194 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



which are globular in the early part, becoming gradually more compressed towards 

 the last chamber, which is roughly lenticular and constitutes more than one-third of 

 the test ; the 6 chambers on the ventral side increase moderately in size (except for 

 the last) and are roughly lenticular, slightly inflated, and compressed ; sutures on 

 the dorsal side short, very gently curved to almost straight, depressed ; on the 

 ventral side they are relatively long, straight, radial and strongly incised ; umbilicus 

 small, shallow and open ; aperture interiomarginal, extraumbilical-umbilical, a low 

 arch with a small, delicate lip ; wall calcareous, perforate ; surface delicately spinose 

 especially along the periphery. 



Dimensions of holotype. 



Maximum diameter = 0-30 mm. 



Minimum diameter = 0-20 mm. 



Thickness = 0-14 mm. (of last chamber) 



Remarks. Globorotalia africana sp. nov. is distinguished from the closely related 

 G. sibaiyaensis sp. nov. by its concavo-convex test, numerous chambers, acute axial 

 periphery, partially developed pseudo-keel, raised, globular early chambers and 

 compressed lenticular later ones. 



The only known Paleocene Globorotalia species with a gently curved plane of 

 coiling along which the test grows in such a way as to produce a shallow concavo- 

 convex form, is Globorotalia kilabiyaensis sp. nov. from the underlying Danian rocks. 

 This species may represent the ancestral stock from which G. africana evolved, 

 although G. kilabiyaensis was not recorded from rocks younger than Upper Danian, 

 while G. africana was only recorded from the uppermost Paleocene. 



Holotype. P.45593. 



Horizon and locality. Holotype from sample No. 50, Gebel Owaina section. 



Stratigraphical range. The species is a rare form in the G. aequa-G. esna- 

 ensis Subzone of uppermost Paleocene age. 



Globorotalia angulata abundocamerata Bolli 

 (PI. 22, figs. 2a-c) 



? 1947 Globorotalia conicotruncata Subbotina (pars) : 115, pi. 4, figs. 11-13 ; pi. 9, figs. 9-11. 

 ? 1949 Globorotalia (Truncorotalia) velascoensis (Cushman) ; Cushman & Bermudez : 41, 



pi. 8, figs. 4-6 

 ? 1951a Globorotalia velascoensis (Cushman) ; Nakkady : 54, pi. 1, fig. 6. 

 1953 Acarinina conicotruncata (Subbotina) Subbotina (pars) : 220-222, pi. 20, figs, sa-qc, 

 non figs. io<z-i2c. 

 ? 1956 Globorotalia angulata White var. Kubanensis Sjutskaya : 93-94, pi. 3, figs. ^a-c. 

 ? 1957a Globorotalia trichotrocha Loeblich & Tappan : 195, pi. 50, figs. $a-c ; pi. 57, figs. ia-2c. 

 1957a Globorotalia apanthesma Loeblich & Tappan (pars) : 187-188, pi. 55, figs, la-c only. 



Non pi. 48, figs. la-c ; pi. 58, figs. a,a-c ; pi. 59, figs. ia-c. 

 I 957^ ) Globorotalia angulata abundocamerata Bolli : 74, pi. 17, figs. 4-6. 

 ? 1959 Globorotalia velascoensis (Cushman) ; Nakkady : 462, pi. 4, figs. ^a-c. 

 19606 Globorotalia angulata abundocamerata Bolli ; Bolli & Cita : 19-20, pi. 33, figs. 6a-c. 



