AGASSIZ: FIJI ISLANDS AND CORAL REEFS. 99 



surrounded by a fringing reef which ends beyond the northern point of 

 the island along the base of the vertical cliffs between it and Tolvalau 

 village (Plate 78), and becomes the merest thread to the soutli of it 

 for a short distance. Along the rest of the west face there is a narrow 

 incipient lagoon studded with coral patches, with from one to two 

 fathoms of depth in places between the outer reef and the shore. 



Gardiner ^ describes the interior plateau of Kambara as being about 

 100 feet above the level of the sea, and that "on the plateau itself are 

 many small hills, rising nearly to the level of the rim, with very steep 

 walls, and some springing almost like buttresses from the rim itself," 

 and that on this plateau there are a number of deep holes in which salt 

 water is found and tidal influences are felt. This description corresponds 

 with what has been observed in the reolian hill basins of the Bahamas 

 and Bermudas, in which atmospheric agencies ai'e at work to form the 

 incipient sounds, and finally the gTeat sounds or lagoons of the islands 

 of these groups. 



Gardiner ^ reports that the hills of Thikombia i ra ai'e certainly of 

 limestone, and at a distance appear distinctly terraced. 



SUNDRY ATOLLS. 



Pitman Reef. 



Plate 18. 



Pitman Reef is an oval atoll about a mile in greatest length. We 

 passed within a cable's length on the west side, and could see the outer 

 edge of tlie reef flat uncovered at points, and patches of corals growing 

 upon it. The reef flat seems to be .300 to 3-50 yards in width. It is 

 widest at the northern extremity. The lagoon is marked on the chart 

 as being eighteen fathoms deep. 



Motua Levu and Motua lai lai. 



Plate 18. 



Motua Levu and iMotua lai lai are two atolls to the eastward of Lau- 

 thala reef. The former is somewhat rectangular, about two miles in 

 length, and encloses a lagoon with a greatest depth of twenty-five 

 fathoms. On the northwest edge boats can cross into the lagoon. The 

 latter is nearly circular, a mile in diameter, enclosing a small lagoon. 



1 Loc. cit., p. 464. 2 Loc. cit., p. 462. 



