184 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
18a. Lecanora cinerea laevata (Fr.) Tuck. Syn. N. A. Lich. 1: 198. 1882. 
Parmelia cinerea laevata Fr. Lich. Eur. 145. 1831, 
Thallus thinner and smooth but becoming somewhat chinky, never areolate; sur- 
face usually more or less shining; apothecia always immersed, minute and often 
irregular. 
Throughout the northern portion of the State and as far south as Taylors Falls. 
On rocks other than calcareous. 
Reported from North American stations as remote as Labrador, Alabama, and Cali- 
fornia, and no doubt generally distributed, though rare. Known also in Europe and 
Asia. 
18b. Lecanora cinerea gibbosa (Ach.) Tuck. Syn. N. A. Lich. 1: 198. 1882, 
Lichen gibbosus Ach. Lich. Suec. 30. 1798. 
Thallus thick and conspicuously roughened-verrucose or areolate, on the whole 
darker than the last; apothecia becoming superficial and larger; spores also rather 
larger. 
Generally distributed in the State. On the same substrata and more common than 
the last. 
No doubt as widely distributed in North America as the species, though apparently 
not yet noted from the Southern States. Found also in Europe and Asia. 
18c. Lecanora cinerea microspora Fink. 
Thallus roughened and verrucose-areolate, thinner and finer than in the last, 
blackish-olivaceous; apothecia and spores small, the latter in ours 11 to 16 ” long and 
6 to 10 » wide. 
Collected in the Leaf Hills. On granitic bowlders. 
Not known elsewhere in North America. Found in Europe. 
Lecanora gibbosa microspora of the preliminary reports, this unpublished name hav- 
ing been communicated by Dr. A. Zahlbruckner. 
19. Lecanora calearea (L.) Nyl. Not. Sallsk. Faun. Flor. Fenn. 5: 154. 1861. 
Lichen calcareus 1. Sp. Pl. 1140. 1753. 
Thallus crustose, scarcely so much roughened as usual forms of the last, chinky, 
verrucose, or areolate, sea-green, ashy or rarely white and mealy, continuous, irregu- 
lar, and spread over considerable areas, or ours more commonly inconspicuous, scat- 
tered or obscured by the numerous apothecia; apothecia of same size as those of the 
last, commonly immersed but in ours becoming adnate in the usual form with poorly 
developed thallus, the disk urceolate or flat, light brown to blackish and commonly 
white-pruinose, the exciple entire or rugose-plicate and surrounding a thin proper 
exciple; hypothecium pale; hymenium pale below and more or less colored above; 
paraphyses simple or branched, commonly enlarged and brownish toward the apex; 
ascl Clavate or ventricose-clavate; spores 2 to 8 in each ascus, ovoid to ellipsoid, in 
ours 10 to 14 long and 4 to 6 » wide and 8 in each ascus (said to be 16 to 30 1 long 
and 12 to 20 » wide). 
The plants referred here for Minnesota and Iowa may all be regarded as doubtful, 
the spores being small and the thallus poorly developed. Some of the forms from 
the calcareous rocks are the same as were referred here by Tuckerman. Others are 
too near the last above, and the one reported from Mankato is much like some forms 
referred to Lecanora dispersa. 
Reported from various portions of the State, but the more probable forms are from 
regions where calcareous rocks occur. On rocks. 
Throughout the northern United States and northward into British America. 
Known also in Europe and Africa, 
