PLATE XXXIX. 



[Proc. Wash. Acad. Sci., Vol. IV, PI. XXII.] 



FIGS, i, a-f. Po lytrichiim yukotiense. 



i, a. Entire plant, natural size. 



i, b, b. Leaves ( X *3)- 



i, c. Transverse section of a leaf ( X34)- 



i, d. Transverse section of a lamella ( X I 35)- 



1, e. Part of a lamella seen from side ( X 2 7)- 

 !,_/". Basal areolation of the leaf ( X I 35)- 



2, a. Polytrichum jensenii, 



2, a. Basal areolation of the leaf ( X 



3, a-e. Brachythecium beringianum. 

 3, a. Entire plant, natural size. 

 3,*. Stem leaf ( X 26). 



3, c, c. Branch-leaves ( X 26). 



3, d. Basal areolation ( X I 3S)- 



3, e. Cells in the middle ( X 2 7)- 



4, a-e. Plagiothecium fallax. 



4, a. Entire plant, natural size. 



4,3. Leaf (X 13). 



4, c. Perigonial leaf ( X 2 ^). 



4, d. Basal areolation of a leaf ( X 



4, e. Areolation in the middle ( X I 35)- 



5, a-e. Hypnnm treleasei. 



5, a. Entire plant, natural size. 

 5, b, b, b. Leaves ( X 2 6). 



5, d. Basal areolation of a leaf ( X 2 7O)- 



5, e. Cells in the middle ( X 2 7)- 

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