3. Stereocaulon 124 



4. Cladonia 125 



5. Thamnolia 127 



III. LECIDEACEAE 128 



1. Biatorella 130 



2. Biatorina 131 



3. Biatora 132 



4. Bilimbia 133 



5. Baciuia 134 



6. Lecidea 135 



7. Celidiopsis .... . . 135 



8. Buelliopsis . . .... 136 



9. Buellia .... .... 136 



10. Calillaria 137 



IT. Megalospora 137 



12. Lopadium 138 



13. Gjalecta 139 



14. Psora 140 



15. Gyrophora 141 



16. Umbilicaria 143 



IV. GRAPHIDACEAE 144 



1. Hazslinskya . . 145 



2. Opegrapha . 146 



3. Graphis ... 146 



4. Xylographa 147 



5. Arthonia . . . 148 



6. Mycoporum 149 



7. Arthothelium 150 



V. PHYSCIACEAE 151 



1. Rinodina 152 



2. Placodium 154 



3. Pyxine . . 155 



4. Physcia 156 



5. Theloschistes 158 



VI. PARMELIACEAE 159 



1. Urceolaria 161 



2. Haernatotnma 162 



3. Lecanora 164 



4. Acarospora 165 



5. Speerschneidera 166 



6. Parmelia 167 



7. Cetraria 169 



8. Evernia 170 



9. Ramalina 172 



10. Alectoria 173 



11. Bryopogon 175; 



12. Usnea 176 



VII. VERRUCARIACEAE 177 



1. Trypethelium . .' 179 



2. Pyrenula 180 



3. Conotrema . 181 



4. Thelotrema . 182 



5. Gyrostomum . . 184 



6. Verrucaria . . ... 185 



7. Pertusaria 186 



8. Dermatocarpon 188 



9. Endocarpon 189 



VIII. COLLEMACEAE 191 



1. Collema 193 



2. Leptogium 194 



3. Mallotium 195 



4. Hydrothyria 196 



IX. PANNARIACEAE 197 



1. Ephebe . . ... 199 



2. Lecothecium . .... 200 



3. Lichina. 201 



4. Omphalaria 203 



5. Polychidium 204 



6. Psoroma 205 



7. Heppia 206 



8. Pannaria 207 



9. Peltigera 209 



10. Solorina 210 



11. Nephromium 212 



12. Stictina 213 



13. Sticta .... 215 



CHAPTER III. 



LEPRARIACEAE Pseudolichenes . . . 217 



1. Lepra 217 



2. Amphiloma 218 



THE CONTINENTAL RANGE OF 



THE GENERA OCCURRING IN 

 THE NORTHEASTERN UNITED 

 STATES -219 



GENERAL INDEX 



223 



