74 GEOLOGY OP THE EFEEKA DISTRICT. 



be considered as common throughout the epoch. The following list com- 

 prises the species common to both upper and lower horizons: 



Stroniatopora, ! Productus sbumaidianus, var. pyxidatus. 



Syi'ingopora perelegans. Productus subaculeatiis. 



Streptorliynchus cliemungen- Spirifera piuonensis. 

 sis var. pandora. Spirifera (M.) maia. 



Ortliis tulliensis. Atrypa recticularis. 



Strophodonta perplana. Ehynchonella castanea. 



Clionetes detiecta. Nyassa parva. 



Productus hallanus. Paracyclas occidentalis. 



Productus shumardianus. Styliola flssurella. 



A complete systematic list of all the genera and species known from 

 the Nevada limestone at Eureka and White Pine tabulated into an upper 

 and lower group, will be found as an appendix at the end of this volume. 



At Eureka, above the light gray, ciystalline strata carrying the 

 Halysites, and somewhere near the base of the Nevada limestone, the beds 

 begin to yield Atrypa reticularis, Spirifera, Stroniatopora, and Edmondia, 

 which have a wide vertical range, all but the latter extending well up 

 nearly to the top of the limestone. The lowest well defined fossiliferous 

 belt carrying a decided Devonian fauna is found at Lone Mountain not 

 far above the Silurian line. The fauna is uncommonly rich in species, no 

 one locality having furnished quite as many forms. They occur in shaly 

 sti'ata in belt No. 2 of the Lone Mountain section. No less than fifty-two 

 species were obtained from this horizon. The list of fossils is as follows : 



Liugula laena. Stropliodouta perplaua. 



Liugula lonensis. Strophodonta puuctulifera. 



Disciua, sp.?. Clionetes filistriata. 



Pholidops bellula. Clionetes liemispberica. 



Pbolidops quadrangularis. Chonetes uiacrostriata. 



Ortbis impressa. Productus sbumardianus. 



Skenidium devonicum. Productus subaculeatus. 

 Streptorbyncbus cbemungensis, var. Productus navicella. 



perversa. Spirifera piiioneusis. 



Stropbomena rbomboidalis. Spirifera raricosta. 



Stropbodonta arcuata. Spirifera varicosa. 



Stropbodonta calviui. Nucleospira concinna. 



Stropbodonta pattersoni. Trematospira iufrequens. 



