SILVER PEAK. 189 



together with paleontological eAndence, may lie readily correlated with the 

 lower part of the Cambrian of Eureka and the Highland Range. The 

 thicknesses are estimated. The section is as follows :' 



South end of Thnpahute Range. Eastern Nevada. 



Feet. 



1. Heavy bedded gray limestone, light and dark 400 



2. Yellow argillaceous shale: 



(a) Yellow shale 350 



(6) Yellow sandstone 75 



(c) Yellow and green shale, with fillets of fossiliferous limestone 



(Conocori/phe) 500 



925 



3. Purple ripple-marked vitreous sandstone, with bands of siliceous shale. . . 1, 000 



Total 2, 325 



The lower bed con-esponds to the Prospect Mountain quartzite. In the 

 overlying yellow shale he collected a few fossils, determined by Mr. Wal- 

 cott as OleneUus gilberti and 0. iddingsi. 



Silver Peak.— Still farther west, in a bed of yellowish bi-own limestone 

 with intercalated gray argillaceous shales at Silver Peak, a small collection 

 of fossils was made, which Prof. J. D. Whitney'^ placed before the Cali- 

 fornia Academy of Sciences as early as 1866. At that time he regarded 

 them as Upper Silurian or Devonian. Quite recently Mr. Walcott^ has ex- 

 amined the collection and determined the following species: 



Archsocyathus atlauticus. KutorgLna (like K. cingulata). 



Archfeocyathus, undt. sp. Hj'oUthes princeps. 



Ethmophyllum whitneyi. Oleuellus gilberti. 



Stiephochetus? sp. ? 



A number of species proved to be identical with those found on the 

 coast of Labrador and the horizon is evidently the equivalent of the Georgia 

 or Lower Cambrian formation of Prosj)ect Mountain. He also determined 

 OleneUus gilberti as closely resembling OleneUus thompsoni from L'Ause au 

 Loup. 



'Geographical Surveys West of One hundredth Meridian. Washington, 1875. vol. .^, p. 169. 

 «Proc. Cal. Acad. Sci., vol. 3, p. 270. 



' Second Contribution to the studies on the Cambrian Faunas of Korth America. U. S. Geol. 

 Surv. Bull. No. 30, 1886, p. 38. 



