of the Deposits of the Nile Delta, obtained by Boring. 37 



The microscopic examinations of these pebbles of igneous rocks 

 shows that they consist of much altered hornblende audesite, or 

 porphyrite (208 feet), and andesitic (porphyritic) tuffs (121 feet, 

 175 feet, 208 feet). These rocks remind one of those of Djebal 

 Dockran, except from the circumstance that they are not coloured 

 by the manganese epidote like the celebrated " Porfido rosso antico." 

 Altered quartz-andesite, dacite, or quartz-porphyrite (160 feet) 

 with rhyolite, showing beautiful flow-structure and many foreign 

 fragments caught up in its mass (160 feet), — and rhyolite or quartz- 

 andesite tuffs (170 feet, 250 feet) were also found. 



Of metamorphic rocks, quartzites, which are evidently altered 

 sandstones, were found somewhat frequently. And in some cases 

 (208 feet, 250 feet) the pebbles showed evidence that the rocks from 

 which they were derived had undergone great crushing — the myloni- 

 tic (cataclastic) structure and the brecciated and veined structures 

 affording striking evidence of the deformation to which the rocks had 

 been subjected. 



Many pebbles of sandstone, sometimes showing stratification and 

 fault-structures, but destitute of organic remains, were obtained at 

 various depths. Some examples of sand-grains bound together with 

 iron oxide (like our " carstone ") also occur among the pebbles. The 

 <?hief fossiliferous rocks found were as follows : — 



Pebbles of flinty limestone from depths of 160, 175, 250 feet con- 

 tain recognisable Foraminifera, and one pebble, from 175 feet, is 

 crowded with specimens recognised by von Zittel as " belonging to 

 the Textularida?, Rotalidse, and Globigerinee." Of these there are 

 other specimens from a depth of 270 feet. Dr. von Zittel states : 

 " I hold it as probable that these pebbles come from the Eocene of the 

 Nile valley. Flinty layers and concretions are extremely common in 

 the Egyptian Eocene (as, for example, in Central and Upper Egypt). 

 The absence of sections of Nummulites and Alveolina is particularly 

 noticeable." 



At the request of Dr. von Zittel the sections containing Foramini- 

 fera were submitted to Professor T. Rupert Jones, F.R.S., who, with 

 the aid of Mr. F. Chapman, has examined and reported upon them. 

 The following notes on certain of the fossiliferous pebbles are based 

 on the reports kindly furnished to me : — 



From a depth of 160 feet a pebble was obtained containing both 

 Foraminifera and, apparently, sponge-spicules. The species recog- 

 nised were — 



Globigerina bulloicles d'Orb. (a form with a thick prickly test, prob- 

 ably a deep-sea variety). 



O. sp., a depressed form. 



Cristellaria or Nummulites ? 



