MILADUMADULU. 



395 



Kolu 



which surrounds the whole velu, being only broken opposite the N.E. passage. The maximum 

 depth found in the velu was 4 fathoms, the central part 

 of the Imsin being a uniform flat at about 3i fathoms. 

 The N.E. passage towards its lagoon end has a maximum 

 depth of 2| fathoms, but to seaward it shallows still further, 

 and between the outer points of the reef — which aie 130 

 yards distant — only reaches a depth of Ih — 2 fathoms. 

 Throughout its whole length the channel is studded with 

 growing coral shoals, almost reaching the surface, with to- 

 wards its lagoon end sandy areas between, but towards tlie 

 open sea with almost its whole bottom covered with sedentarj' 

 organic life. 



Round the E. side of Mafaro the reef, where no 

 land exists, consists of the usual reef flat, boulder zone — 

 either of the two with pinnacles of the elevated rock — and 

 sand flat. Wlierever rocky land is found there is a reef, 

 quite similar to that off Ereadu. The northern three islands 

 are all of rock and appear at one time to have been con- 

 nected, being joined along the reef by a succession of 

 pinnacles of the raised rock ; Farumuli too has traces of 

 a mangrove swamp in its centre. All the islets at the 

 present time are slightly washing away to seaward, but 

 sending out points of loose stony materials towards the 

 lagoon, against which Bodu Hura has a small accumulation 

 of sand. Kolu is separated from the main island by 6 — 9 

 feet of watex-, and consists of rock to the E. and sand, 

 very rapidly washing away, to the W. The main island has 



behind the last a sandy spit strewn with fallen bushes to the E., but possibly slightly growing out 

 to the N.W. S. of this the island has on the N. and S. thirds of its E. side a narrow rocky 

 belt, between which the sea has cut into the land, and is forming a bay. At the S. end is 

 a mangrove swamp. The lagoon side of the island shows no definite change 

 but, if anything, is extending outwards by the piling up of sand. 



Manadu has a narrow stony belt to the E. with a smoother and more 

 marked reef flat than the northern islands of the bank. To the N.E. it has 

 three rocky islets (Fig. 101) that have been cut off by the sea from the main 

 island. With the exception of a rocky seaward belt the latter is formed of 

 sand, which is growing out especially to the N.N.W. and S.S.W. To the N. 

 and S. the reef is 100 yards distant, but to the W. there is no reef, only a 

 series of coral patches to 2 or 3 fathoms, 40 yards from the beach, and then 

 a gradual slope to IS fathoms in an additional 70 yards. An interesting point 

 in traversing the island from W. to E. is a series of sand dunes, almost ridges 

 running N. and S., and varying up to 21 feet in height. These possibly show 

 waves or periods in the growth of the island by the accumulation of sand to 

 the W. They could not on account of the vegetation have been heaped up Fig. 101. Manadu, 

 save in the immediate proximity of the sea. N.E. of the Island 



showing erosion. 



Bdufaro (Fig. 102) has on the W. side a very distinct surface reef with a 



single boat channel to the N., enclosing a lagoon of 2 — 3 fathoms. It has two main islands, which 

 have the usual rocky belt and narrow reef to seaward. The sand has for the most part been 



G. 51 



Fig. 100. Mafaro Island and Reef. 



