i ., UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



3) to show the distribution of the various rock units and the location of the sections 

 studied. 



Every possible outcrop in the region was carefully examined and sampled ; fossils 

 were collected, and lateral as well as vertical variation in the different rock units was 

 considered. The succession was first divided, on the basis of its lithology, into five 

 formations and eight members (Text-fig. 5) which are clearly distinguished in the 

 field. It was then zoned on the basis of the macrofossils in its various units, and was 

 correlated with similar successions in other parts of Egypt. However, because of the 

 restricted geographical distribution of most of these macrofossils, correlation with 

 the type sections or the other known sections outside the Tethyan region could not be 

 achieved, and thus the limits of the various stages and substages could not be 

 definitely decided. 



To overcome this difficulty, eight main sections, representing the succession in 

 different parts of the region (Text-fig. 7) were chosen for the detailed study of 

 planktonic Foraminifera. Several other sections were also examined, but being 

 mainly composed of the Nubia sandstone and/or the Sibaiya phosphate formations, 

 they were either devoid of Foraminifera, or yielded only very rare, indeterminable 

 specimens and are not discussed here. 



The sections were measured and sampled in detail, using a tape, a Brunton compass 

 and an " Abney-level ". Samples were collected every three metres and every 

 metre or even fraction of a metre when necessary (Text-fig. 7). 



About three hundred samples (100 gms. of each) were processed for foraminiferal 

 analysis using standard techniques which differed according to the nature of the 

 rocks. In each case, the residue was dried and passed through a series of sieves 

 (30, 6o, 120 and 200 mesh). 



All the planktonic Foraminifera in each fraction were picked out and examined, 

 counts were made and range charts were constructed. However, as the ranges were 

 found to conform well in all the studied sections, it was not found necessary to present 

 a chart for each section. The ranges on the general charts, here included, represent 

 the ranges in the corresponding parts of each of the studied sections. 



Ninety five species and twenty four subspecies of planktonic Foraminifera are 

 identified, twenty species and six subspecies of which are new. All members of the 

 genera Globotruncana, Globigerina and Globorotalia are described and figured, except 

 for a few rare forms which are not figured. All figures are camera lucida drawings 

 by the author. Members of the genera Abathomphalus , Rugoglobigerina, Tnnitella 

 and Hedbergella are only listed and will be figured and described in a future publi- 

 cation. 



Comparison with type material was carried out wherever possible, and in such 

 cases it is noted in the remarks on each species. 



All types and figured specimens are in the British Museum (Natural History), 

 London ; a duplicate collection is deposited in the Department of Geology, U.C.W., 

 Aberystwyth. 



