stipes rather short, somewhat compressed, corticate with the ascending granules of the crust or naked, often subdivided at the apex. Fr. Lichenogr. p. 257. Bæomyces rupestris, Ach. Lich. p. 573. B. rufus, Wahl. B. Byssoides, Schær. -a. Fr. ; granules of the crust subsquamaceous, crenulate (and deliquescent), greenish-glaucous. Fr. l. c. ß. rupestris, Fr. ; cr. thin, smoothish, subcontiguous (or powdery); apoth. smaller. Fr. l. c. Bæom. rupestris, Pers. —y. lignatilis, Fr. ; cr. rugose, cinereous-glaucescent; apoth. subsessile, fuscous-black. Fr. 1. c. Bæom. lignorum, Pers.

Common in mountainous districts: a, sterile sandy and clayey soils; slides, banks of streams, and road-sides, in the mountains of New England., rocks in mountain forests, New England. New York, Halsey.y, decaying wood, in similar situations with the last, apothecia almost sessile. The three varieties occur often in close neighbourhood at the White Mountains. This species, Stereocaulon Fibula, and S. aciculare illustrate the connection of Stereocaulon with the sessile Biatoræ. The difference of structure, indicated by Fries as generically distinguishing Bæomyces roseus from this and the last species, referred to Bæomyces by Acharius, has been further illustrated by Dr. Küttlinger in Allg. Bot. Zeit. 1845, 1. c.

SECT. II. Thallus effuse, uniform.

7. B. icmadophila, Fr. Crust tartareous, granulate, greenish-glaucous; hypothallus white; apothecia (large) softish, incarnate, exciple cupular, with a thin, evanescent margin. Fr. Lichenogr. p. 258. Lecidea, Ach. Baomyces, DC.

Decaying wood in mountain forests, and on the earth; ascending to alpine districts; New England. New York, Torrey. Pennsylvania, Muhl. Arctic America, Rich. Apothecia sometimes a little stipitate in ours, as in the European Lichen.

8. B. vernalis, Fr. Cr. of minute, glaucescent granules, arising from a membranaceous, whitish hypothallus; apoth. at length subglobose, clustered, flesh-colored, and fulvous-ferrugineous. Lecidea vernalis, Borr. in Hook. Br. Fl. 2, p. 183. L. luteola, Ach.

Trunks in mountain forests, growing over mosses; New England. New York, Halsey. Arctic America, Rich.

9. B. pineti, Fr. Cr. very thin, granulose, greenish-glaucescent; apoth. (minute) sessile, whitish; disk becoming at length yellowish

flesh-colored, finally falling out and the apothecia urceolate. Lecidea,

Ach. Syn. p. 42. Hook. Br. Fl. 1. c.
Scales of fir-bark, and on the earth.

Biatora, Fr. Summ. Fl. Scand.
Pennsylvania, Muhl.

10. B. sanguineo-atra, Fr. Cr. thin, membranaceous, effuse, whitish-cinerous, becoming granulose; apoth. sanguineous, with an obscure paler margin, at length black. Fr. Summ. Fl. Scand. B. vernalis, B. sanguineo-atra, Fr. Lichenogr. p. 263.

Trunks and rocks, growing over mosses, in mountainous districts; New England.

11. B. carneola, Fr. Cr. confused with the hypothallus, cartilagineous-membranaceous, glaucescent, at length granulate-pulverulent ; apoth. sessile, concave, naked, from reddish-flesh-colored becoming fuscous, exciple cupular, with an elevated, at length evanescent, paler margin. Fr. Lichenogr. p. 264. Lecidea, Ach.

Trunks; New England. New York, Halsey. Apothecia somewhat larger in my specimens than in the European Lichen.

12. B. spadicea, Ach. (sub Lecid.). Cr. cartilagineous-membranaceous, granulate, glaucescent; apoth. thick, margin very finely rugulose, at length somewhat convex and excluding the margin, light-chestnut becoming blackish, within of the same color. Lecidea spadicea, Ach. Syn. p. 34.

Trunks; Pennsylvania, Muhl., Ach. Southward. Fries considers this scarcely distinct from the last. (Lichenogr. p. 264.)

13. B. cinnabarina, Sommerf. Cr. confused with the hypothallus, cartilagineous, uneven, glaucous becoming whitish; apoth. appressed, cinnabar-red, naked, becoming at length convex, and immarginate. Fr. Lichenogr. p. 266. Lecidea, Sommerf. Vet. Ac. Handl. 1823 (e Fr.).

Trunks. Greenland, Fries. Lecidea coccinea, Schwein. in Hals. Lich. N. Y. l. c. 1824, which cannot, by the description, be distinguished from this, occurs in New York, Halsey, and appears to extend to N. Carolina! (Mr. Curtis).

14. B. chlorantha, Tuckerm. Cr. of discrete, subsquamaceous-verrucose granules, bright green, and white within (or deliquescent sorediiferous); apoth. somewhat elevated, becoming plane, and at length convex, with a thick, flexuous, paler margin; within white; disk nigrescent.

Bark of Pinus Strobus, and other trees; New England. Resem

bling Lecidea enteroleuca, but with a different crust, and, I think, the apothecia of the present genus.

15. B. decolorans, Fr. Cr. tartareous, confused with the hypothallus, areolate-granulose, glaucescent; apoth. appressed, naked, from flesh-colored becoming fuscous and black, with a thin, elevated, paler margin; finally convex and irregular, and the margin disappearing. Fr. Lichenogr. p. 266. Lecidea, dein Lecanora granulosa, Ach. Lecidea decolorans, Floerk. Ach. Syn.

On the earth, and decaying wood, in mountainous regions; New England. Northward to Arctic America, Rich.

16. B. anomala, Fr. Cr. confused with the white hypothallus, at length granulose, white-cinerascent; apoth. becoming hemisphericalglobose, somewhat hyaline-livid, at length fuscescent and black, margin very thin, evanescent. Fr. Lichenogr. p. 269. Lecanora commutata, Ach. Syn. p. 149.

Trunks, dead wood, &c. New York, Halsey. An obscure species. Nomen omen. Fr.

17. B. mixta, Fr. Cr. cartilagineous, confused with the hypothallus, rugose-verrucose, milky-glaucescent; apoth. adnate, exciple annular, disk at first plane, pruinose, flesh-colored or livid, becoming at length turgid, fuscous, and black, and excluding the obtuse margin. Fr.! Lichenogr. p. 268. Lecidea anomala, Ach. part. Tuckerm. Lich. N. E.

1. c.

Trunks, and dead wood. New England.

18. B. porphyritis, Tuckerm. Cr. subcartilagineous, smooth, chinky, at length rugose, glaucescent (and greenish-sorediiferous); white within; apoth. elevated on a white thalline stratum which constitutes an evanescent spurious margin, or sessile; disk at first somewhat plane, pruinose, with a thick, elevated margin, at length convex, and excluding the margin, fuscous-nigrescent.

Trunks, in the mountains of Massachusetts and New Hampshire. Near to B. mixta, but as that is one of the smallest, this is the largest Biatora that I am acquainted with. Several apothecia sometimes occupy the same thalline stratum, as in B. ochrophæa and B. aurantiaca. With age the apothecia become flexuous, and very large, a single exciple having sometimes a diameter of two lines.

19. B. ochrophæa, Tuckerm. Cr. subcartilagineous, thickish, gran

ulate-verrucose and somewhat plicate, glaucescent; hypoth. pale; apoth. elevated-subpedicellate on a thalline stratum, which constitutes a thick, subcrenulate, at length evanescent spurious margin; disk plane, delicately pruinate, at length convex, and excluding its thin, elevated, proper margin, from pale flesh-colored becoming blackishfuscous.

Trunks in the mountainous districts of Northern New England, common. Apothecia at first closed, and either sessile (when some states resemble Parmelia carneo-lutea, Turn.) or elevated on a protuberant thalline stratum, at length lacerate-dehiscent and becoming plane, with a thick, crenulate thalline margin, which disappears, leaving the marginate disk. It has often all the aspect of a Parmelia, not a little resembling P. rubra. Is the structure of the apothecia in the last-mentioned species, and in P. carneo-lutea, wholly diverse from the structure above described of the present?

20. B. russula, Tuckerm. Cr. subcartilagineous, rimose-areolate, and granulate, glaucescent (often greenish-sorediiferous); apoth. elevated on a thalline stratum which constitutes a thick, mostly entire spurious margin, becoming convex, and excluding the obscure proper margin, fuscous-reddish. Lecidea, Ach. Syn. p. 40. Lecanora, Feé, Crypt. Exot. p. 116.

Trunks of cedars on the coast of New England. Pennsylvania, Muhl. Extending to the tropics.

21. B. rivulosa, Fr. Cr. tartareous, mouse-colored and paler, covering a fuscous-black hypothallus, which often decussates the crust; apoth. produced from the crust, from pale-fuscous becoming blackish, whitish within, with a thin margin. Fr. Lichenogr. p. 271. Lecidea, Ach. Lecanora falsaria, Ach.

Rocks, especially in mountainous districts; New England. Pennsylvania, Muhl. Northward to Arctic America, Rich.

22. B. exigua, Chaub. Cr. of minute, confluent granules, smooth, cartilagineous, cinereous-greenish; decussated by lines of the black hypothallus; apoth. submarginate, from pale-yellowish becoming fuscous. Fr. Lichenogr. p. 278. Lecidea varians, Ach. Syn. p. 38. Tuckerm. Lich. N. E. 1. c. L. versicolor, Schwein. in Hals. Lich. N. Y. l. c. ?

Smooth bark; New England. New York, Halsey? Pennsylvania, Muhl.

23. B. quernea, Fr. Cr. deliquescent, granulose-farinose, fuscescentochroleucous; hypoth. black; apoth. immersed, convex, brown, at length immarginate. Fr. Lichenogr. p. 279. Lecidea, Ach.

Trunks; New England.

24. B. lucida, Fr. Cr. granulate, greenish-yellow, at length deli quescent and ochroleucous; hypoth. white; apoth. (minute), convex, pale yellow, often excluding the paler margin. Fr. Lichenogr. p. 279. Lecidea, Ach.

Stones and decaying wood. Arctic America, Rich.

25. B. aurantiaca, Fr. Cr. cartilagineous, uneven, somewhat granulate, lutescent; innate in a black hypothallus; apoth. somewhat elevated on a thalline stratum which constitutes a crenulate, evanescent, spurious margin, disk dark-orange (and fuscescent), with a thin proper margin. Parmelia, Fr.! Lichenogr. p. 165. Lecidea, Ach. Borr. in Hook. Br. Fl. 2, p. 186. Lecanora salicina, Ach.

Trunks, dead wood, and rocks; New England. New York, Halsey. Pennsylvania, Muhl. Arctic America, Rich.

26. B. fusco-lutea, Hook. (sub Lecid.). Cr. thin, effuse, smooth, somewhat granulose, whitish; apoth. somewhat elevated, plane, yellowish, at length rufous-fuscous, pruinose, with a thin margin. Lecidea, Hook. in Rich. 1. c. Lichen fusco-luteus, Dicks. E. Bot. t. 1007.

Upon mosses; Arctic America, Rich. Fries suspects this to be a state of B. ferruginea. It does not seem to be the Lecidea fusco-lutea, u, of Ach. Syn.

XVI. LECIDEA, Ach., Fr.

Apothecia margined at first by a very black, carbonaceous, proper exciple, becoming scutelliform or hemispherical, solid. Disk at first punctiform-impressed, always open, oftener horny, and placed upon a carbonaceous stratum. Thallus horizontal, arising from a hypothallus, somewhat crustaceous, effigurate, or uniform. Apothecia very black from the first, the margin never, and the disk rarely, otherwise colored. Fr.

SECT. I. Thallus effigurate at the circumference, or wholly rugose

plicate.

1. L. candida, Ach. Crust rugose-plicate, candicant, becoming at length white-farinose, lobed at the circumference; hypothallus black;