194 SCIENCE PROGRESS. 



Summing up the facts in a few words, there are a few 

 plant genera in Australia, South Africa and South America 

 which agree closely with European Culm and Upper 

 Devonian forms. Above this horizon in India, Australia 

 and Africa the typical European plants are practically un- 

 represented, and in their place a new flora suddenly makes 

 its appearance, characterised by Glossopteins and other 

 genera of ferns and equisetaceous plants. In South 

 America, and probably in South Africa, the European facies. 

 seems to have held its ground to a somewhat later period, 

 Lepidophloios and other northern genera being found in 

 association with representatives of the Glossopteris flora. 

 It is a fact of considerable interest that many of the plants 

 characteristic of the Permo-Carboniferous Glossopteris flora 

 not only persist to a later epoch in the Southern Hemi- 

 sphere, but also extend northwards and occur as fairly com- 

 mon species in European Jurassic beds. To mention a few 

 examples, there is a close agreement between NcBggera- 

 thiopsis Hislopi, Bunb., and a leaf figured by Schoralhausen ^ 

 from Russia as Rhiptozamitcs ; the Glossozamites pinnae 

 figured by Feistmantel "^ from India fairly closely resemble 

 similar leaves described by Kurr,'^ Schenk and others from 

 European Jurassic and Wealden strata ; the genus Phyllo- 

 theca is a well-known member of the Jurassic flora of 

 Siberia, Italy, England and other countries; also another 

 South Hemisphere equisetaceous plant, Schizoneiira, occurs 

 in the European Trias. 



From some cause, then, it would appear that the 

 Palaeozoic vegetation, which in Lower Carboniferous times 

 had a more or less world-wide distribution, was replaced in 

 the South by a new set of plants, while in the Northern 

 Hemisphere the older forms continued to flourish until the 

 close of the Permian epoch, and were then superseded by a 

 flora of a newer facies. The widespread glacial deposits of 

 Australia, Africa, India and South America, point to con- 

 ditions favourable to the existence of ice and a lowering of 



^ Schoralliausen, pi. xv., figs. i-ii. 



2 Feistmantel (i), pi. xx., figs. 4 and 5. ^ Kurr, pi. i., fig. 5. 



