IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 59 



Subbotina, G. pentacamerata Subbotina, G. pseudomenardii Bolli, G. pseudoscitula 

 Glaessner, G. simulatilis (Sch wager), G. triplex (Subbotina), G. varianta (Subbotina), 

 and G. velascoensis (Cushman). 



Analysis of their descriptions and figures showed that : 



1. G. area (Cushman) is probably Globotruneana gagnebini Tilev. 



2. G. gansseri Bolli is possibly Globotruneana rosetta rosetta (Carsey). 



3. G. rosetta (Carsey) is Globotrunacna stuarti stuarti (de Lapparent). 



4. G. eocaena Giimbel is apparently Globigerina turgida Finlay. 



5. G. convexa Subbotina is most probably Globorotalia angulata abundocamerata 



Bolli, while the figure described by them under the latter name is a doubtful 

 form which is completely different from Bolli's original description and 

 figures. 



6. G. pentacamerata Subbotina is Globigerina mckannai White. 



7. G. simulatilis (Schwager) probably belongs to Globorotalia occlusa Loeblich & 



Tappan. 



8. G. triplex (Subbotina) is probably Globorotalia loeblichi sp. nov. 



9. G. varianta (Subbotina) is possibly Globorotalia pseudobulloides (Plummer) 



while their G. valescoensis (Cushman) should be assigned to Globorotalia 

 velascoensis velascoensis (Cushman). 

 10. Rugoglobigerina reicheli pustulatais probably Rugoglobigerina rugosa (Plummer), 

 while their R. sp. cf. R. jerseyensis Olsson, their G. cretacea Cushman, 

 Globorotalia imitata Subbotina, G. pseudoscitula Glaessner, G. colligera 

 Schwager, and Globigerina triloculinoides Plummer, are doubtful forms. 



In the present study, the rich planktonic foraminiferal fauna of the Upper Creta- 

 ceous-Lower Tertiary sections provided the only means for precise zonation and 

 inter-regional correlation. The short ranges of most species and their wide geo- 

 graphical distribution points to their great stratigraphical value. However, as is 

 indicated above, previous misidentifications, misinterpretations of stratigraphical 

 ranges, over-brief specific descriptions, crude figures, the abundance of synonyms 

 and homonyms, and the divergent views held by authors on various important 

 taxonomic problems have all helped to mask the value of many species of planktonic 

 Foraminifera in stratigraphical zonation and world correlation, and have filled the 

 literature with an overwhelming amount of confused data. 



Although studies aimed at clarifying the identity and establishing the true 

 stratigraphical ranges of various planktonic species have already been made by 

 Cita (1948), Tilev (1951, 1952), Bolli (1951, i957«, b), Bolli, Loeblich & Tappan 

 (1957), Subbotina (1953), Gandolfi (1955), Bronnimann & Brown (1956), Loeblich 

 & Tappan (1957a), Bolli & Cita (1960&), Berggren (1960a, 1962), Pessagno (i960, 

 1962), and Barr (1962), many problems were left unsolved and a new critical study 

 was badly needed. Thus, this part of the work is mainly devoted to a study of the 

 most important members of the recorded planktonic Foraminifera. Each species is 

 treated in detail. Full synonymies with figures and descriptions, to the end of 

 August, 1963, have been compiled (El-Naggar 1963), but, with a few exceptions, only 

 the correct identifications are listed here. References without figures and descrip- 



