90 EXPLANATION OF PLATES. 



Plate XXI. 



Fig. 1. Verrucaria rugulosa, Borr. (p. 47.) 



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



2. Verrucaria peripherica, Tayl. (p. 48.) 



A. Vertical section of thallus and apothecium. d, Sporidia, 

 loose and in ascus. c. Detached apothecia. 



3. Verrucaria umbrosa, Tayl. (p. 48.) 



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

 c. Apothecium. 



4. Verrucaria macrostoma^ De C. (p. 48.) 



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



5. Verrucaria polysticta, Borr. (p. 49.) 



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

 Plate XXII. 



Fig. 1. Verrucaria tracho7ia,^I axIj, (p. 50.) 



a. Thallus and apothecia in profile, b. Vertical section of apo- 

 thecium. c. Sporidia. d. Thallus and apothecia, as seen 

 from above. 



2. Verrucaria tracho/ia, Tayl. variety, (p. 50.) 



A. Vertical section of apothecium. b. Sporidia. 



3. Verrucaria concinna, Borr. V. Dufourii, D.C. 



(pp. 50 and 76.) 



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



4. Verrucaria Dufourii, E.B.S. V. Borreri. 



(pp. 51 and 76.) 



A. Thallus and apothecia in profile, b. Apothecium, as seen 

 from above, c. c. c. c. Vertical section of apothecium. 

 D. Asci and paraphyses. e. Sporidia. 



