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group (of Gyrophore, Fée, and later authors) represented by U. vellea. 
The brown, granulose spores of the Swedish U. spodochroa, Hofim., Ny1. 
(U. vellea, Fr. pro p.) in specimens collected by the writer near Gottenburg, 
present at length (‘ quasi obsoletissime loculose,’ Norm. 1. c., and Dr. Ny- 
lander puts it more strongly yet in Lich. Scand. p. 115) an almost muri- 
form configuration, which is also expressed in the spores of U. Dillenii; 
and the probability of error in this conception of the spore (the whole 
history of which it is, in this very abnormal genus, by no means easy to 
trace) seems reduced to a meinimam by another lichen of the same group, 
U. haplocarpa, Nyl. (Lich. erot. in. Ann. 4, 11, p.217. Lich. Boliv. 1. ¢. 4, 
15, p. 877) of Peru, in which (and compare also U. calvescens, Nyl., at the 
last-cited place) the earlier differentiation of the at length quite muriform 
spores is distinctly described. Nor need we go so far for an illustration. 
A Californian lichen (U. Semitensis, Tuckerm. msc.) is before me, scarcely 
distinguishable in general aspect from U. angulata of the present writer, 
and like the latter a member of the same cluster with U. spodochroa, which 
is differenced in the spores precisely as U. haplocarpa; these organs (for- 
tunately occurring in eights in the thekes) offering, in the fullest and most 
instructive manner, every known modification in the history of the muri- 
form spore. There scarcely remains then a satisfactory difference to dis- 
tinguish the Gyrophore from Umbilicaria; and this natural genus may be 
taken as affording pertinent evidence of the truth of the proposition — 
that the highest type of spore-structure exhibited in any natural group is 
not to be expected necessarily to appear in every, or even in most of the 
species subsumed (in the general concurrence of characters) under it; 
these species offering, it may be, only subordinate stages of the typical 
differentiation. 
In contrast with the genus next following (Sticta) the present has a. 
decidedly northern range; and a third at least of its species are among 
the most characteristic inhabitants of alpine and arctic rocks throughout 
the northern hemisphere. Others appear to be excluded from or at least 
less at home in alpine districts; and the noble forms first described from 
North American specimens reach their perfection in the warmer regions 
of the southern Appalachians, and of the Atlantic slope. Of the thirty 
more or less distinct species known, all but two or three European, 
and the South American, and Indian ones, described by Nylander, are 
found within the limits of this work.——JU. phea, Tuckerm. Lich. Calif. 
p. 15, is only known to me from the rocks of the coast of California (alt. 
1—3000 ft.) Mr. Bolander. Spores a micromill._lJU. rugifera, Ny}. 
Scand. p. 117, a new species from ‘ Eastern Siberia,’ is represented, with 
scarcely a doubt, here, by a lichen from the Rocky Mountains (Prof. 
Shepard; Dr. Lapham) and the Yosemite Valley, California (Mr. Bo- 
lander) which agreeing generally in aspect with states of U. proboscidea 
is distinguished by its always regular (not gyrose, or proliferous) fruit, as 
by smaller size, lighter colour of the under side, &c. Spores of our plant 
