DIFFERENT PROVINCES OF NORTH AMERICA IN LATE PALEOZOIC TIME 69 



rus according to Osborn, but who after making a cross-section of the supposed 

 bone, and finding no bony structure preserved, pronounced it a concretion, the 

 most remarkable one he had every seen. Many geologists, and other vertebrate 

 paleontologists who have seen the specimen, declare that its concretionary origin 

 is not proven, and that it is most probably a sandstone cast, an actual fossil from 

 which all bony structure and organic material have disappeared before lithifica- 

 tion in its porous matrix, thus preserving only the outside surface and shape of 

 the bone to perfection. 



'"Mr. Hennen found it lying loose upon the surface, near Salt Lick Bridge, 

 Braxton County, a few feet above the horizon of the Ames limestone, where it had 

 evidently weathered out of its original matrix in a greenish, micaceous, fine- 

 grained sandstone. Of course the testimony of this specimen will remain of 

 doubtful value until its true nature is determined beyond question by the dis- 

 covery of other concretions or fossils, as the case may be, in this same region. 

 In this connection it should also be remembered that Scudder, in his Bulletin 

 No. 124, U. S. Geological Survey, has described a fossil insect fauna from just 

 above the Ames limestone near Steubenville, Ohio, in which he finds forms greatly 

 resembling those in the lower Dyas or Permian of Weissig, Saxony, and hence 

 it should not be surprising to find Permian reptilian forms in these Conemaugh 

 red beds, which the writer has for several years insisted were more nearly related 

 to the Permian than to the Carboniferous proper, and that the introduction of 

 red sediments after such a long absence marked a change in physical and biological 

 conditions sufficiently great to warrant a division of the geologic column at or 

 near the horizon of the Ames limestone. It was formerly suggested that this 

 division should come just above the Ames horizon, since its deposition marked 

 the end of marine life in the Appalachian field, but the discoveries of Dr. Raymond 

 of a Permian reptilian fauna at several feet below the Ames limestone would tend 

 to show that this division-line should be drawn at the base of the Pittsburgh red 

 shale, about 100 feet below the Ames horizon, or the top of the Saltsburg sandstone. 



'"As these first red deposits were probably laid down upon an eroded land 

 surface, the great irregularity of their thickness (which varies from 10 to 200 feet) 

 below the Ames limestone would be thus readily explained.' 



"The peculiar type of fossil insects referred to above are described by the 

 late Professor Samuel Scudder in Bulletin 124, U. S. Geological Survey, and on 

 page 12 of the same he gives his reasons for regarding not only those found in 

 the Cassville plant shale as above the horizon of the Pennsylvanian Coal Meas- 

 ures, but also those found near the Ames limestone near Steubenville, Ohio, in 

 the following language: 



'"The West Virginia locality is at Cassville, Monongalia County, not far 

 from Morgantown, and the specimens were found in rocks lying above the 

 Waynesburg coal, in what is termed by Professor I. C. White the Dunkard Creek 

 series, and referred very positively by him and Professor William M. Fontaine 

 to the Permian. The blattarian fauna as thus far determined is unquestionably 

 younger than any known from the Pennsylvania or Illinois rocks, on which we have 

 hitherto depended largely for our knowledge, and consists of a vast assemblage 

 of forms, which will undoubtedly be increased by further search. They number 

 56 species, belonging to 5 genera, the bulk of them (36 species) to Etoblattina. 



'"The Ohio locality lies at the edge of the township of Richmond, on Willis 

 Creek, in the near neighborhood of Steubenville, Jefferson County, and though 

 far less extensive and less thoroughly worked than Cassville, has already yielded 



