[68 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



G. inaequispira is believed to have evolved from G. triloculinoides Plummer. 



Hypotype. P.45578. 



Horizon and locality. Figured specimen, from sample No. 49, Gebel Owaina 

 section. 



Stratigraphical range. Subbotina (1953) described G. inaequispira from the 

 " zone of conical Globorotalias " of the northern Caucasus which she considered as 

 Lower to Middle Eocene. However, Berggren (1960^) considered this zone, on the 

 basis of its pelagic foraminiferal content, to indicate an Upper Paleocene-Lower 

 Eocene age. 



In the Esna-Idfu region, G. inaequispira appears in the lower part of the Middle 

 Paleocene G. angulata Zone. It continues as a rare to common form up to the 

 Upper Paleocene G. velascoensis Zone, fades out gradually in the top part of this 

 zone, dying out completely below the overlying G. wilcoxensis Zone. 



Globigerina kozlowskii Brotzen & Pozaryska 

 (PL 15, figs, la-c, 2) 

 1961 Globigerina kozlowskii Brotzen & Pozaryska : 162-164, P^ s - I_ 3- 



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

 broadly conical with a sharply pointed initial part, and strongly inflated later part ; 

 ventral side strongly inflated ; equatorial periphery broadly ovoid and distinctly 

 lobate, axial periphery rounded ; chambers on the dorsal side about 13 in number, 

 arranged in 3 sinistrally coiled whorls ; initial chambers extremely small, indistinct, 

 inflated, globigerine, increasing slowly in size up to the beginning of the last whorl, 

 where they start to enlarge so rapidly that the final whorl constitutes most of the test ; 

 the last whorl is composed of 3^, relatively large, roughly globular and strongly 

 inflated chambers ; on the ventral side the chambers are 3§, relatively large, globular 

 and inflated ; sutures on the dorsal side curved, depressed in the early part, straight 

 and strongly incised between the later chambers ; on the ventral side they are 

 nearly straight, radial and strongly depressed; umbilicus very small, shallow and 

 nearly closed ; aperture interiomarginal umbilical ; wall calcareous, finely perforate; 

 surface finely papillose. 



Dimensions of described specimen. 

 Maximum diameter = 0-24 mm. 

 Minimum diameter = 0-20 mm. 



Thickness = 0-19 mm. 



Variation. The main variation observed in the rare specimens of G. kozlowskii 

 studied is in the occasional presence of minute, sutural openings and/or small, senile 

 chambers in some specimens, and in the size of the umbilicus which may sometimes 

 be closed. 



Remarks. G. kozlowskii is believed to have evolved from G. daubjergensis 

 Bronnimann in the uppermost Danian by the increase in the size of test, and the 

 development of a finely papillose surface instead of the finely spinose one character- 



