250 SYSTEMATIC PALEOXTOLOGY 



Family GLOBIGERINIDAE. 



Genus GLOBIGERINA d'Orbigny. 



GrLOBiGERiNA BULLOiDES d'Orbigny. 



Plate LXIII, Figs. 15, 16, 16a. 



GloMgerina bnlloides d'Orbigny, 1826, Ann. Sci. Nat., vol. Tii, p. 277, No. 1 ; 



Modeles, No. 17 (young), and No. 76. 

 GloMgerina bulloides d'Orbigny, 1846, Foram. Fossiles Vienne, p. 163, pi. ix, figs. 



4-6. 

 GloMgerina Milloides Brady, 1884, Chal. Kept., a^oI. ix, p. 593, pi. Ixxvii, and 



pi. Ixxix, figs. 3-7. 

 Globigerina hulloides Bagg, 1896, Bull. 141, U. S. Geol. Survey, p. 92. 

 .GloMgerina Milloides Bagg, 1898, Bull. Amer. Pal., No. 10, p. 33. 



Description.—'' Test spiral, siibtrochoid; superior surface convex, in- 

 ferior more or less convex but with deeply-sunken umbilicus; periphery 

 rounded, lobulated; adult specimens composed of about seven globose 

 segments, of which four form the outer convolution, the aperture of the 

 individual chambers opening independently into the umbilical vestibule; 

 diameter sometimes one-fortieth of an inch (0.63 mm.), but oftener 

 much less." (Brady, loc. cit.) 



While this species is not uncommon in the New Jersey Cretaceous it 

 is rare in the Eocene. In New Jersey in the Manasquan (Upper Marl 

 Beds) formation it is however much larger than in the Rancoeas, and is 

 0.4 mm. in diameter in some specimens. 



In the Miocene of Maryland and Virgini'a, it is also rather common 

 but it is most abundant in the Miocene shell marls of Plum Point. 



In present oceans this species of Globigerina is the commonest of all 

 the Glohigerinidae. In temperate zones it exists in enormous abundance 

 and it does not seem to be limited in depth but occurs in dredgings all 

 the way from shallow bottoms to the greatest depths. It is one of the 

 few foraminifera which are truly pelagic in habit, that is, exist at the 

 surface or in mid-water, for strange as it may seem, the majority of 

 genera pass their existence at or near the bottom. Notwithstanding 

 this fact that the great majority of foraminifera pass their existence 

 near the bottom, the surface and middle water forms, far surpass the 

 former in point of numbers and are present in countless millions in all 

 great oceans. It is interesting to note what genera and species belong 



