PREF \< 1 VII 



Ravenel, Aiken, S. < .. who during the past < i ur 1 1 1 <>r more years, has 

 -iit me many interesting specimens, from hi> own State, Georgia and 

 Florida ; ( 'apt. J. I kranell Smith. Baltimore, Md., \\ ho, in 1878 and 1 1 

 -<nt me ov< d hundred specimens of fresh-water Alga L r atli 



in Florida; in his collections the Desmids were not numerous, but they 

 included specimens not found elsewhere ; Mr. I". H. Bosford, assisted 

 by Mi-. ( '. < '<. Pringle, Charlotte, \'t., whose collections were copious 

 in northern Vermont; and Miss ESloise Butler, Minneapolis, Minn., 

 who was a most successful collector of Desmids; I am indebted t" 

 her for all the species in the 1 i t which are assigned t<> Minneapolis. 

 My acknowledgments would not be complete <lil I omit t<> mention 

 the practical interest taken in my labors by the Rev. II I '. Kitchel, 



and hi- ->n. Mr I I - KJtchel. 



In the descriptive part-, I have abbreviated the name of the dis- 

 coverer of each plant, the reader being referred for additional infor- 

 mation, i" the appended list of names alphabetically arranged with 



their abbreviations, and with th<- title of the 1 ks consulted in the 



compilation of this work. 



Although this work is believed t.. be exhaustive of all nun known 

 concerning the Desmids of the United 8t i the author regards 



it only as the pionei much larger and therefore more 



valuable, wherein will be recorded the achievements of those who will 

 perhaps be indebted to this \v>rk for their first introduction t 

 fascinating a study as that of the fresh-water Alga of our country. 



r. w. 



I.i i in i ii i m. Pennsylvania, 

 I'l bki iry, l s-> I 



