152 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
and | to 2 mm. long; color varying from ashy to brown, ours frequently light below 
where not darkened by the hypothallus; lower cortex absent or very poorly developed; 
apothecia adnate, the disk reddish brown and frequently convex, the thalloid margin 
crenate, frequently white-powdery and often disappearing, small, scarcely reaching 
1 mm. in diameter in specimens seen: hypothecium pale or slightly brownish; hy- 
menium pale below and brownish toward the top; asci clavate; paraphyses simple 
or rarely branched, commonly enlarged and brownish toward the apex; spores simple, 
hyaline, ellipsoid to ellipsoid-pointed, 16 to 22 long and 8 to 12 » wide. 
Generally distributed along the western international boundary as far east as Hard- 
ing. On cedars in swamps and rarely on rocks. 
Generally distributed throughout North America east. of the Rocky Mountains. 
Found also in Africa. 
EXPLANATION OF PLATE 25.—Plant on white cedar, showing the apothecia and the squamulose thallus. 
Enlarged 1} diameters. 
3. Pannaria microphylla (Sw.) Mass. Ric. Lich: 112. f. 227, 1852. 
Lichen microphyllus Sw. Vet. Akad. Handl. 301. 1791. 
Thallus squamulose, closely adnate or the margins somewhat raised, the squamules 
more or less imbricated, rather thick, expanded or collected into a continuous crust, 
the margins sometimes rather obscurely crenate, smaller than those of the last above; 
sea-green varying to ashy or tawny-brownish, usually dark below, though the hypo- 
thallus is obscure or absent; lower cortex wanting or poorly developed; apothecia 
adnate, the disk pale brown or blackening, frequently convex, the thalloid margin 
crenate and often disappearing so that the apothecia become biatoroid, small, 0.5 
to 1 mm. in diameter; hypothecium pale; hymenium colorless below and brownish 
above; asci clavate; paraphyses simple or rarely branched, commonly enlarged and 
brownish toward the apex; spores hyaline, simple, ellipsoid, 14 to 19 1 long and 5 to 
7 wide. 
Collected in several widely separate localities and doubtless generally distributed 
over the State. On all rocks except lime. 
The plant is widely distributed in North America. Known in all the grand divi- 
sions except Australia. 
4. Pannaria lepidiota (Sommerf.) Th. Fr. Nov. Act. Soc. Sci. Ups. III. 8: 174. 
1861. 
Lecidea carnosa lepidiota Sommert. Suppl. Fl. Lapp. 174. 1826. 
Thallus squamulose, the squamules larger than in the last, somewhat crenately 
lobed, the margins often warty and gray-sorediate, the marginal lobes more expanded 
and elongated and more deeply lobed, those near the center closely imbricated and 
ascendant and often compacted into a granular and often gray-powdery crust, usually 
dark below where not obscured by the thin, black hypothallus; lower cortex very thin 
and sometimes scarcely developed; apothecia adnate, the disk commonly depressed, 
reddish brown or finally blackening, the margin not containing algal cells (in material 
seen), finally disappearing, rather small, 1 to 2 mm. in diameter; hypothecium pale 
to brownish; hymenium pale or pale brownish below and darker above; asci clavate; 
paraphyses commonly simple, the apices enlarged and usually brownish; spores 
simple, hyaline, ellipsoid-pointed, 20 to 28 « long and 9 to 13 « wide. 
The fibrillose ring below the apothecia mentioned for Lake Superior specimens by 
Tuckerman has not been noticed in the material at hand. 
Confined to the northeastern portion of the State. On rocks and wood. 
Widely distributed in the northern United States and British America, but scarcely 
known to the South. Known also in Europe. 
