72 CHRYSOTRICHACEAE— COLLEMATACEAE 



b. Horizontal scales sterile; apothecia on cylindric podetia 



Tholurna 85 

 3. Thallus fruticose 



a. Thallus hollow; apothecia on the under side 



Pleurocybe 85 



b. Thallus with solid medulla; apothecia terminal 



(i) Apothecia without thalline covering, goblet-like 



Acroscyphus 86 

 (2) Apothecia enclosed in a globose thalline exciple, which finally opens 

 irregularly at the top Sphaerophorus 86 



Family 37. CHRYSOTRICHACEAE 



Zahlbruckner 117, 127 

 Apothecia disk-form, margined, asci persistent ; mazaedium lacking, thallus 

 uniform, cobwebby, cottony or spongy, loose, without layers, algae Palmella, Pleuro- 

 coccus, Chroolepus or Cladophora. 



I. Thallus with Palmella or Pleurococcus 



1. Spores i-celled Crocynia 242 



2. Spores 2-4-celled Chrysothrix 117 



II. Thallus with Chroolepus ; spores clear 



1. Spores i-celled *Holocoenis 128 



2. Spores 2-celled Coenogonium 127 



III. Thallus with Cladophora ; apothecia lacking 



Racodium 128 



Family 38. COLLEMATACEAE 



Zahlbruckner 154, 158, 167, 168 

 Apothecia disk-form or pitcher-form, with persistent asci ; thallus more or less 

 gelatinous when moist, mostly without layers, always with blue-green algae, scaly, 

 foliose or fruticose, rarely crustose. 



I. Algae Gloeocapsa, Chroococcus or Xanthocapsa ; spores typically i-celled, colorless 



Subfamily Pyrenopsidae 158 



1. Algae Gloeocapsa 



a. Thallus crustose, scaly or dwarf fruticose 

 (i) Spores I-celled 



(a) Asci 8-spored Pyrenopsis 159 



(b) Asci 32-spored *Pleopyrenis 160 

 (2) Spores 2-celled Cryptothele 159 



b. Thallus foliose, of a single leaf; spores clear, i-celled 



Phylliscidium 160 



c. Thallus fruticose, with rhizoids ; spores clear, i-celled 



Synalissa 160 



2. Algae Chroococcus 



a. Thallus crustose ; apothecia more or less open 



Pyrenopsidium 160 



b. Thallus foliose, of one leaf, umbilicate ; apothecia closed 



Phylliscum i6i 



