62 "ALBATEOSS" TROPICAL PACIFIC EXPEDITION. 



village is situated, extends a narrow reef platform cut out of the cliffs of the 

 first terrace, similar in every respect to that off the west coast, but perhaps a 

 little wider, with a higher rim and deeper fissured edge. There is no great 

 high sand beach back of the reef platform on the east shore as on the west 

 side ; it abuts against the remnants of the slope of the first terrace. 



On the east face, to the south of the village, the reef platform disap- 

 pears ; its occasional presence is only indicated here and there by a few small 

 sand beaches at the foot of the line of caverns. 



On the face of a vertical cliff immediately south of the village four 

 periods of elevation are most clearly indicated. The edges of the caverns 

 were thickly covered with lines of stalactites running along the face of the 

 cliffs, and giving them the appearance of gray basaltic rocks. 



It is evident that the sea has not had access into the interior of the sink, 

 if it ever had any, after the elevation of the second terrace. It is most 

 difficult to decide whether such sinks as those of Makatea and Niau are the 

 remnants of sounds or of atolls, or merely sinks representing huge " banana 

 holes," as they are called in the Bahamas, or " sounds," as they are termed 

 in the Bermudas. The great sink at Nassau^ has nothing in common with a 

 lagoon, though if the sea were to cut into it we should have a sound having 

 all the appearance of a lagoon, as have the sounds of the Bermudas, yet 

 each owes its origin and present condition to very different causes. The 

 crevasses, pot-holes, spires, pinnacles, and the pitting and honeycombing of the 

 sink of Makatea cleai'ly indicate an enormous amount of erosion and of 

 denudation ; and the existence of the endless caverns in the body of the 

 island " also shows how long this disintegration has been going on, to honey- 

 comb as it were the whole of Makatea on so large a scale. Furthermore, 

 this disintegration and erosion has gone on so long that if the sink is the 

 remnant of an ancient lagoon existing in Makatea before the second terrace 

 was elevated, it has been subsequently so modified by atmospheric agencies 

 as to completely obliterate all that characterizes an atoll of modern times, 

 formed in the existing period. The comparatively flat floor, the gentle slopes 



1 Bull. M. C. Z., XXVI. No 1, PI. 10, fig. 3. 



- Similar caverns are known in nearly all the limestone islands of Fiji, Tonga, the Cook group, 

 Guam, Niue, Ocean and Pleasant Islands in the Pacific, as well as in the Atlantic, at the Bermudas, 

 Bahamas, Cuba, and other limestone islands. 



