yidae, Phtorophryida , Phtorophryinae , Polyspiri- dae , Spirophryinae , Synophryinae , Terebrospirinae , and possibly Kofoidellidae and Perezellidae ) Size, small in tomite stage, to large in feeding tro- phont; shape, ovoid to spherical; free-swimming; somatic kineties, right-spiralled, ranging from about 9 to < 22 ; oral apparatus, as for subclass and with rosette ; macronucleus, globular to extremely elongate and ribbon-like, depending upon the life cycle stage; micronucleus, present; contractile vacuole, present; exuviotrophic, but one genus ( Phtorophrya ) hyperparasite on Gymnodinioides species and another ( Synophrya ) with sanguicolous stage; in marine, rarely brack- ish and freshwater (?), habitats as symbionts (parasites?) on marine crustacea , such as hermit crabs , shrimp , and copepods ; 17 genera and three genera incertae sedis . – Calospira Chatton & Lwoff, 1935 – Foettingeria Caullery & Mesnil, 1903 – Gymnodinioides Minkiewicz, 1912 – Hyalophysa Bradbury, 1966 – Hyalospira Miyashita, 1933 (subj. syn. Gymno- dinioides ) – Metaphrya Ikeda, 1917 – Ophiuraespira Chatton & Lwoff, 1930 – Pericaryon Chatton, 1911 – Phoretophrya Chatton, A. & Μ. Lwoff, 1930 – Phtorophrya Chatton, A. & Μ. Lwoff, 1930 – Polyspira Minkiewicz, 1912 – Rosea de Puytorac, 1994 [nomen nudum] 428 17. The Ciliate Taxa Including Families and Genera – Spirophrya Chatton & Lwoff, 1924 – Synophrya Chatton & Lwoff, 1926 – Terebrospira Debaisieux, 1960 – Traumatiophtora Chatton & Lwoff, 1931 – Vampyrophrya Chatton & Lwoff, 1931 Incertae sedis in Family Foettingeriidae – Jeppsia Corliss, 1960 – Kofoidella Cépède, 1910 – Perezella Cépède, 1910 Order Astomatophorida Jankowski, 1966 (syns. Astomophorina , Nephrocolida , Neph- rocolina ) Size, small to medium; shape of trophont, long, vermiform; free-swimming, but trophont attached by its anterior end to host tissue; somatic ciliation, holotrichous, kineties much spiralled and somatic ciliature markedly thigmotactic; no cytostome (in stages of life cycles known to date), but remnants of oral ciliature; fission of tomont- trophont by sequential formation of tomites (catenulation) or by multiple transverse fission with tomites remaining connected ; macronu- cleus, very variable, from fragmented nodules to an irregular network; micronucleus, present but obscure; contractile vacuole (?); in marine habi- tats as parasites, for example, in the internal organs, such as liver, kidney, and gonad of cephalopods ; one family. Family OPALINOPSIDAE Hartog, 1906 (syns. Chromidinida , Chromidinidae ) With characteristics of the order; two genera. – Chromidina Gonder, 1905 – Opalinopsis Foettinger, 1881 Order Pilisuctorida Jankowski, 1966 Size, small to large; shape, ovoid to elongate; free- swimming but attached to host in the feeding state; body with ventral adhesive organelle ; species of most genera permanently in so-called “neo- tenic” tomite stage; somatic kineties of tomite arched, following rim of flattened ventral sur- face ; mature trophonts (e.g., Conidophrys ), non- ciliated, immobile, characteristically attached to seta or cuticle of host, and a migrating tomite, which is ciliated but lacks a cytostome; tomites produced by synchrony or strobilation ; macro- nucleus, elongate ellipsoid, irregularly shaped to band-form and ribbon-like; micronucleus, present; contractile vacuole, present; feeding on tissue flu- ids (i.e., hemolymph); in marine habitats on the cuticular processes of amphipods , isopods , deca- pods , and cirripeds , and possibly a terrestrial mite ; single host life cycle; one family. NOTE : De Puytorac (1994h) recognized three monotypic families in this order, each includ- ing one of the three genera here included in the single family of this monotypic order. Perhaps gene sequence data will confirm that the genetic diversity of these forms warrants this higher order taxonomy. Family CONIDOPHRYIDAE Kirby, 1941 (for Pilisuctoridae ; syns. Ascophryidae , Askoellida , Askoellidae , Conidophryidae ) With characteristics of the order; three genera. – Ascophrys Campillo & Deroux, 1974 – Askoella Fenchel, 1965 – Conidophrys Chatton & Lwoff, 1934 Subclass Peritrichia Stein, 1859 (syns. Cyclohymenophora , Dexiotricha , Peritri- chasina , Peritrichidea , Peritrichorida , Stomatoda ) Size of zooids, small to medium, rarely large, but colonial forms can be macroscopic; shape, characteristically inverted bell- or goblet-shaped or conical-cylindrical; sessile and sedentary except as dispersive telotrochs or swarmers, although sev- eral taxa are always free-swimming; prominent holdfast derivatives or scopula, which secretes the stalk of sessile species and includes a field of thigmotactic cilia, at aboral pole ; alveoli, well-developed, with pellicle perforated by pores (= parasomal sacs?); somatic ciliature, reduced to subequatorial locomotor fringe, the trochal band, which is permanently ciliated on mobile species and temporarily ciliated on the dis- persal stage or telotroch of sessile species ; oral region, often retractable, encircling apical pole as peristome, bordered by a more or less prominent collarette; oral ciliature, conspicuous, winding counterclockwise around the border of the prominent peristome, from its outer terminus 17.3 The Ciliate Taxa to Genus 429 on an elevated central, often extensible episto- mial disk, with peristomial part of the paroral (haplokinety, stichodyad) on the outside and oral polykinetid (polykinety) 1 on the inside, but both actually originating in an oral cavity, the infundibulum, at the terminus of which is the cytostome ; oral ciliature of infundibulum includ- ing inner parts of paroral and oral polykinetid 1, which is accompanied at its inner terminus by infundibular polykinetids 2 and 3 (formerly called peniculi); stomatogenesis, ophryobuccokinetal, with involvement of germinal field or row of kinetosomes ; fission, with its plane parallel to the major body axis, suggesting that the apical- antapical axis is a secondary adaptation to sessility; conjugation, invariably total, typically involving fusion of a migratory microconjugant with a stationary macroconjugant ; contractile vacuole and cytoproct, emptying into infundibulum ; bacterivorous and microphagous, with symbiotic species ingesting detritus and tissue debris of host; in marine, freshwater, and rarely terrestrial habitats, very widespread with species generally free-living but many occurring as commensals or even parasites on or in diverse hosts, ranging from protozoa to vertebrates; two orders. NOTE : Gong et al. (2006) demonstrated that the mobilid peritrichs are a separate lineage from the sessilid peritrichs based on small subunit rRNA gene sequences, but the two lineages are apparently not sister clades. We remain conservative in our assignment of both sessilids and mobilids to the Subclass Peritrichia until sampling of additional genes and taxa refutes this assignment. Order Sessilida Kahl, 1933 (syns. Aloricata + Loricata , Astylozo(on)ina p.p ., Cothurniina p.p ., Epistylina p.p ., Fibrodiscida p.p ., Lagenophryina p.p ., Loricina p.p ., Natantina p.p ., Operculariina p.p ., Opisthonectina p.p ., Ophrydiina p.p ., Rovinjellina p.p ., Scyphidiina p.p ., Sedentaria , Sessilia , Sessili[i]da , Stylophorina , Syncyathellina p.p ., Thigmodiscina , Vorticellina p.p .) Size of zooids, small to medium, rarely large; shape, inverted bell- or goblet-shaped or coni- cal-cylindrical; zooids, dimorphic, with mature zooids or trophonts, sedentary or sessile, com- monly stalked or with inconspicuous adhesive disc, attached to substrate by scopula, but a few species presumed to be secondarily mobile, and dispersal