IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 149 



na, which was said to differ from Rugoglobigerina in being more highly spired, having 

 a smaller and deeper umbilicus, and in having short apertural flaps which extend into 

 the umbilicus, but do not form a cover-plate. However, as the cover-plate is a 

 delicate structure which is rarely well preserved, and as the other characters are of 

 specific rather than generic importance, Kuglerina Bronnimann & Brown 1956 is 

 considered a junior synonym of Rugoglobigerina Bronnimann 1952. 



Hypotype. P.45654. 



Horizon and Locality. Hypotype from sample No. 23, W. El-Sharawna 

 section. 



Rugoglobigerina rugosa (Plummer) 



1926 Globigerina rugosa Plummer : 38, pi. 2, figs, zoa-d. 



1932 Globigerina rugosa Plummer ; Sandidge : 367, pi. 33, figs. 11, 12. 



1952 Rugoglobigerina (Rugoglobigerina) rugosa rugosa (Plummer) Bronnimann : 28, text-figs. 



iia-i$i. 

 J 955 Globotruncana (Rugoglobigerina) rugosa rugosa (Plummer) ; Gandolfi : 72, pi. 7, figs. 



6a-c ; text-fig. 11c. 

 1957 Rugoglobigerina rugosa (Plummer) ; Bolli, Loeblich & Tappan : 42, pi. 11, figs. za-c. 

 i960 Rugoglobigerina rugosa rugosa (Plummer) ; Olsson : 50, pi. 10, figs. 16-18. 

 1962 Rugoglobigerina rugosa (Plummer) ; Berggren : 71-75 ; pi. n, figs. ia-$b ; text-fig. 



8 (ia- 5 b). 



Remarks. This species occurs throughout the Maestrichtian part of the sections 

 studied, being rare at the base and increasing gradually in number towards the top, 

 where it floods the Middle and Upper Maestrichtian. It was originally described 

 from the Maestrichtian Upper Navarro formation of Texas, and was later recorded 

 from the same formation (Bolli, Loeblich & Tappan 1957), from the Maestrichtian 

 of Alabama (Sandidge 1932), of Trinidad (Bronnimann 1952), of northeastern 

 Colombia (Gandolfi 1955), of New Jersey (Olsson i960) and of Scandinavia (Berggren 

 1962). 



Hypotype. P.45655. 



Horizon and locality. Hypotype from sample No. 18, W. El-Sharawna 

 section. 



Genus TRINITELLA Bronnimann 1952 



Type species. Trinitella scotti Bronnimann 1952. 



1952 Trinitella Bronnimann : 56 (Type species : Trinitella scotti Bronnimann 1952). 



Remarks. Trinitella Bronnimann 1952 is morphologically transitional between 

 Globotruncana Cushman 1927 and Rugoglobigerina Bronnimann 1952. It is dis- 

 tinguished from the former by the lack of an entire keel or keels and an imperforate 

 peripheral band, and from the latter by its compressed last chamber or chambers 

 and partially developed keel. The fact that this genus is monotypic, may suggest 

 its inclusion in either Rugoglobigerina (to which it is more closely related) or Globo- 

 truncana. However, as it does not conform to the present definition of either of these 

 genera, it is best treated separately until further study can reveal its true position. 



