PERMO-CARBONIFEROUS CLIMATIC CHANGES 621 
The climatic cycle——So far as is known the floras preceding the 
period of Permo-carboniferous glaciation in India, Australia, South 
Africa, and South America were essentially identical with those of 
the northern hemisphere. The phytiferous strata as yet brought to 
light show the presence of the cosmopolitan or northern Lower Car- 
boniferous flora in Argentina and Australia, of a Middle Coal Meas- 
ures flora in the Heraclea basin in Asia Minor, and of a Stephanian 
flora (probably Upper Conemaugh or Monongahela in age), in the 
vicinity of Tete, on the Zambesi, in what was later the territory of 
the GANGAMOoPTERIS flora in South Africa. The extermination of 
the northern, or cosmopolitan flora from the regions of the pure 
GANGAMOPTERIS flora can have been due only to the causes producing 
the glacial refrigeration and the GANGAMoPTERIS flora itself in those 
portions of the earth. The presence of a Sigillaria in the Ecca beds 
of South Africa, and the invasion by the above-named Lepidophytes 
in Brazil shows at once not only an amelioration of the climate 
sufficient for the return of some of the northern elements, but also 
that the extent of the land areas was such as to make their return 
possible. In fact, it is probable that no oceanic barrier existed to 
prevent free access of the northern types at any time during the 
period of cold. It is important to note that these hardy invaders 
from the northern flora which, under the influence of ameliorating 
climatic conditions were the first able to regain a foothold in the 
lost territory, belonged to the Lepidophytes, or Lycopodineous 
group. 
It thus appears that in South America, as in South Africa, the 
Lepidophytes were the first to mingle with the flora which succeeded 
the glacial climate, the invaders being apparently in greater force in 
South America.’ The greater variety as well as the far greater 
numerical representation of the Northern Lycopod elements in the 
Brazilian area may be due either to relative nearness to the border of 
t Bodenbender reports the presence of Lepidophloios laricinus, Sigillaria Brardit, 
Pachypteris, and Walchia in Argentina. As to Cardiopteris polymorpha, Adiantites 
antiquus, and Rachopteris (Lower Carboniferous types), and Lepidodendron selagi- 
noides, L. aculeatum, and L. Veltheimianum (Lower coal measures species) also reported 
by him there is room for doubt concerning either the identity of the plants or their 
relations to the GANGAMOPTERIS flora: See Bot. Acad. Nac. Ciencias, Cordoba, Vol. 
XVII, 1902, p. 203. 
