158 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
The relationship of the present family with the last was stated under that family. 
The spore characters and the algal symbionts are indicated in the Outline of Classi- 
fication and under the several genera. 
With the Peltigeraceae we reach the climax in a line of development in lichens, 
conducted hither through several closely related families. Accordingly the pres- 
ent family does not show close relationship with any of the families to follow. 
SOLORINA Ach. Lich. Univ. 27, 149. pl. 1. /. 5, 6. 1810. 
The thallus is foliose, rather indistinctly lobed, prostrate but rather loosely attached 
to the substratum. Its structure resembles that of Peltigera in the absence or very 
rudimentary development of the lower cortex. The upper cortex is present, and is 
frequently thick in some areas and thin in others. Two kinds of algee occur in the 
same plant, supposed to be a Dactylococcus and a Polycoccus. The former predomi- 
nates and commonly lies for most part above the other, extending nearly to the upper 
surface below the thin places in the upper cortex. The medullary layer is well de- 
veloped and extends below into a thicker layer of hyphe, lying for the most part 
in a horizontal position. Bundles of hyphz form ridges or veins on the lower surface 
similar to the veins of Peltigera. Rhizoids are more or less common, extending 
downward from the lower surface. 
The apothecia as a whole resemble those of Peltigera, though they are scattered 
over the upper surface and are even more common near the center instead of being 
marginal. They are commonly impressed, though they may be more or less raised. 
The thalloid margin is usually wanting, but may be made out occasionally, especially 
when the apothecia are somewhat raised. The hypothecium and the hymenium are 
pale or else light or darker brownish. The paraphyses are commonly simple and 
the spores are 2-celled and brown. 
The close relationship of the genus to Peltigera as regards structure of thallus and 
apothecia has already been noted. The spore characters of the two genera, however, 
are so different that the relationship can not be as close as would be supposed from a 
consideration of the thallus and apothecia alone. 
A single species occurs along the shores of Lake Superior. On earth or mossy rocks. 
Type species Solorina crocea (L.) Ach. loc. cit. 
Solorina saccata (L.) Ach. Lich. Univ. 149. pl. 1. /. 6. 1810. PLATE 23, B. 
Lichen saccatus L. Sp. Pl. ed. 3. 1616. 1764. 
Thallus foliose, rather loosely attached to the substratum, smoothish above, more or 
less orbicular, small or middle-sized, 20 to 75 mm. in diameter, the lobes rather short, 
wide and rounded, the ends subentire or more or less irregularly incised, sea-green 
varying toward ashy or brownish, below lighter in color, but sometimes darkening, 
cottony and obscurely veined and rhizoid-bearing, the upper cortex quite uniform 
in thickness; apothecia commonly sunken into the thallus, the disk more or less con- 
cave, dark brown, the thalloid margin seldom distinguishable, middle-sized, 2 to 6 
mm. in diameter; hypothecium light brown; hymenium pale below and pale brownish 
above; paraphyses commonly simple, frequently enlarged and brownish toward the 
apex; asci cylindrical; spores ellipsoid, 40 to 60 » long and 16 to 22 » wide. 
The plant is rare in Minnesota. It has been collected on mossy rocks at Grand 
Portage and near Pork Bay, thus apparently confined to the shore of Lake Superior. 
Seattered across the northern United States from the Rocky Mountains to the 
Atlantic Ocean, but confined for the most part to mountains or cold shores. More 
generally distributed throughout British America. Also known in Europe and Asia, 
EXPLANATION OF PLATE 23.—See page 144, 
