g2 BOTANICAL GAZETTE | FEBRUARY 
In acid waters of overflow. Temperature 74°C. “Thes 
alge are in part coated with Fe, O, on the margins of the pools | 
Echirus Geyser. W. H.W. 1897. 
The width of the filament in the form is somewhat narrowe | 
than that of the species. The specimen shows well the “lette 
H” appearance of the ruptured membrane which De Toni make 
a generic character. 
-CoNFERVA major (Kg.) Rabenh. forma gypsophila, n. f.(/ 
VIL, figs. 9, 10, 11.) 
Forming white or yellowish masses ; filaments encrusted with 
crystals of gypsum ; cells 10-20 u in diameter, twice as long # 
wide, after division equaling in length the diameter; cell cot 
tents granular, colorless; cell membrane thick. 
Lying near vent of spring. Temperature 66° C. Not 
Geyser Basin, Yellowstone National Park. j. EB. te i 
1896. 
This plant likewise differs from the species in having 4 nat 
rower filament. Little spiny or lobed masses of gypsum, 2% 
timeter in thickness, are found entwined with the threads. 
MICROSPORA AMOENA (Kg.) Rabenh. forma thermalis, 2. f(A 
VII, fig. 12.) 
Dark green, stringy; cells cylindrical, 11-14 # in diametth 
before division 2-3 times as long as wide, after division equal? 
ore little more than the diameter in length; membrane smooth 
delicate, firm ; cell contents finely granular, bright green; 
ments not constricted at septations. 
(2) Lying in overflow from spring. Temperature 
Frying Pan Basin, Yellowstone National Park. J. E17 
1896. 
It is difficult to decide whether this plant shoul 
as a Conferva or a Microspora, as the structure of the ae 
plastids could not be made out. It is placed here provisional a 
Its size is not as great as that of the species. a 
(4) A second gathering, slightly different in color, * 
4i° ¢ 
Bie 
d be classed : 
