144 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
above; paraphyses gelatinized and indistinct; asci clavate; spores simple, ellipsoid, 
8 to 11» long’and 5 to 6 » wide, thus somewhat larger than according to Tuckerman’s 
measurements, as are also the apothecia. 
A single collection was made on a bowlder at Mankato in 1899. Forms of Pyren- 
opsis have been noted frequently in various portions of the State, but in the absence 
of fruit it has been impossible, except in this instance and the ones below, to refer 
the specimens to species with any degree of certainty. 
A North American plant, previously only known in the original locality in 
Alabama. 
2. Pyrenopsis phaeococea Tuck. Syn. N. A. Lich. 1: 136. 1882. 
Synalissa phatococea Tuck. Gen. Lich. 80. 1872. 
Thallus of blackish, scarcely coralloid granules, which form an areolate crust; the 
areoles of about the same size as those of the last, rarely reaching 1 mm. in diameter; 
apothecia somewhat larger than in the last, 0.2 to 0.5 mm. in diameter, adnate or im- 
mersed, 1 to 3 in each areole, the disk evident and concave in ours, black with a 
margin of the same color, hypothecium pale brown; hymenium pale below and 
brownish above; paraphyses simple, frequently thickened and brownish toward the 
apex; asci clavate; spores simple or rarely 2-celled, ovoid-ellipsoid, 10 to 20 » long 
and 7 to9 wide. The algal cells are few in each cluster, and in this and other points, 
as the color, the plant seems quite as near the next, though the spores agree better 
here. 
A collection was made at Mankato in 1899 and another at Grand Marais in 1902. 
On bowlders. 
A North American lichen, previously known in North Carolina, Massachusetts, 
and New Hampshire. The other plant which our specimen resembles is also con- 
fined to our grand division, having been collected in Vermont. 
3. Pyrenopsis polycocca (Nyl.) Tuck. Syn. N. A. Lich. 1: 136. 1882. Prare 23, A. 
Synalissa polycocca Nyl. Syn. Lich. 1: 96. 1858. 
Thallus of blackish granules, which pass into a more or less areolate crust, the areoles 
of the same size as those of the last or smaller and for the most part absent when the 
thallus is continuously granulose; apothecia rather numerous, sometimes a dozen or 
more in a single areole and almost completely obscuring the thallus, minute, 0.1 to 
0.3 mm. in diameter, of the same color as the thallus, globose, with a punctiform or 
slightly open and urceolate disk; hypothecium pale or pale brownish; hymenium 
pale below and brownish above; paraphyses more or less coherent and indistinct; asci 
cylindrico-clavate; spores ellipsoid, simple, 12 to 13 » long and 6 to 8 pe wide. 
Collected on rocks along the shore of Lake Superior at Grand Marais. 
A North American plant, previously reported from Vermont. 
EXPLANATION OF PLATE 23.—A, Plant of Pyrenopsis polycocca on rocks, showing the granulate and 
somewhat areolate thallus. B, Plant of Solorina saccata on rocks, showing the foliose thallus and the 
immersed apothecia. A enlarged about 3 diameters; B, about 2} diameters. 
OMPHALARIA Dun. & Gir. in Dur. Fl. Algér. 1: 200. pl. 18.f. 4, 5.1846. 
The thallus is neither strictly fruticose nor yet in most instances foliose. It is com- 
monly small and somewhat raised from the substratum, exhibiting thus at least a 
fruticose tendency, and is attached to the substratum at a single point. There is no 
cellular cortex, but there is an outer gelatinous layer composed of gelatinized hyphe 
and walls of dead algal cells. Within or below this is an algal layer, consisting of the 
algal cells and hyphal branches. The central portions of the thallus, or in the more 
foliose forms the lower part, is frequently differentiated as a more or less distinct 
medullary layer. The algal cells, in all of ours at least, occur in groups, these varying 
considerably in number of cells in each, and each cell of a group having its own 
wall. Yet, in any of the species, the cells may sometimes occur singly, On the 
