Iff :. 



No. 8. — The Foraminifera and other Organisms in the Raised 

 Beefs of Fiji. 1 By R. L. Sherlock. 



The rocks described were obtained from various islands in the Pacific 

 Ocean, but chiefly from the Fiji and Tonga Groups. 



The specimens from Eua, Tonga Tabu, and Vavau in the Tonga Group, 

 Makatea and Niau in the Paumotus, and Guam in the Ladrones were 

 collected by Mr. Alexander Agassiz, and those from Niue by Prof. T. 

 Edgeworth David, of Sydney, N. S. W. The remainder from Mango, 

 Ngillingillah, Vatu Vara, Nainuka, Yathata, Kambara, and Singatoka (in 

 Viti Levu) all in the Fiji Group, were collected by Mr. E. C. Andrews 

 for Mr. A. Agassiz. 



The structure of the islands has been described by Mr. Agassiz in his 

 " The Islands and Coral Reefs of Fiji." Bull. Mus. Coinp. Zool., XXXIII., 

 1899, and in a series of letters published in the American Journal of 

 Science for 1898 and 1900. Mr. E. C. Andrews has given an account 

 of the Fiji Group in his " Notes on the Limestones and General Geology 

 of the Fiji Islands, with special reference to the Lau Group." Based 

 upon Surveys made for Alexander Agassiz. Bull. Mus. Comp. Zool., 

 XXXVIII. , 1900. Mr. J. J. Lister gives some account of the Tonga 

 Group in his " Notes on the Geology of the Tonga Islands." Quart. 

 Journ. Geol. Soc, London, 1891. 



Raised terraces of limestone occur in each of the islands, and the ques- 

 tion has arisen whether the limestones are composed of recent reef-build- 

 ing corals, or are of Tertiary age and of a different origin from the reefs 

 now growing round the islands. 



The chief interest of the terraces lies in the light they may be expected 

 to throw on the question of the origin of atolls. On the theory of slow 

 subsidence, the raised limestones would be composed throughout essen- 

 tially of shallow-water reef-building corals. If, however, the limestones 

 have not this composition, some other theory must be found to explain 

 their formation in these particular cases. 



The Tertiary age of certain of the rocks has been proved in two cases 

 by the discovery of Orbitoides, and in one of these cases the rock is 



1 Contribution from the Geological Laboratory of the Royal College of Science, 

 London. 



vol. xxxviii. — no 8 1 



