74 GEOLOGY OF THE ETTEEKA DISTEICT. 



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

 prises the species common to both upper and lower horizons: 



Stromatopora, ? Productus shumardianus, var. pyxidatus. 



Syringopora perelegans. Productus subaculeatus. 

 Streptorhynchus chemungen- Spirifera pinonensis. 



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



Orthis tulliensis. Atrypa recticularis. 



Strophodonta perplana. Bhynchonella castanea. 



Chonetes deflecta. 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, crystalline strata carrying the 

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

 begin to yield Atrypa reticularis, Spirifera, Stromatopora, 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 denned 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 

 strata 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: 



Liiigula Ifena. Strophodonta perplana. 



Liugula lonensis. Strophodonta puuctulifera. 



Discina, sp. ?. Chonetes filistriata. 



Pholidops bellula. Chonetes hemispherica. 



Pholidops quadrangularis. Chonetes macrostriata. 



Orthis inipressa. Productus shumardianus. 



Skeuidium devonicum. Productus subaculeatus. 

 Streptorhyuchus chemungensis, var. Productus navicella. 



perversa. Spirifera piiioneusis. 



Strophomena rhomboidalis. Spirifera raricosta. 



Strophodonta arcuata. Spirifera varicosa. 



Strophodonta calvini. Nucleospira concinna. 



Strophodonta pattersoni. Trematospira infrequens. 



