The trophic stage consists of limax-type amoebae in all cases, with only the species Pocheina flagellata possessing flagellate cells. All genera in the subclass form microcysts under conditions unfavorable to the trophic stage. Amoebae migrate singly or in small groups to form sorocarps, never exhibiting streams of aggregating cells typical for the Dictyosteliidae. The aggregated cells climb on top of each other, rising off of the substrate to produce a sorocarp that may consist of only one type of encysted cell (sorocysts) or may be differentiated into stalk cells and spores, as is the pattern in Dictyosteliidae. The species with differentiated stalk cells and spores have plate-like mitochondrial cristae while those consisting entirely of sorocysts have tubular mitochondrial cristae.