232 APPENDIX. 



coloured : at the same time I may remark, that these two 

 shoals make a nearer approach to the atoll-like structure than 

 any other within the E . Indian Archipelago. Southward of these 

 shoals there are other low islands and irregular coral-reefs ; 

 and in the space of sea, north of the great volcanic chain, from 

 Timor to Java, we have other islands, such as the Postillions, 

 Kalatoa, Tokan-Bessees, &c, which are chiefly low, and are 

 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 oiBonin, 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, ex- 

 ceedingly probable that some of them ought to be blue. I 

 may add that there is a harbour on the S.E. coast of Bouton, 

 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 

 distant reefs, but I do not know whether with deep water 

 within. I have not thought the evidence sufficient to permit 

 me to colour them. 



Sumatea. — Commencing with the west coast and outlying 

 islands ; Engano Island is represented in the published chart as 

 surrounded by a narrow reef, and Napier, in his Sailing Direc- 

 tions, speaks of the reef being of coral (also Horsburgh, vol. ii. 

 p. 115) ; coloured red. Bat Island (3° 51' S.) is surrounded 

 by reefs of coral, partly dry at low water (Horsburgh, 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 consists 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°) : it is said in an old chart that there are 



