12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



inflation of the test and in nature of the final chamber. As in G. 

 hulloides, the test is sometimes compact, and the final chamber oc- 

 casionally deviates from the axis of coiling and partially covers the 

 umbilicus. Also, the last chamber is often reduced in size. Specimens 

 with a compact test and a reduced final chamber covering the umbilicus 

 are identical with G. pachyderma. Several such specimens have been 

 observed in a few of the samples studied, and two are figured here. 

 These specimens show that G. incompta grades into G. pachyderma. 

 However, they are of rare occurrence in the region studied, and it is 

 useful to retain G. incompta as a subspecies. Parker (1962, p. 224) 

 has shown that in Recent Pacific bottom sediments G. incompta 

 grades into G. pachyderma, with G. pachyderma dominating in the 

 high latitudes. The transition is further shown by Smith (1963) from 

 northeastern Pacific plankton tows. The form that Smith figures (pi. 

 1, figs. 12-14) as a Globigerina pachyderma-eggeri intergrade is 

 identical with G. pachyderma incompta. The relationships, however, 

 with G. eggeri { — G. dutertrei) are not yet completely clear. 



Distribution. — Globigerina pachyderma incompta is next in domi- 

 nance to G. bnlloides in the shelf and slope waters. The highest fre- 

 quencies were observed in the summer (50 percent at stations B and 

 E) and the fall (63 percent at station 2). 



GLOBIGERINA DUTERTREI d'Orbigny 



Plate 2, figures 1, 2 



Globigerina eggeri Rhumbi.er, 1900, Nordische Plankton, pt. 14, Foraminiferen, 



p. 19, text figs. 20a-c. 

 Globigerina eggeri Bradshaw, 1959 (part), Contr. Cusliman Found. Foram. 



Res., vol. 10, pt. 2, p. 35, figs. 5, 10 only.— Be, 1959, Micropaleontol., vol. 5, 



No. 1, pi. 2, figs. 1-3. 

 Globigerina dutertrei d'Orbigny, 1839. — Banner and Blow, 1960, Contr. Cush- 



man Found. Foram. Res., vol. 11, pt. 1, p. 11, pi. 2, fig. 1. 



This species closely resembles botli Globigerina pachyderma in- 

 compta and the early stages of Ptdleniatina obliquiloculata. G. 

 dutertrei is distinguishable from G. pachyderma incompta by its rela- 

 tively high trochoid spire and its broad, open umbilicus. The differ- 

 ences are slight, however (Cifelli, 1961), and future studies of addi- 

 tional material, particularly from the warmer waters, may show that 

 G. dutertrei belongs to the G. pachyderma species group. 



The coiling in G. dutertrei is trochoid throughout except, occasion- 

 ally, for the last chamber, which, like other Globigerina species, tends 

 to deviate toward the umbilicus. Thus, in the last whorl the chambers 



