IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 163 



less, refrained from referring the species to the (probably polyphyletic) genus 

 Globigerinoides.' ' 



Bolli (19576), Hofker (1959a, 1960a, d, g, i, 1961a 1 , 1962a), Bolli & Cita (1960a, b), 

 and Berggren (1962) considered the species to belong to the genus Globigerina 

 although both Hofker and Berggren clearly described and figured these dorsal open- 

 ings. 



Loeblich & Tappan (1957a, b) followed by Olsson (i960) and Hillebrandt (1962), 

 removed this species to the genus Globigerinoides, while Reichel (1953) and Bermudez 

 (1961) considered it to be a ? Globigerina. 



Loeblich & Tappan figured the dorsal views of 7 specimens, only four of which were 

 shown to have supplementary apertures ; they said nothing about the forms without 

 supplementary apertures, nor did they say to which genus these forms should be 

 referred if the species is removed to the genus Globigerinoides. Hofker (1959a, 

 1960a, d, g, i, 1961a 1 , 1962a) and Berggren (1962) tried to explain that these dorsal 

 openings are slight morphological variations in the evolutionary development of the 

 species, and do not warrant its removal to the genus Globigerinoides. 



These so-called supplementary apertures were not observed in specimens of G. 

 daubjergensis from the Esna-Idfu region. Bronnimann (personal communication, 

 April 2, 1963) stated that : " The type of Globigerina daubjergensis Bronnimann does 

 not have any additional apertures, and the removal to the genus Globigerinoides does 

 not seem to be justified." Thus, it is here suggested that the typical G. daubjergensis 

 does not have supplementary apertures, that forms with supplementary apertures 

 should be considered separately, and that the removal of the species to the genus 

 Globigerinoides is not warranted. However, in the very closely related Globigerina 

 kozlowskii Brotzen & Pozaryska which is associated with G. daubjergensis in the 

 Upper Danian, and is believed to have evolved from it, occasional, minute, sutural 

 openings were observed, but seem to be different from the typical Globigerinoides 

 sutural apertures. A detailed study of a whole population of each of these two species 

 at their type localities is essential to establish their relationship and explain the true 

 nature of these supplementary apertures. It is not excluded, that forms described 

 as G. daubjergensis with sutural apertures are actually G. kozlowskii and that the 

 latter represents the ancestral stock from which the genus Globigerinoides has evolved. 



Khalilov (1956) described Globoconusa as a new genus with Globoconusa conusa 

 Khalilov as type species. Examination of the description and figures of the latter 

 species showed clearly that it is a junior synonym of Globigerina daubjergensis 

 Bronnimann 1953, and that Globoconusa is a junior synonym of Globigerina d'Orbigny 

 1826, as mentioned above. 



Hofker (1959a, 1960a, a 1 , g, i, 1962a) studied the orthogenetic changes in the 

 development of G. daubjergensis in the Danian rocks of Denmark, Holland and 

 Belgium. Apparently he had confused G. daubjergensis with small forms of Mae- 

 strichtian Rugoglobigerina and Hedbergella species and also with younger Globigerina 

 species in the overlying Middle Paleocene greensands such as Globigerina kozlowskii, 

 thus obscuring the stratigraphical range and morphological characteristics of the 

 species. This may be mainly due to the occurrence of mixed Maestrichtian- 



