248 
GEOLOGY: R. A. DALY 
PROC. N. A. S. 
tion also explains the 8-foot benches, for the cliffs now being cut on the 
Samoan headlands (where not protected by coral reefs) have regularly 
about 12 feet of water directly at their feet during high tide. The writer 
fully agrees with Mayor's conclusion that reef corals were not living on 
any of these Samoan shores when the emerged caves and benches were 
developed. Hence, the nearly or quite reefless headlands of the present 
time are those where the relation between sea-level and bench-level of the 
earlier period is best determined. 
Correlation of the Samoan and Norj^i American terraces was suggested 
not only by the agreement in level but also by the state of preservation of 
the strand-marks, as well as by the comparable amounts of work done by 
the waves in the two regions during the higher stand of the sea. 
The hypothesis of a eustatic shift must obviously meet the test of 
matching the facts observable on the shores of every continent and of 
most islands. The application of the test is difficult for many reasons 
which need not here be recounted, but a partial study of the records 
scattered through geological literature shows that the hypothesis merits 
discussion and further testing. The actual compilation of facts relates 
to the British Isles, the Atlantic coast of North America south of New York, 
the West Indies, Brazil, Patagonia, Antarctica, New Zealand, Australia, 
and many groups of the Pacific islands. For details the reader is referred 
to an article in a forthcoming number of the Geological Magazine (London). 
A specially instructive example is seen in the agreement of the loWer 
Cape May terrace of New Jersey and Pennsylvania, the Talbot terrace 
of Maryland (marine part), the Satilla terrace of Georgia, and the lower 
Pensacola terrace of Florida in age, height and strength of development, 
both among themselves and with the other terraces above-mentioned. 
The Pensacola-Satilla terrace alone keeps a practically uniform set of 
levels (maximum about 20 feet) for an air-line distance of 500 miles; the 
explanation of its emergence by crustal uplift seems hardly credible. 
According to Andrews, "indications of the apparent elevation of the 
shore-line for a few feet are to be found along the whole eastern side 
of Australia;" he attributes the cause to "either an apparent rise of the 
land, or a retreat of the sea."'^ Siissmilch specifies the amount of the 
emergence (New South Wales) as "10 to 20 feet."^ Cadell notes similarly 
recent emergence of western Australia by amounts between the same limits.^ 
In this case nearly or quite uniform emergence has affected a thousand 
miles of coast on one side of a continent and several hundred miles on the 
other side, and again there is practical agreement with the amount of 
emergence shown in the mid-Pacific, in North America, and in many 
other regions. 
Thus, in spite of complications, including the present-day warping of 
some coasts, the hypothesis appears to stand the test involving the amounts 
of local emergence. 
