SUBSIDENCE IN PACIFIC CORAL REGIONS. 325 



wall, thus described by Capt. Wm. Reynolds, U. S. N., ap- 

 pears to be an indication that the land was once finished off 

 under a cessation of subsidence, but that a sinking of small 

 amount has since taken place, amounting perhaps 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. 



Gambler Group. — 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, Pit- 

 cairn } s and Gambler's. There is evidence, however, in the ex- 

 tensive barrier about the Gambler's (see cut on page 265), 

 that this subsidence, although less than farther north, was by 

 no means of small amount. On page 157, we have estimated 



