When Part VI. of the Catalogue of Canadian plants was pub lished in 1892, there was sufficient material at hand to allow of the inclusion of the Lichens and Liverworts in that number, but there were still such large tracts of country in which no botanical work had been done that it seemed advisable to confine the scope of that volume to the Musci. The present part contains all the species of Lichens and Liverworts known to occur in Canada, and an addendum to Part VI. in which our knowledge of American Mosses north of the United States is brought up to date.

My collections of Hepaticae were commenced in 1862, and the specimens were examined and my determinations verified by Mr. C. F. Austin, who continued to work at them up to the time of his death. There was then no one in America to whom I cared to send difficult species for determination, but shortly afterwards I made the acquaintance of Mr. C. M. Pearson, of Manchester, England, who undertook to examine my material. Mr. Pearson's work resulted in a pamphlet published in 1892, in which were enumerated all the species known to occur in Greenland, Canada and Alaska. The total number of species enumerated in the region covered by Mr. Pearson's list was 165.

For many years, difficult specimens were submitted to Prof. Underwood, who assisted me in many ways in my studies of Liverworts, and later Prof. A. W. Evans, New Haven, Conn., gave me valuable assistance, so valuable that without his help this section of the catalogue could not have been written at this time. Besides naming all my later collections, he carefully examined many doubtful specimens that had accumulated since the publication of Mr. Pearson's list, and I was thus enabled to give these doubtful species their proper place in the series.

During the lifetime of Prof. Tuckerman, all my collections of Lichens were examined by him, and after his death Dr. Eckfeldt, of Philadelphia, Pa., was of much assistance to me in my Lichen studies. In 1895 I opened up a correspondence with Rev. J. S. Deichmann Branth, of Sneptrup, Denmark, and by his kindness and assistance I have been enabled to complete my list of the rock Lichens, and those obscure forms grouped after Lecidea.

The addendum to Part VI. is compiled to agree in arrangement with the previous portion, and the generic names used therein, have for the same reason been kept almost unchanged. As in Part VI., Dr. Kindberg is my authority, unless otherwise stated, for the names of all species except those collected in Ontario in 1901, which were named by Mrs. E. G. Britton. I have, however, freely availed myself of the work of this lady, Dr. A. J. Grout, Dr. Best, Mr. Cheney and others.

Dr. Kindberg's work has been of immense service in increasing our knowledge of Canadian Bryology, as it was he, who, working with Dr.C. Mueller, made known the great wealth of species in our country, and by his invaluable assistance the writer was enabled to separate many new forms from the mass of material which had hitherto been overlooked or misnamed by other workers. A new impetus was given to collecting, and since the publication of Part VI., fully two hundred new forms have been added to our moss-flora. In Part VI, 953 species were enumerated; in the addendum now published, the list is brought up to 1196. and only a few species have been discarded. It is quite true that some of Dr. Kindberg's species have been shown to be only forms of other species, but such corrections must be made in the work of all botanists, and some of his critics, in proportion to their published work, have been as great sinners in this respect as Dr. Kindberg. Dr. Kindberg's work was so far in advance of anything that had been done in Canadian Bryology before his time that there would be great injustice in withholding from him full credit for what he has accomplished.

Whenever genera have been monographed in recent years and the loan of our herbarium sheets has been asked, they have been freely lent, and in the body of the present work the changes made by the writers of these monographs have been indicated.

The specimens of cryptograms in the herbarium of the Geological Survey number over 16,000, so that it will be seen that the great majority of those referred to in Part VI and in the present catalogue are in our own herbarium. The writer has been the chief collector of these specimens, but many others have contributed to both knowledge and material. As the collector's name is in every case given after each citation, the amount of work done by each is evident and no special reference need be made to them here by name.

It should be noted that the word Labrador has in this, as in former catalogues, been used in the broad sense which includes the whole peninsula north of the province of Quebec. With the exception of the records credited to Mr. Waghorne, nearly every other Labrador reference is to Ungava District, which is bounded on the west by the Hudson Bay, on the north by Hudson Strait, on the east by the Atlantic Ocean, and on the south by the Province of Quebec.

JOHN MACOUN. June 12th, 1902.