GEOLOGY: W. M. DAVIS 
475 
case an island were dissected sufficiently to show its abraded platform 
of central volcanic rocks surmounted by residual limestone hills, as in 
sector J, a still earlier uplift would be demanded; and in such case, a 
correspondingly shorter part of the Glacial period would be allowed 
for the initial abrasion of the volcanic island. The more clearly these 
various consequences of the theory are conceived, the more closely 
can the theory be tested when the consequences are confronted with 
the facts, to which we may now turn. 
FIG. 4. 
A number of uplifted and dissected atolls occur in the Lau group of 
southeastern Fiji. The route of my Shaler Memorial voyage of 1914 
did not, to my regret, lead me to them, but most of them have been 
described in some detail by Gardiner^ and Agassiz,^ from whose reports 
the following items are taken. The rough outlines of figure 4 are con- 
structed in perspective, with exaggerated height, from Agassiz charts; 
the squares in the perspective network are 2 nautical miles on a side. 
The dimensions of the uplifted atolls and of some neighboring sea- 
