158 Jfessi's. Barron Sf Hume — Eastern Desert of Egijpt. 



(2) There is a distinct unconformity between the Esna Shales 

 and the Cretaceous. 



(3) Cretaceous Plateau at the foot of Jebel Duioi. — This was 

 hitherto scarcely known, and differs from the previously described 

 area in the absence of the Ptyclwceras, etc., and by their replacement 

 by large Nautili, associated with Libycoceras Ismaeli and beds of 

 Trigonoarca mnltidentata, etc., below which comes a bed crowded 

 with Ostrea Villei. A strong unconformity is also here present 

 between these beds and the Eocene. At the north end of this 

 range, near Saga Plain, the coprolite beds are of unusual thickness. 



(4) Confluence of WacU Safuja and Wadi Wasif — Here there are 

 two well-developed coprolite beds, and a veiy prominent layer of 

 BacuUtes. The conclusion arrived at is that the Cretaceous lime- 

 stones of the area described are of shallower-water origin than those 

 occurring to the north in Wadi Araba, and entirely Carapanian in 

 age, being characterized by the abundance of their oysters, their 

 well-marked coprolite beds, and small thickness. This main type 

 is of great palgeontological variability, the beds near Qena, Qosseir, 

 and Mellaha differing in essential particulars. 



Gypseous Deposits near the Bed Sea. — These occur only in the 

 ' Eaised Beach ' area, and are almost always intimately connected 

 with the limestones of this series. They crop out from under these 

 beds, and, by their invariable unconformit}' and constant height 

 above sea-level, suggest a " plain of marine denudation." They 

 are the Lower Eocene and Cretaceous Limestones which have 

 been altered, not from below as has been previously believed, but 

 from above, as will be shown in tlie Report on Western Sinai by 

 Mr. Barron. 



6. The Nubian Shales and /Sandstone. — These consist of soft green 

 and black carbonaceous shales and marls, and dark-brown and red 

 sandstone. The former being easily weathered are accountable for 

 the formation of the large plains which are met with in the areas 

 occupied by this series. The sandstones show evidence of ripple- 

 marking, sun-cracks, rain-prints, and worm-tracks. In the softer 

 upper beds, the vertebrse of a (?) Mosasaurus and pieces of fossil 

 wood in excellent condition were found. It is everywhere 

 unconformable to the underlying igneous rocks. 



The age of the deposit in this district is Santonian or Lower 

 Senonian, as shown by a bed of oysters found in the sandstone near 

 El Geita by Mr. Barron. No traces of Carboniferous fauna have 

 been discovered. It is later than the igneous range, and not earlier 

 as maintained by Eloyer and Mitchell. 



Part II. 



Igneous and Metamorphic Eocks. — These rocks, forming a wide 

 band running parallel to the Gulf of Suez and the Red Sea, 

 practically constitute the mass of the Red Sea Hills. The latitude 

 of 27 degrees N. closely agrees with an important geological 

 boundary, the granites playing a considerable part among the 

 components of the mountain ranges north of this line, while south 



