In the Abstracts of the Proceedings of the Geological Society of London, No. 1254, of 16th December, 1932, Mr. L. R. Cox described certain siliceous boulders, and their Lower Tertiary fauna, collected for the most part at Hudi, north of the Atbara, by Mr. G. V. Colchester and others. As Mr. Grabham pointed out, the implications that the nature of the boulders and their fauna involve are of supreme importance to the geology of this part of the Nile Basin and, for that matter, of Africa.