332 DAVID WHITE 
amounts of carbon then being stored away in the coalfields as the 
result of plant extraction from the air could have failed to produce 
some effect on the atmospheric content of CO,. 
Though the Stephanian flora has less unity in its distribution than 
had the Westphalian, it is nevertheless remarkable for its geographical 
range. The flora reported by Zalessky' from the Yen-tai mines near 
Mukden in Manchuria embraces eight species, seven of which are 
found in western Europe, while six are present in the Appalachian 
trough. Or, looking southward, at Tete on the Zambesi in southern 
Africa, we find that all of eleven species reported by Zeiller are present 
in Europe and nine or ten, about 80 per cent., in America also. In 
harmony with these facts we find but slight traces of annual rings in 
the woods of the Stephanian, either in Europe or in America. ‘This 
is the more noteworthy because the date of the Gondwana-land 
glaciation has been referred by various geologists to the Stephanian. 
THE PERMIAN FLORAS 
Floral characters —The coming of the Permian is characterized 
not only by orogenic movements in the eastern hemisphere, but also 
by indications of increasing climatic differences. The first paleobo- 
tanical effect of these is the extinction of nearly all characteristic 
Carboniferous types, except in Pecopteris, Cordaites, and Neuropteris, 
the latter, however, disappearing nearly completely by the close of 
the Autunian or lower stage. They are replaced by varied forms 
of Callipteris, the lingulate Odontopteris and the ribbon-like Taeniop- 
teris, together with expanding gymnospermous types, such as Walchia, 
Dicranophyllum, Doleropteris, Psygmophyllum, and Ginkgophyllum. 
Later, in the Saxonian, or Middle Permian, Voltzia, with the thick- 
leaved Equisetites, appears while more of the older types go out; and 
in the Thuringian, or Zechstein (Upper Permian) Rhipidopsis, 
Araucarites, Gomphostrobus, Voltzia, and Ullmannia, become the 
characteristic genera, while Pecopteris, dominant in the Stephanian, 
has nearly vanished. Though lacking the abundant Cycad and 
Cladophlebis-Asterocarpus elements, the Upper Permian is in many 
respects transitional to the older Mesozoic flora. 
The Gangamopteris or lower Gondwana flora——Meanwhile in the 
South a new flora, the Gangamopteris flora, or so-called Glossopteris 
1 Verh. Russ. K. Min. Gesell. (2), Vol. XLII (1905), p. 485. 
