[MATTHEW] CLIMATIC ZONES IN DEVONIAN TIME 127 
in the swamps.” And Heer mentions that many of the typical 
European forms are not represented in the Polar Carboniferous beds as 
for example Calamites, Annularia, Asterophyllites, Sigillara Neu- 
ropteridæ and Pecopteride.” These it will be noted are types of plants 
that grew in the swamps or deltas. 
Here we have brought into view the fact that among these ancient 
genera of the Paleozoic World there are certain forms that are re- 
cognized as palustral or deltaic in their habit of growth, and prominent 
among these are the genera above named. To any one who has studied 
the Carboniferous floras these are familiar names and that they should 
be absent from the lists of Polar Carboniferous plants is a matter of 
much significance, and shows that in these Polar plants we are not 
dealing with the inhabitants of marshy tracts alone, but with plants 
of an upland region as well, having a cooler and probably drier climate 
than that of the Coal Measures in the Temperate Zone. 
The difference that we observe in these Polar plants from those 
of the Coal measures of Central Europe, &e.,are of two kinds, depending 
in one case on difference of climate in the other on habitat. Differences 
from these causes in Devonian floras apparently have so far received 
little attention, but they appear to be fully as strongly marked as in 
those of the Carboniferous Age, and it is chiefly to such differences in 
the floras of the Upper Devonian in eastern Canada that the following 
remarks relate. 
The Northern Range of Basins. 
It was James Hall who first drew general attention to the existence in 
America of land plants in the Chemung Group at the top of the Devonian 
System. The two plants which he figured and described were Sphen- 
opteris lara and Sigillaria Chemungensis.* The first of these names 
being already in use Güppert substituted Cyclopteris Halliana, and 
the generic name of the second species was changed to Lepidodendron, 
but Hall’s specific name was preserved for the latter. At a later date 
Sir J. W. Dawson claimed the former species as a member of his genus 
Archeopteris. 
In the 60 or 70 years that have since elapsed many new localities 
for Devonian land plants have been found, but these two species have 
given the keynote upon which the floras of the Upper Devonian have 
been built up in a range of terranes extending from northern Penn- 
sylvania, through Gaspé and the British Isles to Spitzbergen in the 
Arctic Sea. 
*Nat. Hist. of N. York, Part IV. Geology pp. 274-75 (1843). 
