Reports and Proceedings — Geological Society of London. 43 



white limestones lithologically similar to the Danian white limestone 

 helow them, hut structurally different. These beds, directly under- 

 lying fossiliferous Eocene strata, are honeycombed, closely jointed, 

 and especially subject to erosion by water, the regularly bedded 

 Cretaceous strata differing in these respects. 



(3) A suggestion is made that these variations may be due to fold 

 effects produced while the land was gaining on the sea at the 

 beginning of Eocene times, the Qena limestones being remade 

 Cretaceous material. 



(4) Whereas in Southern Egypt Lower Eocene strata directly 

 overlie the Danian strata, in Northern Egypt very marked uncon- 

 formities exist between the Middle Eocene and the Cretaceous beds. 



(5) The main palseontological differences between the Cretaceous 

 and the Eocene are recorded, the principal feature being the sudden 

 incoming of the large Foraminifera Nummulites and Operculina ; in 

 both formations oysters and sea-urchins are dominant, Brachiopoda 

 being almost entirely absent. 



C. In this section the distribution, zonation, and variation of the 

 Eocene Series is considered, the main points being — 



(6) The apparent uniformity of the fossiliferous Lower Eocene 

 strata wherever developed. 



(7) The lack of uniformity in the Middle Eocene strata, only the 

 lowest zone, that of Nummulites gizehe?isis, being of wide distribution. 

 The nature of the Eocene beds between Baharia Oasis and the 

 depressions of Moela and the Fayum are described, zoned, and 

 compared with the Middle Eocene in other parts of Egypt, the 

 importance of the uppermost zone, the Gisortia Limestone, being 

 emphasized. 



(8) The influence of the gain of land over sea is traced through 

 the Upper Moqattam Beds (with their increase in detrital materials 

 and disappearance of Nummulites) and the Calcareous Grits overlying 

 them to the quartz-chert gravels forming the desert west of Cairo and 

 the Eayum, which are usually considered to be Oligocene, and mark 

 the final stages in the growth of the Oligocene continent. 



The Cretaceous Period in Egypt is, therefore, one marked by the 

 gradual gain of sea over land ; during the Eocene, on the contrary, 

 land appears to have been steadily gaining on the sea, probably 

 accompanied by gentle fold movements which account for the minor 

 differences in the nature of the Eocene deposits. At the close of 

 Eocene times and during the Oligocene Epoch the approach of 

 a continental phase is clearly indicated, all the stages in these varied 

 movements being illustrated in the desert regions. 



2. " The Origin of the British Trias." By A. R. Horwood. 

 (Communicated by Professor T. G. Bonney, Sc.D., F.R.S., E.G.S.) 



It is maintained that, though desert conditions prevailed locally 

 during the Triassic Period in Britain, deposition was brought about 

 solely by the action of water ; and the British Trias is a delta-system. 

 Eor, during Carboniferous, Permian, and Triassic times deposition 

 was mainly in the same area. There is, moreover, a gradual gradation 

 from the Bunter to the Rhsetic, from coarse sediments to fine. The 

 Bunter is known to be of fluviatile origin, since Professor Bonney first 



