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family before us betrays affinity. It is yet nearer, whether we consider 
external habit or important structural details, to Sticta. Umbilicaria 
Jlocculosa, Hoffm., reminds us at once of Sticta fuliginosa; and many 
other forms of the latter genus, as, for instance, dark conditions of 
S. quercizans v. macrophylla, T. herb. (8. macrophylla, Delis.!) S. to- 
mentella, Nyl. (Lindig. Herb. N. Gran. n. 707) S. hirsuta, Mont., and 
others of the same group, as wellas 8. orygmea, night be cited in the same 
connection with Umbilicaria: which is also comparable with the tropical 
genus, aS Fries has noted, in the apothecia. The latter resemblance is 
observable in both species of Omphalodium: and no less in the curious 
form of Umbilicaria pustulata from the Cape of Good Hope, already 
above cited, the thalline exciple of which being quite commonly undis- 
tinguishable in colour from the pale-brownish thallus, is, so far, unmis- 
takedly Parmeliaceous ; in U. Pennsylvanica, &c. 
The now generally received distinction of Umbilicaria and Gyrophora 
goes back to an early date. But Acharius soon gave up his attempt to 
separate generically, by the external fruit-characters, U. pustulata and 
Pennsylvanica (Lecidee, Ach. Meth.) from the other species; and neither 
Wablenberg, Turner and Borrer, Eschweiler, or Fries recognized more 
than one genus. The species named, however, and especially the first of 
them, offer certain differences in the characterization of the thallus; and, 
supported by these, Fée set up once more the old distinction in the apo- 
thecia, and sought later (Suppl. 1837) to confirm it by his interpretation 
of the spores. Flotow next, and much more satisfactorily, defined the 
latter organs; and his improved statement of Fée’s arrangement — sepa- 
rating from Umbilicaria the species with sub-simple spores, and retaining 
for the latter the name Gyrophora,—has been accepted by almost all 
later writers, and has found favour, on anatomical grounds, with Schwen- 
dener. We need not indeed delay long over the question whether the 
thallus of Gyrophora be structurally distinguishable from that of Umbil- 
icaria, for the insufficiency of the argument, illustrated most instructively 
by the same author’s exposition of the contradictions of Sticta (1. ¢. p. 
166) is, in fact, admitted (p. 179) by himself. But it is not so easy to 
dispose of the spore-differences. There is no question that the group of 
alpine lichens represented by U. proboscidea and U. hyperborea, to which, 
as a low-country form, our U. Muhlenbergii (with its originally sub- 
lirelliform, at length strangely aberrant fruit) is to be referred, appears, 
at first sight, sufficiently distinguishable from U. pustwlata and its allies, 
by the alleged microscopical characters. It is yet none the less true that, 
taken together, the spores of the former group are not typically colour- 
less; but that on the contrary, and as explained by the microscopical 
character of its best-developed species (U. vellea, &c.) Gyrophora, Fée, 
must be considered as referable to the coloured series, of which series 
the spores of U. pustulata, &c. (Umbilicaria, Fée) express the perfect 
type. And this type is reached indeed, beyond any question, in the 
