CONTENTS. XXxi 



PAGE 



Z\ Mineralogical. and Chemical character .... 103 



c. Exposure to light, etc. ....... 55, 104 



4. Epirrheology 53, 105 



CHAPTER V. 



Rules for Collection, Preservation, and Examina- 

 tion of Lichens 107 



CHAPTER VI. 



General Classification of Lichens 115 



Synopsis of Natural Orders and Genera 119 



Description of Typical British Species 121 



1. Gymnocarpi 121 



1. Usneacea3 121 



2. Corniculariacese 126 



3. Cetrariacese 150 



4. Peltideacese 161 



5. Umbilicariacese 173 



6. Parmeliacese 181 



7. Lecanoreacese 214 



8. Lecideacese 234 



9. Graphideacese 245 



10. Caliciacese 256 



11. Cladoniacea3 261 



12. Collemaceae 276 



