The EAST COAST OF Borneo appears, in most parts, free from reefs, and where they occur, as on the east coast of PAMAROONG, the sea is very shallow; hence no part is coloured. In MACASSAR Strait itself, in about latitude 2 deg S., there are many small islands with coral-shoals projecting far from them. There are also (old charts by Dalrymple) numerous little flats of coral, not rising to the surface of the water, and shelving suddenly from five fathoms to no bottom with fifty fathoms; they do not appear to have a lagoon-like structure. There are similar coral-shoals a little farther south; and in latitude 4 deg 55' there are two, which are engraved from modern surveys, in a manner which might represent an annular reef with deep water inside: Captain Moresby, however, who was formerly in this sea, doubts this fact, so that I have left them uncoloured: 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 also other islands, such as the POSTILLIONS, KALATOA, TOKAN-BESSEES, etc., 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 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 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 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 Island 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, volume ii., page 115); coloured red.--RAT Island (3 deg 51' S.) is surrounded by reefs of coral, partly dry at low water, (Horsburgh, volume ii., page 96).--TRIESTE Island (4 deg 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," volume i., page 474), I have not coloured it.--PULO DOOA (latitude 3 deg). 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 (volume ii., page 86) says that the rocky coral-bank, which stretches about forty yards from the shore, is steep to all round: in a chart, also, which I have seen, the island is represented as regularly fringed.--PULO MINTAO is lined with reefs on its west side (Horsburgh, volume ii., page 107).--PULO BANIAK; the same authority (volume ii., page 105), speaking of a part, says it is faced with coral-rocks.--MINGUIN (3 deg 36' N.). A coral-reef fronts this place, and projects into the sea nearly a quarter of a mile ("Notices of the Indian Arch." published at Singapore, page 105).--PULO BRASSA (5 deg 46' N.). A reef surrounds it at a cable's length (Horsburgh, volume ii., page 60). I have coloured all the above-specified points red. I may here add, that both Horsburgh and Mr. Moor (in the "Notices" just alluded to) frequently speak of the numerous reefs and banks of coral on the west coast of Sumatra; but these nowhere have the structure of a barrier-reef, and Marsden ("History of Sumatra") states, that where the coast is flat, the fringing-reefs extend furthest from it. The northern and southern points, and the greater part of the east coast, are low, and faced with mud banks, and therefore without coral.
NICOBAR ISLANDS.
The chart represents the islands of this group as fringed by reefs. With regard to GREAT NICOBAR, Captain Moresby informs me, that it is fringed by reefs of coral, extending between two and three hundred yards from the shore. The NORTHERN NICOBARS appear so regularly fringed in the published charts, that I have no doubt the reefs are of coral. This group, therefore, is coloured red.
ANDAMAN ISLANDS.
From an examination of the MS. chart, on a large scale, of this island, by Captain Arch. Blair, in the Admiralty, several portions of the coast appear fringed; and as Horsburgh speaks of coral-reefs being numerous in the vicinity of these islands, I should have coloured them red, had not some expressions in a paper in the "Asiatic Researches" (volume iv., page 402) led me to doubt the existence of reefs; uncoloured.
