CATALOGUE OF PLANTS. 



* Var. rudecta, Tuck. 



More frequently seen on tree trunks (Eckfeldt). 



P. saxatilis (L.), Fries. 



On rocks and trees. (Eckfeldt) ; Seal Harbor (Wilson, Bed- 

 field). 



Var. sulcata, Nyl. 



Seal Harbor (Eckfeldt). 



Var. omphalodes, Fries. 



On rocks. Seal Harbor (Wilson, Eckfeldt). 



P. physodes (L.), Ach. 



On rocks. (Eckfeldt) ; Seal Harbor (Wilson). 

 *Var. obscurata, Ach. 



On rocks. Seal Harbor (Eckfeldt). 



* Var. vittata, Ach. 



On trees. Infertile (Eckfeldt). 

 *P. encausta (Sm.), Nyl. 

 On rocks. (Eckfeldt.) 



P. pertusa (Schrk.), Schaer. 



On trees and rocks. (Eckfeldt) ; Seal Harbor (Wilson). 



P. colpodes (Ach.), Nyl. 



On tree trunks. (Eckfeldt, Wilson.) 



P. olivacea (L.), Ach. 



On trees. (Eckfeldt) ; Seal Harbor (Wilson) ; Southwest 

 Harbor (M. L. Fernald). 



* Var. aspidota, Ach. 



(Eckfeldt.) 

 Var. sorediata (Ach.), Nyl. 



On rocks. Seal Harbor (Wilson). 

 P. stygia (L.), Ach. 



On rocks. Seal Harbor (Wilson). 



