516 STEVENSON— THE FORMATION OF COAL BEDS. [Nov. i, 



able number of the ^^Fercer forms are not recorded, though they have 

 been found in the Conemaugh of Pennsylvania and West Virginia. 

 It is equally probable that the Mercer list is local only, as some forms 

 mentioned in the Palaeontology of Ohio are not given. 



The first deposit of the Conemaugh is the Uffington shale, which 

 is rich in fossils at some places within northern West Virginia. The 

 important list is that by Meek^°' of forms collected at Morgantown, 

 a few miles south from the Pennsylvania line. There are 4 articu- 

 lated brachiopods, 8 pelecypods, 11 gastropods, 3 cephalopods, to 

 which Stevenson in later collections added i coral, 2 crinoids. 4 

 pelecypods and 3 cephalopods. The rock is a black shale, more or 

 less ferruginous, the conditions being very diiTerent from those of 

 the Vanport and Mercer, yet, in this collection of 26 species made 

 at an exposure of about 25 square feet, there are 14 species in com- 

 mon with the Vanport and 12 with the Mercer. The Brush Creek 

 limestone and associated shales are separated from the Ufifington 

 below by the Brush Creek coal and the Mahoning sandstone. Lists 

 from Pennsylvania have been given by Raymond and White and a 

 brief list of forms collected in western Maryland has been published 

 by Martin. ^^® The list by Raymond contains i coral, i inarticulated 

 brachiopod (Lingitia), 12 articulated brachiopods, 9 pelecypods, 15 

 gastropods, 5 cephalopods. To these, White adds one pelecypdd and 

 Martin adds a crinoid and an articulated brachiopod. Thirteen 

 species are in common with the Mercer and 16 with the Vanport. 

 Omitting the Cambridge, to avoid repetition, one comes to the Ames 

 limestone, which is actually continuous over a greater area than that 

 of any other deposit in the whole column. Raymond's^^'' list from 

 five localities on the Pennsylvania railroad, east from Pittsburgh, 

 contains i coral, 2 inarticulated brachiopods, 15 articulated brachio- 

 pods, 6 pelecypods, 10 gastropods and 4 cephalopods. The inarticu- 

 late brachiopods and the pelecypods are rare. Stevenson gave lists 



'"' F. B. Meek, " Lists of Carboniferous Fossils from West Virginia," 

 Third Rep. Regents of W. Va. Unw., 1871. pp. 68-70. 



"'P. E. Raymond, loc. cit., pp. 85-87; L C. White, Rep. Q, p. 34; G. C. 

 Martin, West Va. Geo!. Surv., Vol. IL, 1903, pp. 280, 281. 



""P. E. Raymond, loc. cit., pp. 89-92; J. J. Stevenson, Ohio Geo!. Surv., 

 Vol. in., 1879, pp. 207, 223. 



