THE ARKANSAS COAL MEASURES. 1 89 



mian, because he can find no paleontologic or stratigraphic break 

 to separate them from the Carboniferous. He finds 16 genera 

 characteristic of the Carboniferous, and 7 genera not thought 

 to antedate the Permian in Europe, but associated with genera 

 not thought to occur later than the Carboniferous. Meek^ 

 says that Fiisulina, which occurs in great numbers in the 

 uppermost Carboniferous beds of Nebraska, is considered in 

 Europe to be mainly if not exclusively a Lower Carbonifer- 

 ous genus. In this, however, he was mistaken ; his opin- 

 ion dates from a time when most geologists were inclined to 

 place all Carboniferous limestone in the Lower Carboniferous. 

 But it is now known that the Carboniferous limestone occurs in 

 the Upper Carboniferous about as often as in the Lower, and the 

 Fusuli7ia limestones of Sicily and Russia grade over into beds of 

 undoubted Permian age. This is also true of corresponding 

 beds in the upper part of the Carboniferous of Texas. In fact 

 the Fusulina beds are always either Upper Carboniferous or Per- 

 mian, in eastern Europe and Asia, and nearly always in America. 



Although undoubtedly believing in continuity of life and 

 formations, Meek seems to have based his reasoning on the old 

 idea of catastrophies, since he thought that the absence of a 

 paleontologic or stratigraphic break was a sufificient reason for 

 calling the beds in question Upper Coal Measures rather than 

 Permian. A large majority of the genera and species are char- 

 acteristic of the Carboniferous, and this Meek thinks sufficient 

 to offset the fact that several genera previously considered typi- 

 cal of Permian^ are present. 



In the Upper Coal Measures of Arkansas out of 51 species, 

 there are 25 in common with the doubtful strata of Nebraska, 

 and 6 other species are common to the Nebraskan Permo-Car- 

 boniferous and the Lower Coal Measures of Arkansas, but have 

 not yet been found in the Upper Coal Measures of the latter 



'Page 33, op. cit. 



^In the transactions of the Kansas Academy of Science, Vol. XIII., p. 38, Robert 

 Hay announced that Professor H. S. Williams and Professor Tschernyschew had vis- 

 ited the Fort Riley section, and agree that it was undoubtedly Permian. 



