ON INVESTIGATIONS IN 'THE INDIAN OCEAN. 205 
impression that they are only just dead. On the landward side of the 
cliffs is a ridge, 2 feet or 3 feet higher, of grass-covered sand; this marks 
the seaward edge of the shore zone, which is about 250 yards wide, the 
sand being shallow and lying on a basis of coral rock. Then comes a 
rocky ridge, 4 feet to 6 feet higher than the shore zone, the rock more 
solid and less denuded; this, the highest part of the section, is some 
25 feet above sea-level. From the landward side of this ridge the level 
gradually decreases to about 10 feet above sea-level. It passes into a 
zone of Champignon, which here lies outside the Platin zone, which 
latter extends to the mangrove swamp. The Platin is all very similar in 
appearance, except that it is more wooded near the lagoon ; it terminates 
with a sharp drop through the last 4 feet or 5 feet to the lagoon surface. 
At Takamaka there is a spring of fresh water, and a grove of large 
Calophyllum and Ficus trees. This spring, with three others, all lying 
between Takamaka and the lagoon, is the only constant source of fresh 
water on the islands. The section finishes at Abbot’s Creek, which is 
a narrow passage from the lagoon with a thick undergrowth of man- 
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groves on each side; its bed is rocky and covered with very fine white 
mud; at its termination in the land it passes between small cliffs, all 
much overhung and obviously breaking down. 
In another section, which passes from Vert Island in the lagoon 
northward to the sea, the country is all, with the exception of the shore 
zone, of the Champignon type, Platin being entirely absent. There is 
a gradual slope from the lagoon, becoming steeper at the beginning of 
the shore zone. Right up to the latter salt water is often found in pits 
in the rock, fluctuating, apparently, with the lagoon tides. The cliffs 
on this north coast are 4 feet or 5 feet higher than those before described, 
and are always much overhanging. Caves penetrate far into their faces, 
large portions of which have at intervals fallen on to the reef; this 
fallen rock appears to become disintegrated quickly, as small pieces are 
uncommon, the action of the sea being assisted by boring animals 
{small Gephyreans, boring molluscs, &c.). As elsewhere round the 
coast, the rock shows its component corals in a way which leaves no 
doubt as to their being in the same position as previous to their elevation. 
On the reef here there are three or foyr distinct regions; close to the 
