1145 
The fossils of the limestone of Sg. Silico nevertheless differ from 
the typical L. formosa in having a much smaller diameter. Also this 
limestone may just as well be referred to the middle-old-miocene. 
The limestone of Pulu Burung south of Labuan, which according 
to C. Scamp (l.c.) appears in asyncline, is a true reeflime. J. Motrer 
(Le), therefore, was wrong in considering the limestones of this 
island to be the sedimentary products of calciferous sources. The 
rock is grey, somewhat porous and fairly crystalline. In the thin 
sections may be recognized Lithothamnium, Halimeda, Amphistegina, 
Miliola, Textularidae, a very few Miogypsinae and a few small Lepi- 
docyclinae with a diameter of only 14 mm., of which some still 
possess strong columns, others are quite devoid of skeletons. The 
presence of Miogypsina and of small degenerated Lepidocyclinae and 
the absence of larger Lepidocyclinae points to the fact that the rock 
must be referred to the youngest part of the Lepidocyclina-bearing 
tertiary, which conclusion is substantiated by the geological obser- 
vations in loco. 
The rock of the New Island on the west coast of Klias on the 
other hand certainly originates from the lower part of the sediment- 
series. It is a brownish-gray Foraminifera breccia impregnated with 
limonite. The limonitic substance has to some extent filled up the 
hollows and the pores of the fossils, through which their structure 
bas become very conspicuous. Besides corals, Lithothamnia, Oper- 
culina, Heterostegina and Lepidoeyelina ef. Munieri Lem. et Douv., 
here also occur larger, megalospherical Lepidocyclinae of the Eulepi- 
dina type. They differ little in size from the typical forms of 
L. formosa Schl., with which they have in common the considerable 
flatness, the structure of the embryonic chambers, the absence of 
columns and the considerable thickness of the vertical walls between 
the lateral chambers. 
Two marly limestones, found by G. NierHammer in the rivulets 
Napassu and Blanot, do not include any typical fossils. 
The samples from the boring N° 1 of the Dutch Colonial Oi! 
Company are chiefly hard, gray, sometimes somewhat marly clay- 
shales, very much like the clayshales from the oldest miocene and 
the oligocene of East-Borneo (samples of 773’, 825’, 830’, 975 
980’, 1000’ and 1480’). Sometimes sands or sandstones appear 
(1415—1420’). On various levels Foraminifera were found in the 
marly clayshales, of which the samples presented faunulae that 
differed with the depth at which they. were found. At 800’ 1300’, 
1308—1312’, 138830—1335’, and at 1342’ we found besides indiffe- 
rent forms such as Heterostegina and Cristellaria only small Lepi- 
74 
Proceedings Royal Acad. Amsterdam. Vol. XXIII. 
