Order Desmothoracida, the desmothoracids, are a group of heliozoan protists, usually sessile and found in freshwater environments. The adult is a spherical cell around 10-20 μm in diameter surrounded by a perforated organic lorica, or shell, with many radial pseudopods projecting through the holes to capture food. These are supported by small bundles of microtubules that arise near a point on the nuclear membrane.