Introduction.

The statements and descriptions in this paper are based on the combined study by Mr. K. W. Allison, of the State Forest Service, and myself, over a prolonged period, of the New Zealand liverworts—research work made difficult by the absence from this country of both types and herbaria. However, the late Dr. Marshall Howe, of New York, kindly sent us fragments of Mitten's types from the Bronx Park Herbarium, and these, which are now in the Plant Research Bureau Herbarium, have been of the greatest assistance, though not in connection with this paper. Nor can overseas bryologists give much reliable assistance, as their acquaintance with New Zealand plants is usually a superficial one, though Dr. Th. Herzog, of Jena, has given much of his valuable time to the study and identification of plants and the description of new species, and Dr. Fr. Verdoorn has helped with the section Holostipae of Lejeunia, while Mr. W. E. Nicholson, of Lewes, Sussex, has consistently helped us in many ways.

As regards literature, Sir Joseph Hooker's Handbook of the New Zealand Flora, Part ii, has formed the basis of our work. We have also had at our disposal the Synopsis Hepaticarum of Gottsche, Lindenberg and Nees, published in 1844, and three volumes of Hooker's Botany of the Antarctic Voyage, viz., Flora Antarctica, Flora Novae Zealandiae, and Flora Tasmaniae, published in 1847, 1855, and 1860, respectively. I understand that these old and valuable books were procured for the library of the Hawke's Bay Philosophical Society by the late Rev. William Colenso; and it is most fortunate that they escaped the destructive earthquake fire of 1931.

All efforts to obtain a copy of Band 9 of Engler and Prantl's Pflanzenfamilien proved unsuccessful, though a second edition was supposed to be in course of preparation some years before the war. Stephani's Species Hepaticarum has also been unobtainable, but this work is really indispensible, and through the friendly interest of the late Sir Arthur Hill, Director of Kew, I was enabled to obtain manuscript copies of the descriptions of New Zealand plants, including Stephani's new species. Copies of both drawings and descriptions were also procured from Fräulein Stephani, of Leipsic, and Mr. Nicholson has also kindly copied both drawings and descriptions for us. Even so, the list is still incomplete.

The Students' Handbook of British Hepatics, by S. M. MacVicar, is particularly useful for general information, but unfortunately it has been out of print for some time. A copy of this work was obligingly lent to us by the Librarian of the Auckland Institute and Museum, per Miss Cranwell.

I would take this opportunity of acknowledging our indebtedness to Mr. G. O. K. Sainsbury, of Wairoa, who from the outset has been a tower of strength in his unfailing encouragement and advice.

A very great deal still remains to be done in the systematic study of New Zealand Hepaticae and further gatherings of plants are most welcome, specially from the South Island.