Corals and coral islands.

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CORALS AND CORAL ISLANDS.

Pylstaart's Island, south of Tongatabu, is a small rocky
islet without coral. Tafua and Proby are volcanic cones, and
the former is still active.
Savage Island, a little to the east of the Tonga Group, re.
sembles Vavau in its coral constitution and cavernous cliffs. It
is elevated, according to Williams (pp. 275, 276), one hundred feet.
Beveridge Reef, a hundred miles southeast of Savage, is low
coraL
f. Samoan or Navigator Islands. —No satisfactory evidences of elevation were detected about these islands.
g. Atolls, north of Samoa.
On account of the high tides (four to six feet), the sea
may give a height of twelve to sixteen feet to the land.
Swain's (Gente Hermosas?), near latitude 11~ S., is fifteen
to eighteen feet above the sea where highest, and the beach
is ten to twelve feet high. It is a small island, with a depression at centre, but no lagoon. Probably an elevation of
two or three feet. This island was named Swain, by Capt.
Hudson, of the Wilkes Expedition, because not in the position
assigned to Gente Hermosas.
Fakaafo, ninety miles to the north, is fifteen feet high. The
coral reef-rock is raised in some places three feet above the
present level of the platform. Elevation at least three feet.
Nukunono, or Duke of Clarence, near Fakaafo, was seen
only from shipboard.
Oatafu, or Duke of York's, is in some parts fourteen feet
high. Whether elevated or not is uncertain; probably as
much so as Fakaafo.
h. Scattered islands farther north, near the equator, east of
the Gilbert Group.
Of the Fanning Group, Washington Island, in lat. 4~ 41' S.,