NEWBOLD ON THE SILICIFIED WOOD OF EGYPT. 355 
Gebel Ahmar.—I shall now proceed to 
give the result of the examination of Gebel 
Ahmar (A, fig. 9), which lies on the northern 
limit of the fossil forest, and of the shallow 
valley that separatesthem. The former is 
an irregular dark-coloured ridge that rises 
to the apparent height of about 150 feet 
from the general level of the surrounding 
desert, about a mile in length and half a 
mile in breadth. The rugged and conical 
shapes of portions of this ridge have been 
caused chiefly by a number of excavations 
and mounds of rubbish consisting of frag- 
ments of quarried rock. The lower portions 
of these quarries are often basin-shaped and 
partially filled with the finer sand of the 
Fossil forest. 
thus described by Mr. Jameson Torrie, whose notice 
I did not see till this paper had been written :— 
“ The breccia containing fragments of a conifera is 
from the neighbourhood of Aboosambal or Ipsam- 
bul in Nubia. The rocks of that district are sand- 
stones and conglomerates which form hills present- 
ing very remarkable conical and pyramidal shapes. 
Many of the specimens of sandstone are highly 
ferruginous and much indurated. The colour of 
these fragments is brown internally but brownish- 
black externally, and the external shapes rendered 
apparent by the decomposition of the softer sand- 
stone, are singular, being stalactitic, botryoidal 
perforated, vesicular,&c. The wood breccia is from 
a bed at the edge of a large chasm, which tra- 
verses for a considerable distance sandstone strata, 
to the south-east of the ruined town and castle of 
Kalat Addé, and about a league and a half from 
Ipsambul.” Mr. Nicol affords the following note 
on the structure of the conifera:—‘‘The mass 
containing the conifera is an aggregate, consisting 
of fragments of the fossil wood and grains of quartz, 
united by a cement, consisting chiefly of carbonate 
of lime with a little iron and clay. The fragments 
of wood are of an elongated form and of various 
dimensions, the largest being little more than an 
inch in length. Externally, the woody portions are 
of a greyish-black, but internally the colour, at 
least of one of the specimens, was hair-brown. 
By reflected light, the hair-brown fragment shows 
no appearance of organization even when polished ; 
but when a transverse section of it was reduced to 
the proper thickness, it showed distinctly the reti- 
culated texture of the recent conifere. From the 
faintness of the partitions it is not likely that the 
longitudinal sections would exhibit discs so as to 
enable us to determine whether the fossil belongs 
to the Pine or Araucarian division of Coniferz, and 
I have accordingly not attempted to make a longi- 
Site: section.” —Hdin. New Phil. Journ. vol. xviii. 
Pp. 2 
Fig. 9. 
Section showing valley of erosion. 
f the Mokattem. 
Valley B. 
d. Hard masses of a, a, left on surface of the valley. 
a, a. Sandstone and pudding-stone imbedding silicified trunks, partially covered with sand and gravel of the desert. 
c, c. Marine limestone o 
b, 
Gebel Ahmar. 
