IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 253 



Paratype. P.45671. 



Horizon and locality. Holo- and paratypes, from sample No. 40, Gebel 

 Owaina section. 



Stratigraphical range. The species occurs as a rare to common form through- 

 out the Upper Paleocene G. velascoensis Zone, of the Esna-Idfu region. 



Globorotalia sp. 



(PL 23, figs. 8a-d) 



Description. Test medium-sized, strongly umbilico-convex, coiled in a very low 

 trochospire ; dorsal side slightly depressed, ventral side strongly protruding, equa- 

 torial periphery roughly quadrate, distinctly lobate, with a faint, delicately beaded 

 marginal keel which is sometimes masked by the surface rugosity ; axial periphery, 

 sharply angular, acute ; chambers on the dorsal side about 9, arranged in 2 sinistrally 

 coiled whorls ; the initial chambers are small, indistinct and almost masked by the 

 surface rugosity ; the last whorl is composed of 4! chambers (3I + 1 broken) which 

 are large, roughly oblong-shaped, elongate and increasing slowly in size ; on the 

 ventral side the chambers are 4 \ (3! -f 1 broken), large, inflated, strongly protruding, 

 and much longer than wide ; sutures on the dorsal side short, curved and depressed ; 

 on the ventral side they are radial and strongly incised ; umbilicus very small, 

 narrow and open ; aperture interiomarginal, extraumbilical-umbilical, a long, 

 crescentic arch, extending almost to the periphery ; wall calcareous, perforate ; 

 surface heavily papillose or even nodose, with the nodes sometimes tapering out to 

 form stout spine-like projections. 



Dimensions of described specimen. 

 Maximum diameter = 0-39 mm. 

 Minimum diameter = 0-34 mm. 



Thickness = 0-27 mm. 



Remarks. Although this form could not be assigned to any known species of 

 Globorotalia, it was decided not to describe it as new pending further study. 



It is distinguished by its medium-sized test ; quadrate appearance ; sharply 

 angular axial periphery ; flat or slightly concave dorsal side and protruding ventral 

 one ; oblong shaped chambers on the dorsal side, and triangular, elongated chambers 

 on the ventral; curved, depressed dorsal sutures and radial incised ventral ones ; 

 narrow umbilicus, weakly developed marginal keel, and rough surface. 



The forms described by Loeblich & Tappan (1957a, pi. 46, figs. ja-8c ; pi. 59, 

 figs. 6a-c) as G. aequa Cushman & Renz are very similar. 



Material. P.45644. 



Horizon and locality. Figured specimen, from sample No. 35, Gebel Owaina 

 section. 



Stratigraphical range. This form is rare in the upper part of the Middle 

 Paleocene G. angulata Zone. It crosses the Middle-Upper Paleocene boundary and 

 continues in the lower part of the G. velascoensis Zone, the G. pseudomenardii Sub- 

 zone where it dies out gradually towards the top. 



