STUDIES IN FORAMINIFEBA 



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BLOBISERINA CIPSRO- 

 ENSIS CIPEROENSIS 



































SLOBOROTALIA OPIUA 

 OPIMA 





































SLOBISERINA AMPLI- 

 APERTUKA 





































z 



o 



o 



SAN FERNANDO 



SLOBOROTALIA COCOAENSIS 







































NAVET 



SL0BI6ERAPSIS SEUI- 

 IHVOLUTA 







































TRUNCOROTALOWES ROHRI 







































PORTICUL ASPHAERA 

 MEXICAN A 

























, 



















SLOBOROTALIA LEHNERI 













































BLOBISERAPSIS KU6LERI 













































HANTKENINA ARASONEIfSIS 













































SLOBOROTALIA PALMERAE 





















1 















UPPER 

 LIZARD SPRINGS 



SLOBOROTALIA AMSON- 

 ENSIS 





































SLOBOROTALIA FORMOSA 

 FORMOSA 









































SLOBOROTALIA REX 









































z 

 u 

 o 

 o 



< 

 a. 



LOWER 

 LIZARD SPRINGS 



SLOBOROTALIA 

 VELASCOENSIS 















































SLOBOROTALIA PSEUDO- 

 MENARDII 













































SLOBOROTALIA PUSILLA 

 PVSILLA 







































SLOBOROTALIA UNCINATA 







































SLOBOROTALIA TRIHI- 

 OAOENSIS 







1 

 1 































Figure 16. — Species distribution of Chilogutmbelina, Guembelitria, and Zeauvigerina in the Tertiary of Trinidad, 



B. VV. I. 



ary, at a level which corresponds to the upper Midway 

 and Wilcox groups of North America. A complete 

 change of fauna takes place in the uppermost part of 

 the Lizard Springs formation. After the extinction of 

 all Paleocene-lower Eocene species, Chiloguembelina 

 martini (Pijpers) appears in the Globorotalia aragonensis 

 zone and becomes the dominant Eocene species in size 

 and frequency. Some details of the distribution of 

 other species in the lower to middle part of the Navet 

 formation remain imcertain, owing to the insufficient 

 number of samples from the Globorotalia palmerae zone 



and the poor preservation of the specimens from the 

 Globigerapsis kugleri and Globorotalia lehneri zones. 



Chiloguembelina martini disappears at the Eocene- 

 Oligocene boundary and is therefore a good Eocene 

 marker. The only survivors in the Oligocene are 

 Chiloguembelina cubensis (Palmer) and Chiloguembelina 

 victoriana, new species. The latter species died out 

 suddenly in the middle of the Globigerina ampliapertura 

 zone, and the last occmrence of Chiloguembelina cubensis 

 is in the Globorotalia opima opima zone. 



Specimens of Chiloguembelina occur in great numbers 



