268 PROCEEDINGS OF THE AMERICAN ACADEMY 



horny within, becoming tumid, and covering the margin. Fr. ! Lichen- 

 ogr. p. 368. 



Bark of oaks, and other trees, New England. 



4. O. ahnormis, Ach. Cr. thin, softish, white ; apoth. immersed, 

 very slender, short or very long, flexuous, confluent, rugose-crisped, 

 opake, black ; disk and margin somewhat confluent and indistinct. Ach. 

 Syn. p. 74. 



Hard bark of trees ; Pennsylvania, Muhl., Ach. A mostly tropical 

 species growing on Cascarilla, and other bark. 



Sect. II. Graphis. Apothecia erumpent, coronate for the most part 



with a thalline margin. 



5. O. scripta, Ach., Scha3r. Cr. innate in the matrix, becoming at 

 length exposed, uneven, and pulverulent ; apoth. immersed, erumpent, 

 with a raised accessory thalline margin ; the proper margin tenuescent, 

 smooth ; the disk linear, at first csesious-pruinose, Fr. Lichenogr. p. 

 370. Schcer. ! Spicil. p. 46. — a. limitata, Schser. ; apoth. emergent, 

 scattered irregularly, various. Fr. I. c. Schcer. I. c. — /5. recta, Schser. ; 

 apoth. immersed, straight, parallel, disk somewhat dilated. Fr. I. c. 

 Schoir. I. c. 0. recta, Humb. 0. Cerasi ^ hetuligna, Ach. — /. ser- 

 pentina, Schcer. ; apoth. immersed, flexuous, very long, the thalline 

 margin tumid, evanescent. Fr. I. c. Schcer. I. c. O. serpentina, Ach. 



Bark of trees ; New England. New York (a, /?, and y), Halsey. 

 Pennsylvania (a and /?), Muhl. 



6. O. polymorpha. Cr. sorhewhat pulverulent, whitish-cinerascent 

 or very white ; apoth. somewhat rounded or oblong, irregular, without 

 apparent proper margin, from plane becoming tumid and elevated- 

 punctate, angulose, repand, or somewhat stellate-ramulose, csesious- 

 pruinose, with a more or less conspicuous thalline margin. Arthonia 

 polymorpha, Ach. Syn. p. 7. Fee Crypt. Exot. ji. 53. Eschw. Lich. 

 Bras. I. c. p. 111. O. Cascarillce, Floerlc! herb, {fide ips.). 



North America (Pennsylvania ?), Muhl. A common Lichen of Cas- 

 carilla bark, which Eschweiler (1. c.) has illustrated at length. The 

 arrangement of Muhlenberg's catalogue leaves it probable that he con- 

 sidered it to occur within our limits. 



7. O.inusta, Ach. (sub Graph.). Cr. membranaceous, somewhat 

 rugulose, pale-virescent, decussated by black lines ; apoth. minute, im- 

 mersed, rather short, straight, simple or somewhat stellate-ramose, ob- 



