From the spring of 1861 until the present, I have been collecting Canadian Musci, and in that time have traversed the continent many times. From 1861-1868, I collected in the central counties of Ontario, in 1869 under the auspices of the Natural History Society of Montreal, I spent nearly two months on the north and west shores of Lake Superior. In 1812, I collected from Lake Superior, westward to the Lake of the Woods, thence to Edmonton on the Saskatchewan, thence westward to Peace River in lat. 56°, and from there to Vancouver Island traversing nearly the whole length of British Columbia. The spring of 1875 was spent on Vancouver Island, and the summer occupied in collecting in British Columbia and along the whole length of the Peace River. The summers of 1879-80-81 were spent in Manitoba and the prairie region where many peculiar species were gathered. In 1882-83, I collected in Nova Scotia, Cape Breton, Anticosti and the Gaspé peninsula. The summer of 1884 at Lake Nepigon and the north shore of Lake Superior. The next summer (1885) collections were made in the Rocky and Selkirk Mountains on the line of the Canadian Pacific Railway. Vancouver Island was visited again in 1887, Prince Edward Island in 1888 and the summers of 1889-90 and 1891 were spent making exhaustive collections between the Pacific coast and the eastern base of the Rocky Mountains.

Important and interesting additions have also been made to the collections by the undermentioned gentlemen, including some new species:-

Dr. Robert Bell, of the Geological Survey Department, from Hudson Strait and Bay; J. M. Macoun from the shores of Lake Winnipeg, the islands in Behring Sea, the coast of Alasxa and British Columbia; Mr. John Moser, of Caanan Forks, Queen's County, New Brunswick, from New Brunswick; Mr. J. Dearness from around London, Ontario; Rev. Charles A. Waghorne, of New Harbor, Newfoundland, from Newfoundland and Labrador.

From the foregoing it will be seen that the material for the present work has been accumulating for many years. In 1861 I commenced a correspondence with Sullivant, who was then working on his Icones Muscorum. After some years Mr. Coe F. Austin took up the subject, but failing health and an early death brought his work to a close. Meanwhile Prof. T. P. James rendered me valuable assistance and examined and determined many difficult species.

On the publication of Lesquereux & James' Manual of North American Mosses in 1884, I thought my difficulties were over, but with the increase of knowledge came the increased difficulty of separating the closely related species of Eastern Canada from those of the Rocky Mountains and Pacific Coast. It soon became evident that although this manual might be exhaustive for the United States, it was far from being so for Canada.

Up to 1885 I had, with the assistance of books and the above named authorities, catalogued a large number of species, and it was then decided to distribute sets of one hundred named Canadian mosses to test the accuracy of these determinations.

In 1857 I began to correspond with Professor Nils Conrad Kindberg, Ph. D., the distinguished bryologist of the State College, Linkoeping, Sweden, and we at once saw the value of the discoveries that were being made. With the greatest zest Dr. Kindberg entered into the examination of the large series of specimens we had collected, and the determinations, descriptions and notes on the species are his with very few exceptions. Dr. Carl Mueller, of Halle, the first authority among living bryologists, assisted Dr. Kindberg and reference to his collection, the richest in the world, greatly facilitated the work. Dr. Venturi has examined many specimens of the genus Orthotrichum, while Dr. Warnstorf, of Neuruppin, Germany, has examined all the specimens of Sphagnum, and it is from his determinations that the species have been named, compiled and arranged. Messrs. Renauld and Cardot have also given valuable assistance.

A duplicate of every specimen sent to Dr. Kindberg has been mounted and placed in the herbarium of this department so that almost every species, from each locality mentioned in the pages of the catalogue, is represented in its Museum.

The only lists published without the specimens referred to having been examined are those of Mr. C. N. St. Cyr, Department of Public Instruction, Quebec, Professor Alexander McKay, M.A., Dalhousie College, Halifax, Nova Scotia, and that of Professor James Fowler, D.D., Queen's College, Kingston, Ont.

In compiling the catalogue, Miquelon Island, Newfoundland, Greenland and Alaska have been included so as to embrace all the known northern species, and 1 trust the present catalogue may be useful for reference and stimulate others to follow up the foundation now laid, by additional works which will include the latest discoveries.

In conclusion, I wish to thank the collectors mentioned for their industry and material assistance. Especial thanks are due Dr. Kind-berg for his gratuitous and unremitting labors in examining between 5,000 and 6,000 specimens from 1887 to the present time. Indeed without his assistance the work could never have been done so thoroughly and completely.

John Macoun.

Ottawa, June 16th, 1892.