STUDIES IN FORAMINIFERA 



169 



Globorotalia bolivariana (Fetters) 

 Plate 37, Figures 14a-16 



Globigerina vnlsoni Cole subsp. bolivariana Fetters, Contr. 



Cushman Found. Foram. Res., vol. 5, pt. 1, p. 39, pi. 8, 



figs. 9a-c, 1954.— Weiss, Micropaleontology, vol. 1, No. 4, 



p. 309, pi. 2, figs. 6-8, 1955. 

 Globigerina vnlsoni Cole, Weiss, Micropaleontology, vol. 1, No. 



4, p. 309, pi. 2, figs. 22-23, 1955. 



Stkatigraphic range: Hantkenina aragonensis zone 

 to Truncorotaloides rohri zone, Navet formation. 



Locality: Figured hypotypes (USNM P5736a-c) 

 from the Porticulasphaera mexicana zone, Navet forma- 

 tion; same locality as given for Hastigerina micra 

 (Cole) (p. 161); sample Hg 8581 (TTOC 215782). 



Remarks: Globorotalia bolivariana (Fetters), origi- 

 nally described as subspecies of Globigerina vnlsoni 

 Cole, displays a distinctly interiomarginal, umbilical- 

 extraumbilical aperture; tlie very narrow slit often 

 extends towards the spiral side. The species differs 

 from the Globorotalia opima Bolli in being more involute 

 (chambers of the earlier whorls are almost invisible) 

 and in being almost planispiral. G. bolivariana is 

 restricted to the middle Eocene while G. opima ranges 

 from the uppermost middle Eocene to the Oligocene. 



Globorotalia lehneri Cushman and Jarvis 



Plate 38, Figures 9a-13 



Globorotalia lehneri Cushman and Jarvis, Contr. Cushman Lab. 

 Foram. Res., vol. 5, p. 17, pi. 3, figs. 16a-c, 1929. — Cush- 

 man and Renz, Cushman Lab. Foram. Res., Spec. Fubl. 24, 

 p. 40, pi. 8, figs. 3-4, 1948. — Cushman and Bebmudez, 

 Cushman Lab. Foram. Res., vol. 25, pt. 2, p. 32, pi. 6, 

 figs. 7-9, 1949. 



Stratigraphic range: Globigerapsis kugleri zone 

 (probably upper part only) to Truncorotaloides rohri 

 zone, Navet formation. 



Locality: Figured hypotj-pes from the Porticulas- 

 phaera mexicana zone, Navet formation: (figs. 9, 10, 12, 

 13; USNM P5746a-d): same locality as given for 

 Hastigerina micra (Cole) (p. 161); sample Hg 8581 

 (TTOC 215782); (figs, lla-b; USNM P5747), block in 

 Moruga River, south Trinidad; sample BB 124 (TTOC 

 2548). 



Globorotalia centralis Cushman and Bermudez 



Plate 39, Figures la-4 



Globorotalia centralis Cushman and Bermudez, Contr. Cushman 

 Lab. Foram. Res., vol. 13, p. 26, pi. 2, figs. 62-65, 1937.— 

 Beckmann, Eclog. Geol. Helvetiae, vol. 46, No. 2, p. 396, 

 pi. 26, figs. 8, 9, 1953. — Bermudez, Cushman Lab. Foram. 

 Res., Spec. Fubl. 25, p. 284, pi. 22, figs. 30-32, 1949. 



Globorotalia (Turborotalia) centralis Cushman and Bermudez, 

 Cushman and Bermudez, Cushman Lab. Foram. Res., 

 vol. 25, pt. 2, pp. 44-45, pi. 8, figs. 19-21, 1949. 



Stratigraphic range: Globigerapsis kugleri zone 

 (probably upper part), Navet formation to Globorotalia 

 eocoaensis zone, San Fernando formation. 



Locality: Figured hypotypes (figs. la-3c; USNM 

 P5748a-c) from the Porticulasphaera mexicana zone, 



Navet formation ; same localitv as given for Hastigerina 

 micra (Cole) (p. 161) ; sample Hg 8581 (TTOC 215782). 

 Figured hypotype (fig. 4; USNM P5749) from the 

 Globorotalia eocoaensis zone, San Fernando formation; 

 road cut at intersection of Naparima — Mayaro Road 

 and San Fernando Bypass Road, east of San Fernando; 

 sample KR 20521a (TTOC 113248). 



Remarks: Globorotalia centralis Cushman and Ber- 

 mudez shows considerable variation. During the evolu- 

 tion of the species there is a change in chamber shape 

 from rounded towards subangular. The more sub- 

 angular specimens may be regarded as transitional to 

 G. eocoaensis Cushman. High spired specimens (figs. 

 2a-b) begin to occur in the upper part of the Navet 

 formation. It has already been pointed out (p. 164) 

 that specimens transitional between G. centralis and 

 Globigerina ampliapertura Bolli are found in the Globoro- 

 talia eocoaensis zone, San Fernando formation. Further 

 studies on the Globorotalia centralis group and related 

 species will have to be carried out before it will be 

 possible to establish definitely the genetic relationships. 

 It may then be possible to erect a number of subspecies 

 of stratigraphic value. 



Globorotalia opima nana Bolli 



Globorotalia opima nana Bolli, U. S. Nat. Mus. Bull. 215, p. 118, 

 pi. 28, figs. 3a-c, 1957. 



Stratigraphic range: Truncorotaloides rohri zone, 

 Navet formation to Globigerina ciperoensis dperoensis 

 zone, Cipero formation. 



Globorotalia eocoaensis Cushman 



Plate 39, Figures 5a-7b 



Globorotalia eocoaensis Cushman, Contr. Cushman Lab. Foram. 



Res., vol. 4, pt. 3, p. 75, pi. 10, figs. 3a-c, 1928.— Bandy, 



Bull. Amer. Faleontol., vol. 32, No. 131, p. 79, pi. 12, figs. 



la-c, 1949. 

 Globigerina cerro-azulensis Cole, Bull. Amer. Faleontol., vol. 14, 



No. 53, p. 217, pi. 32, figs. 11-13, 1928. 

 Globorotalia (Turborotalia) cerro-azulensis (Cole), Cushman and 



Bermudez, Cushman Lab. Foram. Res., vol. 25, pt. 2, pp. 



42-43, pi. 8, figs. 10-12, 1949. 



Stratigraphic range: Globigerapsis semiinvoluta 

 zone, Navet formation to Globorotalia eocoaensis zone, 

 San Fernando formation. 



Locality: Figured hypotypes (USNM P5750a-c) 

 from the type locality of Globorotalia eocoaensis zone 

 (see p. 160); sample KR 25684 (TTOC 238769). 



Genus Truncorotaloides Broanimann and Bermudez, 1953 



After completion of the present study on the plank- 

 tonic Foraminifera of the Navet formation, some ex- 

 cellent preserved material of Eocene and Paleocene 

 age from Mid-Pacific seamounts became available for 

 examination through the coiu-tesy of Dr. E. L. Hamil- 

 ton, U. S. Navy Electronics Laboratory, San Diego, 

 California, and the Scripps Institution of Oceanog- 

 raphy. 



The predominantly planktonic fauna of Mid-Pacific 



