COMPARISONS WITH ISTORTHEEI^ ANTHRACITE SECTIONS. 289 



the interval between the Morris, or supposed Clarion coal, and the' Upper 

 Kittanning. In other words, if we take Henry County, from which most 

 of our evidence, both stratigraphic and paleontologic, is drawn, as the 

 stratigraphic type of the base of the Coal Measures of the State, and 

 assume that the conditions are constant along the margin of the coal field 

 in other counties, the evidence of the fossil plants, so far as they are now 

 obtainable, appears to indicate the deposition of the lowest coals in the 

 State at a time subsequent to the formation of the lower coals of the Lower 

 Coal Measures of the eastern regions, including the Morris coal of Illinois, 

 the Brookville and probably the Clarion coal of Ohio and Pennsylvania, 

 yet perhaps earlier than the formation of the Darlington or Upper Kittan- 

 ning coals of the two States last named. 



The difficulties attending correlation by fossil plants in the bituminous 

 fields will presently be pointed out. In the Northern Anthi-acite field, how- 

 ever, in which, thanks to the systematic and scientific methods of collec- 

 tion pursued by Mr. R. D. Lacoe, of Pittston, Pennsylvania, plants have 

 been assembled from nearly every fossiliferous horizon, the paleobotanic 

 section is, as compared with all other areas in this country, relatively com- 

 plete. The study of the distribution of the Henry County flora in this field 

 shows its closest relations in coals D and E, locally known as the "Marcy" 

 and the "Big," or Pittston, coals. But in view of the fact that the E coal 

 of the Pittston and Wilkesbarre regions seems to carry many types of a 

 more modern cast, it is not likely that the Missouri stage is so high in the 

 series as that coal. In the plants of the D coal, not only are a large part 

 of the species identical with those from Missouri, but the flora as a whole is 

 of a similar type. Compared, however, with the somewhat equivocal com- 

 bined flora reported from the C coal,^ the material from the Mississippi 

 Valley appears on the whole fully as recent, while lacking many of the 

 older types found at several of the mines correlated by stratigraphy with 

 that coal. Hence I am inclined to regard the plants from Henry County, 

 JMissouri, as more nearly contemporaneous with those in the roof of the D 

 or "Marcy" coal in the Northern Anthracite field, though they are possibly 

 as old as the C coal. Even in the latter case it is clear that several hundred 

 feet of the sandstones, conglomerates, shales, and coals, comprising the 

 lower part of the Coal Measures and the Pottsville, which lie between the 



' See Coal Floraj vol. iii, p. 859. 

 MON XXXVII 19 



