456 



THALLOPHYTES 



Obs. The foregoing Catalogue of Chester County Lichen*, and 

 Collemas, contains about twenty species never before published in 

 this country,^ one half of which are entirely new. For the deter- 

 mination and description of the most of these, the writer has availed 

 himself of the kind assistance of his friend E. TUCKERMAN, of 

 Cambridge, Mass, whose long and assiduous attention to this much- 

 neglected portion of Cryptogamic Botany has intitled him to be 

 called THE AMEEICAN LICHENIST. *E. M. 





