Still proceeding westward we come to the _New Hebrides;_ on these islands, Mr. G. Bennett (author of “Wanderings in New South Wales”), informs me he found much coral at a great altitude, which he considered of recent origin. Respecting _Santa Cruz_, and the _Salomon Archipelago_, I have no information; but at New Ireland, which forms the northern point of the latter chain, both Labillardière and Lesson have described large beds of an apparently very modern madreporitic rock, with the form of the corals little altered. The latter author[16] states that this formation composes a newer line of coast, modelled round an ancient one. There only remains to be described in the Pacific, that curved line of fringed islands, of which the _Marianas_ form the main part. Of these Guam, Rota, Tiniam, Saypan, and some islets farther north, are described by Quoy and Gaimard,[17] and Chamisso,[18] as chiefly composed of madreporitic limestone, which attains a considerable elevation, and is in several cases worn into successively rising cliffs: the two former naturalists seem to have compared the corals and shells with the existing ones, and state that they are of recent species. _Fais_, which lies in the prolonged line of the Marianas, is the only island in this part of the sea which is fringed; it is ninety feet high, and consists entirely of madreporitic rock.[19] [16] “Voyage de la ‘Coquille’,” Part. Zoolog. [17] Freycinet’s “Voyage autour du Monde.” See also the “Hydrographical Memoir,” page 215. [18] Kotzebue’s “First Voyage.” [19] Lutké’s “Voyage,” volume ii., page 304.