ie 
“= 
Ss. 
360 On Coral Reefs and Islands. 
Above Angau lies Nazrai; though a smaller island than Angau 
the barrier reef is of greater extent, and stretches off far from the 
shores. - To the eastward of Nairai are Vatu Rera, Chichia, and 
Naiau, other examples of islands fringed around with narrow 
reefs. Lakemba, alittle more to the southward, is also encircled 
with coral: but on the east side the reef is a distant barrier. In 
Aiva, immediately south of Lakemba, the same structure is ex- 
emplified ; but the coral ring is singularly large for the little spots 
of land it encloses. The Argo Reef, east of Lakemba, is a still 
larger barrier, encircling two points of rock called Bacon’s isles. 
It is actually a large lagoon island, twenty miles long, with some 
coral islets in the lagoon, and two of basaltic constitution, the 
largest of which is only a mile in diameter. Aiva and Lakemba 
are in fact other lagoon islands, in which the rocky islands of the 
interior bear a larger proportion to the whole area. The same 
view is farther illustrated by comparing the Argo reef with Nairai, 
Angau, or Moala: the only difference in these cases consists in 
the greater distance of the reef from the shores which it encircles, 
and the smaller extent of the enclosed land. 
Passing to the large islands Vanua Levu and Viti Levu, we 
observe the same peculiarities illustrated on a much grander scale. 
Along the southern shores of Viti Levu, the coral reef lies close 
against the coast; and the same is seen on the east side and north - 
extremity of Vanua Levu. But on the west side of these islands, — 
this reef stretches far off from the land, and in some parts is even — 
twenty-five miles distant, with a broad sea within. This sea, 
however, is obstructed by reefs, and besides, along the shores 
there are proper fringing reefs. 
The forms of encircling reefs depend evidently to a great eX-_ 
tent on that of the land they enclose. That this is the case even 
in the Argo reef and such other examples as offer now but a sin- 
gle rock above the surface of the enclosed lagoon, we shall en- 
deavor to make apparent, if not already so, when the cause of the 
orms of coral islands is under discussion. Yet it is also evident 
that this correspondence is not exact, for many parts of the 
shores, and sometimes more than half the coast, may be exposed to 
the sea, while other portions are protected by a wide barrier. 
In recapitulation, we remark, that reefs around islands may be 
(1) entirely encircling; or they may be (2) confined*to a larger 
or a smaller portion of the coast, either continuous or interrupted : 
_ they may (3) constitute throughout a distant barrier; or (4) the 
_Teef may be fringing in one part and a barrier in another ; or (5) 
it may be fringing alone: the barrier may be (6) at great dis- 
tances from the shores, with a wide sea within, or (7) it may S0 
unite to the fringing reef that the channel between will hardly 
float a canoe. These points are fully sustained by all reef re- 
gions ah ae | oe ee mn cm 
