124 



MEMOIRS OF THE NEW YORK BOTAXICAL GARDEX 



PLATE 15 



Figure 2G. Scyloncma evanescens 



Portion of a filament, showing the branching in 

 the upper younger part and the disappearance of 

 tlie cells below x 250 



" 27. Scytonema capitatum 



To tlie left, a single young filament, showing a 

 branch under a heterocyst ; L, showing typical 

 geminate branching and capitate ends x 250 



" 28. Scijionema longkirticuhtfum 



A single typical filament with lamellose sheatli 

 below, younger above, with geminate branching x 250 



" 29. Scytonema suhgrlafmosum 



Portions of filaments showing variations in char- 

 acter of the cells in different parts x 250 



" 30. Scytonema variahile 



Below with single branching, above with gemi- 

 nate branching x 250 



