150 C. ScJmchert — Russian Carboniferous and Permian. 



a part of the Productus-limestone of India. This great uncon- 

 formity will be of much value in the final interpretation as to 

 the proper position in the time scale of the entire Productus- 

 limestone and as well the date for the period of glaciation in 

 the late Paleozoic of India. 



In America, however, in southwestern Texas, there is an un- 

 broken section of more than 9000 feet in thickness, having 

 more than 4000 feet of limestone, with normal marine faunas 

 at various levels. As has been evident from the statements of 

 G-irty, this section has Carboniferous faunas of the Euro- Asiatic 

 type, which are directly comparable with the Spirifer marcoui, 

 Omphalotroclixis whitneyi* Productus cor a, and the Sehwa- 

 gerina zones of TscJiernyschew. These Carboniferous faunas 

 are in the lower portion of the section, above which, in the 

 Capitan limestone, are faunas comparable with those of the 

 Productus-limestone of India {i.e. faunas having Goniocladia, 

 Pichthofenia, Lyttonia ( '= Zeptodus ) etc.), — faunas that for 

 some years have been regarded by several of the leading stratig- 

 raphers as the normal marine record toward the close of the 

 Paleozoic. It is to be hoped that the U. S. Geological Survey 

 will soon enable Dr. Girty to complete his studies, both stratig- 

 raphic and fauna!, regarding this, the most complete Car- 

 boniferous and Permian section known to stratigraphers. 



4. The question as to what name the closing Paleozoic sys- 

 tem shall bear can not as yet be answered. If the rocks of the 

 Permian area of Russia should fall into the Carboniferous, the 

 way will open for another term for the closing system. From 

 the accumulated evidence, there appears to be need of such a 

 system in the classification. However, should the Permian 

 rocks of Russia form but a member of a " Permian system " 

 (the trend of evidence is in this direction), there would then be 

 a choice between the Permian of Russia, the Dyas of Geinitz, 

 the Guadalupian of Girty (Oklahomian of Keyes is rather a 

 formation than a time term), and possibly other terms. 



As workers in many countries are coming more and more to 

 adopt a classification expressing the local physical and faunal 

 events, the time does not seem far away when the matter of an 

 all-embracing or world chronogenesis will have to be taken 

 up by the International Geological Congress. Whatever the 

 criterion for such a terminology, indicating the grander events 

 in the world's chronogenesis, may be, it certainly can not be 

 the one now in use, i.e., the local events of a given area, the 

 first to propose a term or terms however badly understood. 

 A new set of system terms for general application suggested 

 by an organization like the International Geological Congress 

 would at once bring into use, for local areas, such despised 

 terms as Taconic and Cambrian, and thus furnish relief from 



