from shortly-ovid-ellipsoid at length ellipsoid; from simple becoming soon regularly dyblastich (the at first approximate sporoblasts at length more distant, as the spore becomes longer and narrower; and often, finally, irregularly broken) the length from once and a half to thrice exceeding the diameter. Determined mainly by a comparison with the full character of Biatorina proteiformis, Koerb. l.c., a, I have no authentic specimens of the European lichen, which has not before been detected here. The specimens in hand resemble those, with black fruit, of Lecanora atroscarpa, as it occurs, at the same locality, on dead branches of Sarcobalus; accompanied, as is the present lichen, by L. subfusca v. crenulata (L. Hageni, Auct.) but the lecideine char- acter of the present appears to me to be more evident, and the spores (which in the lichen before us, are those of Biatorina, Massal.) sufficiently distinguish the plants. L. epigaea (Pers.) Schær. Spicil. p. 118; & Lich. Helv. n. 299, 300. Fr. Lichenogr. p. 290. Nyl. Prodr. Gall. p. 119. Lichen, Pers. in Ust. Ann. Bot. Psora, Hoffm. D. Fl. 2, p. 164. Diploicia, Massal. Ric. p. 8, t. 179. Koerb. Syst. p. 175; Paserg. p. 117. On the earth, in calcareous soil, Bad lands of Judith, Nebraska; and in sim- ilar situations on the North Platte, Hayden. Thallus crustaceous; effig- urate; softish; of rather convex, white, often mealy lobules, which grow together at the centre, and are elongated, and, rather loosely, radiate, at the circumference. Apothecia of almost middling size; sessile; flattish; but the thin margin, which is at first white-pruinose, at length excluded by the turgid, black disk. Sporesacks club-shaped, octo- sporous. Spores fuscous; variously and irregularly ellipsoid, now oblique, now constricted (biscocitiform, Koerb.) septate-dyblastich; from twice to twice and a half longer than wide. Another very interesting addition to North American lichens, which is a fruit of Dr. Hayden's extensive