LECIDEACEAE 77 



r. Exciple and hypothecium dark or black 



Catillaria 133 

 s. Exciple and hypothecium clear or bright 



Biatorina 134 

 (y) Paraphyses branched, in a slimy hymenium 



*Diphanis 138 

 y. Spores brown ; paraphyses branched 



*Diphaeis 138 



(c) Spores 4-many-celled 



x. Spores elliptic to long-fusoid 



(x) Thallus not corticate, crustose-uniform 

 m. Spores thin-walled Bacidia 135 



n. Spores thick-walled Bombyliospora 136 



(y) Thallus corticate, v/arty to scaly 



Toninia 136 

 y. Spores needle-shaped or filiform 



fScolecosporis 136 

 (Scoliciosporum) 



(d) Spores muriform 

 x. Spores clear 



(x) Spores with mucus covering; paraphyses branched 



*Phalodictyum 138 

 (y) Spores without mucus cover ; paraphyses simple 



Lopadium 137 

 y. Spores brown, mucose Rhizocarpum 137 



(2) Asci many-spored 



(a) Exciple bright-colored, soft Biatorella 151 



(b) Exciple dark or black, hard Sporostatia 152 



II. Thallus scaly or f oliose ; algae Pleurococcus or Palmella 



Subfamily Phyllopsorae 138 



1. Thallus scaly, with rhizoids ; disk even 



a. Spores i-celled 



(1) Hypothecium pseudoparenchymatic 



Phyllopsora 138 



(2) Hypothecium not pseudoparenchymatic 



(a) Exciple clear or bright Psoromaria 183 



(b) Exciple dark or black Psora 132 



b. Spores transeptate Psorella 139 



2. Thallus mostly with one large leaf ; disk often furrowed 



Subfamily Gyrophorae 147 



a. Spores i-celled ; disk furrowed in most of the species 



Gyrophora 147 



b. Spores transeptate 



(1) Spores 2-many-celled, colorless *Merophora 148 



(2) Spores 2-celled, brown Dermatiscum 149 



c. Spores muriform, dark Umbilicaria 149 



III. Thallus dwarf fruticose, of low erect slightly branched podetia, horizontal 

 thallus lacking ; spores clear, 2-celled Sphaerophoropsis 133 



