CORAL REEFS AND SUBMARINE BANKS 301 
the width of the platform [atoll]”’ (192);' but as this conclusion 
would follow equally well whether the reefs have grown up with the 
rising ocean around a still standing abraded platform, or in a 
stationary ocean around a sinking and submountainous foundation, 
no ground for choice between the two theories under discussion is 
here provided. 
A closer scrutiny of the figures, however, reveals considerable 
differences of lagoon depth in atolls of about the same size, and this 
seems more consistent with the variable conditions offered by the 
theory of intermittent subsidence than with the strictly uniform 
conditions assumed under the theory of glacial control. For 
example, among 12 atolls listed in Daly’s table as from 21 to 30 
kilometers in diameter, the smallest value of maximum lagoon 
depth is little more than half the value of the largest maximum; 
and this smallest maximum is in an atoll the diameter of which is 
greater than the one which has the largest maximum. Ringgold 
atoll, in Fiji, is given as having a maximum lagoon depth that is 
more than twice as great as the maximum depth in North Argo 
atoll, of the same group, though both have the same moderate 
diameter of 10 miles. Among wide barrier reefs the one adjoining 
New Caledonia on the northeast has a maximum depth less than 
half that of the lagoon of similar breadth on the northwest of Viti 
Levu, in Fiji. Moreover, some lagoons reach unusual depths. 
In the large lagoon, just mentioned, northwest of Viti Levu, the 
largest island of the Fiji group, the lagoon deepens and the inclosing 
reef is submerged, as the distance from the island increases, in such 
a way as strongly to suggest recent tilting; a sounding of 59 fathoms 
is the maximum there recorded, but the outermost part of the 
lagoon has not been measured. The large lagoon of the Exploring 
Isles in the eastern part of Fiji deepens eastward to 80 or go fathoms, 
and this again suggests tilting, as Agassiz noted. Cases of this 
kind are as significant as they are exceptional. But it should be 
noted that many atolls of the Central Pacific are, according to the 
latest charts of all sources available in the Hydrographic Office at 
Washington, incompletely surveyed; further exploration is needed 
t The misprint “‘direct”’ in the original article is here changed to “‘indirect”’ with 
the author’s approval. 
