438 Illinois State Laboratory of Natural History. 



Volvox. 



Cells about 10,000 (minimum 1,500, maximum 22,000), 

 angular, with stout connecting protoplasmic processes 

 into which the chromatophore may enter. Diameter of 

 colony about 700 /< (minimum 400, maximum 1,200) ; 

 diameter of cell body 3-5 yw. globator L. 



Cells 500-1,000 (minimum 200, maximum 4,400), 

 rounded, with slender connecting protoplasmic processes 

 into which the chromatophore does not enter. Diameter 

 of colony 170-850 /^; diameter of cell body 5-8 /<. 



aureus Ehrb. 



Urbana, 111., Dec. 5, 1809. 



