156 THE CAMBRIAN. [buluSL 



In the Sixth Annual Report of the U. S. Geological Survey of the 

 Territories, Prof. F. H. Bradley states that his section along the Wa- 

 satch range of Utah is not complete. The bedded quartzites, referred 

 to the Potsdam from the character of the overlying strata, rest uncon- 

 formably upon the " Metamorphic." No fossils were found in the 

 quartzite or in the superjacent gray and calcareous shales. The lime- 

 stone above the shales is referred to the Niagara. 1 



During the progress of the survey west of the one hundredth merid- 

 ian Mr. G. K. Gilbert visited the Antelope Spring locality, discovered 

 by Mr. J. E. Clayton, and mentioned by Prof. Whitney when calling 

 attention to the Primordial fossils found there. The fauna occurs in a 

 blue gray, calcareous shale, some 200 feet in thickness. In addition to 

 the species described by Mr. Meek, he collected BathyUrellus (Asaphis- 

 cus) wheeleri, Agnostus, and Disciua. Beneath the blue gray shales is 

 a massive gray limestone, 900 feet in thickness, superjacent to a vit- 

 reous sandstone. 2 From our present knowledge of the Cambrian rocks 

 in Nevada, the gray limestone, blue gray shales, and an upper gray 

 limestone some 200 feet in thickness all belong to the Cambrian. 



The section of the Oquirrh range at Ophir City, Utah, was found by 

 Mr. Gilbert to have, near its base, 100 feet of light gray limestone con- 

 taining Conocoryphe and Dikelocephalus. Subjacent to this a mas- 

 sive limestone with coralline mottling extends downward some 300 feet 

 to an argillaceous shale, in which Mr. J. E. Clayton found Olenus gil- 

 berti? At the south end of the Timpahute range of eastern Nevada 

 Mr. Gilbert also discovered a succession of shales and sandstones, in 

 which he found Conocoryphe in the lower portion, and above, a band 

 of purple ripple-marked vitreous sandstone, with bands of siliceous 

 shale. 4 The descriptions of Olenus (Olenellus) gilberti and O. (O.) hoie- 

 elli of Meek are printed on pages 182 and 383 of Mr. Gilbert's report. 



In the same volume Mr. E. E. Howell states that at Pioche, Nevada, 

 the massive quartzite forming the base of the section is subjacent to 

 about 400 feet of arenaceous and calcareous shales of a reddish yellow 

 color, containing in the more calcareous portions several types of 

 Primordial fossils in great abundance. 5 From the material found by 

 Mr. Howell, Mr. Meek described two species of trilobites, Olenellus 

 howelli and O. gilberti. 



On the map accompanying the Wheeler survey reports, published 

 in 1874, the Cambrian rocks are included under the same color with 

 those of the Silurian. 



1 Report of Frank H. Bradley, geologist of the Suake River division. U. S. Geol. Sarv. of the Terr., 

 6th Ann. Rep., 1873, p. 194. 



2 Report on the geology of portions of Nevada, Utah, California, and Arizona, examined in the years 

 1871 and 1872. Report on Geog. and Geol. Exp!, and Survey west of the 100th meridian, in charge of 

 Lieut. Geo. M. Wheeler, vol. 3, Geology, 1875, p. 167. 



3 Op. cit., pp. 160, 167. 



4 Op. cit.,p. 169. 



5 Report on the geology of portions of Utah, Nevada, Arizona, and New Mexico examined in the 

 years of 1872 aud 1873. Rept. Geog. and Geol. Expl. Sur. west of the 100th mer., in charge of Lieut. 

 Geo. M. Wheeler, vol. 3, Geology, 1875, p. 258. 





