XXV111 INTRODUCTION. 



present, to group more in accordance with their botanical relation- 

 ships. It is interesting to find that, among the fronds hitherto 

 assigned to the latter, some are here removed to the genus Clado- 

 phlebis, as having more in common with this Mesozoic type of 

 Fern-like plant than with the Palaeozoic. CladopMebis, like 

 Tceniopteris, is essentially a Mesozoic frond. 



The Indian genus Palccovittaria is unlike in habit any member 

 of the northern flora. The species assigned to Merianopteris and 

 Belemnopteris are, however, too imperfectly known to warrant 

 consideration in this connection. All three genera are of rare 

 occurrence. 



As compared with the northern flora, that of Gondwanaland is 

 distinguished by the absence of such genera as Alethopteris, 

 Neuropteris, Odontopteris, Linopte-ris, etc., as well as by a rarity 

 of fronds of the true Pecopteris type. 



On the whole the Fern-like plants of Gondwanaland stand out 

 as remarkably distinct in habit from those of the northern flora, 

 such features as are common, for instance the occurrence of 

 Tmiiopteru, being chiefly due to the gradual incoming of plants 

 of a Mesozoic facies. 



Lycopodiales. In striking contrast to the Fern-like plants, the 

 Lvcopods associated with the Glossopteris flora are all generically, 

 and often specifically, identical with those of the northern flora. 

 In India and Australia the group is entirely unrepresented, though 

 at an earlier period both Lepidodendron and Bothrodendron flourished 

 in New South Wales and Queensland, and the former also in 

 Victoria. Lepidodendron also occurred in Argentina in Lower 

 Carboniferous times. All the four great genera, Lepidodendron, 

 Lepidophloios, Sigillaria, and Bothrodendron, have been found in 

 association with the Glossopteris flora in either South Africa or 

 South America, and these are the characteristic Lycopods of the 

 Northern Hemisphere. The evidence of this remarkable association 

 is one of the most striking results of recent research (see Historical 

 Sketch). Bearing in mind the entire absence of this group from 

 India and Australia, one is almost driven to the conclusion that 

 in the Glossopteris flora proper the Lycopodean element was not 

 represented. The occurrence of this group in South Africa and 

 South America is probably best explained by the assumption that 

 land connections existed in these regions between the Northern and 



