PHYSCIA. 71 



now apiculate, and these apices, next, free) and in P. comosa as 

 well as P. leucomela, so as to suggest at least a quadrilocular 

 structure, which Nylander has indicated also in the stock of 

 P. obscura ; but it will scarcely be pretended that this evident 

 luxuriance is of great account ; or that, in the present species 

 at least, the spores are other than typically bilocular. 



3. P. ciliaris (L.) DC. ; thallus cartilagineous, diffusely 

 ca3spitose, more or less downy, whitish-ash-coloured becoming 

 at length brown ; beneath mostly ecorticate and whitish ; the 

 elongated, linear lobes many-cleft and soon imbricately inter- 

 tangled, their edges beset, especially towards the tips, with 

 simple fibrils ; apothecia middling-sized to largish, pedicellate ; 

 disk flat, sub-pruinose, with an incurved, mostly toothed border. 



Parmelia, Fr. L. E. p. 77. Physcia, Nyl. Syn. 1, p. 414. 



b. crinalis, Schser. ; thallus much narrowed ; apothecia also 



reduced. Spores bilocular, ^^ mic. Schcer. Enum. p. 10. 



Borrera crinalis, Schleich. 1823. B. angustata, Delis. ! in herb. 

 Spreng. Parm. ciliaris, v. angustata, Tuckerm. Syn. N. Eng. 

 p. 32 ; Physcia, Obs. Lich. 1. c. p. 388. 



Upon rocks, and on the earth (only &), Arctic America (Rich- 

 ardson), Hooker L c. 1823. Newfoundland, Despreaux. Kocky 

 Mountains, Herb. Hook. Shores of the Great Lakes, Miss M. L. 



Wilson. Shore of Willoughby Lake, Vermont, Frost. Our 



lichen agrees closely with the slender form of the European 

 one, but has a more northern range, being scarcely known 

 far south of Canada. Width of lobes for the most part less than 

 O mm -, 5, or about a quarter of the largest width of a, in Europe. 

 Apothecia 2-4 mm - wide ; those of a, in Europe, having a width 

 of 3-6 mm -. 



4. P. aquila (Ach.) Nyl.; thallus cartilagineous, stellate, 

 appressed, naked, tawny-brown ; beneath corticate, pale with 

 scattered, finally blackening fibrils ; lobes multipartite, linear, 

 at length much narrowed, those of the centre convex and 

 densely crowded, those of the circumference more dilated and 

 flat ; apothecia smallish to middling-sized, sessile ; the disk flat, 

 brownish-black, soon naked, with a tumid, sub-crenate border. 



Nyl. Syn. 1, p. 422. Parmelia, Ach. L. U. p. 488. 



b. detonsa, Tuckerm. ; thallus commonly pale- but at length 

 tawny-brown as in a, now isidiophorous, or the lobes oftener 





