Editing Gymnosphaerid (section)

==Genera==
There are only three genera, each with a single species: ''Gymnosphaera albida'', ''Hedraiophrys hovassei'', and ''Actinocoryne contractilis''.

*''Gymnosphaera albida'' is free-living, usually benthic in shallow water.  The cells are round and naked, around 70-100 μm in diameter, and resemble the unrelated ''[[actinophryid|Actinosphaerium]]''.  The outer cytoplasm, or ectoplasm, forms a distinct layer containing large vesicles.
*''Hedraiophrys hovassei'' is larger and lives attached to [[alga]]e and other objects.  The cells have a conical base, and are covered with long siliceous spicules.  The ectoplasm is distinct and frothy, and typically contains bacterial and algal [[endosymbiont]]s.
*''Actinocoryne contractilis'' is benthic.  When feeding, it has a [[multinucleate]] base and a contractile stalk up to 150 μm in length, supporting a relatively small [[uninucleate]] head, where the central granule and axopods are located.  In order to move, it collapses the stalk and head into an amoeboid form which is capable of migration.<ref>{{cite journal|title=Preliminary study of the motility processes in the stalked heliozoan ''Actinocoryne contractilis'' |author=Febvre-Chevalier C |journal=Biosystems |volume=14 |issue=3–4 |date=1981 |pages=337–343 |pmid=7337812 |doi=10.1016/0303-2647(81)90040-X}}</ref> Reproduction is either by budding off the head or fragmentation of the headless form, producing small free-living cells similar to ''Gymnosphaera'', which then attach themselves and regrow the stalk and base.