PREFACE 



The work of this monograph was begun during the autumn of 

 1906. its object being to give a better understanding of the North 

 American species of the order treated. 



The work is based largely on the collections of fungi in the New 

 York Botanical Garden, including the extensive Ellis collections. 

 Other herbaria which have been visited for the purpose of study 

 during the course of the work are the Schweinitz collection in 

 Philadelphia, the collections of Dr. C. H. Peck in the State Museum 

 at Albany, and those of the United States Department of Agricul- 

 ture, Washington, D. C. In addition to these, I have been 

 permitted to examine the fungi of this group from the herbarium 

 of the late A. P. Morgan, of Ohio, which collection is now in the 

 State University of Iowa, and have also examined numerous 

 tyi^es from the Royal Gardens, Kew, England. 



In the preparation of this work, I wish to acknowledge my 

 indebtedness to Dr. N. L. Britton, Dr. W. A. Murrill, and other 

 members of the staff of the New York Botanical Garden, also to 

 Professor T. H. Macbride of the State University of Iowa and 

 to the late Professor L. M. Underwood, of Columbia University. 

 The names of other persons who have contributed to the com- 

 l^letion of the work ai)])ear on the following pages. 



