DESCRIPTION OF THE PLATES. 



xxiii 



7. 0. externa, apex of fertile podetium, showing the apo- 

 thecium, a, and the spermogones, b. 



8. Ditto, section of an apothecium and of the fistulous pode- 

 tium. 



9. Ditto, thecse and paraphyses. 



10. Ditto, spores. 



11. Ditto, spermogones, magnified, one of them sectioned. 



12. Ditto, sterigmata and spermatia. 



13. C. Pajpillaria. 



14. C. gracilis. 



15. C. furcata. . 



16. C. stellata, var. iincialis. 



17. Ditto, apices of ramules, magnified. 



18. C. hellidiflora. 



19. Ditto, apothecia and podetium, magnified. 



20. 0. deformis. 



21. C. cervicornis. 



PLATE XIX. 



1. Collema granosum> sterile thallus. 



2. Ditto, portions of thallus, showing apothecia, magnified. 



3. Ditto, portion of thallus, showing papulose character of 

 surface, magnified. 



4. Ditto, section of apothecium. 



5. C. atro-cceruleum, var. lacerum, sterile thallus. 



6. Ditto, portion of sterile thallus, magnified. 



