262 ME. W. T. BLANEOED OX THE OCCUEEE^'CE OF 



of glacial action in the lower part of the Karoo beds, which buried 

 glaciated surfaces on rocks probably of Archaean age. 



Prof. Dfttca]!^ said that it was very satisfactory to know that the 

 recent discoveries strengthened Mr. Blanford's original opinions re- 

 garding the Palaeozoic age of the Lower Gondwanas. Having had the 

 advantage of studying the rocks and fossils of the Gondwana series 

 in the Museum of the Eoyal Indian Engineering College, he (Prof. 

 Duncan) was impressed with the necessity of approaching the study 

 of the age of the Lower Gondwana series from above, for there were 

 no fossiliferous deposits beneath them. There were Purbeck- 

 Wealdens in Kachh, and also beds containing a Jurassic flora placed 

 between marine strata, and the MoUusca were often identical speci- 

 fically with those of the European type. Then the Eajmahal beds 

 must be lower than the Oolitic and the facies of the plants was 

 Liassic. The succession below was through a great depth of sedi- 

 mentary rock with thick plant-beds, and the Upper and Lower 

 Damudas had a different flora from the Eajmahal above and the 

 Karharbari beds of the Talchirs below. The flora was Mesozoic in 

 facies, but there were such forms as Neuropteris valida and many 

 Equisetacese, which gave a kind of European Palaeozoic appearance. 

 He considered that the animal remains must be considered of 

 greater classificatory value than the floras. With regard to the 

 glacial question, he considered that the Talchir boulders were the re- 

 mains of the moraines on the flanks of mountains which had sunken. 



Eev. E. Hill remarked that when people change the axis of the 

 earth, they do not change its shape. Hence, for glacial conditions to 

 thus arise in the southern localities alluded to, one pole of the earth 

 must have been somewhere about the middle of the Indian Ocean, 

 and the equator about where England now is. Dr. CroU claimed 

 that there was a Glacial period in the Carboniferous epoch. 



Prof. Seelet thought it was an exceedingly doubtful proceeding 

 to attempt correlation of beds on the ground of traces of glaciation. 

 It seemed to him desirable that we should get fuller evidence that 

 the glaciation referred to in the paper had really existed. A few 

 scratches appeared to be doubtful evidence. The pebbles and 

 boulders described by the author were in some cases several feet in 

 diameter and rounded ; and in how many cases were there those 

 smoothed surfaces with striae which furnished unmistakable evidence 

 of glacial conditions ? He referred to other causes of such phenomena, 

 and even of scratches, quite independent of glaciation. . 



As regarded the question of fossils as indicating the age of de- 

 posits, he thought that we are not justified in taking such a plant as 

 Glossopteris as c.haracteristic of a particular geological period. He 

 referred to the case of Trigonia as indicating the mistakes into 

 which we may easily be led by attaching too much importance in 

 this respect to particular types, and maintained that, however good 

 such a mode of settling the age of deposits may have been in past 

 time, with our present knowledge it is liable to lead to a delusion. 

 From the reptiles found in the Indian rocks referred to, no one 

 would have any reason for regarding them as referable to a sharply 



