ANALYTICAL KEY. 



TO THE SUBORDERS, FAMItlES A.1SD GENERA OF 

 THE 



NORTH AMERICAN P Y R E N iVl Y C ET E S AND 

 HYSTERIACEAE. 



The Nat. ORDER PYRENOMYCETES embraces those 

 fuDf^i in which the asci and sporidia are enclosed in a perithccium. 

 and is divided into 4 SUBORDERS as follows : 



Perilhecia superficial, astomous, membranaccaus, 



mostly OFK^a suliiculum. - - Perisporiaceae. 



Pcrithecia carnose, ,or membranaceo-catnose, : 

 ostiolate, bright colored (red, yellow, etc..) 

 not black. - Hypocreaceue. 



Perithecia black or brown, mostly ostiolate, of 

 various consisience, membranaceous, cOt 

 riaceous, carbonaceoo?, woody or corky, but 

 not carnose; stroma when present not car- 

 nose, dark colored outside, often white 

 within. - - ■ Sphaeriaceae. 



Stroma always present, of firm texture not carnose, 

 black outside. Perithecia reduced to mere 

 cells in the stroma. - DotMdeaceae. 



KEY TO THE FAMILIES. 



SUBORDER PERISPORIACEAE. 



Mycelium of colorless, interwoven threads. Per- 

 ithecia seated singly on the mycelium, subglobosc. 



