170 CORALS AND CORAL ISLANDS. 
miles, and includes hardly six square miles of wooded land. 
In the Marshall Islands the dry land is not over one-hundredth 
of the whole surface; while in the Pescadores the proportion 
of land to the whole area is about as 1 to 200. 
The distribution of the land upon the reef is obvious from 
the sketches already given. It is seen, as long since remarked. 

MENCHICOFF ATOLL. 
1-20 of an inch to a mile. 
that the windward side is, in general, the highest. It is also 
apparent that there are not only great irregularities of form, 
but that on one side the reef may at times be wholly wanting 
or deeply submerged. 
In many islands there is a ship-entrance through the reef, 
sometimes six or eight fathoms deep, to the lagoons, where 
good anchorage may be ‘had; but the larger part have only 
shallow passages, or none at all. In the Paumotus, out of the 
twenty-eight visited by the Expedition, not one-half were 
found to have navigable entrances. In the Carolines, where 
the islands are large and not so much wooded, entrances are 
of more common occurrence. About half of the Kingsmill 
Islands afford a good entrance and ‘safe anchorage. Through 
these openings in the reefs, there is usually a rapid outward 
