Family: Test round, thin, firm to elastic, some with spines or spicules (Illustrated Guide, 1985).
Genus:
Test consisting of a thin, flexible, homogeneous envelope, colorless or translucent, without adherent paticles;
pseudostome terminal, elastic; cytoplasm colorless, granular, completely filling the test;
nucleus large, placed posteriorly; pseudopodia numerous, long, branching but not anastomosing
(Cash & Wailes, 1915).
Pseudostome oval, cells clustered (Illustrated Guide, 1985).