STUDIES IN FORAMTNIFEHA 



101 



Bolli, new species, is restricted to the zone. The genus 

 Globigerinoides makes its appearance in the upper part 

 of the zone. Glohigerina juvenilis BoUi, new species, 

 and Qlobigerina hradyi Wiesner are other species which 

 are recorded for the first time in the Glohorotalia kugleri 

 zone. 



Catapgydrax diBsimilis Zone 



Type locality: South bank of San Fernando Bypass 

 Road, approximately 1,050 feet northeast from north 

 end of road bridge across the Siparia railway line. 

 Coordinates N:226600 links; E:362200 links. Type 

 sample Bo 267 (TTOC 201216). 



Lithology: Cream to Ught grey marl, with yellow 

 limonite patches, gypsiferous; black iron stains. 



Remarks: The Catapsydrax dissimilis zone, as com- 

 pared with the Glohorotalia kugleri zone, shows a 

 marked increase of planktonic Foraminifera from 16 

 to 25 species or subspecies. Various species of Globi- 

 gerinoides are to a large degree responsible for the 

 increase. 



Catapsydrax stainforthi Zone 



Type locality: Cipero type section, between 2,150 

 and 3,200 feet southwest from fixed point (see p. 103) 

 at the southern end of the exposed section. Coordi- 

 nates N:227300 links; E:352900 links. Type sample K. 

 9397 (TTOC 193790). 



Lithology: Cream to grey brown marl, occasionally 

 blotchy. 



Remarks: Globigerinatella insueta Cushman and 



Stainforth first appears in the Catapsydrax stainforthi 

 zone, where it occurs with the zonal marker and 

 Catapsydrax dissimilis (Cushman and Bermudez). 

 Globoquadrina dehiscens (Chapman, Parr, and Collins) 

 and Globoquadrina altispira altispira (Cushman and 

 Jarvis) also make their first appearance in this zone. 

 Otherwise the planktonic fauna is very much the same 

 as that of the underlying Catapsydraor dissimilis zone. 



Globigerinatella insueta Zone 



Type locality: Cipero type section, small promon- 

 tory generally known as "Cipero Nose," approximately 

 820 feet southwest from fixed point (see p. 103). Co- 

 ordinates N:229450 links; E:354250 links. Rz 108 

 (TTOC 21743), the type sample for Cushman and 

 Stainforth's Zone II {Globigerinatella insueta zone), 

 comes from the same section. A co-locality, repre- 

 senting the Radiolaria rich facies of the zone, has been 

 established near the Retrench trigonometrical station, 

 Golconda Estate. Coordmates N:217296 links; E:371482 

 links. 



Lithology: Massive, cream to yeUow grey marl, 

 fairly resistent to weathering, hence forming topo- 

 graphic highs. 



Remarks: The Globigerinatella insueta zone is charac- 

 terized by the zonal marker and by the absence of 

 Catapsydrax dissimilis (Cushman and Bermudez). 

 Globigerinoides diminuta BoUi, new species, is a charac- 

 teristic form restricted to the zone or part of it. Blow 



(1956), in his study on the origin and evolution of the 

 genus Orbvlina, described the first occurrence of Globi- 

 gerinoides bispherica Todd in the upper half of the 

 Globigerinatella insueta zone. Within the short time 

 interval of the uppermost part of the zone he then 

 showed the development of Orbulina from this species 

 (op. cit., p. 69, text-fig. 4). Based on these evolutionary 

 trends, a further subdivision of the upper part of the 

 Globigerinatella insueta zone could readily be estab- 

 lished. 



Glohorotalia foshi barisanensis Zone 



Type locality: Hermitage Quarry, on the west 

 side of the road leading from Hermitage Village to 

 AUy's Creek about 1,200 feet northwest from the road 

 junction in the village, south Trinidad. Coordinates 

 N:208100 links; E:351800 links. Type sample Bo 

 202 (TTOC 193125). 



Lithology: Cream to white marl with yellow limo- 

 nitic patches. 



Remarks: Globigerinatella insueta Cushman and 

 Stainforth and Catapsydrax stainforthi BoUi, Loeblich, 

 and Tappan have become extinct before the Glohorotalia 

 fohsi barisanensis zone. The transitional forms leading 

 from Globigerinoides bispherica Todd to Orbulina dis- 

 appear in the lower part of the zone. The character- 

 istic Hastigerinella hermudezi Bolli, new species, has 

 thus far been recorded only from this zone. 



Globoratalia fohsi fohei Zone 



Type locality: On east bank of cricket ground 

 southwest of Golconda Estate house which is about 

 one-sixth mile south of Golconda Village, south Trini- 

 dad. Coordinates N;208100 links; E:357800 links. 

 Type sample Bo 185A (TTOC 193121). 



Lithology: Cream to light yellow marl, with grey 

 patches ; slightly limonitic and gypsiferous. 



Remarks: Glohorotalia fohsi fohsi Cushman and 

 Ellisor, the zonal marker, developed from Glohorotalia 

 fohsi barisanensis Le Roy in the basal part of the zone. 

 Glohorotalia scitula (Brady) appears first in the upper 

 part of the zone. 



Glohorotalia fohsi lobata Zone 



Type locality: Cipero type section, between 1,500 

 and 1,700 feet from fixed point (see p. 103). Type 

 sample JS 32 (TTOC 193786). Rz 425 (TTOC 

 61418), the type sample for Cushman and Stainforth's 

 Zone III, {Glohorotalia fohsi zone) comes from the same 

 section. 



Lithology: Light bluish grey marl with black 

 streaks. 



Remarks: Glohorotalia fohsi lobata Bermudez, the 

 zonal marker, develops from Glohorotalia fohsi fohsi 

 Cushman and Ellisor in the basal part of the zone. 



Glohorotalia fohsi robusta Zone 



Type locality: Cipero type section, between 850 

 and 1,400 feet southwest of fixed point (see p. 103) south 



