12 which I have yet been fortunate enough to see, are those of Dr. Hayden. L. (Psora) icterica, Montag. in Ann. Sci. Nat. 2, 2, p. 373; Syll. p. 337 (sub Biatora) L. endochlora, Taylor. New Lich. in Hook. Lond. Journ. Bot. 6, p. 151. Nyl. Enum. Gén. l.c. p. 123. Lecanora Wrightii, Tuckerm. Suppl. l.c. p. 425. On the earth in denud- ated spots, near the South Bend of Red River, Minnesota (lat. 46°) Mr. Lapham; and doubtless also within the range of the present list; the species becoming common on the prairies and hills of the Blanco (M? Wright) and in the valley of the Rio Grande, Texas (D. J. M. Bige- low) and extending southward to Mendoza (Taylor, l.c.) and Valparaiso (Montagne, l.c.) Thallus of separate, rather thin, crenate- lobate, at length bright-yellow scales; with raised, paler margins. Apothecia adnate; the reddish-brown disk equally the paler margin; finally turgid and blackish, and the margin disappearing. Spore- sacks octosporous. Spores small; colourless; ovoid; simple; often limi- bote, or the protoplasm becoming at length guttulose. Apothecia at first with a Lecanorine aspect (as in the last species, which Acharius, in one of his works, referred to Lecanora) but properly Biat- orine. L. (Biatora) erysibe (Fr.) Biatora erysibe, Fr. Lichenogr. p. 271. Bilimbria, Koerb. Geomorph Syst. p. 213. Lecanota, Nyl. Prodr. p. 88; lich. Scand. p. 167. Patellaria Rabenhorstii, Hepp. Lich. Eur. n. 75. Biatorina, Massal. Symm. p. 43. B. prot- eiformis, Massal. Sched. Crit. cit. Koerb. Koerb. Parerg. p. 139. Lecidea luteola, v. erysibe, Ach., 2 specim., vide Fr. l.c. On calcareous sand- stones, Deer Creek, North Platte, Hayden. Thallus crustaceous; thickish; somewhat areolate; or verruculose; pale whitish-brown. Hypothallus obscure. Apothecia minute; flatish; the naked, brownish-black disk bordered more or less evidently marginate; and, more or less by a margin, of the substance of, but whiter than, the thallus; finally convex and mi- marginate. Spores in eight, in club-shaped spore-sacks; colourless;