ELEVATIONS IN PACIFIC CORAL REGIONS. 371 
is erghty feet. It is one of the southeastern Paumotus, near 
Ducie’s. 
Ducie’s [sland is described by Beechey as twelve feet high, 
which would indicate a probable elevation of one or two feet. 
Osnaburgh Island, according to the same author, affords evi- 
dence of having increased its height since the wreck of the Matil- 
da, in 1792. He contrasts the change from a “reef of rocks,” 
as reported by the crew, to ‘‘a conspicuously wooded island,” 
the condition when he visited it; and states, further, that the 
anchor, iron works, and a large gun (4-pounder) of this vessel 
were two hundred yards inside of the line of breakers. Cap- 
tain Beechey suggests that the coral had grown, and thus in- 
creased the height. But this process might have buried the 
anchor if the reef were covered with growing corals (which 
is improbable), and could not have raised its level. If there 
has been any increase of height (which we do not say is cer- 
tain), it must have arisen from an upheaval. 
ce. Tahitian Group.—tThe island of Tahiti presents no 
conclusive evidence of elevation. The shore plains are said to 
rest on coral, which the mountain débris has covered; but 
they do not appear to indicate a rise of the land. 
The descriptions by different authors of the other islands 
of this group do not give sufficient reason for confidently be- 
lieving that any of them have been elevated. The change, 
however, of the barrier reef around Bolabola into a verdant 
belt encircling the island, may be evidence that a long period 
has elapsed since the subsidence ceased; and, as such a change 
is not common in the Pacific, we may suspect that it has been 
furthered by at least a small amount of elevation. The observa- 
tion by the Rev. D. Tyerman with regard to the shells found at 
Huahine high above the sea, may be proof of elevation; but 
the earlier erroneous conclusions with regard to Tahiti (on 
