IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 215 



dorsal side and strongly protruding ventral side ; its high umbilical shoulder ; wide, 

 deep umbilicus; its curved, depressed dorsal, and radial strongly incised ventral 

 sutures ; its subcircular, lobate, densely spinose, equatorial periphery and angular 

 axial one ; and its slit-like, long, narrow aperture. 



Globorotalia hispidicidaris possibly evolved from G. apanthesma Loeblich & Tappan, 

 by the development of the unequally biconvex test, angular axial periphery, more 

 densely spinose surface, a high umbilical shoulder, a narrower, deeper umbilicus, a 

 narrower, longer aperture, and a thick spinose pseudo-keel. On the other hand, it is 

 not excluded that G. hispidicidaris has evolved from G. mckannai, with forms like G. 

 strabocella Loeblich & Tappan as transitional stages. 



Hypotype. P.45610. 



Horizon and locality. Figured specimen, from sample No. 55, Gebel Owaina 

 section. 



Stratigraphical range. The species was first described by Loeblich & Tappan 

 (1957a) from the Aquia formation of Virginia which they considered to be of Upper 

 Landenian or Sparnacian age. 



In the Esna-Idfu region, G. hispidicidaris is a rare to common form in the upper- 

 most part of the G. velascoensis Zone (the upper part of the G. aequa-G. esnaensis 

 Subzone) of uppermost Palecoene age. 



Globorotalia imitata Subbotina 

 (PL 17, figs. 6a-c) 



!953 Globorotalia imitata Subbotina : 206-207, pi- J 6. figs. i^a-i6c. 



1957a Globorotalia imitata Subbotina ; Loeblich & Tappan (pars) : 190-191, pi. 45, figs. 6a-c ; 



pi. 54, figs. 8a-c, ? ga-c ; pi. 59, figs. $a-c ; pi. 63, figs. $a-c ; ? pi. 44, figs. ^a-c. 

 i960 Globorotalia imitata Subbotina ; Olsson : 46, pi. 9, figs. 7-9. 



Description. Test small, coiled in a very low trochospire ; dorsal side flat in the 

 early part, weakly inflated later ; ventral side moderately inflated, slightly protruding 

 equatorial periphery subcircular, lobate ; axial periphery rounded ; chambers on 

 the dorsal side 14, arranged in 2 sinistrally coiled whorls ; the initial chambers are 

 small, globigerine, compressed and very tightly coiled ; the last whorl is composed of 

 6 relatively large, roughly globular and weakly inflated chambers, which increase 

 moderately in size except for the last which is slightly smaller than the penultimate ; 

 on the ventral side the chambers are 6, globular and moderately inflated ; sutures on 

 the dorsal side curved, depressed in the early part, almost straight, radial and 

 depressed later ; on the ventral side they are straight, radial and strongly depressed ; 

 umbilicus relatively large, shallow and open ; aperture interiomarginal, extraumbili- 

 cal-umbilical, a low arch bordered above by a narrow, delicate lip ; wall calcareous, 

 perforate ; surface smooth. 



Dimensions of described specimen. 



Maximum diameter = 0-25 mm. 



Minimum diameter = 0-20 mm. 



Thickness = o-ii mm. (of last chamber) 



