210 THE GEOLOGY OF SOUTH-CENTEAL CEYLON. [May I9OI, 



Mr. Bakrow noted the resemblance of the specimens and slides 

 to those from Deeside. There the gneisses are largely of sedimentary 

 origin, and among them is a limestone closely resembling that 

 described by the Author. Did he consider that his limestone was of 

 sedimentary origin or not ? If he did, how was the absence of all 

 other sediments to be accounted for ? Some of the specimens claimed 

 as igneous contained structures which were characteristic of altered 

 sediments, and had never been met with by the speaker in the 

 igneous gneisses. One of the supposed igneous rocks (a fine biotite- 

 garnet-gneiss) bore a close resemblance to an altered sediment which 

 occurs close to the Galloway granite. 



Prof. BoNNEY said that these rocks of Ceylon were especially 

 interesting because they had, on the whole, escaped from the effects 

 of crushing. He had not understood the Author to deny that the 

 marble had once been a sediment, but he had his doubts as to the 

 banded gneiss to which Mr. Barrow assigned that origin. It was also 

 very interesting to get interchange of materials between the intruding 

 and the older rocks. It would be worth while trying to ascertain 

 under what circumstances this mixing occurred. 



Mr. Prior pointed out that many of these rocks from Ceylon 

 could be matched from the gneissic and granulitic rocks of tropical 

 East Africa ; but since this was equally true of rocks from Deeside, 

 as stated by Mr. Barrow, he did not feel inclined to use it as an 

 argument for the former connection of Africa and India. 



The President and Mr. R. D. Oldham also spoke. 



The Author, after thanking the Society for the very kind way 

 in which they had received his paper, said, in reply to Dr. Evans, 

 that he had subdivided the granulitic rocks described as far as he 

 felt to be wise, but that the structural and mineralogical resemblances 

 of the whole were so close that he felt compelled to regard them as 

 products of one magma. He concurred with Gen. McMahon in the 

 opinion that the foliation and bending of the Ceylon rocks were not 

 due to earth-movement ; in this his work agreed with that of 

 Mr. Coomara-Swfimy. In reply to Mr. Barrow he said that the lime- 

 stones occurred to a very limited extent within the area described, 

 and that the question of their origin was outside the scope of the 

 paper. Concerning the igneous origin of the other rocks he felt 

 not the slightest doubt, since appearances in the field and the 

 evidence obtained by means of the microscope clearly indicated such 

 a conclusion. 



