a 
1898] SOME WEST AMERICAN THERMAL ALGA: 97 
cells one to two times longer than wide, middle cells two to 
three times longer than wide, and upper cells in general sub- 
quadrate, with apex prolonged into a thread; cell contents 
granular. 
Forming a calcareous crust on bottom of ditch. Natural 
Sulphur Springs, Banff, Canada. J. E. T. 13 Ag 1897. 
This growth occurs toward the lower end of the ditch where 
the water is slightly warm and the current very swift. The gen- 
eral appearance and microscopic characters agree very well with 
authentic specimens in the Minnesota herbarium. 
HAPALOSIPHON MAJOR Tild. Am. Alg. Cent. II. no. 167. 1896. 
(Pl. IX, figs. r0, rr, 12, ee 
Stratum widely expanded, bright aeruginous in color; fila- 
ments sheathed, branched, composed of cells sometimes cylin- 
drical, 3-6 in width, showing no dissepiments, or divided into 
short somewhat quadrate to very long cells, sometimes globose 
up ei II in diameter ; branches single or geminate, sometimes 
geniculate ; heterocysts intercalated, oblong, cask-shaped, about 
8 in width, one to two times as long as wide. 
(2) Completely coating bed of very swift mountain rivulet, 
at vent of hot spring. Temperature of spring 61° C. Algal 
Srowth begins here and disappears at a distance of fifty-five 
feet from Spring where temperature is 51° C. Most luxuriant 
i. thirty-five feet from spring at temperature of 54°C. 
‘ Ountains near Lower Geyser Basin, Yellowstone National 
ark, «J, E. T. 28 Je 1806. 
, (4) In hot spring. Temperature 55°C. Cascade mountains, 
*< 45° 20’. Francis E. Lloyd, 1895. 
The filaments of /. major are nearly twice the diameter of 
sie ay H. laminosus. An important character of the latter 
ss os habit of forming crystals of lime, according to Cohn, 
Studied the plant at Carlsbad. The Yellowstone species 
tho: 
OCcurr, = a el 
€d in siliceous waters only, at least it was not discovered 
at Mammoth Hot s 
rings, where the waters contain calcium 
