(141) 
fore only because no more definite position, whether within, or, what is 
the rather to be anticipated, without the Class, has yet been determined. 
MM. Duriei, Mont. & Berk. in Fl. Alg., the original species (Pyrenees, 
Montagne! Mass. Lich. Ital. n.27! Rabenh. Lich. Hur. n. 635!) has 
been traced already to Algeria, to Australia, and South America (Brazil, 
Pabst! Lindig Herb. N. Gran. n. 2583, 2669, 2789!) and, teaching Cuba 
(Wright !) should be likely to appear also within our southern boundaries. 
And the plant (MW. Curtisii, Mont. & Berk.) which does occur here, and 
extends northward along the coast (Carolina, Curtis, Ravenel; Alabama, 
T. M. Peters; Massachusetts, C. J. Sprague, H. Willey) though certainly 
noticeable, at least in its best conditions, for general luxuriance — the 
larger thallus becoming also effigurate, and the apothecia perhaps more 
perfectly lecanoroid—is by no means satisfactorily distinguished from 
the other. The ‘striate-plicate’ circumference found by Montagne in 
both his species, and re-affirmed by Massalongo of M. Duriei, may in 
fact be considered as implying the at length certainly striking, but incon- 
stant.lobation of the North American Myriangium ; and one of the New 
Granada forms of the older species (Lindig n. 2583) as determined by 
Nylamder, is quite as distinctly effigurate as the Carolina plant.1 The 
apothecia are similar in both, and similarly modified; and the supposed 
diversity in the thekes (Mont. Syll.). is far from characteristical. And 
this last remark applies also to the results obtained by Nylander (Syn.) 
from the specimens before him; neither the thekes of the Carolina plant, 
nor its spores differing, in a wide view, in any important respect, from 
those of M. Duriai. The lobulate margin of the North American 
plant is at length quite free from the substrate, when the under side of 
the fringe is seen to be entirely similar in all respects, whether of con- 
figuration, colour, or smoothness, to the upper; an observation not perhaps 
wholly without bearing on the question of the affinity of Myriangium. 
1 It is, in this connection, observable, that both the species, as defined, are 
now recognized as European plants ;— If Durici, Millard, in Mem. Soc. Sct. Nat. 
Strasb., being referred by Dr. Nylander (Flora, 1869, p. 298) to AL. Curtisii. 
® Very commonly roundish-ovoid, or ‘ ovate-ventricose’ (Mass.) and not much 
exceeding 0,050™™- in their longest diameter, the thekes of Myriangium occur also 
oblong, or ‘ obovate-oblong’; and the latter condition was understood by Mon- 
tagne to be characteristical of his M/Z. Curtisii. But this exceptionally elongated 
state, which I have observed to measure 0,069-92"™- in length by 0,023-35™™- 
in width, is by no means confined to the North American specimens, or even more 
frequent in them. Spores of the Carolina plant averaging 0,025-35™™- in length 
by 0,007-11™™- in width. 
