e 3 ^d ; Au 
P" thins 
227 
450 — ^  Lichenes of New England. 
matic Arrangements of the Lichens, together with 
some Hints on their Uses, from. such -sources as I 
have been able to avail myself of, are added. - 
4 de. dim did as much for this, as for every eiat 
branch of botany. He arranged the known species, 
to which he added very many, in natural groups, and 
of the: whole, constituted his genus Lichen: | This 
scheme is so. simple, that every botanist in the Lin- 
wan age was acquainted with these plants, and 
there is hardly.one of the excellent Floras of that 
age, which does not include them. In Ko ud 
“Enumeratio Lichenum” of G, F. Hoffman appeé 
This was the first of a series of works, by the sam 
author, which introduced the ayaportant : changes 
which have since been made in the sys 
rangement of the lichens. He is the first, so far 
1 have been able to find; who proposed o erect Lin- 
neus's groups into genera, and he described many 
species, for which Scherer, Sprengel, and other conti- 
nental writers have given him credit in their works. 
Nearly all his writings had appeared before Acharius 
had published any thing. . But Hoffman had soon, in 
the latter Swedish botanist, a laborious competitor, 
who before long occupied almost the whole field. 
The * Prodromus Lichenographia Suecice,” of 
Erik Acharius, was published at Linkioping in Swe- 
den, in 1798, and was the first of the works of this 
author, who has long been the common authority of i 
lichenists in Great Britain and this country. In the 
« Prodromus," Acharius distributes the Lichenes in 
+ three large groups called Families, — the Crustacei, 
