Cap 17

arc-like file that 
parallels the anterior left serial oral polyki-
netids and a frontoventral cirral zig-zag with 
362 17. The Ciliate Taxa Including Families and Genera
1–6 files to the right of left marginal cirral file 
and also with several cirral files to the left of the 
right marginal cirri; multiple “marginal files” 
derive from unique anlagen during morpho-
genesis ; transverse cirri, present or absent; caudal 
cirri, absent; dorsal somatic ciliature as several 
files of bristle dikinetids; oral ciliature as for order 
with paroral and endoral; macronucleus, ellipsoid, 
multiple; micronucleus, present; contractile vacu-
ole, present; cytoproct, likely present; feeding on 
bacteria, algae, smaller protists, including testate 
amoebae and ciliates; in freshwater and terrestrial 
habitats; three genera. 
 – Hemicycliostyla Stokes, 1886 
 – Pseudourostyla Borror, 1972 
 – Trichotaxis Stokes, 1891 
 Family UROSTYLIDAE Bütschli, 1889 
 (syns. Bakuellidae , Bakuellinae , Erionellidae , 
 Holostichidae , Holostichina , Holostichinae , 
 Holostichoidea , Psammomitrinae Pseudoam-
phisiellidae , Urostylinae , Urostyloidea ) 
 Size, small to large; shape, elongate ovoid with 
some tailed forms; free-swimming; somatic ven-
tral ciliature with several frontal cirri some-
what larger than other frontoventral cirri, and 
with frontoventral cirri as a single zig-zag file 
of paired cirri or a series of shorter files off-
set at their anterior and posterior ends (e.g., 
Bakuella, Eschaneustyla ) and typically not with 
additional “marginal files” on both sides of this 
zig-zag (cf. Pseudourostylidae) ; transverse cirri, 
may be numerous; caudal cirri, present or absent; 
dorsal somatic ciliature as three to many files of 
bristle dikinetids; oral ciliature as for order with 
paroral and endoral; during division morpho-
genesis, frontoventral cirri differentiate from a 
longitudinal field of more than five oblique cili-
ary streaks; macronucleus, ellipsoid, two to many 
nodules; micronucleus, present; contractile vacu-
ole, present; cytoproct, likely present; feeding on 
bacteria, algae, and smaller protists, including 
ciliates; in marine, freshwater, and terrestrial 
habitats; 24 genera. 
 – Afrothrix Foissner, 1999 
 – Anteholosticha Berger, 2003 *
 – Australothrix Blatterer & Foissner, 1988 
 – Bakuella Agamaliev & Alekperov, 1976 
 – Biholosticha Berger, 2003 *
 – Birojimia Berger & Foissner, 1989 
 – Caudiholosticha Berger, 2003 *
 – Diaxonella Jankowski, 1979 
 – Holosticha Wrzesniowski, 1877 
 – Holostichides Foissner, 1987 
 – Metabakuella Alekperov, 1989 
 – Metaurostylopsis Song, Petz, & Warren, 2001 *
 – Notocephalus Petz, Song, & Wilbert, 1995 
 – Parabirojimia Hu, Song, & Warren, 2002 *
 – Paragastrostyla Hemberger, 1985 
 – Paramitrella Jankowski, 1978 
 – Paruroleptus Wenzel, 1953 (subj. syn. Uroleptus ) 
 – Periholosticha Hemberger, 1985 
 – Perisincirra Jankowski, 1978 
 – Psammomitra Borror, 1972 (subj. syn. 
Uroleptus ) 
 – Pseudoamphisiella Song, 1996 
 – Pseudobakuella Alekperov, 1992 
 – Tunicothrix Xu, Lei & Choi, 2006 *
 – Uroleptus Ehrenberg, 1831 
 – Urostyla Ehrenberg, 1830 
Incertae sedis in Subclass Stichotrichia 
 – Erniella Foissner, 1987 
 – Gastrosticha Kahl, 1932 [nomen dubium] 
 – Saudithrix Berger, Al-Rasheid, & Foissner, 2006 *
 – Stenotricha Jankowski, 1978 
 – Uncinata Bullington, 1940 
 Subclass Oligotrichia Bütschli, 1887/1889 
 (syns. Oligotricha , Oligotrichorida ) 
 Size, small to large, shape, typically rounded 
or gently pointed posteriorly, sometimes tailed; 
free-swimming; a perilemma present in many spe-
cies; internal polysaccharide plates in some spe-
cies; somatic kineties, reduced in number and 
variable in pattern, forming girdles and spirals, 
typically derived from an “equatorial” girdle 
kinety and a “ventral” kinety of dikinetids that 
originates near the posterior pole ; extrusomes 
often prominent rod-like “trichites”; oral region 
on anterior half with oral polykinetids extensive 
and conspicuous in two sections – a “collar” out 
on the body surface encircling anterior pole of 
organism and a “lapel” inside the oral cavity 
proper ; paroral, a single file of kinetosomes (i.e., 
monostichomonad); stomatogenesis, apokinetal, 
often in a below-surface pouch; division morpho-
17.3 The Ciliate Taxa to Genus 363
genesis, enantiotropic-like; macronucleus, globular 
to ellipsoid to band-like, often multiple; micronu-
cleus, present; contractile vacuole, at least present 
in freshwater forms; cytoproct, possibly absent; 
feeding on bacteria, microalgae, and smaller pro-
tists, but mixotrophic species common; in marine 
and freshwater habitats, free-living as plankton but 
several species endocommensals in echinoids; one 
order. 
NOTE : Our classification reflects the molecu-
lar genetic analyses that suggest the halteriids , 
classically considered oligotrichs , arose within
the stichotrichs while the strombidiids are a sepa-
rate lineage probably related to the choreotrichs 
(Snoeyenbos-West, Salcedo, McManus, & Katz, 
2002; Strüder-Kypke & Lynn, 2003). 
 Order Strombidiida Petz & Foissner, 1992 
 (syn. Strombidiina ) 
 With characterististics of the class; two families. 
 Family STROMBIDIIDAE Fauré-Fremiet, 1970 
 (syns. Cyrtostrombidiidae , Pelagostrombidiidae ) 
 With characteristics of the order; without an 
elongate and conspicuous contractile tail, but tail 
is often lost in fixed specimens (see Tontoniidae 
below); 17 genera. 
NOTE : We have listed all the names of strom-
bidiid genera considered valid by Aescht (2001) 
and Agatha (2004). However, it is highly doubtful 
given recent research on the molecular evolution of 
 strombidiids that all these genera represent mono-
phyletic clades (e.g., see Agatha, Strüder-Kypke, 
Beran, & Lynn, 2005; Snoeyenbos-West et al., 
2002; Strüder-Kypke & Lynn, 2003). 
 – Buehringa Busch, 1921 (subj. syn. Strombidium ) 
 – Cyrtostrombidium Lynn & Gilron, 1993 
 – Echinostrombidium Jankowski, 1978 
 – Laboea Lohmann, 1908 
 – Limnostrombidium Krainer, 1995 
 – Lissostrombidium Jankowski, 1978 
 – Metastrombidium Fauré-Fremiet, 1924 
 – Novistrombidium Song & Bradbury, 1998 
 – Omegastrombidium Agatha, 2004 *
 – Parallelostrombidium Agatha, 2004 *
 – Pelagostrombidium Krainer, 1991 
 – Peristrombidium Jankowski, 1978 
 – Pseudostrombidium Horváth, 1933 
 – Seravinella Alekperov & Mamajeva, 1992 
 – Spirostrombidium Jankowski, 1978 
 – Strombidium Claparède & Lachmann, 1859 
 – Thigmostrombidium Jankowski, 1978 
 Family TONTONIIDAE Agatha, 2004 
 With characteristics of the order; with elongate 
and conspicuous contractile tail, but tail is often 
lost in fixed specimens ; four genera. 
 – Paratontonia Jankowski, 1978 (subj. syn. 
Tontonia ) 
 – Pseudotontonia Agatha, 2004 *
 – Spirotontonia Agatha, 2004 *
 – Tontonia Fauré-Fremiet, 1914 
 Class ARMOPHOREA Lynn, 2004 
 Size, small to large; shape, varied from top-
shaped with spines to laterally flattened and 
leaf-like; alveoli, conspicuous to absent; somatic 
dikinetids with both kinetosomes bearing cilia, 
typically distributed in kineties covering entire 
body, but in smaller forms ciliature reduced to 
tufts or cirri; hydrogenosomes, with remnant 
genome retained in some forms, replacing 
mitochondria; oral polykinetids on left side 
of oral cavity, few and inconspicuous to many, 
forming an adoral zone; stomatogenesis, typi-
cally pleurokinetal; macronucleus, single, large, 
and ellipsoid to elongate, but sometimes multi-
ple; conjugation, typically temporary, but may 
be total in some armophorids; contractile vacu-
ole, present, sometimes with collecting canals; 
cytoproct, may be present; bacterivorous, but 
also with endosymbiotic methanogens; in marine, 
freshwater, and rarely terrestrial anaerobic habi-
tats (i.e. polysaprobic), typically in sediments 
and the intestinal