FAUNA OF THE POGONIP. 51 



A number of localities southeast of Ruby Hill represent, in their fauna, 

 a somewhat higher horizon, the most favorable for collecting being found 

 on the first ridge southeast of the Jackson Mine, where the base of the 

 Pogonip beds are wanting, having been cut off by the Jackson fault. 

 These beds yielded the following species : 



Lingulepis msera. Ptychoparia (Enloma) affinis. 



Lingnla manticula. Arethusina americaim. 



Acrotreta gemma. JJlaeuurus eurekensis. 



Leptoeua melita. Asaphus caribouensis. 



Orthis hamburgensis. Asaphus (sp. undt.). 



Directly east of the Hamburg Ridge ,and several hundred feet above 

 the last locality, a grouping of fossils comes in which is characteristic 

 of a slightly higher horizon : 



Lingulepis ina-va. Triplesia calcifera. 



Lingula mauticula. Tellinomya! hamburgensis. 



Disciua (sp. undt.). Dicellocephalus finalis. 



Acrotreta gemma. Dicellocephalus inexpectans. 



Schizambon typicalis. Ptychoparia annectans. 



Obolella ambigua. Ptychoparia oweni. 



Orthis hamburgensis. Amphiou (sp. undt.). 

 Orthis testudinaria. 



This horizon may be easily identified by collections of fossils more or 

 less complete from numerous other localities in the district. From about 

 this point in the limestone the older persistent forms gradually disappear, 

 and the new species introduced in the above list become more and more 

 abundant, as is evidenced by the increasing number of localities where they 

 occur as higher strata are reached. 



In a compact gray limestone southwest of McCoy's Ridge are the fol- 

 lowing : 



Orthis perveta. Plumulites (sp. undt.). 



Orthis testudinaria. Ceraurus (sp. undt.). 



Triplesia calcifera. Elcenurus eurekensis. 



Maclurea annulata. ' Asaphus caribouensis. 



Midway in the Pogonip, the genera Meceptaculites, CJuefcff*, rimroto- 

 maria, Maclurea, Bathyurus, Asaphus, and Cyphaspis, make a decided change 



