1898] SOME WEST AMERICAN THERMAL ALG 93 
vegetative green becoming yellowish. It occurred in soft 
masses on bottom of a spring. Temperature 38°C. Locality 
and date same as above. 
In the first collection small prickly masses of mineral forma- 
tion, probably gypsum, also occurred. Chrootoccus varius was 
present in great quantity. The second collection contained 
Protococcus cells. 
Microspora Weedii, n. sp. (Pl. VIZ/, fig. 73.) 
Cespitose-floccose, dark green in denser parts, pale bluish- 
green in thinner portions ; vegetative cells cylindrical, some- 
times a little constricted at the septations, 7-9 in diameter, 
before division 0.5—3 times longer than diameter; membrane 
homogeneous, hyaline, thin. : 
(2) Bright green. Forms jelly on slope. Temperature 49°C. 
aig Norris Basin, Yellowstone National Park. W. H. W. 
1097. 
The peculiar bluish-green color is no doubt caused by the 
action of the formalin upon the plant, but it is worth noting 
Since it has not been observed in other formalin material of the 
green alge. The plant probably is nearest to M. abbreviata 
(Rabenh. ) Lagerh. but differs from it in being entirely free 
from the ferruginous color, in having a thin membrane, and in 
its habitat. 
BSIOCLONIOM ‘HiEROGLYPAICUM (Ag.) Kg. var. atro-brun- 
neu, n. var. (Pl. VIM, figs. 14, 15, 16, 17-) 
Bin strings, dark brown ( fuligineus) ; normal vegetative 
luge a in diameter, less than once as long to three times 
fey T than wide, very variable in size in the same filament, 
fresh) oC. short rhizoids ; cell contents (examined when 
ark brown, granular. 
(2) In shallow water, plastered to surface of ground, most 
Beare in slow current. In overflow, through grass, of hot 
hig on bank above. Temperature 24°C. Norris Geyser 
n, Yellowstone National Fark. J], Bet. 27 Je 1600. 
lux: 
