CORAL ISLANDS. 53 
depressed about the centre, a fact indicating that there was formerly 
a lagoon. 
Fig. 1. 
HENUAKE or HONDEN. 
Fig. 3. Fig. 4. 
SWAIN’S ISLAND. JARVIS ISLAND, 
FAKAAFO, 
Fakaafo, or Bowditch, (fig. 5,) 200 miles north of Samoa, is the 
type of a large part of coral islands. The bank of reef has only here 
and there emerged from the waves and become verdant; in other por- 
tions the reef is of the usual height,—that is, near low tide level,— 
excepting a few spots elevated a little by the accumulation of sand. 
The Paumotu Archipelago, the crowded cluster of coral islands just 
northeast of Tahiti, is a most instructive study for the reader; and a 
map of these islands by the Expedition, inserted in the Narrative 
of the Expedition, and also in the Hydrographical Atlas, will well 
repay close study. It is called the Low or Dangerous Archipelago. 
Sailing among these.islands, but four of which are over twelve feet 
high, exclusive of the vegetation, two or three are almost constantly 
in sight from the mast-head. 
The small amount of habitable land on these reef-islands is one of 
their most peculiar features. Nearly the whole surface is water; the 
land around the lagoon is but a narrow rim, the greater part of which 
is usually under water at high tide. This fact will be rendered more 
apparent from the following table, containing a statement of the sizes 
and areas of several islands, with the amount of habitable land. ‘The 
measures are given in geographical miles. 
14 
