the Anatomy of the Genus Selaginella , Spr. 155 
Fig. 19. Transverse section of the ventral leaf of S. suberosa. Three of the 
sclerotic fibres are shown, x 350. 
Fig. 20. Transverse section of the ventral leaf of S . canaliculata near the 
margin. X350. 
Fig. 21. Transverse section, ventral leaf of S. plumosa. X350. 
Fig. 22. Transverse section, ventral leaf of S. viticulosa. X350. 
Fig. 23. Longitudinal section of the ventral leaf of S. helvetica. x 350. 
Figs. 24, 25. S. concinna: Fig. 24 from the margin of the leaf, Fig. 25 from 
near the midrib, x 350. 
Fig. 26. Transverse section, leaf of S. spinosa. X350. 
Figs. 27, 28. S. rupestris : Fig. 27, a longitudinal section, X350; Fig. 28, trans- 
verse section, X75. 
Fig. 29. Transverse section of the ventral leaf of S. serpens . 
Figs. 30, 31. S. Wildenowii, Fig. 30 from near the margin ; Fig. 31 through 
the midrib. X350. The latter section is taken across the upper half of the leaf, 
where the xylem of the vascular bundle consists chiefly of reticulate elements. 
