Ill 



northern part of British America and Alaska, and in the elevated 

 regions along the Rocky Mountain chain further South. 



The Erysiphea3 in this Vol. (pp. 2-30) have been elaborated and 

 prepared by Professor T. J. Bui-rill, of the University of Illinois, who 

 wishes here to express his thanks for contributions of much service 

 mostly specimens, to the following named gentlemen, viz.: F. W. 

 Anderson, J, C. Arthur, Geo. F. Atkinson, W. J. Beal, H. W. Hark- 

 ness, W. A. Kellerman, T. H. McBride, L. H. Pammel, C. H. Peck, 

 S. M. Tracy, Win. Trelease. A. B. Seymour, and Geo. P. Clinton. 



We regard it as extremely fortunate that Prof. B. was willing to 



/ c^ 



undertake the editing of the Erysiphece, as his previous studies in 

 this difficult Family have made him specially competent to do the 

 work thoroughly. 



i> 



The index of genera and species at the end of the volume is the 



work of our friend W. C. Stevenson, Jr., to whom we are already 



. 



indebted for the indices of species and their habitats in the ''North 

 American Fungi." 



* 



( 

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