One hundred and fifty-one species and four varieties of Musci are documented from northern Ellesmere Island, Arctic Canada. My studies have added 39 species and four varieties to the northern Ellesmere moss flora. The annotations include comments on distribution and abundance, habitats, altitudinal range, and fertility of each taxon on northern Ellesmere. Where appropriate, morphological variation and taxonomy are discussed. A new variety, Splachnum vasculosum var. heterophyllum, is proposed to accommodate arctic specimens of S. vasculosum. Cyrtomnium hymenophylloides, Distichium hagenii, Fissidens arcticus, and Polytrichum hyperboreum are illustrated. New data and observations on the taxonomy of the following taxa are presented: Aulacomnium acuminatum, Brachythecium groenlandicum, B. turgidum, Fissidens arcticus, Funaria arctica, Grimmia apocarpa var. nigrescens, Splachnum vasculosum, Voitia hyperborea, and V. nivalis. The following annotated list of northern Ellesmere Island mosses is arranged in the taxonomic order of Crum, Steere, and Anderson (1965), which is also used as the nomenclatural base. I have generally followed their taxonomic concepts, but where mine differ I state the reasons. Taxa whose names are enclosed in square brackets are provisionally excluded from the northern Ellesmere moss flora. Important synonyms are cited, in parentheses, following the names of certain taxa. After the name of each taxon I have listed the localities from which it is known. The localities and their abbreviations as used in the checklist are as follows: AF, Ayles Fiord; AL, Alert; BP, Barbeau Peak; cM, Clements Markham Inlet; DB, Doidge Bay; FC, Fort Conger; GG, Gilman Glacier; GI, Garlic Island (tentative name); HL, Heintzelman Lake; JL, Jasper Lakes (tentative name); LB, Lincoln Bay; LH, Lake Hazen; OF, Otto Fiord; 1 Part of a doctoral dissertation submitted to the University of Ottawa, Canada. Financial assistance for the field studies came from the National Museum of Natural Sciences, Canada, the National Research Council of Canada (grant A730 to R. E. Beschel), and the New York Botanical Garden (National Science Foundation grant GB-1313 to W. C. Steere). The Defence Research Board of Canada provided logistic support during all three field seasons. I thank the members of Operation Tanquary, especially Dr. Royce Longton, my companion in 1967. I am greatly indebted to the bryologists who willingly identified or verified specimens for me: Dr. Howard Crum and Dr. W. C. Steere, both of whom examined many specimens, Dr. Kjeld Holmen, Dr. A. Crundwell, and Mr. Harry Williams. The curators and staffs of the following herbaria allowed me full use of their facilities and collections: National Museum of Natural Sciences (CANM), New York Botanical Garden (NY), Plant Research Institute, Ottawa (DAO), Queen's University (QK). 2 Department of Biology, University of Ottawa, Ottawa, Canada. Present address: Department of Biology, Memorial University, St. John's, Newfoundland, Canada. This content downloaded from 207.46.13.111 on Tue, 09 Aug 2016 05:20:17 UTC All use subject to http://about.jstor.org/terms 1971] BRASSARD: NORTHERN ELLESMERE ISLAND MOSSES II 283 TF, Tanquary Fiord; TI, Taconite Inlet; VH, Van Hauen Pass; wB, Wrangle Bay; wH, Ward Hunt Island; YB, Yelverton Bay. Each locality abbreviation is followed by collection numbers in italics (which are mine unless otherwise preceded by a name); an asterisk (*) indicates a specimen with sporophytes and an exclamation point (!) denotes specimens which I have examined but which were not collected by me. A name and date in parentheses, e.g., (Steere, 1959), is a published report based on specimens which I have been unable to study. A fire at Van Hauen Pass in 1967 destroyed many of my moss specimens, and a few species which I had definitely identified in the field but of which no specimens remain are cited as sight record. After the list of localities and specimens for each taxon I have added annotations about its biology and ecology on northern Ellesmere. Where appropriate I have also included comments on taxonomy, morphological variation, illustrations, or keys. The following list comprises 71 genera, 151 species, and four varieties of Musci. I expect that future investigations on northern Ellesmere will raise its known moss flora to at least 160 species, and will in addition provide more material of rare species.