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passes into the elegantly lecanoroid v. millegrana (Lich. Cub. n. 219).—— 
In the last-named form (v. millegrana) the margin is now white-pruinose, 
when it is not always easy to distinguish it from a similar European state 
of a (v. porriginosa, Ach.; Herb. Borr.; Rabenh. Lich. Eur. n. 581) not 
unknown here; but in a very frequent North American condition, the 
margin of which is undistinguishable in colour from the soon dark disk, 
the whole apothecium is often suffused with white (Biat. suffusa, Fr.; 
Tuck. ers. n. 135) indicating the v. suffusa. This occurs on trunks 
throughout the northern States, and southward to South Carolina (Mr. 
Ravenel) and has also been found on schist in Vermont (Mr. Frost). — 
But the Lecidea spadicea of Acharius, is defined by him as finally black- 
ening, and this varjation becomes remarkably conspicuous in another 
North American lichen, which may be said to touch, on the one hand, the 
last, and, on the other, the immediately succeeding variety. This (Biat. 
Schweinitzii, Fr. herb. Tuck. exs. n. 136) with a thallus commonly granu- 
lose, but occurring also mvre compacted, offers apothecia passing at 
length, from paler and biatorine conditions, into entirely black ones, the 
opake disk and shining margin of which exceedingly resemble Lecidea 
premnea, Fr. Lich. Suec. n. 26 (being the plant so-called in the writer’s 
Syn. N. E. p. 67) and may be designated v. Schweinitzii. Very near to 
the last, but distinguishable by its smaller size and shorter spores, is the 
v. incompta, Nyl. (Prodr.p.115. Lecidea incompta, Borr.! Scher. Lich. 
Helv. n. 212) a trunk-lichen, occurring, sufficiently well-marked, in New 
England, in New York (Dr. E. C. Howe) and in Texas (Mr. Wright). 
But this bark-form is not easily to be separated, at least here, from a 
more common terricoline state (f. mzscorum, Nyl. Herb.Th. Fr. Rabenh. 
Lich. Eur. n. 514) with longer spores, which is frequent in New England, 
and extends westward to Minnesota (Afr. Lapham) and northward to 
Behring’s Straits (Mr. Wright). I possess at least a New England, terric- 
oline lichen which scarcely-differs appreciably from the cited European 
specimens (or from Rabenh. Lich. Eur. n. 496) of the v. incompta, except- 
ing only that the now short spores become finally rather elongated; thus 
agreeing generally with those of the three next preceding states, which 
are, in like manner, sufficiently congruous with those of a, and of Stenh. 
Lich. Suec. n. 53. These conditions of B. rubella (as bere understood) 
are members of what appears a single series of mutually related forms. 
It remains to notice some small varieties, sometimes less easily referable 
to the type. Among those known to Europe, v. fusco-rubella, Nyl. (Lecid. 
laurocerasi, Delis.! in Herb. Dubis.) approaches however (as compare 
Nyl. in Prod. N. Gran. p. 64, not.) too closely to the American v. spadi- 
cea, to be readily distinguishable; and either of these names might per- 
haps be adopted for the American lichen.—Very close to the last is the 
v. atro-grisea (Biat. atro-grisea, Delis. Lecid. luteola v. endoleuca, Nyl.) 
combining a pale hypothecium with externally blackened apothecia, — 
which I cannot but recognize in a Californian lichen (Mr. Botander).— 
