OF ARTS AND SCIENCES. 203 



leuca, Ach. — /?. sarmentosa, Fr. ; th. filamentous, sarmentose-pendu- 

 lous, much branched, softish, ochroleucous or pale, apices elongated, 

 of the same color. Alectoria sarmentosa^ Ach. 



Mountainous, alpine, and arctic regions. — a, on the earth ; White 

 Mountains, infertile. Arctic America, Rich. (Herb. Hook. !), i?. Br. 

 (Parry's First Voy.), fertile. — /?, on the trunks and branches of trees 

 in the mountains of New England, and northward, fertile ; and on the 

 earth, alpine and arctic, sterile, a does not seem to be well represent- 

 ed on our mountains. The arctic specimens are very fine. 



5. E. vulpi7ia, Ach. Th. much branched, rigid, angular, com- 

 pressed-lacunose, greenish-yellow ; apoth. sessile, disk fuscous. Fr. 

 Lichenogr.p. 23. 



Trunks and rails, N. W. America, Menzies ! and Rocky Mountains, 

 Herb. Hook. ! fertile. A few specimens in my possession, from the 

 White Mountains, and elsewhere, may belong to this ; but most of the 

 degenerate plants commonly referred to it here are, perhaps, as safely 

 placed with E. prunastri. 



§ II. Dufourea, Fr. Fruticulose, inflated, apothecia terminal. 



6. E. ramulosa, Hook, (sub Dufourea). Th. ca^spitose, terete-com- 

 pressed, scarcely lacunose, fuscous-glaucescent, much branched and 

 fuscous-olivaceous above, branches subdichotomous, tuberculate-ramu- 

 lose, obtusish. Dufourea ramulosa, Hook. App. to Parry''s Sec. Voy. 

 p. 42^. 



Arctic America, Hook. Considered by Hooker nearest to E. ma- 

 dreporiformis, from which he remarks that it differs in color, in its 

 branching, and in being fistulous. 



7. E. arctica, Rich, (sub Dufourea). Th. somewhat csespitose, sub- 

 simple, or with a few short branches above, subulate-ventricose, smooth, 

 sulphureous becoming brownish ; apoth. chestnut, with an obscure, 

 crenulate thalline margin. Dufourea arctica, Rich, in Frankl. Narr. 

 p. 762 & Icon, ^ 31. 



Bear Lake, and elsewhere in Arctic America, Rich. (herb. Hook. !). 

 I follow Fries in considering the Dufourese a section of the present 

 genus. Hooker (App. to Parry's Sec. Voy. 1. c.) refers Dufourea no- 

 dosa, R. Br. (Ross's Voyage), to a variety of the present species. I 

 have not seen the description of Brown. 



§ III. Physcia, Fr. Foliaceous-compressed, the under side chan- 

 nelled. 



