MIDDLESEX FLORA. 173 



Opegrapha, (Humb.) Ach., Nyl. 



O. varia, (Pers.) Fr. 



Sherborn. 

 O. vulgata, CAch.) Nyl. 



Sherboiu. 



Xylographa, Fr., Nyl. 



X. opegraphella, Nyl. 



Waltham (C. J. Sprague;. 



Graphis, Ach., Nyl. 



C. scripta, (L.) Ach. 



Wiiltli<am, Natick. 

 G. dendritica, Ach. 



Sherborn. 



Arthonu, Ach., Nyl. 



A. astroidea, Ach. 



Cambridge. 

 A. punctiformis, Ach. 



Sherl)oru. 



AcOLiuM (Fee) De Not. 



A. tigillare, (Ach.) De Not. 

 Cambridge, Waltham, Natick. 



Calicium. Pers., Ach., Fr. 

 C. subtile, Fr. 



Natick. 

 C. turbinatum, Fers. 

 Cambridge. 



Endocarpon, Hedw., Fr. 



E. miniatum, (L.) Schaer. 



Arlington, Waltham, Natick. 

 E. miniatum, (L.) Schaer., var. complicatum, Schaer. 



Cambridge. 

 E. miniatum, (L.) Schaer., var. aquaticum, Schaer. 



Medford, Waltham. 



Verrucaria, (Pers.) Tuck. 



V. nigrescens, Pers. 



Cambridge. 

 V. muralis, Ach. 



Watertown. 



