(tet-rah-might-us) is one of the heterolobose amoebae, which can be found as amoebae, flagellates or cysts. The amoebae produce their pseudopodia suddenly, a pattern of behaviour referred to as eruptive as opposed to the more usual slow progressive formation of pseudopodia. With file filaments making up the posterior uroid. Contractile vacuole located at the posterior end of the cell. Phase contrast.