74 THE AMERICAN MONTHLY [Mar., 



1 Spores muriform, colored, Apo. patelliform 3. — Continued. 



3 Exciple paler than the disk 45 Heterothecium 



3 Ex. coal black 47 Bnellia 

 a Apothecia dittbrm, rouuded or oblong 4 



4 In a diffbrm rounded or stellate pseudo-stroma 56 Arthonia 



4 Black in a difform pseudo-stroma 57 Mycoporum 

 a Apothecia crateriform 60 Acolium 

 a Apo. globular immersed 5 



5 In the thallus 63 Endocarpon 

 5 In thalline warts 66 Staurothele 

 5 In a stroma 67 Trypethelium 

 5 Solitary or confluent prominent 70 Pyrenula 

 5 Sol. or confluent turbinate 71 Pyrenastrum 



b Apothecia lirellseform 53 Graphis 



b Apo. urccelate 37 Thelotrema 



b Apo. patellseform 1 



1 Exciple paler than the disk 45 Heterothecium 



1 Ex. coal black 47 Buellia 

 b Apothecia scutellseform 2 



2 Apothecia blackened, gyrose plicate thallus attached to the 



subtrate by a single point 13 Umbilicaria 



2 Thallus crustaceous, squamulose, granulose, parenchymatous 



22 Pannaria 

 2 Thallus dark green 27 Coll em a 



2 Th. lead colored 28 Leptogium 

 b Apothecia rounded or oblong 3 



3 Difform in a white stroma 54 Chiodecton 

 3 In a diiform pseudo-stroma 57 Mycoporum 



3 In a rounded or stellate pseudo-stroma 56 Arthonia 

 b Apothecia immersed 4 



4 In the thallus 63 Endocarpon 

 4 In thalline warts 67 Trypethelium 

 4 Innate 69 Verrucaria 

 4 Prominent 70 Pyrenula 



Spores oblong. 



1 Oblong only a 

 1 Oblong ovoid b 

 1 Oblong ellipsoid c 

 1 Oblong fusiform d 

 a Colored 1 



a Colorless or decolorate 2 



a Fucescent 22 Pannaria 



1 Thallus fruticulose 7 Schizopelte 



1 Th. foliaceous squamulose or crustaceous 63 Endocarpon 



1 Th. uniform z 



z Apothecia patellseform 45 Heterothecium 



z Apo. rounded or oblong x 



X Apo. concave black in a white stroma 55 Glyphis 



X Apo. in a diffbrm rounded or stellate pseudo stroma 



56 Arthonia 

 X Apo. black in a diffbrm pseudo-stroma 57 Mycoporum 



1 Apo. crateriform, stipitate 61 Calicium 



2 Colorless or decoloi ate y 



y Thallus squamseform or monophyllous 64 Normandina 



