cent; hypothallus pale; apothecia tumid, disk plane, pale, innate-pruinose, with an erect, entire, persistent margin. Fr. Lichenogr. p. 132. Lecanora Parella, ß. Ach. Lichen pallescens, L. Spec. Pl. — ß. Parella, Fr. ; crust amylaceous-tartareous, plicate-verrucose, milk-white, disk at length chinky or verrucose. Fr. l. c. Lecanora Parella, Ach. Lichen Parellus, L. Mant.

Trunks, rails, stones, &c., ascending to alpine districts.ẞ, rocks near the sea and large lakes. New England. New York, Torrey. Pennsylvania, Muhl. Northward to Arctic America, Rich.

52. P. tartarea, Ach. Cr. tartareous, granulate-conglomerate, glaucescent; hypoth. pale; apoth. adnate, disk plane, rugulose, pale-yellowish-flesh-colored, with an inflexed, entire margin. Fr. Lichenogr. p. 133. -ß. frigida, Ach. ; hypothallus confused with the thallus; crust at length granulate, whitish; apoth. smaller, reddish-flesh-colored. Fr. l. c.

Rocks; incrusting twigs, mosses, lichens, &c., and ascending to alpine districts; New England. New York, Halsey. Arctic America, Grev. (Pl. W. Greenl.).

53. P. rubra, Ach. Cr. subcartilagineous, smoothish, at length granulate-pulverulent, glaucescent; hypoth. pale; apoth. adnate, disk concave, red, with a tumid, inflexed, crenulate margin. Fr. Lichenogr. p. 134. Lecanora, Ach.

Trunks in mountainous districts; New England. Pennsylvania, Muhl.

54. P. oculata, Fr. Cr. cartilagineous-tartareous, rugose, uneven, papillose, glaucescent; hypoth. pale; apoth. sessile, concave, disk subfuscous, with an elevated, very entire margin, which is whiter than the thallus. Fr. Lichenogr. p. 135. —ẞ; thallus isidioid, branched; apoth. becoming black. Fr. l. c. Isidium oculatum, Ach. Turn. & Borr. Lich. Brit. p. 103.

Trunks in mountainous districts; White Mountains. Northward to Arctic America, Rich., Hook.

55. P. subfusca, Fr. Cr. cartilagineous, at first contiguous, smooth, becoming chinky and granulate, glaucescent; hypoth. macular; apoth. adnate, disk plano-convex, subfuscous, whitish within, with an erect margin colored like the thallus. Fr. Lichenogr. p. 136 (excl. P. albella).a. discolor, Fr. ; cr. as above; apoth. regular, disk thickish, always naked (red, rufous, fuscous, or black), margin entire, or at

length rugose. Fr. l. c. Lecanora subfusca, & L. epibryon, Ach. — B. distans, Fr. ; cr. thin; apoth. orbiculate, margin elevated, crenulate, disk thin, pale, at first pruinose, finally naked. Fr. 1. c. Lecanora distans, Ach.

Trunks, dead wood, rocks, and stones. -, trunks. New England. New York, Torrey. Pennsylvania, Muhl. Northward to Arctic America, Rich.

56. P. albella, Ach. Cr. cartilagineous, thin, milk-white; apoth. orbiculate, tumid, pale-flesh-colored, whitish-pruinose, margin very entire, subevanescent. Ach. Syn. p. 168. Fr. Summ. Fl. Scand. P. subfusca, y. Fr. Lichenogr. p. 139. —ß. angulosa, Fr.; apoth. aggregated, angulose-irregular, disk livid-fuscous, glaucous-pruinose, with a flexuous, subpersistent margin. Fr. Summ. Fl. Scand. P. subfusca, 8. Fr. Lichenogr. p. 139. P. angulosa, Ach.

Trunks; New England. New York (a and ß), Halsey.

57. P. casio-rubella, Ach. Cr. thin, softish, white; apoth. scattered (rather large), disk plane, becoming at length somewhat tumid, pale-reddish and fuscescent, at first casious-pruinose, equalling the tumid very entire margin. Ach. Syn. p. 267.

Trunks; New England. New York, Halsey. Pennsylvania, Muhl.

58. P. atra, Ach. Cr. cartilagineous, at length granulose-verrucose, glaucescent; hypoth. black; apoth. sessile, disk at length somewhat tumid, polished, very black, within black, with an elevated, persistent, subentire margin. Fr. Lichenogr. p. 141.

Rocks and stones; New England. New York, Halsey. Pennsylvania, Muhl. Arctic America, Rich.

59. P. cinerea, Fr. Cr. subtartareous, areolate-rimose, glaucous-cinereous; hypoth. black; apoth. innate, disk naked, nigrescent, pale within, with a black, obtuse, subelevated thalline margin. Fr. Lichenogr. p. 142. Urceolaria, Ach.

Rocks and stones, very common, and passing into many varieties. An ochraceous state (Urceolaria Acharii, Ach.) occurs not uncommonly about mountain streams. New England. New York, Halsey. Arctic America, Rich.

60. P. badia, Fr. Cr. cartilagineous, rimose-areolate, subsquamulose, dark-olive; hypoth. black; disk naked, polished, fuscous-black, with an entire, persistent thalline margin. Fr. Lichenogr. p. 147.

Rocks and stones (granite), ascending to alpine districts; New England. Arctic America, Rich. Areole sometimes dispersed and squamaceous, with subimmersed, punctiform (imperfect) apothecia. Such a state, according to Fries, is the Endocarpon smaragdulum of some authors; and a similar one, tinged dark red by the oxide of iron, the Endocarpon Sinopicum, Wahl. The former is common in New England, and occurs in New York, Halsey. The latter is frequent on alpine and subalpine rocks on our higher mountains.

61. P. sophodes, Ach. Cr. tartareous, verrucose-granulate, from green becoming fuscescent; hypoth. black; disk opake, unpolished, fuscous-nigrescent, thalline margin thick, at length rugulose. Fr. Lichenogr. p. 149. Lecanora, Ach. — ß. exigua, Fr. ; small; crust fuscous-cinerascent; hypoth. obsolete; margins of the apothecia whitish, and disappearing. Fr. 1. c. Lecanora, Ach.

Trunks and dead wood; New England. New York (« and p), Halsey. Pennsylvania (a), Muhl. Arctic America (3), Rich..

62. P. ventosa, Ach. Cr. tartareous, rimose-areolate, pale-yellow; hypoth. white; apoth. appressed, at length irregular, disk somewhat convex, dark-brownish-red, with a thir, pale, very entire margin. Fr. Lichenogr. p. 153. Lecanora, Ach.

Alpine and subalpine rocks; White Mountains. Pylaie, and northward to Arctic America, Rich.

Newfoundland,

63. P. varia, Fr. Cr. cartilagineous, areolate-verrucose, yellowishgreen, becoming ochroleucous; hypoth. smooth, macular; apoth. sessile, disk polished, yellowish-flesh-colored, or discolored, with a thin, erect, entire margin. Fr. Lichenogr. p. 156.a. Fr. ; apoth. scutelliform, plano-concave, with a persistent, sometimes crenulate, or pulverulent thalline margin. Fr. ! l. c. P. varia, Ach. — ß. symmicta, Fr. ; disk of the apothecia somewhat excluding the paler, very entire margin, from pale-yellowish becoming fuscous. Fr.! 1. c.—y. sepincola, Fr.; apoth. somewhat immersed, convex, immarginate, from fulvous becoming black. Fr. 1. c. Lecidea, Ach.-8. polytropa, Fr.; crust. areolate and granulate; margins of the apothecia pale, entire, somewhat flexuous. Fr. l. c. Lecidea, Ach.

Dead wood, stones, and trunks; New England. New York, Halsey. Pennsylvania, Muhl. - ß, granite rocks in mountainous districts; New England. Arctic America, Rich.

64. P. vitellina, Ach. Cr. tartareous, granulose-coacervate, darkreddish-yellow; hypoth. macular, white; apoth. sessile, disk yellow becoming fuscous, margin simple, thin, erect, entire, at length of the same color. Fr. Lichenogr. p. 162. Lecanora, Ach.

Dead wood and rocks; New England. Pennsylvania, Muhl.

65. P. fulva, Schwein. (sub Lecanora). Cr. cartilagineous, chinky and granulate-verrucose, sulphureous or pallescent, upon a blackish hypothallus; apoth. sessile, disk reddish-orange, immarginate, with a thick, inflected, at length flexuous margin. Lecanora fulva, Schwein. in Hals. Lich. N. Y. l. c. p. 13. Tuckerm. Lich. N. E. 1. c. Trunks; New England. New York, Halsey.

66. P. cerina, Ach. Cr. at first contiguous, at length granulate, cinereous, upon a bluish-black hypothallus; apoth. sessile, disk immar. ginate, somewhat wax-colored, with a thin, equal, opake, entire thalline margin. Fr. Lichenogr. p. 160. Lecanora, Ach.

Trunks, rocks, and stones; New England. Pennsylvania, Muhl.

Subsect IX. URCEOLARIA, Fr.

67. P. glaucoma, Ach., Fr. Crust tartareous, contiguous, rimoseareolate, glaucous-white; hypothallus white; apothecia innate, disk pale-flesh-colored, pruinose, at length convex, and becoming blackish, with a very entire, evanescent thalline margin. Fr. Summ. Fl. Scand. P. sordida, Fr. Lichenogr. p. 178. Lecanora glaucoma, Ach. Rocks (especially granite). New York, Halsey. Arctic America,

Rich.

68. P. verrucosa, Ach., Fr. Cr. cartilagineous, verrucose, naked, glaucous-white; hypoth. white; disk immersed in the verrucæ, concave, blackish, subpruinose, the proper margin connate with the convex thalline margin. Fr. Lichenogr. p. 186. Icon, Laur. in Sturm's Fl. t. 21. a. Urceolaria, Fr.; normal. Urceolaria verrucosa, Ach. ß. Pertusaria, Fr.; verrucæ closed, disk prominent like a black ostiole. Porina glomerata, Ach.

Incrusting dead mosses and sticks, in alpine districts; White Mountains.

69. P. calcarea, Ach., Fr. Cr. subcartilagineous, areolate-verrucose, glaucescent (often mealy and white); disk immersed in the areolæ, from concave becoming plane, blackish, cæsious-pruinose, with a

thin, at length discrete, entire proper margin; thalline margin somewhat prominent, subentire, or rugose-crenate. Fr. Lichenogr. p. 187. Urceolaria, Ach.

Limestone, and from this passing to other rocks; New England. New York, Halsey.

70. P. scruposa, Sommerf. Cr. tartareous, rugose-granulate, glaucous-cinerascent; hypoth. white; apoth. immersed, disk urceolate, cœsious-black, with a connivent, cinerous-blackish proper margin, which is at first covered by the crenate thalline margin. Fr. Lichenogr. p. 190. Urceolaria, Ach. B. bryophila, Ach. ; cr. rugose; apoth. smaller, disk emergent, urceolate, with a contracted mouth, thalline margin subevanescent. Fr. 1. c. Gyalecta, Ach.

Rocks, stones, dead wood, trunks, and on the earth; New England. - incrusting mosses; Pennsylvania, Muhl. Arctic America, Rich.

X. THELOTREMA, Ach.

Apothecia subconical-trupcate, at length open, urceolate-scutelliform; a discrete, lax, membranaceous, lacerate-dehiscent, interior exciple veiling a rigescent disk. Thallus crustaceous.

T. lepadinum, Ach. Disk blackish, at first cæsious-pruinose. Fr. Lichenogr. p. 428. Schær. ! Spicil. p. 67.

Trunks, somewhat rare; New England. Arctic America, Rich. (Herb. Hook.!). Our Lichen, as well as that of Arctic America, agrees with the European; and the species is found also in Brazil (Eschwei ler).

XI. GYALECTA, Ach., Fr.

Apothecia orbiculate, urceolate, at first closed, then variously dehiscent, the elevated, discrete, colored border of the exciple surrounding the disk. Disk at first included, like a nucleus, and gelatinous, becoming at length open, explanate, indurated. Thallus horizontal, crustaceous, somewhat tartareous.

G. cupularis, Schær. Apothecia radiate-dehiscent, urceolate-open; border orbicular, elevated, tumid, pale, disk pale-flesh-colored. Fr. Lichenogr. p. 195.

Rocks (especially limestone and sandstone, Fr.) and on the earth. New York, Halsey. Pennsylvania, Muhl.