STUDIES IN FORAMINIFEBA 



91 



Types: Figured holotype (USNM P5774) and para- 

 types (USNM P5775, 5776a-d), unfigured paratypes 

 (USNM P5777). 



Chiloguembelina cf. multicellaris (Hussey) 



Plate 21, Figure 17 



IGumhelina multicellaris Hussey, 1949, p. 130, pi. 27, fig. 10 

 (Eocene, Louisiana, U. S. A.). 



The specimens from Trinidad are rare and badly 

 preserved. They are similar to Hussey's species, but 

 the chambers increase more regularly in size. The 

 Trinidad specimens differ from Chiloguembelina cubensis 

 (Palmer) in having a larger, arched apertirre, but the 

 shape of the testis the same as in many slender specimens 

 of Chiloguembelina cubensis. 



Length: 0.15-0.2 mm. 



Occurrence: Navet formation (Eocene), Hant- 

 kenina aragonensis zone to Globorotalia lehneri zone. 



Types: Figured hypo type (USNM P5778) and un- 

 figured hypotypes (USNM P5779). 



Chiloguemblina paraUela Beckmann, new species 



Plate 21, Figure 8; Text-figure 15 (36-38) 



Test short, thick, rapidly tapering towards the base, 

 slightly compressed. Chambers subglobular, usually 8 

 to 12 in number, biserially arranged, rapidly increasing 

 in size. Sutures oblique, depressed. Wall smooth or 

 slightly spinose. Aperture high and narrow, symmetri- 

 cal, bordered by two parallel lateral flanges, occasion- 

 ally covered by a small end chamber of irregular shape 

 (text-fig. 15, Nos. 36, 38). 



Holotype from the lower Eocene, upper Lizard 

 Springs formation, Globorotalia rex zone, left bank tribu- 

 tary of Cascas River, 180 feet from its junction with the 

 Cascas River, Moruga, south Trinidad (coordinates 

 N:138700 links, E:435000 links), coUected by L. W. 

 Hawkins (No. 1831) (TTOC 228484). 



This species is easily separated from other species of 

 Chiloguembelina by its symmetrical, high and narrow 

 aperture. Its restricted range makes it a good index 

 fossil. The holotype is a large specimen, hence a few 

 smaller paratypes are illustrated in the text-figure in 

 order to give the full size range of the species. 



Length: 0.22-0.42 mm.; holotype 0.4 mm. 



Occurrence : Upper Lizard Springs formation (lower 

 Eocene), Globorotalia rex zone. 



Types: Figured holotype (USNM P5780) and para- 

 types (USNM P5781a-c), unfigured paratypes (USNM 

 P5782). 



Chiloguembelina subtriangularig Beckmann, new species 

 Plate 21, Figure 5; Text-figure 15 (39-42) 



Test small, subtriangular, pointed at the base, com- 

 pressed, with a subangular periphery. Chambers bise- 

 rial, very slightly inflated. Sutures nearly horizontal, 

 slightly depressed, at least in the later stages. Wall 

 smooth. Aperture commonly slightly eccentric, semi- 

 circular to subquadrangular, may have a slight collar. 



Holotype from the Paleocene, lower Lizard Springs 

 formation, Globorotalia 'pusilla pusilla zone. Locality: 

 TTOC well Guayaguayare No. 159, southeast Trinidad 

 (coordinates N:151361 links, E:554095 Jinks), core 

 4778-90 feet (TTOC 232706). 



The compressed, subtriangular test makes it easy to 

 distinguish Chiloguembelina subtriangularis , new species, 

 from other Chiloguembelina species. The variability is 

 shown in the text-figure but the extreme forms (Nos. 39 

 and 42) are rare. C. subtriangularis occurs in all zones 

 of the lower Lizard Springs formation, but is most com- 

 mon in the Globorotalia pusilla pusilla zone. The 

 specimens from the Globorotalia trinidadensis zone have 

 a more rounded periphery, slightly cm-ved sutures and 

 resemble compressed specimens of C. midwayensis mid- 

 luayensis. 



Length: 0.14-0.22 mm.; holotype, 0.21mm. 



Occurrence : Lower Lizard Springs formation (Pale- 

 ocene). 



Types: Figured holotype (USNM P5783) and para- 

 types (USNM P5784a-d), unfigured paratypes (USNM 

 P5785). 



Chiloguembelina trinitatensis (Cushman and Renz) 



Plate 21, Figure 7; Text-figure 15 (43-45) 



Gumbelina trinilalensia Cushman and Renz, 1942, p. 8, pi. 2, 

 fig. 8 (Paleocene, Soldado Rock, Trinidad, B.W.I.).— 

 Cushman, 1951, p. 38, pi. 11, fig. 9 (same locality). 



The specimens from Trinidad, especially those from 

 the Lizard Springs type area, are commonly slightly 

 larger than the types from Soldado Rock, but the other 

 morphological characters are the same. 



Length: 0.26-0.38 mm. 



Occurrence: Lower Lizard Springs formation (Pale- 

 ocene), Globorotalia velascoensis zone. 



Types: Figured hypotypes (USNM P5786, P5787a-c) 

 and unfigured hypotypes (USNM P5788). 



Chiloguembelina victoriana Beckmann, new species 



Plate 21, Figures 19, 20; Text-figure 15 (46-48) 



Test elongate, slender, somewhat compressed. Pe- 

 riphery rounded, slightly lobate. Chambers biserial, 

 broader than high, slightly inflated. Sutures straight, 

 depressed, oblique in the early portion of the test, later 

 more or less horizontal. Wall smooth. Aperture 

 semicicular, sometimes with a faint lip, in an oblique 

 position, i. e., with one side projecting more than the 

 other. 



Holotype from the upper Eocene, San Fernando 

 formation, Globorotalia cocoaensis zone. Branch of 

 Pointe-a-Pierre Road, between Joga Grant Street and 

 Jarvis Street, San Fernando, Trinidad, 90 feet east of 

 southern end of Joga Grant Street (coordinates 

 N:239020 links, E:363330 links), collected by H. G. 

 Kugler (No. 9613) (TTOC 240966). 



The variability of the species is shown by the text- 

 figure. The specimens from the upper Eocene (pi. 21, 

 fig. 19) are, on an average, slightly more elongated 

 than the specimens from the Oligocene (pi. 21, fig. 20). 

 Some specimens are moderately twisted at the base. 



