XX 



DESCRIPTION OF THE PLATES. 



8. Arthonia Swartziana. 



9. Ditto, ardellse, magnified. 



10. Ditto, section of an ardella. 



11. Ditto, spore. 



12. Coniocarpon cinnabarinum. 



13. Ditto, ardellae, magnified. 



14. Ditto, ditto, still more highly magnified. 



15. Ditto, section of an ardella. 



16. Ditto, spore. 



17. Opegrapha cerebrina, spore. 



18. Aulacographa elegans, section of lirella. 



19. CMographa Lyellii, section of lirella. 



20. Ditto, spore. 



21. Hymenodecton dendriticum, section of lirella. 



22. Lecanactis lyncea, ditto. 



23. Opegrwpha atra, ditto. 



PLATE XYI. 



1. Spliarophoron coralloides. 



2. Ditto, young apothecium, still closed. 



3. Ditto, section of apothecium, showing the floccose-pul- 

 verulent thalamium. 



4. Ditto, section of young apothecium. 



5. 6. Ditto, showing the splitting up of the thalamium in old 

 apothecia. 6 a. Section. 



7. Ditto, thecse and spores in different stages of development. 



