Eudorina
Eudorina is commonly found in the plankton of hard-water lakes. The genus is cosmopolitan with about 7 species, several of which are found in the United States and Canada. The species Eudorina elegans is among the most common green algae.
 
Eudorina is polyphyletic, so some species may eventually be transferred to new genera to reflect the differences in evolutionary ancestry.