Notices of Memoirs ~C. W. Andrews— On Christmas Island. 25 



sketch of the structure of the neighbourhood of Flying Fish Cove 

 is given. 



Round the greater part of the cove, about half-way up the cliff, 

 there is a thick bed of yellow foraminiferal limestone, the nearly 

 vertical face of which is from 15 to 60 feet high. Beneath this, and 

 apparently penetrating its lower surface, are several masses of 

 volcanic rock, mainly basaltic. Above the limestone is another 

 bed of basalt, upon which there are thick bands of palagonite 

 tuifs, and occasionally traces of basalt above these again ; but 

 the upper slopes are so thickly covered with soil and fallen 

 blocks of limestone, that it is difficult to determine the exact 

 structure of this part of the cliff. About the middle of the cove 

 the hard limestone is found at a rather higher level, apparently 

 the result of faulting, but its relations to the volcanic series are the 

 same. Southward of this the bed dips downward towards the shore, 

 and the basalt and tuffs resting upon it disappear abruptly, their 

 edges being overlapped by hard white limestone with Orbitoides. 

 This rock forms the upper 50 feet or so of the cliff throughout its 

 length, and on the summit occurs in low cliffs, ridges, and pinnacles. 

 At the southern end of the cove it thickens out to a cliff some 250 to 

 300 feet high, the lower part of which is penetrated by masses of 

 basalt. Above the cliff to the southward this limestone is found on. 

 the eastern and western sides of a broad belt of basalt, which forms 

 a series of rounded hills with valleys opening towards the sea. On 

 the eastern side its base is about 600 feet above the sea; on the 

 west, where it is largely concealed by the more recent deposits 

 forming the cliffs and terraces representing the first inland cliff, it is 

 only 300 to 350 feet. No doubt this limestone completely covered 

 the basalt, but has been removed by denudation ; and, in fact, further 

 south the volcanic rock is completely concealed by limestones. 



Further inland, above the orbitoidal limestones comes the steep 

 slope of the second inland cliff, which is here largely composed of 

 corals ; shells of mollusca are also found, and there are some beds of 

 foraminiferal limestone without Orbitoides. Above this cliff is a long 

 slope with lines of limestone pinnacles parallel to its edge, and above 

 this, again, the upper inland cliff, or rather slope. Along the foot of 

 this there are some ridges of coral limestone ; but towards the 

 summit it rises into rounded hills of dolomitic limestone, with 

 a great many blocks of phosphate of lime here and there. These 

 piles are probably the remains of islets along the edge of the lagoon 

 (now the plateau) before the first elevation of the island took place. 



The history of the island, as far as it can be made out, seems to 

 have been as follows : — At first, at no great depth, there was 

 a submarine bank upon which numerous foraminifera, including 

 Orbitoides, lived, and the shells of which formed thick beds of 

 limestone. The foundation of this bank was volcanic, and from 

 time to time lava was erupted through and upon the limestones : 

 the occurrence of thick bands of palagonite tuff indicate that the 

 eruptions were submarine. Some elevation took place, and the 



