332 PALAEOZOIC TIME CARBONIFEROUS AGE. 



Feet. 



1. Shale, brown, ferruginous, and sandy 30 



2. Sandstone, gray and slaty 25 



3. Shale, yellow and brown 20 



4. Limestone, — the Great Limestone south of Pittsburg (including two 



COAL beds, 2£ feet and 1 foot) 70 



5. Shale and sandstone 17 



6. Limestone 1 



7. Shale and sandstone 40 



8. COAL 6 



9. Shale, brown and yellow 10 



10. Sandstone, coarse, brown 35 



11. Shale 7 



12. COAL H 



13. Limestone 4 feet, shale 4, limestone 4, shale 3 15 



14. Shale 10 feet, sandstone 20, shale 10 40 



15. COAL 1 



16. Sandstone (at Waynesburg), with 4 feet of shale 24 



Sections of the strata of Kentucky, Missouri, Ohio, and Michigan, will be 

 found in the Geological Reports on those States, and others of Nova Scotia in 

 Dawson's Acadian Geology, and the Quarterly Jour. Geol. Soc. 1854, page 60. 

 Mr. Lesquereux has published a memoir on the equivalency of the coal beds of 

 the United States in the Geological Report of Kentucky. 



The relations of the sandstones, limestones, and shales that alternate with 

 the coal beds over the wide region stretching from the Appalachians west, are 

 but partially understood. Although these strata seem to be generally limited 

 in range, there is still an equivalency to be ascertained for the whole succession. 

 The rocks, as in other ages, are consecutive records of the events of the period ; 

 and until fully elucidated, the history of the American Carboniferous era will 

 remain imperfectly known. 



III. Life. 



1. Plants. 



The abundance of Fossil Plants is the most striking charac- 

 teristic of the Coal era ; and the remains are so widely diffused, 

 and are distributed through so great a thickness of rock and coal, 

 that we may be sure we have in them a good representation of the 

 Forest and Marsh as well as Marine Vegetation of the Carboniferous 

 age. In the marine, there is little peculiar to note. The land- 

 plants, on the contrary, afford evidences of progress in the life of 

 the globe, and reveal an expansion of some departments of the 

 Vegetable kingdom which would not have been susnected were 

 it not for the evidence in the rocks 



This vegetation began, as already shown, in the early Devonian, 

 and was well displayed before its close. The general characters 



