30 Transactions of the Society. 



contractile vacuoles which pulsate independently of one another, 

 and that this is one of the chief distinguishing characters between 

 Sphceretta (Hacmcttococcus) and Chlamydomonas. He agrees with 

 Wille that Sphcerella nivalis should be regarded as a species of 

 Chlamydomonas, C. nivalis, but before this view can be definitely 

 accepted the motile state of Sphmrella nivalis requires a good 

 deal of detailed investigation. 



