144 ENVIRONMENT OF VERTEBRATE LIFE, ETC. 



the Manzano group, which includes 500 to 1,000 feet of red beds (Abo sandstone) 

 that thin out to the south." 



That the red beds of the Rio Grande Valley and western New Mexico 

 and Arizona, with their associated rocks, belong in a distinct faunal and 

 depositional province (the Basin Province), the author has already attempted 

 to demonstrate (Carnegie Inst. Wash. Pub. No. 207,1915), but the relation 

 of the Guadalupianand the overlying beds to the uppermost beds of Kansas 

 (Kiger of the Cimmaron series), Oklahoma (Quartermaster and Whitehorse), 

 is a matter of uncertainty. Girty, if I understand him correctly, would 

 place the Capitan limestone entirely above the Whitehorse beds of Oklahoma, 

 placing them in the Artinskian or Artinskian and Permian; while Beede 

 regards the distinction in fauna as due to environmental conditions and 

 regards both as Permian. 



Girty discusses the relations at some length in his monograph upon the 

 Guadalupian fauna. ^ On page 48 he says: 



"In passing northward it appears that the Hueco beds, typically consisting 

 of dark limestones, change their color and lithology, and are represented by red 

 beds interspersed with limestones. In the Grand Canyon section they appear 

 as the Aubrey sandstone and limestone, while in Utah the Weber quartzite seems 

 to be equivalent to them. These correlations are at present provisional. With 

 still greater reserve are the red-beds faunas of Wyoming correlated with the 

 Weber on the one hand and the upper part of the Kansas section on the other. 

 Their relationship with the eastern fauna is far stronger than with the western. 

 At present I see no evidence of their being younger than the Weber, but they 

 may be older. Consers'atively they may be placed in the same epoch. If we 

 accept this correlation of the Hueco formation with the Gschelian on the one 

 hand and the Kansas Carboniferous on the other, the Guadalupian would conse- 

 quently correspond to the Artinsk or to the Artinsk and the Permian. * * *" 



(Page 50.) "It seems to me more probable that the upper Carboniferous 

 of the ]\Iississippi Valley represents not the Pre-Hueconian alone of the trans- 

 Pecos and New Mexico section, but the pre-Guadalupian as a whole * * *." 



In another place- he says that the fauna of Hueco may be equal to eastern 

 faunas, of the Mississippi Valley, but that the Guadalupian fauna certainly 

 can not, though the difference may be due to environmental conditions. 



"Provisionally I am regarding the Guadalupian as younger than any known 

 faunas of the eastern region, thus interpreting the faunal differences of the 

 Hueconian when compared with the Pennsylvanian and Permian of the East, as 

 due to environment rather than to time." 



Beede has long contended that the fauna of the upper red beds of Okla- 

 homa (Whitehorse) is truly Permian and equivalent in time to the Guada- 

 lupian. In his review of Girty's monograph he says:' 



1 Girty, G. H., The Guadalupian Fauna, U. S. Geological Survey, Professional Paper No. 



58, 1908. 

 'Girty, Geo. H., Outlines of Geologic History, University of Chicago Press, pp. 133, 134, 



1910. 

 ^ Beede, J. \V., Jour. Geol., vol. xvn, p. 677, 1909. 



