188 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 
Apothecia 1 to 5 in each verruca. 
Spores 4 to 8 in each ascus.....------+eeeeee ee eee eee 6. P. leioplaca. 
Spores | or 2 in each ascus. 
Thallus sea-green to ashy, yellowish or brownish; 
apothecia-containing verrucse somewhat raised.. 4. P. pustulata, 
Thallus whitish; apothecia-containing verrucze 
flattish....... cece cece cece eee eee eee eeeeeeeee 5. P. finkii. 
1. Pertusaria velata (Turn.) Nyl. Not. Sallsk. Faun. Flor. Fenn. 5: 179. 1861. 
Parmelia velata Turn. Trans. Linn. Soc. Lond. 9: 143. pl. 12. f. 1. 1808. 
Puate 34, B. 
Thallus rather thin and smooth or becoming thicker and plicate-rugose, chinky or 
somewhat irregularly roughened or verrucose, sea-green to milky-white, suborbi- 
cular, 3.5 to 10 cm. in longest dimension, the circumference commonly lighter- 
colored and frequently zonate, the upper pseudocortex of interwoven hyphe and 
becoming a structureless mass; apothecia immersed 2 or 3 in a small to almost middle- 
sized verruca, this 0.4 to 1.2 mm. in diameter, depressed and disk-shaped, the disk 
concave and usually lighter than the thallus, and sometimes densely white-sorediate; 
hypothecium commonly pale; hymenium pale below and commonly brownish above; 
paraphyses quite commonly branched, not often enlarged or darker toward the apex; 
asci cylindrical or cylindrico-clavate; spores oblong-ellipsoid, 150 to 250 long and 
40 to 80 » wide, one in each ascus, or, according to Tuckerman, rarely two. 
Found throughout the State. On trees and rarely on rocks. 
Throughout eastern North America and westward to the Rocky mountains. Also 
in Alaska. Known in all of the grand divisions. 
EXPLANATION of Plate 34.—See page 180. 
2. Pertusaria multipuncta (Turn.) Nyl. Not. Sallsk. Faun. Flor. Fenn, 5: 179. 1861. 
Variolaria multipuncta Turn. Trans, Linn. Soc. Lond. 9 : 137. pl. 10, f. 1, 1808. 
Thallus much as in the last, but on the whole inclined to be thinner and smoother, 
sea-ereen to pale ashy, more inclined to irregularity in form and either not lighter 
and zonate toward the circumference or indistinctly so, cortex as in the last or even 
less developed; apothecia-containing verruces also much as in the last, but not so 
uniformly depressed and disk-like, frequently becoming irregular and blackened, or 
passing into powdery-sorediate heaps, numbering 2 to 4 in each verruca; hypothe- 
cium, hymenium, and paraphyses as in the last; asci more inclined to be clavate or 
ventricose; spores distinctly smaller, 75 to 150 » long and 25 to 65 wide, one in each 
ascus, or rarely two. 
Throughout the northern portion of the State. On trees. 
Distributed throughout North America. Found also in all the grand divisions 
except Africa, 
2a. Pertusaria multipuncta ophthalmiza Nyl. Not. Sillsk. Faun. Flor. Penn. 
5:180. 1861. 
Thallus thin and smooth; apothecia-bearing verruce uniformly disk-like and black- 
ening above, usually scattered and each containing a single apothecium. 
Distribution in the State as that of the species. On trees and old wood. 
Elsewhere in North America in Newfoundland or Labrador. Known also in Europe. 
Pertusaria ophthalmiza and P. multipuncta laevigata of the preliminary reports. 
3. Pertusaria communis Lam. & DC. FI. Fr. ed. 3. 22320. 1805. 
Ficure 15. 
Thallus thin and smoothish or soon becoming rougher and chinky and finally 
stongly rugose-verrucose and subareolate, sea-green or lighter-colored and rarely 
somewhat zonate at the circumference, commonly irregular and often widely spread 
over the substratum, the layers distinct, but the upper cortex commonly a structure- 
less gelatinized mass; apothecia-containing verruce 0.5 to 2 mm. in diameter, de- 
