127 
plan adopted throughout the work of introducing each genus with 
a headline, giving the name and author and a diagnosis, after 
which follow the diagnoses and paragraphs with observations and 
a statement of the habitat. In the case of the lichens the diagnoses 
under the headlines are verbatim copies of the corresponding diag- 
noses of Acharius’ ‘‘ tribus,’’ and the names in the headlines are 
those used to designate the ‘‘ tribus,’’ with the addition of ‘‘ Ach.”’ 
That Michaux actually intended to give Acharius’ “ tribus’’ the 
status of genera may be inferred not only from the typographical 
exposition which is in accordance with that adopted in the re- 
mainder of the work, but also from the fact that he forms his 
specific names by combining the specific epithet with the 
“ tribus’’? name of Acharius, and not with the Linnean genus 
“lichen ’’ as Acharius did. Now, among the “‘ genera’’ recorde 
there, we find on p. 323 Setaria and as sole representative of it 
S. trichodes, both of which have to be credited to Michaux. What 
this Setaria trichodes .which the elder Michaux collected in 
Canada was, is uncertain. Acharius, referring to it in a note in 
his Lichenographia, p. 594, says “utrum huius generis (i.e., 
Alectoriae) species sit an Alectoriae jubatae tantum varietas, 
icere non audeo,’’ and Krempelhuber (Geschichte u. Literatur d. 
Lichenologie, ii. 551) omits it altogether from the list of new 
species described by Michaux in his Flora Boreali-Americana ; 
nor is it included in part vii. of Macoun’s Catalogue of Canadian 
Plants which deals with the Hepatics and Lichens. In fact, the 
only reference to it seems to be in Tuckerman’s Synopsis of the 
North American Lichens, part i. 44, where it is quoted as a 
synonym of Alectoria jubata var. implera; but Tuckerman has 
evidently not seen it, as he quotes only Hall’s (Rocky Mountains) 
and Richardson’s (Arctic America) collections, nor do Nylander 
or Fries, whom he cites for Alectoria and the variety impleza 
grass genus. : 
T should not have considered it worth while to deal with a mere 
way. 
