56 



tnsriTED STATES NATIONAL MUSEUM BULLETIN 215 



Genus Rotalipora Brotzen, 1942 



Rotalipora ticiuensis ticinensis (Gandolfi) 



Plate 12, Figures la-c 



Globotruncana ticinensis Gandolfi, Riv. Italiana Paleontol. 



Stratigr., vol. 48, Suppl. Mem. 4, pp. 113-135, pi. 2, 



figs. 3, 4, 1942. 

 Thalmanninella ticinensis ticinensis (Gandolfi), Reichel, Ec- 



log. Geol. Helvetlae, vol. 42, pt. 2, p. 603, pi. 16, fig. 6, and 



pi. 17, fig. 6, 1949. 



Shape of test: low trochospiral, biconvex, with spiral 

 side slightly more convex; equatorial periphery nearly 

 circular, with single keel. Wall: calcareous, perforate, 

 surface smooth. Chambers: compressed; 18-20, ar- 

 ranged in 2K-3 whorls; the 7-8 chambers of the last 

 whorl increase slowly in size. Sutures: spiral side 

 curved, depressed, occasionally slightly raised; umbiU- 

 cal side radial, depressed. Umbilicus: details obscure; 

 part appears to be covered by extensions of chambers. 

 Apertures: primary aperture an interiomarginal, um- 

 bilical-extraumbilical slit; no secondary sutural aper- 

 tures have been observed in the rather poorly preserved 

 Trinidad specimens. Coiling: random; of the 25 speci- 

 mens counted, 15 coiled sinistrally. 



Dimensions of figured hypotype: diameter 0.31 mm.; 

 thickness 0.11 mm. 



Range: Rotalipora ticinensis ticinensis zone, Gautier 

 formation. 



Type and occurrence: Figured hypotype (USNM 

 P4792) from Trinidad Leaseholds well Marac 1, Trini- 

 dad (coordinates N:152141 links, E:424447 Hnks), 

 sample at 11,979 feet (TLL 178532). 



Family Globotruncanidae Brotzen, 1942 



Genus Globotruncana Cushman, 1927 



Globotruncana helvetica Bolli 



Plate 13, Figure 1 a-c 



Globotruncana helvetica Bolli, Eclog. Geol. Helvetiae, vol. 26, 

 No. 2, p. 226, pi. 9, figs. 6-8, figs. 9-12 of text-fig. 1, 1945.— 

 SlQAL, 19th Congr. G6ol. Internat., Monogr. R^g., ser. 

 1, No. 26, p. 31, fig. 32 1962.— Hagn and Zeil, Eclog. 

 Geol. Helvetiae, vol. 47, No. 1, p. 30, pi. 3 figs, la-c, 1954. 



Shape of test: very low trochospiral; spiral side 

 almost flat, inner whorls often slightly raised, mnbilical 

 side strongly inflated; equatorial periphery lobate, in 

 well developed specimens a distinct keel is present 

 though it is often weakened in the last chamber; speci- 

 mens with faint or missing keels, transitional to rugo- 

 globigerine forms, were observed in material from 

 Tunisia. Wall: calcareous, perforate, surface rugose 

 especially on mnbilical side. Chambers: hemispherical; 

 15-18, arranged in 2-3 whorls; the 5 chambers of the 

 last whorl increase rapidly in size, early whorl is small 

 by comparison. Sutures: spiral side curved, depressed; 

 umbihcal side almost radial, depressed. Umbilicus: 



deep, wide. Apertures: primary apertures interio- 

 marginal, umbihcal; tegiila with accessory apertures 

 not preserved in examined specimens. Coihng: the 

 few specimens recorded so far in Trinidad coil dextrally ; 

 of 100 specimens counted in a sample from Tunisia, 98 

 coiled dextrally. 



Dimensions of figured hypotype: diameter 0.44 mm.; 

 thickness 0.24 mm. 



Range: Globotruncana inomata zone, Naparima Hill 

 formation. 



Type and occurrence: Figured hypotype (USNM 

 P4796) from Trinidad Petroleum Development well 

 Moruga 15, Trinidad (coordinates N: 149878 links, 

 E:497002 hnks), sample from core 6980-7005 feet 

 (TLL 228918). 



Globotruncana repanda Belli, new species 

 Plate 13, Figures 2 a-c 



Shape of test: very low trochospiral, spiral side con- 

 cave, umbilical side strongly inflated; equatorial 

 periphery lobate, early chambers of last whorl with 

 double keel, which may be absent in the ultimate and 

 penultimate chambers. Wall: calcareous, perforate; 

 surface in well preserved specimens shghtly rugose, 

 especially on the umbilical side. Chambers: globular 

 to hemispherical; 12-15, arranged in 2-3 whorls; the 4 

 chambers of the last whorl increase rapidly in size, 

 earlier whorls small by comparison. Sutures: spiral 

 side almost radial, depressed; mnbilical side radial, de- 

 pressed. Umbilicus: deep, wide. Apertures: primary 

 apertures interiomarginal, umbilical; tegiila with acces- 

 sory apertures not preserved in Trinidad material, but 

 present in specimens of this species from the Gulf Coast. 

 Coiling: the 25 specimens counted aU coiled dextrally. 



Dimensions of holotype: diameter 0.4 mm. ; thickness 

 0.24 mm. 



Range: Globotruncana fomicata zone to Globotruncana 

 lapparenti tricarinata zone, Naparima Hill formation. 

 Holotype from Globotruncana stuarti zone, Naparima 

 Hill formation. 



Type and occurrence: Holotype (USNM P4797) 

 from Usine Ste. Madeleine Quarry, southeast end of 

 Naparima Hill, San Fernando, Trinidad (coordinates 

 N:235800 Hnks, E:364000 Imks), sample Bt. 37 (TLL 

 151935). 



Remarks: In its planoconvex shape, Globotruncana 

 repanda, new species, shows similarities to G. helvetica 

 Bolli, G. gansseri Bolli, G. concavata (Brotzen), and G. 

 ventricosa White. It differs from the last two by having 

 in the last whorl fewer and more inflated chambers, 

 which are bent upwards on the spiral side. It is 

 usually slightly smaller in size. From Globotruncana 

 helvetica and G. gansseri the new species differs in having 

 two peripheral keels, a more concave spiral side, and a 

 less rugose surface. The stratigraphic range of Globo- 

 truncana repanda is similar to that of G. ventricosa but 

 differs considerably from that of the other three species. 



