400 Prof. Bailey on the Alge@ of the United States. 
hweinitz’s labels. True name. 
Iraparnaldia glomerata, Ag. 
Sc 
Conferva mutabilis, Salem, N. Ca. a 
rnali. at BS = Fragillaria pectinalis, Lyngb- 
#6 lubrica, « ss =  Oscillatoria, sp. 
ve vaginata, oy == Microcoleus repens, Harv- 
ay genuflexa, sis = Mougeotia genuflexa, Ag. 
“  jugalis, Ad 4 = Zygnema quininum, Ag. 
ns uitans, Schweinitz, Salem, N. €a. 
és amphibea, “ce ce “ce 
# setiformis, “eg ee «Not recognized. 
se varia, “ce “é os | 
gc semistrangulata, * ts sae, SY 
It appears from the above, that to Schweinitz is due the credit 
of being the first to collect and study any of our fluviatile Alge. 
Hydrodictyon utriculatum, Roth. This most interesting plant 
was found by Dr. Paul B. Goddard and myself, growing abun- 
dantly in a small pond at the foot of Broad street, in Philadelphia, 
also succeeded in sending living specimens to correspondents in 
London. | 
Mougeotia genuflera, Ag. Providence, R.1. West Point, N. 
Y. Detroit, Michigan. Fort Winnebago, Ouisconsin. 
Tyndaridea cruciata, Harv. Common in the Northern States. 
so in Virginia. = 
Tyndaridea pectinata, Harv. Common with the above. 
Zygnema nitidum, Ag. Waterville, Maine, to Culpepper Co., 
Virginia, and west to Ouisconsin. 
ygnema deciminum, Ag. Alabama, Dr. Gates! Very com- 
mon with the above. roa 
Zygnema quininum, Ag. Salem, N. Ca., Schweinitz! Com- 
mon with the above. 4 
If the numerous forms described and figured by Hassall, are 
really distinct species, the list of our species of Zygnema and 
Tyndaridea might be greatly extended, as I recognize among his 
figures many forms which are common in the United States, and 
which appear to me to be merely varieties of the above mentioned 
very polymorphous species. 
Spheroplea crispa, Berk. West Point, N. Y. 
Vaucheria velutina. Shores of Hudson River, at West Point ; 
in fruit in September. Shores of Seakonk River, near Provr 
dence, R. I. 
Ocean House, Newport, R. I. ‘ 
Rivularia calcarea, Sm. Niagara Falls, on rocks wet with 
y: 
