WHITE.] PALEONTOLOGIC DIVISIONS OF THE FORMATION. ( ( 5 



the flora as a whole is perhaps more closely united with that of the 

 Buck Mountain coal and the succeeding- Lower Coal Measures. These 

 two beds, which are obviously younger than the Upper Lykens division, 

 yet are not less than 200 feet below the Twin coal, will, therefore, be 

 treated as representative of an Upper Intermediate division, which, as 

 will appear later, in the discussion of the floras, seems to be transi- 

 tional to the Lower Coal Measures as that formation was defined })v 

 Rogers and has since been commonly recognized. 



The combined distribution of the species between the four divisions 

 of the Pottsville formation somewhat temporarily proposed above is 

 condensed in the four columns at the right-hand border of the table. 

 It may be sununarized as follows (p. 790) : 



