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,” p. 95) to have any reefs, nor does _ Rosario_ Island (from Lutké’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 (p. 21, “Voyage to New Guinea”) alludes to the coral-reefs lining the heads of Piapis Bay; and Horsburgh (vol. ii, p. 599, 4th edit.), 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 edit. of Carteret’s “Voyage,” must be an atoll. Krusenstern says the islets are very low; coloured blue.—_Carteret’s Shoals_, in 2° 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