Test free, monothalamous, fusiform, <300 um in length and <70um in width;organic wall transparent from 2to7um in width, thicker around the aperture. The single aperture is funnel-shape with a tubular internal extension. Multinucleate cytoplasm (up to 11 nuclei); granular, in constant rapid movement. Reticulopodes very active with rapidly forming reticulopodial network and fast moving granules. Specimens emit GAF (green autofluorescence), which disappeared with fixation.
Genera of family “Clade I”
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.