TROPICAL PACIFIC FORAMUNTIFERA OF "ALBATROSS" 71 



distinctly incised. The apertural lip is limbate and, in some speci- 

 mens, encrusted with small knobs. The umbilicus is open and the 

 aperture rather widely open. 



Found with these more typical specimens are others that may be 

 separated on the basis of their thicker tests, lower apertural opening, 

 and smaller size. There is some variation in outline of test: from 

 circular, with lobulated periphery, to elongate, with nearly smooth 

 periphery. The number of chambers in the final whorl is five or six 

 as it is in the typical form of G. menardii. One of these variants, 

 having the coarsely spinose ornamentation characteristic of the 

 variety fimbriata, is illustrated (pi. 28, fig. 2). On this specimen, the 

 spinosity extends beyond the limbate keel, to which it is usually 

 restricted, and is scattered over the chamber walls as well. 



GLOBOROTALIA MENARDII UNGULATA Bermudez 



Plate 28, Figure 3 



Globorotalia ungulata Bermudez, 1960, Venezuela: Ministerio de Minas e Hidro- 

 carburos, Bol. Geol., Publ. Espec. No. 3, p. 1304, pi. 15, fig. 6. 



Globorotalia cf. G. menardii (d'Orbigny). — Bradshaw, 1959, Contr. Cushman 

 Found. Foram. Res., vol. 10, p. 44, pi. 8, figs. 10-12. 



This form was described originally from 615 fathoms off the coast 

 of Cuba and was stated to be distinct from Globorotalia tumida in its 

 more delicate construction, thinner wall, and more inflated and 

 angular ventral face of the final chamber. It seems to be related 

 more closely to G. menardii than to G. tumida and, thus, is regarded 

 as a subspecies of G. menardii. In the present material, it is at least 

 as frequently found as the typical form, and there are a few transitional 

 forms connecting the two. 



This subspecies is distinguished easily from the typical form and 

 is characterized by its thinner and clearer wall, curved dorsal surface, 

 and peaked appearance of the inner ends of the chambers on the 

 ventral side. Specimens are usually smaller than the typical forms, 

 and the encrustation of a crystalline deposit around the apertural 

 area is much finer than on the typical form. 



The subspecies has already been found and illustrated from plankton 

 tows in the Pacific (Bradshaw, 1959, p. 44, pi. 8, figs. 10-12) and 

 may be found to be nearly as cosmopolitan as the typical form. 



GLOBOROTALIA TUMIDA (Brady) 



Plate 28, Figure 1 



Pulvinulina menardii d'Orbigny var. tumida Brady, 1877, Geol. Mag. [Great 

 Britain], decade 2, vol. 4, p. 535. — Banner and Blow, 1960, Contr. Cushman 

 Found. Foram. Res., vol. 11, p. 26, pi. 5, fig. 1. 



Pulvinulina tumida Brady, 1884, Rep. Voy. Challenger, Zoology, vol. 9, p. 692, 

 pi. 103, figs. 4-6. 



