AGASSIZ : FIJI ISLANDS AND CORAL REEFS. 79 



the conditions which I imagine to have existed in the Fijis,^ although the 

 terraces indicate two periods of elevation, with one of rest, during which 

 an interior basin similar to the central basin of islands like Kambara, 

 Wangava, and the like, in Fiji, was formed by atmospheric agencies 

 probably. 



The rocks underlying the coralliferous limestones are stated by Pro- 

 fessor Judd to be igneous rocks, but not modern volcanic material. 

 He says, " They are suggestive of ancient volcanic masses that have 

 been exposed at the surface by denudation, . . . and it is quite incor- 

 rect to quote examples like this as lending support to the view that all 

 oceanic islands are of volcanic origin." 



Speaking of Eua, which belongs to group (b), Murray according to 

 Lister is of the opinion that the organic deposits of the island are old, 

 yet there is no satisfactory evidence to refer them to the Tertiary 

 period. 



Nine or Savage Island is an elevated coralliferous limestone island, 

 said to be 200 feet high ; - the younger Foster considers that the cen- 

 tral plain represents an ancient lagoon. It is skirted with enormous 

 caverns. 



The figure and description given by Dana " of Metia or Aurora Island, 

 one of the ^Yestern Paumotus, recalls many of the raised limestone 

 islands of Fiji. In the Hervey group at Atiu similar caverns exist, and 

 they have also been noticed by Captain Beechey at Henderson Island. 

 Its cliffs worn into caverns rise abruptly to about 230 feet on all sides 

 except the south, where the island slopes very abruptly, much as Vatu 

 Leile in Fiji. The surfixce of Metia, as described by Dana, resembles 

 closely that of Ngele Levu, and he describes the wide shore platform, 

 "resembling that of the low coral islands" and the modern reef about 

 its margin. 



It will be interesting to see if the great masses of coral blocks, figured 

 and mentioned by Dana * may not throw some new light on the nature 

 of the substratum of some of the Paumotus, where he observed them. 



The sections of the small island of Masamashu in the Eed Sea^ do 

 uot seem to me to indicate subsidence, as is stated by Bonney (p. 312). 



1 See also the account of Eua, by J. J. Lister, in Q. J. Geol. Soc. of London, 

 Vol. XLVIL p. 590, 189L 



2 Sailing Directions, Pacific Islands, Vol. II. p. 54. 



3 Loc. cit., p. 193. 



* Loc. cit., pp. 179 and 203. 



5 Nature, Vol. XXX VL p. 413. 



