A Small series of rocks collected at several localities in the Tonga Islands by Lieutenant J. A. Waugb, R.N., during the voyage of the “Penguin” in 1895, has been forwarded to the Geological Survey for examination, by Admiral Wharton, R.N., F.R.S., Hydrographer to the Admiralty. As in some particulars these rocks supplement those already described by Mr. A. Harker (GKOL. MAG. 1891, p. 250), from the same group of islands, it seems desirable that a short account of them should be placed on record.