36 
can be referred to one or other of the sections into which the old 
genus Ammonites is now broken up, and the facies of which is suffi- 
ciently clear for broad generalisation.”! 
In 1892, a series of petrographical notes upon some of the 
volcanic rocks from New Guinea, were contributed by the late Mr. 
A. W. Clarke, at one time Mineralogical Lecturer to the Queensland 
Government, to the Geology and Palaeontology of Queensland by 
Messrs. Jack and Etheridge ; whilst the reports by the different mem- 
bers of the Geological Survey Staff of Queensland, on specimens sub- 
mitted by the Administrator, have added a little further light upon the 
petrology and geology. 
CORAL REEFS, CORAL ISLANDS, &c. 
The coral formations of British New Guinea present features of 
unusual interest. The up-raised reef masses and the associated 
deposits took up the great portion of the time I was enabled to devote 
to this subject ; these occupy a considerable portion of the north-east 
coast, the Louisiades, and some of the adjacent islands. Ail grada- 
tions from reefs only a few feet above the water up to 2,000 feet above 
the level of the sea were noticed. 
The rocks, of which these up-raised reef masses are composed, 
present pretty much the same lithological characters throughout, viz., 
very hard and sonorous compact limestones, of a whitish color ; some 
varieties, however, have a distinct yellow or reddish-brown hue. Coral 
fragments do not appear to be very common in the raised reefs ; this 
scarcity need excite no surprise, for recent researches have shown that 
corals play but a subordinate part in the building up of coral reefs, 
and that calcareous a l gee, foraminifera echinodermata , polyzoa , 
lamellibranchiata , and other organisms form by far the large portion of 
the rocks. Some of the up-raised reefs masses examined were found to 
contain numerous molluscan remains, but up to the present time, no 
opportunity of critically examining these fossils has presented itself. 
It was found in the majority of instances that the limestone of 
the elevated reefs was seamed with veinlets of carbonate of lime ■ 
generally speaking, it was found that the coralline structure had been 
almost obliterated by the changes which the limestones had undergone 
since their formation. This alteration had not, however, proceeded 
throughout the whole thickness of the rock, for in one of the islands, 
Misima, the base of one of the up-raised reef masses was found to con- 
sist of a chalky limestone, in which the remains of corals still exist. 
f Etheridge- Palaeontology of New Guinea, Records Geol. Sun New South Wales. 
Vol. I., part 3, pp. 175. 
