64 BULLETIN 161, UNITED STATES NATIONAL MUSEUM 



trilobus (Reuss) (essentially rectangular and 3-lobed, with the sutures 

 at right angles and with the supplementary dorsal and ventral aper- 

 tures at their junctions) through the progressive stages as the final 

 chamber is slightly elongated, is slightly flattened, and is set at a slight 

 angle (downward) from the dorsal surface. In addition to observing 

 these progressive stages in a single individual, one finds (as if they 

 were incomplete individuals) examples of each of these various stages. 

 It would seem inappropriate to separate them as subspecies, and they 

 are regarded, therefore, as merely forms of the species Globigerinoides 

 sacculifer. 



GLOBIGERINOIDES SACCULIFER FISTULOSA (Schubert) 



Plate 26, Figure 3 



Globigerina fistulosa Schubert, 1910, Verh. Geol. Reichs., no. 14, p. 324, text 

 fig. 2. — Schubert, 1911, Abh. Geol. Reichs., vol. 20, pt. 4, p. 100, text 

 fig. 13. 



Globigerinoides sacculifera (H. B. Brady) var. fistulosa (Schubert). — Cushman, 

 1933, Cushman Lab. Foram. Res. Spec. Publ. 5, pi. 34, fig. 6. — Boomgaart, 

 1949, Thesis, Univ. Utrecht, p. 141, pi. 10, fig. 7. — Cushman, Todd, and 

 Post, 1954, U.S. Geol. Surv. Prof. Paper 260-H, p. 369, pi. 91, fig. 13.— 

 Hamilton and Rex, 1959, U.S. Geol. Surv. Prof. Paper 260- W, p. 792, pi. 

 254, fig. 14. 



Globigerinoides sacculifer fistulosa (Schubert). — Todd, 1964, U.S. Geol. Surv. 

 Prof. Paper 260-CC, p. 1084, pi. 290, fig. 6. 



Only six specimens of this distinctive subspecies of Globigerinoides 

 sacculifer were found in the present material. The four Albatross 

 samples in which they occur are all suspect as to their strictly Recent 

 origin; three of them contain manganese and the fourth volcanic 

 particles. 



The most abundant recorded occurrence of this subspecies seems 

 to be in a short deep-sea core taken off Eniwetok in the Marshall 

 Islands, where the fistulosa-be&rmg section was interpreted to be of 

 Pliocene or Pleistocene age. 



Specimens of G. sacculifer showing fistulose outgrowths on their 

 final chambers have never been reported from plankton and there have 

 been no verified Recent occurrences of this form. It is, therefore, 

 believed to have been a short-lived offshoot from G. sacculifer s.s., 

 which may prove to be a useful marker in the late Cenozoic or 

 Quaternary. 



Genus GLOBIGERINELLA Cushman, 1927 



GLOBIGERINELLA AEQUILATERALIS (Brady) 



Plate 25, Figures 4, 5 



Globigerina aequilateralis Brady, 1884, Rep. Voy. Challenger, Zoology, vol. 9, 

 p. 605, pi. 80, figs. 18-21. 



