CORAL REEFS AND SUBMARINE BANKS 291 
support. The previously stated arguments which lead to this 
conclusion need not be repeated here, but additional evidence 
to the same end may be presented from Hawaii, Tahiti, and 
Murea. 
Evidence from Hawai, Tahiti, and Murea.—Let it first be noted 
that Hawaii, Tahiti, and Murea are three of four islands—the 
other is Rotuma, north of Fiji—which Daly instances as having 
“submarine benches so narrow as to prove the extraordinary power 
of fresh lavas to resist the Pleistocene breakers” (182). Rotuma 
I have not seen, but Gardiner’s account of it’ suggests that the 
narrowness or absence of an abraded bench around it may be due 
rather to the recency of its latest lava flows than to their resistance. 
Hawaii also was not reached during my voyage of 1914, but Bran- 
ner’s account of it? and the several excellent topographic sheets 
recently published by the United States Geological Survey of its 
northern and northeastern coast give good reason for thinking that 
the general absence of a cliff-backed bench around its shores is due 
to the recency of the eruptions that have covered most of its slopes 
with lava flows in which valleys are not yet eroded; while the 
occurrence of deep consequent valleys and strongly clift intervalley 
spur ends in the Hamakua district of the northeast coast gives 
equally good reason for regarding that part of the island as much 
older than the rest—old enough in fact to have suffered submature 
dissection and mature abrasion, but at a time when the island stood 
several hundred feet higher than now, as Branner has so well shown. 
By constructing longitudinal sections and cross-sections of the 
great valleys from the topographical maps, I have inferred that 
the amount of submergence since the valleys were cut down and 
the cliffs were cut back is some 800 feet. But whether submerged 
or not, the island of Hawaii ought not to be instanced in proof of the 
belief that the absence of spur-end cliffs on the central islands of 
barrier reefs elsewhere in the Pacific is due to the resistance of 
their lavas: to my reading Hawaii supports the other side of the 
tJ. S. Gardiner, “‘The Coral Reefs of Funafuti, Rotuma, and Fiji... . ,” Proc. 
Cambr. Phil. Soc., UX (1898), 417-503. 
2J. C. Branner, ‘‘Notes on the Geology of the Hawaiian Islands,” Amer. Jour. 
Sci., XVI (1903), 301-16. 
