IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 195 



? 1961 Globorotalia convexa Subbotina ; Said & Kerdany : 329, pi. 1, figs. 7a— c. 

 1962 Globorotalia (Truncorotalia) angulata (White) ; Hillebrandt : 131-132, pi. 13, figs. 

 i/\a-i$c. 



Description. Test large, planoconvex, umbilico-convex, coiled in a very low 

 trochospire ; dorsal side almost flat and very slightly imbricate ; ventral side distinctly 

 convex and strongly protruding ; equatorial periphery circular, slightly lobate ; 

 axial periphery subacute, with a faint, delicately beaded keel in the early part which 

 fades out gradually towards the last chamber ; the 17 chambers on the dorsal side 

 increase slowly in size and are arranged in 2 J sinistrally coiled whorls ; the initial 

 chambers are small, very slightly inflated, globigerine, and are followed by closely 

 coiled crescentic chambers ; the last whorl is composed of 7 chambers which enlarge 

 so slowly that they appear to be roughly equal in size ; the 7 chambers on the ventral 

 side are relatively large, strongly inflated, roughly conical, distinctly angular and 

 strongly truncate laterally ; sutures on the dorsal side curved, slightly depressed, on 

 the ventral side radial, strongly depressed ; umbilicus relatively narrow, deep and 

 open ; aperture a narrow slit, interiomarginal, extraumbilical-umbilical ; wall 

 calcareous perforate ; surface finely pitted, with the ridges between the pits simulating 

 stout spine-like projections covering the surface, especially on the ventral side, and 

 thus the test appears as if it is granular or subspinose. 



Dimensions of described specimen. 

 Maximum diameter = 0-41 mm. 

 Minimum diameter = 0-37 mm. 



Thickness = 0-25 mm. 



Main variation. 



1. Chambers 14-18, arranged in 2-3 1 whorls, generally sinistrally coiled, but 



dextral forms also occur (of 40 specimens chosen at random, 26 coiled 

 sinistrally). 



2. Chambers in the last whorl 6-7. 



Remarks. Globorotalia angulata abundo earner ata was first described by Bolli 

 (19576) as a new subspecies to distinguish the multi-chambered forms of Globoro- 

 talia angulata from the form with few chambers originally described by White (1928). 



Subbotina (1947, 1953) described as Globorotalia conicotruncata and Acarinina 

 conicotruncata respectively, forms which most probably belong to both G. angulata 

 abundocamerata and G. angulata angulata. However, examination of the holotype of 

 G. conicotruncata Subbotina is needed before using her name for the present sub- 

 species. 



Sjutskaya (1956) described as Globorotalia angulata (White) var. kubanensis a form 

 which probably belongs to the present subspecies. However, as her description 

 was very brief, Bolli's name is used here. If Sjutskaya's varietal name is later 

 proved to be a senior synonym it should be raised to subspecific rank as warranted by 

 its morphological features and stratigraphical range. Again, comparison with the 

 holotype of G. conicotruncata Subbotina may prove both Sjutkaya's variety and the 

 present subspecies to be junior synonyms of G. conicotruncata. In its turn the latter 



