 "B. mandrillaris" is a free-living, heterotrophic amoeba, consisting of a standard complement of organelles surrounded by a three-layered cell wall (thought to be made of cellulose), and with an abnormally large cell nucleus.On average, a "Balamuthia" trophozoite is about 30 to 120 μm in diameter.The cysts fall around this range, as well.