626 DAVID WHITE 
bined in a single continent or included in several very closely situated 
land masses comprising the greater “‘Gondwana-land” of Permian 
time is also indicated by the vast areas of freshwater sediments 
unconformably laid down in the Indian, South African, and South 
American regions. 
AGE OF THE GANGAMOPTERIS FLORA 
It has been shown that the GANGAMOPTERIS or Lower Gondwana 
flora dates from the time of the glacial bowlder conglomerates—i. e., 
from the glacial period itself. Though many geologists and paleon- 
tologists appear still to disagree as to the geological time of this date, 
the criteria are sufficient to fix it within very close limits. The 
refrigeration cannot have antedated the flora at Tete’ on the Zam- 
besi, which is of middle or lower Stephanian age. So also the very 
late Coal Measures plants from the province of Shansi in China? and 
the flora representing a horizon close to the base of the Permian at 
Jantai in Manchooria? show no important climatic differences from 
the topmost Carboniferous floras of western Europe. On the other 
hand the mingling of GANGAMOPTERIS and Glossopteris species with 
Callipteris, Lepidodendron, and Zechstein animal remains in northern 
Russia+ show that the flora was well established and becoming 
enriched at that time. The invertebrate fauna of the marine beds 
associated with the conglomerates in New South Wales are regarded 
by Frech5 as Permian. The introduction of Lepidodendron, Lepi- 
dophloios, and Sphenophyllum in the GANGAMOPTERIS flora probably 
occurred before the close of the Rothliegende. It becomes most 
highly probable, therefore, that the refrigeration attending the birth 
of the flora was consequent to the great terrestrial uplift and with- 
drawal of the sea at the close of the Carboniferous or at the beginning 
of the Permian. ‘The flora may accordingly be regarded as dating 
from the close of the former. The approximate equivalences of the 
formations, so far as recognized, in the at present detached areas of 
_' Zeiller, Ann. d. Mines (2) Mem. Vol. IV, 1883, p. 594. 
2 Schenck, in Von Richthofen: China, Vol. IV, 1883, p. 209. Also Abbado, 
Pal. Italica, Vol. V, 1900, p. 125. 
3 Zalessky, Verh. k. min. gesell., St. Petersb. (2), Vol. XLII, 1905, p. 385. 
4 Amalitzsky, Comptes Rendus, Vol. CXXXII, 1901, p. 591. 
5 Lethaea palaeozoica, Vol. II, Lief. 4, 1892, p. 590. 
