It will be observed that the greatly increased space occupied by original articles, viz, 351 pages as against 248 pages in Vol. II., has also excluded from publication Lectures and Addresses of a general character, such as were inserted in a separate section of the preceding volume. The Appendix contains the usual Summary of the Meteorological Returns for the year, for assistance in the compilation of which the Editor is indebted to Mr. R. B. Gore. The List of Members of the Institute shows that in addition to the nine Honorary Members, the Affiliated Societies have now 544 Ordinary Members; the number on last year's roll being 342. This increase is due in part to the affiliation during the past year of the Nelson Association, and also to the large accession of new Members, especially in the Societies established in Auckland and Dunedin. Notwithstanding that in several cases illustrations sent with papers have been omitted when not absolutely necessary to explain the text, the number of Plates has increased in this volume to 3+; there being in last year's volume only 23. The Governors have again to tender their thanks to Mr. J. Buchanan for the great zeal with which he has devoted himself to the preparation of these illustrations, and to the Hon. the Colonial Secretary for placing at their disposal the superior skill and appliances of the Government Lithographic Printing Department. For assistance in revising a portion of the work for the press during his temporary absence, the Editor has to thank the Hon. W. B. D. Mantell. Wellington, 20th April, 1871.