Dr. Muller, in Beitrag., n. 1173 , describes Rhizocarfton atrotesta- 
ceum, ( Lecidea , Fr., Syst. p. 286;) sent to the latter by Schweinitz. 
as occurring on non-calcareous rocks in N. America. Dr. Eckfeldt 
informs me that the plant is not to be found in Schweinitz’s herba¬ 
rium in Philadelphia. I subjoin the description, which may enable 
collectors to look for and identity it. Thallus pale copper-colored, a 
little shining, thin, diffract — or here and there dispersed-—areolate, 
bordered by a dark zone; the areoles commonly crowded, convex, 
the apoth. 2-4 times smaller, -i-i mm. in diameter, convex, black 
without and within, naked, plane, or finally a little convex, with a 
thin margin; epithecium and hypothecium thick blackish-brown, the 
lamina hyaline-fuscescent. Spores in 8s, .025-30 by .013-17 mm., 
enveloped in a halo, finally brown, 4-locular, the cells 2-4 times 
divided. 
Tribe III. GRAPHIDACEI, Eschw., Nyl. 
88. AGYRIUM, (Fr.) Nyl. 
1. A. rtlfum, (Pers.) Fr. On dead wood, 1866; on dead stems of 
Osmunda cimramomea : and on living bark of swamp huckleberry, 
1884. On dead branches of red cedar, Cotuitport, Cape Cod, 1S86. 
89 . XYLOGRAPHA, Fr. 
1. X. (llssemiuatil, Willey. On old rails and shingles, and dead 
cypress roots, 1870. On living bark of cypress, 1876. 
2. X. opegraplielLa, Nyl. On rails; common. Bxsic., Lojka, 
n. 142. 
There are two other plants of rare occurrence which seem to belong 
to this Genus, But not having had any opportunity to compare them 
with X. Iciricicola and A', cedrina. Nyl., T feel unable to give a defi¬ 
nite opinion about them. 
40. PL AT YGRAPH A , Nyl. 
1. P. periclea, (Ach.) Nyl. On hemlock spruce, 1S67, and near 
Mvrick’s station on the Old Colony railroad. Very rare. 
41. GRAPHIS, Ach., Nyl. 
1. G. SCripta, (L.) Ach. On trees. Common. 
b. recta , (Humb.) On white birch. 
c. limitata , Ach. 
d. serpentina , (x\ch.) 
c. assimilis, (Ach.) Rare. 
