WA1.< "IT | 



SUMMARY — UTAH AND NEVADA. 



315 



Obolella (like O. pretiosa). 

 Lingula manticula. 

 Kutorgina whitfleldi. 

 Orthis eurekensis. 

 Stenotbeca elongata. 

 Agnostus communis. 



bidens. 



neon. 



ricbmondensis. 



Protypus senectus. 



expansus. 

 Dicellocephalus ? riasutua. 

 Ptycboparia oweni. 



haguei. 



occidentals. 



dissiniilis. 

 Olenoides spinosus. 



Of the succeeding formation, or the Secret Caiion shale, Mr. Hague 

 says: 



The Prospect Mountain limestone passes, by gradual transition, from shaly lime- 

 stoue into brown and yellow argillaceous shales. * * * In their broadest de- 

 velopment they measure 1,000 feet, although in places where they are encroached 

 upon by the Hamburg limestone they occur considerably thinner. 1 



Only a few scattering fossils are found in the lower portion of the 

 Secret Caiion shale, but near the summit of the fauna is large and charac- 

 teristic. It includes, according to Mr. C. D. Walcott, the following : 2 



Protospongia fenestrata. 

 Lingulepis maera. 



minuta. 

 Lingula ? manticnla. 



Iphidea depressa. 

 Acrotreta gemma. 

 Kutorgina minutissima. 

 Hyolithes primordialis. 

 Agnostus communis, 

 bidens. 



neon. 



t 



seclusus. 

 Dicellocephalus ? nasutus. 



Dicellocephalus ricbmondensis. 

 Ptychoparia pernasnta. 



laticeps. 



bella. 



linnarssoni. 



oweni. 



haguei. 



siiuilis. 



unisulcata. 



lsBviceps. 

 Chariocephalus tumifrons. 

 Ogygia ? problematica. 



Of the species in this list DiJcelocephalus % nasutus, and D. riehmon- 

 densis do not belong to the genus Dikelocephalus and the form referred 

 to Ogygia^. problematica represents an uudefined genus. Asa whole, as 

 suggested by Dr. Brogger, this horizon may possibly be referred to the 

 Paradoxides zone. 



.Number 4 of the section, or the Hamburg limestone, is a dark gray 

 and granular limestone; surface, weathering rough and ragged; only 

 slight traces of bedding. Very few traces of fossils were found in the 

 entire 1,200 feet of rocks referred to this formation. 



No. 5, or the Hamburg shale, resembles the Secret Caiion shale except 

 that it is by no means as uniform in composition, showing very rapid 

 changes in conditions of deposition and becoming more or less arena- 

 ceous and calcareous throughout its development as well as in its lateral 

 extension. Throughout its entire thickness of 350 feet fossils are more 



Abstract of Report on Geology of the Eureka District, Nevada. 

 Report, 1881-1882, 1883, p. 255. 

 'Ibid., p. 32. 



TJ. S. Geol. Surv., 3d Annual 



