EXPLANATION OF PLATES. 93 



Plate XXVII. 



Fig. 1. Ferrucaria nigrescens^ Pers. (p. 62.) 



A. Vertical section of thallus and perithecium. b. Sporidia. 



2. Verrucaria elaina, Borr. (p. 63.) 



A. Vertical section of thallus and perithecium. b. Apothecia. 

 c. Ascus, with enclosed sporidia. d. Sporidia. 



3. Verrucaria Gagei, Borr. (p. 63.) 



A. Vertical section of thallus and perithecium. b. Upper sur- 

 face of thallus. 



4. Verrucaria epigcea, Ach. (p. 64.) 



A. Vertical section of thallus and perithecium. b. Sporidia. 



5. Verrucaria HooJceri, Borr. (p. 64.) 



A. Vertical section of thallus, showing the immersed apothecium. 

 B. a. b. c. Sporidia in different states. 



Plate XXVIIL 



Fig. 1. Tyrenothea leucocephala, Fries, (p. 65.) 



A. Vertical section of thallus and apothecium. b. Sporidia. 



2. Fatellul(B on Pgrenothea leucocejphala, Fries. 



(p. 66.) 



A. Vertical section of patellula, b, Sporidia. 



3. Lecidea ahietina, Bohl. Lich. Brit. (p. ^^^ 



A. Vertical section of patellula. b. b. Sporidia. 



4. Lichen GriffitJdi, E. Bot. (p. QQ.) 



A. Sporidia. 



5. Fyrenothea rudis, (p. Qi^.) 



A. Vertical section of thallus and apothecia. b. Sporidia. 



6. Fyrenothea rudis pseudo-leucocephala. (p. 66.) 



A. Vertical section of thallus and apothecia. 



7. Fyrenothea aphanes, (p. 67.) 



A. Vertical section of thallus and apothecium. b. Sporidia. 



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