The dimorphids or heliomonads are a small group of heliozoa that are unusual in possessing flagella throughout their life-cycle. There are two genera: Dimorpha, a tiny organism found in freshwater the larger Tetradimorpha, which is distinguished by having four rather than two flagella. Bundles of microtubules, typically in square array, arise from a body near the flagellar bases and support the numerous axopods that project from the cell surface. Dimorphids have a single nucleus, and mitocho… (More on Dimorphid)