OF ARTS AND SCIENCES. 283 



green, the lobes elongated, radiant, multifid, with elevated, waved and 

 crisped, crenate margins ; apoth. submarginal, somewhat plane, at length 

 rufescent, with a subgranulate margin. Ach. ! Syn. p. 315. — /5. jaco- 

 hcBifoliu7n, Ach. ; lacinise narrow, strict, lacerate-pinnatifid ; apoth. mar- 

 ginal, with an entire margin. Ach. I. c. Exs. Schcer. ! Lich. Helv. 422. 

 Rocks among mosses and trunks. New England. 



8. C. pahnatum, Ach. Th. csespitose-pulvinate, brownish-green, of 

 crowded, erectish, palmate-divided, somewhat linear and terete lacinise ; 

 apoth. rufous-fuscous. Ach. Syn. p. 319. 



On the earth, and trunks. Pennsylvania, Muhl. 



9. C. nigrescens, Ach. Th. somewhat monophyllous, membrana- 

 ceous, expanded, round-lobed, rugose-plicate, olivaceous-nigrescent ; 

 costate-lacunose beneath ; apoth. (minute) central, crowded, at length 

 convex, rufous-fuscous, with a very entire margin. Ach. Sy7i. p. 321. 

 Hook. Br. FL 2, p. 211. Exs. Schcer. ! Lich. Helv. 410. 



Eocks and trunks. N. England. N. York, Halsey. Penn., Muhl. 



10. C. Jlaccidum, Ach. Th. foliaceous, membranaceous, smooth, 

 flaccid, blackish-green ; lobes somewhat ascending, rounded, rather en- 

 tire, undulate-plicate; apoth. scattered (small), somewhat plane, rufous. 

 Ach. Syn. p. 322. Hook. Br. Fl. 2, p. 211. Exs. Schcer. ! Lich. Helv. 

 412. 



Rocks and trunks. New England. 



11. C. tunceforme, Ach. Th. foliaceous, membranaceous, somewhat 

 rugose, blackish-green, besprinkled with fuliginous powder ; lobes ob- 

 long, deeply cut, sinuate-laciniate, obtuse, flexuous, crisped, subcrenate ; 

 apoth. scattered, somewhat plane, fuscous, with a very entire margin. 

 Ach. Syn. p. 322. 



Rocks (especially limestone, Ach.). Pennsylvania, Muhl. in herb. 

 Willd. ! The specimen appeared to me to agree with an original one 

 from Acharius. Schserer refers the species to C. flaccidum. It is 

 said to occur in Massachusetts. 



12. C. pulchellmn, Ach. Th. membranaceous, orbicular, plane, 

 somewhat laciniate, round-lobed at the circumference, plicate-papulose 

 and dark-green above, beneath paler and deeply lacunose ; apoth. 

 crowded, elevated, the disk urceolate, pale, the margin thin, coarctate, 

 very entire, at length somewhat rugulose. Ach. Syn. p. 321. 



Trunks and rocks, New England. Pennsylvania, Muhl. ! Ohio, 

 Mr. Lea ! 



