284 F. CHAPMAN. 
are of true Cainozoic age, and this opinion as regards the 
mudstones is further confirmed by Stanley’s determination 
of the fossils from the petroleum-bearing mudstones as 
consisting largely of Plewrotomiidce and Dentaliidce. Bear- 
ing in mind the fact that both the mudstone and the lime- 
stone form part of a nearly synchronous series, it is most 
necessary to follow up this discovery of a Lower Miocene 
limestone by further collecting in other areas of the country. 
The close relationship of these Lepidocyclina limestones 
with oil-bearing strata is not confined to Papua, but is a 
prominent feature in Borneo, Sumatra and Java, with which 
fields the present locality is undoubtedly stratigraphically 
connected. Verbeek and HKennema, in their exhaustive 
geological treatise on Java and Madoura* refer to the 
probability of the vast number of foraminifera found having 
been the source of the petroleum in those islands. Thus 
these authors observe’ that ‘‘il est tres probable que l’on 
doit chercher l’origine du pétrole dans la masse sarcodaire 
de ces foraminiféres, trés petits il est vrai, mais existant a 
des millions d’ examplaires; en effet, cette masse contient 
des matieres grasses, et déja l’on a réussi a fabriquer arti- 
ficiellement du pétrole par distillation des graisses.”’ 
As a corollary to this theory of a foraminiferal origin of 
the petroleum in certain areas, one may mention that many 
of the foraminiferal limestones of Carboniferous age in 
Hngland and Scotland, as the Endothyra and Saccammina 
limestones, are often highly bituminous; and there is also 
a limestone rich in bitumen found in the Carboniferous of 
Russia, which is crowded with the remains of the fora- 
minifer, Schwagerina. Whilst pointing out the economic 
value of the foraminiferal remains as a source of hydro- 
carbon, it is also noted that the fish remains found in these 
1 Description géologique de Java et Madoura, Vols. 1and u, Amsterdam, 
1896. * Op. cit., Vol. t1, p. 1043. 
ia 
