CORAL REEFS AND SUBMARINE BANKS 405 
according to Carne’ and Laing.? Its cliffs rise 250 feet above sea- 
level and form a wall-like coast with few indentations; it surmounts 
a vast bank which is represented on British Admiralty charts 215 
and 1110 as measuring 60 miles north and south by 20 miles in 
breadth, with depths of 20 fathoms near the island and of 4o or 
50 fathoms near the margin. Similarly, Lord Howe Island, east 
of Australia, in latitude 32° S. (not to be confounded with a great 
atoll sometimes given the same name, but better known as “Ongtong 
Java,” north of the Solomon group), presents, as described by 
Etheridge, a ragged and clift margin on its convex northeastern 
side, and a coral reef inclosing a narrow lagoon on its concave south- 
western side; it is shown on Admiralty chart 2014 to rise from a 
bank from 8 to 12 miles in diameter, submerged to depths of from 
20 fathoms near the island to 40 fathoms near the bank margin. 
Not far away the gigantic volcanic stack, known as Balls Pyramid, 
with a height of 1,816 feet that exceeds its shorter diameter at sea- 
level, rises from a 3X7-mile bank, with cliff-base depths of 15 or 
20 fathoms, and marginal depths of 40 or 50 fathoms. As in the 
case of Bird and Necker islands, these two southern examples 
may have been reef-encircled in preglacial or interglacial time, and 
may have suffered abrasion after the reefs were dead; but if so the 
reefs around the islands of the torrid sea cannot have been killed, 
for those islands are as a rule not clift. 
Mention may be made in this connection of certain exceptional 
intertropical islands that, like Tahiti and part of Hawaii, do possess 
cliftspurends. Tutuila, the easternmost of the three larger Samoan 
Islands, is ancient enough to be more or less dissected, and yet 
modern enough to be still mountainous; it is well embayed, and 
some of the bays at least seem to be drowned erosional valleys and 
not merely unfilled spaces between adjacent volcanic masses; but 
on this significant though elementary point no sufficient evidence 
is available. According to Hydrographic chart 90, the salient 
1 J. E. Carne [Notes on Norfolk Island], App. H., Ann. Rep. Dept. Mines N.S.W., 
for 1885 (Sydney, 1886), pp. 145-47. 
2R. M. Laing, ‘‘Notes on the Chief Physiographic Features of Norfolk Island,” 
Trans. N. Z. Inst., XLV (1913), 323-26. 
3R. Etheridge, “The Physical and Geological Structure of Lord Howe Island,” 
Mem. Austral. Museum, No. 2. 
