( 280 ) 
those of Floerke (herb.!) Fries, Scherer, and Mongeot and Nestler (n. 739). 
From this, P. placorodia, Ach. Syn. (Cetraria, Tuckerm. 1. ¢.) is not well distin- 
guishable even as a variety ; and is fully united (under his P. placorodia which is 
our Cetr. alcurites) with the form common to America and Europe, by Nylander 
(Seand.). It is yet worthy of mention that this abundantly fertile v. placorodia 
affords better opportunities of observing that the apothecia are commonly attached 
as in Cetraria, than a. With C. aleurites is readily associable C. Fendleri 
(Parmelia, Tuckerm. Platysma, Nyl.) the condition of which growing on dead 
wood, with compacter and more complicated thallus, differs from the arboricoline 
exactly as the corresponding states of C. ciliaris, &c. In the tree-form of C’. Fend- 
leri the spermogones are more strictly marginal, as observed by Nylander, than I 
hare seen them in the other; but their variation in this regard is perhaps no 
greater than we find in some other Cefraria.—Nest to C. Fendleri will follow 
C, Fahlunensis (.) Scher.; which proves to be, in some respects. not ill-compar- 
able even with C. ciliaris. To this last succeeds (’. sepincola (Ebrh.) Ach.—— 
I have never found spermatia in C. Oakesiana, belonging, it should seem, with 
C. sepincola ; nor in C. aurescens, so well comparable with some of the species 
just named, but belonging, it should seem, with C. juniperina. 
P.10. CETRARIA lacunosa. The lichen is said to occur also in the Scottish 
mountains (Leight. Lichen-fl. Gr. Brit. p. 103) and even to have been detected on 
trees (‘in ramis pinuum, Th. Fr. Lieh. Aret. p. 39;—but this is exactly as C, 
ylauca is found) in Norway. <A reticulate-lacunose specimen, evidently from 
rocks, and ticketed by Mr. Borrer, from whom I received it, “ Cetraria, Breadal- 
bane mountains,” is, in fact, though differing possibly in rather wider lobes, per- 
haps better referable to C. glauca than to the other, properly American lichen. I 
incline to a similar view of a rock-specimen from Newfoundland, lacunose, like 
the Scotch one, and similarly black beneath, which Delise (Herb. V. d. Bosch, e 
herb. Spreng.) referred to (’. lacunosa ; and to suspect some of the other localities 
named above. Whatever its rank, as undoubtedly a very near relative of C. glauca, 
the American (. lacunosa, though exceedingly common on trees, and dead wood, 
1y as yet unknown to me as occurring on rocks. 
a 
P. 24, line 24, after oblonga, add rarissime clongata, acicularia. 
P. 35. The note belongs to 8. Ravenelii, on the opposite page. 
P. 52, line 24. Pannaria plonbea was found by me, the past season, in excel- 
Jent condition, but very sparingly, on an old Oak on Newport Mountain, Mt. 
Desert, Maine. 
P. 72, twelfth line from bottom ; read truticulose. 
P. 120, line 13. L. molybdina occurred to me not uncommonly, the last year, 
on maritime rocks of Mt. Desert, Maine. 
P. 129. ConoTREMA. Spermogones superficial, black. Sterigmata simple. 
Spermatia oblong, straight, 0035-004™™- long, and a quarter as wide. (H. Willey 
in litt.) 
P. 138. THELOTREMA subtile. T. bicinctulum, Nyl., to which he referred, as 
a form (Consp. Thelotr.) the earlier 7. subtile, is unknown to me, and appears now 
