660 HISTORICAL GEOLOGY. 



Coal D, Carbon Hill, Pittston, Pa. ; Vermilion County, Ind. ; Duquoin and St. John, 

 111. 



Coal D or E, Sullivan County, Ind. ; Hopkins and Christian counties, Ky. 



Coal E, Mammoth bed at Pottsville, Pittston, Yatesville, Pa. ; Nelsonville and Cosh- 

 octon, Ohio ; Stark and Peoria counties. 111. 



Coal E and F, Wilkesbarre, Pa. ; Nelsonville and Coshocton, Ohio. 



Coal F, Plymouth, Pittston, and Maltby, Pa. 



Coal G, Olyphant, Plainsville, Gate and Salem veins, Pottsville, Pa. ; Pomeroy, Ohio. 



At Cannelton, Pa., the number of species of plants obtained from the coal-bed of the 

 B or C horizon, according to Lesquereux, is 140 ; at Mazon Creek, 111., from the 

 bottom of the coal-bed B, 150 species, and adding those from the overlying clay-bed, 200 

 species ; and if the species from the same bed at Murphysboro be added, with others 

 the bed affords in Missouri, the number mounts up to 250 species, vyhich is a very large 

 flora for one coal-bed level. The vsrhole number of plants thus far described from the 

 American Coal-measures, the Permian portion included, is 900. 



3. Peemian Period, 

 rocks — kinds and distribution. 



It has been stated that the Upper Barren Measures of Pennsylvania and 

 West Virginia, having a thickness in Monongalia County of 1044 feet, were 

 of the age of the Permian period, though continuous in bedding with the 

 strata below. Similarly, the upper beds — clayey beds, sandstones, with some 

 impure limestones — in the Coal-measures of Kansas, Missouri, Illinois, 

 Nebraska, and Texas, are referred to the Permian. The same is true for an 

 upper part of the Coal-measures of Nova Scotia, New Brunswick, and Prince 

 Edward Island. The evidence of Permian age consists in the presence of 

 remains of plants, Mollusks and Vertebrates, like those of the foreign 

 Permian. Permian beds have also been identified in the region of the 

 Colorado Canon in Arizona and Utah, where 845 feet of limestone and shales 

 containing gypsum, overlying Carboniferous limestone, are referred to this 

 period. In the Wasatch, the beds have a thickness of 600 feet. 



Permian beds v^ere identified in the San Francisco Mountains by Marcou in 1853 ; and 

 in the Guadalupe Mountains, New Mexico (a white limestone), by B. F. Shumard in 1858. 

 About the Colorado Canon they have been studied by Walcott (in 1880) and others. The 

 rock in the Wasatch is the " Bellerophon limestone " described by King (1878). Permian 

 was identified in Nova Scotia by Dawson in 1845 ; in Kansas, by Meek, Swallow and 

 Hawn, in 1858 ; in Illinois, by Worthen, in 1858 ; and soon after in Missouri and 

 Nebraska by Meek ; in Pennsylvania and West Virginia, by Fontaine and I. C. White, in 

 1880. Cope's observations in Illinois and Texas were made in 1875, and later ; C. A. 

 White's, in Texas, in 1889. On the Kansas Permian, see, furtlier, Prosser's paper of 1894, 



The Texas Permian occupies the western portion of the Carboniferous area. North of 

 the Brazos River the lower beds, in the Wichita of Cummins, are red clays and sand- 

 stones, with some impure limestone at top. The fossils described by C. A. White are 

 from this part of the series, and so also the Vertebrates described by Cope. Above are 

 the so-called Clear-Fork and Double Mountain division, and then come the Dockum 

 beds, different in rocks and fossils, which are referred to the Triassic. 



