292 



FRED J. PACK 



The Olenellus fauna is confined to the lower 100 feet of No. 2, a 



part which is not exposed in the area covered by this report. Walcott 



gives the following list of fossils which he collected at a point five or 



six miles east of Pioche : 



Eocystites ? ? longidactylus Hyolithes billingsi 



Lingulella ella Olenellus gilberti 



Kutorgina pannula Olenoides levis 



Acrothele subsidia Crepicephalus augusta 



Acrotreta gemma Crepicephalus liliana 

 Orthis highlandensis 



No. 4 of the section given above comprises the second strongly 



marked faunal horizon. It is best exposed in the Half Moon Gulch 



about two miles west of Pioche. It forms part of the south member 



of the anticline, and is nearly horizontal, although occasionally it is 



slightly tilted. Mining operators have thrown large quantities of this 



material over their dumps ; it was from these places that most of the 



writer's fossils were collected. The shale also occurs near the city 



water-tank on the hill southwest of Pioche ; the outcrop, however, is 



highly altered and consequently most of the fossils are destroyed. 



The following is a list of the species thus far obtained at this horizon: 



Eocystites?? longidactylus Bathyuriscus productus 



Lingulella ella Bathyuriscus howelli 



Kutorgina pannula Lingulella genei 



Hyolithes billingsi Ptychoparia kempi 



Ptychoparia piochensis Zacanthoides grabaui 

 Zacanthoides typicalis 



DESCRIPTION OF SPECIES 

 ECHINODERMATA 



GENUS EOCYSTITES, Billings 

 Eocystites, Billings, 186S: Acadian Geology, p. 643, Fig. 220. 

 Eocystites?? longidactylus, Walcott 



(Plate I, Figs. i,'uj, ib) 



Eocystites?? longidactylus, Walcott, 1886: Bulletin No. 30, U. S. Geological 

 Survey, p. 94, Plates 5, 6. 



In 1886 Mr. Walcott tentatively referred the species longidactylus 

 to the genus Eocystites, awaiting a further description of Eocystis, 

 BilHngs, (1868), and Protocystis, Hicks (1872). These forms, how- 

 ever, have never been properly described or figured, and, according 

 to Bather, " since they cannot be well distinguished from Eocystites ( ?) 



