354 The American Geologist. Inne, 1892 
‘he discussion of the Permo-Carboniferous is based chiefly on 
studies made in Pennsylvania and West Virginia, the references 
to Ohio sufficing merely to show the extent of the area in that state. 
The remarkable flora in the roof shales and partings of the 
Waynesbuargh coal bed in southwest Pennsylvania and the northern 
part of West Virginia is briefly described. It was determined by 
Fentaine and White, who showed its intimate relation to the Per- 
mian flora of Kurope. The exact relation of this upper portion 
of the Appalachian column to the section west from the Cincin- 
nati axis has yet to be determined; and the problem is compli- 
cated in many ways. The writer is inclined to think that the 
Permo-Carboniferous beds of southwest Pennsylvania are con- 
temporaneous with the upper part of the Upper Coal Measures 
within the Mississippi-Missouri region as well as with the Permian 
of Texas. Long after the appearance and after the practical dis- 
appearance of this flora within the Appalachian region, an incur- 
sion of the sea brought Hhizodus from the outer ocean, so that 
seales of that fish are abundant in the shales accompanying the 
Blackville limestone at 120 feet above the Waynesburgh coal bed. 
But this in no wise affects the cardinal point in the case; the pres- 
ence of the plants attests that a portion of the Upper Carboniferous 
in this area is contemporaneous with the Permian of Europe, in 
so far as the testimony of plants can be taken in detail respecting 
a time when passage from the old into the newer had begun. So 
that now, there can be no doubt that our American Carboniferous 
represents the whole of the age as known in Europe, though, ap- 
parently, no change occurred in the American ocean or seas such 
as to justify the separation of the Permian as a distinct division 
of equal importance with our lower or upper Carboniferous. 
Prof. White’s grouping of sections shows noteworthy variations 
in the southern limits of the principal beds of the Upper Coal 
Measures. The southern limit of the Pittsburgh and Waynes- 
burgh practically forms a northward loop around the Volean9s 
anti-cline, so well known as the line along which oil wells have 
been productive in West Virginia and Ohio for more than twenty- 
five years. The series is persistent here but the coals are want- 
ing. The sections of the Lower Coal Measures show a similar 
east and west loop in the Upper Freeport extending from Law- 
rence county of Kentucky into Raleigh county of West Virginia. 
The Barren Measures receive careful treatment; the description 
