60 CONTRIBUTIONS FROM TILE NATIONAL HERBARIUM. 
Melaspilea arthonioides (Fée) Nyl. Act. Soc. Linn. Bord, 21: 416, 1856. 
Lecidea arthonioides Fée, Essai Crypt. 107. 1824. 
Thallus as above; apothecia circular in outline or rarely somewhat oblong, scarcely 
reaching middle size, 0.4 to 1 mm. in diameter, adnate or at first more or less im- 
mersed, the disk black, plane or convex, the exciple black and prominent or rarely 
disappearing; hypothecium dark brown; hymenium pale below and brownish above; 
paraphyses simple or rarely branched, commonly enlarged and colored toward the 
apex; asci clavate; spores hyaline in ours at least, constricted at the septum so that 
each of the two cells frequently is spheroidal in form, 12 to 17 » long and 6 to 8.5» wide. 
Generally distributed in the State, but easily overlooked. On trees. 
Elsewhere in North America in New England, Iowa, and Nebraska, the specimen 
from the latter State, determined by me for J. M. Bates, collected in 1898. Known also 
in Europe, Africa, and South America. 
LECANACTIS Eschw. Syst. Lich. 14. 25. f. 7. 1824. 
FIGURE 8. 
The thallus is crustose, consisting of a continuous or scattered crust, sometimes 
chinky or verrucose, but scarcely reaching plainly areolate conditions, sometimes 
scurfy or mealy, without cellular cor- 
tex or medullary or algal layers. The 
algal symbiont is plainly Chroolepus, 
showing the cells linked together in 
the usual form, but the alge are pe- 
culiar in that they often show a red- 
dish yellow color. The above char- 
acters of the thallus, especially the 
nature of the algal symbiont, are 
quite like those of the present sub- 
order, but the apothecial characters 
_are, in some of the species, more like 
those of the Lecideaceae. 
The apothecia are commonly 
rounded, but sometimes oblong, and 
have a black proper exciple. The 
» &.— hee tis biet? . ba secti . 
Fig. 8 Lecanac is abietina. a, Plant; b, section of the spores are 4 to several-celled, finger- 
thallus, showing the heavy, dark proper exciple and 1 fusi . Th 
the hymenium within. Enlarged 40 diameters. shaped or fusiform, hyaline. e€ 
From Reinke. lecideoid nature of the apothecia has 
led some lichenists to place the 
plants, or part of them, with the Lecideaceaé, and surely there is ground for this view. 
The present genus is, then, a transitional form, showing close relationship with two 
suborders of lichens, the rounded apothecia of some species being much like those 
of Lecidea, but the spores being more like those of the present suborder. However, 
the species having oblong apothecia are in this respect quite as near certain forms of 
Opegrapha. 
A single species is known in Minnesota. 
ta) 
Type species Lecanactis lobata Eschw. loc. cit. 
1. Lecanactis premnea (Ach.) Tuck. Proc. Amer. Acad. 12: 284. 1866. 
Lecidea premnea Ach, Lich. Univ. 173. 1810. 
Thallus a thin, continuous, smoothish or variously roughened, granulate or chinky 
crust, widely and irregularly spread over the substratum, greenish, sea-green, or ashy 
in color, sometimes surrounded by a blackening hypothallus; apothecia middle- 
sized, 0.75 to 1.5 mm. in diameter, rounded or becoming flexuous, sessile, the disk 
usually flat, black and commonly greenish-pruinose, the prominent exciple black and 
persistent; hypothecium dark brown; hymenium pale or brownish; paraphyses 
