Age of the Tipton Run Coal- — White. 27 
character of the coal and the lithology of the enclosing rocks, 
is sufl&cient to demonstrate the Coal Measure age of the same. 
This list of plants was submitted to Prof. Wm. M. Fontaine, 
the eminent palaeo-botanist, who is so well acquainted with 
the Pocono or Lower Carboniferous flora of Virginia and W. 
Virginia, and his opinion is the same as my own, viz., that the 
plants could come only in the Coal Measures. It is true that 
Neuropteris tenuifolia and SigiUaria mamillaris have 
been reported from the Pocono, since they are long-lived forms 
which pass from the base of the Carboniferous system almost 
to its top, and on this account Prof. Lesley would call the 
whole list Pocono plants, but we must recollect that neither 
Pecopteris nor Alethopteris have yet been found in the 
Pocono rocks of the Appalachian region. Then too, it is not 
alone ihe presence of typical Coal Measure forms which gives 
this list geological significance, but the absence of the types 
which everywhere else characterize the Pocono flora, as the 
archaeopterids triphyllopterids, and small Lepidodendra ; see 
"Permian Flora," Fontaine and White, pages 6, 7 and 8. The 
evidence from the character of the interstratified rocks is 
alone conclusive of the Coal Measure age. Any geologist 
thoroughly acquainted with the physical land lithological 
character of the sandstones and conglomerates of the Coal 
Measures, and also with those of the Pocono need not be told 
they differ from each other so greatly that it is not a difficult 
task to distinguish the one from the other. This difference 
consists in many things, the shape of the pebbles in the con- 
glomerates (as shown by Mr. Carll), the character of the sand- 
stones as to hardness, color, purity, &c., facts which are very 
real to the geologist who has noted them and learned them, 
but not readily embodied in description. The evidence of this 
nature is so strongly in favor of the Coal Measure age of the 
Tipton beds, that it would have been conclusive to me had no 
plants been found. 
The coal furnished by this bed is quite as pure as the average 
of the Clearfield region which it adjoins, and this fact of itself 
should have some weight, in view of the well known reputation 
of the Pocono coals of Virginia, W. Virginia, &c., they all 
being very high in both ash and sulphur. 
After this paper was about completed the writer learned 
from Prof. Lesley that Mr. J. W. Scott, a former mining engi- 
