ISLANDS SOUTH OF THE SANDWICH ARCHIPELAGO.

CHRISTMAS Island (2 deg N., 157 deg W.). Captain Cook, in his "Third Voyage" (Volume ii., chapter x.), has given a detailed account of this atoll. The breadth of the islets on the reef is unusually great, and the sea near it does not deepen so suddenly as is generally the case. It has more lately been visited by Mr. F.D. Bennett ("Geographical Journal," volume vii., page 226); and he assures me that it is low and of coral-formation: I particularly mention this, because it is engraved with a capital letter, signifying a high island, in D'Urville and Lottin's chart. Mr. Couthouy, also, has given some account of it ("Remarks," page 46) from the Hawaiian "Spectator"; he believes it has lately undergone a small elevation, but his evidence does not appear to me satisfactory; the deepest part of the lagoon is said to be only ten feet; nevertheless, I have coloured it blue.—FANNING Island (4 deg N., 158 deg W.) according to Captain Tromelin ("Ann. Maritim." 1829, page 283), is an atoll: his account as observed by Krusenstern, differs from that given in Fanning's "Voyage" (page 224), which, however, is far from clear; coloured blue.— WASHINGTON Island (4 deg N., 159 deg W.) is engraved as a low island in D'Urville's chart, but is described by Fanning (page 226) as having a much greater elevation than Fanning Island, and hence I presume it is not an atoll; not coloured.—PALMYRA Island (6 deg N., 162 deg W.) is an atoll divided into two parts (Krusenstern's "Mem. Suppl." page 50, also Fanning's "Voyage," page 233); blue.—SMYTH'S or Johnston's Islands (17 deg N., 170 deg W.). Captain Smyth, R.N., has had the kindness to inform me that they consist of two very low, small islands, with a dangerous reef off the east end of them. Captain Smyth does not recollect whether these islets, together with the reef, surrounded a lagoon; uncoloured.

SANDWICH ARCHIPELAGO.

HAWAII; in the chart in Freycinet's "Atlas," small portions of the coast are fringed by reefs; and in the accompanying "Hydrog. Memoir," reefs are mentioned in several places, and the coral is said to injure the cables. On one side of the islet of Kohaihai there is a bank of sand and coral with five feet water on it, running parallel to the shore, and leaving a channel of about fifteen feet deep within. I have coloured this island red, but it is very much less perfectly fringed than others of the group.—MAUI; in Freycinet's chart of the anchorage of Raheina, two or three miles of coast are seen to be fringed; and in the "Hydrog. Memoir," "banks of coral along shore" are spoken of. Mr. F.D. Bennett informs me that the reefs, on an average, extend about a quarter of a mile from the beach; the land is not very steep, and outside the reefs the sea does not become deep very suddenly; coloured red.—MOROTOI, I presume, is fringed: Freycinet speaks of the breakers extending along the shore at a little distance from it. From the chart, I believe it is fringed; coloured red.—OAHU; Freycinet, in his "Hydrog. Memoir," mentions some of the reefs. Mr. F.D. Bennett informs me that the shore is skirted for forty or fifty miles in length. There is even a harbour for ships formed by the reefs, but it is at the mouth of a valley; red.—ATOOI, in La Peyrouse's charts, is represented as fringed by a reef, in the same manner as Oahu and Morotoi; and this, as I have been informed by Mr. Ellis, on part at least of the shore, is of coral-formation: the reef does not leave a deep channel within; red.—ONEEHOW; Mr. Ellis believes that this island is also fringed by a coral-reef: considering its close proximity to the other islands, I have ventured to colour it red. I have in vain consulted the works of Cook, Vancouver, La Peyrouse, and Lisiansky, for any satisfactory account of the small islands and reefs, which lie scattered in a N.W. line prolonged from the Sandwich group, and hence have left them uncoloured, with one exception; for I am indebted to Mr. F.D. Bennett for informing me of an atoll-formed reef, in latitude 28 deg 22', longitude 178 deg 30' W., on which the "Gledstanes" was wrecked in 1837. It is apparently of large size, and extends in a N.W. and S.E. line: very few islets have been formed on it. The lagoon seems to be shallow; at least, the deepest part which was surveyed was only three fathoms. Mr. Couthouy ("Remarks," page 38) describes this island under the name of OCEAN island. Considerable doubts should be entertained regarding the nature of a reef of this kind, with a very shallow lagoon, and standing far from any other atoll, on account of the possibility of a crater or flat bank of rock lying at the proper depth beneath the surface of the water, thus affording a foundation for a ring-formed coral-reef. I have, however, thought myself compelled, from its large size and symmetrical outline, to colour it blue.

SAMOA OR NAVIGATOR GROUP.

Kotzebue, in his "Second Voyage," contrasts the structure of these islands with many others in the Pacific, in not being furnished with harbours for ships, formed by distant coral-reefs. The Rev. J. Williams, however, informs me, that coral-reefs do occur in irregular patches on the shores of these islands; but that they do not form a continuous band, as round Mangaia, and other such perfect cases of fringed islands. From the charts accompanying La Peyrouse's "Voyage," it appears that the north shore of SAVAII, MAOUNA, OROSENGA, and MANUA, are fringed by reefs. La Peyrouse, speaking of Maouna (page 126), says that the coral-reef surrounding its shores, almost touches the beach; and is breached in front of the little coves and streams, forming passages for canoes, and probably even for boats. Further on (page 159), he extends the same observation to all the islands which he visited. Mr. Williams in his "Narrative," speaks of a reef going round a small island attached to OYOLAVA, and returning again to it: all these islands have been coloured red.—A chart of ROSE Island, at the extreme west end of the group, is given by Freycinet, from which I should have thought that it had been an atoll; but according to Mr. Couthouy ("Remarks," page 43), it consists of a reef, only a league in circuit, surmounted by a very few low islets; the lagoon is very shallow, and is strewed with numerous large boulders of volcanic rock. This island, therefore, probably consists of a bank of rock, a few feet submerged, with the outer margin of its upper surface fringed with reefs; hence it cannot be properly classed with atolls, in which the foundations are always supposed to lie at a depth, greater than that at which the reef-constructing polypifers can live; not coloured.

BEVERIDGE Reef, 20 deg S., 167 deg W., is described in the "Naut. Mag." (May 1833, page 442) as ten miles long in a N. and S. line, and eight wide; "in the inside of the reef there appears deep water;" there is a passage near the S.W. corner: this therefore seems to be a submerged atoll, and is coloured blue.

SAVAGE Island, 19 deg S., 170 deg W., has been described by Cook and Forster. The younger Forster (volume ii., page 163) says it is about forty feet high: he suspects that it contains a low plain, which formerly was the lagoon. The Rev. J. Williams informs me that the reef fringing its shores, resembles that round Mangaia; coloured red.

FRIENDLY ARCHIPELAGO.

PYLSTAART Island. Judging from the chart in Freycinet's "Atlas," I should have supposed that it had been regularly fringed; but as nothing is said in the "Hydrog. Memoir" (or in the "Voyage" of Tasman, the discoverer) about coral-reefs, I have left it uncoloured.—TONGATABOU: In the "Atlas of the Voyage of the 'Astrolabe'," the whole south side of the island is represented as narrowly fringed by the same reef which forms an extensive platform on the northern side. The origin of this latter reef, which might have been mistaken for a barrier-reef, has already been attempted to be explained, when giving the proofs of the recent elevation of this island.— In Cook's charts the little outlying island also of EOAIGEE, is represented as fringed; coloured red.—EOUA. I cannot make out from Captain Cook's charts and descriptions, that this island has any reef, although the bottom of the neighbouring sea seems to be corally, and the island itself is formed of coral-rock. Forster, however, distinctly ("Observations," page 14) classes it with high islands having reefs, but it certainly is not encircled by a barrier-reef and the younger Forster ("Voyage," volume i., page 426) says, that "a bed of coral-rocks surrounded the coast towards the landing-place." I have therefore classed it with the fringed islands and coloured it red. The several islands lying N.W. of Tongatabou, namely ANAMOUKA, KOMANGO, KOTOU, LEFOUGA, FOA, etc., are seen in Captain Cook's chart to be fringed by reefs, in several of them are connected together. From the various statements in the first volume of Cook's "Third Voyage," and especially in the fourth and sixth chapters, it appears that these reefs are of coral-formation, and certainly do not belong to the barrier class; coloured red.—TOUFOA AND KAO, forming the western part of the group, according to Forster have no reefs; the former is an active volcano.—VAVAO. There is a chart of this singularly formed island, by Espinoza: according to Mr. Williams it consists of coral-rock: the Chevalier Dillon informs me that it is not fringed; not coloured. Nor are the islands of LATTE and AMARGURA, for I have not seen plans on a large scale of them, and do not know whether they are fringed.

NIOUHA, 16 deg S., 174 deg W., or KEPPEL Island of Wallis, or COCOS Island. From a view and chart of this island given in Wallis's "Voyage" (4to edition) it is evidently encircled by a reef; coloured blue: it is however remarkable that BOSCAWEN Island, immediately adjoining, has no reef of any kind; uncoloured.

WALLIS Island, 13 deg S., 176 deg W., a chart and view of this island in Wallis's "Voyage" (4to edition) shows that it is encircled. A view of it in the "Naut. Mag." July 1833, page 376, shows the same fact; blue.

ALLOUFATOU, or HORN Island, ONOUAFU, or PROBY Island, and HUNTER Islands, lie between the Navigator and Fidji groups. I can find no distinct accounts of them.

FIDJI or VITI GROUP.

The best chart of the numerous islands of this group, will be found in the "Atlas of the 'Astrolabe's' Voyage." From this, and from the description given in the "Hydrog. Memoir," accompanying it, it appears that many of these islands are bold and mountainous, rising to the height of between 3,000 and 4,000 feet. Most of the islands are surrounded by reefs, lying far from the land, and outside of which the ocean appears very deep. The "Astrolabe" sounded with ninety fathoms in several places about a mile from the reefs, and found no bottom. Although the depth within the reef is not laid down, it is evident from several expressions, that Captain D'Urville believes that ships could anchor within, if passages existed through the outer barriers. The Chevallier Dillon informs me that this is the case: hence I have coloured this group blue. In the S.E. part lies BATOA, or TURTLE Island of Cook ("Second Voyage," volume ii., page 23, and chart, 4to edition) surrounded by a coral-reef, "which in some places extends two miles from the shore;" within the reef the water appears to be deep, and outside it is unfathomable; coloured pale blue. At the distance of a few miles, Captain Cook (Ibid., page 24) found a circular coral-reef, four or five leagues in circuit, with deep water within; "in short, the bank wants only a few little islets to make it exactly like one of the half-drowned isles so often mentioned,"—namely, atolls. South of Batoa, lies the high island of ONO, which appears in Bellinghausen's "Atlas" to be encircled; as do some other small islands to the south; coloured pale blue; near Ono, there is an annular reef, quite similar to the one just described in the words of Captain Cook; coloured dark blue.

ROTOUMAH, 13 deg S., 179 deg E.—From the chart in Duperrey's "Atlas," I thought this island was encircled, and had coloured it blue, but the Chevallier Dillon assures me that the reef is only a shore or fringing one; red.

INDEPENDENCE Island, 10 deg S., 179 deg E., is described by Mr. G. Bennett, ("United Service Journal," 1831, part ii., page 197) as a low island of coral-formation, it is small, and does not appear to contain a lagoon, although an opening through the reef is referred to. A lagoon probably once existed, and has since been filled up; left uncoloured.

ELLICE GROUP.

OSCAR, PEYSTER, and ELLICE Islands are figured in Arrowsmith's "Chart of the Pacific" (corrected to 1832) as atolls, and are said to be very low; blue.—NEDERLANDISCH Island. I am greatly indebted to the kindness of Admiral Krusenstern, for sending me the original documents concerning this island. From the plans given by Captains Eeg and Khremtshenko, and from the detailed account given by the former, it appears that it is a narrow coral-island, about two miles long, containing a small lagoon. The sea is very deep close to the shore, which is fronted by sharp coral-rocks. Captain Eeg compares the lagoon with that of other coral-islands; and he distinctly says, the land is "very low." I have therefore coloured it blue. Admiral Krusenstern ("Memoir on the Pacific," Append., 1835) states that its shores are eighty feet high; this probably arose from the height of the cocoa-nut trees, with which it is covered, being mistaken for land. —GRAN COCAL is said in Krusenstern's "Memoir," to be low, and to be surrounded by a reef; it is small, and therefore probably once contained a lagoon; uncoloured.—ST. AUGUSTIN. From a chart and view of it, given in the "Atlas of the 'Coquille's' Voyage," it appears to be a small atoll, with its lagoon partly filled up; coloured blue.

GILBERT GROUP.

The chart of this group, given in the "Atlas of the 'Coquille's' Voyage," at once shows that it is composed of ten well characterised atolls. In D'Urville and Lottin's chart, SYDENHAM is written with a capital letter, signifying that it is high; but this certainly is not the case, for it is a perfectly characterised atoll, and a sketch, showing how low it is, is given in the "'Coquille's' Atlas." Some narrow strip-like reefs project from the southern side of DRUMMOND atoll, and render it irregular. The southern island of the group is called CHASE (in some charts, ROTCHES); of this I can find no account, but Mr. F.D. Bennett discovered ("Geographical Journal", volume vii., page 229), a low extensive island in nearly the same latitude, about three degrees westward of the longitude assigned to Rotches, but very probably it is the same island. Mr. Bennett informs me that the man at the masthead reported an appearance of lagoon-water in the centre; and, therefore, considering its position, I have coloured it blue. —PITT Island, at the extreme northern point of the group, is left uncoloured, as its exact position and nature is not known.—BYRON Island, which lies a little to the eastward, does not appear to have been visited since Commodore Byron's voyage, and it was then seen only from a distance of eighteen miles; it is said to be low; uncoloured.

OCEAN, PLEASANT, and ATLANTIC Islands all lie considerably to the west of the Gilbert group: I have been unable to find any distinct account of them. Ocean Island is written with small letters in the French chart, but in Krusenstern's "Memoir" it is said to be high.

MARSHALL GROUP.

We are well acquainted with this group from the excellent charts of the separate islands, made during the two voyages of Kotzebue: a reduced one of the whole group may be easily seen in Krusenstern's "Atlas," and in Kotzebue's "Second Voyage." The group consists (with the exception of two LITTLE islands which probably have had their lagoon filled up) of a double row of twenty-three large and well-characterised atolls, from the examination of which Chamisso has given us his well-known account of coral-formations. I include GASPAR RICO, or CORNWALLIS Island in this group, which is described by Chamisso (Kotzebue's "First Voyage," volume iii., page 179) "as a low sickle-formed group, with mould only on the windward side." Gaspard Island is considered by some geographers as a distinct island lying N.E. of the group, but it is not entered in the chart by Krusenstern; left uncoloured. In the S.W. part of this group lies BARING Island, of which little is known (see Krusenstern's "Appendix," 1835, page 149). I have left it uncoloured; but BOSTON Island I have coloured blue, as it is described (Ibid.) as consisting of fourteen small islands, which, no doubt, enclose a lagoon, as represented in a chart in the "'Coquille's' Atlas."—Two islands, AUR KAWEN and GASPAR RICO, are written in the French chart with capital letters; but this is an error, for from the account given by Chamisso in Kotzebue's "First Voyage," they are certainly low. The nature, position, and even existence, of the shoals and small islands north of the Marshall group, are doubtful.

NEW HEBRIDES.

Any chart, on even a small scale, of these islands, will show that their shores are almost without reefs, presenting a remarkable contrast with those of New Caledonia on the one hand, and the Fidji group on the other. Nevertheless, I have been assured by Mr. G. Bennett, that coral grows vigorously on their shores; as indeed, will be further shown in some of the following notices. As, therefore, these islands are not encircled, and as coral grows vigorously on their shores, we might almost conclude, without further evidence, that they were fringed, and hence I have applied the red colour with rather greater freedom than in other instances.—MATTHEW'S ROCK, an active volcano, some way south of the group (of which a plan is given in the "Atlas of the 'Astrolabe's' Voyage") does not appear to have reefs of any kind about it.—ANNATOM, the southernmost of the Hebrides; from a rough woodcut given in the "United Service Journal" (1831, part iii., page 190), accompanying a paper by Mr. Bennett, it appears that the shore is fringed; coloured red.—TANNA. Forster, in his "Observations" (page 22), says Tanna has on its shores coral-rock and madrepores; and the younger Forster, in his account (volume ii., page 269) speaking of the harbour says, the whole S.E. side consists of coral-reefs, which are overflowed at high-water; part of the southern shore in Cook's chart is represented as fringed; coloured red.—IMMER is described ("United Service Journal," 1831, part iii., page 192) by Mr. Bennett as being of moderate elevation, with cliffs appearing like sandstone: coral grows in patches on its shore, but I have not coloured it; and I mention these facts, because Immer might have been thought from Forster's classification ("Observations," page 14), to have been a low island or even an atoll.— ERROMANGO Island; Cook ("Second Voyage," volume ii., page 45, 4to edition) speaks of rocks everywhere LINING the coast, and the natives offered to haul his boat over the breakers to the sandy beach: Mr. Bennett, in a letter to the Editor of the "Singapore Chron.," alludes to the REEFS on its shores. It may, I think, be safely inferred from these passages that the shore is fringed in parts by coral-reefs; coloured red.—SANDWICH Island. The east coast is said (Cook's "Second Voyage," volume ii., page 41) to be low, and to be guarded by a chain of breakers. In the accompanying chart it is seen to be fringed by a reef; coloured red.—MALLICOLLO. Forster speaks of the reef-bounded shore: the reef is about thirty yards wide, and so shallow that a boat cannot pass over it. Forster also ("Observations," page 23) says, that the rocks of the sea-shore consist of madrepore. In the plan of Sandwich harbour, the headlands are represented as fringed; coloured red.—AURORA and PENTECOST Islands, according to Bougainville, apparently have no reefs; nor has the large island of S. ESPIRITU, nor BLIGH Island or BANKS' Islands, which latter lie to the N.E. of the Hebrides. But in none of these cases, have I met with any detailed account of their shores, or seen plans on a large scale; and it will be evident, that a fringing-reef of only thirty or even a few hundred yards in width, is of so little importance to navigation, that it will seldom be noticed, excepting by chance; and hence I do not doubt that several of these islands, now left uncoloured, ought to be red.

SANTA CRUZ GROUP.

VANIKORO (Figure 1, Plate I.) offers a striking example of a barrier-reef: it was first described by the Chevalier Dillon, in his voyage, and was surveyed in the "Astrolabe"; coloured pale blue.—TIKOPIA and FATAKA Islands appear, from the descriptions of Dillon and D'Urville, to have no reefs; ANOUDA is a low, flat island, surrounded by cliffs ("'Astrolabe' Hydrog." and Krusenstern, "Mem." volume ii., page 432); these are uncoloured. TOUPOUA (OTOOBOA of Dillon) is stated by Captain Tromelin ("Annales Marit." 1829, page 289) to be almost entirely included in a reef, lying at the distance of two miles from the shore. There is a space of three miles without any reef, which, although indented with bays, offers no anchorage from the extreme depth of the water close to the shore: Captain Dillon also speaks of the reefs fronting this island; coloured blue.— SANTA-CRUZ. I have carefully examined the works of Carteret, D'Entrecasteaux, Wilson, and Tromelin, and I cannot discover any mention of reefs on its shores; left uncoloured.—TINAKORO is a constantly active volcano without reefs.—MENDANA ISLES (mentioned by Dillon under the name of MAMMEE, etc.); said by Krusenstern to be low, and intertwined with reefs. I do not believe they include a lagoon; I have left them uncoloured.—DUFF'S Islands compose a small group directed in a N.W. and S.E. band; they are described by Wilson (page 296, "Miss. Voy." 4to edition), as formed by bold-peaked land, with the islands surrounded by coral-reefs, extending about half a mile from the shore; at a distance of a mile from the reefs he found only seven fathoms. As I have no reason for supposing there is deep water within these reefs, I have coloured them red. KENNEDY Island, N.E. of Duff's. I have been unable to find any account of it.

NEW CALEDONIA.

The great barrier-reefs on the shores of this island have already been described (Figure 5, Plate II.). They have been visited by Labillardiere, Cook, and the northern point by D'Urville; this latter part so closely resembles an atoll that I have coloured it dark blue. The LOYALTY group is situated eastward of this island; from the chart and description given in the "Voyage of the 'Astrolabe'," they do not appear to have any reefs; north of this group, there are some extensive low reefs (called ASTROLABE and BEAUPRE,) which do not seem to be atoll-formed; these are left uncoloured.

AUSTRALIAN BARRIER-REEF.

The limits of this great reef, which has already been described, have been coloured from the charts of Flinders and King. In the northern parts, an atoll-formed reef, lying outside the barrier, has been described by Bligh, and is coloured dark blue. In the space between Australia and New Caledonia, called by Flinders the Corallian Sea, there are numerous reefs. Of these, some are represented in Krusenstern's "Atlas" as having an atoll-like structure; namely, BAMPTON shoal, FREDERIC, VINE or Horse-shoe, and ALERT reefs; these have been coloured dark blue.

LOUISIADE.

The dangerous reefs which front and surround the western, southern, and northern coasts of this so-called peninsula and archipelago, seem evidently to belong to the barrier class. The land is lofty, with a low fringe on the coast; the reefs are distant, and the sea outside them profoundly deep. Nearly all that is known of this group is derived from the labours of D'Entrecasteaux and Bougainville: the latter has represented one continuous reef ninety miles long, parallel to the shore, and in places as much as ten miles from it; coloured pale blue. A little distance northward we have the LAUGHLAN Islands, the reefs round which are engraved in the "Atlas of the Voyage of the 'Astrolabe'," in the same manner as in the encircled islands of the Caroline Archipelago, the reef is, in parts, a mile and a half from the shore, to which it does not appear to be attached; coloured blue. At some little distance from the extremity of the Louisiade lies the WELLS reef, described in G. Hamilton's "Voyage in H.M.S. 'Pandora'" (page 100): it is said, "We found we had got embayed in a double reef, which will soon be an island." As this statement is only intelligible on the supposition of the reef being crescent or horse-shoe formed, like so many other submerged annular reefs, I have ventured to colour it blue.

SOLOMON ARCHIPELAGO.

The chart in Krusenstern's "Atlas" shows that these islands are not encircled, and as coral appears from the works of Surville, Bougainville, and Labillardiere, to grow on their shores, this circumstance, as in the case of the New Hebrides, is a presumption that they are fringed. I cannot find out anything from D'Entrecasteaux's "Voyage," regarding the southern islands of the group, so have left them uncoloured.—MALAYTA Island in a rough MS. chart in the Admiralty has its northern shore fringed.—YSABEL Island, the N.E. part of this island, in the same chart, is also fringed: Mendana, speaking (Burney, volume i., page 280) of an islet adjoining the northern coast, says it is surrounded by reefs; the shores, also of Port Praslin appear regularly fringed.—CHOISEUL Island. In Bougainville's "Chart of Choiseul Bay," parts of the shores are fringed by coral-reefs.— BOUGAINVILLE Island. According to D'Entrecasteaux the western shore abounds with coral-reefs, and the smaller islands are said to be attached to the larger ones by reefs; all the before-mentioned islands have been coloured red.—BOUKA Islands. Captain Duperrey has kindly informed me in a letter that he passed close round the northern side of this island (of which a plan is given in his "Atlas of the 'Coquille's' Voyage"), and that it was "garnie d'une bande de recifs a fleur d'eau adherentes au rivage;" and he infers, from the abundance of coral on the islands north and south of Bouka, that the reef probably is of coral; coloured red.

Off the north coast of the Solomon Archipelago there are several small groups which are little known; they appear to be low, and of coral-formation; and some of them probably have an atoll-like structure; the Chevallier Dillon, however, informs me that this is not the case with the B. de CANDELARIA.—OUTONG JAVA, according to the Spanish navigator, Maurelle, is thus characterised; but this is the only one which I have ventured to colour blue.

NEW IRELAND.

The shores of the S.W. point of this island and some adjoining islets, are fringed by reefs, as may be seen in the "Atlases of the Voyages of the 'Coquille' and 'Astrolabe'." M. Lesson observes that the reefs are open in front of each streamlet. The DUKE OF YORK'S Island is also fringed; but with regard to the other parts of NEW IRELAND, NEW HANOVER, and the small islands lying northward, I have been unable to obtain any information. I will only add that no part of New Ireland appears to be fronted by distant reefs. I have coloured red only the above specified portions.

NEW BRITAIN AND THE NORTHERN SHORE OF NEW GUINEA.

From the charts in the "Voyage of the 'Astrolabe'," and from the "Hydrog. Memoir," it appears that these coasts are entirely without reefs, as are the SCHOUTEN Islands, lying close to the northern shore of New Guinea. The western and south-western parts of New Guinea, will be treated of when we come to the islands of the East Indian Archipelago.

ADMIRALTY GROUP.

From the accounts by Bougainville, Maurelle, D'Entrecasteaux, and the scattered notices collected by Horsburgh, it appears, that some of the many islands composing it, are high, with a bold outline; and others are very low, small and interlaced with reefs. All the high islands appear to be fronted by distant reefs rising abruptly from the sea, and within some of which there is reason to believe that the water is deep. I have therefore little doubt they are of the barrier class.—In the southern part of the group we have ELIZABETH Island, which is surrounded by a reef at the distance of a mile; and two miles eastward of it (Krusenstern, "Append." 1835, page 42) there is a little island containing a lagoon.—Near here, also lies CIRCULAR-REEF (Horsburgh, "Direct." volume i., page 691, 4th edition), "three or four miles in diameter having deep water inside with an opening at the N.N.W. part, and on the outside steep to." I have from these data, coloured the group pale blue, and CIRCULAR-REEF dark blue.—the ANACHORITES, ECHEQUIER, and HERMITES, consist of innumerable low islands of coral-formation, which probably have atoll-like forms; but not being able to ascertain this, I have not coloured them, nor DUROUR Island, which is described by Carteret as low.

The CAROLINE ARCHIPELAGO is now well-known, chiefly from the hydrographical labours of Lutke; it contains about forty groups of atolls, and three encircled islands, two of which are engraved in Figures 2 and 7, Plate I. Commencing with the eastern part; the encircling reef round UALEN appears to be only about half a mile from the shore; but as the land is low and covered with mangroves ("Voyage autour du Monde," par F. Lutke, volume i., page 339), the real margin has not probably been ascertained. The extreme depth in one of the harbours within the reef is thirty-three fathoms (see charts in "Atlas of 'Coquille's' Voyage"), and outside at half a mile distant from the reef, no bottom was obtained with two hundred and fifty fathoms. The reef is surmounted by many islets, and the lagoon-like channel within is mostly shallow, and appears to have been much encroached on by the low land surrounding the central mountains; these facts show that time has allowed much detritus to accumulate; coloured pale blue.— POUYNIPETE, or Seniavine. In the greater part of the circumference of this island, the reef is about one mile and three quarters distant; on the north side it is five miles off the included high islets. The reef is broken in several places; and just within it, the depth in one place is thirty fathoms, and in another, twenty-eight, beyond which, to all appearance, there was "un porte vaste et sur" (Lutke, volume ii., page 4); coloured pale blue.—HOGOLEU or ROUG. This wonderful group contains at least sixty-two islands, and its reef is one hundred and thirty-five miles in circuit. Of the islands, only a few, about six or eight (see "Hydrog. Descrip." page 428, of the "Voyage of the 'Astrolabe'," and the large accompanying chart taken chiefly from that given by Duperrey) are high, and the rest are all small, low, and formed on the reef. The depth of the great interior lake has not been ascertained; but Captain D'Urville appears to have entertained no doubt about the possibility of taking in a frigate. The reef lies no less than fourteen miles distant from the northern coasts of the interior high islands, seven from their western sides, and twenty from the southern; the sea is deep outside. This island is a likeness on a grand scale to the Gambier group in the Low Archipelago. Of the groups of low (In D'Urville and Lottin's chart, Peserare is written with capital letters; but this evidently is an error, for it is one of the low islets on the reef of Namonouyto (see Lutke's charts)—a regular atoll.) islands forming the chief part of the Caroline Archipelago, all those of larger size, have the true atoll-structure (as may be seen in the "Atlas" by Captain Lutke), and some even of the very small ones, as MACASKILL and DUPERREY, of which plans are given in the "Atlas of the 'Coquille's' Voyage." There are, however, some low small islands of coral-formation, namely OLLAP, TAMATAM, BIGALI, SATAHOUAL, which do not contain lagoons; but it is probable that lagoons originally existed, but have since filled up: Lutke (volume ii., page 304) seems to have thought that all the low islands, with only one exception, contained lagoons. From the sketches, and from the manner in which the margins of these islands are engraved in the "Atlas of the Voyage of the 'Coquille'," it might have been thought that they were not low; but by a comparison with the remarks of Lutke (volume ii., page 107, regarding Bigali) and of Freycinet ("Hydrog. Memoir 'L'Uranie' Voyage," page 188, regarding Tamatam, Ollap, etc.), it will be seen that the artist must have represented the land incorrectly. The most southern island in the group, namely PIGUIRAM, is not coloured, because I have found no account of it. NOUGOUOR, or MONTE VERDISON, which was not visited by Lutke, is described and figured by Mr. Bennett ("United Service Journal," January 1832) as an atoll. All the above-mentioned islands have been coloured blue.

WESTERN PART OF THE CAROLINE ARCHIPELAGO.

FAIS Island is ninety feet high, and is surrounded, as I have been informed by Admiral Lutke, by a narrow reef of living coral, of which the broadest part, as represented in the charts, is only 150 yards; coloured red.— PHILIP Island., I believe, is low; but Hunter, in his "Historical Journal," gives no clear account of it; uncoloured.—ELIVI; from the manner in which the islets on the reefs are engraved, in the "Atlas of the 'Astrolabe's' Voyage," I should have thought they were above the ordinary height, but Admiral Lutke assures me this is not the case: they form a regular atoll; coloured blue.—GOUAP (EAP of Chamisso), is a high island with a reef (see chart in "Voyage of the 'Astrolabe'"), more than a mile distant in most parts from the shore, and two miles in one part. Captain D'Urville thinks that there would be anchorage ("Hydrog. Descript. 'Astrolabe' Voyage," page 436) for ships within the reef, if a passage could be found; coloured pale blue.—GOULOU, from the chart in the "'Astrolabe's' Atlas," appears to be an atoll. D'Urville ("Hydrog. Descript." page 437) speaks of the low islets on the reef; coloured dark blue.

PELEW ISLANDS.

Krusenstern speaks of some of the islands being mountainous; the reefs are distant from the shore, and there are spaces within them, and not opposite valleys, with from ten to fifteen fathoms. According to a MS. chart of the group by Lieutenant Elmer in the Admiralty, there is a large space within the reef with deepish water; although the high land does not hold a central position with respect to the reefs, as is generally the case, I have little doubt that the reefs of the Pelew Islands ought to be ranked with the barrier class, and I have coloured them pale blue. In Lieutenant Elmer's chart there is a horseshoe-formed shoal, laid down thirteen miles N.W. of Pelew, with fifteen fathoms within the reef, and some dry banks on it; coloured dark blue.—SPANISH, MARTIRES, SANSEROT, PULO ANNA and MARIERE Islands are not coloured, because I know nothing about them, excepting that according to Krusenstern, the second, third, and fourth mentioned, are low, placed on coral-reefs, and therefore, perhaps, contain lagoons; but Pulo Mariere is a little higher.

MARIANA ARCHIPELAGO, or LADRONES.

GUAHAN. Almost the whole of this island is fringed by reefs, which extend in most parts about a third of a mile from the land. Even where the reefs are most extensive, the water within them is shallow. In several parts there is a navigable channel for boats and canoes within the reefs. In Freycinet's "Hydrog. Mem." there is an account of these reefs, and in the "Atlas," a map on a large scale; coloured red.—ROTA. "L'ile est presque entierement entouree des recifs" (page 212, Freycinet's "Hydrog. Mem."). These reefs project about a quarter of a mile from the shore; coloured red.—TINIAN. THE EASTERN coast is precipitous, and is without reefs; but the western side is fringed like the last island; coloured red.—SAYPAN. The N.E. coast, and likewise the western shores appear to be fringed; but there is a great, irregular, horn-like reef projecting far from this side; coloured red.—FARALLON DE MEDINILLA, appears so regularly and closely fringed in Freycinet's charts, that I have ventured to colour it red, although nothing is said about reefs in the "Hydrographical Memoir." The several islands which form the northern part of the group are volcanic (with the exception perhaps of Torres, which resembles in form the madreporitic island of Medinilla), and appear to be without reefs.—MANGS, however, is described (by Freycinet, page 219, "Hydrog.") from some Spanish charts, as formed of small islands placed "au milieu des nombreux recifs;" and as these reefs in the general chart of the group do not project so much as a mile; and as there is no appearance from a double line, of the existence of deep water within, I have ventured, although with much hesitation, to colour them red. Respecting FOLGER and MARSHALL Islands which lie some way east of the Marianas, I can find out nothing, excepting that they are probably low. Krusenstern says this of Marshall Island; and Folger Island is written with small letters in D'Urville's chart; uncoloured.

BONIN OR ARZOBISPO GROUP.

PEEL Island has been examined by Captain Beechey, to whose kindness I am much indebted for giving me information regarding it: "At Port Lloyd there is a great deal of coral; and the inner harbour is entirely formed by coral-reefs, which extend outside the port along the coast." Captain Beechey, in another part of his letter to me, alludes to the reefs fringing the island in all directions; but at the same time it must be observed that the surf washes the volcanic rocks of the coast in the greater part of its circumference. I do not know whether the other islands of the Archipelago are fringed; I have coloured Peel Island red.—GRAMPUS Island to the eastward, does not appear (Meare's "Voyage," page 95) to have any reefs, nor does ROSARIO Island (from Lutke's chart), which lies to the westward. Respecting the few other islands in this part of the sea, namely the SULPHUR Islands, with an active volcano, and those lying between Bonin and Japan (which are situated near the extreme limit in latitude, at which reefs are formed), I have not been able to find any clear account.

WEST END OF NEW GUINEA.

PORT DORY. From the charts in the "Voyage of the 'Coquille'," it would appear that the coast in this part is fringed by coral-reefs; M. Lesson, however, remarks that the coral is sickly; coloured red.—WAIGIOU. A considerable portion of the northern shores of these islands is seen in the charts (on a large scale) in Freycinet's "Atlas" to be fringed by coral-reefs. Forrest (page 21, "Voyage to New Guinea") alludes to the coral-reefs lining the heads of Piapis Bay; and Horsburgh (volume ii., page 599, 4th edition), speaking of the islands in Dampier Strait, says "sharp coral-rocks line their shores;" coloured red.—In the sea north of these islands, we have GUEDES (or FREEWILL, or ST. DAVID'S), which from the chart given in the 4to edition of Carteret's "Voyage," must be an atoll. Krusenstern says the islets are very low; coloured blue.—CARTERET'S SHOALS, in 2 deg 53' N., are described as circular, with stony points showing all round, with deeper water in the middle; coloured blue.—AIOU; the plan of this group, given in the "Atlas of the Voyage of the 'Astrolabe'," shows that it is an atoll; and, from a chart in Forrest's "Voyage," it appears that there is twelve fathoms within the circular reef; coloured blue.—The S.W. coast of New Guinea appears to be low, muddy, and devoid of reefs. The ARRU, TIMOR-LAUT, and TENIMBER groups have lately been examined by Captain Kolff, the MS. translation of which, by Mr. W. Earl, I have been permitted to read, through the kindness of Captain Washington, R.N. These islands are mostly rather low, and are surrounded by distant reefs (the Ki Islands, however, are lofty, and, from Mr. Stanley's survey, appear without reefs); the sea in some parts is shallow, in others profoundly deep (as near Larrat). From the imperfection of the published charts, I have been unable to decide to which class these reefs belong. From the distance to which they extend from the land, where the sea is very deep, I am strongly inclined to believe they ought to come within the barrier class, and be coloured blue; but I have been forced to leave them uncoloured.—The last-mentioned groups are connected with the east end of Ceram by a chain of small islands, of which the small groups of CERAM-LAUT, GORAM and KEFFING are surrounded by very extensive reefs, projecting into deep water, which, as in the last case, I strongly suspect belong to the barrier class; but I have not coloured them. From the south side of Keffing, the reefs project five miles (Windsor Earl's "Sailing Direct. for the Arafura Sea," page 9).

CERAM.

In various charts which I have examined, several parts of the coast are represented as fringed by reefs.—MANIPA Island, between Ceram and Bourou, in an old MS. chart in the Admiralty, is fringed by a very irregular reef, partly dry at low water, which I do not doubt is of coral-formation; both islands coloured red.—BOUROU; parts of this island appear fringed by coral-reefs, namely, the eastern coast, as seen in Freycinet's chart; and CAJELI BAY, which is said by Horsburgh (volume ii., page 630) to be lined by coral-reefs, that stretch out a little way, and have only a few feet water on them. In several charts, portions of the islands forming the AMBOINA GROUP are fringed by reefs; for instance, NOESSA, HARENCA, and UCASTER, in Freycinet's charts. The above-mentioned islands have been coloured red, although the evidence is not very satisfactory.—North of Bourou the parallel line of the XULLA Isles extends: I have not been able to find out anything about them, excepting that Horsburgh (volume ii., page 543) says that the northern shore is surrounded by a reef at the distance of two or three miles; uncoloured.—MYSOL GROUP; the Kanary Islands are said by Forrest ("Voyage," page 130) to be divided from each other by deep straits, and are lined with coral-rocks; coloured red.—GUEBE, lying between Waigiou and Gilolo, is engraved as if fringed; and it is said by Freycinet, that all the soundings under five fathoms were on coral; coloured red.—GILOLO. In a chart published by Dalrymple, the numerous islands on the western, southern (BATCHIAN and the STRAIT OF PATIENTIA), and eastern sides appear fringed by narrow reefs; these reefs, I suppose, are of coral, for it is said in "Malte Brun" (volume xii., page 156), "Sur les cotes (of Batchian) comme DANS LES PLUPART des iles de cet archipel, il y a de rocs de medrepores d'une beaute et d'une variete infimies." Forrest, also (page 50), says Seland, near Batchian, is a little island with reefs of coral; coloured red.—MORTY Island (north of Gilolo). Horsburgh (volume ii., page 506) says the northern coast is lined by reefs, projecting one or two miles, and having no soundings close to them; I have left it uncoloured, although, as in some former cases, it ought probably to be pale blue.—CELEBES. The western and northern coasts appear in the charts to be bold and without reefs. Near the extreme northern point, however, an islet in the STRAITS OF LIMBE, and parts of the adjoining shore, appear to be fringed: the east side of the bay of MANADO, has deep water, and is fringed by sand and coral ("'Astrol.' Voyage," Hydrog. Part, pages 453-4); this extreme point, therefore, I have coloured red.—Of the islands leading from this point to Magindanao, I have not been able to find any account, except of SERANGANI, which appears surrounded by narrow reefs; and Forrest ("Voyage," page 164) speaks of coral on its shores; I have, therefore, coloured this island red. To the eastward of this chain lie several islands; of which I cannot find any account, except of KARKALANG, which is said by Horsburgh (volume ii., page 504) to be lined by a dangerous reef, projecting several miles from the northern shore; not coloured.

ISLANDS NEAR TIMOR.

The account of the following islands is taken from Captain D. Kolff's "Voyage," in 1825, translated by Mr. W. Earl, from the Dutch.—LETTE has "reefs extending along shore at the distance of half a mile from the land."—MOA has reefs on the S.W. part.—LAKOR has a reef lining its shore; these islands are coloured red.—Still more eastward, LUAN has, differently from the last-mentioned islands, an extensive reef; it is steep outside, and within there is a depth of twelve feet; from these facts, it is impossible to decide to which class this island belongs.—KISSA, off the point of Timor, has its "shore fronted by a reef, steep too on the outer side, over which small proahs can go at the time of high water;" coloured red.—TIMOR; most of the points, and some considerable spaces of the northern shore, are seen in Freycinet's chart to be fringed by coral-reefs; and mention is made of them in the accompanying "Hydrog. Memoir;" coloured red.—SAVU, S.E. of Timor, appears in Flinders' chart to be fringed; but I have not coloured it, as I do not know that the reefs are of coral.— SANDALWOOD Island has, according to Horsburgh (volume ii., page 607), a reef on its southern shore, four miles distant from the land; as the neighbouring sea is deep, and generally bold, this probably is a barrier- reef, but I have not ventured to colour it.

N.W. COAST OF AUSTRALIA.

It appears, in Captain King's Sailing Directions ("Narrative of Survey," volume ii, pages 325-369), that there are many extensive coral-reefs skirting, often at considerable distances, the N.W. shores, and encompassing the small adjoining islets. Deep water, in no instance, is represented in the charts between these reefs and the land; and, therefore, they probably belong to the fringing class. But as they extend far into the sea, which is generally shallow, even in places where the land seems to be somewhat precipitous; I have not coloured them. Houtman's Abrolhos (latitude 28 deg S. on west coast) have lately been surveyed by Captain Wickham (as described in "Naut. Mag." 1841, page 511): they lie on the edge of a steeply shelving bank, which extends about thirty miles seaward, along the whole line of coast. The two southern reefs, or islands, enclose a lagoon-like space of water, varying in depth from five to fifteen fathoms, and in one spot with twenty-three fathoms. The greater part of the island has been formed on their inland sides, by the accumulation of fragments of coral; the seaward face consisting of nearly bare ledges of rock. Some of the specimens, brought home by Captain Wickham, contained fragments of marine shells, but others did not; and these closely resembled a formation at King George's Sound, principally due to the action of the wind on calcareous dust, which I shall describe in a forthcoming part. From the extreme irregularity of these reefs with their lagoons, and from their position on a bank, the usual depth of which is only thirty fathoms, I have not ventured to class them with atolls, and hence have left them uncoloured.—ROWLEY SHOALS. These lie some way from the N.W. coast of Australia: according to Captain King ("Narrative of Survey," volume i., page 60), they are of coral-formation. They rise abruptly from the sea, and Captain King had no bottom with 170 fathoms close to them. Three of them are crescent-shaped; they are mentioned by Mr. Lyell, on the authority of Captain King, with reference to the direction of their open sides. "A third oval reef of the same group is entirely submerged" ("Principles of Geology," book iii. chapter xviii.); coloured blue.—SCOTT'S REEFS, lying north of Rowley Shoals, are briefly described by Captain Wickham ("Naut. Mag." 1841, page 440): they appear to be of great size, of a circular form, and "with smooth water within, forming probably a lagoon of great extent." There is a break on the western side, where there probably is an entrance: the water is very deep off these reefs; coloured blue.

Proceeding westward along the great volcanic chain of the East Indian Archipelago, SOLOR STRAIT is represented in a chart published by Dalrymple from a Dutch MS., as fringed; as are parts of FLORES, of ADENARA, and of SOLOR. Horsburgh speaks of coral growing on these shores; and therefore I have no doubt that the reefs are of coral, and accordingly have coloured them red. We hear from Horsburgh (volume ii., page 602) that a coral-flat bounds the shores of SAPY Bay. From the same authority it appears (page 610) that reefs fringe the island of TIMOR-YOUNG, on the N. shore of Sumbawa; and, likewise (page 600), that BALLY town in LOMBOCK, is fronted by a reef, stretching along the shore at a distance of a hundred fathoms, with channels through it for boats; these places, therefore, have been coloured red.—BALLY Island. In a Dutch MS. chart on a large scale of Java, which was brought from that island by Dr. Horsfield, who had the kindness to show it me at the India House, its western, northern, and southern shores appear very regularly fringed by a reef (see also Horsburgh, volume ii., page 593); and as coral is found abundantly there, I have not the least doubt that the reef is of coral, and therefore have coloured it red.

JAVA.

My information regarding the reefs of this great island is derived from the chart just mentioned. The greater part of MADUARA is represented in it as regularly fringed, and likewise portions of the coast of Java immediately south of it. Dr. Horsfield informs me that coral is very abundant near SOURABAYA. The islets and parts of the N. coast of Java, west of POINT BUANG, or JAPARA, are fringed by reefs, said to be of coral. LUBECK, or BAVIAN Islands, lying at some distance from the shore of Java, are regularly fringed by coral-reefs. CARIMON JAVA appears equally so, though it is not directly said that the reefs are of coral; there is a depth between thirty and forty fathoms round these islands. Parts of the shores of SUNDA STRAIT, where the water is from forty to eighty fathoms deep, and the islets near BATAVIA appear in several charts to be fringed. In the Dutch chart the southern shore, in the narrowest part of the island, is in two places fringed by reefs of coral. West of SEGORROWODEE Bay, and the extreme S.E. and E. portions are likewise fringed by coral-reefs; all the above-mentioned places coloured red.

MACASSAR STRAIT.

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.

The coast of MALACCA, TENASSERIM and the coasts northward, appear in the greater part to be low and muddy: where reefs occur, as in parts of MALACCA STRAITS, and near SINGAPORE, they are of the fringing kind; but the water is so shoal, that I have not coloured them. In the sea, however, between Malacca and the west coast of Borneo, where there is a greater depth from forty to fifty fathoms, I have coloured red some of the groups, which are regularly fringed. The northern NATUNAS and the ANAMBAS Islands are represented in the charts on a large scale, published in the "Atlas of the Voyage of the 'Favourite'," as fringed by reefs of coral, with very shoal water within them.—TUMBELAN and BUNOA Islands (1 deg N.) are represented in the English charts as surrounded by a very regular fringe.— ST. BARBES (0 deg 15' N.) is said by Horsburgh (volume ii., page 279) to be fronted by a reef, over which boats can land only at high water.—The shore of BORNEO at TUNJONG APEE is also fronted by a reef, extending not far from the land (Horsburgh, volume ii., page 468). These places I have coloured red; although with some hesitation, as the water is shallow. I might perhaps have added PULO LEAT, in Gaspar Strait, LUCEPARA, and CARIMATA; but as the sea is confined and shallow, and the reefs not very regular, I have left them uncoloured.

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.

PHILIPPINE ARCHIPELAGO.

A chart on a large scale of APPOO SHOAL, which lies near the S.E. coast of Mindoro, has been executed by Captain D. Ross: it appears atoll-formed, but with rather an irregular outline; its diameter is about ten miles; there are two well-defined passages leading into the interior lagoon, which appears open; close outside the reef all round, there is no bottom with seventy fathoms; coloured blue.—MINDORO: the N.W. coast is represented in several charts, as fringed by a reef, and LUBAN Island is said, by Horsburgh (volume ii., page 436), to be "lined by a reef."—LUZON: Mr. Cuming, who has lately investigated with so much success the Natural History of the Philippines, informs me, that about three miles of the shore north of Point St. Jago, is fringed by a reef; as are (Horsburgh, volume ii., page 437) the Three Friars off Silanguin Bay. Between Point Capones and Playa Honda, the coast is "lined by a coral-reef, stretching out nearly a mile in some places," (Horsburgh); and Mr. Cuming visited some fringing- reefs on parts of this coast, namely, near Puebla, Iba, and Mansinglor. In the neighbourhood of Solon-solon Bay, the shore is lined (Horsburgh ii., page 439) by coral-reefs, stretching out a great way: there are also reefs about the islets off Solamague; and as I am informed by Mr. Cuming, near St. Catalina, and a little north of it. The same gentleman informs me there are reefs on the S.E. point of this island in front of Samar, extending from Malalabon to Bulusan. These appear to be the principal fringing-reefs on the coasts of Luzon; and they have all been coloured red. Mr. Cuming informs me that none of them have deep water within; although it appears from Horsburgh that some few extend to a considerable distance from the shore. Within the Philippine Archipelago, the shores of the islands do not appear to be commonly fringed, with the exception of the S. shore of MASBATE, and nearly the whole of BOHOL; which are both coloured red. On the S. shore of MAGINDANAO, Bunwoot Island is surrounded (according to Forrest, "Voyage," page 253), by a coral-reef, which in the chart appears one of the fringing class. With respect to the eastern coasts of the whole Archipelago, I have not been able to obtain any account.

BABUYAN ISLANDS.

Horsburgh says (volume ii., page 442), coral-reefs line the shores of the harbour in Fuga; and the charts show there are other reefs about these islands. Camiguin has its shore in parts lined by coral-rock (Horsburgh, page 443); about a mile off shore there is between thirty and thirty-five fathoms. The plan of Port San Pio Quinto shows that its shores are fringed with coral; coloured red.—BASHEE Islands: Horsburgh, speaking of the southern part of the group (volume ii., page 445) says the shores of both islands are fortified by a reef, and through some of the gaps in it, the natives can pass in their boats in fine weather; the bottom near the land is coral-rock. From the published charts, it is evident that several of these islands are most regularly fringed; coloured red. The northern islands are left uncoloured, as I have been unable to find any account of them.—FORMOSA. The shores, especially the western one, seem chiefly composed of mud and sand, and I cannot make out that they are anywhere lined by reefs; except in a harbour (Horsburgh, volume ii., page 449) at the extreme northern point: hence, of course, the whole of this island is left uncoloured. The small adjoining islands are in the same case.— PATCHOW, or MADJIKO-SIMA GROUPS. PATCHUSON has been described by Captain Broughton ("Voy. to the N. Pacific," page 191); he says, the boats, with some difficulty, found a passage through the coral-reefs, which extend along the coast, nearly half a mile off it. The boats were well sheltered within the reef; but it does not appear that the water is deep there. Outside the reef the depth is very irregular, varying from five to fifty fathoms; the form of the land is not very abrupt; coloured red.—TAYPIN- SAN; from the description given (page 195) by the same author, it appears that a very irregular reef extends, to the distance of several miles, from the southern island; but whether it encircles a space of deep water is not evident; nor, indeed, whether these outlying reefs are connected with those more immediately adjoining the land; left uncoloured. I may here just add that the shore of KUMI (lying west of Patchow), has a narrow reef attached to it in the plan of it, in La Peyrouse's "Atlas;" but it does not appear in the account of the voyage that it is of coral; uncoloured.—LOO CHOO. The greater part of the coast of this moderately hilly island, is skirted by reefs, which do not extend far from the shore, and which do not leave a channel of deep water within them, as may be seen in the charts accompanying Captain B. Hall's voyage to Loo Choo (see also remarks in Appendix, pages xxi. and xxv.). There are, however, some ports with deep water, formed by reefs in front of valleys, in the same manner as happens at Mauritius. Captain Beechey, in a letter to me, compares these reefs with those encircling the Society Islands; but there appears to me a marked difference between them, in the less distance at which the Loo Choo reefs lie from the land with relation to the probable submarine inclination, and in the absence of an interior deep water-moat or channel, parallel to the land. Hence, I have classed these reefs with fringing-reefs, and coloured them red.—PESCADORES (west of Formosa). Dampier (volume i., page 416), has compared the appearance of the land to the southern parts of England. The islands are interlaced with coral-reefs; but as the water is very shoal, and as spits of sand and gravel (Horsburgh, volume ii., page 450) extend far out from them, it is impossible to draw any inferences regarding the nature of the reefs.

CHINA SEA.—Proceeding from north to south, we first meet the PRATAS SHOAL (latitude 20 deg N.) which, according to Horsburgh (volume ii., page 335), is composed of coral, is of a circular form, and has a low islet on it. The reef is on a level with the water's edge, and when the sea runs high, there are breakers mostly all round, "but the water within seems pretty deep in some places; although steep-to in most parts outside, there appear to be several parts where a ship might find anchorage outside the breakers;" coloured blue.—The PARACELLS have been accurately surveyed by Captain D. Ross, and charts on a large scale published: but few low islets have been formed on these shoals, and this seems to be a general circumstance in the China Sea; the sea close outside the reefs is very deep; several of them have a lagoon-like structure; or separate islets (PRATTLE, ROBERT, DRUMMOND, etc.) are so arranged round a moderately shallow space, as to appear as if they had once formed one large atoll.— BOMBAY SHOAL (one of the Paracells) has the form of an annular reef, and is "apparently deep within;" it seems to have an entrance (Horsburgh, volume ii., page 332) on its west side; it is very steep outside.—DISCOVERY SHOAL, also is of an oval form, with a lagoon-like space within, and three openings leading into it, in which there is a depth from two to twenty fathoms. Outside, at the distance (Horsburgh, volume ii., page 333) of only twenty yards from the reef, soundings could not be obtained. The Paracells are coloured blue.—MACCLESFIELD BANK: this is a coral-bank of great size, lying east of the Paracells; some parts of the bank are level, with a sandy bottom, but, generally, the depth is very irregular. It is intersected by deep cuts or channels. I am not able to perceive in the published charts (its limits, however, are not very accurately known) whether the central part is deeper, which I suspect is the case, as in the Great Chagos Bank, in the Indian Ocean; not coloured.—SCARBOROUGH SHOAL: this coral-shoal is engraved with a double row of crosses, forming a circle, as if there was deep water within the reef: close outside there was no bottom, with a hundred fathoms; coloured blue.—The sea off the west coast of Palawan and the northern part of Borneo is strewed with shoals: SWALLOW SHOAL, according to Horsburgh (volume ii., page 431) "is formed, LIKE MOST of the shoals hereabouts, of a belt of coral-rocks, "with a basin of deep water within."—HALF-MOON SHOAL has a similar structure; Captain D. Ross describes it, as a narrow belt of coral-rock, "with a basin of deep water in the centre," and deep sea close outside.—BOMBAY SHOAL appears (Horsburgh, volume ii., page 432) "to be a basin of smooth water surrounded by breakers." These three shoals I have coloured blue.—The PARAQUAS SHOALS are of a circular form, with deep gaps running through them; not coloured.—A bank gradually shoaling to the depth of thirty fathoms, extends to a distance of about twenty miles from the northern part of BORNEO, and to thirty miles from the northern part of PALAWAN. Near the land this bank appears tolerably free from danger, but a little further out it is thickly studded with coral-shoals, which do not generally rise quite to the surface; some of them are very steep-to, and others have a fringe of shoal-water round them. I should have thought that these shoals had level surfaces, had it not been for the statement made by Horsburgh "that most of the shoals hereabouts are formed of a belt of coral." But, perhaps that expression was more particularly applied to the shoals further in the offing. If these reefs of coral have a lagoon-like structure, they should have been coloured blue, and they would have formed an imperfect barrier in front of Palawan and the northern part of Borneo. But, as the water is not very deep, these reefs may have grown up from inequalities on the bank: I have not coloured them.—The coast of CHINA, TONQUIN, and COCHIN-CHINA, forming the western boundary of the China Sea, appear to be without reefs: with regard to the two last-mentioned coasts, I speak after examining the charts on a large scale in the "Atlas of the Voyage of the 'Favourite'."

INDIAN OCEAN.

SOUTH KEELING atoll has been specially described. Nine miles north of it lies North Keeling, a very small atoll, surveyed by the "Beagle," the lagoon of which is dry at low water.—CHRISTMAS Island, lying to the east, is a high island, without, as I have been informed by a person who passed it, any reefs at all.—CEYLON: a space about eighty miles in length of the south-western and southern shores of these islands has been described by Mr. Twynam ("Naut. Mag." 1836, pages 365 and 518); parts of this space appear to be very regularly fringed by coral-reefs, which extend from a quarter to half a mile from the shore. These reefs are in places breached, and afford safe anchorage for the small trading craft. Outside, the sea gradually deepens; there is forty fathoms about six miles off shore: this part I have coloured red. In the published charts of Ceylon there appear to be fringing-reefs in several parts of the south-eastern shores, which I have also coloured red.—At Venloos Bay the shore is likewise fringed. North of Trincomalee there are also reefs of the same kind. The sea off the northern part of Ceylon is exceedingly shallow; and therefore I have not coloured the reefs which fringe portions of its shores, and the adjoining islets, as well as the Indian promontory of MADURA.

CHAGOS, MALDIVA, AND LACCADIVE ARCHIPELAGOES.

These three great groups which have already been often noticed, are now well-known from the admirable surveys of Captain Moresby and Lieutenant Powell. The published charts, which are worthy of the most attentive examination, at once show that the CHAGOS and MALDIVA groups are entirely formed of great atolls, or lagoon-formed reefs, surmounted by islets. In the LACCADIVE group, this structure is less evident; the islets are low, not exceeding the usual height of coral-formations (see Lieutenant Wood's account, "Geographical Journal", volume vi., page 29), and most of the reefs are circular, as may be seen in the published charts; and within several of them, as I am informed by Captain Moresby, there is deepish water; these, therefore, have been coloured blue. Directly north, and almost forming part of this group, there is a long, narrow, slightly curved bank, rising out of the depths of the ocean, composed of sand, shells, and decayed coral, with from twenty-three to thirty fathoms on it. I have no doubt that it has had the same origin with the other Laccadive banks; but as it does not deepen towards the centre I have not coloured it. I might have referred to other authorities regarding these three archipelagoes; but after the publication of the charts by Captain Moresby, to whose personal kindness in giving me much information I am exceedingly indebted, it would have been superfluous.

SAHIA DE MALHA bank consists of a series of narrow banks, with from eight to sixteen fathoms on them; they are arranged in a semicircular manner, round a space about forty fathoms deep, which slopes on the S.E. quarter to unfathomable depths; they are steep-to on both sides, but more especially on the ocean-side. Hence this bank closely resembles in structure, and I may add from Captain Moresby's information in composition, the Pitt's Bank in the Chagos group; and the Pitt's Bank, must, after what has been shown of the Great Chagos Bank, be considered as a sunken, half-destroyed atoll; hence coloured blue.—CARGADOS CARAJOS BANK. Its southern portion consists of a large, curved, coral-shoal, with some low islets on its eastern edge, and likewise some on the western side, between which there is a depth of about twelve fathoms. Northward, a great bank extends. I cannot (probably owing to the want of perfect charts) refer this reef and bank to any class;—therefore not coloured.—ILE DE SABLE is a little island, lying west of C. Carajos, only some toises in height ("Voyage of the 'Favourite'," volume i., page 130); it is surrounded by reefs; but its structure is unintelligible to me. There are some small banks north of it, of which I can find no clear account.—MAURITIUS. The reefs round this island have been described in the chapter on fringing-reefs; coloured red. —RODRIGUEZ. The coral-reefs here are exceedingly extensive; in one part they project even five miles from the shore. As far as I can make out, there is no deep-water moat within them; and the sea outside does not deepen very suddenly. The outline, however, of the land appears to be ("Life of Sir J. Makintosh," volume ii., page 165) hilly and rugged. I am unable to decide whether these reefs belong to the barrier class; as seems probable from their great extension, or to the fringing class; uncoloured. —BOURBON. The greater part of the shores of this island are without reefs; but Captain Carmichael (Hooker's "Bot. Misc.") states that a portion, fifteen miles in length, on the S.E. side, is imperfectly fringed with coral reefs: I have not thought this sufficient to colour the island.

SEYCHELLES.

The rocky islands of primary formation, composing this group, rise from a very extensive and tolerably level bank, having a depth between twenty and forty fathoms. In Captain Owen's chart, and in that in the "Atlas of the Voyage of the 'Favourite'," it appears that the east side of MAHE and the adjoining islands of ST. ANNE and CERF, are regularly fringed by coral-reefs. A portion of the S.E. part of CURIEUSE Island, the N., and part of the S.W. shore of PRASLIN Island, and the whole west side of DIGUE Island, appear fringed. From a MS. account of these islands by Captain F. Moresby, in the Admiralty, it appears that SILHOUETTE is also fringed; he states that all these islands are formed of granite and quartz, that they rise abruptly from the sea, and that "coral-reefs have grown round them, and project for some distance." Dr. Allan, of Forres, who visited these islands, informs me that there is no deep water between the reefs and the shore. The above specified points have been coloured red. AMIRANTES Islands: The small islands of this neighbouring group, according to the MS. account of them by Captain F. Moresby, are situated on an extensive bank; they consist of the debris of corals and shells; are only about twenty feet in height, and are environed by reefs, some attached to the shore, and some rather distant from it.—I have taken great pains to procure plans and information regarding the several islands lying between S.E. and S.W. of the Amirantes, and the Seychelles; relying chiefly on Captain F. Moresby and Dr. Allan, it appears that the greater number, namely—PLATTE, ALPHONSE, COETIVI, GALEGA, PROVIDENCE, ST. PIERRE, ASTOVA, ASSOMPTION, and GLORIOSO, are low, formed of sand or coral-rock, and irregularly shaped; they are situated on very extensive banks, and are connected with great coral-reefs. Galega is said by Dr. Allan, to be rather higher than the other islands; and St. Pierre is described by Captain F. Moresby, as being cavernous throughout, and as not consisting of either limestone or granite. These islands, as well as the Amirantes, certainly are not atoll-formed, and they differ as a group from every other group with which I am acquainted; I have not coloured them; but probably the reefs belong to the fringing class. Their formation is attributed, both by Dr. Allan and Captain F. Moresby, to the action of the currents, here exceedingly violent, on banks, which no doubt have had an independent geological origin. They resemble in many respects some islands and banks in the West Indies, which owe their origin to a similar agency, in conjunction with an elevation of the entire area. In close vicinity to the several islands, there are three others of an apparently different nature: first, JUAN DE NOVA, which appears from some plans and accounts to be an atoll; but from others does not appear to be so; not coloured. Secondly COSMOLEDO; "this group consists of a ring of coral, ten leagues in circumference, and a quarter of a mile broad in some places, enclosing a magnificent lagoon, into which there did not appear a single opening" (Horsburgh, volume i., page 151); coloured blue. Thirdly, ALDABRA; it consists of three islets, about twenty-five feet in height, with red cliffs (Horsburgh, volume i., page 176) surrounding a very shallow basin or lagoon. The sea is profoundly deep close to the shore. Viewing this island in a chart, it would be thought an atoll; but the foregoing description shows that there is something different in its nature; Dr. Allan also states that it is cavernous, and that the coral-rock has a vitrified appearance. Is it an upheaved atoll, or the crater of a volcano?—uncoloured.

COMORO GROUP.

MAYOTTA, according to Horsburgh (volume i., page 216, 4th edition), is completely surrounded by a reef, which runs at the distance of three, four, and in some places even five miles from the land; in an old chart, published by Dalrymple, a depth in many places of thirty-six and thirty-eight fathoms is laid down within the reef. In the same chart, the space of open water within the reef in some parts is even more than three miles wide: the land is bold and peaked; this island, therefore, is encircled by a well-characterised barrier-reef, and is coloured pale blue.—JOHANNA; Horsburgh says (volume I. page 217) this island from the N.W. to the S.W. point, is bounded by a reef, at the distance of two miles from the shore; in some parts, however, the reef must be attached, since Lieutenant Boteler ("Narr." volume i., page 161) describes a passage through it, within which there is room only for a few boats. Its height, as I am informed by Dr. Allan, is about 3,500 feet; it is very precipitous, and is composed of granite, greenstone, and quartz; coloured blue.—MOHILLA; on the S. side of this island there is anchorage, in from thirty to forty-five fathoms, between a reef and the shore (Horsburgh, volume i., page 214); in Captain Owen's chart of Madagascar, this island is represented as encircled; coloured blue.—GREAT COMORO Island is, as I am informed by Dr. Allan, about 8,000 feet high, and apparently volcanic; it is not regularly encircled; but reefs of various shapes and dimensions, jut out from every headland on the W., S., and S.E. coasts, inside of which reefs there are channels, often parallel with the shore, with deep water. On the north-western coasts the reefs appear attached to the shores. The land near the coast is in some places bold, but generally speaking it is flat; Horsburgh says (volume i., page 214) the water is profoundly deep close to the SHORE, from which expression I presume some parts are without reefs. From this description I apprehend the reef belongs to the barrier class; but I have not coloured it, as most of the charts which I have seen, represent the reefs round it as very much less extensive than round the other islands in the group.

MADAGASCAR.

My information is chiefly derived from the published charts by Captain Owen, and the accounts given by him and by Lieutenant Boteler. Commencing at the S.W. extremity of the island; towards the northern part of the STAR BANK (in latitude 25 deg S.) the coast for ten miles is fringed by a reef; coloured red. The shore immediately S. of ST. AUGUSTINE'S BAY appears fringed; but TULLEAR Harbour, directly N. of it, is formed by a narrow reef ten miles long, extending parallel to the shore, with from four to ten fathoms within it. If this reef had been more extensive, it must have been classed as a barrier-reef; but as the line of coast falls inwards here, a submarine bank perhaps extends parallel to the shore, which has offered a foundation for the growth of the coral; I have left this part uncoloured. From latitude 22 deg 16' to 21 deg 37', the shore is fringed by coral-reefs (see Lieutenant Boteler's "Narrative," volume ii., page 106), less than a mile in width, and with shallow water within. There are outlying coral-shoals in several parts of the offing, with about ten fathoms between them and the shore, and the depth of the sea one mile and a half seaward, is about thirty fathoms. The part above specified is engraved on a large scale; and as in the charts on rather a smaller scale the same fringe of reef extends as far as latitude 33 deg 15'; I have coloured the whole of this part of the coast red. The islands of JUAN DE NOVA (in latitude 17 deg S.) appear in the charts on a large scale to be fringed, but I have not been able to ascertain whether the reefs are of coral; uncoloured. The main part of the west coast appears to be low, with outlying sandbanks, which, Lieutenant Boteler (volume ii., page 106) says, "are faced on the edge of deep water by a line of sharp-pointed coral-rocks." Nevertheless I have not coloured this part, as I cannot make out by the charts that the coast itself is fringed. The headlands of NARRENDA and PASSANDAVA Bays (14 deg 40') and the islands in front of RADAMA HARBOUR are represented in the plans as regularly fringed, and have accordingly been coloured red. With respect to the EAST COAST OF MADAGASCAR, Dr. Allan informs me in a letter, that the whole line of coast, from TAMATAVE, in 18 deg 12', to C. AMBER, at the extreme northern point of the island, is bordered by coral-reefs. The land is low, uneven, and gradually rising from the coast. From Captain Owen's charts, also, the existence of these reefs, which evidently belong to the fringing class, on some parts, namely N. of BRITISH SOUND, and near NGONCY, of the above line of coast might have been inferred. Lieutenant Boteler (volume i., page 155) speaks of "the reef surrounding the island of ST. MARY'S at a small distance from the shore." In a previous chapter I have described, from the information of Dr. Allan, the manner in which the reefs extend in N.E. lines from the headlands on this coast, thus sometimes forming rather deep channels within them, this seems caused by the action of the currents, and the reefs spring up from the submarine prolongations of the sandy headlands. The above specified portion of the coast is coloured red. The remaining S.E. portions do not appear in any published chart to possess reefs of any kind; and the Rev. W. Ellis, whose means of information regarding this side of Madagascar have been extensive, informs me he believes there are none.

EAST COAST OF AFRICA.

Proceeding from the northern part, the coast appears, for a considerable space, without reefs. My information, I may here observe, is derived from the survey by Captain Owen, together with his narrative; and that by Lieutenant Boteler. At MUKDEESHA (10 deg 1' N.) there is a coral-reef extending four or five miles along the shore (Owen's "Narr." volume i, page 357) which in the chart lies at the distance of a quarter of a mile from the shore, and has within it from six to ten feet water: this then is a fringing-reef, and is coloured red. From JUBA, a little S. of the equator, to LAMOO (in 2 deg 20' S.) "the coast and islands are formed of madrepore" (Owen's "Narrative," volume i., page 363). The chart of this part (entitled DUNDAS Islands), presents an extraordinary appearance; the coast of the mainland is quite straight and it is fronted at the average distance of two miles, by exceedingly narrow, straight islets, fringed with reefs. Within the chain of islets, there are extensive tidal flats and muddy bays, into which many rivers enter; the depths of these spaces varies from one to four fathoms—the latter depth not being common, and about twelve feet the average. Outside the chain of islets, the sea, at the distance of a mile, varies in depth from eight to fifteen fathoms. Lieutenant Boteler ("Narr." volume i., page 369) describes the muddy bay of PATTA, which seems to resemble other parts of this coast, as fronted by small, narrow, level islets formed of decomposing coral, the margin of which is seldom of greater height than twelve feet, overhanging the rocky surface from which the islets rise. Knowing that the islets are formed of coral, it is, I think, scarcely possible to view the coast, and not at once conclude that we here see a fringing-reef, which has been upraised a few feet: the unusual depth of from two to four fathoms within some of these islets, is probably due to muddy rivers having prevented the growth of coral near the shore. There is, however, one difficulty on this view, namely, that before the elevation took place, which converted the reef into a chain of islets, the water must apparently have been still deeper; on the other hand it may be supposed that the formation of a nearly perfect barrier in front, of so large an extent of coast, would cause the currents (especially in front of the rivers), to deepen their muddy beds. When describing in the chapter on fringing-reefs, those of Mauritius, I have given my reasons for believing that the shoal spaces within reefs of this kind, must, in many instances, have been deepened. However this may be, as several parts of this line of coast are undoubtedly fringed by living reefs, I have coloured it red.— MALEENDA (3 deg 20' S.). In the plan of the harbour, the south headland appears fringed; and in Owen's chart on a larger scale, the reefs are seen to extend nearly thirty miles southward; coloured red.—MOMBAS (4 deg 5' S.). The island which forms the harbour, "is surrounded by cliffs of madrepore, capable of being rendered almost impregnable" (Owen's "Narr." volume i., page 412). The shore of the mainland N. and S. of the harbour, is most regularly fringed by a coral-reef at a distance from half a mile to one mile and a quarter from the land; within the reef the depth is from nine to fifteen feet; outside the reef the depth at rather less than half a mile is thirty fathoms. From the charts it appears that a space about thirty-six miles in length, is here fringed; coloured red.—PEMBA (5 deg S.) is an island of coral-formation, level, and about two hundred feet in height (Owen's "Narr." volume i., page 425); it is thirty-five miles long, and is separated from the mainland by a deep sea. The outer coast is represented in the chart as regularly fringed; coloured red. The mainland in front of Pemba is likewise fringed; but there also appear to be some outlying reefs with deep water between them and the shore. I do not understand their structure, either from the charts or the description, therefore have not coloured them.—ZANZIBAR resembles Pemba in most respects; its southern half on the western side and the neighbouring islets are fringed; coloured red. On the mainland, a little S. of Zanzibar, there are some banks parallel to the coast, which I should have thought had been formed of coral, had it not been said (Boteler's "Narr." volume ii., page 39) that they were composed of sand; not coloured.—LATHAM'S BANK is a small island, fringed by coral-reefs; but being only ten feet high, it has not been coloured.—MONFEEA is an island of the same character as Pemba; its outer shore is fringed, and its southern extremity is connected with Keelwa Point on the mainland by a chain of islands fringed by reefs; coloured red. The four last-mentioned islands resemble in many respects some of the islands in the Red Sea, which will presently be described.— KEELWA. In a plan of the shore, a space of twenty miles N. and S. of this place is fringed by reefs, apparently of coral: these reefs are prolonged still further southward in Owen's general chart. The coast in the plans of the rivers LINDY and MONGHOW (9 deg 59' and 10 deg 7' S.) has the same structure; coloured red.—QUERIMBA Islands (from 10 deg 40' to 13 deg S.). A chart on a large scale is given of these islands; they are low, and of coral-formation (Boteler's "Narr." volume ii., page 54); and generally have extensive reefs projecting from them which are dry at low water, and which on the outside rise abruptly from a deep sea: on their insides they are separated from the continent by a channel, or rather a succession of bays, with an average depth of ten fathoms. The small headlands on the continent also have coral-banks attached to them; and the Querimba islands and banks are placed on the lines of prolongation of these headlands, and are separated from them by very shallow channels. It is evident that whatever cause, whether the drifting of sediment or subterranean movements, produced the headlands, likewise produced, as might have been expected, submarine prolongations to them; and these towards their outer extremities, have since afforded a favourable basis for the growth of coral-reefs, and subsequently for the formation of islets. As these reefs clearly belong to the fringing class, the Querimba islands have been coloured red.—MONABILA (13 deg 32' S.). In the plan of this harbour, the headlands outside are fringed by reefs apparently of coral; coloured red.—MOZAMBIQUE (150 deg S.) The outer part of the island on which the city is built, and the neighbouring islands, are fringed by coral-reefs; coloured red. From the description given in Owen's "Narr." (volume i., page 162), the shore from MOZAMBIQUE to DELAGOA BAY appears to be low and sandy; many of the shoals and islets off this line of coast are of coral-formation; but from their small size and lowness, it is not possible, from the charts, to know whether they are truly fringed. Hence this portion of coast is left uncoloured, as are likewise those parts more northward, of which no mention has been made in the foregoing pages from the want of information.

PERSIAN GULF.

From the charts lately published on a large scale by the East India Company, it appears that several parts, especially the southern shores of this gulf, are fringed by coral-reefs; but as the water is very shallow, and as there are numerous sandbanks, which are difficult to distinguish on the chart from reefs, I have not coloured the upper part red. Towards the mouth, however, where the water is rather deeper, the islands of ORMUZ and LARRACK, appear so regularly fringed, that I have coloured them red. There are certainly no atolls in the Persian Gulf. The shores of IMMAUM, and of the promontory forming the southern headland of the Persian Gulf, seem to be without reefs. The whole S.W. part (except one or two small patches) of ARABIA FELIX, and the shores of SOCOTRA appear from the charts and memoir of Captain Haines ("Geographical Journal," 1839, page 125) to be without any reefs. I believe there are no extensive coral-reefs on any part of the coasts of INDIA, except on the low promontory of MADURA (as already mentioned) in front of Ceylon.

RED SEA.

My information is chiefly derived from the admirable charts published by the East India Company in 1836, from personal communication with Captain Moresby, one of the surveyors, and from the excellent memoir, "Uber die Natur der Corallen-Banken des Rothen Meeres," by Ehrenberg. The plains immediately bordering the Red Sea seem chiefly to consist of a sedimentary formation of the newer tertiary period. The shore is, with the exception of a few parts, fringed by coral-reefs. The water is generally profoundly deep close to the shore; but this fact, which has attracted the attention of most voyagers, seems to have no necessary connection with the presence of reefs; for Captain Moresby particularly observed to me, that, in latitude 24 deg 10' on the eastern side, there is a piece of coast, with very deep water close to it, without any reefs, but not differing in other respects from the usual nature of the coast-line. The most remarkable feature in the Red Sea is the chain of submerged banks, reefs, and islands, lying some way from the shore, chiefly on the eastern side; the space within being deep enough to admit a safe navigation in small vessels. The banks are generally of an oval form, and some miles in width; but some of them are very long in proportion to their width. Captain Moresby informs me that any one, who had not made actual plans of them, would be apt to think that they were much more elongated than they really are. Many of them rise to the surface, but the greater number lie from five to thirty fathoms beneath it, with irregular soundings on them. They consist of sand and living coral; coral on most of them, according to Captain Moresby, covering the greater part of their surface. They extend parallel to the shore, and they are not unfrequently connected in their middle parts by short transverse banks with the mainland. The sea is generally profoundly deep quite close to them, as it is near most parts of the coast of the mainland; but this is not universally the case, for between latitude 15 deg and 17 deg the water deepens quite gradually from the banks, both on the eastern and western shores, towards the middle of the sea. Islands in many parts arise from these banks; they are low, flat-topped, and consist of the same horizontally stratified formation with that forming the plain-like margin of the mainland. Some of the smaller and lower islands consist of mere sand. Captain Moresby informs me, that small masses of rock, the remnants of islands, are left on many banks where there is now no dry land. Ehrenberg also asserts that most of the islets, even the lowest, have a flat abraded basis, composed of the same tertiary formation: he believes that as soon as the surf wears down the protuberant parts of a bank, just beneath the level of the sea, the surface becomes protected from further abrasion by the growth of coral, and he thus accounts for the existence of so many banks standing on a level with the surface of this sea. It appears that most of the islands are certainly decreasing in size.