STUDIES IN FORAMrNIFERA 



167 



Locality: Figured hypotype (USNM P5738) from 

 the Glohorotalia palmerae zone, Navet formation; same 

 locality as given for Glohigerina soldadoensis Bronni- 

 mann (p. 162); sample KTO 145 (TTOC 143701). 



Remarks: The position of the apertures in the type 

 specimens of Globigerina aspensis figured by Colom is 

 interiomarginal, umbilical — extraumbilical. For this 

 reason the species is here placed in Glohorotalia. 

 Colom's specimens show considerable variation in size, 

 number of chambers in the last whorl (5-7) and shape 

 of chambers (spherical to subangular) . A similar range 

 of varieties is foimd in the lower Navet of Trinidad. 

 It appears likely that the species has developed from 

 Globigerina soldadoensis angulosa BoUi. Detailed 

 studies of this group in areas where more complete sec- 

 tions are available might show that differences in the 

 stratigraphic ranges of the varieties justify the erection 

 of a number of subspecies. 



Globorotalia broedermanni Cushman and Bermudez 



Plate 37, Figures 13a-c 



Globorotalia (Truncorotalia) hrodermanni Cushman and Ber- 

 mudez, Contr. Cushman Lab. Foram. Res., vol. 25, pt. 2, 

 p. 40, pi. 7, figs. 22-24, 1949. 



Globorotalia broedermanni Cushman and Bermudez. Bolli, U. S. 

 Nat. Mus. BuU. 215, p. 80, pi. 19, figs. 13-15, 1957. 



Stratigraphic range: Globorotalia rex zone. Lizard 

 Springs formation to Globigerapsis kugleri zone, Navet 

 formation. 



Locality: Figured hypotype (USNM P5735) from 

 the Glohorotalia palmerae zone, Navet formation; same 

 locality as given for Globigerina soldadoensis Bronni- 

 mann (p. 162); sample KTO 145 (TTOC 143701). 



Globorotalia aragonensis Nuttall 

 Plate 38, Figures la-c 



Globorotalia aragonensis Nuttall, Journ. Paleontol. vol. 4, No. 

 3, p. 288, pi. 24, figs. 6-8, 10-11, 1930.— Cushman and 

 Rbnz, Cushman Lab. Foram. Res., Spec. Publ. 24, p. 40, 

 pi. 8, figs. 1-2, 1948. — Bermudez, Cushman Lab. Foram. 

 Res., Spec. Publ. 25, p. 284, pi. 22, figs. 33-35, 1949.— 

 Bolli, U. S. Nat. Mus. Bull. 215, p. 75, pi. 18, figs. 7-9, 

 1957. 



Globorotalia (Truncorotalia) aragonensis Nuttall. Cushman 

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

 25, pt. 2, pp. 38-39, pi. 7, figs. 13-15, 1949. 



Stratigraphic range: Globorotalia jormosa jormosa 

 zone, Lizard Springs formation to Globigerapsis kugleri 

 zone, Navet formation. 



Locality: Figured hypotjrpe (USNM P5739) from 

 the Hantkenina aragonensis zone, Navet formation; 

 Baccus River, Central Range; sample K 8854 (TTOC 

 177804). 



Globorotalia pseudomayeri Bolli, new species 



Plate 37, Figures 17a-c 



Shape of test low trochospiral ; equatorial periphery 

 slightly lobate; axial periphery rounded. Wall cal- 

 careous, perforate, surface very finely pitted. Cham- 

 bers spherical; 10-12, arranged in about 2% whorls; 



The 4 or 5 chambers of the last whorl increase fairly 

 rapidly in size. Sutures on spiral side curved or 

 oblique in early portion, later radial, depressed; on 

 umbilical side radial, depressed. Umbilicus narrow. 

 Aperture a medium to low arch, with or without a 

 faint lip; interiomarginal, umbilical-extraumbilical. 

 Coiling random. Largest diameter of holotjrpe 0.4 mm. 



Stratigraphic range: Hantkenina aragonensis zone, 

 Navet formation. 



Locality: Holotype (USNM P5737) from the Hant- 

 kenina aragonensis zone, Navet formation; in upper 

 part of small ravine between mileposts 12)i and 12)2 

 of the Brasso-Tamana Road and the Navet River 

 (see text-fig. 25) ; sample K 8817 (TTOC 177758). 



Remarks: Globorotalia pseudomayeri, new species, 

 is morphologically very close to G. opima nana Bolli 

 and G. mayeri Cushman and EUisor. It differs from 

 the former in that the chambers of the last whorl 

 increase more rapidly in size. The last whorl consists 

 of 4 to 4M chambers, whereas in 6r. mayeri it has 5 or 6. 

 G. pseudomayeri is restricted to the Hantkenina ara- 

 gonensis zone of the Navet formation, whereas G. 

 opima nana is found from the Truncorotaloides rohri 

 zone, Navet formation to the Globigerina ciperoensis 

 ciperoensis zone, Cipero formation. Globorotalia mayeri 

 is restricted to the Cipero formation and lower part 

 of the Lengua formation. 



Globorotalia bullbrooki Bolli, new species 

 Plate 38, Figures 4a-5c 



Shape of test on spiral side almost flat or low trochospi- 

 ral, umbilical side strongly convex, subangular. Wall 

 calcareous, perforate, surface covered with short, 

 blunt spines. Chambers subangular, inflated; about 

 12-15, arranged in about 2)i whorls; the 4 chambers 

 of the last whorl increase fairly rapidly in size. Su- 

 tures on spiral side oblique or radial, depressed; on 

 umbilical side radial, depressed. Umbilicus narrow, 

 deep. Aperture a low arch, interiomarginal, umbili- 

 cal-extraumbilical. Coiling without distinct pattern 

 in the preliminary study of eight isolated samples 

 belonging to the Hantkenina aragonensis zone. In 

 four of these samples, 70-90 percent of the specimens 

 coiled dextrally, in two a preference for sinistral coiling 

 was observed and in two the specimens coiled at ran- 

 dom. It may be of interest to note that in the sam- 

 ples with a predominance of dextrally coiled specimens, 

 Clavigerinella was found but Hantkenina was absent. 

 To gain a clear picture of the coiling pattern in Globo- 

 rotalia bullbrooki, it will be necessary to make further 

 investigations in a more nearly complete stratigraphic 

 section. Largest diameter of holotype 0.5 mm. 



Stratigraphic range: Hantkenina aragonensis zone 

 to Globigerapsis kugleri zone, Navet formation. 



Locality: Holotype USNM P5742) and figured 

 paratype (USNM P5743) from the Hantkenina arag- 

 onensis zone, Navet formation; holotype from outcrop 

 on left side of right branch of Nariva River, about 

 450 feet from its jimction. Central Range, Trinidad 



