ig6 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



species should be considered as a subspecies of G. angulata (White) and therefore 

 its name should be G. angulata conicotruncata Subbotina. 



Said & Kerdnay (1961, pi. 7, figs, i^a-c) described as G. angulata abundocamerata 

 Bolli, a form which is completely different from Bolli's original description and 

 figures. On the other hand, these authors described as Globorotalia convexa Subbo- 

 tina, forms which most probably belong to G. angulata abundocamerata. 



The form, described as G. conicotruncata Subbotina by Said (i960) from the 

 Lower Eocene Thebes limestone formation of Luxor, Egypt, is neither related to the 

 form described by Subbotina nor to the present subspecies. 



Globorotalia angulata abundocamerata is distinguished by its large, circular 

 umbilico-convex test ; its 6-7 chambers in the last whorl, which increase very slowly 

 in size ; its curved, depressed dorsal sutures, and radial, strongly incised ventral ones ; 

 its small, deep umbilicus ; and partially developed keel. Some of the 6-chambered 

 forms described as G. angulata (White) by various authors, probably belong to this 

 subspecies. 



Globorotalia angulata abundocamerata is believed to have evolved from G. angulata 

 angulata (White), and into G. velascoensis velascoensis (Cushman) as suggested by their 

 morphological features and stratigraphical ranges. However, it is not excluded that 

 G. angulata abundocamerata also evolved into G. apanthesma Loeblich & Tappan by 

 the development of the highly rugose surface. 



Hypotype. P.45594. 



Horizon and locality. Figured specimen, from sample No. 39, Gebel Owaina 

 section. 



Stratigraphical range. G. angidata abundocamerata was first described from 

 the Paleocene lower Lizard Springs formation of Trinidad (Bolli 1957&). It was also 

 recorded from the Paleocene of northern Italy (Bolli & Cita 1960a, b) where its range 

 was wrongly considered as Danian-Lower Montian, although the rest of the planktonic 

 Foraminifera indicated a Middle-basal Upper Paleocene age. Subbotina (1953) 

 recorded her Acarinina conicotruncata which is partly synonymous with this sub- 

 species, from the zone of the Danian Foraminifera which Berggren (1960^), quite 

 justifiably, regards as belonging somewhere between the Middle and the top of the 

 Paleocene. 



Sjutskaya (1956) considered G. angidata and its two varieties — praepentacamerata 

 and kubanensis as the index forms of the Paleocene in the Sub-Caucasus. 



G. angidata abundocamerata was also described as G. velascoensis from the so- 

 called Danian of the Kharga Oasis, Egypt, which is actually Middle Paleocene 

 (Nakkady 1959), and as G. convexa from the so-called Landenian of the Farafra Oasis, 

 Egypt (Said & Kerdany 1961). 



Most of the G. angulata (White) records probably included in part the present 

 subspecies. 



In the Esna-Idfu region, G. angulata abundocamerata appears as a common to a 

 flood form slightly higher in the section than the first appearance of G. angulata 

 angidata and then decreases gradually, dying out in the basal part of the G. velasco- 



