60 



Plate i. Thallus. 



1. ROCELLA. 



5. Efhebe. 6, 



2. USNEA. 

 CcENOGONIUM. 



3. Theloschistes. 4. Collema. 



A. Cortical layer. B. Gonidial do. C. Medullary do. 



Plate 2. Gonidia. 



7. Of Aechilichens. 



10. MiCROGONIDIA. 



8. Of Sclerolichens. 9. Gonimia. 



