To the marine portion of this list, are added those species enumerated 

 by Prof. Harvey, in Nereis Boreali American^ which have escaped 

 my observation, and have been found by others in Rhode Island. 



Of the fresh water species. I have few for distribution. These were 

 obtained mainly in the environs of this City, and were placed in 

 twenty-seven small vials in Goadsby's solution, and sent to Prof. 

 Harvey, who submitted them to the judgment of the most learned 

 English botanist in this particular department, G. H. K. Thwaites, Esq, 

 then of Bristol, England. The large number of species found in this 

 collection, in so limited a range, and collected within a very short period, 

 is surprising, and shows what more persistent collections will develop. 

 I have not time to collate the numerous publications of the lamented 

 Prof. Bailey, or I might have made the list of this portion of Bhode 

 Island plants more complete. The Desmidiere were elaborated by 

 Ralfs in 1848 ; this author was in correspondence with Prof. Bailey, 

 and I have added from his work, British Desmidiece those species 

 as given from Rhode Island, or in a geographical range including it. 



Providence, December 1st, 1871. 



