320 Notices of Memoirs — R. Bullen Newton — 



Gulf. The only post-Tertiary movements that he recognizes over 

 this vast area, extending eastwards from the Atlantic Ocean for 

 some 3,000 miles, are " in the form of subsidence, particularly as 

 great trough-subsidences, which are here and there associated with 

 flexure of the edges. On the other hand, tangential movement and 

 folding are entirely absent, at least as far as we can judge at present ". 

 This view can no longer be maintained if Ave are to understand by 

 " subsidence " movements along normal faults. Flat-bedding, so far 

 as the eye can judge, certainly is the dominant feature in the 

 Egyptian portion of the Nile Valley, in the Oases, and in Sinai. 

 But, as Dr. Hume has pointed out, 1 the V-shaped outcrops on the 

 geological map of Egypt require the assumption of a broad syncline 

 whose axis dips slightly to the north, while the relations of the 

 Cretaceous and Eocene rocks to the lied Sea Hills and Sinai Mountains 

 indicate the presence of a complementary anticline to the east. Thus 

 folds of great amplitude certainly occur in this portion of the desert 

 plateau, reminding one of the swell of the ocean which is often felt 

 far away from the storm centre which produces it. Now Dr. Hume 

 shows us that sharp folding due to tangential pressure is also present. 

 But this alone would probably not have led Suess to modify his 

 general view. He would doubtless have regarded it as connected 

 with a trough subsidence and therefore of only local importance. 



The Report is well illustrated by photographs of scenery and 

 figures of the more characteristic fossils which are briefly described 

 by M. Eourtau in a special chapter. It does not profess to be final. 

 The map is said to be provisional and research is still going on. "We 

 await with interest the communications which are to follow, and 

 conclude by wishing success to those who are engaged in developing 

 the Egyptian oilfield, to whom we are indebted, both directly and 

 indirectly, for so much geological information about this most 

 interesting region. 



J. J. H. T. 



II. — The Conchological Features of the Lenham Sandstones of 

 Kent, and their, stratigraphical importance. By R. Bullen 

 Newton, F.G.S., of the British Museum (Natural History). 



Part II. 



Conclusions. 



WE gather from the previous literature on this subject that 

 the majority of investigators have agreed that the Lenham 

 Beds are equivalent to the Diestian deposits of Belgium, which 

 have been generally recognized by geologists as belonging to 

 the base of the Pliocene system, on account of the shell remains 

 exhibiting a marked Miocene facies with many species identical or 

 related to southern or Mediterranean forms. The Miocene aspect of 

 the Lenham fauna is very pronounced, as out of the seventy-seven 

 conchological species that have been determined in the present work, 

 forty-seven, or sixty per cent, date their origin from the Yindobonian 



1 Explanatory notes to accompany the geological map of Egypt. 



