92 THE DEVONIAN AND CARBONIFEROUS. [bull. so. 



coal. In the anthracite coal fields of Pennsylvania there is so much 

 uncertainty as to the true equivalent of the Pittsburg seam that there 

 is little chance for comparison. 



Considerable difficulty arises in attempting to determine the exact 

 situation of the Coal Measures conglomerate in the various States, nor 

 is the Millstone grit of Indiana and Illinois synchronized, or its equiva- 

 lent in the Alleghany field determined. In Arkansas a Millstone grit 

 is reported, which Mr. Lesquereux declares is part of the coal forma- 

 tion. Mr. Dawson also describes a similar Millstone grit along the 

 Bay of Fundy, but its relation to those of Great Britain or of the 

 United States is not known. 



E. B. Andrews, 1 in 1875, reported some interesting coal plants from 



Ohio: 



In Perry County, Ohio, a thin bituminous shale occurs at the base of the Ohio Coal 

 Measures, containing pieces of plants similar to branches of Calamites, fish scales, and 

 a small Lingula. Just above this layer is a thin stratum of shale carrying leaves of 

 Lepidodendron. In the higher shales are found numerous ferns, etc. The plants found 

 here were well marked Devonian types, with a few more recent than the Coal Meas- 

 ures, while those belonging to the Coal Measures are new species. A new species of 

 Archceopteris is one of the Devonian forms : Megalopteris (Dawson) is another Devon- 

 ian genus. One species of the genus was known in New Brunswick only, and described 

 by Prof. Hartt as Keuropteris dawsoni. With these was found a fern of a new genus, 

 of the order of the Tamiopteridice. The new Ohio genus the author calls Orthogoni- 

 opteris. A new form of Alet'lwpieris was noticed resembling the one found in the coal 

 field of Cape Breton, but specifically different. Also a new Aster ophyllites, Hymeno- 

 phyllitea, Eremopteris, and two species of Lepidodendron, with a few others. These are 

 to be figured in the Ohio reports. 



Mr. Lesley proposed a scheme of the formations 2 called "Table of 

 rock formations, arranged in the order of the ages from above down- 

 wards, as they are recognized in America and according to the present 

 state of our knowledge." 8 



Recent. 



Glacial. 



Tertiary. 



Cretaceous. 



New Red. 

 The Coal Measures, anthracite and bituminous. 



The Great Conglomerate, No. XII, of Mount Pisgah, called by Rogers, "Serai." 

 Red Shale, No. XI, Umbral, around Mauch Chunk. 

 White Catskill, No. X (Vespertine), of the Second Mountain. 

 Red Catskill, No. IX (Old Red of England), Pocono Mountain. 

 Chemung shales (VIII, Cadent) holding the oil rocks. 

 Portage sands and shales (VIII, Vergent). 

 Hamilton black slates (VIII, Scalent) ; streaks of coal. 

 Upper Helderburg limestones, etc. (VIII, Postmeridial). 

 Oriskany sandstones (VII, Meridial), Stone Ridge, Lehigh Gap. 

 Lower Helderburg cement layers, etc. 



1 Andrews, E. B. : Notice of new and interesting coal plants from Ohio. Am. Assoc, Proc., vol. 24, pt. 

 2, 1875, pp. 106-109. 



2 See Geol. Survey of Pennsylvania, Report of Progress D on the Brown Hematite Ore Ranges of 

 Lehigh County, by Frederick Prime, jr., 1874, p. 73. 



•Ibid., p. 63. 



