218 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



Globorotalia kilabiyaensis sp. nov. 

 (PI. 17, figs. 4«-c) 



Diagnosis. A Globorotalia with concavo-convex, compressed test ; lenticular, 

 chambers which increase rapidly in size ; radial, depressed sutures ; wide umbilicus 

 and almost perfectly smooth surface. 



Description. Test medium-sized, concavo-convex, strongly compressed, coiled 

 in a very low trochospire ; dorsal side slightly convex, ventral side concave ; equa- 

 torial periphery roughly ovoid, slightly elongate, moderately lobate ; axial periphery 

 subrounded, compressed ; chambers on the dorsal side 13, arranged in 2 sinistrally 

 coiled whorls ; the initial ones are small, globigerine, compressed and increase slowly 

 in size ; the last whorl is composed of \\, roughly lenticular, slightly compressed 

 chambers which increase rapidly in size ; on the ventral side the chambers are 4J, 

 roughly lenticular and increase rapidly in size ; sutures on the dorsal side curved, 

 depressed in the early part, almost straight, depressed later ; on the ventral side 

 they are straight, radial and strongly depressed ; umbilicus large, shallow and open ; 

 aperture interiomarginal, extraumbilical-umbilical, covered with a prominent, 

 flaring lip ; wall calcareous, perforate ; surface perfectly smooth with few, small, 

 delicate papillae on the ventral side of the early chambers. 



Dimensions of holotype. 



Maximum diameter = 0-300 mm. 



Minimum diameter = 0-225 mm. 



Thickness = o-ioo mm. 



Remarks. Globorotalia kilabiyaensis sp. nov. is distinguished from G. compressa 

 (Plummer) by its distinctly concavo-convex test, much wider umbilicus and 

 delicately papillose surface. The form described as G. compressa by Loeblich & 

 Tappan (1957a, pi. 44, figs, ga-c) shows a slightly concave ventral side and may be 

 transitional between G. compressa and G. kilabiyaensis. 



Holotype. P.45613. 



Paratype. P.45614. 



Horizon and locality. Holo- and paratypes, from sample No. 7, Gebel El- 

 Kilabiya section. 



Stratigraphical range. Globorotalia kilabiyaensis sp. nov. occurs in abundance 

 in the Upper Danian rocks of the Esna-Idfu region, immediately above the disconfor- 

 mity separating it from the underlying Maestrichtian strata. It ranges throughout 

 the Upper Danian, fading out gradually towards its top, and dying out completely 

 before the first appearance of G. angulata angulata, which marks the base of the 

 Middle Paleocene. 



Globorotalia loeblichi sp. nov. 

 (PI. 23, figs. la-c) 



? 1953 Acarinina pseudotopilensis Subbotina (pars) : 227, pi. 22, figs, la-c ; non figs. 2a-^c, 

 pi. 21, figs. 8a— gc. 



