374 POSITIONS OF ANCIENT CONTINENTS 
distribution of the Gangamopteris (Glossopteris) flora, together 
with the widely spread glacial beds, call for a vast Permian conti¬ 
nent extending from South America to Australia. 
We believe to have advanced evidence from at least three mu¬ 
tually independent sources that there undoubtedly existed, at the 
end of Pre-Cambrian, and quite surely also far back into Archean 
time, three immense tracts of super-continental size upon the earth 
that behaved like continental segments or units in their reaction 
to orogenic and epeirogenic forces, to marine invasions and in the 
character of their sediments. We have designated these tracts 
as arch-continents to indicate their ancestral relation to the later 
and the present continents. In order to emphasize more fully this 
important relation and at the same time give expression to these 
differences in size and outline that distinguish them from their 
Paleozoic descendants, we propose to add the prefix “Arch” to the 
names of the continental masses which later appear in their place. 
We will then have the three primeval continental masses of Arch- 
Eurasia, Arch-America and Arch-Gondwana. Each of these arch¬ 
continents contain certain nuclei, or shields, which are positive 
elements that remained undisturbed from later folding and more or 
less also from transgressions. These are the Baikal shield, or the 
ancient Angaraland of Asia, the Baltic shield of Europe and the 
Laurentian shield of America. Nearly the whole of Africa, the 
“Brazilian mass” and West Australia hold similar positions of 
areas that remained relatively undisturbed. 
It may in time become desirable to distinguish the continental 
masses in their changing outlines in the different periods by sep¬ 
arate names. Clarke has, in recognition of the confusion possible 
from retaining one name for a changing continental mass, proposed 
the name “Falklandia” for the Devonic representative of Gond- 
wanaland, because it was connected with Antarctica. We do not 
know whether the Pre-Cambrian ancestor of Falklandia and Gond- 
wana was in any way connected with Antarctica, and, therefore, 
can not properly use the name Falklandia for the still earlier de¬ 
velopment of the continent. It may be suggested that such stages 
could be distinguished by prefixing the name of the period to the 
continuous land mass, as Siluro-America and Cambro-Eurasia, re¬ 
taining the names Eurasia, America and Gondwana for the three 
arch-continental masses, here described. 
