IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 161 



forms with a moderately convex dorsal side (e.g. pi. 49, figs. 40-0) or even a flat dorsal 

 side (e.g. pi. 61, figs. 8a-c). 



Globigerina chascanona has probably evolved from G. aquiensis Loeblich & Tappan, 

 by the development of the prominently spinose surface. The morphological 

 characters and stratigraphical ranges of the two species support this proposition. 



Specimens of G. chascanona from the Esna-Idfu region conform well with Loeblich 

 & Tappan 's original description and figures although they are slightly larger. 



Hypotype. P. 45574. 



Horizon and locality. Figured specimen from sample No. 64, Gebel Owaina 

 section. 



Stratigraphical range. Loeblich & Tappan (1957a) described G. chascanona 

 from the Hornerstown formation of New Jersey and the Aquia formation of Virginia, 

 as well as from the Nanafalia formation of Alabama which they considered as Upper 

 Landenian (Sparnacian) and Lower Eocene respectively. But, as previously 

 mentioned, both Bramlette & Sullivan (1961) and Gartner & Hay (1962) considered 

 the Nanafalia formation to be of Paleocene rather than of Lower Eocene age. 



G. chascanona was also recorded from the Lower Eocene of northwestern Germany 

 (Berggren 1960a), and from the type Ilerdian of Spain (Gartner & Hay 1962), 

 although Berggren 's forms appear to be somewhat different from the type specimens 

 of G. chascanona. 



In the Esna-Idfu region, G. chascanona is rare in the upper part of the Upper 

 Paleocene G. velascoensis Zone and dies out completely below the overlying Lower 

 Eocene G. wilcoxensis Zone. 



Globigerina daubjergensis Bronnimann 

 (PL 15, figs. 3a-c) 



1953 Globigerina daubjergensis Bronnimann : 340-341, text-fig. 1. 



1956 Globoconusa conusa Khalilov : 249, pi. 5, figs. za-c. 



19576 Globigerina daubjergensis Bronnimann ; Bolli : 70, pi. 16, figs. 13-15. 



1957 Globigerina daubjergensis Bronnimann ; Troelsen : 128, pi. 30, figs. ia-2c. 



1957a Globigerinoides daubjergensis (Bronnimann) Loeblich & Tappan (pars) : 184-185, pi. 40, 

 ? figs. la-c, 8a-c ; pi. 41, figs, ga-c ; pi. 42, ? figs. 6a-jc ; pi. 43, figs. la-c ; pi. 44, ? figs. 

 7-8c. 



1959a Globigerina daubjergensis Bronnimann ; Hofker : 22, text-fig. 5. 



i960 Globigerinoides daubjergensis (Bronnimann) : Olsson : 43 pi. 8, figs. 4-6. 



1960a Globigerina daubjergensis Bronnimann primitiva Hokfer (pars) : 226, ? text-fig. 25 ; 

 228, text-fig. 34. 



1960a Globigerina cf. daubjergensis Bronnimann ; Hofker : 228, text-fig. 36. 



19600' Globigerina daubjergensis Bronnimann ; Hofker (pars) : 34-41, pi. 3, (? Danian II, 

 Danian III, Danian IV, non Danian V, non white chalk of Denmark ; non Cr 4, non Mc, 

 ? holes in hard ground, non Lower Paleocene of Holland) ; non pi. 1, figs. B, E ; non pi. 2, 

 fig. B. 



1960^ Globigerina daubjergensis Bronnimann ; Hofker : 74-76, text-figs. 290-346, table 4. 



19601 Globigerina daubjergensis Bronnimann ; Hofker : 1 19-120, pi. 1, figs. 1-8. 



Description. Test very small, coiled in a high trochospire ; dorsal side broadly 

 conical with a sharply pointed initial part and inflated later part ; ventral side 



