1898 ] SOME WEST AMERICAN THERMAL ALG poe 
Hormiscia FLAcciDA (Kg.) Lagerh. var. cCALDARIA (Kg.) 
Hansg. Prodr. 61. 1886-1888 and in Flora 265. 1888. Tilden. 
Am. Alg. Cent. II. no. 130. 1896. (Pl. VII, figs. 4, 5.) 
Stratum dull green, soft, in long strings, dark green in the 
current, light green scum in the standing water; vegetative cells 
5-7.5 wide, 0.5-2 times as long as the diameter. 
In water from hot spring flowing down a grassy bank. 
Temperature 23° C. Norris Geyser Basin, Yellowstone National 
Park. J.E.T. 26 Je 1896. 
This form seems to agree almost equally well with the above 
variety and with H. subtilis (Kg.) De Toni var. thermarum 
(Wartm.) Rabenh. Like the former, it occurs in soft some- 
what lubricous masses. Its measurements correspond exactly, 
ifthe cells undergoing division be excepted. A filament made 
up entirely of mature cells would resemble Kiitzing’s figure in 
Tab. Phyc. 3: pl. 32, f. 3. 1853. On the other hand, its habitat 
scems to accord better with the latter variety. When compared 
— Rabenhorst’s Algen Sachs. no. 655 (placed here by De 
Toni) there is found to be no special difference in appearance. 
The diameter of Rabenhorst’s specimen is slightly greater, per- 
haps, and the length of the cells, while in general 1~1.5 times 
the diameter, in many cases is twice the diameter. It would 
then appear that the Yellowstone plant agrees with the des- 
mig ai of one species and an authentic specimen of another 
*peciés as these are offered in De Toni’s Sylloge Algarum. If 
rn crassior Hansg. of var. thermarum be taken into account, 
of sce oem to be no objection to making a single variety 
In that s ce ey as they belong to species so nearly related. 
tela ase, according to the rule of priority, the plant would 
above name. 
ConFErva 
VIL, figs, 6,7 
co (ferrugineus, fulvus) ; filaments encrusted with fer- 
ing fae €, 0;), sometimes in narrow bands, generally form- 
diameter sie Coatings; cells 13-20 in diameter, twice the 
ength, after division equaling the diameter. 
MAJOR (Kg.) Rabenh, forma ferruginea, n. f. (77. 
8. : 
