84 EXPLANATION OF PLATES. 



Plate IX. 



Fig. 1. Chiodecton albidum. (p. 25.) 



a. Apotheciuin as seen from above, showing the false border to 

 the discs, formed by the substance of the thallodal wart, 

 subsequently disappearing, h. Apothecium older, the false 

 border having disappeared, c. c. Horizontal sections of 

 apothecia, showing the form of the divisions of the torus. 



2. CJdodedon myrticolay Fee. (p. 25.) 



a. Apothecium as seen from above, h. Horizontal section of 

 apothecium, showing the form of the divisions of the torus. 



3. Pertusaria communis, De C. (p. 27.) 



A. Section of thallus and apothecia. a. Cortical layer, h. Me- 

 dullary layer, c. Apothecia. d. Receptacle, e. Nucleus, 

 consisting of asci and paraphyses. b. Sporidia. *c. Ascus 

 with sporidia enclosed. 



4. Pertusaria ceuthocarpa, Turn, and Borr. (p. 28.) 



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



Plate X. 



Fig. 1. Pertusaria ceuthocarpa. Turn, and Borr.; from 

 Pigeon Island, (p. 28.) 



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

 c. Ascus with sporidia enclosed. 



2. Pertusaria fallax, Ach. (p. 29.) 



A. Vertical section of thallodal wart and apothecium. b. Spo- 

 ridia. c. Asci with enclosed sporidia embedded among the 

 paraphyses. 



3. Pertusaria melaleuca. (p. 29.) 



A. A. Vertical sections of thallodal wart and apothecium. b. 

 Sporidia. 



4. Pertusaria pustulat a. (p. 30.) 



A, Vertical section of thallodal wart and apothecium. b. Spo- 

 ridium. 



