FINK—-THE LICHENS OF MINNESOTA. 171 
areoles or squamules flat or rarely more or less convex and of moderate size, 0.3 to 2 
mm. across, lemon-yellow, the upper cortex present, distinctly cellular, as is the 
whole thallus, the squamules sometimes scattered; apothecia small or minute, 0.2 to 
0.5 » in diameter (said to be sometimes larger), immersed, the disk flat or some- 
what concave, frequently somewhat irregular and reddish brown or rarely blackish, 
the thalloid exciple usually evident and entire; hypothecium pale; hymenium of 
same color, or darker above; paraphyses simple or rarely branched, frequently some- 
what enlarged and brownish toward the apex; asci clavate, cylindrico-clavate, or 
somewhat irregular; spores ovoid, 3 to 3.5 ” long and 1.5 to 2 ” wide. 
The plant has been collected in such widely separate portions of the State as 
Minneapolis, Battle Lake, and several localities in the southwestern part. On 
rocks other than calcareous 
Generally distributed over the United States and northward into British America. 
Known also in South America and Africa. 
Lecanora xanthophana of the preliminary reports. 
2. Acarospora cervina (Wahl.) Koerb. Syst. Lich. 154. 1855. 
Lichen cervinus Wahl. Fl. Lapp. 421. 1812. 
Thallus composed of subpeltate or crenate-lobate squamules, which are closely 
adnate and may be scattered or more commonly compacted into an areolate crust, 
the areoles or squamules rather smaller than those of the last, commonly flat and rarely 
imbricate, yellowish brown (cervine) to dark chestnut; microscopic structure as in the 
last; apothecia much as in the last, but rather larger and sometimes becoming adnate, 
the thalloid exciple perhaps disappearing more often; hypothecium pale; hymenium 
of same colors or brownish above; paraphyses slender, simple or rarely branched, 
usually slightly enlarged and brownish toward the apex; asci ventricose or cylin- 
drico-clavate; spores oblong to subspherical, 3 to 5 » long and 1 to 2 » wide in the ob- 
long forms. 
Generally distributed over the State. On rocks other than calcareous. 
Throughout North America, except the Southern States and southward. Found 
also in Europe and Africa. 
Lecanora cervina (Pers.) Nyl. of the preliminary reports. 
2a. Acarospora cervina cinereoalba Fink, Minn. Bot. Stud. 2: 319. 1899. 
Thallus ashy or ashy-white. Otherwise as the species. 
Collected at Mankato and at Granite Falls. On granite with the usual form of the 
species. 
A North American form not known elsewhere. 
Lecanora cervina cinereoalba of the preliminary reports. 
2b. Acarospora cervina fuscata (Schrad.) Fink. 
Lichen fuscatus Schrad. Spic. Fl. Germ. 83. 1794. 
Thallus inclined to more squamulose and lobed conditions, the squamules rather 
larger and often scattered; apothecia rather smaller and sometimes punctiform; spores 
said to be larger (Nylander). 
Usually regarded as a distinct species. 
No doubt generally distributed over the State, but very difficult to distinguish. 
On rocks. 
North American distribution much as that of the species. Known also in South 
America, Europe, and Africa. 
Lecanora fuscata and subspecies rufescens of the preliminary reports. 
LECANORA Ach. Lich. Univ. 77, 344, pl. 7. f. 3-7. 1810. 
The thallus varies from foliose or subfoliose to strictly crustose forms, the latter 
being the more common and representative thalli of the genus. In the best de- 
veloped thalli the whole structure is nearly or quite as closely adnate as in the more 
