PALEOBOTANY — BERRY. 385 



in the Tete basin in southeast Africa in rocks as young as the Upper 

 Carboniferous (Stephanian) . 



The earlier Glossopteris floras immediately overlying the Glacial 

 boulder beds, or in some cases, as in the Greta series of New South 

 "Wales, intercalated between glacial deposits, are everywhere rela- 

 tively simple and unmixed and characterized by the plant types men- 

 tioned above. With changing conditions that can only be inter- 

 preted as an amelioration of the climate, various members of the 

 northern cosmopolitan flora, especially the Lepidophytes, succeeded 

 in reestablishing themselves. It is probable that they were never 

 entirely extinct in the whole of Gondwana Land, but that they had 

 been present throughout the Glacial period in northern Africa and 

 northern South America. 



This recolonization of the South by the cosmopolitan types is 

 especially well illustrated in Brazil, where the farther the plant bed 

 is above the basal boulder bed, the more cosmopolitan is the facies 

 of the contained flora, which in the upper beds shows petrified 

 gymnospermous wood lacking annual rings such as were typically 

 developed in similar woods in beds immediately overlying the boulder 

 beds in Australia. In India, which at that time was geographically 

 difficult of access to returning northern types, no Lepidodendrons, 

 Sigillarias, or true Calamites have been recognized, although a species 

 of Sphenophyllum is recorded, and the genus Noeggerathiopsis may 

 really represent the true Cordaites. In South Africa the immigrants 

 from the North included Lepidodendron, Sigillaria, Bothrodendron, 

 and a doubtful Sphenophyllum. In South America they include 

 Lepidodendron, Lepidophlois, Sigillaria, Bothrodendron, and the 

 Paleozoic tree fern Psaronius. 



Indicative of the Lower Permian age of the Glossopteris flora, 

 as well as of a land connection to the northward, is the presence of 

 Glossopteris and Noeggerathiopsis in the Upper Permian (Zech- 

 stein) of the Vologda and Petschora districts of northern Russia and 

 in the Altai Mountains and elsewhere in Siberia, showing that these 

 types spread northward from Gondwana Land into the region still 

 occupied b} T the cosmopolitan flora before the close of the Paleozoic. 

 The genus Glossopteris itself, as well as some of its associates, not 

 including Gangamopteris, are known to have survived the Permian 

 and were present as dwindling relics as late as the Upper Triassic 

 (Rhaetian), or even in the Lower Jurassic, Glossopteris having been 

 recorded from beds of Jurassic age (Liassic) in southern Mexico. 

 Glossopteris has also been discovered in south latitude 85° in the 

 Beacon sandstone series, which has been traced for over 700 miles 

 across Antarctica, where it is coalbearing and probably of Permian 

 age, although part of it may be younger. Other genera of the 

 Glossopteris flora such as Schizoneura and Neuropteridium occur 



