ORIGINAL ARTICLES. 
The Jurassic and Lower Cretaceous Rocks of 
Northern Sinai.! 
By W. F. Hume, D.Sc., F.R.S.E., A.R.S.M., R. Fourtau, 
F. W. Moon, B.E., F.G.S., and H. Sapex, B.Sc. 
Ok many years this portion of Egypt had remained a blank so 
far as its geological structure was concerned, and when the 
geological map of Egypt was issued by the Survey Department in 
1910 this extensive area was deliberately left uncoloured. Efforts 
were made by the writer ? to interest the various parties which were 
mapping the topography of this region, but the fossils submitted 
by them only indicated the presence of beds of Upper Cretaceous 
age, including a facies identical with that developed in the Abu 
Roash hills near Cairo. 
New and unexpected light was thrown on this problem when M. J. 
Barthoux commenced a geological map of the Isthmus of Suez on 
behalf of the Suez Canal Company. He was deeply impressed day 
by day with a sight of the unknown hills lying behind the sand- 
dune belt to the east, and finally resolved to cross the waste and 
solve the mystery of their structure. His energy and resource 
(shown later during the war by his escape from Germany after being 
captured near Soissons) were rewarded with success, for in the 
collections which he brought to the Cairo Geological Museum for 
study, M. Fourtau recognized species of sea-urchins of definitely 
Lower Cretaceous age. This indicated that the locality visited was 
of exceptional interest, and finally led to the discovery of the now 
famous Jurassic strata of Gebel Maghara. The species thus identified 
were Pseudodiadema libanoticum de Loriol, Holectypus macropygus 
var. neocomiensis Gras, and Pliotoxaster Collegnoi, race orientalis, 
Fourtau (R. Fourtau, “ Echinides Aptiens d’figypte et de Syrie,” 
Bull. de Inst. Egypt. 1913, pp. 43-58). At an early stage in the 
further examination of this area, M. Barthoux kindly invited the 
writer to accompany him, but as this was impossible owing to other 
duties demanding attention, it was arranged for M. Fourtau to join 
him. This has led to a very careful paleontological and strati- 
graphical study of the area by M. Fourtau, the results of which will 
appear in due course.? M. Douvillé was associated with M. Barthoux 
in the earliest publications on this subject, one of the first notes being 
that on “ Le Jurassique dans le désert & Vest de Visthme de Suez ”’, 
1 Published by permission of the Surveyor-General, Egyptian Government. 
2 This note has been written by Dr. W. F. Hume (hence termed the writer), 
but the facts on which it is based largely depend upon the work of those who 
are associated in the title as co-authors. 
3 Owing to the death of M. Fourtau since these words were written, it is 
uncertain how far this can Le fulfilled, but every effort will be made to 
publish the work in so far as it was completed by this indefatigable and 
enthusiastic student, whose early less to science we lament. 
