OX A.LG2E FROM THE AMAZONS AND ITS TEIBUTAEIES. 123 



Notes on Algae from the Amazons/and its Tributaries. 

 By Professor G. DifrtiE, M.D. 



[Read May 6, 1880.] 



Pbofessor J. "W. H. Trail, during explorations on the Amazons 

 and branches, was very assiduous in collecting the Algae of the 

 regions visited. The materials thus accumulated have enabled 

 me to compile the present summary. 



Nordstedt has described some Brazilian freshwater Algae, 

 chiefly Desmids. A few collected by A. Glaziou were re- 

 corded by Dr. Gr. de Martens in 1871. In the following lists I 

 am indebted to Mr. John Hoy for notes of the Desmids ; and I 

 have also to acknow ledge assistance from the llev. G. Davidson in 

 recording the Diatoms ; some of them have also been submitted 

 to Grrunow, who is one of the highest authorities in this depart- 

 ment. 



Lemaniacej:. 



Compsofogon leftoclados, Mont. Ipiranga, Rio Purus ; 

 Lago Manacapuru, Bio Solimoes ; and Bio Tonantins. 



BaTRACHOSPERMACEjE. 



Thorea Tratli, n. sp. Dense caespitosa, uncialis, obscure viri- 

 dis ; ramis rigidis, ramulis flaccidis, articulis diametro 5-6 longio- 

 ribus. 



Forming dense tufts on wet sandstone rocks at Caxoeira grande, 

 near Manaos, and de Taruma. 



Batrachospermum moniliforme, Both., var. pbolifebum, 

 near Manaos ; var. nodiflorvm, near Obydos. 



Ch^tophorace^;. 

 Sti geocloniem plumosum, Kuetz. Seems but a variety of the 

 Cayenne plant. Lake Manacapuru. 



Coleoch^te scutata, Breb. A form of the European species. 

 Upon fallen leaves in Bio Negro. 



Microthamnion strictissimum, Babenh. The specimens cor- 

 respond well with the figure and description of the species. Mouth 

 of the Bio Negro at Lagos. 



LINN. JOURN. — BOTANY, VOL. XTIII. L 



