1138 
PeLLEKAAN in the territory between Tami- and Biri-river, and 
originating from localities, at the farthest some 50 km. from the 
shore. The results of this investigation, the publication of which 
was so liberally permitted by the “Bataafsche Petroleum-Maatschappij’’, 
evidenced that we were right in supposing that tertiary and especially 
neogene sediments are widely spread over the whole coastal moun- 
tain range between the Tami-, and the Biri-river, while also indi- 
cations were present of the occurrence of older, basic eruptive rocks. 
What has been stated above will appear from the following 
description of a number of thin sections. 
-R/Bo nuslle 
IG. 
JJ: £SO00 000 
Previous investigations tended to show that eocene rocks are of 
rare occurrence in the coastal region of North-New Guinea. Hitherto 
we know only boulders of eocene reeflimestone from the Tawarin- 
river *), which however cannot be derived from the present riverbasin. 
WICHMANN suspects that their mother-rock is to be looked for in the 
territory of the Sermuwai, which rises much farther in the interior’). 
This hypothesis tallies with the fact that the collection Housr 
PELLEKAAN also comprises only two eocene limestones, which were 
found in the river Nanggoi in the South-Nimboran Mountains i.e. in 
the basin of the river Sermuwai. They are two blackish-grey rocks 
of reeflimestone. The one contains Alveolina s.str., the other Alveo- 
lina s.str., Lithothamnium, Nummulites cf. Bagalensis Verb. and 
Orthophragmina; their age is doubtless eocene. 
By far the greater number of the collection are of oligomiocene 
age, and belong to the Lepidocyclina-bearing neogene. They all 
1) Nova Guinea. VI. p. 35. 
3) Nova Guinea. IV. p. 266—267. 
