232 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
cose or passing into areolar conditions, the verruce or areoles becoming much raised, 
giving the thallus a roughened surface; sea-green, ashy or whitish; apothecia com- 
monly immersed, but becoming adnate, especially when the thallus is thin, small or 
minute, 0.3 to 1 mm. in diameter, the disk urceolate and black or grayish-pruinose, 
the more or less denticulate and dark-colored proper exciple often hidden by the 
Fig. 16.— Urceolaria scruposa. a, Portion of a thallus with several apothecia; b, section of an apothec1um 
showing a proper exciple within athalloid one. a, Enlarged 3 diameters; b, 50 diameters. From Reinke. 
thalloid one, or the latter disappearing more or less and the former becoming promi- 
nent; hypothecium commonly dark brown; hymenium pale or brownish below and 
brownish or brown above; paraphyses simple or rarely branched, sometimes enlarged 
and brownish toward the apex; asci cylindrical or eylindrico-clavate; spores oblong- 
ellipsoid, muriformly many-celled, 20 to 28 » long and 10 to 15 wide, 
Generally distributed over the State. On rocks and rarely on earth and old wood. 
Widely distributed in North America. Known also in all of the grand divisions, 
2. Urceolaria actinostoma (Pers.) Tuck. Gen. Lich. 135. 1872. 
Verrucaria actinostoma Pers.: Ach. Lich. Univ. 288. 1810. 
Thallus at first smoothish but becoming somewhat verrucose-roughened and finally 
plainly areolate, the areoles or verruce smaller and flatter than in the last, of the 
same colors and spread over the substratum in much the same way, though scarcely 
so large or so widely spread; apothecia minute and immersed, the disk dark and 
opening by a pore, or sometimes somewhat open and more properly disk-like, the 
proper exciple dark and radiate-striate above, frequently gray-pruinose, the thalloid 
exciple commonly wanting; hypothecium usually dark brown; hymenium pale or 
brownish below and brownish or brown above; paraphyses simple or rarely branched, 
sometimes enlarged and brownish toward the apex; asci cylindrico-clavate; spores 
somewhat shorter and broader, 18 to 28 » long and 11 to 18 mw wide, 
Collected at Granite Falls. On granite. 
Elsewhere in North America in Connecticut, South Carolina, lowa, and Kansas. 
Known also in South America, Europe, and Asia. 
Family VERRUCARIACEAE. 
Considering apothecial structure of more importance than thallus structure, the 
present family, at least as represented in our flora by the genus Verrucaria, is the 
lowest of the Pyrenocarpineae. This appears both in the short and commonly gela- 
tinized and indistinct or disappearing paraphyses and in the uniformly simple spores, 
However, when we include Thelidium found elsewhere, we find spores that are not 
simple but still colorless. Zahlbruckner would also include Staurothele with its 
