222 Lieut. Newbold on the Geology of Egypt. 
bably occur where they grew ; but until the vertical stems are traced 
down to roots fixed in a given stratum or at certain levels, marking, 
as in the Portland “‘ dirt-bed,’’ the ancient surface of dry land, Mr. 
Newbold hesitates to admit the hypothesis that the Cairo fossil de- 
posit is the site of a submerged forest. 
Reposing horizontally, and at the height of 300 feet, on the in- 
clined limestone of the Gebel Ataka range which skirts the shore of 
the Red Sea below Suez, is a calcareous conglomerate, which Mr. 
Newbold thinks may represent the sandstone formation, as it rests 
on the marine limestone, and contains similar pebbles ; but it contains 
no silicified wood, nor any other fossils, except such as have been 
derived from the subjacent limestone. 
6. Post-Pliocene Deposits.—Around the head of the Gulf of Suez, 
as well as between the Red Seaand the cliffs which skirt its western 
shore, is an interrupted fringe rising in some parts to a height of 60 
feet, with an extreme breadth of four or five miles, composed of cal- 
careous deposits containing the remains of testacea, radiaria and 
corals, which now inhabit the Red Sea. Kossier and several other 
towns stand upon this formation. It is suspected by some observers, 
on account of the obliteration or shallowing of anciently deep har- 
bours, that the process by which the fringe was raised above the 
level of the sea is still in operation, and Mr. Newbold is of opinion 
that the forces which effected the upheaval acted gently and gradually. 
He objects, however, to the inference that the isthmus of Suez has 
been recently raised, on account of the difference in the faune of the 
Mediterranean and the Red Sea. 
Among the post-pliocene formations, the author includes the ac- 
cumulations now forming around the Red Sea and in the Mediterra- 
nean on the shores of Sicily, Greece, Asia Minor, &c. On the west 
shores of the Red Sea he has noticed them five or six feet above 
high-water mark, overlying a raised coral beach. They sometimes 
enclose bones of the camel; and in the island of Rhodes Mr. New- 
bold observed in a similar formation fragments of ancient pottery. 
In the valley of the Nile, on the plain of Benihassan, myriads of 
Nummulites, washed from the overhanging limestone, are partially 
re-cemented by calcareous matter deposited from springs and form 
layers which alternate horizontally with others composed of clay, 
sand and gravel, the whole in some places attaining a thickness of 
more than 30 feet. In the valley of Kossier, beds of gravel and other 
detritus are gradually becoming consolidated by a calcareous or fer- 
ruginous cement derived from percolating water; and in the cliffs 
skirting the Mediterranean, between Alexandria and Aboukir, Mr. 
Newbold observed a bed of bleached bones, derived from Roman and 
Greek cemeteries, with an intermixture of more modern human re- 
mains, overlaid by a layer of occasionally agglutinated sand or gravel, 
sometimes from three to four feet thick. 
7. Drift.—Under this head the author includes, Ist, the saline 
sands and gravel of the deserts, derived in great part, he believes, from 
the fossil-wood sandstone formation, but generally much influenced 
in each portion of the deserts by the character of the rocks in the im- 
