102 BOTANICAL .GAZETTE [ FEBRUARY 
purplish-black (atro-cyaneus), straight or somewhat flexuows, ) 
eter, not attenuate at apex, straight or but slightly arcuate a) 
extremities ; articulation 0.25-0.5 times as long as wide, 3) 
long; protoplasm homogeneous ; dissepiments sometimes grat 
ulose ; apical cell conical, not capitate ; no calyptra. 
In small mountain spring in a bog, together with moss ail 
watercress. Water tepid. Valley of Nez Perces creek, Lowy 
Geyser Basin, Yellowstone National Park. J. E.T. 28 Je 18% 
OscILLATORIA AMPHIBIA Ag. Aufzahlung, etc. in Flora 1 
632. 1827. (Pl. LX, fig. 21.) 
Stratum aeruginous, red or orange colored ; trichomes dilute 
aeruginous, straight or arcuate, fragile, not constricted at dissef | 
iments, 1.5—2u in diameter, arcuate for some distance at extrem 
ities, apex neither attenuate nor capitate ; articulations two t 
three times longer than diameter of trichome, 3-4# in length; 
dissepiments sometimes marked by two protoplasmic granules, | 
sometimes not distinct ; cell contents granular ; apical cell rotund. 
Forming lining in channel of spring. Above Beehive Gey 
ser, Upper Geyser Basin, Yellowstone National Park. W. H.¥ 
1897. 
The red and orange colors in this material are caused by at 
presence of bacteria. | 
OSCILLATORIA GEMINATA Menegh. Conspect. Algol. euganee 
9. 1837. Tilden, Am. Alg. Cent. II. no. 191. 1896. (Ae 
Jig. 22.) ie 
sepiments pellucid, not granulated; apical cell rotund; * 
calyptra. 
Covering bottom of creek in swift current. Tempe! 
/ 
