Peniculina

Suborder (3) Peniculina Fauré-Fremiet in Corliss, 1956

Syns. Trichohymenostomata and Vestibulata sensu von Gelei;
Frontoniina + Quadrulina;
Peniculida

Peniculi of oral ciliature deep in buccal caviry (itself sometimes preceded by oral-area depression or groove, the prebuccal caviry); stomatogenesis buccokinetal; distinct pre- and postoral sutures; spindle trichocysts and nematodesmata, but not mucocysts, of common occurrence; many species with endosymbiotic algae or bacteria; sizable but monomorphic, generally microphagous, forms, often without cysts; widely distributed, predominantly in fresh-water habitats.

[This suborder possibly warrants elevation to separate ordinal status.]

With characteristics of suborder s.s, (above). Conspicuous prebuccal caviry (formerly called a "vestibulum") leading to equatorially löcated buccal caviry; oral ciliature comprised of distinctive paroral membrane, two peniculi, and single quadrulus; two contractile vacuoles. Family PARAMECIIDAE Dujardin, 1840

Prebuccal area shallow or absent; several ophryokineties to right of oral area; three peniculi in buccal cavity, in anterior third of body; cytostome expansible, and area rich in nematodesmata and specialized phagoplasm; single contractile vacuole; body usually large; cysts common in some species; mostly herbivorous in feeding preference and free-living, but one species commensal on gills of Amphioxus. Family FRONTONIIDAE Kahl, 1926

Quite similar to the Frontoniidae (above); cytopharyngeal "basket" of nematodestnata particularly striking. Family CLATHROSTOMATIDAE Kahl, 1926

Body short, cylindrical, with two broad encircling bands of closely set cilia plus an eccentric posterior tuft; no depressed prebuccal area, and buccal cavity subequatorial in location; contractile vacuole single, with multiple collecting canals; common planktonic or polysaprobic organisms in fresh-water habitats. Family UROCENTRIDAE Claparéde & Lachmann, 1858

Distinctively cone- (with rounded angles) or heart-shaped body, with relatively large buccal area covering much of the apical (base of cone) and ventral surfaces of the organism; otherwise, much like other peniculines. Family STOKESIIDAE Roque, 1961

Large (up to 710 µm in length), "heterotrich-looking" (an extensive false AZM, etc.), pantropical peniculine, perhaps most like Stokesia (preceding family) in general characteristics though more like Paramecium in shape; prominent trichocysts; two contractile vacuoles; carnivorous on other ciliates. Family NEOBURSARIDIIDAE Dragesco & Tuffrau, 1967

Unique in extensiveness of buccal caviry, occupying nearly entire ventral surface; buccal ciliature, however, reduced to large "membrane" on left and modest one on right, though infraciliature (and its fibrillar system) rather complex; body fully ciliated, often with tuft of longer cilia caudally; single contractile vacuole. Family LEMBADIONIDAE Jankowski, n. fam.

With characteristics of suborder s.s, (above). Conspicuous prebuccal caviry (formerly called a "vestibulum") leading to equatorially löcated buccal caviry; oral ciliature comprised of distinctive paroral membrane, two peniculi, and single quadrulus; two contractile vacuoles.	*Family PARAMECIIDAE* Dujardin, 1840**
Prebuccal area shallow or absent; several ophryokineties to right of oral area; three peniculi in buccal cavity, in anterior third of body; cytostome expansible, and area rich in nematodesmata and specialized phagoplasm; single contractile vacuole; body usually large; cysts common in some species; mostly herbivorous in feeding preference and free-living, but one species commensal on gills of Amphioxus.	*Family FRONTONIIDAE* Kahl, 1926**
Quite similar to the Frontoniidae (above); cytopharyngeal "basket" of nematodestnata particularly striking.	*Family CLATHROSTOMATIDAE* Kahl, 1926**
Body short, cylindrical, with two broad encircling bands of closely set cilia plus an eccentric posterior tuft; no depressed prebuccal area, and buccal cavity subequatorial in location; contractile vacuole single, with multiple collecting canals; common planktonic or polysaprobic organisms in fresh-water habitats.	*Family UROCENTRIDAE* Claparéde & Lachmann, 1858**
Distinctively cone- (with rounded angles) or heart-shaped body, with relatively large buccal area covering much of the apical (base of cone) and ventral surfaces of the organism; otherwise, much like other peniculines.	*Family STOKESIIDAE* Roque, 1961**
Large (up to 710 µm in length), "heterotrich-looking" (an extensive false AZM, etc.), pantropical peniculine, perhaps most like Stokesia (preceding family) in general characteristics though more like Paramecium in shape; prominent trichocysts; two contractile vacuoles; carnivorous on other ciliates.	*Family NEOBURSARIDIIDAE* Dragesco & Tuffrau, 1967**
Unique in extensiveness of buccal caviry, occupying nearly entire ventral surface; buccal ciliature, however, reduced to large "membrane" on left and modest one on right, though infraciliature (and its fibrillar system) rather complex; body fully ciliated, often with tuft of longer cilia caudally; single contractile vacuole.	*Family LEMBADIONIDAE* Jankowski, n. fam.**