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° 32′ S.). In the plan of this harbour, the headlands outside are fringed by reefs apparently of coral; coloured red.—_Mozambique_ (150° 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.” (vol. i, p. 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 (_Geograph. Journ._, 1839, p. 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.