294 D. WHITE — AGE OF LOWER COALS OE HENRY CO., MISSOURI. 



section of the Coal Measures is, thanks to the farseeing and systematic 

 efforts of Mr R. D. Lacoe, of Pittston, Pennsylvania, more completely 

 elaborated than in any other of our Carboniferous basins. A comparison 

 of the range of the Missouri species through the series in the Wyoming 

 valley shows that, while only two of the tabulated species are confined 

 to or are even present in the collections from the coals below the D vein, 

 nearly one-half are present in coals D or E. The occurrence in the flora 

 of the E coal of younger types similar to those found in the Missouri 

 material emphasizes the close relation, which is at once apparent from the 

 distribution ; but the general character of the flora in hand is ikr closer 

 to that of the D or " Marcy " coal than to any other in the Northern field. 

 On the other hand, many of the earlier types seen among the plants from 

 Missouri or from the D coal are wanting in the E or " Pittston vein," the 

 roof shales of which are characterized predominantly by forms of later 

 affinities. It is accordingly probable that the stage of the Missouri flora 

 is near that of the Marcy (D) coal in the Northern Anthracite field. A 

 study of the distribution of the species nearest related to those in hand 

 leads to essentially the same conclusions. 



Relative Age of Henry County Plant Beds. 



comparison with other floras of the united states. 



The comparison of the flora in hand with other floras and of the verti- 

 cal distribution of the species, especially in the paleobotanically better 

 known lower two-thirds of the Lower Productive Coal Measures, shows 

 that the lower coals of Henry county, Missouri, were probably deposited 

 later than the Morris coal of Illinois, the Clarion coal of the bituminous 

 regions of Ohio and Pennsylvania, or coal C of the Northern Anthracite 

 field, although their deposition can hardly have been so late as the Upper 

 Kittanning coal of the bituminous regions or coal E of the Anthracite 

 series, the approximate horizon of the Missouri flora being probably not 

 very far from the Lower Kittanning coal of the bituminous sections and 

 very near to coal D of the Northern Anthracite region. Thus the syn- 

 chronologic evidence of the fossil plants appears to show that the process 

 of the deposition of the Mesocarboniferous terranes was well advanced, 

 so that in the bituminous fields of Illinois, Ohio, and Pennsylvania not 

 only the Potts ville series (xn), ranging from 15 feet to 1,200 feet or more 

 in thickness north of the Potomac river, but also the lower portion of the 

 Lower Productive Coal Measures or Alleghany series (xiii), including 

 probably the Clarion coal, had been laid down on the Eocarboniferous 

 floor before the lower coals in the vicinity of Clinton, Missouri, were 

 sedimented in shallow ponds or marshes fringing the shore of the trans- 



