386 



J. STANLEY GARDINER. 



In the N.E. part of S. Mahlos there seemed to be so little change within the lagoon that 

 references to individual reefs are unnecessary. All the islands are of sand formation, here and there 

 losing or gaining. Usually there is a well-marked ridge of sand above the beach, blown up by the 

 wind. A reef 40 — 80 yards broad commonly surrounds the land. It may have a boat channel, a few 

 feet deep, inside, but the outer part is as a rule rather loosely built up of coral. 



Kudera-helu belongs rather- to the intermediate area of Mahlos, and is a sandy island, which 

 has little changed in the last few years. It is surrounded by a reef 60 — 150 yards broad, having 

 a distinct reef flat, boulder zone, and boat channel on each side with a few pinnacles, apparently 

 of the elevated coral rock, still remaining. Batala is now a faro with a velu of about 4 fathoms 

 to the N. The former single island to the south has become cut into two parts, a rocky island 

 on the S.E. of the reef and a sandy one behind. 



III. North Mahlosmadulu (PI. XI.). 



In every part of this bank changes of some sort or other were found, but most have 

 been already dealt with in Chapter VI. The details about additional islands and reefs on 

 the bank, that I could add to that account, in every way accord with the conclusions therein 

 reached. I have, however, considered both the reefs showing the most striking changes and 

 conditions and those which are least changed, so that with the exception of a reference to 

 a few particular islands and reefs to illustrate special points no further account is necessary 

 here. Among the following notes those about Rasmadu, Duwafuri, and Hudufaro I owe to 

 my companion Mr Forster Cooper. 



Rasmadu island lies E.b.N. and W.b.S. It is considerably broader at its E. or seaward 

 end, which is protected by a line of the elevated coral rock 

 from the encroachment of the sea, the rest of the land behind 

 this line of rock being formed of sand. The solid rock forms 

 a belt on the beach, and is topped by a line of boulders, 

 piled up from the same, but somewhat admixed with sand. 

 To the E. the edge of the reef is 50 — 60 yards distant from 

 the base of the beach. The reef broadens by the sides of the 

 island, but the widest part of the whole shoal is near its 

 seaward end. The S. side of the island has much beach rock, 

 but the N. shore is formed of loose sand with a single patch 

 of sandstone near its lagoon end. The W. end of the island 

 is growing outwards into the lagoon ; it has a broad beach 

 of sand and stones, the latter provided by the rock on the 

 sides of the island as well as by the sweepings of the reefs. 

 The muddiness of the water after moderately heavy N.E. 



winds was especially observed by Mr Forster Cooper. It seemed to be due to the washing out of 

 the sand from a narrow boat channel of 2 — 3 feet which extends nearly round the island. 



Duwafuri shows considerable changes in that the large island, which is built entirely of sand, 

 has sent out a long narrow spit towards the small island marked on the N. of the reef. The latter 

 islet is now a mere patch of rock, over which the water sweeps in rough weather when the tide is 

 high. The reef to the E. is nowhere less than 100 yards distant from the land, and has the regular 

 reef flat, boulder zone — which is continuous with the N. islet — and boat channel, the latter with 



Fig. 98. Easmadu Island and Eeef. 



