Explanation of Plate. 



[FRONTISPIECE.] 



CxENERA OF DESMIDS. 

 Each Figure is numbered to correspond with the number of the genus. 



FIG 



I 



2 



3 



4. 



5 

 6 



9 



lO 



II 



12 

 13 



14 



15 

 16, 



17 

 18, 



19 



20 

 21 



22 

 23 

 24 



Gonatozygon. Omitted; the cell needs no figure. 



Genicularia. 



Hyalotheca. 



Bambusina. 



Leptozosma. Omitted; the cell needs no figure. 



Desmidium. 



Phymatodocis. 



Sphaerozosma. 



Onychonema. 



Mesotsenium. 



Spirotaenia. 



Penium. 



Closterium; three figures, showing central inflation and ends 



produced into beaks. 

 Docidium. 



Triploceras; end and part of cell. 

 Calocylindrus. 

 Cosmarium. 

 Tetmemorus. 

 Xanthidium. 



Arthrodesmus; 20a, front view, h, end view. 

 Euastrum. 



Micrasterias; five forms. 



Staurastrum; four forms; 23a, front view, b, end. 

 Pediastrum; three forms. 



