—45 — 



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*ll# 



Cf.tr ARIA PiATVPUvi.i.A, Tuckm. 

 (Fig. 6.) Thallus foliaceous. rather rigid, 

 leaf-like and much wrinkled. It is dark 

 brown, rather paler beneath, with no 

 fibrils. The lobes are round and slightly 

 notched. The apothecia are medium, 

 marginal, disk a little darker brown 

 than the thallus, and the edges are 

 rough. C. plaiyphylla resembles some 

 of the vStictas in appearance. 



Cetraria ai.eurites. (Ach.) Th. Fr.. 

 a common one in the Northern and Middle States, and is found in the moun- 

 tains of the Southern States. It grows on trees and dead wood, especially 

 on coniferous trees, and adheres closely to the substratum. The thallus is folia- 

 ceous. with deep clefts, and is usually covered with isidiod granules which 

 at the center sometmies form a thick crust. It is straw color, in some speci- 

 mens is greener than in others. Beneath it is paler and much wrinkled with 

 brown fibrils. Apothecia are found on the margin of the thallus; they are a 

 pale chestnut color, with granules on the margin. 



Fig. 6. C. platyphylla x I. 

 is not a conspicuous l.,ichen, but is 



SCAPANIA EVANSII N. SP. 



By N. Bryhn. 



In appearance not unlike the larger forms of Scapania conve.xa Scop. 

 {Sc. umbrosa Dum.) Dioicus, the male plants mixed with the female, 

 about lo mm. high, with the leaves 2.25 to 2.5 mm. wide, caespitose, the 

 tufts quite spread out, not very dense, below dark green, above yellowish- 

 or ochraceous-green, very closely set with leaves. 



Stem rigid, slightly and distantly branched, ascending or erect, on the 

 under side densely covered with long hyaline radicles, dark colored, below 

 blackish, o 2 mm. thick, in cross-section round-oval, the peripheral cells with 

 pigmented walls in one or two layers. 



Leaves pellucid, but firm, quite densely imbricated, equal or subequal, 

 spreading at a right angle with the stem, folded and sharply keeled, two- 

 thirds to three-fourths divided into two unequal lobes; the keel of the 

 leaves distinctly winged below the conduplicate angle of the lobes, the wing 

 entire, two to four cells wide. 



Posterior lobe of leaves obliquely obovate-oval, very slightly convex, 

 hardly decurrent, with obtuse apex, and with margin throughout more or 

 less densely dentate with small, sharp and slender teeth, each formed of a 



single cell. 



Anterior lobe half as large, closely pressed against the stem and the 

 posterior lobe, obliquely cordate-reniform, reaching well across the stem, 

 strongly convex, its apex obtuse, the incurved margin finely and distantly 

 dentate with small teeth. 



