The LOW ARCHIPELAGO.—This group consists of about eighty atolls: it will be quite superfluous to refer to descriptions of each. In D’Urville and Lottin’s chart, one island (_Wolchonsky_) is written with a capital letter, signifying, as explained in a former chapter, that it is a high island; but this must be a mistake, as the original chart by Bellinghausen shows that it is a true atoll. Captain Beechey says of the thirty-two groups which he examined (of the greater number of which I have seen beautiful MS. charts in the Admiralty), that twenty-nine now contain lagoons, and he believes the other three originally did. Bellinghausen (see an account of his Russian voyage, in the “Biblioth. des Voyages,” 1834, p. 443) says, that the seventeen islands which he discovered resembled each other in structure, and he has given charts on a large scale of all of them. Kotzebue has given plans of several; Cook and Bligh mention others; a few were seen during the voyage of the _Beagle_; and notices of other atolls are scattered through several publications. The _ Actæon_ group in this archipelago has lately been discovered (_Geograph. Journ._, vol. vii, p. 454); it consists of three small and low islets, one of which has a lagoon. Another lagoon-island has been discovered (_Naut. Mag._, 1839, p. 770), in 22° 4′ S., and 136° 20′ W. Towards the S.E. part of the group, there are some islands of different formation: _ Elizabeth_ Island is described by Beechey (p. 46, 4to ed.) as fringed by reefs, at the distance of between two and three hundred yards; coloured red. _Pitcairn_ Island, in the immediate neighbourhood, according to the same authority, has no reefs of any kind, although numerous pieces of coral are thrown up on the beach; the sea close to its shore is very deep (see “Zool. of Beechey’s Voyage,” p. 164); it is left uncoloured. _Gambier_ Islands (see Plate I Fig. 8), are encircled by a barrier-reef; the greatest depth within is thirty-eight fathoms; coloured pale blue. _Aurora_ Island, which lies N.E. of Tahiti close to the large space coloured dark blue in the map, has been already described in a note (), on the authority of Mr. Couthouy; it is an upraised atoll, but as it does not appear to be fringed by living reefs, it is left uncoloured.