FAUNAL EVIDENCE AND CORRELATION. 



219 



This fauna is so closely similar to that fi-om the Wasatch limestone of Utah and 

 the Madison limestone of the Yellowstone National Park that detailed comparisons 

 can well be omitted. A somewhat alien feature is the presence of Myalina arkan- 

 sasanaf. The identification is not certain, but the association of this form, thus 

 imperfectlj^ identified, with an earlj- Mississippian fauna is reasonablj' sure. 

 Though the age of the fossils from station 2385 is not entireh' unassailable, j^et the 

 stratigraphic, together with the direct and indirect paleontologic evidence, raises it 

 almost above suspicion. This form, to which it will be necessarj' to refer later, 

 while possibly belonging to a somewhat distinct horizon, nevertheless forms a part 

 of and is of the same geological age as the regular Ouray Mississippian fauna. 



CEESTED BUTTE QUADKANGLE. 



The fossils here considered were collected in connection with the areal work for 

 the Anthracite-Crested Butte folio." Ten local collections (stations 2360 to 2359) 

 and 15 species constitute the available data. The local representation and distribu- 

 tion of species can be seen in the accompanying table. 



Table II. '' — Table showing distribution of Mississippian species in the Leadville limestone of the Crested 



Butte district. 





2350. 



2351. 



2352. 



2353. 



2354. 



2355. 



2356. 



2357. 



2368. 



2359. 



-Total. 



C(ELENTEBATA. 





X 



X 

 X 



X 

 X 





X 







X 





5 











2 



















X 



1 





















>< 

 X 



1 



BRACHIOPODA. 



















1 



Orthothetes insequalis . 















X 





1 













X 

 X 















X 





X 





X 

 X 



X 



X 







6 









I 



Spirifer pec'uliaris "^ 

















X 



X 







1 























GASTEROPODA. 







X 

 X 







X 





X 



3 



Straparollus ophirensis . 















1 



Loxonema ? sp 



X 

 X 















X 























1 

























The most diagnostic assemblage of species occurs at station 2358. The assign- 

 ment of this fauna to a period in the Mississippian older than the Grsnevieve will 

 hardly, I think, excite objection. The other local collections are less extensive and 

 in general less diagnostic, but so far as they are significant indicate essentially the 



aU. S. Geol. Surv., Geol. Atlas U. S., folio 9, 1894. 



I> For a description of the localities indicated by number in this table see locality register, pp. 519-.=)3'2. 



