KUSAIE. 339 



the outliers and outcrops of volcanic rock still indicate the mode of origin 

 of the wide reef platform. 



On the outer sea face, especially on the eastern face, a number of 

 cocoanut trees and hardwood logs have been thrown up on the shingle 

 beaches. To the east of Port Lottin a small fresh-water river flows 

 through the volcanic shingle, so that a considerable amount of volcanic 

 silt has been carried out bj the river to the outer edge of the inner 

 harbor. The corals flanking the harbor are partly killed by this volcanic 

 silt. We found heads of Porites, of Maeandrina, of Pocillipores, of Mad- 

 repores, and of Millepores growing luxuriantly on all the flats and shoals 

 and ledges of the lagoon to the west of Port Lottin. In the lagoon to 

 the west of Port Lottin an outcrop of volcanic rock occurs in the very 

 midst of the mangrove islands. On the western side of Kusaie the 

 reef fiat gradually becomes narrower, until at Point Vauvilliers the outer 

 edge of the reef flat is only separated from the western slope of Kusaie 

 by a narrow lagoon. • 



The lagoon channel to the south of Chabrol Harbor is undoubtedly kept 

 clear by the streams running down the slopes of the eastern coast. 



As we steamed out of Port Lottin and followed the outer belt of land 

 rim towards Point Vauvilliers, we found the outer beach to consist of 

 volcanic sand mixed with fine coralline sand. At our anchorage, in 

 twenty-one fathoms, volcanic sand or silt composed the greater part of 

 the material we brought up, although at a comparatively small distance 

 on both sides of us were extensive reef flats on which corals were growing. 

 On examining the wide lagoon to the east of the anchorage, we foimd, 

 as we approached the shore, the bottom to consist of fine volcanic silt, 

 brought down by the rains from the hill slopes, and carried to the very 

 edge of the reef flat. The patches of corals and coral heads were as 

 frequently killed by volcanic sand as by coral sand, formed by the dis- 

 integration of the coral heads overwhelmed by the sand coming from 

 the outer sea face. About three quarters of a mile from Port Lottin is 

 the western lagoon ; its outer sea beach is formed of heavy shingle and 

 of coral boulders thrown up to a height of seven to nine feet. On the 

 top of the shingle beach an extensive belt of mangroves was growing, 



