Arnoldiellina

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.