Sarcodina amidst diatoms. This subgroup of protozoa includes the familiar shape-shifting amoebas. Most sarcodines are free living; others are parasitic.They use their pseudopods (feet) for locomotion and feeding. Sarcodinas use their pseudopods to engulf or latch onto prey, which may include bacteria, algae or other protozoa. Several species in the sarcodina group, including some species of amoebas, cover themselves with protective shell-like coverings called tests. These tests are stippled with many small and large openings through which water can flow in and out and through which the pseudopods protrude. Anoptial contrast. Mag., x80.