The water shoals gradually towards the whole west coast of _Borneo:_ I cannot make out that it has any reefs of coral. The islands, however, off the northern extremity, and near the S.W. end of _Palawan_, are fringed by very distant coral-reefs; thus the reefs in the case of _Balabac_ are no less than five miles from the land; but the sea, in the whole of this district, is so shallow, that the reefs might be expected to extend very far from the land. I have not, therefore, thought myself authorised to colour them. The N.E. point of Borneo, where the water is very shoal, is connected with Magindanao by a chain of islands called the _Sooloo Archipelago_, about which I have been able to obtain very little information; _Pangootaran_, although ten miles long, entirely consists of a bed of coral-rock (“Notices of E. Indian Arch.” page 58): I believe from Horsburgh that the island is low; not coloured.—_Tahow Bank_, in some old charts, appears like a submerged atoll; not coloured. Forrest (“Voyage,” page 21) states that one of the islands near Sooloo is surrounded by coral-rocks; but there is no distant reef. Near the S. end of _Basselan_, some of the islets in the chart accompanying Forrest’s “Voyage,” appear fringed with reefs; hence I have coloured, though unwillingly, parts of the Sooloo group red. The sea between Sooloo and Palawan, near the shoal coast of Borneo, is interspersed with irregular reefs and shoal patches; not coloured: but in the northern part of this sea, there are two low islets, _Cagayanes_ and _Cavilli_, surrounded by extensive coral-reefs; the breakers round the latter (Horsburgh, volume ii., page 513) extend five or six miles from a sandbank, which forms the only dry part; these breakers are steep to outside; there appears to be an opening through them on one side, with four or five fathoms within: from this description, I strongly suspect that Cavilli ought to be considered an atoll; but, as I have not seen any chart of it, on even a moderately large scale, I have not coloured it. The islets off the northern end of _Palawan_, are in the same case as those off the southern end, namely they are fringed by reefs, some way distant from the shore, but the water is exceedingly shallow; uncoloured. The western shore of Palawan will be treated of under the head of China Sea.