Viii BULLETIN OP THE UNIVERSITY OF WISCONSIN. 



lated from Latin, French, or German, with most of which 

 he is also to be credited. Perhaps his most difficult task 

 was in preparing the new part of the key to the genera of 

 Hypnacese, and the keys to the species of Hypnum. The 

 incorporation of the many new species in the keys to the 

 larger genera, such as Sphagnum, Barbula, Grimmia and 

 Bryum, was also a difficult task, made doubly difficult by im- 

 perfect descriptions and want of figures. There is scarcely 

 a key which he has not altered more or less to permit 

 these insertions, and some are completely rearranged. 



In this work advantage has been freely taken of the 

 suggestions, and sometimes of the very characters, in the 

 keys found in Limpricht's Laubmoose, Braithwaite's British 

 Moss Flora, Husnot's Muscologia Gallica, and Warns torf's Char- 

 acteristik und Uebersichtdernord-, mittel-, und sudamerikanischen 

 Tor/moose. 



For the key of Dicranum thanks are due to Professor R. 

 H. True and for that of Amblystegium to Professor L. S. 

 Cheney, both of the University of Wisconsin. 



The first draft of the manuscript prepared by Mr. Heald 

 I have carefully edited, revised, and, in some parts, re- ar- 

 ranged. In the absence of Mr. Heald from the country, 

 the not inconsiderable labor of attending to the details of 

 publication has fallen upon me. 



For corrections to the previous edition acknowledgments 

 are due to Mrs. E. G. Britton, Miss Clara E. Cummings, Mr. 

 E. A. Rau, Dr. C. W. Swan, Mr. Marshall A. Howe, Mr. Edo 

 Claassen, Professor L. S. Cheney and Professor R. H. True. 



The unfailing kindness of Mrs. E. G. Britton in supply- 

 ing specimens, information as to particular species, and 

 copies of several inaccessible descriptions receives also our 

 grateful recognition. 



Professor Conway MacMillan has also put us under ob- 

 ligations by the loan of periodicals not accessible here. 



We shall be grateful for notice of errors or omissions 

 in the present edition. 



