ADDU. 147 



The southern part of the eastern face of the southeast pass is flanked 

 by a long spit edged by a belt of coral boulders, with patches of shingle 

 near the western extremity of the spit, the position of which is clearly 

 indicated by a line of breakers skirting its edge. 



The largest islands of Addu are on its western face, separated by com- 

 paratively narrow gaps. Several of the islands on the western face are 

 throwing out spits towards the outer edge, and forming bays partly shut off 

 from the sea. 1 The larger islands all show traces of having been made up 

 of separate islands now united by sand spits or bars. This is well seen at 

 Hitadu on the western and at Midu on the eastern face. The layoon 

 beaches of the islands of Addu are high and steep, far steeper than those 

 we have seen near any of our anchorages. 



The northern part of the southeast face is flanked by a reef flat at the 

 angle of which is the large island of Midu, forming the northeast horn of 

 Addu. To the south of Midu the greater part of the reef flat is occupied 

 by a line of narrow islands far smaller than those on the west face of Addu ; 

 they do not compare in size with Hitadu, which is four miles in length 

 and a mile wide in places. 



There are no islands in the lagoon of Addu, and only five small sand-bars. 

 The greater part of the lagoon is about thirty fathoms in depth ; it varies 

 from twenty-four to thirty-nine fathoms, its greatest depth. 



At Gan (PI. 76) the vegetation on the lagoon side reaches to the summit 

 of the beach. In places the lagoon seems to be slightly encroaching on the 



1 Mr. Gardiner* has called attention to the seven small islands thrown up (since 1835) off the west 

 face of Gan and Faidu, close to the outer edge of the reef flat. According to him, the topography of 

 the northeast horn of Addu, which we did not visit, has been considerably modified. The line of small 

 islands to the west of Midu consists of a greater number of islands than is indicated on Moresby's Chart. f 

 The western face of the flat of the northeast horn is figured by Gardiner as much wider than on the 

 Admiralty Chart, having encroached upon the northeast bay of the lagoon, and formed a false velu, % 

 as he calls the deep and narrow strip of water, five fathoms deep, separated from the lagoon by an outer 

 reef. Such false velus are like those of Tahanea, and are found in many of the Paumotus. I have 

 called them secondary lagoons. § In the Paumotus they are usually parallel to the outer reef flat. The 

 northwestern horn, which was charted clear of coral heads by Moresby, is now partly shut off by coral 

 knolls. He also states that the bank off the western point of the eastern reef flat of the southeastern 

 pass has become united with the reef flat ; it is, however, on his chart still indicated as an independent 

 bank. The bank with seven fathoms on the opposite side of the pass is, I think, a spit of the western 

 face of the pass. 



* Loc. cit., p. 415. } Loc. cit., p. 415. 



t Loc. cit., pp. 318, 415. § Mem. M. C. Z., Vol. XXVIII., p. 86. 



