FOSSIL BUTTE. 195 



tions are readily (leterniiiic(l. At this locality, in l)e(ls helow the Eureka 

 qiiartziti', ^Ir. Walcott niaile the tollowini!;- eollectidii: 



Oitliis pcMVCta. SubulitfS sp. ? 



Ortbis tiiceuariii. Orthoceia.s .sp ? 



Ortllis pogonlpensis. Ortlioceras (Ammlated simcies). 



Strophomcna fontinalis. Leperditia bivia. 



Modiolopsis occideus. Cerauius sp. ? 



Modiolopsis pogouipensis. Illa-iius c-rassicauda. 



Raphistoina acuta. Bathjmrus jwgoiiipensis. 



Mun-hisoiiia, 2 sp.^ Pleiirotimiaria loiionsis. 



Fossil Butte.— At Fossil Biitte, 10 miles north ot" H>k(), on the east side 

 of Pahranayat ^^alley, the Pogoiiip is afj-ain seen overlain 1)\' the Eureka 

 quartzite. The l)utte stands out as an elevated ridi^'e, l)ut jjresentiug an 

 exacth" similar succession of .strata as seen along the east side of Prospect 

 ]\Iountain, Pogonip Ridge, and the western base of Loiie Mountain. In the 

 limestone occur the following species: 



Eeceptaculites maiiimillaris. Metoptoma phillipsi. 



Ortbis trieenaria. Ecculiouipbalus, like E. distaus. 



Stropboinena fontinalis. Orthoceras niulticameratnm. 



Triplesiat sp.? Endoceras mnltitubulattuu. 



Leperditia bivia. Modiolopsis occidens. 



Maclurea subaunnlata. INIodiolopsis pogouipensis. 



Machu-ea, 2 sp., iindet. Illa'uus crassicaiida. 



Taken together these two groups from Bennett Spring and Fossil 

 Butte carry the more marked fauna of the Upper Pogonip. Overlying the 

 quartzite occur some light gra}' limestones, without organic remains, but 

 resembling the Lone Mountain beds. Along the east side of Pahranagat 

 Valley limestone ridges extend for several miles. The beds have been 

 much distm'bed and have undei'gone considerable faulting, preventing accu- 

 rate sections, but it is estimated that there are from 2,000 to 3,000 feet of 

 limestones exposed. They are more or le.ss siliceous, weathering reddish 

 brown and brownish gray. The lower members may possibly belong to the 

 Lone Mountain series. Near Hyko there is an exposure of shaly limestone, 

 overlain 1)\- massive l)eds ol' dai'k arenaceous limestone, carrying a Devonian 



