56 PAKMEL1A. 



.3. P. Icevigata (Sm.) Nyl.; thallus more narrowed, membra- 

 naceous, smooth, glaucescent ; beneath black, and more or less 

 densely black-fibrillose ; lobes sinuate-pinuatifid : the tips now 

 sorediiferous ; apothecia middling-sized ; disk chestnut, with an 

 entire, or at length toothed margin. Spores ellipsoid, " " mic. 



Nyl. Syn. p. 384. P. sinuosa, Fr. L. E. p. 63. 



b. sinuosa, Nyl. ; thallus pale-yellowish. -- P. sinuosa (Sm.) 

 Ach., teste Borr. P. relicina, /?, Fr. L. E. p. 70. 



Trees, and rocks, a, Louisiana, Hale. -- 6, Nova Scotia, 

 (Menzies) Ach. Syn. 1814. Mexico, Nylander. 



The species is ill-represented here. The first form (Louisiana, 

 Hale] referred also by Nylander (Syn.) to P. Icevigata, and 

 closely resembling the European / revoluta, Nyl., under which 

 he arranges it, stands yet in difficult relation to P. cetrata. - 

 &, is at present quite unknown here as a North American lichen. 

 P. tlliacea approaches the present more closely here, and in 

 tropical America, than in Europe ; and barren specimens of the 

 former scarcely now differ at all from the latter (as exhibited in 

 Nyl. Lich. Par. n. 112) but in smaller size: the fertile ones are 

 separable by the spores. 



P. aurulenta, Tuckenn. ; lobes rugose, less divided and 

 more compacted than in the last preceding, at length thickly 

 besprinkled with now confluent soredia ; the medullary layer 

 sulphur-yellow ; -apothecia middling-sized ; disk chestnut. Spores 

 ellipsoid, ~ mic. -- Suppl. 1, 1. c. p. 424. Nyl. Syn. I, p. 382. 

 Trunks in the White Mountains, and rocks of the Blue Ridge, 

 Virginia, fertile, Tuckerman I. c. 1858. Rocks and trunks, Illi- 

 nois, fertile, Hall Trees, South Carolina, fertile, Ravenel. 

 Alabama, J. F. Beaumont. Louisiana, Hale. -- The lichen of 

 the White Mountains was the P. Icevigata of the author's Syn. 

 N. Eng., and would perhaps make the best representative that 

 we have of the European species, were it not for the coloration 

 (more or less distinct) of the medullary layer. 



4. P. Camtschadalis (Ach.) Eschw. ; thallus ascendant, 

 dichotomously branch-lobed ; smoothish or now isidiophorous ; 

 whitish or now cinereous-glaucescent ; beneath channelled, soon 

 blackening and becoming wrinkled and very black, and beset, at 

 least at the margins, with black fibrils, which are now deficient ; 

 the narrow lobes finally elongated, attenuate, and densely inter- 



