INTRODUCTION. XXXIX 



that it was during this period that the Glossopteris flora, as a 

 whole, attained to its maximum development and differentiation, 

 though many of the typical genera still survived, as we shall see, 

 in early Mesozoic times. 



We may briefly examine the evidence as to the geological age of 

 the rocks of Gondwanaland, so far as it is based on the occurrence 

 of plant-bearing deposits. 



Between the years 1845 and 1886, the Glossopteris - bearing 

 sequence in India and Australia had received considerable attention, 

 but the precise age of the beds was much in dispute. The first 

 real evidence on this point was obtained from Australia. The 

 earlier Glossopferis-bea.riag rocks in New South Wales — the Muree 

 Series, known locally as the " Lower Coal Measures " — are underlain 

 and overlain by marine beds containing a rich invertebrate fauna. 

 The mollusca collected from these rocks were worked out in 

 1876-7 by de Kouinck, who showed that they were largely 

 identical with those of the Carboniferous deposits of Europe. 

 Hence the Glossopteris - bearing sequence is, in part at least, of 

 Carboniferous age. 



During the period referred to above, the examination of these 

 deposits had resulted in the discovery of a remarkable series of 

 beds of glacial origin in India and Australia, 1 underlying the 

 earlier Glossopteris-hcaving sediments. The Talchir boulder beds in 

 India, the conglomerates at the base of the Muree Series in New 

 South "Wales, the Bacchus Marsh boulder beds in Victoria, and 

 similar accumulations elsewhere in Australia 2 are cases in point. 



It had thus become clear that there was evidence of the existence 

 of widespread glacial conditions immediately antecedent to the first 

 appearance of Glossopteris and its allies, and this discovery helped 

 materially in the correlation of the Indian and Australian deposits. 3 

 In 1886, Waagen 4 showed that deposits, similar in character to the 

 Talchir boulder beds, occur in the Salt Range of Northern India, 

 and are overlain by sediments, containing Conularia and other 

 typical members of the European Carboniferous fauna. This 



1 W. T. Blanford (84), (86). 



- See David (96). 



3 II. F. Blanford (75) ; W. T. Blanford (86] ; R. L>. Oldham (86). 



1 Waagen (86) : W. T. Blanford (86). 



