HOW TO KNOW THE FRESH-WATER ALGAE 



175b Chloroplast a massive, axial body with processes which are flat- 

 tened against the wall. Fig. 126V2 KENTROSPHAERA 



Fig. 126V2. Kentrosphaera Bristolae G. M. Smith. 



There are 2 or 3 species of this genus (often 

 included in the genus Chloiochytrium (Fig. 94) 

 but only K. Bristolae has been reported from 

 this country. The cells are similar in shape 

 but have a free-living habit, usually occurring 

 in damp soil. 



Figure 12614 

 176a (174) Cells with spines 177 



176b Cells without spines 179 



177a Spines distributed over the cell wall 178 



177b Spines localized at the poles or at the midregion of the cell. See 

 Fig. 118 LAGERHEIMIA (CHODATELLA) 



178a Spines shorter than the diameter of the cell. See Fig. 120 



BOHLINIA 



1 78b Spines needle-like, as long as or longer than the diameter of the 

 cell; cell solitary or in 2's. See Fig. 73 FRANCEIA 



179a (176) Cells with spiral, longitudinal ribs on the walls. Fig. 127. 

 SCOTIELLA 



Fig. 127. Scotiella nivalis (Chod.) Fritsch. 



This genus contains a number of species, most of 

 which have been collected in the flora of red snow 

 at high altitudes. Differences lie in the shape of the 

 cell and the type of ridged decorations on the wall. 

 Occasionally Scotiella species are collected in the 

 tychoplankton at low altitudes. Some authorities place 

 this genus in the Volvocales because of the type of 

 chloroplast and the evidence of basal-distal differen- 

 tiation in the cell; whereas others include it with the 

 Chlorococcales. 



Figure 127 



84 



