SUBSIDENCE IN PACIFIC CORAL REGIONS. 361 
This bare wall, thus described by Capt. Wm. Reynolds, 
U.S. N., appears to be an indication that the land was once 
finished off under a cessation of subsidence, but that a sink- 
ing of small amount has since taken place, amounting per- 
haps to four or five feet. 
Ocean Island, in 28° 25’ N., 178° 25’ W., another of this 
range, is very similar to Brook’s in its wall of coral rock on 
the east; and so also is Pearl and Hermes’ reef, in 27° 50’ 
N., 176° W., though the wall of the latter is more a series of 
detached rocks than a continuous parapet. 
Marquesas.—The Marquesas are remarkable for their ab- 
rupt shores, often inaccessible cliffs, and deep bays. The ab- 
sence of gentle slopes along the shores, their angular features, 
abrupt soundings close alongside the island, and deep inden- 
tations, all bear evidence of subsidence to some extent; for 
their features are very similar to those which Kauai or Ta- 
hiti would present, if buried half its height in the sea, leaving 
only the sharper ridges and peaks out of water. They are 
situated but five degrees north of the Paumotus, where eighty 
islands or more have disappeared, including one at least fifty 
miles in length. There is sufficient evidence that they partici- 
pated in the subsidence of the latter, but not to the same ex- 
tent. They are nearly destitute of coral, and apparently be- 
cause of the depth of water about the islands. 
Gambier Growp.—In the southern limits of the Paumotu 
Archipelago, where, in accordance with the foregoing views, 
the least depression in that region should have taken place, 
there are actually, as we have stated, two high islands, Put- 
cairn’s and Gambier’s. There is evidence, however, in the ex- 
tensive barrier about the Gambier’s (see cut on page 266), 
that this subsidence, although less than farther north, was by 
no means of small amount. On page 157, we have estimated 
