Suborder (1) Exogemmina Jankowski, 1972

External budding, commonly only one bud at a time; body long and cylindrical, relatively large, and typically with well-developed collar; spines absent or poorly developed; usual attachment by undistinguished pedicel (rather than "true" stalk); macronuclear orthomere directed apically; species occur on marine, brackish, and fresh-water crustaceans (amphipods, isopods, mysids, decapods) and one marine alga.

Body elongate, bottle-shaped, not flattened; apical end simple, conical, slightly flared, often with two dorsal lobes; collar distinct; no spines; pedicel rypical of suborder; macronucleus ovoid; presumably primitive forms, found only in marine or brackish habitats - but with very wide distribution - on isopods and amphipods, with one unique species on an alga.	Family LOBOCHONIDAE Jankowski, 1967
Body cylindrical or bottle-shaped, large, not flattened; apical end simple, conical and unadorned; collar distinct and markedly elongate, with several heavy spines nearby; pedicel low and broad; macronucleus ovoid; marine, on isopods.	Family FILICHONIDAE Jankowski, 1973
Body leaf-shaped, not elongate, flattened dorsoventrally; apical end drawn out uniquely into huge, broad, flat plate; collar absent; some short lateral spines; pedicel in form of wide disc; macronucleus massive; marine, on isopods.	Family PHYLLOCHONIDAE Jankovski, 1972
Body bottle-shaped, elongate to sac-like, not flattened; apical end large, flat, fanned out, bearing rows of conspicuous spines giving whole structure a fimbriated appearance; collar distinct, usually short; pedicel rypical of suborder; macronucleus ovoid; marine or brackish habitats, on amphipods.	Family HELIOCHONIDAE Jankowski, 1972
Body ovoid or pyriform, massive, not flattened; apical end large, cylindrical, flaring slightly; collar indistinct or absent; no spines; body walls markedly thickened; long, wide, solid stalk (rather than pedicel rypical of suborder); macronucleus elongate; widely distributed on marine decapods in littoral and sublittoral habitats.	Family CHILODOCHONIDAE Wallengren, 1895
Body vase-shaped, elongate, not flattened; apical end flared, with dorsal wall multiplyspiraled in characteristic helical coils (as many as half a dozen full turns); collar short~ no spines; pedicel low and broad; macronucleus ovoid; on gammarid amphipods (generally the gills) in fresh-water, brackish, and marine habitats.	Family SPIROCHONIDAE Stein, 1854