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APPENDIX. 
AGYRIUM, (Fr.) Nyl. 
Nyl. Prodr. Lich. Gall. p. 148; Lich. Scand. p. 250. Coem. Notice sur 
quelques Crypt.p.19. Th. Fr. Lich. Arct. p.242; Gen. p.100. Stizenb. 
Beitr. 1.c. p.152. Anz. Symb. p.20. Stictis, dein Tremellx sp., Pers. 
Obs. Myc.; Syn. Agyrii sp., Fr. Syst. Myc. 2, p. 231. 
Apothecia rotundata l. oblonga, homogenea, ceracea, immarginata. 
Sporee (in thecis clavatis) ellipsoidew, simplices, sub-incolores. Sper 
matia haud cognita. Thallus ‘parum vel vix visibilis.’ 
A Fungus, according to Persoon, and Fries, but referred to Lichens by 
Nylander, who associates it with Xylographa, in his tribe Xylographidei, 
placed next before Graphidei. Dr. Th. Fries has accepted this construc- 
tion of the plant, but reduces Xylographidei to a sub-family (that is, 
family, in our arrangement) of Graphidei. Dr. Stizenberger equally 
accepts the assumed lichenose character of both types, but puts Xylographa 
in Opegraphei, and Agyrium, Nyl., in Arthoniei. A significant approach 
to the latter view may be found in the Prodromus of Nylander, where the 
rock-Opegraphe with simple spores (Lithographa, Nyl.) make one of the 
members of his Xylographidet. 
If we admit Xylographa as a Graphidaceous type, explained’ and 
primarily represented by X. opegraphella, Nyl., there seems to be no 
reason for excluding it from its natural association with the Opegraphei. 
With regard however to Agyriwm, Nyl., sufficient grounds for disposing 
it with, or even near either of the other groups named, scarcely appear. 
It is associable even with Arthonia by little more than superficial habit. 
And the evidence of lichenose affinity is confined to the (only occasional ?) 
presence of gonidia in the now, but not always, whitened patches of woody 
fibre upon which the apothecia grow; and the, in itself alone scarcely 
conclusive, reaction of the latter with iodine. These apothecia are finally 
immarginate, and are deprived in fact, according to Mr. Coemans, of any 
true exciple. He yet remarks ‘autour des jewnes apothéces. . . un 
mince anneau, forme de cellules brundtres, vestige dun conceptacle partiel 
et fugace, which, if it be what I think I observe in some of the specimens 
before me (Moug. & Nestl. n. 1096. Anz. Lich. Lang. n. 466) deserves 
perhaps further consideration; and suggests rather a biatoroid fruit, than 
an Arthoniine. 
A. rufum (Pers.) Fr., is the only species of Agyriwm, as here under- 
stood, and is a native of the middle and north of Europe. Specimens 
from dead wood at New Bedford, collected by Mr. Willey, who alone, of 
American botanists, has observed the plant, agree with the European 
(Nyl.in Fellm. Lich. Arct. n. 206) and behave similarly (the hymenium 
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