ANALYTICAL KEYS 



TO THE 



GENERA AND SPECIES 



OF THE 



FRESH WATER 



AND 



The Desmidieae of the United States, 



FOUNDED ON THE CLASSIFICATION OF 



THE REV. FRANCIS WOLLE'S MONOGRAPHS, 



BY 



DR. ALFRED C. S'TOKES, 



* ; -.i_ 

 ^ 



Author of "Microscopy for Beginners;" "A Contribution toward 



a Natural History of the Fresh Water Infusoria 



of the United States," etc. 



PORTLAND, CONN.: 



EDWARD F. BIGELOW, PUBLISHER. 

 1893- 



