AGASSIZ: FIJI ISLANDS AND CORAL REEFS. 65 
elevated to nearly three hundred feet, and it has been subject for a long 
period to the action of the atmosphere and of the sea; the one wearing 
down the limestone land into an inner basin or cutting it out into 
valleys, and finally into islands and islets ; the other encroaching into it 
from the outside, and eventually forming an interior basin studded with 
islets, which to all appearance would be a lagoon surrounded by an 
encircling reef with its heads and patches and islands and islets. And 
yet it would really be a crater-like basin, a ‘‘ Sound,” which by erosion 
had become connected with the true barrier reef lagoon, and finally even 
all trace of the Sound character of the inner basin might vanish with 
the disappearance of the old shore line, and the existence of only islets 
to indicate the former land area. 
In the case of Fulanga, Gardiner? has well described the action of the 
sea both as a solvent and as a disintegrating factor in reducing the rocks 
and islets to mushroom-shaped structures, and in the great undercutting 
of the cliffs, of which he gives the same illustration as that I give here, 
which was kindly furnished me by the Hon. W. L. Allardyce. He says: 
“The final result should be a perfect atoll reef just awash, the land be- 
ing dissolved away while the living reef round it continues to grow.” 
So it does, but the reef has played no part in the shaping of the atoll, 
the lagoon of which owes its existence to the formation of the interior 
Sound by the decomposition of the elevated tertiary limestone reef mass, 
and has no connection with the recent coral reef growing upon the reef 
flats or external platform of submarine erosion. 
SOUTHEAST POINT OF MARAMBO. 
Marambo. 
Plate 22. 
-Marambo is a small circular island about three quarters of a mile in 
diameter (Plate 22). It is composed of elevated limestone rising to 
160 feet in height. It is surrounded by a fringing reef fully a mile in 
1 Loe. cit., p. 459. 
VOL. XXXIII. 5 
