Carteria Diesing
Note the eyespot indicated by the arrow.	This unicellular green alga is similar in morphology to Chlamydomonas but is quadriflagellate (bearing four flagella) rather than biflagellate. The cell walls are not swollen, and instead tightly surround the protoplast. Some species may have four contractile vacuoles or two eyespots, or both.   Evidence from molecular phylogenetic analyses indicates that Carteria is paraphyletic, meaning that the genus does not include all descendents of a common ancestor.   The existence of two distinct evolutionary groups is also supported by flagellar ultrastructure data and scanning electron microscopy images of a distinctive arrangement of anterior cell wall papillae.       Note the four flagella on each cell.