MIDDLESEX FLOKA. 173 



OPEGRAPHA, (Humb.) Ach., Nyl. 



O. varia, (Pers.) Fr. 



Sherborn. 

 O. vulgata, (Ach.) Nyl. 



Sherborn. 



XYLOGRAPHA, Fr., Nyl. 



X. opegraphella, Nyl. 

 Waltham (C. J. Sprague). 



GRAPHIS, Ach., Nyl. 



G. scripta, (L.) Ach. 



Waltham, Natick. 

 G. dendritica, Ach. 



Sherborn. 



ARTHONIA, Ach., Nyl. 



A. astroidea, Ach. 



Cambridge. 

 A. punctiformis, Ach. 



Sherborn. 



ACOLIUM (F6e) De Not. 



A. tigillare, (Ach.) De Not. 

 Cambridge, Waltham, Natick. 



CALICIUM, Pers., Ach., Fr. 

 C. subtile, Fr. 



Natick. 

 C. turbinatum, Pers. 



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. 



