2 2 Charles E. Besscy v 



ing through, pointed or elongated into neck-like projections; 

 saprophytes. Botryosphaeria, Melogramma. (Pf. I, i, 477.) 



Family 89. Xylariaceae. Perithecia peripheral in the massive 

 stroma, which is often hemispherical or clavate, black, or brown, 

 woody or carbonaceous. Hypoxylon, Xylaria, Nummularia, 

 Ustulina. (Pf. I, i, 480.) 



Order Hysteriales. Slit Fungi. True fungi, saprophytic or 

 parasitic, with a branching mycelium, often forming a stroma ; 

 apothecia sessile, or at first sunken and later erumpent, usually 

 elongated, dark-colored, leathery or carbonaceous, with a narrow 

 slit. 



Family 90. Hypodermataceae. Apothecia sunken, leathery, 

 round or elongated, black ; saprophytes. Hypoderma, Lophioder- 

 mium. (Pf. I, I, 267.) 



Family 91. Dichaenaceae. Apothecia at first sunken, later 

 erumpent, leathery, black, elongated, or round ; bark-saprophytes. 

 Dichaena. (Pf. I, i, 270.) 



Family 92. Ostropaceae. Apothecia at first deeply sunken, 

 later somewhat erumpent, leathery, black, roundish ; saprophytes. 

 Ostropa. (Pf. I, I, 271.) 



Family 93. Hysteriaceae. Apothecia sessile, narrowly elon- 

 gated to broad, and even lobed, black, carbonaceous or leathery; 

 saprophytes. Hysterinm, Hysterographium. (Pf. I, i, 272.) 



Family 94. Acrospermaceae. Apothecia sessile, erect clavate, 

 corneous, brown, spores very long, filamentous ; saprophytes. 

 Acrospermiim. (Pf. I, i, 277.) 



Order Perisporiales. Mildews. Plants filamentous, produc- 

 ing minute, simple, mostly spherical spore-fruits, consisting of one 

 to many asci enclosed in a hard, cellular shell (perithecium). 



Family 95. Erysiphaceae. Superficial parasites upon higher 

 plants, the filaments white with abundant, simple, vertical conidi- 

 ophores, the blackish, spherical spore-fruits with radiating, usu- 

 ally forked appendages. ,Erysiphe, Sphaerotheca, Microsphaera, 

 Podosphaera, Uncinula. (Pf. I, i, 328.) 



58 



