33 



Protococcus nivalis, Ag. ; West Point. 

 Stigonema mammilosum, Ag. ; ponds. 

 Sphaeioplea crispa, Berkley ; West Point. 

 Tetraspora perforata, Bailey ; West Point. 

 T. gelatinosa Desvime ; common. 

 T. lucunosa, Duby. 



Thorea veridis, Bory St. Vincent ; fresh water. 

 Tolypothrix distorta" Kiitzing ; ponds, 

 Tyndaridea cruciata, Harvey ; New York. 

 T. pectinata, Harvey ; common. 

 Zygnema quininum, Ag. ; common, 

 Z. nitidum, Ag. ; Maine. 

 9 Sp. ? or new. 



DIATOMACEyE. 



Achnanthes longipe. 



Exilaria. Sp. ? Greville. 



Synedra. Sp. ? 



Hymantidium arcus, Ehenbergh. 



Tabellaria floccosum, Ehenbergh. 



Meredion circulare, Agardh. 



Ossa. Sp. ? or new. New York Bay. 



Schyzonema quadrapunctata ; New York Bay. 



4 Sp. ? or new. 



This imperfect Catalogue of American Algae plainly shows the 

 wide and almost unexplored field open to the investigation of the 

 Naturalist, or even the lover of the curious and the beautiful ; for 

 it is herein shown how rapid the progress in the discovery of 

 species has been ; and, by the locations given, it will be understood 

 how wide a field remains unexplored ; for in 1835, Professor 

 Hitchcock, in his report to the Governor of Massachusetts of the 

 catalogue of plants found in that State, enumerates but eleven ; and 

 Dr. Torrey sent about as many from New York to the elder Agardh, 

 which were all that were known in the States until Professor 

 Bailey, in 1848, published his enlarged Catalogue, in which he 

 enumerates 172 species, namely — 



Melanosperms , . . . .31 

 Rhodosperms .... .59 

 Chlorosperms 82 



Total . .... 172 



