242 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



Bolli, to distinguish them from the related but stratigraphically younger forms of the 

 third group described here as G. uncinata carinata subsp. nov. 



G. uncinata uncinata Bolli is distinguished by its flat to slightly inflated dorsal 

 side ; protruding ventral side ; rounded to subangular axial periphery ; curved, 

 depressed dorsal sutures and radial, incised ventral ones ; its crescentic, slightly 

 overlapping chambers on the dorsal side ; small, open umbilicus ; and delicately 

 papillose to roughly nodose surface. 



Bolli & Cita (19606) described as G. uncinata Bolli, specimens which, most probably 

 are transitional between this species and G. angulata angulata (White). 



Hillebrandt (1962) included G. uncinata Bolli in the synonymy of G. inconstant 

 (Subbotina). However, G. inconstans differs from G. uncinata in its rounded axial 

 periphery, almost straight dorsal sutures, and smooth, very finely pitted surface. 

 It may represent a transitional stage between G. trinidadensis and G. uncinata 

 uncinata. 



Hypotypes. P.45636-37. 



Horizon and locality. Figured hypotypes (PI. 18, figs. la-c) from sample 

 No. 34 ; (PI. 19, figs. 2a-c) from sample No. 35, Gebel Owaina section. 



Stratigraphical range. The subspecies was first described from the Paleocene 

 lower Lizard Springs formation of Trinidad, where it was found to characterize the 

 Globorotalia uncinata Zone, and to continue through the overlying G. p^lsilla pusilla 

 Zone. 



In the Esna-Idfu region, it is common in the Upper Danian, and continues as 

 common to abundant in the lower part of the Middle Paleocene G. angulata Zone, 

 characterizing the G. uncinata Subzone. It continues as a rare form in the over- 

 lying G. pusilla Subzone where it dies out completely. 



Globorotalia velascoensis caucasica Glaessner 

 (PL 19, figs. 6a-c) 



1937a Globorotalia aragonensis Nuttall var. caucasica Glaessner : 31, pi. 1, figs. 6a-c. 

 ? 1953 Globorotalia velascoensis (Cushman) ; Hamilton (pars) : 231, pi. 30, figs. 16-18, non 

 fig. 23 ; non pi. 31, figs. 24, 28-31. 



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

 low trochospire ; dorsal side flat although some of the chambers are weakly inflated 

 and slope gently towards the depressed sutures, giving the surface, in places, a 

 weakly undulating appearance ; ventral side distinctly protruding ; equatorial 

 periphery circular, strongly lobate, with a well-developed, broad, thick, heavily 

 beaded keel ; axial periphery distinctly acute ; chambers on the dorsal side 13, 

 arranged in 2 dextrally coiled whorls ; the initial ones are relatively large, almost 

 indistinct and very weakly raised ; the last whorl is composed of 6\ large chambers 

 which are typically crescentic in the early part, roughly trapezoidal later, and increase 

 slowly in size except the last one, which is smaller than the penultimate ; on the 

 ventral side the chambers are 6£, large, angular conical and distinctly protruding 

 with their distal ends thickened to form an everted collar surrounding the umbili- 



