STUDIES nsr fokaminifera 



115 



Sphaeroidinella rutschi Cushnian and Renz 



Plate 26, Figures 6a-7b 



Sphaeroidinella rutschi Cushman and Renz, Contr. Cushman 

 Lab.'Foram. Res., vol. 17, pt. 1, p. 25, pi. 4, fig. 5, 1941.— 

 Renz, Geol. Soc. Amer., Mem. 32, p. 167, pi. 10, figs. 

 la-c. 



Sphaeroidinella seminulina (Schwager) , Bermudez, Cushman 

 Lab. Foram. Res., Spec. Publ. 25, p. 283, pi. 21, fig. 59, 

 1949. 



Stratigraphic range (in Lengua formation): 

 Glohorotalia mayeri zone to Globorotalia menardii zone. 



Locality: Figured hypotypes (USNM P5645a,b) 

 from the Globorotalia menardii zone; ditch sample at 

 1,938 feet of Trinidad Leaseholds, Ltd. (now The 

 Trinidad Oil Company), well Barrackpore 352 (TTOC 

 194771). 



Remarks: Sphaeroidinella rutschi has probably de- 

 veloped from the Sphaeroidinella grimsdalei Keijzer 

 group and may be regarded as the ancestor of Sphae- 

 roidinella dehiscens (Parker and Jones). 



Subfamily Orbulininae Schultze, 1854 

 Genus Porticulasphaera Belli, Loeblich, and Tappan, 1957 



In a paper on the evolution of the genus Orbulina 

 Blow (1956) described a number of forms under the 

 genus Globigerinoides that are regarded as transitional 

 between Globigerinoides and Orbulina. They resemble 

 Orbulina suturalis Bronnimann in having a strongly 

 embracing inflated final chamber and small sutural 

 supplementary apertures, but differ in the absence of 

 areal supplementary apertures. They resemble Glo- 

 bigerinoides in having sutural supplementary apertm'es, 

 but differ in possessing a final, strongly embracing 

 chamber which has no distinct primary umbilical aper- 

 ture. These intermediate forms fit into the definition 

 given for the short-lived middle Eocene genus Porticu- 

 lasphaera. Although there is no genetic relation be- 

 tween the middle Eocene and the lower Miocene forms, 

 Blow's transitional species are here placed in Porticu- 

 lasphaera. Possibly further comparative studies will 

 reveal differences between the Eocene and Miocene 

 forms that will allow the separation of Blow's species 

 as a distinct genus. 



For detailed species and subspecies descriptions and 

 evolutionary trends, reference is made to Blow (1956). 



Porticulasphaera glomerosa curva (Blow) 



Plate 27, Figure 7 



Globigerinoides glomerosa curva Blow, Mioropaleontol., vol. 2, 

 No. 1, p. 64, text-fig. 1, Nos. 9-14, 1956. 



Stratigraphic range (in Cipero formation) : Upper 

 part of the Globigerinatella insueta zone to the basal 

 part of the Globorotalia fohsi barisanensis zone. 



Locality: Figured hypotype (USNM P5647) from 

 the Globigerinatella insueta zone; sample KWB 7446A 

 (TTOC 125125). 



Porticulasphaera glomerosa glomerosa (Blow) 



Plate 27, Figure 8 



Globigerinoides glomerosa glomerosa Blow, Micropaleontol., vol. 

 2, No. 1, p. 65, text-fig. 1, Nos. 15-19, text-fig. 2, Nos. 1-2, 

 1956. 



Stratigraphic range (in Cipero formation): 

 Uppermost part of the Globigerinatella insueta zone to 

 the basal part of the Globorotalia fohsi barisanensis zone. 



Locality: Figured hypotype (USNM P5648) from 

 the Globigerinatella insueta zone, sample KWB 7446A 

 (TTOC 125125). 



Porticulasphaera glomerosa circularis (Blow) 



Plate 27, Figure 2 



Globigerinoides glomerosa circularis Blow, Micropaleontol., vol. 

 2, No. 1, p. 65, text-fig. 2, Nos. 3-4, 1956. 



Stratigraphic range (in Cipero formation): Top- 

 most part of the Globigerinatella insueta zone to the 

 lower part of the Globorotalia fohsi barisanensis zone. 



Locality: Figured hypotype (USNM P5649) from 

 the Globigerinatella insueta zone, sample KWB 7446A 

 (TTOC 125125). 



Porticulasphaera transitoria (Blow) 



Plate 27, Figure 3 



Globigerinoides transitoria Blow, Micropaleontol., vol. 2, No. 1, 

 p. 65, text-fig. 2, Nos. 12-15, 1956. 



Stratigraphic range (in Cipero formation): Upper 

 part of the Globigerinatella insueta zone. 



Locality: Figured hypotype (USNM P5650) from 

 the Globigerinatella insueta zone, sample KWB 7446A 

 (TTOC 125125). 



Genus Orbulina d'Orbigny, 1839 



Orbulina suturalis Bronnimann 



Plate 27, Figure 4 



Orbulina suturalis Bronnimann, Contr. Cushman Found. 

 Foram. Res., vol. 2, pt. 4, p. 135, text-fig. 2, figs. 1-2, 5-8, 

 10; text-fig. 3, figs. 3-8, 11, 13-16, IS, 20-22; text-fig. 4, 

 figs. 2-4, 7-12, 15-16, 19-22, 1951.— Blow, Micropaleontol., 

 vol. 2, No. 1, p. 66, text-fig. 2, Nos. 5-7, 1956. 



Candorbulina unitiersa Jedlitschka, Cushman and Stainforth, 

 Cushman Lab. Foram. Res., Spec. Publ. 14, p. 69, pi. 13, 

 fig. 10, 1945. 



Stratigraphic range (in Cipero and Lengua for- 

 mations): Topmost part of the Globigerinatella in- 

 sueta zone to the Globorotalia menardii zone. 



Locality: Figured hypotype (USNM P5651) from 

 the type locality of the Globorotalia menardii zone, 

 sample KR 23425 (TTOC 17SS90). 



Orbulina universa d'Orbigny 



Plate 27, Figure 5 



Orbulina universa d'Orbigny, Bermudez, Cushman Lab. Foram. 

 Res., Spec. Publ. 2.5, p. 282, pi. 21, fig. 3, 1949.— Bron- 

 nimann, Cushman Lab. Foram. Res., vol. 2, pt. 4, p. 134, 

 pi. 4, fig. 1, 1951. — Blow, Micropaleontol., vol. 2, No. 1, 

 p. 66, text-fig. 2, Nos. 8-9, 1956. 



Stratigraphic range (in Cipero and Lengua for- 



