The Difflugia is a small amoeba and belongs to the Phyllum Sarcodina.
It lives in a rather large chitinous "test" (shell). The shell is usually covered completely with sand grains. The Difflugia is from 200-250 microns long.
Pseudopods extend out from the shell and are used for locomotion.
This shelled rhizopod feeds mainly on Spirogyria (a green algae)
These amoebas are available from science supply companies and the shell architecture and feeding habits make the Difflugia interesting to observe.