C. D. Walcott — Camhrian Fossils from Mt. Stephens. 163 



21. Buff to pinkish argillaceous shale, with fossils, and a 



few interbedded layers of limestone from 3 to 15 

 inches thick 125 



Fossils : Eocystites ff longi 'dactylics, Lingulella Ella, 

 Eutorgina pannula, Hyolithes Billing si, Ptyaho- 

 paria Piochensis, Zacanthoides typioalis, Bathyur- 

 iscus Howelli and B. producta. 



22. Massive-bedded, siliceous limestone; weathering rough 



and broken into great belts, 200 to 300 feet thick, 

 by bands of color in light gray, dark lead to bluish 

 black ; on some of the cliff faces the weathered sur- 

 face is reddish 1,570 



23.* Bluish black limestone in massive strata, that break 

 up into shaly layers on exposure to the weather. 

 The latter feature is less distinct 850 feet up, and 

 the limestone becomes more siliceous, with occa- 

 sional shaly beds __ 1,430 



Fossils : Near the summit specimens were found that 

 are referred to Ptychoparia minor. 



Summary of Section. 



1. Quartzite 350 



2. Limestone and shales (argillaceous and arenaceous) 1,450 



3. Massive limestone 3,000 



4,800 



At the horizon of Nos. 2 and 3 of the section, the Olenellns 

 or Middle Cambrian fauna occurs ; a fauna whose stratigraphic 

 position is known in several sections. The next well-marked 

 grouping of fossils occurs in No. 21, where, in the section 

 and at a corresponding horizon in the Pioche section, the 

 species mentioned in No. 21 were found. Of this fauna the 

 two following species occur in the collection from Mt. Steph- 

 ens, viz : Zacanthoides spinosus and Bathyuriscus Howelli. 

 The same type of fauna occurs in the Cambrian section of 

 the House range, at Antelope Spring, Western Utah, where, of 

 the species found at Mt. Stephens, there occur : Agnostus inter- 

 strictus and Olenoicles Nevadensis. 



Acrotreta gemma is found in No. 2, in the Highland section, 

 near Pioche, Nevada, and it ranges up into the Upper Cam- 

 brian, in the Eureka District. Hyolithellus micans, although 

 a common Middle* Cambrian species, lias not been identified, 

 heretofore, west of New York. 



Of the eight species found at Mt. Stephens, six are strati- 

 graphically located in the Cambrian system. Two species — 

 Ogygia ff Klotzi and Ptychoparia Coi'dillerw—are unknown 

 to me from any other locality. 



* Quite a fauna occurs in 23, as found one mile farther south ou the liue of section. 



