NO. 4 TLANKTONIC FORAMINIFERA — CIFELLI 25 



vious chamber. This arrangement of chambers might possibly be 

 thought of as an extreme streptospiral coil, with the coil changing 90 

 degrees in direction with the addition of each chamber. The test is 

 nonumbilicate, as in the mature G. conglobatus. The chamber ar- 

 rangement of G. elongatiis is identical with that of G. ruber. 



The chamber arrangement in Globigerinoides trilobus is more ob- 

 scure. In edge view the test is rather flattened and the chambers ap- 

 pear to adhere to the trochospiral coil as in Globigerina. At the same 

 time, however, portions of the new chambers overlap the ventral side 

 of the test considerably, so that the umbilicus is almost obscured and 

 the aperture is low and elongate. In overall appearance G. trilobus 

 is similar to G. ruber when viewed from the ventral side, where 3 

 chambers are visible with 1 larger chamber set above 2 smaller, earlier 

 chambers. However, in G. ruber the primary aperture is symmetrical 

 above the 2 earlier chambers, while in G. trilobus it is asymmetrical 

 (Bolli, 1957, p. 112). 



GLOBIGERINOIDES ELONGATUS (d'Orbigny) 



Plate 8, figures 1, 4 



Globigerina rubra d'Orbigny, 1839, in De la Sagra, Hist. Phys. Pol. Nat. Cuba, 



Foraminiferes, p. 82, pi. 4, figs. 12-14. — Banner and Blow, 1960, Contr. 



Cushman Foratn. Res., vol. 11, pt. 1, p. 19, pi. 3, figs. 8a, b. 

 Globigerinoides rubra Bradshaw, 1959, Contr. Cushman Found. Forani. Res., 



vol. 10, pt. 2, p. 42, pi. 7, figs. 12, 13.— Be, 1959, Micropaleontol., vol. 5, 



No. 1, pi. 2, figs. 16, 17. 



This species is nonumbilicate, and each new chamber is added above 

 the primary aperture of the earlier chamber. The final chamber is 

 sometimes reduced in size, appearing like a small bubble on the pre- 

 vious part of the test. The primary aperture is a broad arched open- 

 ing at the base of the last chamber, which is symmetrically located 

 above the 2 earlier chambers. There are 2 supplementary apertures 

 on the side of the chamber opposite to the primary aperture. The 

 supplementary apertures vary from low slits to broad, rounded 

 openings; on some of the smaller specimens they are barely per- 

 ceptible. When well developed, the supplementary apertures can be 

 seen on the last 2 or 3 chambers. 



The color in Globigerinoides ruber ranges from white through 

 various shades of pink to bright red. Most often, the red or pink 

 color is confined, appearing only in part, particularly the early part, 

 of the test. In the summer traverse over 75 percent of the specimens 

 were red or pink in color, and most of these were bright red. In the 



