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64 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
urceolate, and the disk tends toward closed conditions like those encountered in the 
perithecia of Verrucaria and allied genera. The presence of Cystococcus instead of 
Chroolepus looks toward the present family, to which the present genus is doubtless 
more closely related. The spores are, however, quite different. ; 
The single species has been met once in the State. On trees. 
Type species Conotrema urceolatum (Ach.) Tuck. loc. cit. 
EXPLANATION OF PLATE 3.—Fig. 1, a, an apothecium; 0, thallus, natural size. Fig. 2, an apothecium 
and a portion of the thallus. Fig. 3, section of an apothecium; a, the hymenium; 5b, the hypothecium. 
Fig. 4, a section of the thallus; @, the pseudocortex of entangled hyphae; 4, the layer of algal cells and fungal 
hyphe below. Fig. 5, paraphyses and an ascus. Fig. 6, free compound spores; a, the exosporium; b, the 
cell lumina. Fig. 1, natural size; fig. 2, enlarged about 20 diameters; figs. 3, 4, enlarged about 400 diame- 
ters; figs. 5,6, enlarged 650 diameters. From Schneider. 
Conotrema urceolatum (Ach.) Tuck. Syn. Lich. N. E. 86. 1848. Pate 3. 
Lecidea urceolata Ach. Syn. Meth. Lich. 27. 1814. 
Thallus crustose, thin, and smooth, or becoming somewhat chinky, scurfy, or 
more or less distinctly areolate, ashy-whitish, sometimes partly disappearing, a layer 
of mostly horizontally interwoven hyphz forming somewhat of a protective pseudo- 
cortex, somewhat orbicular and 15 to 65 mm. across, or irregular'and more widely 
spread over the substratum; apothecia small or subminute, 0.4 to 0.75 mm. in diam- 
eter, partly hypophloeodal, but extending above the thin thallus and usually appear- 
ing externally to be adnate or sessile, deeply urceolate and commonly more or less 
white-pruinose within, the exciple proper, blackish, at first surrounded by a thin thal- 
loid one; hypothecium and hymenium pale, or the latter sometimes darker above; 
paraphyses more or less branched toward the apex, there also slightly thickened 
and darker; asci cylindrical; spores cylindrical, 100 to 160 » long and 3 to 4.5 fe wide, 
30 to 40-celled. 
Collected at Hibbing in the northern part of the State, by-Anna M. Kimball. On 
trees. , 
Throughout the eastern half of North America, in mountains toward the south. 
Known also in South America and Europe. 
Family LECIDEACEAE. 
Unlike the last two families, the present is one of the largest in our Minnesota 
lichen flora, including many species and some of our best-known lichens. Notwith- 
standing the large number of genera included, there is considerable similarity in 
apothecial structure throughout. Indeed, taking only this apothecial structure into 
account, the genera of the family would seem to be closely related, exhibiting various 
conditions in the evolution of a strong and persistent proper exciple. Doubtless 
some members of the Patellariaceae are the fungal ancestors of all the members of 
the present lichen family, but when we consider the great range of difference in the 
spore characters in the Lecideaceae, including, indeed, the extremes in spore evo- 
lution, viz, the simple hyaline spore and the brown muriform spore, we can only 
suppose that the various genera must have arisen from quite different fungal ancestors. 
The thallus is crustose in the family as limited in this volume, and varies from 
inconspicuous and evanescent leprose or granular conditions to verrucose, areolate, 
or even subsquamulose states. The apothecia are commonly rounded, and are 80 
much alike in the different genera that one often can not be certain even of the genus 
in the field. However, the darker apothecia, as a rule, belong to the genera having 
the stronger exciples. Some suggestion of a thalloid exciple may be made out, out- 
side the proper one, in a few species. The algal symbiont is Cystococcus, except 
perhaps in some Biatorinas. 
The family is closely related to the Baeomycetaceae, differing mainly in the 
absence of a stipe, and also certain transitional forms with some showing of thalloid 
exciple seem to look toward the Lecanoraceae. Finally, the genera having brown 
