26 Notices of Memoirs — C. W. Andreics — On Christmas Inland. 



beds of tuff became consolidated by the infiltration of lime. In 

 tlie next place, the whole was covered with thick beds of white 

 limestone crowded with large Orbitoides. These strata seem to 

 have overlapped the edges of the beds of tuff, and in places it can 

 be seen that they dip away from the central mass. The deposits 

 resting on the orbitoidal limestones are for the most part covered 

 with recent accumulations, but they appear to have been mainly 

 foraminiferal limestones. 



Upon the foundation thus prepared extensive reefs grew up and 

 formed an atoll-shaped group of islands, the reef flat and islands 

 being now represented by the raised rim of the plateau and the hills 

 rising from it, the lagoon by the central plateau itself. The 

 rounded hills and lofty pinnacles found within the raised margin are 

 probably the remains of knolls and masses of coral growing up in 

 the lagoon, such as may be seen in the Cocos-Keeling Islands at the 

 present day. The height of the hills over North-West and South 

 Points may be accounted for by supposing either that they are points 

 of local elevation greater than that affecting the main mass of the 

 island, or that they represent the higher parts of the bank, upon 

 which reefs were formed before the greater part of it was near 

 enough to the surface for the growth of reef corals. During the 

 formation of these higher reefs, the material derived from their 

 wear, mingled with the remains of organisms living around the 

 coast, formed thick deposits of limestone upon the flanks of the 

 island. 



The first important movement which took place seems to have 

 resulted in the elevation of the northern and eastern sides of the 

 island, the south and west probably remaining submerged. At this 

 time the reefs forming the second inland cliff grew round the north 

 and east coast, and probably some of the ridges of coral limestone 

 running across the middle of the island were formed near the new 

 shore-line on the side of the lagoon. 



The next extensive elevation affected the whole area equally, and 

 along the new shore-line the second inland cliff was cut back into 

 the reefs just formed, or even in some places into the central 

 foraminiferal limestones. Subsequently a series of movements of 

 elevation led to the formation of the first inland cliff, or, on the 

 more gentle slopes, to the succession of small cliffs and ridges of 

 coral rock which represent it. 



During these various movements much slipping and faulting took 

 place round the island ; the effects of this at Steep Point and 

 North-East Point have already been described. As a result of this, 

 and of the action of the waves around the coast, a submarine talus 

 slope was formed, upon which a fringing reef was established, and 

 at the next elevation this was converted into the shore terrace, 

 while its margins were cut back into the present sea-cliff. Finally, 

 as already mentioned, a reef is now growing around the coast which 

 some day may form yet another raised ten-ace round the island. It 

 is a point of some intei'est that Mr. Andrew Ross, during the eight 

 or nine years he has been residing on the island, has noted the 



