Actinopodea

(invertebrate zoology) A class of protozoans belonging to the superclass Sarcodina; most are free-floating, with highly specialized pseudopodia.

A class of Sarcodina. Some of these protozoans have more or less permanent pseudopodia, composed of axial filaments surrounded by a cytoplasmic envelope (axopodia); others have delicate and often radially arranged filopodia (filamentous pseudopodia) or filoreticulopodia (filamentous branched pseudopodia) without axial filaments. Although some are stalked and sessile, most are floating types. There are four subclasses: Radiolaria, Acantharia, Heliozoia, and Proteomyxidia. See also Acantharia; Heliozoia; Proteomyxidia; Radiolaria; Sarcodina.