194 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



Leaves long lanceolate, costa filling the acumen, 



brown B. pseudo-rigidala, I40. 



b. Leaves papillose. 



i. Cells at base roundish, quadrate, or ehort-rectangular. 



Annulus none or indistinct. 

 Leaves twisted when dry. 



Costa 7Q« wide at base and tapering gradually . B. fallax, 121. 

 Costa 50/< wide, of equal breadth to middle B. recnrrifolia, 122. 



Leaves not twisted when dry. 

 Costa pale, percurrent . . . . B. sabicmadophila, IS7. 

 Costa brown, short excurrent . . . B. melanocarpa, 1S8. 



Annulus pale, compound ...... B. elata, 125. 



ii. Cells at base rectangular, often elongated. 



IB. fallax may be sought here.] 



Leaves erect-incurved, imbricate when dry. 



Cells (above) 5-7/i diameter B. vinealls, 124. 



Cells twice as large B. virescens, 124. 



Leaves squarrose-spreading or reflexed, twisted when dry. 

 Perichaetial leaves open, sheathing only at base, revolute 



on edges B. snbfallax, 121. 



Perichaetial leaves half sheathing. 

 Annulus simple, narrow, persistent. 

 Leaves erect, half clasping at base . . B. semitorta,^ 126. 

 Leaves recurved, deeply concave . . B. circinnatnla, I4I. 

 Annulus double or triple. 



Cells ^7;. m diameter .... {l^^^^^^^: 



Cells twice as large B. virescens, 124. 



£B. vinealis, flexifolia, virescens, cylindrica, with possibly semi- 

 torta and circinnatula, are doubtless forms of one species, so that the 

 key will probably break down here. 



BB. decursivula, Dieckii, horridifolia, robustifolia, and subcylin- 

 drica, belonging to this section, are described from sterile specimens and 

 therefore cannot be included in the key, but descriptions will be found in 

 the Appendix nos. 132, 134, 142, 143, and 145. 



^In L. & J. Man. 126, in note under S. semitorta, read "Comparable to B. vinealis" 

 instead of B. braehyphylla. See Paoif. E. E. Eept. 4: 186. 



