No. II.] THE BRYOPHYTES OF CONNECTICUT. TJ 



Chlorophyll cells elliptical, spindle-shaped, or rectangular 

 in cross section, not triangular or trapezoidal (except in 

 S. dasyphyllutu) 20 



4. Base toward the inner surface of the leaf; hyaline cells 



strongly convex toward the outer surface; branch leaves 



erect (Acutifolia, p. 83) 5 



Base toward the outer surface of the leaf; hyaline cells 

 usually strongly convex toward the inner surface 13 



5. Stem leaves lacerate-fringed at the broadly rounded apex, 



without fibrils 6 



Stem leaves more or less truncate and toothed at the apex, 

 not fringed 7 



6. Stem leaves broadened above, spatulate, apex and upper 



margins fringed; monoicous S. fimbriatum 



Stem leaves not broadened above, Ungulate, fringed only 

 at the apex; dioicous S. Girgensohnii 



7. Stem leaves lingulate, fibrils usually absent, though some- 



times present in the upper part of the leaf 8 



Stem leaves triangularly lingulate to equilaterally tri- 

 angular, usually with fibrils lO 



8. Plants usually red, never brown 9 



Plants usually brown, never red; pores as in 5". Warnstorfii; 



stem leaves without fibrils S. fuscum 



9. Pores present on outer surface of the branch leaves, small, 



round, and situated in the cell angles; stem leaves with- 

 out fibrils S. Warnstorfii 



Pores present on outer surface of the lower branch leaves, 

 large, more or less semicircular, and situated along the 

 lateral margins of the cells; stem leaves frequently with 



fibrils S. rubellum 



ID. Branch leaves when dry distinctly s-ranked;. outer wall of 

 cortical cells in stem often with irregular pores in the 

 upper ends of the cells S. qiiinquefarium 



Branch leaves when dry not arranged in distinct rows. ... 11 



11. Stem leaves with fibrils and pores; branch leaves not 



glossy when dry 12 



Stem leaves mostly without fibrils or pores; branch leaves 

 glossy when dry ; cortical cells of stem seldom with 

 pores; hyaline cells of stem leaves usually 2-6-septate 



S. subnitens 



12. Outer wall of cortical cells in stem often with irregular 



pores in the upper ends of the cells; hyaline cells of 

 stem leaves not divided, or, if so, uniseptate. .S. acutifolium 

 Cortical cells in stem without pores; hyaline cells of stem 

 leaves copiously divided by oblique walls S. tenerum 



