in Western North America. 205 



Eureka District* Nevada. 



The faunas of the lower part of the Pogonip are but 

 imperfectly known, yet there is more evidence of the Cera- 

 topyge zone than was noted by Broegger. Ilhcnurus eure- 

 kensis is a Symphysurus, and Dikelocephalus finalis an 

 ApatoJcephalus, as pointed out by Broegger. Symphy- 

 surus 9 goldfussi Walcott belongs to the genus Ceratopyge 

 itself, and Asaphus caribouensis is SiHemigyraspis (cran- 

 idium and free cheek only ; the pygidium associated is that 

 of Symphysurus eurekensis). Ptychoparia (Eidoma) 

 affinis is, however, probably not a Euloma. 



The ranges of the fossils in the Pogonip are not very 

 definitely established. Hague gives the thickness of the 

 formation as about 3,000 feet near Eureka, and at White 

 Pine over 5,000 feet. Near the base are such important 

 species as Syntrophia nundina, Hemigyraspis caribouen- 

 sis, and Symphysurus eurekensis. 



"Several hundred feet higher," the fauna contains, 

 among others : 



Schizambon typicalis, Dalmanella liamburgensis, Syn- 

 trophia nundina and ApatoJcephalus finalis. 



From Hague's descriptions, it may be judged that the 

 lower several hundred feet, and probably more than a 

 thousand, hold the Ceratopyge fauna. Receptaculites, 

 Maclu rites and other genera suggestive of Beekmantown 

 appear about midway in the Pogonip, according to him. 

 In one list, Receptaculites, Syntrophia nundina and Sym- 

 physurus are found together and other lists indicate a 

 mingling of Ceratopyge and Beekmantown faunas to 

 within 800 feet of the top. This indicates a much greater 

 vertical range for this assemblage than is known any- 

 where in Europe. In the lower part of the Pogonip, there 

 is a strong admixture of Upper Cambrian species. 



Utah. 



Walcott has described a section in the House Range, 

 Millard County, 15 western Utah. The highest formation 

 of the Upper Cambrian is named the Notch Peak. No 

 fossils were found in place, but a drift-boulder supposed 



4 Walcott, Mon. 8, 1884 ; Hague, Mon. 20, 1892, IT. S. G. S. 



5 Smithson. Miscl. Colls., vol. 53, p. 173, 1908. 



