THE RELATIONS OF SOME CARBONIFEROUS FAUNAS 9 



and cherty limestone, Wyman sandstone, Fayetteville shale, 

 Batesville sandstone, Marshall shale, Archimedes limestone, 

 Washington shale and sandstone, Pentremital limestone, coal- 

 bearing shale and Kessler limestone. 



The coal-bearing shale contains a rich flora, which, though 

 the fact has generally escaped recognition by invertebrate pale- 

 ontologists, was identified several years ago by Mr. David 

 White as of latest middle or earliest " Upper Pottsville " age. 

 Nevertheless, the Boston group, that is, beds up to and includ- 

 ing the Kessler limestone, has otherwise, without exception so 

 far as I am aware, been assigned to the Lower Carboniferous. I 

 have recently studied with some care the upper faunas of this 

 section, and although my investigations are still incomplete, 

 feel safe in making the following statement, of which my report, 

 when published, will give the evidence in full. 



The Kessler limestone is as a rule scantily fossiliferous, but 

 where a fauna has been obtained from it, it proves to be essen- 

 tially the same as that of the Petremital limestone. Thus these 

 2 limestones, carrying between them the coal-bearing shale with 

 its " Upper Pottsville " flora, are inseparable upon paleontologic 

 evidence. The line, whatever division is used, must pass above 

 the Kessler or below the Pentremital. The Kessler-Pentrem- 

 ital fauna is quite distinct from any standard Lower Carbon- 

 iferous fauna ; it is also markedly different from the fauna of 

 the Archimedes Hmestone. There is thus a distinct faunal 

 break between the Archimedes and Pentremital beds. The 

 Pentremital-Kessler fauna is itself one of great interest. Besides 

 many species which are new, it contains some showing Lower 

 Carboniferous affinities, such as Pcntremites, Sfiriferina trans- 

 versa, etc., and others which are distinctly Upper Carbonifer- 

 ous, e. g., Hustedia and Squamhlaria. Few paleontologists 

 will at first be willing to accept Pcntremttes as ranging above 

 the top of the sub-Carboniferous, but the evidence at hand 

 leaves no other conclusion tenable, unless one be prepared to 

 place the Pottsville beds in the Lower Carboniferous. 



From what has already been said, the Pottsville, from its 

 faunal side, is of little interest in the vvay of correlation in the 

 Central and Eastern States. It will, however, probably establish 



