INTRODUCTION. XXV11 



and China. Both genera, however, migrated into Kussia during 

 Permian times, though they do not appear to have penetrated 

 further into Europe at any period, despite assertions to the contrary 

 in past times. 



The fructification of Gangamopteris is entirely unknown, while 

 that of Ghssopteris is still too imperfectly understood to afford any 

 evidence of value as to the botanical affinities of the genus. Both 

 these fronds are, however, quite unlike any plant-remains known 

 from the Northern Hemisphere. 



In the genus Neuropteridium, we have an important type, probably 

 not nearly connected with the European genus Nburopteris, as the 

 name would seem to imply. In habit, at least, it would appear to 

 be quite distinct. It is a frond which is never very abundant in 

 Gondwanaland, but at the same time widely distributed. A single 

 species is known from India, the Cape Colony, and South America, 

 and thus affords an important aid in the correlation of these 

 widely separated regions. Its botanical affinities are still 

 obscure. It seems to have continued to flourish after the close 

 of the Pernio - Carboniferous period, when it had migrated into 

 Europe, for fronds almost identical with the Indian .-.pecies are 

 found in the Punter of the Yosges and elsewhere in the Trias 

 of Europe. 



In Taniopteris, which is associated with the Glossopteris flora 

 in India, and possibly also in Natal, we have a type of Fern- 

 like plant which is not specially characteristic of the flora of 

 Gondwanaland. The same genus also occurs, but sparingly, in the 

 Carboniferous and Permian rocks of the Northern Hemisphere. 

 It is essentially a Mesozoic type of frond, reaching its maximum 

 development in Triassic and Jurassic times. In the Palaeozoic 

 beds of both Europe and North America, as of Gondwanaland, 

 we seem to see the first incomings of races of great importance 

 at later geological epochs, but not specially characteristic of the 

 period at which they first appear. Taniopteris is a case in point. 



The genera Sphenopteris and Pecopteria, represented alike in both 

 the northern and southern type of flora, are unworthy of detailed 

 consideration here. They include many plants of very different 

 geological ages, and no doubt of quite distinct relationships, which 

 possess a particular type of frond-habit, and which, in the absence 

 of a knowledge of their fructifications, we are unable, fur the 



