AGASSIZ: FIJI ISLANDS AND COKAL REEFS. 33 



of volcanic rocks, and has been very much eroded by the action of the 

 sea (Phite 54). Corals grow upon its slopes, but they are not very 

 flourishing, either there or upon the many patches found inside the 

 lagoon, and which are separated by broad sand lanes, or by dark patches 

 of nullipores and algse, with a few scattered coral heads. 



The reef enclosing the lagoon is continuous except on the north side, 

 where there are two entraiices into the lagoon, one with thirteen and tiie 

 other with three fathoms in the channel. The inner side of the weather 

 reef can be reached quite close to the breakers. There is from one and a 

 half to two fathoms of water on the reef flat, which is covered by a great 

 number of flourishing patches of coral, mainly Madrepores, Pociliopores, 

 heads of Astreans and Mreandrinas, with a few Gorgonians. The patches 

 are separated by wide areas of coral and coralline sand. Towards the 

 inner part of the lagoon, as the water deepens, the coral patches are 

 separated by masses of dead corals and of fragments. Dark patches of 

 coralline Algse become more abundant, and the coral patches less flour- 

 ishing and more distant. On the outer edge of the reef, to the south 

 of Beagle Passage, the reef flat is somewhat narrower than on the east- 

 ern face, where it varies from 1,000 to 1,800 feet in width ; it is cov- 

 ered by one to two fathoms of water, and the coral patches appear to 

 flourish upon its surface fully as luxuriantly as upon the eastern face. 

 The corals descended in steps to ten or even eighteen fethoms, rising 

 from the coral and coralline sand separating the heads. They were 

 most flourishing in the belt of from six to ten fathoms in depth. The 

 prevailing trades drive a strong current across the lagoon, and the 

 water of the lagoon rushes out through the northern passages and over 

 the western reef flats with considerable velocity. The bottom inside 

 of the lagoon consists mainly of alga, of coralline algte, and of broken 

 shells and fragments of coral. 



It is quite probable that the North Asti'olabe Reef represents an 

 eroded peak adjacent to the former greater Kandavu, of which Solo 

 Eock is the only witness left (Plate 53). 



Budd Reef. 



Plates 4, 18, 70. 



Budd Reef (Plate 18) has a narrow outer reef of irregular shape, broken 

 into many separate patches. These become quite distant on the south- 

 ern side, leaving the outline of the reef indistinct. The lagoon, as 

 well as the channels separating the islands enclosed within the outer 



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