[MATTHEW | CLIMATIC ZONES IN DEVONIAN TIME 139 
far north as latitude 70° N. From the preceding remarks it will be seen 
that the Upper Devonian flora, recognized as such, extended from the 
highlands of Pennsylvania through Quebec in eastern Canada to the 
British Isles and to the islands of the Arctic Ocean; and the lowest 
latitude where it is known is Pennsylvania (40° N,), and the highest 
Bear Island and Spitzbergen, and everywhere we find it characterized 
by Archeopteris. But this genus had an earlier source than the Upper 
Devonian for it occurs in its two principal manifestations in the middle 
Devonian of Pennsylvania, namely the species with fringed pinnules 
and those in which the pinnules are broad and entire, or only lobed. 
The Structure of the Upper Devonian Terrane in South Eastern Canada. 
In southern New Brunswick, to which this paper chiefly relates 
the Upper Devonian rocks are easily distinguished from those below 
by the absence of slaty cleavage in the finer beds and by the small 
amount of change which the vegetable remains they contain has 
undergone, the plants being simply blackened or charred, while those 
of the older terranes have been deprived of their hydrocarbons, 
or graphitized. 
This Upper Devonian terrane is the first great mass of sediments 
accumulated after the ““Devonian upturning,’* which affected all the 
older sediments, crushing and folding the older strata and leading to 
the extrusion of granitic masses along and near the anticlines. 
In Upper Devonian Time these granitic ridges and the intervening 
ridges of early Paleozoic rocks, were no doubt more prominent than 
now, and were the sources from which the materials of the conglomerates 
of Upper Devonian Age were derived. It would seem highly probable 
that on the higher parts of these ridges glaciers existed, that helped to 
wear them down and furnish in the resulting morainic material 
the boulders which are so plentiful in the Upper Devonian con- 
glomerates. The evidence in favor of the existence of glaciers at that 
time is the great number of sub-angular boulders, the confused massing 
of great thicknesses of boulder beds, the great irregularity in their thick- 
ness, and the fact that some few boulders are striated. 
The time of the extrusion of the granites in these ridges is fixed as 
later than Silurian Time by the field studies of the geologists of the 
Canadian Geological Survey, by the observations of G. Otis Smith of 
the United States Geological Survey on the source of the materials of 
the Upper Devonian conglomerates of the Perry Basin, and more exactly 
* See Dana’s Manual of Geology New York 1896 p. 630. 
