1146 
docyclinae, which belonged to various species (L. aff. Mumeri Lem. 
et Douv., L. aff. inflata Provale, L. sp.). I shall not enter into their 
specific determination or their description, since they are of no 
special value for stratigraphy. At 1355’— 1370’ and at 1412—1415’ 
however we found along with small Lepidocyclinae also larger indi- 
viduals, notably the same flat, column-less Kulepidines about 10 mm. 
in diameter, which also occur in the limestone of New Island, 
but along with them also other forms characterized by having 
numerous columns diffused over the whole surface. The former are 
allied to L. formosa, the latter are related te L. insulaenatalis JonEs 
and CHapmaN. We see, therefore, that these larger forms begin to 
appear only in the deeper horizons of the boring. 
Whereas all the rocks, described above, certainly belong to one 
and the same series of sediments, the habitus of the limestone, found 
by Hotz on a lime reef to the north of Pulu Kalumpunian to the 
north of Pulu Tega, is different. [t is a grey, pseudo-oolitic rock, 
containing a great many Lithothamnia and some Miliolidae, but in 
which the typical litoral Foraminifera of the oligomiocene are alto- 
gether lacking. This limestone also may belong to the Tertiary, but 
it is quite impossible to say to which subdivision. 
Our examination of the rocks described above shows first of all 
that the oil-formation of Northwest Borneo and more particularly 
that of the peninsula of Klias and the island of Labuan is not, as 
hitherto assumed, of eocene age, but that its anticlinal cores hardly 
reach the oligocene'), the typical large Lepidoeyelina which characte- 
rize the oligocene being absent here; neither do we find here reticu- 
late Nummulites. (Deeper parts of the boring Klias I, rock from New 
Island). The youngest rock examined (limestone from P. Burung 
South of Labuan) — which, however, does not yet belong to the 
youngest part of the sediments-series — must still be considered to 
belong to the miocene s.str.; the fossils, however, prove the rock 
to originate from the topmost part of the Lepidocyclina-bearing 
tertiary. 
It appears then, that a satisfactory stratigraphical concordance 
exists between the oil-formations of Northwest- and those of kast- 
Borneo. 
Both formations originated in the same period of prolonged 
sedimentation, attended with subsidence of the sedimentation-regions, 
') It may be, of course, that the eocene is developed under the anticlinal cores. 
As to this nothing can be said for certain, nor can anything be surmised on the 
basis of the examined material. 
