78 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



Remarks. Globotruncana aegyptiaca was first validly described by Nakkady 

 (1950). He had, however, previously (1949) used the name without any description 

 or figures. 



Nakkady (1950) gave only the dorsal view of the holotype, and the ventral and 

 lateral views of two different paratypes. His choice of the paratype (1950, pi. 90, 

 fig. 22) was rather unfortunate as it is a deformed specimen which does not reflect 

 the ventral character of the holotype or the other paratypes. He described the 

 umbilicus as wide, while on his fig. 22 it was shown to be rather narrow. He also 

 stated that the dorsal side is always flat and that the periphery is " single keeled in 

 most specimens but occasionally with a double keel ". However, examination of the 

 holotype and paratypes of Nakkady (B.M.N.H.) Nos. P. 41773 and P. 41774, respec- 

 tively) showed clearly that all the specimens are double keeled with a rare tendency 

 towards the reduction of the ventral keel on the last chamber only (e.g. the holotype), 

 and that the dorsal side is not always perfectly flat, but is sometimes weakly inflated, 

 giving the test a very gently arched appearance. 



Nakkady (1950) described as varieties of G. aegyptiaca two distinct forms which he 

 named G. aegyptiaca var. duwi and G. aegyptiaca var. /. Examination of the 

 holotype of G. aegyptiaca var. duwi Nakkady (B.M.N.H. No. P. 41775) and 3 para- 

 types, (P. 41776), and comparison with specimens in the present study, showed clearly 

 that this variety is worthy of distinction as a separate subspecies, in contrast to 

 Berggren's (1962) statement that it can probably be included in G. aegyptiaca. 

 Thus the name is changed here to G. aegyptiaca aegyptiaca to distinguish it from 

 G. aegyptiaca duwi. 



Globotruncana aegyptiaca var. /. Nakkady is a single keeled form which most 

 probably belongs to the G. gansseri Bolli group, as previously mentioned by Berggren 

 (1962) and substantiated by the examination of Nakkady 's holotype and one 

 paratype (B.M.N.H. Nos. P.41777 and P.41778 respectively). 



Berggren (1962) considered G. gagnebini Tilev to be a junior synonym of G. 

 aegyptiaca Nakkady. However, the study of a great number of individuals of both 

 species has revealed that they are morphologically distinct. Globotruncana gagne- 

 bini has a less lobulate, more tightly coiled, distinctly elongate test ; chambers 

 which increase very rapidly in size, a much larger or much smaller last chamber and a 

 greater number of chambers in the last whorl. 



Nakkady & Osman (1954) recorded G. aegyptiaca aegyptiaca from the Esna shales 

 and chalk of both the Qabeliat and Sudr sections (southwestern Siani, Egypt), 

 but their figures are not at all clear. 



Bronnimann & Brown (1956) described as Rugotruncana skewesae from the Middle 

 Maestrichtian of Texas, a form which only differs from the holotype of G. aegyptiaca 

 aegyptiaca Nakkady in having a distinctly developed spinose periphery, and faint, 

 discontinuous costellae on the early chambers of the last whorl on the ventral side. 

 Forms of G. aegyptiaca aegyptiaca with a distinctly spinose periphery and spinose 

 early chambers on the ventral side were mentioned by Nakkady (1950), were 



