6 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



Many of the species are pelagic at least at some stage in their life 

 liistory and occur in enormous numbers in the ocean currents such 

 as the Gulf Stream. A few species occur in cold waters, but the 

 greatest development seems to be in the Tropics or subtropical 

 waters, except where these are widely distributed by ocean currents. 



The tendency in the family, as in all pelagic foraminifera, is to 

 develop a form in which the protoplasm of the test may have free access 

 to the surface. This is accomplished in part by a large umbilical 

 aperture or in other species by numerous accessory apertures leading 

 to various parts of the surface. The protoplasm in the pelagic forms, 

 as has been shown by numerous authors, is very vesicular and is far 

 greater in bulk than the test. In some of the species long spines are 

 developed which radiate from the surface and apparently help in 

 supporting the protoplasm. These are easily broken and are there- 

 fore usually wanting in bottom specimens. In the interior chambers 

 of various species they may be often seen. 



Another adaptation to pelagic life is the taking on of a generall}^ 

 spherical character. This is best seen in Orhulina universa, but a 

 nearly spherical shape occurs in Glohigerina conglohata, which is 

 roughly spherical. All the species have inflated chambers. 



While the species are widely distributed, especially the pelagic 

 ones, there are others which seem to be evidently bottom-living 

 forms and do not have the broad distribution of the former. In the 

 western Atlantic there seem to be certain forms which differ with 

 latitude or bottom temperature, and although these are not here 

 separated, it is not impossible that it may later be possible to do so. 



Genus GLOBIGERINA D'Orbigny, 1826. 



Glohigerina D'Orbigny (type, G. bulloides D'Orbigny), Ann. Sci. Nat., vol. 

 7, 1826, p. 277.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 

 1884, p. 589.— Ch.\pman, The Foraminifera, 1902, p. 205. — Cushman, 

 Bull. 71. U. S. Nat. Mus., pt. 4, 1914, p. 5. 



Deficri'ptioj}. — Test composed of numerous inflated chambers 

 arranged typically in a trochoid manner, but which in later develop- 

 ment may be variously arranged; wall typically coarsely perforate, 

 reticulate; aperture large, arched, at the base of the inner margin of 

 the chamber, in some species opening on the umbilicus, in others 

 with numerous accessory openings. 



This genus has a number of very well characterized species, largely 

 those described by Brady in the Challenger report and a few others. 

 They make up the larger constituent of the typical Glohigerina-ooze 

 and form also a large element in Pteropod-ooze. There are evi- 

 dently a considerable number of bottom-living species which should 

 be more closely studied, for from the present studies it seems that 



