OF ARTS AND SCIENCES. 201 



and flexile, filiform, smooth, somewhat branched, whitish-pallescent ; 

 fibres horizontal, scattered, rather secund, flexuous ; apoth. small, with 

 an elevated, thin, entire margin. Ach. Syn. p. 307. Icon, Ach. Meth., 

 t. 8, /. 1. 



Nova Scotia, Menzies, fide Ach. Canada, flerS. Michaux! The 

 specimen in herb. Floerk. ! which Floerke supposed might be U. tri- 

 chodea, Ach., is referred by him to U. plicata. 



5. U. sphacelata, R. Br. Th. erectish, fruticulose, the principal 

 branches ochroleucous, biack-vittate, smooth, the ultimate ones attenu- 

 ate, black, all sorediiferous. R. Br. Suppl. to Parry'^s Voy.p. 307. 



Melville Island, JR. Br. I have not seen American specimens, but I 

 have received fine ones from Dr. Vahl, collected by him in Spitzbergen. 



11. EVERNIA, Ach., Fr. 



Apothecia rounded, scutelliform, marginal ; disk open, placed upon 

 the cottony medullary layer, colored. Thallus originally erect, te- 

 retish-fruticulose or compressed-foliaceous (abnormally filamentous or 

 pendulous), within uniform, and either fistulous, or filled with the cot- 

 tony medullary layer. 



The third section of this genus (Physcia) is further represented in 

 the South of Europe by three species not as yet known with us : — E. 

 iniricata, Fr., with a much-branched, linear, glaucous thallus; E. viU 

 losa, Fr., with a villous, multifid, glaucous thallus ; and E. Jlavicons, 

 Fr , with a much branched, linear, bright yellow thallus; of which 

 the first and last species attain to the southern coast of England 

 (Borrer) ; the first two are found in the Canary Islands (Montague) ; 

 the second in Peru (Acharius) ; and the last in the West Indies (Ach.) 

 and South America (Eschweiler). It is possible that one or more of 

 these species may occur in the Southern States. In the North, E. di- 

 varicata, Ach., nearest to E. prunastrr, with a more or less filamentous, 

 softish, lacunose thallus, is the only European Lichen of the present 

 section that is wanting with us. 



§1. Cornicularia, Fr. Fruticulose, passing into filamentous 

 or pendulous forms. 



1. E,. furcellafa, Fr.,with long (terete-compressed .?) di-trichotomous- 

 ly divided, suberect, entangled branches, from hoary becoming cinere- 

 ous, or slightly greenish, with furcate fuscous apices, Dill. Muse. t. 85, 



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