SUBSIDENCE IN PACIFIC CORAL REGIONS. 373)/( 
II. SUBSIDENCE INDICATED BY ATOLLS AND BARRIER 
REEFS. 
Looking at atolls as covering buried islands, we observe 
that through the equatorial latitudes such marks of. subsi- 
dence abound from the Kastern Paumotus to the Western 
~ Carolines, a distance of about six thousand geographical miles. 
In the Paumotu Archipelago there are about eighty of these 
atolls. Going westward, a little to the north of west they 
are found to dot the ocean at irregular intervals; and the 
| Kingsmill or Gilbert Group, the Marshall Group, and the 
Carolines comprise seventy-five or eighty atolls. 
If a line be drawn from Pitcairn’s Island, the southern- 
most of the Paumotus, by the Gambier Group, the north of 
the Society Group, the Navigators, and the Solomon Islands 
to the Pelews, it will form nearly a straight boundary, trend- 
ing N. 70° W., running between the atolls on one side and 
the high islands of the Pacific on the other, the former lying 
to the north of the line, and the latter to the south. 
Between this boundary line and the Hawaiian Islands, an 
area nearly two thousand miles wide and six thousand long, 
there are two hundred and four islands, of which only three, 
exclusive of the eight Marquesas, and the Ladrones with Yap, 
Hunter’s, and Los Matelotas in the line of the Ladrones and 
Pelews, are not of coral. These three are Kusaie or Ualan, 
Ponape, and Truk or Hogoleu, all in the Caroline Archipelago. 
South of the same line, within three degrees of it, there is an 
occasional atoll; but beyond this distance, there are none 
excepting the few in the Friendly Group, and one or two in 
the Feejees. ° 
If each coral island scattered over this wide area indicates 
the subsidence of an island, we may believe that subsidence 
