Volvox aureus form spherical colonies of up to 50,000 cells and have green orbs that move slowly. Paramecium are oval shaped with crater-like openings and closings that can move, digest food, and reproduce. Euglena resemble small green caterpillars and move slowly with clear structures on their bodies. Amoebas are clear, shape-shifting cells that move extremely fast. The document describes and compares these four protists: Volvox aureus, Paramecium, Euglena, and Amoebas.