PLATE XV. 



Figs, i, a-g. Barbtcla rigens. 



i, a. Entire plant, natural size. 



i, b, b. Leaves ( X 26). 



i, c. Apex of a leaf ( X !35)- 



i, d. Basal areolation ( X 135) • 



1, e. Cells in the middle of a leaf ( X I 3S)- 



*,_/. Transverse section of the leaf in the lower part ( X J 35)- 



1, g. Transverse section of the leaf in the upper part ( X 180). 



2, a-g. Barbula treleasei. 



2, a. Entire plant, natural size. 



2,5. Leaf (X 26). 



2, c. Perichaetial leaf ( X26). 



2, d. Apex of the stem leaf ( X 60). 



2, e. Basal areolation of same ( X I 35)« 



2,f. Cells in middle of same ( X l ZS)- 



2, g. Old capsule in dry state ( X !3)- 



3, a-h. Rhacomitrium cyclodictyon. 

 3, a. Entire plant, natural size. 

 3, b, b. Leaves ( X 26). 



3, c. Perichaetial leaf ( X 26). 



3, d. Transverse section of a stem leaf ( X 100). 



3, e. Basal areolation of same ( X 270). 



3,/". Areolation in the middle ( X 270). 



3, g. Areolation of the apex ( X ^S)' 



3, k. Old capsule in moist state ( X 1 3)- 

 At a ~g' Ulota alaskana. 



4, a. Entire plant, natural size. 

 4, b, b, b. Leaves ( X I 3)- 



4, c. Marginal areolation in the lower part ( X I 35)« 



4, d. Capsule and calyptra ( X l 3)- 



4, e. Capsule and lid ( X !3)- 



4,_/. Capsule ripe, in dry state ( X I 3)- 



4, g. Same, in moist state ( X 13)* 



(352) 



