106 upper cretaceous-lower tertiary foraminifera 



Dimensions of described specimen. 

 Maximum diameter = 0-51 mm. 

 Minimum diameter = 0-39 mm. 



Thickness = 0-24 mm. 



Main variation. 



1. Test medium-sized to large, subcircular to ovoid in outline. 



2. Dorsal side very slightly raised to moderately convex, gently plicate to 



slightly folded. 



3. Ventral side inflated, slightly to moderately protruding. 



4. Chambers 14-18, arranged in 2^-3 whorls, usually dextrally coiled (of 60 



specimens picked at random, 4 coiled sinistrally) . 



5. Usually 4 or 5 chambers in the last whorl : specimens with 3! or 6 chambers 



occur very rarely. 



6. The peripheral band varies in width and in degree of inclination towards the 



ventral side. 



7. The two keels can either be occasionally developed or the ventral keel may 



equally weaken towards the last chamber. 



8. The surface is generally smooth but is sometimes delicately papillose in the 



early part. 



Remarks. As was mentioned in part by Gandolfi (1955) Globotruncana fornicata 

 Plummer (1931) and of authors, is actually a group of closely related forms. These 

 are generally characterized by a biconvex, double-keeled test, small, globigerine, 

 early chambers, and long, narrow highly arched later ones ; these are slightly to 

 moderately plicate on the dorsal side and moderately to strongly overlapping on the 

 ventral. They are also characterized by a slightly inclined peripheral band and 

 dorsal sutures which merge into relatively sharp depressions from the periphery 

 inwards. 



Gandolfi considered some of these related forms to be subspecies of G. fornicata, 

 and described the following : 



Globotruncana fornicata fornicata Plummer 1931. 



Globotruncana fornicata plummer ae Gandolfi 1955. 



Globotruncana fornicata ackermanni Gandolfi 1955. 



Globotruncana fornicata cesarensis Gandolfi 1955. 



Globotruncana fornicata manaurensis Gandolfi 1955. 



However, Gandolfi's specimen described as G. fornicata fornicata Plummer 

 differs from Plummer's original description and figures and may possibly be a 

 distinct form. On the other hand, examination of topotypes of G. fornicata plum- 

 merae, kindly presented by Dr. R. Gandolfi, proved their identity with G. fornicata 

 fornicata Plummer from the Esna-Idfu region and with topotype material kindly 

 sent by Dr. E. A. Pessagno, Jr., of the University of California. Thus G. fornicata 

 plummer ae Gandolfi is considered to be a junior synonym of G. fornicata fornicata 

 Plummer. 



The other forms described by Gandolfi are here recognized as valid subspecies. 

 A new subspecies of G. fornicata was also discovered during the present study and 



