TROPICAL PACIFIC FORAMINIFERA OF "ALBATROSS" 65 



Globigerinella aequilateralis (Brady). — Bradshaw, 1959, Contr. Cushman Found. 



Foram. Res., vol. 10, p. 38, pi. 7, figs. 1, 2.— Todd, 1964, U.S. Geol. Surv. 



Prof. Paper 260-CC, p. 1086, pi. 290, fig. 5. 

 Globorotalia obesa Bolli, 1957, U.S. Nat. Mus. Bull. 215, p. 119, pi. 29, figs. 2, 



3.— Blow, 1959, Bull. Amer. Paleont., vol. 39, no. 178, p. 218, pi. 19, fig. 



124.— Hamilton and Rex, 1959, U.S. Geol. Surv. Prof. Paper 260-W, p. 



791 (ftn.), pi. 253, fig. 14. — Jenkins, 1960, Micropaleontology, vol. 6, p. 



364, pi. 5, fig. 2. 

 Globigerina obesa (Bolli) .—Todd, 1964, U.S. Geol. Surv. Prof. Paper 260-CC, p. 



1079, pi. 292, fig. 4. 

 Hastigerina (Hastigerina) siphonifera (d'Orbigny). — Banner and Blow, 1960, 



Micropaleontology, vol. 6, p. 22, text figs. 2, 3. 

 Globigerinella siphonifera (d'Orbigny). — Parker, 1962, Micropaleontology, vol.8, 



p. 228, pi. 2, figs. 22-28. 



This well-known and widely distributed species occurs in most of 

 the deeper-water samples and is common or abundant in many of 

 them. 



The wall is densely hispid. The coiling is planispiral in the adult 

 with some tests so loosely coiled that the umbilical area appears 

 open from side view and with other tests so tightly coiled that the 

 aperture virtually is obscured by the inflated final chamber. In 

 some specimens, it is possible to observe the initial coiling on one 

 side within the depressed umbilicus. And in a few individuals, the 

 test is clearly evolute on one side with the coil of early chambers 

 raised above the plane of coiling. The identity of these specimens, 

 formerly separated as Globorotalia (and Globigerina) obesa, with 

 Globigerinella aequilateralis can be seen by the densely hispid wall 

 and the low slitlike aperture extending into the umbilicus on the 

 involute side, as well as by the presence of individuals showing all 

 gradations between the two forms (see Parker, 1962, pi. 2, figs. 22-28). 

 Globorotalia obesa, described from the Miocene of Trinidad and re- 

 corded from the Miocene and Pliocene of Venezuela and the Miocene 

 of Australia and of Sylvania Guyot in the Central Pacific, is regarded, 

 therefore, as a synonym of Globigerinella aequilateralis. 



The more tightly coiled specimens in this species have been sep- 

 arated under the name var. involula by various authors. The validity 

 of this distinction has been discussed (Todd, 1964, p. 1086); it seems 

 to be not worthy of taxonomic recognition. 



GLOBIGERINELLA ADAMSI (Banner and Blow) 



Plate 26, Figures 1, 2 



Hastigerina (Bolliella) adamsi Banner and Blow, 1959, Palaeontology, vol. 2, 

 pt. 1, p. 13, text figs. 4a-d. — Banner and Blow, 1960, Micropaleontology, 

 vol. 6, no. 1, p. 24, text figs. 4a-c. 



Globigerina digitata Brady (part), 1884, Rep. Voy. Challenger, Zoology, vol. 9, 

 p. 599, pi. 82, figs. 6, 7 (not pi. 80, figs. 6-10). 



