APPENDIX. 207 



reef is about thirty yards wide, and so shallow that a boat 

 cannot pass over it. Forster also {Observat., p. 23) says, 

 that the rocks of the sea-shore consist of madrepore. In 

 the plan of Sandwich harbour, the headlands are repre- 

 sented as fringed ; coloured red. — Aurora and Pentecost 

 Islds., according to Bougainville, apparently have no reefs; 

 nor has the large isld. of S. Espiritu, nor Bligh Isld. or 

 Banks' Isld., which latter lie to the N.E. of the Hebrides. 

 But in none of these cases have I met with any detailed 

 account of their shores, or seen plans on a large scale ; and 

 it will be evident, that a fringing-reef of only thirty or even 

 a few hundred yards in width, is of so little importance to 

 navigation, that it will seldom be noticed, excepting by 

 chance; and hence I do not doubt that several of these 

 islands, now left uncoloured, ought to be red. 



Santa-Cruz Group. — Vanikoro (Fig. 1, PL I.) offers a 

 striking example of a barrier-reef: it was first described 

 by the Chevalier Dillon, in his Voyage, and was surveyed in 

 the Astrolabe; coloured pale blue. — Tikopia and Fataka 

 islands appear, from the descriptions of Dillon and 

 D'Urville, to have no reefs; Anouda is a low, flat isld., 

 surrounded by cliffs {Astrolabe Hydrog., and Krusenstern, 

 Mem., vol. ii. p. 432) ; these are uncoloured. Toupoua 

 {Otooboa of Dillon) is stated by Capt. Tromelin {Annates 

 Marit., 1829, p. 289) to be almost entirely included in a 

 reef, lying at the distance of two miles from the shore. 

 There is a space of three miles without any reef, which, 

 although indented with bays, offers no anchorage from the 

 extreme depth of the water close to the shore : Capt. 

 Dillon also speaks of the reefs fronting this island; 

 coloured blue. — Santa-Cruz. I have carefully examined 

 the works of Carteret, D'Entrecasteaux, Wilson, and 

 Tromelin, and I cannot discover any mention of reefs on 



