FINK—THE LICHENS OF MINNESOTA. 81 
Collected at Gunflint, along Snowbank Lake and in the Misquah Hills. On old 
wood. 
Found in New England, Iowa, Colorado, and Alaska. Known also in Europe. 
EXPLANATION OF PLATE 4.—See page 67. 
MEGALOSPORA Meyer, Nov. Act. Acad. Caes. Leop. Car. Suppl. 191: 228. 1843. 
The thallus is crustose and variously roughened and verrucose. There is no dis- 
tinct cortical layer, nor were the algal and medullary layers very distinctly differenti- 
ated in most of the material examined. The alge are modified forms of Cystococcus, 
the cells varying considerably in size and form. Hyphal rhizoids serve for attaching 
organs, but are neither numerous nor conspicuous in the sections. The thallus is 
further described under our single species of the genus. 
The apothecia are middle-sized or large, and are adnate. The exciple is proper and 
is evanescent, the disk commonly more or less convex. The hymenium and the 
hypothecium are sufficiently characterized in the description of the species. The 
spores are simple, hyaline, very large, one in each ascus, 
Tuckerman included our single species in the genus Heterothecium, which includes 
also species having compound spores and others having compound-muriform and 
brown spores. That such a genus should not stand is certain enough. The present 
genus is closely related to Lecidea, from which it differs in the large and solitary 
spores and also in the commonly present red coloration of the hypothecium or adjoin- 
ing portions of the apothecium. Perhaps the 2-celled members of the genus. Hetero- 
thecium of Tuckerman’s Synopsis are as closely related to the present genus as are the 
Lecideas. 
The single American species and a subspecies occur in the northern portion of the 
State. On trees and dead wood. 
Type species Megalospora sulphurata Meyer, loc. cit. 
1. Megalospora sanguinaria (L.) Koerb. Syst. Lich. 257. 1855. PLATE 7. 
Lichen sanguinarius L. Sp. Pl. 1140. 1753. 
Thallus crustose, consisting of granules, these commonly becoming flattened 
and running together into a verrucose and more or less chinky and polished crust, 
sea-green, varying toward ashy, commonly widely and irregularly spread over the 
substratum as a continuous crust of moderate thickness; apothecia middle-sized or 
larger, | to 3 mm. in diameter, adnate, sometimes clustered and becoming irregular, 
the disk black and more or less shining, commonly convex, the exciple pale or rarely 
darkening or reddish, soon disappearing and seldom seen except in very young 
apothecia; hypothecium pale above and reddish below and resting upon a blood-red 
layer (hypothecium said to be sometimes black, while some authors consider the 
whole structure pale and the red layer wholly subhypothecial and others yet speak 
of the hypothecium as red); hymenium pale or reddish brown below and only 
slightly darker above; paraphyses simple or rarely branched, somewhat thickened 
and darker toward the apex; asci clavate or more or less irregular; spores oblong- 
ellipsoid, hyaline or pale, 56 to 90 » long and 22 to 46 » wide. 
Thus far collected only in the northeastern portion of the State. On trees and old 
wood and rarely on rocks. 
Elsewhere in North America, in New England, New York, California, and Oregon, 
and widely distributed in British America. Known also in Europe and Asia. 
Heterothecium sanguinarium of the preliminary reports. 
EXPLANATION OF PLATE 7.—Plants on wood, showing the crustose thallus and the apothecia. 
Enlarged to about 1} diameters. , 
la. Megalospora sanguinaria affinis (Schaer.) Fink. 
Lecidea affinis Schaer. Enum. Lich. Eur. 132. 1850. 
Apothecia without the red coloration below the hymenium and in the exciple; 
whole plant smaller in ours. 
