INTRODUCTION. 



Southern Continents, 1 and that a migration of part of the northern 

 flora into Gondwanaland took place. There are other reasons for 

 such a conclusion. The existence of a typical Upper Carboniferous 

 flora of the northern type at Tete 3 on the Zambesi, whereas 

 Glossopteris-he&r'mg rocks are known to stretch both to the north 

 and south of that river, can only be explained by some such 

 hypothesis. Further, the difficulty which might be raised as to 

 why, on this assumption, the Lycopods are the only northern types 

 found in the Transvaal in association with Glossopteris, is met by the 

 fact that both Calamites, Cycadofilices, and Ferns of that type occur 

 in the Tete basin, thus showing that other members of the northern 

 flora were not absent from South Africa at this period. We may 

 therefore conclude, at least provisionally, that the Lycopodean 

 element was unrepresented in the Glossopteris flora proper. The 

 absence of any new members of this group in either South Africa 

 or South America is thus explained. 



Cordaitales. In the Northern Hemisphere this group is repre- 

 sented by a single member, Cordaites, of great importance. In 

 Gondwanaland we have the genus Noeggerathiopsis, whose precise 

 affinities are still imperfectly understood. The leaves of Noeggera- 

 thiopsis, the only organs of that plant known, are very closely 

 similar to those of Cordaites, and on the present imperfect 

 evidence it would seem that the northern and southern members 

 of this group were probably closely related. The occurrence of 

 petrified wood, similar in structure to Badoxylon, the stem of 

 Cordaites, and of seeds of the type of Cardiocarpus, in association 

 with the Glossopteris flora, tends to confirm this conclusion. 



The genus Noeggerathiopsis, especially the species N. Hislopi 

 (Bunb.), is widely distributed, being recorded from all the great 

 provinces of Gondwanaland. Similar leaves also occur in the 

 Triasso-Rha3tic of Tonquin and China. 



Cycadophyta. A critical examination of the Glossopteris flora 

 has tended to show that only two representatives of this group are 

 known, and one of these (Cyeadites) is of a somewhat doubtful 

 nature. The other is a Pteropkyllum, not unlike the earlier 

 Cycadean leaves of Europe, and very similar to some fronds from 



1 See Seward (03-), p. 833; Blanford, W. T. (90). 



2 Zeiller (83). 



