imestones and clay slates of very doubtful age, the
most interesting being a radiolarian clay which occurs on the south
side of the Matinang Mountains, at the north end of Lake Posso, &c.;
it may correspond with the radiolarian cherts of Borneo. Tertiary beds
are found, especially near the coast. The Eocene includes a series of
sandstones and marls with lignite, and these are overlaid by nummulite
limestones. The Miocene contains an _Orbitoides_ limestone. Intrusive
and volcanic rocks of great variety and of various ages occur.
Peridotite and gabbro form much of the eastern peninsula (Banggai).
Leucite and nepheline rocks have been found in various parts of the
island, especially in the south-west. In Minahassa, at the northern
extremity, there is a large area of tuffs and agglomerates consisting
chiefly of augite andesite, and in this area there are many recent
volcanic cones. Eruptions still take place at intervals, but the
volcanoes for the most part seem to have reached the solfataric stage.

_Climate._--The climate of the island, everywhere accessible to the
influence of the sea, is maritime-tropical, the temperature ranging
generally between 77 deg. and 80 deg. F., the extremes being about 90
deg. and 70 deg. F., only on the higher mountains falling during the
night to 54 deg. or 55 deg. F. The rainfall in the northern peninsula
(north of the equator) differs from that of the southern; the former has
rains (not caused by the monsoon), and of smaller amount, 102 in.
annually; the latter has a greater rainfall, 157 in., brought by the
north-western monsoon, and of which the west coast receives a much
larger share than the east.

_Fauna and Flora._--In spite of its situation in the centre of the
archipelago, Celebes possesses a fauna of a very distinctive kind. The
number of species is small, but in many cases they are peculiar to the
island. Of land birds, for example, about 160 species are known, and of
these not less than about 90 are peculiar, the majority of the remainder
being Asiatic in distinction from Australian. Mammals are few in
species, but remarkable, especially _Macacus niger_, an ape found
nowhere else but in Bachian; _Anoa depressicornis_, a small ox-like
quadruped which inhabits the mountainous districts; and the babirusa or
pig-deer of the Malays. Some of the animals are probably descendants of
specimens introduced by man; others are allied in species, but not
identical