PALEOZOIC SECTION IN CENTRAL NEVADA. 



The geologic portion of the accompanying section is taken from the 

 "Abstract of Report on the Geology of the Eureka District, Nevada, by 

 Arnold Hague," contained in the Third Annual Report of the Director of 

 the United States Geological Survey, p. 253. It is introduced to enable 

 the student at a glance to locate in the geologic section the position of any 

 portion of the Paleozoic fauna described in the preceding list. 



All of the Cambrian fauna is included under the head of " Prospect 

 Mountain Group," in the systematic list. 



The Lower Silurian includes the fauna of the Pogonip limestone and 

 the base of the Lone Mountain limestone, only two or three species of corals 

 indicating the presence of an Upper Silurian fauna. 



The Devonian limestones are highly fossiliferous throughout. The 

 fauna is best preserved within 500 feet of the base and summit, the massive 

 beds of the central portions yielding but very few good specimens. 



The White Pine shales in the Eureka District gave but two identified 

 species and fragments of ten others referred to genera. In the White Pine 

 District the fauna is scattered through the shale and embraces fourteen 

 named species and eleven referred to genera. 



The large fauna of the Lower Carboniferous occurs within a range of 

 500 feet above the summit of the Diamond Peak quartzite. Only 24 of the 

 132 species of the Carboniferous fauna occur above that horizon, and of 

 these 10 are present in the lower beds. 



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