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PACIFIC SCIENCE, Vol. XVII, January 1963 
races range on various sides of the island from 
30 ft to 500 ft, their grouping suggests that 
terracing occurred at about four separate levels. 
The shoalest and widest terrace commonly ex- 
tends to depths of 40 to 90 ft; others extend 
from about 150 ft to between 240 to 350 ft; 
and for the deepest, to about 450 ft. The latter 
depth presumably marks the outer edge of a 
wave-cut terrace formed during a still stand 
near the lowest Wisconsin Sea Level. Generally, 
the 450-ft contour ranges from 1 to 2 miles 
from shore, although it extends to 4 miles off 
the west coast. 
The most gently sloping part of the insular 
shelf, that part shoaler than 90 ft, is frequently 
characterized by many apparently closed depres- 
sions, generally ranging from 10 to 30 ft deep. 
These are most common on the north coast, 
although a very large depression occurs on the 
west coast off Makaha Point ( Fig. 2 ) . The con- 
figuration of the submarine ridge surrounding 
this depression suggests that it may be a relic 
coastal sand dune, formed at a lower stand of 
the sea, or possibly a relic barrier beach or reef. 4 
4 Observations made while diving on this reef dur- 
ing September 1962 subsequent to submission of this 
manuscript show the reef to consist of a framework of 
coral. It is believed that it represents a barrier reef 
formed during a previous lower stand of sea, and the 
name "Kaheko” is proposed for the reef because of 
its presumed great age. 
Fig. 2. Topography, bathymetry, and sample locations. Numbers along coastline refer to sample designations 
listed in text and in Table 2. Intermittent jagged line along shore shows location of major reefs. 
