438 



DELTA OF THE NILE. 



[Ch. XVIII. 



position of certain tombs near Alexandria, and their present 

 level relatively to the Mediterranean, and the ruins of certain 



towns half sub 

 admitted to im 



Menzaleh 



in Egypt within the historical period. 



The occurrence of former oscillations of level is also attested 

 by the existence, at different heights, from 30 to 100 feet and 

 upward s, above the level of the present alluvial plain, of a 



of terraces composed of fluviatile alluvium. In 



succession 



Messrs 



the same species as those now inhabiting the waters of the 



Nile, such as Mil 



pullus, I 



familiar 



Bulimus 



fluminalis. The last-mentioned shell is 

 as being so common in the ancient or Post- 



pliocene river-deposits of the Thames, in London and the 

 neighbourhood, in which the bones of a hippopotamus and 

 other extinct animals are found. 



Such terraces occur both above and below the first cata- 



ract ; 



Nubia, the molar 



of a large hippopotamus were obtained, and were identified 

 by the late Dr. Falconer, with the species now living in the 



Nile. 



These and other proofs of gradual movements which have 



occurred in Post-tertiary times, in Egypt, might have been 

 looked for by geologists, after they had come by independent 

 researches to the conclusion, that the northern borders of the 

 Red Sea, and a large part of the Sahara, or, in other words, 

 vast regions east and west of Egypt, had been upraised within 

 the Post-pliocene epoch. On the one side is the Great Desert, 

 formerly submerged beneath the sea, and now laid dry,* With 

 the Cardium edule frequently strewn over its surface ; on the 

 other side, or to the eastward, are littoral deposits 200 feet 

 hiorh, bordering the western shore of the Red Sea (lat. ~° 

 1ST.), which, are chiefly made up of corals and shells of recen 

 species, indicating a modern conversion of the ancient sea- 

 bottom into land. During such great continental niovemen 



C* 



$ 



lH 



* Elements of Geology, p. 174. 



