REPORT OF THE DIRECTOR I918 I79 



thsse cherts date back to that epoch. This will be referred to 

 under our discussion of the age of these cherts. The chert types 

 vary greatly in size, measuring from but o.io mm in some of the 

 smaller forms to 0.28 mm in the larger specimens. 



Globigerina aequilateralis Brady 



Plate 5,' figures 1-3 



Globigerina aequilateralis Brady 1 879, Quar. Jour. Micros. Sci. , 



n. s., 19: 71 

 Globigerina aequilateralis Brady, 1884, Chal. Rep't, 9:605, 



pi. Ixxx, figs. 18-21 

 Globigerina aequilateralis Goss, 1 894, K. Sv. Vet. Akad. 



Handl., Bd. 25, no. 9, p. 86, pi. xiv, fig. 767 



It S33ms strange that the large, coarsely constructed, aequilateral 

 Globigerina, doubtfully known under the name Phanerosto- 

 mum asperum Ehrenberg, from the island of Rugen Chalk 

 could possibly go back into Lower Paleozoic time; and we have 

 hitherto considered that this type belonged entirely to modern 

 oceans, although it is known in the Miocene. The large, globular- 

 chambered Globigerina showing three well-defined but large seg- 

 ments, with a partial view of a fourth on one side, seen on slide 6, 

 apparently belongs here. It has thick walls, anastomosing segments, 

 and measures 0.2 mm in transverse section. There is an infilling 

 with clouded greenish brown material. The form is too large for 

 G. cretacea and shows too widely- jointed chambers to be 

 identified with G. pachyderma, which it seems to resemble 

 in some particulars. 



A partial section, also on slide 6 and showing but three chambers, 

 apparently belongs here also. On slide 2, there also appears a 

 large Globigerina filled in its interior with the same greenish brown 

 substance found on slide 6; and we believe this also represents 

 the G. aequilateralis of existing oceans, but only four 

 segments are seen in this example. 



Globigerina bilobata d'Orbigny 



Plate 4, figures 14, 15 



Globigerina bilobata d'Orbigny, 1846, Foram. Foss. Vienne, 

 p. 164, pi. ix, figs. 11-14 



There are numerous bilobed Foraminifera on nearly all the slides, 

 and among these is undoubtedly the two-lobed G. bilobata 

 d'Orbigny. There is always a possibility, however, that some of 

 8 



