452 Lichenes of New England. 
reckoned distinct, and placed, as by Hooker, far apart 
from. each other. The Cladonie are arranged in 
three Tribes, which, in his subsequent works, Acha- 
rius reduced to one genus, Cenomyce; this last ar- 
rangement being, however, anticipated by the genus 
Cladonia of Hoffman. The Gyrophore we find con- 
stituting the Tribe Umbilicaria, which name also is 
adopted from Hoffman, and has priority of the former. 
: The next work of Acharius was the “ Methodus,” 
which was published at Stockholm, in 1803, and 
was meant to include all the known species. In 
this, the ground was firmly taken that the Lichenes | 
ought to be regarded as constituting. an Order, rather 
than a Genus: — “ potius. Familiam vel. Ordinem 
Cryptogamie Classis quam Genus solum constituere." 
& 
(prem. p. 5.) The necessity of this change is as- ewe 
serted both on the ground of conformity with nature, 
and also on that of the immense number of species 
which must be included in the Linnwan genus. 
The characters of the Genera are taken from those 
regular and most highly organized parts called apo- 
thecia; their position, constitution, and figure being 
ls regarded. The groups of species are ac- 
cordant, to à great extent, with those of the Lin- 
nsan arrangement, which may be called obviously 
natural. ‘There are, however, defects incident to the 
nature of a system, which are also perceptible in - 
that of Acharius ; some of the arrangements being 
probably | eei and many species appearing to be 
paradoxical, upon whose right place authors seem. 
hever to have been able to agree. It does not require 
. any great attainments in the new. method of the 
