(9) 
place of which in Cetraria may be considered to be determined by C. Isl- 
andica and C. odontella, but no less with Alectoria divergens, Nyl.: and 
it is worthy of note that, after an exhaustive analysis of the little-known 
apothecia of the last, Nylander (in Prodr. Fl. N. Gran. p.14, n.) goes far 
to confirm, from this point of view, its otherwise observable resemblance 
to the first; while Schwendener’s remarks on the thalline structure of 
both, if not conclusive, may be said to point in the same direction. The 
last-named author, who has no hesitation in accepting the anatomical 
correctness of Fries’s reference of Cornicuwlaria aculeata, Ach., to Cetraria, 
and whose results indicate the position of C. tristis to be in some sort 
intermediate between Cetraria proper and Alectoria, is however once 
more with Fries, and wholly without doubt, as to the generical distinctness 
of A. divergens. In this uncertainty as to the true place of Lichen tristis, 
it is open to us to fall back upon Cetrarza ; and declining to recognize the 
sufficiency, in so loose a genus, of the observed amount of anatomical 
discrepance, to find, rather, with the author of the Lichenographia Eur- 
opea, that, whether in thallus or apothecia, C. tristis is in fact not ill- 
comparable with C. odontella. Nylander has sought to reconstruct the 
whole group in accordance simply with the characters afforded by the 
spermogones and spermatia; and he thus separates the two lichens we 
have just compared: it is important then to notice that no special indica- 
tion is made by him of the observation of spermogones in C. odontella ; 
and that C. tristis is equally included in his Cetrariei (our Cetraria) 
a reference the more difficult that the spermogones of the species last 
named are admitted to point in other directions.——C. Californica, Tuck- 
erm. Suppl. 2 (Amer. Journ. Sci., 28) p. 203, a tree-lichen, discovered by 
Menzies, and looking often rather like a discoloured, small form of Ram- 
alina calicaris,! but in fact comparable, as respects the thallus, with 
Cetraria aculeata, and, especially as respects the apothecia, with C. tristis, 
proves also to agree with the latter in its spermogones and spermatia ; 
and constitutes therefore a very interesting addition to our scanty mate- 
rial for the final determination of the place of C. tristis. 
It is quite impossible summarily to reject the evidence, confirmed now 
by the spermogones, that Cetraria aculeata is inseparable generically from 
1 Tulasne (1. ¢. p. 170) remarks on C. tristis, that its whole organization is 
closely comparable with that of Ramalina scopulorum; with which may be com- 
pared Schwendener’s observations on R. calicaris, doc. (Untersuch. 1. ¢. 2, p. 155) 
and C. tristis (p. 150). There is no doubt much to be said against regarding 
Lichen tristis as an exceptionally ascendant Parmelia, and the question of its true 
position might rather be supposed to hang between Cetraria and Alectoria; the 
plant being either united, as an extreme member, to one of these groups, or set up 
itself as the type of an intermediate one (Cornicularia, Hoffm.). But the difficulty 
remains (as compare Nylander, l. c. p. 307, and Anzi p. 29) of its apparent natural 
associableness with Lichen lanatus ; and this, however Alectoriiform, is yet, with 
common consent, reduced to Parmelia. 
2 
