II —Green AlgE. i. 2, Pediastrum. 3. Kirchnenella. 4. Dictyosphse- 

 rium. s, Characium. 6, Bulbocluete. 7. Selenastrum. 8, 9, Cctlastrum. 10, 

 Botrvococcus. 11, 12, Ankistrodesmus. 13, Richtenella. 14, Scenedesmus. 

 IS Ophiocvtium. 16, Sorastrum. 17, vSpirogyra. 18 19, Mougeotia. 20, 

 Zvgnema. '21, Tetraspora. 22, 23, Pleurococcus. 24, Cladophora. 25 Hy- 

 drodictyon. 26, Crucigenia. 27. Cluetophora. 28, Microspora. 29, Ulothnx. 

 30, Oedogoniuui. 31, Tribonema. 32, Draparnaldia. 



