15. L. premnea, Ach. Cr. glaucescent, softish, deliquescing and leprous, obliterating the hypothallus; apoth. elevated; exciple cupular, with an obtuse margin; disk horny, very opake, and obsoletely blackpruinose, white within. Fr.! Lichenogr. p. 329. Patellaria leucoplaca, DC. Fl. Fr. 2, p. 347 (e Fr.).

Trunks and rails; New England. New York, Halsey.

16. L. parasema, Fr. Cr. somewhat leprous, glaucescent, becoming at length verrucose-areolate, somewhat limited by the black hypothallus; apoth. sessile, opake; exciple cupular, with a thin margin; disk horny, naked, very black. Fr. Lichenogr. p. 330. L. punctata, Floerk.! D. Lich. n. 81. Schar.! Helv. n. 197 - 199.

Trunks, and degenerant on dead wood; New England. New York, Halsey. Pennsylvania, Muhl. Arctic America, Rich. A most common and widely diffused species, but all black apothecia with a thin or without any crust are not to be referred to it. Fr. Compare Borr. in Hook. Br. Fl. 2, p. 176.

17. L. enteroleuca, Fr. Cr. at first contiguous, glaucescent, deliquescing and leprous, somewhat limited by the black hypothallus; apoth. adnate; exciple annular, with a thin margin; disk somewhat waxy (often hyaline or cerulescent), whitish within. Fr.! Lichenogr. p. 331. p. olivacea, Fr.; cr. yellowish-virescent; apoth. often irregular and rugose, ærugineous-black. Fr. l. c. L. elæochroma, Ach. Syn.

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

Subsect.. II. GRANULOSE, Fr. Crust at length becoming somewhat granulose. Hypothallus white.

18. L. sanguinaria, Ach. Granules confluent in a tartareous crust, glaucescent; hypoth. white; apoth. superficial, naked, at length convex; exciple annular; disk placed upon a blood-red stratum. Fr. Lichenogr. p. 335.

Trunks, decaying wood, and stones, in mountainous and subalpine districts; New England. New York, Halsey.

19. L. albo-atra, Schær. Cr. areolate-verrucose, glaucous-white, often somewhat tartareous and mealy; hypoth. white; apoth. (small) innate-protuberant, at first coronate with the crust, cæsious-pruinose, coal-black within, with a thin, evanescent margin. Fr. Lichenogr. p.

336. Schær. Spicil. p. 140. Borr. in Hook. Br. Fl. 2, p. 180. L. corticola, Ach. Syn.

Trunks on the coast of New England. New York, Halsey. Pennsylvania, Muhl.

20. L. dolosa, Wahl. Cr. somewhat verrucose, greenish-glaucous, oftener leprous and white; apoth. (minute) depressed; exciple cupular, with a very thin margin; disk very black, nearly naked, often punctate-scabrous, cinereous-blackish within. Fr. Lichenogr. p. 337. L. pinicola, Sommerf. Suppl. Fl. Lapp. p. 153. L. pinicola, Borr. in Hook. Br. Fl. 2, p. 176? Tuckerm. Lich. N. E. 1. c.

Scaly bark of old pines; New England.

21. L. melancheima, Tuckerm. Cr. cartilagineous, areolate-verrucose, becoming somewhat lobulate, glaucous-white, confused with the hypothallus; apoth. appressed, somewhat plane, disk equalling the very thin margin, at length convex, scarcely excluding the margin, very black, polished, and shining.

Trunks; and very common on rails on the coast of Massachusetts (Ipswich, Mr. Oakes, Lynn, Hingham, &c.), and occurring on dead wood at the White Mountains. Disk sometimes a little pallescent, but the margin always very black.

22. L. sabuletorum, Fr. Cr. cartilagineous, at first contiguous, becoming rimose-areolate, granulate and somewhat lobulate, cinerascent or fuscous, confused with the hypothallus; apoth. produced from the crust, horny; exciple annular, with an evanescent margin; disk naked, often fuscescent. Fr. Lichenogr. p. 339. Lichen s. Lecidea muscorum, Auct. quorund.

On the earth, decaying wood and mosses, stones, and trees, ascending to alpine districts; New England. New York, Torrey. Pennsyl vania, Muhl. Arctic America, Rich.

23. L. arctica, Sommerf. Granules of the crust cartilagineous, at first discrete, papillæ form, persistent, fuscescent-cinereous; apoth. immixed, somewhat immarginate, cæsious-pruinose, horny and cinerascent within. Fr. Lichenogr. p. 342. Sommerf. Suppl. Fl. Lapp. p. 156. Upon mosses in alpine districts; White Mountains.

24. L. milliaria, Fr. Granules of the crust at first discrete, fuscous, and cinereous-white, often deliquescent and leprous; apoth. produced among the granules, globose, somewhat immarginate, naked; exciple

cupular; disk at length rugulose and tuberculate, blackish within. Fr. Lichenogr. p. 342.—a. terrestris, Fr.- ß. saxatilis, Fr.—y. ligniaria, Fr.! Lichen dubius, E. Bot. t. 2347 (e Fr.). L. dubia, Turn. · & Borr. in Hook. Br. Fl. 2, p. 176. Tuckerm. Lich. N. E. l. c. On old rails (7), common; New England.

Tribe III. GRAPHIDACEÆ, Fr.

XVII. UMBILICARIA, Hoffm.

Apothecia superficial; an originally closed thalline exciple converted into a carbonaceous proper exciple, becoming more or less open, of various form. Disk horny, ascigerous, at length chinky, or gyrose-plicate, with an incurved margin. Thallus horizontal, cartilagineous, foliaceous, somewhat monophyllous, affixed by a central point.

This most natural genus can, perhaps, still be retained in the place given it in the Lichenographia Europea, though I have, in pursuance of Fries's suggestion (1. c. p. 347), confirmed by all the observations that I have been able to make, preferred to alter the generic character, and make it indicate more fully the relations of the group. It appears to me as analogous to Biatora as to Sticta; and as the former genus is considered to indicate a Lecideaceous type, irrespective of its approximations to Parmelia, so Umbilicaria may perhaps be taken as typically representative of a peculiar (perhaps properly lirellæ form, or Graphidaceous) type, irrespective of the approach which some of the species make to the characters of Parmeliaceæ.

Sect. I. PATELLATE. Apothecia orbiculate-patellæform; disk at length chinky, plicate, or proliferous-papillate.

1. U. mammulata, Ach. (sub Gyroph.). Thallus membranaceous, smooth, irregularly round-lobed and somewhat crenate, fuscous-nigrescent; on the under side very black, papillose-granulate, and fibrillose; apothecia elevated, orbiculate; margin rather thick; disk plane, chinky, becoming at length convex, and proliferous-papillate. Gyrophora mammulata, Ach. Syn. p. 67. G. mamillata, Muhl. Catal. p. 105.

Rocks. Pennsylvania, Muhl. (North Carolina, Mr. Curtis !) Very distinct from the next.

2. U. Pennsylvanica, Hoffm. Th. coriaceous-membranaceous, papulose, dark-fuscous; on the under side papillose-granulate and nigrescent; apoth. elevated, orbiculate; margin rather thin; disk plane, but becoming at length convex, chinky, and plicate. Hoffm. Pl. Lich. 3, p. 5, & t. 69, f. 1, 2. Lecidea, Ach. Meth. p. 86. Gyrophora, Ach. Lichenogr, p. 227. Ach. Syn. p. 67. Hook. in Rich. App. Frankl. Narr. p. 759. U. pustulata, Michx.! Fl. 2, p. 322, non Hoffm.

Rocks. Mountains of Pennsylvania, Muhl. New York, Halsey. New England, common, and fertile. Canada, Michaux !

3. U. pustulata, Hoffm. Th. coriaceous, papulose, cinerascent; on the under side smooth, and reticulate-lacunose; apoth. appressed, orbiculate-patellæ form, somewhat simple; margin obtuse. Fr. Lichenogr. p. 351. Hook.! Br. Fl. 2, p. 219. Gyrophora, Ach.-B. papulosa, Tuckerm.; apoth. at length subpedicellate, irregularly proliferous-papillate, excluding the margin. Gyrophora papulosa, Ach. Lich. Univ. p. 226. Ach. Syn. p. 67. U. lævis, Pers. (ex Ach.). Gyroph. bullata, Willd. herb.!

Rocks. a, New York, Halsey. -8, Nova Scotia, 'used for dyeing reds and browns'; Gov. Wentworth, 1795, Herb. Smith! Newfoundland, Bory in herb. Kunth! New York, Torrey. Pennsylvania, Muhl.! New England, common and fertile, and ascending to alpine districts, where it is often smaller, thicker, and glaucous-pruinose. does not seem to afford any constant characters to distinguish it from the European Lichen but the luxuriant development of the apothecia. In the var. papillata, Hampe! a Cape of Good Hope Lichen, the apothecia are papillate, and perhaps also by a proliferous growth of the patellæform apothecium; but this variety, though in other respects resembling ours, is distinct from it. The small, fruticulose tufts almost characterizing this species in Europe, which I have also observed in the Swedish U. vellea, are generally wanting in the American plant, which is almost always normal and fertile.

4. U. anthracina (Schær.), Fr. Th. coriaceous, not papulose, black; on the under side smooth and black-pruinose; apoth. elevated, orbiculate-patellaform, simple; margin tumid, disk somewhat plane and even. Fr. Summ. Fl. Scand. U. atro-pruinosa, Schær. in Ser. Mus. (cit. Fr.). Fr. Lichenogr. p. 351. Lecidea, Schar.! Spicil. 1, p. 104. Lichen anthracinus, Wulf.-a; th. smooth and even above. Schar. 1. c. Fr. 1. c. p. tessellata, Schær.; th. above finely rimose-areolate or punc

tate-verrucose, rugose at the central point. Schar. l. c. Fr. l. c. — 7. reticuluta, Schær.; th. reticulate-rugose above. Schar. l. c. Fr. 1. c.

Rocks in alpine districts. a, Newfoundland, Bory in herb. Willd.! Bear Lake, and elsewhere in Arctic America, Hook.! (Parry's Sec. and Third Voy.).

5. U. polyphylla, Hoffm. Th. coriaceous-cartilagineous, smooth, corrugated, fuscous-black; on the under side very black and glabrous; 'apoth. sessile, at first patellæform, marginate, becoming at length convex, and concentrically plicate.' Fr. Lichenogr. p. 352. Gyrophora, Hook.! Br. Fl. 2, p. 217. Lichen, L. Gyrophora glabra, Ach.B. deusta, Fr.; th. thinner, furfuraceous-flocculose; somewhat lacunose and paler on the under side. Fr. l. c. Umbilicaria deusta, Hoffm. Gyrophora, Ach. Lichen, L.

Rocks on mountains; a, alpine; -ß, descending. White Mountains, infertile. Northward to Newfoundland, Pylaie, and Greenland, Herb. Banks!

6. U. proboscidea, DC., Stenh. Th. submembranaceous, reticulaterugose, olivaceous-fuligineous; on the under side pale and fibrillose; apoth. somewhat elevated, orbiculate-patellæ form, becoming at length convex, very gyrose, or proliferous-papillate, somewhat excluding the margin. Fr. Lichenogr. p. 354. Gyrophora, Ach. Hook.! Br. Fl. 2, p. 219.-ẞ. tornata, Ach.; th. indurated, complicated, plicate-rugose; obsoletely fibrillose beneath. Ach. Syn. p. 65. Hook. in Rich. 1. c. p. 758, & ICON, t. 30, f. 4.-7. arctica, Ach.; th. incrassated, rugose; glabrous beneath. Ach. l. c. Fr. l. c.

Alpine and subalpine rocks. White Mountains; and Chin of Mansfield in the Green Mountains, fertile. Northward to Arctic America, Rich.

7. U. cylindrica, Ach. (sub Gyroph.). Th. subcoriaceous, rigid, smoothish, livid, cinereous-pruinose, ciliated with elongated, rigid, ramose, black fibres (or naked); on the under side somewhat pale-ochroleucous; apoth. pedicellate, orbiculate-patellæform, plane, becoming at length hemispherical, gyrose-plicate, scarcely excluding the margin. Gyrophora cylindrica, Ach. Hook.! Br. Fl. 2, p. 218. Lichen, L. U. proboscidea, ß, Fr. Lichenogr. p. 356.

Alpine rocks. A single specimen from Bear Lake, Herb. Hook.!