the lower Mons, 

 and to compare the subjacent thick-bedded magnesian limestones with 

 the Upper Cambrian Lyell formation of the Glacier Lake section. 

 During the following field season of 1924, a fortunate discovery of a 

 strongly defined Upper Cambrian fauna in interbedded gray lime- 

 stones and shales near the top of the Lyell formation and beneath the 

 Mons in the northern Sawback Range at Tilted Mountain proved that 

 a fauna similar to the one at Sabine Mountain was of undoubted 

 Upper Cambrian age, and also that the genus Briscoia of the lower 

 Mons occurred in association with it. This makes it possible to apply 

 the name Sabine, as used by Schofield, to at least the lower portion of 

 the formation on Sabine Mountain, and strengthens the view that the 

 magnesian limestone beneath the Sabine should be correlated with the 

 Lyell formation of the Sawback Mountains and the upper Saskatche- 

 wan River areas. 



Type locality. — Sabine Mountain, at the south end of the Stanford- 

 Brisco Range, near Canal Flats, British Columbia. 



Character. — Usually rather light colored, granular limestones, filled 

 with fossils. 



Geographic distribution. — This formation occurs to the south of the 

 type locality, at Ram Creek, and to the north in Sinclair Canyon. 

 These three localities are all situated on the eastern margin of the 

 Rocky Mountain Trench. 



It is interesting to note that the Sabine formation occurs also far 

 to the northeast in the Tilted Mountain and Glacier Lake sections. 



Fauna. — The Sabine formation contains a typical Upper Greensand 

 fauna of the Franconia formation as developed in Wisconsin. It 

 contains Ptychaspis, and particularly a close ally of Ellipsocephalus 

 curtiis. 



Lyell Formation. Walcott, 1919, 1923' 



Type locality. — Head of Glacier Lake Canyon at foot of southeast 

 branch of Lyell glacier, and extending along the northern cliffs of 

 Mount Forbes (see pi. 88). 



Derivation of name. — From Lyell Mountain and glacier. 



Character. — Dark and light gray, thick-bedded, hard, more or less 

 siliceous and magnesian rough-weathering limestones of a somewhat 

 uniform character in the Glacier Lake, Sawback Range, and Beaver- 

 foot Troughs. 



* Smithsonian Misc. Coll., Vol. 67, No. 8, 1923, p. 460. 



