IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 213 



G. aequo, , the G. aequajG. esnaensis Subzone. It crosses the Paleocene/Lower 

 Eocene boundary and fades out gradually in the basal Eocene. All records of G. 

 esnaenensis from rocks older than the upper part of the Upper Paleocene are erroneous. 



Glob <o rot alia far agi sp. nov. 

 (PI. 19, figs. 4a-c) 



Diagnosis. A Globorotalia with biconvex, low trochospirally coiled test ; depres- 

 sed sutures ; very narrow umbilicus ; long slit-like aperture and papillose surface. 



Description. Test medium sized, trochospirally coiled, inflated ; dorsal side 

 slightly convex with the early whorls moderately raised above the level of the final 

 whorl ; ventral side strongly inflated ; equatorial periphery almost circular, strongly 

 lobate ; axial periphery rounded ; chambers on the dorsal side 16, arranged in 3 

 dextrally coiled whorls ; the initial ones are small, inflated, globigerine and are 

 followed by slightly larger, ovoid chambers ; the last whorl is composed of 5 large, 

 subglobular chambers which are slightly elongated in the direction of coiling and 

 increase slowly in size ; on the ventral side the chambers are 5, large, subglobular, 

 inflated and increase so slowly that they all appear to be roughly equal in size ; 

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

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

 incised ; umbilicus very small ; aperture a long narrow slit, interiomarginal, 

 extraumbilical-umbilical, extending slightly on to the dorsal side ; wall calcareous, 

 perforate ; surface delicately papillose on the dorsal side, more strongly so on the 

 ventral. 



Dimensions of holotype. 



Maximum diameter = 0-43 mm. 



Minimum diameter = 0-35 mm. 



Thickness = 0-26 mm. 



Main variation. 



1. Test small to medium sized, moderately to strongly inflated. 



2. Coiling is mainly dextral (of 42 specimens studied, 4 coiled sinistrally) . 



3. The aperture is interiomarginal, extraumbilical-umbilical, but in some 



specimens it extends slightly on to the dorsal side. 



4. The surface is delicately to strongly papillose. 



Remarks. Globorotalia faragi is morphologically similar to G. reissi Loeblich & 

 Tappan from which it is distinguished by its much larger size, papillose surface and 

 rounded axial periphery. It differs from G. convexa Subbotina in its globular form, 

 larger size, non-spinose surface, rounded axial periphery and raised early whorls on 

 the dorsal side. 



The form described here as Globorotalia cf . convexa is morphologically very similar 

 to the present species, but is distinguished by its flat, less globular, strongly 

 overlapping chambers which increase more rapidly in size, are typically crescentic 

 in the early stage and roughly quadrangular later. 



