AN 



ENUMER A TION 



NORTH AMERICAN LICHENES, 



A PRELIMINARY VIEW OF THE STRUCTURE AND 

 GENERAL HISTORY OF THESE PLANTS, 



AND OF 



THE FRIESIAN SYSTEM: 



TO WHICH IS PREFIXED 



AN ESSAY 



ON THE 



NATURAL SYSTEMS OF OKEN, FRIES, AND ENDLICHER. 



Bv EDWARD TUCKERMAN, LL. B., 



RESIDENT GRADUATE OF HARVARD UNIVERSITY. 



" Ibia honeatus, 



Poatquam egregiam tu quoque sortem 

 Nactua abia, dextri prece sollicitatus amici." 

 MILT. SYLV. 



CAMBRIDGE: 



PUBLISHED BY JOHN OWEN. 

 1845. 



LIBRARY 



