— 395 — 
Others of the local species of these cosmopolitan genera, together 
With the identical northern species, viz Volézia heterophylia in the 
Karharbari and Raniganj of India, Sigillaria Brardii in the Transvaal, 
and Brazil, and Lepidophloios laricinus in Argentina (1) and Brazil are 
probably either hardy invaders from the Northern flora or indigenous 
to the transitional zone between the colder-regions and the base- 
levelled regions. The presence of the Psygmophyllum, Walchia, and 
Voltzia elements points to a Permian age for the series. 
The principal extra-Gondwana evidence as to the age of the 
Gangamopteris flora relates to the discovery by Amalitzky (2) of 
Gangamopteris major (== Gangamopteris obovata ), Glossopteris indice, 
Glossopteris augustifolia, Glossopterts stricta and Vertebraria, 
mingled with Callipteris conferta, Lepidodendron, aud upper Zechstein 
invertebrata, in northern Russia; the occurrence of older Gondwana 
types of Phyllotheca in the Permian of the Altai and Siberia, and the 
collection by Noetling (3) ofa Gangamopteris from the Permian of the 
Salt Range series in Kashmir. The Siberian and north Russian 
representatives of the Gangamopteris flora are presumably migrants in 
the domain of the Northern flora. 
The mingling of Northern and Southern species in Siberia, Northern 
Russia, South Africa, Argentina and Brazil, is conclusively in evidence 
against acomplete isolation of the Gangamopteris flora by a geographical 
barrier. 
Either there were means of migration in Permian time at seve- 
ral points between Gondwana-land and the province of the northern 
flora, or there were left room somewhere on Gondwana-land for a 
transitional or possibly the typical cosmopolitan domain of the pure 
Gangamopteris flora. 
That the early glaciation and boulder-bed deposition could not long 
have antedated the beginnig of the Permian is irrefragably shown I:—by 
the presence, at Tete on the Zambesi in Portuguse Southeast Africa, of a 
pure and typical flora (4) of middle or lower Stephanian age, in a region 
well within the known distribution, at alater period, of the Gangamo- 
(1) Cardiopteris polymorpha, Adiantites antiquus, Lepidendrvon selaginoides, Lepido- 
dendron aculeatum and Lepidodendron Veltheimianum, quoted by Bodenbender ( Bol. 
Acad. Nacional Ciencias, Cordoba, vol. XVII. 1902, pp. 212, 252, 263) are here omitted, 
since I am not certain as to their mode of occurrence with reference to the Gondwana 
Species. 
(2) Comptes Rendus, vol. CXNXII, 1901, p. 594. 
(3) Gen, Rept. Geol. Surv. India, 1902—1903, (1903), p. 22. 
(4) See Zeiller, Annales des Mines, (8) mem., vol. IV, 1883, p. 594. 
