370 ON SOME EEODED AGATE PEBBLES EEOM THE SOUDAN. 



The Pkesident said that his first impression had been that the 

 erosion might have been produced by wind and sand, but such 

 action produced more rounded contours than those of these pebbles. 



The AtjihoPv, in reply, said that he had not lost sight of the possi- 

 bility of Tvind-action. It was quite possible that some effect might 

 have been produced in this way, but the pebbles had the appearance 

 of a banded material which had been acted upon by a solvent. 



