OF ARTS AND SCIENCES. 259 



** CorticolcB. 



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 pbsoletely black- 

 pruinose, white within. Fr. ! Lichenogr. p. 329. Patellaria leucopla- 

 ca, 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 hypothal- 

 lus ; 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. Schcer. ! Helv. n. 197-199. 



Trunks, and degenerant on dead wood ; New England. New York, 

 Halsey. Pennsylvania, Muhl. Arctic America, Rich. A most com- 

 mon 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, deli- 

 quescing 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. — /?. olivacea, Fr. ; cr. yellowish-virescent ; apoth. often irregular 

 and rugose, serugineous-black. Fr. I. c. L. elaiochroma, Ach. Syn. 



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



Subsect. II. Granulosa, Fr. Crust at length becoming somewhat 

 granulose. Hypothallus white. 



18. L. sangtcinaria, Ach. Granules confluent in a tartareous crust, 

 glaucescent ; hypoth. white ; apoth. superficial, naked, at length con- 

 vex ; exciple annular ; disk placed upon a blood-red stratum. Fr. Li- 

 chenogr. p. 335. 



Trunks, decaying wood, and stones, in mountainous and subalpine 

 districts ; New England. New York, Halsey. 



19. L. albo-atra, Schaer. Cr. areolate-verrucose, glaucous-white, 

 often somewhat tartareous and mealy; hypoth. white ; apoth. (small) 

 innate-protuberant, at first coronate with the crust, csesious-pruinose, 

 coal-black within, with a thin, evanescent margin. Fr. Lichenogr. p. 



