An order of Mycetozoia. These are slime molds which form a plasmodium, a multinucleate stage that may in some species measure a foot or more across. The plasmodium, typically found on decaying plant material, is a migratory phagotroph preying on microorganisms. A mature plasmodium is a sheet of protoplasm containing a network of channels through which rapid endoplasmic streaming occurs. Direction of flow is reversible at intervals (shuttle-flow movement), but with a net unidirectional movement of the plasmodium. The cytoplasm often contains pigment (yellow, orange, green, or other colors).