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° 51′ S.) is surrounded by reefs of coral, partly dry at low water, (Horsburgh, volume ii., page 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,” volume i., page 474), I have not coloured it.—_Pulo Dooa_ (latitude 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 (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° 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° 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.