224 APPENDIX. 



surrounded by very irregular and distant reefs. From the 

 imperfect charts I have seen, I have not been able to 

 decide whether they belong to the atoll or barrier-classes, 

 or whether they merely fringe submarine banks, and gently 

 sloping land. In the Bay of Bonin, between the two 

 southern arms of Celebes, there are numerous coral-reefs ; 

 but none of them seem to have an atoll-like structure. I 

 have, therefore, not coloured any of the islands in this part 

 of the sea ; I think it, however, exceedingly probable that 

 some of them ought to be blue. I may add that there is a 

 harbour on the S.E. coast of Bonton which, according to an 

 old chart, is formed by a reef, parallel to the shore, with 

 deep water within ■ and in the voyage of the Coquille, some 

 neighbouring islands are represented with reefs a good way 

 distant, but I do not know whether with deep water within. 

 I have not thought the evidence sufficient to permit me to 

 colour them. 



Sumatra. — Commencing with the west coast and outlying 

 islands, Engano Isld. is represented in the published chart 

 as surrounded by a narrow reef, and Napier, in his sailing 

 directions, speaks of the reef being of coral (also Horsburgh, 

 vol. ii. p. 115) j coloured red. — Rat Isld. (3 51' S.) is sur- 

 rounded by reefs of coral, partly dry at low water (Hors- 

 burgh, vol. ii. p. 96). — Trieste Island (4 2 S.). The shore 

 is represented in a chart which I saw at the India House, 

 as fringed in such a manner, that I feel sure the fringe con- 

 sists of coral; but as the island is so low, that the sea 

 sometimes flows quite over it (Dampier, Voyage, vol. i. 

 p. 474), I have not coloured it. — Pulo Dooa (lat. 3 ). In 

 an old chart it is said there are chasms in the reefs round 

 the island, admitting boats to the watering-place, and that 

 the southern islet consists of a mass of sand and coral. — 

 Pulo Pisang ; Horsburgh (vol. ii. p. 86) says that the rocky 



