166 FRESH-WATER ALG^E OF THE UNITED STATES. 



a division of a green cell into four parts; fig. 34, comple- 

 tion of the division of a green cell into four, each part 

 developing a complete zygospore with two cilia ; fig. 35, an 

 abnormal division of a cell into six parts, producing four 

 cells of normal size and two smaller ones ; fig. 36, same as 

 last ; fig. 37,' a vegetative green primordial cell ; fig. 38, cell 

 dissolving, the primordial cell breaking up into green and 

 red granules ; fig. 39, a resting cell developing a colorless end ; 

 commencement of germination ; fig. 40, division of a resting 

 cell into two somewhat elliptical cells, center red, sur- 

 rounded by light and then darker green ; fig. 41, elliptic cell, 

 middle red, margins lighter or darker green ; fig. 42, divi- 

 sion of a resting cell into eight. The maternal cell dissolves 

 into a gelatinous mass containing eight cylindrical, red, mo- 

 tile cells ; fig. 43, two cylindrical cells developed from the 

 young forms in fig. 42, red, with margins green ; fig. 44, 

 green cell, center red ; fig. 45, eight small, light green cells 

 with red centers resulting from the division of a single cell ; 

 fig. 46, grape-like cluster developed from an unsheathed 

 form, resting without having passed through the usual 

 swarming period of life; fig. 47, a large, deep green cell 

 developed from a sheathed resting spore, containing many 

 green granules ; fig. 48, cell similar to the last, but red, 

 which during observation broke up into eight small sub- 

 cylindrical parts, which soon broke through the membrane 

 as active zoospores; fig. 49, similar to the preceding (48), 

 breaks up into more numerous parts, but in consequence of 

 previous dried condition the parts become resting spores; 

 fig. 50, large resting spore, red, breaks up into a larger 

 number of smaller parts; fig. 51, zoospore with hyaline 

 membranous envelope, dark red. 



These 41 are selected from Cohn's 114 figures. Each a 

 different condition of the same plant. 



CHLAMYDOCOCCUS NIVALIS, A.Br. 



Cells globose, red, at first with a hyaline border, which is 

 the thickened epispore, but gradually disappears with age. 

 Diameter of cells, 10-35 jw. 



Syn. Haematococcus nivalis, Ag. ; Protococcus nivalis, Ag. ; Pal- 

 mella nivalis, Hook ; Coccophysium nivale, Link. ; Tremella 

 nivalis, A.Br.; Uredo nivalis, Bauer. 



This plant, familiarly known as BED SNOW, is frequently 

 found on the higher peaks of the Rocky Mountains. It is 



