L. chrysops, Tuck. Suppl. in Amer. journ. Sci. 25, p.425. Cretaceous sandstones, Deer Creek, North Platte, Hayden. The white form also occurs, and is not unlike L. calcaria v. Hoffmanni; but by wetting the specimen, their typical colour becomes recognizable. Spores very numerous in oblong sporesacks; very minute; colourless; simple. Ureolaria Scruposa (L.) Ach Pers rebri For Ureolaria scruposa (L.) Ach. Koerb. byst. p.168. Nyl. Prodr. p.96; Lich. Scand, p.176. Parmelia, Fr. Lichenogr. p.190. Tuckerm. Synopp. p.43. Nyl. Lich. Scand. p.177. var. gypsacea, Sommerf. Lapp. p.100. Koerb. l.c., U. scruposa v. albifima, Ach. Meth. p. 147. Ureolaria gypsacea, Ach. Lichenogr. p.338; Syn. p. 142. Lime-rocks, and on the earth in calcareous soil. Bad lands of Judith, Nebraska, Hayden. Not before recognized here. (Psora) Lecidea Russellii, Tuck. Obs. Lich. in Proceed. Acad. Amer. Rocks (Jurassic) at the head of Fire Powder river, Hayden Detected, at about the same time, on lime-rocks in Vermont, by M. Russell, and in Texas, by Mr. Wright. I have since found it on similar rocks in Maryland, and Mr. Peters has sent it from Alabama. And what I suspect to be a condition of the same lichen was collected by Mr. Wright on an island of Behring's Strait. Scales commonly much more separate than in L. globifera, but in these specimens they are crowded; differing however from the species named in being smaller, less lobed, and paler, with raised, white-powdery edges. And the large, rufous, well-marginated apothecia sufficiently dis- tinguish the present, which appears, in fact, in several respects, to ap- proach rather to L. testacea. It has also often much the aspect of fine specimens of Lecanora cervina, a. glauco carpa. (Psora) Lecidea luridella, Tuck. Obs. Lich. l.c. On the earth, Snake fork of the Columbia