THE GEOLOGY OF EGYPT. 405 



close correspondence between the Egyptian beds and those 

 of France, and has attempted to correlate even the smaller 

 sub-divisions. 



The structure of the hill is very simple. It is formed of 

 a series of beds dipping pretty regularly towards the east. 

 Even at a distance two divisions are clearly recognisable, 

 for the lower beds are white in colour and the upper beds 

 brown. The lower division consists chiefly of fossiliferous 

 limestones characterised by the abundance of nummulites, 

 especially N. Gizchensis and N. curvispira. Amongst the 

 other fossils we can mention only Echinolampas Fraasi, E. 

 africana, and the remarkable crab Lobocarcinus. An 

 interesting peculiarity of this division is the common occur- 

 rence of celestine (1, 4). 



The upper division consists of an alternation of brown 

 clays and sands, with beds of limestone. Fossils are not so 

 numerous as in the lower beds, but some banks are filled 

 with Ostrea Clot-Bey i and other species of oyster. The large 

 nummuhtes have mostly disappeared, and N. Gizehensis is 

 unknown ; but A". Beaumonti and N. sub-Beaiimonti occur 

 throughout. 



According to Zittel these divisions are only of local value 

 and cannot be recognised, for example, at Beni Hassan and 

 Minieh. The whole Mokattam stage must, therefore, be 

 looked upon as one, and it is correlated by Zittel with the 

 Parisian. Mayer-Eymar (17), however, recognises at Mo- 

 kattam all the numerous sub-divisions which he has adopted 

 in the Parisian of Europe, and he states that the resem- 

 blance to the European sequence is very close. 



In the northern wall of the depression of Fayum a 

 succession of beds very similar to that of Mokattam has 

 been described by Schweinfurth (26). The most inter- 

 esting of the fossils which he records are the remains of 

 Zeuglodon and of a number of Teleostean fish which have 

 been described by Dames. According to Schweinfurth the 

 bed from which they are derived, corresponds with a part of 

 the upper division of the Mokattam stage. 



Throughout the greater part of Egypt the marine Eocene 

 concludes with the Mokattam stage. But in the west. 



