66 THE AMERICAN MONTHLY [Mat-., 



8 Sp. 2 to 4 plurilocular or multilocnlar D 



9 Sp. bi-locular D b 



10 Sp. polar bi-locular E 



11 Sp. t'usiibrm F 



12 Sp. acicular G 



13 Sp. • muriform H 



14 Sp. oblong I 



15 Sp. ovoiri K 



16 Sp. ellipsoid x 



X Sp. ellipsoid — simple. See under B 

 X Not simple L 



A 



Spores dactyloid. 

 1 Sp. colorless 48 Lecanactis 



1 Sp. brown or decolorate 51 Opegrapba 



B 



Spores simple. 



2 Sp. violet, black, spherical 58 Sphaerophorus 

 2 Sp. ovoid y 



y Apo. scutellaeform 1 



1 Th. frondose, villous beneath clothed vyith a pannose hypothallus 



17 Erioderma 

 1 Th. monophylous, or multifid, squamulose or crustaceous 



22 Pannaria 

 1 Th. folliaceous, very rarely fruticulose, gonimia almost always 



concatenate 27 CoUeraa 



1 Th. folliaceous, lead colored 28 Leptogium 



y Apothecia orbicular 20 Heppia 



y Apo. depressed-globose urceolate, at length opened 25 Pyrenopsis 

 y Apo. rounded or oblong, flat 50 Melaspilea 



y Apo. mostly cephaloid, variously colored, not black 41 Cladonia 



y Apo. immersed in the thallus 63 Eudocarpon 



y Apo. innate 69 Verrucaria 



y Apo. depressed-globose thallus epiphyllous, passing into a lobu- 



late crust 72 Strigula 



2 Sp. ellipsoid or sub ellipsoid, colored a 

 2 Sp. ellipsoid or sub-ellipsoid, colorless b 

 a Sp. fucescent 22 Pannaria 



a Sp. brown 1 



1 Apothecia scutellaeform, black gyrose — plicate 13 Umbilicaria 



1 Apo. rounded, oblong, black 50 Melaspilea 



1 Apo. crateriform, stipitate, thallus crustaceous 61 Calicium 



1 Apo. turbinate with an ostiole 71 Pyrenastrum 



b Th. of jointed filaments 42 Co^nogonium 



b Th. evernifftbrm 10 Parmelia 



b Th. fruticulose 1 



1 Disk colored differently from the thallus 3 

 1 Disk and thallus pale 4 



1 Th. brownish black 24 Lichina 



1 Th. attached to substrate by a single point 26 Omphalaria 



1 Th. orange 30 Placodium 



1 Th. yellowish or flesh colored 31 Lecanora 



1 Th. with podetia 40 Pilophorus 



1 Th. composed of jointed filaments 43 Cffinogonium 



3 Apotheciaattachedtothetipsor margin of the thallus 3 Cetraria 



3 Disk concave, apo. often cyathiform 4 Evernia 



3 Thallus rounded cottony within, alike on all sides 6 Alectoria 



