1898.] Funafuti, Rotumu and Fiji. 419 



CONTENTS. 



Part I. The Atoll of Funafuti. 

 Part II. Rotuma. 

 Part III. The Reefs of Fiji. 

 Part IV. The Raised Reefs of Fiji. 



Section 1. Viti Levu. 



Section 2. The Lau Group. 



Section 3. Summary and Conclusions. 



Part V. Special Features in the Natural History of Corals. 

 Section 1. The Structure of a Reef. 

 Section 2. The Bathymetrical Limits of Coral Growth. 

 Section 3. The Food of Corals. 

 Section 4. Conditions affecting the Growth of Coral 



Reefs. 

 Section 5. The Rate of Growth of Corals. 



Part VI. The Formation of Coral Reefs. 



PART I. 



THE ATOLL OF FUNAFUTI. 



The atoll of Funafuti was chosen as a typical atoll by the 

 Coral Reef Boring Committee of the Royal Society in 1896. It 

 belongs to the Ellice islands, which lie to the north of the Fiji 

 Group, and extend in a broad line from lat. 11° S. to lat. 5° 30"S., 

 running almost north-north-west and south-south-east. In the 

 same line to the north at a distance of about 150 miles lie the 

 Gilbert islands, which are themselves continued north by the 

 Radack and Ralick chains of the Marshall islands. All are of 

 coral origin and many of atoll form. 



In the bathymetrical charts, published in the Report of the 

 Challenger Expedition, the Ellice islands are seen to lie on a 

 plateau of about 1500 fathoms with the Fijian, Tongan and 

 Samoan Groups, the whole in a deep of over 2000 fathoms. The 

 soundings of Captain Field, H.M.S. Penguin, in 1896 proved, 

 however, that the Ellice islands are separated from this plateau 

 by depths of over 2000 fathoms, and snowed also that Funafuti 

 rises as an isolated reef in this deep. Further soundings of the 

 Penguin by Nui, Nukulailai and towards Nukufetau from Funafuti 

 indicate that these atolls probably rise in a similar manner so 



