Pro/. J. W. Dawson— Geology of the Nile-Valley. 291 



Balani, but we observed no other species. Under and against the 

 edges of the rock has been jDiled a very coarse sea beach, composed 

 of rounded fragments of limestone, with a few basaltic-like pebbles 



Fig. 3. Terraces in Eocene Limestone arove Assiout, on Arabian side 

 OF THE Nile. 



not native to the locality. The interstices of these are often packed 

 with loose oyster shells. The pebbles of the beach are somewhat 

 cemented together by calcareous matter, but otherwise the whole is 

 as fresh as if only recently deserted by the sea. The old beach has 

 however been cut by subsequent aqueous erosion since it became 

 consolidated, as it now stands on the side of the cliff with a vertical 

 face about forty feet above the sandy plain below. 



A little way over this plain to the southward are the well-knowu 

 beds containing Clypeaster lEgyptiacus, Pecten benedictiis, and P. 

 adimcus. Dr. Schweinfurth has recently found 0. Forskali, and other 

 modern species in these beds, which he states in some places pass 

 into a solid breccia. He regards their age as probably Pliocene, and 

 I have little doubt that they belong to the same sea-bottom with the 

 beach of Het-el-Orab. I am aware that they have been regarded as 

 Miocene, but the evidence of the fossils is against this. Dr. 

 Schweinfurth informs me that ancient Egyptian tombs have been 

 excavated in the breccia associated with the Clypeaster beds. 



It is evident that the submergence indicated by these sea-margins 

 would with the present levels carry the sea far up the Nile Valley, 

 as the top of the cataract at Assouan is only 300 feet above the sea- 

 level. I noticed at various points on the Nile as far up as Alsilis, 

 a terrace correspondiug with the height of the raised beaches, and 

 probably a continuation of the same shore, indicating that in the 

 Pliocene or Pleistocene age the Nile valley was an arm of the sea. 

 With this submergence I would also associate the older beds of con- 

 solidated gravel seen at Thebes and elsewhere in the Nile valley, 

 and the transport of boulders from the hills east of the Nile into 

 Lybia as seen at Denderah. The Theban gravels above referred to 

 are those in which flint flakes supposed to be of human workmanship 

 were found by General Pitt Rivers. If really of this origin, they 

 would prove the residence of man in Egypt at a time when only the 

 higher parts of the country were above the level of the sea. For 



