Astrammina

Test free, large, up to 6.5 mm in diameter, in the form of a single spherical or flattened polygonal chamber with one to five narrow stolon-like arms radiating in various directions but usually in nearly the same plane and the longest ones commonly very flexible, may also have fragile conical projections and may produce rounded buds; protoplasmic body enclosed in a thick tripartite theca with a single oral region.