PERMIAN. , 395 



of the city of San Angelo. From here its western boundary lies along the 

 foot of the Staked Plains, probably to the north line of the State. No at- 

 tempt has been made to trace the western boundary fully, but it has been 

 found at Big Springs; at Dockum's Ranch, in Dickens County; at Mobeetie, 

 in Wheeler County, and as far north as the Canadian River. The rocks of 

 this formation also lie on all sides of the Wichita Mountains, in the Indian 

 Territory. 



RELATION TO ADJACENT STRATA. 



It seems to be still an open question whether the Permian Beds shall be 

 placed with the Paleozoic or with the Mesozoic group. There has been an 

 effort on the part of some to place it in the Mesozoic, while there has been 

 an equal effort on the part of others to retain it in the Paleozoic. 



Professor Jules Marcou says: "I include the Permian in the New Red 

 Sandstone formation. I know that good reasons, based exclusively on pal- 

 eontological grounds, have been advanced by geologists desirous to place the 

 Permian in the Paleozoic; but I think the old classification a better one; and 

 more, I think the term Permian, at least as given by Murchison for the strata 

 of the government of Perm, a very improper one. There are strong suspi- 

 cions that Murchison has put in his Permian of Russia a part, if not the 

 whole, of the Trias; and I am certain that if geologists accept the Russian 

 Permian, as Murchison has denned it, as a type, the Trias will disappear from 

 classification in Asia, Africa, America, and Australia."* 



On the other hand, Dr. C. A. White says, "All the hitherto recognized or 

 reputed Permian of North America is far more intimately related, both pal- 

 eontologically and stratigraphically, with the Paleozoic than with the Meso- 

 zoic. "f 



The International Congress held at Berlin left the matter still undeter- 

 mined. 



I shall not enter into the controversy in this Report, but as a matter of con- 

 venience place the Permian in the Paleozoic group. As stated, I intend to 

 include in the Permian all the strata that shall be found to lie between the 

 top of the Coal Measures and the base of the Triassic, as defined in American 

 Geology. 



That there is a hiatus between these two formations as defined in North 

 America is a well known fact. By evidence that will be given hereafter, I 

 wish to show that the series of strata that I here call Permian is different 

 from either the Triassic above or the Carboniferous below, as they have been 

 formerly identified. In discussing the question I shall not confine myself to 



* American Geology, Zurich, 1858. 



f Proceedings American Association for the Advancement of Science, p. 212, 1889. 



