FAUNAL EVIDENCE AND CORRELATION. 



221 



LEADVILLE REGION. 



The material studied by me is that collected in the earh' eighties in the course 

 of the areal work for the Leadville monograph."' Since that time no new collections 

 have been made, though it is possible that the old ones have suffered in some slight 

 degree from loss. The fossils under immediate consideration came fi"om the Blue or 

 Leadville limestone, which is eponymous of this region. It comprises ten species, 

 from seven localities, a meager and unsatisfactory fauna. The favina and its different 

 local facies can be seen from the accompanying table: 



Table lY^—Tahl 



shoving distributimi of Missiisippkm !ipecii.'.-< in the Leadi^lle Ihnestone of the Leadville 

 district. 





2372. 



2373. 



2374. 



2375. 



2376. 



2377. 



2378. 



Total. 



CtELENTEEATA. 



Zaphrentis ? sp. b 







X 











1 



BEACHIOPODA. 



Orthothetes ingequalis. 











X 

 X 



X 



X 

 X 



(?) 

 1 



Spirifer sp. a 















X 



X 





X 



X 



(?) 





5 





3 



Eumetria woosteri . 









(?) 

 2 



PELECYPODA. 



X 









X 





Conocarrlium sp . 







X 





i 



GASTEROPODA. 



Straparollus cf. spergenensis 







X 



X 







2 









. 







All of these collections are recorded as from the Blue or, as it has since been 

 called, the Leadville limestone; and with slight exceptions the physical character of 

 the matrix and the fossil faunas which they carr^' are corresponding!}- similar. "The 

 only fossils obtained from this horizon were found in the extreme upper part of the 

 foi-mation, either in the limestone itself or in chert nodules, which are found scat- 

 tered over its weathered surface."''' This statement occurs in the Leadville mono- 

 graph, and the following specific list, drawn up by R. P. Whitfield, is appended 

 (page 66): 



Euomphalua ap. cf. Eu. spergenensis. 

 Spiriferina-. sp., probably new, resembling Sp. 



kentuckyensis. 

 Athyris subtilita,. 

 Pleurophorus oblongus. 

 Productus costatus. 



Spirifera (Martinia) lineata. 

 Spirifera rockymontana. 

 Streptorhynchus crassus (crenistria). 

 Cyathophylloid corals, resembling Zaphrentis, or 

 Cyathaxonia cynodon. 



a Geology and mining industrj' of Leadville, Colo., by S. F. Emmons; U. S. Geol. Surv., Mon., vol. 12, 1886. 

 J" For a description of the localities indicated by number in this table see locality register, pp. 519-532. 

 cV. S. Geol. Surv., Mon., vol. 12, 1886, p. 66. 



