
OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 187 
Species 8. JU. erosa, Hoffm., 
Which occurs in Europe and America. This appears to me a particularly bad 
“species, inasmuch as all the Umbilicarias are liable to erosion of the margins of 
the thallus, though this is greatest in the preceding species, to which U. erosa 
ought chiefly to pertain asavariety. Next to U. hyperborea, erosion of the thallus 
is common in U. proboscidea and U. cylindrica. Though spermogones are usually 
abundant in U. erosa, they are not easily seen, from being of the same colour as 
the thallus, or from their minute size. They are papillzeform or punctiform; im- 
mersed; with a diameter of +,th to jth. The cavity is simple; the envelope 
black, and moderately thick; and the internal tissue ash-gray. 
Specimen 1.—Ben Macdhui, Braemar, August 1856, W. L. L. Spermogones are 
abundant and distinct as black cones or papillee, scattered about the margins of the 
pitchy or bronze-coloured thallus. They are intermediate in size, between those 
of U. cylindrica and U. polyphylla ; the spermogones of the latter species being 
the smallest I have met with in Umbilicaria. The ostiole is generally distinct, 
round, chink-like, triangular or stellate-fissured, according to age; in the older 
spermogones it is large and patent. The spermatia are rod-shaped, and about 
auth long. Another specimen from the same locality has more the character of 
U. cylindrica ; but the margin of the thallus is decidedly and distinctly erose. 
The spermogones are mostly old; the ostiole is large and saucer-like, surrounded 
by a turgid black border. The thallus seems roughened over with a multitude 
of little saucers, which are most profusely scattered about the edge of the lobes. 
Specimen 2.—Ben Nevis, August 1856, W. L. L. Old spermogones are here 
also abundant, especially about the periphery of the thallus. They have large 
saucer-like ostioles. 
Specimen 3.—Hills east of Sligachan, Isle of Skye, August 1856, W. L. L.; 
apothecia abundant. ‘This appears to be a mere form or state of U. hyperborea. 
The spermogones are large black warts or papillee, scattered over the bronze- 
coloured thallus. The spermatia are about sath long; the sterigmata irregular, 
thickish, composed of short roundish cells or articulations. 
Specimen 4.—Highlands of Scotland, 1778; collected by Atex. Menzies; in 
Herb. Menzies, Royal Botanic Garden, Edinburgh. This plant, too, has quite the 
aspect of U. hyperborea, except as to the erose or cribriform thallus. It is beau- 
tifully studded over with spermogones. 
Specimen 5.—Mangerton, County Kerry, Ireland; coll. Isaac Carrot. Thal- 
Ius much deformed. The spermogones are minute black papille; of the 
old ones nothing remains but the irregular gaping ostiole. The cavity seems 
frequently multiple, apparently from coalescence of several spermogones Asso- 
_ ciated with the ordinary spermatiferous sterigmata are numerous long, hyper- 
trophied, sterile filaments, somewhat as in Ramalina, but neither so long nor so 
