I have just finished the revision of the Neogene Echinids of Egypt preserved in the collections of the Cairo Geological Museum. Before the publication of this work, which will form the fourth fascicule of the Catalogue of the Fossil Invertebrates of Egypt, it has seemed to me that it might be useful to consider the fauna as a whole, drawing from it some conclusions as to the palæobiology of the Neogene seas of Egypt. I wish further to ascertain if the Echinids of this region can be of some aid as regards the stratigraphical divisions, and in synchronizing these with the divisions already established in the other regions of the Neogene basin of the Mediterranean.