SUBPHYLUM POSTCILIODESMATOPHORA

These taxa have postciliodesmata, ribbon-like microtubular structures that are parts of the elaborate ciliary (flagellar) root system. They overlap, and, in this subphylum, tend to support the cytopharynx. Alveolar system poorly developed. The macronucleus divides by microtubular spindles that occur outside of the nuclear membrane. Two Classes.

CLASS KARYORELICTEA

Cells long and flattened. 2-many macronuclei that differentiate from micronuclei. Micronuclei divide by eumitosis. Highly contractile. 3 Orders.

• ORDER PROTOSTOMATIDA
  • Naked (unciliated) ventral surface. Some with no permanent cytostome. Often with symbiotic bacteria on the ventral surface.
  • Kentrophoros, Trachelophoros, Prototrachelocerca, Tracheloraphis, Trachelonema, Tracelocerca.

• ORDER LOXODIDA
  • Flattened with simple cytostome at anterior. Somatic ciliation on right; naked on bottom and sparse on left.
  • Loxodes, Remanella, Cryptopharynx, Apocryptopharynx.

• ORDER PROTOHETEROTRICHIDA
  • Holotrichs. Cytostome ventral with complex ciliature.
  • Avelia, Geleia.

CLASS HETEROTRICHEA

Dikinetids with overlapping postciliary microtubular ribbons. Oral kinetids conspicuous at anterior end. Macronucleus divided by particular microtubules. Many are sessile. 2 Orders.

• ORDER LICNOPHORIDA
  • Cell shaped like an hour glass that is flattened on both ends. Adoral disk with rings of cilia and cytostome. Temporarily attaches and moves by smaller attachment disk.
  • Licnophora

• ORDER HETEROTRICHIDA
  • Kinetid pairs either both ciliated or anterior one ciliated only. Left oral cirri (polykinetids) used for locomotion and feeding; with cytopyge. Alveolar membrane poorly developed.
  • Magnifolliculina, Folliculina, Parafolliculina, Metafolliculina, Pebrilla, Peritromus, Stentor, Parablepharisma, Anigsteinia, Blepharisma, Pseudoblepharisma, Sprostomum, Gruberia, Condylostoma, Condylostomides, Linostoma, Fabrea, Climacostomum, Copemetopus.

SUBPHYLUM INTRAMACRONUCLEATA

These taxa have macronuclei that divide by intramacronuclear spindles. 8 Classes

CLASS SPIROTRICHEA

Cells with an adoral band of membranelles and cirri (both polykinetids) which wind clockwise to the cytostome, which often is deep. Somatic ciliation ranges from fully covered to nearly naked. Some are loricate. This class has 5 Subclasses.

• SUBCLASS PROTOCRUZIIDA
  • Small cells with series of 5-8 (usually 6) kinetids. Rows of membranelles in oral region. 1 Order
  • ORDER PROTOCRUZIIDA
    • Protocruzia.

• SUBCLASS HYPOTRICHIA
  • Cells usually dorsoventrally flattened cells; marginal cirri absent or in broken rows. 1 Order
  • ORDER EUPLOTIDA
    • Psammocephalus, Marginotricha, Prodiscocephalus, Discocephalus, Paradiophrys, Uronychia, Diophryopsis, Diophrys, Euplotapsis, Certesia, Gastrocirrhus, Euplotidium, Cytharoides, Euplotes.

• SUBCLASS CHOREOTRICHIA
  • Cell conical or bell-shaped; membranelles and cirri encircle broad oral region; no cytopyge. Planktonic or sessile. Some raptorial. 2 Orders.
  • ORDER TINTINNIDA
    • Usually sessile; attached by aboral process to lorica.
    • Tintinnidium, Tintinnopsis, Poroecus, Codonella, Codonaria, Stenosemella, Codonellopsis, Laackmanniella, Coxiella, Nolaclusilis, Climacocylis, Coxiella, Helicostomella, Metacylis, Acanthostomella, Ascampbelliella, Epiplocylis, Ptychocylis, Rhabdonella, Rhabdonellopsis, Petalotricha, Cyttarocylis, Xystonella, Cymatocylis, Favella, Parafavella, Parundella, proplectella, Undella, Tintinnus, Eutintinnus, Amphorellopsis, Salpingacantha, Salpingella, Amphorides, Steenstrupiella.
  • ORDER CHOREOTRICHIDA
    • Cell bell-shaped; not sesslile, not loricate.
    • Strombilidium, Strombidiniopsis, Leegaardiella, Lohmanniella.

• SUBCLASS STICHOTRICHIA
  • Somatic cilia in rows or scattered cirri; oral ciliature with collar and lapel arrangement; cells round to dorsoventrally flattened. 4 Orders.
  • ORDER PLAGIOTOMIDA
    • Cirri in rows on dorsal and ventral sides of cell; not grouped; symbionts of animals, usually oligochaetes.
    • Plagiotoma.
  • ORDER UROSTYLIDA
    • Anterioventral cirri in more one or more series of zig-zag rows.
    • Notocephalus, Eschaneustyla, Birojima, Urostyla, Australothrix, Paruroleptus, Parabakuella, Bakuella, Holosticha, Territricha, Pseudourostyla, Keronella, Tricoronella, Bicoronella, Pseudokeronopsis.
  • ORDER STICHOTRICHIDA
    • Ventral cirri in one or more rows (not zig-zag).
    • Chaetospira, Stichotricha, Hypotrichidium, Atractos, Spiretella, Mucotrichidium, Strongylidium, Urostrongylum, Psilotricha, Kerona, Keronopsis, Paraholosticha, Pseudouroleptus, Gastrostyla, Hemiamphisiella, Paramphisiella, Amphisiellides, Paragastrostyla, Orthoamphisiella, Periholosticha, Uroleptoides, Amphisiella, Neogeneia, Pseudokahliella, Kahliella, Trachelochaeta, Wallackia, Paraurostyla, Parakahliella, Cladotricha, Parentocirrus, Engelmanniella, Deviata.
  • ORDER SPORADOTRICHIDA
    • Cirri scattered in distinct frontal and ventral groups.
    • Terricirra, Hemisincirra, Trachelostyla, Lamtostyla, Gonostomum, Ancystropodium, Pleurotricha, Histriculus, Parastylonychia, Tachysoma, Laurentiella, Onychodromus, Coniculostomum, Onychodromopsis, Cyrtohymena, Pseudostrombidium, Sterkiella, Notohymena, Steinia, Australocirrus, Stylonychia, Urosoma, Urosomoida, Oxytricha.

• SUBCLASS OLIGOTRICHIA
  • Oral polykinetids (membranelles and cirri) form an anterior open collar and ventral lapel. Somatic cilia reduced. No lorica. Mostly planktonic. 2 Orders.
  • ORDER HALTERIIDA
    • Somatic cilia sparse, but very long (>10 µm) forming bristles or stiff cilia. Cells round.
    • Meseres, Halteria, Pelagohalteria.
  • ORDER STROMBIDIIDA
    • Somatic cilature reduced to an encircling, often spiral girdle that begins at the posterior end of the cell. Some with internal plates.
    • Tontonia, Laboea, Cyrtostrombidium, Strombidium.
  • ORDER ARMOPHORIDA
    • Cells twisted to the left; oral region spiraled. Some are endosymbionts of echinoids.
    • Bothrostoma, Palmarella, Tesnospira, Brachonella, Eometopus, Metopus, Parametopsis, Cirranter, Caenomorpha, Ludio.
  • ORDER ODONTOSTOMATIDA
    • Cells laterally compressed and very small. Somatic ciliature separated into anterior and posterior groups. Anaerobic.
    • Mylestoma, Discomorphella, Atopodinium, Epalxella, Saprodinium.
  • ORDER CLEVELANDELLIDA
    • Rows of kinities meeting in sutures, that are distinctive; body usually laterally compressed. Nucleus supported by particular fibers. Many gut symbionts of many animals (vertebrates and invertebrates).
    • Clevelandella, Pronyctotherus, Nyctotherus, Nyctositum, Pygmotheroides, Nyctotheroides, Metanyctotherus, Paracichlidotherus, Cichlidotherus, Prosicuophora, Metasicuophora, Parasicuophora, Sicuophora.
  • ORDER PHACODINIIDA
    • Cells oviod and laterally compressed; cytostome in posterior half of the cell with oral membranelle extending into the anterior end of the cell.
    • Phacodinium.

CLASS LITOSTOMATEA

Somatic ciliature of monokinetids with two transverse ribbons and one posterior ribbon in the infraciliature. 2 Subclasses.

• SUBCLASS HAPTORIA
  • Poorly-developed alveoli, but separated from cytoplasm by a thick inner layer of the alveolar cortex called a tela corticalis. Toxicysts and clavate cilia (short, non-motile flagella that lack the inner two microtubules; 9+0), and rhabdos (tubular cytostomal structures). 3 Orders.
  • ORDER CYCLOTRICHIDA
    • Ciliature cirrus-like with rhabdos; no clavate cilia.
    • Myrionecta, Mesodinium, Rhabdoaskinasia, Askenasia, Pelagovasicola.
  • ORDER HAPTORIDA
    • Ciliature uniform monokinetids, rhabdos present. Carnivores.
    • Paraenchelys, Pseudoholophrya, Ovalorhabdos, Didinium, Monodidinium, Cyclotrichium, Pseudotrachelocerca, Actinobolina, Paradileptus, Trachelius, Dileptus, Helicoporodon, Pleuroplites, Phialina, Lacrymaria, Homalozoon, Papillorhabdos, Enchelys, Enchelydium, Fuscheria, Acropisthium, Bryophyllum, Perispira, Myriokaryon, Cranotheridium, Protospathidium, Spathidium, Supraspathidium, Arcuospathidium, Epispathidium, Lepidotrachelophyllum, Foissnerides, Chaenea, Acaryophyra, Enchelyodon, Lagynophrya, Trachelophyllum.
  • ORDER PLEUROSTOMATIDA
    • Cell laterally compressed, all ciliated, but may be different (e.g. bristles on one side). Oral kinetids extend along ventral edge of cell.
    • Opisthodon, Amphileptus, Pseudoamphileptus, Loxophyllum, Siroloxophyllum, Litonotus, Acineria.

• SUBCLASS TRICHOSTOMATIA
  • No toxicysts; oral cavity heavily ciliated (sometimes with membranelles). Most are endosymbionts of vertebrates. 2 Orders.
  • ORDER VESTIBULIFERIDA
    • Cytostome in a depression that is densely ciliated, no membranelles. Holotrichous.
    • Paraisotricha, Dasytricha, Isotricha, Balantidium, Vestibulongum.
  • ORDER ENTODINIOMORPHIDA
    • Somatic cilia in bands or tufts. Thick layer between ecto and endoplasm.
    • Wolskana, Polymorphella, Didesmis, Alloiozona, Circodinium, Raabena, Blepharocorys, Ochoterenaia, Ophryoscolex, Eudiplodinium, Ostracodinium, Endoplastron, Cycloposthium, Triplumaria, Prototapirella, Cochliatoxum, Troglodytella.

CLASS PHYLLOPHARYNGEA

Somatic kinities mostly monokinitids with lateral fibrils and a transverse fiber that is left-directed and convergent postciliary ribbon. Oral region with radially-arranged microtubular ribbons (the phyllae). 4 Subclasses.

• SUBCLASS PHYLLOPHARYNGIA
  • Mostly free-swimming, some sessile, some endosymbionts of external body cavities. True cytostome and cytopharynx. Macronucleus heteromerous (divided into regions with different DNA and RNA contents). 2 Orders.
  • ORDER CHLAMYDODONTIDA
    • Dorsoventrally flattened and may attach to substrate by ventral thigmotactic cilia. Somatic cilia mostly on the ventral side (usually in two somewhat equal fields).
    • Gymnozoum, Chitonella, Gaustronauta, Chlamydodon, Cyrtophoron, Thigmogaster, Trithigmostoma, Phascolodon, Chilodonatella, Chilodonella, Pseudochilodonopsis, Chlamydonellopsis, Coeloperix, Atopochilodon, Lynchella, Chlamydonella.
  • ORDER DYSTERIIDA
    • Laterally compressed but dorsal surface rounded; ventral cilia not thigmotactic, but attach by an unciliated adhesive region or by a conical foot-like appendage or stalk called a podite. Some exclusively on cetaceans.
    • Karoikeus, Pithites, Atelepithites, Trochochilodon, Plesiotrichopus, Aegyriana, Trochopodiella, Microxysma, Brooklynella, Orthotrochilia, Trochilioides, Hartmannula, Hartmannulopsis, Microdysteria, Dysteria, Trochilia.

• SUBCLASS RHYNCHODIA
  • Oral apparatus a suctorial tube supported by phyllae enclosing extrusosomes. Macronucleus homomerous. Predators or endosymbionts of marine invertebrates. 2 Orders.
  • ORDER HYPOCOMATIDA
    • Dorsoventrally flattened; somatic ciliature on ventral part of the cell. Posterior adhesive region. Predators of peritrichs, suctorians, ascidians and barnacles.
    • Crateristoma, Parahypocoma, Hypocoma.
  • ORDER RHYNCHODIDA
    • Ciliature in one or two thigmotactic field; much of the cell is naked. No posterior adhesive region. Parasites of gills of invertebrates.
    • Sphenophrya, Stegotricha, Ancistrocoma, Insignicoma, Hypocomides, Crebricoma, Raabella, Hypocomatidium, Colligocineta, Hypocomella, Ignotocoma.

• SUBCLASS CHONOTRICHIA
  • A group of sessile ciliates. The anterior end is transformed into a funnel-like swirling apparatus. The rows of cilia running along it transport food to the cytostome. The rest of the cell is not ciliated. Reproduction by budding to form a motile swarmer. Ecto-commensals on crustaceans. 2 Orders.
  • ORDER CRYPTOGEMMIDA
    • Eight or fewer buds (tomites or daughter cells) in a brood pouch (marsupium).
    • Actinochona, Cristichona, Rhizochona, Carinichona, Isochonopsis, Isochona, Trichochona, Pleochona, Inversochona, Chonosaurus, Ceratochona, Kentrochona, Spinichona, Dentichona, Oxychonina, Eriochona, Stylochona, Armichona, Flectichona, Coronochona, Echinochona, Eurychona.
  • ORDER EXOGEMMIIDA
    • One tomite or bud produced at a time.
    • Phyllochona, Chilodochona, Vasichona, Spirochona, Cavichona, Serpentichona, Filichona, Aurichona, Heliochona, Heterochona, Toxochona, Oenophoracona, Physochona, Lobochona.

• SUBCLASS SUCTORIA
  • Sessile ciliates which take up food by tentacles rather than by a cytostome. Reproduction simple or multiple budding. Only swarmer cells are ciliated. Many species form a stalk and lorica. 3 Orders.
  • ORDER EXOGENIDA
    • Budding and cytokinesis occur at the surface of the parental cell ( = exogenous budding).
    • Phalacrocleptes, Stylostoma, Trophogemma, Dendrosomides, Loricodendron, Ophryodendron, Spelaeophrya, Ephelota, Parapodophrya, Mucophrya, Manuelophrya, Gajewskajophrya, Sphaerophrya, Kystopus, Podophrya, Tachyblaston, Metacineta, Thecacineta, Paracineta, Urnula, Corynophrya, Ophryodendron.
  • ORDER ENDOGENIDA
    • Budding and cytokinesis occur in a pouch; larva exits through pore of pouch (= endogenous budding). Kinetosomes of larval kineties first develop around center of larva.
    • Dendrosoma, Lernaeophrya, Trichophrya, Platophrya, Heliophrya, Enchelyomorpha, Endosphaera, Trypanococcus, Pseudogemma, Acinetopsis, Solenophrya, Acineta, Pseudocorynophrya, Loricophrya, Erastophrya, Rhyncheta, Choanophrya, Tokophrya, Staurophrya, Allantosoma, Dendrosoma, Dendromectes.
  • ORDER EVAGINOGENIDA
    • Kinetosomes of larval Kineties develop on parental surface of brood pouch; cytokinesis completed exogenously.
    • Cyathdinium, Stylocometes, Cometodendron, Dendrocometides, Dendrocometes, Dactylosoma, Rhynchophrya, Cyclophrya, Prodiscophrya, Discophrya, Periacineta.

CLASS NASSOPHOREA

Somatic ciliature variable (monokinetids, dikinetids, cirri, and membranelles); alveoli well developed. Cell with typical tubular cytostomal structure that lacks toxicysts (called cyrtos). Fibrous trichocysts. 3 Orders.

• ORDER SYNHYMENIIDA
  • Small membranelles of four fused kinetids wind around anterior end of cell. Cyrtos present.
  • Phasmatopsis, Nassulopsis, Orthodonella, Zosterodasys.

• ORDER NASSULIDA
  • Cell densely ciliated with large cyrtos.
  • Obertrumia, Naxella, Rhinakis, Nassula, Furgasonia, Parafurgasonia, Paranassula, Enneameron, Pedohymena, Colpodium.

• ORDER MICROTHORACIDA
  • Few rows of somatic cilia. Cyrtos small.
  • Colpodidium, Discotricha, Trochiliopsis, Stammeridium, Microthorax, Drepanomonas, Leptopharynx, Pseudomicrothorax.

CLASS COLPODEA

Somatic cilia of dikinetids; infraciliature makes a network. Resting cysts common. 6 Orders.

• ORDER BRYOPHRYIDA
  • Right oral ciliature with kinetosomes arranged radially. Division in cysts.
  • Parabryophrya, Bryophrya, Puytoraciella.

• ORDER COLPODIDA
  • Right oral ciliature with small membranelles (few to many and somewhat disordered).
  • Grossglockneria, Pseudoplatyophyra, Ilsiella, Maryna, Bresslaua, Krassnigga, Colpoda, Kalometopia, Hausmanniella.

• ORDER CYRTOLOPHOSIDIDA
  • Shallow oral cavity; apical to subapical. Micronucleus in perinuclear space.
  • Cyrtolophosis, Sagittaria, Woodruffia, Rostrophrya, Kuklikophrya, Reticulowooruffia, Cirrophrya, Platyophrya.

• ORDER BURSARIOMORPHIDA
  • Left oral membranelles long. Anterior oral cavity very deep. Carniverous.
  • Bursaria, Bursaridium, Paraconylostoma.

• ORDER SOROGENIDA
  • Oral region at anterior end of cell enclosed by membranelles. Form aerial spore-bearing sorocarps.
  • Sorogena.

• ORDER BRYOMETOPIDA
  • Oral region subapical or at center of cell.
  • Jaroschia, Pentahymena, Trihymena, Thylakidium, Bryometopus, Kreyella, Orthokreyella.

CLASS PROSTOMATEA

Somatic ciliature monokinetids; cytostome terminal or subapical. Rhabdos-like cytopharynx. 2 Orders.

• ORDER PROSTOMATIDA
  • Apical cytostome; somatic kinetids at right angles to form prominent rows around the cell rather that longitudinal.
  • Apsiktrata, Metacystis, Pelatractus, Vasicola.

• ORDER PRORODONTIDA
  • Apical to subapical cytostome; cell with rows of cilia (several wide) around the cell in narrow, spaced bands. Toxicysts.
  • Plagiocampa, Malacophrys, Balanion, Dissothigma, Urotricha, Rhagadostoma, Placus, Spathidiopsis, Tiarina, Plagiopogon, Macrocoleps, Planicoleps, Lagynus, Prorodon, Pleurofragma, Holophrya, Bursellopsis.

CLASS PLAGIOPYLEA

Somatic ciliature with monokinetids; cytostome almost encircled by one or two rows of dikinetids. In anaerobic habitats. 1 Order.

• ORDER PLAGIOPLYIDA
  • Trimyema, Sonderia, Parasondaria, Plagiopyla, Lechriopyla, Pseudoplagiopyla.

CLASS OLIGOHYMENOPHOREA

Oral apparatus distinctive with a right oral dikinetid and three left oral membranelles. In ventral oral cavity with a deeper infundibulum that surrounds the cytostome. 6 Subclasses.

• SUBCLASS PENICULA
  • Long axis of oral membranelles parallel to the long axis of the cell. No cyrtos. 1 Order.
  • ORDER PENICULIDA
    • Lembadion, Marituja, Stokesia, Clathrostoma, Disematostoma, Wenrichia, Didieria, Frontonia, Paraclathrostoma, Urocentrum, Neobursaridium, Paramecium.

• SUBCLASS SCUTICOCILATIA
  • Somatic ciliature of dikinetids over most of the cell; some cilia form thigmotactic field. 3 Orders.
  • ORDER PHILASTERIDA
    • Paroral dikinetid shorter than other oral elements.
    • Thigmophrya, Urozona, Cinetochilum, Sphenostomella, Cardiostomatella, Paraloxocephalus, Loxocephalus, Paradexiotricha, Paratetrahymena, Dexiotricha, Pseudocohnilembus, Uronema, Uropedalium, Urocyclon, Homalogastra, Entorhipidium, Entodiscus, Biggaria, Cohnilembus, Philaster, Philasterides, Paraphilaster, Plagiopyliella, Thyrophylax, Cryptolembus, Ovolembus, Mesolembus, Paralembus, Mugardia, Anophryoides, Mesanophrys, Metanophrys, Paranophrys, Orchitophrya, Glauconema, Miamiensis, Potomacus.
  • ORDER PLEURONEMATIDA
    • Paroral cilia long forming veil or curtain. Cell distinctly ribbed; cytostomal apparatus in anterior 3/4 of the cell.
    • Calyptotricha, Composomella, Hippocomos, Ctedoctema, Paractedoctema, Histiobalantium, Peniculistoma, Echinosociella, Schizocalyptra, Pleurocoptes, Pleuronema, Dragescoa, Cristigera, Pseudocyclidium, Echinocyclidium, Cyclidium, Paurotricha, Paracyclidium, Isocyclidium, Conchophthirus, Thigmacoma.
  • ORDER THIGMOTRICHIDA
    • No velum, ribbed wall not obvious; cytostome in posterior 1/4 of cell. With thigmotactic flagella and anterior sucker. Symbiont of oligochaetes, mollusks, and echinoderms.
    • Ancistrumina, Protophrya, Hemispeira, Plagiospira, Proboveria, Boveria, Kozloffia, Raabellocineta, Histerocineta, Ptychostomum, Paraptychostomum.

• SUBCLASS HYMENOSTOMATIA
  • Holotrichous, mostly monokinetids; dikinetids only at anterior end of cell. Some with lifecycles in which stages vary in form. 1 Order.
  • ORDER HYMENOSTOMATIDA
    • Curimostoma, Spirozona, Stegochilum, Tetrahymena, Lambornella, Deltopylum, Colpidium, Turaniella, Glaucomella, Glaucoma, Jaocorlissia, Espejoia, Bursostoma.
    • Ichthyophthirius, Ophryoglena.

• SUBCLASS APOSTOMATIA
  • Ciliates with elaborate life cycles. Usually epizootic on marine crustacea. Cytostomes rosette-like; ciliary rows sparse and in spirals. 3 Orders.
  • ORDER PILISUCTORIDA
    • Usually attached to the setae of host. Tomites (swarmer cells) formed by sequential division.
    • Coniodophrys, Askoella.
  • ORDER ASTOMATOPHORIDA
    • Tomites long and they form chains by sequential division; Kineties spiraled down tomites. Endoparasites of cephalopods.
    • Chromidina.
  • ORDER APOSTOMATIDA
    • Trophonts (feeding adult cells) ciliated; tomites by multiple fission.
    • Collinia, Spirophrya, Phtorophrya, Phoretophrya, Hyalophysa, Gymnodiniodes.

• SUBCLASS PERITRICHIA
  • Anterior end of the cell broadened to a disk-shaped peristome; 2 rows of cilia wind to cytostome in counterclockwise direction. Food collected in a vestibulum; contractile vacuole empties into vestibulum. Myonemes involved in stalk contraction. Reproduction by longitudinal fission. Parasites and free-living. 2 Orders.
  • ORDER MOBILIA
    • Cells mobile or free-swimming.
    • Pallitrichodina, Trichodina, Vauchomia, Urceolaria, Leiotrocha, Polycycla, Trichodinopsis.
  • ORDER SESSILIDA
    • Cells attached to substrate.
    • Termitophyra, Astylozoon, Opisthonecta, Telotrochidium, Ophrydium, Platycola, Pyxicola, Cothurnia, Thuricola, Vaginocola, Ellobiophrya, Operculigera, Paragenophrys, Clistolagenophrys, Setonophrys, Lagenophrys, Stylohedra, Usconophrys, Rovinjella, Vorticella, Charchesium, Ruthiella, Intranstylum, Zoothamnium, Bededniella, Opercularia, Orbopercularia, Propyxidium, Ampullaster, Scyphidia, Apiosoma, Nidula, Campanella, Heteropolaria, Epistylis.

• SUBCLASS ASTOMATIA
  • No cytostome. Parasites or commensals of oligochaetes. Reproduction by terminal budding. Daughter cells can remain connected to mother cell and form a chain. 1 Order.
  • ORDER ASTOMATIA
    • Njinella, Almophrya, Anoplophrya, Steinella, Cepedietta, Haptophrya, Haptophryopsis, Clausicola, Maupasella, Intrshellina, Contophrya, Dicontophrya, Acanthodiophrya, Mrazekiella, Helella, Anthonyella, Radiophrya, Metaracoelophrya, Metaraiophrya, Hoplitophrya, Delphyella, Buetschliellopsis, Juxtaradiophrya, Radiophryoides, Kofoidella, Herpetophrya, Butschliella, Steinella, Sieboldiella, Mesnilella, Opalinopsis, Chromidina.