IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 173 



transitional stage between it and a possible direct descendant, G. soldadoensis 

 Bronnimann. 



Globigerina nodosa sp. nov. 



(PL 15, figs. 6a-c) 



Diagnosis. A Globigerina species with roughly triglobular, compressed test ; 

 nodose, spinose surface ; wide, deep umbilicus ; radial, depressed sutures ; and small 

 last chamber. 



Description. Test small, coiled in a low trochospire, roughly triglobular, 

 compressed ; dorsal side weakly convex ; ventral side moderately inflated ; equa- 

 torial periphery roughly ovoid, distinctly lobate ; axial periphery rounded ; chambers 

 on the dorsal side appear to be 14 in number ; they are arranged in 3 sinistrally coiled 

 whorls, and increase rapidly in size in the early part and slowly later ; initial cham- 

 bers small, indistinct and almost masked by the surface rugosity ; the last whorl is 

 composed of 4! chambers (3^ normal + 1 abortive) : with one exception these are 

 relatively large, roughly ovoid, moderately inflated and slightly compressed ; the 

 abortive chamber is relatively small, roughly ovoid and indistinct ; on the ventral 

 side the chambers are \\, roughly globular, slightly compressed and increase moder- 

 ately in size except for the small abortive chamber ; 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 incised ; umbilicus wide, deep 

 and open ; aperture interiomarginal, umbilical ; wall calcareous, perforate ; surface 

 distinctly papillose or even nodose, with the nodes tapering out in the form of thick 

 stout, spine-like projections especially along the periphery and around the umbilicus. 



Dimensions of holotype. 



Maximum diameter = 0-40 mm. 



Minimum diameter = 0-31 mm. 



Thickness = 0-25 mm. (along the middle part of test) 



Remarks. This form is rather rare in the samples studied. However, it is quite 

 distinct from all known Globigerina species and is therefore described as new despite 

 its rarity. 



Globigerina nodosa is distinguished from G. triloculinoides Plummer by its non- 

 reticulate, nodose, spinose surface ; its much wider umbilicus ; its compressed test ; 

 and by the lack of the well-developed apertural lip. It is distinguished from G. 

 inaequispira Subbotina by its smaller, compressed, non-elongate test, its heavily 

 spinose surface and its much smaller last chamber. The forms described as Globi- 

 gerina inaequispira Subbotina, by Loeblich & Tappan (1957a) and by Olsson (i960) 

 are completely different from Subbotina's original description and figures, but may 

 belong to the present species, although they are much more inflated. Similarly the 

 spinose forms described as G. triloculinoides Plummer byShifflett (1948) belong to the 

 present species. Globigerina chascanona Loeblich & Tappan has a similar surface 

 texture but is much higher on the dorsal side, has more chambers and a much 

 narrower umblicus. Globigerina stonei Weiss has a more inflated test, an almost 



