74 CORAL FORMATIONS. 
Kawehe, or Vincennes Island, Paumotu Archipelago, 15° 30’ S., 145° 
10’ W. 13 miles by 9, trending north-northwest. Shape irregularly 
oval. Having a large lagoon, and mostly wooded around, least so to 
leeward. Between the wooded islets, (as on Raraka and elsewhere,) 
surface consisted of angular masses of coral rock, (among which the 
Porites prevailed,) strewed in great numbers together; and in some 
parts bearing a few vines and purslane among the blocks, though 
scarcely any appearance of soil, or even of coral sand. In other parts, 
not as high, no vegetation, and surface still wet by high tide. A 
few large masses of coral on the shore platform, either lying loose, or 
firmly attached below. Some of these were six feet cube, and one was 
raised seven feet above high water mark. Those that were attached 
were so firmly cemented to the reef-rock as to seem to be a part of it, 
and they were partly worn off below by the wash of the sea. ‘The sur- 
face was extremely rough, owing to wear by rains. These masses 
were sometimes single individual corals, and others were conglomerate 
in character. Shore platform about a hundred yards wide, rather the 
highest at the edge, and much of its surface two to four feet under 
water at low tide. As elsewhere, this platform is nothing but a com- 
pact coral conglomerate, having no growing coral over it, except in 
some shallow pools near its outer margin, where also there are 
numerous holes in which crabs are concealed, with small fish and 
other animals of the shores. On the lagoon shore, layers of beach 
sand-rock, six or seven in number, dipping at an angle of seven de- 
grees towards the lagoon, and outcropping one from beneath the 
other. Similar layers on the sea-shore side. 
Manhn, Wilson’s or Waterlandt, Paumotu Archipelago, 14° 25’ S., 
146° W. 15 miles by 6, trending E.N.I. A large lagoon with a 
deep entrance on the west side. Shape oblong triangular. 
Shore platform as usual; mostly under water at low tide. Large 
masses of coral here and there, standing on this reef, either cemented 
to it or not. One top-shaped mass is figured on p. 61. High water 
did not reach the part of it which was most worn; and this was 
evidently owing to the fact that the action of the swell, or waves, was 
greatest above the actual level of the tide at the time. This mass was 
not of fragmentary composition; it was apparently the remains of a 
single individual Astrea. Another loose mass was five and a half feet 
high, and averaged ten feet across, (fig. 3, p. 61.) It consisted of 
large masses of Astreeas, Madrepores, and Porites cemented together, 
and contained imbedded shells, an Astrea, Cyprea, &c. The reef- 
