24 BULLETIN 104, UNITED STATES NATIONAL MUSEUM, 



Globigerina sacculif era— material examined — Continued. 



GLOBIGERINA HELICINA D'Orbigny. 



Plate 4, fig. 9. 



Globigerina helicina D'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 277, No. 5. — 

 Parker, Jones, and H. B. Brady, Ann. Mag. Nat. Hist., ser. 4, vol. 8» 

 1871, p. 175, pi. 11, fig. 113.— H. B. Brady, Quart. Journ. Micr. Sci., 

 vol. 19, 1879, p. 287; Rep. Voy. Challenger, ZoologJ^ vol. 9, 1884, 

 p. 605, pi. 81, figs. 4, 5. — Egger, Abh. kon. bay. Akad. Wiss. Miinchen, 

 CI. II, vol. 18, 1893, p. 370, pi. 5, fig. 6.— Fornasini, Mem. Accad. 

 Sci. 1st. Bologna, ser. 5, vol. 7, 1899, p. 583, pi. 3, figs. 11, 12.— 

 MiLLETT, Journ. Roy. Micr. Soc, 1903, p. 688, pi. 7, fig. 1.— Bagg, 

 Proc. U. S. Nat. Mus., vol. 34, 1908, p. 154. — Sidebottom, Mem. Proc. 

 Manchester Lit. Philos. Soc, vol. 52, No. 13, 1908, p. 4, pi. 1, fig. 9.— 

 CusHMAN, Bull. 71, U. S. Nat. Mus., pt. 4, 1914, p. 12, pi. 3, figs. 1, 2.— 

 Sidebottom, Journ. Roy. Micr. Soc, 1918, p. 149. 



Description. — Test oblong or ovate, composed of several chambers 

 more or less irregularly arranged, inflated, the later chambers being 

 added on the periphery of the test without regard to the spiral 

 arrangement of the earlier ones; wall reticulate; aperture on the 

 basal side of the inner margin of the chamber, but also are added 

 one or more accessory apertural openings on the upper side of the 

 test, especially in the added last chambers. 



Diameter up to 1 mm. 



Distribution. — Specimens which can be referred to this species are 

 rare in the Albatross dredgings. It is recorded from both the North 

 and South Atlantic by Brady. 



There seems to be some doubt as to wliether this should be recog- 

 nized as a valid species. It has very much the appearance of an 

 abnormal form in specimens which I have found both in the Atlantic 

 and Pacific. Some of the specimens of G. rubra where abnormal 

 chambers are developed give much the appearance of the specimens 

 of G. helicina figured by various authors. 



