CALCAREOUS FORMATIONS OF THE SOLOMON GROUP. 577 



point, which was one constantly before my mind during my examination of the 

 calcareous formations of these islands. The explanation of their origin held by 

 many natives is that they have fallen from the sky ; and since many of these 

 flints have all the characters of flint implements of the palaeolithic type, we are 

 thus reminded of a similar superstition prevalent amongst the agricultural 

 classes of some of the English counties as to the source of the polished stone 

 implements named " celts." (For further information on this subject vide 

 some notes of my own read by Professor Liversidge before the Royal Society 

 of New South Wales [Journal for 1883, vol. xvii. p. 223.]) 



Conclusion. 

 [Added December 16, 1885.] 



From the general character of these calcareous formations it may be safely 

 inferred that they will be found wherever there has been elevation during the 

 recent period in regions where coral reefs are flourishing. Amongst other 

 localities we may look to the West Indies, the Indian Archipelago, New 

 Guinea (more particularly the south coast), New Britain, New Ireland, the 

 Santa Cruz Group, the New Hebrides, the Loyalty Islands, New Caledonia, and 

 the Fiji and Tonga Groups, as likely to possess at the sea- border formations of 

 a similar character. 



I have thought it best to add to the completeness of this paper by making 

 a feAV general remarks on the general bearing of these observations. 



In this, the largest of the Pacific groups, I not only found existing fringing- 

 reefs, barrier-reefs, and atolls, but I discovered pre-existing reefs of these three 

 chief classes, which have been recently elevated to a height sometimes of 

 several hundred feet above the sea. My observations on these recently ele- 

 vated reefs and their foundations have enabled me to approach the problem of 

 the formation of coral reefs by the inductive rather than by the a priori method, 

 for it is evident that in passing from the consideration of a probable cause of 

 the formation of existing reefs to the examination of ancient reefs that have 

 been raised with their foundations above the sea, we enter a domain 

 of greater certainty. I will begin by briefly restating the principal points 

 of this paper. 



In the first place, there are numerous small islands and islets less than a 

 hundred feet in height, which are composed entirely of coral limestone. Then 

 there are islands of larger size, which are composed in bulk of partially con- 

 solidated volcanic muds, such as are at present forming around oceanic volcanic 

 islands. Coral limestones encrust the lower slopes of these islands, and do not 

 attain a greater thickness than 150 feet. In the next place, we have islands of 

 similar structure, but possessing in their centre some ancient volcanic peak 



VOL. XXXII. PART III. 5 B 



