Hyland — On some Specimens from Wady-Malfa. 439 



organic fibres, and presents, under crossed nicols, a mosaic-like 

 structure. Where crystalline quartz occurs, the organic structure 

 is obliterated. A certain amount of carbonate of lime is present — 

 a fact that Russegger long ago remarked when visiting the locality. 1 



The fossil wood, which covers the desert to the East of Cairo, 

 has long filled the passing traveller with surprise. At Jebel 

 Ahmar, or the lied Mountain, near Cairo, it occurs, according to 

 Sir W. Dawson, " in prostrate trunks, sometimes flattened, and 

 imperfectly preserved, and sometimes perfectly silicified, and occa- 

 sionally lying in disintegrated cuboidal fragments, showing that 

 the wood was imbedded in its natural state, and in a decayed 

 condition, and afterwards silicified." 2 The fossil wood of the 

 Jebel Ahmar and the " petrified forests " has been examined and 

 described by various authors. 3 It includes several species of 

 Nicolla, also conifers and a Palm. 



The collection also contains " scrapers " of varying shape. 

 They are made of jasper, do not exceed four inches in length, 

 and are almost all fabricated upon a plan which has been noticed 

 elsewhere in Egypt, viz. by taking a rather flat stone and chipping 

 away upon one surface only so as to leave the whole of the flatter 

 side, whilst but a small central portion of the upper surface was 

 left. Many of the flakes are trimmed articles with carefully 

 worked edges : the material selected for these was a bright and 

 yellow cornelian. There are also very fine pebbles, consisting of 

 fibrous chalcedony, streaked with parallel lines of iron oxide, and 

 presenting a beautiful picture under crossed nicols. One section 

 shows the line of growth or infiltration, and inclined to this, at an 

 angle of nearly 60°, the chalcedonic fibres have formed. The iron 

 oxide exhibits a tendency to develop a sort of oolitic structure — 

 in fact, at times the reddish layers consist almost entirely of such 



1 Neues Jahrbuch fur Mineralogie, etc., 1836, p. 688. (Letter to v. Leonhard, 

 dated Alexandria, April 17, 1836). 



- Notes on the Geology of Egypt, Geol. Mag. 1884, iii. vol. i., p. 385 ; also, 

 Xewbold, On the Geological Position of the Silicified Wood of the Egyptian and 

 Libyan Deserts, with a Description of the " Petrified Forest," near Cairo, Q. J. G. S., 

 Lon., 184S, vol. iv., pp. 349-357. 



3 R. Brown, Q. J. G. S., Lon., iv., p. 354 ; W. Carruthers, Petrified Forest near 

 Cairo, Geol. Mag., vol. vii. (1870), p. 306 ; Zittel, Ueber den Geol. Bau der Libyschen 

 Wuste: Miinchen, 1880. 



SCIEN. PltOC. K.D.S. VOL. VI., PAKT VIII. 2 L 



