PLATE XXXI. 



CHARA CONTRARIA. 



Fiit- 1, Plant, natural size. 

 '• 2, Stem, showiiii; oorticiitioii. leaf, ami stiimlar uiicirl. \'ii). 

 " 3, Part of a leaf shovviug naked eud-L'ells, and two fertile eoiti 



cated nodes. x."0. 

 •■ i. Cross-section of stem; a yoiinj,' spine. x.")0. 



