i 9 2 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



curved, depressed, dorsal sutures, which were vaguely described by Renz (1951) as 

 rather well-pronounced dorsal sutures. 



Nakkady (1951a) described as Globorotalia colligera (Schwager), forms which 

 most probably belong to G. aequa as examination of his specimens (B.M.N.H., 

 P. 41766) has revealed. 



Subbotina (1947, 1953) described as G. crassata (Cushman) forms which are 

 actually G. aequa Cushman & Renz. 



Sjutskaya (1956) described as Globorotalia praenartanensis sp. nov., a form which 

 appears to be identical with G. aequa and is thus considered to be a junior synonym. 



Said & Kenawy (1956) described as Truncorotalia crassata aequa, forms which are 

 not related to this species, but which probably belong to G. aragonensis Nuttall as can 

 be seen from their figures. 



Loeblich & Tappan (1957a) described as G. aequa, forms with a marginal keel, 

 although G. aequa has no keel. These forms most probably belong to G. quetra 

 Bolli, G. loeblichi sp. nov. and to other undescribed forms. 



The form described by Olsson (i960) as G. aequa is apparently G. angulata angulata 

 (White) and that described by Kupper (1961) as G. (Truncorotalia) aequa, may be 

 transitional to G. angulata angulata (White). 



Hillebrandt (1962) considered G. aequa as a group of three distinct subspecies, 

 namely : 



Globorotalia (Truncorotalia) aequa aequa Cushman & Renz. 

 Globorotalia (Truncorotalia) aequa simulatilis (Schwager). 

 Globorotalia (Truncorotalia) aequa marginodentata (Subbotina). 

 He also considered both G. rex Martin and G. kolchidica Morozova to be junior 

 synonyms of G. simulatilis (Shwager), and G. jormosa gracilis Bolli to be a junior 

 synonym of G. marginodentata Subbotina, and then regarded both G. simulatilis and 

 G. marginodentata to be two distinct subspecies of his Globorotalia (Truncorotalia) 

 aequa group. However, Berggren (1960a : 58) stated that " G. subbotinae Morozova, 

 may be the correct name for G. marginodentata Subbotina if the two species should 

 prove to be synonymous. Illustrations and descriptions in several Russian papers 

 appear to indicate their identity, although a resemblance of G. subbotinae to G. 

 wilcoxensis is also noted in some cases. A study of type material has shown Globo- 

 rotalia marginodentata Subbotina to be a synonym of G. rex Martin." In other words, 

 it is understood from Berggren's statement that both G. marginodentata Subbotina 

 and G. rex Martin are possibly junior synonyms of G. subbotinae Morozova, but the 

 brief description of the latter species does not allow any decision. Until this con- 

 fusion is cleared up by examination of the holotypes of Globorotalia simulatilis 

 (Schwager), G. subbotinae Morozova, G. rex Martin, G. marginodentata Subbotina, 

 G. jormosa gracilis Bolli and G. kolchidica Morozova, it is best to keep Globorotalia 

 aequa Cushman & Renz as a separate species. 



Globorotalia aequa Cushman & Renz is distinguished by its large, strongly umbilico- 

 convex test ; its distinctly lobate, serrate periphery ; its small number of chambers 

 which increase very rapidly in size in the last whorl, and its last chamber which 



