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stratum but when damp is easily removed. It is found in the Eastern 

 and Southern States, but is not common in the West, 



Physcia HYPOLEUCA (MuHL.) TucKM. Plate III. 2.) Thallus large and 

 smooth, light gray-brown, the lobes rather flat with crenate margins, which 

 are sometimes powdery. Beneath the thallus is either white or light brown, 

 densely covered with tufts of black bristle-like fibrils, with which it adheres 

 •closely to the substratum. The apothecia are rather large, crowded at the 

 centre, cup-shaped, the disk black with crenulate folded over margin. P. 

 kypoleuca is usually found on trees, and oftener in the South than at the 

 North. 



Physcia coMosA (EscHW.) Nyl. (Plate III. i.) This very pretty lichen 

 is found throughout the Southern States. The thallus is erect and smooth, 

 and the narrow lobes are coveVed with grayish white fibrils. The apothecia, 

 which are large, are on the ends of the lobes, the disk is blue-gray or prui- 

 nose, surrounded by a thin white border from which extends white cilia. 

 Underneath, the lobes of the thallus are convex, pale gray, thickly covered 

 with long white fibrils. It^adheres lightly to the trees on which it grows. 

 After a rain large specimens are often found on the ground. 



Physcia leucomela (L.) Michx. 

 (Fig. I. ) Thallus ascendant and elong- 

 ated, smooth with long ribbon - like 

 lobes, which become much intertangled 

 and are irregularly divided. Beneath, 

 these lobes are very white, and the 

 margins are covered with strong black 

 fibrils. The edges are rolled over giv- 

 Fig. I. Physcia leucomela. ing the thallus a channeled appearance. 

 While much like P. comosa it can readily be distinguished from it by the 

 color of the fibrils; in P . comosa they are light gray or white, in P. leucoi?tela 

 they are dark brown or black. Apothecia, which are very abundant in P . 

 comosa, are rare in P. leucomela. They are of medium size, pedicellate, 

 the disk almost white, the border beset with lobules. It is found on trees, and 

 is very abundant in the mountains of North Carolina. 



Physcia ciliaris (L.) DC. (Fig. 2). Thal- 

 lus somewhat downy, the lobes long and nar- 

 row, many cleft and much intertangled. Their 

 edges, especially toward the tips, are beset with 

 spine-like fibrils. The thallus is light brown 

 above, beneath a brownish white. Apothecia 

 are medium in size, cup-shaped, with a dark gray 

 Fig. 2. Physcia ciliaris. disk, which has a toothed border. P. ciliaris 

 much resembles P. leuco7nela, but the ribbon-like lobes are firmer, the color 

 of the thallus is light brown, that of P. leticomela is grayish white. P. 

 €iliaris is found on rocks, a small variety grows on the earth. While typi- 

 cally a Northern lichen it has been collected in New England and Minnesota. 



