On Coral Reefs and Islands. 193 
yond a certain rate. 
The annexed figure represents the effect of 
@ cessation or diminution of subsidence on the 
outlines of barrier reefs. Compare Angau of 
the Feejees, with Tari-tari of the Tarawan 
Group; Nairai or Moala with Tarawa; Na- 
huku with Maiana or Apamama. ‘The resem- 
blance is close; and in the same manner we 
might find all the forms of lagoon reefs repre- 
sented among barrier reefs. We observe all 
those configurations which would be derived 
from land of various shapes of outline, whether 
the narrow mountain ridge, (as at Taputeouea, 
One of the Tarawan Islands,) or wide areas of 
‘regular slopes and mountain ranges. Amon 
the groups of high islands, we observe that 
8 Shores may occasion the absence of a 
eo 
As the lagoon islets cover the summits of the subsided mountains ins, they afford 
the depth required for this purpose on an islet in the lagoon would be haré 
fourth what would be necessary on the enclosing reef} 
Stconp Serres, Vol, XIII, No, 38.—March, 1852. 25 
