AGASSIZ: FIJI ISLANDS AND CORAL REEFS. 49 



liferous limestone rock, and are the remnants of the former land mass 

 once covering the area of the atoll of Ngele Leva. 



Nuku Mbasanga. 



Plates 18, 2?^'^, Fig. 18, and Plate 108. 



We skirted along a part of the southwestern edge of jSTuku Mbasanga 

 atoll (Plate 18). The atoll is oblong, a little over two miles long, open 

 to the northwest, where the reef flats are broken up into numerous 

 coral heads. "Within the broad reef flats are a small sandy cay, ^""uku 

 Mbalate on the western face of the atoll, and the islet of Nuku Mbasanga 

 (Plate 108), the shores of which are covered with coral beacli rock, or 

 patches of elevated reef rock, judging from the character of the negro- 

 heads which crop out on the western side. Both the islands are covered 

 with coacoanuts and shrubs. 



There is every reason to believe that the islands of the ISTuku Mba- 

 sanga group are the remnants of an island composed of elevated lime- 

 stone, which has been denuded and eroded to its present condition, and 

 partly covered, as Wailangilala has been, with coral sand. 



Nukusemanu and Nanuku Reefs. 



Plates 18, 103-107. 



To the eastward of Budd Reef, and separated from it by a channel 

 about nine miles wide, is situated an elongated, angulai", irregularly 

 shaped atoll, terminating at its southern extremity in a long ridge of 

 reef flats called the Nanuku Reef. These send out spurs, the extension 

 of which connects with the Nukusemanu Reef and encloses a lagoon 

 fully twenty-four miles long and from two to six miles broad. -The 

 greater part of the eastern face of the reef is not awash, being made up 

 of a long series of coral reef patches, with from one to six fathoms of 

 water, with deeper water between it and the extension of the Nanuku 

 Eeef. A tongue of the ocean runs westward from 118 fathoms in the 

 gap separating the extremities of the reefs, rising to a ridge with five 

 to ten fixthoms, separating it from a deep pool with as much as forty-six 

 fathoms near the eastern face of the central part of the western reef flat 

 of Nanuku Reef. Only an occasional reef patch rises to the surface on 

 that face. On the northeast horn is situated Nukusemanu Island, a 

 small sand key covered with cocoanuts. On the northwest face the 

 Nukusemanu Reef flats are seen to be well covered with flourishing coral 



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