Heterotrichina

Suborder (1) Heterotrichina Stein, 1859

Syns. Blepharismina,
Bursariina,
Condylostomatina,
Stentorina

With characteristics of order s.s. (above). Somatic ciliature well developed, but buccal organelles (paramembranelles) also numerous and prominent; of large body size, often contractile; single conspicuous contractile vacuole at posterior end of body; mucocysts in abundance, and pigment vesicles common in many species; no loricae, but cysts common; essentially all freeliving forms [endosymbiotic families formerly included here now comprise separate suborder: see below] , widely distributed in great variety of habitats.

Large, often elongate, cylindrical forms, some highly contractile, some pigmented; long, narrow peristomial field, sometimes with buccal ciliature relatively inconspicuous; somatic ciliation uniform, often dense, and typically complete; contractile vacuole posterior, frequently large, and may have lengthy collecting canal; macronucleus compact, ovoid to elongate-moniliform; free-living in fresh-water (predominantly), marine, or edaphic habitats. Family SPIROSTOMIDAE Stein, 1867

Body ovoid in shape, compressed laterally, with rigid and ribbed pellicle (= cuirass); cytoplasm nonpigmented; lengthy peristomial field, with conspicuous membranelles, terminating very near posterior pole of organism; somatic ciliature, in widely spaced rows, occurs in little packets of 6-8 delicate cilia each; macronucleus horseshoe-shaped; these hypotrich-like organisms show world-wide distribution, found mainly in edaphic habitats (e.g., moss on trees). Family PHACODINIIDAE n. fam.

Anterior part of body uniquely twisted to left, and posterior part sometimes tailed and/or bearing tuft of longer (caudal) cilia; buccal membranelles large, yet rather inconspicuous; uniform somatic ciliation, but often not dense; macronucleus compact, centrally located; widely distributed as fresh-water polysaprobic forms, but some also marine and psammophilic or inquilinic in echinoids. Family METOPIDAE Kahl, 1927

Body typically large, heavily ciliated, contractile; buccal ciliature, including paroral membrane, prominent; macronucleus long and moniliform in type-genus; body very elongate in some forms, nearly ellipsoidal in others; contractile vacuole often with long feeding canal; in various habitats: fresh-water, edaphic, and especially marine. Family CONDYLOSTOMATIDAE Kahl in Doflein & Reichenow, 1929

Body ellipsoidal, with narrowed peristomial field; somatic ciliation uniform, occasionally slightly spiraled; macronucleus elongate but not moniliform; in fresh-water or edaphic habitats. Family REICHENOWELLIDAE Kahl, 1932

Body large, ovoid, with very prominent peristomial field (buccal caviry) occupying much of anterior part of body; stomatogenesis parakinetal; paramembranelles conspecuous; somatic ciliation dense; macronucleus usually in form of thick ribbon, often coiled and lengthy; symbiotic zoochlorellae in some species; fresh-water and marine forms. Family CLIMACOSTOMIDAE Repak, 1972

Majestic in size and movement; trumpet-shaped, elongate, uniformly ciliated, highly conüactile; oral ciliature spirals clockwise nearly 360° around flared-out anterior end; stomatogenesis apokinetal; often pigmented and/or with symbiotic zoochlorellae; a few species with mucilaginous loricae; macronucleus commonly moniliform; rypically in fresh-water habitats only. Family STENTORIDAE Carus, 1863

Body large and broad, with rounded posterior (though tailed in one species) end and truncate anterior end; buccal caviry prominent, funnel-like, opening at apical end of organism and remaining open down onto ventral surface for some distance; elongate, rod-like macronucleus, with up to 35 micronuclei; heavy-walled cyst; predominantly fresh-water forms. Family BURSARIIDAE Dujardin, 1840

Body large and somewhat rotund, with gently pointed posterior end; buccal caviry opens apically and bears full circle of strong membranelles; stomatogenesis apokinetal, with new infraciliary bases developing in oligotrich-like pouch; macronucleus very long, with loops; a unique "posteroaxial caviry," containing cilia, opens at posterior pole; in polluted brackish waters. Family CHATTONIDIIDAE Villeneuve-Brachon, 1940

Body ellipsoidal, dorsoventrally flattened, with regular ciliation on ventral surface only; lateral edges and dorsal surface bear short stiff spines, associated in latter location with curious wart-like prominences; buccal membranelles conspicuous at apical end of organism, curving down left side to cytostome located in anterior third of body; pair of ovoid-to-spherical macronuclei present; like hypotrichs (where formerly classified) in number of characteristics; generally in marine habitats, including salt marshes. Family PERITROMIDAE Stein, 1867

Large, often elongate, cylindrical forms, some highly contractile, some pigmented; long, narrow peristomial field, sometimes with buccal ciliature relatively inconspicuous; somatic ciliation uniform, often dense, and typically complete; contractile vacuole posterior, frequently large, and may have lengthy collecting canal; macronucleus compact, ovoid to elongate-moniliform; free-living in fresh-water (predominantly), marine, or edaphic habitats.	*Family SPIROSTOMIDAE* Stein, 1867**
Body ovoid in shape, compressed laterally, with rigid and ribbed pellicle (= cuirass); cytoplasm nonpigmented; lengthy peristomial field, with conspicuous membranelles, terminating very near posterior pole of organism; somatic ciliature, in widely spaced rows, occurs in little packets of 6-8 delicate cilia each; macronucleus horseshoe-shaped; these hypotrich-like organisms show world-wide distribution, found mainly in edaphic habitats (e.g., moss on trees).	*Family PHACODINIIDAE* n. fam.**
Anterior part of body uniquely twisted to left, and posterior part sometimes tailed and/or bearing tuft of longer (caudal) cilia; buccal membranelles large, yet rather inconspicuous; uniform somatic ciliation, but often not dense; macronucleus compact, centrally located; widely distributed as fresh-water polysaprobic forms, but some also marine and psammophilic or inquilinic in echinoids.	*Family METOPIDAE* Kahl, 1927**
Body typically large, heavily ciliated, contractile; buccal ciliature, including paroral membrane, prominent; macronucleus long and moniliform in type-genus; body very elongate in some forms, nearly ellipsoidal in others; contractile vacuole often with long feeding canal; in various habitats: fresh-water, edaphic, and especially marine.	*Family CONDYLOSTOMATIDAE* Kahl in Doflein & Reichenow, 1929**
Body ellipsoidal, with narrowed peristomial field; somatic ciliation uniform, occasionally slightly spiraled; macronucleus elongate but not moniliform; in fresh-water or edaphic habitats.	*Family REICHENOWELLIDAE* Kahl, 1932**
Body large, ovoid, with very prominent peristomial field (buccal caviry) occupying much of anterior part of body; stomatogenesis parakinetal; paramembranelles conspecuous; somatic ciliation dense; macronucleus usually in form of thick ribbon, often coiled and lengthy; symbiotic zoochlorellae in some species; fresh-water and marine forms.	*Family CLIMACOSTOMIDAE* Repak, 1972**
Majestic in size and movement; trumpet-shaped, elongate, uniformly ciliated, highly conüactile; oral ciliature spirals clockwise nearly 360° around flared-out anterior end; stomatogenesis apokinetal; often pigmented and/or with symbiotic zoochlorellae; a few species with mucilaginous loricae; macronucleus commonly moniliform; rypically in fresh-water habitats only.	*Family STENTORIDAE* Carus, 1863**
Body large and broad, with rounded posterior (though tailed in one species) end and truncate anterior end; buccal caviry prominent, funnel-like, opening at apical end of organism and remaining open down onto ventral surface for some distance; elongate, rod-like macronucleus, with up to 35 micronuclei; heavy-walled cyst; predominantly fresh-water forms.	*Family BURSARIIDAE* Dujardin, 1840**
Body large and somewhat rotund, with gently pointed posterior end; buccal caviry opens apically and bears full circle of strong membranelles; stomatogenesis apokinetal, with new infraciliary bases developing in oligotrich-like pouch; macronucleus very long, with loops; a unique "posteroaxial caviry," containing cilia, opens at posterior pole; in polluted brackish waters.	*Family CHATTONIDIIDAE* Villeneuve-Brachon, 1940**
Body ellipsoidal, dorsoventrally flattened, with regular ciliation on ventral surface only; lateral edges and dorsal surface bear short stiff spines, associated in latter location with curious wart-like prominences; buccal membranelles conspicuous at apical end of organism, curving down left side to cytostome located in anterior third of body; pair of ovoid-to-spherical macronuclei present; like hypotrichs (where formerly classified) in number of characteristics; generally in marine habitats, including salt marshes.	*Family PERITROMIDAE* Stein, 1867**