PREFACE. 



Ill the jirofont state of uiyc!olo,<2;ii'a) kii()wle(l,ii'e, the elaHsiliention 

 and description oi' tlie species of Xortii American Pyrenoniycetes is 

 attended witli many diiliculties; eliiof among whicli is the fact tliat 

 many ol' th(! piililishcd diagnoses are too iinjierfect to enahle one to 

 recotfiii/.e the species, of wliich many ol" the types are either lost or 

 practically inaccessilile. An examination of the Schwcinitzian Herha- 

 riiim, at the Academy of Natural Sciences at rhiladeljihia, reveals the 

 fact that about two hundred of the most valuable sficcies descril»cd in 

 Schweinity/ Synopsis of North American Fungi arc not rei)resented in 

 the lierbfirium at all, and that many of tlie s])eciniens still remaining 

 are too meager or too imjierfcct to be of much service. Coming to the 

 s[)ccics described by Berkeley & Curtis, the case is no better, but, as 

 far as specimens are concerned, even worse, the ty])es being entirely 

 beyond the reach of the ordinary student. Our knowlr^dge of these 

 species is derived from the brief descriptions in Grevillea and the 

 sup])lomentary notes by Dr. M. C. Cooke, who has also examined and 

 determined, l)y coni])arison with the original types, many of the species 

 included in the present work. 'Wo are also indebted to Di-s, Rehin, 

 Winter, and Saccardo for the identilication of many doubtful species; 

 Ijiit al)ove all to the many collectors who have furnished abundant 

 material from all parts oi" the country, thus making it possible to give 

 ail approximately comjjlete synopsis of the North American species of 

 this extensive Order. The names of these contributors ajipear in con- 

 nection with the species they have furnished. The name of Kavcnel 

 is attached to most of the sj)ecies collected by him ami described by 

 Berkeley A: Curtis in Grevillea; and Schweinitz or "'Schw." to his 

 species publisheil in the Synopsis of North American Fungi. 



